Assessing Stream Ecosystem Condition in the United States

Science.gov (United States)

Faustini, John M.; Kaufmann, Philip R.; Herlihy, Alan T.; Paulsen, Steven G.

2009-09-01

When the U.S. Congress passed the Federal Water Pollution Control Act in 1972, later amended by the Clean Water Act (CWA) of 1977, it tasked the newly created U.S. Environmental Protection Agency (EPA), in cooperation with the states, with periodically assessing the quality of U.S. waters and reporting on progress toward meeting the goals of the CWA. In subsequent decades, reviews by various governmental and nongovernmental organizations consistently have found available water quality data and reporting to be inadequate to evaluate the nation's progress [Shapiro et al., 2008]. In response to these concerns, in 1989 EPA's Office of Research and Development initiated the Environmental Monitoring and Assessment Program (EMAP) to develop and demonstrate scientific tools to monitor the status of, and trends in, U.S. aquatic resources and environmental stressors affecting them. Recent EPA-led efforts involve monitoring wadeable perennial streams (streams or rivers shallow enough to be wadeable during seasonal low flows), which make up an estimated 90% of the total length of all perennial flowing waters in the United States [EPA, 2006]. Selected results from the first national survey of these streams, the national Wadeable Streams Assessment (WSA) [EPA, 2006; Paulsen et al., 2008], illustrate how such surveys can provide critical information to guide management of this important resource. Nonmonitoring applications of data from the WSA and earlier regional surveys show the wide-ranging applicability of these rich data sets.

Jet Streams as Power Generating Electrical Energy in Libya

International Nuclear Information System (INIS)

Shibani, Abdelfatah H.

2014-01-01

The supreme wind sources are extremely huge, and according to estimations, these winds can supply Libya with great quantity of electrical energy. Among the examples of contemporary engineering technologies in this field, is to create a new generation of Airborne Wind Turbines. Scientists realized that winds near the Earth's surface are too weak to provide a regular source of energy due to the presence of aerobic swirls and obstacles, which represent a source of ground friction being the cause of weakening wind power. Some consider that the Earth's surface is a totally inappropriate place for investing wind energy. As an alternative solution, we start to think about the establishment of wind farms in another place away from the Earth's surface by developing a new type that can run within the upper-air layers, precisely at jet streams areas. In comparison with fluctuating winds blowing gently near the Earth's surface, scientists estimate that the energy of jet streams increases a thousand times than that can be gathered from the most powerful winds on high hills. To be able to provide a clear picture of the possibility of energy investment of jet streams, we shall present, across the pages of this paper, an explanation of the topic through the following aspects: How do Airborne Wind Turbines' trip start, their advantages and difficulties faced, benefits and economic feasibility, General Atmospheric Circulation and jet streams. Since Libya is among the fortunate countries in the world, through which subtropical jet streams pass, we made an analysis and follow-up of daily synoptic charts, which show jet winds' speed, direction and their altitudes for a period of 60 consecutive months starting from January 1, 2003 until December 31, 2007. Also, an analysis was made of daily observational data of jet winds recorded by Tripoli Upper-air Station during the period from the beginning of March 1987 until the end of February 1989. The paper's results summarized that jet

Water Energy Resources of the United States with Emphasis on Low Head/Low Power Resources: Appendix A - Assessment Results by Hydrologic Region

Energy Technology Data Exchange (ETDEWEB)

Hall, Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab. (INEEL)

2004-04-01

Analytical assessments of the water energy resources in the 20 hydrologic regions of the United States were performed using state-of-the-art digital elevation models and geographic information system tools. The principal focus of the study was on low head (less than 30 ft)/low power (less than 1 MW) resources in each region. The assessments were made by estimating the power potential of all the stream segments in a region, which averaged 2 miles in length. These calculations were performed using hydrography and hydraulic heads that were obtained from the U.S. Geological Survey’s Elevation Derivatives for National Applications dataset and stream flow predictions from a regression equation or equations developed specifically for the region. Stream segments excluded from development and developed hydropower were accounted for to produce an estimate of total available power potential. The total available power potential was subdivided into high power (1 MW or more), high head (30 ft or more)/low power, and low head/low power total potentials. The low head/low power potential was further divided to obtain the fractions of this potential corresponding to the operating envelopes of three classes of hydropower technologies: conventional turbines, unconventional systems, and microhydro (less than 100 kW). Summing information for all the regions provided total power potential in various power classes for the entire United States. Distribution maps show the location and concentrations of the various classes of low power potential. No aspect of the feasibility of developing these potential resources was evaluated. Results for each of the 20 hydrologic regions are presented in Appendix A

River longitudinal profiles and bedrock incision models: Stream power and the influence of sediment supply

Science.gov (United States)

Sklar, Leonard; Dietrich, William E.

The simplicity and apparent mechanistic basis of the stream power river incision law have led to its wide use in empirical and theoretical studies. Here we identify constraints on its calibration and application, and present a mechanistic theory for the effects of sediment supply on incision rates which spotlights additional limitations on the applicability of the stream power law. On channels steeper than about 20%, incision is probably dominated by episodic debris flows, and on sufficiently gentle slopes, sediment may bury the bedrock and prevent erosion. These two limits bound the application of the stream power law and strongly constrain the possible combination of parameters in the law. In order to avoid infinite slopes at the drainage divide in numerical models of river profiles using the stream power law it is commonly assumed that the first grid cell is unchanneled. We show, however, that the size of the grid may strongly influence the calculated equilibrium relief. Analysis of slope-drainage area relationships for a river network in a Northern California watershed using digital elevation data and review of data previously reported by Hack reveal that non-equilibrium profiles may produce well defined slope-area relationships (as expected in equilibrium channels), but large differences between tributaries may point to disequilibrium conditions. To explore the role of variations in sediment supply and transport capacity in bedrock incision we introduce a mechanistic model for abrasion of bedrock by saltating bedload. The model predicts that incision rates reach a maximum at intermediate levels of sediment supply and transport capacity. Incision rates decline away from the maximum with either decreasing supply (due to a shortage of tools) or increasing supply (due to gradual bed alluviation), and with either decreasing transport capacity (due to less energetic particle movement) or increasing transport capacity (due less frequent particle impacts per unit bed

Flywheel and power unit

Energy Technology Data Exchange (ETDEWEB)

Seeley, R.W.

1992-10-28

A power unit, e.g. for an electrically driven vehicle, incorporates a flywheel for storing kinetic energy and a battery for storing electrical energy. The battery is incorporated as a substantial part of the rotating mass of the flywheel. Preferably the unit further includes an electrical machine being a motor or generator or machine operable either as a motor or a generator for transferring energy between the battery and the flywheel and/or for the input or output of rotary energy therefrom or thereto. The motor may be used for powering the flywheel and may also operate in a regenerative mode for recharging the unit on de-acceleration of the vehicle. The unit of the invention may also be utilized as an electrical stored power source, e.g. wind or water driven. (author)

New Stream-reach Development: A Comprehensive Assessment of Hydropower Energy Potential in the United States

Energy Technology Data Exchange (ETDEWEB)

Kao, Shih-Chieh [ORNL; McManamay, Ryan A [ORNL; Stewart, Kevin M [ORNL; Samu, Nicole M [ORNL; Hadjerioua, Boualem [ORNL; DeNeale, Scott T [ORNL; Yeasmin, Dilruba [California State University, Fresno; Pasha, M. Fayzul K. [California State University, Fresno; Oubeidillah, Abdoul A [ORNL; Smith, Brennan T [ORNL

2014-04-01

The rapid development of multiple national geospatial datasets related to topography, hydrology, and environmental characteristics in the past decade have provided new opportunities for the refinement of hydropower resource potential from undeveloped stream-reaches. Through 2011 to 2013, the Oak Ridge National Laboratory (ORNL) was tasked by the Department of Energy (DOE) Water Power Program to evaluate the new stream-reach development (NSD) resource potential for more than 3 million US streams. A methodology was designed that contains three main components: (1) identification of stream-reaches with high energy density, (2) topographical analysis of stream-reaches to estimate inundated surface area and reservoir storage, and (3) environmental attribution to spatially join information related to the natural ecological systems, social and cultural settings, policies, management, and legal constraints to stream-reaches of energy potential. An initial report on methodology (Hadjerioua et al., 2013) was later reviewed and revised based on the comments gathered from two peer review workshops. After implementing the assessment across the entire United States, major findings were summarized in this final report. The estimated NSD capacity and generation, including both higher-energy-density (>1 MW per reach) and lower-energy-density (<1 MW per reach) stream-reaches is 84.7 GW, around the same size as the existing US conventional hydropower nameplate capacity (79.5 GW; NHAAP, 2013). In terms of energy, the total undeveloped NSD generation is estimated to be 460 TWh/year, around 169% of average 2002 2011 net annual generation from existing conventional hydropower plants (272 TWh/year; EIA, 2013). Given the run-of-river assumption, NSD stream-reaches have higher capacity factors (53 71%), especially compared with conventional larger-storage peaking-operation projects that usually have capacity factors of around 30%. The highest potential is identified in the Pacific Northwest

Experience in connecting the power generating units of thermal power plants to automatic secondary frequency regulation within the united power system of Russia

International Nuclear Information System (INIS)

Zhukov, A. V.; Komarov, A. N.; Safronov, A. N.; Barsukov, I. V.

2009-01-01

The principles of central control of the power generating units of thermal power plants by automatic secondary frequency and active power overcurrent regulation systems, and the algorithms for interactions between automatic power control systems for the power production units in thermal power plants and centralized systems for automatic frequency and power regulation, are discussed. The order of switching the power generating units of thermal power plants over to control by a centralized system for automatic frequency and power regulation and by the Central Coordinating System for automatic frequency and power regulation is presented. The results of full-scale system tests of the control of power generating units of the Kirishskaya, Stavropol, and Perm GRES (State Regional Electric Power Plants) by the Central Coordinating System for automatic frequency and power regulation at the United Power System of Russia on September 23-25, 2008, are reported.

Linear perturbation theory for tidal streams and the small-scale CDM power spectrum

Science.gov (United States)

Bovy, Jo; Erkal, Denis; Sanders, Jason L.

2017-04-01

Tidal streams in the Milky Way are sensitive probes of the population of low-mass dark matter subhaloes predicted in cold dark matter (CDM) simulations. We present a new calculus for computing the effect of subhalo fly-bys on cold streams based on the action-angle representation of streams. The heart of this calculus is a line-of-parallel-angle approach that calculates the perturbed distribution function of a stream segment by undoing the effect of all relevant impacts. This approach allows one to compute the perturbed stream density and track in any coordinate system in minutes for realizations of the subhalo distribution down to 105 M⊙, accounting for the stream's internal dispersion and overlapping impacts. We study the statistical properties of density and track fluctuations with large suites of simulations of the effect of subhalo fly-bys. The one-dimensional density and track power spectra along the stream trace the subhalo mass function, with higher mass subhaloes producing power only on large scales, while lower mass subhaloes cause structure on smaller scales. We also find significant density and track bispectra that are observationally accessible. We further demonstrate that different projections of the track all reflect the same pattern of perturbations, facilitating their observational measurement. We apply this formalism to data for the Pal 5 stream and make a first rigorous determination of 10^{+11}_{-6} dark matter subhaloes with masses between 106.5 and 109 M⊙ within 20 kpc from the Galactic centre [corresponding to 1.4^{+1.6}_{-0.9} times the number predicted by CDM-only simulations or to fsub(r matter is clumpy on the smallest scales relevant for galaxy formation.

Shifting stream planform state decreases stream productivity yet increases riparian animal production

Science.gov (United States)

Venarsky, Michael P.; Walters, David M.; Hall, Robert O.; Livers, Bridget; Wohl, Ellen

2018-01-01

In the Colorado Front Range (USA), disturbance history dictates stream planform. Undisturbed, old-growth streams have multiple channels and large amounts of wood and depositional habitat. Disturbed streams (wildfires and logging production, emerging aquatic insect flux, and riparian spider biomass. Organic matter and macroinvertebrate production did not differ among sites per unit area (m−2), but values were 2 ×–21 × higher in undisturbed reaches per unit of stream valley (m−1 valley) because total stream area was higher in undisturbed reaches. Insect emergence was similar among streams at the per unit area and per unit of stream valley. However, rescaling insect emergence to per meter of stream bank showed that the emerging insect biomass reaching the stream bank was lower in undisturbed sites because multi-channel reaches had 3 × more stream bank than single-channel reaches. Riparian spider biomass followed the same pattern as emerging aquatic insects, and we attribute this to bottom-up limitation caused by the multi-channeled undisturbed sites diluting prey quantity (emerging insects) reaching the stream bank (riparian spider habitat). These results show that historic landscape disturbances continue to influence stream and riparian communities in the Colorado Front Range. However, these legacy effects are only weakly influencing habitat-specific function and instead are primarily influencing stream–riparian community productivity by dictating both stream planform (total stream area, total stream bank length) and the proportional distribution of specific habitat types (pools vs riffles).

Age and admission times as predictive factors for failure of admissions to discharge-stream short-stay units.

Science.gov (United States)

Shetty, Amith L; Shankar Raju, Savitha Banagar; Hermiz, Arsalan; Vaghasiya, Milan; Vukasovic, Matthew

2015-02-01

Discharge-stream emergency short-stay units (ESSU) improve ED and hospital efficiency. Age of patients and time of hospital presentations have been shown to correlate with increasing complexity of care. We aim to determine whether an age and time cut-off could be derived to subsequently improve short-stay unit success rates. We conducted a retrospective audit on 6703 (5522 inclusions) patients admitted to our discharge-stream short-stay unit. Patients were classified as appropriate or inappropriate admissions, and deemed successful if discharged out of the unit within 24 h; and failures if they needed inpatient admission into the hospital. We calculated short-stay unit length of stay for patients in each of these groups. A 15% failure rate was deemed as acceptable key performance indicator (KPI) for our unit. There were 197 out of 4621 (4.3%, 95% CI 3.7-4.9%) patients up to the age of 70 who failed admission to ESSU compared with 67 out of 901 (7.4%, 95% CI 5.9-9.3%, P 70 years of age have higher rates of failure after admission to discharge-stream ESSU. Although in appropriately selected discharge-stream patients, no age group or time-band of presentation was associated with increased failure rate beyond the stipulated KPI. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Sensitivity of intermittent streams to climate variations in the United States

Science.gov (United States)

Eng, K.

2015-12-01

There is growing interest in the effects of climate change on streamflows because of the potential negative effects on aquatic biota and water supplies. Previous studies of climate controls on flows have primarily focused on perennial streams, and few studies have examined the effect of climate variability on intermittent streams. Our objectives in this study were to (1) identify regions showing similar patterns of intermittency, and (2) evaluate the sensitivity of intermittent streams to historical variability in climate in the United States. This study was carried out at 265 intermittent streams by evaluating: (1) correlations among time series of flow metrics (number of zero-flow events, the average of the central 50% and largest 10% of flows) with precipitation (magnitudes, durations and intensity) and temperature, and (2) decadal changes in the seasonality and long-term trends of these flow metrics. Results identified five distinct seasonal patterns of flow intermittency: fall, fall-to-winter, non-seasonal, summer, and summer-to-winter intermittent streams. In addition, strong associations between the low-flow metrics and historical climate variability were found. However, the lack of trends in historical variations in precipitation results in no significant seasonal shifts or decade-to-decade trends in the low-flow metrics over the period of record (1950 to 2013).

Catheter Related Blood Stream Infections In Patients Of The Intensive Care Unit

Directory of Open Access Journals (Sweden)

Ana Carolina Coimbra de Castro

2017-07-01

Full Text Available Objective: To identify the prevalence of bloodstream infection associated with the Catheter related Blood stream infections in patients of the Intensive Care Unit, and the characteristics of its use and handling. Methods: Descriptive and transversal study with a sample of 88 participants. Data were collected through the observational method and the records in the medical records. The absolute and relative frequencies were used for data analysis. Results: 73.86% of the patients had central venous access in the subclavian vein, 100% used double lumen Catheter related Blood stream infections, 0.5% chlorhexidine solution for skin antisepsis, dressing coverage is performed mostly with Sterile gauze and tape, with a daily exchange. The rate of infection related to the use of the Catheter related Blood stream infections was (6.81%. The most infused pharmacological drugs were antimicrobials (69.32%. Conclusion: The study showed that care with central venous accesses is performed according to recommendations for prevention of bloodstream infection related to the use of these devices. The infection rate is close to the standards found in the literature. Key words: Central Venous Catheterization. Hospital Infection. Intensive care unit. Risk factors. Catheter-Related Infection..

Shifting stream planform state decreases stream productivity yet increases riparian animal production

Science.gov (United States)

Venarsky, Michael P.; Walters, David M.; Hall, Robert O.; Livers, Bridget; Wohl, Ellen

2018-01-01

In the Colorado Front Range (USA), disturbance history dictates stream planform. Undisturbed, old-growth streams have multiple channels and large amounts of wood and depositional habitat. Disturbed streams (wildfires and logging tested how these opposing stream states influenced organic matter, benthic macroinvertebrate secondary production, emerging aquatic insect flux, and riparian spider biomass. Organic matter and macroinvertebrate production did not differ among sites per unit area (m−2), but values were 2 ×–21 × higher in undisturbed reaches per unit of stream valley (m−1 valley) because total stream area was higher in undisturbed reaches. Insect emergence was similar among streams at the per unit area and per unit of stream valley. However, rescaling insect emergence to per meter of stream bank showed that the emerging insect biomass reaching the stream bank was lower in undisturbed sites because multi-channel reaches had 3 × more stream bank than single-channel reaches. Riparian spider biomass followed the same pattern as emerging aquatic insects, and we attribute this to bottom-up limitation caused by the multi-channeled undisturbed sites diluting prey quantity (emerging insects) reaching the stream bank (riparian spider habitat). These results show that historic landscape disturbances continue to influence stream and riparian communities in the Colorado Front Range. However, these legacy effects are only weakly influencing habitat-specific function and instead are primarily influencing stream–riparian community productivity by dictating both stream planform (total stream area, total stream bank length) and the proportional distribution of specific habitat types (pools vs riffles).

Stabilization of gas turbine unit power

Science.gov (United States)

Dolotovskii, I.; Larin, E.

2017-11-01

We propose a new cycle air preparation unit which helps increasing energy power of gas turbine units (GTU) operating as a part of combined cycle gas turbine (CCGT) units of thermal power stations and energy and water supply systems of industrial enterprises as well as reducing power loss of gas turbine engines of process blowers resulting from variable ambient air temperatures. Installation of GTU power stabilizer at CCGT unit with electric and thermal power of 192 and 163 MW, respectively, has resulted in reduction of produced electrical energy production costs by 2.4% and thermal energy production costs by 1.6% while capital expenditures after installation of this equipment increased insignificantly.

Channel water balance and exchange with subsurface flow along a mountain headwater stream in Montana, United States

Science.gov (United States)

R.A. Payn; M.N. Gooseff; B.L. McGlynn; K.E. Bencala; S.M. Wondzell

2009-01-01

Channel water balances of contiguous reaches along streams represent a poorly understood scale of stream-subsurface interaction. We measured reach water balances along a headwater stream in Montana, United States, during summer base flow recessions. Reach water balances were estimated from series of tracer tests in 13 consecutive reaches delineated evenly along a 2.6-...

METRIC context unit architecture

Energy Technology Data Exchange (ETDEWEB)

Simpson, R.O.

1988-01-01

METRIC is an architecture for a simple but powerful Reduced Instruction Set Computer (RISC). Its speed comes from the simultaneous processing of several instruction streams, with instructions from the various streams being dispatched into METRIC's execution pipeline as they become available for execution. The pipeline is thus kept full, with a mix of instructions for several contexts in execution at the same time. True parallel programming is supported within a single execution unit, the METRIC Context Unit. METRIC's architecture provides for expansion through the addition of multiple Context Units and of specialized Functional Units. The architecture thus spans a range of size and performance from a single-chip microcomputer up through large and powerful multiprocessors. This research concentrates on the specification of the METRIC Context Unit at the architectural level. Performance tradeoffs made during METRIC's design are discussed, and projections of METRIC's performance are made based on simulation studies.

Power conditioning unit for photovoltaic power systems

Science.gov (United States)

Beghin, G.; Nguyen Phuoc, V. T.

Operational features and components of a power conditioning unit for interconnecting solar cell module powers with a utility grid are outlined. The two-stage unit first modifies the voltage to desired levels on an internal dc link, then inverts the current in 2 power transformers connected to a vector summation control to neutralize harmonic distortion up to the 11th harmonic. The system operates in parallel with the grid with extra inductors to absorb line-to-line voltage and phase differences, and permits peak power use from the PV array. Reactive power is gained internally, and a power system controller monitors voltages, frequencies, and currents. A booster preregulator adjusts the input voltage from the array to provide voltage regulation for the inverter, and can commutate 450 amps. A total harmonic distortion of less than 5 percent is claimed, with a rating of 5 kVA, 50/60 Hz, 3-phase, and 4-wire.

Sour streams in appalachia: mapping nature’s buffer against sulfur deposition

Science.gov (United States)

Natasha Vizcarra; Nicholas Povak; Paul Hessburg; Keith Reynolds

2015-01-01

Even while emissions are in decline, sulfur released into the air primarily by coal- and oil-burning power plants continues to acidify streams in the eastern United States, stressing vegetation and harming aquatic life. Watersheds rich in base cations—nutrients that attract and bind acidic molecules—naturally buffer streams against acidification. These watersheds can...

Thermoeconomic cost analysis of CO_2 compression and purification unit in oxy-combustion power plants

International Nuclear Information System (INIS)

Jin, Bo; Zhao, Haibo; Zheng, Chuguang

2015-01-01

Highlights: • Thermoeconomic cost analysis for CO_2 compression and purification unit is conducted. • Exergy cost and thermoeconomic cost occur in flash separation and mixing processes. • Unit exergy costs for flash separator and multi-stream heat exchanger are identical. • Multi-stage CO_2 compressor contributes to the minimum unit exergy cost. • Thermoeconomic performance for optimized CPU is enhanced. - Abstract: High CO_2 purity products can be obtained from oxy-combustion power plants through CO_2 compression and purification unit (CPU) based on phase separation method. To identify cost formation process and potential energy savings for CPU, detailed thermoeconomic cost analysis based on structure theory of thermoeconomics is applied to an optimized CPU (with double flash separators). It is found that the largest unit exergy cost occurs in the first separation process while the multi-stage CO_2 compressor contributes to the minimum unit exergy cost. In two flash separation processes, unit exergy costs for the flash separator and multi-stream heat exchanger are identical but their unit thermoeconomic costs are different once monetary cost for each device is considered. For cost inefficiency occurring in CPU, it mainly derives from large exergy costs and thermoeconomic costs in the flash separation and mixing processes. When compared with an unoptimized CPU, thermoeconomic performance for the optimized CPU is enhanced and the maximum reduction of 5.18% for thermoeconomic cost is attained. To achieve cost effective operation, measures should be taken to improve operations of the flash separation and mixing processes.

Correlation of Pc5 wave power inside and outside themagnetosphere during high speed streams

Directory of Open Access Journals (Sweden)

R. L. Kessel

2004-01-01

Full Text Available We show a clear correlation between the ULF wave power (Pc5 range inside and outside the Earth's magnetosphere during high speed streams in 1995. We trace fluctuations beginning 200R_E upstream using Wind data, to fluctuations just upstream from Earth's bow shock and in the magnetosheath using Geotail data and compare to pulsations on the ground at the Kilpisjarvi ground station. With our 5-month data set we draw the following conclusions. ULF fluctuations in the Pc5 range are found in high speed streams; they are non-Alfvénic at the leading edge and Alfvénic in the central region. Compressional and Alfvénic fluctuations are modulated at the bow shock, some features of the waveforms are preserved in the magnetosheath, but overall turbulence and wave power is enhanced by about a factor of 10. Parallel (compressional and perpendicular (transverse power are at comparable levels in the solar wind and magnetosheath, both in the compression region and in the central region of high speed streams. Both the total parallel and perpendicular Pc5 power in the solar wind (and to a lesser extent in the magnetosheath correlate well with the total Pc5 power of the ground-based H-component magnetic field. ULF fluctuations in the magnetosheath during high speed streams are common at frequencies from 1–4mHz and can coincide with the cavity eigenfrequencies of 1.3, 1.9, 2.6, and 3.4mHz, though other discrete frequencies are also often seen.

Key words. Interplanetary physics (MHD waves and turbulence – Magnetospheric physics (solar wind-magnetosphere interactions; MHD waves and instabilities

Behavioral System Level Power Consumption Modeling of Mobile Video Streaming applications

OpenAIRE

Benmoussa , Yahia; Boukhobza , Jalil; Hadjadj-Aoul , Yassine; Lagadec , Loïc; Benazzouz , Djamel

2012-01-01

National audience; Nowadays, the use of mobile applications and terminals faces fundamental challenges related to energy constraint. This is due to the limited battery lifetime as compared to the increasing hardware evolution. Video streaming is one of the most energy consuming applications in a mobile system because of its intensive use of bandwidth, memory and processing power. In this work, we aim to propose a methodology for building and validating a high level global power consumption mo...

Power quality improvement of unbalanced power system with distributed generation units

DEFF Research Database (Denmark)

Hu, Y.; Chen, Zhe; Excell, P.

2011-01-01

This paper presents a power electronic system for improving the power quality of the unbalanced distributed generation units in three-phase four-wire system. In the system, small renewable power generation units, such as small PV generator, small wind turbines may be configured as single phase...... and control of the converter are described. Simulation results have demonstrated that the system can effectively correct the unbalance and enhance the system power quality....... generation units. The random nature of renewable power sources may result in significant unbalance in the power network and affect the power quality. An electronic converter system is proposed to correct the system unbalance and harmonics so as to deal with the power quality problems. The operation...

Nuclear power in the United States

International Nuclear Information System (INIS)

Johnston, J.B.

1985-01-01

All over the world except in the United States, nuclear energy is a low cost, secure, environmentally acceptable form of energy. In the United States, civilian nuclear power is dead. 112 nuclear power plants have been abandoned or cancelled in the last decade, and there has been no new order for nuclear plants since 1978. It will be fortunate to have 125 operating nuclear plants in the United States in the year 2000. There are almost 90 completed nuclear power plants and about 45 under construction in the United States, but several of those under construction will eventually be abandoned. About 20 % of the electricity in the United States will be generated by nuclear plants in 2000 as compared with 13 % supplied in the last year. Under the present regulatory and institutional arrangement, American electric utilities would not consider to order a new nuclear power plant. Post-TMI nuclear plants became very expensive, and there is also ideological opposition to nuclear power. Coal-firing plants are also in the similar situation. The uncertainty about electric power demand, the cost of money, the inflation of construction cost and regulation caused the situation. (Kako, I.)

Modeling of immision from power plants using stream-diffusion model

International Nuclear Information System (INIS)

Kanevce, Lj.; Kanevce, G.; Markoski, A.

1996-01-01

Analyses of simple empirical and integral immision models, comparing with complex three dimensional differential models is given. Complex differential models needs huge computer power, so they can't be useful for practical engineering calculations. In this paper immision modeling, using stream-diffusion approach is presented. Process of dispersion is divided into two parts. First part is called stream part, it's near the source of the pollutants, and it's presented with defected turbulent jet in wind field. This part finished when the velocity of stream (jet) becomes equal with wind speed. Boundary conditions in the end of the first part, are initial for the second, called diffusion part, which is modeling with tri dimensional diffusion equation. Gradient of temperature, wind speed profile and coefficient of diffusion in this model must not be constants, they can change with the height. Presented model is much simpler than the complete meteorological differential models which calculates whole fields of meteorological parameters. Also, it is more complex and gives more valuable results for dispersion of pollutants from widely used integral and empirical models

21 CFR 890.5950 - Powered heating unit.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered heating unit. 890.5950 Section 890.5950...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5950 Powered heating unit. (a) Identification. A powered heating unit is a device intended for medical purposes that...

Sensitivity of intermittent streams to climate variations in the western United States

Science.gov (United States)

Eng, K.; Wolock, D.; Dettinger, M. D.

2014-12-01

There is a great deal of interest in streamflow changes caused by climate change because of the potential negative effects on aquatic biota and water supplies. Most previous studies have focused on perennial streams, and only a few studies have examined the effect of climate variability on intermittent streams. Our objective in this study was to evaluate the sensitivity of intermittent streams to historical variability in climate in the semi-arid regions of the western United States. This study was carried out at 45 intermittent streams that had a minimum of 45 years of daily-streamgage record by evaluating: (1) correlations among time series of flow metrics (number of zero-flow events, the average of the central 50% and largest 10% of flows) with climate, and (2) decadal changes in the seasonality and long-term trends of these flow metrics. Results showed strong associations between the low-flow metrics and historical changes in climate. The decadal analysis, in contrast, suggested no significant seasonal shifts or decade-to-decade trends in the low-flow metrics. The lack of trends or changes in seasonality is likely due to unchanged long-term patterns in precipitation over the time period examined.

Investigation of plasma stream collision produced by thin films irradiated by powerful pulsed electron beam

International Nuclear Information System (INIS)

Efremov, V P; Demidov, B A; Ivkin, M V; Mescheryakov, A N; Petrov, V A; Potapenko, A I

2006-01-01

Collision of fast plasma streams in vacuum is investigated. Plasma streams were produced by irradiation of thin foils with a powerful pulsed electron beam. Interaction of the plasma flows was studied by using frame and streak cameras. One-dimensional numerical simulation was carried out. Application of this method for porous ICF targets and high-energy physics is discussed

Behavioural differential equations : a coinductive calculus of streams, automata, and power series

NARCIS (Netherlands)

J.J.M.M. Rutten (Jan)

2000-01-01

textabstractStreams, (automata and) languages, and formal power series are viewed coalgebraically. In summary, this amounts to supplying these sets with a deterministic automaton structure, which has the universal property of being final. Finality then forms the basis for both definitions and proofs

Optimizing the performance of streaming numerical kernels on the IBM Blue Gene/P PowerPC 450 processor

KAUST Repository

Malas, Tareq Majed Yasin

2012-05-21

Several emerging petascale architectures use energy-efficient processors with vectorized computational units and in-order thread processing. On these architectures the sustained performance of streaming numerical kernels, ubiquitous in the solution of partial differential equations, represents a challenge despite the regularity of memory access. Sophisticated optimization techniques are required to fully utilize the CPU. We propose a new method for constructing streaming numerical kernels using a high-level assembly synthesis and optimization framework. We describe an implementation of this method in Python targeting the IBM® Blue Gene®/P supercomputer\\'s PowerPC® 450 core. This paper details the high-level design, construction, simulation, verification, and analysis of these kernels utilizing a subset of the CPU\\'s instruction set. We demonstrate the effectiveness of our approach by implementing several three-dimensional stencil kernels over a variety of cached memory scenarios and analyzing the mechanically scheduled variants, including a 27-point stencil achieving a 1.7× speedup over the best previously published results. © The Author(s) 2012.

Hierarchical Object-Based Mapping of Riverscape Units and in-Stream Mesohabitats Using LiDAR and VHR Imagery

Directory of Open Access Journals (Sweden)

Luca Demarchi

2016-01-01

Full Text Available In this paper, we present a new, semi-automated methodology for mapping hydromorphological indicators of rivers at a regional scale using multisource remote sensing (RS data. This novel approach is based on the integration of spectral and topographic information within a multilevel, geographic, object-based image analysis (GEOBIA. Different segmentation levels were generated based on the two sources of Remote Sensing (RS data, namely very-high spatial resolution, near-infrared imagery (VHR and high-resolution LiDAR topography. At each level, different input object features were tested with Machine Learning classifiers for mapping riverscape units and in-stream mesohabitats. The GEOBIA approach proved to be a powerful tool for analyzing the river system at different levels of detail and for coupling spectral and topographic datasets, allowing for the delineation of the natural fluvial corridor with its primary riverscape units (e.g., water channel, unvegetated sediment bars, riparian densely-vegetated units, etc. and in-stream mesohabitats with a high level of accuracy, respectively of K = 0.91 and K = 0.83. This method is flexible and can be adapted to different sources of data, with the potential to be implemented at regional scales in the future. The analyzed dataset, composed of VHR imagery and LiDAR data, is nowadays increasingly available at larger scales, notably through European Member States. At the same time, this methodology provides a tool for monitoring and characterizing the hydromorphological status of river systems continuously along the entire channel network and coherently through time, opening novel and significant perspectives to river science and management, notably for planning and targeting actions.

Generating units performances: power system requirements

Energy Technology Data Exchange (ETDEWEB)

Fourment, C; Girard, N; Lefebvre, H

1994-08-01

The part of generating units within the power system is more than providing power and energy. Their performance are not only measured by their energy efficiency and availability. Namely, there is a strong interaction between the generating units and the power system. The units are essential components of the system: for a given load profile the frequency variation follows directly from the behaviour of the units and their ability to adapt their power output. In the same way, the voltage at the units terminals are the key points to which the voltage profile at each node of the network is linked through the active and especially the reactive power flows. Therefore, the customer will experience the frequency and voltage variations induced by the units behaviour. Moreover, in case of adverse conditions, if the units do not operate as well as expected or trip, a portion of the system, may be the whole system, may collapse. The limitation of the performance of a unit has two kinds of consequences. Firstly, it may result in an increased amount of not supplied energy or loss of load probability: for example if the primary reserve is not sufficient, a generator tripping may lead to an abnormal frequency deviation, and load may have to be shed to restore the balance. Secondly, the limitation of a unit performance results in an economic over-cost for the system: for instance, if not enough `cheap` units are able to load-following, other units with higher operating costs have to be started up. We would like to stress the interest for the operators and design teams of the units on the one hand, and the operators and design teams of the system on the other hand, of dialog and information exchange, in operation but also at the conception stage, in order to find a satisfactory compromise between the system requirements and the consequences for the generating units. (authors). 11 refs., 4 figs.

About choosing the power unit of NPP

International Nuclear Information System (INIS)

Alekseev, P.N.; Mordashev, V.M.; Proshkin, A.A.; Stukalov, V.A.; Subbotin, S.A.; Tsibul'skij, V.F.; Chernilin, Yu.F.

2008-01-01

The present-day domestic nuclear power industry faces the necessity to make both process and economy related decisions. The mentioned decisions should cover all the aspects of the nuclear power complex. In particular, as of now, no substantiation of the present-day and the future requirements for the power unit of the WWER and fast reactor NPPs is available. The choice of the unit power of an NPP should involve consideration of all factors and should not be boiled down to the efforts to ensure the minimization of the investment and the operation constituents of the electric power generation costs. The aim of the present paper was to ensure elaboration of the recommendations to substantiate the optimal unit power of NPP power units based on the analysis of various factors to design, to construct and to operate an NPP (investment, time of construction, the unscheduled shutdown losses, the unification, the fabrication quality, the accident damage, etc.), and the electrical network potentialities and the regional electric power demands [ru

NORD STREAM 2 and its Soft Power – an Unfolding Playground for the European Union

Directory of Open Access Journals (Sweden)

Roxana Ioana Banciu

2016-06-01

Full Text Available This paper focuses on the Nord Stream 2 pipeline in a double reflection (Russia - the candle, Germany - the mirror handling one particular aspect that influences Russia-EU relations since the Ukrainian factor emerged as a playground for both East and West tectonic plates - namely the energy sector. It is vital for any global power to understand this approach in order to reach people’s minds, in order to emerge as leaders on the world map and to build a strong perception over a political scene. A recently debated subject is Nord Stream 2. The reason why I have chosen to explore this subject is because I am very interested in how Kremlin seeks to have an exclusive control over Eastern Europe, given the full debate in the last three years. In this thesis I will also discuss some important elements of the Russian Soft Power over Europe introducing the plot of South Stream project.

14 CFR 23.1142 - Auxiliary power unit controls.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 23.1142... Powerplant Controls and Accessories § 23.1142 Auxiliary power unit controls. Means must be provided on the... power unit. [Doc. No. 26344, 58 FR 18974, Apr. 9, 1993] ...

Portable Power And Digital-Communication Units

Science.gov (United States)

Levin, Richard R.; Henry, Paul K.; Rosenberg, Leigh S.

1992-01-01

Conceptual network of electronic-equipment modules provides electrical power and digital radio communications at multiple sites not served by cables. System includes central communication unit and portable units powered by solar photovoltaic arrays. Useful to serve equipment that must be set up quickly at remote sites or buildings that cannot be modified to provide cable connections.

Relationship between bifenthrin sediment toxic units and benthic community metrics in urban California streams.

Science.gov (United States)

Hall, Lenwood W; Anderson, Ronald D

2013-08-01

The objective of this study was to use ecologically relevant field measurements for determining the relationship between bifenthrin sediment toxic units (TUs) (environmental concentrations/Hyalella acute LC50 value) and 15 benthic metrics in four urban California streams sampled from 2006 to 2011. Data from the following four California streams were used in the analysis: Kirker Creek (2006, 2007), Pleasant Grove Creek (2006, 2007, and 2008), Arcade Creek (2009, 2010, and 2011), and Salinas streams (2009, 2010, and 2011). The results from univariate analysis of benthic metrics versus bifenthrin TU calculations for the four California streams with multiple-year datasets combined by stream showed that there were either nonsignificant relationships or lack of metric data for 93 % of cases. For 7 % of the data (4 cases) where significant relationships were reported between benthic metrics and bifenthrin TUs, these relationships were ecologically meaningful. Three of these significant direct relationships were an expression of tolerant benthic taxa (either % tolerant taxa or tolerance values, which are similar metrics), which would be expected to increase in a stressed environment. These direct significant tolerance relationships were reported for Kirker Creek, Pleasant Grove Creek, and Arcade Creek. The fourth significant relationship was an inverse relationship between taxa richness and bifenthrin TUs for the 3-year Pleasant Grove Creek dataset. In summary, only a small percent of the benthic metric × bifenthrin TU relationships were significant for the four California streams. Therefore, the general summary conclusion from this analysis is that there is no strong case for showing consistent meaningful relationships between various benthic metrics used to characterize the status of benthic communities and bifenthrin TUs for these four California streams.

The energy and greenhouse-gas implications of internet video streaming in the United States

International Nuclear Information System (INIS)

Shehabi, Arman; Walker, Ben; Masanet, Eric

2014-01-01

The rapid growth of streaming video entertainment has recently received attention as a possibly less energy intensive alternative to the manufacturing and transportation of digital video discs (DVDs). This study utilizes a life-cycle assessment approach to estimate the primary energy use and greenhouse-gas emissions associated with video viewing through both traditional DVD methods and online video streaming. Base-case estimates for 2011 video viewing energy and CO 2 (e) emission intensities indicate video streaming can be more efficient than DVDs, depending on DVD viewing method. Video streaming benefits from relatively more efficient end-user devices than DVD viewing, though much of that savings is lost when accounting for the additional energy from network data transmission. Video streaming appears distinctly favorable when compared against any DVD viewing that includes consumer driving, which significantly increases the energy and CO 2 (e) emissions per viewing hour. Total US 2011 video viewing required about 192 PJ of primary energy and emitted about 10.5 billion kg of CO 2 (e). Shifting all 2011 DVD viewing to video streaming reduces the total primary energy use to about 162 PJ and the CO 2 (e) emissions to about 8.6 billion kg, representing a savings equivalent to the primary energy used to meet the electricity demand of nearly 200 000 US households each year. Sensitivity analysis indicates that results are most influenced by the end-user DVD player power demand, data transmission energy, and consumer travel for store DVDs. Data center energy use—both operational and embodied within the IT equipment—account for <1% of the total video streaming energy use. Results from this study indicate that designers and policy makers should focus on the efficiency of end-user devices and network transmission energy to curb future increases in energy use from the proliferation of video streaming. (letters)

Complementary Power Control for Doubly Fed Induction Generator-Based Tidal Stream Turbine Generation Plants

Directory of Open Access Journals (Sweden)

Khaoula Ghefiri

2017-06-01

Full Text Available The latest forecasts on the upcoming effects of climate change are leading to a change in the worldwide power production model, with governments promoting clean and renewable energies, as is the case of tidal energy. Nevertheless, it is still necessary to improve the efficiency and lower the costs of the involved processes in order to achieve a Levelized Cost of Energy (LCoE that allows these devices to be commercially competitive. In this context, this paper presents a novel complementary control strategy aimed to maximize the output power of a Tidal Stream Turbine (TST composed of a hydrodynamic turbine, a Doubly-Fed Induction Generator (DFIG and a back-to-back power converter. In particular, a global control scheme that supervises the switching between the two operation modes is developed and implemented. When the tidal speed is low enough, the plant operates in variable speed mode, where the system is regulated so that the turbo-generator module works in maximum power extraction mode for each given tidal velocity. For this purpose, the proposed back-to-back converter makes use of the field-oriented control in both the rotor side and grid side converters, so that a maximum power point tracking-based rotational speed control is applied in the Rotor Side Converter (RSC to obtain the maximum power output. Analogously, when the system operates in power limitation mode, a pitch angle control is used to limit the power captured in the case of high tidal speeds. Both control schemes are then coordinated within a novel complementary control strategy. The results show an excellent performance of the system, affording maximum power extraction regardless of the tidal stream input.

The paradox of cooling streams in a warming world: Regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States

Science.gov (United States)

Arismendi, Ivan; Johnson, Sherri; Dunham, Jason B.; Haggerty, Roy; Hockman-Wert, David

2012-01-01

Temperature is a fundamentally important driver of ecosystem processes in streams. Recent warming of terrestrial climates around the globe has motivated concern about consequent increases in stream temperature. More specifically, observed trends of increasing air temperature and declining stream flow are widely believed to result in corresponding increases in stream temperature. Here, we examined the evidence for this using long-term stream temperature data from minimally and highly human-impacted sites located across the Pacific continental United States. Based on hypothesized climate impacts, we predicted that we should find warming trends in the maximum, mean and minimum temperatures, as well as increasing variability over time. These predictions were not fully realized. Warming trends were most prevalent in a small subset of locations with longer time series beginning in the 1950s. More recent series of observations (1987-2009) exhibited fewer warming trends and more cooling trends in both minimally and highly human-influenced systems. Trends in variability were much less evident, regardless of the length of time series. Based on these findings, we conclude that our perspective of climate impacts on stream temperatures is clouded considerably by a lack of long-termdata on minimally impacted streams, and biased spatio-temporal representation of existing time series. Overall our results highlight the need to develop more mechanistic, process-based understanding of linkages between climate change, other human impacts and stream temperature, and to deploy sensor networks that will provide better information on trends in stream temperatures in the future.

BN-1200 Reactor Power Unit Design Development

International Nuclear Information System (INIS)

Vasilyev, B.A.; Shepelev, S.F.; Ashirmetov, M.R.; Poplavsky, V.M.

2013-01-01

Main goals of BN-1200 design: • Develop a reliable new generation reactor plant for the commercial power unit with fast reactor to implement the first-priority objectives in changing over to closed nuclear fuel cycle; • Improve technical and economic indices of BN reactor power unit to the level of those of Russian VVER of equal power; • Enhance the safety up to the level of the requirements for the 4th generation RP

Headwater Stream Management Dichotomies: Local Amphibian Habitat vs. Downstream Fish Habitat

Science.gov (United States)

Jackson, C. R.

2002-12-01

, specifically the role of woody debris in habitat formation, documented for larger streams do not apply to headwater streams. Relatively small wood (diameters between 10 and 40 cm), inorganic material, and organic debris (diameters less than 10 cm) were major step-forming agents while big woody debris pieces (> 40 cm dia.) created less than 10% of steps. Streams in virgin and managed stands did not differ in relative importance of very large woody debris. Due to low fluvial power, pool habitat was rare. These streams featured mostly step-riffle morphology, not step-pool, indicating insufficient flow for pool-scour. Stream power and unit stream power were dominant channel shaping factors.

EnviroAtlas - Percent Stream Buffer Zone As Natural Land Cover for the Conterminous United States

Science.gov (United States)

This EnviroAtlas dataset shows the percentage of land area within a 30 meter buffer zone along the National Hydrography Dataset (NHD) high resolution stream network, and along water bodies such as lakes and ponds that are connected via flow to the streams, that is classified as forest land cover, modified forest land cover, and natural land cover using the 2006 National Land Cover Dataset (NLCD) for each Watershed Boundary Dataset (WBD) 12-digit hydrological unit (HUC) in the conterminous United States. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

Anticorrosion and halobios control for tidal power generating units

International Nuclear Information System (INIS)

Shen, J C; Ding, L X

2012-01-01

The anticorrosion and halobios control is the key techniquesrelated to the safety and durability of tidal power generating units. The technique of material application, antifouling coating and cathodic protection are often adopted. The technical research, application, updating and development are carried on Jiangxia Tidal Power Station, which is based on the old Unit 1-Unit 5 operated for nearly 30 years, and the new Unit 6 operated in 2007. It is found that stainless steeland the antifouling coating used in Unit 1- Unit 5 are very effective, but cathodic protection is often likely to fail because of the limitation of structure and installation. Analyses and studies for anticorrosion and halobios control techniques of tidal power generating units according to theory, experience and actual effects have been done, which can be for reference to the tidal power station designers and builders.

Study on the power control system for NPP power unit with the WWER-440 reactor

International Nuclear Information System (INIS)

Aleksandrova, N.D.; Naumov, A.V.

1981-01-01

Results of model investigations into basic version of the power control systems (PCS) conformably to the WWER-440 NPP power unit are stated. Transient processes in the power unit system when being two PCS versions during perturbations of different parameters: unit power, vapour pressure or position of control rods have been simulated. Investigations into the different PCS versions show that quality of operation of a traditional scheme with a turbine power controller and reactor pressure controller can be significantly improved with the introduction of a high-speed signal of pressure into the reactor controller. The PCS version with the compensation of interrelations between the turbine and reactor controllers constructed according to the same principles as the standard schemes of power units of thermal electric power plant is perspective as well [ru

Behavioural differential equations : a coinductive calculus of streams, automata, and power series

OpenAIRE

Rutten, Jan

2000-01-01

textabstractStreams, (automata and) languages, and formal power series are viewed coalgebraically. In summary, this amounts to supplying these sets with a deterministic automaton structure, which has the universal property of being final. Finality then forms the basis for both definitions and proofs by coinduction, the coalgebraic counterpart of induction. Coinductive definitions take the shape of what we have called behavioural differential equations, after Brzozowski's notion of input deriv...

An ecohydrological stream type cassification of intermittent and ephemeral streams in the Southwestern United States 2397

Science.gov (United States)

Ephemeral and intermittent streams are the predominant fluvial forms in arid and semi-arid environments. Various studies have shown biological and habitat diversity in these lands to be considerably higher along stream corridors in comparison to adjacent uplands, yet knowledge of how these streams f...

High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

Science.gov (United States)

Bozak, Karin E.; Pinero, Luis R.; Scheidegger, Robert J.; Aulisio, Michael V.; Gonzalez, Marcelo C.; Birchenough, Arthur G.

2015-01-01

A silicon carbide brassboard power processing unit has been developed by the NASA Glenn Research Center in Cleveland, Ohio. The power processing unit operates from two sources: a nominal 300 Volt high voltage input bus and a nominal 28 Volt low voltage input bus. The design of the power processing unit includes four low voltage, low power auxiliary supplies, and two parallel 7.5 kilowatt (kW) discharge power supplies that are capable of providing up to 15 kilowatts of total power at 300 to 500 Volts (V) to the thruster. Additionally, the unit contains a housekeeping supply, high voltage input filter, low voltage input filter, and master control board, such that the complete brassboard unit is capable of operating a 12.5 kilowatt Hall effect thruster. The performance of the unit was characterized under both ambient and thermal vacuum test conditions, and the results demonstrate exceptional performance with full power efficiencies exceeding 97%. The unit was also tested with a 12.5kW Hall effect thruster to verify compatibility and output filter specifications. With space-qualified silicon carbide or similar high voltage, high efficiency power devices, this would provide a design solution to address the need for high power electric propulsion systems.

Effects of SMES units on power system stability

International Nuclear Information System (INIS)

Byerly, R.T.; Juves, J.A.

1980-01-01

A mathematical model suitable for representing SMES units in power system stability studies has been developed and incorporated into an existing large-scale stability program. Demonstration studies have been performed which emphasize the use of SMES units to improve the damping of oscillations associated with synchronizing power flow among generators. The capability exists to conduct stability studies of large systems which include SMES units

Optimizing the performance of streaming numerical kernels on the IBM Blue Gene/P PowerPC 450 processor

KAUST Repository

Malas, Tareq Majed Yasin; Ahmadia, Aron; Brown, Jed; Gunnels, John A.; Keyes, David E.

2012-01-01

Several emerging petascale architectures use energy-efficient processors with vectorized computational units and in-order thread processing. On these architectures the sustained performance of streaming numerical kernels, ubiquitous in the solution

Random power series in the unit ball of Cn

International Nuclear Information System (INIS)

Shi Jihuai.

1989-07-01

The random power series in the unit disc has been studied by many authors. In this paper, we studied the random power series in the unit ball of C n and generalized some results in the unit disc to the unit ball, in particular, the result obtained recently by Duren has been generalized to the unit ball. The main tool used here is the generalized Salem-Zygmund's theorem. (author). 12 refs

14 CFR 25.1142 - Auxiliary power unit controls.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 25.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

14 CFR 29.1142 - Auxiliary power unit controls.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Auxiliary power unit controls. 29.1142... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Powerplant Controls and Accessories § 29.1142 Auxiliary power unit controls. Means must be provided on the flight deck for starting...

Concentration of WWER-1000 unit power on one site

International Nuclear Information System (INIS)

Rousek, J.; Kysel, J.; Sladek, V.

1987-01-01

The problem of a suitable number of nuclear power plant units built on one site is discussed. Using an example of three sites being prepared now in Czechoslovakia, two alternatives - one with two WWER-1000 units, the other with four WWER-1000 units on one site - are evaluated from the viewpoint of long-range nuclear power development program in Czechoslovakia, costs, transmission of electric power and heat supply. (author). 10 tabs., 13 refs

Architecture of nuclear power units

International Nuclear Information System (INIS)

Malaniuk, B.

1981-01-01

Nuclear units with circulation cooling using cooling towers are dominating points of the landscape. The individual cooling towers or pairs of cooling towers should be situated in the axes of double units and should also linearly be arranged, rhythmically in the respective zone. Examples are shown of the architectural designs of several nuclear power plants in the USA, the UK, the USSR, France, the FRG and Italy. (H.S.)

Development of a method to evaluate shared alternate AC power source effects in multi-unit nuclear power plants

International Nuclear Information System (INIS)

Jung, Woo Sik; Yang, Joon Eun

2003-07-01

In order to evaluate accurately a Station BlackOut (SBO) event frequency of a multi-unit nuclear power plant that has a shared Alternate AC (AAC) power source, an approach has been developed which accommodates the complex inter-unit behavior of the shared AAC power source under multi-unit Loss Of Offsite Power (LOOP) conditions. The approach is illustrated for two cases, 2 units and 4 units at a single site, and generalized for a multi-unit site. Furthermore, the SBO frequency of the first unit of the 2-unit site is quantified. The SBO frequency at a target unit of Probabilistic Safety Assessment (PSA) could be underestimated if the inter-unit dependency of the shared AAC power source is not properly modeled. The effect of the inter-unit behavior of the shared AAC power source on the SBO frequency is not negligible depending on the Common Cause Failure (CCF) characteristics among AC power sources. The methodology suggested in the present report is believed to be very useful in evaluating the SBO frequency and the core damage frequency resulting from the SBO event. This approach is also applicable to the probabilistic evaluation of the other shared systems in a multi-unit nuclear power plant

A cost effective waste management methodology for power reactor waste streams

International Nuclear Information System (INIS)

Granus, M.W.; Campbell, A.D.

1984-01-01

This paper describes a computer based methodology for the selection of the processing methods (solidification/dewatering) for various power reactor radwaste streams. The purpose of this methodology is to best select the method that provides the most cost effective solution to waste management. This method takes into account the overall cost of processing, transportation and disposal. The selection matrix on which the methodology is based is made up of over ten thousand combinations of liner, cask, process, and disposal options from which the waste manager can choose. The measurement device for cost effective waste management is the concurrent evaluation of total dollars spent. The common denominator is dollars per cubic foot of the input waste stream. Dollars per curie of the input waste stream provides for proper checks and balances. The result of this analysis can then be used to assess the total waste management cost. To this end, the methodology can then be employed to predict a given number of events (processes, transportation, and disposals) and project the annual cost of waste management. For the purposes of this paper, the authors provide examples of the application of the methodology on a typical BWR at 2, 4 and 6 years. The examples are provided in 1984 dollars. Process selection is influenced by a number of factors which must be independently evaluated for each waste stream. Final processing cost is effected by the particular process efficiency and a variety of regulatory constraints. The interface between process selection and cask selection/transportation driven by the goal of placing the greatest amount of pre-processed waste in the package and remaining within the bounds of weight, volume, regulatory, and cask availability limitations. Disposal is the cost of burial and can be affected by disposal, but availability of burial space, and the location of the disposal site in relation to the generator

49 CFR 173.172 - Aircraft hydraulic power unit fuel tank.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Aircraft hydraulic power unit fuel tank. 173.172... Class 1 and Class 7 § 173.172 Aircraft hydraulic power unit fuel tank. Aircraft hydraulic power unit fuel tanks containing a mixture of anhydrous hydrazine and monomethyl hydrazine (M86 fuel) and designed...

Energy efficiency of computer power supply units - Final report

Energy Technology Data Exchange (ETDEWEB)

Aebischer, B. [cepe - Centre for Energy Policy and Economics, Swiss Federal Institute of Technology Zuerich, Zuerich (Switzerland); Huser, H. [Encontrol GmbH, Niederrohrdorf (Switzerland)

2002-11-15

This final report for the Swiss Federal Office of Energy (SFOE) takes a look at the efficiency of computer power supply units, which decreases rapidly during average computer use. The background and the purpose of the project are examined. The power supplies for personal computers are discussed and the testing arrangement used is described. Efficiency, power-factor and operating points of the units are examined. Potentials for improvement and measures to be taken are discussed. Also, action to be taken by those involved in the design and operation of such power units is proposed. Finally, recommendations for further work are made.

High performance stream computing for particle beam transport simulations

International Nuclear Information System (INIS)

Appleby, R; Bailey, D; Higham, J; Salt, M

2008-01-01

Understanding modern particle accelerators requires simulating charged particle transport through the machine elements. These simulations can be very time consuming due to the large number of particles and the need to consider many turns of a circular machine. Stream computing offers an attractive way to dramatically improve the performance of such simulations by calculating the simultaneous transport of many particles using dedicated hardware. Modern Graphics Processing Units (GPUs) are powerful and affordable stream computing devices. The results of simulations of particle transport through the booster-to-storage-ring transfer line of the DIAMOND synchrotron light source using an NVidia GeForce 7900 GPU are compared to the standard transport code MAD. It is found that particle transport calculations are suitable for stream processing and large performance increases are possible. The accuracy and potential speed gains are compared and the prospects for future work in the area are discussed

The hydroelectric power market in the United States

International Nuclear Information System (INIS)

2002-01-01

The second-largest producer of hydroelectric power in the world is the United States, right after Canada. In the United States, 7.1 per cent of net electricity generation was attributed to hydroelectric power in 2000, which totalled 269 terawatt hours (TWh). Aging facilities, outdated technology in some facilities, a cumbersome licensing process, and increasing environmental demands from interest groups for the preservation of river systems and surrounding wildlife challenge the industry. Pacific Coast states, especially California, were faced with electric power shortages during the summer of 2001, due to low market prices, high power usage among consumers and drought. The problems with the deregulation of the electricity market were brought to light by these shortages. Legislation to restructure the electric power industry in 25 states had not been enacted as of January 2002. The purchase of more power from both Canada and the Mexico is being considered by the government of the United States, as is the creation of a national power grid to allow for power transmission throughout the country. The Canada-United States energy trade might be affected by such a move, and result in project construction opportunities for Canadian companies. Renewable energy sources must be responsible for the generation of 10 per cent of power generation levels by 2020, on a gradual basis as mandated by law. By 2005, New York City must purchase 10 per cent of its power from renewable energy sources, reaching 20 per cent by 2010. The repair and replacement of aging dam equipment, the development of advanced turbine technology to protect fish stocks and water quality, dam removal, the construction of power lines are all opportunities open to Canadian companies. 60 refs., 5 tabs

Analyzing indicators of stream health for Minnesota streams

Science.gov (United States)

Singh, U.; Kocian, M.; Wilson, B.; Bolton, A.; Nieber, J.; Vondracek, B.; Perry, J.; Magner, J.

2005-01-01

Recent research has emphasized the importance of using physical, chemical, and biological indicators of stream health for diagnosing impaired watersheds and their receiving water bodies. A multidisciplinary team at the University of Minnesota is carrying out research to develop a stream classification system for Total Maximum Daily Load (TMDL) assessment. Funding for this research is provided by the United States Environmental Protection Agency and the Minnesota Pollution Control Agency. One objective of the research study involves investigating the relationships between indicators of stream health and localized stream characteristics. Measured data from Minnesota streams collected by various government and non-government agencies and research institutions have been obtained for the research study. Innovative Geographic Information Systems tools developed by the Environmental Science Research Institute and the University of Texas are being utilized to combine and organize the data. Simple linear relationships between index of biological integrity (IBI) and channel slope, two-year stream flow, and drainage area are presented for the Redwood River and the Snake River Basins. Results suggest that more rigorous techniques are needed to successfully capture trends in IBI scores. Additional analyses will be done using multiple regression, principal component analysis, and clustering techniques. Uncovering key independent variables and understanding how they fit together to influence stream health are critical in the development of a stream classification for TMDL assessment.

Factors affecting stream nutrient loads: A synthesis of regional SPARROW model results for the continental United States

Science.gov (United States)

Preston, Stephen D.; Alexander, Richard B.; Schwarz, Gregory E.; Crawford, Charles G.

2011-01-01

We compared the results of 12 recently calibrated regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models covering most of the continental United States to evaluate the consistency and regional differences in factors affecting stream nutrient loads. The models - 6 for total nitrogen and 6 for total phosphorus - all provide similar levels of prediction accuracy, but those for major river basins in the eastern half of the country were somewhat more accurate. The models simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and climatic (precipitation, temperature), landscape (e.g., soils, geology), and aquatic factors affecting nutrient fate and transport. The results confirm the dominant effects of urban and agricultural sources on stream nutrient loads nationally and regionally, but reveal considerable spatial variability in the specific types of sources that control water quality. These include regional differences in the relative importance of different types of urban (municipal and industrial point vs. diffuse urban runoff) and agriculture (crop cultivation vs. animal waste) sources, as well as the effects of atmospheric deposition, mining, and background (e.g., soil phosphorus) sources on stream nutrients. Overall, we found that the SPARROW model results provide a consistent set of information for identifying the major sources and environmental factors affecting nutrient fate and transport in United States watersheds at regional and subregional scales. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

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

Science.gov (United States)

2010-12-22

..., Shearon Harris Nuclear Power Plant, Unit No. 1; Exemption 1.0 Background Carolina Power & Light Company... operation of the Shearon Harris Nuclear Power Plant (HNP), Unit 1. The license provides, among other things... request to generically extend the rule's compliance date for all operating nuclear power plants, but noted...

Effects of urban development on stream ecosystems in nine metropolitan study areas across the United States

Science.gov (United States)

Coles, James F.; McMahon, Gerard; Bell, Amanda H.; Brown, Larry R.; Fitzpatrick, Faith A.; Scudder Eikenberry, Barbara C.; Woodside, Michael D.; Cuffney, Thomas F.; Bryant, Wade L.; Cappiella, Karen; Fraley-McNeal, Lisa; Stack, William P.

2012-01-01

Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the day-to-day realities of most Americans. Nowhere are the environmental changes associated with urban development more evident than in urban streams. Contaminants, habitat destruction, and increasing streamflow flashiness resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic species. Every stream is connected downstream to larger water bodies, including rivers, reservoirs, and ultimately coastal waters. Inputs of chemical contaminants or sediments at any point along the stream can cause degradation downstream with adverse effects on biological communities and on economically valuable resources, such as fisheries and tourism.

Reliability of Power Units in Poland and the World

OpenAIRE

Józef Paska

2015-01-01

One of a power system’s subsystems is the generation subsystem consisting of power units, the reliability of which to a large extent determines the reliability of the power system and electricity supply to consumers. This paper presents definitions of the basic indices of power unit reliability used in Poland and in the world. They are compared and analysed on the basis of data published by the Energy Market Agency (Poland), NERC (North American Electric Reliability Corporation – USA), ...

Unit for wind power plants and water power. Aggregat fuer Windkraftanlagen und Wasserkraft

Energy Technology Data Exchange (ETDEWEB)

Armonies, H.; Armonies, G.

1983-01-13

The invention concerns the manufacture and process of kinetic thermal units for wind power plants and water power. It is characterized by the fact that the supporting frame of the unit is made so that it carries the unit shaft bearing and also a fixed flange for a hollow body, pump part, unit shaft pushback device and thermal insulation. The unit shaft running in bearings is made so that it can rotate in the two bearings or a double bearing and can also slide between 2 flanges on the unit shaft in the longitudinal direction of the bearings. The end of the unit shaft projecting beyond the supporting frame is made so that the wind blades, rotors or water turbines can be connected to it by flanges. The rotor shaft can be pressed against a hollow body carrying a liquid by a friction disc. A heat resistant liquid pump is also situated on the supporting frame. It is driven by the unit shaft. (HWJ).

Dissolved-solids sources, loads, yields, and concentrations in streams of the conterminous United States

Science.gov (United States)

Anning, David W.; Flynn, Marilyn E.

2014-01-01

Recent studies have shown that excessive dissolved-solids concentrations in water can have adverse effects on the environment and on agricultural, domestic, municipal, and industrial water users. Such effects motivated the U.S. Geological Survey’s National Water Quality Assessment Program to develop a SPAtially-Referenced Regression on Watershed Attributes (SPARROW) model that has improved the understanding of sources, loads, yields, and concentrations of dissolved solids in streams of the conterminous United States.

The 2014 assessment of stream quality in the Piedmont and southern Appalachian Mountain region of southeastern United States

Science.gov (United States)

Celeste Journey; Paul M. Bradley; Peter Van Metre

2016-01-01

During the spring and summer of 2014, the U.S. Geological Survey (USGS) National Water- Quality Assessment Program (NAWQA) assessed stream quality across the Piedmont and southern Appalachian Mountain region in the southeastern United States.

Evaluation of power commissioning of the Mochovce Unit 1 power level up to 100 % Nnom

International Nuclear Information System (INIS)

Sarvaic, I.; Mickolci, M.

1998-01-01

The document contains an evaluation of the power phase of power commissioning of the Mochovce Unit 1 in the phase up to the power level of 100 % N nom .In the document, the courses and results of tests in this phase of power commissioning are summarized, evaluation of the performance of important systems and equipment of the unit is carried out, and the compliance with Limits and Conditions in the course of the phase is assessed. On this basis, conclusions are drawn and recommendations for the unit to be ready for subsequent phases of the power commissioning. The evaluation was developed by the scientific management of the Mochovce commissioning providing an independent support for the operators for supervising the commissioning tasks from the point of nuclear safety

Occurrence and in vitro bioactivity of estrogen, androgen, and glucocorticoid compounds in a nationwide screen of United States stream waters

Data.gov (United States)

U.S. Environmental Protection Agency — In vitro bioactivity concentrations and chemical concentrations of estrogens, androgens, and glucocorticoids from a nationwide screen of United States stream water...

Development and application of automatic frequency and power control systems for large power units

Energy Technology Data Exchange (ETDEWEB)

V.A. Bilenko; A.D. Melamed; E.E. Mikushevich; D.Y. Nikol' skii; R.L. Rogachev; N.A. Romanov [ZAO Interavtomatika (Interautomatika AG), Moscow (Russian Federation)

2008-07-01

We describe the results of work carried out at ZAO Interavtomatika on the development and putting into use of a system for automatically controlling the frequency and power output of large coal-fired power units involving the retrofitting of the turbine's hydraulic automatic control system. Certificates affirming conformity to the Standard of the System Operator Centralized Dispatching Administration (SO-CDA) have been received for eight power units as an outcome of these efforts.

Exploiting the Power of Relational Databases for Efficient Stream Processing

NARCIS (Netherlands)

E. Liarou (Erietta); R.A. Goncalves (Romulo); S. Idreos (Stratos)

2009-01-01

textabstractStream applications gained significant popularity over the last years that lead to the development of specialized stream engines. These systems are designed from scratch with a different philosophy than nowadays database engines in order to cope with the stream applications

Preoperation of Hamaoka Nuclear Power Station Unit No. 4

International Nuclear Information System (INIS)

Fukuyo, Tadashi; Kurata, Satoshi

1994-01-01

Chubu Electric Power Co. finished preoperation of Hamaoka Nuclear Power Station Unit No. 4 in September, 1993. Although unit 4 has the same reactor design as unit 3, its rated electrical output (1,137MW) is 37MW more than that of unit 3. This increase was achieved mainly by adopting a Moisture Separater Heater in the turbine system. We started preoperation of unit 4 in November 1992 and performed various tests at electrical outputs of 20%, 50%, 75%, and 100%. We finished preoperation without any scram or other major problems and obtained satisfactory results for the functions and performance of the plant. This paper describes the major results of unit 4 preoperation. (author)

Density/area power-law models for separating multi-scale anomalies of ore and toxic elements in stream sediments in Gejiu mineral district, Yunnan Province, China

Directory of Open Access Journals (Sweden)

Q. Cheng

2010-10-01

Full Text Available This contribution introduces a fractal filtering technique newly developed on the basis of a spectral energy density vs. area power-law model in the context of multifractal theory. It can be used to map anisotropic singularities of geochemical landscapes created from geochemical concentration values in various surface media such as soils, stream sediments, tills and water. A geochemical landscape can be converted into a Fourier domain in which the spectral energy density is plotted against the area (in wave number units, and the relationship between the spectrum energy density (S and the area (A enclosed by the above-threshold spectrum energy density can be fitted by power-law models. Mixed geochemical landscape patterns can be fitted with different S-A power-law models in the frequency domain. Fractal filters can be defined according to these different S-A models and used to decompose the geochemical patterns into components with different self-similarities. The fractal filtering method was applied to a geochemical dataset from 7,349 stream sediment samples collected from Gejiu mineral district, which is famous for its word-class tin and copper production. Anomalies in three different scales were decomposed from total values of the trace elements As, Sn, Cu, Zn, Pb, and Cd. These anomalies generally correspond to various geological features and geological processes such as sedimentary rocks, intrusions, fault intersections and mineralization.

Membrane systems and their use in nuclear power plants. Treatment of primary coolant

Energy Technology Data Exchange (ETDEWEB)

Kus, Pavel; Bartova, Sarka; Skala, Martin; Vonkova, Katerina [Research Centre Rez, Husinec-Rez (Czech Republic). Technological Circuits Innovation Dept.; Zach, Vaclav; Kopa, Roman [CEZ a.s., Temelin (Czech Republic). Nuclear Power Plant Temelin

2016-03-15

In nuclear power plants, drained primary coolant containing boric acid is currently treated in the system of evaporators and by ion exchangers. Replacement of the system of evaporators by membrane system (MS) will result in lower operating cost mainly due to lower operation temperature. In membrane systems the feed primary coolant is separated into two output streams: retentate and permeate. Retentate stream consists of the concentrated boric acid solution together with other components, while permeate stream consists of purified water. Results are presented achieved by testing a pilot-plant unit of reverse osmosis in nuclear power plant (NPP) Temelin.

Stream Habitat Reach Summary - North Coast [ds63

Data.gov (United States)

California Natural Resource Agency — The shapefile is based on habitat unit level data summarized at the stream reach level. The database represents salmonid stream habitat surveys from 645 streams of...

Power supply control units for APS ring magnets

International Nuclear Information System (INIS)

Despe, O.D.

1990-01-01

The APS storage ring (1104 meters) is divided into 40 sectors. Each sector has 38 magnet coils in five magnet bases. Every alternate sector has an additional quadrupole magnet for skew correction. AR the main dipole magnets, two in each sector are connected in series and fed from one power supply unit. A base is controlled by one power supply control unit (PSCU). Each PSCU is connected to the host computer via a local area network (LAN). This note discusses the hardware configuration of the typical power supply control system used by the APS magnets and the software commands supported by the PSCU

Influence of ultrasound power on acoustic streaming and micro-bubbles formations in a low frequency sono-reactor: mathematical and 3D computational simulation.

Science.gov (United States)

Sajjadi, Baharak; Raman, Abdul Aziz Abdul; Ibrahim, Shaliza

2015-05-01

This paper aims at investigating the influence of ultrasound power amplitude on liquid behaviour in a low-frequency (24 kHz) sono-reactor. Three types of analysis were employed: (i) mechanical analysis of micro-bubbles formation and their activities/characteristics using mathematical modelling. (ii) Numerical analysis of acoustic streaming, fluid flow pattern, volume fraction of micro-bubbles and turbulence using 3D CFD simulation. (iii) Practical analysis of fluid flow pattern and acoustic streaming under ultrasound irradiation using Particle Image Velocimetry (PIV). In mathematical modelling, a lone micro bubble generated under power ultrasound irradiation was mechanistically analysed. Its characteristics were illustrated as a function of bubble radius, internal temperature and pressure (hot spot conditions) and oscillation (pulsation) velocity. The results showed that ultrasound power significantly affected the conditions of hotspots and bubbles oscillation velocity. From the CFD results, it was observed that the total volume of the micro-bubbles increased by about 4.95% with each 100 W-increase in power amplitude. Furthermore, velocity of acoustic streaming increased from 29 to 119 cm/s as power increased, which was in good agreement with the PIV analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Reliability of Power Units in Poland and the World

Directory of Open Access Journals (Sweden)

Józef Paska

2015-09-01

Full Text Available One of a power system’s subsystems is the generation subsystem consisting of power units, the reliability of which to a large extent determines the reliability of the power system and electricity supply to consumers. This paper presents definitions of the basic indices of power unit reliability used in Poland and in the world. They are compared and analysed on the basis of data published by the Energy Market Agency (Poland, NERC (North American Electric Reliability Corporation – USA, and WEC (World Energy Council. Deficiencies and the lack of a unified national system for collecting and processing electric power equipment unavailability data are also indicated.

Improving Size and Power in Unit Root Testing

DEFF Research Database (Denmark)

Haldrup, Niels; Jansson, Michael

A frequent criticism of unit root tests concerns the poor power and size properties that many of such testsexhibit. However, the past decade or so intensive research has been conducted to alleviate these problems and great advances have been made. The present paper provides a selective survey...... of recent contributions to improve upon both size and power of unit root tests and in so doing the approach of using rigorous statistical optimality criteria in the development of such tests is stressed. In addition to presenting tests where improved size can be achieved by modifying the standard Dickey......-Fuller class of tests, the paper presents theory of optimal testing and the construction of power envelopes for unit root tests underdifferent conditions allowing for serial correlation, deterministic components, assumptions regarding the initial condition, non-Gaussian errors, and the use of covariates....

Water-quality assessment of part of the Upper Mississippi River Basin Study Unit, Minnesota and Wisconsin- Nutrients, chlorophyll a, phytoplankton, and suspended sediment in streams, 1996-98

Science.gov (United States)

Kroening, Sharon E.; Lee, Kathy E.; Goldstein, R.M.

2003-01-01

Stream water-quality data from part of the Upper Mississippi River Basin Study Unit (Study Unit) from 1995 through 1998 was used to describe the distribution of nutrients, chlorophyll a, phytoplankton, and suspended sediment; and the influence of natural and anthropogenic factors on reported concentrations, loads, and yields. During the study period, streamflows generally were near to greater than average. Agricultural land cover, particularly on tile-drained soils, had the most substantial influence on nutrients, chlorophyll a, and suspended sediment in the Study Unit. The greatest concentrations and yields of total nitrogen, dissolved nitrite plus nitrate nitrogen, dissolved nitrite nitrogen, total organic plus ammonia nitrogen, total phosphorus, and suspended sediment were measured in a stream representing agricultural land cover on tile-drained soils. Total nitrogen yields also were about 6 times greater in a stream representing agricultural land cover on tile-drained soils than in a stream representing agricultural land cover on naturally welldrained soils.

Radioactive contamination of fishes in lake and streams impacted by the Fukushima nuclear power plant accident

International Nuclear Information System (INIS)

Yoshimura, Mayumi; Yokoduka, Tetsuya

2014-01-01

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in March 2011 emitted radioactive substances into the environment, contaminating a wide array of organisms including fishes. We found higher concentrations of radioactive cesium ( 137 Cs) in brown trout (Salmo trutta) than in rainbow trout (Oncorhynchus nerka), and 137 Cs concentrations in brown trout were higher in a lake than in a stream. Our analyses indicated that these differences were primarily due to differences in diet, but that habitat also had an effect. Radiocesium concentrations ( 137 Cs) in stream charr (Salvelinus leucomaenis) were higher in regions with more concentrated aerial activity and in older fish. These results were also attributed to dietary and habitat differences. Preserving uncontaminated areas by remediating soils and releasing uncontaminated fish would help restore this popular fishing area but would require a significant effort, followed by a waiting period to allow activity concentrations to fall below the threshold limits for consumption. - Highlight: • Concentration of 137 Cs in brown trout was higher than in rainbow trout. • 137 Cs concentration of brown trout in a lake was higher than in a stream. • 137 Cs concentration of stream charr was higher in region with higher aerial activity. • Concentration of 137 Cs in stream charr was higher in older fish. • Difference of contamination among fishes was due to difference in diet and habitat

Power unit impedance and distance protection functions during faults in the external power grid

Directory of Open Access Journals (Sweden)

Marcin Lizer

2012-12-01

Full Text Available This paper presents the problem of the risk of an unnecessary tripping of a generation unit’s underimpedance protection functions in circumstances of generator power swings following elimination of long-lasting fault in the external power grid. The fi rst part describes typical solutions of a generator impedance protection function (21e and unit distance protection function (21s. Starting characteristics of these protection functions are shown, as well as their typical operating logics and ways of calculating their settings. Then exemplary (the most common solutions of unit under-impedance relays power swing blocking functions are described. Following this introduction, the issues of the threat of unnecessary operation of fast-tripping protection zones of 21e and 21s protection functions are described, which arises in the circumstances of generator asynchronous power swings occurring after elimination of long-lasting faults in the grid supplied by the power unit. The paper also shows that the available power swing blocking functions may not be able to correctly detect the described conditions, thus allowing the unnecessary operation of under-impedance relays. How an impedance calculation algorithm affects the impedance trajectory seen by a protection relay is also resented.

The future of nuclear power in the United Kingdom

International Nuclear Information System (INIS)

Jones, P.M.S.

1990-01-01

The arguments that have been put forward in the United Kingdom to justify the contention by its opponents that nuclear power should not be seen as a safe, economic, strategically desirable and environmentally attractive energy source are examined. Counter arguments are presented to support the belief that these are wholly wrong. In the short to medium term, however, economic and political considerations suggest that the prospects for nuclear power in the United Kingdom are not optimistic. The long term evolution of nuclear power is uncertain but it is possible that the security of energy supply, comparative economics and environmental attractions associated with nuclear power will become more apparent and work in its favour eventually. The conviction is expressed that, by the middle of the next century, the United Kingdom will be reaping the benefits of the fast reactor on a significant scale. (UK)

The Midwest Stream Quality Assessment—Influences of human activities on streams

Science.gov (United States)

Van Metre, Peter C.; Mahler, Barbara J.; Carlisle, Daren M.; Coles, James F.

2018-04-16

Healthy streams and the fish and other organisms that live in them contribute to our quality of life. Extensive modification of the landscape in the Midwestern United States, however, has profoundly affected the condition of streams. Row crops and pavement have replaced grasslands and woodlands, streams have been straightened, and wetlands and fields have been drained. Runoff from agricultural and urban land brings sediment and chemicals to streams. What is the chemical, physical, and biological condition of Midwestern streams? Which physical and chemical stressors are adversely affecting biological communities, what are their origins, and how might we lessen or avoid their adverse effects?In 2013, the U.S. Geological Survey (USGS) conducted the Midwest Stream Quality Assessment to evaluate how human activities affect the biological condition of Midwestern streams. In collaboration with the U.S. Environmental Protection Agency National Rivers and Streams Assessment, the USGS sampled 100 streams, chosen to be representative of the different types of watersheds in the region. Biological condition was evaluated based on the number and diversity of fish, algae, and invertebrates in the streams. Changes to the physical habitat and chemical characteristics of the streams—“stressors”—were assessed, and their relation to landscape factors and biological condition was explored by using mathematical models. The data and models help us to better understand how the human activities on the landscape are affecting streams in the region.

Quantifying tolerance indicator values for common stream fish species of the United States

Science.gov (United States)

Meador, M.R.; Carlisle, D.M.

2007-01-01

The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program to calculate tolerance indicator values for 10 physicochemical variables using weighted averaging. Tolerance indicator values (TIVs) for ammonia, chloride, dissolved oxygen, nitrite plus nitrate, pH, phosphorus, specific conductance, sulfate, suspended sediment, and water temperature were calculated for 105 common fish species of the United States. Tolerance indicator values for specific conductance and sulfate were correlated (rho = 0.87), and thus, fish species may be co-tolerant to these water-quality variables. We integrated TIVs for each species into an overall tolerance classification for comparisons with judgment-based tolerance classifications. Principal components analysis indicated that the distinction between tolerant and intolerant classifications was determined largely by tolerance to suspended sediment, specific conductance, chloride, and total phosphorus. Factors such as water temperature, dissolved oxygen, and pH may not be as important in distinguishing between tolerant and intolerant classifications, but may help to segregate species classified as moderate. Empirically derived tolerance classifications were 58.8% in agreement with judgment-derived tolerance classifications. Canonical discriminant analysis revealed that few TIVs, primarily chloride, could discriminate among judgment-derived tolerance classifications of tolerant, moderate, and intolerant. To our knowledge, this is the first empirically based understanding of fish species tolerance for stream fishes in the United States.

Design and Application of a Power Unit to Use Plug-In Electric Vehicles as an Uninterruptible Power Supply

Directory of Open Access Journals (Sweden)

Gorkem Sen

2016-03-01

Full Text Available Grid-enabled vehicles (GEVs such as plug-in electric vehicles present environmental and energy sustainability advantages compared to conventional vehicles. GEV runs solely on power generated by its own battery group, which supplies power to its electric motor. This battery group can be charged from external electric sources. Nowadays, the interaction of GEV with the power grid is unidirectional by the charging process. However, GEV can be operated bi-directionally by modifying its power unit. In such operating conditions, GEV can operate as an uninterruptible power supply (UPS and satisfy a portion or the total energy demand of the consumption center independent from utility grid, which is known as vehicle-to-home (V2H. In this paper, a power unit is developed for GEVs in the laboratory to conduct simulation and experimental studies to test the performance of GEVs as a UPS unit in V2H mode at the time of need. The activation and deactivation of the power unit and islanding protection unit are examined when energy is interrupted.

Power unit-cargo space link in transport

Directory of Open Access Journals (Sweden)

Radmilović Zoran R.

2005-01-01

Full Text Available This paper deals with transportation technology regarding links between power unit and cargo space. These links can be divided into two groups: rigid and flexible. Rigid link, established between power unit and cargo space, is dominant in maritime and road transport (sea ships and trucks, and occasionally in transport on inland waterways (self- propelled barges. Flexible link is used in the railroad transport (systems with trailers and semi trailers, and in inland waterway transport (push - towing and pulling systems, and combinations of the systems. The main goal of this research is determination of possible link types and organization of the means of transportation.

Design tradeoffs in long-term research for stream salamanders

Science.gov (United States)

Brand, Adrianne B,; Grant, Evan H. Campbell

2017-01-01

Long-term research programs can benefit from early and periodic evaluation of their ability to meet stated objectives. In particular, consideration of the spatial allocation of effort is key. We sampled 4 species of stream salamanders intensively for 2 years (2010–2011) in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA to evaluate alternative distributions of sampling locations within stream networks, and then evaluated via simulation the ability of multiple survey designs to detect declines in occupancy and to estimate dynamic parameters (colonization, extinction) over 5 years for 2 species. We expected that fine-scale microhabitat variables (e.g., cobble, detritus) would be the strongest determinants of occupancy for each of the 4 species; however, we found greater support for all species for models including variables describing position within the stream network, stream size, or stream microhabitat. A monitoring design focused on headwater sections had greater power to detect changes in occupancy and the dynamic parameters in each of 3 scenarios for the dusky salamander (Desmognathus fuscus) and red salamander (Pseudotriton ruber). Results for transect length were more variable, but across all species and scenarios, 25-m transects are most suitable as a balance between maximizing detection probability and describing colonization and extinction. These results inform sampling design and provide a general framework for setting appropriate goals, effort, and duration in the initial planning stages of research programs on stream salamanders in the eastern United States.

Deadbeat control of power leveling unit with bidirectional buck/boost DC/DC converter

OpenAIRE

Hamasaki, Shin-ichi; Mukai, Ryosuke; Yano, Yoshihiro; Tsuji, Mineo

2014-01-01

As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is...

Waste Heat to Power Market Assessment

Energy Technology Data Exchange (ETDEWEB)

Elson, Amelia [ICF International, Fairfax, VA (United States); Tidball, Rick [ICF International, Fairfax, VA (United States); Hampson, Anne [ICF International, Fairfax, VA (United States)

2015-03-01

Waste heat to power (WHP) is the process of capturing heat discarded by an existing process and using that heat to generate electricity. In the industrial sector, waste heat streams are generated by kilns, furnaces, ovens, turbines, engines, and other equipment. In addition to processes at industrial plants, waste heat streams suitable for WHP are generated at field locations, including landfills, compressor stations, and mining sites. Waste heat streams are also produced in the residential and commercial sectors, but compared to industrial sites these waste heat streams typically have lower temperatures and much lower volumetric flow rates. The economic feasibility for WHP declines as the temperature and flow rate decline, and most WHP technologies are therefore applied in industrial markets where waste heat stream characteristics are more favorable. This report provides an assessment of the potential market for WHP in the industrial sector in the United States.

Radioactive contamination of fishes in lake and streams impacted by the Fukushima nuclear power plant accident

Energy Technology Data Exchange (ETDEWEB)

Yoshimura, Mayumi, E-mail: yoshi887@ffpri.affrc.go.jp [Kansai Research Center, Forestry and Forest Products Research Institute, Nagaikyuutaro 68, Momoyama, Fushimi, Kyoto 612-0855 (Japan); Yokoduka, Tetsuya [Tochigi Prefectural Fisheries Experimental Station, Sarado 2599, Ohtawara, Tochigi 324-0404 (Japan)

2014-06-01

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in March 2011 emitted radioactive substances into the environment, contaminating a wide array of organisms including fishes. We found higher concentrations of radioactive cesium ({sup 137}Cs) in brown trout (Salmo trutta) than in rainbow trout (Oncorhynchus nerka), and {sup 137}Cs concentrations in brown trout were higher in a lake than in a stream. Our analyses indicated that these differences were primarily due to differences in diet, but that habitat also had an effect. Radiocesium concentrations ({sup 137}Cs) in stream charr (Salvelinus leucomaenis) were higher in regions with more concentrated aerial activity and in older fish. These results were also attributed to dietary and habitat differences. Preserving uncontaminated areas by remediating soils and releasing uncontaminated fish would help restore this popular fishing area but would require a significant effort, followed by a waiting period to allow activity concentrations to fall below the threshold limits for consumption. - Highlight: • Concentration of {sup 137}Cs in brown trout was higher than in rainbow trout. • {sup 137}Cs concentration of brown trout in a lake was higher than in a stream. • {sup 137}Cs concentration of stream charr was higher in region with higher aerial activity. • Concentration of {sup 137}Cs in stream charr was higher in older fish. • Difference of contamination among fishes was due to difference in diet and habitat.

Occurrence and Distribution of Ordinary High Water Mark (OHWM) Indicators in Non-Perennial Streams in the Western Mountains, Valleys, and Coast Region of the United States

Science.gov (United States)

2014-08-01

this is only a generalized model and that, as with most natural systems, a wide spectrum of possible geomorphic arrangements exists in stream...1 Common hydrogeomorphic units that form in stream systems in response to spatially and temporally varying hydrologic and geomorphic processes... geomorphic , and vegetative indica- tors for use in OHWM delineations in arid streams and categorized their typical landscape positions with respect

Responses of stream nitrate and DOC loadings to hydrological forcing and climate change in an upland forest of the northeastern United States

Science.gov (United States)

Stephen D. Sebestyen; Elizabeth W. Boyer; James B. Shanley

2009-01-01

In coming decades, higher annual temperatures, increased growing season length, and increased dormant season precipitation are expected across the northeastern United States in response to anthropogenic forcing of global climate. We synthesized long-term stream hydrochemical data from the Sleepers River Research Watershed in Vermont, United States, to explore the...

Present state of electric power business in United States and Europe

International Nuclear Information System (INIS)

Onishi, Kenichi

2011-01-01

This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

Frequency effects on the scale and behavior of acoustic streaming.

Science.gov (United States)

Dentry, Michael B; Yeo, Leslie Y; Friend, James R

2014-01-01

Acoustic streaming underpins an exciting range of fluid manipulation phenomena of rapidly growing significance in microfluidics, where the streaming often assumes the form of a steady, laminar jet emanating from the device surface, driven by the attenuation of acoustic energy within the beam of sound propagating through the liquid. The frequencies used to drive such phenomena are often chosen ad hoc to accommodate fabrication and material issues. In this work, we seek a better understanding of the effects of sound frequency and power on acoustic streaming. We present and, using surface acoustic waves, experimentally verify a laminar jet model that is based on the turbulent jet model of Lighthill, which is appropriate for acoustic streaming seen at micro- to nanoscales, between 20 and 936 MHz and over a broad range of input power. Our model eliminates the critically problematic acoustic source singularity present in Lighthill's model, replacing it with a finite emission area and enabling determination of the streaming velocity close to the source. At high acoustic power P (and hence high jet Reynolds numbers ReJ associated with fast streaming), the laminar jet model predicts a one-half power dependence (U∼P1/2∼ ReJ) similar to the turbulent jet model. However, the laminar model may also be applied to jets produced at low powers-and hence low jet Reynolds numbers ReJ-where a linear relationship between the beam power and streaming velocity exists: U∼P∼ReJ2. The ability of the laminar jet model to predict the acoustic streaming behavior across a broad range of frequencies and power provides a useful tool in the analysis of microfluidics devices, explaining peculiar observations made by several researchers in the literature. In particular, by elucidating the effects of frequency on the scale of acoustically driven flows, we show that the choice of frequency is a vitally important consideration in the design of small-scale devices employing acoustic streaming

Ocean Current Power Generator. Final Report

Energy Technology Data Exchange (ETDEWEB)

O' Sullivan, G. A.

2002-07-26

The Ocean Power Generator is both technically and economically suitable for deployment in the Gulf Stream from the US Navy facility in Dania, Florida. Yet to be completed is the calibration test in the Chesapeake Bay with the prototype dual hydroturbine Underwater Electric Kite. For the production units a revised design includes two ballast tanks mounted as pontoons to provide buoyancy and depth control. The power rating of the Ocean Power Generator has been doubled to 200 kW ready for insertion into the utility grid. The projected cost for a 10 MW installation is $3.38 per watt, a cost that is consistent with wind power pricing when it was in its deployment infancy, and a cost that is far better than photovoltaics after 25 years of research and development. The Gulf Stream flows 24 hours per day, and water flow is both environmentally and ecologically perfect as a renewable energy source. No real estate purchases are necessary, and you cannot see, hear, smell, or touch an Ocean Power Generator.

Power Dissipation Challenges in Multicore Floating-Point Units

DEFF Research Database (Denmark)

Liu, Wei; Nannarelli, Alberto

2010-01-01

, we analyze the impact of power dissipation in floating-point (FP) units and we consider different alternatives in the implementation of FP-division that lead to substantial energy savings. We compare the implementation of division in a Fused Multiply-Add (FMA) unit based on the Newton-Raphson...

A preliminary design and BOP cost analysis of M-C Power`s MCFC commerical unit

Energy Technology Data Exchange (ETDEWEB)

Chen, T.P. [Bechtel Corp, San Francisco, CA (United States)

1996-12-31

M-C Power Corporation plans to introduce its molten carbonate fuel cell (MCFC) market entry unit in the year 2000 for distributed and on-site power generation. Extensive efforts have been made to analyze the cell stack manufacturing costs. The major objective of this study is to conduct a detailed analysis of BOP costs based on an initial design of the market entry unit.

76 FR 1469 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

Science.gov (United States)

2011-01-10

... Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 Environmental Assessment... Plant, LLC, the licensee, for operation of the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2... Impact Statement for License Renewal of Nuclear Plants, Calvert Cliffs Nuclear Power Plant (NUREG-1437...

Main unit electrical protection at Sizewell 'B' power station

International Nuclear Information System (INIS)

Fischer, A.; Keates, T.

1992-01-01

For any power station, reliable electrical protection of the main generating units (generators plus generator transformers) has important commercial implications. Spurious trips cause loss of generation and consequent loss of revenue, while failure to rapidly isolate a fault leads to unnecessary damage and again, loss of generation and revenue. While these conditions apply equally to Sizewell B there are additional factors to be taken into consideration. A spurious trip of a main generating unit may lead to a trip of the reactor with an associated challenge to the shutdown and core cooling plant. The generator transformers, besides exporting power from the generators to the 400 kV National Grid, also import power from the Grid to the 11 kV Main Electrical System, which in turn is the preferred source of supply to the Essential Electrical System. The Main Unit Protection is designed to clear generator faults leaving this off-site power route intact. Hence failure to operate correctly could affect the integrity of the Essential Electrical Supplies. (Author)

Mapping watershed potential to contribute phosphorus from geologic materials to receiving streams, southeastern United States

Science.gov (United States)

Terziotti, Silvia; Hoos, Anne B.; Harned, Douglas; Garcia, Ana Maria

2010-01-01

As part of the southeastern United States SPARROW (SPAtially Referenced Regressions On Watershed attributes) water-quality model implementation, the U.S. Geological Survey created a dataset to characterize the contribution of phosphorus to streams from weathering and erosion of surficial geologic materials. SPARROW provides estimates of total nitrogen and phosphorus loads in surface waters from point and nonpoint sources. The characterization of the contribution of phosphorus from geologic materials is important to help separate the effects of natural or background sources of phosphorus from anthropogenic sources of phosphorus, such as municipal wastewater or agricultural practices. The potential of a watershed to contribute phosphorus from naturally occurring geologic materials to streams was characterized by using geochemical data from bed-sediment samples collected from first-order streams in relatively undisturbed watersheds as part of the multiyear U.S. Geological Survey National Geochemical Survey. The spatial pattern of bed-sediment phosphorus concentration is offered as a tool to represent the best available information at the regional scale. One issue may weaken the use of bed-sediment phosphorus concentration as a surrogate for the potential for geologic materials in the watershed to contribute to instream levels of phosphorus-an unknown part of the variability in bed-sediment phosphorus concentration may be due to the rates of net deposition and processing of phosphorus in the streambed rather than to variability in the potential of the watershed's geologic materials to contribute phosphorus to the stream. Two additional datasets were created to represent the potential of a watershed to contribute phosphorus from geologic materials disturbed by mining activities from active mines and inactive mines.

Alteration in reactor installation (addition of Unit 2) in Shimane Nuclear Power Station, Chugoku Electric Power Co., Inc. (inquiry)

International Nuclear Information System (INIS)

1983-01-01

An inquiry was made by the Ministry of International Trade and Industry to Nuclear Safety Commission on the addition of Unit 2 in Shimane Nuclear Power Station of The Chugoku Electric Power Co., Inc., concerning the technical capability of Chugoku Electric Power Co., Inc., and the plant safety. The NSC requested the Committee on Examination of Reactor Safety to make a deliberation on this subject. Both the technical capability and the safety of Unit 1 were already confirmed by MITI. Unit 2 to be newly added in the Shimane Nuclear Power Station is a BWR power plant with electric output of 820 MW. The examination made by MITI is described: the technical capability of Chugoku Electric Power Co., Inc., the safety of Unit 2 about its siting, reactor proper, reactor cooling system, radioactive waste management, etc. (J.P.N.)

Control units for APS power supplies

International Nuclear Information System (INIS)

Despe, O.D.; Saunders, C.; McGhee, D.G.

1993-01-01

The Advanced Photon Source (APS) accelerator facility is made up of five major subsystems in addition to the linac: the positron accumulator ring (PAR), low energy transport (LET), booster synchrotron (SYNCH), high energy transport (HET), the storage ring (SR). Each subsystem has multiple magnet power supply combinations, some requiring multiple of operation. These magnet and power supply combinations computer controlled and monitored. The power supply control unit (PSCU) is the first layer of hardware and software above the power supply itself and is described in this paper. The description includes the basic philosophy for each of operation and how it influences the topology and of implementing control. The design of the analog reference blocks (ARBs) influenced the design of other custom functions well as the feedback controls for vibration and other dynamic corrections. The command set supported by the PSCU is discussed

High nitrate concentrations in some Midwest United States streams in 2013 after the 2012 drought

Science.gov (United States)

Van Metre, Peter C.; Frey, Jeffrey W.; Musgrove, MaryLynn; Nakagaki, Naomi; Qi, Sharon L.; Mahler, Barbara J.; Wieczorek, Michael; Button, Daniel T.

2016-01-01

Nitrogen sources in the Mississippi River basin have been linked to degradation of stream ecology and to Gulf of Mexico hypoxia. In 2013, the USGS and the USEPA characterized water quality stressors and ecological conditions in 100 wadeable streams across the midwestern United States. Wet conditions in 2013 followed a severe drought in 2012, a weather pattern associated with elevated nitrogen concentrations and loads in streams. Nitrate concentrations during the May to August 2013 sampling period ranged from nitrate concentrations at the 100 sites were compared with May to June concentrations predicted from a regression model developed using historical nitrate data. Observed concentrations for 17 sites, centered on Iowa and southern Minnesota, were outside the 95% confidence interval of the regression-predicted mean, indicating that they were anomalously high. The sites with a nitrate anomaly had significantly higher May to June nitrate concentrations than sites without an anomaly (means, 19.8 and 3.6 mg L−1, respectively) and had higher antecedent precipitation indices, a measure of the departure from normal precipitation, in 2012 and 2013. Correlations between nitrate concentrations and watershed characteristics and nitrogen and oxygen isotopes of nitrate indicated that fertilizer and manure used in crop production, principally corn, were the dominant sources of nitrate. The anomalously high nitrate levels in parts of the Midwest in 2013 coincide with reported higher-than-normal nitrate loads in the Mississippi River.

Dedicated auxiliary power units for Hybrid Electric Vehicles

NARCIS (Netherlands)

Mourad, S.; Weijer, C.J.T. van de

1998-01-01

The use of a dedicated auxiliary power unit is essential to utilize the potential that hybrid vehicles offer for efficient and ultra-clean transportation. An example of a hybrid project at the TNO Road-Vehicles Research Institute shows the development and the results of a dedicated auxiliary power

75 FR 66802 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

Science.gov (United States)

2010-10-29

... Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Notice of Withdrawal of...) has granted the request of Calvert Cliffs Nuclear Power Plant, LLC, the licensee, to withdraw its... for the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2, located in Calvert County, MD. The...

A modelling study of hyporheic exchange pattern and the sequence, size, and spacing of stream bedforms in mountain stream networks, Oregon, USA.

Science.gov (United States)

Michael N. Gooseff; Justin K. Anderson; Steven M. Wondzell; Justin LaNier; Roy. Haggerty

2005-01-01

Studies of hyporheic exchange flows have identified physical features of channels that control exchange flow at the channel unit scale, namely slope breaks in the longitudinal profile of streams that generate subsurface head distributions. We recently completed a field study that suggested channel unit spacing in stream longitudinal profiles can be used to predict the...

StreamStats in Oklahoma - Drainage-Basin Characteristics and Peak-Flow Frequency Statistics for Ungaged Streams

Science.gov (United States)

Smith, S. Jerrod; Esralew, Rachel A.

2010-01-01

The USGS Streamflow Statistics (StreamStats) Program was created to make geographic information systems-based estimation of streamflow statistics easier, faster, and more consistent than previously used manual techniques. The StreamStats user interface is a map-based internet application that allows users to easily obtain streamflow statistics, basin characteristics, and other information for user-selected U.S. Geological Survey data-collection stations and ungaged sites of interest. The application relies on the data collected at U.S. Geological Survey streamflow-gaging stations, computer aided computations of drainage-basin characteristics, and published regression equations for several geographic regions comprising the United States. The StreamStats application interface allows the user to (1) obtain information on features in selected map layers, (2) delineate drainage basins for ungaged sites, (3) download drainage-basin polygons to a shapefile, (4) compute selected basin characteristics for delineated drainage basins, (5) estimate selected streamflow statistics for ungaged points on a stream, (6) print map views, (7) retrieve information for U.S. Geological Survey streamflow-gaging stations, and (8) get help on using StreamStats. StreamStats was designed for national application, with each state, territory, or group of states responsible for creating unique geospatial datasets and regression equations to compute selected streamflow statistics. With the cooperation of the Oklahoma Department of Transportation, StreamStats has been implemented for Oklahoma and is available at http://water.usgs.gov/osw/streamstats/. The Oklahoma StreamStats application covers 69 processed hydrologic units and most of the state of Oklahoma. Basin characteristics available for computation include contributing drainage area, contributing drainage area that is unregulated by Natural Resources Conservation Service floodwater retarding structures, mean-annual precipitation at the

Development of a Plasma Streaming System for the Mirror Fusion Test Facility

International Nuclear Information System (INIS)

Holdsworth, T.; Clark, R.N.; McCotter, R.E.; Rossow, T.L.; Cruz, G.E.

1979-01-01

The Plasma Streaming System (PSS) is an essential portion of the Mirror Fusion Test Facility (MFTF), scheduled for completion in October 1981. The PSS will develop a plasma density of at least 2 x 10 12 particles/cm 3 at the MFTF magnet centerline by injecting particles along the field lines. The plasma will have a midplane plasma radius as large as 40 cm with variable plasma particle energy and beam geometry. Minimum amounts of impurities will be injected, with emphasis on minimizing high Z materials. Each of the 60 PSS units will consist of a gun magnet assembly (GMA) and a power supply. Each GMA consists of a plasma streaming gun, a pulse magnet that provides variable beam shaping, and a fast reaction pulse gas valve

Distinctive channel geometry and riparian vegetation: A geomorphic classification for arid ephemeral streams

Science.gov (United States)

Sutfin, N.; Shaw, J. R.; Wohl, E. E.; Cooper, D.

2012-12-01

Interactions between hydrology, channel form, and riparian vegetation along arid ephemeral streams are not thoroughly understood and current stream classifications do not adequately represent variability in channel geometry and associated riparian communities. Relatively infrequent hydrologic disturbances in dryland environments are responsible for creation and maintenance of channel form that supports riparian communities. To investigate the influence of channel characteristics on riparian vegetation in the arid southwestern United States, we develop a geomorphic classification for arid ephemeral streams based on the degree of confinement and the composition of confining material that provide constraints on available moisture. Our conceptual model includes five stream types: 1) bedrock channels entirely confined by exposed bedrock and devoid of persistent alluvium; 2) bedrock with alluvium channels at least partially confined by bedrock but containing enough alluvium to create bedforms that persist through time; 3) incised alluvium channels bound only by unconsolidated alluvial material into which they are incised; 4) braided washes that exhibit multi-thread, braided characteristics regardless of the composition of confining material; and 5) piedmont headwater 0-2nd order streams (Strahler) confined only by unconsolidated alluvium and which initiate as secondary channels on piedmont surfaces. Eighty-six study reaches representing the five stream types were surveyed on the U.S. Army Yuma Proving Ground in the Sonoran Desert of southwestern Arizona. Non-parametric multivariate analysis of variance (PERMANOVA) indicates significant differences between the five stream types with regards to channel geometry (i.e., stream gradient, width-to-depth ratio, the ratio between valley width and channel width (Wv/Wc), shear stress, and unit stream power) and riparian vegetation (i.e., presence and canopy coverage by species, canopy stratum, and life form). Discriminant analysis

BIOTIC INTEGRITY OF STREAMS IN THE SAVANNAH RIVER SITE INTEGRATOR OPERABLE UNITS, 1996 TO 2003

Energy Technology Data Exchange (ETDEWEB)

Paller, M; Susan Dyer, S

2004-11-08

The Savannah River Site (SRS) has been divided into six Integrator Operable Units (IOUs) that correspond to the watersheds of the five major streams on the SRS (Upper Three Runs, Fourmile Branch, Pen Branch, Steel Creek, and Lower Three Runs) and the portions of the Savannah River and Savannah River Swamp associated with the SRS. The streams are the primary integrators within each IOU because they potentially receive, through surface or subsurface drainage, soluble contaminants from all waste sites within their watersheds. If these contaminants reach biologically significant levels, they would be expected to effect the numbers, types, and health of stream organisms. In this study, biological sampling was conducted within each IOU as a measure of the cumulative ecological effects of the waste sites within the IOUs. The use of information from biological sampling to assess environmental quality is often termed bioassessment. The IOU bioassessment program included 38 sites in SRS streams and nine sites in the Savannah River. Sampling was conducted in 1996 to 1998, 2000, and 2003. Four bioassessment methods were used to evaluate ecological conditions in the IOU streams: the Index of Biotic Integrity, the Fish Health Assessment Index, measurement of fish tissue contaminant levels, and two benthic macroinvertebrate indices. The Index of Biotic Integrity (IBI) is an EPA supported method based on comparison of ecologically important and sensitive fish assemblage variables between potentially disturbed and reference (i.e., undisturbed) sites. It is designed to assess the ability of a stream to support a self-sustaining biological community and ecological processes typical of undisturbed, natural conditions. Since many types of contaminants can bioaccumulate, fish tissue contaminant data were used to determine the types of chemicals fish were exposed to and their relative magnitudes among IOUs. The Fish Health Assessment Index (HAI) is an EPA supported method for assessing

Current status of nuclear power in the United States and around the world.

Science.gov (United States)

McKlveen, J W

1990-09-01

Nuclear energy's share of the world electricity market has been growing over the past 35 years. In 1989, eight generating units entered commercial operation abroad and three new units were licensed in the U.S. In early 1990, Mexico became the 26th country to produce electricity from nuclear power. Currently the 426 operating reactors supply one sixth of the world's total electrical capacity. Fourteen countries have now operated nuclear plants for 20 or more years. Since 1980, France has been the leader in the use of nuclear power and currently generates three quarters of its electricity from 54 nuclear plants. The U.S. has 112 nuclear plants, the largest number of any country in the world. These plants satisfy almost 20 percent of U.S. electrical energy requirements. Last year Three Mile Island, the would-be icon for everything that is wrong with the nuclear industry was rated as the most efficient nuclear plant in the world. The worldwide trend toward acceptance of nuclear is improving slightly, but many political and societal issues need to be resolved. Whereas recent polls indicate that a majority of the people realize nuclear must be a major contributor to the energy mix of the future, many are reluctant to support the technology until the issue of waste disposal has been resolved. Fears of another Chernobyl, lack of capital, and a new anti-nuclear campaign by Greenpeace will keep the nuclear debate alive in many countries. Additional stumbling blocks in the U.S. include the need to develop a new generation of improved reactor designs which emphasize passive safety features, standardized designs and a stream-lined federal licensing process. Nuclear power is really not dead. Even environmentalists are starting to give it another look. A nuclear renaissance will occur in the U.S. How soon or under what conditions remain to be seen. The next crisis in the U.S. will not be a shortage of energy, rather a shortage of electricity.(ABSTRACT TRUNCATED AT 250 WORDS)

Neutron streaming evaluation for the DREAM fusion power reactor

International Nuclear Information System (INIS)

Seki, Yasushi; Nishio, Satoshi; Ueda, Shuzo; Kurihara, Ryoichi

2000-01-01

Aiming at high degree of safety and benign environmental effect, we have proposed a tokamak fusion reactor concept called DREAM, which stands for DRastically EAsy Maintenance Reactor. The blanket structure of the reactor is made from very low activation SiC/SiC composites and cooled by non-reactive helium gas. High net thermal efficiency of about 50% is realized by 900 C helium gas and high plant availability is possible with simple maintenance scheme. In the DREAM Reactor, neutron streaming is a big problem because cooling pipes with diameter larger than 80 cm are used for blanket heat removal. Neutron streaming through the cooling pipes could cause hot spots in the superconducting magnets adjacent to the cooling pipes to shorten the magnet lifetime or increase cryogenic cooling requirement. Neutron streaming could also activate components such as gas turbine further away from the fusion plasma. The effect of neutron streaming through the helium cooling pipes was evaluated for the two types of cooling pipe extraction scheme. The result of a preliminary calculation indicates the gas turbine activation prohibits personnel access in the case of inboard pipe extraction while with additional shielding measures, limited contact maintenance is possible in the case of outboard extraction. (author)

North Anna Power Station - Unit 1: Overview of steam generator replacement project activities

International Nuclear Information System (INIS)

Gettler, M.W.; Bayer, R.K.; Lippard, D.W.

1993-01-01

The original steam generators at Virginia Electric and Power Company's (Virginia Power) North Anna Power Station (NAPS) Unit 1 have experienced corrosion-related degradation that require periodic inspection and plugging of steam generator tubes to ensure their continued safe and reliable operation. Despite improvements in secondary water chemistry, continued tube degradation in the steam generators necessitated the removal from service of approximately 20.3 percent of the tubes by plugging, (18.6, 17.3, and 25.1 for steam generators A, B, and C, respectively). Additionally, the unit power was limited to 95 % during, its last cycle of operation. Projections of industry and Virginia Power experience indicated the possibility of mid-cycle inspections and reductions in unit power. Therefore, economic considerations led to the decision to repair the steam generators (i.e., replace the steam generator lower assemblies). Three new Model 51F Steam Generator lower assembly units were ordered from Westinghouse. Virginia Power contracted Bechtel Power Corporation to provide the engineering and construction support to repair the Unit 1 steam generators. On January 4, 1993, after an extended coastdown period, North Anna Unit 1 was brought off-line and the 110 day (breaker-to-breaker) Steam Generator Replacement Project (SGRP) outage began. As of this paper, the outage is still in progress

Research on unit commitment with large-scale wind power connected power system

Science.gov (United States)

Jiao, Ran; Zhang, Baoqun; Chi, Zhongjun; Gong, Cheng; Ma, Longfei; Yang, Bing

2017-01-01

Large-scale integration of wind power generators into power grid brings severe challenges to power system economic dispatch due to its stochastic volatility. Unit commitment including wind farm is analyzed from the two parts of modeling and solving methods. The structures and characteristics can be summarized after classification has been done according to different objective function and constraints. Finally, the issues to be solved and possible directions of research and development in the future are discussed, which can adapt to the requirements of the electricity market, energy-saving power generation dispatching and smart grid, even providing reference for research and practice of researchers and workers in this field.

Economics of superconductive energy storage inductor-converter units in power systems

International Nuclear Information System (INIS)

Yadavalli, S.R.

1975-01-01

Since the original proposal by Boom and Peterson in 1972, there has been growing interest in superconductive energy storage inductor converter units (IC units) for use in large power systems for peak shaving and load leveling. Different aspects of it are being studied at the University of Wisconsin and elsewhere. An economic study of such IC units shows that large IC units, bigger than about 1000 MWh, are economically competitive with other peaking alternatives, larger units being more economical. External electrical circuit losses in IC units have negligible effect on their storage and power capacities. There are three credits which could be of significant economic value to IC units. These are: (1) transmission credit which varied from about $4 to $60/kW peak power, with a typical value of about $35/kW; (2) pollution credit which varied from about $5 to $160/kW with a typical value of $80/kW; and Spinning Reserve Credit which varied from about $20 to $370/kW with a typical value of $90/kW

Outline of construction and facility features of Onagawa nuclear power station Unit No. 2

International Nuclear Information System (INIS)

Umimura, Yoshiharu; Tsunoda, Ryohei; Watanabe, Kazunori

1996-01-01

Tohoku Electric Power Company promotes development of various power sources to provide a stable supply of electricity in the future, and nuclear power takes a leading part. In August 1989, construction of Onagawa nuclear power plant Unit No. 2 (825MW) was started, following Unit No. 1 (524MW) which went on line in 1984 as Tohoku Electric's first nuclear power plant unit. Unit No. 2 began commercial operation in July 1995 through satisfactory construction work such as RPV hydraulic test in March 1994, fuel loading in October 1994, and various startup tests in each power stage. The design and construction of Unit No. 2 reflect construction and operation experience gained from Unit No. 1, and the latest technology, including that of the LWR Improvement and Standardization Program, was adopted to enhance facility reliability, improve operation and maintenance performance, and reduce worker dosage. Features of the facility, construction techniques, and a description of preoperation of Onagawa nuclear power plant Unit No. 2 are described in this paper. (author)

National Aquatic Resource Surveys (NARS) N/P Values for Streams - Wadeable Streams Assessment

Data.gov (United States)

U.S. Environmental Protection Agency — The National Aquatic Resource Survey (NARS) findings for nutrients in streams and lakes highlight that nutrient pollution is widespread across the United States and...

Methodical recommendations for power unit comprehensive engineering and radiation survey

International Nuclear Information System (INIS)

Nosovskij, A.V.

2000-01-01

The article describes power unit radiation survey methods developed and applied during conduction of Ch NPP unit I Comprehensive Engineering Radiation Survey. Special requirements for units under decommissioning, main survey principals, criteria for definition of volume and the order of survey for various systems of a NPP Unit are included

Stingray tidal stream energy device - phase 3

International Nuclear Information System (INIS)

2005-01-01

The 150 kW Stingray demonstrator was designed, built and installed by The Engineering Business (EB) in 2002, becoming the world's first full-scale tidal stream generator. The concept and technology are described in the reports from Phases 1 and 2 of the project. This report provides an overview of Phase 3 - the re-installation of Stingray in Yell Sound in the Shetland Isles between July and September 2003 for further testing at slack water and on the flood tide to confirm basic machine characteristics, develop the control strategy and to demonstrate performance and power collection through periods of continuous operation. The overall aim was to demonstrate that electricity could be generated at a potentially commercially viable unit energy cost; cost modelling indicated a future unit energy cost of 6.7 pence/kWh when 100 MW capacity had been installed. The report describes: project objectives, targets and activities; design and production; marine operations including installation and demobilisation; environmental monitoring and impact, including pre-installation and post-decommissioning surveys; stakeholder involvement; test results on machine characteristics, sensor performance, power cycle analysis, power collection, transmission performance and efficiency, current data analysis; validation of the mathematical model; the background to the economic model; cost modelling; and compliance with targets set by the Department of Trade and Industry (DTI)

Stingray tidal stream energy device - phase 3

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The 150 kW Stingray demonstrator was designed, built and installed by The Engineering Business (EB) in 2002, becoming the world's first full-scale tidal stream generator. The concept and technology are described in the reports from Phases 1 and 2 of the project. This report provides an overview of Phase 3 - the re-installation of Stingray in Yell Sound in the Shetland Isles between July and September 2003 for further testing at slack water and on the flood tide to confirm basic machine characteristics, develop the control strategy and to demonstrate performance and power collection through periods of continuous operation. The overall aim was to demonstrate that electricity could be generated at a potentially commercially viable unit energy cost; cost modelling indicated a future unit energy cost of 6.7 pence/kWh when 100 MW capacity had been installed. The report describes: project objectives, targets and activities; design and production; marine operations including installation and demobilisation; environmental monitoring and impact, including pre-installation and post-decommissioning surveys; stakeholder involvement; test results on machine characteristics, sensor performance, power cycle analysis, power collection, transmission performance and efficiency, current data analysis; validation of the mathematical model; the background to the economic model; cost modelling; and compliance with targets set by the Department of Trade and Industry (DTI).

South Stream Project and the Ukrainian Factor

Directory of Open Access Journals (Sweden)

Roxana Ioana Banciu

2015-03-01

Full Text Available The paper seeks to develop an analysis of the South Stream project in view of the Ukrainian crisis. We cannot put aside the internal factor as Ukraine is facing serious internal issues such as corruption and instability, therefore Russia’s invasion of Ukraine can not be simply ignored in this pipeline project. The article uses mostly facts that happened throughout last years, as well as for and against declarations in the case of the South Stream project and its mother Russia. When we hear about South Stream, we think of Russia and since 2007, this pipeline has encouraged Putin’s faith in energy superpower. A good point to start with was to gather all declarations since then and cover all actions that regard the South Stream game. In Russian foreign policy for the South Stream race, Soft Power was used more than enough and it has recently made room for Hard Power, which is the Ukraine never ending episode. Insights of the South Stream story have been lately related both softly and hardly, this is the reason why I have chosen to analyse both sides in order to complete the energy landscape.

Safstor decommissioning of the Humboldt Bay Power Plant Unit No. 3

International Nuclear Information System (INIS)

Nelson, R.T.

1985-01-01

The Humboldt Bay Power Plant is located near Eureka, California, about 265 miles north of San Francisco. The plant consists of two fossil fueled units, two mobil gas turbine peaking units, and a nuclear unit - Unit No. 3. Unit No. 3, which utilized a boiling water reactor, was constructed between 1960 and 1963. The unit began commercial operation in August 1963 and operated until July 2, 1976 when it was shutdown for refueling, seismic modifications, and additional seismic and geologic studies. During the years Unit 3 operated it had one of the best operating records of any nuclear power plant in the United States. For its operating lifetime Unit 3 had an overall capacity factor of 63.0% and an availability factor of 85.9%. The unit included certain design features which made it unique among nuclear power plants of its era. Some of these unique features included natural circulation recirculation flow which eliminated the need for costly recirculation pumps, utilization of a pressure suppression containment system which had been developed jointly by PG and E and the General Electric Company, and the fact that the reactor vessel and the containment system were constructed in a caisson below ground level. These design features reduced the overall construction cost of the unit and improved its inherent safety

Control system for a nuclear power producing unit

International Nuclear Information System (INIS)

Durrant, O.W.

1978-01-01

The invention provides in a control system for a nuclear power producing unit comprising a pressurized water reactor, a once-through steam generator provided with feedwater supply means, a turbine-generator supplied with steam from the steam generator and means maintaining a flow of pressurized water through the reactor and steam generator. The combination comprising; means generating a feed forward control signal proportional to the desired power output of the power producing unit, a second means for adjusting the reactor heat release, a third means for adjusting the rate of flow of feedwater to the steam generator, the second and third means solely responsive to and operated in parallel from the feed forward control signal whereby the reactor heat release and the rate of flow of feedwater to the steam generator are each maintained in a discrete functional relationship to the feed forward control signal

Analysis of an integrated cryogenic air separation unit, oxy-combustion carbon dioxide power cycle and liquefied natural gas regasification process by exergoeconomic method

International Nuclear Information System (INIS)

Mehrpooya, Mehdi; Zonouz, Masood Jalali

2017-01-01

Highlights: • Exergoeconomic analyses is done on an integrated cryogenic air separation unit. • Liquefied natural gas cold energy is used in the process. • The main multi stream heat exchanger is the worst device based on the results. - Abstract: Exergoeconomic and sensitivity analyses are performed on the integrated cryogenic air separation unit, oxy-combustion Carbon dioxide power cycle and liquefied natural gas regasification process. Exergy destruction, exergy efficiency, cost rate of exergy destruction, cost rate of capital investment and operating and maintenance, exergoeconomic factor and relative cost difference have been calculated for the major components of the process. The exergy efficiency of the process is around 67.1% and after mixers, tees, tank and expansion valves the multi-stream heat exchanger H-3 have the best exergy efficiency among all process components. Total exergy destruction rate of the process is 1.93 × 10"7 kW. Results of exergoeconomic analysis demonstrates that maximum exergy destruction and capital investment operating and maintenance cost rate are related to the multi-stream heat exchanger H-1 and pump P-1 with the values of 335,144 ($/h) and 12,838 ($/h), respectively. In the sensitivity analysis section the effects of the varying economic parameters, such as interest rate and plant life time are investigated on the trend of the capital investment operating and maintenance cost rate of the major components of the process and in another cases the effect of the gas turbine isentropic efficiency on the exergy and exergoeconomic parameters are studied.

Stochastic PSO-based heat and power dispatch under environmental constraints incorporating CHP and wind power units

Energy Technology Data Exchange (ETDEWEB)

Piperagkas, G.S.; Anastasiadis, A.G.; Hatziargyriou, N.D. [National Technical University of Athens, School of Electrical and Computer Engineering, Electric Power Division, 9, Iroon Polytechneiou Str., GR-15773 Zografou, Athens (Greece)

2011-01-15

In this paper an extended stochastic multi-objective model for economic dispatch (ED) is proposed, that incorporates in the optimization process heat and power from CHP units and expected wind power. Stochastic restrictions for the CO{sub 2}, SO{sub 2} and NO{sub x} emissions are used as inequality constraints. The ED problem is solved using a multi-objective particle swarm optimization technique. The available wind power is estimated from a transformation of the wind speed considered as a random variable to wind power. Simulations are performed on the modified IEEE 30 bus network with 2 cogeneration units and actual wind data. Results concerning minimum cost and emissions reduction options are finally drawn. (author)

AN AIRPLANE WITH UNCONVENTIONALLY PLACED PROPELLER POWER UNIT

Directory of Open Access Journals (Sweden)

Jan Červinka

2017-02-01

Full Text Available The significance of the influence of operating propellers on the aircraft aerodynamic characteristics is well-known. Wind tunnel testing of an airplane model with operating propellers is a complex task regarding the required similarity of the full-scale and the model case. Matching sufficient similarity in axial and rotational velocities in the propeller slipstream is the primordial condition for the global aerodynamic similarity of the windtunnel testing. An example of the model power units with related devices is presented. Examples of the wind tunnel testing results illustrate the extent of the propeller influence on aerodynamic characteristics of an aircraft of unconventional configuration with power units positioned at the fuselage afterbody.

Salamander occupancy in headwater stream networks

Science.gov (United States)

Grant, E.H.C.; Green, L.E.; Lowe, W.H.

2009-01-01

1. Stream ecosystems exhibit a highly consistent dendritic geometry in which linear habitat units intersect to create a hierarchical network of connected branches. 2. Ecological and life history traits of species living in streams, such as the potential for overland movement, may interact with this architecture to shape patterns of occupancy and response to disturbance. Specifically, large-scale habitat alteration that fragments stream networks and reduces connectivity may reduce the probability a stream is occupied by sensitive species, such as stream salamanders. 3. We collected habitat occupancy data on four species of stream salamanders in first-order (i.e. headwater) streams in undeveloped and urbanised regions of the eastern U.S.A. We then used an information-theoretic approach to test alternative models of salamander occupancy based on a priori predictions of the effects of network configuration, region and salamander life history. 4. Across all four species, we found that streams connected to other first-order streams had higher occupancy than those flowing directly into larger streams and rivers. For three of the four species, occupancy was lower in the urbanised region than in the undeveloped region. 5. These results demonstrate that the spatial configuration of stream networks within protected areas affects the occurrences of stream salamander species. We strongly encourage preservation of network connections between first-order streams in conservation planning and management decisions that may affect stream species.

A computational modeling approach of the jet-like acoustic streaming and heat generation induced by low frequency high power ultrasonic horn reactors.

Science.gov (United States)

Trujillo, Francisco Javier; Knoerzer, Kai

2011-11-01

High power ultrasound reactors have gained a lot of interest in the food industry given the effects that can arise from ultrasonic-induced cavitation in liquid foods. However, most of the new food processing developments have been based on empirical approaches. Thus, there is a need for mathematical models which help to understand, optimize, and scale up ultrasonic reactors. In this work, a computational fluid dynamics (CFD) model was developed to predict the acoustic streaming and induced heat generated by an ultrasonic horn reactor. In the model it is assumed that the horn tip is a fluid inlet, where a turbulent jet flow is injected into the vessel. The hydrodynamic momentum rate of the incoming jet is assumed to be equal to the total acoustic momentum rate emitted by the acoustic power source. CFD velocity predictions show excellent agreement with the experimental data for power densities higher than W(0)/V ≥ 25kWm(-3). This model successfully describes hydrodynamic fields (streaming) generated by low-frequency-high-power ultrasound. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Cross-connected onsite emergency A.C. power supplies for multi-unit nuclear power plant sites

International Nuclear Information System (INIS)

Martore, J.A.; Voss, J.D.; Duncil, B.

1987-01-01

Recently, utility management, both at the corporate and plant operations levels, have reinforced their commitment to assuring increased plant reliability and availability. One means of achieving this objective involves an effective preventive maintenance program with technical specifications which allow implementation of certain preventive maintenance without plant shutdown. To accomplish this, Southern California Edison Company (SCE) has proposed a design change for San Onofre nuclear generating station (SONGS) units 2 and 3 to permit on emergency diesel generator for one unit to perform as an available AC power source for both units. Technical specifications for SCE's SONGS units 2 and 3, as at most nuclear power plants, currently require plant shutdown should one of the two dedicated onsite emergency AC power sources (diesel generators) become inoperable for more than 72 hours. This duration hinders root cause failure analysis, tends to limit the flexibility of preventive maintenance and precludes plant operation in the event of component failure. Therefore, this proposed diesel generator cross-connect design change offers an innovative means for averting plant shutdown should a single diesel generator become inoperable for longer than 72 hours. (orig./GL)

Quest for clean streams in North Carolina: An historical account of stream pollution control in North Carolina. Special report

International Nuclear Information System (INIS)

Howells, D.H.

1990-11-01

The second historical report dealing with North Carolina's water resources traces the evolution of the state's stream pollution control regulations and programs. From the colonial development of streams and rivers to power mills to the effects of land conversion for agriculture and later for commercial and industrial facilities, the report catalogs the various of stream pollution over time. Developments of waste water treatment under both state and federal laws and regulations are described. The report concluded with a look at contemporary stream pollution issues

Environmental stressors afflicting tailwater stream reaches across the United States

Science.gov (United States)

Miranda, Leandro E.; Krogman, R. M.

2014-01-01

The tailwater is the reach of a stream immediately below an impoundment that is hydrologically, physicochemically and biologically altered by the presence and operation of a dam. The overall goal of this study was to gain a nationwide awareness of the issues afflicting tailwater reaches in the United States. Specific objectives included the following: (i) estimate the percentage of reservoirs that support tailwater reaches with environmental conditions suitable for fish assemblages throughout the year, (ii) identify and quantify major sources of environmental stress in those tailwaters that do support fish assemblages and (iii) identify environmental features of tailwater reaches that determine prevalence of key fish taxa. Data were collected through an online survey of fishery managers. Relative to objective 1, 42% of the 1306 reservoirs included in this study had tailwater reaches with sufficient flow to support a fish assemblage throughout the year. The surface area of the reservoir and catchment most strongly delineated reservoirs maintaining tailwater reaches with or without sufficient flow to support a fish assemblage throughout the year. Relative to objective 2, major sources of environmental stress generally reflected flow variables, followed by water quality variables. Relative to objective 3, zoogeography was the primary factor discriminating fish taxa in tailwaters, followed by a wide range of flow and water quality variables. Results for objectives 1–3 varied greatly among nine geographic regions distributed throughout the continental United States. Our results provide a large-scale view of the effects of reservoirs on tailwater reaches and may help guide research and management needs.

Regulatory, design and methodological impacts in determining tidal-in-stream power resource potential

International Nuclear Information System (INIS)

Atwater, Joel F.; Lawrence, Gregory A.

2011-01-01

Tidal-in-Stream energy has been heralded by many as a significant potential source for clean power, a scheme where kinetic energy is extracted from tidal currents. A number of estimates have suggested that tidal power may become a sizeable fraction of overall electricity generation, however these estimates have been largely based on a resource assessment methodology that dramatically oversimplifies the physical phenomenon at play. This paper develops a model that considers the effect of energy extraction on the bulk flow, showing that tidal energy inventories that assess solely kinetic energy flux may represent both an order-of-magnitude overestimation of the resource and a significant oversimplification of regulatory impacts. The interplay between the characteristics of a flow and the regulatory and economic issues will likely limit tidal power generation to levels significantly below the physical maximums. Permitted flow reduction, turbine design and staging of development all have significant and predictable impacts on the extractible resource. Energy planners must therefore understand these relationships in order to appropriately assess the magnitude of generation that can be realistically be produced from tidal energy. - Research highlights: → Inventorying kinetic energy is not appropriate for assessing the tidal energy potential and may overestimate the resource by orders of magnitude. → The physical maximum for tidal power extraction is 38% of the total fluid power of a channel and causes a flow reduction of 42%. → Any amount of tidal power generation will reduce the flow rate in a channel. → Limiting the permitted reduction in flow significantly reduces the available resource. → Turbine efficiency is important as extraneous resistance depletes the resource without providing power generation.

Methods for removing radioactive isotopes from contaminated streams

International Nuclear Information System (INIS)

Hoy, D.R.; Hickey, T.N.; Spulgis, I.S.; Parish, H.C.

1979-01-01

Methods for removing radioactive isotopes from contaminated gas streams for use in atmospheric containment and cleanup systems in nuclear power plants are provided. The methods provide for removal of radioactive isotopes from a first portion of the contaminated stream, separated from the remaining portion of the stream, so that adsorbent used to purify the first portion of the contaminated stream by adsorption of the radioactive isotopes therefrom can be tested to determine the adsorbing efficacy of the generally larger portion of adsorbent used to purify the remaining portion of the stream

Green Power Marketing in the United States: A Status Report (2009 Data)

Energy Technology Data Exchange (ETDEWEB)

Bird, L.; Sumner, J.

2010-09-01

This report documents green power marketing activities and trends in the United States. First, aggregate green power sales data for all voluntary purchase markets across the United States are presented. Next, we summarize data on utility green pricing programs offered in regulated electricity markets; green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of RECs; and renewable energy sold as greenhouse gas offsets in the United States. Finally, this is followed by a discussion of key market trends and issues. The data presented in this report are based primarily on figures provided to NREL by utilities and independent renewable energy marketers.

Green Power Marketing in the United States. A Status Report (2009 Data)

Energy Technology Data Exchange (ETDEWEB)

Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sumner, Jenny [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2010-09-01

This report documents green power marketing activities and trends in the United States. First, aggregate green power sales data for all voluntary purchase markets across the United States are presented. Next, we summarize data on utility green pricing programs offered in regulated electricity markets; green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of RECs; and renewable energy sold as greenhouse gas offsets in the United States. Finally, this is followed by a discussion of key market trends and issues. The data presented in this report are based primarily on figures provided to NREL by utilities and independent renewable energy marketers.

The Northeast Stream Quality Assessment

Science.gov (United States)

Van Metre, Peter C.; Riva-Murray, Karen; Coles, James F.

2016-04-22

In 2016, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) is assessing stream quality in the northeastern United States. The goal of the Northeast Stream Quality Assessment (NESQA) is to assess the quality of streams in the region by characterizing multiple water-quality factors that are stressors to aquatic life and evaluating the relation between these stressors and biological communities. The focus of NESQA in 2016 will be on the effects of urbanization and agriculture on stream quality in all or parts of eight states: Connecticut, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont.Findings will provide the public and policymakers with information about the most critical factors affecting stream quality, thus providing insights about possible approaches to protect the health of streams in the region. The NESQA study will be the fourth regional study conducted as part of NAWQA and will be of similar design and scope to the first three, in the Midwest in 2013, the Southeast in 2014, and the Pacific Northwest in 2015 (http://txpub.usgs.gov/RSQA/).

Upgrade of KNPEC no.2 Simulator for Kori Unit 3 Power Uprating

Energy Technology Data Exchange (ETDEWEB)

Hong, Jin-Hyuk; Lee, Seung-Ho [KEPRI, Daejeon (Korea, Republic of)

2007-07-01

Kori-Unit 3 and 4 is preparing the operation of the power-uprating (2900MWt), and therefore the Korea regulatory body(KINS) requested the operator training with the simulator reflecting the power-uprating. As a result of the intensive research and expertise of KEPRI on the simulators, KEPRI accomplished the upgrade project of KNPEC no.2 simulator for Kori-Unit 3 power-uprating. This project includes various high-tech methods incorporating - realtime neutronics model based on MASTER (Multi-purpose Analyzer for Static and Transient Effects of Reactors) code, best-estimate neutronics code by the KINS, (By using the RMASTER, the precision of the simulation of the neutron behaviors in the core is highly improved.) - betterment of the reactor coolant system and the balance-of-plant system - modification of the corresponding setpoints due to the power-uprating And the acceptance test procedure (ATP) was successfully carried out through the integration of system models and its performance tests. Through the success of this project, the operator training for the power uprating of the Kori-Unit 3 will be accomplished before its power operation and, after all, this simulator will contribute to the safe operation for the power-uprating of the Kori-Unit 3 and 4.

Climate Change Impacts on Stream Temperature in Regulated River Systems: A Case Study in the Southeastern United States

Science.gov (United States)

Cheng, Y.; Niemeyer, R. J.; Zhang, X.; Yearsley, J. R.; Voisin, N.; Nijssen, B.

2017-12-01

Climate change and associated changes in air temperature and precipitation are projected to impact natural water resources quantity, quality and timing. In the past century, over 280 major dams were built in the Southeastern United States (SEUS) (GRanD database). Regulation of the river system greatly alters natural streamflow as well as stream temperature. Understanding the impacts of climate change on regulated systems, particularly within the context of the Clean Water Act, can inform stakeholders how to maintain and adapt water operations (e.g. regulation, withdrawals). In this study, we use a new modeling framework to study climate change impacts on stream temperatures of a regulated river system. We simulate runoff with the Variable Infiltration Capacity (VIC) macroscale hydrological model, regulated streamflow and reservoir operations with a large-scale river routing-reservoir model (MOSART-WM), and stream temperature using the River Basin Model (RBM). We enhanced RBM with a two-layer thermal stratification reservoir module. This modeling framework captures both the impact of reservoir regulation on streamflow and the reservoir stratification effects on downstream temperatures. We evaluate changes in flow and stream temperatures based on climate projections from two representative concentration pathways (RCPs; RCP4.5 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5 (CMIP5). We simulate river temperature with meteorological forcings that have been downscaled with the Multivariate Constructed Analogs (MACA) method. We are specifically interested in analyzing extreme periods during which stream temperature exceeds water quality standards. In this study, we focus on identifying whether these extreme temperature periods coincide with low flows, and whether the frequency and duration of these operationally-relevant periods will increase under future climate change.

Power conversion unit for the South African direct cycle HTGR

International Nuclear Information System (INIS)

Liebenberg, J.J.

1997-01-01

The system parameters chosen to optimise the thermal efficiency of the Eskom PBMR whilst maintaining component simplicity is discussed. Power Conversion Unit components, which are now at a preliminary design stage comprise a precooler, two turbo units consisting of a turbine driven compressor, recuperator and a power turbine, driving an alternator. Design aspects of every component is mentioned and the inventory method of poorer control is explained with reference to start-up and and shut-down events, the system an effective load following device, down to 4% of full power. Application of the same design principles for HTGRs smaller than 25 MWe is discussed. (author)

Streaming Italian horror cinema in the United Kingdom: Lovefilm Instant

OpenAIRE

Baschiera, Stefano

2017-01-01

This article investigates the distribution of Italian horror cinema in the age of video streaming, analyzing its presence and categorization on the platform Lovefilm Instant UK, in order to investigate the importance of ‘niche’ in what is known as the long tail of online distribution and the online availability of exploitation films. I argue that looking at the streaming presence of Italian horror and comparing it to its prior distribution on home video formats (in particular VHS and DVD) we ...

Polymer electrolyte fuel cell mini power unit for portable application

Energy Technology Data Exchange (ETDEWEB)

Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

2007-06-20

This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

Designing a nuclear power plant with 1000 MW WWER-type units

Energy Technology Data Exchange (ETDEWEB)

Berkovich, V; Kaloshin, J; Tatarnikov, V; Shenderovich, A

1977-06-01

A brief description is presented of a WWER-1000 nuclear power plant also considering its environmental impact and the problem of core poisoning. The following indicators are graphically shown in relation to the reactor output: turbogenerator unit outputs, efficiency, specific capital costs and own costs of electric power generated by the Voronezh nuclear power plant. Also listed are the specific consumption of metal and concrete, specific equipment weight and the specific volume of the buildings of the main generating unit as well as the cross section thereof.

77 FR 50533 - Dominion Nuclear Connecticut, Inc.; Millstone Power Station, Unit 3

Science.gov (United States)

2012-08-21

....; Millstone Power Station, Unit 3 AGENCY: Nuclear Regulatory Commission. ACTION: Environmental assessment and... search, select ``ADAMS Public Documents'' and then select ``Begin Web- based ADAMS Search.'' For problems... Optimized ZIRLO\\TM\\ fuel rod cladding in future core reload applications for Millstone Power Station, Unit 3...

Solar wind stream interfaces

International Nuclear Information System (INIS)

Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

1978-01-01

Measurements aboard Imp 6, 7, and 8 reveal that approximately one third of all high-speed solar wind streams observed at 1 AU contain a sharp boundary (of thickness less than approx.4 x 10 4 km) near their leading edge, called a stream interface, which separates plasma of distinctly different properties and origins. Identified as discontinuities across which the density drops abruptly, the proton temperature increases abruptly, and the speed rises, stream interfaces are remarkably similar in character from one stream to the next. A superposed epoch analysis of plasma data has been performed for 23 discontinuous stream interfaces observed during the interval March 1971 through August 1974. Among the results of this analysis are the following: (1) a stream interface separates what was originally thick (i.e., dense) slow gas from what was originally thin (i.e., rare) fast gas; (2) the interface is the site of a discontinuous shear in the solar wind flow in a frame of reference corotating with the sun; (3) stream interfaces occur at speeds less than 450 km s - 1 and close to or at the maximum of the pressure ridge at the leading edges of high-speed streams; (4) a discontinuous rise by approx.40% in electron temperature occurs at the interface; and (5) discontinuous changes (usually rises) in alpha particle abundance and flow speed relative to the protons occur at the interface. Stream interfaces do not generally recur on successive solar rotations, even though the streams in which they are embedded often do. At distances beyond several astronomical units, stream interfaces should be bounded by forward-reverse shock pairs; three of four reverse shocks observed at 1 AU during 1971--1974 were preceded within approx.1 day by stream interfaces. Our observations suggest that many streams close to the sun are bounded on all sides by large radial velocity shears separating rapidly expanding plasma from more slowly expanding plasma

Strategies for the Use of Tidal Stream Currents for Power Generation

Science.gov (United States)

Orhan, Kadir; Mayerle, Roberto

2015-04-01

Indonesia is one of the priority countries in Southeast Asia for the development of ocean renewable energy facilities and The National Energy Council intends to increase the role of ocean energy significantly in the energy mix for 2010-2050. To this end, the joint German-Indonesian project "Ocean Renewable Energy ORE-12" aims at the identification of marine environments in the Indonesian Archipelago, which are suitable for the efficient generation of electric power by converter facilities. This study, within the ORE-12 project, is focused on the tidal stream currents on the straits between the Indian Ocean and Flores Sea to estimate the energy potentials and to develop strategies for producing renewable energy. FLOW module of Delft3D has been used to run hydrodynamic models for site assessment and design development. In site assessment phase, 2D models have been operated for a-month long periods and with a resolution of 500 m. Later on, in design development phase, detailed 3D models have been developed and operated for three-month long periods and with a resolution of 50 m. Bathymetric data for models have been obtained from the GEBCO_08 Grid and wind data from the Global Forecast System of NOAA's National Climatic Data Center. To set the boundary conditions of models, tidal forcing with 11 harmonic constituents was supplied from TPXO Indian Ocean Atlas (1/12° regional model) and data from HYCOM+NCODA Global 1/12° Analysis have been used to determine salinity and temperature on open boundaries. After the field survey is complete, water level time-series supplied from a tidal gauge located in the domain of interest (8° 20΄ 9.7" S, 122° 54΄ 51.9" E) have been used to verify the models and then energy potentials of the straits have been estimated. As a next step, correspondence between model outputs and measurements taken by the radar system of TerraSAR-X satellite (DLR) will be analysed. Also for the assessment of environmental impacts caused by tidal stream

Changing Snow Cover and Stream Discharge in the Western United States - Wind River Range, Wyoming

Science.gov (United States)

Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Barton, Jonathan S.; Riggs, George A.

2011-01-01

Earlier onset of springtime weather has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack has important implications for the management of water resources. We studied ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover products, 40 years of stream discharge and meteorological station data and 30 years of snow-water equivalent (SWE) SNOw Telemetry (SNOTEL) data in the Wind River Range (WRR), Wyoming. Results show increasing air temperatures for.the 40-year study period. Discharge from streams in WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades. Changes in streamflow may be related to increasing air temperatures which are probably contributing to a reduction in snow cover, although no trend of either increasingly lower streamflow or earlier snowmelt was observed within the decade of the 2000s. And SWE on 1 April does not show an expected downward trend from 1980 to 2009. The extent of snow cover derived from the lowest-elevation zone of the WRR study area is strongly correlated (r=0.91) with stream discharge on 1 May during the decade of the 2000s. The strong relationship between snow cover and streamflow indicates that MODIS snow-cover maps can be used to improve management of water resources in the drought-prone western U.S.

A flowsheet for a wave power unit

Energy Technology Data Exchange (ETDEWEB)

Sobierajski, E.; Kasperowicz, Z.

1984-01-01

A flowsheet is examined for a wave power unit designed to produce electricity, for flooding or drying a coastal zone, cleaning or protecting water areas of ports from sand deposits. The unit includes a vertical cylinder attached to the sea floor with input and output water ducts and valves. The cylinder has a rod with piston that is actuated through a flexible cable by float arranged next to the cylinder. The water injected under pressure into the pressure pipe can be used directly or as an intermediate energy source.

The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments (Version 2.1) for the Conterminous United States: Base Flow Index

Science.gov (United States)

This dataset represents the base flow index values within individual, local NHDPlusV2 catchments and upstream, contributing watersheds. Attributes of the landscape layer were calculated for every local NHDPlusV2 catchment and accumulated to provide watershed-level metrics. (See Supplementary Info for Glossary of Terms) The base-flow index (BFI) grid for the conterminous United States was developed to estimate (1) BFI values for ungaged streams, and (2) ground-water recharge throughout the conterminous United States (see Source_Information). Estimates of BFI values at ungaged streams and BFI-based ground-water recharge estimates are useful for interpreting relations between land use and water quality in surface and ground water. The bfi (%) was summarized by local catchment and by watershed to produce local catchment-level and watershed-level metrics as a continuous data type (see Data Structure and Attribute Information for a description).

Transformation of QSPA plasma streams in longitudinal magnetic field

International Nuclear Information System (INIS)

Makhlaj, V.A.; Bandura, A.N.; Chebotarev, V.V.; Kulik, N.V.; Wuerz, H.

2002-01-01

The main aim of this work is analysis of efficiency of QSPA powerful plasma streams transportation in longitudinal magnetic field in dependence on operational mode of accelerator and plasma stream parameters

Designing a nuclear power plant with 1000 MW WWER-type units

International Nuclear Information System (INIS)

Berkovich, V.; Kaloshin, J.; Tatarnikov, V.; Shenderovich, A.

1977-01-01

A brief description is presented of a WWER-1000 nuclear power plant also considering its environmental impact and the problem of core poisoning. The following indicators are graphically shown in relation to the reactor output: turbogenerator unit outputs, efficiency, specific capital costs and own costs of electric power generated by the Voronezh nuclear power plant. Also listed are the specific consumption of metal and concrete, specific equipment weight and the specific volume of the buildings of the main generating unit as well as the cross section thereof. (J.B.)

Brayton-Cycle Power-Conversion Unit Tested With Ion Thruster

Science.gov (United States)

Hervol, David S.

2005-01-01

Nuclear electric propulsion has been identified as an enabling technology for future NASA space science missions, such as the Jupiter Icy Moons Orbiter (JIMO) now under study. An important element of the nuclear electric propulsion spacecraft is the power conversion system, which converts the reactor heat to electrical power for use by the ion propulsion system and other spacecraft loads. The electrical integration of the power converter and ion thruster represents a key technical challenge in making nuclear electric propulsion technology possible. This technical hurdle was addressed extensively on December 1, 2003, when a closed- Brayton-cycle power-conversion unit was tested with a gridded ion thruster at the NASA Glenn Research Center. The test demonstrated end-to-end power throughput and marked the first-ever coupling of a Brayton turbo alternator and a gridded ion thruster, both of which are candidates for use on JIMO-type missions. The testing was conducted at Glenn's Vacuum Facility 6, where the Brayton unit was installed in the 3-m-diameter vacuum test port and the ion thruster was installed in the 7.6-m-diameter main chamber.

Hydrogen Fuel Cell Performance as Telecommunications Backup Power in the United States

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Saur, Genevieve [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprik, Sam [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-03-01

Working in collaboration with the U.S. Department of Energy (DOE) and industry project partners, the National Renewable Energy Laboratory (NREL) acts as the central data repository for the data collected from real-world operation of fuel cell backup power systems. With American Recovery and Reinvestment Act of 2009 (ARRA) co-funding awarded through DOE's Fuel Cell Technologies Office, more than 1,300 fuel cell units were deployed over a three-plus-year period in stationary, material handling equipment, auxiliary power, and backup power applications. This surpassed a Fuel Cell Technologies Office ARRA objective to spur commercialization of an early market technology by installing 1,000 fuel cell units across several different applications, including backup power. By December 2013, 852 backup power units out of 1,330 fuel cell units deployed were providing backup service, mainly for telecommunications towers. For 136 of the fuel cell backup units, project participants provided detailed operational data to the National Fuel Cell Technology Evaluation Center for analysis by NREL's technology validation team. NREL analyzed operational data collected from these government co-funded demonstration projects to characterize key fuel cell backup power performance metrics, including reliability and operation trends, and to highlight the business case for using fuel cells in these early market applications. NREL's analyses include these critical metrics, along with deployment, U.S. grid outage statistics, and infrastructure operation.

Hydraulic modeling of thermal discharges into shallow, tidal affected streams

International Nuclear Information System (INIS)

Copp, H.W.; Shashidhara, N.S.

1981-01-01

A two-unit nuclear fired power plant is being constructed in western Washington state. Blowdown water from cooling towers will be discharged into the Chehalis River nearby. The location of a diffuser is some 21 miles upriver from Grays Harbor on the Pacific Ocean. Because the Chehalis River is classified as an excellent stream from the standpoint of water quality, State regulatory agencies required demonstration that thermal discharges would maintain water quality standards within fairly strict limits. A hydraulic model investigation used a 1:12 scale, undistorted model of a 1300-foot river reach in the vicinity of the diffuser. The model scale was selected to insure fully turbulent flows both in the stream and from the diffuser (Reynolds similitude). Model operation followed the densimetric Froude similitude. Thermistors were employed to measure temperatures in the model; measurements were taken by computer command and such measurements at some 250 positions were effected in about 2.5 seconds

Surry Power Station, Units 1 and 2. Semiannual operating report, January--June 1975

International Nuclear Information System (INIS)

1975-01-01

Net electric power generated by Unit 1 was 2,315,124 MWH(e) and Unit 2 generated 2,062,954 MWH(e) with Unit 1 generator on line for 3,157.8 hrs and Unit 2 on line for 2,881.2 hrs. Information is presented concerning power generation, shutdowns, corrective maintenance, chemistry and radiochemistry, occupational radiation exposure, release of radioactive materials, abnormal occurrences, and environmental monitoring. (FS)

The economic aspect of transition to power units with supercritical steam parameters

Energy Technology Data Exchange (ETDEWEB)

V.R. Kotler

2007-09-15

Information on the development and use of power units for supercritical and ultrasupercritical steam parameters in the United States, as well as in Europe and Japan, is presented. It is shown that increasing the parameters of steam reduces not only the fuel consumption, but also the specific emissions of toxic and greenhouse gases. Results of a calculation carried out at the EPRI (the United States) are presented, which show that it is advisable to construct power units for supercritical parameters only at certain (sufficiently high) price of the fuel being fired.

Environmental Impact Assessment for Olkiluoto 4 Nuclear Power Plant Unit in Finland

International Nuclear Information System (INIS)

Dersten, Riitta; Gahmberg, Sini; Takala, Jenni

2008-01-01

In order to improve its readiness for constructing additional production capacity, Teollisuuden Voima Oyj (TVO) initiated in spring 2007 the environmental impact assessment procedure (EIA procedure) concerning a new nuclear power plant unit that would possibly be located at Olkiluoto. When assessing the environmental impacts of the Olkiluoto nuclear power plant extension project, the present state of the environment was first examined, and after that, the changes caused by the projects as well as their significance were assessed, taking into account the combined impacts of the operations at Olkiluoto. The environmental impact assessment for the planned nuclear power plant unit covers the entire life cycle of the plant unit. (authors)

Environmental Impact Assessment for Olkiluoto 4 Nuclear Power Plant Unit in Finland

Energy Technology Data Exchange (ETDEWEB)

Dersten, Riitta; Gahmberg, Sini; Takala, Jenni [Teollisuuden Voima Oyj, Olkiluoto, FI-27160 Eurajoki (Finland)

2008-07-01

In order to improve its readiness for constructing additional production capacity, Teollisuuden Voima Oyj (TVO) initiated in spring 2007 the environmental impact assessment procedure (EIA procedure) concerning a new nuclear power plant unit that would possibly be located at Olkiluoto. When assessing the environmental impacts of the Olkiluoto nuclear power plant extension project, the present state of the environment was first examined, and after that, the changes caused by the projects as well as their significance were assessed, taking into account the combined impacts of the operations at Olkiluoto. The environmental impact assessment for the planned nuclear power plant unit covers the entire life cycle of the plant unit. (authors)

Changing Perceptions of Nuclear Power in The United States

International Nuclear Information System (INIS)

Taylor, John

1989-01-01

Although many new nuclear power plants have been brought on line in that time, resulting in a capacity of 110 plants with operating permits and another twelve in the last stages of completion, all of these plants were authorized before 1978. The fundamental reason for this moratorium in new orders was the precipitous reduction in electricity demand, arising from the OPEC embargo and Iran revolution, which created excess electric capacity throughout the United States. In fact, many nuclear and coal plants were cancelled to minimize the over capacity problem and no large base load generating units have been ordered of any kind in the past decade. So the 'moratorium' is not really unique to nuclear power. Progress, coupled with increased awareness that nuclear power is one of the keys to solving atmospheric environmental problems, will swing political and public acceptance back to being favorable. Successful progress in these matters will be of benefit to public acceptance around the world and, conversely, serious technical difficulties, particularly entailing any major incident with a nuclear power plants anywhere in the world, will adversely affect the improvement in political and public acceptance in the United States. It is vitally important, therefore, that we continue to further enhance international cooperation in nuclear power. We are pleased the Korea Electric power Corporation and the Korea Advanced Energy Research Institute are participating in EPRI development programs, and hope that cooperation will increase in the future. We're most encouraged by the formation of the World Association of Nuclear Operators, which will be initiated in Moscow next month. The nuclear electric utilities and their governments around the world, the International Atomic Energy Agency, and the Nuclear Energy Agency of OECD should be commended for their initiative in international cooperation

The 3rd power unit roofing decontamination

International Nuclear Information System (INIS)

Samojlenko, Yu.N.; Golubev, V.V.

1989-01-01

The most features of the 3rd power unit (PU) roofing decontamination are described: 1) the most active materials were thrown into the 4th PU ruins before the Ukrytie construction completion; 2) the decontamination was fulfilled using remote-controlled mechanisms and manual devices (the main part). 6 figs.; 1 tab

14 CFR 33.96 - Engine tests in auxiliary power unit (APU) mode.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Engine tests in auxiliary power unit (APU... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.96 Engine tests in auxiliary power unit (APU) mode. If the engine is designed with a propeller brake which...

Green Power Marketing in the United States. A Status Report (Tenth Edition)

Energy Technology Data Exchange (ETDEWEB)

Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dagher, Leila [National Renewable Energy Lab. (NREL), Golden, CO (United States); Swezey, Blair [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2007-12-01

This report documents green power marketing activities and trends in the United States, focusing on consumer decisions to purchase electricity supplied from renewable energy sources and how this choice represents a powerful market support mechanism for renewable energy development. The report presents aggregate green power sales data for all voluntary purchase markets across the United States. It also provides summary data on utility green pricing programs offered in regulated electricity markets, on green power marketing activity in competitive electricity markets, and green power sold to voluntary purchasers in the form of renewable energy certificates. It also includes a discussion of key market trends and issues.

Green Power Marketing in the United States: A Status Report (Tenth Edition)

Energy Technology Data Exchange (ETDEWEB)

Bird, L.; Dagher, L.; Swezey, B.

2007-12-01

This report documents green power marketing activities and trends in the United States, focusing on consumer decisions to purchase electricity supplied from renewable energy sources and how this choice represents a powerful market support mechanism for renewable energy development. The report presents aggregate green power sales data for all voluntary purchase markets across the United States. It also provides summary data on utility green pricing programs offered in regulated electricity markets, on green power marketing activity in competitive electricity markets, and green power sold to voluntary purchasers in the form of renewable energy certificates. It also includes a discussion of key market trends and issues.

Brayton Power Conversion Unit Tested: Provides a Path to Future High-Power Electric Propulsion Missions

Science.gov (United States)

Mason, Lee S.

2003-01-01

Closed-Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. Advantages include high efficiency, long life, and high power density for power levels from about 10 kWe to 1 MWe, and beyond. An additional benefit for Brayton is the potential for the alternator to deliver very high voltage as required by the electric thrusters, minimizing the mass and power losses associated with the power management and distribution (PMAD). To accelerate Brayton technology development for NEP, the NASA Glenn Research Center is developing a low-power NEP power systems testbed that utilizes an existing 2- kWe Brayton power conversion unit (PCU) from previous solar dynamic technology efforts. The PCU includes a turboalternator, a recuperator, and a gas cooler connected by gas ducts. The rotating assembly is supported by gas foil bearings and consists of a turbine, a compressor, a thrust rotor, and an alternator on a single shaft. The alternator produces alternating-current power that is rectified to 120-V direct-current power by the PMAD unit. The NEP power systems testbed will be utilized to conduct future investigations of operational control methods, high-voltage PMAD, electric thruster interactions, and advanced heat rejection techniques. The PCU was tested in Glenn s Vacuum Facility 6. The Brayton PCU was modified from its original solar dynamic configuration by the removal of the heat receiver and retrofitting of the electrical resistance gas heater to simulate the thermal input of a steady-state nuclear source. Then, the Brayton PCU was installed in the 3-m test port of Vacuum Facility 6, as shown. A series of tests were performed between June and August of 2002 that resulted in a total PCU operational time of about 24 hr. An initial test sequence on June 17 determined that the reconfigured unit was fully operational. Ensuing tests provided the operational data needed to characterize PCU

Inspection of licensed nuclear power plants in the United States

International Nuclear Information System (INIS)

Thornburg, H. D.

1977-01-01

Inspection of licensed nuclear power plants in the United States is performed by the Office of Inspection and Enforcement (IE), United States Nuclear Regulatory Commission. IE has several key functions : a) Inspection of licensees and investigation of incidents, occurrences and allegations. b) Detection and correction of safety and security problems. c) Enforcement of rules, regulations, and Commission orders. d) Feedback to the industry and others regarding safety experience. e) Informing the public and others. Major enforcement actions and events involving operating power reactors for the past several years will be summarized. (author)

Thunderstorm Algorithm for Determining Unit Commitment in Power System Operation

Directory of Open Access Journals (Sweden)

Arif Nur Afandi

2016-12-01

Full Text Available Solving the unit commitment problem is an important task in power system operation for deciding a balanced power production between various types of generating units under technical constraints and environmental limitations. This paper presents a new intelligent computation method, called the Thunderstorm Algorithm (TA, for searching the optimal solution of the integrated economic and emission dispatch (IEED problem as the operational assessment for determining unit commitment. A simulation using the IEEE-62 bus system showed that TA has smooth convergence and is applicable for solving the IEED problem. The IEED’s solution is associated with the total fuel consumption and pollutant emission. The proposed TA method seems to be a viable new approach for finding the optimal solution of the IEED problem.

Temperature of the Gulf Stream

Science.gov (United States)

2002-01-01

The Gulf Stream is one of the strong ocean currents that carries warm water from the sunny tropics to higher latitudes. The current stretches from the Gulf of Mexico up the East Coast of the United States, departs from North America south of the Chesapeake Bay, and heads across the Atlantic to the British Isles. The water within the Gulf Stream moves at the stately pace of 4 miles per hour. Even though the current cools as the water travels thousands of miles, it remains strong enough to moderate the Northern European climate. The image above was derived from the infrared measurements of the Moderate-resolution Imaging Spectroradiometer (MODIS) on a nearly cloud-free day over the east coast of the United States. The coldest waters are shown as purple, with blue, green, yellow, and red representing progressively warmer water. Temperatures range from about 7 to 22 degrees Celsius. The core of the Gulf Stream is very apparent as the warmest water, dark red. It departs from the coast at Cape Hatteras, North Carolina. The cool, shelf water from the north entrains the warmer outflows from the Chesapeake and Delaware Bays. The north wall of the Gulf Stream reveals very complex structure associated with frontal instabilities that lead to exchanges between the Gulf Stream and inshore waters. Several clockwise-rotating warm core eddies are evident north of the core of the Gulf Stream, which enhance the exchange of heat and water between the coastal and deep ocean. Cold core eddies, which rotate counter clockwise, are seen south of the Gulf Stream. The one closest to Cape Hatteras is entraining very warm Gulf Stream waters on its northwest circumference. Near the coast, shallower waters have warmed due to solar heating, while the deeper waters offshore are markedly cooler (dark blue). MODIS made this observation on May 8, 2000, at 11:45 a.m. EDT. For more information, see the MODIS-Ocean web page. The sea surface temperature image was created at the University of Miami using

QUALITY EVALUATION OF THE TPP POWER GENERATING UNITS WEAR RECONDITIONING

Directory of Open Access Journals (Sweden)

E. M. Farhadzadeh

2016-01-01

Full Text Available Reconditioning of the power generating unit worn equipment and devices is conducted during the scheduled repair period. Quality of wear reconditioning is evaluated by technical state and repair work implementation. Quality of the repair work execution characterizes logistical activities of the power station and the repair services and is rated by a five-grade scale. There are three technical conditions: adequate, subject to reservations, falling short of the technical standard documentation requirements. In practical work these constraints give place to essential ambiguity of the decision. Further to regulating techniques by way of informational support, the authors propose conducting the wear-reconditioning quality evaluation (repair quality accordingly the technical-and-economic indexes pattern of change. The paper recommends applying similarly the fivegrade system in evaluating the power generating unit technical state and distinguishes intolerable, dissatisfactory, fair, good and model estimates. The study demonstrates the assessment criteria dependence on the character of reliability and economical efficiency of performance variation after the repair with increase or decrease of the technical-and-economic indexes in reference to their mean, minimum and maximum values before the repair. The cases ascribed to intolerable quality of the wear reconditioning are those with one or more technical-and-economic indexes that not only failed to improve their values but deteriorated, and at that they became the worst amongst observable values. The model quality estimate of the wear reconditioning is allotted under condition that the power unit technical-and-economic index valuations after the repair not merely improved but also exceeded the best among those under observation. The developed method and algorithm for quality evaluation of the scheduled repair implementation contribute to practical realization of the independent monitoring. This monitoring

Characterization of RNS multiply-add units for power efficient DSP

DEFF Research Database (Denmark)

Cardarilli, Gian Carlo; Nannarelli, Alberto; Petricca, Massimo

2015-01-01

) for a fused multiply-add unit by taking into account four metrics: area, delay, power consumption, and switching activity. The results of the DSE are verified against the TCS and RNS implementation of parallel FIR filters of different characteristics. In both the DSE and the filter implementation, we consider......In the past decades, the Residue Number System (RNS) has been adopted in DSP as an alternative to the traditional two's complement number system (TCS) because of the savings in area, higher speed and reduced power dissipation. In this work, we perform a comprehensive Design Space Exploration (DSE...... two design corners: maximum speed and minimum area. The experimental results demonstrate that for high data rates and high order filters, the RNS implementation is more power efficient than the TCS because of the reduced switching activity and the larger amount of low-power cells placed in the unit....

Securing the United States' power infrastructure

Energy Technology Data Exchange (ETDEWEB)

Happenny, Sean F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-08-01

The United States’ power infrastructure is aging, underfunded, and vulnerable to cyber attack. Emerging smart grid technologies may take some of the burden off of existing systems and make the grid as a whole more efficient, reliable, and secure. The Pacific Northwest National Laboratory (PNNL) is funding research into several aspects of smart grid technology and grid security, creating a software simulation tool that will allow researchers to test power distribution networks utilizing different smart grid technologies to determine how the grid and these technologies react under different circumstances. Demonstrating security in embedded systems is another research area PNNL is tackling. Many of the systems controlling the U.S. critical infrastructure, such as the power grid, lack integrated security and the networks protecting them are becoming easier to breach. Providing a virtual power substation network to each student team at the National Collegiate Cyber Defense Competition, thereby supporting the education of future cyber security professionals, is another way PNNL is helping to strengthen the security of the nation’s power infrastructure.

Proposal for the Award of a Contract for the Supply of the Power Units for LHC Thyristor Power Converters

CERN Document Server

2003-01-01

This document concerns the award of a contract for the supply of 12 power units of thyristor power converters rated from 365 to 770 kW for the LHC. Following a market survey carried out among 98 firms in nineteen Member States, a call for tenders (IT-3003/SL/LHC) was sent on 25 October 2002 to six firms in four Member States. By the closing date, CERN had received five tenders from five firms in four Member States. The Finance Committee is invited to agree to the negotiation of a contract with OCEM (IT), the lowest bidder, for the supply of 12 power units of thyristor power converters for a total amount of 981 484 Swiss francs not subject to revision, with options for three additional units of the power part of thyristor power converters, for an additional amount of 249 681 Swiss francs, subject to revision for inflation from 1 August 2006, bringing the total amount to 1 231 165 Swiss francs. The firm has indicated the following distribution by country of the contract value covered by this adjudication propos...

Transport of RFID tracers in a glacierized Andean stream (Estero Morales, Chile)

Science.gov (United States)

Rainato, Riccardo; Toro, Matteo; Mao, Luca; Fraccarollo, Luigi; Brardinoni, Francesco; Aristide Lenzi, Mario

2015-04-01

A proper quantification of bedload transport is crucial in order to improve the knowledge on the morphology and dynamics of river systems. Unfortunately, bedload surveys in mountain streams are notoriously difficult. Also, equations for predicting the transport capacity often overestimate the actual bedload rates, and field measurement are still rare. An alternative to direct bedload sampling during floods is the use of tracers, which allow to obtain precious data on sediment dynamic and transport due to different conditions of hydraulic forcing, especially in mountain streams. In this work, the results obtained by the employment of passive RFID tracers in a steep Andean channel are presented. The study site is the Estero Morales, a high-gradient stream located in the Metropolitan Region (central Chile). The channel bed exhibits boulder-cascade, step-pool and plane bed morphologies while the average slope is of about 9.5%. The basin (27 km2) hosts the San Francisco glacier (1.8 km2) that strongly affects the hydrological regime. In particular during the melt period (December-March) the glacier ensures daily discharge fluctuations with highly variable associated bedload transport rates. Overall, 429 RFID tracers were installed in the Estero Morales and the displacements over a reach of approximately 700 m were monitored through 15 surveys, performed between January and March 2014. The recovery rate ranges between 19% and 97%. Tracers travel distance were paired to the peaks of stream power per unit area (ω, in W/m2) that occurred during the study period. Due to the wide range of flow magnitude observed, the values of stream power were grouped in three classes: low (650-750 W/m2), moderate (750-800 W/m2), and high (800-900 W/m2). Despite the different conditions of hydraulic forcing, moderate and low classes show mean displacement very similar, equal to 33 m and 24 m, respectively. In either cases a size selective transport was observed. On the other hand, the high

Improved control system power unit for large parachutes

Science.gov (United States)

Chandler, J. A.; Grubbs, T. M.

1968-01-01

Improved control system power unit drives the control surfaces of very large controllable parachutes. The design features subassemblies for determining control surface position and cable loading, and protection of the load sensor against the possibility of damage during manipulation.

Green Power Marketing in the United States. A Status Report (11th Edition)

Energy Technology Data Exchange (ETDEWEB)

Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kreycik, Claire [National Renewable Energy Lab. (NREL), Golden, CO (United States); Friedman, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2008-10-01

This report documents green power marketing activities and trends in the United States. It presents aggregate green power sales data for all voluntary purchase markets across the United States. It also provides summary data on utility green pricing programs offered in regulated electricity markets and green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of renewable energy certificates. Key market trends and issues are also discussed.

Green Power Marketing in the United States: A Status Report (11th Edition)

Energy Technology Data Exchange (ETDEWEB)

Bird, L.; Kreycik, C.; Friedman, B.

2008-10-01

This report documents green power marketing activities and trends in the United States. It presents aggregate green power sales data for all voluntary purchase markets across the United States. It also provides summary data on utility green pricing programs offered in regulated electricity markets and green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of renewable energy certificates. Key market trends and issues are also discussed.

Teachers Environmental Resource Unit: Energy and Power.

Science.gov (United States)

Bemiss, Clair W.

Problems associated with energy production and power are studied in this teacher's guide to better understand the impact of man's energy production on the environment, how he consumes energy, and in what quantities. The resource unit is intended to provide the teacher with basic information that will aid classroom review of these problems. Topics…

Jet Noise Scaling in Dual Stream Nozzles

Science.gov (United States)

Khavaran, Abbas; Bridges, James

2010-01-01

Power spectral laws in dual stream jets are studied by considering such flows a superposition of appropriate single-stream coaxial jets. Noise generation in each mixing region is modeled using spectral power laws developed earlier for single stream jets as a function of jet temperature and observer angle. Similarity arguments indicate that jet noise in dual stream nozzles may be considered as a composite of four single stream jets representing primary/secondary, secondary/ambient, transition, and fully mixed zones. Frequency filter are designed to highlight spectral contribution from each jet. Predictions are provided at an area ratio of 2.0--bypass ratio from 0.80 to 3.40, and are compared with measurements within a wide range of velocity and temperature ratios. These models suggest that the low frequency noise in unheated jets is dominated by the fully mixed region at all velocity ratios, while the high frequency noise is dominated by the secondary when the velocity ratio is larger than 0.80. Transition and fully mixed jets equally dominate the low frequency noise in heated jets. At velocity ratios less than 0.50, the high frequency noise from primary/bypass becomes a significant contributing factor similar to that in the secondary/ambient jet.

Abstractions for aperiodic multiprocessor scheduling of real-time stream processing applications

NARCIS (Netherlands)

Hausmans, J.P.H.M.

2015-01-01

Embedded multiprocessor systems are often used in the domain of real-time stream processing applications to keep up with increasing power and performance requirements. Examples of such real-time stream processing applications are digital radio baseband processing and WLAN transceivers. These stream

A study of the public opinion concerning nuclear power generation in the United States

International Nuclear Information System (INIS)

Oiso, Shinichi

2008-01-01

In this study, I surveyed the outcome of opinion poll about people's attitude toward nuclear power and analysed their awareness of nuclear power generation in the United States. As a result, it was found that percentage of the people who have positive attitude toward nuclear power has been over 60% since 1998. This result corresponds to the fact that people's preference is tending more toward nuclear power generation which is called the nuclear power Renaissance in the United States. Furthermore, analysis of the outcome of the opinion poll in power stations site region was also conducted and it was found that attitude of the people in the site region was more positive than that of average level in the United States. (author)

Requirements under decree 430 UJD for unit outlet and standby power supply

International Nuclear Information System (INIS)

Vanco, K.

2012-01-01

At present, the nuclear power plants are only sufficient resources, which can cover a huge demand for electricity. Concentration so huge power in one place require adequate security from the perspective lead power outlet and standby power supply of reactor unit. (Author)

Optimization models of the supply of power structures’ organizational units with centralized procurement

Directory of Open Access Journals (Sweden)

Sysoiev Volodymyr

2013-01-01

Full Text Available Management of the state power structures’ organizational units for materiel and technical support requires the use of effective tools for supporting decisions, due to the complexity, interdependence, and dynamism of supply in the market economy. The corporate nature of power structures is of particular interest to centralized procurement management, as it provides significant advantages through coordination, eliminating duplication, and economy of scale. This article presents optimization models of the supply of state power structures’ organizational units with centralized procurement, for different levels of simulated materiel and technical support processes. The models allow us to find the most profitable options for state power structures’ organizational supply units in a centre-oriented logistics system in conditions of the changing needs, volume of allocated funds, and logistics costs that accompany the process of supply, by maximizing the provision level of organizational units with necessary material and technical resources for the entire planning period of supply by minimizing the total logistical costs, taking into account the diverse nature and the different priorities of organizational units and material and technical resources.

Revitalization of Tuzla Thermal Power Plant's Unit 3 (100 MW)

International Nuclear Information System (INIS)

Sakovic, A.; Praso, N.

1998-01-01

Power Plant Revitalization is a highly ranged concept essentially aimed at continued operations of the generating unit at, or near, rated capacities for the rest of the economic life of the plant or even for an extended life. In essence, the need to rehabilitate may arise due to reasons such as low availability factor, low efficiency, increasing operating and maintenance costs, loss of reliability, drop in safety of plant and personnel, poor maintainability or environmental requirements. The term revitalization is therefore normally used in the context to cover the range of activities including repairing components, replacing equipment, modifying systems, adding new system and equipment and perhaps restoration to rated capacities. This exercise on already complex power generation process will naturally require the application of various technologies in order to ensure a safe and efficient installation of electricity supply. In normal conditions of producing and consumption of electricity (load demands) in order to answer the question of what kind of revitalization to undertake it is necessary to state at the very beginning: - whether it is necessary, from the point of equipment wear-out, to revitalize all equipment at once (one-phase revitalization), or - whether it is possible to postpone the revitalization of a part of equipment for the next period (phased revitalization). Both concepts have some specific advantages and disadvantages. In essence the decision-making process between these two approaches, three basic conditions should be considered: technical-technological adequacy, energy-economy adequacy and financial adequacy. This paper covers general considerations, approach and methodology implemented during the revitalization the Tuzla Thermal Power Plant's Unit 3 (100MW) which was imposed by urgent demands of the Power System, the war conditions and financial possibilities including: - General data on TPP Tuzla and Unit 3 - Scope of work and economic effects

Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

DEFF Research Database (Denmark)

Jansson, Michael

This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

A simple metric to predict stream water quality from storm runoff in an urban watershed.

Science.gov (United States)

Easton, Zachary M; Sullivan, Patrick J; Walter, M Todd; Fuka, Daniel R; Petrovic, A Martin; Steenhuis, Tammo S

2010-01-01

The contribution of runoff from various land uses to stream channels in a watershed is often speculated and used to underpin many model predictions. However, these contributions, often based on little or no measurements in the watershed, fail to appropriately consider the influence of the hydrologic location of a particular landscape unit in relation to the stream network. A simple model was developed to predict storm runoff and the phosphorus (P) status of a perennial stream in an urban watershed in New York State using the covariance structure of runoff from different landscape units in the watershed to predict runoff in time. One hundred and twenty-seven storm events were divided into parameterization (n = 85) and forecasting (n = 42) data sets. Runoff, dissolved P (DP), and total P (TP) were measured at nine sites distributed among three land uses (high maintenance, unmaintained, wooded), three positions in the watershed (near the outlet, midwatershed, upper watershed), and in the stream at the watershed outlet. The autocorrelation among runoff and P concentrations from the watershed landscape units (n = 9) and the covariance between measurements from the landscape units and measurements from the stream were calculated and used to predict the stream response. Models, validated using leave-one-out cross-validation and a forecasting method, were able to correctly capture temporal trends in streamflow and stream P chemistry (Nash-Sutcliffe efficiencies, 0.49-0.88). The analysis suggests that the covariance structure was consistent for all models, indicating that the physical processes governing runoff and P loss from these landscape units were stationary in time and that landscapes located in hydraulically active areas have a direct hydraulic link to the stream. This methodology provides insight into the impact of various urban landscape units on stream water quantity and quality.

Analysis of the Opportunity for an Increase in the Thermal Power of Power Generating Units of Nuclear Power Plants (Part 1)

OpenAIRE

Chernousenko, Olga Yuriivna; Nikulenkova, Tetiana Volodymyrivna; Nikulenkov, Anatolii Hennadiiovych

2017-01-01

For Ukraine the realization of available reserves to increase the power of operating power units of nuclear plants is a vital problem the solution of which would allow us to increase electric power output. A special role is also played by economic priorities; in particular an increase in power by 1 kW is ten times cheaper in comparison with the construction of 1 kW of new power facilities. One more factor is the world experience in the field of an increase in the thermal power of operating po...

Fission Surface Power Technology Demonstration Unit Test Results

Science.gov (United States)

Briggs, Maxwell H.; Gibson, Marc A.; Geng, Steven M.; Sanzi, James L.

2016-01-01

The Fission Surface Power (FSP) Technology Demonstration Unit (TDU) is a system-level demonstration of fission power technology intended for use on manned missions to Mars. The Baseline FSP systems consists of a 190 kWt UO2 fast-spectrum reactor cooled by a primary pumped liquid metal loop. This liquid metal loop transfers heat to two intermediate liquid metal loops designed to isolate fission products in the primary loop from the balance of plant. The intermediate liquid metal loops transfer heat to four Stirling Power Conversion Units (PCU), each of which produce 12 kWe (48 kW total) and reject waste heat to two pumped water loops, which transfer the waste heat to titanium-water heat pipe radiators. The FSP TDU simulates a single leg of the baseline FSP system using an electrically heater core simulator, a single liquid metal loop, a single PCU, and a pumped water loop which rejects the waste heat to a Facility Cooling System (FCS). When operated at the nominal operating conditions (modified for low liquid metal flow) during TDU testing the PCU produced 8.9 kW of power at an efficiency of 21.7 percent resulting in a net system power of 8.1 kW and a system level efficiency of 17.2 percent. The reduction in PCU power from levels seen during electrically heated testing is the result of insufficient heat transfer from the NaK heater head to the Stirling acceptor, which could not be tested at Sunpower prior to delivery to the NASA Glenn Research Center (GRC). The maximum PCU power of 10.4 kW was achieved at the maximum liquid metal temperature of 875 K, minimum water temperature of 350 K, 1.1 kg/s liquid metal flow, 0.39 kg/s water flow, and 15.0 mm amplitude at an efficiency of 23.3 percent. This resulted in a system net power of 9.7 kW and a system efficiency of 18.7 percent.

Modeling and simulation of the power demand and supply of a hydrothermal power generating system

International Nuclear Information System (INIS)

Pronini, R.A.

1996-01-01

Security of supply of electric energy is measured by the capacity to cover the energy demand and power of a supply grid. This coverage is important because the winter peak load period in Switzerland will become problematical in the near future. The objective of this research project is to analyze the ability of a power generating system to satisfy the power requirements of the corresponding supply network. The behaviour of the energy system in critical cases (loss of the largest generator, lack of available power from an external supplier or reduced capacity for energy storage) is tested for the present situation and for the rise in the annual load. The simulation of the load of the supply network is carried out by using a model developed for this project. This model is based on the analysis of half-hourly changes of load and on the statistical maximum values. The power generating system consists of nuclear generating units, hydro units with large reservoirs, run of the river installations and imported energy. Standby units such as gas turbines, spot market and coal-fired power stations are also available. Stochastic and deterministic energy and power models have been developed for the various power stations of the hydrothermal power system. In the case of nuclear power stations, a model has been developed on the basis of the output level, production losses and time and length of outages. The possible feeder streams of the run of the river installations and of the hydro units with a large reservoir are simulated using stochastic methods based on the historical values of the last 35 years. The commitment of the hydro units depends on the peak load requirements. The load and capacity over a period of several days and weeks have been simulated with stochastic models based on the Monte Carlo method and constantly (by half hour intervals) compared. In this manner each month can be simulated. (author) figs., tabs., 46 refs

Effects of the accident at Mihama Nuclear Power Plant Unit 3 on the public's attitude to nuclear power generation

International Nuclear Information System (INIS)

Kitada, Atsuko

2005-01-01

As part of an ongoing public opinion survey regarding nuclear power generation, which started in 1993, a survey was carried out in the Kansai and Kanto regions two months after the accident at Unit 3 of the Mihama Nuclear Power Plant. In addition to analyzing the statistically significant changes that have taken place since the previous survey (taken in 2003), increase and decrease of the ratio of answers to all the questions related to nuclear power before and after the two accidents were compared in the case of the accidents which occurred in the Mihama Unit 3 and the JCO company's nuclear-fuel plant. In the Kansai region, a feeling of uneasiness about the risky character of nuclear power generation increased to some extent, while the public's trust in the safety of nuclear power plants decreased somewhat. After a safety-related explanation on ''Early detection of troubles'' and Accident prevention'' was given from a managerial standpoint, people felt a little less at ease than they had before. Uneasiness, however, did not increase in relation to the overall safety explanation given about the engineering and technical functioning of the plant. There was no significant negative effect on the respondents' evaluation of or attitude toward nuclear power generation. It was found that the people's awareness about the Mihama Unit 3 accident was lower and the effect of the accident on their awareness of nuclear power generation was more limited and smaller when compared with the case of the JCO accident. In the Kanto region, people knew less about the Mihama Unit 3 accident than those living in the Kansai region, and they remembered the JCO accident, the subsequent cover-up by Tokyo Electric Power Company, and the resulting power shortage better than those living in Kansai. This suggested that there was a little difference in terms of psychological distance in relation to the accidents an incidents depending on the place where the events occurred and the company which

Knowledge acquisition for nuclear power plant unit diagnostic system

International Nuclear Information System (INIS)

Li Xiaodong; Xi Shuren

2003-01-01

The process of acquiring knowledge and building a knowledge base is critical to realize fault diagnostic system at unit level in a nuclear power plant. It directly determines whether the diagnostic system can be applied eventually in a commercial plant. A means to acquire knowledge and its procedures was presented in this paper for fault diagnostic system in a nuclear power plant. The work can be carried out step by step and it is feasible in a commercial nuclear power plant. The knowledge base of the fault diagnostic system for a nuclear power plant can be built after the staff finish the tasks according to the framework presented in this paper

Application of CFB technology for large power generating units and CO2 capture

International Nuclear Information System (INIS)

Ryabov, G. A.; Folomeev, O. M.; Sankin, D. A.; Khaneev, K. V.; Bondarenko, I. G.; Mel'nikov, D. A.

2010-01-01

Data on the development of the circulating fluidized bed (CFB) technology for combustion of fuels in large power generating units are examined. The problems with raising the steam parameters and unit power of boilers with a circulating fluidized bed are examined. With the boiler system at the 460 MW unit at Lagisza (Poland) as an example, the feasibility of raising the efficiency of units with CFB boilers through deep recovery of the heat of the effluent gases and reducing expenditure for in-house needs is demonstrated. Comparative estimates of the capital and operating costs of 225 and 330 MW units are used to determine the conditions for optimum use of CFB boilers in the engineering renovation of thermal power plants in Russia. New areas for the application of CFB technology in CO 2 capture are analyzed in connection with the problem of reducing greenhouse gas emissions.

Linking Stream Dissolved Oxygen with the Dynamic Environmental Drivers across the Pacific Coast of U.S.A.

Science.gov (United States)

Araya, F. Z.; Abdul-Aziz, O. I.

2017-12-01

This study utilized a systematic data analytics approach to determine the relative linkages of stream dissolved oxygen (DO) with the hydro-climatic and biogeochemical drivers across the U.S. Pacific Coast. Multivariate statistical techniques of Pearson correlation matrix, principal component analysis, and factor analysis were applied to a complex water quality dataset (1998-2015) at 35 water quality monitoring stations of USGS NWIS and EPA STORET. Power-law based partial least squares regression (PLSR) models with a bootstrap Monte Carlo procedure (1000 iterations) were developed to reliably estimate the relative linkages by resolving multicollinearity (Nash-Sutcliffe Efficiency, NSE = 0.50-0.94). Based on the dominant drivers, four environmental regimes have been identified and adequately described the system-data variances. In Pacific North West and Southern California, water temperature was the most dominant driver of DO in majority of the streams. However, in Central and Northern California, stream DO was controlled by multiple drivers (i.e., water temperature, pH, stream flow, and total phosphorus), exhibiting a transitional environmental regime. Further, total phosphorus (TP) appeared to be the limiting nutrient for most streams. The estimated linkages and insights would be useful to identify management priorities to achieve healthy coastal stream ecosystems across the Pacific Coast of U.S.A. and similar regions around the world. Keywords: Data analytics, water quality, coastal streams, dissolved oxygen, environmental regimes, Pacific Coast, United States.

Stream II-V5: Revision Of Stream II-V4 To Account For The Effects Of Rainfall Events

International Nuclear Information System (INIS)

Chen, K.

2010-01-01

STREAM II-V4 is the aqueous transport module currently used by the Savannah River Site emergency response Weather Information Display (WIND) system. The transport model of the Water Quality Analysis Simulation Program (WASP) was used by STREAM II to perform contaminant transport calculations. WASP5 is a US Environmental Protection Agency (EPA) water quality analysis program that simulates contaminant transport and fate through surface water. STREAM II-V4 predicts peak concentration and peak concentration arrival time at downstream locations for releases from the SRS facilities to the Savannah River. The input flows for STREAM II-V4 are derived from the historical flow records measured by the United States Geological Survey (USGS). The stream flow for STREAM II-V4 is fixed and the flow only varies with the month in which the releases are taking place. Therefore, the effects of flow surge due to a severe storm are not accounted for by STREAM II-V4. STREAM II-V4 has been revised to account for the effects of a storm event. The steps used in this method are: (1) generate rainfall hyetographs as a function of total rainfall in inches (or millimeters) and rainfall duration in hours; (2) generate watershed runoff flow based on the rainfall hyetographs from step 1; (3) calculate the variation of stream segment volume (cross section) as a function of flow from step 2; (4) implement the results from steps 2 and 3 into the STREAM II model. The revised model (STREAM II-V5) will find the proper stream inlet flow based on the total rainfall and rainfall duration as input by the user. STREAM II-V5 adjusts the stream segment volumes (cross sections) based on the stream inlet flow. The rainfall based stream flow and the adjusted stream segment volumes are then used for contaminant transport calculations.

Evaluation of the performance of combined cooling, heating, and power systems with dual power generation units

International Nuclear Information System (INIS)

Knizley, Alta A.; Mago, Pedro J.; Smith, Amanda D.

2014-01-01

The benefits of using a combined cooling, heating, and power system with dual power generation units (D-CCHP) is examined in nine different U.S. locations. One power generation unit (PGU) is operated at base load while the other is operated following the electric load. The waste heat from both PGUs is used for heating and for cooling via an absorption chiller. The D-CCHP configuration is studied for a restaurant benchmark building, and its performance is quantified in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE). Cost spark spread, PEC spark spread, and CDE spark spread are examined as performance indicators for the D-CCHP system. D-CCHP system performance correlates well with spark spreads, with higher spark spreads signifying greater savings through implementation of a D-CCHP system. A new parameter, thermal difference, is introduced to investigate the relative performance of a D-CCHP system compared to a dual PGU combined heat and power system (D-CHP). Thermal difference, together with spark spread, can explain the variation in savings of a D-CCHP system over a D-CHP system for each location. The effect of carbon credits on operational cost savings with respect to the reference case is shown for selected locations. - Highlights: • We investigate benefits from using combined cooling, heating, and power systems. • A dual power generation unit configuration is considered for CCHP and CHP. • Spark spreads for cost, energy, and emissions correlate with potential savings. • Thermal difference parameter helps to explain variations in potential savings. • Carbon credits may increase cost savings where emissions savings are possible

Benthic algae of benchmark streams in agricultural areas of eastern Wisconsin

Science.gov (United States)

Scudder, Barbara C.; Stewart, Jana S.

2001-01-01

Benthic algae were collected from 20 streams in the Western Lake Michigan Drainages by the U.S. Geological Survey in May and June of 1993 as part of the National Water-Quality Assessment program. These streams were selected to represent "benchmark" streams that were minimally affected by human activities, especially agriculture, for comparison to other streams in similar environmental settings. Streams were chosen from four relatively homogeneous units (RHU's) in agricultural areas with differing texture of surficial deposits and bedrock type.

Subsequent flue gas desulfurization of coal-fired power plant units

International Nuclear Information System (INIS)

Willibal, U.; Braun, Gy.

1998-01-01

The presently operating coal-fired power plant in Hungary do not satisfy the pollution criteria prescribed by the European Union norms. The main polluting agent is the sulfur dioxide emitted by some of the power plants in Hungary in quantities over the limit standards. The power plant units that are in good operating state could be made competitive by using subsequent desulfurization measures. Various flue gas desulfurization technologies are presented through examples that can be applied to existing coal-fired power plants. (R.P.)

EFFECTS OF STREAM RESTORATION ON DENITRIFICATION In AN URBANIZING WATERSHED

Science.gov (United States)

Increased delivery of nitrogen due to urbanization and stream ecosystem degradation is contributing to eutrophication in coastal regions of the eastern United States. We tested whether geomorphic restoration involving hydrologic “reconnection” of a stream to its floodplain could ...

77 FR 29701 - Impact of Construction (Under a Combined License) of New Nuclear Power Plant Units on Operating...

Science.gov (United States)

2012-05-18

... New Nuclear Power Plant Units on Operating Units at Multi-Unit Sites AGENCY: Nuclear Regulatory... construct and operate new nuclear power plants (NPPs) on multi-unit sites to provide an evaluation of the... License) of New Nuclear Power Plants on Operating Units at Multi-Unit Sites (Package). ML112630039 Federal...

Stream Tracker: Crowd sourcing and remote sensing to monitor stream flow intermittence

Science.gov (United States)

Puntenney, K.; Kampf, S. K.; Newman, G.; Lefsky, M. A.; Weber, R.; Gerlich, J.

2017-12-01

Streams that do not flow continuously in time and space support diverse aquatic life and can be critical contributors to downstream water supply. However, these intermittent streams are rarely monitored and poorly mapped. Stream Tracker is a community powered stream monitoring project that pairs citizen contributed observations of streamflow presence or absence with a network of streamflow sensors and remotely sensed data from satellites to track when and where water is flowing in intermittent stream channels. Citizens can visit sites on roads and trails to track flow and contribute their observations to the project site hosted by CitSci.org. Data can be entered using either a mobile application with offline capabilities or an online data entry portal. The sensor network provides a consistent record of streamflow and flow presence/absence across a range of elevations and drainage areas. Capacitance, resistance, and laser sensors have been deployed to determine the most reliable, low cost sensor that could be mass distributed to track streamflow intermittence over a larger number of sites. Streamflow presence or absence observations from the citizen and sensor networks are then compared to satellite imagery to improve flow detection algorithms using remotely sensed data from Landsat. In the first two months of this project, 1,287 observations have been made at 241 sites by 24 project members across northern and western Colorado.

Electrical Power Generated from Tidal Currents and Delivered to USCG Station Eastport, ME

Science.gov (United States)

2011-01-21

35 Theory of Operation The ORPC Pre-Commercial Beta Turbine Generator Unit (“Beta TGU”) uses a hydrokinetic cross flow turbine based on Darrieus ...development in the wind turbine industry. The power coefficient (a measure of energy extraction effectiveness) is defined as follows: 31 2 turbine ...stream area of the device. Axial flow wind turbines have demonstrated power coefficients to an estimated 48% which approaches the theoretical “Betz

Hidden power system inflexibilities imposed by traditional unit commitment formulations

International Nuclear Information System (INIS)

Morales-España, Germán; Ramírez-Elizondo, Laura; Hobbs, Benjamin F.

2017-01-01

Highlights: • Quality and accuracy of traditional-energy- and power-based UCs are evaluated. • Real-time performance evaluation simulating “perfect” stochastic UCs. • Ideal energy-based stochastic UC formulations impose hidden system inflexibilities. • A deterministic power-based UC may outperform an ideal energy-based stochastic UC. • Power-based UC overcomes flaws of energy-based UC: lower cost and wind curtailment. - Abstract: Approximations made in traditional day-ahead unit commitment model formulations can result in suboptimal or even infeasible schedules for slow-start units and inaccurate predictions of actual costs and wind curtailment. With increasing wind penetration, these errors will become economically more significant. Here, we consider inaccuracies from three approximations: the use of hourly intervals in which energy production from each generator is modeled as being constant; the disregarding of startup and shutdown energy trajectories; and optimization based on expected wind profiles. The results of unit commitment formulations with those assumptions are compared to models that: (1) use a piecewise-linear power profiles of generation, load and wind, instead of the traditional stepwise energy profiles; (2) consider startup/shutdown trajectories; and (3) include many possible wind trajectories in a stochastic framework. The day-ahead hourly schedules of slow-start generators are then evaluated against actual wind and load profiles using a model real-time dispatch and quick-start unit commitment with a 5 min time step. We find that each simplification usually causes expected generation costs to increase by several percentage points, and results in significant understatement of expected wind curtailment and, in some cases, load interruptions. The inclusion of startup and shutdown trajectories often yielded the largest improvements in schedule performance.

Pilgrim Nuclear Power Station, Unit 1. Annual operating report for 1976

International Nuclear Information System (INIS)

Net electrical power generated was 2,415,511 MWH with the generator on line 5,333.6 hrs. Information is presented concerning operations, procedure changes, tests, experiments, maintenance, unit shutdowns and power reductions, and radiation doses to personnel

Factoring stream turbulence into global assessments of nitrogen pollution.

Science.gov (United States)

Grant, Stanley B; Azizian, Morvarid; Cook, Perran; Boano, Fulvio; Rippy, Megan A

2018-03-16

The discharge of excess nitrogen to streams and rivers poses an existential threat to both humans and ecosystems. A seminal study of headwater streams across the United States concluded that in-stream removal of nitrate is controlled primarily by stream chemistry and biology. Reanalysis of these data reveals that stream turbulence (in particular, turbulent mass transfer across the concentration boundary layer) imposes a previously unrecognized upper limit on the rate at which nitrate is removed from streams. The upper limit closely approximates measured nitrate removal rates in streams with low concentrations of this pollutant, a discovery that should inform stream restoration designs and efforts to assess the effects of nitrogen pollution on receiving water quality and the global nitrogen cycle. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Silicon-Carbide Power MOSFET Performance in High Efficiency Boost Power Processing Unit for Extreme Environments

Science.gov (United States)

Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Del Castillo, Linda Y.; Fitzpatrick, Fred; Chen, Yuan

2016-01-01

Silicon-Carbide device technology has generated much interest in recent years. With superior thermal performance, power ratings and potential switching frequencies over its Silicon counterpart, Silicon-Carbide offers a greater possibility for high powered switching applications in extreme environment. In particular, Silicon-Carbide Metal-Oxide- Semiconductor Field-Effect Transistors' (MOSFETs) maturing process technology has produced a plethora of commercially available power dense, low on-state resistance devices capable of switching at high frequencies. A novel hard-switched power processing unit (PPU) is implemented utilizing Silicon-Carbide power devices. Accelerated life data is captured and assessed in conjunction with a damage accumulation model of gate oxide and drain-source junction lifetime to evaluate potential system performance at high temperature environments.

Temporal Segmentation of MPEG Video Streams

Directory of Open Access Journals (Sweden)

Janko Calic

2002-06-01

Full Text Available Many algorithms for temporal video partitioning rely on the analysis of uncompressed video features. Since the information relevant to the partitioning process can be extracted directly from the MPEG compressed stream, higher efficiency can be achieved utilizing information from the MPEG compressed domain. This paper introduces a real-time algorithm for scene change detection that analyses the statistics of the macroblock features extracted directly from the MPEG stream. A method for extraction of the continuous frame difference that transforms the 3D video stream into a 1D curve is presented. This transform is then further employed to extract temporal units within the analysed video sequence. Results of computer simulations are reported.

Contingency-Constrained Unit Commitmentin Meshed Isolated Power Systems

DEFF Research Database (Denmark)

Sokoler, Leo Emil; Vinter, Peter; Bærentsen, Runi

2015-01-01

is kept above a predefined limit in the event of a contingency. The minimum frequency constraints are formulated using novel sufficient conditions that take into account the system inertia and the dynamics of the power generators. The proposed sufficient conditions are attractive from both a computational...... and a modelling point of view. We compare the ORPP to a unit commitment problem that only considers the stationary behavior of the frequency. Simulations based on a Faroe Islands case study show that, without being overly conservative, potential blackouts and power outages can be avoided using the ORPP...

Design study on the efficiency of the thermal scheme of power unit of thermal power plants in hot climates

Science.gov (United States)

Sedlov, A.; Dorokhov, Y.; Rybakov, B.; Nenashev, A.

2017-11-01

At the stage of pre-proposals unit of the thermal power plants for regions with a hot climate requires a design study on the efficiency of possible options for the structure of the thermal circuit and a set of key parameters. In this paper, the thermal circuit of the condensing unit powerfully 350 MW. The main feature of the external conditions of thermal power plants in hot climates is the elevated temperature of cooling water of the turbine condensers. For example, in the Persian Gulf region as the cooling water is sea water. In the hot season of the year weighted average sea water temperature of 30.9 °C and during the cold season to 22.8 °C. From the turbine part of the steam is supplied to the distillation-desalination plant. In the hot season of the year heat scheme with pressure fresh pair of 23.54 MPa, temperature 570/560 °C and feed pump with electric drive (EDP) is characterized by a efficiency net of 0.25% higher than thermal schem with feed turbine pump (TDP). However, the supplied power unit with PED is less by 11.6 MW. Calculations of thermal schemes in all seasons of the year allowed us to determine the difference in the profit margin of units of the TDP and EDP. During the year the unit with the TDP provides the ability to obtain the profit margin by 1.55 million dollars more than the unit EDP. When using on the market subsidized price of electricity (Iran) marginal profit of a unit with TDP more at 7.25 million dollars.

Simulator of nuclear power plant with WWER-440 units

International Nuclear Information System (INIS)

Krcek, V.

1985-01-01

The use is discussed of simulators in the training of qualified personnel for the construction and operation of nuclear power plants. Simulators are used for training all activities and thinking processes related to the control of a nuclear reactor in the course of quasi-steady and non-steady states. The development and implementation is summed up of the construction of such a simulator for WWER-440 nuclear power plants. The main parts of the simulator include the unit control room, the computer system, the teacher's workplace and the interface system. The possibility of simulating the functions of the unit for personnel training is based on the description of the behaviour of the simulated object in form of mathematical models of its basic technological subsystems and their interrelations within the range of operating patterns. (J.C.)

Modeling and Optimization of the Medium-Term Units Commitment of Thermal Power

Directory of Open Access Journals (Sweden)

Shengli Liao

2015-11-01

Full Text Available Coal-fired thermal power plants, which represent the largest proportion of China’s electric power system, are very sluggish in responding to power system load demands. Thus, a reasonable and feasible scheme for the medium-term optimal commitment of thermal units (MOCTU can ensure that the generation process runs smoothly and minimizes the start-up and shut-down times of thermal units. In this paper, based on the real-world and practical demands of power dispatch centers in China, a flexible mathematical model for MOCTU that uses equal utilization hours for the installed capacity of all thermal power plants as the optimization goal and that considers the award hours for MOCTU is developed. MOCTU is a unit commitment (UC problem with characteristics of large-scale, high dimensions and nonlinearity. For optimization, an improved progressive optimality algorithm (IPOA offering the advantages of POA is adopted to overcome the drawback of POA of easily falling into the local optima. In the optimization process, strategies of system operating capacity equalization and single station operating peak combination are introduced to move the target solution from the boundary constraints along the target isopleths into the feasible solution’s interior to guarantee the global optima. The results of a case study consisting of nine thermal power plants with 27 units show that the presented algorithm can obtain an optimal solution and is competent in solving the MOCTU with high efficiency and accuracy as well as that the developed simulation model can be applied to practical engineering needs.

Work plan for determining the occurrence of glyphosate, its transformation product AMPA, other herbicide compounds, and antibiotics in midwestern United States streams, 2002

Science.gov (United States)

Battaglin, W.A.; Thurman, E.M.; Kolpin, D.W.; Scribner, E.A.; Sandstrom, M.W.; Kuivila, K.M.

2003-01-01

Changes in herbicide use in the Midwestern United States have been substantial over the last 5 years. Most significant is a tripling in the use of glyphosate (N-[phosphonomethyl]glycin). Over this same time period (1997­2001), atrazine use increased by 20 percent and acetochlor use increased by 10 percent, while cyanazine use decreased by 99 percent, alachlor use decreased by 70 percent, and metolachlor use decreased by 55 percent. Previous studies have documented that herbicide flushes occur in midwestern streams during runoff events for several weeks to several months following application, and that herbicide concentrations in midwestern streams during flushing events are related to rates of herbicide use.

Experience in lifetime extension of the first generation WWER-440 power units

International Nuclear Information System (INIS)

Medvedev, P.

2002-01-01

In connection with the expiration of the lifetime for the first generation WWER-440 reactors in Russian Federation (Novo Voronezh and Kola NPP), the legal procedures and Life Time Extension (LTE) Program are discussed. The LTE Program includes: development of regulation basis; economic efficiency studies; power unit modernization; power unit comprehensive examination and justification od equipment resource; in-dept safety assessment; operational license acquisition. As a result from the LTE Program the safety level of the unit 3 of the Novo Voronezh NPP is significantly increases, the operational period has been justified and a 5-year license has been issued

Large-Scale Combined Heat and Power (CHP) Generation at Loviisa Nuclear Power Plant Unit 3

International Nuclear Information System (INIS)

Bergroth, N.

2010-01-01

Fortum has applied for a Decision in Principle concerning the construction of a new nuclear power plant unit (Loviisa 3) ranging from 2800-4600 MWth at its site located at the southern coast of Finland. An attractive alternative investigated is a co-generation plant designed for large-scale district heat generation for the Helsinki metropolitan area that is located approximately 75 km west of the site. The starting point is that the district heat generation capacity of 3 unit would be around 1 000 MWth.The possibility of generating district heat for the metropolitan area by Loviisa's two existing nuclear power plant units was investigated back in the 1980s, but it proved unpractical at the time. With the growing concern of the climate change and the subsequent requirements on heat and power generation, the idea is much more attractive today, when recognising its potential to decrease Finland's carbon dioxide emissions significantly. Currently the district heat generation in metropolitan area is based on coal and natural gas, producing some five to seven million tonnes of carbon dioxide emissions annually. Large-scale combined heat and power (CHP) generation at the 3 unit could cut this figure by up to four million tonnes. This would decrease carbon dioxide emissions by as much as six percent. In addition, large-scale CHP generation would increase the overall efficiency of the new unit significantly and hence, reduce the environmental impact on the local marine environment by cutting heat discharges into the Gulf of Nuclear energy has been used for district heating in several countries both in dedicated nuclear heating plants and in CHP generation plants. However, the heat generation capacity is usually rather limited, maximum being around 250 MWth per unit. Set against this, the 3 CHP concept is much more ambitious, not only because of the much larger heat generation output envisaged, but also because the district heating water would have to be transported over a

Design Analysis of Power Extracting Unit of an Onshore OWC Based Wave Energy Power Plant using Numerical Simulation

Directory of Open Access Journals (Sweden)

Zahid Suleman

2011-07-01

Full Text Available This research paper describes design and analysis of power extracting unit of an onshore OWC (Oscillating Water Column based wave energy power plant of capacity about 100 kilowatts. The OWC is modeled as solid piston of a reciprocating pump. The power extracting unit is designed analytically by using the theory of reciprocating pumps and principles of fluid mechanics. Pro-E and ANSYS workbench softwares are used to verify the analytical design. The analytical results of the flow velocity in the turbine duct are compared with the simulation results. The results are found to be in good agreement with each other. The results achieved by this research would finally assist in the overall design of the power plant which is the ultimate goal of this research work.

DataCell: Exploiting the Power of Relational Databases for Efficient Stream Processing

NARCIS (Netherlands)

E. Liarou (Erietta); M.L. Kersten (Martin)

2009-01-01

htmlabstractDesigned for complex event processing, DataCell is a research prototype database system in the area of sensor stream systems. Under development at CWI, it belongs to the MonetDB database system family. CWI researchers innovatively built a stream engine directly on top of a database

Nova Scotia Power : in-stream tidal

International Nuclear Information System (INIS)

Meade, K.

2007-01-01

The Government of Nova Scotia, the Government of New Brunswick, Nova Scotia Power and others have funded a feasibility study of North American sites for commercial instream tidal power. In July 2007, Nova Scotia Power received partial funding for a demonstration project. This presentation provided information on a demonstration plant for tidal power run by Nova Scotia Power. It discussed the benefits of the Open Hydro technology for this plant. In this simple design, the generator is on the circumference of the turbine. The design does not involve any power transmission systems or any pitching of blades. In addition, the technology is environmentally sound as it is completely shrouded, has low rotational speed, and a large open centre allows fish to pass through, and it does not require lubricants. The last benefit that was presented was the scale up of 250 kW machine deployed in a European test facility. The presentation also discussed the advantages of developing tidal power at this time. It was concluded that tidal energy has significant potential. Although it is intermittent, it is predictable and bulk power system can be scheduled to accommodate it. figs

A Stream Erosion Susceptibility Identification Tool for use in Hydromodification Planning

Science.gov (United States)

Berntsen, E.; Bowles, C.

2008-12-01

A stream erosion susceptibility identification tool has been developed for use in hydromodification planning based on a three-tiered approach. Tier 1 involved development of a susceptibility map. This included conducting a watershed scale GIS- and remote sensing-based screening analysis of two methodologies to quantify stream susceptibility to hydromodification. Tier 2 will involve conducting rapid geomorphic assessments for selected areas that were screened to have high and low erosion potential in Tier 1. Tier 3 will identify key geomorphic thresholds (e.g., relationship between channel slope, median particle size, and drainage area for stable and unstable channels, critical bank heights in various channel materials, channel response to changes in flow and sediment supply, etc.) from comparison of stable and unstable channels. This poster will primarily cover the methodology and results in Tier 1 for a pilot project in the Laguna Creek Watershed in Sacramento County, California. We used two methodologies, relying on readily available topographic information (i.e., USGS 10-meter DEM), for producing the Tier 1 susceptibility map: Hack's relationship (Hack, 1957; Bledsoe and Watson, 2004) and specific stream power (Simons and Downs, 1995). Hack's relationship involved calculating the hydraulic stability number (Nh), which is the ratio of the existing channel slope to the corresponding equilibrium slope, whereby a value greater than 1 represents a relatively unstable channel. Specific stream power involved calculating the power expended per unit area of the streambed (in Watts/m2), whereby a value greater than 35 represents a relatively unstable channel. The results of the Tier 1 analysis indicated that the two methodologies compared favorably in their predictions of channel instability. Comparisons of the two methodologies were also made with existing channel conditions as observed by others in a recent study in the watershed and completed in 2007. As shown by this

20 kHz main inverter unit. [for space station power supplies

Science.gov (United States)

Hussey, S.

1989-01-01

A proof-of-concept main inverter unit has demonstrated the operation of a pulse-width-modulated parallel resonant power stage topology as a 20-kHz ac power source driver, showing simple output regulation, parallel operation, power sharing and short-circuit operation. The use of a two-stage dc input filter controls the electromagnetic compatibility (EMC) characteristics of the dc power bus, and the use of an ac harmonic trap controls the EMC characteristics of the 20-kHz ac power bus.

Mobile power plant units

Energy Technology Data Exchange (ETDEWEB)

Radtke, R

1979-10-05

Diesel engines of the MaK line 282 AK/332 with a cylinder power up to 160 kW are used, either as 6-cylinder or 8-cylinder in-line engine or as 12-cylinder V engine. Fuel consumption is between 207 and 212 g/kW. The engine is mounted on a frame, together with a generator. The fuel reserve in the tank will last for 8 hours. The lubricating system, the cooling water and starting air system, the switchboard system, and the frame are described. The switchboard plant is mounted either on a skid undercarriage or on the undercarriage. The plant can be operated independently or parallel to the network. The unit can be remote-controlled via push buttons or control knobs. A picture is presented of a mobile diesel aggregate which is in service in Libya.

Sampling the stream landscape: Improving the applicability of an ecoregion-level capture probability model for stream fishes

Science.gov (United States)

Mollenhauer, Robert; Mouser, Joshua B.; Brewer, Shannon K.

2018-01-01

Temporal and spatial variability in streams result in heterogeneous gear capture probability (i.e., the proportion of available individuals identified) that confounds interpretation of data used to monitor fish abundance. We modeled tow-barge electrofishing capture probability at multiple spatial scales for nine Ozark Highland stream fishes. In addition to fish size, we identified seven reach-scale environmental characteristics associated with variable capture probability: stream discharge, water depth, conductivity, water clarity, emergent vegetation, wetted width–depth ratio, and proportion of riffle habitat. The magnitude of the relationship between capture probability and both discharge and depth varied among stream fishes. We also identified lithological characteristics among stream segments as a coarse-scale source of variable capture probability. The resulting capture probability model can be used to adjust catch data and derive reach-scale absolute abundance estimates across a wide range of sampling conditions with similar effort as used in more traditional fisheries surveys (i.e., catch per unit effort). Adjusting catch data based on variable capture probability improves the comparability of data sets, thus promoting both well-informed conservation and management decisions and advances in stream-fish ecology.

Phasor Measurement Units in the Eastern Danish power system

DEFF Research Database (Denmark)

Nielsen, Arne Hejde; Pedersen, Knud Ole Helgesen; Jørgensen, Preben

2006-01-01

Technology. After power system events data can be extracted and analyzed offline. The purpose of the project is to do research within various utilizations of PMU data. On 8 January 2005 a severe storm passed Denmark, and wind speeds were so high, that wind turbines disconnected from the transmission grid...... because of their self protection. Nysted offshore wind farm was among the wind power units that disconnected from the grid, and PMU data from that event are analyzed. The case illustrates the close relation between voltages, power flows and voltage phase angles over a wide area. The voltage phase angle...

Suppression of acoustic streaming in tapered pulse tubes

International Nuclear Information System (INIS)

Olson, J.R.; Swift, G.W.

1998-01-01

In a pulse tube cryocooler, the gas in the pulse tube can be thought of as an insulating piston, transmitting pressure and velocity from the cold heat exchanger to the hot end of the pulse tube. Unfortunately, convective heat transfer can carry heat from the hot end to the cold end and reduce the net cooling power. Here, the authors discuss one driver of such convection: steady acoustic streaming as generated by interactions between the boundary and the oscillating pressure, velocity, and temperature. Using a perturbation method, they have derived an analytical expression for the streaming in a tapered pulse tube with axially varying mean temperature in the acoustic boundary layer limit. The calculations showed that the streaming depends strongly on the taper angle, the ratio of velocity and pressure amplitudes, and the phase between the velocity and pressure, but it depends only weakly on the mean temperature profile and is independent of the overall oscillatory amplitude. With the appropriate tapering of the tube, streaming can be eliminated for a particular operating condition. Experimentally, the authors have demonstrated that an orifice pulse tube cryocooler with the calculated zero-streaming taper has more cooling power than one with either a cylindrical tube or a tapered pulse tube with twice the optimum taper angle

GAGES: A stream gage database for evaluating natural and alteredflow conditions in the conterminous United States

Science.gov (United States)

Falcone, James A.; Carlisle, Daren M.; Wolock, David M.; Meador, Michael R.

2010-01-01

Stream flow is a controlling element in the ecology of rivers and streams. Knowledge of the natural flow regime facilitates the assessment of whether specific hydrologic attributes have been altered by humans in a particular stream and the establishment of specific goals for stream-flow restoration. Because most streams are ungaged or have been altered by human influences, characterizing the natural flow regime is often only possible by estimating flow characteristics based on nearby stream gages of reference quality, i.e., gaged locations that are least disturbed by human influences. The ability to evaluate natural stream flow, that which is not altered by human activities, would be enhanced by the existence of a nationally consistent and up-to-date database of gages in relatively undisturbed watersheds.

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

1998-01-01

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

Peach Bottom Atomic Power Station, Units 2 and 3. Annual operating report: January--December 1976

International Nuclear Information System (INIS)

1977-01-01

Unit 2 experienced 11 forced outages, 5 power reductions, and one major refueling outage which lasted about 3 months during which time the feedwater spargers were replaced. Net electrical power generated was 5,569,633 MWH with the generator on line 5,998 hrs. Unit 3 experienced 17 forced outages, 11 power reductions and 2 major outages. The first refueling outage began 12/24/77. Net electrical power generated was 6,049,644 MWH with the unit on line 6,829 hrs. Information is presented concerning operations, personnel exposures, radioactive releases, maintenance, and irradiated fuel examination

Renovation of the 'old' NPP units as an economically effective way of nuclear power development

International Nuclear Information System (INIS)

Zrodnikov, A.V.; Toshinsky, G.I.; Komlev, O.G.; Dragunov, Yu.G.; Stepanov, V.S.; Klimov, N.N.; Kopytov, I.I.; Krushelnitsky, V.N.

2005-01-01

In the process of nuclear power development there comes a phase when the old' power-units, which reactor installations have expired the designed and extended service lifetime are withdrawn from operating. At this phase in the case of the same annual investments into nuclear power, the increase of the total set up capacity of the nuclear power will be terminated because introduction of capacities due to construction of 'new' power-units only compensates for the reduction of capacities caused by withdrawing from operating the 'old' power-units. Along with this, taking into account a sizeable difference in the service lifetime of the nuclear steam supplying systems and the rest infrastructure of the nuclear power plants, it is an opportunity to find the solution to the problem of compensating for the withdrawn capacities without considerable increasing the annual investments. This opportunity is connected with use of the innovative nuclear power technology based on multipurpose small power modular fast reactors with lead-bismuth coolant for replacement of the withdrawn capacities (renovation of power-units). The features of the innovative nuclear power technology based on the SVBR-76/100 reactor installations, the results of the technical and economical investigations that demonstrate the high economical efficiency of use of the renovation technology using the SVBR-75/100 reactor modules are presented in the Paper. (author)

Inventory of power plants in the United States: December 1979

International Nuclear Information System (INIS)

Gilliam, L.R.

1980-01-01

This 1979 inventory of power plants provides a comprehensive list of existing, standby, out-of-service, retired and projected electric generating plants in the U.S. Arranged under the broad sections of existing, jointly owned and projected units, tabulated data on individual plants in each state are presented. These data include unit name, location, type, MW rating, primary fuel, alternative fuel, status, year built, and whether or not it is jointly owned. Jointly owned plants are separately identified as to the percent of ownership belonging to named owners. Projected plants have data on plant characteristics, current status and scheduled completion date. Summaries of the total number of each type of power plant in each state are also provided

Open Source Initiative Powers Real-Time Data Streams

Science.gov (United States)

2014-01-01

Under an SBIR contract with Dryden Flight Research Center, Creare Inc. developed a data collection tool called the Ring Buffered Network Bus. The technology has now been released under an open source license and is hosted by the Open Source DataTurbine Initiative. DataTurbine allows anyone to stream live data from sensors, labs, cameras, ocean buoys, cell phones, and more.

Accelerating the energy policy turnaround with combined heat and power units; Mit Blockheizkraftwerken die Energiewende rund machen

Energy Technology Data Exchange (ETDEWEB)

Lange, Joerg; Geiler, Nikolaus [Klimabuendnis Freiburg, Freiburg im Breisgau (Germany)

2013-03-15

No other type of decentralized power plants transforms natural gas to electric power so efficiently as a combined heat and power unit. In the long term, the climate-friendly effect using renewable hydrogen or renewably generated 'natural gas' even could be increased. Thus, combined heat and power units are ideal to achieve the national climate change objectives. Despite their advantages, the implementation of combined heat and power units advances only sluggishly.

Water-Chemistry and Its Utility Systems in CCP Power Units (Review)

Science.gov (United States)

Larin, B. M.

2018-01-01

Damageability of heat transfer surfaces of waste heat recovery steam generators (HRSG) of combined- cycle plants (CCP) can be reduced due to an increase in the quality of make-up and feed water, the use of phosphate-alkaline or amino compound water chemistry (WC), and improved chemical quality control of the heat carrier and make-up water preparation techniques. Temporary quality standards for the heat medium developed by the All-Russia Thermal Engineering institute (VTI) for CCP power units are presented in comparison with the IAPWS standards; preferences for the choice of a WC type for some power units commissioned in Russia in the first decade of this century are shown; and operational data on the quality of feed, boiler water, and steam for two large CCP-450 and CCP-425 power units are given. The state and prospects for the development of chemical-technological monitoring systems and CCP water treatment plants are noted. Estimability of some CCP diagnostic parameters by measuring specific electric conductivity and pH is shown. An extensive bibliography on this topic is given.

Job creation due to nuclear power resurgence in the United States

International Nuclear Information System (INIS)

Kenley, C.R.; Klingler, R.D.; Plowman, C.M.; Soto, R.; Turk, R.J.; Baker, R.L.; Close, S.A.; McDonnell, V.L.; Paul, S.W.; Rabideau, L.R.; Rao, S.S.; Reilly, B.P.

2009-01-01

The recent revival of global interest in the next generation of nuclear power reactors is causing a re-examination of the role of nuclear power in the United States. This renewed interest has led to questions regarding the capability and capacity of current US industries to support a renewal of nuclear power plant deployment. Key among the many questions currently being asked is what potential exists for the creation of new jobs as a result of developing and operating these new plants? Idaho National Laboratory and Bechtel Power Corporation collaborated to perform a Department of Energy-sponsored study that evaluated the potential for job creation in the United States should these new next generation nuclear power plants be built. The study focused primarily on providing an initial estimate of the numbers of new manufacturing jobs that could be created, including those that could be repatriated from overseas, resulting from the construction of these new reactors. In addition to the growth in the manufacturing sector, the study attempted to estimate the potential increase in construction trades necessary to accomplish the new construction. (author)

Summary revaluation of energetic start-up of the unit 1 of nuclear power plant Mochovce

International Nuclear Information System (INIS)

Sarvaic, I.; Miskolci, M.

1998-01-01

The document contents stage revaluation of energetic start-up of the unit 1 of nuclear power plant Mochovce. Test results of the stage of energetic start-up are summarized in the document, valuation of important systems and block devices as well as fulfilling the operation limits and conditions has been performed. On that base conclusions and recommendations for start-up the unit 2 and for commercial operation of the unit 1 are elaborated. The valuation has been elaborated by a scientific management for start-up nuclear power plant Mochovce of nuclear safety of nuclear power facilities. Scientific management for start-up of nuclear power plant Mochovce performed continuous valuation of individual power levels after ending of each individual level and it gave its valuation to energy power level with recommendations and conditions for further start-up process and operation. Scientific management finished its activity at the unit 1 of nuclear power plant Mochovce according to a statute of scientific management for start-up after successful completion of conclusive block run. Scientific management group was founded in February 1998 at nuclear power plant Mochovce. Its members are experts from Slovak, Czech, Russian and French organizations which are participating in power plant completion. Members are listed in a supplement No. 2

Start up and commercial operation of Laguna Verde nuclear power plant. Unit 1

International Nuclear Information System (INIS)

Torres Ramirez, J.F.

1991-01-01

Prior to start up of Laguna Verde nuclear power plant preoperational tests and start tests were performed and they are described in its more eminent aspects. In relation to commercial operation of nuclear station a series of indicator were set to which allow the measurement of performance in unit 1, in areas of plant efficiency and personal safety. Antecedents. Laguna Verde station is located in Alto Lucero municipality in Veracruz state, 70 kilometers north-northeast from port of Veracruz and a 290 kilometers east-northeast from Mexico city. The station consist of two units manufactured by General Electric, with a nuclear system of vapor supply also called boiling water (BWR/5), and with a system turbine-generator manufactured by Mitsubishi. Each unit has a nominal power of 1931 MWt and a level design power of 675 Mwe and a net power of 654 Electric Megawatts

Draft environmental impact statement. River Bend Nuclear Power Station, Unit 1

International Nuclear Information System (INIS)

Anon.

1980-01-01

Federal financing of an undivided ownership interest of River Bend Nuclear Power Station Unit 1 on a 3293-acre site near St. Francisville, Louisiana is proposed in a supplement to the final environmental impact statement of September 1974. The facility would consist of a boiling-water reactor that would produce a maximum of 2894 megawatts (MW) of electrical power. A design level of 3015 MW of electric power could be realized at some time in the future. Exhaust steam would be cooled by mechanical cooling towers using makeup water obtained from and discharged to the Mississippi River. Power generated by the unit would be transmitted via three lines totaling 140 circuit miles traversing portions of the parishes of West Feliciana, East Feliciana, East Baton Rouge, West Baton Rouge, Pointe Coupee, and Iberville. The unit would help the applicant meet the power needs of rural electric consumers in the region, and the applicant would contribute significanlty to area tax base and employment rolls during the life of the unit. Construction related activities would disturb 700 forested acres on the site and 1156 acres along the transmission routes. Of the 60 cubic feet per second (cfs) taken from the river, 48 cfs would evaporate during the cooling process and 12 cfs would return to the river with dissolved solids concentrations increased by 500%. The terrace aquifer would be dewatered for 16 months in order to lower the water table at the building site, and Grants Bayou would be transformed from a lentic to a lotic habitat during this period. Fogging and icing due to evaporation and drift from the cooling towers would increase slightly. During the construction period, farming, hunting, and fishing on the site would be suspended, and the social infractructure would be stressed due to the influx of a maximum of 2200 workers

THE PAL 5 STAR STREAM GAPS

International Nuclear Information System (INIS)

Carlberg, R. G.; Hetherington, Nathan; Grillmair, C. J.

2012-01-01

Pal 5 is a low-mass, low-velocity-dispersion, globular cluster with spectacular tidal tails. We use the Sloan Digital Sky Survey Data Release 8 data to extend the density measurements of the trailing star stream to 23 deg distance from the cluster, at which point the stream runs off the edge of the available sky coverage. The size and the number of gaps in the stream are measured using a filter which approximates the structure of the gaps found in stream simulations. We find 5 gaps that are at least 99% confidence detections with about a dozen gaps at 90% confidence. The statistical significance of a gap is estimated using bootstrap resampling of the control regions on either side of the stream. The density minimum closest to the cluster is likely the result of the epicyclic orbits of the tidal outflow and has been discounted. To create the number of 99% confidence gaps per unit length at the mean age of the stream requires a halo population of nearly a thousand dark matter sub-halos with peak circular velocities above 1 km s –1 within 30 kpc of the galactic center. These numbers are a factor of about three below cold stream simulation at this sub-halo mass or velocity but, given the uncertainties in both measurement and more realistic warm stream modeling, are in substantial agreement with the LCDM prediction.

Pattern of Blood Stream Infections within Neonatal Intensive Care Unit, Suez Canal University Hospital, Ismailia, Egypt.

Science.gov (United States)

Kishk, Rania Mohammed; Mandour, Mohamed Fouad; Farghaly, Rasha Mohamed; Ibrahim, Ahmed; Nemr, Nader Attia

2014-01-01

Introduction. Blood stream infection (BSI) is a common problem of newborn in neonatal intensive care units (NICUs). Monitoring neonatal infections is increasingly regarded as an important contributor to safe and high-quality healthcare. It results in high mortality rate and serious complications. So, our aim was to determine the incidence and the pattern of BSIs in the NICU of Suez Canal University Hospital, Egypt, and to determine its impact on hospitalization, mortality, and morbidity. Methods. This study was a prospective one in which all neonates admitted to the NICUs in Suez Canal University hospital between January, 2013 and June 2013 were enrolled. Blood stream infections were monitored prospectively. The health care associated infection rate, mortality rate, causative organism, and risk factors were studied. Results. A total of 317 neonates were admitted to the NICU with a mortality rate of 36.0%. During this study period, 115/317 (36.3%) developed clinical signs of sepsis and were confirmed as BSIs by blood culture in only 90 neonates with 97 isolates. The total mean length of stay was significantly longer among infected than noninfected neonates (34.5 ± 18.3 and 10.8 ± 9.9 days, resp., P value Suez Canal University Hospital was relatively high with high mortality rate (36.0%).

Ejectors of power plants turbine units efficiency and reliability increasing

Science.gov (United States)

Aronson, K. E.; Ryabchikov, A. Yu.; Kuptsov, V. K.; Murmanskii, I. B.; Brodov, Yu. M.; Zhelonkin, N. V.; Khaet, S. I.

2017-11-01

The functioning of steam turbines condensation systems influence on the efficiency and reliability of a power plant a lot. At the same time, the condensation system operating is provided by basic ejectors, which maintain the vacuum level in the condenser. Development of methods of efficiency and reliability increasing for ejector functioning is an actual problem of up-to-date power engineering. In the paper there is presented statistical analysis of ejector breakdowns, revealed during repairing processes, the influence of such damages on the steam turbine operating reliability. It is determined, that 3% of steam turbine equipment breakdowns are the ejector breakdowns. At the same time, about 7% of turbine breakdowns are caused by different ejector malfunctions. Developed and approved design solutions, which can increase the ejector functioning indexes, are presented. Intercoolers are designed in separated cases, so the air-steam mixture can’t move from the high-pressure zones to the low-pressure zones and the maintainability of the apparatuses is increased. By U-type tubes application, the thermal expansion effect of intercooler tubes is compensated and the heat-transfer area is increased. By the applied nozzle fixing construction, it is possible to change the distance between a nozzle and a mixing chamber (nozzle exit position) for operating performance optimization. In operating conditions there are provided experimental researches of more than 30 serial ejectors and also high-efficient 3-staged ejector EPO-3-80, designed by authors. The measurement scheme of the designed ejector includes 21 indicator. The results of experimental tests with different nozzle exit positions of the ejector EPO-3-80 stream devices are presented. The pressure of primary stream (water steam) is optimized. Experimental data are well-approved by the calculation results.

Partial Key Grouping: Load-Balanced Partitioning of Distributed Streams

OpenAIRE

Nasir, Muhammad Anis Uddin; Morales, Gianmarco De Francisci; Garcia-Soriano, David; Kourtellis, Nicolas; Serafini, Marco

2015-01-01

We study the problem of load balancing in distributed stream processing engines, which is exacerbated in the presence of skew. We introduce PARTIAL KEY GROUPING (PKG), a new stream partitioning scheme that adapts the classical “power of two choices” to a distributed streaming setting by leveraging two novel techniques: key splitting and local load estimation. In so doing, it achieves better load balancing than key grouping while being more scalable than shuffle grouping. We test PKG on severa...

How wide is a stream? Spatial extent of the potential "stream signature" in terrestrial food webs using meta-analysis.

Science.gov (United States)

Muehlbauer, Jeffrey D; Collins, Scott F; Doyle, Martin W; Tockner, Klement

2014-01-01

The magnitude of cross-ecosystem resource subsidies is increasingly well recognized; however, less is known about the distance these subsidies travel into the recipient landscape. In streams and rivers, this distance can delimit the "biological stream width," complementary to hydro-geomorphic measures (e.g., channel banks) that have typically defined stream ecosystem boundaries. In this study we used meta-analysis to define a "stream signature" on land that relates the stream-to-land subsidy to distance. The 50% stream signature, for example, identifies the point on the landscape where subsidy resources are still at half of their maximum (in- or near-stream) level. The decay curve for these data was best fit by a negative power function in which the 50% stream signature was concentrated near stream banks (1.5 m), but a non-trivial (10%) portion of the maximum subsidy level was still found > 0.5 km from the water's edge. The meta-analysis also identified explanatory variables that affect the stream signature. This improves our understanding of ecosystem conditions that permit spatially extensive subsidy transmission, such as in highly productive, middle-order streams and rivers. Resultant multivariate models from this analysis may be useful to managers implementing buffer rules and conservation strategies for stream and riparian function, as they facilitate prediction of the extent of subsidies. Our results stress that much of the subsidy remains near the stream, but also that subsidies (and aquatic organisms) are capable of long-distance dispersal into adjacent environments, and that the effective "biological stream width" of stream and river ecosystems is often much larger than has been defined by hydro-geomorphic metrics alone. Limited data available from marine and lake sources overlap well with the stream signature data, indicating that the "signature" approach may also be applicable to subsidy spatial dynamics across other ecosystems.

Groundwater Discharge along a Channelized Coastal Plain Stream

Energy Technology Data Exchange (ETDEWEB)

LaSage, Danita M [Ky Dept for natural resources, Div of Mine Permits; Sexton, Joshua L [JL Sexton and Son; Mukherjee, Abhijit [Univ of Tx, Jackson School of Geosciences, Bur of Econ. Geology; Fryar, Alan E [Univ of KY, Dept of Earth and Geoligical Sciences; Greb, Stephen F [Univ of KY, KY Geological Survey

2015-10-01

In the Coastal Plain of the southeastern USA, streams have commonly been artificially channelized for flood control and agricultural drainage. However, groundwater discharge along such streams has received relatively little attention. Using a combination of stream- and spring-flow measurements, spring temperature measurements, temperature profiling along the stream-bed, and geologic mapping, we delineated zones of diffuse and focused discharge along Little Bayou Creek, a channelized, first-order perennial stream in western Kentucky. Seasonal variability in groundwater discharge mimics hydraulic-head fluctuations in a nearby monitoring well and spring-discharge fluctuations elsewhere in the region, and is likely to reflect seasonal variability in recharge. Diffuse discharge occurs where the stream is incised into the semi-confined regional gravel aquifer, which is comprised of the Mounds Gravel. Focused discharge occurs upstream where the channel appears to have intersected preferential pathways within the confining unit. Seasonal fluctuations in discharge from individual springs are repressed where piping results in bank collapse. Thereby, focused discharge can contribute to the morphological evolution of the stream channel.

Efficiency limits of rehabilitation of the Thermal Power Plant Turceni units

International Nuclear Information System (INIS)

Gheorghiu, D.; Stoenescu, R.; Balcan, I.; Panait, L.; Pressel, S.; Ghioca, L.

1996-01-01

The paper analyses the efficiency limits of the programs A 2 and A 3 of rehabilitation of the TPP Turceni units considering the current economic situation and the power and energy balances in the Romania's National Power System. Starting from the current net income and also, taking into account the performances which can be reached by the units to be rehabilitated, according to the guarantee figures provided by the German Consortium ABB-DBE, one is determined the maximum investment for rehabilitation so that the adjusted net income to be equal to the expenses and adjusted investments (reverse method). (author). 1 fig., 1 tab

Second periodic safety review of Angra Nuclear Power Station, unit 1

Energy Technology Data Exchange (ETDEWEB)

Martins, Carlos F.O.; Crepaldi, Roberto; Freire, Enio M., E-mail: ottoncf@tecnatom.com.br, E-mail: emfreire46@gmail.com, E-mail: robcrepaldi@hotmail.com [Tecnatom do Brasil Engenharia e Servicos Ltda, Rio de Janeiro, RJ (Brazil); Campello, Sergio A., E-mail: sacampe@eletronuclear.gov.br [Eletrobras Termonuclear S.A. (ELETRONUCLEAR), Rio de Janeiro, RJ (Brazil)

2015-07-01

This paper describes the second Periodic Safety Review (PSR2-A1) of Angra Nuclear Power Station, Unit 1, prepared by Eletrobras Eletronuclear S.A. and Tecnatom do Brasil Engenharia e Servicos Ltda., during Jul.2013-Aug.2014, covering the period of 2004-2013. The site, in Angra dos Reis-RJ, Brazil, comprises: Unit 1, (640 MWe, Westinghouse PWR, operating), Unit 2 (1300 MWe, KWU/Areva, operating) and Unit 3 (1405 MWe, KWU/Areva, construction). The PSR2-A1 attends the Standards 1.26-Safety in Operation of Nuclear Power Plants, Brazilian Nuclear Regulatory Commission (CNEN), and IAEA.SSG.25-Periodic Safety Review of Nuclear Power Plants. Within 18 months after each 10 years operation, the operating organization shall perform a plant safety review, to investigate the evolution consequences of safety code and standards, regarding: Plant design; structure, systems and components behavior; equipment qualification; plant ageing management; deterministic and probabilistic safety analysis; risk analysis; safety performance; operating experience; organization and administration; procedures; human factors; emergency planning; radiation protection and environmental radiological impacts. The Review included 6 Areas and 14 Safety Parameters, covered by 33 Evaluations.After document evaluations and discussions with plant staff, it was generated one General and 33 Specific Guide Procedures, 33 Specific and one Final Report, including: Description, Strengths, Deficiencies, Areas for Improvement and Conclusions. An Action Plan was prepared by Electronuclear for the recommendations. It was concluded that the Unit was operated within safety standards and will attend its designed operational lifetime, including possible life extensions. The Final Report was submitted to CNEN, as one requisite for renewal of the Unit Permanent Operation License. (author)

Second periodic safety review of Angra Nuclear Power Station, unit 1

International Nuclear Information System (INIS)

Martins, Carlos F.O.; Crepaldi, Roberto; Freire, Enio M.; Campello, Sergio A.

2015-01-01

This paper describes the second Periodic Safety Review (PSR2-A1) of Angra Nuclear Power Station, Unit 1, prepared by Eletrobras Eletronuclear S.A. and Tecnatom do Brasil Engenharia e Servicos Ltda., during Jul.2013-Aug.2014, covering the period of 2004-2013. The site, in Angra dos Reis-RJ, Brazil, comprises: Unit 1, (640 MWe, Westinghouse PWR, operating), Unit 2 (1300 MWe, KWU/Areva, operating) and Unit 3 (1405 MWe, KWU/Areva, construction). The PSR2-A1 attends the Standards 1.26-Safety in Operation of Nuclear Power Plants, Brazilian Nuclear Regulatory Commission (CNEN), and IAEA.SSG.25-Periodic Safety Review of Nuclear Power Plants. Within 18 months after each 10 years operation, the operating organization shall perform a plant safety review, to investigate the evolution consequences of safety code and standards, regarding: Plant design; structure, systems and components behavior; equipment qualification; plant ageing management; deterministic and probabilistic safety analysis; risk analysis; safety performance; operating experience; organization and administration; procedures; human factors; emergency planning; radiation protection and environmental radiological impacts. The Review included 6 Areas and 14 Safety Parameters, covered by 33 Evaluations.After document evaluations and discussions with plant staff, it was generated one General and 33 Specific Guide Procedures, 33 Specific and one Final Report, including: Description, Strengths, Deficiencies, Areas for Improvement and Conclusions. An Action Plan was prepared by Electronuclear for the recommendations. It was concluded that the Unit was operated within safety standards and will attend its designed operational lifetime, including possible life extensions. The Final Report was submitted to CNEN, as one requisite for renewal of the Unit Permanent Operation License. (author)

Low-level radioactive waste from nuclear power generating stations: Characterization, classification and assessment of activated metals and waste streams

International Nuclear Information System (INIS)

Thomas, V.W.; Robertson, D.E.; Thomas, C.W.

1993-02-01

Since the enactment of 10 CFR Part 61, additional difficult-to-measure long-lived radionuclides, not specified in Tables 1 2 of Part 61, have been identified (e.g., 108m Ag, 93 Mo, 36 Cl, 10 Be, 113m Cd, 121m Sn, 126 Sn, 93m Nb) that may be of concern in certain types of waste. These nuclides are primarily associated with activated metal and perhaps other nuclear power low-level waste (LLW) being sent to disposal facilities. The concentration of a radionuclide in waste materials is normally determined by direct measurement or by indirect calculational methods, such as using a scaling factor to relate inferred concentration of a difficult-to-measure radionuclide to another that is easily measured. The total disposal site inventory of certain difficult-to-measure radionuclides (e.g., 14 C, 129 I, and 99 Tc) often control the total quantities of radioactive waste permitted in LLW burial facilities. Overly conservative scaling factors based on lower limits of detection (LLD), often used in the nuclear power industry to estimate these controlling nuclides, could lead to premature closure of a disposal facility. Samples of LLW (Class B and C activated metals [AM] and other waste streams) are being collected from operating nuclear power stations and analyzed for radionuclides covered in 10 CFR Part 61 and the additional difficult-to-measure radionuclides. This analysis will enhance the NRC's understanding of the distribution and projected quantities of radionuclides within AM and LLW streams from commercial nuclear power stations. This research will also provide radiological characterization of AM specimens for others to use in leach-rate and lysimeter experiments to determine nuclide releases and subsequent movement in natural soil environments

Solution and scope of utilization of the cross-stream cooling towers

International Nuclear Information System (INIS)

Zembaty, W.

1995-01-01

Technical solutions and operational properties of the cross-stream cooling towers as well as the scope of their utilization are presented. The differences within thermodynamic calculations of the cross-stream and counter-stream cooling towers due to the direction of the air flow as well as water flow in sprinkling system are discussed. The assessment of the capital and operational costs of the cross-stream cooling towers is given and compared with the cost of counter-stream cooling towers (utilizing as an example a calculation conducted for the cooling towers of the 720, 1100 and 1400 MW units). (author). 6 refs, 9 figs

New nuclear power plant unit in Finland accepted by the Finnish Parliament

International Nuclear Information System (INIS)

Kaetkae, M.

2002-01-01

The nuclear option has been included in Finland's energy strategy since late 1990's. Based on TVO's application the Finnish Parliament accepted in May 2002 the decision in principle to build a new nuclear power plant unit. The main arguments were the growth of electricity demand, reduction of CO 2 emissions, security of energy supply and reasonable as well as predictable electricity price. TVO's intention is to get the new power plant unit into commercial operation at the end of this decade.(author)

System for processing an encrypted instruction stream in hardware

Science.gov (United States)

Griswold, Richard L.; Nickless, William K.; Conrad, Ryan C.

2016-04-12

A system and method of processing an encrypted instruction stream in hardware is disclosed. Main memory stores the encrypted instruction stream and unencrypted data. A central processing unit (CPU) is operatively coupled to the main memory. A decryptor is operatively coupled to the main memory and located within the CPU. The decryptor decrypts the encrypted instruction stream upon receipt of an instruction fetch signal from a CPU core. Unencrypted data is passed through to the CPU core without decryption upon receipt of a data fetch signal.

Nuclear power generation costs in the United States of America

International Nuclear Information System (INIS)

Willis, W.F.

1983-01-01

Increasing world energy prices and shortages of fuel resources make the utilization of nuclear power extremely important. The United States nuclear power industry represents the largest body of nuclear power experience in the world. Analysis of the recent United States experience of substantial increases in the cost of nuclear power generation provides good insight into the interdependence of technological, financial, and institutional influences and their combined impact on the economic viability of nuclear power generation. The various factors influencing ultimate generation costs, including construction cost, fuel cost, regulatory reviews, and siting considerations are discussed, and their relative impacts are explored, including discussion of design complexity and related regulatory response. A closer look into the recent relatively high escalation of nuclear plant construction costs shows how differing economic conditions can affect the relative cost effectiveness of various methods of power generation. The vulnerability of capital-intensive, long-lead-time projects to changes in economic conditions and uncertainty in future power demands is discussed. Likewise, the pitfalls of new designs and increased sophistication are contrasted to the advantages which result from proven designs, reliable engineering, and shorter lead times. The value of reliable architect-engineers experienced in the design and construction of the plant is discussed. A discussion is presented of additional regulatory requirements stemming from public safety aspects of nuclear power. These include recognition of requirements for the very large effort for quality assurance of materials and workmanship during plant construction and operation. Likewise, a discussion is included of the demanding nature of operations, maintenance, and modification of plants during the operational phase because of the need for highly qualified operations and maintenance personnel and strict quality assurance

ESTIMATION OF THE TEMPERATURE RISE OF A MCU ACID STREAM PIPE IN NEAR PROXIMITY TO A SLUDGE STREAM PIPE

International Nuclear Information System (INIS)

Fondeur, F; Michael Poirier, M; Samuel Fink, S

2007-01-01

Effluent streams from the Modular Caustic-Side Solvent Extraction Unit (MCU) will transfer to the tank farms and to the Defense Waste Processing Facility (DWPF). These streams will contain entrained solvent. A significant portion of the Strip Effluent (SE) pipeline (i.e., acid stream containing Isopar(reg s ign) L residues) length is within one inch of a sludge stream. Personnel envisioned the sludge stream temperature may reach 100 C during operation. The nearby SE stream may receive heat from the sludge stream and reach temperatures that may lead to flammability issues once the contents of the SE stream discharge into a larger reservoir. To this end, personnel used correlations from the literature to estimate the maximum temperature rise the SE stream may experience if the nearby sludge stream reaches boiling temperature. Several calculation methods were used to determine the temperature rise of the SE stream. One method considered a heat balance equation under steady state that employed correlation functions to estimate heat transfer rate. This method showed the maximum temperature of the acid stream (SE) may exceed 45 C when the nearby sludge stream is 80 C or higher. A second method used an effectiveness calculation used to predict the heat transfer rate in single pass heat exchanger. By envisioning the acid and sludge pipes as a parallel flow pipe-to-pipe heat exchanger, this method provides a conservative estimation of the maximum temperature rise. Assuming the contact area (i.e., the area over which the heat transfer occurs) is the whole pipe area, the results found by this method nearly matched the results found with the previous calculation method. It is recommended that the sludge stream be maintained below 80 C to minimize a flammable vapor hazard from occurring

Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

DEFF Research Database (Denmark)

Schmidt, Lasse; Liedhegener, Michael; Bech, Michael Møller

2016-01-01

Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors....... In the analysis of supplied drives, both linear and rotary, emphasis is commonly placed on the drives themselves and the related loads, and the supply system dynamics is often given only little attention, and usually neglected or taken into account in a simplified fashion. The simplified supply system dynamics...... and drives will reduce the flow-to-pressure gain of the supply system, and hence increase the time constant of the sup-ply pressure dynamics. A consequence of this may be large vari-ations in the supply pressure, hence large variations in the pump shaft torque, and thereby the induction motor load torque...

Evaluation of Shoreham Nuclear Power Station, Unit 1 technical specifications

International Nuclear Information System (INIS)

Baxter, D.E.; Bruske, S.J.

1985-08-01

This document was prepared for the Nuclear Regulatory Commission (NRC) to assist them in determining whether the Shoreham Nuclear Power Station Unit 1 Technical Specifications (T/S), which govern plant systems configurations and operations, are in conformance with the assumptions of the Final Safety Analysis Report (FSAR) as amended, and the requirements of the Safety Evaluation Report (SER) as supplemented. A comparative audit of the FSAR as amended, and the SER as supplemented was performed with the Shoreham T/S. Several discrepancies were identified and subsequently resolved through discussions with the cognizant NRC reviewer, NRC staff reviewers and/or utility representatives. The Shoreham Nuclear Power Station Unit 1 T/S, to the extent reviewed, are in conformance with the FSAR and SER

IDENTIFYING STAR STREAMS IN THE MILKY WAY HALO

Energy Technology Data Exchange (ETDEWEB)

King, Charles III; Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J., E-mail: cking@cfa.harvard.edu, E-mail: wbrown@cfa.harvard.edu, E-mail: mgeller@cfa.harvard.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-05-01

We develop statistical methods for identifying star streams in the halo of the Milky Way that exploit observed spatial and radial velocity distributions. Within a great circle, departures of the observed spatial distribution from random provide a measure of the likelihood of a potential star stream. Comparisons between the radial velocity distribution within a great circle and the radial velocity distribution of the entire sample also measure the statistical significance of potential streams. The radial velocities enable construction of a more powerful joint statistical test for identifying star streams in the Milky Way halo. Applying our method to halo stars in the Hypervelocity Star (HVS) survey, we detect the Sagittarius stream at high significance. Great circle counts and comparisons with theoretical models suggest that the Sagittarius stream comprises 10%-17% of the halo stars in the HVS sample. The population of blue stragglers and blue horizontal branch stars varies along the stream and is a potential probe of the distribution of stellar populations in the Sagittarius dwarf galaxy prior to disruption.

IDENTIFYING STAR STREAMS IN THE MILKY WAY HALO

International Nuclear Information System (INIS)

King, Charles III; Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.

2012-01-01

We develop statistical methods for identifying star streams in the halo of the Milky Way that exploit observed spatial and radial velocity distributions. Within a great circle, departures of the observed spatial distribution from random provide a measure of the likelihood of a potential star stream. Comparisons between the radial velocity distribution within a great circle and the radial velocity distribution of the entire sample also measure the statistical significance of potential streams. The radial velocities enable construction of a more powerful joint statistical test for identifying star streams in the Milky Way halo. Applying our method to halo stars in the Hypervelocity Star (HVS) survey, we detect the Sagittarius stream at high significance. Great circle counts and comparisons with theoretical models suggest that the Sagittarius stream comprises 10%-17% of the halo stars in the HVS sample. The population of blue stragglers and blue horizontal branch stars varies along the stream and is a potential probe of the distribution of stellar populations in the Sagittarius dwarf galaxy prior to disruption.

Stream invertebrate productivity linked to forest subsidies: 37 stream-years of reference and experimental data.

Science.gov (United States)

Wallace, J Bruce; Eggert, Susan L; Meyer, Judy L; Webster, Jackson R

2015-05-01

Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance, biomass, and secondary production in rockface (RF) and mixed substrates (MS) of forested headwater streams. Using a mesh canopy covering the entire treatment stream, we examined effects of litter ex'clusion, small- and large-wood removal, and addition of artificial wood (PVC) and leaves of varying quality on organic matter standing crops and invertebrate community structure and function. We assessed differences in functional feeding group distribution between substrate types as influenced by organic matter manipulations and long-term patterns of predator and prey production in manipulated vs. reference years. Particulate organic matter standing crops in MS of the treatment stream declined drastically with each successive year of litter exclusion, approaching zero after three years. Monthly invertebrate biomass and annual secondary production was positively related to benthic organic matter in the MS habitats. Rockface habitats exhibited fewer changes than MS habitats across all organic matter manipulations. With leaf addition, the patterns of functional group distribution among MS and RF habitats returned to patterns seen in reference streams. Secondary production per unit organic matter standing crop was greatest for the leaf addition period, followed by the reference streams, and significantly less for the litter exclusion and wood removal periods. These data indicate that the limited organic matter remaining in the stream following litter exclusion and wood removal was more refractory than that in the reference streams, whereas the added leaf material was more labile and readily converted into

Quality Service Analysis and Improvement of Pharmacy Unit of XYZ Hospital Using Value Stream Analysis Methodology

Science.gov (United States)

Jonny; Nasution, Januar

2013-06-01

Value stream mapping is a tool which is needed to let the business leader of XYZ Hospital to see what is actually happening in its business process that have caused longer lead time for self-produced medicines in its pharmacy unit. This problem has triggered many complaints filed by patients. After deploying this tool, the team has come up with the fact that in processing the medicine, pharmacy unit does not have any storage and capsule packing tool and this condition has caused many wasting times in its process. Therefore, the team has proposed to the business leader to procure the required tools in order to shorten its process. This research has resulted in shortened lead time from 45 minutes to 30 minutes as required by the government through Indonesian health ministry with increased %VA (valued added activity) or Process Cycle Efficiency (PCE) from 66% to 68% (considered lean because it is upper than required 30%). This result has proved that the process effectiveness has been increase by the improvement.

Quality Service Analysis and Improvement of Pharmacy Unit of XYZ Hospital Using Value Stream Analysis Methodology

International Nuclear Information System (INIS)

Jonny; Nasution, Januar

2013-01-01

Value stream mapping is a tool which is needed to let the business leader of XYZ Hospital to see what is actually happening in its business process that have caused longer lead time for self-produced medicines in its pharmacy unit. This problem has triggered many complaints filed by patients. After deploying this tool, the team has come up with the fact that in processing the medicine, pharmacy unit does not have any storage and capsule packing tool and this condition has caused many wasting times in its process. Therefore, the team has proposed to the business leader to procure the required tools in order to shorten its process. This research has resulted in shortened lead time from 45 minutes to 30 minutes as required by the government through Indonesian health ministry with increased %VA (valued added activity) or Process Cycle Efficiency (PCE) from 66% to 68% (considered lean because it is upper than required 30%). This result has proved that the process effectiveness has been increase by the improvement.

Streams with Strahler Stream Order

Data.gov (United States)

Minnesota Department of Natural Resources — Stream segments with Strahler stream order values assigned. As of 01/08/08 the linework is from the DNR24K stream coverages and will not match the updated...

Risk analysis of NPP in multi-unit site for configuration of AAC power source

International Nuclear Information System (INIS)

Kim, Myung Ki

2000-01-01

Because of the difficulties in finding new sites for nuclear power plants, more units are being added to the existing sites. In these multi-unit sites, appropriate countermeasures should be established to cope with the potential station blackout (SBO) accident. Currently, installation of additional diesel generator (DG) is considered to ensure an alternative AC power source, but it has not been decided yet how many DGs should be installed in a multi-unit site. In this paper, risk informed decision making method, which evaluates reliability of electrical system, core damage frequency, and site average core damage frequency, is introduced to draw up the suitable number of DG in multi-unit site. The analysis results show that installing two DGs lowered the site average core damage frequency by 1.4% compared to one DG in six unit site. In the light of risk-informed decisions in regulatory guide 1.174, there is no difference of safety between two alternatives. It is concluded that one emergency diesel generator sufficiently guarantees safety against station blackout of nuclear power plants in multi-unit site. (author)

Situation and development trend of nuclear power and uranium industry in the united states and Russia

International Nuclear Information System (INIS)

Tan Chenglong

2005-01-01

This paper introduces the situation, trend of nuclear electrical and uranium industry in the United States and Russia. The United States and Russia are the two biggest countries in the world which generated nuclear power earliest. After 40 years' development, nuclear power in the United States and Russia are approximately 20%, 11% respectively of the total generation capacity in 2001. In the United States, only 6% of the nuclear power consumed uranium resource is domestic, in Russia about half of its uranium production is for export. Due to the collision between the energy development and environment protection, nuclear power in USA is still strong, but the uranium industry declines. In the future, uranium production for nuclear power in the United States will depend on the international market and the uranium storage of different levels. On the basis of pacifying people and making the country prosper, Russia has established their great plans for nuclear power with their substantial uranium resources. The author considers the supply and demand of uranium industry will remain balanced in the future decade on the whole, despite the United States and Russia's trend of uranium industry could take a major effect on uranium industry to the world. (authors)

The paradox of cooling streams in a warming world: regional climate trends do not parallel variable local trends in stream temperature in the Pacific continental United States

Science.gov (United States)

Ivan Arismendi; Sherri L. Johnson; Jason B. Dunham; Roy Haggerty

2012-01-01

Temperature is a fundamentally important driver of ecosystem processes in streams. Recent warming of terrestrial climates around the globe has motivated concern about consequent increases in stream temperature. More specifically, observed trends of increasing air temperature and declining stream flow are widely believed to result in corresponding increases in stream...

Impact of distributed generation units with power electronic converters on distribution network protection

NARCIS (Netherlands)

Morren, J.; Haan, de S.W.H.

2008-01-01

An increasing number of distributed generation units (DG units) are connected to the distribution network. These generators affect the operation and coordination of the distribution network protection. The influence from DG units that are coupled to the network with a power electronic converter

EnviroAtlas - Percentage of stream and water body shoreline lengths within 30 meters of >= 5% or >= 15% impervious cover by 12-Digit HUC for the Conterminous United States

Data.gov (United States)

U.S. Environmental Protection Agency — This EnviroAtlas dataset shows the percentages of stream and water body shoreline lengths within 30 meters of impervious cover by 12-digit Hydrologic Unit (HUC)...

Method and apparatus of prefetching streams of varying prefetch depth

Science.gov (United States)

Gara, Alan [Mount Kisco, NY; Ohmacht, Martin [Yorktown Heights, NY; Salapura, Valentina [Chappaqua, NY; Sugavanam, Krishnan [Mahopac, NY; Hoenicke, Dirk [Seebruck-Seeon, DE

2012-01-24

Method and apparatus of prefetching streams of varying prefetch depth dynamically changes the depth of prefetching so that the number of multiple streams as well as the hit rate of a single stream are optimized. The method and apparatus in one aspect monitor a plurality of load requests from a processing unit for data in a prefetch buffer, determine an access pattern associated with the plurality of load requests and adjust a prefetch depth according to the access pattern.

High Power Alternator Test Unit (ATU) Electrical System Test

Science.gov (United States)

Birchenough, Arthur; Hervol, David

2007-01-01

The Alternator Test Unit (ATU) in the Lunar Power System Facility (LPSF) located at the NASA Glenn Research Center (GRC) in Cleveland, OH was used to simulate the operating conditions and evaluate the performance of the ATU and it s interaction with various LPSF components in accordance with the JIMO AC Power System Requirements. The testing was carried out at the breadboard development level. Results of these tests will be used for the development and validation of analytical models for performance and lifetime prediction.

Geothermal electric power generation in Iceland for the proposed Iceland/United Kingdom HVDC power link

International Nuclear Information System (INIS)

Hammons, T.J.; Palmason, G.; Thorhallsson, S.

1991-01-01

The paper reviews geothermal electric power potential in Iceland which could economically be developed to supplement hydro power for the proposed HVDC Power Link to the United Kingdom, and power intensive industries in Iceland, which are envisaged for development at this time. Technically harnessable energy for electricity generation taking account of geothermal resources down to an assumed base depth, temperature distribution in the crust, probable geothermal recovery factor, and accessibility of the field, has been assessed. Nineteen known high-temperature fields and 9 probable fields have been identified. Technically harnessable geo-heat for various areas is indicated. Data on high temperature fields suitable for geothermal electric power generation, and on harnessable energy for electric power generation within volcanic zones, is stated, and overall assessments are made. The paper then reviews how the potential might be developed, discussing preference of possible sites, and cost of the developments at todays prices. Cost of geothermal electric power generation with comparative costs for hydro generation are given. Possible transmission system developments to feed the power to the proposed HVDC Link converter stations are also discussed

Fast-Valving of Large Steam Turbine Units as a Means of Power System Security Enhancement

Directory of Open Access Journals (Sweden)

Bogdan Sobczak

2014-03-01

Full Text Available Fast-valving assists in maintaining system stability following a severe transmission system fault by reducing the turbine mechanical power. Fast-valving consists in rapid closing and opening of steam valves in an adequate manner to reduce the generator accelerating power following the recognition of a severe fault. FV can be an effective and economical method of meeting the performance requirements of a power system in the presence of an increase in wind and solar generation in the power system, newly connected large thermal units and delaying of building new transmission lines. The principle of fast-valving and advantages of applying this technique in large steam turbine units was presented in the paper. Effectiveness of fast-valving in enhancing the stability of the Polish Power Grid was analyzed. The feasibility study of fast-valving application in the 560 MW unit in Kozienice Power Station (EW SA was discussed.

Contributions of Phosphorus from Groundwater to Streams in the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces, Eastern United States

Science.gov (United States)

Denver, Judith M.; Cravotta,, Charles A.; Ator, Scott W.; Lindsey, Bruce D.

2011-01-01

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces in the eastern United States were compiled and analyzed to evaluate the sources, fate, and transport of phosphorus. The median concentrations of phosphate in groundwater from the crystalline and siliciclastic bedrock settings (0.017 and 0.020 milligrams per liter, respectively) generally were greater than the median for the carbonate setting (less than 0.01 milligrams per liter). In contrast, the median concentrations of dissolved phosphate in stream base flow from the crystalline and siliciclastic bedrock settings (0.010 and 0.014 milligrams per liter, respectively) were less than the median concentration for base-flow samples from the carbonate setting (0.020 milligrams per liter). Concentrations of phosphorus in many of the stream base-flow and groundwater samples exceeded ecological criteria for streams in the region. Mineral dissolution was identified as the dominant source of phosphorus in the groundwater and stream base flow draining crystalline or siliciclastic bedrock in the study area. Low concentrations of dissolved phosphorus in groundwater from carbonate bedrock result from the precipitation of minerals and (or) from sorption to mineral surfaces along groundwater flow paths. Phosphorus concentrations are commonly elevated in stream base flow in areas underlain by carbonate bedrock, however, presumably derived from in-stream sources or from upland anthropogenic sources and transported along short, shallow groundwater flow paths. Dissolved phosphate concentrations in groundwater were correlated positively with concentrations of silica and sodium, and negatively with alkalinity and concentrations of calcium

Using of CFD software for setting the location of water stream micro turbines

Directory of Open Access Journals (Sweden)

Borsuk Łukasz

2016-01-01

Full Text Available The aim of this work was to estimate the efficiency of CFD software in calculating flow velocity magnitude in natural water streams. These kinds of estimations are essential for setting the locations of water stream micro turbines. These devices can be useful to provide electricity in areas remote from power generating facilities or as backup power supply in case of power grid failure. The analysed water stream has length of 100 m and its average slope was approximately 10%. Water velocity varies in the range from 0.5 m3*s−1 to 5 m3*s−1. Additionally, the influence of ground roughness on the stream velocity was also an important factor. Results proved to be satisfactory. In the analysed stream, velocities were in a range which allows the proposed micro turbine to be effective. Calculation grid created by CFD software did not have many areas which may raise doubts. Also, the influence of changes in the ground roughness factor was noticeable. Preliminary CFD simulations allow to estimate where in the stream the micro turbine will be most efficient. On the other hand, despite these calculations, profitability and return on the investment still can be questionable.

Inventory of power plants in the United States, 1993

International Nuclear Information System (INIS)

1994-12-01

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended

Inventory of power plants in the United States, 1993

Energy Technology Data Exchange (ETDEWEB)

1994-12-01

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), U.S. Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended.

Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

Science.gov (United States)

Fuller, Robert L.

2010-01-01

A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

Detecting climate change oriented and human induced changes in stream temperature across the Southeastern U.S.

Science.gov (United States)

Zhang, X.; Voisin, N.; Cheng, Y.; Niemeyer, R. J.; Nijssen, B.; Yearsley, J. R.; Zhou, T.

2017-12-01

In many areas, climate change is expected to alter the flow regime and increase stream temperature, especially during summer low flow periods. During these low flow periods, water management increases flows in order to sustain human activities such as water for irrigation and hydroelectric power generation. Water extraction from rivers during warm season can increase stream temperature while reservoir regulation may cool downstream river temperatures by releasing cool water from deep layers. Thus, it is reasonable to hypothesize that water management changes the sensitivity of the stream temperature regime to climate change when compared to unmanaged resources. The time of emergence of change refers to the point in time when observations, or model simulations, show statistically significant changes from a given baseline period, i.e. above natural variability. Here we aim to address two questions by investigating the time of emergence of changes in stream temperature in the southeastern United States: what is the sensitivity of stream temperature under regulated flow conditions to climate change and what is the contribution of water management in increasing or decreasing stream temperature sensitivity to climate change. We simulate regulated flow by using runoff from the Variable Infiltration Capacity (VIC) macroscale hydrological model as input into a large scale river routing and reservoir model MOSART-WM. The River Basin Model (RBM), a distributed stream temperature model, includes a two-layer thermal stratification module to simulate stream temperature in regulated river systems. We evaluate the timing of emergence of changes in flow and stream temperature based on climate projections from two representative concentration pathways (RCPs; RCP4.5 and RCP8.5) from the Coupled Model Intercomparison Project Phase 5 (CMIP5). We analyze the difference in emergence of change between natural and regulated streamflow. Insights will be provided toward applications for

Development of a Power Electronics Unit for the Space Station Plasma Contactor

Science.gov (United States)

Hamley, John A.; Hill, Gerald M.; Patterson, Michael J.; Saggio, Joseph, Jr.; Terdan, Fred; Mansell, Justin D.

1994-01-01

A hollow cathode plasma contactor has been baselined as a charge control device for the Space Station (SS) to prevent deleterious interactions of coated structural components with the ambient plasma. NASA LeRC Work Package 4 initiated the development of a plasma contactor system comprised of a Power Electronics Unit (PEU), an Expellant Management Unit (EMU), a command and data interface, and a Plasma Contactor Unit (PCU). A breadboard PEU was designed and fabricated. The breadboard PEU contains a cathode heater and discharge power supply, which were required to operate the PCU, a control and auxiliary power converter, an EMU interface, a command and telemetry interface, and a controller. The cathode heater and discharge supplies utilized a push-pull topology with a switching frequency of 20 kHz and pulse-width-modulated (PWM) control. A pulse ignition circuit derived from that used in arcjet power processors was incorporated in the discharge supply for discharge ignition. An 8088 based microcontroller was utilized in the breadboard model to provide a flexible platform for controller development with a simple command/data interface incorporating a direct connection to SS Mulitplexer/Demultiplexer (MDM) analog and digital I/O cards. Incorporating this in the flight model would eliminate the hardware and software overhead associated with a 1553 serial interface. The PEU autonomously operated the plasma contactor based on command inputs and was successfully integrated with a prototype plasma contactor unit demonstrating reliable ignition of the discharge and steady-state operation.

Sources and preparation of data for assessing trends in concentrations of pesticides in streams of the United States, 1992–2010

Science.gov (United States)

Martin, Jeffrey D.; Eberle, Michael; Nakagaki, Naomi

2011-01-01

This report updates a previously published water-quality dataset of 44 commonly used pesticides and 8 pesticide degradates suitable for a national assessment of trends in pesticide concentrations in streams of the United States. Water-quality samples collected from January 1992 through September 2010 at stream-water sites of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program and the National Stream Quality Accounting Network (NASQAN) were compiled, reviewed, selected, and prepared for trend analysis. The principal steps in data review for trend analysis were to (1) identify analytical schedule, (2) verify sample-level coding, (3) exclude inappropriate samples or results, (4) review pesticide detections per sample, (5) review high pesticide concentrations, and (6) review the spatial and temporal extent of NAWQA pesticide data and selection of analytical methods for trend analysis. The principal steps in data preparation for trend analysis were to (1) select stream-water sites for trend analysis, (2) round concentrations to a consistent level of precision for the concentration range, (3) identify routine reporting levels used to report nondetections unaffected by matrix interference, (4) reassign the concentration value for routine nondetections to the maximum value of the long-term method detection level (maxLT-MDL), (5) adjust concentrations to compensate for temporal changes in bias of recovery of the gas chromatography/mass spectrometry (GCMS) analytical method, and (6) identify samples considered inappropriate for trend analysis. Samples analyzed at the USGS National Water Quality Laboratory (NWQL) by the GCMS analytical method were the most extensive in time and space and, consequently, were selected for trend analysis. Stream-water sites with 3 or more water years of data with six or more samples per year were selected for pesticide trend analysis. The selection criteria described in the report produced a dataset of 21

Low prevalence of chytrid fungus (Batrachochytrium dendrobatidis) in amphibians of U.S. headwater streams

Science.gov (United States)

Hossack, Blake R.; Adams, Michael J.; Campbell Grant, Evan H.; Pearl, Chistopher A.; Bettaso, James B.; Barichivich, William J.; Lowe, Winsor H.; True, Kimberly; Ware, Joy L.; Corn, Paul Stephen

2010-01-01

Many declines of amphibian populations have been associated with chytridiomycosis, a disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd). Despite the relatively high prevalence of chytridiomycosis in stream amphibians globally, most surveys in North America have focused primarily on wetland-associated species, which are frequently infected. To better understand the distribution and prevalence of Bd in headwater amphibian communities, we sampled 452 tailed frogs (Ascaphus truei and Ascaphus montanus) and 304 stream salamanders (seven species in the Dicamptodontidae and Plethodontidae) for Bd in 38, first- to third-order streams in five montane areas across the United States. We tested for presence of Bd by using PCR on skin swabs from salamanders and metamorphosed tailed frogs or the oral disc of frog larvae. We detected Bd on only seven individuals (0.93%) in four streams. Based on our study and results from five other studies that have sampled headwater- or seep-associated amphibians in the United States, Bd has been detected on only 3% of 1,322 individuals from 21 species. These results differ strongly from surveys in Central America and Australia, where Bd is more prevalent on stream-breeding species, as well as results from wetland-associated anurans in the same regions of the United States that we sampled. Differences in the prevalence of Bd between stream- and wetland-associated amphibians in the United States may be related to species-specific variation in susceptibility to chytridiomycosis or habitat differences.

ANNOTATED BIBLIOGRAPHY OF HISTORICAL CONDITIONS IN STREAMS AND RIVERS OF THE WESTERN UNITED STATES

Science.gov (United States)

Resource managers are often challenged by the lack of adequate benchmarks, or reference conditions, for assessing the biological condition of streams. Increasing human alteration of landscapes reduces the availability of minimally-disturbed stream sites that can be used to repre...

Experimental Results From a 2kW Brayton Power Conversion Unit

Science.gov (United States)

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

Evaluation of Perry Nuclear Power Plant Unit 1 technical specifications

International Nuclear Information System (INIS)

Baxter, D.E.; Bruske, S.J.

1985-11-01

This document was prepared for the Nuclear Regulatory Commission (NRC) to assist them in determining whether the Perry Nuclear Power Plant Unit 1 Technical Specifications (T/S), which govern plant systems configurations and operations, are in conformance with the requirements of the Final Safety Analysis Report (FSAR) as amended, and the requirements of the Safety Evaluation Report (SER) as supplemented. A comparative audit of the FSAR as amended, and the SER as supplemented was performed with the Perry T/S. Several discrepancies were identified and subsequently resolved through telephone conversations with the staff reviewer and the utility representative. Pending completion of the resolutions noted in Parts 3 and 4 of this report, the Perry Nuclear Power Plant Unit 1 T/S, to the extent reviewed, are in conformance with the FSAR and SER

Start-up test of Fukushima Daini Nuclear Power Station Unit No.3

International Nuclear Information System (INIS)

Inomata, Toshio; Umezu, Akira; Kajikawa, Makoto; Koibuchi, Hiroshi; Netsu, Nobuhiko.

1986-01-01

In Unit 3 of the Fukushima Nuclear Power Station II (daini), a BWR power plant of output 1,100 MW, commercial operation was started in June 1985. Its start-up test was finished successfully in about nine months. That is, new equipments introduced were demonstration tested. Though the items of testing are increased, the start-up test took short time, resulting in construction period only 54.7 months of the Unit 3, the shortest in the world. During the test, there was no scramming other than the planned. Described are the following: an outline of the Unit 3, the items of its improvement and standardization, including the new equipments, preparations for the start-up test, the start-up test and its evaluation. (Mori, K.)

Primary shutdown system monitoring unit for nuclear power plants

International Nuclear Information System (INIS)

Khan, Tahir Kamal; Balasubramanian, R.; Agilandaeswari, K.

2013-01-01

Shut off rods made up of neutron absorbing material are used as Primary Shutdown System. To reduce the power of the reactor under certain abnormal operating conditions, these rods must go down into the core within a specified time. Any malfunctioning in the movement of rods cannot be tolerated and Secondary Shutdown System (SSS) must be actuated within stipulated time to reduce the reactor power. A special safety critical, hardwired electronics unit has been designed to detect failure of PSS Shut off rods movements and generate trip signals for initiating SSS. (author)

Climate change impacts on thermoelectric-power generation in the United States

Science.gov (United States)

Liu, L.

2015-12-01

Thermoelectric-power generation accounts for more than 70% of the total electricity generation in the United States, which requires large amounts of water for cooling purposes. Water withdrawals for thermoelectric-power generation accounted for 45% of total water use in the United States in 2010. Across the country, water demand from power plants is increasing due to pressures from growing populations and other needs, and is straining existing water resources. Moreover, temperature exceedance in receiving waters has increasingly caused power plants shut downs across parts of the country. Thermoelectric power is vulnerable to climate change owing to the combined effects of lower summer river flows and higher receiving water temperatures. In addition, the efficiency of production is reduced as air temperature rises, which propagates to more unfulfilled power demand during peak seasons. Therefore, a holistic modeling framework of water-energy-climate for the contiguous U.S. is presented here to quantify thermal output from power plants and estimate water use and energy production fluctuations due to ambient climate as well as environmental regulations. The model is calibrated on a plant-by-plant basis for year 2010 and 2011 using the available power plant inventory from the Energy Information Administration (EIA). Simulations were carried out for years 2012 and 2013, and results show moderate improvements in capturing thermal output variabilities after calibration. Future power plant operations under scenarios featuring different climate and regulatory settings were investigated. Results demonstrate the interplay among water, energy and climate, and that future changes in climate and socioeconomics significantly affect power plant operations, which may provide insights to climate change mitigation considerations and energy decisions.

A multi-scaled approach to evaluating the fish assemblage structure within southern Appalachian streams USA.

Science.gov (United States)

Kirsch, Joseph; Peterson, James T.

2014-01-01

There is considerable uncertainty about the relative roles of stream habitat and landscape characteristics in structuring stream-fish assemblages. We evaluated the relative importance of environmental characteristics on fish occupancy at the local and landscape scales within the upper Little Tennessee River basin of Georgia and North Carolina. Fishes were sampled using a quadrat sample design at 525 channel units within 48 study reaches during two consecutive years. We evaluated species–habitat relationships (local and landscape factors) by developing hierarchical, multispecies occupancy models. Modeling results suggested that fish occupancy within the Little Tennessee River basin was primarily influenced by stream topology and topography, urban land coverage, and channel unit types. Landscape scale factors (e.g., urban land coverage and elevation) largely controlled the fish assemblage structure at a stream-reach level, and local-scale factors (i.e., channel unit types) influenced fish distribution within stream reaches. Our study demonstrates the utility of a multi-scaled approach and the need to account for hierarchy and the interscale interactions of factors influencing assemblage structure prior to monitoring fish assemblages, developing biological management plans, or allocating management resources throughout a stream system.

A regional modeling framework of phosphorus sources and transport in streams of the southeastern United States

Science.gov (United States)

Garcia, Ana Maria.; Hoos, Anne B.; Terziotti, Silvia

2011-01-01

We applied the SPARROW model to estimate phosphorus transport from catchments to stream reaches and subsequent delivery to major receiving water bodies in the Southeastern United States (U.S.). We show that six source variables and five land-to-water transport variables are significant (p < 0.05) in explaining 67% of the variability in long-term log-transformed mean annual phosphorus yields. Three land-to-water variables are a subset of landscape characteristics that have been used as transport factors in phosphorus indices developed by state agencies and are identified through experimental research as influencing land-to-water phosphorus transport at field and plot scales. Two land-to-water variables – soil organic matter and soil pH – are associated with phosphorus sorption, a significant finding given that most state-developed phosphorus indices do not explicitly contain variables for sorption processes. Our findings for Southeastern U.S. streams emphasize the importance of accounting for phosphorus present in the soil profile to predict attainable instream water quality. Regional estimates of phosphorus associated with soil-parent rock were highly significant in explaining instream phosphorus yield variability. Model predictions associate 31% of phosphorus delivered to receiving water bodies to geology and the highest total phosphorus yields in the Southeast were catchments with already high background levels that have been impacted by human activity.

Myosin-Powered Membrane Compartment Drives Cytoplasmic Streaming, Cell Expansion and Plant Development.

Science.gov (United States)

Peremyslov, Valera V; Cole, Rex A; Fowler, John E; Dolja, Valerian V

2015-01-01

Using genetic approaches, particle image velocimetry and an inert tracer of cytoplasmic streaming, we have made a mechanistic connection between the motor proteins (myosins XI), cargo transported by these motors (distinct endomembrane compartment defined by membrane-anchored MyoB receptors) and the process of cytoplasmic streaming in plant cells. It is shown that the MyoB compartment in Nicotiana benthamiana is highly dynamic moving with the mean velocity of ~3 μm/sec. In contrast, Golgi, mitochondria, peroxisomes, carrier vesicles and a cytosol flow tracer share distinct velocity profile with mean velocities of 0.6-1.5 μm/sec. Dominant negative inhibition of the myosins XI or MyoB receptors using overexpression of the N. benthamiana myosin cargo-binding domain or MyoB myosin-binding domain, respectively, resulted in velocity reduction for not only the MyoB compartment, but also each of the tested organelles, vesicles and cytoplasmic streaming. Furthermore, the extents of this reduction were similar for each of these compartments suggesting that MyoB compartment plays primary role in cytosol dynamics. Using gene knockout analysis in Arabidopsis thaliana, it is demonstrated that inactivation of MyoB1-4 results in reduced velocity of mitochondria implying slower cytoplasmic streaming. It is also shown that myosins XI and MyoB receptors genetically interact to contribute to cell expansion, plant growth, morphogenesis and proper onset of flowering. These results support a model according to which myosin-dependent, MyoB receptor-mediated transport of a specialized membrane compartment that is conserved in all land plants drives cytoplasmic streaming that carries organelles and vesicles and facilitates cell growth and plant development.

Water Stress on U.S. Power Production at Decadal Time Horizons

Energy Technology Data Exchange (ETDEWEB)

Ganguly, Auroop R. [Northeastern Univ., Boston, MA (United States). Sustainability and Data Sciences Lab.. Civil and Environmental Engineering Dept.; Ganguli, Poulomi [Northeastern Univ., Boston, MA (United States). Sustainability and Data Sciences Lab.; Kumar, Devashish [Northeastern Univ., Boston, MA (United States). Sustainability and Data Sciences Lab.

2014-09-01

Thermoelectric power production at risk, owing to current and projected water scarcity and rising stream temperatures, is assessed for the contiguous United States at decadal scales. Regional water scarcity is driven by climate variability and change, as well as by multi-sector water demand. While a planning horizon of zero to about thirty years is occasionally prescribed by stakeholders, the challenges to risk assessment at these scales include the difficulty in delineating decadal climate trends from intrinsic natural or multiple model variability. Current generation global climate or earth system models are not credible at the spatial resolutions of power plants, especially for surface water quantity and stream temperatures, which further exacerbates the assessment challenge. Population changes, which are difficult to project, cannot serve as adequate proxies for changes in the water demand across sectors. The hypothesis that robust assessments of power production at risk are possible, despite the uncertainties, has been examined as a proof of concept. An approach is presented for delineating water scarcity and temperature from climate models, observations and population storylines, as well as for assessing power production at risk by examining geospatial correlations of power plant locations within regions where the usable water supply for energy production happens to be scarcer and warmer. Our analyses showed that in the near term, more than 200 counties are likely to be exposed to water scarcity in the next three decades. Further, we noticed that stream gauges in more than five counties in the 2030s and ten counties in the 2040s showed a significant increase in water temperature, which exceeded the power plant effluent temperature threshold set by the EPA. Power plants in South Carolina, Louisiana, and Texas are likely to be vulnerable owing to climate driven water stresses. In all, our analysis suggests that under various combinations of plausible climate

Risk of nuclear power generation as business (continued)

International Nuclear Information System (INIS)

Sato, Satoshi

2017-01-01

This paper described the following: (1) fleet formation of power companies that operate nuclear power plants in the U.S., (2) collaboration, competition, and merger between plant makers, (3) stress corrosion cracking of stream generators for PWR and their thin heat transfer tubes, especially stress corrosion cracking under primary cooling water environment (PWSCC), and (4) replacement project from Inconel 600 MA to Inconel 600 TT or 690 TT of steam generator thin heat transfer tubes of PWR plants in the U.S. and others. In addition, it described the troubles at San Onofre Nuclear Power Station in California: wear of steam generator thin tubes of Units 2 and 3, and leakage from primary system to secondary system of Unit 3, and permanent shutdown. It also described the detail of damages compensation talks between South California Edison Company that operates San Onofre nuclear power plant and Mitsubishi Heavy Industries Ltd. which supplied the steam generator. Although the operation of the 1.7 million kW plant became impossible due to the bud shedding of nuclear power renaissance, these troubles might have saved the nightmare of drifting on the way. (A.O.)

Wave power as a source of energy along the Indian coast

Digital Repository Service at National Institute of Oceanography (India)

Das, V.K.

stream_size 16 stream_content_type text/plain stream_name Power_Directory_1992_141.pdf.txt stream_source_info Power_Directory_1992_141.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Strategies for managing the effects of urban development on streams

Science.gov (United States)

Cappiella, Karen; Stack, William P.; Fraley-McNeal, Lisa; Lane, Cecilia; McMahon, Gerard

2012-01-01

Urban development remains an important agent of environmental change in the United States. The U.S. population grew by 17 percent from 1982 to 1997, while urbanized land area grew by 47 percent, suggesting that urban land consumption far outpaced population growth (Fulton and others, 2001; Sierra Club, 2003; American Farmland Trust, 2009). Eighty percent of Americans now live in metropolitan areas. Each American effectively occupies about 20 percent more developed land (for housing, schools, shopping, roads, and other related services) than 20 years ago (Markham and Steinzor, 2006). Passel and Cohn (2008) predict a dramatic 48 percent increase in the population of the United States from 2005 to 2050. The advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the day-to-day realities of most Americans. Nowhere are the environmental changes associated with urban development more evident than in urban streams. The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program investigation of the effects of urban development on stream ecosystems (EUSE) during 1999–2004 provides the most spatially comprehensive analysis of stream impacts of urban development that has been completed in the United States. A nationally consistent study design was used in nine metropolitan areas of the United States—Portland, Oregon; Salt Lake City, Utah; Birmingham, Alabama; Atlanta, Georgia; Raleigh, North Carolina; Boston, Massachusetts; Denver, Colorado; Dallas, Texas; and Milwaukee, Wisconsin. A summary report published as part of the EUSE study describes several of these impacts on urban streams (Coles and others, 2012).

Green Power Marketing in the United States: A Status Report (2008 Data)

Energy Technology Data Exchange (ETDEWEB)

Bird, L.; Kreycik, C.; Friedman, B.

2009-09-01

Voluntary consumer decisions to buy electricity supplied from renewable energy sources represent a powerful market support mechanism for renewable energy development. In the early 1990s, a small number of U.S. utilities began offering 'green power' options to their customers. Since then, these products have become more prevalent, both from traditional utilities and from renewable energy marketers operating in states that have introduced competition into their retail electricity markets or offering renewable energy certificates (RECs) online. Today, more than half of all U.S. electricity customers have an option to purchase some type of green power product directly from a retail electricity provider, while all consumers have the option to purchase RECs. This report documents green power marketing activities and trends in the United States including utility green pricing programs offered in regulated electricity markets; green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of RECs; and renewable energy sold as greenhouse gas offsets in the United States. These sections are followed by a discussion of key market trends and issues. The final section offers conclusions and observations.

Green Power Marketing in the United States. A Status Report (2008 Data)

Energy Technology Data Exchange (ETDEWEB)

Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kreycik, Claire [National Renewable Energy Lab. (NREL), Golden, CO (United States); Friedman, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2009-09-01

Voluntary consumer decisions to buy electricity supplied from renewable energy sources represent a powerful market support mechanism for renewable energy development. In the early 1990s, a small number of U.S. utilities began offering 'green power' options to their customers. Since then, these products have become more prevalent, both from traditional utilities and from renewable energy marketers operating in states that have introduced competition into their retail electricity markets or offering renewable energy certificates (RECs) online. Today, more than half of all U.S. electricity customers have an option to purchase some type of green power product directly from a retail electricity provider, while all consumers have the option to purchase RECs. This report documents green power marketing activities and trends in the United States including utility green pricing programs offered in regulated electricity markets; green power marketing activity in competitive electricity markets, as well as green power sold to voluntary purchasers in the form of RECs; and renewable energy sold as greenhouse gas offsets in the United States. These sections are followed by a discussion of key market trends and issues. The final section offers conclusions and observations.

Browns Ferry Nuclear Power Station, Units 1, 2, and 3. Annual operating report: January--December 1976

International Nuclear Information System (INIS)

1977-01-01

Units 1 and 2 were down for the first half of the year caused by the fire of March 1975. Net electrical power generated by Unit 1 this year was 1,301,183 MWH with the generator on line 2,175.25 hrs. Unit 2 generated 1,567,170 MWH with the generator on line 2,548.73 hrs. Unit 3 began full power operation on November 20th and generated 1,416,891 MWH with the generator on line 2,058.20 hrs. Information is presented concerning operations, fuel performance, surveillance testing, containment leak testing, changes, power generation, shutdown and forced reductions, coolant chemistry, occupational radiation exposures, and maintenance

Accident analysis of Fukushima Daiichi Nuclear Power Station unit 1

International Nuclear Information System (INIS)

Kobayashi, Masahide; Narabayashi, Tadashi; Tsuji, Masashi; Chiba, Go; Nagata, Yasunori; Shimoe, Tomohiro

2015-01-01

As a result of the Great East Japan Earthquake that occurred on 11 March 2011, all AC and DC power at the Fukushima Daiichi NPP units 1 to 3 were lost soon after the tsunami. The core cooling function was lost, and the cores of units 1 to 3 were damaged. The purpose of this work is to clarify the progress of the accident in unit 1, which was damaged the earliest among the 3 units. Therefore, an original severe accident analysis code was developed, and the progress of the accident was evaluated from the analysis results and the actual data. As a result, the leakage path from a pressure vessel was clarified, and some lessons and knowledge were gained. (author)

Hydroelectric plant turbine, stream and spillway flow measurement

Energy Technology Data Exchange (ETDEWEB)

Lampa, J.; Lemon, D.; Buermans, J. [ASL AQ Flow Inc., Sidney, BC (Canada)

2004-07-01

This presentation provided schematics of the turbine flow measurements and typical bulb installations at the Kootenay Canal and Wells hydroelectric power facilities in British Columbia. A typical arrangement for measuring stream flow using acoustic scintillation was also illustrated. Acoustic scintillation is portable, non-intrusive, suitable for short intakes, requires minimal maintenance and is cost effective and accurate. A comparison between current meters and acoustic scintillation was also presented. Stream flow measurement is valuable in evaluating downstream areas that are environmentally important for fish habitat. Stream flow measurement makes it possible to define circulation. The effects of any changes can be assessed by combining field measurements and numerical modelling. The presentation also demonstrated that computational fluid dynamics modelling appears promising in determining stream flow and turbulent flow at spillways. tabs., figs.

Relative Linkages of Stream Dissolved Oxygen with the Hydroclimatic and Biogeochemical Drivers across the Gulf Coast of U.S.A.

Science.gov (United States)

Gebreslase, A. K.; Abdul-Aziz, O. I.

2017-12-01

Dynamics of coastal stream water quality is influenced by a multitude of interacting environmental drivers. A systematic data analytics approach was employed to determine the relative linkages of stream dissolved oxygen (DO) with the hydroclimatic and biogeochemical variables across the Gulf Coast of U.S.A. Multivariate pattern recognition techniques of PCA and FA, alongside Pearson's correlation matrix, were utilized to examine the interrelation of variables at 36 water quality monitoring stations from USGS NWIS and EPA STORET databases. Power-law based partial least square regression models with a bootstrap Monte Carlo procedure (1000 iterations) were developed to estimate the relative linkages of dissolved oxygen with the hydroclimatic and biogeochemical variables by appropriately resolving multicollinearity (Nash-Sutcliffe efficiency = 0.58-0.94). Based on the dominant drivers, stations were divided into four environmental regimes. Water temperature was the dominant driver of DO in the majority of streams, representing most the northern part of Gulf Coast states. However, streams in the southern part of Texas and Florida showed a dominant pH control on stream DO. Further, streams representing the transition zone of the two environmental regimes showed notable controls of multiple drivers (i.e., water temperature, stream flow, and specific conductance) on the stream DO. The data analytics research provided profound insight to understand the dynamics of stream DO with the hydroclimatic and biogeochemical variables. The knowledge can help water quality managers in formulating plans for effective stream water quality and watershed management in the U.S. Gulf Coast. Keywords Data analytics, coastal streams, relative linkages, dissolved oxygen, environmental regimes, Gulf Coast, United States.

Crevasse-squeeze ridge corridors: Diagnostic features of late-stage palaeo-ice stream activity

Science.gov (United States)

Evans, David J. A.; Storrar, Robert D.; Rea, Brice R.

2016-04-01

A 200-km-long and 10-km-wide linear assemblage of till-filled geometrical ridges on the bed of the Maskwa palaeo-ice stream of the late Wisconsinan southwest Laurentide Ice Sheet are interpreted as crevasse-squeeze ridges (CSR) developed during internal flow unit reorganization, immediately prior to ice stream shutdown. Ridge orientations are predominantly orientated WNW-ESE, with a subordinate WSW-ENE alignment, both indicative of ice fracture development transverse to former ice stream flow, as indicated by NNE-SSW aligned MSGL. Subglacial till injection into basal and/or full depth, mode I and II crevasses occurred at the approximate centreline of the ice stream, in response to extension and fracturing. Landform preservation indicates that this took place during the final stages of ice streaming, immediately prior to ice stream shutdown. This linear zone of ice fracturing therefore likely represents the narrowing of the fast-flowing trunk, similar to the plug flow identified in some surging valley glaciers. Lateral drag between the final active flow unit and the slower moving ice on either side is likely recorded by the up-ice bending of the CSR limbs. The resulting CSR corridor, here related to an individual ice stream flow unit, constitutes a previously unreported style of crevasse infilling and contrasts with two existing CSR patterns: (1) wide arcuate zones of CSRs related to widespread fracturing within glacier surge lobes; and (2) narrow concentric arcs of CSRs and recessional push moraines related to submarginal till deformation at active temperate glacier lobes.

Standardization of nuclear power plants in the United States: recent regulatory developments

International Nuclear Information System (INIS)

Cowan, B.Z.; Tourtellotte, J.R.

1992-01-01

On April 18, 1989, the United States (U.S.) Nuclear Regulatory Commission (NRC) amended the regulations governing the process for licensing nuclear power plants in the United States to provide for issuance of early site permits, standard design certifications and combined construction permits and operating licenses for nuclear power reactors. The new regulations are designed to achieve early resolution of licensing issues and facilitate standardization of nuclear power plants in the United States. The program for design standardization is central to efforts mounted by the U.S. government and industry to ensure that there will be a next generation of nuclear power facilities in the U.S. The most significant changes are provisions for certification of standard designs and for issuance prior to start of construction of combined licenses which incorporate a construction permit and an operating license with conditions. Such certifications and combined licenses must contain tests, inspections and analyses, and acceptance criteria, which are necessary and sufficient to provide reasonable assurance that the facility has been constructed and will operate in accordance with the combined license. A number of significant implementation issues have arisen. In addition a major court case brought by several anti-nuclear groups is pending, challenging NRC authority to issue combined licenses. It is the goal of the U.S. nuclear industry to have the first of the next generation of standardized nuclear power plants ordered, licensed, constructed and on-line by the year 2000. (author)

ASP - Grid connections of large power generating units; ASP - Anslutning av stoerre produktionsanlaeggningar till elnaetet

Energy Technology Data Exchange (ETDEWEB)

Larsson, Aake; Larsson, Richard [Vattenfall Power Consultants, Stockholm (Sweden)

2006-12-15

Grid connections of large power generating units normally require more detailed studies compared to small single units. The required R and D-level depends on the specific characteristics of the production units and the connecting grid. An inquiry for a grid connection will raise questions for the grid owner regarding transmission capability, losses, fault currents, relay protection, dynamic stability etc. Then only a few larger wind farms have been built, the experiences from these types of grid connections are limited and for that reason it can be difficult to identify issues appropriate for further studies. To ensure that electric power generating units do not have unacceptable impact on the grid, directions from the Swedish TSO (Svenska Kraftnaet) have been stated. The directions deal, for example, with power generation in specific ranges of voltage level and frequency and the possibility to remain connected to the grid when different faults occur. The requirements and the consequences of these directions are illustrated. There are three main issues that should be considered: Influence on the power flow from generating units regarding voltage level, currents, losses etc.; Different types of electric systems in generating units contribute to different levels of fault currents. For that reason the resulting fault current levels have to be studied; It is required that generating units should remain connected to the grid at different modes of operation and faults. These modes have to be verified. Load flow and dynamic studies normally demand computer models. Comprehensive models, for instance of wind farms, can bee difficult to design and normally large computer capacity is required. Therefore simplified methods to perform relevant studies are described. How to model an electric power generating unit regarding fault currents and dynamic stability is described. An inquiry for a grid connection normally brings about a discussion concerning administration. To make it

Improved gravitational search algorithm for unit commitment considering uncertainty of wind power

International Nuclear Information System (INIS)

Ji, Bin; Yuan, Xiaohui; Chen, Zhihuan; Tian, Hao

2014-01-01

With increasing wind farm integrations, unit commitment (UC) is more difficult to solve because of the intermittent and fluctuation nature of wind power. In this paper, scenario generation and reduction technique is applied to simulate the impacts of its uncertainty on system operation. And then a model of thermal UC problem with wind power integration (UCW) is established. Combination of quantum-inspired binary gravitational search algorithm (GSA) and scenario analysis method is proposed to solve UCW problem. Meanwhile, heuristic search strategies are used to handle the constraints of thermal unit for each scenario. In addition, a priority list of thermal units based on the weight between average full-load cost and maximal power output is utilized during the optimization process. Moreover, two UC test systems with and without wind power integration are used to verify the feasibility and effectiveness of the proposed method as well as the performance of the algorithm. The results are analyzed in detail, which demonstrate the model and the proposed method is practicable. The comparison with other methods clearly shows that the proposed method has higher efficiency for solving UC problems with and even without wind farm integration. - Highlights: • Impact of wind fluctuation on unit commitment problem (UCW) is investigated. • Quantum-inspired gravitational search algorithm (QBGSA) is used to optimize UC. • A new method combines QBGSA with scenario analysis is proposed to solve UCW. • Heuristic search strategies are applied to handle the constraints of the UCW. • The results verify the proposed method is feasible and efficient for handling UCW

Power enhancing by reversing mode sequence in tuned mass-spring unit attached vibration energy harvester

Directory of Open Access Journals (Sweden)

Jae Eun Kim

2013-07-01

Full Text Available We propose a vibration energy harvester consisting of an auxiliary frequency-tuned mass unit and a piezoelectric vibration energy harvesting unit for enhancing output power. The proposed integrated system is so configured that its out-of-phase mode can appear at the lowest eigenfrequency unlike in the conventional system using a tuned unit. Such an arrangement makes the resulting system distinctive: enhanced output power at or near the target operating frequency and very little eigenfrequency separation, not observed in conventional eigenfrequency-tuned vibration energy harvesters. The power enhancement of the proposed system is theoretically examined with and without tip mass normalization or footprint area normalization.

Shortening start-up and an extension of the power unit load range

Directory of Open Access Journals (Sweden)

Taler Jan

2017-01-01

Full Text Available A power plant with additional water pressure tanks was proposed. The maximum rise in the block electric power resulting from the shut-off of low-pressure regenerative heaters was determined. At that time, the boiler is fed with hot water from water pressure tanks acting as heat accumulators. Accumulation of hot water in water tanks is also proposed in the periods of the power unit small load. In order to lower the plant electric power in the off-peak night hours, water heated to the nominal temperature in low-pressure regenerative heaters is directed from the feed water tank to pressure tanks. The water accumulated during the night is used to feed the boiler during the period of peak demand for electricity. Pressure accumulators are proposed to be used for the rapid start-up of the boiler from a cold state. The evaporator of the boiler is filled at the beginning of start-up with hot water from the accumulators. Drops in the power block electric power were determined for different capacities of the tanks and periods when they are charged. The tanks may also be used to ensure a sudden increase in the electric power of the unit that is operating in the automatic system of frequency and power control (in Polish: ARCM.

Day-Ahead Coordination of Vehicle-to-Grid Operation and Wind Power in Security Constraints Unit Commitment (SCUC

Directory of Open Access Journals (Sweden)

Mohammad Javad Abdollahi

2015-08-01

Full Text Available In this paper security constraints unit commitment (SCUC in the presence of wind power resources and electrical vehicles to grid is presented. SCUC operation prepare an optimal time table for generation unit commitment in order to maximize security, minimize operation cost and satisfy the constraints of networks and units in a period of time, as one of the most important research interest in power systems. Today, the relationship between power network and energy storage systems is interested for many researchers and network operators. Using Electrical Vehicles (PEVs and wind power for energy production is one of the newest proposed methods for replacing fossil fuels.One of the effective strategies for analyzing of the effects of Vehicle 2 Grid (V2G and wind power in optimal operation of generation is running of SCUC for power systems that are equipped with V2G and wind power resources. In this paper, game theory method is employed for deterministic solution of day-ahead unit commitment with considering security constraints in the simultaneous presence of V2G and wind power units. This problem for two scenarios of grid-controlled mode and consumer-controlled mode in three different days with light, medium and heavy load profiles is analyzed. Simulation results show the effectiveness of the presence of V2G and wind power for decreasing of generation cost and improving operation indices of power systems.

Station black out of Fukushima Daiichi Nuclear Power Station Unit 1 was not caused by tsunamis

International Nuclear Information System (INIS)

Ito, Yoshinori

2013-01-01

Station black out (SBO) of Fukushima Daiichi Nuclear Power Station Unit 1 would be concluded to be caused before 15:37 on March 11, 2011 because losses of emergency ac power A system was in 15:36 and ac losses of B system in 15:37 according to the data published by Tokyo Electric Power Co. (TEPCO) in May 10, 2013. Tsunami attacked the site of Fukushima Daiichi Nuclear Power Station passed through the position of wave amplitude meter installed at 1.5 km off the coast after 15:35 and it was also recognized tsunami arrived at the coast of Unit 4 sea side area around in 15:37 judging from a series of photographs taken from the south side of the site and general knowledge of wave propagation. From a series of photographs and witness testimony, tsunami didn't attack Fukushima Daiichi Nuclear Power Station uniformly and tsunami's arrival time at the site of Unit 1 would be far later than arrival time at the coast of Unit 4 sea side area, which suggested it would be around in 15:39. TEPCO insisted tsunami passed through 1.5 km off the coast around in 15:33 and clock of wave amplitude meter was incorrect, which might be wrong. Thus SBO of Fukushima Daiichi Nuclear Power Station Unit 1 occurred before tsunami's arrival at the site of Unit 1 and was not caused by tsunami. (T. Tanaka)

Model for Estimating Power and Downtime Effects on Teletherapy Units in Low-Resource Settings

Directory of Open Access Journals (Sweden)

Rachel McCarroll

2017-10-01

Full Text Available Purpose: More than 6,500 megavoltage teletherapy units are needed worldwide, many in low-resource settings. Cobalt-60 units or linear accelerators (linacs can fill this need. We have evaluated machine performance on the basis of patient throughput to provide insight into machine viability under various conditions in such a way that conclusions can be generalized to a vast array of clinical scenarios. Materials and Methods: Data from patient treatment plans, peer-reviewed studies, and international organizations were combined to assess the relative patient throughput of linacs and cobalt-60 units that deliver radiotherapy with standard techniques under various power and maintenance support conditions. Data concerning the frequency and duration of power outages and downtime characteristics of the machines were used to model teletherapy operation in low-resource settings. Results: Modeled average daily throughput was decreased for linacs because of lack of power infrastructure and for cobalt-60 units because of limited and decaying source strength. For conformal radiotherapy delivered with multileaf collimators, average daily patient throughput over 8 years of operation was equal for cobalt-60 units and linacs when an average of 1.83 hours of power outage occurred per 10-hour working day. Relative to conformal treatments delivered with multileaf collimators on the respective machines, the use of advanced techniques on linacs decreased throughput between 20% and 32% and, for cobalt machines, the need to manually place blocks reduced throughput up to 37%. Conclusion: Our patient throughput data indicate that cobalt-60 units are generally best suited for implementation when machine operation might be 70% or less of total operable time because of power outages or mechanical repair. However, each implementation scenario is unique and requires consideration of all variables affecting implementation.

Hydrogen recovery by pressure swing adsorption. [From ammonia purge-gas streams

Energy Technology Data Exchange (ETDEWEB)

1979-06-01

A pressure swing absorption process (PSA) designed to recover H/sub 2/ from ammonia purge-gas streams developed by Bergbarr-Forschung GmbH of West Germany is reviewed. The PSA unit is installed in the process stream after the ammonia absorber unit which washes the ammonia-containing purge gas which consists of NH/sub 3/, H/sub 2/O, CH/sub 4/, Ar, N/sub 2/, and H/sub 2/. Usually 4 absorber units containing carbon molecular sieves make up the PSA unit; however, only one unit is generally used to absorb all components except H/sub 2/ while the other units are being regenerated by depressurization. Economic comparisons of the PSA process with a cryogenic process indicate that for some ammonia plants there may be a 30% saving in fuel gas requirements with the PSA system. The conditions of the purge gas strongly influence which system of recovery is more suitable.

Fuel defect detection, localization and removal in Bruce Power units 3 through 8

International Nuclear Information System (INIS)

Stone, R.; Armstrong, J.; Iglesias, F.; Oduntan, R.; Lewis, B.

2005-01-01

Fuel element defects are occurring in Bruce 'A' and Bruce 'B' Units. A root-cause investigation is ongoing, however, a solution is not yet in-hand. Fuel defect management efforts have been undertaken, therefore, in the interim. Fuel defect management tools are in-place for all Bruce Units. These tools can be categorized as analysis-based or operations-based. Analysis-based tools include computer codes used primarily for fuel defect characterization, while operations-based tools include Unit-specific delayed-neutron ('DN') monitoring systems and gaseous fission product ('GFP') monitoring systems. Operations-based tools are used for fuel defect detection, localization and removal activities. Fuel and Physics staff use defect detection, localization and removal methodologies and guidelines to disposition fuel defects. Methodologies are 'standardized' or 'routine' procedures for implementing analysis-based and operations-based tools to disposition fuel defects during Unit start-up operation and during operation at high steady-state power levels. Guidelines at present serve to supplement fuel defect management methodologies during Unit power raise. (author)

Theoretical parameter histories of dynamic tests during power commissioning of Mochovce units power level up to 100 % Nnom

International Nuclear Information System (INIS)

Jagrik, J.; Mraz, M.; Rapant, M.; Stefanovic, P.; Kotasek, J.; Gieci, A.; Macko, J.; Mosny, J.

1998-01-01

Theoretical histories of selected parameters for dynamic tests carried out in the course of power commissioning of the Mochovce Unit 1 at the power level 100% N nom are shown in the report. The expected histories given were developed based on calculations performed by means of simulator in Nuclear Power Plants Research Institute Trnava, Inc., simulator in EGU Praha and simulator at the Mochovce plant, as well as based on similar tests at both Bohunice and Dukovany plants

Inventory of Power Plants in the United States, October 1992

Energy Technology Data Exchange (ETDEWEB)

1993-10-27

The Inventory of Power Plants in the United States is prepared annually by the Survey Management Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), US Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units operated by electric utilities in the United States (the 50 States and the District of Columbia). The publication also provides a 10-year outlook of future generating unit additions. Data summarized in this report are useful to a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. Data presented in this report were assembled and published by the EIA to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. The report is organized into the following chapters: Year in Review, Operable Electric Generating Units, and Projected Electric Generating Unit Additions. Statistics presented in these chapters reflect the status of electric generating units as of December 31, 1992.

Assessment of Energy Production Potential from Ocean Currents along the United States Coastline

Energy Technology Data Exchange (ETDEWEB)

Haas, Kevin

2013-09-15

Increasing energy consumption and depleting reserves of fossil fuels have resulted in growing interest in alternative renewable energy from the ocean. Ocean currents are an alternative source of clean energy due to their inherent reliability, persistence and sustainability. General ocean circulations exist in the form of large rotating ocean gyres, and feature extremely rapid current flow in the western boundaries due to the Coriolis Effect. The Gulf Stream system is formed by the western boundary current of the North Atlantic Ocean that flows along the east coastline of the United States, and therefore is of particular interest as a potential energy resource for the United States. This project created a national database of ocean current energy resources to help advance awareness and market penetration in ocean current energy resource assessment. The database, consisting of joint velocity magnitude and direction probability histograms, was created from data created by seven years of numerical model simulations. The accuracy of the database was evaluated by ORNL?s independent validation effort documented in a separate report. Estimates of the total theoretical power resource contained in the ocean currents were calculated utilizing two separate approaches. Firstly, the theoretical energy balance in the Gulf Stream system was examined using the two-dimensional ocean circulation equations based on the assumptions of the Stommel model for subtropical gyres with the quasi-geostrophic balance between pressure gradient, Coriolis force, wind stress and friction driving the circulation. Parameters including water depth, natural dissipation rate and wind stress are calibrated in the model so that the model can reproduce reasonable flow properties including volume flux and energy flux. To represent flow dissipation due to turbines additional turbine drag coefficient is formulated and included in the model. Secondly, to determine the reasonableness of the total power

Determination of technical and economic parameters of an ionic transport membrane air separation unit working in a supercritical power plant

Directory of Open Access Journals (Sweden)

Kotowicz Janusz

2016-09-01

Full Text Available In this paper an air separation unit was analyzed. The unit consisted of: an ionic transport membrane contained in a four-end type module, an air compressor, an expander fed by gas that remains after oxygen separation and heat exchangers which heat the air and recirculated flue gas to the membrane operating temperature (850 °C. The air separation unit works in a power plant with electrical power equal to 600 MW. This power plant additionally consists of: an oxy-type pulverized-fuel boiler, a steam turbine unit and a carbon dioxide capture unit. Life steam parameters are 30 MPa/650 °C and reheated steam parameters are 6 MPa/670 °C. The listed units were analyzed. For constant electrical power of the power plant technical parameters of the air separation unit for two oxygen recovery rate (65% and 95% were determined. One of such parameters is ionic membrane surface area. In this paper the formulated equation is presented. The remaining technical parameters of the air separation unit are, among others: heat exchange surface area, power of the air compressor, power of the expander and auxiliary power. Using the listed quantities, the economic parameters, such as costs of air separation unit and of individual components were determined. These quantities allowed to determine investment costs of construction of the air separation unit. In addition, they were compared with investment costs for the entire oxy-type power plant.

Purchasing power parity in OECD countries: nonlinear unit root tests revisited

OpenAIRE

Juan Carlos Cuestas; Paulo José Regis

2010-01-01

The aim of this paper is to provide additional evidence on the purchasing power parity empirical fulfillment in a pool of OECD countries. We apply the Harvey et al. (2008) linearity test and the Kruse (2010) nonlinear unit root test. The results point to the fact that the purchasing power parity theory holds in a greater number of countries than has been reported in previous studies.

Mathematical models of power plant units with once-through steam generators

International Nuclear Information System (INIS)

Hofmeister, W.; Kantner, A.

1977-01-01

An optimization of effective control functions with the current complex control loop structures and control algorithms is practically not possible. Therefore computer models are required which may be optimized with the process and plant data known before start-up of thermal power plants. The application of process computers allows additional predictions on the control-dynamic behavior of a thermal power plant unit. (TK) [de

Cooling unit for a superconducting power cable. Two years successful operation

Energy Technology Data Exchange (ETDEWEB)

Herzog, Friedhelm [Messer Group GmbH, Krefeld (Germany); Kutz, Thomas [Messer Industriegase GmbH, Bad Soden (Germany); Stemmle, Mark [Nexans Deutschland GmbH, Hannover (Germany); Kugel, Torsten [Westnetz GmbH, Essen (Germany)

2016-07-01

High temperature super conductors (HTS) can efficiently be cooled with liquid nitrogen down to a temperature of 64 K (-209 C). Lower temperatures are not practical, because nitrogen becomes solid at 63 K (-210 C). To achieve this temperature level the coolant has to be vaporized below atmospheric pressure. Messer has developed a cooling unit with an adequate vacuum subcooler, a liquid nitrogen circulation system, and a storage vessel for cooling an HTS power cable. The cooling unit was delivered in 2013 for the German AmpaCity project of RWE Deutschland AG, Nexans and Karlsruhe Institute of Technology. Within this project RWE and Nexans installed the worldwide longest superconducting power cable in the city of Essen, Germany. The cable is in operation since March 10th, 2014.

Audit Calculations of LBLOCA for Ulchin Unit 1 and 2 Power Up rate

Energy Technology Data Exchange (ETDEWEB)

Kang, Donggu; Huh, Byunggil; Yoo, Seunghunl; Yang, Chaeyong; Seul, Kwangwon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2013-05-15

The KINS-Realistic Evaluation Model (KINS-REM) was developed for the independent audit calculation in 1991, and the code accuracy and statistical method have been improved. To support the licensing review and to confirm the validity of licensee's calculation, regulatory auditing calculations have been also conducted. Currently, the modification of Ulchin 1 and 2 operating license for 4.5% power up rate is under review. In this study, the regulatory audit calculation for LBLOCA of Ulchin Unit 1 and 2 with 4.5% power up rate was performed by applying KINS-REM. In this study, the regulatory audit calculation for LBLOCA of Ulchin Unit 1 and 2 with 4.5% power up rate was performed by applying KINS-REM. It is confirmed that the analysis results of LBLOCA for Ulchin 1 and 2 power up rate meets the PCT acceptance criteria.

Study of regeneration system of 300 MW power unit based on nondeaerating heat balance diagram at reduced load

Science.gov (United States)

Esin, S. B.; Trifonov, N. N.; Sukhorukov, Yu. G.; Yurchenko, A. Yu.; Grigor'eva, E. B.; Snegin, I. P.; Zhivykh, D. A.; Medvedkin, A. V.; Ryabich, V. A.

2015-09-01

More than 30 power units of thermal power stations, based on the nondeaerating heat balance diagram, successfully operate in the former Soviet Union. Most of them are power units with a power of 300 MW, equipped with HTGZ and LMZ turbines. They operate according to a variable electric load curve characterized by deep reductions when undergoing night minimums. Additional extension of the range of power unit adjustment makes it possible to maintain the dispatch load curve and obtain profit for the electric power plant. The objective of this research is to carry out estimated and experimental processing of the operating regimes of the regeneration system of steam-turbine plants within the extended adjustment range and under the conditions when the constraints on the regeneration system and its equipment are removed. Constraints concerning the heat balance diagram that reduce the power unit efficiency when extending the adjustment range have been considered. Test results are presented for the nondeaerating heat balance diagram with the HTGZ turbine. Turbine pump and feed electric pump operation was studied at a power unit load of 120-300 MW. The reliability of feed pump operation is confirmed by a stable vibratory condition and the absence of cavitation noise and vibration at a frequency that characterizes the cavitation condition, as well as by oil temperature maintenance after bearings within normal limits. Cavitation performance of pumps in the studied range of their operation has been determined. Technical solutions are proposed on providing a profitable and stable operation of regeneration systems when extending the range of adjustment of power unit load. A nondeaerating diagram of high-pressure preheater (HPP) condensate discharge to the mixer. A regeneration system has been developed and studied on the operating power unit fitted with a deaeratorless thermal circuit of the system for removing the high-pressure preheater heating steam condensate to the mixer

Site selection and evaluation of nuclear power units in Egypt

International Nuclear Information System (INIS)

Bonnefille, R.

1980-01-01

The selection of sites for nuclear power units in Egypt by SOFRATOME for Nuclear Plants Authority is carried on using a method based on interaction between different criteria. The method and the main results on criterion 'radio-ecological impact' are sketched briefly [fr

Day-Ahead Coordination of Vehicle-to-Grid Operation and Wind Power in Security Constraints Unit Commitment (SCUC)

OpenAIRE

Mohammad Javad Abdollahi; Majid Moazzami

2015-01-01

In this paper security constraints unit commitment (SCUC) in the presence of wind power resources and electrical vehicles to grid is presented. SCUC operation prepare an optimal time table for generation unit commitment in order to maximize security, minimize operation cost and satisfy the constraints of networks and units in a period of time, as one of the most important research interest in power systems. Today, the relationship between power network and energy storage systems is interested...

A Three-Stage Birandom Program for Unit Commitment with Wind Power Uncertainty

Directory of Open Access Journals (Sweden)

Na Zhang

2014-01-01

Full Text Available The integration of large-scale wind power adds a significant uncertainty to power system planning and operating. The wind forecast error is decreased with the forecast horizon, particularly when it is from one day to several hours ahead. Integrating intraday unit commitment (UC adjustment process based on updated ultra-short term wind forecast information is one way to improve the dispatching results. A novel three-stage UC decision method, in which the day-ahead UC decisions are determined in the first stage, the intraday UC adjustment decisions of subfast start units are determined in the second stage, and the UC decisions of fast-start units and dispatching decisions are determined in the third stage is presented. Accordingly, a three-stage birandom UC model is presented, in which the intraday hours-ahead forecasted wind power is formulated as a birandom variable, and the intraday UC adjustment event is formulated as a birandom event. The equilibrium chance constraint is employed to ensure the reliability requirement. A birandom simulation based hybrid genetic algorithm is designed to solve the proposed model. Some computational results indicate that the proposed model provides UC decisions with lower expected total costs.

Photovoltaic power stations in Germany and the United States: A comparative study by data envelopment analysis

International Nuclear Information System (INIS)

Sueyoshi, Toshiyuki; Goto, Mika

2014-01-01

This study compares Photovoltaic (PV) power stations between Germany and the United States to examine which country more efficiently provides renewable energy in their usages. For the comparative analysis, this study utilizes Data Envelopment Analysis (DEA) as a methodology to evaluate the performance of PV power stations from the perspective of both solar and land usages. A total of one hundred sixty PV power stations (eighty in Germany and eighty in the United States) are used for this comparison. The demand for sustainable energy and energy security has been rapidly increasing over the past decade because of concerns about environment and limited resources. PV solutions are one of many renewable technologies that are being developed to satisfy a recent demand of electricity. Germany is the world's top installer and consumer of PV power and the United States is one of the top five nations. Germany leads the way in installed PV capacity even though the nation has less solar resources and land area. Due to limited solar resources, low insolation and sunshine, and land area, the United States should have a clear advantage over Germany. However, the empirical result of this study exhibits that PV power stations in Germany operate more efficiently than those of the United States even if the latter has many solar and land advantages. The surprising result indicates that the United States has room for improvement when it comes to utilizing solar and land resources and needs to reform the solar policy. For such a purpose, Feed-In Tariff (FIT) may be an effective energy policy at the state level in the United States because the FIT provides investors such as utility companies and other types of energy firms with financial incentives to develop large PV power stations and generation facilities for other renewable energy. It may be true that the FIT is a powerful policy tool to promote PV and other renewable installation and support a reduction of an amount of greenhouse

Brayton rotating units for space reactor power systems

Energy Technology Data Exchange (ETDEWEB)

Gallo, Bruno M.; El-Genk, Mohamed S. [Institute for Space and Nuclear Power Studies and Chemical and Nuclear Engineering Dept., The Univ. of New Mexico, Albuquerque, NM 87131 (United States)

2009-09-15

Designs and analyses models of centrifugal-flow compressor and radial-inflow turbine of 40.8kW{sub e} Brayton Rotating Units (BRUs) are developed for 15 and 40 g/mole He-Xe working fluids. Also presented are the performance results of a space power system with segmented, gas cooled fission reactor heat source and three Closed Brayton Cycle loops, each with a separate BRU. The calculated performance parameters of the BRUs and the reactor power system are for shaft rotational speed of 30-55 krpm, reactor thermal power of 120-471kW{sub th}, and turbine inlet temperature of 900-1149 K. With 40 g/mole He-Xe, a power system peak thermal efficiency of 26% is achieved at rotation speed of 45 krpm, compressor and turbine inlet temperatures of 400 and 1149 K and 0.93 MPa at exit of the compressor. The corresponding system electric power is 122.4kW{sub e}, working fluid flow rate is 1.85 kg/s and the pressure ratio and polytropic efficiency are 1.5% and 86.3% for the compressor and 1.42% and 94.1% for the turbine. For the same nominal electrical power of 122.4kW{sub e}, decreasing the molecular weight of the working fluid (15 g/mole) decreases its flow rate to 1.03 kg/s and increases the system pressure to 1.2 MPa. (author)

Stream classification of the Apalachicola-Chattahoochee-Flint River System to support modeling of aquatic habitat response to climate change

Science.gov (United States)

Elliott, Caroline M.; Jacobson, Robert B.; Freeman, Mary C.

2014-01-01

A stream classification and associated datasets were developed for the Apalachicola-Chattahoochee-Flint River Basin to support biological modeling of species response to climate change in the southeastern United States. The U.S. Geological Survey and the Department of the Interior’s National Climate Change and Wildlife Science Center established the Southeast Regional Assessment Project (SERAP) which used downscaled general circulation models to develop landscape-scale assessments of climate change and subsequent effects on land cover, ecosystems, and priority species in the southeastern United States. The SERAP aquatic and hydrologic dynamics modeling efforts involve multiscale watershed hydrology, stream-temperature, and fish-occupancy models, which all are based on the same stream network. Models were developed for the Apalachicola-Chattahoochee-Flint River Basin and subbasins in Alabama, Florida, and Georgia, and for the Upper Roanoke River Basin in Virginia. The stream network was used as the spatial scheme through which information was shared across the various models within SERAP. Because these models operate at different scales, coordinated pair versions of the network were delineated, characterized, and parameterized for coarse- and fine-scale hydrologic and biologic modeling. The stream network used for the SERAP aquatic models was extracted from a 30-meter (m) scale digital elevation model (DEM) using standard topographic analysis of flow accumulation. At the finer scale, reaches were delineated to represent lengths of stream channel with fairly homogenous physical characteristics (mean reach length = 350 m). Every reach in the network is designated with geomorphic attributes including upstream drainage basin area, channel gradient, channel width, valley width, Strahler and Shreve stream order, stream power, and measures of stream confinement. The reach network was aggregated from tributary junction to tributary junction to define segments for the

Experience in start-up of the South-Ukrainian-2 power unit with the WWER-1000 reactor

International Nuclear Information System (INIS)

Belov, Yu.V.; Kazakov, V.A.; Kirilov, V.V.; Kryakvin, L.V.

1987-01-01

The volume, sequence and dates of works fulfilled during hot testing, physical and power start-ups and while bringing output of the South-Ukranian-2 power unit with the WWER-1000 reactor to the design figure are described. The works were fulfilled according to the standard schedules from October in 1984 till April in 1985. Combination of the stages and intensification of works before the physical start-up have allowed to shorten the dates by 90 days as compared to the schedule. The physical and power start-ups, including bringing reactor output to the design figure, were performed during 140 days, that permits to shorten the dates by 20 days more. The results of physical experiments carried out at the South-Ukranian-2 power unit, are in good agreement with the data obtained at the first power units of the given and Kalinin NPPs. Besides, during physical and power start-ups additional measures ensuring nuclear safety are developed

The Research of Utilization Hours of Coal-Fired Power Generation Units Based on Electric Energy Balance

Science.gov (United States)

Liu, Junhui; Yang, Jianlian; Wang, Jiangbo; Yang, Meng; Tian, Chunzheng; He, Xinhui

2018-01-01

With grid-connected scale of clean energy such as wind power and photovoltaic power expanding rapidly and cross-province transmission scale being bigger, utilization hours of coal-fired power generation units become lower and lower in the context of the current slowdown in electricity demand. This paper analyzes the influencing factors from the three aspects of demand, supply and supply and demand balance, and the mathematical model has been constructed based on the electric energy balance. The utilization hours of coal-fired power generation units have been solved considering the relationship among proportion of various types of power installed capacity, the output rate and utilization hours. By carrying out empirical research in Henan Province, the utilization hours of coal-fired units of Henan Province in 2020 has been achieved. The example validates the practicability and the rationality of the model, which can provide a basis for the decision-making for coal-fired power generation enterprises.

Inventory of power plants in the United States 1994

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-10-18

The Inventory of Power Plants in the US provides year-end statistics on generating units operated by electric utilities in the US (the 50 States and the District of Columbia). Statistics presented in this report reflect the status of generating units as of December 31, 1994. The publication also provides a 10-year outlook for generating unit additions. This report is prepared annually by the Coal and Electric Data and Renewables Division; Office of Coal, Nuclear, Electric and Alternate Fuels; Energy Information Administration (EIA); US Department of Energy (DOE). Data summarized in this report are useful to a wide audience including Congress, Federal, and State agencies; the electric utility industry; and the general public. This is a report of electric utility data; in cases where summary data of nonutility capacity are presented, it is specifically noted as such.

Facing technological challenges of Solar Updraft Power Plants

Science.gov (United States)

Lupi, F.; Borri, C.; Harte, R.; Krätzig, W. B.; Niemann, H.-J.

2015-01-01

The Solar Updraft Power Plant technology addresses a very challenging idea of combining two kinds of renewable energy: wind and solar. The working principle is simple: a Solar Updraft Power Plant (SUPP) consists of a collector area to heat the air due to the wide-banded ultra-violet solar radiation, the high-rise solar tower to updraft the heated air to the atmosphere, and in between the power conversion unit, where a system of coupled turbines and generators transforms the stream of heated air into electric power. A good efficiency of the power plant can only be reached with extra-large dimensions of the tower and/or the collector area. The paper presents an up-to-date review of the SUPP technology, focusing on the multi-physics modeling of the power plant, on the structural behavior of the tower and, last but not least, on the modeling of the stochastic wind loading process.

Reactor units for power supply to the Russian Arctic regions: Priority assessment of nuclear energy sources

Directory of Open Access Journals (Sweden)

Mel'nikov N. N.

2017-03-01

Full Text Available Under conditions of competitiveness of small nuclear power plants (SNPP and feasibility of their use to supply power to remote and inaccessible regions the competition occurs between nuclear energy sources, which is caused by a wide range of proposals for solving the problem of power supply to different consumers in the decentralized area of the Russian Arctic power complex. The paper suggests a methodological approach for expert assessment of the priority of small power reactor units based on the application of the point system. The priority types of the reactor units have been determined based on evaluation of the unit's conformity to the following criteria: the level of referentiality and readiness degree of reactor units to implementation; duration of the fuel cycle, which largely determines an autonomy level of the nuclear energy source; the possibility of creating a modular block structure of SNPP; the maximum weight of a transported single equipment for the reactor unit; service life of the main equipment. Within the proposed methodological approach the authors have performed a preliminary ranking of the reactor units according to various criteria, which allows quantitatively determining relative difference and priority of the small nuclear power plants projects aimed at energy supply to the Russian Arctic. To assess the sensitivity of the ranking results to the parameters of the point system the authors have observed the five-point and ten-point scales under variations of importance (weights of different criteria. The paper presents the results of preliminary ranking, which have allowed distinguishing the following types of the reactor units in order of their priority: ABV-6E (ABV-6M, "Uniterm" and SVBR-10 in the energy range up to 20 MW; RITM-200 (RITM-200M, KLT-40S and SVBR-100 in the energy range above 20 MW.

Monitoring Cs-134 and 137 released by Fukushima Dai-ichi Nuclear Power Plant accident in ground, soil, and stream waters

Science.gov (United States)

Tsujimura, Maki; Onda, Yuichi; Hada, Manami; Ishwar, Pun; Abe, Yutaka

2013-04-01

Due to Fukushima Dai-ichi Nuclear power plant accident occurred in March 2011, large amount of radionuclides was released into the atmosphere and was fallen onto ground by rainfall. Few researches have monitored radioactive cesium dynamics in whole hydrological cycle system such as groundwater, soil water, spring water and stream water. Thus, the purpose of this study is to monitor concentration of radioactive cesium in those waters in time series in the headwaters. We have performed an intensive monitoring at three small mountainous catchments in Yamakiya district, Kawamata town, Fukushima prefecture, locating 35 km northwest from Fukushima Dai-ichi Nuclear Power Plant since June 2011, also we consider the movement of radioactive cesium and its relation with the hydrological cycle.

Surry Power Station, Units 1 and 2. Semiannual operating report, July--December 1974

International Nuclear Information System (INIS)

1974-01-01

Net electric power generated by Surry Unit 1 was 6,930,353 MWH with the generator on line for 10,417.7 hours. Net electric power generated by Unit 2 was 5,699,299 MWH with the generator on line for 8,384.2 hours. Information is presented concerning operation, radioactive effluent releases, solid radioactive wastes, fuel shipments, occurrences in which temperature limitations on the condenser cooling water discharge were exceeded, changes in station organization, occupational personnel radiation exposure, nonradiological monitoring including thermal, physical, and biological programs, and the radiological environmental monitoring program. (U.S.)

Counter rotating type hydroelectric unit suitable for tidal power station

International Nuclear Information System (INIS)

Kanemoto, T; Suzuki, T

2010-01-01

The counter rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures,was proposed to utilize effectively the tidal power. In the unit, the front and the rear runners counter drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the flow direction at the front runner inlet, because the angular momentum through the rear runner must coincides with that through the front runner. That is, the flow runs in the axial direction at the rear runner outlet while the axial inflow at the front runner inlet. Such operations are suitable for working at the seashore with rising and falling tidal flows, and the unit may be able to take place of the traditional bulb type turbines. The tandem runners were operated at the on-cam conditions, in keeping the induced frequency constant. The output and the hydraulic efficiency are affected by the adjustment of the front and the blade setting angles. The both optimum angles giving the maximum output and/or efficiency were presented at the various discharges/heads. To promote more the tidal power generation by this type unit, the runners were also modified so as to be suitable for both rising and falling flows. The hydraulic performances are acceptable while the output is determined mainly by the trailing edge profiles of the runner blades.

Unit commitment with wind power generation: integrating wind forecast uncertainty and stochastic programming.

Energy Technology Data Exchange (ETDEWEB)

Constantinescu, E. M.; Zavala, V. M.; Rocklin, M.; Lee, S.; Anitescu, M. (Mathematics and Computer Science); (Univ. of Chicago); (New York Univ.)

2009-10-09

We present a computational framework for integrating the state-of-the-art Weather Research and Forecasting (WRF) model in stochastic unit commitment/energy dispatch formulations that account for wind power uncertainty. We first enhance the WRF model with adjoint sensitivity analysis capabilities and a sampling technique implemented in a distributed-memory parallel computing architecture. We use these capabilities through an ensemble approach to model the uncertainty of the forecast errors. The wind power realizations are exploited through a closed-loop stochastic unit commitment/energy dispatch formulation. We discuss computational issues arising in the implementation of the framework. In addition, we validate the framework using real wind speed data obtained from a set of meteorological stations. We also build a simulated power system to demonstrate the developments.

AMERICAN ELECTRIC POWER'S CONESVILLE POWER PLANT UNIT NO.5 CO2 CAPTURE RETROFIT STUDY

Energy Technology Data Exchange (ETDEWEB)

Carl R. Bozzuto; Nsakala ya Nsakala; Gregory N. Liljedahl; Mark Palkes; John L. Marion

2001-06-30

ALSTOM Power Inc.'s Power Plant Laboratories (ALSTOM) has teamed with American Electric Power (AEP), ABB Lummus Global Inc. (ABB), the US Department of Energy National Energy Technology Laboratory (DOE NETL), and the Ohio Coal Development Office (OCDO) to conduct a comprehensive study evaluating the technical feasibility and economics of alternate CO{sub 2} capture and sequestration technologies applied to an existing US coal-fired electric generation power plant. The motivation for this study was to provide input to potential US electric utility actions concerning GHG emissions reduction. If the US decides to reduce CO{sub 2} emissions, action would need to be taken to address existing power plants. Although fuel switching from coal to natural gas may be one scenario, it will not necessarily be a sufficient measure and some form of CO{sub 2} capture for use or disposal may also be required. The output of this CO{sub 2} capture study will enhance the public's understanding of control options and influence decisions and actions by government, regulators, and power plant owners in considering the costs of reducing greenhouse gas CO{sub 2} emissions. The total work breakdown structure is encompassed within three major reports, namely: (1) Literature Survey, (2) AEP's Conesville Unit No.5 Retrofit Study, and (3) Bench-Scale Testing and CFD Evaluation. The report on the literature survey results was issued earlier by Bozzuto, et al. (2000). Reports entitled ''AEP's Conesville Unit No.5 Retrofit Study'' and ''Bench-Scale Testing and CFD Evaluation'' are provided as companion volumes, denoted Volumes I and II, respectively, of the final report. The work performed, results obtained, and conclusions and recommendations derived therefrom are summarized.

The effects of electric power industry restructuring on the safety of nuclear power plants in the United States

Science.gov (United States)

Butler, Thomas S.

Throughout the United States the electric utility industry is restructuring in response to federal legislation mandating deregulation. The electric utility industry has embarked upon an extraordinary experiment by restructuring in response to deregulation that has been advocated on the premise of improving economic efficiency by encouraging competition in as many sectors of the industry as possible. However, unlike the telephone, trucking, and airline industries, the potential effects of electric deregulation reach far beyond simple energy economics. This dissertation presents the potential safety risks involved with the deregulation of the electric power industry in the United States and abroad. The pressures of a competitive environment on utilities with nuclear power plants in their portfolio to lower operation and maintenance costs could squeeze them to resort to some risky cost-cutting measures. These include deferring maintenance, reducing training, downsizing staff, excessive reductions in refueling down time, and increasing the use of on-line maintenance. The results of this study indicate statistically significant differences at the .01 level between the safety of pressurized water reactor nuclear power plants and boiling water reactor nuclear power plants. Boiling water reactors exhibited significantly more problems than did pressurized water reactors.

Grid-connected in-stream hydroelectric generation based on the doubly fed induction machine

Science.gov (United States)

Lenberg, Timothy J.

Within the United States, there is a growing demand for new environmentally friendly power generation. This has led to a surge in wind turbine development. Unfortunately, wind is not a stable prime mover, but water is. Why not apply the advances made for wind to in-stream hydroelectric generation? One important advancement is the creation of the Doubly Fed Induction Machine (DFIM). This thesis covers the application of a gearless DFIM topology for hydrokinetic generation. After providing background, this thesis presents many of the options available for the mechanical portion of the design. A mechanical turbine is then specified. Next, a method is presented for designing a DFIM including the actual design for this application. In Chapter 4, a simulation model of the system is presented, complete with a control system that maximizes power generation based on water speed. This section then goes on to present simulation results demonstrating proper operation.

Scale-up of a mixer-settler extractor using a unit operations approach

International Nuclear Information System (INIS)

Lindholm, D.C.; Bautista, R.G.

1976-01-01

The results of scale-up studies on a continuous, multistage horizontal mixer-settler extractor are presented. The chemical and mechanical system involves the separation of lanthanum from a mixture of rare earth chlorides using di(2-ethylhexyl) phosphoric acid as the solvent and dilute HCl as a scrub solution in a bench scale extractor. Each stage has a hold-up of 2.6 l. A single stage unit is utilized for scale-up studies. Results are obtained on four sizes of geometrically similar units, the largest being six times the volume of the original bench size. A unit operations technique is chosen so that mixing and settling can be examined independently. Variables examined include type of continuous phase, flow rate of inlet streams, and power input to the mixer. Inlet flow-rate ratios are kept constant for all tests. Two potential methods of unbaffled pump-mixer scale-up are explored; the maintenance of constant impeller tip speed and constant power input. For the settler, the previously successful method of basing design on constant flow-rate per unit cross-sectional area is used

Ambient groundwater flow diminishes nitrogen cycling in streams

Science.gov (United States)

Azizian, M.; Grant, S. B.; Rippy, M.; Detwiler, R. L.; Boano, F.; Cook, P. L. M.

2017-12-01

Modeling and experimental studies demonstrate that ambient groundwater reduces hyporheic exchange, but the implications of this observation for stream N-cycling is not yet clear. We utilized a simple process-based model (the Pumping and Streamline Segregation or PASS model) to evaluate N- cycling over two scales of hyporheic exchange (fluvial ripples and riffle-pool sequences), ten ambient groundwater and stream flow scenarios (five gaining and losing conditions and two stream discharges), and three biogeochemical settings (identified based on a principal component analysis of previously published measurements in streams throughout the United States). Model-data comparisons indicate that our model provides realistic estimates for direct denitrification of stream nitrate, but overpredicts nitrification and coupled nitrification-denitrification. Riffle-pool sequences are responsible for most of the N-processing, despite the fact that fluvial ripples generate 3-11 times more hyporheic exchange flux. Across all scenarios, hyporheic exchange flux and the Damkohler Number emerge as primary controls on stream N-cycling; the former regulates trafficking of nutrients and oxygen across the sediment-water interface, while the latter quantifies the relative rates of organic carbon mineralization and advective transport in streambed sediments. Vertical groundwater flux modulates both of these master variables in ways that tend to diminish stream N-cycling. Thus, anthropogenic perturbations of ambient groundwater flows (e.g., by urbanization, agricultural activities, groundwater mining, and/or climate change) may compromise some of the key ecosystem services provided by streams.

Optimized open-flow mixing: insights from microbubble streaming

Science.gov (United States)

Rallabandi, Bhargav; Wang, Cheng; Guo, Lin; Hilgenfeldt, Sascha

2015-11-01

Microbubble streaming has been developed into a robust and powerful flow actuation technique in microfluidics. Here, we study it as a paradigmatic system for microfluidic mixing under a continuous throughput of fluid (open-flow mixing), providing a systematic optimization of the device parameters in this practically important situation. Focusing on two-dimensional advective stirring (neglecting diffusion), we show through numerical simulation and analytical theory that mixing in steady streaming vortices becomes ineffective beyond a characteristic time scale, necessitating the introduction of unsteadiness. By duty cycling the streaming, such unsteadiness is introduced in a controlled fashion, leading to exponential refinement of the advection structures. The rate of refinement is then optimized for particular parameters of the time modulation, i.e. a particular combination of times for which the streaming is turned ``on'' and ``off''. The optimized protocol can be understood theoretically using the properties of the streaming vortices and the throughput Poiseuille flow. We can thus infer simple design principles for practical open flow micromixing applications, consistent with experiments. Current Address: Mechanical and Aerospace Engineering, Princeton University.

Assessing the chemical contamination dynamics in a mixed land use stream system.

Science.gov (United States)

Sonne, Anne Th; McKnight, Ursula S; Rønde, Vinni; Bjerg, Poul L

2017-11-15

Traditionally, the monitoring of streams for chemical and ecological status has been limited to surface water concentrations, where the dominant focus has been on general water quality and the risk for eutrophication. Mixed land use stream systems, comprising urban areas and agricultural production, are challenging to assess with multiple chemical stressors impacting stream corridors. New approaches are urgently needed for identifying relevant sources, pathways and potential impacts for implementation of suitable source management and remedial measures. We developed a method for risk assessing chemical stressors in these systems and applied the approach to a 16-km groundwater-fed stream corridor (Grindsted, Denmark). Three methods were combined: (i) in-stream contaminant mass discharge for source quantification, (ii) Toxic Units and (iii) environmental standards. An evaluation of the chemical quality of all three stream compartments - stream water, hyporheic zone, streambed sediment - made it possible to link chemical stressors to their respective sources and obtain new knowledge about source composition and origin. Moreover, toxic unit estimation and comparison to environmental standards revealed the stream water quality was substantially impaired by both geogenic and diffuse anthropogenic sources of metals along the entire corridor, while the streambed was less impacted. Quantification of the contaminant mass discharge originating from a former pharmaceutical factory revealed that several 100 kgs of chlorinated ethenes and pharmaceutical compounds discharge into the stream every year. The strongly reduced redox conditions in the plume result in high concentrations of dissolved iron and additionally release arsenic, generating the complex contaminant mixture found in the narrow discharge zone. The fingerprint of the plume was observed in the stream several km downgradient, while nutrients, inorganics and pesticides played a minor role for the stream health. The

Concrete works in Igata Nuclear Power Station Unit-2

International Nuclear Information System (INIS)

Yanase, Hidemasa

1981-01-01

The construction of Igata Nuclear Power Station Unit-2 was started in February, 1978, and is scheduled to start the commercial operation in March, 1982. Construction works are to be finished by August, 1981. The buildings of Igata Nuclear Power Station are composed of large cross section concrete for the purpose of shielding and the resistance to earth quakes. In response to this, moderate heat Portland cement has been employed, and in particular, the heat of hydration has been controlled. In this report, also fine and coarse aggregates, admixtures and chemical admixtures, and further, the techniques to improve the quality are described. Concrete preparation plant was installed in the power station site. Fresh concrete was carried with agitator body trucks from the preparation plant to the unloading point, and from there with pump trucks. Placing of concrete was carried out, striving to obtain homogeneous and dense concrete by using rod type vibrators. Further, concrete was placed in low slump (8 - 15 cm) to reduce water per unit volume, and its temperature was also carefully controlled, e.g., cold water (temperature of mixing water was about 10 deg C) was used in summer season (end of June to end of September). As a result, the control target was almost satisfied. As for testing and inspection, visual appearance test was done as well as material testing in compliance with JIS and other standards. (Wakatsuki, Y.)

Power systems simulations of the western United States region

International Nuclear Information System (INIS)

Conzelmann, G.; Koritarov, V.; Poch, L.; Thimmapuram, P.; Veselka, T.

2010-01-01

This report documents a part of a broad assessment of energy-water-related issues in the western United States. The full analysis involved three Department of Energy national laboratories: Argonne National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories. Argonne's objective in the overall project was to develop a regional power sector expansion forecast and a detailed unit-level operational (dispatch) analysis. With these two major analysis components, Argonne estimated current and future freshwater withdrawals and consumption related to the operation of U.S. thermal-electric power plants in the Western Electricity Coordinating Council (WECC) region for the period 2005-2025. Water is withdrawn and used primarily for cooling but also for environmental control, such as sulfur scrubbers. The current scope of the analysis included three scenarios: (1) Baseline scenario as a benchmark for assessing the adequacy and cost-effectiveness of water conservation options and strategies, (2) High nuclear scenario, and (3) High renewables scenario. Baseline projections are consistent with forecasts made by the WECC and the Energy Information Administration (EIA) in its Annual Energy Outlook (AEO) (EIA 2006a). Water conservation scenarios are currently limited to two development alternatives that focus heavily on constructing new generating facilities with zero water consumption. These technologies include wind farms and nuclear power plants with dry cooling. Additional water conservation scenarios and estimates of water use associated with fuel or resource extraction and processing will be developed in follow-on analyses.

The 1987 United Kingdom radioactive waste inventory

International Nuclear Information System (INIS)

1988-10-01

This report describes the stocks of radioactive wastes in the United Kingdom, together with projections of future arisings. Operational and decommissioning wastes are considered for both committed and prospective plant. Arisings are from power reactors, commercial reprocessing, fuel manufacture, medical and industrial sources and research and development. Data are presented for the wastes in their raw form and as conditioned for disposal. The data which refer to the situation on 1.1.87 are shown by producer and globally, in summary tables. The information presented for each producer includes a description of the activities that generate the wastes and a discussion of how stocks and arisings may have changed from earlier predictions. This is supplemented by a stream by stream tabulation showing the waste type, volume, density, conditioning factor and gross alpha and beta activity. The global projections are presented in tabular and graphical manner, and the changes from earlier projections are discussed. The scenarios which underly the projections are also presented. (author)

The operating performance tests of power unit A1 in HPP 'Zvornik' in load-frequency control

Directory of Open Access Journals (Sweden)

Stanojčić Vladimir

2012-01-01

Full Text Available The turbine-governing system characteristics derived from testing hydropower unit A1 in HPP 'Zvornik' are presented. These tests give insights into the setup state and parameters of the governing system, as well as the qualitative analysis of load-frequency control response of the case study power unit within the power system of Serbia. Verification of relevant turbine-governing parameters was performed by direct application of appropriate standards and policies. The presented results can be used as a basis for the derivation of a turbine governor mathematical model and for a complete mathematical model of a hydropower unit as an element embedded in the power system.

Tidal Turbines’ Layout in a Stream with Asymmetry and Misalignment

Directory of Open Access Journals (Sweden)

Nicolas Guillou

2017-11-01

Full Text Available A refined assessment of tidal currents variability is a prerequisite for successful turbine deployment in the marine environment. However, the numerical evaluation of the tidal kinetic energy resource relies, most of the time, on integrated parameters, such as the averaged or maximum stream powers. Predictions from a high resolution three-dimensional model are exploited here to characterize the asymmetry and misalignment between the flood and ebb tidal currents in the “Raz de Sein”, a strait off western Brittany (France with strong potential for array development. A series of parameters is considered to assess resource variability and refine the cartography of local potential tidal stream energy sites. The strait is characterized by strong tidal flow divergence with currents’ asymmetry liable to vary output power by 60% over a tidal cycle. Pronounced misalignments over 20 ∘ are furthermore identified in a great part of energetic locations, and this may account for a deficit of the monthly averaged extractable energy by more than 12%. As sea space is limited for turbines, it is finally suggested to aggregate flood and ebb-dominant stream powers on both parts of the strait to output energy with reduced asymmetry.

STREAMFINDER I: A New Algorithm for detecting Stellar Streams

Science.gov (United States)

Malhan, Khyati; Ibata, Rodrigo A.

2018-04-01

We have designed a powerful new algorithm to detect stellar streams in an automated and systematic way. The algorithm, which we call the STREAMFINDER, is well suited for finding dynamically cold and thin stream structures that may lie along any simple or complex orbits in Galactic stellar surveys containing any combination of positional and kinematic information. In the present contribution we introduce the algorithm, lay out the ideas behind it, explain the methodology adopted to detect streams and detail its workings by running it on a suite of simulations of mock Galactic survey data of similar quality to that expected from the ESA/Gaia mission. We show that our algorithm is able to detect even ultra-faint stream features lying well below previous detection limits. Tests show that our algorithm will be able to detect distant halo stream structures >10° long containing as few as ˜15 members (ΣG ˜ 33.6 mag arcsec-2) in the Gaia dataset.

Significance of oceanographic field investigations for siting coastal thermal and nuclear power plants

Digital Repository Service at National Institute of Oceanography (India)

Krishnakumar, V.; Swamy, G.N.; Sastry, J

stream_size 7 stream_content_type text/plain stream_name Irrig_Power_J_49_129.pdf.txt stream_source_info Irrig_Power_J_49_129.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

Design and methods of the Southeast Stream Quality Assessment (SESQA), 2014

Science.gov (United States)

Journey, Celeste A.; Van Metre, Peter C.; Bell, Amanda H.; Button, Daniel T.; Garrett, Jessica D.; Nakagaki, Naomi; Qi, Sharon L.; Bradley, Paul M.

2015-07-15

During 2014, the U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) assessed stream quality across the Piedmont and southern Appalachian Mountain regions of the southeastern United States. This Southeast Stream Quality Assessment (SESQA) simultaneously characterized watershed and stream-reach water-quality stressors along with instream biological conditions, in order to better understand regional stressor-effects relations. The goal of SESQA is to provide communities and policymakers with information about those human and environmental factors that have the greatest impact on stream quality across the region. The SESQA design focused on hydrologic alteration and urbanization because of their importance as ecological stressors of particular concern to Southeast region resource managers.

Global Thermal Power Plants Database: Unit-Based CO2, SO2, NOX and PM2.5 Emissions in 2010

Science.gov (United States)

Tong, D.; Qiang, Z.; Davis, S. J.

2016-12-01

There are more than 30,000 thermal power plants now operating worldwide, reflecting a tremendously diverse infrastructure that includes units burning oil, natural gas, coal and biomass and ranging in capacity from 1GW. Although the electricity generated by this infrastructure is vital to economic activities across the world, it also produces more CO2 and air pollution emissions than any other industry sector. Here we present a new database of global thermal power-generating units and their emissions as of 2010, GPED (Global Power Emissions Database), including the detailed unit information of installed capacity, operation year, geographic location, fuel type and control measures for more than 70000 units. In this study, we have compiled, combined, and harmonized the available underlying data related to thermal power-generating units (e.g. eGRID of USA, CPED of China and published Indian power plants database), and then analyzed the generating capacity, capacity factor, fuel type, age, location, and installed pollution-control technology in order to determine those units with disproportionately high levels of emissions. In total, this work is of great importance for improving spatial distribution of global thermal power plants emissions and exploring their environmental impacts at global scale.

Identification of unmeasured variables in the set of model constraints of the data reconciliation in a power unit

Science.gov (United States)

Szega, Marcin; Nowak, Grzegorz Tadeusz

2013-12-01

In generalized method of data reconciliation as equations of conditions beside substance and energy balances can be used equations which don't have precisely the status of conservation lows. Empirical coefficients in these equations are traded as unknowns' values. To this kind of equations, in application of the generalized method of data reconciliation in supercritical power unit, can be classified: steam flow capacity of a turbine for a group of stages, adiabatic internal efficiency of group of stages, equations for pressure drop in pipelines and equations for heat transfer in regeneration heat exchangers. Mathematical model of a power unit was developed in the code Thermoflex. Using this model the off-design calculation has been made in several points of loads for the power unit. Using these calculations identification of unknown values and empirical coefficients for generalized method of data reconciliation used in power unit has been made. Additional equations of conditions will be used in the generalized method of data reconciliation which will be used in optimization of measurement placement in redundant measurement system in power unit for new control systems

Interaction of powerful hot plasma and fast ion streams with materials in dense plasma focus devices

Energy Technology Data Exchange (ETDEWEB)

Chernyshova, M., E-mail: maryna.chernyshova@ipplm.pl [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Gribkov, V.A. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Kowalska-Strzeciwilk, E.; Kubkowska, M.; Miklaszewski, R.; Paduch, M.; Pisarczyk, T.; Zielinska, E. [Institute of Plasma Physics and Laser Microfusion, Warsaw (Poland); Demina, E.V.; Pimenov, V.N.; Maslyaev, S.A. [Institution of Russian Academy of Sciences A.A. Baikov Institute of Metallurgy and Material Science RAS, Moscow (Russian Federation); Bondarenko, G.G. [National Research University Higher School of Economics (HSE), Moscow (Russian Federation); Vilemova, M.; Matejicek, J. [Institute of Plasma Physics of the CAS, Prague (Czech Republic)

2016-12-15

Highlights: • Materials perspective for use in mainstream nuclear fusion facilities were studied. • Powerful streams of hot plasma and fast ions were used to induce irradiation. • High temporal, spatial, angular and spectral resolution available in experiments. • Results of irradiation were investigated by number of analysis techniques. - Abstract: A process of irradiating and ablating solid-state targets with hot plasma and fast ion streams in two Dense Plasma Focus (DPF) devices – PF-6 and PF-1000 was examined by applying a number of diagnostics of nanosecond time resolution. Materials perspective for use in chambers of the mainstream nuclear fusion facilities (mainly with inertial plasma confinement like NIF and Z-machine), intended both for the first wall and for constructions, have been irradiated in these simulators. Optical microscopy, SEM, Atomic Emission Spectroscopy, images in secondary electrons and in characteristic X-ray luminescence of different elements, and X-ray elemental analysis, gave results on damageability for a number of materials including low-activated ferritic and austenitic stainless steels, β-alloy of Ti, as well as two types of W and a composite on its base. With an increase of the number of shots irradiating the surface, its morphology changes from weakly pronounced wave-like structures or ridges to strongly developed ones. At later stages, due to the action of the secondary plasma produced near the target materials they melted, yielding both blisters and a fracturing pattern: first along the grain and then “in-between” the grains creating an intergranular net of microcracks. At the highest values of power flux densities multiple bubbles appeared. Furthermore, in this last case the cracks were developed because of microstresses at the solidification of melt. Presence of deuterium within the irradiated ferritic steel surface nanolayers is explained by capture of deuterons in lattice defects of the types of impurity atoms

Pattern of Blood Stream Infections within Neonatal Intensive Care Unit, Suez Canal University Hospital, Ismailia, Egypt

Directory of Open Access Journals (Sweden)

Rania Mohammed Kishk

2014-01-01

Full Text Available Introduction. Blood stream infection (BSI is a common problem of newborn in neonatal intensive care units (NICUs. Monitoring neonatal infections is increasingly regarded as an important contributor to safe and high-quality healthcare. It results in high mortality rate and serious complications. So, our aim was to determine the incidence and the pattern of BSIs in the NICU of Suez Canal University Hospital, Egypt, and to determine its impact on hospitalization, mortality, and morbidity. Methods. This study was a prospective one in which all neonates admitted to the NICUs in Suez Canal University hospital between January, 2013 and June 2013 were enrolled. Blood stream infections were monitored prospectively. The health care associated infection rate, mortality rate, causative organism, and risk factors were studied. Results. A total of 317 neonates were admitted to the NICU with a mortality rate of 36.0%. During this study period, 115/317 (36.3% developed clinical signs of sepsis and were confirmed as BSIs by blood culture in only 90 neonates with 97 isolates. The total mean length of stay was significantly longer among infected than noninfected neonates (34.5 ± 18.3 and 10.8 ± 9.9 days, resp., P value < 0.001. The overall mortality rates among infected and noninfected neonates were 38.9% and 34.8%, respectively, with a significant difference. Klebsiella spp. were the most common pathogen (27.8% followed by Pseudomonas (21.6% and Staphylococcus aureus (15.4%. Conclusion. The rate of BSIs in NICU at Suez Canal University Hospital was relatively high with high mortality rate (36.0%.

Increase of power and efficiency of the 900 MW supercritical power plant through incorporation of the ORC

Science.gov (United States)

Ziółkowski, Paweł; Mikielewicz, Dariusz; Mikielewicz, Jarosław

2013-12-01

The objective of the paper is to analyse thermodynamical and operational parameters of the supercritical power plant with reference conditions as well as following the introduction of the hybrid system incorporating ORC. In ORC the upper heat source is a stream of hot water from the system of heat recovery having temperature of 90 °C, which is additionally aided by heat from the bleeds of the steam turbine. Thermodynamical analysis of the supercritical plant with and without incorporation of ORC was accomplished using computational flow mechanics numerical codes. Investigated were six working fluids such as propane, isobutane, pentane, ethanol, R236ea and R245fa. In the course of calculations determined were primarily the increase of the unit power and efficiency for the reference case and that with the ORC.

On different types of adjustment usable to calculate the parameters of the stream power law

Science.gov (United States)

Demoulin, Alain; Beckers, Arnaud; Bovy, Benoît

2012-02-01

Model parameterization through adjustment to field data is a crucial step in the modeling and the understanding of the drainage network response to tectonic or climatic perturbations. Using as a test case a data set of 18 knickpoints that materialize the migration of a 0.7-Ma-old erosion wave in the Ourthe catchment of northern Ardennes (western Europe), we explore the impact of various data fitting on the calibration of the stream power model of river incision, from which a simple knickpoint celerity equation is derived. Our results show that statistical least squares adjustments (or misfit functions) based either on the stream-wise distances between observed and modeled knickpoint positions at time t or on differences between observed and modeled time at the actual knickpoint locations yield significantly different values for the m and K parameters of the model. As there is no physical reason to prefer one of these approaches, an intermediate least-rectangles adjustment might at first glance appear as the best compromise. However, the statistics of the analysis of 200 sets of synthetic knickpoints generated in the Ourthe catchment indicate that the time-based adjustment is the most capable of getting close to the true parameter values. Moreover, this fitting method leads in all cases to an m value lower than that obtained from the classical distance adjustment (for example, 0.75 against 0.86 for the real case of the Ourthe catchment), corresponding to an increase in the non-linear character of the dependence of knickpoint celerity on discharge.

Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard 3.8 kW silicon carbide (SiC) power supply for the Power Processing Unit (PPU) of...

Operation time extension for power units of the first generation NPP and the liability for potential damage

International Nuclear Information System (INIS)

Kovalevich, O.M.

2000-01-01

The problem on the operation time extension for the six operating NPP first generation power units is discussed. However it is not advisable to improve the safety of these power units up to the acceptable level, therefore there arises the contradiction between the operation time extension of these power units and potential damage for the population. The possibility of having the increased civilian-legal responsibility for potential harm and losses in case of an accident is proposed to be considered as a compensating measure. The measures for realization of this civilian-legal responsibility are described [ru

A decomposition method for network-constrained unit commitment with AC power flow constraints

International Nuclear Information System (INIS)

Bai, Yang; Zhong, Haiwang; Xia, Qing; Kang, Chongqing; Xie, Le

2015-01-01

To meet the increasingly high requirement of smart grid operations, considering AC power flow constraints in the NCUC (network-constrained unit commitment) is of great significance in terms of both security and economy. This paper proposes a decomposition method to solve NCUC with AC power flow constraints. With conic approximations of the AC power flow equations, the master problem is formulated as a MISOCP (mixed integer second-order cone programming) model. The key advantage of this model is that the active power and reactive power are co-optimised, and the transmission losses are considered. With the AC optimal power flow model, the AC feasibility of the UC result of the master problem is checked in subproblems. If infeasibility is detected, feedback constraints are generated based on the sensitivity of bus voltages to a change in the unit reactive power generation. They are then introduced into the master problem in the next iteration until all AC violations are eliminated. A 6-bus system, a modified IEEE 30-bus system and the IEEE 118-bus system are used to validate the performance of the proposed method, which provides a satisfactory solution with approximately 44-fold greater computational efficiency. - Highlights: • A decomposition method is proposed to solve the NCUC with AC power flow constraints • The master problem considers active power, reactive power and transmission losses. • OPF-based subproblems check the AC feasibility using parallel computing techniques. • An effective feedback constraint interacts between the master problem and subproblem. • Computational efficiency is significantly improved with satisfactory accuracy

High Power Vanadate lasers

CSIR Research Space (South Africa)

Strauss

2006-07-01

Full Text Available stream_source_info Strauss1_2006.pdf.txt stream_content_type text/plain stream_size 3151 Content-Encoding UTF-8 stream_name Strauss1_2006.pdf.txt Content-Type text/plain; charset=UTF-8 Laser Research Institute... University of Stellenbosch www.laser-research.co.za High Power Vanadate lasers H.J.Strauss, Dr. C. Bollig, R.C. Botha, Prof. H.M. von Bergmann, Dr. J.P. Burger Aims 1) To develop new techniques to mount laser crystals, 2) compare the lasing properties...

Nuclear power reactor licensing and regulation in the United States

International Nuclear Information System (INIS)

Shapar, H.K.

1979-01-01

The report is devoted to four subjects: an explanation of the origins, statutory basis and development of the present regulatory system in the United States; a description of the various actions which must be taken by a license applicant and by the Nuclear Regulatory Commission before a nuclear power plant can be constructed and placed on-line, an account of the current regulatory practices followed by the US NRC in licensing nuclear power reactors; an identification of some of the 'lessons learned' from the Three Mile Island accident and some proposed regulatory and legislative solutions. (NEA) [fr

New generation nuclear power units of PWR type integral reactors

International Nuclear Information System (INIS)

Mitenkov, F.M.; Kurachen Kov, A.V.; Malamud, V.A.; Panov, Yu.K.; Runov, B.I.; Flerov, L.N.

1997-01-01

Design bases of new generation nuclear power units (nuclear power plants - NPP, nuclear co-generation plants - NCP, nuclear distract heating plants - NDHP), using integral type PWPS, developed in OKBM, Nizhny Novgorod and trends of design decisions optimization are considered in this report. The problems of diagnostics, servicing and repair of the integral reactor components in course of operation are discussed. The results of safety analysis, including the problems of several accident localization with postulated core melting and keeping corium in the reactor vessel and guard vessel are presented. Information on experimental substantiation of the suggested plant design decisions is presented. (author)

Competitive bidding for independent power: developments in the United States

International Nuclear Information System (INIS)

Kliman, M.

1995-01-01

In the United States electric utilities are using competitive bidding programs to procure power supplies from non-utility generators and, in some cases, to establish contracts with energy service companies for the implementation of demand-side management projects. Such programs are viewed as a path to efficient contracts in the private power industry. But bidding programs are complex, subject to pitfalls, and are developing very quickly. This paper reports on that development as of the early 1990s and, as an illustration, briefly describes and analyzes the bidding program of an electric utility in the State of New York. (author). 2 tabs

75 FR 82414 - Carolina Power & Light Company; H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption

Science.gov (United States)

2010-12-30

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-261; NRC-2010-0062] Carolina Power & Light Company; H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption 1.0 Background Carolina Power & Light... authorizes operation of the H.B. Robinson Steam Electric Plant, Unit 2 (HBRSEP). The license provides, among...

75 FR 11579 - Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption

Science.gov (United States)

2010-03-11

... NUCLEAR REGULATORY COMMISSION [Docket No. 50-261; NRC-2010-0062] Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2; Exemption 1.0 Background Carolina Power & Light... of the H. B. Robinson Steam Electric Plant, Unit 2 (HBRSEP). The license provides, among other things...

Stream-Groundwater Interaction Buffers Seasonal Changes in Urban Stream Water Quality

Science.gov (United States)

Ledford, S. H.; Lautz, L. K.

2013-12-01

Urban streams in the northeastern United States have large road salt inputs during winter, increased nonpoint sources of inorganic nitrogen, and decreased short-term and permanent storage of nutrients. Meadowbrook Creek, a first order stream in Syracuse, New York, flows along a negative urbanization gradient, from a channelized and armored stream running through the middle of a roadway to a pool-riffle stream meandering through a broad, vegetated floodplain with a riparian aquifer. In this study we investigated how reconnection to groundwater and introduction of riparian vegetation impacted surface water chemistry by making bi-weekly longitudinal surveys of stream water chemistry in the creek from May 2012 until June 2013. Chloride concentrations in the upstream, urban reach of Meadowbrook Creek were strongly influenced by discharge of road salt to the creek during snow melt events in winter and by the chemistry of water draining an upstream retention basin in summer. Chloride concentrations ranged from 161.2 mg/L in August to 2172 mg/L in February. Chloride concentrations in the downstream, 'connected' reach had less temporal variation, ranging from 252.0 mg/L in August to 1049 mg/L in January, and were buffered by groundwater discharge, as the groundwater chloride concentrations during the sampling period ranged from 84.0 to 655.4 mg/L. Groundwater discharge resulted in higher chloride concentrations in summer and lower concentrations in winter in the connected reach relative to the urban reach, minimizing annual variation. In summer, there was little-to-no nitrate in the urban reach due to a combination of limited sources and high primary productivity. In contrast, during the summer, nitrate concentrations reached over 1 mg N/L in the connected reach due to the presence of riparian vegetation and lower nitrate uptake due to cooler temperatures and shading. During the winter, when temperatures fell below freezing, nitrate concentrations in the urban reach

Assessment of Energy Production Potential from Tidal Streams in the United States

Energy Technology Data Exchange (ETDEWEB)

Haas, Kevin A. [Georgia Inst. of Technology, Savannah, GA (United States); Fritz, Hermann M. [Georgia Inst. of Technology, Savannah, GA (United States); French, Steven P. [Georgia Inst. of Technology, Atlanta, GA (United States); Smith, Brennan T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Neary, Vincent [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2011-06-29

The project documented in this report created a national database of tidal stream energy potential, as well as a GIS tool usable by industry in order to accelerate the market for tidal energy conversion technology.

Twitter and Non-Elites: Interpreting Power Dynamics in the Life Story of the (#)BRCA Twitter Stream.

Science.gov (United States)

Vicari, Stefania

2017-09-01

In May 2013 and March 2015, actress Angelina Jolie wrote in the New York Times about her choice to undergo preventive surgery. In her two op-eds, she explained that - as a carrier of the BRCA1 gene mutation - preventive surgery was the best way to lower her heightened risk of developing breast and ovarian cancer. By applying a digital methods approach to BRCA-related tweets from 2013 and 2015, before, during, and after the exposure of Jolie's story, this study maps and interprets Twitter discursive dynamics at two time points of the BRCA Twitter stream. Findings show an evolution in curation and framing dynamics occurring between 2013 and 2015, with individual patient advocates replacing advocacy organizations as top curators of BRCA content and coming to prominence as providers of specialist illness narratives. These results suggest that between 2013 and 2015, Twitter went from functioning primarily as an organization-centered news reporting mechanism, to working as a crowdsourced specialist awareness system. This article advances a twofold contribution. First, it points at Twitter's fluid functionality for an issue public and suggests that by looking at the life story-rather than at a single time point-of an issue-based Twitter stream, we can track the evolution of power roles underlying discursive practices and better interpret the emergence of non-elite actors in the public arena. Second, the study provides evidence of the rise of activist cultures that rely on fluid, non-elite, collective, and individual social media engagement.

Reactor units for power supply of remote and inaccessible regions: Selection issue

Directory of Open Access Journals (Sweden)

Melnikov N.N.

2015-06-01

Full Text Available The paper briefly presents the problem aspects on power supply for the remote and inaccessible regions of Russia. Reactor units of different type and installed electric capacity have been considered in relation to the issue of power supply during mineral deposit development in the Chukotka autonomous region, Yakutia and Irkutsk region. Some preliminary assessment of the possible options for use of small nuclear power plants in various sectors of energy consumption have been carried out based on the analysis of different scenarios for economic development of the regions considered

Jaquari-Mirim, Inhadiju and Piquiri Streams in their geomorphologic context

Directory of Open Access Journals (Sweden)

Eléia Righi

2009-10-01

Full Text Available The present article aims at the mapping of the Geomorphologic Units of the Hydrographic Basins of the Jaguari Mirim, Inhadiju, and Piquiri Streams, located in the west of Rio Grande do Sul – Brazil. Data analyzes defined six units characterized as: Unit I – Plane Top Relief in Volcanic Spill: shows plane relief with relatively low erosive processes and intemperism; Unit II – Hills in Volcanic Spill: slightly wavy areas underneath the plateau summit; Unit III – Hills and Small Size Hills in Volcanic Rock: formed by strongly wavy relief and with scarps; Unit IV – Small Size Hills in Sandstone: composed by isolated small size hills with origin associated to the existence of united sandstones that keeps the plane top relief; Unit V – Hills in Sandstone: Relief of hills located at the medium and low course of the streams, with the occurrence of accelerated erosive processes which produce sand dunes and accelerated erosions, and sometimes with the blooming of united sandstones in the half-slope or in the top; Unit IV -  Plane Relief in Low Altitude: Relief of plane topography that predisposes the superficial dynamic processes, generating the accumulation of sediments as well as the formation of fluvial terraces. The fragility of the natural systems, in face of the antropic interventions, is largely associated to its genetic characteristics. Thus, the geomorphologic analysis in the environmental studies is a tool for the maintainable planning of the activities introduced in the region.

The Stream-Catchment (StreamCat) and Lake-Catchment ...

Science.gov (United States)

Background/Question/MethodsLake and stream conditions respond to both natural and human-related landscape features. Characterizing these features within contributing areas (i.e., delineated watersheds) of streams and lakes could improve our understanding of how biological conditions vary spatially and improve the use, management, and restoration of these aquatic resources. However, the specialized geospatial techniques required to define and characterize stream and lake watersheds has limited their widespread use in both scientific and management efforts at large spatial scales. We developed the StreamCat and LakeCat Datasets to model, predict, and map the probable biological conditions of streams and lakes across the conterminous US (CONUS). Both StreamCat and LakeCat contain watershed-level characterizations of several hundred natural (e.g., soils, geology, climate, and land cover) and anthropogenic (e.g., urbanization, agriculture, mining, and forest management) landscape features for ca. 2.6 million stream segments and 376,000 lakes across the CONUS, respectively. These datasets can be paired with field samples to provide independent variables for modeling and other analyses. We paired 1,380 stream and 1,073 lake samples from the USEPAs National Aquatic Resource Surveys with StreamCat and LakeCat and used random forest (RF) to model and then map an invertebrate condition index and chlorophyll a concentration, respectively. Results/ConclusionsThe invertebrate

Seasonal patterns in nutrients, carbon, and algal responses in wadeable streams within three geographically distinct areas of the United States, 2007-08

Science.gov (United States)

Lee, Kathy E.; Lorenz, David L.; Petersen, James C.; Greene, John B.

2012-01-01

The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total

Predictions of the impurities in the CO2 stream of an oxy-coal combustion plant

International Nuclear Information System (INIS)

Liu, Hao; Shao, Yingjuan

2010-01-01

Whilst all three main carbon capture technologies (post-combustion, pre-combustion and oxy-fuel combustion) can produce a CO 2 dominant stream, other impurities are expected to be present in the CO 2 stream. The impurities in the CO 2 stream can adversely affect other processes of the carbon capture and storage (CCS) chain including the purification, compression, transportation and storage of the CO 2 stream. Both the nature and the concentrations of potential impurities expected to be present in the CO 2 stream of a CCS-integrated power plant depend on not only the type of the power plant but also the carbon capture method used. The present paper focuses on the predictions of impurities expected to be present in the CO 2 stream of an oxy-coal combustion plant. The main gaseous impurities of the CO 2 stream of oxy-coal combustion are N 2 /Ar, O 2 and H 2 O. Even the air ingress to the boiler and its auxiliaries is small enough to be neglected, the N 2 /Ar concentration of the CO 2 stream can vary between ca. 1% and 6%, mainly depending on the O 2 purity of the air separation unit, and the O 2 concentration can vary between ca. 3% and 5%, mainly depending on the combustion stoichiometry of the boiler. The H 2 O concentration of the CO 2 stream can vary from ca. 10% to over 40%, mainly depending on the fuel moisture and the partitioning of recycling flue gas (RFG) between wet-RFG and dry-RFG. NO x and SO 2 are the two main polluting impurities of the CO 2 stream of an oxy-coal combustion plant and their concentrations are expected to be well above those found in the flue gas of an air-coal combustion plant. The concentration of NO x in the flue gas of an oxy-coal combustion plant can be up to ca. two times to that of an equivalent air-coal combustion plant. The amount of NO x emitted by the oxy-coal combustion plant, however, is expected to be much smaller than that of the air-coal combustion plant. The reductions of the recirculated NO x within the combustion

A study of toxic emissions from a coal-fired power plant utilizing an ESP while demonstrating the ICCT CT-121 FGD Project. Final report

Energy Technology Data Exchange (ETDEWEB)

1994-06-16

The US Department of Energy is performing comprehensive assessments of toxic emissions from eight selected coal-fired electric utility units. This program responds to the Clean Air Act Amendments of 1990, which require the US Environmental Protection Agency (EPA) to evaluate emissions of hazardous air pollutants (HAPs) from electric utility power plants for Potential health risks. The resulting data will be furnished to EPA utility power plants and health risk determinations. The assessment of emissions involves the collection and analysis of samples from the major input, process, and output streams of each of the eight power plants for selected hazardous Pollutants identified in Title III of the Clean Air Act. Additional goals are to determine the removal efficiencies of pollution control subsystems for these selected pollutants and the Concentrations associated with the particulate fraction of the flue gas stream as a function of particle size. Material balances are being performed for selected pollutants around the entire power plant and several subsystems to identify the fate of hazardous substances in each utility system. Radian Corporation was selected to perform a toxics assessment at a plant demonstrating an Innovative Clean Coal Technology (ICCT) Project. The site selected is Plant Yates Unit No. 1 of Georgia Power Company, which includes a Chiyoda Thoroughbred-121 demonstration project.

Lower Red River Meadow Stream Restoration Project

International Nuclear Information System (INIS)

1996-05-01

As part of a continuing effort to restore anadromous fish populations in the South Fork Clearwater River basin of Idaho, Bonneville Power Administration (BPA) proposes to fund the Lower Red River Meadow Restoration Project (Project). The Project is a cooperative effort with the Idaho Soil and Water Conservation District, Nez Perce National Forest, Idaho Department of Fish and Game (IDFG), and the Nez Perce Tribe of Idaho. The proposed action would allow the sponsors to perform stream bank stabilization, aquatic and riparian habitat improvement activities on IDFG's Red River Management Area and to secure long-term conservation contracts or agreements for conducting streambank and habitat improvement activities with participating private landowners located in the Idaho County, Idaho, study area. This preliminary Environmental Assessment (EA) examines the potential environmental effects of stabilizing the stream channel, restoring juvenile fish rearing habitat and reestablishing a riparian shrub community along the stream

Evaluation of power commissioning of the Mochovce Unit 1 demonstration run

International Nuclear Information System (INIS)

Sarvaic, I.; Miskolci, M.

1998-01-01

The document contains evaluation of the 144 hour demonstration run of the Mochovce Unit 1. In the document, the courses and results of additional tests in this phase of power commissioning are summarized, evaluation of the performance of important systems and equipment of the unit is carried out, as well as of the compliance with Limits and Conditions in the course of the demonstration run. On this basis, conclusions are drawn and recommendations given for the unit to by ready for trial operation. The evaluation was developed by the scientific management of the Mochovce commissioning providing an independent support for the operators for supervising the commissioning tasks from the point of nuclear safety

Streaming Pool: reuse, combine and create reactive streams with pleasure

CERN Multimedia

CERN. Geneva

2017-01-01

When connecting together heterogeneous and complex systems, it is not easy to exchange data between components. Streams of data are successfully used in industry in order to overcome this problem, especially in the case of "live" data. Streams are a specialization of the Observer design pattern and they provide asynchronous and non-blocking data flow. The ongoing effort of the ReactiveX initiative is one example that demonstrates how demanding this technology is even for big companies. Bridging the discrepancies of different technologies with common interfaces is already done by the Reactive Streams initiative and, in the JVM world, via reactive-streams-jvm interfaces. Streaming Pool is a framework for providing and discovering reactive streams. Through the mechanism of dependency injection provided by the Spring Framework, Streaming Pool provides a so called Discovery Service. This object can discover and chain streams of data that are technologically agnostic, through the use of Stream IDs. The stream to ...

Assessing the chemical contamination dynamics in a mixed land use stream system

DEFF Research Database (Denmark)

Sonne, Anne Thobo; McKnight, Ursula S.; Rønde, Vinni

2017-01-01

Traditionally, the monitoring of streams for chemical and ecological status has been limited to surface water concentrations, where the dominant focus has been on general water quality and the risk for eutrophication. Mixed land use stream systems, comprising urban areas and agricultural production......, are challenging to assess with multiple chemical stressors impacting stream corridors. New approaches are urgently needed for identifying relevant sources, pathways and potential impacts for implementation of suitable source management and remedial measures. We developed a method for risk assessing chemical...... stressors in these systems and applied the approach to a 16-km groundwater-fed stream corridor (Grindsted, Denmark). Three methods were combined: (i) in-stream contaminant mass discharge for source quantification, (ii) Toxic Units and (iii) environmental standards. An evaluation of the chemical quality...

Interaction between stream temperature, streamflow, and groundwater exchanges in alpine streams

Science.gov (United States)

Constantz, James E.

1998-01-01

Four alpine streams were monitored to continuously collect stream temperature and streamflow for periods ranging from a week to a year. In a small stream in the Colorado Rockies, diurnal variations in both stream temperature and streamflow were significantly greater in losing reaches than in gaining reaches, with minimum streamflow losses occurring early in the day and maximum losses occurring early in the evening. Using measured stream temperature changes, diurnal streambed infiltration rates were predicted to increase as much as 35% during the day (based on a heat and water transport groundwater model), while the measured increase in streamflow loss was 40%. For two large streams in the Sierra Nevada Mountains, annual stream temperature variations ranged from 0° to 25°C. In summer months, diurnal stream temperature variations were 30–40% of annual stream temperature variations, owing to reduced streamflows and increased atmospheric heating. Previous reports document that one Sierra stream site generally gains groundwater during low flows, while the second Sierra stream site may lose water during low flows. For August the diurnal streamflow variation was 11% at the gaining stream site and 30% at the losing stream site. On the basis of measured diurnal stream temperature variations, streambed infiltration rates were predicted to vary diurnally as much as 20% at the losing stream site. Analysis of results suggests that evapotranspiration losses determined diurnal streamflow variations in the gaining reaches, while in the losing reaches, evapotranspiration losses were compounded by diurnal variations in streambed infiltration. Diurnal variations in stream temperature were reduced in the gaining reaches as a result of discharging groundwater of relatively constant temperature. For the Sierra sites, comparison of results with those from a small tributary demonstrated that stream temperature patterns were useful in delineating discharges of bank storage following

Inventory of power plants in the United States 1989. [Contains glossary

Energy Technology Data Exchange (ETDEWEB)

1990-09-21

This document is prepared annually by the Electric Power Division, Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), US Department of Energy (DOE). The purpose of this publication is to provide year-end statistics about electric generating units in operation and to provide a 10-year outlook of future generating unit additions by electric utilities in the United States (the 50 states and the District of Columbia). Data summarized in this report are useful to a wide audience including Congress, federal and state agencies, the electric utility industry, and the general public. The data presented in this report were assembled and published by the EIA, to fulfill its data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275) as amended. The report is organized into the following chapters: Summary Statistics; Operable Electric Generating Units; and Projected Electric Generating Unit Additions.

Fractionating power and outlet stream polydispersity in asymmetrical flow field-flow fractionation. Part I: isocratic operation.

Science.gov (United States)

Williams, P Stephen

2016-05-01

Asymmetrical flow field-flow fractionation (As-FlFFF) has become the most commonly used of the field-flow fractionation techniques. However, because of the interdependence of the channel flow and the cross flow through the accumulation wall, it is the most difficult of the techniques to optimize, particularly for programmed cross flow operation. For the analysis of polydisperse samples, the optimization should ideally be guided by the predicted fractionating power. Many experimentalists, however, neglect fractionating power and rely on light scattering detection simply to confirm apparent selectivity across the breadth of the eluted peak. The size information returned by the light scattering software is assumed to dispense with any reliance on theory to predict retention, and any departure of theoretical predictions from experimental observations is therefore considered of no importance. Separation depends on efficiency as well as selectivity, however, and efficiency can be a strong function of retention. The fractionation of a polydisperse sample by field-flow fractionation never provides a perfectly separated series of monodisperse fractions at the channel outlet. The outlet stream has some residual polydispersity, and it will be shown in this manuscript that the residual polydispersity is inversely related to the fractionating power. Due to the strong dependence of light scattering intensity and its angular distribution on the size of the scattering species, the outlet polydispersity must be minimized if reliable size data are to be obtained from the light scattering detector signal. It is shown that light scattering detection should be used with careful control of fractionating power to obtain optimized analysis of polydisperse samples. Part I is concerned with isocratic operation of As-FlFFF, and part II with programmed operation.

Conceptual design of free-piston Stirling conversion system for solar power units

Science.gov (United States)

Loktionov, Iu. V.

A conversion system has been conceptually designed for solar power units of the dish-Stirling type. The main design objectives were to demonstrate the possibility of attaining such performance characteristics as low manufacturing and life cycle costs, high reliability, long life, high efficiency, power output stability, self-balance, automatic (or self-) start-up, and easy maintenance. The system design includes a heat transfer and utilization subsystem with a solar receiver, a free-piston engine, an electric power generation subsystem, and a control subsystem. The working fluid is helium. The structural material is stainless steel for hot elements, aluminum alloys and plastics for others. The electric generation subunit can be fabricated in three options: with an induction linear alternator, with a permanent magnet linear alternator, and with a serial rotated induction generator and a hydraulic drive subsystem. The heat transfer system is based on heat pipes or the reflux boiler principle. Several models of heat transfer units using a liquid metal (Na or Na-K) have been created and demonstrated.

Two-Stage Robust Security-Constrained Unit Commitment with Optimizable Interval of Uncertain Wind Power Output

Directory of Open Access Journals (Sweden)

Dayan Sun

2017-01-01

Full Text Available Because wind power spillage is barely considered, the existing robust unit commitment cannot accurately analyze the impacts of wind power accommodation on on/off schedules and spinning reserve requirements of conventional generators and cannot consider the network security limits. In this regard, a novel double-level robust security-constrained unit commitment formulation with optimizable interval of uncertain wind power output is firstly proposed in this paper to obtain allowable interval solutions for wind power generation and provide the optimal schedules for conventional generators to cope with the uncertainty in wind power generation. The proposed double-level model is difficult to be solved because of the invalid dual transform in solution process caused by the coupling relation between the discrete and continuous variables. Therefore, a two-stage iterative solution method based on Benders Decomposition is also presented. The proposed double-level model is transformed into a single-level and two-stage robust interval unit commitment model by eliminating the coupling relation, and then this two-stage model can be solved by Benders Decomposition iteratively. Simulation studies on a modified IEEE 26-generator reliability test system connected to a wind farm are conducted to verify the effectiveness and advantages of the proposed model and solution method.

78 FR 49305 - Luminant Generation Company LLC, Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2...

Science.gov (United States)

2013-08-13

... NUCLEAR REGULATORY COMMISSION [Docket Nos. 50-445 and 50-446; NRC-2013-0182] Luminant Generation Company LLC, Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2; Application for Amendment to Facility... Operating License Nos. NPF-87 and NPF-89 for the Comanche Peak Nuclear Power Plant, Unit Nos. 1 and 2...

Wet and Dry Atmospheric Mercury Deposition Accumulates in Watersheds of the Northeastern United States

Science.gov (United States)

Boyer, E. W.; Grant, C.; Grimm, J.; Drohan, P. J.; Bennett, J.; Lawler, D.

2013-12-01

Mercury emissions to the atmosphere from coal-fired power plants and other sources such as waste incineration can be deposited to landscapes in precipitation and in dry fallout. Some mercury reaches watersheds and streams, where it can accumulate in sediments and biota. Human exposure to mercury occurs primarily through fish consumption, and currently mercury fish eating advisories are in place for many of the streams and lakes in the state. Here, we explored mercury in air, soils, water, and biota. To quantify atmospheric mercury deposition, we measured both wet and dry mercury deposition at over 10 locations in Pennsylvania, from which we present variation in mercury deposition and initial assessments of factors affecting the patterns. Further, we simulated mercury deposition at unmonitored locations in Pennsylvania and the northeastern United States over space and time with a high-resolution modeling technique that reflects storm tracks and air flow patterns. To consider mercury accumulation in watersheds, we collected data on soil mercury concentrations in a set of soil samples, and collected baseline data on mercury in streams draining 35 forested watersheds across Pennsylvania, spanning gradients of atmospheric deposition, climate and geology. Mercury concentrations were measured in stream water under base-flow conditions, in streambed sediments, aquatic mosses, and in fish tissues from brook trout. Results indicate that wet and dry atmospheric deposition is a primary source of mercury that is accumulating in watersheds of Pennsylvania and the northeastern United States.

Relation between Streaming Potential and Streaming Electrification Generated by Streaming of Water through a Sandwich-type Cell

OpenAIRE

Maruyama, Kazunori; Nikaido, Mitsuru; Hara, Yoshinori; Tanizaki, Yoshie

2012-01-01

Both streaming potential and accumulated charge of water flowed out were measured simultaneously using a sandwich-type cell. The voltages generated in divided sections along flow direction satisfied additivity. The sign of streaming potential agreed with that of streaming electrification. The relation between streaming potential and streaming electrification was explained from a viewpoint of electrical double layer in glass-water interface.