Science.gov

Sample records for water-moderated water-cooled power

  1. Seismicity and seismic response of the Soviet-designed VVER (Water-cooled, Water moderated Energy Reactor) reactor plants

    SciTech Connect

    Ma, D.C.; Gvildys, J.; Wang, C.Y.; Spencer, B.W.; Sienicki, J.J.; Seidensticker, R.W.; Purvis, E.E. III

    1989-01-01

    On March 4, 1977, a strong earthquake occurred at Vrancea, Romania, about 350 km from the Kozloduy plant in Bulgaria. Subsequent to this event, construction of the unit 2 of the Armenia plant was delayed over two years while seismic features were added. On December 7, 1988, another strong earthquake struck northwest Armenia about 90 km north of the Armenia plant. Extensive damage of residential and industrial facilities occurred in the vicinity of the epicenter. The earthquake did not damage the Armenia plant. Following this event, the Soviet government announced that the plant would be shutdown permanently by March 18, 1989, and the station converted to a fossil-fired plant. This paper presents the results of the seismic analyses of the Soviet-designed VVER (Water-cooled, Water moderated Energy Reactor) plants. Also presented is the information concerning seismicity in the regions where VVERs are located and information on seismic design of VVERs. The reference units are the VVER-440 model V230 (similar to the two units of the Armenia plant) and the VVER-1000 model V320 units at Kozloduy in Bulgaria. This document provides an initial basis for understanding the seismicity and seismic response of VVERs under seismic events. 1 ref., 9 figs., 3 tabs.

  2. Department of Energy's team's analyses of Soviet designed VVERs (water-cooled water-moderated atomic energy reactors)

    SciTech Connect

    Not Available

    1989-09-01

    This document contains apprendices A through P of this report. Topics discussed are: a cronyms and technical terms, accident analyses reactivity control; Soviet safety regulations; radionuclide inventory; decay heat; operations and maintenance; steam supply system; concrete and concrete structures; seismicity; site information; neutronic parameters; loss of electric power; diesel generator reliability; Soviet codes and standards; and comparisons of PWR and VVER features. (FI)

  3. 78 FR 35330 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ... COMMISSION Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory Commission... revision to Regulatory Guide (RG), 1.68, ``Initial Test Programs for Water-Cooled Nuclear Power Plants... Initial Test Programs (ITPs) for light water cooled nuclear power plants. ADDRESSES: Please refer...

  4. 77 FR 73056 - Initial Test Programs for Water-Cooled Nuclear Power Plants

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... COMMISSION Initial Test Programs for Water-Cooled Nuclear Power Plants AGENCY: Nuclear Regulatory Commission...) is issuing for public comment draft regulatory guide (DG), DG-1259, ``Initial Test Programs for Water... considers acceptable for Initial Test Programs (ITPs) for light water cooled nuclear power plants....

  5. Reliability of water-cooled high-power diode laser modules

    NASA Astrophysics Data System (ADS)

    Treusch, Georg; Srinivasan, Raman; Brown, Dennis; Miller, Robert; Harrison, Jim

    2005-03-01

    High power diode lasers have demonstrated reliable output power of more than 50W per diode far beyond 10,000 hours. Record output power of more than 300W per diode laser bar has been reported. The improved reliability of the semiconductor material demands a review of the performance of the actively water cooled heatsink with regards to the expected lifetime. Results from corrosion tests at various water conditions for durations of more than 13,000 hours predict an extended usage of water-cooled heatsink beyond 20,000 hours without significant performance change.

  6. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors J Appendix J to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. J Appendix J to Part 50—Primary Reactor Containment Leakage Testing for Water-Cooled...

  7. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors J Appendix J to Part 50 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Pt. 50, App. J Appendix J to Part 50—Primary Reactor Containment Leakage Testing for Water-Cooled...

  8. Optimization of power-cycle arrangements for Supercritical Water cooled Reactors (SCWRs)

    NASA Astrophysics Data System (ADS)

    Lizon-A-Lugrin, Laure

    The world energy demand is continuously rising due to the increase of both the world population and the standard of life quality. Further, to assure both a healthy world economy as well as adequate social standards, in a relatively short term, new energy-conversion technologies are mandatory. Within this framework, a Generation IV International Forum (GIF) was established by the participation of 10 countries to collaborate for developing nuclear power reactors that will replace the present technology by 2030. The main goals of these nuclear-power reactors are: economic competitiveness, sustainability, safety, reliability and resistance to proliferation. As a member of the GIF, Canada has decided to orient its efforts towards the design of a CANDU-type Super Critical Water-cooled Reactor (SCWR). Such a system must run at a coolant outlet temperature of about 625°C and at a pressure of 25 MPa. It is obvious that at such conditions the overall efficiency of this kind of Nuclear Power Plant (NPP) will compete with actual supercritical water-power boilers. In addition, from a heat-transfer viewpoint, the use of a supercritical fluid allows the limitation imposed by Critical Heat Flux (CHF) conditions, which characterize actual technologies, to be removed. Furthermore, it will be also possible to use direct thermodynamic cycles where the supercritical fluid expands right away in a turbine without the necessity of using intermediate steam generators and/or separators. This work presents several thermodynamic cycles that could be appropriate to run SCWR power plants. Improving both thermal efficiency and mechanical power constitutes a multi-objective optimization problem and requires specific tools. To this aim, an efficient and robust evolutionary algorithm, based on genetic algorithm, is used and coupled to an appropriate power plant thermodynamic simulation model. The results provide numerous combinations to achieve a thermal efficiency higher than 50% with a mechanical power of 1200 MW. It is observed that in most cases the landscape of Pareto's front is mostly controlled only by few key parameters. These results may be very useful for future plant design engineers. Furthermore, some calculations for pipe sizing and temperature variation between coolant and fuel have been carried out to provide an idea on their order of magnitude.

  9. A Methodology for Discerning Incipient Boiling of the Coolant in a Water-Moderated, Water-Cooled (Pressurized-Water) Nuclear Reactor by Means of the Bayesian Neutron-Noise Classifier

    SciTech Connect

    Sharayevskij, Igor

    2006-07-01

    Noise signals at the output of the technological parameters of a nuclear power plant (neutron flux, dynamic pressure, etc.) contain important information on the stale of the equipment. Effective algorithms have been developed for identifying random processes which, after appropriate transformation, are treated as multidimensional random vectors. These vectors are automatically classified by means of the aforementioned algorithms on the basis of the likelihood function, in particular, of the Bayesian classifier and resolving functions. The use of the Bayesian classifier is based on constructing multidimensional distributions of probabilities in the attribute space with the applicable dimensionality, which serves to describe random representing vectors of the applicable images that are subject to automatic classification. (author)

  10. 78 FR 64029 - Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ...The U.S. Nuclear Regulatory Commission (NRC) is issuing revision 1 to Regulatory Guide (RG) 1.110, ``Cost-Benefit Analysis for Radwaste Systems for Light-Water-Cooled Nuclear Power Reactors,'' in which the NRC made editorial corrections and formatting changes with no substantive changes in the staff regulatory positions. This guide describes methods and procedures that the staff of the NRC......

  11. Feasibility Study of Supercritical Light Water Cooled Reactors for Electrical Power Production, 5th Quarterly Report, October - December 2002

    SciTech Connect

    Philip MacDonald; Jacopo Buongiorno; Cliff Davis; J. Stephen Herring; Kevan Weaver; Ron Latanision; Bryce Mitton; Gary Was; Luca Oriani; Mario Carelli; Dmitry Paramonov; Lawrence Conway

    2003-01-01

    The overall objective of this project is to evaluate the feasibility of supercritical light water cooled reactors for electric power production. The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies for the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR that can also burn actinides. The project is organized into three tasks:

  12. Hydraulic design of a re-circulating water cooling system of a combined cycle power plant in Thailand

    SciTech Connect

    Sarkar, C.K.; Pandit, D.R.; Kwon, S.G.

    1998-12-31

    The paper describes the hydraulic design and hydraulic transient analysis of the re-circulating water cooling system of the combined cyclo Sipco power cogeneration plant in Thailand. The power plant of 450 MW total capacity is proposed to be built in two stages. Stage one will produce 300 MW of power and will consist of two gas turbine generators (GTG) and one steam turbine generator (STG). Stage two will produce 150 MW of power and will consist of one GTG and one STG. The cooling system will consist of one GTG and one STG. The cooling system will consist of cooling towers, a combined collecting basin and pump intake sump, pumps and motors, and separate conveyance systems and condensers for the generator units in the two stages. In a re-circulating water cooling system, cold water is pumped from the pump intake sump to the condensers through the conveyance system and hot water from the condensers is carried through the returning pipeline system to the cooling towers, whence the water after cooling is drained into the sump at the base of the towers. Total cooling water requirement for the system in stage one is estimated to be 112,000 gallons per minute (GPM), and that in stage two, 56,000 GPM. The sump is designed using the computer program HEC-2, developed by the US Army Corps of Engineers (COE) and the pump intake basin, following the recommendations of the Hydraulic Institute. The pumps were sized by computing the head loss in the system, and, the steady state and transient performances (during pump start-up and shut-down procedures and due to possible power or mechanical failure of one or all pumps) of the system were analyzed by mathematically modeling the system using the computer program WHAMO (Water Hammer nd Mass Oscillations), also developed by the COE.

  13. Power scaling to high-brightness kW systems using semiconductor bars in water-cooled stacks

    NASA Astrophysics Data System (ADS)

    Schleuning, David; Guinn, Keith; Luong, Calvin; Zhang, Yu; Kuchibhotla, Krishna; Kim, Serguei; Ryu, Geunmin; Griffin, Mike; Chryssis, Athanasios; Acklin, Bruno

    2013-02-01

    The scalability of semiconductor diode lasers to multi-kilowatt power levels has increasing importance in direct diode material processing applications. These applications require hard-pulse on-off cycling capability and high brightness achieved using low fill-factor (FF) bars with a tight vertical pitch. Coherent uses 20%FF bars operated at <60W/bar packaged on water-cooled packages with a 1.65mm vertical pitch in the Highlight D-series, which achieves <8kW of power in a < 1mm x 8mm beam line at a working distance of ~ 280mm. We compare thermal measurement results to thermal fluid flow simulations to show the emitters are cooled to low junction temperatures with minimal thermal crosstalk, similar to single emitter packaging. Good thermal performance allows for scaling to operation at higher power and brightness. We present accelerated life-testing results in both CW and hard-pulse on-off cycling conditions.

  14. Natural Circulation in Water Cooled Nuclear Power Plants Phenomena, models, and methodology for system reliability assessments

    SciTech Connect

    Jose Reyes

    2005-02-14

    In recent years it has been recognized that the application of passive safety systems (i.e., those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. In 1991 the IAEA Conference on ''The Safety of Nuclear Power: Strategy for the Future'' noted that for new plants the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate''.

  15. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production

    SciTech Connect

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

    2002-01-01

    The use of supercritical temperature and pressure light water as the coolant in a direct-cycle nuclear reactor offers potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to 46%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type recirculation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If a tight fuel rod lattice is adopted, it is possible to significantly reduce the neutron moderation and attain fast neutron energy spectrum conditions. In this project a supercritical water reactor concept with a simple, blanket-free, pancake-shaped core will be developed. This type of core can make use of either fertile or fertile-free fuel and retain the hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity.

  16. WATER COOLED RETORT COVER

    DOEpatents

    Ash, W.J.; Pozzi, J.F.

    1962-05-01

    A retort cover is designed for use in the production of magnesium metal by the condensation of vaporized metal on a collecting surface. The cover includes a condensing surface, insulating means adjacent to the condensing surface, ind a water-cooled means for the insulating means. The irrangement of insulation and the cooling means permits the magnesium to be condensed at a high temperature and in massive nonpyrophoric form. (AEC)

  17. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production, Progress Report for Work Through September 2003, 2nd Annual/8th Quarterly Report

    SciTech Connect

    Philip E. MacDonald

    2003-09-01

    The supercritical water-cooled reactor (SCWR) is one of the six reactor technologies selected for research and development under the Generation-IV program. SCWRs are promising advanced nuclear systems because of their high thermal efficiency (i.e., about 45% vs. about 33% efficiency for current Light Water Reactors, LWRs) and considerable plant simplification. SCWRs are basically LWRs operating at higher pressure and temperatures with a direct once-through cycle. Operation above the critical pressure eliminates coolant boiling, so the coolant remains single-phase throughout the system. Thus the need for recirculation and jet pumps, a pressurizer, steam generators, steam separators and dryers is eliminated. The main mission of the SCWR is generation of low-cost electricity. It is built upon two proven technologies, LWRs, which are the most commonly deployed power generating reactors in the world, and supercritical fossil-fired boilers, a large number of which is also in use around the world.

  18. Water Cooled Mirror Design

    SciTech Connect

    Dale, Gregory E.; Holloway, Michael Andrew; Pulliam, Elias Noel

    2015-03-30

    This design is intended to replace the current mirror setup being used for the NorthStar Moly 99 project in order to monitor the target coupon. The existing setup has limited movement for camera alignment and is difficult to align properly. This proposed conceptual design for a water cooled mirror will allow for greater thermal transfer between the mirror and the water block. It will also improve positioning of the mirror by using flexible vacuum hosing and a ball head joint capable of a wide range of motion. Incorporating this design into the target monitoring system will provide more efficient cooling of the mirror which will improve the amount of diffraction caused by the heating of the mirror. The process of aligning the mirror for accurate position will be greatly improved by increasing the range of motion by offering six degrees of freedom.

  19. Water cooled steam jet

    DOEpatents

    Wagner, Jr., Edward P.

    1999-01-01

    A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

  20. Water cooled steam jet

    DOEpatents

    Wagner, E.P. Jr.

    1999-01-12

    A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed there between. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock. 2 figs.

  1. Development of a high-power water cooled beryllium target for use in accelerator-based boron neutron capture therapy.

    PubMed

    Blackburn, B W; Yanch, J C; Klinkowstein, R E

    1998-10-01

    In order for ABNCT (accelerator-based boron neutron capture therapy) to be successful, 10-16 kW or more must be dissipated from a target. Beryllium is well suited as a high-power target material. Beryllium has a thermal conductivity of 200 W/mK at 300 K which is comparable to aluminum, and it has one of the highest strength to weight ratios of any metal even at high temperatures (100 MPa at 600 degrees C). Submerged jet impingement cooling has been investigated as an effective means to remove averaged power densities on the order of 2 x 10(7) W/m2 with local power densities as high as 6 x 10(7) W/m2. Water velocities required to remove these power levels are in excess of 24 m/s with volumetric flow rates of nearly 100 GPM. Tests on a prototype target revealed that the heat transfer coefficient scaled as Re0.6. With jet-Reynolds numbers as high as 5.5 x 10(5) heat transfer coefficients of 2.6 x 10(5) W/m2K were achieved. With this type of cooling configuration 30 kW of power could be effectively removed from a beryllium target placed on the end of an accelerator. A beryllium target utilizing a proton beam of 3.7 MeV and cooled by submerged jet impingement could be used to deliver a dose of 13 RBE cGy/min mA to a tumor at a depth of 4 cm. With a beam power of 30 kW, 1500 cGy could be delivered in 14.2 min. PMID:9800705

  2. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and feedwater piping and other systems which penetrate containment of direct-cycle boiling water power... CFR 50.12, are still applicable to Option B of this appendix if necessary, unless specifically revoked... 10 Energy 1 2010-01-01 2010-01-01 false Primary Reactor Containment Leakage Testing for...

  3. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and feedwater piping and other systems which penetrate containment of direct-cycle boiling water power... CFR 50.12, are still applicable to Option B of this appendix if necessary, unless specifically revoked... 10 Energy 1 2012-01-01 2012-01-01 false Primary Reactor Containment Leakage Testing for...

  4. 10 CFR Appendix J to Part 50 - Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and feedwater piping and other systems which penetrate containment of direct-cycle boiling water power... CFR 50.12, are still applicable to Option B of this appendix if necessary, unless specifically revoked... 10 Energy 1 2011-01-01 2011-01-01 false Primary Reactor Containment Leakage Testing for...

  5. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, 3rd Quarterly Report

    SciTech Connect

    Mac Donald, Philip Elsworth

    2002-06-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed.

  6. HEAVY WATER MODERATED NEUTRONIC REACTOR

    DOEpatents

    Szilard, L.

    1958-04-29

    A nuclear reactor of the type which utilizes uranium fuel elements and a liquid coolant is described. The fuel elements are in the form of elongated tubes and are disposed within outer tubes extending through a tank containing heavy water, which acts as a moderator. The ends of the fuel tubes are connected by inlet and discharge headers, and liquid bismuth is circulated between the headers and through the fuel tubes for cooling. Helium is circulated through the annular space between the outer tubes in the tank and the fuel tubes to cool the water moderator to prevent boiling. The fuel tubes are covered with a steel lining, and suitable control means, heat exchange means, and pumping means for the coolants are provided to complete the reactor assembly.

  7. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, Progress Report for Work Through September 2002, 4th Quarterly Report

    SciTech Connect

    Mac Donald, Philip Elsworth

    2002-09-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR. The Generation IV Roadmap effort has identified the thermal spectrum SCWR (followed by the fast spectrum SCWR) as one of the advanced concepts that should be developed for future use. Therefore, the work in this NERI project is addressing both types of SCWRs.

  8. Design, testing, and maintenance criteria for post-accident engineered-safety-feature atmosphere cleanup system air filtration and adsorption units of light-water-cooled nuclear power plants. Revision 2, March 1978

    SciTech Connect

    Not Available

    1981-01-01

    This guide presents methods acceptable to the NRC staff for implementing the Commission's regulations in Appendix A to 10 CFR Part 50 with regard to design, testing, and maintenance criteria for air filtration and adsorption units of engineered-safety-feature (ESF) atmosphere cleanup systems in light-water-cooled nuclear power plants. This guide applies only to postaccident engineered-safety-feature atmosphere cleanup systems designed to mitigate the consequences of postulated accidents. It addresses the ESF atmosphere cleanup system, including the various components and ductwork, in the postulated design basis accident (DBA) environment. This guide does not apply to atmosphere cleanup systems designed to collect airborne radioactive materials during normal plant operation, including anticipated operational occurrences. Regulatory Guide 1.140 Design, Testing, and Maintenance Criteria for Normal Ventilation Exhaust System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants, provides guidance for normal ventilation exhaust systems.

  9. Wetland Water Cooling Partnership: The Use of Constructed Wetlands to Enhance Thermoelectric Power Plant Cooling and Mitigate the Demand of Surface Water Use

    SciTech Connect

    Apfelbaum, Steven; Duvall, Kenneth; Nelson, Theresa; Mensing, Douglas; Bengtson, Harlan; Eppich, John; Penhallegon, Clayton; Thompson, Ry

    2013-09-30

    Through the Phase I study segment of contract #DE-NT0006644 with the U.S. Department of Energy’s National Energy Technology Laboratory, Applied Ecological Services, Inc. and Sterling Energy Services, LLC (the AES/SES Team) explored the use of constructed wetlands to help address stresses on surface water and groundwater resources from thermoelectric power plant cooling and makeup water requirements. The project objectives were crafted to explore and develop implementable water conservation and cooling strategies using constructed wetlands (not existing, naturally occurring wetlands), with the goal of determining if this strategy has the potential to reduce surface water and groundwater withdrawals of thermoelectric power plants throughout the country. Our team’s exploratory work has documented what appears to be a significant and practical potential for augmenting power plant cooling water resources for makeup supply at many, but not all, thermoelectric power plant sites. The intent is to help alleviate stress on existing surface water and groundwater resources through harvesting, storing, polishing and beneficially re-using critical water resources. Through literature review, development of conceptual created wetland plans, and STELLA-based modeling, the AES/SES team has developed heat and water balances for conventional thermoelectric power plants to evaluate wetland size requirements, water use, and comparative cooling technology costs. The ecological literature on organism tolerances to heated waters was used to understand the range of ecological outcomes achievable in created wetlands. This study suggests that wetlands and water harvesting can provide a practical and cost-effective strategy to augment cooling waters for thermoelectric power plants in many geographic settings of the United States, particularly east of the 100th meridian, and in coastal and riverine locations. The study concluded that constructed wetlands can have significant positive ancillary socio-economic, ecosystem, and water treatment/polishing benefits when used to complement water resources at thermoelectric power plants. Through the Phase II pilot study segment of the contract, the project team partnered with Progress Energy Florida (now Duke Energy Florida) to quantify the wetland water cooling benefits at their Hines Energy Complex in Bartow, Florida. The project was designed to test the wetland’s ability to cool and cleanse power plant cooling pond water while providing wildlife habitat and water harvesting benefits. Data collected during the monitoring period was used to calibrate a STELLA model developed for the site. It was also used to inform management recommendations for the demonstration site, and to provide guidance on the use of cooling wetlands for other power plants around the country. As a part of the pilot study, Duke Energy is scaling up the demonstration project to a larger, commercial scale wetland instrumented with monitoring equipment. Construction is expected to be finalized in early 2014.

  10. Water-Cooled Optical Thermometer

    NASA Technical Reports Server (NTRS)

    Menna, A. A.

    1987-01-01

    Water-cooled optical probe measures temperature of nearby radiating object. Intended primarily for use in silicon-growing furnace for measuring and controlling temperatures of silicon ribbon, meniscus, cartridge surfaces, heaters, or other parts. Cooling water and flushing gas cool fiber-optic probe and keep it clean. Fiber passes thermal radiation from observed surface to measuring instrument.

  11. Electrochemistry of Water-Cooled Nuclear Reactors

    SciTech Connect

    Macdonald, Dgiby; Urquidi-Macdonald, Mirna; Pitt, Jonathan

    2006-08-08

    This project developed a comprehensive mathematical and simulation model for calculating thermal hydraulic, electrochemical, and corrosion parameters, viz. temperature, fluid flow velocity, pH, corrosion potential, hydrogen injection, oxygen contamination, stress corrosion cracking, crack growth rate, and other important quantities in the coolant circuits of water-cooled nuclear power plants, including both Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). The model is being used to assess the three major operational problems in Pressurized Water Reactors (PWR), which include mass transport, activity transport, and the axial offset anomaly, and provide a powerful tool for predicting the accumulation of SCC damage in BWR primary coolant circuits as a function of operating history. Another achievement of the project is the development of a simulation tool to serve both as a training tool for plant operators and as an engineering test-bed to evaluate new equipment and operating strategies (normal operation, cold shut down and others). The development and implementation of the model allows us to estimate the activity transport or "radiation fields" around the primary loop and the vessel, as a function of the operating parameters and the water chemistry.

  12. Preliminary studies on the heat exchanger option for S-CO{sub 2} power conversion cycle coupled to water cooled SMR

    SciTech Connect

    Ahn, Y.; Lee, J.; Lee, J. I.

    2012-07-01

    For more than a half century, the steam Rankine cycle had been the major power conversion cycle for a nuclear power plant. However, as the interest on the next generation reactors grows, a variety of alternative power conversion systems have been studied. Among them, the S-CO{sub 2} cycle (Supercritical carbon dioxide Brayton cycle) is considered as a promising candidate due to several benefits such as 1) Relatively high thermal efficiency at relatively low turbine inlet temperature, 2) High efficiency with simple lay-out 3) Compactness of turbo-machineries. 4) Compactness of total cycle combined with PCHE (Printed Circuit Heat Exchanger). According to the conventional classification of heat exchangers (HE), there are three kind of HE, 1) Tubular HEs, 2) Plate-type HEs, 3) Extended surface HEs. So far, the researcher has mostly assumed PCHE type HE for the S-CO{sub 2} cycle due to its compactness with reasonably low pressure drop. However, PCHE is currently one of the most expensive components in the cycle, which can have a negative effect on the economics of the cycle. Therefore, an alternative for the HE should be seriously investigated. By comparing the operating condition (pressure and temperature) there are three kind of HE in the S-CO{sub 2} cycle, 1) IHX (Intermediate Heat exchanger) 2) Recuperator and 3) Pre-cooler. In each heat exchanger, hot side and cold side coolants are different, i.e. reactor coolant to S-CO{sub 2} (IHX), S-CO{sub 2} to S-CO{sub 2}(Recuperator), S-CO{sub 2} to water (Pre-cooler). By considering all the attributes mentioned above, all existing types of heat exchangers are compared to find a possible alternative to PCHE. The comparing factors are 1) Size(volume), 2) Cost. Plate fin type HEs are considered to be the most competitive heat exchanger regarding the size and the cost after some improvements on the design limit are made. (authors)

  13. Heat dissipation in water-cooled reflectors

    NASA Technical Reports Server (NTRS)

    Kozai, Toyoki

    1994-01-01

    The energy balance of a lamp varies with the thermal and optical characteristics of the reflector. The photosynthetic radiation efficiency of lamps, defined as input power divided by photosynthetically active radiation (PAR, 400-700 nm) emitted from the lamp ranges between 0.17 and 0.26. The rest of the energy input is wasted as longwave (3000 nm and over) and non-PAR shortwave radiation (from 700 nm to 3000 nm), convective, and conductive heat from the lamp, reflector, and ballast, and simply for increasing the cooling load. Furthermore, some portion of the PAR is uselessly absorbed by the inner walls, shelves, vessels, etc. and some portion of the PAR received by the plantlets is converted into sensible and latent heat. More than 98% of the energy input is probably converted into heat, with only less than 2% of the energy input being converted into chemical energy as carbohydrates by photosynthesis. Therefore, it is essential to reduce the generation of heat in the culture room in order to reduce the cooling load. Through use of a water-cooled reflector, the generation of convective and conductive heat and longwave radiation from the reflector can be reduced, without reduction of PAR.

  14. Heat dissipation in water-cooled reflectors

    NASA Astrophysics Data System (ADS)

    Kozai, Toyoki

    1994-03-01

    The energy balance of a lamp varies with the thermal and optical characteristics of the reflector. The photosynthetic radiation efficiency of lamps, defined as input power divided by photosynthetically active radiation (PAR, 400-700 nm) emitted from the lamp ranges between 0.17 and 0.26. The rest of the energy input is wasted as longwave (3000 nm and over) and non-PAR shortwave radiation (from 700 nm to 3000 nm), convective, and conductive heat from the lamp, reflector, and ballast, and simply for increasing the cooling load. Furthermore, some portion of the PAR is uselessly absorbed by the inner walls, shelves, vessels, etc. and some portion of the PAR received by the plantlets is converted into sensible and latent heat. More than 98% of the energy input is probably converted into heat, with only less than 2% of the energy input being converted into chemical energy as carbohydrates by photosynthesis. Therefore, it is essential to reduce the generation of heat in the culture room in order to reduce the cooling load. Through use of a water-cooled reflector, the generation of convective and conductive heat and longwave radiation from the reflector can be reduced, without reduction of PAR.

  15. Air and water cooled modulator

    DOEpatents

    Birx, Daniel L.; Arnold, Phillip A.; Ball, Don G.; Cook, Edward G.

    1995-01-01

    A compact high power magnetic compression apparatus and method for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air.

  16. Air and water cooled modulator

    DOEpatents

    Birx, D.L.; Arnold, P.A.; Ball, D.G.; Cook, E.G.

    1995-09-05

    A compact high power magnetic compression apparatus and method are disclosed for delivering high voltage pulses of short duration at a high repetition rate and high peak power output which does not require the use of environmentally unacceptable fluids such as chlorofluorocarbons either as a dielectric or as a coolant, and which discharges very little waste heat into the surrounding air. A first magnetic switch has cooling channels formed therethrough to facilitate the removal of excess heat. The first magnetic switch is mounted on a printed circuit board. A pulse transformer comprised of a plurality of discrete electrically insulated and magnetically coupled units is also mounted on said printed board and is electrically coupled to the first magnetic switch. The pulse transformer also has cooling means attached thereto for removing heat from the pulse transformer. A second magnetic switch also having cooling means for removing excess heat is electrically coupled to the pulse transformer. Thus, the present invention is able to provide high voltage pulses of short duration at a high repetition rate and high peak power output without the use of environmentally unacceptable fluids and without discharging significant waste heat into the surrounding air. 9 figs.

  17. Water cooling considerations for the SSC

    SciTech Connect

    O'Meara, J.

    1984-11-02

    The purpose of this note is to specify parameters for hypothetical SSC water cooling systems, in order that the comparative advantages of these system can be studied. The various methods of heat rejection considered include: cooling towers, cooling ponds, ground water recharge system, water-to-air (dry) cooling towers, use of tunnel sump water, or some combination.

  18. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production, Nuclear Energy Research Initiative Project 2001-001, Westinghouse Electric Co. Grant Number: DE-FG07-02SF22533, Final Report

    SciTech Connect

    Philip E. MacDonald

    2005-01-01

    The supercritical water-cooled reactor (SCWR) is one of the six reactor technologies selected for research and development under the Generation IV program. SCWRs are promising advanced nuclear systems because of their high thermal efficiency (i.e., about 45% versus about 33% efficiency for current Light Water Reactors [LWRs]) and considerable plant simplification. SCWRs are basically LWRs operating at higher pressure and temperatures with a direct once-through cycle. Operation above the critical pressure eliminates coolant boiling, so the coolant remains single-phase throughout the system. Thus, the need for a pressurizer, steam generators, steam separators, and dryers is eliminated. The main mission of the SCWR is generation of low-cost electricity. It is built upon two proven technologies: LWRs, which are the most commonly deployed power generating reactors in the world, and supercritical fossil-fired boilers, a large number of which are also in use around the world. The reference SCWR design for the U.S. program is a direct cycle system operating at 25.0 MPa, with core inlet and outlet temperatures of 280 and 500 C, respectively. The coolant density decreases from about 760 kg/m3 at the core inlet to about 90 kg/m3 at the core outlet. The inlet flow splits with about 10% of the inlet flow going down the space between the core barrel and the reactor pressure vessel (the downcomer) and about 90% of the inlet flow going to the plenum at the top of the rector pressure vessel, to then flow down through the core in special water rods to the inlet plenum. Here it mixes with the feedwater from the downcomer and flows upward to remove the heat in the fuel channels. This strategy is employed to provide good moderation at the top of the core. The coolant is heated to about 500 C and delivered to the turbine. The purpose of this NERI project was to assess the reference U.S. Generation IV SCWR design and explore alternatives to determine feasibility. The project was organized into three tasks: Task 1. Fuel-cycle Neutronic Analysis and Reactor Core Design Task 2. Fuel Cladding and Structural Material Corrosion and Stress Corrosion Cracking Task 3. Plant Engineering and Reactor Safety Analysis. moderator rods. materials.

  19. Water-Cooled Total-Temperature Probe

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Reece, Garland D.

    1992-01-01

    Water-cooled supersonic total-pressure, static-pressure, and total-temperature probes developed to study high-temperature jet plumes. Total-temperature probe tested up to 2,000 degrees F incorporates annular cooling system up to thermocouple lead. Lead extends into test chamber to sense temperature of supersonic external flow. Design novel and significant. Applicable in development of jet engines and in research on fast flows of hot gases.

  20. Pyrographite water-cooled target analysis

    SciTech Connect

    Bennett, G.A.

    1980-09-01

    This report presents a study of two pyrographic water-cooled targets planned for use in the Clinton P. Anderson Meson Physics Facility. A steady-state thermal stress analysis was done that included a parameter study on the physical and numerical variables that affect the problem. The maximum target temperatures and stresses were calculated and compared for a variety of conditions. The comparisons show that the 0.6-cm half-width fin target proposed for the A-2 line is the most vulnerable of the targets analyzed.

  1. Prospects for development of an innovative water-cooled nuclear reactor for supercritical parameters of coolant

    NASA Astrophysics Data System (ADS)

    Kalyakin, S. G.; Kirillov, P. L.; Baranaev, Yu. D.; Glebov, A. P.; Bogoslovskaya, G. P.; Nikitenko, M. P.; Makhin, V. M.; Churkin, A. N.

    2014-08-01

    The state of nuclear power engineering as of February 1, 2014 and the accomplished elaborations of a supercritical-pressure water-cooled reactor are briefly reviewed, and the prospects of this new project are discussed based on this review. The new project rests on the experience gained from the development and operation of stationary water-cooled reactor plants, including VVERs, PWRs, BWRs, and RBMKs (their combined service life totals more than 15 000 reactor-years), and long-term experience gained around the world with operation of thermal power plants the turbines of which are driven by steam with supercritical and ultrasupercritical parameters. The advantages of such reactor are pointed out together with the scientific-technical problems that need to be solved during further development of such installations. The knowledge gained for the last decade makes it possible to refine the concept and to commence the work on designing an experimental small-capacity reactor.

  2. Water-cooled units in ultrapower electric arc furnaces

    NASA Astrophysics Data System (ADS)

    Kuz'min, M. G.; Cherednichenko, V. S.; Bikeev, R. A.; Cherednichenko, M. V.

    2014-12-01

    The thermophysical processes that occur in the skull-metallic pipe-water system under quasistationary and dynamic conditions, when shock heat flows appear, are analyzed. The limiting conditions of water cooling of panels, which are accompanied by the appearance of boiling crisis and pre-emergency and emergency thermophysical processes, are considered.

  3. Computational Simulation of a Water-Cooled Heat Pump

    NASA Technical Reports Server (NTRS)

    Bozarth, Duane

    2008-01-01

    A Fortran-language computer program for simulating the operation of a water-cooled vapor-compression heat pump in any orientation with respect to gravity has been developed by modifying a prior general-purpose heat-pump design code used at Oak Ridge National Laboratory (ORNL).

  4. Accident analysis of heavy water cooled thorium breeder reactor

    SciTech Connect

    Yulianti, Yanti; Su’ud, Zaki; Takaki, Naoyuki

    2015-04-16

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The power reactor has a peak value before reactor has new balance condition. The analysis showed that temperatures of fuel and claddings during accident are still below limitations which are in secure condition.

  5. Accident analysis of heavy water cooled thorium breeder reactor

    NASA Astrophysics Data System (ADS)

    Yulianti, Yanti; Su'ud, Zaki; Takaki, Naoyuki

    2015-04-01

    Thorium has lately attracted considerable attention because it is accumulating as a by-product of large scale rare earth mining. The objective of research is to analyze transient behavior of a heavy water cooled thorium breeder that is designed by Tokai University and Tokyo Institute of Technology. That is oxide fueled, PWR type reactor with heavy water as primary coolant. An example of the optimized core has relatively small moderator to fuel volume ratio (MFR) of 0.6 and the characteristics of the core are burn-up of 67 GWd/t, breeding ratio of 1.08, burn-up reactivity loss during cycles of < 0.2% dk/k, and negative coolant reactivity coefficient. One of the nuclear reactor accidents types examined here is Unprotected Transient over Power (UTOP) due to withdrawing of the control rod that result in the positive reactivity insertion so that the reactor power will increase rapidly. Another accident type is Unprotected Loss of Flow (ULOF) that caused by failure of coolant pumps. To analyze the reactor accidents, neutron distribution calculation in the nuclear reactor is the most important factor. The best expression for the neutron distribution is the Boltzmann transport equation. However, solving this equation is very difficult so that the space-time diffusion equation is commonly used. Usually, space-time diffusion equation is solved by employing a point kinetics approach. However, this approach is less accurate for a spatially heterogeneous nuclear reactor and the nuclear reactor with quite large reactivity input. Direct method is therefore used to solve space-time diffusion equation which consider spatial factor in detail during nuclear reactor accident simulation. Set of equations that obtained from full implicit finite-difference method is solved by using iterative methods. The indication of UTOP accident is decreasing macroscopic absorption cross-section that results large external reactivity, and ULOF accident is indicated by decreasing coolant flow. The power reactor has a peak value before reactor has new balance condition. The analysis showed that temperatures of fuel and claddings during accident are still below limitations which are in secure condition.

  6. Summary of research and development effort on air and water cooling of gas turbine blades

    SciTech Connect

    Fraas, A.P.

    1980-03-01

    The review on air- and water-cooled gas turbines from the 1904 Lemale-Armengaud water-cooled gas turbine, the 1948 to 1952 NACA work, and the program at GE indicates that the potential of air cooling has been largely exploited in reaching temperatures of 1100/sup 0/C (approx. 2000/sup 0/F) in utility service and that further increases in turbine inlet temperature may be obtained with water cooling. The local heat flux in the first-stage turbine rotor with water cooling is very high, yielding high-temperature gradients and severe thermal stresses. Analyses and tests indicate that by employing a blade with an outer cladding of an approx. 1-mm-thick oxidation-resistant high-nickel alloy, a sublayer of a high-thermal-conductivity, high-strength, copper alloy containing closely spaced cooling passages approx. 2 mm in ID to minimize thermal gradients, and a central high-strength alloy structural spar, it appears possible to operate a water-cooled gas turbine with an inlet gas temperature of 1370/sup 0/C. The cooling-water passages must be lined with an iron-chrome-nickel alloy must be bent 90/sup 0/ to extend in a neatly spaced array through the platform at the base of the blade. The complex geometry of the blade design presents truly formidable fabrication problems. The water flow rate to each of many thousands of coolant passages must be metered and held to within rather close limits because the heat flux is so high that a local flow interruption of only a few seconds would lead to a serious failure.Heat losses to the cooling water will run approx. 10% of the heat from the fuel. By recoverying this waste heat for feedwater heating in a command cycle, these heat losses will give a degradation in the power plant output of approx. 5% relative to what might be obtained if no cooling were required. However, the associated power loss is less than half that to be expected with an elegant air cooling system.

  7. Copper corrosion & clogging in APS deionized water cooling system

    NASA Astrophysics Data System (ADS)

    Adak, Bijaya

    An extensive amount of work has been performed on copper corrosion in last century due to its abundant use in domestic and industrial water systems. However, work on copper corrosion in deionized water is very limited. The water cooling system of Advanced Photon Source (APS) at Argonne National Laboratory uses deionized water containing very low dissolved oxygen (less than 10 ppb). Therefore, It is expected that copper corrosion would be less in this system. On the contrary, APS suffers significant clogging in its water cooling circuit resulting from the deposition of corrosion product and carries out frequent expensive maintenance to retain the required flow rate. The location of pH and corrosion potential of APS water cooling system is very close to the boundary condition of the two oxides (CuO and Cu 2O) of the Pourbaix diagram of copper. While a single phase presence of either of these two oxides is stable as a protective layer, a mixture of the two oxides is unstable. An unstable protective layer results in spalling of the oxide layer. A fluctuation in water chemistry (which is common in an industrial facility) triggers a phase transformation between these two oxides due to its near boundary values. It was observed that the location of pH and corrosion potential was away from the boundaries in high dissolved oxygen condition (more than 2000 ppm). Hence, the possibility of phase transformation becomes lesser in high dissolved oxygen condition than in low dissolved oxygen condition. A test station, that was a replica of the APS water cooling system, was used to perform experiments in both high and low oxygen condition. It was demonstrated that high oxygen condition results in less clogging than in low oxygen condition. Microstructural characterization was performed on the coupons from test station and on some components from APS to evaluate oxide surface and determine phases. Mechanism of the phase transformation was suggested.

  8. Deployment Scenario of Heavy Water Cooled Thorium Breeder Reactor

    SciTech Connect

    Mardiansah, Deby; Takaki, Naoyuki

    2010-06-22

    Deployment scenario of heavy water cooled thorium breeder reactor has been studied. We have assumed to use plutonium and thorium oxide fuel in water cooled reactor to produce {sup 233}U which will be used in thorium breeder reactor. The objective is to analysis the potential of water cooled Th-Pu reactor for replacing all of current LWRs especially in Japan. In this paper, the standard Pressurize Water Reactor (PWR) has been designed to produce 3423 MWt; (i) Th-Pu PWR, (ii) Th-Pu HWR (MFR = 1.0) and (iii) Th-Pu HWR (MFR 1.2). The properties and performance of the core were investigated by using cell and core calculation code. Th-Pu PWR or HWR produces {sup 233}U to introduce thorium breeder reactor. The result showed that to replace all (60 GWe) LWR by thorium breeder reactor within a period of one century, Th-Pu oxide fueled PWR has insufficient capability to produce necessary amount of {sup 233}U and Th-Pu oxide fueled HWR has almost enough potential to produce {sup 233}U but shows positive void reactivity coefficient.

  9. Thermal Hydraulic Design and Analysis of a Water-Cooled Ceramic Breeder Blanket with Superheated Steam for CFETR

    NASA Astrophysics Data System (ADS)

    Cheng, Xiaoman; Ma, Xuebin; Jiang, Kecheng; Chen, Lei; Huang, Kai; Liu, Songlin

    2015-09-01

    The water-cooled ceramic breeder blanket (WCCB) is one of the blanket candidates for China fusion engineering test reactor (CFETR). In order to improve power generation efficiency and tritium breeding ratio, WCCB with superheated steam is under development. The thermal-hydraulic design is the key to achieve the purpose of safe heat removal and efficient power generation under normal and partial loading operation conditions. In this paper, the coolant flow scheme was designed and one self-developed analytical program was developed, based on a theoretical heat transfer model and empirical correlations. Employing this program, the design and analysis of related thermal-hydraulic parameters were performed under different fusion power conditions. The results indicated that the superheated steam water-cooled blanket is feasible. supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy of China (Nos. 2013GB108004, 2014GB122000 and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  10. Improved water-cooled cyclone constructions in CFBs

    SciTech Connect

    Alliston, M.G.; Luomaharju, T.; Kokko, A.

    1999-07-01

    The construction of CFB boilers has advanced in comparison with early designs. One improvement has been the use of water or steam cooled cyclones, which allows the use of thin refractories and minimizes maintenance needs. Cooled cyclones are also tolerant of wide load variations when the main fuel is biologically based, and coal or some other fuel is used as a back-up. With uncooled cyclones, load changes with high volatile fuels can mean significant temperature transients in the refractory, due to post-combustion phenomena in the cyclone. Kvaerner's development of water-cooled cyclones for CFBs began in the early 1980s. The first boiler with this design was delivered in 1985 in Sweden. Since then, Kvaerner Pulping has delivered over twenty units with cooled cyclones, in capacity ranging from small units up to 400 MW{sub th}. Among these units, Kvaerner has developed unconventional solutions for CFBs, in order to simplify the constructions and to increase the reliability for different applications. The first of them was CYMIC{reg{underscore}sign}, which has its water-cooled cyclone built inside the boiler furnace. There are two commercial CYMIC boilers in operation and one in project stages. The largest CYMIC in operation is a 185 MW{sub th} industrial boiler burning various fuels. For even larger scale units Kvaerner developed the Integrated Cylindrical Cyclone and Loopseal (ICCL) assembly. One of these installations is in operation in USA, having steaming capacity of over 500 t/h. The design bases of these new solutions are quite different in comparison with conventional cyclones. Therefore, an important part of the development has been cold model testing and mathematical modeling of the cyclones. This paper reviews the state-of-the-art in water-cooled cyclone construction. The new solutions, their full-scale experience, and a comparison of the actual experience with the preliminary modeling work are introduced.

  11. Pink-Beam, Highly-Accurate Compact Water Cooled Slits

    SciTech Connect

    Lyndaker, Aaron; Deyhim, Alex; Jayne, Richard; Waterman, Dave; Caletka, Dave; Steadman, Paul; Dhesi, Sarnjeet

    2007-01-19

    Advanced Design Consulting, Inc. (ADC) has designed accurate compact slits for applications where high precision is required. The system consists of vertical and horizontal slit mechanisms, a vacuum vessel which houses them, water cooling lines with vacuum guards connected to the individual blades, stepper motors with linear encoders, limit (home position) switches and electrical connections including internal wiring for a drain current measurement system. The total slit size is adjustable from 0 to 15 mm both vertically and horizontally. Each of the four blades are individually controlled and motorized. In this paper, a summary of the design and Finite Element Analysis of the system are presented.

  12. Water cooled metal optics for the Advanced Light Source

    SciTech Connect

    McKinney, W.R.; Irick, S.C.; Lunt, D.L.J.

    1991-10-28

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications, and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and mid-period error. We will briefly describe out improved version of the Long Trace Profiler, and its importance to out metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of Peter Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  13. Water cooled metal optics for the advanced light source

    NASA Astrophysics Data System (ADS)

    McKinney, Wayne R.; Irick, Steven C.; Hunt, David L. J.

    1992-08-01

    The program for providing water cooled metal optics for the Advanced Light Source at Berkeley is reviewed with respect to fabrication and metrology of the surfaces. Materials choices, surface figure and smoothness specifications. and metrology systems for measuring the plated metal surfaces are discussed. Results from prototype mirrors and grating blanks will be presented, which show exceptionally low microroughness and midperiod error. We will briefly describe our improved version of the long trace profiler, and its importance to our metrology program. We have completely redesigned the mechanical, optical and computational parts of the profiler system with the cooperation of P. Takacs of Brookhaven, Continental Optical, and Baker Manufacturing. Most important is that one of our profilers is in use at the vendor to allow testing during fabrication. Metrology from the first water cooled mirror for an ALS beamline is presented as an example. This 15 in. long Glidcop TM mirror is coated with electroless nickel from Acteron Corporation in Redwood City, CA. The preplating processing and grinding and polishing were done by Tucson Optical. We will show significantly better surface microroughness on electroless nickel, over large areas, than has been reported previously.

  14. Numerical analysis of thermal effects in semiconductor disk laser with water cooling

    NASA Astrophysics Data System (ADS)

    Zhu, Renjiang; Pan, Yingjun; Jiang, Maohua; Zhang, Peng

    2014-11-01

    This paper has established a thermal model of Vertical-external-cavity surface-emitting semiconductor laser (VECSELs) with water-cooled heatsink, calculated the distribution of temperature field with finite element method, and studied the effects of pumping light, heat transfer coefficient, and heatsink characteristics on the maximum temperature of the quantum well. Calculations show that there is an optimal heat transfer coefficient value interval, thermal conductivity of the VECSELs heatsink will have a significant impact on the maximum temperature of the quantum well, and increasing area of cooler heatsink would help to improve heat dissipation performance. It also shows that the maximum temperature of the quantum well has a linear relationship with pump power, and a nearly inverse relationship with the spot size. Due to thermal diffusion of water-cooled heatsink for VECSELs point heat source, the maximum temperature of quantum well is not sensitive to thickness and area of the heatsink, heat dissipation performance which uses a diamond heatsink is about 1.7 times the oxygen-free copper heatsink.

  15. Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

    1975-01-01

    A steady-state ExB plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasma with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage. Neutrons were produced from deuterium plasma, but it was not established whether thay came from the plasma volume or from the electrode surfaces.

  16. Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

    NASA Technical Reports Server (NTRS)

    Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

    1975-01-01

    The paper reports on hot-ion plasma experiments conducted in a magnetic mirror facility. A steady-state E x B plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasmas with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage.

  17. Water cooled vibrating grate stoker for proven, efficient and reliable combustion of biomass fuels

    SciTech Connect

    Giaier, T.A.

    1996-12-31

    Bioenergy from waste sources and dedicated crops can provide substantial contributions for energy production. Together, these energy technologies are the wave of the future as they offer a localized, decentralized way of meeting electricity and process steam needs. The biomass industry accounts for about 15% of energy production worldwide, according to the National Wood Energy Association. For developing countries, the percentage is much higher. Currently, many types of combustible solid waste products like bark, wood waste, wood chips, sawdust, municipal and industrial refuse, agricultural wastes such as bagasse, spent coffee, etc.; are profitably utilized as excellent fuel sources. Many of these produce less acid gas than the fossil fuels they replace. Additionally, biomass feed stocks can reduce the quantity of carbon dioxide CO{sub 2} over fossil fuel burning since CO{sub 2} is used in the growth cycle of biomass feed stocks. Water cooled grates, both vibrating and stationary, have been used for many years for the combustion of biomass fuels. Both grates have relatively low maintenance and operating costs, thus making each grate a popular choice for a wide variety of applications. This paper chronicles combustion technologies for biomass fuels and the development of the water cooled grate followed by two case histories. The first case describes the conversion of an existing black liquor recovery boiler to wood firing and the second is the installation of the largest biomass fired Independent Power Producing plant in North America.

  18. XHM-1 alloy as a promising structural material for water-cooled fusion reactor components

    NASA Astrophysics Data System (ADS)

    Solonin, M. I.; Alekseev, A. B.; Kazennov, Yu. I.; Khramtsov, V. F.; Kondrat'ev, V. P.; Krasina, T. A.; Rechitsky, V. N.; Stepankov, V. N.; Votinov, S. N.

    1996-10-01

    Experience gained in utilizing austenitic stainless steel components in water-cooled power reactors indicates that the main cause of their failure is the steel's propensity for corrosion cracking. In search of a material immune to this type of corrosion, different types of austenitic steels and chromium—nickel alloys were investigated and tested at VNIINM. This paper presents the results of studying physical and mechanical properties, irradiation and corrosion resistance in a water coolant at < 350°C of the alloy XHM-1 as compared with austenitic stainless steels 00Cr16Ni15Mo3Nb, 00Cr20Ni25Nb and alloy 00Cr20Ni40Mo5Nb. Analysis of the results show that, as distinct from the stainless steels studied, the XHM-1 alloy is completely immune to corrosion cracking (CC). Not a single induced damage was encountered within 50 to 350°C in water containing different amounts of chlorides and oxygen under tensile stresses up to the yield strength of the material. One more distinctive feature of the alloy compared to steels is that no change in the strength or total elongation is encountered in the alloy specimens irradiated to 32 dpa at 350°C. The XHM-1 alloy has adequate fabricability and high weldability characteristics. As far as its properties are concerned, the XHM-1 alloy is very promising as a material for water-cooled fusion reactor components.

  19. Research of a Supercritical Pressure Water Cooled Reactor in Korea

    SciTech Connect

    Bae, Yoon-Yeong; Joo, Hyung-Kook; Jang, Jinsung; Jeong, Yong-Hwan; Song, Jin-ho; Yoon, Han-Young; Yoo, Jung-Yul

    2004-07-01

    In this paper the activities on the supercritical pressure water-cooled reactor (SCWR) in Korea are briefly introduced. Four projects on a SCWR are being conducted in Korea. Three of them are supported by the I-NERI program while one is by KAERI. Two of the I-NERI-supported projects concern suitable materials for supercritical pressure and temperature, and radiation environment. The other I-NERI-supported project surveys numerically and experimentally the proper turbulence modeling for the numerical calculation of heat transfer phenomena at a supercritical condition. Heat transfer at a supercritical condition is being studied at KAERI experimentally using carbon dioxide as a coolant. The test loop is to be completed by the end of 2004. (authors)

  20. Water-cooled hard-soldered kilowatt laser diode arrays operating at high duty cycle

    NASA Astrophysics Data System (ADS)

    Klumel, Genady; Karni, Yoram; Oppenhaim, Jacob; Berk, Yuri; Shamay, Moshe; Tessler, Renana; Cohen, Shalom; Risemberg, Shlomo

    2010-04-01

    High brightness laser diode arrays are increasingly found in defense applications either as efficient optical pumps or as direct energy sources. In many instances, duty cycles of 10- 20 % are required, together with precise optical collimation. System requirements are not always compatible with the use of microchannel based cooling, notwithstanding their remarkable efficiency. Simpler but effective solutions, which will not involve high fluid pressure drops as well as deionized water, are needed. The designer is faced with a number of challenges: effective heat removal, minimization of the built- in and operational stresses as well as precise and accurate fast axis collimation. In this article, we report on a novel laser diode array which includes an integral tap water cooling system. Robustness is achieved by all around hard solder bonding of passivated 940nm laser bars. Far field mapping of the beam, after accurate fast axis collimation will be presented. It will be shown that the design of water cooling channels , proper selection of package materials, careful design of fatigue sensitive parts and active collimation technique allow for long life time and reliability, while not compromising the laser diode array efficiency, optical power density ,brightness and compactness. Main performance characteristics are 150W/bar peak optical power, 10% duty cycle and more than 50% wall plug efficiency with less than 1° fast axis divergence. Lifetime of 0.5 Gshots with less than 10% power degradation has been proved. Additionally, the devices have successfully survived harsh environmental conditions such as thermal cycling of the coolant temperature and mechanical shocks.

  1. Temperature dynamics and control of a water-cooled fuel cell stack

    NASA Astrophysics Data System (ADS)

    O'Keefe, Daniel; El-Sharkh, M. Y.; Telotte, John C.; Palanki, Srinivas

    2014-06-01

    In this paper, a time-varying proportional-integral (PI) controller is designed for controlling the temperature of a water-cooled 5 kW hydrogen fuel cell stack. This controller is designed using a mathematical model for the stack temperature, which is derived using basic chemical engineering material and energy balances. The controller affects the stack temperature by changing the flow rate of cooling water that passes across the stack. The model is then analyzed using a number of power demand profiles to determine the effectiveness of the controller. The results show that a time-varying PI controller is adequate for maintaining the stack temperature within 5 K of the target point.

  2. Silver bonded, internally water-cooled monochromators for CHESS wiggler beamlines

    SciTech Connect

    Smolenski, Karl W.; Shen Qun; Doing, Park

    1997-07-01

    Intense synchrotron radiation from high power wiggler sources has long been a difficult high-heat-load problem to the design of properly cooled x-ray optics. Large, high power and very intense beams thermally distort crystal optics, reducing throughput and broadening rocking curves. An internally cooled silicon monochromator has been fabricated which demonstrated the capability of diffracting wiggler radiation of unprecedented power without significant degradation of the beam. Cooling water flows through rectangular cooling channels 1 mm wide, 1 mm below the diffracting surface, fed by a manifold bonded to the underside of the diffracting crystal. A novel silver diffusion bond was used to ensure leak-tight UHV performance. Recent test results at wiggler station F2 show a linear behavior of the x-ray flux with increasing storage ring current up to a total power of 3 kW and a peak surface power density of 5 W/mm{sup 2}. The improved monochromator has led to an increase of x-ray flux by a factor of six over previous contact-cooled designs and shows that internal water-cooling can be an effective solution to high-heat-load problems at high power wiggler stations.

  3. Design of Balanced Reactor Welded with Water-Cooled Aluminum Busbars

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Fu, Peng; Song, Zhiquan

    2011-04-01

    A new process of welding aluminum water-cooled busbars is proposed. It can not only reduce the weight and cost, but also improve the dynamic and thermal stability. Furthermore, both finite element method analysis and a prototype test testify the advantages of the design which is not limited by load current and provides a new approach for water-cooled reactors.

  4. Water-cooled furnace heads for use with standard muffle tube furnaces

    NASA Technical Reports Server (NTRS)

    Williams, R. J.; Mullins, O.

    1975-01-01

    The design of water-cooled furnace seals for use in high-temperature controlled-atmosphere gas and vacuum studies is presented in detailed engineering drawings. Limiting design factors and advantages are discussed.

  5. Repair of a water-cooled field coil for a hydroelectric motor/generator

    SciTech Connect

    Miller, L.J. III

    1983-01-01

    Four reversible pump/turbine units at TVA's Raccoon Mountain Pumped-Storage Plant were placed in service in 1978 to 1979. The stator and rotor windings for the motor/generators are direct water cooled. This paper describes repairs to a water-cooled coil of one of the 24 field poles of Unit No. 3 motor/generator placed in service in February 1979.

  6. Inhibition of radioactive cobalt deposition in water-cooled nuclear reactors

    SciTech Connect

    Peterson, G.E.; Robinson, R.N.; Ruiz, C.P.; Marble, W.J.; Gordon, B.M.; Gordon, G.M.

    1990-08-21

    This patent describes a method for inhibiting intergranular stress corrosion cracking and the deposition of radioactive cobalt in a water-bearing vessel of a water-cooled nuclear reactor. It comprises: adding zinc to water entering the water-bearing vessel continuously during operation of the water-cooled nuclear reactor, wherein the amount of zinc oxide is selected to achieve a concentration in the range from about 25 to 150 ppb.

  7. Startup Thermal Considerations for Supercritical-Pressure Light Water-Cooled Reactors

    SciTech Connect

    Nakatsuka, Toru; Oka, Yoshiaki; Koshizuka, Seiichi

    2001-06-15

    Supercritical-pressure light water-cooled reactors (SCRs) are innovative systems aimed at high efficiency and cost reduction. The once-through direct-cycle plant system is the leading system of fossil-fired power plants (FPPs). Estimates of the coolability and necessary sizes of the SCR startup systems, sequences, and required equipment for startup are investigated with reference to supercritical FPPs. There are two types of supercritical boilers. One is a constant pressure boiler, and the other is a variable pressure boiler.First, startup of the constant pressure boiler is examined. The reactor starts at a supercritical pressure. A startup bypass system consisting of a flash tank and pressure-reducing valves is required. Second, startup of the variable pressure boiler is investigated. The reactor starts at a subcritical pressure, and the pressure increases with the load. A steam-water separator and a drain tank are required for startup.The results of computer calculations show that with both constant pressure and variable pressure startup, the peak cladding temperature does not exceed the operating limit through startup, and both startup sequences are feasible. The sizes of the components required for the startup systems are assessed. To simplify the plant system and to reduce the component size, variable pressure startup with steam separators in the bypass line appears desirable.

  8. Improving of the photovoltaic / thermal system performance using water cooling technique

    NASA Astrophysics Data System (ADS)

    Hussien, Hashim A.; Numan, Ali H.; Abdulmunem, Abdulmunem R.

    2015-04-01

    This work is devoted to improving the electrical efficiency by reducing the rate of thermal energy of a photovoltaic/thermal system (PV/T).This is achieved by design cooling technique which consists of a heat exchanger and water circulating pipes placed at PV module rear surface to solve the problem of the high heat stored inside the PV cells during the operation. An experimental rig is designed to investigate and evaluate PV module performance with the proposed cooling technique. This cooling technique is the first work in Iraq to dissipate the heat from PV module. The experimental results indicated that due to the heat loss by convection between water and the PV panel's upper surface, an increase of output power is achieved. It was found that without active cooling, the temperature of the PV module was high and solar cells could only achieve a conversion efficiency of about 8%. However, when the PV module was operated under active water cooling condition, the temperature was dropped from 76.8°C without cooling to 70.1°C with active cooling. This temperature dropping led to increase in the electrical efficiency of solar panel to 9.8% at optimum mass flow rate (0.2L/s) and thermal efficiency to (12.3%).

  9. Prototype of 10 Tesla Water Cooled Bitter-type Magnet System

    NASA Astrophysics Data System (ADS)

    Bates, E. M.; Birmingham, W. J.; Riverva, W. F.; Romero-Talamas, C. A.

    2015-11-01

    A 1 Tesla water cooled Bitter-type magnetic system has been designed and is under construction at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County (UMBC). It is a scaled version of a 10 T Bitter-type magnet that will be used in dusty plasma experiments where dust larger than 500 nm diameter will be strongly magnetized. We present here the design methods used for both magnets, and discuss the design parameters that drive the magnet cooling and power storage bank subsystems. The pressure vessel and plasma vacuum chamber subsystems are then built with the aforementioned subsystems as constraints. To validate our design, magnetic field and temperature measurements within the prototype magnet are compared to finite element analysis (FEA) and analytical methods used for preliminary designing. This knowledge will be used to finalize the 10 T magnet design. Once operational, the 10 T magnet will be programmable to be on for at least ten seconds to several minutes, with up to 20 plasma events planned per day.

  10. Thermal Aspects of Using Alternative Nuclear Fuels in Supercritical Water-Cooled Reactors

    NASA Astrophysics Data System (ADS)

    Grande, Lisa Christine

    A SuperCritical Water-cooled Nuclear Reactor (SCWR) is a Generation IV concept currently being developed worldwide. Unique to this reactor type is the use of light-water coolant above its critical point. The current research presents a thermal-hydraulic analysis of a single fuel channel within a Pressure Tube (PT)-type SCWR with a single-reheat cycle. Since this reactor is in its early design phase many fuel-channel components are being investigated in various combinations. Analysis inputs are: steam cycle, Axial Heat Flux Profile (AHFP), fuel-bundle geometry, and thermophysical properties of reactor coolant, fuel sheath and fuel. Uniform and non-uniform AHFPs for average channel power were applied to a variety of alternative fuels (mixed oxide, thorium dioxide, uranium dicarbide, uranium nitride and uranium carbide) enclosed in an Inconel-600 43-element bundle. The results depict bulk-fluid, outer-sheath and fuel-centreline temperature profiles together with the Heat Transfer Coefficient (HTC) profiles along the heated length of fuel channel. The objective is to identify the best options in terms of fuel, sheath material and AHFPS in which the outer-sheath and fuel-centreline temperatures will be below the accepted temperature limits of 850°C and 1850°C respectively. The 43-element Inconel-600 fuel bundle is suitable for SCWR use as the sheath-temperature design limit of 850°C was maintained for all analyzed cases at average channel power. Thoria, UC2, UN and UC fuels for all AHFPs are acceptable since the maximum fuel-centreline temperature does not exceed the industry accepted limit of 1850°C. Conversely, the fuel-centreline temperature limit was exceeded for MOX at all AHFPs, and UO2 for both cosine and downstream-skewed cosine AHFPs. Therefore, fuel-bundle modifications are required for UO2 and MOX to be feasible nuclear fuels for SCWRs.

  11. An economic analysis of a light and heavy water moderated reactor synergy: burning americium using recycled uranium

    SciTech Connect

    Wojtaszek, D.; Edwards, G.

    2013-07-01

    An economic analysis is presented for a proposed synergistic system between 2 nuclear utilities, one operating light water reactors (LWR) and another running a fleet of heavy water moderated reactors (HWR). Americium is partitioned from LWR spent nuclear fuel (SNF) to be transmuted in HWRs, with a consequent averted disposal cost to the LWR operator. In return, reprocessed uranium (RU) is supplied to the HWRs in sufficient quantities to support their operation both as power generators and americium burners. Two simplifying assumptions have been made. First, the economic value of RU is a linear function of the cost of fresh natural uranium (NU), and secondly, plutonium recycling for a third utility running a mixed oxide (MOX) fuelled reactor fleet has been already taking place, so that the extra cost of americium recycling is manageable. We conclude that, in order for this scenario to be economically attractive to the LWR operator, the averted disposal cost due to partitioning americium from LWR spent fuel must exceed 214 dollars per kg, comparable to estimates of the permanent disposal cost of the high level waste (HLW) from reprocessing spent LWR fuel. (authors)

  12. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOEpatents

    Jukkola, Walfred W.; Leon, Albert M.; Van Dyk, Jr., Garritt C.; McCoy, Daniel E.; Fisher, Barry L.; Saiers, Timothy L.; Karstetter, Marlin E.

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  13. European reference design of the water-cooled lithium-lead blanket for a demonstration reactor

    SciTech Connect

    Giancarli, L.; Baraer, L.; Bielak, B.; Eid, M.; Fuetterer, M.; Proust, E.; Raepsaet, X.; Salavy, J.F.; Sedano, L.; Severi, Y.

    1994-11-01

    The water-cooled Pb-17Li blankets represent one of the blanket lines selected within the European Union for DEMO-relevant design and R&D activities. This paper gives a presentation of the reference conceptual design for water-cooled Pb-17Li DEMO blankets and an overview on the results of its performance assessments. Moreover, a critical discussion about the technical aspects requiring further improvements and/or modifications is performed taking into account the present status of the associated R&D. This concept appears to be a very promising candidate for a DEMO reactor breeding blanket.

  14. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    SciTech Connect

    Loss, W.M.; Dietz, R.N.

    1991-09-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called hi-pot'' (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven's Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the double source'' method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

  15. Locating of leaks in water-cooled generator stator bars using perfluorocarbon tracers

    SciTech Connect

    Loss, W.M.; Dietz, R.N.

    1991-09-01

    Water cooled stator bars in power plant generators often fail during the maintenance cycle due to water leakage. After the hydrogen pressure in the generator shell has been released water can leak through cracks in the copper and through the insulation. Leaking bars, but not the leaks themselves, are detected with so-called ``hi-pot`` (high potential) tests where direct electrical current is applied to the stator bar windings. A study initiated by ConEd and Brookhaven`s Tracer Technology Center to explore the cause of these leakage problems to determine if the failures originate in the manufacturing process or are created in service by phase related torque stresses. To this purpose bars that had failed the hi-pot test were investigated first with the insulation in place and then stripped to the bare copper. The bars were pressurized with gases containing perfluorocarbon tracers and the magnitude and location of the leaks was detected by using tracers technology principles and instruments such as the ``double source`` method and the Dual Trap Analyzer. In the second part of the project the windings within a generator were tested in-situ for leaks during an outage using tracer principles. Recommendations are given suggesting the shut down of stator bar cooling water before hydrogen bleeding during outages and a revision of the current vent flow rate. The new standard should establish a reasonable leak rate for the stator bar windings proper and exclude leakage of pump seals and connections. Testing during the maintenance cycle in generators should include routine tracer leak detection following the hi-pot test.

  16. Numerical Simulation on Subcooled Boiling Heat Transfer Characteristics of Water-Cooled W/Cu Divertors

    NASA Astrophysics Data System (ADS)

    Han, Le; Chang, Haiping; Zhang, Jingyang; Xu, Tiejun

    2015-04-01

    In order to realize safe and stable operation of a water-cooled W/Cu divertor under high heating condition, the exact knowledge of its subcooled boiling heat transfer characteristics under different design parameters is crucial. In this paper, subcooled boiling heat transfer in a water-cooled W/Cu divertor was numerically investigated based on computational fluid dynamic (CFD). The boiling heat transfer was simulated based on the Euler homogeneous phase model, and local differences of liquid physical properties were considered under one-sided high heating conditions. The calculated wall temperature was in good agreement with experimental results, with the maximum error of 5% only. On this basis, the void fraction distribution, flow field and heat transfer coefficient (HTC) distribution were obtained. The effects of heat flux, inlet velocity and inlet temperature on temperature distribution and pressure drop of a water-cooled W/Cu divertor were also investigated. These results provide a valuable reference for the thermal-hydraulic design of a water-cooled W/Cu divertor. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2010GB104005), Funding of Jiangsu Innovation Program for Graduate Education (CXLX12_0170), the Fundamental Research Funds for the Central Universities of China

  17. Correction analysis for a supersonic water cooled total temperature probe tested to 1370 K

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1991-01-01

    The authors address the thermal analysis of a water cooled supersonic total temperature probe tested in a Mach 2 flow, up to 1366 K total temperature. The goal of this experiment was the determination of high-temperature supersonic jet mean flow temperatures. An 8.99 cm exit diameter water cooled nozzle was used in the tests. It was designed for exit Mach 2 at 1366 K exit total temperature. Data along the jet centerline were obtained for total temperatures of 755 K, 1089 K, and 1366 K. The data from the total temperature probe were affected by the water coolant. The probe was tested through a range of temperatures between 755 K and 1366 K with and without the cooling system turned on. The results were used to develop a relationship between the indicated thermocouple bead temperature and the freestream total temperature. The analysis and calculated temperatures are presented.

  18. Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas; Seiner, John M.

    1990-01-01

    Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

  19. Improving the water distribution system of a mechanical water-cooling tower

    SciTech Connect

    Kolivashko, A.S.; Mizin, V.A.; Kozlova, L.N.; Merenkov, V.V.; Chenyshov, Yh.A.; Basan, S.M.

    1984-01-01

    In order to improve the efficiency of mechanical water-cooling towers by improving the use of their effective capacity, a water distribution system with changes in their locations in the coking plants is proposed. Bench tests of the new system were carried out at the Dnepropetrovsk Institute, and the new system was introduced at the Zaporoshye Coking Plant. The efficiency of the performance of the system is discussed.

  20. Thermogalvanic effects on the pitting corrosion of water-cooled heat exchangers

    SciTech Connect

    Kaluzhina, S.A.; Zatsepina, N.A.

    1995-05-01

    Thermogalvanic corrosion of St3 steel in a temperature range from 25 to 50{degrees}C with a 3.84{degrees}C/cm gradient was studied in a neutral media flow. It is shown that the thermogalvanic effect on the pitting corrosion of water-cooled heat exchangers is decisive but dual. Depending on the composition of the cooling medium, thermogalvanic corrosion may either enhance (0.5 M NaCl) or inhibit (tap water) pitting corrosion.

  1. Evaluation of water cooled supersonic temperature and pressure probes for application to 2000 F flows

    NASA Technical Reports Server (NTRS)

    Lagen, Nicholas T.; Seiner, John M.

    1990-01-01

    The development of water cooled supersonic probes used to study high temperature jet plumes is addressed. These probes are: total pressure, static pressure, and total temperature. The motivation for these experiments is the determination of high temperature supersonic jet mean flow properties. A 3.54 inch exit diameter water cooled nozzle was used in the tests. It is designed for exit Mach 2 at 2000 F exit total temperature. Tests were conducted using water cooled probes capable of operating in Mach 2 flow, up to 2000 F total temperature. Of the two designs tested, an annular cooling method was chosen as superior. Data at the jet exit planes, and along the jet centerline, were obtained for total temperatures of 900 F, 1500 F, and 2000 F, for each of the probes. The data obtained from the total and static pressure probes are consistent with prior low temperature results. However, the data obtained from the total temperature probe was affected by the water coolant. The total temperature probe was tested up to 2000 F with, and without, the cooling system turned on to better understand the heat transfer process at the thermocouple bead. The rate of heat transfer across the thermocouple bead was greater when the coolant was turned on than when the coolant was turned off. This accounted for the lower temperature measurement by the cooled probe. The velocity and Mach number at the exit plane and centerline locations were determined from the Rayleigh-Pitot tube formula.

  2. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  3. Minor actinide transmutation in thorium and uranium matrices in heavy water moderated reactors

    SciTech Connect

    Bhatti, Zaki; Hyland, B.; Edwards, G.W.R.

    2013-07-01

    The irradiation of Th{sup 232} breeds fewer of the problematic minor actinides (Np, Am, Cm) than the irradiation of U{sup 238}. This characteristic makes thorium an attractive potential matrix for the transmutation of these minor actinides, as these species can be transmuted without the creation of new actinides as is the case with a uranium fuel matrix. Minor actinides are the main contributors to long term decay heat and radiotoxicity of spent fuel, so reducing their concentration can greatly increase the capacity of a long term deep geological repository. Mixing minor actinides with thorium, three times more common in the Earth's crust than natural uranium, has the additional advantage of improving the sustainability of the fuel cycle. In this work, lattice cell calculations have been performed to determine the results of transmuting minor actinides from light water reactor spent fuel in a thorium matrix. 15-year-cooled group-extracted transuranic elements (Np, Pu, Am, Cm) from light water reactor (LWR) spent fuel were used as the fissile component in a thorium-based fuel in a heavy water moderated reactor (HWR). The minor actinide (MA) transmutation rates, spent fuel activity, decay heat and radiotoxicity, are compared with those obtained when the MA were mixed instead with natural uranium and taken to the same burnup. Each bundle contained a central pin containing a burnable neutron absorber whose initial concentration was adjusted to have the same reactivity response (in units of the delayed neutron fraction β) for coolant voiding as standard NU fuel. (authors)

  4. Modifications to MELCOR for the analysis of heavy-water moderated, U-A1 fuel reactors

    SciTech Connect

    Church, J.P. ); Leonard, M.T.; Williams, K.A. )

    1990-01-01

    The MELCOR computer code is being used as the point of departure to develop an integrated severe accident analysis computer code for the heavy-water moderated U-Al fuel reactors. The resulting computer code (MELCOR/SR) provides a practical and comprehensive analytical tool for evaluating severe accident behavior in the Savannah River Site (SRS) production reactors. The technical scope of this development effort is summarized in this paper. Other companion papers are cited that provide additional details regarding particular models.

  5. Soy-Based, Water-Cooled, TC W-III Two Cycle Engine Oil

    SciTech Connect

    Scharf, Curtis R.; Miller, Mark E.

    2003-08-30

    The objective of this project was to achieve technical approval and commercial launch for a biodegradable soy oil-based, environmentally safe, TC W-III performance, water-cooled, two cycle engine oil. To do so would: (1) develop a new use for RBD soybean oil; (2) increase soybean utilization in North America in the range of 500 K-3.0 MM bushels; and (3) open up supply opportunities of 1.5-5.0 MM bushels worldwide. These goals have been successfully obtained.

  6. Fuel Breeding and Core Behavior Analyses on In Core Fuel Management of Water Cooled Thorium Reactors

    SciTech Connect

    Permana, Sidik; Sekimoto, Hiroshi; Waris, Abdul; Subhki, Muhamad Nurul; Ismail,

    2010-12-23

    Thorium fuel cycle with recycled U-233 has been widely recognized having some contributions to improve the water-cooled breeder reactor program which has been shown by a feasible area of breeding and negative void reactivity which confirms that fissile of 233U contributes to better fuel breeding and effective for obtaining negative void reactivity coefficient as the main fissile material. The present study has the objective to estimate the effect of whole core configuration as well as burnup effects to the reactor core profile by adopting two dimensional model of fuel core management. About more than 40 months of cycle period has been employed for one cycle fuel irradiation of three batches fuel system for large water cooled thorium reactors. All position of fuel arrangement contributes to the total core conversion ratio which gives conversion ratio less than unity of at the BOC and it contributes to higher than unity (1.01) at the EOC after some irradiation process. Inner part and central part give the important part of breeding contribution with increasing burnup process, while criticality is reduced with increasing the irradiation time. Feasibility of breeding capability of water-cooled thorium reactors for whole core fuel arrangement has confirmed from the obtained conversion ratio which shows higher than unity. Whole core analysis on evaluating reactivity change which is caused by the change of voided condition has been employed for conservative assumption that 100% coolant and moderator are voided. It obtained always a negative void reactivity coefficient during reactor operation which shows relatively more negative void coefficient at BOC (fresh fuel composition), and it becomes less negative void coefficient with increasing the operation time. Negative value of void reactivity coefficient shows the reactor has good safety properties in relation to the reactivity profile which is the main parameter in term of criticality safety analysis. Therefore, this evaluation has confirmed that breeding condition and negative coefficient can be obtained simultaneously for water-cooled thorium reactor obtains based on the whole core fuel arrangement.

  7. Effect of thermal barrier coatings on the performance of steam and water-cooled gas turbine/steam turbine combined cycle system

    NASA Technical Reports Server (NTRS)

    Nainiger, J. J.

    1978-01-01

    An analytical study was made of the performance of air, steam, and water-cooled gas-turbine/steam turbine combined-cycle systems with and without thermal-barrier coatings. For steam cooling, thermal barrier coatings permit an increase in the turbine inlet temperature from 1205 C (2200 F), resulting in an efficiency improvement of 1.9 percentage points. The maximum specific power improvement with thermal barriers is 32.4 percent, when the turbine inlet temperature is increased from 1425 C (2600 F) to 1675 C (3050 F) and the airfoil temperature is kept the same. For water cooling, the maximum efficiency improvement is 2.2 percentage points at a turbine inlet temperature of 1683 C (3062 F) and the maximum specific power improvement is 36.6 percent by increasing the turbine inlet temperature from 1425 C (2600 F) to 1730 C (3150 F) and keeping the airfoil temperatures the same. These improvements are greater than that obtained with combined cycles using air cooling at a turbine inlet temperature of 1205 C (2200 F). The large temperature differences across the thermal barriers at these high temperatures, however, indicate that thermal stresses may present obstacles to the use of coatings at high turbine inlet temperatures.

  8. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production

    SciTech Connect

    Philip MacDonald; Jacopo Buongiorno; James Sterbentz; Cliff Davis; Robert Witt; Gary Was; J. McKinley; S. Teysseyre; Luca Oriani; Vefa Kucukboyaci; Lawrence Conway; N. Jonsson: Bin Liu

    2005-02-13

    The supercritical water reactor (SCWR) has been the object of interest throughout the nuclear Generation IV community because of its high potential: a simple, direct cycle, compact configuration; elimination of many traditional LWR components, operation at coolant temperatures much higher than traditional LWRs and thus high thermal efficiency. It could be said that the SWR was viewed as the water counterpart to the high temperature gas reactor.

  9. Water-Cooled Data Center Packs More Power Per Rack | Poster

    Cancer.gov

    By Frank Blanchard and Ken Michaels, Staff Writers Behind each tall, black computer rack in the data center at the Advanced Technology Research Facility (ATRF) is something both strangely familiar and oddly out of place: It looks like a radiator. The back door of each cabinet is gridded with the coils of the Liebert cooling system, which circulates chilled water to remove heat generated by the high-speed, high-capacity, fault-tolerant equipment.

  10. IAEA coordinated research project on thermal-hydraulics of Supercritical Water-Cooled Reactors (SCWRs)

    SciTech Connect

    Yamada, K.; Aksan, S. N.

    2012-07-01

    The Supercritical Water-Cooled Reactor (SCWR) is an innovative water-cooled reactor concept, which uses supercritical pressure water as reactor coolant. It has been attracting interest of many researchers in various countries mainly due to its benefits of high thermal efficiency and simple primary systems, resulting in low capital cost. The IAEA started in 2008 a Coordinated Research Project (CRP) on Thermal-Hydraulics of SCWRs as a forum to foster the exchange of technical information and international collaboration in research and development. This paper summarizes the activities and current status of the CRP, as well as major progress achieved to date. At present, 15 institutions closely collaborate in several tasks. Some organizations have been conducting thermal-hydraulics experiments and analysing the data, and others have been participating in code-to-test and/or code-to-code benchmark exercises. The expected outputs of the CRP are also discussed. Finally, the paper introduces several IAEA activities relating to or arising from the CRP. (authors)

  11. Water cooling system using a piezoelectrically actuated flow pump for a medical headlight system

    NASA Astrophysics Data System (ADS)

    Pires, Rogério F.; Vatanabe, Sandro L.; de Oliveira, Amaury R.; Nakasone, Paulo H.; Silva, Emílio C.

    2007-04-01

    The microchips inside modern electronic equipment generate heat and demand, each day, the use of more advanced cooling techniques as water cooling systems, for instance. These systems combined with piezoelectric flow pumps present some advantages such as higher thermal capacity, lower noise generation and miniaturization potential. The present work aims at the development of a water cooling system based on a piezoelectric flow pump for a head light system based on LEDs. The cooling system development consists in design, manufacturing and experimental characterization steps. In the design step, computational models of the pump, as well as the heat exchanger were built to perform sensitivity studies using ANSYS finite element software. This allowed us to achieve desired flow and heat exchange rates by varying the frequency and amplitude of the applied voltage. Other activities included the design of the heat exchanger and the dissipation module. The experimental tests of the cooling system consisted in measuring the temperature difference between the heat exchanger inlet and outlet to evaluate its thermal cooling capacity for different values of the flow rate. Comparisons between numerical and experimental results were also made.

  12. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe

    PubMed Central

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes. PMID:26201073

  13. Heat Transfer Modeling of an Annular On-Line Spray Water Cooling Process for Electric-Resistance-Welded Steel Pipe.

    PubMed

    Chen, Zejun; Han, Huiquan; Ren, Wei; Huang, Guangjie

    2015-01-01

    On-line spray water cooling (OSWC) of electric-resistance-welded (ERW) steel pipes can replace the conventional off-line heat treatment process and become an important and critical procedure. The OSWC process improves production efficiency, decreases costs, and enhances the mechanical properties of ERW steel pipe, especially the impact properties of the weld joint. In this paper, an annular OSWC process is investigated based on an experimental simulation platform that can obtain precise real-time measurements of the temperature of the pipe, the water pressure and flux, etc. The effects of the modes of annular spray water cooling and related cooling parameters on the mechanical properties of the pipe are investigated. The temperature evolutions of the inner and outer walls of the pipe are measured during the spray water cooling process, and the uniformity of mechanical properties along the circumferential and longitudinal directions is investigated. A heat transfer coefficient model of spray water cooling is developed based on measured temperature data in conjunction with simulation using the finite element method. Industrial tests prove the validity of the heat transfer model of a steel pipe undergoing spray water cooling. The research results can provide a basis for the industrial application of the OSWC process in the production of ERW steel pipes. PMID:26201073

  14. Sensitivity Analysis of Fuel Centerline Temperatures in SuperCritical Water-cooled Reactors (SCWRs)

    NASA Astrophysics Data System (ADS)

    Abdalla, Ayman

    SuperCritical Water-cooled Reactors (SCWRs) are one of the six nuclear-reactor concepts currently being developed under the Generation-IV International Forum (GIF). A main advantage of SCW Nuclear Power Plants (NPPs) is that they offer higher thermal efficiencies compared to those of current conventional NPPs. Unlike today's conventional NPPs, which have thermal efficiencies between 30 - 35%, SCW NPPs will have thermal efficiencies within a range of 45 - 50%, owing to high operating temperatures and pressures (i.e., coolant temperatures as high as 625°C at 25 MPa pressure). The use of current fuel bundles with UO2 fuel at the high operating parameters of SCWRs may cause high fuel centerline temperatures, which could lead to fuel failure and fission gas release. Studies have shown that when the Variant-20 (43-element) fuel bundle was examined at SCW conditions, the fuel centerline temperature industry limit of 1850°C for UO2 and the sheath temperature design limit of 850°C might be exceeded. Therefore, new fuel-bundle designs, which comply with the design requirements, are required for future use in SCWRs. The main objective of this study to conduct a sensitivity analysis in order to identify the main factors that leads to fuel centerline temperature reduction. Therefore, a 54-element fuel bundle with smaller diameter of fuel elements compared to that of the 43-element bundle was designed and various nuclear fuels are examined for future use in a generic Pressure Tube (PT) SCWR. The 54-element bundle consists of 53 heated fuel elements with an outer diameter of 9.5 mm and one central unheated element of 20-mm outer diameter which contains burnable poison. The 54-element fuel bundle has an outer diameter of 103.45 mm, which is the same as the outer diameter of the 43-element fuel bundle. After developing the 54-element fuel bundle, one-dimensional heat-transfer analysis was conducted using MATLAB and NIST REFPROP programs. As a result, the Heat Transfer Coefficient (HTC), bulk-fluid, sheath and fuel centerline temperature profiles were generated along the heated length of 5.772 m for a generic fuel channel. The fuel centerline and sheath temperature profiles have been determined at four Axial Heat Flux Profiles (AHFPs) using an average thermal power per channel of 8.5 MWth. The four examined AHFPs are the uniform, cosine, upstream-skewed and downstream-skewed profiles. Additionally, this study focuses on investigating a possibility of using low, enhanced and high thermal-conductivity fuels. The low thermal-conductivity fuels, which have been examined in this study, are uranium dioxide (UO 2), Mixed Oxide (MOX) and Thoria (ThO2) fuels. The examined enhanced thermal-conductivity fuels are uranium dioxide - silicon carbide (UO2 - SiC) and uranium dioxide - beryllium oxide (UO2 - BeO). Lastly, uranium carbide (UC), uranium dicarbide (UC2) and uranium nitride (UN) are the selected high thermal-conductivity fuels, which have been proposed for use in SCWRs. A comparison has been made between the low, enhanced and high thermal-conductivity fuels in order to identify the fuel centerline temperature behaviour when different nuclear fuels are used. Also, in the process of conducting the sensitivity analysis, the HTC was calculated using the Mokry et al. correlation, which is the most accurate supercritical water heat-transfer correlation so far. The sheath and the fuel centerline temperature profiles were determined for two cases. In Case 1, the HTC was calculated based on the Mokry et al. correlation, while in Case 2, the HTC values calculated for Case 1 were multiplied by a factor of 2. This factor was used in order to identify the amount of decrease in temperatures if the heat transfer is enhanced with appendages. Results of this analysis indicate that the use of the newly developed 54-element fuel bundle along with the proposed fuels is promising when compared with the Variant-20 (43-element) fuel bundle. Overall, the fuel centerline and sheath temperatures were below the industry and design limits when most of the proposed fuels were examined in the 54-element fuel bundle, however, the fuel centerline temperature limit was exceeded while MOX fuel was examined. Keywords: SCWRs, Fuel Centerline Temperature, Sheath Temperature, High Thermal Conductivity Fuels, Low Thermal Conductivity Fuels, HTC.

  15. Optimal Environmental Performance of Water-cooled Chiller System with All Variable Speed Configurations

    NASA Astrophysics Data System (ADS)

    Yu, Fu Wing; Chan, Kwok Tai

    This study investigates how the environmental performance of water-cooled chiller systems can be optimized by applying load-based speed control to all the system components. New chiller and cooling tower models were developed using a transient systems simulation program called TRNSYS 15 in order to assess the electricity and water consumption of a chiller plant operating for a building cooling load profile. The chiller model was calibrated using manufacturer's performance data and used to analyze the coefficient of performance when the design and control of chiller components are changed. The NTU-effectiveness approach was used for the cooling tower model to consider the heat transfer effectiveness at various air-to-water flow ratios and to identify the makeup water rate. Applying load-based speed control to the cooling tower fans and pumps could save an annual plant operating cost by around 15% relative to an equivalent system with constant speed configurations.

  16. Thermal analysis and water-cooling design of the CSNS MEBT 324 MHz buncher cavity

    NASA Astrophysics Data System (ADS)

    Liu, Hua-Chang; Ouyang, Hua-Fu

    2008-04-01

    At least two bunchers are needed in the 3 MeV H- Medium Energy Beam Transport (MEBT) line located between RFQ and DTL for the CSNS (China Spallation Neutron Source). A nose-cone geometry has been adopted as the type of buncher cavity for its simplicity, higher impedance and lower risk of multipacting. By making use of the results got from the simulations on the buncher with two-dimension code SUPERFISH, the thermal and structural analyses have been carried out, the process and results to determine the resulting frequency shift due to thermal and structural distortion of the cavity are presented, the water-cooling channel position and the optimum cooling water temperature as well as the tuning method by adjusting the cooling water temperature when the cavity is out of resonance are also determined through the analyses.

  17. Passive decay heat removal system for water-cooled nuclear reactors

    DOEpatents

    Forsberg, Charles W.

    1991-01-01

    A passive decay-heat removal system for a water-cooled nuclear reactor employs a closed heat transfer loop having heat-exchanging coils inside an open-topped, insulated box located inside the reactor vessel, below its normal water level, in communication with a condenser located outside of containment and exposed to the atmosphere. The heat transfer loop is located such that the evaporator is in a position where, when the water level drops in the reactor, it will become exposed to steam. Vapor produced in the evaporator passes upward to the condenser above the normal water level. In operation, condensation in the condenser removes heat from the system, and the condensed liquid is returned to the evaporator. The system is disposed such that during normal reactor operations where the water level is at its usual position, very little heat will be removed from the system, but during emergency, low water level conditions, substantial amounts of decay heat will be removed.

  18. Directly water-cooled crystal development for SPring-8 bending magnet beamlines

    NASA Astrophysics Data System (ADS)

    Takeshita, Kunikazu; Goto, Shunji; Ishikawa, Tetsuya

    2007-09-01

    The directly water-cooled first crystal of the SPring-8 standard monochromator for bending magnet beamlines has been developed. Thanks to the bonding technique, the performance of the new crystal has been improved without decreasing the cooling efficiency. The finite element analyses show the deformation of the crystal by the hydraulic pressure and by the crystal clamping is negligible small, which were dominated for the previous crystal. Both Si(111) and Si(311) crystal were evaluated in SPring-8 beamlines, the deformation induced while the bonding process is comparable to the thermal deformation. and long-term endurance test shows the lifetime of the O-ring becomes long because they are not on the direct path of the SR beam. Although the overall performance is insufficient, much improvement was shown.

  19. Thermohydraulic responses of a water-cooled tokamak fusion DEMO to loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Nakamura, M.; Tobita, K.; Someya, Y.; Utoh, H.; Sakamoto, Y.; Gulden, W.

    2015-11-01

    Major in- and ex-vessel loss-of-coolant accidents (LOCAs) of a water-cooled tokamak fusion DEMO reactor have been analysed. Analyses have identified responses of the DEMO systems to these accidents and pressure loads to confinement barriers for radioactive materials. As for the in-VV LOCA, we analysed the multiple double-ended break of the first wall cooling pipes around the outboard toroidal circumference. As for the ex-VV LOCA, we analysed the double-ended break of the primary cooling pipe. The thermohydraulic analysis results suggest that the in- and ex-vessel LOCAs crucially threaten integrity of the primary and final confinement barriers, respectively. Mitigations of the loads to the confinement barriers are also discussed.

  20. Analytical study of a microfludic DNA amplification chip using water cooling effect.

    PubMed

    Chen, Jyh Jian; Shen, Chia Ming; Ko, Yu Wei

    2013-04-01

    A novel continuous-flow polymerase chain reaction (PCR) chip has been analyzed in our work. Two temperature zones are controlled by two external controllers and the other temperature zone at the chip center is controlled by the flow rate of the fluid inside a channel under the glass chip. By employing a water cooling channel at the chip center, the sequence of denaturation, annealing, and extension can be created due to the forced convection effect. The required annealing temperature of PCR less than 313 K can also be demonstrated in this chip. The Poly(methyl methacrylate) (PMMA) cooling channel with the thin aluminum cover is utilized to enhance the temperature uniformity. The size of this chip is 76 mm × 26 mm × 3 mm. This device represents the first demonstration of water cooling thermocycling within continuous-flow PCR microfluidics. The commercial software CFD-ACE+(TM) is utilized to determine the distances between the heating assemblies within the chip. We investigate the influences of various chip materials, operational parameters of the cooling channel and geometric parameters of the chip on the temperature uniformity on the chip surface. Concerning the temperature uniformity of the working zones and the lowest temperature at the annealing zone, the air gap spacing of 1 mm and the cooling channel thicknesses of 1 mm of the PMMA channel with an aluminum cover are recommended in our design. The hydrophobic surface of the PDMS channel was modified by filling it with 20 % Tween 20 solution and then adding bovine serum albumin (BSA) solution to the PCR mixture. DNA fragments with different lengths (372 bp and 478 bp) are successfully amplified with the device. PMID:23179465

  1. Annular seed-blanket thorium fuel core concepts for heavy water moderated reactors

    SciTech Connect

    Bromley, B.P.; Hyland, B.

    2013-07-01

    New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWR) are highly advantageous for implementing the use of thorium-based fuels because of their high neutron economy and on-line re-fuelling capability. The use of heterogeneous seed-blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize the fissile utilization and conversion of fertile fuel. The lattice concept chosen is a 35-element bundle made with a homogeneous mixture of reactor grade Pu and Th, and with a central zirconia rod to help reduce coolant void reactivity. Several annular heterogeneous seed-blanket core concepts with plutonium-thorium-based fuels in a 700-MWe-class PT-HWR were analyzed, using a once-through thorium (OTT) cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, fissile utilization, power distributions, and other performance parameters. It was found that the various core concepts can achieve a fissile utilization that is up to 30% higher than is currently achieved in a PT-HWR using conventional natural uranium fuel bundles. Up to 67% of the Pu is consumed; up to 43% of the energy is produced from thorium, and up to 363 kg/year of U-233 is produced. Seed-blanket cores with ∼50% content of low-power blanket bundles may require power de-rating (∼58% to 65%) to avoid exceeding maximum limits for peak channel power, bundle power and linear element ratings. (authors)

  2. Checkerboard seed-blanket thorium fuel core concepts for heavy water moderated reactors

    SciTech Connect

    Bromley, B.P.; Hyland, B.

    2013-07-01

    New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWR) are highly advantageous for implementing the use of thorium-based fuels because of their high neutron economy and on-line re-fuelling capability. The use of heterogeneous seed-blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize the fissile utilization and conversion of fertile fuel. The lattice concept chosen was a 35-element bundle made with a homogeneous mixture of reactor grade Pu (about 67 wt% fissile) and Th, and with a central zirconia rod to help reduce coolant void reactivity. Several checkerboard heterogeneous seed-blanket core concepts with plutonium-thorium-based fuels in a 700-MWe-class PT-HWR were analyzed, using a once-through thorium (OTT) cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, fissile utilization, power distributions, and other performance parameters. It was found that various checkerboard core concepts can achieve a fissile utilization that is up to 26% higher than that achieved in a PT-HWR using more conventional natural uranium fuel bundles. Up to 60% of the Pu is consumed; up to 43% of the energy is produced from thorium, and up to 303 kg/year of Pa-233/U-233/U-235 are produced. Checkerboard cores with about 50% of low-power blanket bundles may require power de-rating (65% to 74%) to avoid exceeding maximum limits for channel and bundle powers and linear element ratings. (authors)

  3. Lattice cell and full core physics of internally cooled annular fuel in heavy water moderated reactors

    SciTech Connect

    Armstrong, J.; Hamilton, H.; Hyland, B.

    2013-07-01

    A program is underway at Atomic Energy of Canada Limited (AECL) to develop a new fuel bundle concept to enable greater burnups for PT-HWR (pressure tube heavy water reactor) cores. One option that AECL is investigating is an internally cooled annular fuel (ICAF) element concept. ICAF contains annular cylindrical pellets with cladding on the inner and outer diameters. Coolant flows along the outside of the element and through the centre. With such a concept, the maximum fuel temperature as a function of linear element rating is significantly reduced compared to conventional, solid-rod type fuel. The preliminary ICAF bundle concept considered in this study contains 24 half-metre long internally cooled annular fuel elements and one non-fuelled centre pin. The introduction of the non-fuelled centre pin reduces the coolant void reactivity (CVR), which is the increase in reactivity that occurs on voiding the coolant in accident scenarios. Lattice cell and full core physics calculations of the preliminary ICAF fuel bundle concept have been performed for medium burnups of approximately 18 GWd/tU using WIMS-AECL and reactor fuel simulation program (RFSP). The results will be used to assist in concept configuration optimization. The effects of radial and axial core power distributions, linear element power ratings, refuelling rates and operational power ramps have been analyzed. The results suggest that burnups of greater than 18 GWd/tU can be achieved in current reactor designs. At approximately 18 GWd/tU, expected maximum linear element ratings in a PT-HWR with online-refuelling are approximately 90 kW/m. These conditions would be prohibitive for solid-rod fuel, but may be possible in ICAF fuel given the reduced maximum fuel temperature as a function of linear element rating. (authors)

  4. Characterization of neutron fields from bare and heavy water moderated (252)Cf spontaneous fission source using Bonner Sphere Spectrometer.

    PubMed

    Atanackovic, Jovica; Yonkeu, Andre; Dubeau, Jacques; Witharana, Sampath Hakmana; Priest, Nicholas

    2015-05-01

    In this work a calibrated Bonner Sphere Spectrometer (BSS), together with ISO shadow cones, was used to quantify the total and scattered components of bare and heavy water moderated (252)Cf neutron fields. All measurements were performed with a BSS that was calibrated at the National Physical Laboratory (NPL), Teddington, UK, which is a global primary standard laboratory and world-leading facility for neutron metrology and neutron instruments calibration. The fields were characterized for source-spectrometer distances of 80, 100, 150 and 200cm; and at heights of 103 and 200cm from the facility floor. As expected, the scattered contribution was greatest at the farthest distance from the source and closer to the floor. Hence, at a distance of 200cm and a height of 103cm, the scatter added to the direct field up to 162% of the total neutron fluence and up to 61% of the ambient dose equivalent, while at the same distance and height of 200cm above the floor, these values were up to 146% and 52%, respectively. In the case of heavy water moderated (252)Cf neutron fields, a shadow cone subtraction technique could not be implemented, however Monte Carlo simulations were utilized in order to differentiate between the direct and scatter components of the neutron fields. In this case, at a source-detector distance of 200cm and a height of 103cm, the scatter added to the direct field up to 148% of the total neutron fluence and up to 45% of the ambient dose equivalent, while at the same distance and a height of 200cm above the floor, these values were up to 134% and 42%, respectively. PMID:25752569

  5. Fabrication of gas turbine water-cooled composite nozzle and bucket hardware employing plasma spray process

    DOEpatents

    Schilke, Peter W.; Muth, Myron C.; Schilling, William F.; Rairden, III, John R.

    1983-01-01

    In the method for fabrication of water-cooled composite nozzle and bucket hardware for high temperature gas turbines, a high thermal conductivity copper alloy is applied, employing a high velocity/low pressure (HV/LP) plasma arc spraying process, to an assembly comprising a structural framework of copper alloy or a nickel-based super alloy, or combination of the two, and overlying cooling tubes. The copper alloy is plamsa sprayed to a coating thickness sufficient to completely cover the cooling tubes, and to allow for machining back of the copper alloy to create a smooth surface having a thickness of from 0.010 inch (0.254 mm) to 0.150 inch (3.18 mm) or more. The layer of copper applied by the plasma spraying has no continuous porosity, and advantageously may readily be employed to sustain a pressure differential during hot isostatic pressing (HIP) bonding of the overall structure to enhance bonding by solid state diffusion between the component parts of the structure.

  6. Improvement in Stability of SPring-8 Standard X-Ray Monochromators with Water-Cooled Crystals

    NASA Astrophysics Data System (ADS)

    Yamazaki, Hiroshi; Shimizu, Yasuhiro; Miura, Takanori; Tanaka, Masayuki; Kishimoto, Hikaru; Matsuzaki, Yasuhisa; Shimizu, Nobtaka; Kawano, Yoshiaki; Kumasaka, Takashi; Yamamoto, Masaki; Koganezawa, Tomoyuki; Sato, Masugu; Hirosawa, Ichiro; Senba, Yasunori; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

    2010-06-01

    SPring-8 standard double-crystal monochromators containing water-cooled crystals were stabilized to a sufficient level to function as a part of optics components to supply stable microfocused x-ray beams, by determining causes of the instability and then removing them. The instability was caused by two factors—thermal deformation of fine stepper stages in the monochromator, which resulted in reduction in beam intensity with time, and vibrations of coolant supply units and vacuum pumps, which resulted in fluctuation in beam intensity. We remodeled the crystal holders to maintain the stage temperatures constant with water, attached x-ray and electron shields to the stages in order to prevent their warming up, introduced accumulators in the water circuits to absorb pressure pulsation, used polyurethane tubes to stabilize water flow, and placed rubber cushions un der scroll vacuum pumps. As a result, the intensity reduction rate of the beam decreased from 26% to 1% per hour and the intensity fluctuation from 13% to 1%. The monochromators were also modified to prevent radiation damage to the crystals, materials used as a water seal, and motor cables.

  7. Improvement in Stability of SPring-8 Standard X-Ray Monochromators with Water-Cooled Crystals

    SciTech Connect

    Yamazaki, Hiroshi; Shimizu, Nobtaka; Kumasaka, Takashi; Koganezawa, Tomoyuki; Sato, Masugu; Hirosawa, Ichiro; Senba, Yasunori; Ohashi, Haruhiko; Goto, Shunji; Shimizu, Yasuhiro; Miura, Takanori; Tanaka, Masayuki; Kishimoto, Hikaru; Matsuzaki, Yasuhisa; Kawano, Yoshiaki; Yamamoto, Masaki; Ishikawa, Tetsuya

    2010-06-23

    SPring-8 standard double-crystal monochromators containing water-cooled crystals were stabilized to a sufficient level to function as a part of optics components to supply stable microfocused x-ray beams, by determining causes of the instability and then removing them. The instability was caused by two factors--thermal deformation of fine stepper stages in the monochromator, which resulted in reduction in beam intensity with time, and vibrations of coolant supply units and vacuum pumps, which resulted in fluctuation in beam intensity. We remodeled the crystal holders to maintain the stage temperatures constant with water, attached x-ray and electron shields to the stages in order to prevent their warming up, introduced accumulators in the water circuits to absorb pressure pulsation, used polyurethane tubes to stabilize water flow, and placed rubber cushions under scroll vacuum pumps. As a result, the intensity reduction rate of the beam decreased from 26% to 1% per hour and the intensity fluctuation from 13% to 1%. The monochromators were also modified to prevent radiation damage to the crystals, materials used as a water seal, and motor cables.

  8. Neutronics Comparison Analysis of the Water Cooled Ceramics Breeding Blanket for CFETR

    NASA Astrophysics Data System (ADS)

    Li, Jia; Zhang, Xiaokang; Gao, Fangfang; Pu, Yong

    2016-02-01

    China Fusion Engineering Test Reactor (CFETR) is an ITER-like fusion engineering test reactor that is intended to fill the scientific and technical gaps between ITER and DEMO. One of the main missions of CFETR is to achieve a tritium breeding ratio that is no less than 1.2 to ensure tritium self-sufficiency. A concept design for a water cooled ceramics breeding blanket (WCCB) is presented based on a scheme with the breeder and the multiplier located in separate panels for CFETR. Based on this concept, a one-dimensional (1D) radial built breeding blanket was first designed, and then several three-dimensional models were developed with various neutron source definitions and breeding blanket module arrangements based on the 1D radial build. A set of nuclear analyses have been carried out to compare the differences in neutronics characteristics given by different calculation models, addressing neutron wall loading (NWL), tritium breeding ratio (TBR), fast neutron flux on inboard side and nuclear heating deposition on main in-vessel components. The impact of differences in modeling on the nuclear performance has been analyzed and summarized regarding the WCCB concept design. supported by the National Special Project for Magnetic Confined Nuclear Fusion Energy (Nos. 2013GB108004, 2014GB122000, and 2014GB119000), and National Natural Science Foundation of China (No. 11175207)

  9. The effectiveness of power-generating complexes constructed on the basis of nuclear power plants combined with additional sources of energy determined taking risk factors into account

    NASA Astrophysics Data System (ADS)

    Aminov, R. Z.; Khrustalev, V. A.; Portyankin, A. V.

    2015-02-01

    The effectiveness of combining nuclear power plants equipped with water-cooled water-moderated power-generating reactors (VVER) with other sources of energy within unified power-generating complexes is analyzed. The use of such power-generating complexes makes it possible to achieve the necessary load pickup capability and flexibility in performing the mandatory selective primary and emergency control of load, as well as participation in passing the night minimums of electric load curves while retaining high values of the capacity utilization factor of the entire power-generating complex at higher levels of the steam-turbine part efficiency. Versions involving combined use of nuclear power plants with hydrogen toppings and gas turbine units for generating electricity are considered. In view of the fact that hydrogen is an unsafe energy carrier, the use of which introduces additional elements of risk, a procedure for evaluating these risks under different conditions of implementing the fuel-and-hydrogen cycle at nuclear power plants is proposed. Risk accounting technique with the use of statistical data is considered, including the characteristics of hydrogen and gas pipelines, and the process pipelines equipment tightness loss occurrence rate. The expected intensities of fires and explosions at nuclear power plants fitted with hydrogen toppings and gas turbine units are calculated. In estimating the damage inflicted by events (fires and explosions) occurred in nuclear power plant turbine buildings, the US statistical data were used. Conservative scenarios of fires and explosions of hydrogen-air mixtures in nuclear power plant turbine buildings are presented. Results from calculations of the introduced annual risk to the attained net annual profit ratio in commensurable versions are given. This ratio can be used in selecting projects characterized by the most technically attainable and socially acceptable safety.

  10. Cell configuration effect on feasibility of water cooled thorium breeder reactor

    SciTech Connect

    Permana, S.; Takaki, N.; Sekimoto, H.

    2006-07-01

    As a fuel candidate, thorium cycle shows some advantages such as good breeding capability, higher performance of burn-up and from proliferation point of view, thorium is more proliferation resistant. The shipping-port reactor and molten salt breeder reactor showed that breeding is possible with thorium in a thermal spectrum. Breeding is made possible by the high value of neutron regeneration ratio {eta} for {sup 233}U in thermal energy region. In the present study, feasibility of water cooled thorium breeder reactor is investigated. A calculation method by coupling the equilibrium fuel cycle burn-up calculation and cell calculation of PIJ module of SRAC2002 code have been performed. The reactor is fueled by {sup 233}U-Th Oxide and it has used the light water coolant and zircaloy-4 as moderator and cladding, respectively. The key properties such as flux, enrichment, criticality and breeding performances are evaluated for different moderator to fuel ratios (MFR) and burn-ups. The different pin cell types have been investigated in order to analyze the effect of different fuel pin diameter. The results show the feasibility of breeding for different fuel pin cell types. The required {sup 233}U enrichment is about 2% - 9% as initial fissile loading. The lower MFR and the higher enrichment of {sup 233}U are preferable to improve the average burn-up; however the design feasible window is shrunk. The thicker pin cell shows wider feasible areas and requires lower enrichment than thinner pin cell. It means that thicker fuel pin diameter obtains better performances for breeding and reducing the fissile material utilization. (authors)

  11. Heat-transfer phenomena in water-cooled zinc-fuming furnace jackets

    NASA Astrophysics Data System (ADS)

    Scholey, K. E.; Richards, G. G.; Samarasekera, I. V.

    1991-04-01

    In the zinc slag-fuming process, zinc is removed from lead blast furnace slag by reduction with a coal-air mixture injected into the slag through submerged tuyeres. The furnace is constructed of water-cooled jackets which freeze a slag layer and contain the bath. This greatly reduces vessel wear caused by the violently agitated and corrosive bath. The jackets, however, fail due to the formation of cracks which grow from the slag face through the working face of the jacket to the water channel. In this study, in-plant measurements and mathematical modeling of heat transfer in the jackets have been combined to elucidate the mechanism of failure. The working face of a water jacket was instrumented with thermocouples and installed in a fuming furnace at the Trail smelter of Cominco Ltd., Trail, BC. Measurements revealed the presence of large thermal transients or temperature “spikes” in the panel in the region immediately above the tuyeres. These were generally observed during charging and tapping of the furnace and are likely associated with disturbances on the surface of the bath or gas injection effects when the liquid level is low. Temperatures at the midthickness were seen to rise by as much as 180 °C above the steady-state level. Under these conditions, low-cycle fatigue may lead to crack formation and propagation. A mathematical modeling analysis of the transient freezing phenomena indicates that the temperature spikes are associated with sudden slag falloff and direct contact of molten slag on the jacket. In order to reduce slag falloff, an increased number of anchoring fins should be used in critical areas.

  12. Numerical Calculation of the Peaking Factor of a Water-Cooled W/Cu Monoblock for a Divertor

    NASA Astrophysics Data System (ADS)

    Han, Le; Chang, Haiping; Zhang, Jingyang; Xu, Tiejun

    2015-09-01

    In order to accurately predict the incident critical heat flux (ICHF, the heat flux at the heated surface when CHF occurs) of a water-cooled W/Cu monoblock for a divertor, the exact knowledge of its peaking factors (fp) under one-sided heating conditions with different design parameters is a key issue. In this paper, the heat conduction in the solid domain of a water-cooled W/Cu monoblock is calculated numerically by assuming the local heat transfer coefficients (HTC) of the cooling wall to be functions of the local wall temperature, so as to obtain fp. The reliability of the calculation method is validated by an experimental example result, with the maximum error of 2.1% only. The effects of geometric and flow parameters on the fp of a water-cooled W/Cu monoblock are investigated. Within the scope of this study, it is shown that the fp increases with increasing dimensionless W/Cu monoblock width and armour thickness (the shortest distance between the heated surface and Cu layer), and the maximum increases are 43.8% and 22.4% respectively. The dimensionless W/Cu monoblock height and Cu thickness have little effect on fp. The increase of Reynolds number and Jakob number causes the increase of fp, and the maximum increases are 6.8% and 9.6% respectively. Based on the calculated results, an empirical correlation on peaking factor is obtained via regression. These results provide a valuable reference for the thermal-hydraulic design of water-cooled divertors. supported by National Magnetic Confinement Fusion Science Program of China (No. 2010GB104005) and Funding of Jiangsu Innovation Program for Graduate Education, China (CXLX12_0170), the Fundamental Research Funds for the Central Universities of China

  13. Design and Dynamic Performance of a Small Water Cooled Reactor Fuelled with Plutonium in Rock-Like Oxide (ROX) Form

    SciTech Connect

    Gaultier, M.; Danguy, G.; Ritchie, D.; Williams, A.; Thompson, A.; Brushwood, J.; Beeley, P.A.; Greenlees, L.; Perry, A.

    2006-07-01

    The results of a design study for a small water-cooled reactor with plutonium fuel in a rock like oxide (ROX) form are reported. A summary is given of the five study areas, Physics, Thermal Hydraulics, Materials, Navalisation and Dynamics, and Shielding and Decommissioning. The dynamics simulation for the whole plant is then described in more detail. The physics of the fuel module is studied using the WIMS suite of deterministic codes with selected computations checked with the Monte-Carlo code MONK. Whole core calculations are undertaken with the WIMS/SNAP code. Essential parameters are provided to the other study areas including reactivity feedback coefficients for the Dynamics. The Thermal Hydraulic design aims to remove the required maximum power using pumped flow and also to provide significant power removal using natural circulation. The major components of the primary circuit are sized and flow rates in pumped and natural circulation calculated by hand and by using the TRACPFQ code. This information is also used in the dynamics study. Further details of the Physics and Thermal hydraulics studies will be given at PHYSOR 2006. The materials study is being published elsewhere, but a brief description of the temperature and stress calculations for the fuel pellet performed with the ABACUS finite element code is given. Navalisation and dynamics of the plant are examined. The power requirements for the plant are estimated and a suitable electric propulsion system is proposed and sized. A whole plant model is built using the AcslXtreme computer package in which a block diagram of the system is constructed via a graphical interface and simulations of the system transients are produced. The block diagram for the whole system is described followed by the describing equations for the major blocks representing neutron kinetics, fuel element heat transfer, thermal hydraulics of the primary circuit and of the steam generators. Also included are describing equations for the flow rate in natural circulation and equations to represented major electrical components. A number of key transients are simulated including the warm up to self sustaining power, variations in vessel speed, the transition to natural circulation flow and a control rod ejection at full speed. The influence of the Pu ROX fuel on plant dynamics is discussed, particularly the need for movement of control rods during certain transients and SCRAM timing. Conclusions are drawn on the feasibility of the whole propulsion system. A study of shielding and decommissioning aspects of the plant is reported. A shield design is proposed and analysed using the MCBEND code. Annual dose calculations to key personnel are presented and discussed. Decommissioning of ROX fuel is examined by selecting nuclides of interest and calculating their evolution over long time periods using the ORIGEN code. Decay heat and shut down gamma dose rates are calculated and a disposal path for the fuel is proposed. (authors)

  14. Prediction of critical heat flux in water-cooled plasma facing components using computational fluid dynamics.

    SciTech Connect

    Bullock, James H.; Youchison, Dennis Lee; Ulrickson, Michael Andrew

    2010-11-01

    Several commercial computational fluid dynamics (CFD) codes now have the capability to analyze Eulerian two-phase flow using the Rohsenow nucleate boiling model. Analysis of boiling due to one-sided heating in plasma facing components (pfcs) is now receiving attention during the design of water-cooled first wall panels for ITER that may encounter heat fluxes as high as 5 MW/m2. Empirical thermalhydraulic design correlations developed for long fission reactor channels are not reliable when applied to pfcs because fully developed flow conditions seldom exist. Star-CCM+ is one of the commercial CFD codes that can model two-phase flows. Like others, it implements the RPI model for nucleate boiling, but it also seamlessly transitions to a volume-of-fluid model for film boiling. By benchmarking the results of our 3d models against recent experiments on critical heat flux for both smooth rectangular channels and hypervapotrons, we determined the six unique input parameters that accurately characterize the boiling physics for ITER flow conditions under a wide range of absorbed heat flux. We can now exploit this capability to predict the onset of critical heat flux in these components. In addition, the results clearly illustrate the production and transport of vapor and its effect on heat transfer in pfcs from nucleate boiling through transition to film boiling. This article describes the boiling physics implemented in CCM+ and compares the computational results to the benchmark experiments carried out independently in the United States and Russia. Temperature distributions agreed to within 10 C for a wide range of heat fluxes from 3 MW/m2 to 10 MW/m2 and flow velocities from 1 m/s to 10 m/s in these devices. Although the analysis is incapable of capturing the stochastic nature of critical heat flux (i.e., time and location may depend on a local materials defect or turbulence phenomenon), it is highly reliable in determining the heat flux where boiling instabilities begin to dominate. Beyond this threshold, higher heat fluxes lead to the boiling crisis and eventual burnout. This predictive capability is essential in determining the critical heat flux margin for the design of complex 3d components.

  15. Compatibility of water-cooled chromia-containing refractories with a high iron oxide acidic coal-ash slag at 1575/sup 0/C

    SciTech Connect

    Kennedy, C.R.

    1981-12-01

    Sixteen water-cooled refractories were exposed to a synthetic high iron oxide acidic coal slag. The importance of high chromia content and density in minimizing corrosive attack was evident. The beneficial effect of water cooling was also demonstrated. All the refractories reacted with the slag to form complex intermediate spinel layers. Refractories high in chromia resist fluxing by iron oxide better than refractories high in alumina.

  16. The Corrected Simulation Method of Critical Heat Flux Prediction for Water-Cooled Divertor Based on Euler Homogeneous Model

    NASA Astrophysics Data System (ADS)

    Zhang, Jingyang; Han, Le; Chang, Haiping; Liu, Nan; Xu, Tiejun

    2016-02-01

    An accurate critical heat flux (CHF) prediction method is the key factor for realizing the steady-state operation of a water-cooled divertor that works under one-sided high heating flux conditions. An improved CHF prediction method based on Euler's homogeneous model for flow boiling combined with realizable k-ɛ model for single-phase flow is adopted in this paper in which time relaxation coefficients are corrected by the Hertz-Knudsen formula in order to improve the calculation accuracy of vapor-liquid conversion efficiency under high heating flux conditions. Moreover, local large differences of liquid physical properties due to the extreme nonuniform heating flux on cooling wall along the circumference direction are revised by formula IAPWS-IF97. Therefore, this method can improve the calculation accuracy of heat and mass transfer between liquid phase and vapor phase in a CHF prediction simulation of water-cooled divertors under the one-sided high heating condition. An experimental example is simulated based on the improved and the uncorrected methods. The simulation results, such as temperature, void fraction and heat transfer coefficient, are analyzed to achieve the CHF prediction. The results show that the maximum error of CHF based on the improved method is 23.7%, while that of CHF based on uncorrected method is up to 188%, as compared with the experiment results of Ref. [12]. Finally, this method is verified by comparison with the experimental data obtained by International Thermonuclear Experimental Reactor (ITER), with a maximum error of 6% only. This method provides an efficient tool for the CHF prediction of water-cooled divertors. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2010GB104005) and National Natural Science Foundation of China (No. 51406085)

  17. Numerical study on the limiting characteristics of an open-type water-cooled flat-plate solar collector

    SciTech Connect

    Song, B.; Inaba, H.; Horibe, A.

    2000-01-01

    The effects of various parameters on the limiting characteristics of an open-type water-cooled flat-plate collector were studied numerically. The results showed that the heat and mass transfer was enhanced with an increase in the inlet water temperature. The operating temperature and the interfacial mass flux maintained a higher constant for 4 and 2 hours around the noontime, respectively. An increase in atmospheric temperature or humidity and a decrease in the film thickness caused the operating temperature to rise to some extent. The wind velocity exerted a great influence on the operating temperature.

  18. Cooling of Gas Turbines. 6; Computed Temperature Distribution Through Cross Section of Water-Cooled Turbine Blade

    NASA Technical Reports Server (NTRS)

    Livingood, John N. B.; Sams, Eldon W.

    1947-01-01

    A theoretical analysis of the cross-sectional temperature distribution of a water-cooled turbine blade was made using the relaxation method to solve the differential equation derived from the analysis. The analysis was applied to specific turbine blade and the studies icluded investigations of the accuracy of simple methods to determine the temperature distribution along the mean line of the rear part of the blade, of the possible effect of varying the perimetric distribution of the hot gas-to -metal heat transfer coefficient, and of the effect of changing the thermal conductivity of the blade metal for a constant cross sectional area blade with two quarter inch diameter coolant passages.

  19. Water-cooled Pb?17Li test blanket module for ITER: Impact of the structural material grade on the neutronic responses

    NASA Astrophysics Data System (ADS)

    Vella, G.; Aiello, G.; Fütterer, M. A.; Giancarli, L.; Oliveri, E.; Tavassoli, F.

    1998-10-01

    The Water-Cooled Lithium Lead (WCLL) DEMO blanket is one of the two EU lines to be further developed with the aim of manufacturing by 2010 a Test Blanket Module for ITER (TBM). In this paper results of a 3D-Monte Carlo neutronic analysis of the TBM design are reported. A fully 3D heterogeneous model of the WCLL-TBM has been inserted into an existing ITER model accounting for a proper D-T neutron source. The structural material assumed for the calculations was martensitic 9% Cr steel code named Z 10 CDV Nb 9-1. Results have been compared with those obtained using MANET. The main nuclear responses of the TBM have been determined, such as detailed power deposition density, material damage through DPA and He and H gas production rate, radial distribution of tritium production rate and total tritium production in the module. The impact of using natural Lithium on the TBM system operation has also been evaluated.

  20. Development of a brazing process for the production of water- cooled bipolar plates made of chromium-coated metal foils for PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Mueller, M.; Hoehlich, D.; Scharf, I.; Lampke, T.; Hollaender, U.; Maier, H. J.

    2016-03-01

    Beside lithium batteries, PEM fuel cells are the most promising strategy as a power source to achieve the targets for introducing and increasing the usage of electric vehicles. Due to limited space and weight problems, water cooled, metallic bipolar plates in a fuel cell metal stack are preferred in motor vehicles. These plates are stamped metal sheets with a complex structure, interconnected media-tight. To meet the multiple tasks and requirements in use, complex and expensive combinations of materials are currently in use (carbon fiber composites, graphite, gold-plated nickel, stainless and acid resistant steel). The production of such plates is expensive as it is connected with considerable effort or the usage of precious metals. As an alternative, metalloid nitrides (CrN, VN, W2N, etc.) show a high chemical resistance, hardness and a good conductivity. So this material category meets the basic requirements of a top layer. However, the standard methods for their production (PVD, CVD) are expensive and have a slow deposition rate and a lower layer thicknesses. Because of these limitations, a full functionality over the life cycle of a bipolar plate is not guaranteed. The contribution shows the development and quantification of an alternative production process for bipolar plates. The expectation is to get significant advantages from the combination of chromium electrodeposition and thermochemical treatment to form chromium nitrides. Both processes are well researched and suitable for series production. The thermochemical treatment of the chromium layer also enables a process-integrated brazing.

  1. The influence of EI-21 redox ion-exchange resins on the secondary-coolant circuit water chemistry of vehicular nuclear power installations

    NASA Astrophysics Data System (ADS)

    Moskvin, L. N.; Rakov, V. T.

    2015-06-01

    The results obtained from testing the secondary-coolant circuit water chemistry of full-scale land-based prototype bench models of vehicular nuclear power installations equipped with water-cooled water-moderated and liquid-metal reactor plants are presented. The influence of copper-containing redox ionexchange resins intended for chemically deoxygenating steam condensate on the working fluid circulation loop's water chemistry is determined. The influence of redox ion-exchange resins on the water chemistry is evaluated by generalizing an array of data obtained in the course of extended monitoring using the methods relating to physicochemical analysis of the quality of condensate-feedwater path media and the methods relating to metallographic analysis of the state of a faulty steam generator's tube system surfaces. The deoxygenating effectiveness of the normal state turbine condensate vacuum deaeration system is experimentally determined. The refusal from applying redox ion-exchange resins in the condensate polishing ion-exchange filters is formulated based on the obtained data on the adverse effect of copper-containing redox ionexchange resins on the condensate-feedwater path water chemistry and based on the data testifying a sufficient effect from using the normal state turbine condensate vacuum deaeration system. Data on long-term operation of the prototype bench model of a vehicular nuclear power installation without subjecting the turbine condensate to chemical deoxygenation are presented.

  2. Fabrication of water-cooled laser silicon mirror by direct laser sintering.

    PubMed

    He, Chongwen; Zhu, Haihong; Hu, Panpan

    2014-04-21

    Coppery heat sink with micro pores and Sub-millimeter channel has been fabricated by direct laser sintering on the back of the silicon mirror. To verify the heat dissipation capability of the fabricated heat sink, a Twyman-Green interferometer was employed to measure the thermal deformation of the silicon mirror radiated by a high power laser. It is shown that the thermal deformation of the mirror increases with the irradiating time and laser intensity. The heat balance can be achieved after several seconds of laser irradiation even when the net absorbed laser power density is up to 5.3 × 10(5) W/m(2). The time for reaching the heat balance also increases with the laser intensity. The maximum thermal deformation of the mirror is 0.65 µm if the net absorbed laser power density is 5.3 × 10(5) W/m(2). PMID:24787872

  3. Numerical and experimental study of the elimination of shrinkage in complex and small investment castings using water cooling process

    NASA Astrophysics Data System (ADS)

    Yuan, You-lu; Li, Zhu-guo

    2013-05-01

    Shrinkage porosity, one of the most serious defects, is usually formed in castings. The traditional ways in solving these kinds of defects are adding feeding channels, risers, placing metallic chills, optimizing the gating system, and so on. Indeed, they are effective methods to solve shrinkage defects in large castings, but not to the complex and small castings. In this research, one small and complex investment casting was investigated for its inner shrinkage defects. Since the defects are unsuitable to the traditional optimal ways. A novel method, dipping the preheated shell mold in water, was used to optimize the order of solidification. Both finite element method (FEM) analysis and experiment results show that the solidification sequence was optimized, and the shrinkage was eliminated. It shows that the water cooling process is an available approach to eliminate shrinkage defects in those complex, small, while with big length to width ratio investment castings.

  4. Ocean frontal formation due to shallow water cooling effects as observed by satellite and simulated by a numerical model

    NASA Astrophysics Data System (ADS)

    Garwood, Roland W.; Fett, Robert W.; Rabe, Kevin M.; Brandli, Henry W.

    1981-11-01

    During the winter season, infrared data from meteorological satellites reveal the outline of the Little Bahama Bank and the Great Bahama Bank as cold areas conforming almost precisely to the bathymetry as outlined by the 20 m contour line. During the summer season the effect is reversed and the Banks appear as warm areas, distinct from the deeper water that surrounds them. This paper investigates the winter season phenomena by using a one-dimensional numerical model to calculate the heat and salt budgets for a variety of atmospheric scenarios including a sudden air temperature drop over the banks as a result of cold frontal passage. It is found that such an event results in shallow water cooling producing distinct temperature fronts and mild salinity fronts. Increased wind speed, under low humidity conditions, maximizes the effect.

  5. Spent nuclear fuel project cold vacuum drying facility tempered water and tempered water cooling system design description

    SciTech Connect

    IRWIN, J.J.

    1998-11-30

    This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Tempered Water (TW) and Tempered Water Cooling (TWC) System . The SDD was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-O02, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the TW and TWC equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SOD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved.

  6. Water-cooled non-thermal gliding arc for adhesion improvement of glass-fibre-reinforced polyester

    NASA Astrophysics Data System (ADS)

    Kusano, Yukihiro; Sørensen, Bent F.; Andersen, Tom L.; Toftegaard, Helmuth L.; Leipold, Frank; Salewski, Mirko; Sun, Zhiwei; Zhu, Jiajian; Li, Zhongshan; Alden, Marcus

    2013-04-01

    A non-equilibrium quenched plasma is prepared using a gliding-arc discharge generated between diverging electrodes and extended by a gas flow. It can be operated at atmospheric pressure and applied to plasma surface treatment to improve adhesion properties of material surfaces. In this work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding-arc discharge with air flow to improve adhesion with a vinylester adhesive. The electrodes were water-cooled so as to operate the gliding arc continually. The treatment improved wettability and increased the density of oxygen-containing polar functional groups on the surfaces. Double cantilever beam specimens were prepared for fracture mechanic characterization of the laminate adhesive interface. It was found that gliding-arc treatment significantly increases the fracture resistance in comparison with a standard peel-ply treatment.

  7. Characteristics of Laser Diode Bar and Stack with Jet-Type, Water-Cooled Heatsink

    NASA Astrophysics Data System (ADS)

    Miyajima, Hirofumi; Kan, Hirofumi; Furuta, Shin-ichi; Uchiyama, Takayuki; Oishi, Satoru; Yamanaka, Masanobu; Izawa, Yasukazu; Nakai, Sadao

    2004-09-01

    Our group has developed a funryu (“fountain flow” in Japanese) heatsink structure for a 1 cm laser diode (LD) bar. The funryu heatsink is only 1.1 mm in thickness and is designed in stackable form. With the help of a good indium soldering technique and detailed thermal analysis, this device achieved a thermal resistance of only 0.25°C/W, defined by the temperature increase per unit of heat dissipation. This thermal resistance is one of the lowest ever attained by a laser diode bar. By stacking 30 LD bars equipped with these funryu heatsinks, we achieved a CW output power of 2.3 kW from a 10 mm× 45.8 mm laser-emitting area within the stacked-LD module. This power intensity corresponds to 502 W/cm2.

  8. Magnetically Diffused Radial Electric-Arc Air Heater Employing Water-Cooled Copper Electrodes

    NASA Technical Reports Server (NTRS)

    Mayo, R. F.; Davis, D. D., Jr.

    1962-01-01

    A magnetically rotated electric-arc air heater has been developed that is novel in that an intense magnetic field of the order of 10,000 to 25,000 gauss is employed. This field is supplied by a coil that is connected in series with the arc. Experimentation with this heater has shown that the presence of an intense magnetic field transverse to the arc results in diffusion of the arc and that the arc has a positive effective resistance. With the field coil in series with the arc, highly stable arc operation is obtained from a battery power supply. External ballast is not required to stabilize the arc when it is operating at maximum power level. The electrode erosion rate is so low that the airstream contamination is no more than 0.07 percent and may be substantially less.

  9. Nuclear characteristics of a fissioning uranium plasma test reactor with light-water cooling

    NASA Technical Reports Server (NTRS)

    Whitmarsh, C. L., Jr.

    1973-01-01

    An analytical study was performed to determine a design configuration for a cavity test reactor. Test section criteria were that an average flux of 10 to the 15th power neutrons/sq cm/sec (E less than or equal to 0.12 eV) be supplied to a 61-cm-diameter spherical cavity at 200-atm pressure. Design objectives were to minimize required driver power, to use existing fuel-element technology, and to obtain fuel-element life of 10 to 100 full-power hours. Parameter calculations were made on moderator region size and material, driver fuel arrangement, control system, and structure in order to determine a feasible configuration. Although not optimized, a configuration was selected which would meet design criteria. The driver fuel region was a cylindrical annular region, one element thick, of 33 MTR-type H2O-cooled elements (Al-U fuel plate configuration), each 101 cm long. The region between the spherical test cavity and the cylindrical driver fuel region was Be (10 vol. % H2O coolant) with a midplane dimension of 8 cm. Exterior to the driver fuel, the 25-cm-thick cylindrical and axial reflectors were also Be with 10 vol. % H2O coolant. The entire reactor was contained in a 10-cm-thick steel pressure vessel, and the 200-atm cavity pressure was equalized throughout the driver reactor. Fuel-element life was 50 hr at the required driver power of 200 MW. Reactor control would be achieved with rotating poison drums located in the cylindrical reflector region. A control range of about 18 percent delta k/k was required for reactor operation.

  10. High-enthalpy, water-cooled and thin-walled ICP sources characterization and MHD optimization

    NASA Astrophysics Data System (ADS)

    Herdrich, G.; Petkow, D.

    2008-06-01

    The development of the inductively driven plasma wind tunnel PWK3, which enables the electrodeless generation of high-enthalpy plasmas for the development of heat shield materials required for space vehicles performing entry manoeuvres in the atmospheres of Venus, Earth and Mars, is described. The facility with its modular inductive plasma generators allows operation with gases such as carbon dioxide, air, oxygen and nitrogen and was qualified for thermal plasma powers up to 60 kW. Previously developed models for determining plasma properties and plasma source related characteristics enable a maximum plasma power in combination with long operational periods using different operational gases and gas mixtures. This is achieved by an optimization using the optimum operational frequency, a minimization of field losses using very thin plasma tube wall thicknesses and the successful application of MHD effects. Based on the solved cylinder problem for ICPs, a one-dimensional model for radial Lorentz forces and magnetic pressure has been developed. Here, a synthesis of previously published data and works is made where the new algebraic model for the calculation of Lorentz forces and magnetic pressures in an ICP was used and applied to experimental data. In addition, results from the model using the experimental data are shown to be consistent and, in addition, a comparison with a simpler model based on the well-known exponential approach for ICPs showed that the simpler model is covered without fail by the new model. The new model also states that there is a maximum of the Lorentz forces over the damping parameter d/δ (plasma diameter divided by skin depth) which almost corresponds with the position of the maximum plasma power of the cylindric model for ICPs. For the magnetic pressure the position of the maximum pressure is identical to the value for d/δ for the maximum plasma power.

  11. The performance of a mobile air conditioning system with a water cooled condenser

    NASA Astrophysics Data System (ADS)

    Di Battista, Davide; Cipollone, Roberto

    2015-11-01

    Vehicle technological evolution lived, in recent years, a strong acceleration due to the increased awareness of environmental issues related to pollutants and climate altering emissions. This resulted in a series of international regulations on automotive sector which put technical challenges that must consider the engine and the vehicle as a global system, in order to improve the overall efficiency of the system. The air conditioning system of the cabin, for instance, is the one of the most important auxiliaries in a vehicle and requires significant powers. Its performances can be significantly improved if it is integrated within the engine cooling circuit, eventually modified with more temperature levels. In this paper, the Authors present a mathematical model of the A/C system, starting from its single components: compressors, condenser, flush valve and evaporator and a comparison between different refrigerant fluid. In particular, it is introduced the opportunity to have an A/C condenser cooled by a water circuit instead of the external air linked to the vehicle speed, as in the actual traditional configuration. The A/C condenser, in fact, could be housed on a low temperature water circuit, reducing the condensing temperature of the refrigeration cycle with a considerable efficiency increase.

  12. Influence of the pulse frequency and water cooling on the femtosecond laser ablation of bovine cortical bone

    NASA Astrophysics Data System (ADS)

    Cangueiro, L. T.; Vilar, R.

    2013-10-01

    Ultrafast lasers are extremely promising tools for minimally-invasive orthopedic surgery, but the ablated volumes per pulse are low, so a high pulse frequency is necessary to reach practical ablation rates. The purpose of this work was to study in vitro the influence of the pulse repetition rate on the ablation rate, surface topography and surface composition of bone using of bovine cortical femur as a model. The tests were carried out by scanning the laser beam in relation to the sample, using pulse frequencies between 50 and 3000 Hz, scanning velocities from 0.5 to 10 mm/s and average pulse energy of 650 μJ. The experiments were performed in dry conditions and with water irrigation. The higher ablation rates were obtained at high scanning velocity without water irrigation but severe thermal effects such as resolidification, cracking and, eventually, carbonization occurred in these conditions due to heat accumulation in the tissue. Thermal damage was avoided for all the laser processing parameters ranges tested by using water cooling. The highest ablation rate achieved was 1.4 mm3/min for a scanning velocity of 10 mm/s at 2 kHz pulse repetition rate under water irrigation.

  13. Legionella species and serogroups in Malaysian water cooling towers: identification by latex agglutination and PCR-DNA sequencing of isolates.

    PubMed

    Yong, Stacey Foong Yee; Goh, Fen-Ning; Ngeow, Yun Fong

    2010-03-01

    In this study, we investigated the distribution of Legionella species in water cooling towers located in different parts of Malaysia to obtain information that may inform public health policies for the prevention of legionellosis. A total of 20 water samples were collected from 11 cooling towers located in three different states in east, west and south Malaysia. The samples were concentrated by filtration and treated with an acid buffer before plating on to BCYE agar. Legionella viable counts in these samples ranged from 100 to 2,000 CFU ml(-1); 28 isolates from the 24 samples were examined by latex agglutination as well as 16S rRNA and rpoB PCR-DNA sequencing. These isolates were identified as Legionella pneumophila serogroup 1 (35.7%), L. pneumophila serogroup 2-14 (39%), L. pneumophila non-groupable (10.7%), L. busanensis, L. gormanii, L. anisa and L. gresilensis. L. pneumophila was clearly the predominant species at all sampling sites. Repeat sampling from the same cooling tower and testing different colonies from the same water sample showed concurrent colonization by different serogroups and different species of Legionella in some of the cooling towers. PMID:20009251

  14. RESONANCE CONTROL FOR THE COUPLED CAVITY LINAC AND DRIFT TUBE LINAC STRUCTURES OF THE SPALLATION NEUTRON SOURCE LINAC USING A CLOSED-LOOP WATER COOLING SYSTEM

    SciTech Connect

    Bernardin, J. D.; Brown, R. L.; Brown, S. K.; Bustos, G. R.; Crow, M.L.; Gregory, W. S.; Hood, M. E.; Jurney, J. D.; Medalen, I.; Owen, A. C.; Weiss, Robert E.

    2001-01-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the protons to an energy of 185 MeV. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems.

  15. LIGHT WATER MODERATED NEUTRONIC REACTOR

    DOEpatents

    Christy, R.F.; Weinberg, A.M.

    1957-09-17

    A uranium fuel reactor designed to utilize light water as a moderator is described. The reactor core is in a tank at the bottom of a substantially cylindrical cross-section pit, the core being supported by an apertured grid member and comprised of hexagonal tubes each containing a pluralily of fuel rods held in a geometrical arrangement between end caps of the tubes. The end caps are apertured to permit passage of the coolant water through the tubes and the fuel elements are aluminum clad to prevent corrosion. The tubes are hexagonally arranged in the center of the tank providing an amulus between the core and tank wall which is filled with water to serve as a reflector. In use, the entire pit and tank are filled with water in which is circulated during operation by coming in at the bottom of the tank, passing upwardly through the grid member and fuel tubes and carried off near the top of the pit, thereby picking up the heat generated by the fuel elements during the fission thereof. With this particular design the light water coolant can also be used as the moderator when the uranium is enriched by fissionable isotope to an abundance of U/sup 235/ between 0.78% and 2%.

  16. Computation Results from a Parametric Study to Determine Bounding Critical Systems of Homogeneously Water-Moderated Mixed Plutonium--Uranium Oxides

    SciTech Connect

    Shimizu, Y.

    2001-01-11

    This report provides computational results of an extensive study to examine the following: (1) infinite media neutron-multiplication factors; (2) material bucklings; (3) bounding infinite media critical concentrations; (4) bounding finite critical dimensions of water-reflected and homogeneously water-moderated one-dimensional systems (i.e., spheres, cylinders of infinite length, and slabs that are infinite in two dimensions) that were comprised of various proportions and densities of plutonium oxides and uranium oxides, each having various isotopic compositions; and (5) sensitivity coefficients of delta k-eff with respect to critical geometry delta dimensions were determined for each of the three geometries that were studied. The study was undertaken to support the development of a standard that is sponsored by the International Standards Organization (ISO) under Technical Committee 85, Nuclear Energy (TC 85)--Subcommittee 5, Nuclear Fuel Technology (SC 5)--Working Group 8, Standardization of Calculations, Procedures and Practices Related to Criticality Safety (WG 8). The designation and title of the ISO TC 85/SC 5/WG 8 standard working draft is WD 14941, ''Nuclear energy--Fissile materials--Nuclear criticality control and safety of plutonium-uranium oxide fuel mixtures outside of reactors.'' Various ISO member participants performed similar computational studies using their indigenous computational codes to provide comparative results for analysis in the development of the standard.

  17. Subscale, hydrogen-burning, airframe-integrated-scramjet: Experimental and theoretical evaluation of a water cooled strut airframe-integrated-scramjet: Experimental leading edge

    NASA Technical Reports Server (NTRS)

    Pinckney, S. Z.; Guy, R. W.; Beach, H. L., Jr.; Rogers, R. C.

    1975-01-01

    A water-cooled leading-edge design for an engine/airframe integrated scramjet model strut leading edge was evaluated. The cooling design employs a copper cooling tube brazed just downstream of the leading edge of a wedge-shaped strut which is constructed of oxygen-free copper. The survival of the strut leading edge during a series of tests at stagnation point heating rates confirms the practicality of the cooling design. A finite difference thermal model of the strut was also proven valid by the reasonable agreement of calculated and measured values of surface temperature and cooling-water heat transfer.

  18. Water Powered Tools

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Space Spin-Offs, Inc. under a contract with Lewis Research Center and Marshall Space Flight Center produced a new water-powered saw that cuts through concrete and steel plate reducing danger of explosion or electric shock in rescue and other operations. In prototype unit efficient water-powered turbine drives an 8 inch diameter grinding disk at 6,600 rpm. Exhaust water cools disk and workpiece quenching any sparks produced by cutting head. At maximum power, tool easily cuts through quarter inch steel plate. Adapter heads for chain saws, impact wrenches, heavy duty drills, and power hack saws can be fitted.

  19. Theoretical analysis of transurethral laser-induced thermo-therapy for treatment of benign prostatic hyperplasia. Evaluation of a water-cooled applicator

    NASA Astrophysics Data System (ADS)

    Sturesson, C.; Andersson-Engels, S.

    1996-03-01

    A mathematical model for predicting the temperature rise in transurethral laser-induced thermo-therapy for benign prostatic hyperplasia was developed. In the model an optical line source emitting light from an Nd:YAG laser isotropically was placed in the urethra. Water cooling of the urethral epithelium was modelled using a two-tube system. The relationship between the difference in outlet and inlet water temperatures and the highest tissue temperature level reached was theoretically investigated. It was found that the water temperature difference was linearly dependent on the steady-state maximum tissue temperature. The theoretical calculations suggest that the water-cooled applicator can be used to measure the maximum tissue temperature. With temperature control, the prostatic tissue temperature can be prevented from exceeding the boiling point of water, excluding tissue carbonization. The model was also used to evaluate the influence of a number of different parameters on the damaged tissue volume. Increasing the urethral lumen radius by a factor of two by means of inserting different sized tubes was found to augment the tissue volume raised to therapeutic temperatures by up to 50%. The calculations showed that cooling of the urethral epithelium can result in an increase in the damaged volume by 80% as compared to not applying any cooling. The temperature of the cooling water was found to influence the tissue temperature only to a small extent.

  20. Blade-to-coolant heat-transfer results and operating data from a natural-convection water-cooled single-stage turbine

    NASA Technical Reports Server (NTRS)

    Diaguila, Anthony J; Freche, John C

    1951-01-01

    Blade-to-coolant heat-transfer data and operating data were obtained with a natural-convection water-cooled turbine over range of turbine speeds and inlet-gas temperatures. The convective coefficients were correlated by the general relation for natural-convection heat transfer. The turbine data were displaced from a theoretical equation for natural convection heat transfer in the turbulent region and from natural-convection data obtained with vertical cylinders and plates; possible disruption of natural convection circulation within the blade coolant passages was thus indicated. Comparison of non dimensional temperature-ratio parameters for the blade leading edge, midchord, and trailing edge indicated that the blade cooling effectiveness is greatest at the midchord and least at the trailing edge.

  1. Application of a scattered-light radiometric power meter

    NASA Astrophysics Data System (ADS)

    Caron, James N.; DiComo, Gregory P.; Ting, Antonio C.; Fischer, Richard P.

    2011-04-01

    The power measurement of high-power continuous-wave laser beams typically calls for the use of water-cooled thermopile power meters. Large thermopile meters have slow response times that can prove insufficient to conduct certain tests, such as determining the influence of atmospheric turbulence on transmitted beam power. To achieve faster response times, we calibrated a digital camera to measure the power level as the optical beam is projected onto a white surface. This scattered-light radiometric power meter saves the expense of purchasing a large area power meter and the required water cooling. In addition, the system can report the power distribution, changes in the position, and the spot size of the beam. This paper presents the theory of the scattered-light radiometric power meter and demonstrates its use during a field test at a 2.2 km optical range.

  2. Application of a scattered-light radiometric power meter.

    PubMed

    Caron, James N; DiComo, Gregory P; Ting, Antonio C; Fischer, Richard P

    2011-04-01

    The power measurement of high-power continuous-wave laser beams typically calls for the use of water-cooled thermopile power meters. Large thermopile meters have slow response times that can prove insufficient to conduct certain tests, such as determining the influence of atmospheric turbulence on transmitted beam power. To achieve faster response times, we calibrated a digital camera to measure the power level as the optical beam is projected onto a white surface. This scattered-light radiometric power meter saves the expense of purchasing a large area power meter and the required water cooling. In addition, the system can report the power distribution, changes in the position, and the spot size of the beam. This paper presents the theory of the scattered-light radiometric power meter and demonstrates its use during a field test at a 2.2 km optical range. PMID:21528989

  3. Feasibility study for use of the natural convection shutdown heat removal test facility (NSTF) for VHTR water-cooled RCCS shutdown.

    SciTech Connect

    Tzanos, C.P.; Farmer, M.T.; Nuclear Engineering Division

    2007-08-31

    In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance of a reference water-cooled RCCS, the scaling analysis presented here needs to be 'validated' by analysis of the steady state and transient performance of a reference water-cooled RCCS design. The analysis of the RCCS performance by CFD and system codes presents a number of challenges including: strong 3-D effects in the cavity and the RCCS tubes; simulation of turbulence in flows characterized by natural circulation, high Rayleigh numbers and low Reynolds numbers; validity of heat transfer correlations for system codes for heat transfer in the cavity and the annulus of the RCCS tubes; the potential of nucleate boiling in the tubes; water flashing in the upper section of the RCCS return line (during limiting transient); and two-phase flow phenomena in the water tanks. The limited simulation of heat transfer in cavities presented in Section 4.0, strongly underscores the need of experimental work to validate CFD codes, and heat transfer correlations for system codes, and to support the analysis and design of the RCCS. Based on the conclusions of the scaling analysis, a schematic that illustrates key attributes of the experiment system is shown in Fig. 4. This system contains the same physical elements as the PBMR RCCS, plus additional equipment to facilitate data gathering to support code validation. In particular, the prototype consists of a series of oval standpipes surrounding the reactor vessel to provide cooling of the reactor cavity during both normal and off-normal operating conditions. The standpipes are headered (in groups of four in the prototype) to water supply (header) tanks that are situated well above the reactor vessel to facilitate natural convection cooling during a loss of forced flow event. During normal operations, the water is pumped from a heat sink located outside the containment to the headered inlets to the standpipes. The water is then delivered to each standpipe through a centrally located downcomer that passes the coolant to the bottom of each pipe. The water then turns 180{sup o} and rises up through the annular gap while extracting heat from the reactor cavity due to a combination of natural convection and radiation across the gap between the reactor vessel and standpipes. The water exits the standpipes at the top where it is headered (again in groups of four) into a return line that passes the coolant to the top of the header tank. Coolant is drawn from each tank through a fitting located near the top of the tank where it flows to the heat rejection system located outside the containment. This completes the flow circuit for normal operations. During off-normal conditions, forced convection water cooling in the RCCS is presumed to be lost, as well as the ultimate heat sink outside the containment. In this case, water is passively drawn from an open line located at the bottom of the header tank. This line is orificed so that flow bypass during normal operations is small, yet the line is large enough to provide adequate flow during passive operations to remove decay heat while maintaining acceptable fuel temperatures. In the passive operating mode, water flows by natural convection from the bottom of the supply tank to the standpipes, and returns through the normal pathway to the top of the tanks. After the water reaches saturation and boiling commences, steam will pass through the top of the tanks and be vented to atmosphere. In the experiment system shown in Fig. 4, a steam condensation and collection system is included to quantify the boiling rate, thereby providing additional validation data. This system does not exist in the prototype. The first part of the report presents the non-dimensional conservation equations describing the response of the water-based RCCS during steady-state and transient operations. These equations are used to develop similarity relationships that define a scaling of the NSTF that minimizes distortions between scaled experiments and prototype operation. Then, some limited simulations of heat transfer in cavities are presented that strongly underscore the need of experimental work to validate CFD codes, and heat transfer correlations for system codes, and to support the analysis and design of the RCCS. Finally, a summary is provided of the NSTF modifications needed to conduct scaled simulations of the RCCS.

  4. Conceptual design description for the tritium recovery system for the US ITER (International Thermonuclear Experimental Reactor) Li sub 2 O/Be water cooled blanket

    SciTech Connect

    Finn, P.A.; Sze, D.K. . Fusion Power Program); Clemmer, R.G. )

    1990-11-01

    The tritium recovery system for the US ITER Li{sub 2}O/Be water cooled blanket processes two separate helium purge streams to recover tritium from the Li{sub 2}O zones and the Be zones of the blanket, to process the waste products, and to recirculate the helium back to the blanket. The components are selected to minimize the tritium inventory of the recovery system, and to minimize waste products. The system is robust to either an increase in the tritium release rate or to an in-leak of water in the purge system. Three major components were used to process these streams, first, 5A molecular sieves at {minus}196{degree}C separate hydrogen from the helium, second, a solid oxide electrolysis unit is used to reduce all molecular water, and third, a palladium/silver diffuser is used to ensure that only hydrogen (H{sub 2}, HT) species reach the cryogenic distillation unit. Other units are present to recover tritium from waste products but the three major components are the basis of the blanket tritium recovery system. 32 refs.

  5. Conceptual design description for the tritium recovery system for the US ITER Li sub 2 O/Be water cooled blanket

    SciTech Connect

    Finn, P.A.; Sze, D.K. ); Clemmer, R.G. )

    1990-09-01

    The tritium recovery system for the US ITER Li{sub 2}O/Be water cooled blanket processes two separate helium purge streams to recovery tritium from the Li{sub 2}O zones and the Be zones of the blanket, to process the waste products, and to recirculate the helium back to the blanket. The components are selected to minimize the tritium inventory of the recovery system, and to minimize waste products. The system is robust to either an increase in the tritium release rate or to an in-leak of water in the purge system. Three major components were used to process these streams, first, 5A molecular sieves at {minus}196{degree}C separate hydrogen from the helium, second, a solid oxide electrolysis unit is used to reduce all molecular water, and third, a palladium/silver diffuser is used to ensure that only hydrogen (H{sub 2}, HT) species reach the cryogenic distillation unit. The total tritium process inventory is 20g. The total capital cost is {approximately}$14M. Technical advantages of a solid oxide electrolysis unit and a palladium/silver diffuser are presented. 5 refs., 1 fig., 3 tabs.

  6. Design of beam line components for the high power wiggler beam line at CHESS

    NASA Astrophysics Data System (ADS)

    Shen, Qun; Henderson, C.; Keeffe, M.; Marston, M.; Finkelstein, K. D.; Batterman, B. W.

    1994-08-01

    We present a water-cooled copper beam stop design for the 25-pole wiggler beam line at CHESS. Finite element thermal analyses and simulated heat load tests indicate that the new design should be able to operate safely at a machine current of 500 mA, absorbing 32 kW of total power at a surface density of 400 W/mm 2 normal to the beam. The basic design can also be used for water-cooled masks and apertures on the high power beam line.

  7. "Hot" for Warm Water Cooling

    SciTech Connect

    IBM Corporation; Energy Efficient HPC Working Group; Hewlett Packard Corporation; SGI; Cray Inc.; Intel Corporation; U.S. Army Engineer Research Development Center; Coles, Henry; Ellsworth, Michael; Martinez, David J.; Bailey, Anna-Maria; Banisadr, Farhad; Bates, Natalie; Coghlan, Susan; Cowley, David E.; Dube, Nicholas; Fields, Parks; Greenberg, Steve; Iyengar, Madhusudan; Kulesza, Peter R.; Loncaric, Josip; McCann, Tim; Pautsch, Greg; Patterson, Michael K.; Rivera, Richard G.; Rottman, Greg K.; Sartor, Dale; Tschudi, William; Vinson, Wade; Wescott, Ralph

    2011-08-26

    Liquid cooling is key to reducing energy consumption for this generation of supercomputers and remains on the roadmap for the foreseeable future. This is because the heat capacity of liquids is orders of magnitude larger than that of air and once heat has been transferred to a liquid, it can be removed from the datacenter efficiently. The transition from air to liquid cooling is an inflection point providing an opportunity to work collectively to set guidelines for facilitating the energy efficiency of liquid-cooled High Performance Computing (HPC) facilities and systems. The vision is to use non-compressor-based cooling, to facilitate heat re-use, and thereby build solutions that are more energy-efficient, less carbon intensive and more cost effective than their air-cooled predecessors. The Energy Efficient HPC Working Group is developing guidelines for warmer liquid-cooling temperatures in order to standardize facility and HPC equipment, and provide more opportunity for reuse of waste heat. This report describes the development of those guidelines.

  8. Partially-reflected water-moderated square-piteched U(6.90)O2 fuel rod lattices with 0.67 fuel to water volume ratio (0.800 CM Pitch)

    SciTech Connect

    Harms, Gary A.

    2015-09-01

    The US Department of Energy (DOE) Nuclear Energy Research Initiative funded the design and construction of the Seven Percent Critical Experiment (7uPCX) at Sandia National Laboratories. The start-up of the experiment facility and the execution of the experiments described here were funded by the DOE Nuclear Criticality Safety Program. The 7uPCX is designed to investigate critical systems with fuel for light water reactors in the enrichment range above 5% 235U. The 7uPCX assembly is a water-moderated and -reflected array of aluminum-clad square-pitched U(6.90%)O2 fuel rods.

  9. Power

    NASA Technical Reports Server (NTRS)

    Corbett, R.

    1984-01-01

    The space station requires an increase in power or energy of at least several orders of magnitude compared to previous space missions. With the requirement up in the range of 10 kilowatt hours, this obviiously requires the development of new technology. Although the power area is very well integrated in the spacecraft itself, it represents a diverse set of components necessary for energy conversion, electronics, and energy distribution. Considerable work is ongoing at NASA Lewis in the power devices development area, including transformers, large area solid-state chips, transistors, and fast recovery diodes. This work is oriented toward eventual application to both AC and DC power conversion approaches. In the energy storage area, there are many options available to fit into the space station representing various degrees of risk and leverage combination, such as the near-term integral-pressure-vessel nickel hydrogen battery, an advanced Ni-H2 battery concept, and the regenrative hydrogen-oxygen system utilizing essentially the Shuttle orbiter type of fuel cell.

  10. 10 CFR 50.63 - Loss of all alternating current power.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., each light-water-cooled nuclear power plant licensed under subpart C of 10 CFR part 52 after the... coolant, control, and protection systems, including station batteries and any other necessary support... information used in their coping evaluations available for NRC review. (b) Limitation of scope. Paragraph...

  11. A CONTINUOUS HIGH POWER BEAM DUMP OF THE HOT-DOG-COOKER TYPE

    SciTech Connect

    Yoshikawa, Kiyoshi

    1980-03-01

    A beam dump with partially rotating water-cooled tube arrays is proposed and studied for the dump of continuous high power density unneutralized ion beams out of the neutral beam injectors. Analyses were made of both steady and transient heat transfer characteristics.

  12. Long-term effects of a single application of a water-cooled pulsed Nd:YAG laser in supplement to scaling and root planing in patients with periodontal inflammation.

    PubMed

    Qadri, Talat; Javed, Fawad; Poddani, Pavlina; Tunér, Jan; Gustafsson, Anders

    2011-11-01

    The aim of this work was to investigate the long-term effects of a single application of a water-cooled pulsed neodymium yttrium aluminium garnet (Nd:YAG) laser, in combination with scaling and root planing (SRP) for the treatment of periodontal inflammation. Twenty-two patients were included in this split-mouth single blind randomized controlled clinical trial. The parameters of the air and water-cooled Nd:YAG laser were: 4 W, 80 mJ/pulse, 50 Hz and a pulse width of 350 μs. The "test side" was treated with a single application of Nd:YAG laser and SRP; while the "control side " was treated with SRP alone. At baseline, and after a median follow-up time of 20 months (range 12-39), periodontal inflammatory parameters (plaque index [PI], gingival index [GI], probing pocket depth [PPD]), and marginal bone loss (on digital bite-wing radiographs) were measured. Gingival crevicular fluid (GCF) was collected from the teeth 35, 36, 45, and 46 at baseline and at follow-up. Pl (p < 0.01), GI (p < 0.01), and PPD (p < 0.001) were significantly lower on the test side compared to the control side at follow-up. Radiological results showed significantly less bone loss on the test side compared to the control side (p < 0.05). GCF volume was lower on the test side compared to the control side (p < 0.01). In conclusion, a single application of Nd:YAG laser in combination with SRP had a positive long-term effect on periodontal health compared to treatment by SRP alone. PMID:20582610

  13. Thermodynamic Analysis of the Use a Chemical Heat Pump to Link a Supercritical Water-Cooled Nuclear Reactor and a Thermochemical Water-Splitting Cycle for Hydrogen Production

    NASA Astrophysics Data System (ADS)

    Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.; Pioro, Igor

    Increases in the power generation efficiency of nuclear power plants (NPPs) are mainly limited by the permissible temperatures in nuclear reactors and the corresponding temperatures and pressures of the coolants in reactors. Coolant parameters are limited by the corrosion rates of materials and nuclear-reactor safety constraints. The advanced construction materials for the next generation of CANDU reactors, which employ supercritical water (SCW) as a coolant and heat carrier, permit improved “steam” parameters (outlet temperatures up to 625°C and pressures of about 25 MPa). An increase in the temperature of steam allows it to be utilized in thermochemical water splitting cycles to produce hydrogen. These methods are considered by many to be among the most efficient ways to produce hydrogen from water and to have advantages over traditional low-temperature water electrolysis. However, even lower temperature water splitting cycles (Cu-Cl, UT-3, etc.) require an intensive heat supply at temperatures higher than 550-600°C. A sufficient increase in the heat transfer from the nuclear reactor to a thermochemical water splitting cycle, without jeopardizing nuclear reactor safety, might be effectively achieved by application of a heat pump, which increases the temperature of the heat supplied by virtue of a cyclic process driven by mechanical or electrical work. Here, a high-temperature chemical heat pump, which employs the reversible catalytic methane conversion reaction, is proposed. The reaction shift from exothermic to endothermic and back is achieved by a change of the steam concentration in the reaction mixture. This heat pump, coupled with the second steam cycle of a SCW nuclear power generation plant on one side and a thermochemical water splitting cycle on the other, increases the temperature of the “nuclear” heat and, consequently, the intensity of heat transfer into the water splitting cycle. A comparative preliminary thermodynamic analysis is conducted of the combined system comprising a SCW nuclear power generation plant and a chemical heat pump, which provides high-temperature heat to a thermochemical water splitting cycle for hydrogen production. It is concluded that the proposed chemical heat pump permits the utilization efficiency of nuclear energy to be improved by at least 2% without jeopardizing nuclear reactor safety. Based on this analysis, further research appears to be merited on the proposed advanced design of a nuclear power generation plant combined with a chemical heat pump, and implementation in appropriate applications seems worthwhile.

  14. High power radio frequency attenuation device

    DOEpatents

    Kerns, Quentin A.; Miller, Harold W.

    1984-01-01

    A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

  15. Study of high power laser mirror shape maintenance technology

    NASA Astrophysics Data System (ADS)

    Li, Gang; Wang, Feng; Liu, Shunfu; Deng, Songwen; Sun, Tianxiang; Liu, Yushi; Zhang, Zengbao; Sun, Long; Jin, Yuqi

    2015-02-01

    With the laser power and operation time increasing, the surface distortion of the laser cavity mirrors has been a critical problem to be resolved. In order to maintain the mirror shape under intense laser irradiation, in this paper, a new type of micro channel silicon water cooled mirror is given. The water cooled mirror includes three layers, the first layer is mirror seat made of Invar materials with water inlet and outlet, the second layer is water manifold unit made of silicon with millimeter channels; the third layer is reflection plate with micro-channels. These three layers are bonded together by vacuum soldering. Then the thickness of the reflection plate is reduced to 0.5mm by grinding, and polished by traditional pitch polishing method. In order to reduce the coating stress, conventional all dielectric coating is replaced by a metal dielectric film stack. At last, a 100mm×100mm water cooled mirror is fabricated with surface figure 0.22λ@632.8 nm. The mirror surface distortion is 0.12λ、0.24λ、0.33 λ respectively corresponding to 7.3w/cm2 、11.9 w/cm2 、17.6 w/cm2 heat load.

  16. The effect of ligaments on the reinitiation of fracture at the tip of a crack arrested during a hypothetical thermal shock event in a water-cooled reactor pressure vessel

    NASA Astrophysics Data System (ADS)

    Smith, E.

    1984-11-01

    During a hypothetical thermal shock event involving a water-cooled nuclear reactor pressure vessel, a crack can propagate deep into the reactor vessel thickness by a series of run-arrest-reinitiation events. Within the transition temperature regime, crack propagation and arrest in pressure vessel steels is associated with a combination of cleavage and dimpled rupture processes, the dimpled rupture regions being contained within ligaments that are normal to the crack plane and parallel to the direction of crack propagation. The present paper models the effect of ligaments on the reinitiation of fracture at the tip of an arrested crack, and the results of a theoretical analysis define the conditions under which ligaments might increase the reinitiation value above k IC, assuming that they fracture by a ductile rupture process. By comparing the predictions with experimental results for model vessels subject to thermal shock, it is shown that the ligaments, which are present at arrest, are unlikely to fail entirely by ductile rupture prior to the reinitiation of fracture at an arrested crack tip. Instead it is suggested that the ligaments fail by cleavage, whereupon they do not markedly affect the reinitiation K value, which thus correlates with K IC.

  17. Diversion assumptions for high-powered research reactors

    SciTech Connect

    Binford, F.T.

    1984-01-01

    This study deals with diversion assumptions for high-powered research reactors -- specifically, MTR fuel; pool- or tank-type research reactors with light-water moderator; and water, beryllium, or graphite reflectors, and which have a power level of 25 MW(t) or more. The objective is to provide assistance to the IAEA in documentation of criteria and inspection observables related to undeclared plutonium production in the reactors described above, including: criteria for undeclared plutonium production, necessary design information for implementation of these criteria, verification guidelines including neutron physics and heat transfer, and safeguards measures to facilitate the detection of undeclared plutonium production at large research reactors.

  18. Water cooling of HVDC thyristor valves

    SciTech Connect

    Lips, H.P. )

    1994-10-01

    It is generally accepted that water is a very effective medium to remove heat losses from any type of equipment. When used for HVDC thyristor valves, the fundamentals of electrolyte conduction and water chemistry need to be considered in the design of the cooling circuit. The characteristics of the materials used, in conjunction with high voltage stresses and circuit configuration, play an important role to assure longevity and corrosion-free performance.

  19. Salt water cooling tower retrofit experience

    SciTech Connect

    Rittenhouse, R.C.

    1994-06-01

    This article describes the experience of engineers at Atlantic Electric Co. with a recent cooling tower fill retrofit at the company's B.L. England Station, Unit 3. Note that this tower is unique. It is the first natural draft salt water tower to be built in the United States. Unit 3's closed-loop saltwater cooling system features a double condenser and two 50% capacity horizontal circulating water pumps. A natural draft cooling tower rejects heat to the atmosphere through evaporation and sensible heat transfer. The tower is 180 ft in diameter at the base and 208 ft high, and features a counterflow design. It was designed to cool 63,500 gpm of circulating salt water through a range of 26 F with an approach of 19.2 degrees at an ambient wet bulb temperature of 76 F and 60% relative humidity. A drift rate of 0.002% of circulating water flow was specified to avoid excessive salt water carryover.

  20. Increasing thermal oxidizer capacity with water cooling

    SciTech Connect

    Alford, G.N.; Sudnick, J.J.

    1997-06-01

    Title III of the Clean Air Act Amendments of 1990, as well as state air regulations, require substantial reductions of volatile organic compounds (VOCs) and hazardous air pollutants (HAPs). Industrial facilities affected by these mandated reductions have several options available to comply with the new requirements. These include: process and operational modifications; changes in raw materials; installation of new air pollution control equipment; and modification of existing air pollution control equipment. The focus here will be on some of the process, mechanical and operational changes that need to be considered when modifying existing control equipment. A chemical manufacturer operates a number of processes that generate streams containing VOC and HAP emissions. Stream 1 is from a drying operation and is composed predominantly of air with small amounts of organics. The flow rate is constant, although there may be some variation in the organic concentrations in the stream. Stream 2 is a reactor vent of mostly organics with some nitrogen generated by the reactor purge. This stream is intermittent, having a flow duration of between five and 15 minutes. Stream 3 also is a reactor vent, composed primarily of organics with some nitrogen from the reactor purge. The constituent profile of each stream is given. The three streams are controlled by a thermal oxidizer system. The facility`s plans to add reactor capacity which will create a fourth vent stream. Like streams 2 and 3, this additional stream will consist primarily of organics with some purge nitrogen.

  1. Numerical study on mirror of high power laser with heatpipe cooling

    NASA Astrophysics Data System (ADS)

    Chen, Jiayuan, II; Zhu, Haihong; Cheng, Zuhai

    2008-12-01

    Mirror surface of high power laser would be deformed by the pressure of the coolant in a liquid cooling mirror system. In order to eliminate the impact of pressure and vibration of cooling water to the stability of the output beam, a cooling mirror with heatpipe is designed. With the same structure and conditions, solid mirror, water cooling mirror and heat pipe cooling mirror are simulated by ANSYS program. The time-varying thermal deformations of the group mirrors after 60s under the net heat absorption of 12W/cm2 are obtained. The maximal peak and valley difference value of mirror surface deformation of solid mirror along Z-axis, water cooling mirror and heat pipe cooling mirror after 60s is 1.33μm, 0.845 μm and 0.1094 μm respectively.

  2. Modification of film structure by plasma potential control using triode high power pulsed magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Nakano, Takeo; Umahashi, Takuya; Baba, Shigeru

    2014-02-01

    We have designed a new triode configuration in a magnetron sputtering apparatus to control the plasma potential of the discharge. An additional chimney electrode was introduced above the conventional sputter gun to apply a positive voltage. The discharge power was provided by a pulse power source to achieve high power pulsed magnetron sputtering operation. We confirmed that the plasma potential increased with increasing positive electrode voltage. Copper films with substantially flatter surfaces could be obtained on a water-cooled and electrically grounded substrate at an Ar gas pressure of 5 Pa.

  3. Diamond cooling of high power diode pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Tzuk, Yitshak; Tal, Alon; Goldring, Sharone; Glick, Yaakov; Lebiush, Eyal; Kaufman, Guy; Lavi, Raphael

    2003-06-01

    We have demonstrated the feasibility of cooling high power solid-stae lasers with diamond windows, whose thermal conductivity is about two orders of magnitude higher than sapphire's. An output power of 200Watt was achieved froma single Nd:YVO4 slab in a zigzag configuration when pumped with 600Watt diodes at 808nm. The maximum output power reported in the literature with conventional cooling schemes is about 50W. A 2.3x4x24mm3 slab was pumped from its broad side (4x24 mm2) through a 0.3mm thick optical diamond window placed in close contact with the lasing crystal. The diamond window, held in a water-cooled copper housing acted as a heat conductor. The other broad side of the crystal was cooled directly by its water-cooled copper housing. Since pumping and cooling were along the same axis, a Cartesian thermal gradient was achieved, while the zigzag scheme was used to minimize thermal lensing. By using a BBO Q-switch, 70Watt average power was obtained at 20kHz with a pulse width of 19msec and with a beam quality of 3 and 12 times diffraction limit in the zigzag and transverse directions respectively. The output of a two-head configuration was 295Watt.

  4. High-power radio-frequency attenuation device

    DOEpatents

    Kerns, Q.A.; Miller, H.W.

    1981-12-30

    A resistor device for attenuating radio frequency power includes a radio frequency conductor connected to a series of fins formed of high relative magnetic permeability material. The fins are dimensional to accommodate the skin depth of the current conduction therethrough, as well as an inner heat conducting portion where current does not travel. Thermal connections for air or water cooling are provided for the inner heat conducting portions of each fin. Also disclosed is a resistor device to selectively alternate unwanted radio frequency energy in a resonant cavity.

  5. Advancements in high-power diode laser stacks for defense applications

    NASA Astrophysics Data System (ADS)

    Pandey, Rajiv; Merchen, David; Stapleton, Dean; Patterson, Steve; Kissel, Heiko; Fassbender, Wilhlem; Biesenbach, Jens

    2012-06-01

    This paper reports on the latest advancements in vertical high-power diode laser stacks using micro-channel coolers, which deliver the most compact footprint, power scalability and highest power/bar of any diode laser package. We present electro-optical (E-O) data on water-cooled stacks with wavelengths ranging from 7xx nm to 9xx nm and power levels of up to 5.8kW, delivered @ 200W/bar, CW mode, and a power-conversion efficiency of >60%, with both-axis collimation on a bar-to-bar pitch of 1.78mm. Also, presented is E-O data on a compact, conductively cooled, hardsoldered, stack package based on conventional CuW and AlN materials, with bar-to-bar pitch of 1.8mm, delivering average power/bar >15W operating up to 25% duty cycle, 10ms pulses @ 45C. The water-cooled stacks can be used as pump-sources for diode-pumped alkali lasers (DPALs) or for more traditional diode-pumped solid-state lasers (DPSSL). which are power/brightness scaled for directed energy weapons applications and the conductively-cooled stacks as illuminators.

  6. Diversion assumptions for high-powered research reactors. ISPO C-50 Phase 1

    SciTech Connect

    Binford, F.T.

    1984-01-01

    This study deals with diversion assumptions for high-powered research reactors -- specifically, MTR fuel; pool- or tank-type research reactors with light-water moderator; and water, beryllium, or graphite reflectors, and which have a power level of 25 MW(t) or more. The objective is to provide assistance to the IAEA in documentation of criteria and inspection observables related to undeclared plutonium production in the reactors described above, including: criteria for undeclared plutonium production, necessary design information for implementation of these criteria, verification guidelines including neutron physics and heat transfer, and safeguards measures to facilitate the detection of undeclared plutonium production at large research reactors.

  7. Water-Moderated and -Reflected Slabs of Uranium Oxyfluoride

    SciTech Connect

    Margaret A. Marshall; John D. Bess; J. Blair Briggs; Clinton Gross

    2010-09-01

    A series of ten experiments were conducted at the Oak Ridge National Laboratory Critical Experiment Facility in December 1955, and January 1956, in an attempt to determine critical conditions for a slab of aqueous uranium oxyfluoride (UO2F2). These experiments were recorded in an Oak Ridge Critical Experiments Logbook and results were published in a journal of the American Nuclear Society, Nuclear Science and Engineering, by J. K. Fox, L. W. Gilley, and J. H. Marable (Reference 1). The purpose of these experiments was to obtain the minimum critical thickness of an effectively infinite slab of UO2F2 solution by extrapolation of experimental data. To do this the slab thickness was varied and critical solution and water-reflector heights were measured using two different fuel solutions. Of the ten conducted experiments eight of the experiments reached critical conditions but the results of only six of the experiments were published in Reference 1. All ten experiments were evaluated from which five critical configurations were judged as acceptable criticality safety benchmarks. The total uncertainty in the acceptable benchmarks is between 0.25 and 0.33 % ?k/keff. UO2F2 fuel is also evaluated in HEU-SOL-THERM-043, HEU-SOL-THERM-011, and HEU-SOL-THERM-012, but these those evaluation reports are for large reflected and unreflected spheres. Aluminum cylinders of UO2F2 are evaluated in HEU-SOL-THERM-050.

  8. Design of Recycle Pressurized Water Reactor with Heavy Water Moderation

    SciTech Connect

    Hibi, Koki; Uchita, Masato

    2004-03-15

    This study presents the conceptual design of the recycle pressurized water reactor (RPWR), which is an innovative PWR fueled with mixed oxide, moderated by heavy water, and having breeding ratios around 1.1. Most of the systems of RPWR can employ those of PWRs. The RPWR has no boric acid systems and has a small tritium removal system. The construction and operation costs would be similar to those of current PWRs. Heavy water cost has decreased drastically with up-to-date producing methods. The reliability of the systems of the RPWR is high, and the research and development cost for RPWR is very low because the core design is fundamentally based on the current PWR technology.

  9. Design of Recycle PWR with Heavy Water Moderation

    SciTech Connect

    Hibi, K.; Uchita, M.

    2002-07-01

    This study shows the conceptual plant design of the recycle PWR (RPWR), which is an innovative MOX-PWR with breeding ratios around 1.1 moderated by heavy water. Most of the plant systems of RPWR can employ the systems of PWRs. RPWR has no acid boron systems and has a small tritium removal system. The construction and operation costs are similar to the current PWRs. While, heavy water cost will be decreased drastically with up-to-date producing methods. The reliability for the plant systems of RPWR is high and R and D cost for realizing RPWR is very low because the core design of RPWR is fundamentally based on the current PWR technology. (authors)

  10. METHOD OF OPERATING A HEAVY WATER MODERATED REACTOR

    DOEpatents

    Vernon, H.C.

    1962-08-14

    A method of removing fission products from the heavy water used in a slurry type nuclear reactor is described. According to the process the slurry is steam distilled with carbon tetrachloride so that at least a part of the heavy water and carbon tetrachloride are vaporized; the heavy water and carbon tetrachloride are separated; the carbon tetrachloride is returned to the steam distillation column at different points in the column to aid in depositing the slurry particles at the bottom of the column; and the heavy water portion of the condensate is purified. (AEC)

  11. Initial results for a 170 GHz high power ITER waveguide component test stand

    NASA Astrophysics Data System (ADS)

    Bigelow, Timothy; Barker, Alan; Dukes, Carl; Killough, Stephen; Kaufman, Michael; White, John; Bell, Gary; Hanson, Greg; Rasmussen, Dave

    2014-10-01

    A high power microwave test stand is being setup at ORNL to enable prototype testing of 170 GHz cw waveguide components being developed for the ITER ECH system. The ITER ECH system will utilize 63.5 mm diameter evacuated corrugated waveguide and will have 24 >150 m long runs. A 170 GHz 1 MW class gyrotron is being developed by Communications and Power Industries and is nearing completion. A HVDC power supply, water-cooling and control system has been partially tested in preparation for arrival of the gyrotron. The power supply and water-cooling system are being designed to operate for >3600 second pulses to simulate the operating conditions planned for the ITER ECH system. The gyrotron Gaussian beam output has a single mirror for focusing into a 63.5 mm corrugated waveguide in the vertical plane. The output beam and mirror are enclosed in an evacuated duct with absorber for stray radiation. Beam alignment with the waveguide is a critical task so a combination of mirror tilt adjustments and a bellows for offsets will be provided. Analysis of thermal patterns on thin witness plates will provide gyrotron mode purity and waveguide coupling efficiency data. Pre-prototype waveguide components and two dummy loads are available for initial operational testing of the gyrotron. ORNL is managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under Contract DE-AC-05-00OR22725.

  12. Overview of the STARFIRE reference commercial tokamak fusion power reactor design

    SciTech Connect

    Baker, C.C.; Abdou, M.A.; DeFreece, D.A.; Trachsel, C.A.; Graumann, D.; Barry, K.

    1980-01-01

    The purpose of the STARFIRE study is to develop a design concept for a commercial tokamak fusion electric power plant based on the deuterium/tritium/lithium fuel cycle. The major features for STARFIRE include a steady-state operating mode based on a continuous rf lower-hybrid current drive and auxiliary heating, solid tritium breeder material, pressurized water cooling, limiter/vacuum system for impurity control and exhaust, high tritium burnup, superconducting EF coils outside the TF superconducting coils, fully remote maintenance, and a low-activation shield.

  13. A novel power block for CSP systems

    SciTech Connect

    Mittelman, Gur; Epstein, Michael

    2010-10-15

    Concentrating Solar Thermal Power (CSP) and in particular parabolic trough, is a proven large-scale solar power technology. However, CSP cost is not yet competitive with conventional alternatives unless subsidized. Current CSP plants typically include a condensing steam cycle power block which was preferably designed for a continuous operation and higher operating conditions and therefore, limits the overall plant cost effectiveness and deployment. The drawbacks of this power block are as follows: (i) no power generation during low insolation periods (ii) expensive, large condenser (typically water cooled) due to the poor extracted steam properties (high specific volume, sub-atmospheric pressure) and (iii) high installation and operation costs. In the current study, a different power block scheme is proposed to eliminate these obstacles. This power block includes a top Rankine cycle with a back pressure steam turbine and a bottoming Kalina cycle comprising another back pressure turbine and using ammonia-water mixture as a working fluid. The bottoming (moderate temperature) cycle allows power production during low insolation periods. Because of the superior ammonia-water vapor properties, the condensing system requirements are much less demanding and the operation costs are lowered. Accordingly, air cooled condensers can be used with lower economical penalty. Another advantage is that back pressure steam turbines have a less complex design than condensing steam turbines which make their costs lower. All of these improvements could make the combined cycle unit more cost effective. This unit can be applicable in both parabolic trough and central receiver (solar tower) plants. The potential advantage of the new power block is illustrated by a detailed techno-economical analysis of two 50 MW parabolic trough power plants, comparing between the standard and the novel power block. The results indicate that the proposed plant suggests a 4-11% electricity cost saving. (author)

  14. A high average power beam dump for an electron accelerator

    NASA Astrophysics Data System (ADS)

    Liu, Xianghong; Bazarov, Ivan; Dunham, Bruce M.; Kostroun, Vaclav O.; Li, Yulin; Smolenski, Karl W.

    2013-05-01

    The electron beam dump for Cornell University's Energy Recovery Linac (ERL) prototype injector was designed and manufactured to absorb 600 kW of electron beam power at beam energies between 5 and 15 MeV. It is constructed from an aluminum alloy using a cylindrical/conical geometry, with water cooling channels between an inner vacuum chamber and an outer jacket. The electron beam is defocused and its centroid is rastered around the axis of the dump to dilute the power density. A flexible joint connects the inner body and the outer jacket to minimize thermal stress. A quadrant detector at the entrance to the dump monitors the electron beam position and rastering. Electron scattering calculations, thermal and thermomechanical stress analysis, and radiation calculations are presented.

  15. An improved method for stripping cladding light in high power fiber lasers

    NASA Astrophysics Data System (ADS)

    Li, Tenglong; Wu, Juan; Sun, Yinghong; Wang, Yanshan; Ma, Yi

    2015-02-01

    In order to ensure the high power all-fiber laser reliability and excellent beam quality, it is necessary to strip the unwanted cladding light. The common method for stripping cladding light is to recoat the double cladding fiber with a high index gel, but localized heating and low thermal conductivity of the recoating gel are the prime factors limiting the power-handling capability of the cladding power stripper(CPS). An improved fabrication technique to manufacture the CPS is presented. Light stripping section of the fiber is fused with a transparent quartz tube, by applying different amount of etchant along the quartz tube, frosted surface is created and uniformly removal of the cladding light is achieved. The quartz tube is joined to water-cooled thermal enclosure tightly without the gel to avoid heat aggregation. The power-handling capability of the device is tested under 200W of cladding light, and attenuation of 20 dB is achieved.

  16. Evolution of the core physics concept for the Canadian supercritical water reactor

    SciTech Connect

    Pencer, J.; Colton, A.; Wang, X.; Gaudet, M.; Hamilton, H.; Yetisir, M.

    2013-07-01

    The supercritical water cooled reactor (SCWR) is one of the advanced reactor concepts chosen by the GEN-IV International Forum (GIF) for research and development efforts. Canada's contribution is the Canadian SCWR, a heavy water moderated, pressure tube supercritical light water cooled reactor. Recent developments in the SCWR lattice and core concepts, primarily the introduction of a large central flow tube filled with coolant combined with a two-ring fuel assembly, have enabled significant improvements compared to earlier concepts. These improvements include a reduction in coolant void reactivity (CVR) by more than 10 mk, and an almost 40% increase in fuel exit burnup, which is achieved via balanced power distribution between the fuel pins in the fuel assembly. In this paper the evolution of the physics concept is reviewed, and the present lattice and core physics concepts are presented.

  17. STARFIRE: a commercial tokamak fusion power plant study

    SciTech Connect

    Not Available

    1980-09-01

    STARFIRE is a 1200 MWe central station fusion electric power plant that utilizes a deuterium-tritium fueled tokamak reactor as a heat source. Emphasis has been placed on developing design features which will provide for simpler assembly and maintenance, and improved safety and environmental characteristics. The major features of STARFIRE include a steady-state operating mode based on continuous rf lower-hybrid current drive and auxiliary heating, solid tritium breeder material, pressurized water cooling, limiter/vacuum system for impurity control and exhaust, high tritium burnup and low vulnerable tritium inventories, superconducting EF coils outside the superconducting TF coils, fully remote maintenance, and a low-activation shield. A comprehensive conceptual design has been developed including reactor features, support facilities and a complete balance of plant. A construction schedule and cost estimate are presented, as well as study conclusions and recommendations.

  18. A Solar Thermophotovoltaic Electric Generator for Remote Power Applications

    NASA Technical Reports Server (NTRS)

    Fatemi, Navid S.

    1998-01-01

    We have successfully demonstrated that a solar thermophotovoltaic (TPV) system with a SiC graybody emitter and the monolithic interconnected module device technology can be realized. A custom-designed solar cavity was made to house the SiC emitter and the MIM strings for testing in a Stirling dish solar concentrator. Five 1x1-cm MIMs, with a bandgap of 0.74 eV,were mounted on a specially designed water-cooled heatsink and were electrically connected in series to form a string. Two such strings were fabricated and tested, as well as high-performance 2x2-cm MIMs with a bandgap of 0.74 eV. Very high output power density values between 0.82 and 0.90 W/sq cm were observed for an average emitter temperature of 1501 K.

  19. A Solar Thermophotovoltaic Electric Generator for Remote Power Applications

    NASA Technical Reports Server (NTRS)

    Fatemi, Navid S.

    1998-01-01

    We have successfully demonstrated that a solar thermophotovoltaic (TPV) system with a SiC graybody emitter and the monolithic interconnected module device technology can be realized. A custom-designed solar cavity was made to house the SiC emitter and the Monolithic Integrated Module (MIM) strings for testing in a Stirling dish solar concentrator. Five 1x1-cm MIMs, with a bandgap of 0.74 eV, were mounted on a specially designed water-cooled heatsink and were electrically connected in series to form a string. Two such strings were fabricated and tested, as well as high-performance 2x2-cm MIMs with a bandgap of 0.74 eV. Very high output power density values between 0.82 and 0.90 W/ square cm were observed for an average emitter temperature of 1501 K.

  20. Small-Scale Geothermal Power Plant Field Verification Projects: Preprint

    SciTech Connect

    Kutscher, C.

    2001-07-03

    In the spring of 2000, the National Renewable Energy Laboratory issued a Request for Proposal for the construction of small-scale (300 kilowatt [kW] to 1 megawatt [MW]) geothermal power plants in the western United States. Five projects were selected for funding. Of these five, subcontracts have been completed for three, and preliminary design work is being conducted. The three projects currently under contract represent a variety of concepts and locations: a 1-MW evaporatively enhanced, air-cooled binary-cycle plant in Nevada; a 1-MW water-cooled Kalina-cycle plant in New Mexico; and a 750-kW low-temperature flash plant in Utah. All three also incorporate direct heating: onion dehydration, heating for a fish hatchery, and greenhouse heating, respectively. These projects are expected to begin operation between April 2002 and September 2003. In each case, detailed data on performance and costs will be taken over a 3-year period.

  1. Flow reversal power limit for the HFBR

    SciTech Connect

    Cheng, L.Y.; Tichler, P.R.

    1997-01-01

    The High Flux Beam Reactor (HFBR) is a pressurized heavy water moderated and cooled research reactor that began operation at 40 MW. The reactor was subsequently upgraded to 60 MW and operated at that level for several years. The reactor undergoes a buoyancy-driven reversal of flow in the reactor core following certain postulated accidents. Questions which were raised about the afterheat removal capability during the flow reversal transition led to a reactor shutdown and subsequent resumption of operation at a reduced power of 30 MW. An experimental and analytical program to address these questions is described in this report. The experiments were single channel flow reversal tests under a range of conditions. The analytical phase involved simulations of the tests to benchmark the physical models and development of a criterion for dryout. The criterion is then used in simulations of reactor accidents to determine a safe operating power level. It is concluded that the limit on the HFBR operating power with respect to the issue of flow reversal is in excess of 60 MW. Direct use of the experimental results and an understanding of the governing phenomenology supports this conclusion.

  2. A new high current laboratory and pulsed homopolar generator power supply at the University of Texas

    NASA Astrophysics Data System (ADS)

    Floyd, J. E.; Aanstoos, T. A.

    1984-03-01

    The University of Texas at Austin is constructing a facility for research in pulse power technology for the Center for Electromechanics at the Balcones Research Center. The facility, designed to support high-current experiments, will be powered by six homopolar generators, each rated at 10 MJ and arranged to allow matching the requirements of resistive and inductive loads at various voltage and current combinations. Topics covered include the high bay, the power supply configuration and parameters, the speed and field control, and the magnetic circuit. Also considered are the removable air-cooled brushes, the water-cooled field coils, the hydraulic motor sizing and direct coupling, the low-impedance removable field coils, and the hydrostatic bearing design.

  3. Power Handling Upgrade of Debuncher Stochastic Cooling Kicker Tanks

    SciTech Connect

    McGinnis, D.

    1991-06-01

    The Debuncher Stochastic Cooling Power Upgrade tripled the number of TWTs from 16 to 48. The power desired for each TWT is about 120 W. The debuncher stochastic cooling system contains 6 kicker tanks (4 short tanks, 2 long tanks) with a total number of 64 microwave feedthroughs. Thus, the power per feedthrough increased from 30W to 90 W as a result of the upgrade. The kicker array inside the vacuum tank is connected to the microwave feedthrough on the vacuum flange by means of a rigid 0.25-inch diameter coaxial cable which is 12-inch long. With 90 W flowing through the coax, the amount of power dissipated is 2.5 W. A lab test on a single debuncher kicker tank showed that this power dissipation caused the temperature of the coaxial cable to rise to greater than 175 C. At this point the Teflon dielectric of the coax and the solder joints in the coax might seriously degrade. As a temporary stop-gap solution, transistor heat sinks were placed around the outside of the coaxial cable. (The amount of heat sinks need for all the cables was 3400.) The primary function of the transistor heat sinks around the coaxial cable was to remove thermal energy generated in the coax by radiation. Lab tests showed that the with the heat sinks in place, the temperature of the coax was brought below 110 C. However, with the tanks installed, the maximum total amount of power that could be applied to the tanks and keep the ion pumps safely below their trip level (The trip level on the ion pumps is about 1 x 10{sup -6} Torr. We kept the ion pumps at about 3 x 10{sup -7} Torr.) was about 2250 W or 35 W per feedthrough. The ion pumps with the highest pressure in the kicker sector (D30) were D:IP202 and D:IP305. These pumps are mounted directly on the two long kicker tanks. These two long kicker tanks account for one half of the total microwave feedthroughs. Further bench studies showed that 2.5 W were also dissipated in the microwave vacuum feedthrough. This 2.5 W that was generated caused a large temperature rise in the vacuum feedthrough because of the poor heat sinking of the feedthrough. The poor heat sinking was the result of the stainless steel walled bellowed flange on which the feedthrough is mounted. To alleviate the vacuum problem. the two long kicker tanks were removed during the fall shutdown of 1990. The 32 bellowed flanges were replaced with solid flanges that mounted directly on the tank. The microwave feedthrough was welded into the flange and was heat sunk by means of a copper collar that screwed directly on to the feedthrough. The copper collar was cooled by chilled water. Because there are no bellows on the new flange design, the rigid 0.25-inch diam. coaxial cable was replaced by flexible, braided 0.141-inch diam. cable in order to allow a good vacuum seal. The flexible coaxial cable was heat sunk along most of its length by means of a 8-inch long copper collar. The collar itself was heat sunk to a 1-inch diameter copper bar that extended to outside the vacuum tank and was water cooled. The water cooling of the copper bar for each feedthrough was tied in series by 3/8-inch copper water line. The 3/8-inch copper water line itself was in series with the chilled water of the kicker tank. In this way, no flow was diverted from the chilled water into the kicker tank. The entire coax and flange assembly is shown in Fig. 1. As an added precaution, the elbow launcher on the array was water cooled by tapping off the kicker resistor chilled water cooling lines in side the vacuum tank. The extra lines were placed in series with the existing kicker resistor water lines so as not divert any flow from the kicker resistors. The water cooled lines were attached to the launcher elbow by means of a copper clip. With the above modifications in place, the temperature of each feedthrough coax could be kept under 60 C with an applied power of 90 W. Because of time constraints, the 4 short kicker tanks were not modified. Instead, the ratio of the power feeding the long tanks to the power feeding the short tanks was changed to 2:1. The power that could now be achieved while still keeping the ion pump pressure below 3 x 10{sup -78} Torr was now 3600 W which is 2/3 of the desired maximum power. This 3600 W corresponds to 75 W per feedthrough for the long tanks and 37.5 W per feedthrough for the short tanks. With the power to the short tanks off, a total power of 2700 W could be delivered to the 2 long tanks which corresponds to 84 W per feedthrough. Although it is difficult to separate the outgassing rates for the different tanks, it is believed that the limitation on the vacuum is now constrained by the shorter tanks. Thus, the above cooling scheme will be applied to the 4 short tanks after the fixed target run of 1991.

  4. NASA Ames Research Center 60 MW Power Supply Modernization

    NASA Technical Reports Server (NTRS)

    Choy, Yuen Ching; Ilinets, Boris V.; Miller, Ted; Nagel, Kirsten (Technical Monitor)

    2001-01-01

    The NASA Ames Research Center 60 MW DC Power Supply was built in 1974 to provide controlled DC power for the Thermophysics Facility Arc Jet Laboratory. The Power Supply has gradually losing reliability due to outdated technology and component life limitation. NASA has decided to upgrade the existing rectifier modules with contemporary high-power electronics and control equipment. NASA plans to complete this project in 2001. This project includes a complete replacement of obsolete thyristor stacks in all six rectifier modules and rectifier bridge control system. High power water-cooled thyristors and freewheeling diodes will be used. The rating of each of the six modules will be 4000 A at 5500 V. The control firing angle signal will be sent from the Facility Control System to six modules via fiberoptic cable. The Power Supply control and monitoring system will include a Master PLC in the Facility building and a Slave PLC in each rectifier module. This system will also monitor each thyristor level in each stack and the auxiliary equipment.

  5. Robust focusing optics for high-power laser welding

    NASA Astrophysics Data System (ADS)

    McAllister, Blake

    2014-02-01

    As available power levels from both fiber and disc lasers rapidly increase, so does the need for more robust beam delivery solutions. Traditional transmissive optics for 1 micron lasers have proven to be problematic in the presence of higher power densities and are more susceptible to focal shift. A new, fully-reflective, optical solution has been developed using mirrors rather than lenses and windows to achieve the required stable focal spot, while still protecting the delicate fiber end. This patent-approved beam focusing solution, referred to as high power reflective focusing optic (HPRFO), involves specialty mirrors and a flowing gas orifice that prevents ingress of contaminants into the optically sensitive region of the assembly. These mirrors also provide a unique solution for increasing the distance between the sensitive optics and the contamination-filled region at the work, without sacrificing spot size. Longer focal lengths and lower power densities on large mass, water-cooled, copper mirrors deliver the robustness needed at increasingly high power levels. The HPRFO exhibits excellent beam quality and minimal focal shift at a fraction of commercially available optics, and has demonstrated consistent reliability on applications requiring 15 kW with prolonged beam-on times.

  6. Next Generation Geothermal Power Plants

    SciTech Connect

    Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

    1995-09-01

    A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine cycle. Results of this study indicate that dual flash type plants are preferred at resources with temperatures above 400 F. Closed loop (binary type) plants are preferred at resources with temperatures below 400 F. A rotary separator turbine upstream of a dual flash plant can be beneficial at Salton Sea, the hottest resource, or at high temperature resources where there is a significant variance in wellhead pressures from well to well. Full scale demonstration is required to verify cost and performance. Hot water turbines that recover energy from the spent brine in a dual flash cycle improve that cycle's brine efficiency. Prototype field tests of this technology have established its technical feasibility. If natural gas prices remain low, a combustion turbine/binary hybrid is an economic option for the lowest temperature sites. The use of mixed fluids appear to be an attractive low risk option. The synchronous turbine option as prepared by Barber-Nichols is attractive but requires a pilot test to prove cost and performance. Dual flash binary bottoming cycles appear promising provided that scaling of the brine/working fluid exchangers is controllable. Metastable expansion, reheater, Subatmospheric flash, dual flash backpressure turbine, and hot dry rock concepts do not seem to offer any cost advantage over the baseline technologies. If implemented, the next generation geothermal power plant concept may improve brine utilization but is unlikely to reduce the cost of power generation by much more than 10%. Colder resources will benefit more from the development of a next generation geothermal power plant than will hotter resources. All values presented in this study for plant cost and for busbar cost of power are relative numbers intended to allow an objective and meaningful comparison of technologies. The goal of this study is to assess various technologies on an common basis and, secondarily, to give an approximate idea of the current costs of the technologies at actual resource sites. Absolute costs at a given site will be determined by the specifics of a given project.

  7. Advanced water-cooled phosphoric acid fuel cell development

    SciTech Connect

    Not Available

    1989-01-01

    Fabrication of repeat parts for small area short stack is underway: 100 electrode substrates and 150 ERP substrates were graphitized, and 30 electrode substrates were run through each manufacturing step. Teflon content and compaction pressure of shop-made electrodes for the small area short stack was optimized based on single cell tests. A single cell with GSB-18P catalyst and 1 mg/cm[sup 2] loading is performing very well; performance is 0.66 V per cell after 1200 h at 300 ASF. 3 integral separator plate configurations have been selected for verification in the upcoming short stack. Bubble pressures over 7 psid have been demonstrated in filler bands applied with a production curtain and coating process. 5 full-size (small area) coolers were molded, and encapsulation development for molded and commercial graphite coolers continued.

  8. Advanced Water-Cooled Phosphoric Acid Fuel Cell Development

    SciTech Connect

    Not Available

    1989-01-01

    Electrode substrate handsheets were formed. A new electrode edge seal with in-plane bubble pressures 40--50 psid and through-plane pressures 8--9 psid was demonstrated. A new polymeric edge seal for ERP's with bubble pressure greater than 30 psid was tested and shown to be stable after 5 thermal cycles. A thin (1.2 mil) natrix was applied to full-size electrodes using a curtain coater. Full-size coolers were fabricated using both molded and commercial graphite holders.

  9. Water-cooled insulated steam-injection wells

    NASA Technical Reports Server (NTRS)

    Back, L. H.; Jaffe, L. D.

    1980-01-01

    Water is used as insulated coolant and heat-transfer medium for steam-injection oil wells. Approach is somewhat analogous to cooling system in liquid-propellant rocket. In addition to trapping and delivering heat to steam-injection point, water will also keep casing cooler, preventing or reducing casing failures caused by thermal stresses.

  10. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, C.J.; Warner, D.K.

    1984-02-16

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an rf induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the rf heating coil is disposed around the outer tube above and adjacent to the water inlet.

  11. Low-pressure water-cooled inductively coupled plasma torch

    DOEpatents

    Seliskar, Carl J.; Warner, David K.

    1988-12-27

    An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an r.f. induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the r.f. heating coil is disposed around the outer tube above and adjacent to the water inlet.

  12. Rotation and penetrative convection in water cooled from below}

    NASA Astrophysics Data System (ADS)

    Alboussiere, T.; Labrosse, S.; Dubuffet, F.; Thibon, F.; Huguet, L.; Deguen, R.

    2012-12-01

    It has already been suggested that the outer core of the Earth might not be entirely in a convective regime [1], for instance in a region close to the CMB where the heat conducted along the adiabat could be larger than the net heat transfer and where compositional buoyancy vanishes. Radial dependence of thermal conductivity could also produce neighbouring stable and unstable regions. To what extent does convection spread into the stable region is then an important issue. Liquid water and its maximum density at 4°C provides a convenient way to observe penetrative convection. We have performed experiments where a volume of water (of square cross-section 16 cm by 16 cm and height 20 cm) initially at room temperature (around 22°C) is then suddenly cooled around 0°C at the bottom while the sides and top walls are (imperfectly) thermally insulated. Near the bottom, where temperature is below 4°C, unstable buoyancy conditions prevail and we observe convective cells. Above 4°C, quiescent stable stratification is observed. Temperature is close to 4°C within the bulk of the convective zone, so that the flux of heat extracted from the bottom is used to change the temperature from 22°C to 4°C within the successive layers of water, while the height of the convective zone increases and eventually reaches the top of the volume. Temperatures have been measured on a array of 15 PT100 probes protruding 5 mm into water along a vertical side wall. the extreme probes are 1 cm away from the lower and upper boundaries respectively. The evolution of all 15 temperatures can be seen on left-hand side of Fig. 1. Another type of information was obtained from a synthetic schlieren technique, whereby pictures of a random pattern placed behind the transparent water-filled box (perspex walls) are taken every 5 s with a digital camera. The cross-correlation of the different images provides a dynamical visualization of the gradients of refraction index within the volume of water. A snapshot is displayed on the right-hand side of Fig. 1. In a second step, we will analyze the influence of rotation on the configuration described above. The experiments will be performed in October and the results will be available for discussion during the AGU fall meeting. When transposed to the conditions of the Earth's outer core, we expect to be able to assess how stable and unstable regions can exist next to each other. [1] Braginsky, S.I., Phys. Earth Planet. Int., vol. 111, 21--34, 1999; Temperatures on the left, time derivative of index horizontal gradient on the right

  13. Design of a thrust stand for high power electric propulsion devices

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.

    1989-01-01

    A thrust stand for use with high power electric propulsion devices was designed and tested. The thrust stand was specifically tailored to the needs of a 100 to 250 kW magnetoplasmadynamic (MPD) thruster program currently in progress at the NASA Lewis Research Center. The thrust stand structure was built as an inverted pendulum arrangement, supported at the base by water-cooled electrical power flexures. Thrust stand tares due to thruster discharge current were demonstrated to be negligible. Tares due to an applied field magnet current, after considerable effort, were reduced to less than 3.0 percent of measured thrust. These tares, however, could be determined independently and subtracted from the indicated thrust measurement. A detailed description is given for the thrust stand design and operation with a 100 kW class MPD device. Other thrust stand tares due to vibration and thermal effects are discussed, along with issues of accuracy and repeatability.

  14. Physical model and experimental results of cathode erosion related to power supply ripple

    NASA Technical Reports Server (NTRS)

    Harris, W. J.; O'Hair, E. A.; Hatfield, L. L.; Kristiansen, M.

    1992-01-01

    This paper discusses the physical effects of power supply ripple on cathode erosion and cathode arc attachment in a water-cooled, 30 kW nitrogen arcjet. Experimental results are presented for 2 percent thoriated tungsten, which show that the long-term cathode erosion rate is a decreasing function of current ripple over the range 1-13 percent. Above this range, the cathode discharge becomes unstable, and the erosion rate rapidly increases. A qualitative model of this effect is given in terms of a magnetically induced radial motion of the arc column, and an overall increase in the cathode spot radius due to the higher peak current associated with higher ripple. The most important effect of power supply ripple is therefore shown to be its ability to collectively drive the cathode attachment away from the cathode center. This leads to an increase in the cathode attachment area, and a subsequent decrease in the cathode erosion rate.

  15. Anode arc motion in high power arcjets

    NASA Technical Reports Server (NTRS)

    Harris, W. J.; O'Hair, E. A.; Hatfield, L. L.; Kristiansen, M.; Mankins, J. S.

    1992-01-01

    The long-term operational lifetime of most medium to high power arcjets is currently limited by the rapid deterioration of the arcjet electrodes. To a large extent, the rate of this deterioration is related to the motion of the arc discharge on the electrode surfaces. This paper details a series of experiments aimed at studying the temporal behavior of dc arcs on a water-cooled radially-segmented 30 kW class arcjet anode. The experimental anode used for these tests was made of copper, and was divided into four equivalent radial segments which were electrically isolated with aluminum oxide gaskets. The current carried by each segment was measured independently using four calibrated resistive shunts, and was analyzed by digital computer. The tests were limited to nitrogen propellant over a current range of 100-250 A dc. Results show that for the range of total currents considered here, the current distribution in the segmented arcjet anode is generally asymmetric, exhibiting random fluctuations over a wide range of frequencies.

  16. Klystron Cluster Scheme for ILC High Power RF Distribution

    SciTech Connect

    Nantista, Christopher; Adolphsen, Chris; /SLAC

    2009-07-06

    We present a concept for powering the main linacs of the International Linear Collider (ILC) by delivering high power RF from the surface via overmoded, low-loss waveguides at widely spaced intervals. The baseline design employs a two-tunnel layout, with klystrons and modulators evenly distributed along a service tunnel running parallel to the accelerator tunnel. This new idea eliminates the need for the service tunnel. It also brings most of the warm heat load to the surface, dramatically reducing the tunnel water cooling and HVAC requirements. In the envisioned configuration, groups of 70 klystrons and modulators are clustered in surface buildings every 2.5 km. Their outputs are combined into two half-meter diameter circular TE{sub 01} mode evacuated waveguides. These are directed via special bends through a deep shaft and along the tunnel, one upstream and one downstream. Each feeds approximately 1.25 km of linac with power tapped off in 10 MW portions at 38 m intervals. The power is extracted through a novel coaxial tap-off (CTO), after which the local distribution is as it would be from a klystron. The tap-off design is also employed in reverse for the initial combining.

  17. On monitoring nuclear power plant emergency diesel generator reliability

    SciTech Connect

    Martz, H.F.; Tietjen, G.L.; Kvam, P.H.; Abramson, L.R.

    1993-08-11

    If offsite power is interrupted, the availability of onsite alternating current power supplies is a major factor in assuring acceptable safety at commercial light-water-cooled nuclear power plants. To control the risk of severe care damage during station blackout accidents at a given plant, the reliability of the emergency diesel generators (EDGS) to start and load-run upon demand must be maintained at a sufficiently high level. The minimum EDG reliability, which we denote by RT, is targeted at either 0.95 or 0.975 per nuclear unit consistent with the reliability level that the plant operator assumed in the coping analysis for station blackout. In 1992 the US Nuclear Regulatory Commission (NRC) considered an amendment that would require licensees to test and monitor EDG reliability against performance-based criteria that indicate possible degradation from the EDG target reliability levels. They originally proposed the following set of fixed sample-size triggers for use in monitoring EDG reliability. The purpose of this report is to compare the performance of the proposed triggers with corresponding alternative sequential variable sample-size triggers which potentially permit earlier detection of EDG reliability degradation without significantly increasing the false alarm rate. The comparison is to be done in a simulated use environment by means of Monte Carlo simulation. We are also interested in the inverse conditional probabilities of reliability degradation given that a trigger has occurred.

  18. High-power, low-pressure, inductively coupled RF plasma source using a FET-based inverter power supply

    NASA Astrophysics Data System (ADS)

    Komizunai, Shota; Oikawa, Kohei; Saito, Yuta; Takahashi, Kazunori; Ando, Akira

    2015-01-01

    A high-density plasma of density greater than 1019 m-3 is successfully produced in 1.5 Pa argon by an inductively coupled RF discharge with a 70-mm-diameter source cavity, where a 10-turn water-cooled RF loop antenna is wound onto the source tube and an axial magnetic field of 70 G is applied by two solenoids to reduce plasma loss onto the source cavity. The RF antenna is powered from a frequency-tunable field-effect-transistor-based inverter power supply, which does not require variable capacitors to match the impedance, at a frequency of 350 kHz and the RF power can be increased up to 8 kW. It is also demonstrated that the source is operational with an axial magnetic field provided by permanent magnet (PM) arrays; then the density in the case of the PM arrays is higher than that in the case of the solenoids. The role of the magnetic filter downstream of the source tube is demonstrated; a radially uniform plasma density exceeding 1018 m-3 and an electron temperature of 1-2 eV are obtained at 100 mm downstream of the open exit of the source tube.

  19. An experimental study of energy loss mechanisms and efficiency considerations in the low power dc arcjet

    NASA Technical Reports Server (NTRS)

    Curran, F. M.

    1985-01-01

    The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30 percent of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage.

  20. An experimental study of energy loss mechanisms and efficiency consideration in the low power dc arcjet

    NASA Technical Reports Server (NTRS)

    Curran, F. M.

    1985-01-01

    The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30% of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage.

  1. Terbium gallium garnet ceramic-based Faraday isolator with compensation of thermally induced depolarization for high-energy pulsed lasers with kilowatt average power

    NASA Astrophysics Data System (ADS)

    Yasuhara, Ryo; Snetkov, Ilya; Starobor, Alexey; Palashov, Oleg

    2014-12-01

    A scalable aperture Faraday isolator for high-energy pulsed lasers with kW-level average power was demonstrated using terbium gallium garnet ceramics with water cooling and compensation of thermally induced depolarization in a magnetic field. An isolation ratio of 35 dB (depolarization ratio γ of 3.4 × 10-4) was experimentally observed at a maximum laser power of 740 W. By using this result, we estimated that this isolator maintains an isolation ratio of 30 dB for laser powers of up to 2.7 kW. Our results provide the solution for achieving optical isolation in high-energy (100 J to kJ) laser systems with a repetition rate greater than 10 Hz.

  2. Terbium gallium garnet ceramic-based Faraday isolator with compensation of thermally induced depolarization for high-energy pulsed lasers with kilowatt average power

    SciTech Connect

    Yasuhara, Ryo; Snetkov, Ilya; Starobor, Alexey; Palashov, Oleg

    2014-12-15

    A scalable aperture Faraday isolator for high-energy pulsed lasers with kW-level average power was demonstrated using terbium gallium garnet ceramics with water cooling and compensation of thermally induced depolarization in a magnetic field. An isolation ratio of 35 dB (depolarization ratio γ of 3.4 × 10{sup −4}) was experimentally observed at a maximum laser power of 740 W. By using this result, we estimated that this isolator maintains an isolation ratio of 30 dB for laser powers of up to 2.7 kW. Our results provide the solution for achieving optical isolation in high-energy (100 J to kJ) laser systems with a repetition rate greater than 10 Hz.

  3. EOIL power scaling in a 1-5 kW supersonic discharge-flow reactor

    NASA Astrophysics Data System (ADS)

    Davis, Steven J.; Lee, Seonkyung; Oakes, David B.; Haney, Julie; Magill, John C.; Paulsen, Dwane A.; Cataldi, Paul; Galbally-Kinney, Kristin L.; Vu, Danthu; Polex, Jan; Kessler, William J.; Rawlins, Wilson T.

    2008-02-01

    Scaling of EOIL systems to higher powers requires extension of electric discharge powers into the kW range and beyond with high efficiency and singlet oxygen yield. We have previously demonstrated a high-power microwave discharge approach capable of generating singlet oxygen yields of ~25% at ~50 torr pressure and 1 kW power. This paper describes the implementation of this method in a supersonic flow reactor designed for systematic investigations of the scaling of gain and lasing with power and flow conditions. The 2450 MHz microwave discharge, 1 to 5 kW, is confined near the flow axis by a swirl flow. The discharge effluent, containing active species including O II(a1Δ g, b1Σ g +), O( 3P), and O 3, passes through a 2-D flow duct equipped with a supersonic nozzle and cavity. I2 is injected upstream of the supersonic nozzle. The apparatus is water-cooled, and is modular to permit a variety of inlet, nozzle, and optical configurations. A comprehensive suite of optical emission and absorption diagnostics is used to monitor the absolute concentrations of O II(a), O II(b), O( 3P), O 3, I II, I(2P 3/2), I(2P 1/2), small-signal gain, and temperature in both the subsonic and supersonic flow streams. We discuss initial measurements of singlet oxygen and I* excitation kinetics at 1 kW power.

  4. Development of a high temperature solar powered water chiller

    NASA Astrophysics Data System (ADS)

    English, R. A.

    1982-03-01

    The objectives of this program are: to develop a high temperature solar powered air cooled 25 ton chiller utilizing 250 to 300 F solar hot water suitable for commercial and multi-family applications; to study, design, and build a prototype Rankine powered vapor compression cycle; and to demonstrate and evaluate performance through steady state and dynamic laboratory testing. Cycle studies and preliminary turbo machine studies were completed under Phase I establishing the final conceptual approach and anticipated cost/performance. The evaluation of the working fluid thermal stability has satisfactorily shown that R-113 has excellent life potential in an oil-free steel boiler at the maximum expected temperature, 320 F, for this application. The detailed design of the turbo machine and the chiller has been completed. The turbomachine has been completed and has successfully passed its qualification tests on air. The chiller has been built in the water cooled configuration, has been installed in a test facility, instrumented and charged. A two stage boiler feed pump has been developed and successfully tested on R-113 in a separate loop.

  5. Medium power arcjet thruster experiments

    NASA Technical Reports Server (NTRS)

    Glocker, Bernd; Auweter-Kurtz, Monika; Goelz, Thomas M.; Kurtz, Helmut L.; Schrade, Herbert O.

    1990-01-01

    Experimental results on the electrothermal behavior and operating performance of water-cooled laboratory model arcjet thrusters using a variety of propellants in the range of 5-50 kW are reported. The highest voltage and specific impulse are attained with hydrogen propellant and the lowest with argon propellant; intermediate results are obtained with nitrogen and a mixture of hydrogen and nitrogen. The highest cathode erosion rate is measured with argon while the lowest is associated with hydrogen.

  6. Power Play.

    ERIC Educational Resources Information Center

    Aho, Timothy A.

    1998-01-01

    Describes how to integrate technology into old buildings beginning with an evaluation of the electric power systems. A case study is highlighted showing the process in determining existing conditions, assessing electric power needs, and designing upgrades. (GR)

  7. Power processing

    NASA Technical Reports Server (NTRS)

    Schwarz, F. C.

    1971-01-01

    Processing of electric power has been presented as a discipline that draws on almost every field of electrical engineering, including system and control theory, communications theory, electronic network design, and power component technology. The cost of power processing equipment, which often equals that of expensive, sophisticated, and unconventional sources of electrical energy, such as solar batteries, is a significant consideration in the choice of electric power systems.

  8. Power supply

    DOEpatents

    Yakymyshyn, Christopher Paul; Hamilton, Pamela Jane; Brubaker, Michael Allen

    2007-12-04

    A modular, low weight impedance dropping power supply with battery backup is disclosed that can be connected to a high voltage AC source and provide electrical power at a lower voltage. The design can be scaled over a wide range of input voltages and over a wide range of output voltages and delivered power.

  9. Space Power

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Appropriate directions for the applied research and technology programs that will develop space power systems for U.S. future space missions beyond 1995 are explored. Spacecraft power supplies; space stations, space power reactors, solar arrays, thermoelectric generators, energy storage, and communication satellites are among the topics discussed.

  10. High-power room-temperature operating cw CO laser excited by microwave discharge

    NASA Astrophysics Data System (ADS)

    Luo, X.; Schaefer, Johannes H.; Uhlenbusch, Juergen

    1995-03-01

    In this contribution we present a high power cw CO laser operating at room temperature. A scheme of forced convective cooling by fast axial gas flow combined with microwave discharge excitation has been developed. A T-shaped laser tube made of Pyrex glass with 5.1 cm i.d. is located in a microwave resonator of 12.5 cm (W) X 5.6 cm (H) X 30 cm (L) in dimension. The microwave at 2.45 GHz of up to 6 kW power generated by a magnetron is coupled into the resonator using the R26 waveguide technique. The laser gas flows through the T-shaped laser tube and is circulated by a rootspump in a closed loop. Two water cooled heat exchangers cool away the waste heat and the compression heat. The optical cavity consists of a total reflecting gold coated copper mirror and an output coupling flat from CaF2 with 10% transmission. A maximum output power of 440 watts (or 1.4 kW/m) has been obtained from this laser system with a maximum efficiency of 8%. The laser characteristics have been studied. It is found that both Xe and O2 are important for the high power CO laser operation at room temperature. The laser is characterized by the modular construction of the discharging section, so that it can be easily extended to a multimodular system to increase the laser output power.

  11. Mode controlling study on narrow-linewidth and high power all-fiber amplifier

    NASA Astrophysics Data System (ADS)

    Lei, Min; Qi, Yunfeng; Liu, Chi; Yang, Yifeng; Zheng, Ye; Zhou, Jun

    2015-05-01

    In this paper, we demonstrate an ytterbium-doped all-fiber master-oscillator power amplifier (MOPA) system which uses a narrow-linewidth seed source, generating narrow-linewidth and high power continuous-wave output power at 1064nm. Our MOPA configuration system consist of three amplifier stages. We use single-mode Yb-doped fiber as the gain fiber in the first and second pre-amplifier stages, so it can keep good beam quality before entering the main amplifier stage. In order to raise the threshold of nonlinear effects, such as SBS and SRS, and to relieve heat effect, our high power system choose large mode area (LMA) fiber as the gain fiber in the main amplifier stage. For the sake of suppressing high-order modes in LMA fiber, we design novel watering cooling plates of different sizes, and using them in our main amplifier stage. By optimizing its structure, we get very good laser beam pattern on CCD at high power output. The beam quality factor (M2) was about 1.4 at 1.31 kW.

  12. Laser Excitation Power and the Flow Cytometric Resolution of Complex Karyotypes

    PubMed Central

    Ng, Bee L.; Carter, Nigel P.

    2014-01-01

    The analytical resolution of individual chromosome peaks in the flow karyotype of cell lines is dependent on sample preparation and the detection sensitivity of the flow cytometer. We have investigated the effect of laser power on the resolution of chromosome peaks in cell lines with complex karyotypes. Chromosomes were prepared from a human gastric cancer cell line and a cell line from a patient with an abnormal phenotype using a modified polyamine isolation buffer. The stained chromosome suspensions were analyzed on a MoFlo sorter (Beckman Coulter) equipped with two water-cooled lasers (Coherent). A bivariate flow karyotype was obtained from each of the cell lines at various laser power settings and compared to a karyotype generated using laser power settings of 300 mW. The best separation of chromosome peaks was obtained with laser powers of 300 mW. This study demonstrates the requirement for high-laser powers for the accurate detection and purification of chromosomes, particularly from complex karyotypes, using a conventional flow cytometer. PMID:20506467

  13. Fission Surface Power Systems (FSPS) Project Final Report for the Exploration Technology Development Program (ETDP): Fission Surface Power, Transition Face to Face

    NASA Technical Reports Server (NTRS)

    Palac, Donald T.

    2011-01-01

    The Fission Surface Power Systems Project became part of the ETDP on October 1, 2008. Its goal was to demonstrate fission power system technology readiness in an operationally relevant environment, while providing data on fission system characteristics pertinent to the use of a fission power system on planetary surfaces. During fiscal years 08 to 10, the FSPS project activities were dominated by hardware demonstrations of component technologies, to verify their readiness for inclusion in the fission surface power system. These Pathfinders demonstrated multi-kWe Stirling power conversion operating with heat delivered via liquid metal NaK, composite Ti/H2O heat pipe radiator panel operations at 400 K input water temperature, no-moving-part electromagnetic liquid metal pump operation with NaK at flight-like temperatures, and subscale performance of an electric resistance reactor simulator capable of reproducing characteristics of a nuclear reactor for the purpose of system-level testing, and a longer list of component technologies included in the attached report. Based on the successful conclusion of Pathfinder testing, work began in 2010 on design and development of the Technology Demonstration Unit (TDU), a full-scale 1/4 power system-level non-nuclear assembly of a reactor simulator, power conversion, heat rejection, instrumentation and controls, and power management and distribution. The TDU will be developed and fabricated during fiscal years 11 and 12, culminating in initial testing with water cooling replacing the heat rejection system in 2012, and complete testing of the full TDU by the end of 2014. Due to its importance for Mars exploration, potential applicability to missions preceding Mars missions, and readiness for an early system-level demonstration, the Enabling Technology Development and Demonstration program is currently planning to continue the project as the Fission Power Systems project, including emphasis on the TDU completion and testing.

  14. High Power Flex-Propellant Arcjet Performance

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.

    2011-01-01

    A MW-class electrothermal arcjet based on a water-cooled, wall-stabilized, constricted arc discharge configuration was subjected to extensive performance testing using hydrogen and simulated ammonia propellants with the deliberate aim of advancing technology readiness level for potential space propulsion applications. The breadboard design incorporates alternating conductor/insulator wafers to form a discharge barrel enclosure with a 2.5-cm internal bore diameter and an overall length of approximately 1 meter. Swirling propellant flow is introduced into the barrel, and a DC arc discharge mode is established between a backplate tungsten cathode button and a downstream ringanode/ spin-coil assembly. The arc-heated propellant then enters a short mixing plenum and is accelerated through a converging-diverging graphite nozzle. This innovative design configuration differs substantially from conventional arcjet thrusters, in which the throat functions as constrictor and the expansion nozzle serves as the anode, and permits the attainment of an equilibrium sonic throat (EST) condition. During the test program, applied electrical input power was varied between 0.5-1 MW with hydrogen and simulated ammonia flow rates in the range of 4-12 g/s and 15-35 g/s, respectively. The ranges of investigated specific input energy therefore fell between 50-250 MJ/kg for hydrogen and 10-60 MJ/kg for ammonia. In both cases, observed arc efficiencies were between 40-60 percent as determined via a simple heat balance method based on electrical input power and coolant water calorimeter measurements. These experimental results were found to be in excellent agreement with theoretical chemical equilibrium predictions, thereby validating the EST assumption and enabling the utilization of standard TDK nozzle expansion analyses to reliably infer baseline thruster performance characteristics. Inferred specific impulse performance accounting for recombination kinetics during the expansion process implied nearly frozen flow in the nozzle and yielded performance ranges of 800-1100 sec for hydrogen and 400-600 sec for ammonia. Inferred thrust-to-power ratios were in the range of 30-10 lbf/MWe for hydrogen and 60-20 lbf/MWe for ammonia. Successful completion of this test series represents a fundamental milestone in the progression of high power arcjet technology, and it is hoped that the results may serve as a reliable touchstone for the future development of MW-class regeneratively-cooled flex-propellant plasma rockets.

  15. Continuous improvement of high-efficiency high-power 800-980nm diode lasers at Spectra-Physics

    NASA Astrophysics Data System (ADS)

    Li, Hanxuan; Towe, Terry; Chyr, Irving; Jin, Xu; Miller, Robert; Romero, Oscar; Liu, Daming; Brown, Denny; Truchan, Tom; Nguyen, Touyen; Crum, Trevor; Wolak, Ed; Bullock, Robert; Mott, Jeff; Harrison, James

    2009-02-01

    New-generation multi-mode 9xx mini-bars used in fiber pump modules have been developed. The epitaxial designs have been improved for lower fast-axis and slow-axis divergence, higher slope efficiency and PCE by optimizing layer structures as well as minimizing internal loss. For 915nm mini-bars with 5-mm cavity length, maximum PCE is as high as ~61% for 35W operation and remains above 59% at 45W. For 808nm, a PCE of 56% at 135W CW operation has been demonstrated with 36%-fill-factor, 3-mm-cavity-length, water-cooled bars at 50°C coolant temperature. On passive-cooled standard CS heatsinks, PCE of >51% is measured for 100W operation at 50°C heatsink temperature. Leveraging these improvements has enabled low-cost bars for high-power, high-temperature applications.

  16. From the first nuclear power plant to fourth-generation nuclear power installations [on the 60th anniversary of the World's First nuclear power plant

    NASA Astrophysics Data System (ADS)

    Rachkov, V. I.; Kalyakin, S. G.; Kukharchuk, O. F.; Orlov, Yu. I.; Sorokin, A. P.

    2014-05-01

    Successful commissioning in the 1954 of the World's First nuclear power plant constructed at the Institute for Physics and Power Engineering (IPPE) in Obninsk signaled a turn from military programs to peaceful utilization of atomic energy. Up to the decommissioning of this plant, the AM reactor served as one of the main reactor bases on which neutron-physical investigations and investigations in solid state physics were carried out, fuel rods and electricity generating channels were tested, and isotope products were bred. The plant served as a center for training Soviet and foreign specialists on nuclear power plants, the personnel of the Lenin nuclear-powered icebreaker, and others. The IPPE development history is linked with the names of I.V. Kurchatov, A.I. Leipunskii, D.I. Blokhintsev, A.P. Aleksandrov, and E.P. Slavskii. More than 120 projects of various nuclear power installations were developed under the scientific leadership of the IPPE for submarine, terrestrial, and space applications, including two water-cooled power units at the Beloyarsk NPP in Ural, the Bilibino nuclear cogeneration station in Chukotka, crawler-mounted transportable TES-3 power station, the BN-350 reactor in Kazakhstan, and the BN-600 power unit at the Beloyarsk NPP. Owing to efforts taken on implementing the program for developing fast-neutron reactors, Russia occupied leading positions around the world in this field. All this time, IPPE specialists worked on elaborating the principles of energy supertechnologies of the 21st century. New large experimental installations have been put in operation, including the nuclear-laser setup B, the EGP-15 accelerator, the large physical setup BFS, the high-pressure setup SVD-2; scientific, engineering, and technological schools have been established in the field of high- and intermediate-energy nuclear physics, electrostatic accelerators of multicharge ions, plasma processes in thermionic converters and nuclear-pumped lasers, physics of compact nuclear reactors and radiation protection, thermal physics, physical chemistry and technology of liquid metal coolants, and physics of radiation-induced defects, and radiation materials science. The activity of the institute is aimed at solving matters concerned with technological development of large-scale nuclear power engineering on the basis of a closed nuclear fuel cycle with the use of fast-neutron reactors (referred to henceforth as fast reactors), development of innovative nuclear and conventional technologies, and extension of their application fields.

  17. REVIEW: High-power CO lasers in Russia

    NASA Astrophysics Data System (ADS)

    Ionin, Andrei A.

    1993-02-01

    The research-and-development effort on CO lasers and applications of these lasers in Russia are reviewed. Various types of cw, pulsed, and periodic-pulse CO lasers have been developed in various laboratories. Sealed-off, water-cooled cw CO lasers with an output power of 5-10 W, pumped by a self-sustained electric discharge, are being used successfully in the manufacture of electronic devices and in medicine. The output power of fast-flow cryogenic cw CO lasers with a self-sustained discharge ranges up to ~1 kW. The use of electron-beam pumping has made it possible to develop pulsed electron-beam-sustained (EBS) CO lasers with an energy up to ~1 kJ and also to develop cw and periodic-pulse EBS CO lasers with a power of 10 kW and an efficiency up to ~40%. Research on pulsed electron-beam-sustained CO lasers has been the scientific foundation for the construction of CO laser systems of the (master oscillator)-amplifier type and periodic-pulse CO lasers. A CO laser system with an output energy ~200 J and an output beam divergence of 2·10-4 rad has been developed. Requirements on the effective gain in the active medium and on the transport through atmospheric air of multifrequency output pulses from CO laser with various spectral and temporal characteristics have been formulated. A supersonic EBS CO laser with a peak power ~105 W and a 10-kW periodic-pulse EBS CO laser with subsonic flow have been developed. The latter laser generates pulses with an energy ~100 J and a repetition frequency up to 100 Hz. The EBS CO lasers with injection of the laser mixture in the liquid phase are discussed. Lasers using nuclear ionization of the active medium are also discussed.

  18. Numerical investigation of mass transfer in the flow path of the experimental model of the PGV-1500 steam generator's steam receiving section with two steam nozzles

    NASA Astrophysics Data System (ADS)

    Golibrodo, L. A.; Krutikov, A. A.; Nadinskii, Yu. N.; Nikolaeva, A. V.; Skibin, A. P.; Sotskov, V. V.

    2014-10-01

    The hydrodynamics of working medium in the steam volume model implemented in the experimental setup constructed at the Leipunskii Institute for Physics and Power Engineering was simulated for verifying the procedure of calculating the velocity field in the steam space of steam generators used as part of the reactor plants constructed on the basis of water-cooled water-moderated power-generating reactors (VVER). The numerical calculation was implemented in the environment of the STAR-CCM+ software system with its cross verification in the STAR-CD and ANSYS CFX software systems. The performed numerical investigation served as a basis for substantiating the selection of the computation code and parameters for constructing the computer model of the steam receiving device of the PGV-1500 steam generator experimental model, such as the quantization scheme, turbulence model, and mesh model.

  19. Solid state power amplifier as 805 MHz master source for the LANSCE coupled-cavity linac

    SciTech Connect

    Lyles, J.; Davis, J.

    1998-12-31

    From 100 to 800 MeV, the Los Alamos Neutron Science Center (LANSCE) proton linac receives RF power from forty-four 1.25 MW klystrons at 805 Megahertz (MHz). A single master RF source provides a continuous high level phase reference signal which drives the klystrons along the 731 meter-long linac through a coaxial transmission line. A single point failure of this system can deenergize the entire coupled-cavity linac (CCL) RF plant. The authors replaced a physically large air-cooled tetrode amplifier with a compact water-cooled unit based on modular amplifier pallets developed at LANSCE. Each 600 Watt pallet utilizes eight push-pull bipolar power transistor pairs operated in class AB. Four of these can easily provide the 2000 watt reference carrier from the stable master RF source. A radial splitter and combiner parallels the modules. This amplifier has proven to be completely reliable after two years of operation without failure. A second unit was constructed and installed for redundancy, and the old tetrode system was removed in 1998. The compact packaging for cooling, DC power, impedance matching, RF interconnection, and power combining met the electrical and mechanical requirements. CRT display of individual collector currents and RF levels is made possible with built-in samplers and a VXI data acquisition unit.

  20. Design and operating experience of a 40 MW, highly-stabilized power supply

    NASA Astrophysics Data System (ADS)

    Boenig, Heinrich J.; Ferner, James A.; Bogdan, Ferenc; Morris, Gary C.; Rumrill, Ron S.

    Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of less than 10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload capability of 20 kA. The isolated output terminals of each power supply module are connected to a reversing switch. An extensive high-current bus system allows the modules to be connected to 16 magnet cells. This paper presents the detailed design of the power supply components. Various test results taken during the commissioning phase with a 10 MW resistive load and results taken with the research magnets are shown. The effects of the modules on the electrical supply system and the operational behavior of the power factor correction/harmonic filters are described. Included also are results of a power supply module feeding a superconducting magnet during quench propagation tests. Problems with the power supply design and solutions are presented. Some suggestions on how to improve the performance of these supplies are outlined.

  1. Design and operating experience of a 40 MW, highly-stabilized power supply

    SciTech Connect

    Boenig, H.J.; Ferner, J.A.; Bogdan, F.; Morris, G.C.; Rumrill, R.S.

    1995-07-01

    Four 10 MW, highly-stabilized power supply modules have been installed at the National High Magnetic Field Laboratory in Tallahassee, FL, to energize water-cooled, resistive, high-field research magnets. The power supply modules achieve a long term current stability if 10 ppM over a 12 h period with a short term ripple and noise variation of <10 ppM over a time period of one cycle. The power supply modules can operate independently, feeding four separate magnets, or two, three or four modules can operate in parallel. Each power supply module consists of a 12.5 kV vacuum circuit breaker, two three-winding, step-down transformers, a 24-pulse rectifier with interphase reactors, and a passive and an active filter. Two different transformer tap settings allow rated dc supply output voltages of 400 and 500 V. The rated current of a supply module is 17 kA and each supply module has a one-hour overload capability of 20 kA. The isolated output terminals of each power supply module are connected to a reversing switch. An extensive high-current bus system allows the modules to be connected to 16 magnet cells. This paper presents the detailed design of the power supply components. Various test results taken during the commissioning phase with a 10 MW resistive load and results taken with the research magnets are shown. The effects of the modules on the electrical supply system and the operational behavior of the power factor correction/harmonic filters are described. Included also are results of a power supply module feeding a superconducting magnet during quench propagation tests. Problems with the power supply design and solutions are presented. Some suggestions on how to improve the performance of these supplies are outlined.

  2. Solid State Power Amplifier for 805 MegaHertz at the Los Alamos Neutron Science Center

    SciTech Connect

    Davis, J.L.; Lyles, J.T.M.

    1998-10-19

    Particle accelerators for protons, electrons, and other ion species often use high-power vacuum tubes for RF amplification, due to the high RF power requirements to accelerate these particles with high beam currents. The final power amplifier stages driving large accelerators are unable to be converted to solid-state devices with the present technology. In some instances, radiation levels preclude the use of transistors near beamlines. Work is being done worldwide to replace the RF power stages under about ten kilowatts CW with transistor amplifiers, due to the lower maintenance costs and obsolescence of power tubes in these ranges. This is especially practical where the stages drive fifty Ohm impedance and are not located in high radiation zones. The authors are doing this at the Los Alamos Neutron Science Center (LANSCE) proton linear accelerator (linac) in New Mexico. They replaced a physically-large air-cooled UHF power amplifier using a tetrode electron tube with a compact water-cooled unit based on modular amplifier pallets developed at LANSCE. Each module uses eight push-pull bipolar power transistor pairs operated in class AB. Four pallets can easily provide up to 2,800 watts of continuous RF at 805 MHz. A radial splitter and combiner parallels the modules. This amplifier has proven to be completely reliable after over 10,000 hours of operation without failure. A second unit was constructed and installed for redundancy, and the old tetrode system was removed in 1998. The compact packaging for cooling, DC power, impedance matching, RF interconnection, and power combining met the electrical and mechanical requirements. CRT display of individual collector currents and RF levels is made possible with built-in samplers and a VXI data acquisition unit.

  3. Diastatic power

    Technology Transfer Automated Retrieval System (TEKTRAN)

    diastatic power: Diastatic power, abbreviated DP, is the total activity of malt starch degrading enzymes that hydrolyze starch to fermentable sugars. The starch degrading enzymes contributing to this process are a-amylase, ß-amylase, limit dextrinase, and a-glucosidase. The driving force for DP a...

  4. Power Source

    ERIC Educational Resources Information Center

    Schooley, Michael L.

    2010-01-01

    Principals are powerful: They are the primary catalysts for creating a lasting foundation for learning, driving school and student performance, and shaping the long-term impact of school improvement efforts. Yet few principals would characterize themselves as powerful. Rather, they're self-effacing, adaptable, pragmatic, and quick to share credit…

  5. Power system

    DOEpatents

    Hickam, Christopher Dale

    2008-03-18

    A power system includes a prime mover, a transmission, and a fluid coupler having a selectively engageable lockup clutch. The fluid coupler may be drivingly connected between the prime mover and the transmission. Additionally, the power system may include a motor/generator drivingly connected to at least one of the prime mover and the transmission. The power-system may also include power-system controls configured to execute a control method. The control method may include selecting one of a plurality of modes of operation of the power system. Additionally, the control method may include controlling the operating state of the lockup clutch dependent upon the mode of operation selected. The control method may also include controlling the operating state of the motor/generator dependent upon the mode of operation selected.

  6. Power performance

    SciTech Connect

    Anderson, J.

    1996-04-01

    Two power generation engineering and construction firms with international markets are briefly described in this article. Bibb and Associates and Black & Veatch, both Kansas-based companies, are discussed. Current projects and services provided by the companies are described.

  7. Fusion Power.

    ERIC Educational Resources Information Center

    Dingee, David A.

    1979-01-01

    Discusses the extraordinary potential, the technical difficulties, and the financial problems that are associated with research and development of fusion power plants as a major source of energy. (GA)

  8. 76 FR 82323 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... Postaccident Engineered-Safety-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants... of engineered-safety-feature (ESF) atmosphere cleanup systems in light-water-cooled nuclear power... Postaccident Engineered-Safety-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power...

  9. 75 FR 20868 - Notice of Issuance of Regulatory Guide

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... Demonstrate Remote Shutdown ] Capability for Water-Cooled Nuclear Power Plants.'' FOR FURTHER INFORMATION... Test Program to Demonstrate Remote Shutdown Capability for Water-Cooled Nuclear Power Plants,'' was... guide is applicable to water-cooled nuclear power plants. II. Further Information In August 2009,...

  10. Power combiner

    DOEpatents

    Arnold, Mobius; Ives, Robert Lawrence

    2006-09-05

    A power combiner for the combining of symmetric and asymmetric traveling wave energy comprises a feed waveguide having an input port and a launching port, a reflector for reflecting launched wave energy, and a final waveguide for the collection and transport of launched wave energy. The power combiner has a launching port for symmetrical waves which comprises a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which comprises a sawtooth rotated about a central axis.

  11. Power Supply

    NASA Astrophysics Data System (ADS)

    1991-01-01

    Maxwell Laboratories capacitor charging power supply is the first commercial spinoff from the NASA CCDS program - a consortia of industries and government establishments to accelerate development of ground and space based commercial applications of NASA technology. The power supply transforms and conditions large voltages to charge capacitors used in x-ray sources, medical accelerators, etc. It is lighter, more reliable, more compact and efficient. Originally developed for space lasers, its commercial potential was soon recognized.

  12. Component development for 500 watt diesel fueled portable thermophotovoltaic (TPV) power supply

    NASA Astrophysics Data System (ADS)

    DeBellis, Crispin L.; Scotto, Mark V.; Fraas, Lewis; Samaras, John; Watson, Ron C.; Scoles, Stephen W.

    1999-03-01

    McDermott Technology, Inc. (MTI) and JX Crystals have developed an innovative design for a compact, 500-watt, thermophotovoltaic (TPV) power supply using diesel fuel. Under a contract with the Defense Advanced Research Projects Agency (DARPA) and managed by the U.S. Army Communications-Electronics Command (CECOM), this design is being reduced to hardware. Prototypes of the two main subsystems, the power converter assembly (PCA) and the burner/emitter/recuperator (BER), have been designed, fabricated, and tested. The PCA uses low-band-gap gallium antimonide (GaSb) photovoltaic (PV) cells for high efficiency and power density. The prototype PCA will be air cooled for system simplicity and portability. However, initial testing was performed on a water-cooled PCA. The BER uses a thermal vaporizer to produce a stable, high-intensity, low-emissions combustion zone inside an impervious emitter. A thermally integrated recuperator is utilized to boost system efficiency by transferring the unused energy in the exhaust stream to the incoming fuel and combustion air. This paper describes the design, testing and performance of the first-generation PCA and BER along with model predictions used for design and evaluation.

  13. Field tests of a vertical-fluted-tube condenser in the prototype power plant at the Raft River Geothermal Test Site

    SciTech Connect

    Murphy, R.W.

    1983-04-01

    A vertical-fluted-tube condenser was designed, fabricated, and tested with isobutane as the shell-side working fluid in a binary prototype power plant at the Raft River Geothermal Test Site. After shakedown and contamination removal operations were completed, the four-pass water-cooled unit (with 102 outside-fluted Admiralty tubes) achieved performance predictions while operating with the plant surface evaporator on-line. A sample comparison shows that use of this enhanced condenser concept offers the potential for a reduction of about 65% from the size suggested by corresponding designs using conventional horizontal-smooth-tube concepts. Subsequent substitution of a direct-contact evaporator for the surface evaporator brought drastic reductions in system performance, the apparent consequence of high concentrations of noncondensible gases introduced by the brine/working-fluid interaction.

  14. Power struggle

    SciTech Connect

    Smith, J.H.

    1995-05-01

    Private power development in Mexico or at least the dream of it, can be characterized by three words - turmoil, tragedy and trauma. The saga continues for all parties concerned and there is little question that the worst suffering is being experienced by the Mexican people themselves. There are signs along the road that changing political, social, economic and market factors are laying the foundation for real, substantive support of a long-term private power development business sector in Mexico. Developers may still experience some potholes and wrong turns, but there is little doubt that private energy and power development will play a dominant role in Mexico`s future if for no other reason than it has to - to meet the needs of the Mexican people, the Mexican economy and the foreign investment community. There are three fundamental reasons for this guarded optimism: Basic energy/economic growth factors which originally attracted electric power investors have not changed; Legal, financial and regulatory frameworks necessary for private power investment are still in place, and are expected to grow even stronger; and, The Salinas administration`s handcuffs on the Mexican energy sector are slowly being removed, but Mexico`s economic restructuring may speed up the process.

  15. Power inverters

    DOEpatents

    Miller, David H.; Korich, Mark D.; Smith, Gregory S.

    2011-11-15

    Power inverters include a frame and a power module. The frame has a sidewall including an opening and defining a fluid passageway. The power module is coupled to the frame over the opening and includes a substrate, die, and an encasement. The substrate includes a first side, a second side, a center, an outer periphery, and an outer edge, and the first side of the substrate comprises a first outer layer including a metal material. The die are positioned in the substrate center and are coupled to the substrate first side. The encasement is molded over the outer periphery on the substrate first side, the substrate second side, and the substrate outer edge and around the die. The encasement, coupled to the substrate, forms a seal with the metal material. The second side of the substrate is positioned to directly contact a fluid flowing through the fluid passageway.

  16. Developing powers

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Three new reports commissioned by the Pew Center on Global Climate Change examine the electric power sectors in Argentina, Brazil, and China, and the potential impact that energy use in each country has on climate change.In 1999, Argentina voluntarily agreed to lower its greenhouse gas emissions to 2 10% below projected emissions for 2012. The report looks at additional steps that could further reduce emissions, including adopting policies that favor renewable energy sources and nuclear power, and increasing energy efficiency by end-users.

  17. Thrust stand for high-power electric propulsion devices

    NASA Astrophysics Data System (ADS)

    Haag, T. W.

    1991-05-01

    A thrust stand for use with magnetoplasmadynamic (MPD) thrusters operated at powers up to 250 kW steady state has been built and tested. The stand was based on an inverted pendulum configuration which resulted in large displacements and high resolution. Up to 50 mm of deflection was observed under a force of 5 N. This large range of displacement significantly reduced the effects of facility induced vibrations on thrust measurements. A remotely operated system was provided for in situ calibration of the thrust stand prior to and immediately after data were obtained. Calibrations showed that thrust measurements were linear and repeatable to within a fraction of 1%. Structural distortions of the vacuum facility due to pumpdown were detected with an inclinometer located in the thrust stand base. Slope deviations as small as 10 arcsec could be compensated using a remotely controlled leveling motor. Early problems with magnetically induced tares caused by the thruster discharge current were reduced by rerouting high-current cables to decrease stray fields. Tares due to discharge current were on the order of 26 mN at 3000 A, and those due to an applied field current were 63 mN at 1400 A. The thrust stand was used with a water-cooled, applied field, steady-state MPD device at power levels up to 125 kW. Hot thruster firings as long as 1 h were performed. By precisely maintaining a level thrust stand base, thermal drift was held to about 2% of the full scale reading over this period. The remaining thermal drift could be subtracted from the thrust measurement to further reduce systematic error. Tares caused by the applied magnetic field were similarly removed. By subtracting tabulated discharge current magnetic tares, thrust measurement uncertainty was reduced to approximately 2% of the measured value.

  18. Power, Revisited

    ERIC Educational Resources Information Center

    Roscigno, Vincent J.

    2011-01-01

    Power is a core theoretical construct in the field with amazing utility across substantive areas, levels of analysis and methodologies. Yet, its use along with associated assumptions--assumptions surrounding constraint vs. action and specifically organizational structure and rationality--remain problematic. In this article, and following an…

  19. Power Controller

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The power factor controller (PFC) senses shifts in the relationship between voltage and current, and matches them with a motor's need. This prevents waste as motors do not need a high voltage when they are not operating at full load conditions. PFC is manufactured by Nordic Controls Company, among others, and has proved extremely cost effective.

  20. Star Power

    SciTech Connect

    2014-10-17

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  1. POWER SEWING.

    ERIC Educational Resources Information Center

    HILLINGER, YVONNE M.

    ALTHOUGH THE PRIMARY PURPOSE OF THIS STUDY GUIDE IS TO PROVIDE A TEXT IN POWER SEWING FOR DEAF PUPILS, IT CAN ALSO BE USED FOR STUDENTS WITH READING OR LEARNING DIFFICULTIES. DEVELOPED BY AN INSTRUCTOR WITH FACULTY HELP, THE TEXT FOLLOWS A COURSE OF STUDY APPROVED BY THE BOARD OF EDUCATION AND HAS BEEN TESTED IN VARIOUS CLASSROOMS. UNITS ARE --…

  2. Power Trains.

    ERIC Educational Resources Information Center

    Kukuk, Marvin; Mathis, Joe

    This curriculum guide is part of a series designed to teach students about diesel engines. The materials in this power trains guide apply to both on-road and off-road vehicles and include information about chain and belt drives used in tractors and combines. These instructional materials, containing nine units, are written in terms of student…

  3. Star Power

    ScienceCinema

    None

    2014-11-18

    The U.S. Department of Energy's Princeton Plasma Physics Laboratory has released ''Star Power,'' a new informational video that uses dramatic and beautiful images and thought-provoking interviews to highlight the importance of the Laboratory's research into magnetic fusion.

  4. Power branding

    SciTech Connect

    Chambers, A.

    1998-12-31

    For most of its century-long history, electricity was a natural monopoly, due in part to the excessive cost of the necessary infrastructure. In the past decade, however, politics have pushed the industry toward competition and consumer choice. At the same time, technology has been developed that allows consumers to choose their electricity supplier and to track the flow of power through the various grids and lines. In her new book, Power Branding, author and industry expert Ann Chambers examines marketing and branding of electricity -- what it is, how it`s done, what its benefits are for electric utilities, marketers, and even natural gas companies allied with the utilities. She surveys industry leaders who have already taken a dive into the ocean of marketing and offers lessons drawn from their experiences. She also takes a look at other formerly regulated industries -- airlines, telephone, natural gas -- and describes how their rebirth as free-market industries may affect the course of the electric utility industry`s experience. The contents include: Introduction; Basics of branding: Brand image; Value-added services; Southern Company; Duke Energy; UtiliCorp/EnergyOne/Aquila--big and brand; Engage energy; Florida Power and Light Co.; Enron; Convergence; Lessons from the natural gas industry; Lessons from other industries; Conclusion; Resources; Glossary of branding, marketing and Btu convergence; and Major federal legislation affecting the electric power industry.

  5. Power Struggle.

    ERIC Educational Resources Information Center

    Cook, Glenn

    2001-01-01

    California's "power struggle" will probably not be replicated in the other 23 states that have deregulated electricity, but costs are rising everywhere. The Environmental Protection Agency/Department of Energy's new Energy Star online rating system should help school officials measure their buildings' efficiency and remove barriers to improvement.…

  6. Power Struggle.

    ERIC Educational Resources Information Center

    Cook, Glenn

    2001-01-01

    California's "power struggle" will probably not be replicated in the other 23 states that have deregulated electricity, but costs are rising everywhere. The Environmental Protection Agency/Department of Energy's new Energy Star online rating system should help school officials measure their buildings' efficiency and remove barriers to improvement.

  7. Fuel cell power source for a cold region

    NASA Astrophysics Data System (ADS)

    Datta, B. K.; Velayutham, G.; Goud, A. Prasad

    Electric power generation at Maitri—the Indian Antarctic station is based on a conventional diesel generator. In spite of the high reliability and simplicity of operation, the main disadvantages of this kind of power source are its pollution potential and fuel transportation costs. In a place like Antarctica environmental protection requirements are of prime importance. Apart from gas pollution, they also suffer from various other problems such as degradation of performance due to sub-zero temperature of operation, noise pollution, solidification of lubricants and mechanical wear and tear. Fuel cells find an ideal application for alternate energy solution, and can maintain the pristine nature of Antarctica. With this objective in mind, Research & Development Establishment (Engineers), Pune, Defence Research & Development Organisation, Ministry of Defence, Government of India joined hands with Centre for Electro-Chemical & Energy Research, SPIC Science Foundation, Chennai and developed three prototype 500 W, 12 V, PEMFC fuel cell power sources for this application. PEMFC has been chosen for study and experimentation at Antarctica because the solid electrolyte Nafion-117 is used in this cell and the electro-chemical reaction is exothermic so that the fuel cell can be activated at low temperature. PEMFC was first installed and successfully demonstrated during the XVII Indian Antarctic Expedition. Further studies continued during the XVIII Indian Antarctic Expedition and a series of scientific experiments were conducted in the areas of optimisation of humidification, temperature for reactants (hydrogen and oxygen), elimination of existing humidification system, feasibility of provision of air-cooling system in lieu of water cooling system, humidifcation of gases using membrane as a medium, charging/discharging characteristics of a metal hydride container for hydrogen storage, and performance of a dc-dc converter and static inverter under sub-zero temperature of operation. Based on the results of these experiments, the design of the fuel cell power source for cold region application has been finalised. The paper deals with the design criteria and design factors to be considered for the fuel cell power source for cold region application and details of tests and test results that led to the final design concept for such an application. The paper also deals with a proposed hybrid power plant taking into account the exploitation of wind energy with a fuel cell and generation of hydrogen by an electrolyser and provision of hydrogen storage.

  8. Water-carbon trade-off in China's coal power industry.

    PubMed

    Zhang, Chao; Anadon, Laura Diaz; Mo, Hongpin; Zhao, Zhongnan; Liu, Zhu

    2014-10-01

    The energy sector is increasingly facing water scarcity constraints in many regions around the globe, especially in China, where the unprecedented large-scale construction of coal-fired thermal power plants is taking place in its extremely arid northwest regions. As a response to water scarcity, air-cooled coal power plants have experienced dramatic diffusion in China since the middle 2000s. By the end of 2012, air-cooled coal-fired thermal power plants in China amounted to 112 GW, making up 14% of China's thermal power generation capacity. But the water conservation benefit of air-cooled units is achieved at the cost of lower thermal efficiency and consequently higher carbon emission intensity. We estimate that in 2012 the deployment of air-cooled units contributed an additional 24.3-31.9 million tonnes of CO2 emissions (equivalent to 0.7-1.0% of the total CO2 emissions by China's electric power sector), while saving 832-942 million m(3) of consumptive water use (about 60% of the total annual water use of Beijing) when compared to a scenario with water-cooled plants. Additional CO2 emissions from air-cooled plants largely offset the CO2 emissions reduction benefits from Chinese policies of retiring small and outdated coal plants. This water-carbon trade-off is poised to become even more significant by 2020, as air-cooled units are expected to grow by a factor of 2-260 GW, accounting for 22% of China's total coal-fired power generation capacity. PMID:25215622

  9. Reliable high-power diode lasers: thermo-mechanical fatigue aspects

    NASA Astrophysics Data System (ADS)

    Klumel, Genady; Gridish, Yaakov; Szafranek, Igor; Karni, Yoram

    2006-02-01

    High power water-cooled diode lasers are finding increasing demand in biomedical, cosmetic and industrial applications, where repetitive cw (continuous wave) and pulsed cw operation modes are required. When operating in such modes, the lasers experience numerous complete thermal cycles between "cold" heat sink temperature and the "hot" temperature typical of thermally equilibrated cw operation. It is clearly demonstrated that the main failure mechanism directly linked to repetitive cw operation is thermo-mechanical fatigue of the solder joints adjacent to the laser bars, especially when "soft" solders are used. Analyses of the bonding interfaces were carried out using scanning electron microscopy. It was observed that intermetallic compounds, formed already during the bonding process, lead to the solders fatigue both on the p- and n-side of the laser bar. Fatigue failure of solder joints in repetitive cw operation reduces useful lifetime of the stacks to hundreds hours, in comparison with more than 10,000 hours lifetime typically demonstrated in commonly adopted non-stop cw reliability testing programs. It is shown, that proper selection of package materials and solders, careful design of fatigue sensitive parts and burn-in screening in the hard pulse operation mode allow considerable increase of lifetime and reliability, without compromising the device efficiency, optical power density and compactness.

  10. Development and extended operation of a high power radiation loaded heat pipe

    SciTech Connect

    Merrigan, M.A.; Keddy, E.S.; Runyan, J.R.; Martinez, H.E.

    1984-06-01

    A high temperature, high power molybdenum-lithium heat pipe has been fabricated and tested at 1500 K for 1700 hours with radiant heat rejection. Power throughput during the test was approximately 14 kW, corresponding to an axial flux density of 11 kW/cm/sup 2/ for the 1.59 cm diameter heat pipe. Radial flux density was 70 W/cm/sup 2/ over an evaporator length of 40.0 cm. Condenser length was approximately 150 cm with radiant heat rejection from the condenser to a coaxial water cooled radiation calorimeter. A plasma sprayed, high emissivity coating was used on the condenser surface to increase the radiant heat rejection during the tests. The heat pipe was operated for 514 hours at steady state conditions before being damaged during a planned shutdown for test equipment maintenance. The damage was repaired and the initial 1000 hour test period completed without further incident. After physical examination of the heat pipe at 1000 hours the test was resumed and the heat pipe operated at the same conditions for an additional 700 hours before conclusion of this test phase.

  11. Record Electricity-to-Gas Power Efficiency of a Silicon Solar Cell Based TPV System

    NASA Astrophysics Data System (ADS)

    Bitnar, Bernd; Mayor, Jean-Claude; Durisch, Wilhelm; Meyer, Andreas; Palfinger, Günther; von Roth, Fritz; Sigg, Hans

    2003-01-01

    In this paper we report on the development and characterisation of a small TPV prototype system, which uses silicon photocells and a rare earth selective emitter. A simulation model of this system was developed, which allows studying the system theoretically. The fabrication of the selective incandescent mantle emitter from Yb2O3 and detailed measurements of its radiation power and emissivity are presented. The maximum emissivity was 0.85 at 1.27 eV. An emitter temperature of 1735 K was obtained for an approximately 75 cm2 large emitter heated by a butane burner. A SnO2 filter tube was developed. The photocell generator is composed of monocrystalline silicon solar cells and a water-cooling circuit. The prototype system reached, without a selective filter and without preheating of the combustion air, a record electricity-to-gas power efficiency of 2.4 %. We compare the experimentally achieved system efficiency with simulations using our model. The possibilities to further increase the system efficiency are discussed.

  12. Ion cyclotron resonance heating systems upgrade toward high power and CW operations in WEST

    NASA Astrophysics Data System (ADS)

    Hillairet, Julien; Mollard, Patrick; Zhao, Yanping; Bernard, Jean-Michel; Song, Yuntao; Argouarch, Arnaud; Berger-By, Gilles; Charabot, Nicolas; Chen, Gen; Chen, Zhaoxi; Colas, Laurent; Delaplanche, Jean-Marc; Dumortier, Pierre; Durodié, Frédéric; Ekedahl, Annika; Fedorczak, Nicolas; Ferlay, Fabien; Goniche, Marc; Hatchressian, Jean-Claude; Helou, Walid; Jacquot, Jonathan; Joffrin, Emmanuel; Litaudon, Xavier; Lombard, Gilles; Maggiora, Riccardo; Magne, Roland; Milanesio, Daniele; Patterlini, Jean-Claude; Prou, Marc; Verger, Jean-Marc; Volpe, Robert; Vulliez, Karl; Wang, Yongsheng; Winkler, Konstantin; Yang, Qingxi; Yuan, Shuai

    2015-12-01

    The design of the WEST (Tungsten-W Environment in Steady-state Tokamak) Ion cyclotron resonance heating antennas is based on a previously tested conjugate-T Resonant Double Loops prototype equipped with internal vacuum matching capacitors. The design and construction of three new WEST ICRH antennas are being carried out in close collaboration with ASIPP, within the framework of the Associated Laboratory in the fusion field between IRFM and ASIPP. The coupling performance to the plasma and the load-tolerance have been improved, while adding Continuous Wave operation capability by introducing water cooling in the entire antenna. On the generator side, the operation class of the high power tetrodes is changed from AB to B in order to allow high power operation (up to 3 MW per antenna) under higher VSWR (up to 2:1). Reliability of the generators is also improved by increasing the cavity breakdown voltage. The control and data acquisition system is also upgraded in order to resolve and react on fast events, such as ELMs. A new optical arc detection system comes in reinforcement of the Vr/Vf and SHAD systems.

  13. High-power laser diodes at SCD: performance and reliability for defence and space applications

    NASA Astrophysics Data System (ADS)

    Risemberg, Shlomo; Karni, Yoram; Klumel, Genadi; Levy, Moshe; Berk, Yuri; Rech, Markus; Becht, Hubert; Frei, Bruno

    2009-05-01

    High Power Laser Diode Arrays developed and produced at SCD-SemiConductor Devices support a number of advanced defence and space programs. High efficiency and unsurpassed reliability at high operating temperatures are mandatory features for those applications. We report lifetime results of high power bar stacks, operating in QCW mode that rely on a field-proven design comprising Al-free wafer material technology and hard soldering robust packaging. A variety of packaging platforms have been implemented and tested at very harsh environmental conditions. Results include a long operational lifetime study totaling 20 billion pulses monitored in the course of several years for 808 nm QCW bar stacks.. Additionally, we report results of demanding lifetime tests for space qualification performed on these stacks at different levels of current load in a unique combination with operational temperature cycles in the range of -10 ÷60 °C. Novel solutions for highly reliable water cooled devices designed for operation in long pulses at different levels of PRF, are also discussed. The cooling efficiency of microchannel coolers is preserved while reliability is improved.

  14. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P.

    2003-06-10

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  15. Power superconducting power transmission cable

    DOEpatents

    Ashworth, Stephen P.

    2003-01-01

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  16. Power converter

    NASA Technical Reports Server (NTRS)

    Black, J. M. (Inventor)

    1981-01-01

    A dc-to-dc converter employs four transistor switches in a bridge to chop dc power from a source, and a voltage multiplying diode rectifying ladder network to rectify and filter the chopped dc power for delivery to a load. The bridge switches are cross coupled in order for diagonally opposite pairs to turn on and off together using RC networks for the cross coupling to achieve the mode of operation of a free running multivibrator, and the diode rectifying ladder is configured to operate in a push-pull mode driven from opposite sides of the multivibrator outputs of the ridge switches. The four transistor switches provide a square-wave output voltage which as a peak-to-peak amplitude that is twice the input dc voltage, and is thus useful as a dc-to-ac inverter.

  17. Power saw

    NASA Technical Reports Server (NTRS)

    Bradley, Jimmy D. (Inventor)

    1991-01-01

    A power saw is disclosed for space or robotic operations with jaw members for clamping to a work piece by an operation of a lever arm. The saw assembly is slidably mounted on the jaw assembly and fed into the work piece by a hand operated feed screw. The saw assembly includes a motor and gear belt. A current sensing circuit provides a current signal which actuates colored lights to visually depict the load on the saw blade during the cutting operations.

  18. Fluid power

    SciTech Connect

    Sullivan, J.

    1989-01-01

    Illustrations and analysis are combined in this book that show the design and function of components and circuits in fluid power and pneumatic systems. Explanations are given for ASTM standards and conventional tests and step-by-step troubleshooting guidelines are provided. Other topics of discussion include friction losses in hydraulic systems, hydraulic fluids, pumps, hydraulic cylinders and cushioning devices, hydraulic motors, valves, seals and packing, system components, hydraulic circuit configurations, and controls.

  19. Power supply

    DOEpatents

    Hart, Edward J.; Leeman, James E.; MacDougall, Hugh R.; Marron, John J.; Smith, Calvin C.

    1976-01-01

    An electric power supply employs a striking means to initiate ferroelectric elements which provide electrical energy output which subsequently initiates an explosive charge which initiates a second ferroelectric current generator to deliver current to the coil of a magnetic field current generator, creating a magnetic field around the coil. Continued detonation effects compression of the magnetic field and subsequent generation and delivery of a large output current to appropriate output loads.

  20. Stigma Power

    PubMed Central

    Link, Bruce G.; Phelan, Jo

    2015-01-01

    When people have an interest in keeping other people down, in or away, stigma is a resource that allows them to obtain ends they desire. We call this resource “stigma power” and use the term to refer to instances in which stigma processes achieve the aims of stigmatizers with respect to the exploitation, control or exclusion of others. We draw on Bourdieu (1987; 1990) who notes that power is often most effectively deployed when it is hidden or “misrecognized.” To explore the utility of the stigma power concept we examine ways in which the goals of stigmatizers are achieved but hidden in the stigma coping efforts of people with mental illnesses. We developed new self-report measures and administered them to a sample of individuals who have experienced mental illness to test whether results are consistent with the possibility that, in response to negative societal conceptions, the attitudes, beliefs and behaviors of people with psychosis lead them to be concerned with staying in, propelled to stay away and induced to feel downwardly placed –precisely the outcomes stigmatizers might desire. Our introduction of the stigma power concept carries the possibility of seeing stigmatizing circumstances in a new light. PMID:24507908

  1. Tidal power

    SciTech Connect

    Hammons, T.J. )

    1993-03-01

    The paper reviews the physics of tidal power considering gravitational effects of moon and sun; semidiurnal, diurnal, and mixed tides; and major periodic components that affect the tidal range. Shelving, funneling, reflection, and resonance phenomena that have a significant effect on tidal range are also discussed. The paper then examines tidal energy resource for principal developments estimated from parametric modeling in Europe and worldwide. Basic parameters that govern the design of tidal power schemes in terms of mean tidal range and surface area of the enclosed basin are identified. While energy extracted is proportional to the tidal amplitude squared, requisite sluicing are is proportional to the square root of the tidal amplitude. Sites with large tidal amplitudes are therefore best suited for tidal power developments, whereas sites with low tidal amplitudes have sluicing that may be prohibitive. It is shown that 48% of the European tidal resource is in the United Kingdom, 42% in France and 8% in Ireland, other countries having negligible potential. Worldwide tidal resource is identified. Tidal barrage design and construction using caissons is examined, as are alternative operating modes (single-action generation, outflow generation, flood generation, two-way generation, twin basin generation, pumping, etc), development trends and possibilities, generation cost at the barrage boundary, sensitivity to discount rates, general economics, and markets. Environmental effects, and institutional constraints to the development of tidal barrage schemes are also discussed.

  2. Power Controller

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The device called the Power Factor Controller (PFC) offers exceptional energy conservation potential by virtue of its ability to sense shifts in the relationship between voltage and current flow, and to match them with the motor's need. Originating from the solar heating/cooling program, the PFC senses a light load, it cuts the voltage level to the minimum needed which in turn reduces current flow and heat loss. Laboratory tests showed that the PFC could reduce power used by six to eight percent under normal motor loads, and as much as 65 percent when the motor was idling. Over 150 companies have been granted NASA licenses for commercial use of this technology. One system that utilizes this technology is the Vectrol Energy System, (VES) produced by Vectrol, Inc. a subsidiary of Westinghouse. The VES is being used at Woodward & Lothrop, on their escalators. Energy use is regulated according to how many people are on the escalator at any time. It is estimated that the energy savings are between 30 to 40 percent.

  3. Wireless Power Transmission Technology State-Of-The-Art

    NASA Astrophysics Data System (ADS)

    Dickinson, R. M. T.

    2002-01-01

    This first Bill Brown SSP La Crescenta, CA 91214 technology , including microwave and laser systems for the transfer of electric , as related to eventually developing Space Solar Power (SSP) systems. Current and past technology accomplishments in ground based and air and space applied energy conversion devices, systems and modeling performance and cost information is presented, where such data are known to the author. The purpose of the presentation is to discuss and present data to encourage documenting and breaking the current technology records, so as to advance the SOA in WPT for SSP . For example, regarding DC to RF and laser converters, 83% efficient 2.45 GHz cooker-tube magnetrons with 800W CW output have been jointly developed by Russia and US. Over 50% wa11-plug efficient 1.5 kW/cm2 CW, water cooled, multibeam, solid state laser diode bar-arrays have been developed by LLNL at 808 nm wavelength. The Gennans have developed a 36% efficient, kW level, sing1e coherent beam, lateral pumped semiconductor laser. The record for end-to-end DC input to DC output power overall WPT link conversion efficiency is 54% during the Raytheon-JPL experiments in 1975 for 495.6 W recovered at 1.7-mrange at 2.4469 GAz. The record for usefully recovered electric power output ( as contrasted with thennally induced power in structures) is 34 kW OC output at a range of 1.55 km, using 2.388 GHz microwaves, during the JPL- Raytheon experiments by Bill Brown and the author at Goldstone, CA in 1975. The GaAs-diode rectenna array had an average collection-conversion efficiency of 82.5%. A single rectenna element operating a 6W RF input, developed by Bill Brown demonstrated 91.4% efficiency. The comparable record for laser light to OC output power conversion efficiency of photovoltaics is 590/0. for AlGaAs at 1.7 Wand 826nm wavelength. Russian cyclotron-wave converters have demonstrated 80% rectification efficiency at S-band. Concerning WPT technology equipment costs, magnetron conversion devices for microwave ovens are approximately O.O25/W, due to the large manufacturing quantities. Comparable, remanufactured lasers for industrial applications at the 4 kW CW level are of order 25/W. Industrial klystrons cost over 1/W and solid state power amplifiers cost over 3/W. Model tethered helicopters, model airplanes, a smal1 airship and several small rovers have been powered with microwave beams at 2.45, 5.8 and 35 GHz. Smal1 rovers have been powered with laser beams. Two space-to-space microwave power link experiments have been conducted by the Japanese and with Texas A&M assistance in one case. International records for WPT link electric power delivered, range, 1ink efficiency and other salient parameters for both wireless-laser and -microwave power demonstrations win be reviewed. Also, costing models for WPT -system figure- of-merit (FOM) in terms of capital costs, in /MW -km, as a fonction of range and power level are reviewed. Records in Japan. France, Korea, Russia, Canada and the US will be reviewed for various land based WPT demonstrations. SSP applicable elements of technology in fiber and wireless links, cell phones and base stations, aircraft, and spacecraft phased arrays, industrial and scientific klystrons and lasers, military equipment (where information is available in open literature) microwave heating, and other telecommunication activities win be presented, concerning power handling, frequency or wavelength, conversion efficiency, specific mass, specific cost, etc. Previously studied and proposed applications of WPT technology will be presented to show the range of WPT technology being considered for commercial and other applications that will lead to advancing the SOA of WPT technology that win benefit SSP .

  4. Power optics

    SciTech Connect

    Apollonov, V V

    2014-02-28

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it. The theoretical estimates are compared with the experimental data. We discuss the issues related to the technology of fabrication of power optics elements based on materials with a porous structure, of lightweight highly stable large optics based on highly porous materials, multi-layer honeycomb structures and silicon carbide, as well as problems of application of physical and technical fundamentals of power optics in modern cutting-edge technology. (invited paper)

  5. Power optics

    NASA Astrophysics Data System (ADS)

    Apollonov, V. V.

    2014-02-01

    By using the theory we developed in the early 1970s, a broad range of phenomena is considered for an optical surface of a solid body that is exposed to radiation arbitrarily varying in time and producing temperature fields, thermoelastic stresses and thermal deformations on the surface layer. The examination is based on the relations (which are similar to Duhamel's integral formula from the theory of heat conduction) between the quantities characterising the thermal stress state in any nonstationary regimes of energy input into a solid. A peculiar feature of the analysis of the thermal stress state in this case consists in the fact that this relation comprises time as a parameter, which in turn is a consequence of incoherence of the quasi-stationary problem of thermoelasticity. This phenomenon is particularly important for the optics of high-power, high-pulse repetition rate lasers, which are being actively developed. In the review, we have recently published in Laser Physics, the thermal stress state of a solid is analysed. In this state, time is treated as an independent variable used in differentiation. Such an approach greatly reduces the applicability of the method. The review published contains data on the use of capillary porous structures made of various materials with different degrees of the surface development. Moreover, such structures can be efficiently employed to increase the heat exchange at a temperature below the boiling point of the coolant. In the present review we discuss the dependences of the limiting laser intensities on the duration of a pulse or a pulse train, corresponding to the three stages of the state of the reflecting surface and leading to unacceptable elastic deformations of the surface, to the plastic yield of the material accompanied by the formation of residual stresses and to the melting of the surface layer. We also analyse the problem of heat exchange in the surface layer with a liquid metal coolant pumped through it. The theoretical estimates are compared with the experimental data. We discuss the issues related to the technology of fabrication of power optics elements based on materials with a porous structure, of lightweight highly stable large optics based on highly porous materials, multi-layer honeycomb structures and silicon carbide, as well as problems of application of physical and technical fundamentals of power optics in modern cutting-edge technology.

  6. High-power microwave power divider concept

    NASA Technical Reports Server (NTRS)

    Kolbly, R. B.

    1969-01-01

    Variable power divider keeps microwave transmitter at full power. This preserves the bandwidth and modulation characteristics and proportions any amount of the full power from the normal antenna into a dissipative load.

  7. POWER REACTOR

    DOEpatents

    Zinn, W.H.

    1958-07-01

    A fast nuclear reactor system ls described for producing power and radioactive isotopes. The reactor core is of the heterogeneous, fluid sealed type comprised of vertically arranged elongated tubular fuel elements having vertical coolant passages. The active portion is surrounded by a neutron reflector and a shield. The system includes pumps and heat exchangers for the primary and secondary coolant circuits. The core, primary coolant pump and primary heat exchanger are disposed within an irapenforate tank which is filled with the primary coolant, in this case a liquid metal such as Na or NaK, to completely submerge these elements. The tank is completely surrounded by a thick walled concrete shield. This reactor system utilizes enriched uranium or plutonium as the fissionable material, uranium or thorium as a diluent and thorium or uranium containing less than 0 7% of the U/sup 235/ isotope as a fertile material.

  8. Power oscillator

    DOEpatents

    Gitsevich, Aleksandr

    2001-01-01

    An oscillator includes an amplifier having an input and an output, and an impedance transformation network connected between the input of the amplifier and the output of the amplifier, wherein the impedance transformation network is configured to provide suitable positive feedback from the output of the amplifier to the input of the amplifier to initiate and sustain an oscillating condition, and wherein the impedance transformation network is configured to protect the input of the amplifier from a destructive feedback signal. One example of the oscillator is a single active element device capable of providing over 70 watts of power at over 70% efficiency. Various control circuits may be employed to match the driving frequency of the oscillator to a plurality of tuning states of the lamp.

  9. Power management system

    DOEpatents

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2007-10-02

    A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

  10. Application of evaporative cooling technology in super-high power density magnet.

    PubMed

    Xiong, B; Ruan, L; Gu, G B; Guo, S Q; Cao, R; Li, Z G; Lu, W; Zhang, X Z; Sun, L T; Zhao, H W

    2014-02-01

    Evaporative cooling technology utilizes phase-change heat transfer mode to achieve the cooling for heating equipment. The heat transfer capacity of evaporative cooling technology is far more than air or water cooling technology. The Electron Cyclotron Resonance ion source magnet is a typical super-high power density magnet, and the evaporative cooling technology is an ideal cooling method for the coils of magnet. In this paper we show the structure and process of coils and the special design of flow channels of coolant for an experiment magnet model. Additionally, the heat transfer circulation is presented and analyzed. By the finite element method, the flow channels are optimized to rationally allocate coolant and to reduce the temperature of coils. For the experiment model, the current density of copper wire of coils is 19 A/mm(2), and the coil-windows current density is larger than 12 A/mm(2). The max temperature of coils is below 80 °C, and the total heat is about 200 kW. PMID:24593492

  11. High power tests of an electroforming cavity operating at 11.424 GHz

    NASA Astrophysics Data System (ADS)

    Dolgashev, V. A.; Gatti, G.; Higashi, Y.; Leonardi, O.; Lewandowski, J. R.; Marcelli, A.; Rosenzweig, J.; Spataro, B.; Tantawi, S. G.; Yeremian, D. A.

    2016-03-01

    The achievement of ultra high accelerating gradients is mandatory in order to fabricate compact accelerators at 11.424 GHz for scientific and industrial applications. An extensive experimental and theoretical program to determine a reliable ultra high gradient operation of the future linear accelerators is under way in many laboratories. In particular, systematic studies on the 11.424 GHz frequency accelerator structures, R&D on new materials and the associated microwave technology are in progress to achieve accelerating gradients well above 120 MeV/m. Among the many, the electroforming procedure is a promising approach to manufacture high performance RF devices in order to avoid the high temperature brazing and to produce precise RF structures. We report here the characterization of a hard high gradient RF accelerating structure at 11.424 GHz fabricated using the electroforming technique. Low-level RF measurements and high power RF tests carried out at the SLAC National Accelerator Laboratory on this prototype are presented and discussed. In addition, we present also a possible layout where the water-cooling of irises based on the electroforming process has been considered for the first time.

  12. Women, Power, and Libraries.

    ERIC Educational Resources Information Center

    Schuman, Patricia Glass

    1984-01-01

    Discusses the concept of power in the context of women and the library profession, citing views of power by Max Weber, John Kenneth Galbraith, Letty Cottin Pogrebin, and Rosabeth Moss Kantor. Male power and female submission, defining power, organizing for power, and sharing power are highlighted. A 12-item bibliography is included. (EJS)

  13. Knowledges and abilities catalog for nuclear power plant operators: Savannah River Site (SRS) production reactors

    SciTech Connect

    Not Available

    1990-06-20

    The Knowledges and Abilities Catalog for Nuclear Power Plant Operations: Savannah River Site (SRS) Production Reactors, provides the basis for the development of content-valid certification examinations for Senior Reactor Operators (SROs) and Central Control Room Supervisors (SUP). The position of Shift Technical Engineer (STE) has been included in the catalog for completeness. This new SRS reactor operating shift crew position is held by an individual holding a CCR Supervisor Certification who has received special engineering and technical training. Also, the STE has a Bachelor of Science degree in engineering or a related technical field. The SRS catalog contains approximately 2500 knowledge and ability (K/A) statements for SROs and SUPs at heavy water moderated production reactors. Each K/A statement has been rated for its importance to the safe operation of the plant in a manner ensuring the health and safety of the public. The SRS K/A catalog is presently organized into five major sections: Plant Systems grouped by Safety Function, Plant Wide Generic K/As, Emergency Plant Evolutions, Theory and Components (to be developed).

  14. Power electronics for low power arcjets

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Hill, Gerald M.

    1991-01-01

    In anticipation of the needs of future light-weight low-power spacecraft, arcjet power electronics in the 100- to 400-W operating range were developed. Power topologies similar to those in the higher 2-kW and 5- to 30-kW power range were implemented, including a four-transistor bridge-switching circuit, current-mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs, allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter.

  15. ESBWR response to an extended station blackout/loss of all AC power

    SciTech Connect

    Barrett, A. J.; Marquino, W.

    2012-07-01

    U.S. federal regulations require light water cooled nuclear power plants to cope with Station Blackouts for a predetermined amount of time based on design factors for the plant. U.S. regulations define Station Blackout (SBO) as a loss of the offsite electric power system concurrent with turbine trip and unavailability of the onsite emergency AC power system. According to U.S. regulations, typically the coping period for an SBO is 4 hours and can be as long as 16 hours for currently operating BWR plants. Being able to cope with an SBO and loss of all AC power is required by international regulators as well. The U.S. licensing basis for the ESBWR is a coping period of 72 hours for an SBO based on U.S. NRC requirements for passive safety plants. In the event of an extended SBO (viz., greater than 72 hours), the ESBWR response shows that the design is able to cope with the event for at least 7 days without AC electrical power or operator action. ESBWR is a Generation III+ reactor design with an array of passive safety systems. The ESBWR primary success path for mitigation of an SBO event is the Isolation Condenser System (ICS). The ICS is a passive, closed loop, safety system that initiates automatically on a loss of power. Upon Station Blackout or loss of all AC power, the ICS begins removing decay heat from the Reactor Pressure Vessel (RPV) by (i) condensing the steam into water in heat exchangers located in pools of water above the containment, and (ii) transferring the decay heat to the atmosphere. The condensed water is then returned by gravity to cool the reactor again. The ICS alone is capable of maintaining the ESBWR in a safe shutdown condition after an SBO for an extended period. The fuel remains covered throughout the SBO event. The ICS is able to remove decay heat from the RPV for at least 7 days and maintains the reactor in a safe shutdown condition. The water level in the RPV remains well above the top of active fuel for the duration of the SBO event. Beyond 7 days, only a few simple actions are needed to cope with the SBO for an indefinite amount of time. The operation of the ICS as the primary success path for mitigation of an SBO, allows for near immediate plant restart once power is restored. (authors)

  16. Power Struggles. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Neugebauer, Bonnie; Duffy, Roslyn; Garbarino, James; Gonzalez-Mena, Janet

    2001-01-01

    Presents four articles about children's power struggles: (1) "The Personal Side of Power" (Bonnie Neugebauer); (2) "Learning To Harness Human Power" (Roslyn Duffy); (3) "Power Struggles: Early Experiences Matter" (James Garbarino); and (4) "Personal Power: Creating New Realities" (Janet Gonzalez-Mena). (DLH)

  17. INCREASING SCIENTIFIC POWER WITH STATISTICAL POWER

    EPA Science Inventory

    A brief survey of basic ideas in statistical power analysis demonstrates the advantages and ease of using power analysis throughout the design, analysis, and interpretation of research. he power of a statistical test is the probability of rejecting the null hypothesis of the test...

  18. Dynamic power systems for power generation

    SciTech Connect

    English, R.E.

    1984-04-01

    The characteristics of dynamic power systems have considerable potential value, especially for the space station. The base of technology that makes these dynamic power systems practical is reviewed. The following types of power-generating systems are examined herein: organic Rankine cycle, potassium Rankine cycle, Brayton cycle, and Stirling cycle.

  19. Closed Brayton cycle power conversion systems for nuclear reactors :

    SciTech Connect

    Wright, Steven A.; Lipinski, Ronald J.; Vernon, Milton E.; Sanchez, Travis

    2006-04-01

    This report describes the results of a Sandia National Laboratories internally funded research program to study the coupling of nuclear reactors to gas dynamic Brayton power conversion systems. The research focused on developing integrated dynamic system models, fabricating a 10-30 kWe closed loop Brayton cycle, and validating these models by operating the Brayton test-loop. The work tasks were performed in three major areas. First, the system equations and dynamic models for reactors and Closed Brayton Cycle (CBC) systems were developed and implemented in SIMULINKTM. Within this effort, both steady state and dynamic system models for all the components (turbines, compressors, reactors, ducting, alternators, heat exchangers, and space based radiators) were developed and assembled into complete systems for gas cooled reactors, liquid metal reactors, and electrically heated simulators. Various control modules that use proportional-integral-differential (PID) feedback loops for the reactor and the power-conversion shaft speed were also developed and implemented. The simulation code is called RPCSIM (Reactor Power and Control Simulator). In the second task an open cycle commercially available Capstone C30 micro-turbine power generator was modified to provide a small inexpensive closed Brayton cycle test loop called the Sandia Brayton test-Loop (SBL-30). The Capstone gas-turbine unit housing was modified to permit the attachment of an electrical heater and a water cooled chiller to form a closed loop. The Capstone turbine, compressor, and alternator were used without modification. The Capstone systems nominal operating point is 1150 K turbine inlet temperature at 96,000 rpm. The annular recuperator and portions of the Capstone control system (inverter) and starter system also were reused. The rotational speed of the turbo-machinery is controlled by adjusting the alternator load by using the electrical grid as the load bank. The SBL-30 test loop was operated at the manufacturers site (Barber-Nichols Inc.) and installed and operated at Sandia. A sufficiently detailed description of the loop is provided in this report along with the design characteristics of the turbo-alternator-compressor set to allow other researchers to compare their results with those measured in the Sandia test-loop. The third task consisted of a validation effort. In this task the test loop was operated and compared with the modeled results to develop a more complete understanding of this electrically heated closed power generation system and to validate the model. The measured and predicted system temperatures and pressures are in good agreement, indicating that the model is a reasonable representation of the test loop. Typical deviations between the model and the hardware results are less than 10%. Additional tests were performed to assess the capability of the Brayton engine to continue to remove decay heat after the reactor/heater is shutdown, to develop safe and effective control strategies, and to access the effectiveness of gas inventory control as an alternative means to provide load following. In one test the heater power was turned off to simulate a rapid reactor shutdown, and the turbomachinery was driven solely by the sensible heat stored in the heater for over 71 minutes without external power input. This is an important safety feature for CBC systems as it means that the closed Brayton loop will keep cooling the reactor without the need for auxiliary power (other than that needed to circulate the waste heat rejection coolant) provided the heat sink is available.

  20. Infrared power cells for satellite power conversion

    NASA Technical Reports Server (NTRS)

    Summers, Christopher J.

    1991-01-01

    An analytical investigation is performed to assess the feasibility of long-wavelength power converters for the direct conversion of IR radiation onto electrical power. Because theses devices need to operate between 5 and 30 um the only material system possible for this application is the HgCdTe system which is currently being developed for IR detectors. Thus solar cell and IR detector theories and technologies are combined. The following subject areas are covered: electronic and optical properties of HgCdTe alloys; optimum device geometry; junction theory; model calculation for homojunction power cell efficiency; and calculation for HgCdTe power cell and power beaming.

  1. Solar powered multipurpose remotely powered aircraft

    NASA Technical Reports Server (NTRS)

    Alexandrou, A. N.; Durgin, W. W.; Cohn, R. F.; Olinger, D. J.; Cody, Charlotte K.; Chan, Agnes; Cheung, Kwok-Hung; Conley, Kristin; Crivelli, Paul M.; Javorski, Christian T.

    1992-01-01

    Increase in energy demands coupled with rapid depletion of natural energy resources have deemed solar energy as an attractive alternative source of power. The focus was to design and construct a solar powered, remotely piloted vehicle to demonstrate the feasibility of solar energy as an effective, alternate source of power. The final design included minimizing the power requirements and maximizing the strength-to-weight and lift-to-drag ratios. Given the design constraints, Surya (the code-name given to the aircraft), is a lightweight aircraft primarily built using composite materials and capable of achieving level flight powered entirely by solar energy.

  2. Oxidation of Zircaloy Fuel Cladding in Water-Cooled Nuclear Reactors

    SciTech Connect

    Macdonald, Digby; Urquidi-Macdonald, Mirna; Chen, Yingzi; Ai, Jiahe; Park, Pilyeon; Kim, Han-Sang

    2006-12-12

    Our work involved the continued development of the theory of passivity and passivity breakdown, in the form of the Point Defect Model, with emphasis on zirconium and zirconium alloys in reactor coolant environments, the measurement of critically-important parameters, and the development of a code that can be used by reactor operators to actively manage the accumulation of corrosion damage to the fuel cladding and other components in the heat transport circuits in both BWRs and PWRs. In addition, the modified boiling crevice model has been further developed to describe the accumulation of solutes in porous deposits (CRUD) on fuel under boiling (BWRs) and nucleate boiling (PWRs) conditions, in order to accurately describe the environment that is contact with the Zircaloy cladding. In the current report, we have derived expressions for the total steady-state current density and the partial anodic and cathodic current densities to establish a deterministic basis for describing Zircaloy oxidation. The models are “deterministic” because the relevant natural laws are satisfied explicitly, most importantly the conversation of mass and charge and the equivalence of mass and charge (Faraday’s law). Cathodic reactions (oxygen reduction and hydrogen evolution) are also included in the models, because there is evidence that they control the rate of the overall passive film formation process. Under open circuit conditions, the cathodic reactions, which must occur at the same rate as the zirconium oxidation reaction, are instrumental in determining the corrosion potential and hence the thickness of the barrier and outer layers of the passive film. Controlled hydrodynamic methods have been used to measure important parameters in the modified Point Defect Model (PDM), which is now being used to describe the growth and breakdown of the passive film on zirconium and on Zircaloy fuel sheathing in BWRs and PWRs coolant environments. The modified PDMs recognize the existence of a thick oxide outer layer over a thin barrier layer. From thermodynamic analysis, it is postulated that a hydride barrier layer forms under PWR coolant conditions whereas an oxide barrier layer forms under BWR primary coolant conditions. Thus, the introduction of hydrogen into the solution lowers the corrosion potential of zirconium to the extent that the formation of ZrH2 is predicted to be spontaneous rather than the ZrO2. Mott-Schottky analysis shows that the passive film formed on zirconium is n-type, which is consistent with the PDM, corresponding to a preponderance of oxygen/hydrogen vacancies and/or zirconium interstitials in the barrier layer. The model parameter values were extracted from electrochemical impedance spectroscopic data for zirconium in high temperature, de-aerated and hydrogenated environments by optimization. The results indicate that the corrosion resistance of zirconium is dominated by the porosity and thickness of the outer layer for both cases. The impedance model based on the PDM provides a good account of the growth of the bi-layer passive films described above, and the extracted model parameter values might be used, for example, for predicting the accumulation of general corrosion damage to Zircaloy fuel sheath in BWR and PWR operating environments. Transients in current density and film thickness for passive film formation on zirconium in dearated and hydrogenated coolant conditions have confirmed that the rate law afforded by the Point Defect Model (PDM) adequately describes the growth and thinning of the passive film. The experimental results demonstrate that the kinetics of oxygen or hydrogen vacancy generation at the metal/film interface control the rate of film growth, when the potential is displaced in the positive direction, whereas the kinetics of dissolution of the barrier layer at the barrier layer/solution interface control the rate of passive film thinning when the potential is stepped in the negative direction. In addition, the effects of second phase particles (SPPs) on the electrochemistry of passive zirconium in the hydrogenated, high temperature aqueous solutions were examined by using different heat-treated Zircaloy-4 samples; i.e., as-received, -quenched, and -annealed. The average size of the second phase particles in the Zircaloy-4 samples was in the sequence of -quenched < -annealed < as-received, with the reverse sequence being observed in the areal density. Electrochemical studies show that the size and density of the second phase particles are the determining factors of the electrochemical properties of the passive films. The second phase particles may cause short circuits in the electrical path across the passive film, which would explain the effect of the size and the density of the SPPs, and hence heat treatment, on the corrosion properties of passive Zircaloy-4.

  3. Extending the life of water-cooled copper cooling fingers for furnace refractories

    NASA Astrophysics Data System (ADS)

    Plascencia, Gabriel; Utigard, Torstein A.; Plascencia, Gabriel; Jaramillo, David

    2005-10-01

    To extend the service life of refractory linings in high-temperature furnaces, it is becoming common to embed copper cooling devices in the lining. These devices extract enough heat from the hearth of the furnace to freeze a protective thin layer of slag onto the surface of the lining. However, the cooling devices may lose their efficiency over time. It is believed that high-temperature oxidation of copper is responsible for the loss in heat-extraction capacity. To test coolers under severe conditions, immersion tests were carried out in molten matte and slag of laboratory-scale cooling elements protected by various means. A composite cooler was developed that consists of a copper core shielded by a Cu-4 wt.% Al alloy sheet. Although the rate of heat extraction is not as high as that of the un-alloyed copper, this cooler still extracts heat at a very high rate.

  4. Heat transfer characteristics for some coolant additives used for water cooled engines

    SciTech Connect

    Abou-Ziyan, H.Z.; Helali, A.H.B.

    1996-12-31

    Engine coolants contain certain additives to prevent engine overheating or coolant freezing in cold environments. Coolants, also, contain corrosion and rust inhibitors, among other additives. As most engines are using engine cooling solutions, it is of interest to evaluate the effect of engine coolants on the boiling heat transfer coefficient. This has its direct impact on radiator size and environment. This paper describes the apparatus and the measurement techniques. Also, it presents the obtained boiling heat transfer results at different parameters. Three types of engine coolants and their mixtures in distilled water are evaluated, under sub-cooled and saturated boiling conditions. A profound effect of the presence of additives in the coolant, on heat transfer, was clear since changes of heat transfer for different coolants were likely to occur. The results showed that up to 180% improvement of boiling heat transfer coefficient is experienced with some types of coolants. However, at certain concentrations other coolants provide deterioration or not enhancement in the boiling heat transfer characteristics. This investigation proved that there are limitations, which are to be taken into consideration, for the composition of engine coolants in different environments. In warm climates, ethylene glycol should be kept at the minimum concentration required for dissolving other components, whereas borax is beneficial to the enhancement of the heat transfer characteristics.

  5. Topical report : NSTF facilities plan for water-cooled VHTR RCCS : normal operational tests.

    SciTech Connect

    Farmer, M. T.; Kilsdonk, D. J.; Tzanos, C. P.; Lomperski, S.; Aeschlimann, R. W.; Nuclear Engineering Division

    2006-09-01

    As part of the Department of Energy (DOE) Generation IV roadmapping activity, the gas-cooled Very High Temperature Reactor (VHTR) has been selected as the principal concept for hydrogen production and other process-heat applications such as district heating and potable water production. On this basis, the DOE has selected the VHTR for additional R&D with the ultimate goal of demonstrating emission-free electricity and hydrogen production with this advanced reactor concept.

  6. NUCLEAR CHEMISTRY OF WATER-COOLED FUSION REACTORS: ISSUES AND SOLUTIONS

    SciTech Connect

    Petrov, Andrei Y; Flanagan, George F

    2010-01-01

    ITER is an experimental Tokamak fusion energy reactor that is being built in Cadarache, France, in collaboration with seven agencies representing China, the European Union, India, Japan, Republic of Korea, the Russian Federation, and the United States. The main objective of ITER is to demonstrate the scientific and technical feasibility of a controlled fusion reaction An important U.S. contribution is the design, fabrication, and delivery of the Tokamak Cooling Water System (TCWS). This paper describes the main sources of radioactivity in TCWS water, which are the nitrogen isotopes 16N and 17N, tritium, activated corrosion products, and the carbon isotope 14C; the relative contribution of each of these sources to the total radioactive contamination of water; issues related to excess accumulation of these species; and methods to control TCWS radioactivity within acceptable limits. Among these methods are: (1) water purification to minimize corrosion of materials in contact with TCWS water; (2) monitoring of vital chemistry parameters and control of water chemistry; (3) design of proper building structure and/or TCWS loop/geometry configuration; and (4) design of an ITER liquid radwaste facility tailored to TCWS operational requirements. Design of TCWS nuclear chemistry control is crucial to ensuring that the inventory of radioactive species is consistent with the principle of 'As Low as Reasonably Achievable.'

  7. In pursuit of non-phosphorus corrosion inhibitors for cold water cooling systems

    SciTech Connect

    Wyman, D.P.

    1998-12-31

    An exploratory program was conducted to evaluate a number of polymers and carboxylic acid combinations with polymers as non-phosphorus containing, all organic corrosion inhibitors for cold water systems such as evaporative towers. The concentrations of treatment were approximately those which would obtain for current commercial formulations. There was a strong dependency of performance on the aggressiveness of the water, especially the conductivity. The polymers were adequate for non-aggressive waters, and one, polymaleic acid (as the sodium salt) performed reasonably in somewhat more corrosive systems. Certain alkenyl substituted dibasic acids were also found to perform well in the less challenging waters as did simpler dibasic materials such as maleic, fumaric and aspartic acids. A tetrabasic acid with the carboxyl groups located in proximity to each other, BTA, in combination with certain, but, not all, polymers showed considerable promise.

  8. Design of 95 GHz gyrotron based on continuous operation copper solenoid with water cooling.

    PubMed

    Borodin, Dmitri; Ben-Moshe, Roey; Einat, Moshe

    2014-07-01

    The design work for 2nd harmonic 95 GHz, 50 kW gyrotron based on continuous operation copper solenoid is presented. Thermionic magnetron injection gun specifications were calculated according to the linear trade off equation, and simulated with CST program. Numerical code is used for cavity design using the non-uniform string equation as well as particle motion in the "cold" cavity field. The mode TE02 with low Ohmic losses in the cavity walls was chosen as the operating mode. The Solenoid is designed to induce magnetic field of 1.8 T over a length of 40 mm in the interaction region with homogeneity of ±0.34%. The solenoid has six concentric cylindrical segments (and two correction segments) of copper foil windings separated by water channels for cooling. The predicted temperature in continuous operation is below 93 °C. The parameters of the design together with simulation results of the electromagnetic cavity field, magnetic field, electron trajectories, and thermal analyses are presented. PMID:25085157

  9. Design of 95 GHz gyrotron based on continuous operation copper solenoid with water cooling

    SciTech Connect

    Borodin, Dmitri; Ben-Moshe, Roey; Einat, Moshe

    2014-07-15

    The design work for 2nd harmonic 95 GHz, 50 kW gyrotron based on continuous operation copper solenoid is presented. Thermionic magnetron injection gun specifications were calculated according to the linear trade off equation, and simulated with CST program. Numerical code is used for cavity design using the non-uniform string equation as well as particle motion in the “cold” cavity field. The mode TE02 with low Ohmic losses in the cavity walls was chosen as the operating mode. The Solenoid is designed to induce magnetic field of 1.8 T over a length of 40 mm in the interaction region with homogeneity of ±0.34%. The solenoid has six concentric cylindrical segments (and two correction segments) of copper foil windings separated by water channels for cooling. The predicted temperature in continuous operation is below 93 °C. The parameters of the design together with simulation results of the electromagnetic cavity field, magnetic field, electron trajectories, and thermal analyses are presented.

  10. Zirconium carbide coating for corium experiments related to water-cooled and sodium-cooled reactors

    NASA Astrophysics Data System (ADS)

    Plevacova, K.; Journeau, C.; Piluso, P.; Zhdanov, V.; Baklanov, V.; Poirier, J.

    2011-07-01

    Since the TMI and Chernobyl accidents the risk of nuclear severe accident is intensively studied for existing and future reactors. In case of a core melt-down accident in a nuclear reactor, a complex melt, called corium, forms. To be able to perform experiments with prototypic corium materials at high temperature, a coating which resists to different corium melts related to Generation I and II Water Reactors and Generation IV sodium fast reactor was researched in our experimental platforms both in IAE NNC in Kazakhstan and in CEA in France. Zirconium carbide was selected as protective coating for graphite crucibles used in our induction furnaces: VCG-135 and VITI. The method of coating application, called reactive wetting, was developed. Zirconium carbide revealed to resist well to the (U x, Zr y)O 2-z water reactor corium. It has also the advantage not to bring new elements to this chemical system. The coating was then tested with sodium fast reactor corium melts containing steel or absorbers. Undesirable interactions were observed between the coating and these materials, leading to the carburization of the corium ingots. Concerning the resistance of the coating to oxide melts without ZrO 2, the zirconium carbide coating keeps its role of protective barrier with UO 2-Al 2O 3 below 2000 °C but does not resist to a UO 2-Eu 2O 3 mixture.

  11. Thermal-hydraulic limitations on water-cooled fusion reactor components

    SciTech Connect

    Cha, Y.S.; Misra, B.

    1986-01-01

    An assessment of the cooling requirements for fusion reactor components, such as the first wall and limiter/divertor, was carried out using pressurized water as the coolant. In order to establish the coolant operating conditions, a survey of the literature on departure from nucleate boiling, critical heat flux, asymmetrical heating and heat transfer augmentation techniques was carried out. The experimental data and the empirical correlations indicate that thermal protection for the fusion reactor components based on conventional design concepts can be provided with an adequate margin of safety without resorting to either high coolant velocities, excessive coolant pressures, or heat transfer augmentation techniques. If, however, the future designs require unconventional shapes or heat transfer enhancement techniques, experimental verification would be necessary since no data on heat transfer augmentation techniques exist for complex geometries, especially under asymmetrically heated conditions. Since the data presented herein are concerned primarily with thermal protection of the reactor components, the final design should consider other factors such as thermal stresses, temperature limits, and fatigue.

  12. Temperature-time distribution and thermal stresses on the RTG fins and shell during water cooling

    NASA Technical Reports Server (NTRS)

    Turner, R. H.

    1983-01-01

    Radioisotope thermoelectric generator (RTG) packages designed for space missions generally do not require active cooling. However, the heat they generate cannot remain inside of the launch vehicle bay and requires active removal. Therefore, before the Shuttle bay door is closed, the RTG coolant tubes attached to the heat rejection fins must be filled with water, which will circulate and remove most of the heat from the cargo bay. There is concern that charging a system at initial temperature around 200 C with water at 24 C can cause unacceptable thermal stresses in the RTG shell and fins. A computer model is developed to estimate the transient temperature distribution resulting from such charging. The thermal stresses resulting from the temperature gradients do not exceed the elastic deformation limit for the material. Since the simplified mathematical model for thermal stresses tends to overestimate stresses, it is concluded that the RTG can be cooled by introducing water at 24 C to the initially hot fin coolant tubes while the RTG is in the Shuttle cargo bay.

  13. Experiments on FTU with an actively water cooled liquid lithium limiter

    NASA Astrophysics Data System (ADS)

    Mazzitelli, G.; Apicella, M. L.; Apruzzese, G.; Crescenzi, F.; Iannone, F.; Maddaluno, G.; Pericoli-Ridolfini, V.; Roccella, S.; Reale, M.; Viola, B.; Lyublinski, I.; Vertkov, A.

    2015-08-01

    In order to prevent the overheating of the liquid Li surface and the consequent Li evaporation for T > 500 °C, an advanced version of the liquid lithium limiter has been realized and installed on FTU. This new system, named Cooled Lithium Limiter (CLL), has been optimized to demonstrate the lithium limiter capability to sustain thermal loads as high as 10 MW/m2 with up to 5 s of plasma pulse duration. The CLL operates with an actively cooled system with water circulation at the temperature of about 200 °C, for heating lithium up to the melting point and for the heat removal during the plasma discharges. To characterize CLL during discharges, a fast infrared camera and the spectroscopic signals from Li and D atom emission have been used. The experiments analyzed so far and simulated by ANSYS code, point out that heat loads as high as 2 MW/m2 for 1.5 s have been withstood without problems.

  14. Effect of Water Cooling on the Performances of Friction Stir Welding Heat-Affected Zone

    NASA Astrophysics Data System (ADS)

    Zhang, H. J.; Liu, H. J.; Yu, L.

    2012-07-01

    The heat-affected zone (HAZ) is generally the intrinsic weakest location of the normal friction stir welded precipitate hardened aluminum alloys. In order to improve the mechanical properties of the HAZ by controlling the temperature level, underwater friction stir welding (FSW) of an Al-Cu aluminum alloy was conducted in the present study. The results indicate that the hardness of the HAZ can be improved through underwater FSW. Microstructural analysis reveals that the hardness improvement is attributed to the lowering of precipitate coarsening level and the narrowing of precipitate free zone, which are essentially induced by the variations of welding thermal cycles under the cooling effect of water.

  15. Apparatus and method of direct water cooling several parallel circuit cards each containing several chip packages

    DOEpatents

    Cipolla, Thomas M.; Colgan, Evan George; Coteus, Paul W.; Hall, Shawn Anthony; Tian, Shurong

    2011-12-20

    A cooling apparatus, system and like method for an electronic device includes a plurality of heat producing electronic devices affixed to a wiring substrate. A plurality of heat transfer assemblies each include heat spreaders and thermally communicate with the heat producing electronic devices for transferring heat from the heat producing electronic devices to the heat transfer assemblies. The plurality of heat producing electronic devices and respective heat transfer assemblies are positioned on the wiring substrate having the regions overlapping. A heat conduit thermally communicates with the heat transfer assemblies. The heat conduit circulates thermally conductive fluid therethrough in a closed loop for transferring heat to the fluid from the heat transfer assemblies via the heat spreader. A thermally conductive support structure supports the heat conduit and thermally communicates with the heat transfer assemblies via the heat spreader transferring heat to the fluid of the heat conduit from the support structure.

  16. Power electronics for low power arcjets

    NASA Technical Reports Server (NTRS)

    Hamley, John A.; Hill, Gerald M.

    1991-01-01

    In anticipation of the needs of future light-weight, low-power spacecraft, arcjet power electronics in the 100 to 400 W operating range were developed. Limited spacecraft power and thermal control capacity of these small spacecraft emphasized the need for high efficiency. Power topologies similar to those in the higher 2 kW and 5 to 30 kW power range were implemented, including a four transistor bridge switching circuit, current mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter. Electromagnetic compatibility requirements were not considered in this work, and control power for the converter was derived from AC mains. Addition of input filters and control power converters would result in an efficiency of on the order of 90 percent for a flight unit. Due to the developmental nature of arcjet systems at this power level, the exact nature of the thruster/power processor interface was not quantified. Output regulation and current ripple requirements of 1 and 20 percent respectively, as well as starting techniques, were derived from the characteristics of the 2 kW system but an open circuit voltage in excess of 175 V was specified. Arcjet integration tests were performed, resulting in successful starts and stable arcjet operation at power levels as low as 240 W with simulated hydrazine propellants.

  17. Combination power plant

    SciTech Connect

    Nakamoto, Y.; Terayama, T.

    1983-11-29

    A combination power plant is disclosed including an ocean thermal energy conversion power plant and a steam generation power plant. Water discharged from a condenser in the ocean thermal energy conversion power plant is mixed with water discharged from an evaporator in the ocean thermal energy conversion power plant. The mixed water is used as cooling water for a condenser in the steam generation power plant. Part of the water discharged from the condenser in the steam generation power plant is used as heating water for the evaporator in the ocean thermal energy conversion power plant.

  18. Wireless power transmission technology state of the art the first Bill Brown lecture

    NASA Astrophysics Data System (ADS)

    Dickinson, Richard M.

    2003-08-01

    This first Bill Brown SSP Technology Lecture covers the state-of-the-art (SOA) in wireless power transmission (WPT) technology including microwave and laser systems for the transfer of CW electric power, as related to eventually developing Space Solar Power (SSP) systems. Current and past technology accomplishments in ground based and air and space applied energy conversion devices, systems and modeling information is presented, where such data are known to the author. The purpose of the presentation is to discuss and present data to encourage documenting and breaking the current records, so as to advance the SOA in WPT for SSP. For example, regarding DC to RF and laser converters, 83% efficient 2.45 GHz cooker-tube magnetrons with 800 W CW output have been developed by CPII and the Russians. Over 50% wall-plug efficient 1.5 kW/cm 2 CW, water-cooled, multibeam, solid state laser diode bar-arrays have been developed by LLNL at 808 nm wavelength. The Germans have developed a 36% efficient, kW level, single coherent beam, lateral pumped semiconductor laser. The record for end-to-end DC input to DC output power overall WPT link conversion efficiency is 54% achieved during the Raytheon-JPL experiments in 1975 for 495.6 W recovered at 1.7 -m range, at 2.4469 GHz The record for usefully recovered electric power output (as contrasted with thermally induced power in structures) is 34 kW DC output at a range of 1.55 km, using 2.388 GHz microwaves, during the JPL-Raytheon experiments by Bill Brown and the author at Goldstone, CA in 1975. The GaAs-diode rectenna array had an average collection-conversion efficiency of 82.5%. A single rectenna element developed by Bill Brown demonstrated 91.4% efficiency. The comparable record for laser light to DC output power conversion efficiency of photovoltaics is 59%, for AlGaAs at 1.7 W and 826-nm wavelength.

  19. Fibre-coupled air-cooled high-power diode laser systems

    NASA Astrophysics Data System (ADS)

    Bartoschewski, Daniel; Meinschien, Jens; Fornahl, Udo

    2008-02-01

    Current laser systems based on high-power laser diode bars need active cooling either water cooling or the use of thermo-electric coolers to ensure an adequate operating temperature for a reasonable lifetime. Here is a solution with a bonded fin heat sink and forced ventilation introduced, a diode laser bar with an improved efficiency and a low thermal resistance as well as an optical system for a highly efficient fibre coupling. With this system it is possible to couple 25 Watt continuous wave power from a single laser diode bar on a passive heat sink into a fibre with 200 μm core diameter. The basis for this performance is a heat sink with an exceptionally low thermal resistance. Several new features are introduced to reach a low overall gradient between the laser diode temperature and the ambient temperature. In addition, it does geometrically fit to the layout of the optical design. Shape and aspect ratio of both heat sink and housing of the laser system are matched to each other. Another feature is the use of hard-soldered or pressed bars to achieve a thermo-mechanically stable performance. The long-term thermal characteristic was tested. The operation temperature comes to saturation after about 30 minutes. Therefore it can be used for continuous wave operation at 25 Watt output power. At a quasi continuous operation at 70 percent duty cycle a peak power of 30 Watt out of the fibre is possible. From this technology results a compact fibre coupled laser system what is simple to drive compared with current high power laser systems, because there is no need to control the operating temperature. This gives way for more compact driver solutions. Fields of application are laser marking systems and material processing, where a simple driver system is requested. Also medical applications need this requirement and a compact cooling too so that mobile integrated solutions become possible. Further developments allow multiple laser diode systems for specific industrial applications demanding more power. Our measurements show the potential for direct air-cooled laser systems with 100 Watt power out of the fibre.

  20. Synchronous Generator with HTS-2G field coils for Windmills with output power 1 MW

    NASA Astrophysics Data System (ADS)

    Kovalev, K.; Kovalev, L.; Poltavets, V.; Samsonovich, S.; Ilyasov, R.; Levin, A.; Surin, M.

    2014-05-01

    Nowadays synchronous generators for wind-mills are developed worldwide. The cost of the generator is determined by its size and weight. In this deal the implementation of HTS-2G generators is very perspective. The application of HTS 2G field coils in the rotor allows to reduce the size of the generator is 1.75 times. In this work the design 1 MW HTS-2G generator is considered. The designed 1 MW HTS-2G generator has the following parameters: rotor diameter 800 mm, active length 400 mm, phase voltage 690V, rotor speed 600 min-1 rotor field coils with HTS-2G tapes. HTS-2G field coils located in the rotating cryostat and cooled by liquid nitrogen. The simulation and optimization of HTS-2G field coils geometry allowed to increase feed DC current up to 50A. Copper stator windings are water cooled. Magnetic and electrical losses in 1 MW HTS-2G generator do not exceed 1.6% of the nominal output power. In the construction of HTS-2G generator the wave multiplier with ratio 1:40 is used. The latter allows to reduce the total mass of HTS-2G generator down to 1.5 tons. The small-scale model of HTS-2G generator with output power 50 kW was designed, manufactured and tested. The test results showed good agreement with calculation results. The manufacturing of 1 MW HTS-2G generator is planned in 2014. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry".

  1. High rep rate high performance plasma focus as a powerful radiation source

    SciTech Connect

    Lee, S.; Lee, P.; Zhang, G.; Feng, X.; Liu, M.; Serban, A.; Wong, T.K.S.; Gribkov, V.A.

    1998-08-01

    Basic operational characteristics of the plasma focus are considered from design perspectives to develop powerful radiation sources. Using these ideas the authors have developed two compact plasma focus (CPF) devices operating in neon with high performance and high repetition rate capacity for use as an intense soft X-ray (SXR) source for microelectronics lithography. The NX1 is a four-module system with a peak current of 320 kA when the capacitor bank (7.8 {micro}F {times} 4) is charged to 14 kV. It produces 100 J of SXR per shot (4% wall plug efficiency) giving at 3 Hz, 300 W of average SXR power into 4{pi}. The NX2 is also a four-module system. Each module uses a rail gap switching 12 capacitors each with a capacity of 0.6 {micro}F. The NX2 operates with peak currents of 400 kA at 11.5 kV into water-cooled electrodes at repetition rates up to 16 Hz to produce 300 W SXR in burst durations of several minutes. SXR lithographs are taken from both machines to demonstrate that sufficient SXR lithographs are taken from both machines to demonstrate that sufficient SXR flux is generated for an exposure with only 300 shots. In addition, flash electron lithographs are also obtained requiring only ten shots per exposure. Such high performance compact machines may be improved to yield over 1 kW of SXR, enabling sufficient exposure throughput to be of interest to the wafer industry. In deuterium the neutron yield could be over 10{sup 10} neutrons per second over prolonged bursts of minutes.

  2. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Godfroy, Thomas J.

    2008-01-01

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

  3. Offshore Floating Wind Turbine-driven Deep Sea Water Pumping for Combined Electrical Power and District Cooling

    NASA Astrophysics Data System (ADS)

    Sant, T.; Buhagiar, D.; Farrugia, R. N.

    2014-06-01

    A new concept utilising floating wind turbines to exploit the low temperatures of deep sea water for space cooling in buildings is presented. The approach is based on offshore hydraulic wind turbines pumping pressurised deep sea water to a centralised plant consisting of a hydro-electric power system coupled to a large-scale sea water-cooled air conditioning (AC) unit of an urban district cooling network. In order to investigate the potential advantages of this new concept over conventional technologies, a simplified model for performance simulation of a vapour compression AC unit was applied independently to three different systems, with the AC unit operating with (1) a constant flow of sea surface water, (2) a constant flow of sea water consisting of a mixture of surface sea water and deep sea water delivered by a single offshore hydraulic wind turbine and (3) an intermittent flow of deep sea water pumped by a single offshore hydraulic wind turbine. The analysis was based on one year of wind and ambient temperature data for the Central Mediterranean that is known for its deep waters, warm climate and relatively low wind speeds. The study confirmed that while the present concept is less efficient than conventional turbines utilising grid-connected electrical generators, a significant portion of the losses associated with the hydraulic transmission through the pipeline are offset by the extraction of cool deep sea water which reduces the electricity consumption of urban air-conditioning units.

  4. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    SciTech Connect

    Polzin, Kurt A.; Godfroy, Thomas J.

    2008-01-21

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m{sup 3}/hr.

  5. Ideological Power in Education

    ERIC Educational Resources Information Center

    Laursen, Per F.

    2006-01-01

    This article agues that ideological power plays an important role in education and that it is part of a general trend in policy and social sciences to underestimate ideological and overestimate the role of political and economic power. The article sketches a concept of power in general and especially of ideological power based primarily on the…

  6. Wind Power Now!

    ERIC Educational Resources Information Center

    Inglis, David Rittenhouse

    1975-01-01

    The government promotes and heavily subsidizes research in nuclear power plants. Federal development of wind power is slow in comparison even though much research with large wind-electric machines has already been conducted. Unless wind power programs are accelerated it will not become a major energy alternative to nuclear power. (MR)

  7. Power system restoration issues

    SciTech Connect

    Adibi, M.M. ); Kafka, R.J. )

    1991-04-01

    This article describes some of the problems encountered in the three phases of power system restoration (PSR). The three phases of PSR are: Planning for restart and reintegration of the bulk power supply; Actions during system degradation for saving and retaining critical sources of power; Restoration when the power system has stabilized at some degraded level.

  8. Programable Power Conditioner

    NASA Technical Reports Server (NTRS)

    Lanier, J. R.; Kapustka, R. E.; Graves, J. R.

    1984-01-01

    Accepts range of inputs and produces range of outputs. Versatile power conditioner programed to handle power from wide range of sources such as solar arrays, fuel cells, and electrochemical batteries. Conditioner consists of two parts. Power stage is switching regulator. Controller stage uses microprocessor to generate analog control signal for power stage.

  9. Human Powered Centrifuge

    NASA Technical Reports Server (NTRS)

    Mulenburg, Gerald M. (Inventor); Vernikos, Joan (Inventor)

    1997-01-01

    A human powered centrifuge has independently established turntable angular velocity and human power input. A control system allows excess input power to be stored as electric energy in a battery or dissipated as heat through a resistors. In a mechanical embodiment, the excess power is dissipated in a friction brake.

  10. Planning for Power.

    ERIC Educational Resources Information Center

    Failla, Victor A.; Birk, Thomas A.

    1999-01-01

    Discusses the electrical power problems that can arise when schools try to integrate educational technology components into an existing facility, and how to plan the electrical power design to avoid power failures. Examines setting objectives, evaluating current electrical conditions, and developing the technology power design. (GR)

  11. Power Switching Device

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The MOS-Controlled Thyristor is a new type of power switching device for faster and more efficient control and management of power electronics. It enables power electronic switching at frequencies of 50 to 100 thousand times a second with much lower power losses than other semiconductor devices. Advantages include electric power savings and smaller space. The device is used in motor and power controllers, AC & DC motor drives and induction heating. Early development was supported by Lewis Research Center (LEW) and other agencies. General Electric''s power semiconductor operation, the initial NASA contractor, was later purchased by Harris Semiconductor.

  12. Geothermal Power Generation

    SciTech Connect

    2007-11-15

    The report provides an overview of the renewed market interest in using geothermal for power generation including a concise look at what's driving interest in geothermal power generation, the current status of geothermal power generation, and plans for the future. Topics covered in the report include: an overview of geothermal power generation including its history, the current market environment, and its future prospects; an analysis of the key business factors that are driving renewed interest in geothermal power generation; an analysis of the challenges that are hindering the implementation of geothermal power generation projects; a description of geothermal power generation technologies; a review of the economic drivers of geothermal power generation project success; profiles of the major geothermal power producing countries; and, profiles of the major geothermal power project developers.

  13. Power Plant Systems Analysis

    NASA Technical Reports Server (NTRS)

    Williams, J. R.; Yang, Y. Y.

    1973-01-01

    Three basic thermodynamic cycles of advanced nuclear MHD power plant systems are studied. The effect of reactor exit temperature and space radiator temperature on the overall thermal efficiency of a regenerative turbine compressor power plant system is shown. The effect of MHD pressure ratio on plant efficiency is also described, along with the dependence of MHD power output, compressor power requirement, turbine power output, mass flow rate of H2, and overall plant efficiency on the reactor exit temperature for a specific configuration.

  14. Evolution of Carbide Precipitates in 2.25Cr-1Mo Steel during Long-Term Service in a Power Plant

    NASA Astrophysics Data System (ADS)

    Yang, Yong; Chen, Yiren; Sridharan, Kumar; Allen, Todd R.

    2010-03-01

    Carbide precipitation from the steel matrix during long-term high-temperature exposure can adversely affect the fracture toughness and high-temperature creep resistance of materials with implications on the performance of power plant components. In the present work, carbide evolution in 2.25Cr-1Mo steel after long-term aging during service was investigated. Boiler pipe samples of this steel were removed from a supercritical water-cooled coal-fired power plant after service times of 17 and 28 years and a mean operational temperature of 810 K (537 °C). The carbide precipitation and coarsening effects were studied using the carbon extraction replica technique followed by analysis using transmission electron microscopy and energy dispersive X-ray spectroscopy. The carbides extracted using an electrolytic technique were also analyzed using X-ray diffraction to evaluate phase transformations of the carbides during long-term service. Small ball punch and Vickers hardness were used to evaluate the changes in mechanical performance after long-term aging during service.

  15. Evolution of carbide precipitates in 2.25Cr-1Mo steel during long-term service in a power plant.

    SciTech Connect

    Yang, Y.; Chen, Y.; Sridharan, K.; Allen, T. R.; Nuclear Engineering Division; Univ. of Wisconsin at Madison

    2010-06-01

    Carbide precipitation from the steel matrix during long-term high-temperature exposure can adversely affect the fracture toughness and high-temperature creep resistance of materials with implications on the performance of power plant components. In the present work, carbide evolution in 2.25Cr-1Mo steel after long-term aging during service was investigated. Boiler pipe samples of this steel were removed from a supercritical water-cooled coal-fired power plant after service times of 17 and 28 years and a mean operational temperature of 810 K (537C). The carbide precipitation and coarsening effects were studied using the carbon extraction replica technique followed by analysis using transmission electron microscopy and energy dispersive X-ray spectroscopy. The carbides extracted using an electrolytic technique were also analyzed using X-ray diffraction to evaluate phase transformations of the carbides during long-term service. Small ball punch and Vickers hardness were used to evaluate the changes in mechanical performance after long-term aging during service.

  16. High power fast ramping power supplies

    SciTech Connect

    Marneris,I.; Bajon, E.; Bonati, R.; Sandberg, J.; Roser, T.; Tsoupas, N.

    2009-05-04

    Hundred megawatt level fast ramping power converters to drive proton and heavy ion machines are under research and development at accelerator facilities in the world. This is a leading edge technology. There are several topologies to achieve this power level. Their advantages and related issues will be discussed.

  17. The power of PowerPoint.

    PubMed

    Niamtu, J

    2001-08-01

    Carousel slide presentations have been used for academic and clinical presentations since the late 1950s. However, advances in computer technology have caused a paradigm shift, and digital presentations are quickly becoming standard for clinical presentations. The advantages of digital presentations include cost savings; portability; easy updating capability; Internet access; multimedia functions, such as animation, pictures, video, and sound; and customization to augment audience interest and attention. Microsoft PowerPoint has emerged as the most popular digital presentation software and is currently used by many practitioners with and without significant computer expertise. The user-friendly platform of PowerPoint enables even the novice presenter to incorporate digital presentations into his or her profession. PowerPoint offers many advanced options that, with a minimal investment of time, can be used to create more interactive and professional presentations for lectures, patient education, and marketing. Examples of advanced PowerPoint applications are presented in a stepwise manner to unveil the full power of PowerPoint. By incorporating these techniques, medical practitioners can easily personalize, customize, and enhance their PowerPoint presentations. Complications, pitfalls, and caveats are discussed to detour and prevent misadventures in digital presentations. Relevant Web sites are listed to further update, customize, and communicate PowerPoint techniques. PMID:11496193

  18. Active Power Control from Wind Power (Presentation)

    SciTech Connect

    Ela, E.; Brooks, D.

    2011-04-01

    In order to keep the electricity grid stable and the lights on, the power system relies on certain responses from its generating fleet. This presentation evaluates the potential for wind turbines and wind power plants to provide these services and assist the grid during critical times.

  19. Power and revenge.

    PubMed

    Strelan, Peter; Weick, Mario; Vasiljevic, Milica

    2014-09-01

    We took an individual differences approach to explain revenge tendencies in powerholders. Across four experimental studies, chronically powerless individuals sought more revenge than chronically powerful individuals following a high power episode (Studies 1 and 2), when striking a powerful pose (Study 3), and when making a powerful hand gesture (Study 4). This relationship vanished when participants were not exposed to incidental power. A meta-analysis revealed that, relative to a lack of power or a neutral context, exposure to incidental power increased vengeance among the chronically powerless and reduced vengeance among the chronically powerful. These findings add to previous research on relations between power and aggression, and underscore the role of individual differences as a determinant of powerholders' destructive responses. PMID:23841749

  20. Space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Carpenter, R. T.

    1972-01-01

    Space nuclear power systems are considered for use in those particular spacecraft applications for which nuclear power systems offer unique advantages over solar and/or chemical space power systems. Both isotopic and reactor heated space electrical power units are described in an attempt to illustrate their operating characteristics, spacecraft integration aspects, and factory-to-end of mission operational considerations. The status of technology developments in nuclear power systems is presented. Some projections of those technologies are made to form a basis for the applications of space nuclear power systems to be expected over the next 10-15 years.

  1. Steady-state operation of a large-area high-power RF ion source for the neutral beam injector

    NASA Astrophysics Data System (ADS)

    Chang, Doo-Hee; Park, Min; Jeong, Seung Ho; Kim, Tae-Seong; Lee, Kwang Won; In, Sang Ryul

    2014-10-01

    A large-area high-power RF-driven ion source is being developed in Germany for the heating and current drive (H&CD) of an ITER device. Negative hydrogen ion sources are the major components of neutral beam injection systems in future large-scale fusion devices such as an the ITER and the DEMO. The first and the second long-pulse ion sources (LPIS-1 and LPIS-2) have been successfully developed with a magnetic-bucket plasma generator, including a filament heating structure for the first NBI (NBI-1) system of the KSTAR tokamak. A development plan exists for a large-area high-power RF ion source for steady-state operation (more than 300 seconds) at the Korea Atomic Energy Research Institute (KAERI) to extract positive ions, which can be used for the NBI heating and current drive systems, and to extract negative ions for future fusion devices such as a Fusion Neutron Source and Korea — DEMO. The RF ion source consists of a driver region, including a helical antenna and a discharge chamber, and an expansion region (magnetic bucket of the prototype LPIS-1). RF power can be transferred at up to 10 kW with a fixed frequency of 2 MHz through an optimized RF matching system. An actively water-cooled Faraday shield is located inside the driver region of the ion source for stable and steady-state operation of the RF discharge. The uniformities of the plasma parameters are measured at the lowest area of the expansion bucket by using two RF-compensated electrostatic probes along the directions of the short and the long dimensions of the expansion region.

  2. Power beaming providing a space power infrastructure

    SciTech Connect

    Bamberger, J.A.; Coomes, E.P.

    1992-08-01

    This study, based on two levels of technology, applies the power beaming concept to four planned satellite constellations. The analysis shows that with currently available technology, power beaming can provide mass savings to constellations in orbits ranging from low earth orbit to geosynchronous orbit. Two constellations, space surveillance and tracking system and space based radar, can be supported with current technology. The other two constellations, space-based laser array and boost surveillance and tracking system, will require power and transmission system improvements before their breakeven specific mass is achieved. A doubling of SP-100 conversion efficiency from 10 to 20/% would meet or exceed breakeven for these constellations.

  3. Maximum power tracking

    SciTech Connect

    O'Sullivan, G.

    1983-03-01

    By definition, a maximum power tracking device causes the photovoltaic array to operate on the locus of maximum power points within a specified accuracy. There are limitations to the application of maximum power tracking. A prerequisite is that the load be capable of absorbing all of the power availble at all times. Battery chargers, electrical heaters, water pumps, and most significantly, returning power to the utility grid, are prime examples of applications that are adaptable to maximum power tracking. Maximum power tracking is available to either dc or ac loads. An inverter equipped with a means of changing input voltage by controlling its input impedance can deliver maximum power to ac loads. The inverter can be fixed or variable frequency and fixed or variable voltage, but must be compatible with the ac load. The discussion includes applications, techniques, and cost factors.

  4. Space Solar Power Program

    SciTech Connect

    Arif, H.; Barbosa, H.; Bardet, C.; Baroud, M.; Behar, A.; Berrier, K.; Berthe, P.; Bertrand, R.; Bibyk, I.; Bisson, J.; Bloch, L.; Bobadilla, G.; Bourque, D.; Bush, L.; Carandang, R.; Chiku, T.; Crosby, N.; De Seixas, M.; De Vries, J.; Doll, S.; Dufour, F.; Eckart, P.; Fahey, M.; Fenot, F.; Foeckersperger, S.; Fontaine, J.E.; Fowler, R.; Frey, H.; Fujio, H.; Gasa, J.M.; Gleave, J.; Godoe, J.; Green, I.; Haeberli, R.; Hanada, T.; Ha

    1992-08-01

    Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

  5. Technologies. [space power sources

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.

    1992-01-01

    Energy technologies to meet the power requirements of future space missions are reviewed. Photovoltaic, solar dynamic, and solar thermal technologies are discussed along with techniques for energy storage and power management and distribution.

  6. Synchronizing redundant power oscillators

    NASA Technical Reports Server (NTRS)

    Jenson, K. J.

    1969-01-01

    Outputs of oscillators are synchronized by summing the power transformer phase voltages, the summed voltages are applied to the frequency determining inductors of the individual voltage-controlled power oscillators. The beat frequency is eliminated when synchronization is achieved.

  7. Electrical power generating system

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (inventor)

    1983-01-01

    A power generating system for adjusting coupling an induction motor, as a generator, to an A.C. power line wherein the motor and power line are connected through a triac is described. The triac is regulated to normally turn on at a relatively late point in each half cycle of its operation, whereby at less than operating speed, and thus when the induction motor functions as a motor rather than as a generator, power consumption from the line is substantially reduced.

  8. Switched power workshop. [Switched power electron guns

    SciTech Connect

    Palmer, R.B.

    1988-01-01

    This paper discusses the design of a switched power electron gun. Particular topics discussed are: vacuum photodiode switch; laser switched solid state diodes; gun performance; charging supply; and laser requirements. (LSP)

  9. Solar lunar power

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Landis, Geoffrey A.

    1994-01-01

    Current and projected technology is assessed for photovoltaic power for a lunar base. The following topics are discussed: requirements for power during the lunar day and night; solar cell efficiencies, specific power, temperature sensitivity, and availability; storage options for the lunar night; array and system integration; the potential for in situ production of photovoltaic arrays and storage medium.

  10. Fluid Power Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2008-01-01

    Fluid power technicians, sometimes called hydraulic and pneumatic technicians, work with equipment that utilizes the pressure of a liquid or gas in a closed container to transmit, multiply, or control power. Working under the supervision of an engineer or engineering staff, they assemble, install, maintain, and test fluid power equipment.

  11. The Administrative Power Grab

    ERIC Educational Resources Information Center

    Sorenson, Richard D.

    2007-01-01

    Administrative power for some school teachers can be an aphrodisiac that can be applied negatively, especially when a leader has devastating instinct for the weaknesses of others. A leader's intellect and heart closes shop and ceases to function when drunk on power. In this article, the author describes how the use of administrative power can be…

  12. Power Plant Cycling Costs

    SciTech Connect

    Kumar, N.; Besuner, P.; Lefton, S.; Agan, D.; Hilleman, D.

    2012-07-01

    This report provides a detailed review of the most up to date data available on power plant cycling costs. The primary objective of this report is to increase awareness of power plant cycling cost, the use of these costs in renewable integration studies and to stimulate debate between policymakers, system dispatchers, plant personnel and power utilities.

  13. Power for nursing education.

    PubMed

    Glen, S

    1990-11-01

    The topic of power and politics is a recurrent theme in the nursing literature, but not, I wish to suggest, in the nursing educational literature. This paper introduces the topic of power as a nursing educational issue. It is divided into three sections: (a) what a concept of power might mean for nursing education; (b) the nature and form of power relationships within nursing education; and (c) the nature, form and efficacy of the current professional strategies to gain power. First, two definitions of power for nursing education are explored: (a) the power inherent in organizational structures; and (b) the notion of practising nursing education as an empowering profession. Next, a theoretical framework is applied to specific examples of power relationships within nursing education. Two views of power and their inter-relationship with decision-making in curriculum matters are described: 'overt conflict' and 'control of the institution's agenda'. It is argued that these still fail to pick up important instances of the strategies to gain power. Finally, examples of strategies used to gain power in colleges of nursing are made explicit. Concurrently, questions are raised in relation to their efficacy and alternative strategies more congruent with the role of professional educator are advocated. It is argued that nursing education's most lasting form of power will rest in the development of pedagogical knowledge expertise and a research basis: in essence, the development of an academic identity in nursing education. PMID:2269757

  14. Solar power conditioner

    NASA Technical Reports Server (NTRS)

    Jan, L.; Johnson, N.; Lindena, S.; Mclyman, W. T.; Solario, J. N.

    1979-01-01

    Efficient power-conditioning circuit designed to utilize maximum power available from solar cell array, controls output of array so that excess energy not needed by load is diverted to charge batteries for reserve power when sufficient sunlight is not available.

  15. Space laser power transmission

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Proposed laser transmission applications are reviewed. Technologies for laser power transmissions are assessed. Feasible laser mission systems are set out. Components by wavelength are summarized. Feasible space to space laser power transmission systems are summarized. Space laser transmitter masses for 1 MW and 100 KW output power are summarized.

  16. Aircraft Electric Secondary Power

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed.

  17. Fluid Power Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2008-01-01

    Fluid power technicians, sometimes called hydraulic and pneumatic technicians, work with equipment that utilizes the pressure of a liquid or gas in a closed container to transmit, multiply, or control power. Working under the supervision of an engineer or engineering staff, they assemble, install, maintain, and test fluid power equipment.…

  18. Photovoltaic power system applications

    SciTech Connect

    Hasti, D.E.

    1994-04-01

    This article is an overview of Photovoltaic Power System applications. Photovoltaic power system range in size from watts to megawatts. They are the most modular of all electric power generating systems. PV systems produce electricity for a wide variety of applications. They can be placed in almost any location in the world, and beyond when space applications are included. When PV power for watches, calculators, and similar consumer electronic products is included in the definition of PV power system, system sizes are even smaller and applications more numerous.

  19. Multimegawatt space power reactors

    SciTech Connect

    Dearien, J.A.; Whitbeck, J.F.

    1989-01-01

    In response to the need of the Strategic Defense Initiative (SDI) and long range space exploration and extra-terrestrial basing by the National Air and Space Administration (NASA), concepts for nuclear power systems in the multi-megawatt levels are being designed and evaluated. The requirements for these power systems are being driven primarily by the need to minimize weight and maximize safety and reliability. This paper will discuss the present requirements for space based advanced power systems, technological issues associated with the development of these advanced nuclear power systems, and some of the concepts proposed for generating large amounts of power in space. 31 figs.

  20. Power Simulator for Smartphones

    NASA Astrophysics Data System (ADS)

    Gkolemis, Nikolaos

    The ability to accurately estimate the power and energy dissipation of a smartphone, based on different running applications, has been a crucial demand for both mobile companies and mobile users. Pre-existing solutions are either calibrated for specific devices or lack accuracy due to the use of oversimplified power models or operating restrictions. The developed power simulator for smartphones described here is the first complete attempt to combine generalized power models together with sequential and parallel application execution algorithms and a user friendly graphical user interface in order to create a power

  1. Revealing power in truth

    PubMed Central

    Lee, Kelley

    2015-01-01

    Jeremy Shiffman’s editorial appropriately calls on making all forms of power more apparent and accountable, notably productive power derived from expertise and claims to moral authority. This commentary argues that relationships based on productive power can be especially difficult to reveal in global health policy because of embedded notions about the nature of power and politics. Yet, it is essential to recognize that global health is shot through with power relationships, that they can take many forms, and that their explicit acknowledgement should be part of, rather than factored out of, any reform of global health governance. PMID:25844390

  2. ADEPT: Efficient Power Conversion

    SciTech Connect

    2011-01-01

    ADEPT Project: In today’s increasingly electrified world, power conversion—the process of converting electricity between different currents, voltage levels, and frequencies—forms a vital link between the electronic devices we use every day and the sources of power required to run them. The 14 projects that make up ARPA-E’s ADEPT Project, short for “Agile Delivery of Electrical Power Technology,” are paving the way for more energy efficient power conversion and advancing the basic building blocks of power conversion: circuits, transistors, inductors, transformers, and capacitors.

  3. Multimode power processor

    DOEpatents

    O'Sullivan, George A.; O'Sullivan, Joseph A.

    1999-01-01

    In one embodiment, a power processor which operates in three modes: an inverter mode wherein power is delivered from a battery to an AC power grid or load; a battery charger mode wherein the battery is charged by a generator; and a parallel mode wherein the generator supplies power to the AC power grid or load in parallel with the battery. In the parallel mode, the system adapts to arbitrary non-linear loads. The power processor may operate on a per-phase basis wherein the load may be synthetically transferred from one phase to another by way of a bumpless transfer which causes no interruption of power to the load when transferring energy sources. Voltage transients and frequency transients delivered to the load when switching between the generator and battery sources are minimized, thereby providing an uninterruptible power supply. The power processor may be used as part of a hybrid electrical power source system which may contain, in one embodiment, a photovoltaic array, diesel engine, and battery power sources.

  4. Multimode power processor

    DOEpatents

    O'Sullivan, G.A.; O'Sullivan, J.A.

    1999-07-27

    In one embodiment, a power processor which operates in three modes: an inverter mode wherein power is delivered from a battery to an AC power grid or load; a battery charger mode wherein the battery is charged by a generator; and a parallel mode wherein the generator supplies power to the AC power grid or load in parallel with the battery. In the parallel mode, the system adapts to arbitrary non-linear loads. The power processor may operate on a per-phase basis wherein the load may be synthetically transferred from one phase to another by way of a bumpless transfer which causes no interruption of power to the load when transferring energy sources. Voltage transients and frequency transients delivered to the load when switching between the generator and battery sources are minimized, thereby providing an uninterruptible power supply. The power processor may be used as part of a hybrid electrical power source system which may contain, in one embodiment, a photovoltaic array, diesel engine, and battery power sources. 31 figs.

  5. Nuclear Power in Space

    DOE R&D Accomplishments Database

    1994-01-01

    In the early years of the United States space program, lightweight batteries, fuel cells, and solar modules provided electric power for space missions. As missions became more ambitious and complex, power needs increased and scientists investigated various options to meet these challenging power requirements. One of the options was nuclear energy. By the mid-1950s, research had begun in earnest on ways to use nuclear power in space. These efforts resulted in the first radioisotope thermoelectric generators (RTGs), which are nuclear power generators build specifically for space and special terrestrial uses. These RTGs convert the heat generated from the natural decay of their radioactive fuel into electricity. RTGs have powered many spacecraft used for exploring the outer planets of the solar system and orbiting the sun and Earth. They have also landed on Mars and the moon. They provide the power that enables us to see and learn about even the farthermost objects in our solar system.

  6. 1995 Rural electric power conference

    SciTech Connect

    1995-12-31

    This contains the proceedings of the 39th Annual Rural Electric Power Conference, 1995. The topics of the papers include automation of fault location, load management, automation of power distribution systems, reliability, load forecasting, training, power transmission lines and cables, power conditioning, power system topology management, engineering analysis, wind power plants, data communication in power distribution systems.

  7. Review of High Temperature Water and Steam Cooled Reactor Concepts

    SciTech Connect

    Oka, Yoshiaki

    2002-07-01

    This review summarizes design concepts of supercritical-pressure water cooled reactors (SCR), nuclear superheaters and steam cooled fast reactors from 1950's to the present time. It includes water moderated supercritical steam cooled reactor, SCOTT-R and SC-PWR of Westinghouse, heavy water moderated light water cooled SCR of GE, SCLWR and SCFR of the University of Tokyo, B-500SKDI of Kurchatov Institute, CANDU -X of AECL, nuclear superheaters of GE, subcritical-pressure steam cooled FBR of KFK and B and W, Supercritical-pressure steam cooled FBR of B and W, subcritical-pressure steam cooled high converter by Edlund and Schultz and subcritical-pressure water-steam cooled FBR by Alekseev. This paper is prepared based on the previous review of SCR2000 symposium, and some author's comments are added. (author)

  8. On power and empowerment.

    PubMed

    Pratto, Felicia

    2016-03-01

    This study presents a conceptual analysis of social power. The most common theories of power are social-relational, an approach instantiated in a range of contemporary experiments that give participants the chance to control other people's outcomes. The relational approach is also reflected in various analyses of international relations. In comparing and contrasting relational theories of power, I identify logical inconsistencies and shortcomings in their ability to address empowerment and reductions in inequality. In turn, I propose a new ecological conceptualization of empowerment as the state of being able to achieve one's goals and of power as stemming from a combination of the capacity of the party and the affordances of the environment. I explain how this new conceptualization can describe the main kinds of power social relations, avoid logical contradictions, and moreover, distinguish power from agency and from control. This new conceptualization of power as the possibility of meeting goals, coupled with recognizing survival as the fundamental goal of all living things, implies an absolute and not relative or relational standard for power, namely well-being. It also allows us to conceive of power in ways that help address the many social concerns that have motivated research on power. PMID:26690541

  9. High power communication satellites power systems study

    NASA Astrophysics Data System (ADS)

    Josloff, Allan T.; Peterson, Jerry R.

    1995-01-01

    This paper discusses a planned study to evaluate the commercial attractiveness of high power communication satellites and assesses the attributes of both conventional photovoltaic and reactor power systems. These high power satellites can play a vital role in assuring availability of universally accessible, wide bandwidth communications, for high definition TV, super computer networks and other services. Satellites are ideally suited to provide the wide bandwidths and data rates required and are unique in the ability to provide services directly to the users. As new or relocated markets arise, satellites offer a flexibility that conventional distribution services cannot match, and it is no longer necessary to be near population centers to take advantage of the telecommunication revolution. The geopolitical implications of these substantially enhanced communications capabilities can be significant.

  10. Power Quality Aspects in a Wind Power Plant: Preprint

    SciTech Connect

    Muljadi, E.; Butterfield, C. P.; Chacon, J.; Romanowitz, H.

    2006-01-01

    Although many operational aspects affect wind power plant operation, this paper focuses on power quality. Because a wind power plant is connected to the grid, it is very important to understand the sources of disturbances that affect the power quality.

  11. Power-constrained supercomputing

    NASA Astrophysics Data System (ADS)

    Bailey, Peter E.

    As we approach exascale systems, power is turning from an optimization goal to a critical operating constraint. With power bounds imposed by both stakeholders and the limitations of existing infrastructure, achieving practical exascale computing will therefore rely on optimizing performance subject to a power constraint. However, this requirement should not add to the burden of application developers; optimizing the runtime environment given restricted power will primarily be the job of high-performance system software. In this dissertation, we explore this area and develop new techniques that extract maximum performance subject to a particular power constraint. These techniques include a method to find theoretical optimal performance, a runtime system that shifts power in real time to improve performance, and a node-level prediction model for selecting power-efficient operating points. We use a linear programming (LP) formulation to optimize application schedules under various power constraints, where a schedule consists of a DVFS state and number of OpenMP threads for each section of computation between consecutive message passing events. We also provide a more flexible mixed integer-linear (ILP) formulation and show that the resulting schedules closely match schedules from the LP formulation. Across four applications, we use our LP-derived upper bounds to show that current approaches trail optimal, power-constrained performance by up to 41%. This demonstrates limitations of current systems, and our LP formulation provides future optimization approaches with a quantitative optimization target. We also introduce Conductor, a run-time system that intelligently distributes available power to nodes and cores to improve performance. The key techniques used are configuration space exploration and adaptive power balancing. Configuration exploration dynamically selects the optimal thread concurrency level and DVFS state subject to a hardware-enforced power bound. Adaptive power balancing efficiently predicts where critical paths are likely to occur and distributes power to those paths. Greater power, in turn, allows increased thread concurrency levels, CPU frequency/voltage, or both. We describe these techniques in detail and show that, compared to the state-of-the-art technique of using statically predetermined, per-node power caps, Conductor leads to a best-case performance improvement of up to 30%, and an average improvement of 19.1%. At the node level, an accurate power/performance model will aid in selecting the right configuration from a large set of available configurations. We present a novel approach to generate such a model offline using kernel clustering and multivariate linear regression. Our model requires only two iterations to select a configuration, which provides a significant advantage over exhaustive search-based strategies. We apply our model to predict power and performance for different applications using arbitrary configurations, and show that our model, when used with hardware frequency-limiting in a runtime system, selects configurations with significantly higher performance at a given power limit than those chosen by frequency-limiting alone. When applied to a set of 36 computational kernels from a range of applications, our model accurately predicts power and performance; our runtime system based on the model maintains 91% of optimal performance while meeting power constraints 88% of the time. When the runtime system violates a power constraint, it exceeds the constraint by only 6% in the average case, while simultaneously achieving 54% more performance than an oracle. Through the combination of the above contributions, we hope to provide guidance and inspiration to research practitioners working on runtime systems for power-constrained environments. We also hope this dissertation will draw attention to the need for software and runtime-controlled power management under power constraints at various levels, from the processor level to the cluster level.

  12. Comparative Assessment of Gasification Based Coal Power Plants with Various CO2 Capture Technologies Producing Electricity and Hydrogen

    PubMed Central

    2014-01-01

    Seven different types of gasification-based coal conversion processes for producing mainly electricity and in some cases hydrogen (H2), with and without carbon dioxide (CO2) capture, were compared on a consistent basis through simulation studies. The flowsheet for each process was developed in a chemical process simulation tool “Aspen Plus”. The pressure swing adsorption (PSA), physical absorption (Selexol), and chemical looping combustion (CLC) technologies were separately analyzed for processes with CO2 capture. The performances of the above three capture technologies were compared with respect to energetic and exergetic efficiencies, and the level of CO2 emission. The effect of air separation unit (ASU) and gas turbine (GT) integration on the power output of all the CO2 capture cases is assessed. Sensitivity analysis was carried out for the CLC process (electricity-only case) to examine the effect of temperature and water-cooling of the air reactor on the overall efficiency of the process. The results show that, when only electricity production in considered, the case using CLC technology has an electrical efficiency 1.3% and 2.3% higher than the PSA and Selexol based cases, respectively. The CLC based process achieves an overall CO2 capture efficiency of 99.9% in contrast to 89.9% for PSA and 93.5% for Selexol based processes. The overall efficiency of the CLC case for combined electricity and H2 production is marginally higher (by 0.3%) than Selexol and lower (by 0.6%) than PSA cases. The integration between the ASU and GT units benefits all three technologies in terms of electrical efficiency. Furthermore, our results suggest that it is favorable to operate the air reactor of the CLC process at higher temperatures with excess air supply in order to achieve higher power efficiency. PMID:24578590

  13. Comparative Assessment of Gasification Based Coal Power Plants with Various CO2 Capture Technologies Producing Electricity and Hydrogen.

    PubMed

    Mukherjee, Sanjay; Kumar, Prashant; Hosseini, Ali; Yang, Aidong; Fennell, Paul

    2014-02-20

    Seven different types of gasification-based coal conversion processes for producing mainly electricity and in some cases hydrogen (H2), with and without carbon dioxide (CO2) capture, were compared on a consistent basis through simulation studies. The flowsheet for each process was developed in a chemical process simulation tool "Aspen Plus". The pressure swing adsorption (PSA), physical absorption (Selexol), and chemical looping combustion (CLC) technologies were separately analyzed for processes with CO2 capture. The performances of the above three capture technologies were compared with respect to energetic and exergetic efficiencies, and the level of CO2 emission. The effect of air separation unit (ASU) and gas turbine (GT) integration on the power output of all the CO2 capture cases is assessed. Sensitivity analysis was carried out for the CLC process (electricity-only case) to examine the effect of temperature and water-cooling of the air reactor on the overall efficiency of the process. The results show that, when only electricity production in considered, the case using CLC technology has an electrical efficiency 1.3% and 2.3% higher than the PSA and Selexol based cases, respectively. The CLC based process achieves an overall CO2 capture efficiency of 99.9% in contrast to 89.9% for PSA and 93.5% for Selexol based processes. The overall efficiency of the CLC case for combined electricity and H2 production is marginally higher (by 0.3%) than Selexol and lower (by 0.6%) than PSA cases. The integration between the ASU and GT units benefits all three technologies in terms of electrical efficiency. Furthermore, our results suggest that it is favorable to operate the air reactor of the CLC process at higher temperatures with excess air supply in order to achieve higher power efficiency. PMID:24578590

  14. Peak power ratio generator

    DOEpatents

    Moyer, Robert D.

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  15. Power Subscription Strategy

    SciTech Connect

    None, None

    1998-12-21

    This document lays out the Bonneville Power Administration`s Power Subscription Strategy, a process that will enable the people of the Pacific Northwest to share the benefits of the Federal Columbia river Power System after 2001 while retaining those benefits within the region for future generations. The strategy also addresses how those who receive the benefits of the region`s low-cost federal power should share a corresponding measure of the risks. This strategy seeks to implement the subscription concept created by the Comprehensive Review in 1996 through contracts for the sale of power and the distribution of federal power benefits in the deregulated wholesale electricity market. The success of the subscription process is fundamental to BPA`s overall business purpose to provide public benefits to the Northwest through commercially successful businesses.

  16. Self-powered sensors.

    PubMed

    Arechederra, Robert L; Minteer, Shelley D

    2011-06-01

    One of the problems associated with miniaturization and portability of sensors is the power supply. Power supplies, such as batteries, are difficult to miniaturize and require a sensor design that allows for easy replacement or recharging. This review describes the field of self-powered sensing, where the sensor itself provides the power for the sensing device. Most self-powered-sensing strategies employ either nuclear energy conversion or electrochemical energy conversion. Nuclear energy conversion is employed for radioisotope or nuclear reactor sensing. Electrochemical energy conversion is employed for chemical and biological sensing. This review details the common strategies for self-powered nuclear, chemical, and biological sensing and discusses the future of the technology. PMID:21359574

  17. Peak power ratio generator

    DOEpatents

    Moyer, R.D.

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  18. Space station power system

    NASA Technical Reports Server (NTRS)

    Baraona, Cosmo R.

    1987-01-01

    The major requirements and guidelines that affect the space station configuration and power system are explained. The evolution of the space station power system from the NASA program development-feasibility phase through the current preliminary design phase is described. Several early station concepts are described and linked to the present concept. Trade study selections of photovoltaic system technologies are described in detail. A summary of present solar dynamic and power management and distribution systems is also given.

  19. Power subsystem automation study

    NASA Technical Reports Server (NTRS)

    Tietz, J. C.; Sewy, D.; Pickering, C.; Sauers, R.

    1984-01-01

    The purpose of the phase 2 of the power subsystem automation study was to demonstrate the feasibility of using computer software to manage an aspect of the electrical power subsystem on a space station. The state of the art in expert systems software was investigated in this study. This effort resulted in the demonstration of prototype expert system software for managing one aspect of a simulated space station power subsystem.

  20. Switching power supply filter

    NASA Technical Reports Server (NTRS)

    Kumar, Prithvi R. (Inventor); Abare, Wayne (Inventor)

    1989-01-01

    A filter for a switching power supply. The filter includes a common mode inductor with coil configurations allowing differential mode current from a dc source to pass through but attenuating common mode noise from the power supply so that the noise does not reach the dc source. The invention also includes the use of feed through capacitors at the switching power supply input terminals to provide further high-frequency noise attenuation.

  1. Unified powered flight guidance

    NASA Technical Reports Server (NTRS)

    Brand, T. J.; Brown, D. W.; Higgins, J. P.

    1973-01-01

    A complete revision of the orbiter powered flight guidance scheme is presented. A unified approach to powered flight guidance was taken to accommodate all phases of exo-atmospheric orbiter powered flight, from ascent through deorbit. The guidance scheme was changed from the previous modified version of the Lambert Aim Point Maneuver Mode used in Apollo to one that employs linear tangent guidance concepts. This document replaces the previous ascent phase equation document.

  2. Electric power annual 1993

    SciTech Connect

    Not Available

    1994-12-08

    This report presents a summary of electric power industry statistics at national, regional, and state levels: generating capability and additions, net generation, fossil-fuel statistics, retail sales and revenue, finanical statistics, environmental statistics, power transactions, demand side management, nonutility power producers. Purpose is to provide industry decisionmakers, government policymakers, analysts, and the public with historical data that may be used in understanding US electricity markets.

  3. Interleaved power converter

    DOEpatents

    Zhu, Lizhi

    2007-11-13

    A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.

  4. Power systems integration

    SciTech Connect

    Brantley, L.W.

    1982-06-01

    Power systems integration in large flexible space structures is discussed with emphasis upon body control. A solar array is discussed as a typical example of spacecraft configuration problems. Information on how electric batteries dominate life-cycle costs is presented in chart form. Information is given on liquid metal droplet generators and collectors, hot spot analysis, power dissipation in solar arrays, solar array protection optimization, and electromagnetic compatibility for a power system platform.

  5. Nuclear power browning out

    SciTech Connect

    Flavin, C.; Lenssen, N.

    1996-05-01

    When the sad history of nuclear power is written, April 26, 1986, will be recorded as the day the dream died. The explosion at the Chernobyl plant was a terrible human tragedy- and it delivered a stark verdict on the hope that nuclear power will one day replace fossil fuel-based energy systems. Nuclear advocates may soldier on, but a decade after Chernobyl it is clear that nuclear power is no longer a viable energy option for the twenty-first century.

  6. NEP power subsystem modeling

    NASA Technical Reports Server (NTRS)

    Harty, Richard B.

    1993-01-01

    The Nuclear Electric Propulsion (NEP) system optimization code consists of a master module and various submodules. Each of the submodules represents a subsystem within the total NEP power system. The master module sends commands and input data to each of the submodules and receives output data back. Rocketdyne was responsible for preparing submodules for the power conversion (both K-Rankine and Brayton), heat rejection, and power management and distribution.

  7. CSTI High Capacity Power

    NASA Technical Reports Server (NTRS)

    Winter, Jerry M.

    1989-01-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY-86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase 1 of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY-88, the Advanced Technology Program was incorporated into NASA's new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  8. Hybrid Power Management (HPM)

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2007-01-01

    The NASA Glenn Research Center s Avionics, Power and Communications Branch of the Engineering and Systems Division initiated the Hybrid Power Management (HPM) Program for the GRC Technology Transfer and Partnership Office. HPM is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors and fuel cells. HPM has extremely wide potential. Applications include power generation, transportation systems, biotechnology systems, and space power systems. HPM has the potential to significantly alleviate global energy concerns, improve the environment, and stimulate the economy. One of the unique power devices being utilized by HPM for energy storage is the ultracapacitor. An ultracapacitor is an electrochemical energy storage device, which has extremely high volumetric capacitance energy due to high surface area electrodes, and very small electrode separation. Ultracapacitors are a reliable, long life, maintenance free, energy storage system. This flexible operating system can be applied to all power systems to significantly improve system efficiency, reliability, and performance. There are many existing and conceptual applications of HPM.

  9. The pesky power asymmetry

    NASA Astrophysics Data System (ADS)

    Dai, Liang; Jeong, Donghui; Kamionkowski, Marc; Chluba, Jens

    2013-06-01

    Physical models for the hemispherical power asymmetry in the cosmic microwave background (CMB) reported by the Planck Collaboration must satisfy CMB constraints to the homogeneity of the Universe and quasar constraints to power asymmetries. We survey a variety of models for the power asymmetry and show that consistent models include a modulated scale-dependent isocurvature contribution to the matter power spectrum or a modulation of the reionization optical depth, gravitational-wave amplitude, or scalar spectral index. We propose further tests to distinguish between the different scenarios.

  10. A power fund focus

    SciTech Connect

    Hennagir, T.

    1996-04-01

    The Indeck North American Power Fund LP, which was formed for the purpose of purchasing established non-utility and utility power generating assets in the U.S. and Canada, is discussed in this article. Fund participants are listed, and the two acquisitions made to date are described. The 38 MW(e) Pepperell Power Project in Massachussets was acquired in August 1995 from Kenetech Energy Systems Inc. In October 1995, the Fund purchased the 76 MW(e) Harbor Cogeneration Project in California. The Fund will also consider purchasing equity interests in North American power projects.

  11. A private power plan

    SciTech Connect

    Thompson, M.K.

    1995-09-01

    The South Korean market for electric power equipment and services is booming. Electricity demand is forecast to grow at an average annual rate of 6.4% during 1993 to 2006. Recognizing the importance of abundant, quality and reliable electric power to continued economic growth, the Korean government plans to build 76 new power plants by 2006. More than $5 billion per year will be spent by Korean Electric Power Corp. and its affiliates. The size of the market and the program of economic reforms that is being implemented make this an attractive opportunity for US companies.

  12. Power Factor Controller Study.

    SciTech Connect

    Knudson Engineers, Inc.

    1989-08-01

    The complete report is divided into three parts as follows: (1) This report combines a historical perspective with a current assessment of the use of power factor controllers for three-phase ac motor energy savings. The power factor controller (PFC) is a power electronics device that reduces voltage to a motor during periods of reduced motor torque requirements. (2) A power factor controller (PFC) is a power electronics device that reduces voltage to a motor during periods of reduced motor torque requirements. This report is the DEMONSTRATION phase of the PFC study. The phase report consists of three task reports -- Site Selection, Demonstration Preparation, and Demonstration. The reports explain how three sites were selected for demonstration, describe what was measured at each site and the method of measurement, and compare measured energy savings with calculated predictions of energy savings. The report concludes that PFCs can save energy on carefully selected motor applications. (3) The results of the demonstration task are described in this report. A power factor controller (PFC) is a power electronics device that reduces voltage to a motor during periods of reduced motor torque requirements. The demonstration phase of this study calculates projected energy savings with the use of a PFC and compares measured performance with the calculations. The effect of the PFC on motor power requirements, power factor and energy consumption shall be measured.

  13. Can solar power deliver?

    PubMed

    Nelson, Jenny; Emmott, Christopher J M

    2013-08-13

    Solar power represents a vast resource which could, in principle, meet the world's needs for clean power generation. Recent growth in the use of photovoltaic (PV) technology has demonstrated the potential of solar power to deliver on a large scale. Whilst the dominant PV technology is based on crystalline silicon, a wide variety of alternative PV materials and device concepts have been explored in an attempt to decrease the cost of the photovoltaic electricity. This article explores the potential for such emerging technologies to deliver cost reductions, scalability of manufacture, rapid carbon mitigation and new science in order to accelerate the uptake of solar power technologies. PMID:23816915

  14. Power beaming options

    NASA Technical Reports Server (NTRS)

    Rather, John D. G.

    1989-01-01

    Some large scale power beaming applications are proposed for the purpose of stimulating research. The first proposal is for a combination of large phased arrays on the ground near power stations and passive reflectors in geostationary orbit. The systems would beam excess electrical power in microwave form to areas in need of electrical power. Another proposal is to build solar arrays in deserts and beam the energy around the world. Another proposal is to use lasers to beam energy from earth to orbiting spacecraft.

  15. CSTI high capacity power

    SciTech Connect

    Winter, J.M.

    1994-09-01

    The SP-100 program was established in 1983 by DOD, DOE, and NASA as a joint program to develop the technology necessary for space nuclear power systems for military and civil application. During FY86 and 87, the NASA SP-100 Advanced Technology Program was devised to maintain the momentum of promising technology advancement efforts started during Phase I of SP-100 and to strengthen, in key areas, the chances for successful development and growth capability of space nuclear reactor power systems for future space applications. In FY88, the Advanced Technology Program was incorporated into NASA`s new Civil Space Technology Initiative (CSTI). The CSTI Program was established to provide the foundation for technology development in automation and robotics, information, propulsion, and power. The CSTI High Capacity Power Program builds on the technology efforts of the SP-100 program, incorporates the previous NASA SP-100 Advanced Technology project, and provides a bridge to NASA Project Pathfinder. The elements of CSTI High Capacity Power development include Conversion Systems, Thermal Management, Power Management, System Diagnostics, and Environmental Interactions. Technology advancement in all areas, including materials, is required to assure the high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall program will develop and demonstrate the technology base required to provide a wide range of modular power systems as well as allowing mission independence from solar and orbital attitude requirements. Several recent advancements in CSTI High Capacity power development will be discussed.

  16. Application Power Signature Analysis

    SciTech Connect

    Hsu, Chung-Hsing; Combs, Jacob; Nazor, Jolie; Santiago, Fabian; Thysell, Rachelle; Rivoire, Suzanne; Poole, Stephen W

    2014-01-01

    The high-performance computing (HPC) community has been greatly concerned about energy efficiency. To address this concern, it is essential to understand and characterize the electrical loads of HPC applications. In this work, we study whether HPC applications can be distinguished by their power-consumption patterns using quantitative measures in an automatic manner. Using a collection of 88 power traces from 4 different systems, we find that basic statistical measures do a surprisingly good job of summarizing applications' distinctive power behavior. Moreover, this study opens up a new area of research in power-aware HPC that has a multitude of potential applications.

  17. Peak Power Markets for Satellite Solar Power

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.

    2002-01-01

    This paper introduces first Indonesia, comprises 15,000 islands, has land area of two millions square kilometers. Extending from 95 to 141 degrees East longitude and from 6 degrees North to 11 degrees South latitude. Further the market of the Space Solar Power/SPS must be worldwide, including Indonesia. As we know, it can provide electricity anywhere in the world from the Earth's orbit, mostly Indonesia an equator country. We have to perform case studies of various countries to understand their benefits and disadvantages provided by the SSP, because each country has much different condition on energy from other countries. We are at the moment starting the international collaboration between Indonesia and Japan to carry out the case study for Indonesia. We understand that in Indonesia itself each province has much different micro-climate between one province compared to the other. In Japan, METI (Ministry of Economy, Trade and Industry) has already organized a committee to investigate the feasibility of Space Solar Power and to make a plan to launch a space demonstration of the SPS. While, Indonesia is quickly developing economy and increasing their energy demand. We are investigating the detailed energy conditions of Indonesia, the benefits and disadvantages of the Space Solar Power for Indonesia. Especially, we will perform the investigation on the receiving system for the Japanese pilot Space Power Satellite.

  18. On the Powers of Powerful Knowledge

    ERIC Educational Resources Information Center

    Young, Michael; Muller, Johan

    2014-01-01

    The aim of this paper is to explore and clarify the idea of "powerful knowledge" as a sociological concept and as a curriculum principle. The paper seeks to clarify its conceptual basis and to make its meaning and the arguments it implies, less ambiguous and less open to misunderstanding. This will enable us to suggest some of the…

  19. Power system commonality study

    NASA Astrophysics Data System (ADS)

    Littman, Franklin D.

    1992-07-01

    A limited top level study was completed to determine the commonality of power system/subsystem concepts within potential lunar and Mars surface power system architectures. A list of power system concepts with high commonality was developed which can be used to synthesize power system architectures which minimize development cost. Examples of potential high commonality power system architectures are given in this report along with a mass comparison. Other criteria such as life cycle cost (which includes transportation cost), reliability, safety, risk, and operability should be used in future, more detailed studies to select optimum power system architectures. Nineteen potential power system concepts were identified and evaluated for planetary surface applications including photovoltaic arrays with energy storage, isotope, and nuclear power systems. A top level environmental factors study was completed to assess environmental impacts on the identified power system concepts for both lunar and Mars applications. Potential power system design solutions for commonality between Mars and lunar applications were identified. Isotope, photovoltaic array (PVA), regenerative fuel cell (RFC), stainless steel liquid-metal cooled reactors (less than 1033 K maximum) with dynamic converters, and in-core thermionic reactor systems were found suitable for both lunar and Mars environments. The use of SP-100 thermoelectric (TE) and SP-100 dynamic power systems in a vacuum enclosure may also be possible for Mars applications although several issues need to be investigated further (potential single point failure of enclosure, mass penalty of enclosure and active pumping system, additional installation time and complexity). There are also technical issues involved with development of thermionic reactors (life, serviceability, and adaptability to other power conversion units). Additional studies are required to determine the optimum reactor concept for Mars applications. Various screening criteria (availability, environmental compatibility, mass competitiveness of energy storage, safety, and practicality for the application) were used to define concept applicability for each lunar and Mars application. A screening study resulted in 13 power systems for lunar applications and 15 for Mars applications. A commonality analysis showed several power systems with potentially high commonality (across both lunar and Mars applications). These high commonality systems include d PVA/RFC, dynamic isotope (1033 K Stirling, 1133 K Brayton, and 1300 K Brayton PCU's), SP-100 TE and dynamic derivatives (Mars systems required vacuum enclosure), in-core thermionic reactor, and liquid metal cooled reactor/Stirling cycle (1033 K). The generic commonality results were used to synthesize 3 high commonality power system architectures: (1) predominantly PV (limited nuclear and isotope), (2) predominantly in-core thermionic reactor/DIPS, and (3) predominantly SP-100 reactor/DIPS. The in-core thermionic reactor/DIPS power system architecture had the lowest total mass. Specific outputs from this study included lists of power system requirements, power system candidates, a power system application matrix, power system characteristics (mass), power system commonality ratings, example high commonality power system architectures, architecture masses, and issues/design solutions for lunar/Mars commonality.

  20. Limits to Tidal Power

    NASA Astrophysics Data System (ADS)

    Garrett, C.

    2008-12-01

    Ocean tides have been proposed as a source of renewable energy, though the maximum available power may be shown to be only a fraction of the present dissipation rate of 3.5 TW, which is small compared with global insolation (nearly 105 TW), wind dissipation (103 TW), and even human power usage of 15 TW. Nonetheless, tidal power could be a useful contributor in some locations. Traditional use of tidal power, involving the trapping of water behind a barrage at high tide, can produce an average power proportional to the area of the headpond and the square of the tidal range; the power density is approximately 6 W per square meter for a tidal range of 10 m. Capital costs and fears of environmental damage have put barrage schemes in disfavor, with interest turning to the exploitation of strong tidal currents, using turbines in a manner similar to wind turbines. There is a limit to the available power, however, as adding turbines reduces the flow, ultimately reducing the power. For sinusoidal forcing of flow in a channel connecting two large open basins, the maximum available power may be shown to be given approximately by 0.2ρ g a Q_max, where ρ is the water density, g gravity, a the amplitude of the tidal sea level difference along the channel, and Q_max is the maximum volume flux in the natural state. The same formula applies if the channel is the entrance to a semi-enclosed basin, with a now the amplitude of the external tide. A flow reduction of approximately 40% is typically associated with the maximum power extraction. The power would be reduced if only smaller environmental changes are acceptable, and reduced further by drag on supporting structures, dissipation in turbine wakes, and internal inefficiencies. It can be suggested that the best use of strong, cold, tidal currents is to provide cooling water for nuclear reactors.

  1. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Ashworth, Barry; Riedesel, Joel; Myers, Chris; Miller, William; Jones, Ellen F.; Freeman, Kenneth; Walsh, Richard; Walls, Bryan K.; Weeks, David J.; Bechtel, Robert T.

    1992-01-01

    Autonomous power-distribution system includes power-control equipment and automation equipment. System automatically schedules connection of power to loads and reconfigures itself when it detects fault. Potential terrestrial applications include optimization of consumption of power in homes, power supplies for autonomous land vehicles and vessels, and power supplies for automated industrial processes.

  2. Power from Ocean Waves.

    ERIC Educational Resources Information Center

    Newman, J. N.

    1979-01-01

    Discussed is the utilization of surface ocean waves as a potential source of power. Simple and large-scale wave power devices and conversion systems are described. Alternative utilizations, environmental impacts, and future prospects of this alternative energy source are detailed. (BT)

  3. Miniature Radioisotope Power Source

    NASA Technical Reports Server (NTRS)

    Chmielewski, Artur B.

    1995-01-01

    Proposed miniature power source generates electricity for years from heat developed in small radioisotope unit without addition of fuel or dependence on sunlight. Called powerstick, is relatively inexpensive, lightweight, and rugged. Supplies power to small vehicles or scientific instruments in remote locations on Earth or in outer space. Envisioned uses include Mars miniature rovers and monitoring equipment for toxic or nuclear storage sites.

  4. Language, Power and Identity

    ERIC Educational Resources Information Center

    Wodak, Ruth

    2012-01-01

    How are identities constructed in discourse? How are national and European identities tied to language and communication? And what role does power have--power in discourse, over discourse and of discourse? This paper seeks to identify and analyse processes of identity construction within Europe and at its boundaries, particularly the diversity of…

  5. Talk About Nuclear Power

    ERIC Educational Resources Information Center

    Tremlett, Lewis

    1976-01-01

    Presents an overview of the relation of nuclear power to human health and the environment, and discusses the advantages and disadvantages of nuclear power as an energy source urging technical educators to inculcate an awareness of the problems associated with the production of energy. Describes the fission reaction process, the hazards of…

  6. Power plant design

    SciTech Connect

    Khalil, E.E. )

    1990-01-01

    This overviews basic theories and concepts of power plant design using an accessible approach that moves smoothly from simple to real configurations. Utilizing a large number of worked examples the book provides a treatment and understanding of all aspects of power plant design from basic thermodynamics to complex applications.

  7. Automotive Power Trains.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide mechanics with an understanding of the operation, maintenance, and troubleshooting of automotive power trains and certain auxiliary equipment. The course contains six study units covering basic power trains; clutch principles and operations; conventional…

  8. Laser power transmission

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.

    1992-01-01

    An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

  9. Power-Switching Circuit

    NASA Technical Reports Server (NTRS)

    Praver, Gerald A.; Theisinger, Peter C.; Genofsky, John

    1987-01-01

    Functions of circuit breakers, meters, and switches combined. Circuit that includes power field-effect transistors (PFET's) provides on/off switching, soft starting, current monitoring, current tripping, and protection against overcurrent for 30-Vdc power supply at normal load currents up to 2 A. Has no moving parts.

  10. Solar Powered Refrigeration System

    NASA Technical Reports Server (NTRS)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  11. Electrically powered hand tool

    DOEpatents

    Myers, Kurt S.; Reed, Teddy R.

    2007-01-16

    An electrically powered hand tool is described and which includes a three phase electrical motor having a plurality of poles; an electrical motor drive electrically coupled with the three phase electrical motor; and a source of electrical power which is converted to greater than about 208 volts three-phase and which is electrically coupled with the electrical motor drive.

  12. Power Station Design

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Kuljian Corporation provides design engineering and construction management services for power generating plants in more than 20 countries. They used WASP (Calculating Water and Steam Properties), a COSMIC program to optimize power station design. This enabled the company to substantially reduce lead time and software cost in a recent design project.

  13. Nuclear stopping power

    SciTech Connect

    WA80 Collaboration

    1991-12-31

    Estimators of the stopping power and the attainable energy density in high energy p+A and A+A collisions are discussed. Scaling laws for the stopping power and the energy densities are derived based on a phenomenological parameterization of transverse energy data from the WA80 collaborations at CERN. The shortcomings of the widely used Bjorken formula are discussed.

  14. Reshaping the power industry

    SciTech Connect

    Flaving, C.; Lenssen, N.K.

    1995-05-01

    This paper discusses some of the trends that are reshaping the traditional electric power industry. These include shutting down expensive nuclear reactors, investment in renewable energy technologies, encouragement of customers to install energy efficient lights, windows, and appliances, construction of small, independent power generation plants, retail wheeling, and diversification of utilities into the service sector.

  15. Playing with Powers

    ERIC Educational Resources Information Center

    Sriraman, Bharath; Strzelecki, Pawel

    2004-01-01

    This paper explores the wide range of pure mathematics that becomes accessible through the use of problems involving powers. In particular we stress the need to balance an applied and context based pedagogical and curricular approach to mathematics with the powerful pure mathematics beneath the simplicity of easily stated and understandable…

  16. Nuclear Power Plants. Revised.

    ERIC Educational Resources Information Center

    Lyerly, Ray L.; Mitchell, Walter, III

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. Among the topics discussed are: Why Use Nuclear Power?; From Atoms to Electricity; Reactor Types; Typical Plant Design Features; The Cost of Nuclear Power; Plants in the United States; Developments in Foreign…

  17. The Power of Feedback

    ERIC Educational Resources Information Center

    Hattie, John; Timperley, Helen

    2007-01-01

    Feedback is one of the most powerful influences on learning and achievement, but this impact can be either positive or negative. Its power is frequently mentioned in articles about learning and teaching, but surprisingly few recent studies have systematically investigated its meaning. This article provides a conceptual analysis of feedback and

  18. Explorations in Statistics: Power

    ERIC Educational Resources Information Center

    Curran-Everett, Douglas

    2010-01-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This fifth installment of "Explorations in Statistics" revisits power, a concept fundamental to the test of a null hypothesis. Power is the probability that we reject the null hypothesis when it is false. Four things affect…

  19. Power API Prototype

    SciTech Connect

    2014-12-04

    The software serves two purposes. The first purpose of the software is to prototype the Sandia High Performance Computing Power Application Programming Interface Specification effort. The specification can be found at http://powerapi.sandia.gov . Prototypes of the specification were developed in parallel with the development of the specification. Release of the prototype will be instructive to anyone who intends to implement the specification. More specifically, our vendor collaborators will benefit from the availability of the prototype. The second is in direct support of the PowerInsight power measurement device, which was co-developed with Penguin Computing. The software provides a cluster wide measurement capability enabled by the PowerInsight device. The software can be used by anyone who purchases a PowerInsight device. The software will allow the user to easily collect power and energy information of a node that is instrumented with PowerInsight. The software can also be used as an example prototype implementation of the High Performance Computing Power Application Programming Interface Specification.

  20. Power of a Plan.

    ERIC Educational Resources Information Center

    Mineo, Ronald W.; Stehn, John L.

    1998-01-01

    Discusses the effects of electric power deregulation on an educational facility's planning and purchasing for future power needs. Highlights ways schools can take advantage of deregulation. Examines various chiller technologies and economically assessing these technologies on a life-cycle cost basis. (GR)

  1. Economical space power systems

    NASA Technical Reports Server (NTRS)

    Burkholder, J. H.

    1980-01-01

    A commercial approach to design and fabrication of an economical space power system is investigated. Cost projections are based on a 2 kW space power system conceptual design taking into consideration the capability for serviceability, constraints of operation in space, and commercial production engineering approaches. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance estimated costs are detailed.

  2. Power API Prototype

    Energy Science and Technology Software Center (ESTSC)

    2014-12-04

    The software serves two purposes. The first purpose of the software is to prototype the Sandia High Performance Computing Power Application Programming Interface Specification effort. The specification can be found at http://powerapi.sandia.gov . Prototypes of the specification were developed in parallel with the development of the specification. Release of the prototype will be instructive to anyone who intends to implement the specification. More specifically, our vendor collaborators will benefit from the availability of the prototype.more » The second is in direct support of the PowerInsight power measurement device, which was co-developed with Penguin Computing. The software provides a cluster wide measurement capability enabled by the PowerInsight device. The software can be used by anyone who purchases a PowerInsight device. The software will allow the user to easily collect power and energy information of a node that is instrumented with PowerInsight. The software can also be used as an example prototype implementation of the High Performance Computing Power Application Programming Interface Specification.« less

  3. NUCLEAR POWER PLANT

    DOEpatents

    Carter, J.C.; Armstrong, R.H.; Janicke, M.J.

    1963-05-14

    A nuclear power plant for use in an airless environment or other environment in which cooling is difficult is described. The power plant includes a boiling mercury reactor, a mercury--vapor turbine in direct cycle therewith, and a radiator for condensing mercury vapor. (AEC)

  4. Talk About Nuclear Power

    ERIC Educational Resources Information Center

    Tremlett, Lewis

    1976-01-01

    Presents an overview of the relation of nuclear power to human health and the environment, and discusses the advantages and disadvantages of nuclear power as an energy source urging technical educators to inculcate an awareness of the problems associated with the production of energy. Describes the fission reaction process, the hazards of

  5. A Balance of Power?

    ERIC Educational Resources Information Center

    Mosey, Edward

    1991-01-01

    The booming economy of the Pacific Northwest region promotes the dilemma of balancing the need for increased electrical power with the desire to maintain that region's unspoiled natural environment. Pertinent factors discussed within the balance equation are population trends, economic considerations, industrial power requirements, and…

  6. Fusion Power Deployment

    SciTech Connect

    J.A. Schmidt; J.M. Ogden

    2002-02-06

    Fusion power plants could be part of a future portfolio of non-carbon dioxide producing energy supplies such as wind, solar, biomass, advanced fission power, and fossil energy with carbon dioxide sequestration. In this paper, we discuss key issues that could impact fusion energy deployment during the last half of this century. These include geographic issues such as resource availability, scale issues, energy storage requirements, and waste issues. The resource needs and waste production associated with fusion deployment in the U.S. should not pose serious problems. One important feature of fusion power is the fact that a fusion power plant should be locatable within most local or regional electrical distribution systems. For this reason, fusion power plants should not increase the burden of long distance power transmission to our distribution system. In contrast to fusion power, regional factors could play an important role in the deployment of renewable resources such as wind, solar and biomass or fossil energy with CO2 sequestration. We examine the role of these regional factors and their implications for fusion power deployment.

  7. Solar Power on Mars

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This chart illustrates the variation in available solar power for each of NASA's twin Mars Exploration Rovers over the course of approximately two Mars years. Two factors affect the amount of available power: the tilt of Mars' axis and the eccentricity of the Mars' orbit about the sun.

    The horizontal scale is the number of Martian days (sols) after the Jan. 4, 2004, (Universal Time) landing of Spirit at Mars' Gusev Crater. The vertical scale on the right indicates the amount of available solar power as a ratio of the amount available at the equator when Mars is closest to the sun (perihelion). The red line indicates power availability at Spirit's landing site (Gusev). The blue line indicates power availability at Opportunity's landing site (Meridiani).

    The vertical scale on the right applies to the dotted line, indicating the latitude north or south of Mars' equator where the noon sun is overhead at different times of the Martian year.

  8. Tuning magnet power supply

    SciTech Connect

    Han, B.M.; Karady, G.G.; Thiessen, H.A.

    1989-01-01

    The particles in a Rapid Cycling Accelerator are accelerated by rf cavities, which are tuned by dc biased ferrite cores. The tuning is achieved by the regulation of bias current, which is produced by a power supply. The tuning magnet power supply utilizes a bridge circuit, supplied by a three phase rectifier. During the rise of the current, when the particles are accelerated, the current is controlled with precision by the bridge which operates a power amplifier. During the fall of the current, the bridge operates in a switching mode and recovers the energy stored in the ferrites. The recovered energy is stored in a capacitor bank. The bridge circuit is built with 150 power transistors. The drive, protection and control circuit were designed and built from commercial component. The system will be used for a rf cavity experiment in Los Alamos and will serve as a prototype tuning power supply for future accelerators. 1 ref., 7 figs.

  9. Biomass power in transition

    SciTech Connect

    Marshall, D.K.

    1996-12-31

    Electricity production from biomass fuel has been hailed in recent years as an environmentally acceptable energy source that delivers on its promise of economically viable renewable energy. A Wall Street Journal article from three years ago proclaimed wood to be {open_quotes}moving ahead of costly solar panels and wind turbines as the leading renewable energy alternative to air-fouling fossils fuels and scary nuclear plants.{close_quotes} Biomass fuel largely means wood; about 90% of biomass generated electricity comes from burning waste wood, the remainder from agricultural wastes. Biomass power now faces an uncertain future. The maturing of the cogeneration and independent power plant market, restructuring of the electric industry, and technological advances with power equipment firing other fuels have placed biomass power in a competitive disadvantage with other power sources.

  10. Space Nuclear Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.

    2012-01-01

    Fission power and propulsion systems can enable exciting space exploration missions. These include bases on the moon and Mars; and the exploration, development, and utilization of the solar system. In the near-term, fission surface power systems could provide abundant, constant, cost-effective power anywhere on the surface of the Moon or Mars, independent of available sunlight. Affordable access to Mars, the asteroid belt, or other destinations could be provided by nuclear thermal rockets. In the further term, high performance fission power supplies could enable both extremely high power levels on planetary surfaces and fission electric propulsion vehicles for rapid, efficient cargo and crew transfer. Advanced fission propulsion systems could eventually allow routine access to the entire solar system. Fission systems could also enable the utilization of resources within the solar system.

  11. Nuclear power plant maintainability.

    PubMed

    Seminara, J L; Parsons, S O

    1982-09-01

    In the mid-1970s a general awareness of human factors engineering deficiencies associated with power plant control rooms took shape and the Electric Power Research Institute (EPRI) awarded the Lockheed Corporation a contract to review the human factors aspects of five representative operational control rooms and their associated simulators. This investigation revealed a host of major and minor deficiencies that assumed unforeseen dimensions in the post- Three Mile Island accident period. In the course of examining operational problems (Seminara et al, 1976) and subsequently the methods for overcoming such problems (Seminara et al, 1979, 1980) indications surfaced that power plants were far from ideal in meeting the needs of maintenance personnel. Accordingly, EPRI sponsored an investigation of the human factors aspects of power plant maintainability (Seminara, 1981). This paper provides an overview of the maintainability problems and issues encountered in the course of reviewing five nuclear power plants. PMID:15676441

  12. High Power Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Jankovsky, Robert; Tverdokhlebov, Sergery; Manzella, David

    1999-01-01

    The development of Hall thrusters with powers ranging from tens of kilowatts to in excess of one hundred kilowatts is considered based on renewed interest in high power. high thrust electric propulsion applications. An approach to develop such thrusters based on previous experience is discussed. It is shown that the previous experimental data taken with thrusters of 10 kW input power and less can be used. Potential mass savings due to the design of high power Hall thrusters are discussed. Both xenon and alternate thruster propellant are considered, as are technological issues that will challenge the design of high power Hall thrusters. Finally, the implications of such a development effort with regard to ground testing and spacecraft intecrati'on issues are discussed.

  13. Power supply conditioning circuit

    NASA Technical Reports Server (NTRS)

    Primas, L. E.; Loveland, R.

    1987-01-01

    A power supply conditioning circuit that can reduce Periodic and Random Deviations (PARD) on the output voltages of dc power supplies to -150 dBV from dc to several KHz with no measurable periodic deviations is described. The PARD for a typical commercial low noise power supply is -74 dBV for frequencies above 20 Hz and is often much worse at frequencies below 20 Hz. The power supply conditioning circuit described here relies on the large differences in the dynamic impedances of a constant current diode and a zener diode to establish a dc voltage with low PARD. Power supplies with low PARD are especially important in circuitry involving ultrastable frequencies for the Deep Space Network.

  14. Power module assembly

    DOEpatents

    Campbell, Jeremy B.; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  15. Comparison and evaluation of power plant options for geosynchronous power stations. Part 1: Synchronous solar power

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1973-01-01

    The present state-of-the-art is described for the development of solar power generators in far out synchronous orbit for power generation. Concepts of geosynchronous solar power satellites are discussed including photovoltaic arrays for power satellites, solar-thermal power satellites, and power transmission to earth.

  16. TEP Power Partners Project [Tucson Electric Power

    SciTech Connect

    None, None

    2014-02-06

    The Arizona Governor’s Office of Energy Policy, in partnership with Tucson Electric Power (TEP), Tendril, and Next Phase Energy (NPE), formed the TEP Power Partners pilot project to demonstrate how residential customers could access their energy usage data and third party applications using data obtained from an Automatic Meter Reading (AMR) network. The project applied for and was awarded a Smart Grid Data Access grant through the U.S. Department of Energy. The project participants’ goal for Phase I is to actively engage 1,700 residential customers to demonstrate sustained participation, reduction in energy usage (kWh) and cost ($), and measure related aspects of customer satisfaction. This Demonstration report presents a summary of the findings, effectiveness, and customer satisfaction with the 15-month TEP Power Partners pilot project. The objective of the program is to provide residential customers with energy consumption data from AMR metering and empower these participants to better manage their electricity use. The pilot recruitment goals included migrating 700 existing customers from the completed Power Partners Demand Response Load Control Project (DRLC), and enrolling 1,000 new participants. Upon conclusion of the project on November 19, 2013; 1,390 Home Area Networks (HANs) were registered; 797 new participants installed a HAN; Survey respondents’ are satisfied with the program and found value with a variety of specific program components; Survey respondents report feeling greater control over their energy usage and report taking energy savings actions in their homes after participating in the program; On average, 43 % of the participants returned to the web portal monthly and 15% returned weekly; and An impact evaluation was completed by Opinion Dynamics and found average participant savings for the treatment period1 to be 2.3% of their household use during this period.2 In total, the program saved 163 MWh in the treatment period of 2013.

  17. Inductive power transfer: Powering our future

    NASA Astrophysics Data System (ADS)

    Covic, Grant A.

    2013-12-01

    The ability to provide power without wires was imagined over a century ago, but assumed commercially impractical and impossible to realise. However for more than two decades the University of Auckland has been at the forefront of developing and commercialising this technology alongside its industrial partners. This research has proven that significant wireless power can be transferred over relatively large air-gaps efficiently and robustly. Early solutions were applied in industrial applications to power moving vehicles in clean room systems, industrial plants, and in theme parks, but more recently this research has helped develop technology that has the ability to impact us directly at home. The seminar will describe some of the early motivations behind this research, and introduce some of the solutions which have been developed by the team of researchers at Auckland over two decades, many of which have found their way into the market. It will also describe how the technology has recently been re-developed to enable battery charging of electric vehicles without the need to plug in, and alongside this how it has the potential to change the way we drive in the future.

  18. Power without nukes

    SciTech Connect

    Not Available

    1988-03-01

    Nuclear power is good at producing large quantities of electricity. Barring a big change in the world's pattern of energy consumption, that is the kind of energy that will be most in demand if economic growth is to remain rapid. What are the options if we abandon nuclear power. By the year 2000, even on conservative estimates of economic growth, OECD countries would be generating 25% of their electricity from nuclear power. Total nuclear capacity would be about 400,000 MW. That is the size of the gap that would have to be filled. The rate of economic growth and the progress of conservation both depend partly on the price of energy - and the price of energy depends on the speed and extent of any nuclear phase-out. But if nuclear power stations were shut overnight, power cuts would be impossible to avoid in several countries, and electricity-generating costs would osar. Only oil, gas, and coal could fill the gap. Consumption of either oil or coal would have to rise by 10%. Replacing nuclear power over say 20 years would be less disruptive, but still costly. Some new sources - oil from tar sands and shale, more hydroelectric power, perhaps fuel cells - would fill the gap. But they would not prevent energy prices from rising to at least double their present levels in real terms. Indeed, they would require such a rise, because without it they would make no commercial sense.

  19. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling an dynamic replanning.

  20. Autonomous power expert system

    NASA Technical Reports Server (NTRS)

    Ringer, Mark J.; Quinn, Todd M.

    1990-01-01

    The goal of the Autonomous Power System (APS) program is to develop and apply intelligent problem solving and control technologies to the Space Station Freedom Electrical Power Systems (SSF/EPS). The objectives of the program are to establish artificial intelligence/expert system technology paths, to create knowledge based tools with advanced human-operator interfaces, and to integrate and interface knowledge-based and conventional control schemes. This program is being developed at the NASA-Lewis. The APS Brassboard represents a subset of a 20 KHz Space Station Power Management And Distribution (PMAD) testbed. A distributed control scheme is used to manage multiple levels of computers and switchgear. The brassboard is comprised of a set of intelligent switchgear used to effectively switch power from the sources to the loads. The Autonomous Power Expert System (APEX) portion of the APS program integrates a knowledge based fault diagnostic system, a power resource scheduler, and an interface to the APS Brassboard. The system includes knowledge bases for system diagnostics, fault detection and isolation, and recommended actions. The scheduler autonomously assigns start times to the attached loads based on temporal and power constraints. The scheduler is able to work in a near real time environment for both scheduling and dynamic replanning.

  1. Wind power generating system

    SciTech Connect

    Schachle, Ch.; Schachle, E. C.; Schachle, J. R.; Schachle, P. J.

    1985-03-12

    Normally feathered propeller blades of a wind power generating system unfeather in response to the actuation of a power cylinder that responds to actuating signals. Once operational, the propellers generate power over a large range of wind velocities. A maximum power generation design point signals a feather response of the propellers so that once the design point is reached no increase in power results, but the system still generates power. At wind speeds below this maximum point, propeller speed and power output optimize to preset values. The propellers drive a positive displacement pump that in turn drives a positive displacement motor of the swash plate type. The displacement of the motor varies depending on the load on the system, with increasing displacement resulting in increasing propeller speeds, and the converse. In the event of dangerous but not clandestine problems developing in the system, a control circuit dumps hydraulic pressure from the unfeathering cylinder resulting in a predetermined, lower operating pressure produced by the pump. In the event that a problem of potentially cladestine consequence arises, the propeller unfeathering cylinder immediately unloads. Upon startup, a bypass around the motor is blocked, applying a pressure across the motor. The motor drives the generator until the generator reaches a predetermined speed whereupon the generator is placed in circuit with a utility grid and permitted to motor up to synchronous speed.

  2. Mobile electric power

    NASA Astrophysics Data System (ADS)

    Bloomfield, David P.; Bloomfield, Valerie J.; Grosjean, Paul D.; Kelland, James W.

    1995-02-01

    The objective of this program was to develop a mobile fuel cell power supply for use by soldiers. The Century Series of 100 through 500 watt fuel cell power supplies was developed. The Century Series fuel cell power supplies are made up of a fuel cell stack, chemical hydride hydrogen supply, a fan and a controller. The FC-200, the 200 watt Century Series power supply, weighs 8.8 lb. and has a volume of 322 cu in. The operating point is 0.7 volt/cell at 125 ASF; a power density of 22.7 watts/cu in. or 0.62 watts/cu in. and an energy density of 110 whr/lb. The prototype 750 whr hydrogen supply weighs 7 lbs. and has a volume of 193 cu in. The fuel elements weigh 0.45 lb. and require 0.79 lbs. of water. The FC-200 has powered a scooter requiring a starting current of three times the rated current of the stack. It has also powered a microclimate cooler.

  3. Rural power quality

    SciTech Connect

    Koval, D.O. . Dept. of Electrical Engineering); Chang, J.C. ); Leonard, J. . Dept. of Agricultural Engineering)

    1992-07-01

    Very little published literature is available on the quality of power being delivered to rural industries. This paper will present the results of a detailed power quantity monitoring survey of 17 out of the 23 small rural industries surveyed (i.e., poultry broiler, poultry layer, beef feedlot, and pig (farrow to finish) rural industrial sites) and sponsored by the Canadian Electrical Association; the survey will provide a knowledge base on rural power quality and the possible origins of power supply anomalies. This paper will summarize the major power quality problems experienced at the various industrial sites and present some of the significant results of an across Canada questionnaire survey on On-farm Electrical Power Disturbances. The results of these surveys will provide a basis for mitigating actions by the utilities and their rural industrial customers by enhancing their ability to identify the possible origins of power supply disturbances affecting the performance of electronic and electrical equipment at the various farm industrial sites.

  4. Electric power annual 1992

    SciTech Connect

    Not Available

    1994-01-06

    The Electric Power Annual presents a summary of electric utility statistics at national, regional and State levels. The objective of the publication is to provide industry decisionmakers, government policymakers, analysts and the general public with historical data that may be used in understanding US electricity markets. The Electric Power Annual is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy. ``The US Electric Power Industry at a Glance`` section presents a profile of the electric power industry ownership and performance, and a review of key statistics for the year. Subsequent sections present data on generating capability, including proposed capability additions; net generation; fossil-fuel statistics; retail sales; revenue; financial statistics; environmental statistics; electric power transactions; demand-side management; and nonutility power producers. In addition, the appendices provide supplemental data on major disturbances and unusual occurrences in US electricity power systems. Each section contains related text and tables and refers the reader to the appropriate publication that contains more detailed data on the subject matter. Monetary values in this publication are expressed in nominal terms.

  5. Thermoelectric power generator for variable thermal power source

    SciTech Connect

    Bell, Lon E; Crane, Douglas Todd

    2015-04-14

    Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

  6. Power quality load management for large spacecraft electrical power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1988-01-01

    In December, 1986, a Center Director's Discretionary Fund (CDDF) proposal was granted to study power system control techniques in large space electrical power systems. Presented are the accomplishments in the area of power system control by power quality load management. In addition, information concerning the distortion problems in a 20 kHz ac power system is presented.

  7. AC power system breadboard

    NASA Technical Reports Server (NTRS)

    Wappes, Loran J.; Sundberg, R.; Mildice, J.; Peterson, D.; Hushing, S.

    1987-01-01

    The object of this program was to design, build, test, and deliver a high-frequency (20-kHz) Power System Breadboard which would electrically approximate a pair of dual redundant power channels of an IOC Space Station. This report describes that program, including the technical background, and discusses the results, showing that the major assumptions about the characteristics of this class of hardware (size, mass, efficiency, control, etc.) were substantially correct. This testbed equipment has been completed and delivered to LeRC, where it is operating as a part of the Space Station Power System Test Facility.

  8. Wind power prediction models

    NASA Technical Reports Server (NTRS)

    Levy, R.; Mcginness, H.

    1976-01-01

    Investigations were performed to predict the power available from the wind at the Goldstone, California, antenna site complex. The background for power prediction was derived from a statistical evaluation of available wind speed data records at this location and at nearby locations similarly situated within the Mojave desert. In addition to a model for power prediction over relatively long periods of time, an interim simulation model that produces sample wind speeds is described. The interim model furnishes uncorrelated sample speeds at hourly intervals that reproduce the statistical wind distribution at Goldstone. A stochastic simulation model to provide speed samples representative of both the statistical speed distributions and correlations is also discussed.

  9. Nanosatellite Power System Considerations

    NASA Technical Reports Server (NTRS)

    Robyn, M.; Thaller, L.; Scott, D.

    1995-01-01

    The capability to build complex electronic functions into compact packages is opening the path to miniature satellites on the order of 1 kg mass, 10 cm across, packed with the computing processors, motion controllers, measurement sensors, and communications hardware necessary for operation. Power generation will be from short strings of silicon or gallium arsenide-based solar photovoltaic cells with the array power maximized by a peak power tracker (PPT). Energy storage will utilize a low voltage battery with nickel cadmium or lithium ion cells as the most likely selections for rechargeables and lithium (MnO2-Li) primary batteries for one shot short missions.

  10. TROPIX Power System Architecture

    NASA Technical Reports Server (NTRS)

    Manner, David B.; Hickman, J. Mark

    1995-01-01

    This document contains results obtained in the process of performing a power system definition study of the TROPIX power management and distribution system (PMAD). Requirements derived from the PMADs interaction with other spacecraft systems are discussed first. Since the design is dependent on the performance of the photovoltaics, there is a comprehensive discussion of the appropriate models for cells and arrays. A trade study of the array operating voltage and its effect on array bus mass is also presented. A system architecture is developed which makes use of a combination of high efficiency switching power convertors and analog regulators. Mass and volume estimates are presented for all subsystems.

  11. Solar power station

    SciTech Connect

    Wenzel, J.

    1982-11-30

    Solar power station with semiconductor solar cells for generating electric power is described, wherein the semiconductor solar cells are provided on a member such as a balloon or a kite which carries the solar cells into the air. The function of the balloon or kite can also be fulfilled by a glider or airship. The solar power station can be operated by allowing the system to ascend at sunrise and descend at sunset or when the wind is going to be too strong in order to avoid any demage.

  12. Rotorcraft contingency power study

    NASA Technical Reports Server (NTRS)

    Hirschkron, R.; Haynes, J. F.; Goldstein, D. N.; Davis, R. H.

    1984-01-01

    Twin helicopter engines are often sized by the power requirement of a safe mission completion after the failure of one of the two engines. This study was undertaken for NASA Lewis by General Electric Co. to evaluate the merits of special design features to provide a 2-1/2 Contingency Power rating, permitting an engine size reduction. The merits of water injection, turbine cooling airflow modulation, throttle push, and a propellant auxiliary power plant were evaluated using military Life Cycle Cost (LCC) and commercial helicopter Direct Operating Cost (DOC) merit factors in a rubber engine and a rubber aircraft scenario.

  13. Magnetohydrodynamic power generation

    NASA Technical Reports Server (NTRS)

    Smith, J. L.

    1984-01-01

    Magnetohydrodynamic (MHD) Power Generation is a concise summary of MHD theory, history, and future trends. Results of the major international MHD research projects are discussed. Data from MHD research is included. Economics of initial and operating costs are considered.

  14. Explorations in statistics: power.

    PubMed

    Curran-Everett, Douglas

    2010-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This fifth installment of Explorations in Statistics revisits power, a concept fundamental to the test of a null hypothesis. Power is the probability that we reject the null hypothesis when it is false. Four things affect power: the probability with which we are willing to reject-by mistake-a true null hypothesis, the magnitude of the difference we want to be able to detect, the variability of the underlying population, and the number of observations in our sample. In an application to an Institutional Animal Care and Use Committee or to the National Institutes of Health, we define power to justify the sample size we propose. PMID:20522895

  15. Advanced stellarator power plants

    SciTech Connect

    Miller, R.L.

    1994-07-01

    The stellarator is a class of helical/toroidal magnetic fusion devices. Recent international progress in stellarator power plant conceptual design is reviewed and comparisons in the areas of physics, engineering, and economics are made with recent tokamak design studies.

  16. Solar power roof shingle

    NASA Technical Reports Server (NTRS)

    Forestieri, A. F.; Ratajczak, A. F.; Sidorak, L. G.

    1975-01-01

    Silicon solar cell module provides both all-weather protection and electrical power. Module consists of array of circular silicon solar cells bonded to fiberglass substrate roof shingle with fluorinated ethylene propylene encapsulant.

  17. Power industry wastes

    SciTech Connect

    Chu, T.Y.J.; Olem, H.

    1982-06-01

    This literature review includes the environmental effects of fossil-fuelled power plants, and the treatment, disposal and utilisation of ash and waste from flue gas desulphurization. There is a short section on fluidized bed combustion.

  18. On Student Power

    ERIC Educational Resources Information Center

    Lewy, Guenter; Rothman, Stanley

    1970-01-01

    Beleaguered administrators and faculty who submit to student power" as a way of defusing student unrest and an indication of educational reform are compromising their authority and the future of democratic education. (IR)

  19. Powerful Electromechanical Linear Actuator

    NASA Technical Reports Server (NTRS)

    Cowan, John R.; Myers, William N.

    1994-01-01

    Powerful electromechanical linear actuator designed to replace hydraulic actuator. Cleaner, simpler, and needs less maintenance. Features rotary-to-linear-motion converter with antibacklash gearing and position feedback via shaft-angle resolvers, which measure rotary motion.

  20. Structural power flow measurement

    SciTech Connect

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  1. Power conversion technologies

    SciTech Connect

    Newton, M. A.

    1997-02-01

    The Power Conversion Technologies thrust area identifies and sponsors development activities that enhance the capabilities of engineering at Lawrence Livermore National Laboratory (LLNL) in the area of solid- state power electronics. Our primary objective is to be a resource to existing and emerging LLNL programs that require advanced solid-state power electronic technologies.. Our focus is on developing and integrating technologies that will significantly impact the capability, size, cost, and reliability of future power electronic systems. During FY-96, we concentrated our research efforts on the areas of (1) Micropower Impulse Radar (MIR); (2) novel solid-state opening switches; (3) advanced modulator technology for accelerators; (4) compact accelerators; and (5) compact pulse generators.

  2. Power quality in India

    SciTech Connect

    Deodar, P.S.

    1995-12-01

    This article is a summary of a Faraday Memorial Lecture on the state of power quality and reliability and its impact on the pace of India`s industrial growth and development. Poor quality is hurting industrial competitiveness and therefore their efforts to become a global supplier of goods. In this information age, there is a fast growth of computer usage in industry, commerce, business, trade, finance, healthcare, etc. These sensitive electronic products need clean and consistent power from the utility, and India`s State Electricity Board and other utilities simply cannot deliver it. The users, however, are ultimately response for the health and the safe operation of their equipment. Bad power quality available in India and the clean power requirement of the Informatic infrastructure are the two unfortunate realities of today`s electronic age.

  3. Why Not Solar Power?

    NASA Astrophysics Data System (ADS)

    Pokharel, Reeju; Sheldon, Peter

    2008-03-01

    Most of the world generally depends on energy sources such as fossil fuels and nuclear power to meet our energy consumption needs. As we all know, the excessive use of these resources has large environmental impacts, including displacing habitats, pollution, global warming, and scarcity of resources. Solar power is a clean form of energy that has the potential to fulfill our energy needs while balancing the natural state of our environment. So why do we not power our houses with solar energy? I will give a general overview of the working principles of commercially available solar power, and examine the issues relating to why we should use it and why we currently do not.

  4. The Power of Storytelling.

    ERIC Educational Resources Information Center

    Yoder-Wise, Patricia S.; Kowalski, Karren

    2003-01-01

    Discusses the value of storytelling and offers guidelines for developing stories to use in teaching. Includes sections on presentation skills, overcoming pitfalls, and the power of telling stories. (Contains 13 references.) (JOW)

  5. MHD Power Generation

    ERIC Educational Resources Information Center

    Kantrowitz, Arthur; Rosa, Richard J.

    1975-01-01

    Explains the operation of the Magnetohydrodynamic (MHD) generator and advantages of the system over coal, oil or nuclear powered generators. Details the development of MHD generators in the United States and Soviet Union. (CP)

  6. Power subsystem automation study

    NASA Technical Reports Server (NTRS)

    Imamura, M. S.; Moser, R. L.; Veatch, M.

    1983-01-01

    Generic power-system elements and their potential faults are identified. Automation functions and their resulting benefits are defined and automation functions between power subsystem, central spacecraft computer, and ground flight-support personnel are partitioned. All automation activities were categorized as data handling, monitoring, routine control, fault handling, planning and operations, or anomaly handling. Incorporation of all these classes of tasks, except for anomaly handling, in power subsystem hardware and software was concluded to be mandatory to meet the design and operational requirements of the space station. The key drivers are long mission lifetime, modular growth, high-performance flexibility, a need to accommodate different electrical user-load equipment, onorbit assembly/maintenance/servicing, and potentially large number of power subsystem components. A significant effort in algorithm development and validation is essential in meeting the 1987 technology readiness date for the space station.

  7. Dynamic Power Grid Simulation

    SciTech Connect

    Top, Philip; Woodward, Carol; Smith, Steve; Banks, Lawrence; Kelley, Brian

    2015-09-14

    GridDyn is a part of power grid simulation toolkit. The code is designed using modern object oriented C++ methods utilizing C++11 and recent Boost libraries to ensure compatibility with multiple operating systems and environments.

  8. Powering down quietly

    SciTech Connect

    Norris, R.S. ); Arkin, W.M.

    1993-06-01

    This article describes how the US Navy has quietly begun scuttling much of its nuclear-powered fleet. More than 50 submarines have been scrapped to date--half since 1990-and at least 43 more are scheduled for retirement before 1998. The first nuclear-powered surface ships are also being retired, with five of nine nuclear cruisers to be decommissioned before 1995. Some specific retirements of nuclear submarines and cruisers are also discussed. The ironic move toward an all nuclear-powered aircraft carrier fleet and the design of new nuclear submarines in discussed. As the nuclear-powered fleet dwindles, the base structure that supports it also contracts. The list of planned base closures is briefly reviewed.

  9. Power Harvesting from Rotation?

    ERIC Educational Resources Information Center

    Chicone, Carmen; Feng, Z. C.

    2008-01-01

    We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics. (Contains 2 figures.)

  10. Water Power Program News

    SciTech Connect

    2012-01-19

    News stories about conventional hydropower and marine and hydrokinetic technologies from the U.S. Department of Energy, the Office of Energy Efficiency and Renewable Energy, the Wind and Water Power Program, and other federal agencies.

  11. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis [Burnt Hills, NY; Anderson, Todd Alan [Niskayuna, NY

    2008-02-19

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  12. Power control system and method

    DOEpatents

    Steigerwald, Robert Louis; Anderson, Todd Alan

    2006-11-07

    A power system includes an energy harvesting device, a battery coupled to the energy harvesting device, and a circuit coupled to the energy harvesting device and the battery. The circuit is adapted to deliver power to a load by providing power generated by the energy harvesting device to the load without delivering excess power to the battery and to supplement the power generated by the energy harvesting device with power from the battery if the power generated by the energy harvesting device is insufficient to fully power the load. A method of operating the power system is also provided.

  13. Village power in Thailand

    SciTech Connect

    Bergey, M.

    1997-12-01

    This paper presents an overview of the electric power system in Thailand. 99% of the country is electrified, but much of this is with diesel generators which leaves high costs but a high level of service. The paper discusses renewable energy projects which have been sited in the country, and examples of hybrid systems which have been retrofit into existing diesel generator systems. Photovoltaic and hydroelectric power projects are described. Dedicated systems have been installed for water pumping and battery charging applications.

  14. Space Power Engineering Problems

    NASA Astrophysics Data System (ADS)

    Senkevich, V. P.

    2002-01-01

    Development of space power engineering in the first half of XXI century shall be aimed at preventing the forthcoming energy crisis and ecological catastrophes. The problem can be solved through using solar energy being perpetual, endless, and ecologically safe. As of now, issues on the development and employment of solar power stations and its beaming to the ground stations in the SHF band are put on the agenda. The most pressing problem is to develop orbital solar reflectors to illuminate towns in the polar regions, agricultural regions, and areas of processing sea products. Space-based technologies can be used to deal with typhoons, green house effects, and "ozone holes". Recently, large, frameless film structures formed by centrifugal forces offer the promise of structures for orbital power plants, reflectors, and solar sails. A big success is achieved in the development of power generating solar array elements of amorphous silicon. These innovations would make the development of orbital solar power plants dozens of times cheaper. Such solar arrays shall be used in the nearest future on heavy communication satellites and the Earth remote sensing platforms for generation of 140-160 kW at a specific power beyond 300 W/kg. The cargo traffic needed to develop and maintain the orbital power plants and reflector systems could be equipped with solar sails as the future low thrust propulsion. In 2000, the mankind witnessed an unexpected beginning of energy crisis along with strong hydro- meteorological events (typhoons, floods) that shocked the USA, the Western Europe, England, Japan, and other countries. The total damage is estimated as 90 billions of dollars. The mankind is approaching a boundary beyond which its further existence would depend on how people would learn to control weather and use ecologically safe power sources. Space technology base on the research potential accumulated in the previous century could serve for the solution of this problem.

  15. Power Factor Controller

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Frank Nola invented the Power Factor Controller (PFC) at Marshall Space Flight Center more than a decade ago. Nola came up with a way to curb power wastage in AC induction motors. The PFC matches voltage with the motor's actual need by continuously sensing shifts between voltage and current. When it senses a light load it cuts the voltage to the minimum needed. Potential energy savings range from 8 to 65 percent.

  16. Power Plant Construction

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Stone & Webster Engineering Corporation utilized TAP-A, a COSMIC program originally developed as part of a NASA investigation into the potential of nuclear power for space launch vehicles. It is useful in nuclear power plant design to qualify safety-related equipment at the temperatures it would experience should an accident occur. The program is easy to use, produces accurate results, and is inexpensive to run.

  17. Reactive power compensator

    DOEpatents

    El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

    1992-01-01

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

  18. Reactive Power Compensator.

    DOEpatents

    El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

    1992-07-28

    A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

  19. Integrated Power Source Grant

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Traditional spacecraft power systems incorporate a solar array energy source, an energy storage element (battery), and battery charge control and bus voltage regulation electronics to provide continuous electrical power for spacecraft systems and instruments. Dedicated power conditioning components provide limited fault isolation between systems and instruments, while a centralized power-switching unit provides spacecraft load control. Battery undervoltage conditions are detected by the spacecraft processor, which removes fault conditions and non-critical loads before permanent battery damage can occur. Cost effective operation of a micro-sat constellation requires a fault tolerant spacecraft architecture that minimizes on-orbit operational costs by permitting autonomous reconfiguration in response to unexpected fault conditions. A new micro-sat power system architecture that enhances spacecraft fault tolerance and improves power system survivability by continuously managing the battery charge and discharge processes on a cell-by-cell basis has been developed. This architecture is based on the Integrated Power Source (US patent 5644207), which integrates dual junction solar cells, Lithium Ion battery cells, and processor based charge control electronics into a structural panel that can be deployed or used to form a portion of the outer shell of a micro-spacecraft. The first generation Integrated Power Source is configured as a one inch thick panel in which prismatic Lithium Ion battery cells are arranged in a 3x7 matrix (26VDC) and a 3x1 matrix (3.7VDC) to provide the required output voltages and load currents. A multi-layer structure holds the battery cells, as well as the thermal insulators that are necessary to protect the Lithium Ion battery cells from the extreme temperatures of the solar cell layer. Independent thermal radiators, located on the back of the panel, are dedicated to the solar cell array, the electronics, and the battery cell array. In deployed panel applications, these radiators maintain the battery cells in an appropriate operational temperature range.

  20. Enabling Wind Power Nationwide

    SciTech Connect

    Jose, Zayas; Michael, Derby; Patrick, Gilman; Ananthan, Shreyas; Lantz, Eric; Cotrell, Jason; Beck, Fredic; Tusing, Richard

    2015-05-01

    Leveraging this experience, the U.S. Department of Energy’s (DOE’s) Wind and Water Power Technologies Office has evaluated the potential for wind power to generate electricity in all 50 states. This report analyzes and quantifies the geographic expansion that could be enabled by accessing higher above ground heights for wind turbines and considers the means by which this new potential could be responsibly developed.

  1. 41. GENERAL VIEW OF THE POWER PLANT AND POWER CANAL, ...

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

    41. GENERAL VIEW OF THE POWER PLANT AND POWER CANAL, LOOKING NORTHEAST, WITH THE GERVAIS STREET BRIDGE IN THE FOREGROUND, CLOSER RANGE - Columbia Canal & Power Plant, Waterfront of Broad River, Columbia, Richland County, SC

  2. 40. GENERAL VIEW OF POWER PLANT AND POWER CANAL, LOOKING ...

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

    40. GENERAL VIEW OF POWER PLANT AND POWER CANAL, LOOKING NORTHEAST, WITH THE GERVAIS STREET BRIDGE IN THE FOREGROUND - Columbia Canal & Power Plant, Waterfront of Broad River, Columbia, Richland County, SC

  3. Electric power for space satellites

    NASA Technical Reports Server (NTRS)

    Mackenzie, C. M.

    1974-01-01

    The development of electric power systems for satellites is discussed as an evolutionary process requiring the integration of power generation, power storage, and power control and distribution. The growth of space electric power systems is traced. The capabilities and limitations of the various elements (i.e. silicon solar cells) are discussed together with their impact on future technological growth.

  4. Distributed Space Solar Power

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.

    2001-01-01

    The objective was to assess the feasibility of safely collecting solar power at geostationary orbit and delivering it to earth. A strategy which could harness a small fraction of the millions of gigawatts of sunlight passing near earth could adequately supply the power needs of earth and those of space exploration far into the future. Light collected and enhanced both spatially and temporally in space and beamed to earth provides probably the only practical means of safe and efficient delivery of this space solar power to earth. In particular, we analyzed the feasibility of delivering power to sites on earth at a comparable intensity, after conversion to a usable form, to existing power needs. Two major obstacles in the delivery of space solar power to earth are safety and the development of a source suitable for space. We focused our approach on: (1) identifying system requirements and designing a strategy satisfying current eye and skin safety requirements; and (2) identifying a concept for a potential space-based source for producing the enhanced light.

  5. Powering the Future

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Stirling Technology Company (STC) developed the RG-350 convertor using components from separate Goddard Space Center and U.S. Army Natick SBIR contracts. Based on the RG-350, STC commercialized a product line of Stirling cycle generator sets, known as RemoteGen(TM), with power levels ranging from 10We to 3kWe. Under SBIR agreements with Glenn Research Center, the company refined and extended the capabilities of the RemoteGen convertors. They can provide power in remote locations by efficiently producing electricity from multiple-fuel sources, such as propane, alcohol, gasoline, diesel, coal, solar energy, or wood pellets. Utilizing any fuel source that can create heat, RemoteGen enables the choice of the most appropriate fuel source available. The engines operate without friction, wear, or maintenance. These abilities pave the way for self-powered appliances, such as refrigerators and furnaces. Numerous applications for RemoteGen include quiet, pollution-free generators for RVs and yachts, power for cell phone towers remote from the grid, and off-grid residential power variously using propane, ethanol, and solid biomass fuels. One utility and the National Renewable Energy Laboratory are evaluating a solar dish concentrator version with excellent potential for powering remote irrigation pumps.

  6. Sweden considers wind power

    SciTech Connect

    Baurrau, P.

    1989-09-01

    During 1988, Sweden increased its number of wind generating facilities from 13 to 22, reflecting a new attitude toward wind power developing in the country. Last fall, a 750 kW wind turbine installed in the archipelago of Gothenburg was connected to the grid. The turbine is the biggest in use in Sweden, operated and maintained by the local energy authority of Gothenburg. Most turbines being manufactured have a capacity of 20 to 200 kW. The Maglarp turbine in the south of Sweden has a capacity of 3,000 kW, and the Naesudden turbine on an island in the Baltic Sea has 2,000 kW. The two projects are considered experimental by the owner, Vattenfall, the State Power Board. On the basis of energy production, Maglarp may be the largest in the world. Its highest production, 4,400 MWh, was achieved in 1988. In January 1989, the production was 900 MWh, the third highest monthly production so far since September 1983. The State Power Board, the members of the Swedish Power Association, Sydkraft, together with a number of municipal power companies and stations, have formed the Swedish Energy Development Corporation, SWEDCO. One goal for the new corporation is to include wind power in the Swedish energy system. SWEDCO will provide economic and operation data to pursue wind technology.

  7. Trace-element characterization of evidential cannabis sative samples using k{sub 0}-standardization methodology

    SciTech Connect

    Henderson, D.P. Jr.; Vernetson, W.G.; Ratner, R.T.

    1995-12-31

    The University of Florida Training Reactor (UFTR) facilities including the analytical laboratory are used for a wide range of educational, research, training, and service functions. The UFTR is a 100-kW light-water-cooled, graphite-and-water-moderated modified Argonaut-type reactor. The UFTR utilizes high enriched plate-type fuel in a two-slab arrangement and operates at a 100-kW power level. Since first licensed to operate at 10 kW in 1959, this nonpower reactor facility has had an active but evolving record of continuous service to a wide range of academic, utility, and community users. The services of the UFTR have also been used by various state authorities in criminal investigations. Because of its relatively low power and careful laboratory analyses, the UFTR neutron flux characteristics in several ports are not only well characterized but they are also quite invariant with time. As a result, such a facility is well-suited to the application of the multielement analysis using the k{sub o}-standardization method of neutron activation analysis. The analysis of untreated evidential botanical samples presented a unique opportunity to demonstrate implementation of this method at the UFTR facilities.

  8. Solar power satellite microwave power transmission system description executive summary

    NASA Astrophysics Data System (ADS)

    Woodcock, G. R.

    1980-12-01

    The history of the concept of microwave power beaming to Earth is reviewed with emphasis on transmission frequency selection. Constraints on the system power level results from (1) required rejection of waste heat resulting from inefficiencies in the cover conversion of dc electric power to microwave power; (2) the rf power intensity in the ionosphere; and (3) the effect of sidelobe level on aperture illumination factors. Transmitter arrangement, the power distribution system, attitude control, subarrays, waveguides, and alignment are discussed.

  9. Power outages, power externalities, and baby booms.

    PubMed

    Burlando, Alfredo

    2014-08-01

    Determining whether power outages have significant fertility effects is an important policy question in developing countries, where blackouts are common and modern forms of family planning are scarce. Using birth records from Zanzibar, this study shows that a month-long blackout in 2008 caused a significant increase in the number of births 8 to 10 months later. The increase was similar across villages that had electricity, regardless of the level of electrification; villages with no electricity connections saw no changes in birth numbers. The large fertility increase in communities with very low levels of electricity suggests that the outage affected the fertility of households not connected to the grid through some spillover effect. Whether the baby boom is likely to translate to a permanent increase in the population remains unclear, but this article highlights an important hidden consequence of power instability in developing countries. It also suggests that electricity imposes significant externality effects on rural populations that have little exposure to it. PMID:25007970

  10. Autonomous power system brassboard

    NASA Technical Reports Server (NTRS)

    Merolla, Anthony

    1992-01-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the brassboard hardware and intelligent controlling software, fault circuits have been developed and integrated as part of the brassboard. A description of these fault circuits and their function is included. The brassboard has become an extremely useful test facility, promoting artificial intelligence (AI) applications for power distribution systems. However, there are elements of the brassboard which could be enhanced, thus improving system performance. Modifications and enhancements to improve the brassboard's operation are discussed.

  11. Autonomous power system brassboard

    NASA Astrophysics Data System (ADS)

    Merolla, Anthony

    1992-10-01

    The Autonomous Power System (APS) brassboard is a 20 kHz power distribution system which has been developed at NASA Lewis Research Center, Cleveland, Ohio. The brassboard exists to provide a realistic hardware platform capable of testing artificially intelligent (AI) software. The brassboard's power circuit topology is based upon a Power Distribution Control Unit (PDCU), which is a subset of an advanced development 20 kHz electrical power system (EPS) testbed, originally designed for Space Station Freedom (SSF). The APS program is designed to demonstrate the application of intelligent software as a fault detection, isolation, and recovery methodology for space power systems. This report discusses both the hardware and software elements used to construct the present configuration of the brassboard. The brassboard power components are described. These include the solid-state switches (herein referred to as switchgear), transformers, sources, and loads. Closely linked to this power portion of the brassboard is the first level of embedded control. Hardware used to implement this control and its associated software is discussed. An Ada software program, developed by Lewis Research Center's Space Station Freedom Directorate for their 20 kHz testbed, is used to control the brassboard's switchgear, as well as monitor key brassboard parameters through sensors located within these switches. The Ada code is downloaded from a PC/AT, and is resident within the 8086 microprocessor-based embedded controllers. The PC/AT is also used for smart terminal emulation, capable of controlling the switchgear as well as displaying data from them. Intelligent control is provided through use of a T1 Explorer and the Autonomous Power Expert (APEX) LISP software. Real-time load scheduling is implemented through use of a 'C' program-based scheduling engine. The methods of communication between these computers and the brassboard are explored. In order to evaluate the features of both the brassboard hardware and intelligent controlling software, fault circuits have been developed and integrated as part of the brassboard. A description of these fault circuits and their function is included. The brassboard has become an extremely useful test facility, promoting artificial intelligence (AI) applications for power distribution systems.

  12. 77 FR 60481 - Design, Inspection, and Testing Criteria for Air Filtration and Adsorption Units of Post-Accident...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... Information DG-1274 was published in the Federal Register on December 30, 2011 (76 FR 82323), for a 60-day... Engineered-Safety-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants AGENCY...-Feature Atmosphere Cleanup Systems in Light-Water-Cooled Nuclear Power Plants.'' This guide applies to...

  13. 75 FR 54921 - Withdrawal of Regulatory Guides 1.38, 1.94, and 1.116

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-09

    ... for Packaging, Shipping, Receiving, Storage, and Handling of Items for a Water-Cooled Nuclear Power... Packaging, Shipping, Receiving, Storage, and Handling of Items for Water-Cooled Nuclear Power Plants... (ANSI) Standard N45.2.2--1972, ``Packaging, Shipping, Receiving, Storage and Handling of Items...

  14. Wireless Power Transfer

    NASA Astrophysics Data System (ADS)

    Moreno, Fernando

    A new loop configuration capable of reducing power radiation magnitudes lower than conventional loops has been developed. This configuration is demonstrated for the case of two coaxial loops of 0.1 meter radius coupled via the magnetic reactive field. Utilizing electromagnetism theory, techniques from antenna design and a new near field design initiative, the ability to design a magnetic field has been investigated by using a full wave simulation tool. The method for realization is initiated from first order physics model, ADS and onto a full wave situation tool for the case of a non-radiating helical loop. The exploration into the design of a magnetic near field while mitigating radiation power is demonstrated using an real number of twists to form a helical wire loop while biasing the integer twisted loop in a non-conventional moebius termination. The helix loop setup as a moebius loop convention can also be expressed as a shorted antenna scheme. The 0.1 meter radius helix antenna is biased with a 1MHz frequency that categorized the antenna loop as electrically small. It is then demonstrated that helical configuration reduces the electric field and mitigates power radiation into the far field. In order to compare the radiated power reduction performance of the helical loop a shielded loop is used as a baseline for comparison. The shielded loop system of the same geometric size and frequency is shown to have power radiation expressed as -46.1 dBm. The power radiated mitigation method of the helix loop reduces the power radiated from the two loop system down to -98.72 dBm.

  15. Hybrid Power Management Program Continued

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.

    2002-01-01

    Hybrid Power Management (HPM) is the innovative integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications. The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The advanced power devices include ultracapacitors and photovoltaics. HPM has extremely wide potential with applications including power-generation, transportation, biotechnology, and space power systems. It may significantly alleviate global energy concerns, improve the environment, and stimulate the economy.

  16. Captive Water Current Power System

    SciTech Connect

    Wuenscher, H. F.; Wuenscher, H. A.

    1984-01-31

    Current energy is converted into shaft power in two stages; First, buoyant power units with stationary hydrofoil wings reach faster than the current speed by sweeping out a captive path. Second, turbines at said power units convert the fast relative local current into shaft power. Power units sweeping along the water surface, using cycloidal turbine methods, as well as power units sweeping on a submerged path, using axial flow turbine methods, are described.

  17. Automated Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Thomason, Cindy; Anderson, Paul M.; Martin, James A.

    1990-01-01

    Automated power-distribution system monitors and controls electrical power to modules in network. Handles both 208-V, 20-kHz single-phase alternating current and 120- to 150-V direct current. Power distributed to load modules from power-distribution control units (PDCU's) via subsystem distributors. Ring busses carry power to PDCU's from power source. Needs minimal attention. Detects faults and also protects against them. Potential applications include autonomous land vehicles and automated industrial process systems.

  18. Nuclear Power - Post Fukushima

    NASA Astrophysics Data System (ADS)

    Reyes, Jose, Jr.

    2011-10-01

    The extreme events that led to the prolonged power outage at the Fukushima Daiicchi nuclear plant have highlighted the importance of assuring a means for stable long term cooling of the nuclear fuel and containment following a complete station blackout. Legislative bodies, regulatory agencies and industry are drawing lessons from those events and considering what changes, if any, are needed to nuclear power, post Fukushima. The enhanced safety of a new class of reactor designed by NuScale Power is drawing significant attention in light of the Fukushima events. During normal operation, each NuScale containment is fully immersed in a water-filled stainless steel lined concrete pool that resides underground. The pool, housed in a Seismic Category I building, is large enough to provided 30 days of core and containment cooling without adding water. After 30 days, the decay heat generations coupled with thermal radiation heat transfer is completely adequate to remove core decay heat for an unlimited period of time. These passive power systems can perform their function without requiring an external supply of water of power. An assessment of the NuScale passive systems is being performed through a comprehensive test program that includes the NuScale integral system test facility at Oregon State University

  19. Automating power supply checkout

    SciTech Connect

    Laster, J.; Bruno, D.; D'Ottavio, T.; Drozd, J.; Marr, G.; Mi, C.

    2011-03-28

    Power Supply checkout is a necessary, pre-beam, time-critical function. At odds are the desire to decrease the amount of time to perform the checkout while at the same time maximizing the number and types of checks that can be performed and analyzing the results quickly (in case any problems exist that must be addressed). Controls and Power Supply Group personnel have worked together to develop tools to accomplish these goals. Power Supply checkouts are now accomplished in a time-frame of hours rather than days, reducing the number of person-hours needed to accomplish the checkout and making the system available more quickly for beam development. The goal of the Collider-Accelerator Department (CAD) at Brookhaven National Laboratory is to provide experimenters with collisions of heavy-ions and polarized protons. The Relativistic Heavy-Ion Collider (RHIC) magnets are controlled by 100's of varying types of power supplies. There is a concentrated effort to perform routine maintenance on the supplies during shutdown periods. There is an effort at RHIC to streamline the time needed for system checkout in order to quickly arrive at a period of beam operations for RHIC. This time-critical period is when the checkout of the power supplies is performed as the RHIC ring becomes cold and the supplies are connected to their physical magnets. The checkout process is used to identify problems in voltage and current regulation by examining data signals related to each for problems in settling and regulation (ripple).

  20. SATCOM constellation power simulation

    SciTech Connect

    Capulli, J.; Badke, B.; Davis, G.

    1995-12-31

    Three basic variables directly impact the power and energy generated by the SATCOM satellite constellation and its individual Space Vehicles (SVs). They are (1) telecommunications traffic patterns, (2) network resource management controllables, and (3) system hardware and software performance. This power simulation has verified the robustness of the telecommunications architecture. It has validated the onboard resource allocation process from an SV and network level power and energy perspective. The analyses have led to development of operational procedures that prevent SV node outages, and maximize network telecommunication traffic capacity. The program objective is to optimize overall system operation, availability and quality of service. Achieving this goal requires a thorough understanding of the Electrical Power Subsystem and its interfaces. The EPS simulation model analyzes network level performance by evaluating requirement compliance in the expected operating environments. Specifically, the simulation tool evaluates different design approaches and network operational strategies from a power and energy perspective. As a result, optimal load management solutions will be implemented both on-board the SV and via ground station directed resource allocation strategies.

  1. Beloyarsk Nuclear Power Plant

    SciTech Connect

    1997-08-01

    The Beloyarsk Nuclear Power Plant (BNPP) is located in Zarechny, approximately 60 km east of Ekaterinberg along the Trans-Siberian Highway. Zarechny, a small city of approximately 30,000 residents, was built to support BNPP operations. It is a closed city to unescorted visitors. Residents must show identification for entry. BNPP is one of the first and oldest commercial nuclear power plants in Russia and began operations in 1964. As for most nuclear power plants in the Russian Federation, BNPP is operated by Rosenergoatom, which is subordinated to the Ministry of Atomic Energy of the Russian Federation (Minatom). BNPP is the site of three nuclear reactors, Units 1, 2, and 3. Units 1 and 2, which have been shut-down and defueled, were graphite moderated reactors. The units were shut-down in 1981 and 1989. Unit 3, a BN-600 reactor, is a 600 MW(electric) sodium-cooled fast breeder reactor. Unit 3 went on-line in April 1980 and produces electric power which is fed into a distribution grid and thermal power which provides heat to Zarechny. The paper also discusses the SF NIKIET, the Sverdiovsk Branch of NIKIET, Moscow, which is the research and development branch of the parent NIKEIT and is primarily a design institute responsible for reactor design. Central to its operations is a 15 megawatt IVV research reactor. The paper discusses general security and fissile material control and accountability at these two facilities.

  2. Power Without Wires (POWOW)

    NASA Technical Reports Server (NTRS)

    Brandhorst, Henry W., Jr.; Howell, Joe (Technical Monitor)

    2002-01-01

    Electric propulsion has emerged as a cost-effective solution to a wide range of satellite applications. Deep Space 1 successfully demonstrated electric propulsion as the primary propulsion source for a satellite. The POWOW concept is a solar-electric propelled spacecraft capable of significant cargo and short trip times for traveling to Mars. There it would enter areosynchronous orbit (Mars GEO equivalent) and beam power to surface installations via lasers. The concept has been developed with industrial partner expertise in high efficiency solar cells, advanced concentrator modules, innovative arrays, and high power electric propulsion systems. The present baseline spacecraft design providing 898 kW using technologies expected to be available in 2003 will be described. Areal power densities approaching 350 W/sq m at 80 C operating temperatures and wing level specific powers of over 350 W/kg are projected. Details of trip times and payloads to Mars are presented. Electric propulsion options include Hall, MPD, and ion thrusters of various power levels and trade studies have been conducted to define the most advantageous options. Because the design is modular, learning curve methodology has been applied to determine expected cost reductions and is included.

  3. Advanced Power Electronics Components

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.

    2004-01-01

    This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

  4. The power relay satellite

    NASA Astrophysics Data System (ADS)

    Glaser, Peter E.

    The availability and use of renewable energy sources compatible with reducing risks to the global environment are key to sustainable development. Large-scale, renewable energy resources at undeveloped or underutilized sites are potentially available on several continents. The Power Relay Satellite (PRS) concept has the potential to access these remote energy resources by coupling primary electricity generation from terrestrial transmission lines. A global PRS network can be envisioned to provide a high degree of flexibility for supplying energy demands worldwide with wireless power transmitted from sites on Earth to geosynchronous orbit and then reflected to receivers interfacing with terrestrial power transmision networks. Past developments in wireless power transmission (WPT) are reviewed and recent successful results are noted. The origins of the PRS concept, and a possible configuration are discussed, principles of WPT at microwave frequencies, functional requirements, and system design contraints are outlined, and space transportation concepts presented. PRS assessments including applicable technologies, economic projections, and societal issues are highlighted. It is concluded that the PRS provides a promising option to access renewable resources at great distances from major markets, and represents an important stage in the future development in the future of solar power satellites.

  5. Solar photovoltaic power stations

    NASA Technical Reports Server (NTRS)

    Chowaniec, C. R.; Pittman, P. F.; Ferber, R. R.; Marshall, B. W.

    1977-01-01

    The subsystems of a solar photovoltaic central power system are identified and the cost of major components are estimated. The central power system, which would have a peak power capability in the range of 50 to 1000 MW, utilizes two types of subsystems - a power conditioner and a solar array. Despite differences in costs of inverters, the overall cost of the total power conditioning subsystem is about the same for all approaches considered. A combination of two inverters operating from balanced dc buses as a pair of 6-pulse groups is recommended. A number of different solar cell modules and tracking array structures were analyzed. It is concluded that when solar cell costs are high (greater than $500/kW), high concentration modules are more cost effective than those with low concentration. Vertical-axis tracking is the most effective of the studied tracking modes. For less expensive solar cells (less than $400/kW), fixed tilt collector/reflector modules are more cost effective than those which track.

  6. High power connection system

    DOEpatents

    Schaefer, Christopher E.; Beer, Robert C.; McCall, Mark D.

    2000-01-01

    A high power connection system adapted for automotive environments which provides environmental and EMI shielding includes a female connector, a male connector, and a panel mount. The female connector includes a female connector base and a snap fitted female connector cover. The male connector includes a male connector base and a snap fitted male connector cover. The female connector base has at least one female power terminal cavity for seatably receiving a respective female power terminal. The male connector base has at least one male power terminal cavity for seatably receiving a respective male power terminal. The female connector is covered by a cover seal and a conductive shroud. A pair of lock arms protrude outward from the front end of the male connector base, pass through the panel mount and interface with a lever of a lever rotatably connected to the shroud to thereby mechanically assist mating of the male and female connectors. Safety terminals in the male and female connectors provide a last-to-connect-first-to-break connection with an HVIL circuit.

  7. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  8. Solar powered multipurpose remotely powered aircraft

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Environmental problems such as the depletion of the ozone layer and air pollution demand a change in traditional means of propulsion that is sensitive to the ecology. Solar-powered propulsion is a favorable alternative that is both ecologically harmless as well as cost effective. Integration of solar energy into designs ranging from futuristic vehicles to heating is, therefore, beneficial to society. The design and construction of a Multipurpose Remotely Piloted Vehicle (MPRPV) seeks to verify the feasibility of using solar propulsion as a primary fuel source. This task has been a year-long effort by a group of eight students, divided into four teams, each dealing with different aspects of the design. The aircraft was designed to take off, climb to the design altitude, fly in a sustained figure-eight flight path, and cruise for approximately one hour. This mission requires flight at Reynolds numbers between 150,000 and 200,000 and demands special considerations in the aerodynamic design to achieve flight in this regime. Optimal performance requires a lightweight configuration with both structural integrity and maximum power availability. The structural design and choice of solar cells for the propulsion were governed by weight, efficiency, and cost considerations. The final design is an MPRPV weighing 35 N that cruises at 7 m/s at the design altitude of 50 m. The configuration includes a wing composed of balsa and foam NACA 6409 airfoil sections and carbon fiber spars, a tail of similar construction, and a truss structure fuselage. The propulsion system consists of 98 12.5 percent-efficient solar cells donated by Mobil Solar, a NiCad battery for energy storage, and a folding propeller regulated by a lightweight and efficient control system. The airfoils and propeller chosen for the design were researched and tested during the design process.

  9. Power Systems Development Facility

    SciTech Connect

    Southern Company Services

    2009-01-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, has routinely demonstrated gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This final report summarizes the results of the technology development work conducted at the PSDF through January 31, 2009. Twenty-one major gasification test campaigns were completed, for a total of more than 11,000 hours of gasification operation. This operational experience has led to significant advancements in gasification technologies.

  10. The International Power Exchange

    SciTech Connect

    1994-12-31

    The International Power Exchange (IPEX) is an on-line bulletin board enabling utilities and other subscibers to advertise Wholesale Power. Bulk Transmission and Emission Allowances for sale or purchase. IPEX was created in response of the electric utility industry for a 24-hour per day, 7-day per week, computer-based communication system. The system provides instant access to market prices allowing a subscriber to increase their span of of knowledge when needing to buy or sell energy. The IPEX database provides information for trend analysis and other market research activities. IPEX was designed for investor-owned utilities, generation and transmission cooperatives, municipal organizations, and independent power producers. Capabilities and procedures for using the IPEX are discussion in some detail.

  11. Power converter connection configuration

    DOEpatents

    Beihoff, Bruce C.; Kehl, Dennis L.; Gettelfinger, Lee A.; Kaishian, Steven C.; Phillips, Mark G.; Radosevich, Lawrence D.

    2008-11-11

    EMI shielding is provided for power electronics circuits and the like via a direct-mount reference plane support and shielding structure. The thermal support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support forms a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

  12. Power electronics reliability.

    SciTech Connect

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Stanley, James K.; Smith, Mark A.; Atcitty, Stanley

    2010-10-01

    The project's goals are: (1) use experiments and modeling to investigate and characterize stress-related failure modes of post-silicon power electronic (PE) devices such as silicon carbide (SiC) and gallium nitride (GaN) switches; and (2) seek opportunities for condition monitoring (CM) and prognostics and health management (PHM) to further enhance the reliability of power electronics devices and equipment. CM - detect anomalies and diagnose problems that require maintenance. PHM - track damage growth, predict time to failure, and manage subsequent maintenance and operations in such a way to optimize overall system utility against cost. The benefits of CM/PHM are: (1) operate power conversion systems in ways that will preclude predicted failures; (2) reduce unscheduled downtime and thereby reduce costs; and (3) pioneering reliability in SiC and GaN.

  13. Discontinuous Mode Power Supply

    NASA Technical Reports Server (NTRS)

    Lagadinos, John; Poulos, Ethel

    2012-01-01

    A document discusses the changes made to a standard push-pull inverter circuit to avoid saturation effects in the main inverter power supply. Typically, in a standard push-pull arrangement, the unsymmetrical primary excitation causes variations in the volt second integral of each half of the excitation cycle that could lead to the establishment of DC flux density in the magnetic core, which could eventually cause saturation of the main inverter transformer. The relocation of the filter reactor normally placed across the output of the power supply solves this problem. The filter reactor was placed in series with the primary circuit of the main inverter transformer, and is presented as impedance against the sudden changes on the input current. The reactor averaged the input current in the primary circuit, avoiding saturation of the main inverter transformer. Since the implementation of the described change, the above problem has not reoccurred, and failures in the main power transistors have been avoided.

  14. Economics of nuclear power.

    PubMed

    Rossin, A D; Rieck, T A

    1978-08-18

    With 12 percent of U.S. electricity now being supplied by nuclear power, Commonwealth Edison has found nuclear plants to be good investments relative to other base load energy sources. The country's largest user of nuclear power, Commonwealth Edison, estimates that its commitment to nuclear saved its customers about 10 percent on their electric bills in 1977, compared to the cost with the next best alternative, coal. This advantage is seen as continuing, contrary to criticisms of the economics and reliability of nuclear power and claims that it has hidden subsidies. It is concluded that there is a need for both nuclear and coal and that government policy precluding or restricting either would be unwise. PMID:17794111

  15. Unity power factor converter

    NASA Technical Reports Server (NTRS)

    Wester, Gene W. (Inventor)

    1980-01-01

    A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.

  16. Power line detection system

    DOEpatents

    Latorre, Victor R.; Watwood, Donald B.

    1994-01-01

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard.

  17. Power line detection system

    DOEpatents

    Latorre, V.R.; Watwood, D.B.

    1994-09-27

    A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard. 4 figs.

  18. Powered protrusion cutter

    DOEpatents

    Bzorgi, Fariborz M.

    2010-03-09

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  19. STOCHASTIC COOLING POWER REQUIREMENTS.

    SciTech Connect

    WEI,J.BLASKIEWICZ,M.BRENNAN,M.

    2004-07-05

    A practical obstacle for stochastic cooling in high-energy colliders like RHIC is the large amount of power needed for the cooling system. Based on the coasting-beam Fokker-Planck (F-P) equation, we analytically derived the optimum cooling rate and cooling power for a beam of uniform distribution and a cooling system of linear gain function. The results indicate that the usual back-of-envelope formula over-estimated the cooling power by a factor of the mixing factor M. On the other hand, the scaling laws derived from the coasting-beam Fokker-Planck approach agree with those derived from the bunched-beam Fokker-Planck approach if the peak beam intensity is used as the effective coasting-beam intensity. A longitudinal stochastic cooling system of 4-8 GHz bandwidth in RHIC can effectively counteract intrabeam scattering, preventing the beam from escaping the RF bucket becoming debunched around the ring.

  20. Power optimization in logic isomers

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    Logic isomers are labeled, 2-isomorphic graphs that implement the same logic function. Logic isomers may have significantly different power requirements even though they have the same number of transistors in the implementation. The power requirements of the isomers depend on the transition activity of the input signals. The power requirements of isomorphic graph isomers of n-input NAND and NOR gates are shown. Choosing the less power-consuming isomer instead of the others can yield significant power savings. Experimental results on a ripple-carry adder are presented to show that the implementation using the least power-consuming isomers requires approximately 10 percent less power than the implementation using the most power-consuming isomers. Simulations of other random logic designs also confirm that designs using less power-consuming isomers can reduce the logic power demand by approximately 10 percent as compared to designs using more power-consuming isomers.