Science.gov

Sample records for offsite power transient

  1. Assessment of RELAP5/MOD2 code using loss of offsite power transient data of KNU (Korea Nuclear Unit) No. 1 Plant

    SciTech Connect

    Chung, Bud-Dong; Kim, Hho-Jung . Korea Nuclear Safety Center); Lee, Young-Jin )

    1990-04-01

    This report presents a code assessment study based on a real plant transient that occurred on June 9, 1981 at the KNU {number sign}1 (Korea Nuclear Unit Number 1). KNU {number sign}1 is a two-loop Westinghouse PWR plant of 587 Mwe. The loss of offsite power transient occurred at the 77.5% reactor power with 0.5%/hr power ramp. The real plant data were collected from available on-line plant records and computer diagnostics. The transient was simulated by RELAP5/MOD2/36.05 and the results were compared with the plant data to assess the code weaknesses and strengths. Some nodalization studies were performed to contribute to developing a guideline for PWR nodalization for the transient analysis. 5 refs., 18 figs., 3 tabs.

  2. Analysis of offsite dose calculation methodology for a nuclear power reactor

    SciTech Connect

    Moser, D.M.

    1995-12-31

    This technical study reviews the methodology for calculating offsite dose estimates as described in the offsite dose calculation manual (ODCM) for Pennsylvania Power and Light - Susquehanna Steam Electric Station (SSES). An evaluation of the SSES ODCM dose assessment methodology indicates that it conforms with methodology accepted by the US Nuclear Regulatory Commission (NRC). Using 1993 SSES effluent data, dose estimates are calculated according to SSES ODCM methodology and compared to the dose estimates calculated according to SSES ODCM and the computer model used to produce the reported 1993 dose estimates. The 1993 SSES dose estimates are based on the axioms of Publication 2 of the International Commission of Radiological Protection (ICRP). SSES Dose estimates based on the axioms of ICRP Publication 26 and 30 reveal the total body estimates to be the most affected.

  3. Analysis of Loss-of-Offsite-Power Events 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-02-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses suggest that loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2013. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The emergency diesel generator failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. No statistically significant trends in LOOP frequencies over the 1997–2013 period are identified. There is a possibility that a significant trend in grid-related LOOP frequency exists that is not easily detected by a simple analysis. Statistically significant increases in recovery times after grid- and switchyard-related LOOPs are identified.

  4. Analysis of Loss-of-Offsite-Power Events 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses performed loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience from fiscal year 1998 through 2012. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The EDG failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. A statistically significant increase in industry performance was identified for plant-centered and switchyard-centered LOOP frequencies. There is no statistically significant trend in LOOP durations.

  5. Impact of Uncertainty on Calculations for Recovery from Loss of Offsite Power

    SciTech Connect

    Dana L. Kelly

    2010-06-01

    Uncertainty, both aleatory and epistemic, can have a significant impact on estimated probabilities of recovering from loss of offsite power within a specified time window, and such probabilities are an input to risk-informed decisions as to the significance of inspection findings in the U.S. Nuclear Regulatory Commission’s Reactor Oversight Process. In particular, the choice of aleatory model for offsite power recovery time can have a significant impact on the estimated nonrecovery probability, especially if epistemic uncertainty regarding parameters in the aleatory model is accounted for properly. In past and current analyses, such uncertainty has largely been ignored. This paper examines the impact of both aleatory and epistemic uncertainty on the results, using modern open-source Bayesian inference software, which implements Markov chain Monte Carlo sampling. It includes examples of time-dependent convolution calculations to show the impact that uncertainty can have on this increasingly frequent type of calculation, also. The results show that the “point estimate” result, which is an input to risk-informed decisions, can easily be uncertain by a factor of 10 if both aleatory and epistemic uncertainties are considered. The paper also illustrates the use of Bayesian model selection criteria to aid in the choice of aleatory model.

  6. Multicriteria relocation analysis of an off-site radioactive monitoring network for a nuclear power plant.

    PubMed

    Chang, Ni-Bin; Ning, Shu-Kuang; Chen, Jen-Chang

    2006-08-01

    Due to increasing environmental consciousness in most countries, every utility that owns a commercial nuclear power plant has been required to have both an on-site and off-site emergency response plan since the 1980s. A radiation monitoring network, viewed as part of the emergency response plan, can provide information regarding the radiation dosage emitted from a nuclear power plant in a regular operational period and/or abnormal measurements in an emergency event. Such monitoring information might help field operators and decision-makers to provide accurate responses or make decisions to protect the public health and safety. This study aims to conduct an integrated simulation and optimization analysis looking for the relocation strategy of a long-term regular off-site monitoring network at a nuclear power plant. The planning goal is to downsize the current monitoring network but maintain its monitoring capacity as much as possible. The monitoring sensors considered in this study include the thermoluminescence dosimetry (TLD) and air sampling system (AP) simultaneously. It is designed for detecting the radionuclide accumulative concentration, the frequency of violation, and the possible population affected by a long-term impact in the surrounding area regularly while it can also be used in an accidental release event. With the aid of the calibrated Industrial Source Complex-Plume Rise Model Enhancements (ISC-PRIME) simulation model to track down the possible radionuclide diffusion, dispersion, transport, and transformation process in the atmospheric environment, a multiobjective evaluation process can be applied to achieve the screening of monitoring stations for the nuclear power plant located at Hengchun Peninsula, South Taiwan. To account for multiple objectives, this study calculated preference weights to linearly combine objective functions leading to decision-making with exposure assessment in an optimization context. Final suggestions should be useful for

  7. RHF RELAP5 Model and Preliminary Loss-Of-Offsite-Power Simulation Results for LEU Conversion

    SciTech Connect

    Licht, J. R.; Bergeron, A.; Dionne, B.; Thomas, F.

    2014-08-01

    The purpose of this document is to describe the current state of the RELAP5 model for the Institut Laue-Langevin High Flux Reactor (RHF) located in Grenoble, France, and provide an update to the key information required to complete, for example, simulations for a loss of offsite power (LOOP) accident. A previous status report identified a list of 22 items to be resolved in order to complete the RELAP5 model. Most of these items have been resolved by ANL and the RHF team. Enough information was available to perform preliminary safety analyses and define the key items that are still required. Section 2 of this document describes the RELAP5 model of RHF. The final part of this section briefly summarizes previous model issues and resolutions. Section 3 of this document describes preliminary LOOP simulations for both HEU and LEU fuel at beginning of cycle conditions.

  8. Discrete wavelet analysis of power system transients

    SciTech Connect

    Wilkinson, W.A.; Cox, M.D.

    1996-11-01

    Wavelet analysis is a new method for studying power system transients. Through wavelet analysis, transients are decomposed into a series of wavelet components, each of which is a time-domain signal that covers a specific octave frequency band. This paper presents the basic ideas of discrete wavelet analysis. A variety of actual and simulated transient signals are then analyzed using the discrete wavelet transform that help demonstrate the power of wavelet analysis.

  9. Analysis of loss of off-site power with a PWR at shutdown

    SciTech Connect

    Chu, T.L.; Yoon, W.H.; Fitzpatrick, R.G.

    1987-01-01

    In many probabilistic risk assessments (PRAs), loss of offsite power (LOOP) when a nuclear power plant is operating was found to be a significant contributor to core damage. The purpose of this study is to provide an analysis of a LOOP event that occurs while a pressurized water reactor (PWR) is shut down. The importance of such an analysis was recognized as part of a study to evaluate the core damage frequency due to a loss of decay heat removal (DHR) capability during an outage. When a PWR is in a shutdown condition, there are relatively few technical specification requirements on the operability of safety systems. In fact, some safety systems are intentionally disabled, i.e., the safety injection system and nonoperating charging pumps. Another problem when the reactor is shut down is that the reactor coolant system (RCS) may be partially drained and the steam generators may be unavailable. To determine the time available for operator actions, given that a LOOP occurs during shutdown and the DHR capability is lost, a simple thermal model has been developed. Similar calculations have been performed for other phases of refueling and maintenance outages. A total core damage frequency due to LOOP while the plant is in shutdown has been calculated to be 5.9 x 10/sup -6//yr. This is approximately twice the core damage frequency calculated for LOOP when the plant is at power.

  10. Gas-core reactor power transient analysis

    NASA Technical Reports Server (NTRS)

    Kascak, A. F.

    1972-01-01

    The gas core reactor is a proposed device which features high temperatures. It has applications in high specific impulse space missions, and possibly in low thermal pollution MHD power plants. The nuclear fuel is a ball of uranium plasma radiating thermal photons as opposed to gamma rays. This thermal energy is picked up before it reaches the solid cavity liner by an inflowing seeded propellant stream and convected out through a rocket nozzle. A wall-burnout condition will exist if there is not enough flow of propellant to convect the energy back into the cavity. A reactor must therefore operate with a certain amount of excess propellant flow. Due to the thermal inertia of the flowing propellant, the reactor can undergo power transients in excess of the steady-state wall burnout power for short periods of time. The objective of this study was to determine how long the wall burnout power could be exceeded without burning out the cavity liner. The model used in the heat-transfer calculation was one-dimensional, and thermal radiation was assumed to be a diffusion process.

  11. Example risk management plan and offsite consequence analysis for power plant aging using ammonia and chlorine

    SciTech Connect

    McCann, R.C. Jr.

    1998-07-01

    This paper provides an example of a risk management plan (RMP) for a utility power plant required under Title III of the 1990 Clean Air Act Amendments (CAAA). Under Title III, certain facilities are required to identify hazards associated with chemicals used to prevent accidental releases, and to minimize consequences of releases. Ammonia is used to reduce nitrogen oxides (NO{sub x}) emissions and is injected in the post-combustion system based on the selective catalyst reduction (SCR) process. Chlorine is used in the potable water treatment process. This paper provides an overview of the elements required in the RMP and specific methods and procedures currently recommended by the EPA for estimating hazardous air pollutant emissions and impacts related to the ammonia and chlorination processes cited in this paper. Information is presented that addresses the potential extent of a pollutant's impacts, including methods and assumptions designed to over-estimate concentrations. Alternative approaches are used to estimate more realistic but still conservative concentrations. Based on the results of these analyses, strategies are recommended that the plant could incorporate to reduce the level of potential impacts and, therefore, program requirements under RMP.

  12. Programmable AC power supply for simulating power transient expected in fusion reactor

    SciTech Connect

    Halimi, B.; Suh, K. Y.

    2012-07-01

    This paper focus on control engineering of the programmable AC power source which has capability to simulate power transient expected in fusion reactor. To generate the programmable power source, AC-AC power electronics converter is adopted to control the power of a set of heaters to represent the transient phenomena of heat exchangers or heat sources of a fusion reactor. The International Thermonuclear Experimental Reactor (ITER) plasma operation scenario is used as the basic reference for producing this transient power source. (authors)

  13. Multimachine system transient stability improvement using transient power system stabilizers (TPSS)

    SciTech Connect

    Musaazi, M.K.; Johnson, R.B.I.; Cory, B.J.

    1986-12-01

    Power system stabilizers (PSS) have been designed and installed to improve the dynamic (small signal) response of multimachine systems. This paper presents the theory and test results for improving the transient (large disturbance) behaviour of a multimachine system by supplementing the conventional PSS with a transient power system stabilizer (TPSS). Each generator unit is fitted with a TPSS which, after computation, injects supplementary control signals into both the automatic voltage regulator (AVR) and speed governor control loops.

  14. Transient Stability of the Grid with a Wind Power Plant

    SciTech Connect

    Muljadi, E.; Nguyen, Tony B.; Pai, M. A.

    2009-03-15

    This paper reports on an investigation of the impact of wind power plant penetration on the transient stability of the grid. Transient stability for different faults is investigated via simulation. A wind power plant with 22 turbines operated in variable speed mode will be used as the subject of the study. As a comparison, we replace the wind power plant with a conventional wind power plant (synchronous generator) and compare the results for the same faults. We also consider the effect of different locations.

  15. Wave power extraction from a transient heaving cylinder

    SciTech Connect

    Hudspeth, R. T.; Slotta, L. S.

    1980-01-01

    Wave power extracted from the transient motion of a periodically restrained-released heaving circular cylinder proposed by Falnes and Budal is examined under the limitations of linear wave theory excitation. Numerical estimates for the normalized radiated wave amplitudes required for the waveforce excitation derived by Mei are computed from the computationally efficient variational method developed by Black and Mei for the wave force diffraction regime. Wave power estimates for the rising period only of the heaving motion are given; while the falling period of the motion is neglected. A graphical summary is presented which demonstrates the parametric dependency of the dimensionless wave power rate on the design wave parameters and the body geometry for three general types of transient power systems heaving in deep water conditions. The total power requirements for the complete power extraction system as well as the real fluid viscous effects are not included.

  16. Software Support for Transiently Powered Computers

    SciTech Connect

    Van Der Woude, Joel Matthew

    2015-06-01

    With the continued reduction in size and cost of computing, power becomes an increasingly heavy burden on system designers for embedded applications. While energy harvesting techniques are an increasingly desirable solution for many deeply embedded applications where size and lifetime are a priority, previous work has shown that energy harvesting provides insufficient power for long running computation. We present Ratchet, which to the authors knowledge is the first automatic, software-only checkpointing system for energy harvesting platforms. We show that Ratchet provides a means to extend computation across power cycles, consistent with those experienced by energy harvesting devices. We demonstrate the correctness of our system under frequent failures and show that it has an average overhead of 58.9% across a suite of benchmarks representative for embedded applications.

  17. Gas-core reactor power transient analysis.

    NASA Technical Reports Server (NTRS)

    Kascak, A. F.

    1972-01-01

    The nuclear fuel in the gas-core reactor concept is a ball of uranium plasma radiating thermal photons. The photons are met by an inflowing hydrogen stream, which is seeded with submicron size, depleted uranium particles. A 'wall-burnout' condition exists if the thermal photons can reach the cavity liner because of insufficient absorption by the hydrogen. An analysis was conducted in order to determine the time for which the maximum steady state reactor power could be exceeded without damage to the cavity liner due to burnout. Wall-burnout time as a function of the power increase above the initial steady state condition is shown in a graph.

  18. The Effects of Transients on Photospheric and Chromospheric Power Distributions

    NASA Astrophysics Data System (ADS)

    Samanta, T.; Henriques, V. M. J.; Banerjee, D.; Krishna Prasad, S.; Mathioudakis, M.; Jess, D.; Pant, V.

    2016-09-01

    We have observed a quiet-Sun region with the Swedish 1 m Solar Telescope equipped with the CRISP Imaging SpectroPolarimeter. High-resolution, high-cadence, Hα line scanning images were taken to observe different layers of the solar atmosphere from the photosphere to upper chromosphere. We study the distribution of power in different period bands at different heights. Power maps of the upper photosphere and the lower chromosphere show suppressed power surrounding the magnetic-network elements, known as “magnetic shadows.” These also show enhanced power close to the photosphere, traditionally referred to as “power halos.” The interaction between acoustic waves and inclined magnetic fields is generally believed to be responsible for these two effects. In this study we explore whether small-scale transients can influence the distribution of power at different heights. We show that the presence of transients, like mottles, Rapid Blueshifted Excursions (RBEs), and Rapid Redshifted Excursions (RREs), can strongly influence the power maps. The short and finite lifetime of these events strongly affects all power maps, potentially influencing the observed power distribution. We show that Doppler-shifted transients like RBEs and RREs that occur ubiquitously can have a dominant effect on the formation of the power halos in the quiet Sun. For magnetic shadows, transients like mottles do not seem to have a significant effect on the power suppression around 3 minutes, and wave interaction may play a key role here. Our high-cadence observations reveal that flows, waves, and shocks manifest in the presence of magnetic fields to form a nonlinear magnetohydrodynamic system.

  19. Robust adaptive transient damping in power systems

    SciTech Connect

    Pierre, D.A.; Sadighi, I.; Trudnowski, D.J.; Smith, J.R.; Nehrir, M.H. . Dept. of Electrical Engineering)

    1992-09-01

    This Volume 1 of the final report on RP2665-1 contains two parts. part 1 consists of the following: (1) a literature review of real-time parameter identification algorithms which may be used in self-tuning adaptive control; (2) a description of mathematical discrete-time models that are linear in the parameters and that are useful for self-tuning adaptive control; (3) detailed descriptions of several variations of recursive-least-squares algorithms (RLS algorithms) and a unified representation of some of these algorithms; (4) a new variation of RLS called Corrector Least Squares (CLS); (5) a set of practical issues that need to be addressed in the implementation of RLS-based algorithms; (6) a set of simulation examples that illustrate properties of the identification methods; and (7) appendices With FORTRAN listings of several identification codes. Part 2 of this volume addresses the problem of damping electromechanical oscillations in power systems using advanced control theory. Two control strategies are developed. Controllers are then applied to a power system as power system stabilizer (PSS) units. The primary strategy is a decentralized indirect adaptive control scheme where multiple self-tuning adaptive controllers are coordinated. This adaptive scheme is presented in a general format and the stabilizing properties are demonstrated using examples. Both the adaptive and the conventional strategies are applied to a 17-machine computer-simulated power system. PSS units are applied to four generators in the system. Detailed simulation results are presented that show the feasibility and properties of both control schemes. FORTRAN codes for the control simulations are given in appendices of Part 2, as also are FORTRAN codes for the Prony identification method.

  20. Transient Plasma Photonic Crystals for High-Power Lasers

    NASA Astrophysics Data System (ADS)

    Lehmann, G.; Spatschek, K. H.

    2016-06-01

    A new type of transient photonic crystals for high-power lasers is presented. The crystal is produced by counterpropagating laser beams in plasma. Trapped electrons and electrically forced ions generate a strong density grating. The lifetime of the transient photonic crystal is determined by the ballistic motion of ions. The robustness of the photonic crystal allows one to manipulate high-intensity laser pulses. The scheme of the crystal is analyzed here by 1D Vlasov simulations. Reflection or transmission of high-power laser pulses are predicted by particle-in-cell simulations. It is shown that a transient plasma photonic crystal may act as a tunable mirror for intense laser pulses. Generalizations to 2D and 3D configurations are possible.

  1. Transient Plasma Photonic Crystals for High-Power Lasers.

    PubMed

    Lehmann, G; Spatschek, K H

    2016-06-01

    A new type of transient photonic crystals for high-power lasers is presented. The crystal is produced by counterpropagating laser beams in plasma. Trapped electrons and electrically forced ions generate a strong density grating. The lifetime of the transient photonic crystal is determined by the ballistic motion of ions. The robustness of the photonic crystal allows one to manipulate high-intensity laser pulses. The scheme of the crystal is analyzed here by 1D Vlasov simulations. Reflection or transmission of high-power laser pulses are predicted by particle-in-cell simulations. It is shown that a transient plasma photonic crystal may act as a tunable mirror for intense laser pulses. Generalizations to 2D and 3D configurations are possible. PMID:27314721

  2. System analysis of power transients in advanced WDM networks

    NASA Astrophysics Data System (ADS)

    Gorinevsky, Dimitry; Farber, Gennady

    2002-06-01

    This paper considers dynamical transient effects in the physical layer of an optical circuit-switched WDM network. These transients of the average transmission power have millisecond time scales. Instead of studying detailed nonlinear dynamics of the network elements, such as optical line amplifiers, a linearized model of the dynamics around a given steady state is considered. System-level analysis in this paper uses modern control theory methods and handles nonlinearity as uncertainty. The analysis translates requirements on the network performance into the requirements to the network elements. These requirements involve a few gross measures of performance for network elements and do not depend on the circuit switching state. One such performance measure is the worst amplification gain for all harmonic disturbances of the average transmission power. Another, is cross coupling of the wavelength channel power variations. The derived requirements guarantee system-level performance for all network configurations and can be used for specifying optical components and subsystems.

  3. Power System Transient Stability Analysis through a Homotopy Analysis Method

    SciTech Connect

    Wang, Shaobu; Du, Pengwei; Zhou, Ning

    2014-04-01

    As an important function of energy management systems (EMSs), online contingency analysis plays an important role in providing power system security warnings of instability. At present, N-1 contingency analysis still relies on time-consuming numerical integration. To save computational cost, the paper proposes a quasi-analytical method to evaluate transient stability through time domain periodic solutions’ frequency sensitivities against initial values. First, dynamic systems described in classical models are modified into damping free systems whose solutions are either periodic or expanded (non-convergent). Second, because the sensitivities experience sharp changes when periodic solutions vanish and turn into expanded solutions, transient stability is assessed using the sensitivity. Third, homotopy analysis is introduced to extract frequency information and evaluate the sensitivities only from initial values so that time consuming numerical integration is avoided. Finally, a simple case is presented to demonstrate application of the proposed method, and simulation results show that the proposed method is promising.

  4. HEMP-induced transients in electric power substations. Final report

    SciTech Connect

    Wiggins, C.M.; Thomas, D.E.; Salas, T.M.

    1992-02-01

    A nuclear detonation in or above the earth`s atmosphere produces an intense electromagnetic pulse (EMP). A large portion of the EMP electromagnetic energy is within the RF spectrum. A detonation at high altitudes above 40 km produces an EMP called high-altitude EMP (HEMP). HEMP is a steep-front short duration transient with a rise time on the order of a few nanoseconds which decays to near zero in less than a microsecond. A single high-altitude burst can subject much of the continental United States to intense HEMP electric fields on the order of tens of kilovolts per meter. The intense transient HEMP will induce fast transients in high-voltage transmission lines and bus structures, instrumentation cables, and control wires in power transmission and distribution (T & D) substations. A system of traveling wave coupling models for a 500 kV substation, including models for the high voltage primary bus, components (circuit breakers, disconnect switches, power transformers, and current and voltage instrument transformers), low voltage control wiring circuits, and a number of conducted and radiated interference coupling modes, had been developed earlier by EPRI. These EPRI served as the baseline for the present HEMP coupling investigations. The HEMP effects on protective relays were assessed for a nominal HEMP environment using several new field coupling models merged with the switching transient data. It is found that a representative solid state relay is unlikely to be damaged or to misoperate by the nominal HEMP threat with a peak field strength of 50 kV/m. However, it is possible for both DC control wires to flash over to ground simultaneously, causing fuses to blow and placing the relay in an inoperative state.

  5. HEMP-induced transients in electric power substations

    SciTech Connect

    Wiggins, C.M.; Thomas, D.E.; Salas, T.M. )

    1992-02-01

    A nuclear detonation in or above the earth's atmosphere produces an intense electromagnetic pulse (EMP). A large portion of the EMP electromagnetic energy is within the RF spectrum. A detonation at high altitudes above 40 km produces an EMP called high-altitude EMP (HEMP). HEMP is a steep-front short duration transient with a rise time on the order of a few nanoseconds which decays to near zero in less than a microsecond. A single high-altitude burst can subject much of the continental United States to intense HEMP electric fields on the order of tens of kilovolts per meter. The intense transient HEMP will induce fast transients in high-voltage transmission lines and bus structures, instrumentation cables, and control wires in power transmission and distribution (T D) substations. A system of traveling wave coupling models for a 500 kV substation, including models for the high voltage primary bus, components (circuit breakers, disconnect switches, power transformers, and current and voltage instrument transformers), low voltage control wiring circuits, and a number of conducted and radiated interference coupling modes, had been developed earlier by EPRI. These EPRI served as the baseline for the present HEMP coupling investigations. The HEMP effects on protective relays were assessed for a nominal HEMP environment using several new field coupling models merged with the switching transient data. It is found that a representative solid state relay is unlikely to be damaged or to misoperate by the nominal HEMP threat with a peak field strength of 50 kV/m. However, it is possible for both DC control wires to flash over to ground simultaneously, causing fuses to blow and placing the relay in an inoperative state.

  6. High-speed simulation of transients in nuclear power plants

    SciTech Connect

    Wulff, W.; Cheng, H.S.; Lekach, S.V.; Mallen, A.N.

    1984-01-01

    A combination of advanced modeling techniques and modern, special-purpose peripheral minicomputer technology is presented which affords realistic predictions of plant transient and severe off-normal events in LWR power plants through on-line simulations at a speed ten times greater than actual process speeds. Results are shown for a BWR plant simulation. Results are shown to demonstrate computing capacity, accuracy, and speed. Simulation speeds have been achieved which are 110 times larger than those of a CDC-7600 mainframe computer or ten times greater than real-time speed.

  7. Probabilistic assessment of power system transient stability incorporating SMES

    NASA Astrophysics Data System (ADS)

    Fang, Jiakun; Yao, Wei; Wen, Jinyu; Cheng, Shijie; Tang, Yuejin; Cheng, Zhuo

    2013-01-01

    This paper presents a stochastic-based approach to evaluate the probabilistic transient stability index of the power system incorporating the wind farm and the SMES. Uncertain factors include both sequence of disturbance in power grid and stochastic generation of the wind farm. The spectrums of disturbance in the grid as the fault type, the fault location, the fault clearing time and the automatic reclosing process with their probabilities of occurrence are used to calculate the probability indices, while the wind speed statistics and parameters of the wind generator are used in a Monte Carlo simulation to generate samples for the studies. With the proposed method, system stability is ”measured”. Quantitative relationship of penetration level, SMES coil size and system stability is established. Considering the stability versus coil size to be the production curve, together with the cost function, the coil size is optimized economically.

  8. Optimal subinterval selection approach for power system transient stability simulation

    DOE PAGESBeta

    Kim, Soobae; Overbye, Thomas J.

    2015-10-21

    Power system transient stability analysis requires an appropriate integration time step to avoid numerical instability as well as to reduce computational demands. For fast system dynamics, which vary more rapidly than what the time step covers, a fraction of the time step, called a subinterval, is used. However, the optimal value of this subinterval is not easily determined because the analysis of the system dynamics might be required. This selection is usually made from engineering experiences, and perhaps trial and error. This paper proposes an optimal subinterval selection approach for power system transient stability analysis, which is based on modalmore » analysis using a single machine infinite bus (SMIB) system. Fast system dynamics are identified with the modal analysis and the SMIB system is used focusing on fast local modes. An appropriate subinterval time step from the proposed approach can reduce computational burden and achieve accurate simulation responses as well. As a result, the performance of the proposed method is demonstrated with the GSO 37-bus system.« less

  9. Optimal subinterval selection approach for power system transient stability simulation

    SciTech Connect

    Kim, Soobae; Overbye, Thomas J.

    2015-10-21

    Power system transient stability analysis requires an appropriate integration time step to avoid numerical instability as well as to reduce computational demands. For fast system dynamics, which vary more rapidly than what the time step covers, a fraction of the time step, called a subinterval, is used. However, the optimal value of this subinterval is not easily determined because the analysis of the system dynamics might be required. This selection is usually made from engineering experiences, and perhaps trial and error. This paper proposes an optimal subinterval selection approach for power system transient stability analysis, which is based on modal analysis using a single machine infinite bus (SMIB) system. Fast system dynamics are identified with the modal analysis and the SMIB system is used focusing on fast local modes. An appropriate subinterval time step from the proposed approach can reduce computational burden and achieve accurate simulation responses as well. As a result, the performance of the proposed method is demonstrated with the GSO 37-bus system.

  10. Neural network recognition of nuclear power plant transients

    SciTech Connect

    Bartlett, E.B.; Danofsky, R.; Adams, J.; AlJundi, T.; Basu, A.; Dhanwada, C.; Kerr, J.; Kim, K.; Lanc, T.

    1993-02-23

    The objective of this report is to describe results obtained during the first year of funding that will lead to the development of an artificial neural network (ANN) fault - diagnostic system for the real - time classification of operational transients at nuclear power plants. The ultimate goal of this three-year project is to design, build, and test a prototype diagnostic adviser for use in the control room or technical support center at Duane Arnold Energy Center (DAEC); such a prototype could be integrated into the plant process computer or safety - parameter display system. The adviser could then warn and inform plant operators and engineers of plant component failures in a timely manner. This report describes the work accomplished in the first of three scheduled years for the project. Included herein is a summary of the first year's results as, well as individual descriptions of each of the major topics undertaken by the researchers. Also included are reprints of the articles written under this funding as well as those that were published during the funded period.

  11. A hybrid superconducting fault current limiter for enhancing transient stability in Korean power systems

    NASA Astrophysics Data System (ADS)

    Seo, Sangsoo; Kim, Seog-Joo; Moon, Young-Hwan; Lee, Byongjun

    2013-11-01

    Additional power generation sites have been limited in Korea, despite the fact load demands are gradually increasing. In order to meet these increasing demands, Korea’s power system company has begun constructing new generators at existing sites. Thus, multi-unit plants can create problems in terms of transient stability when a large disturbance occurs. This paper proposes a hybrid superconducting fault current limiter (SFCL) application to enhance the transient stability of multi-unit power plants. SFCLs reduce fault currents, and limitation currents decrease the imbalance of the mechanical and electrical torque of the generators, resulting in an improvement in transient stability.

  12. Research on power-law acoustic transient signal detection based on wavelet transform

    NASA Astrophysics Data System (ADS)

    Han, Jian-hui; Yang, Ri-jie; Wang, Wei

    2007-11-01

    Aiming at the characteristics of acoustic transient signal emitted from antisubmarine weapon which is being dropped into water (torpedo, aerial sonobuoy and rocket assisted depth charge etc.), such as short duration, low SNR, abruptness and instability, based on traditional power-law detector, a new method to detect acoustic transient signal is proposed. Firstly wavelet transform is used to de-noise signal, removes random spectrum components and improves SNR. Then Power- Law detector is adopted to detect transient signal. The simulation results show the method can effectively extract envelop characteristic of transient signal on the condition of low SNR. The performance of WT-Power-Law markedly outgoes that of traditional Power-Law detection method.

  13. CFD research on runaway transient of pumped storage power station caused by pumping power failure

    NASA Astrophysics Data System (ADS)

    Zhang, L. G.; Zhou, D. Q.

    2013-12-01

    To study runaway transient of pumped storage power station caused by pumping power failure, three dimensional unsteady numerical simulations were executed on geometrical model of the whole flow system. Through numerical calculation, the changeable flow configuration and variation law of some parameters such as unit rotate speed,flow rate and static pressure of measurement points were obtained and compared with experimental data. Numerical results show that runaway speed agrees well with experimental date and its error was 3.7%. The unit undergoes pump condition, brake condition, turbine condition and runaway condition with flow characteristic changing violently. In runaway condition, static pressure in passage pulses very strongly which frequency is related to runaway speed.

  14. Improvement of the transient stability using SFCL in Korean power systems

    NASA Astrophysics Data System (ADS)

    Hwang, Intae; Lee, Seung Ryul; Seo, Sangsoo; Yoon, Jaeyoung; Kim, Chul-Hwan

    2013-11-01

    This paper proposed a novel hybrid SFCL system for the enhancement of the transient stability in Korean power transmission system with auto-reclosing operation. The proposed SFCL system has an operation mechanism that the current limiting impedance is eliminated from the power system in a fault clearing time for the enhancement of the transient stability. Also, the system can cover the auto-reclosing operation of the transmission power system. This study analyzed an improvement of the special protection system by applying the proposed SFCL system to real power system in Korea.

  15. Computer simulation of magnetization-controlled shunt reactors for calculating electromagnetic transients in power systems

    SciTech Connect

    Karpov, A. S.

    2013-01-15

    A computer procedure for simulating magnetization-controlled dc shunt reactors is described, which enables the electromagnetic transients in electric power systems to be calculated. It is shown that, by taking technically simple measures in the control system, one can obtain high-speed reactors sufficient for many purposes, and dispense with the use of high-power devices for compensating higher harmonic components.

  16. The use of real-time off-site observations as a methodology for increasing forecast skill in prediction of large wind power ramps one or more hours ahead of their impact on a wind plant.

    SciTech Connect

    Martin Wilde, Principal Investigator

    2012-12-31

    ABSTRACT Application of Real-Time Offsite Measurements in Improved Short-Term Wind Ramp Prediction Skill Improved forecasting performance immediately preceding wind ramp events is of preeminent concern to most wind energy companies, system operators, and balancing authorities. The value of near real-time hub height-level wind data and more general meteorological measurements to short-term wind power forecasting is well understood. For some sites, access to onsite measured wind data - even historical - can reduce forecast error in the short-range to medium-range horizons by as much as 50%. Unfortunately, valuable free-stream wind measurements at tall tower are not typically available at most wind plants, thereby forcing wind forecasters to rely upon wind measurements below hub height and/or turbine nacelle anemometry. Free-stream measurements can be appropriately scaled to hub-height levels, using existing empirically-derived relationships that account for surface roughness and turbulence. But there is large uncertainty in these relationships for a given time of day and state of the boundary layer. Alternatively, forecasts can rely entirely on turbine anemometry measurements, though such measurements are themselves subject to wake effects that are not stationary. The void in free-stream hub-height level measurements of wind can be filled by remote sensing (e.g., sodar, lidar, and radar). However, the expense of such equipment may not be sustainable. There is a growing market for traditional anemometry on tall tower networks, maintained by third parties to the forecasting process (i.e., independent of forecasters and the forecast users). This study examines the value of offsite tall-tower data from the WINDataNOW Technology network for short-horizon wind power predictions at a wind farm in northern Montana. The presentation shall describe successful physical and statistical techniques for its application and the practicality of its application in an operational

  17. Detection and diagnosis of abnormal transients in nuclear power plants

    SciTech Connect

    Lee, J.C.; Rank, P.J.; Hawkes, E.; Wehe, D.K. . Dept. of Nuclear Engineering); Reifman, J. )

    1991-01-01

    This document describes a simulation-based algorithm that combines fuzzy logic with macroscopic conservation equations to diagnose multiple-failure events subject to uncertainties in transient data. Clusters of single-failure data points of similar characteristics are obtained through a pattern recognition algorithm and the cluster centers are combined in the space of macroscopic inventory derivatives to generate multiple-failure cluster centers. A fuzzy membership function is used to represent the likelihood of a data point belonging to a cluster, and failure estimates are obtained through solution of a fuzzy matrix equation. The algorithm has been successful in detecting simulated malfunctions in the pressurizer of a pressurized water reactor. 11 refs., 9 figs., 1 tab.

  18. Transient stability enhancement of electric power generating systems by 120-degree phase rotation

    DOEpatents

    Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

    1982-01-01

    A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

  19. Discharge transient coupling in large space power systems

    NASA Technical Reports Server (NTRS)

    Stevens, N. John; Stillwell, R. P.

    1990-01-01

    Experiments have shown that plasma environments can induce discharges in solar arrays. These plasmas simulate the environments found in low earth orbits where current plans call for operation of very large power systems. The discharges could be large enough to couple into the power system and possibly disrupt operations. Here, the general concepts of the discharge mechanism and the techniques of coupling are discussed. Data from both ground and flight experiments are reviewed to obtain an expected basis for the interactions. These concepts were applied to the Space Station solar array and distribution system as an example of the large space power system. The effect of discharges was found to be a function of the discharge site. For most sites in the array discharges would not seriously impact performance. One location at the negative end of the array was identified as a position where discharges could couple to charge stored in system capacitors. This latter case could impact performance.

  20. Investigation into the Effects of Microsecond Power Line Transients on Line-Connected Capacitors

    NASA Technical Reports Server (NTRS)

    Javor, K.

    2000-01-01

    An investigation was conducted into the effect of power-line transients on capacitors used by NASA and installed on platform primary power inputs to avionics. The purpose was to investigate whether capacitor voltage ratings needs to be derated for expected spike potentials. Concerns had been voiced in the past by NASA suppliers that MIL-STD-461 CS06-like requirements were overly harsh and led to physically large capacitors. The author had previously predicted that electrical-switching spike requirements representative of actual power-line transient potentials, durations. and source impedance would require no derating. This investigation bore out that prediction. It was further determined that traditional low source impedance CS06-like transients also will not damage a capacitor, although the spikes themselves are not nearly as well filtered. This report should be used to allay fears that CS06-like requirements drive capacitor voltage derating. Only that derating required by the relatively long duration transients in power quality specification need concern the equipment designer.

  1. Investigation Into The Effects of Microsecond Power Line Transients On Line-Connected Capacitors

    NASA Technical Reports Server (NTRS)

    Javor, Ken

    1999-01-01

    An investigation was conducted into the effect of power-line transients on capacitors used by NASA and installed on platform primary power inputs to avionics. The purpose was to investigate whether capacitor voltage rating needs to be derated for expected spike potentials. Concerns had been voiced in the past by NASA suppliers that MIL-STD-461 CS06-like requirements were overly harsh and led to physically large capacitors. The author had previously predicted that electrical-switching spike requirements representative of actual power-line transient potentials, durations and source impedance would require no derating. This investigation bore out that prediction. It was further determined that traditional low source impedance CS06-like transients also will not damage a capacitor, although the spikes themselves are not nearly as well filtered. This report should be used to allay fears that CS06-like requirements drive capacitor voltage derating. Only that derating required by the relatively long duration transients in power quality specification need concern the equipment designer.

  2. Offsite demonstrations for MWLID technologies

    SciTech Connect

    Williams, C.; Gruebel, R.

    1995-04-01

    The goal of the Offsite Demonstration Project for Mixed Waste Landfill Integrated Demonstration (MWLID)-developed environmental site characterization and remediation technologies is to facilitate the transfer, use, and commercialization of these technologies to the public and private sector. The meet this goal, the project identified environmental restoration needs of mixed waste and/or hazardous waste landfill owners (Native American, municipal, DOE, and DoD); documenting potential demonstration sites and the contaminants present at each site; assessing the environmental regulations that would effect demonstration activities; and evaluating site suitability for demonstrating MWLID technologies at the tribal and municipal sites identified. Eighteen landfill sites within a 40.2-km radius of Sandia National Laboratories are listed on the CERCLIS Site/Event Listing for the state of New Mexico. Seventeen are not located within DOE or DoD facilities and are potential offsite MWLID technology demonstration sites. Two of the seventeen CERCLIS sites, one on Native American land and one on municipal land, were evaluated and identified as potential candidates for off-site demonstrations of MWLID-developed technologies. Contaminants potentially present on site include chromium waste, household/commercial hazardous waste, volatile organic compounds, and petroleum products. MWLID characterization technologies applicable to these sites include Magnetometer Towed Array, Cross-borehole Electromagnetic Imaging, SitePlanner {trademark}/PLUME, Hybrid Directional Drilling, Seamist{trademark}/Vadose Zone Monitoring, Stripping Analyses, and x-ray Fluorescence Spectroscopy for Heavy Metals.

  3. Off-sites that work.

    PubMed

    Frisch, Bob; Chandler, Logan

    2006-06-01

    Of all the meetings top executives go to in a year, none is more important than the strategy off-site, where the most essential conversations for the future of the business occur. Yet it is the rare management team that can say its strategy off-site truly changed the way the business is run. At best, participants do some vague direction setting and work on team-building skills; at worst, they write off the retreat as a waste of time and resources. It needn't be like that. From their two decades of experience designing and facilitating strategy off-sites in companies large and small around the world, the authors have distilled a set of best practices that businesses can use to make the most of this annual opportunity. Essentially, the problem with most strategy off-sites is that they're insufficiently structured. People think that if you schedule a meeting, invite top leaders (and perhaps an outside expert), and block off units of time to discuss big subjects, the rest will take care of itself. In reality, formlessness leads to aimlessness. Oddly enough, only rigorously designed meetings give rise to truly candid strategy discussions. That rigor starts before the meeting, when the scope of the matters discussed must be limited, the participant list drawn up accordingly, the relevant materials (and only those) sent out and absorbed, and a detailed agenda established. During the meeting, the pace and quality of the conversation can be managed through attention to politics and by using carefully tailored frameworks, decision points, and group exercises. After the meeting, an action plan ensures clear accountability and follow-through. If you and your executive team spend four days a year rafting down rivers together, you'll eventually get good at rafting down rivers. Spend four days a year having well -designed strategy conversations together, and you will transform your annual off-site from a meaningless junket into a genuine turning point for your business. PMID

  4. Building Decision Trees for Characteristic Ellipsoid Method to Monitor Power System Transient Behaviors

    SciTech Connect

    Ma, Jian; Diao, Ruisheng; Makarov, Yuri V.; Etingov, Pavel V.; Zhou, Ning; Dagle, Jeffery E.

    2010-12-01

    The characteristic ellipsoid is a new method to monitor the dynamics of power systems. Decision trees (DTs) play an important role in applying the characteristic ellipsoid method to system operation and analysis. This paper presents the idea and initial results of building DTs for detecting transient dynamic events using the characteristic ellipsoid method. The objective is to determine fault types, fault locations and clearance time in the system using decision trees based on ellipsoids of system transient responses. The New England 10-machine 39-bus system is used for running dynamic simulations to generate a sufficiently large number of transient events in different system configurations. Comprehensive transient simulations considering three fault types, two fault clearance times and different fault locations were conducted in the study. Bus voltage magnitudes and monitored reactive and active power flows are recorded as the phasor measurements to calculate characteristic ellipsoids whose volume, eccentricity, center and projection of the longest axis are used as indices to build decision trees. The DT performances are tested and compared by considering different sets of PMU locations. The proposed method demonstrates that the characteristic ellipsoid method is a very efficient and promising tool to monitor power system dynamic behaviors.

  5. Calculation of MCPR (minimum critical power ratio) for BWR transients using the BNL plant analyzer

    SciTech Connect

    Horak, W.C.; Diamond, D.J.

    1987-06-01

    The critical power ratio (CPR) is used for determining the thermal limits of boiling water reactors. In this study, critical power ratios for a series of transients run on the Brookhaven Plant Analyzer (BPA) (1) have been calculated. The transients include nominal base case simulations, simulations with variations in relief valve setpoints and the number of failed feedwater heaters, simulations at the 100% power, 75% flow point on the extended load line of the MEOD, and a simulation with partial feedwater heating. The plant represented with the BPA is a BWR/4 rated at 3293 MW with a 6.38 m (251'') vessel. Data were obtained by the Plant Analyzer Development Group at BNL from a variety of sources describing the Browns Ferry Plant.

  6. Transient Current Analysis of Induction Generators for Wind Power Generating System

    NASA Astrophysics Data System (ADS)

    Senjyu, Tomonobu; Sueyoshi, Norihide; Uezato, Katsumi; Fujita, Hideki

    In recent year, non-conventional energy generation is coming up for effective use of natural energy, such as wind energy. Induction generators consisting squirrel-cage rotors are widly used as wind generators because of their salient features like robust rotor design, simple in the construction, maintenance free operation, etc. However these induction generators will draw large transient inrush current, several times as large as the machine rated current, the instant when they are connected to utility grid or restored after the fault clearance. Under such situations, there will be a severe voltage fluctuations in the power system. In this paper, we present transient analysis of induction generators before and after a three-phase fault conditions. Theoretical discission is developed to determine the initial phase angle and the time at which maximum transient currents flow in the system.

  7. Transient Stability Improvement of Multi-machine Power System Using Fuzzy Controlled TCSC

    NASA Astrophysics Data System (ADS)

    Rao, Gundala Srinivasa

    2012-07-01

    Power system is subjected to sudden changes in load levels. Stability is an important concept which determines the stable operation of power system. In general rotor angle stability is taken as index, but the concept of transient stability, which is the function of operating condition and disturbances deals with the ability of the system to remain intact after being subjected to abnormal deviations. A system is said to be synchronously stable (i.e., retain synchronism) for a given fault if the system variables settle down to some steady-state values with time, after the fault is removed.For the improvement of transient stability the general methods adopted are fast acting exciters, circuit breakers and reduction in system transfer reactance. The modern trend is to employ FACTS devices in the existing system for effective utilization of existing transmission resources. These FACTS devices contribute to power flow improvement besides they extend their services in transient stability improvement as well.In this paper, the studies had been carried out in order to improve the Transient Stability of WSCC 9 Bus System with Fixed Compensation on Various Lines and Optimal Location has been investigated using trajectory sensitivity analysis for better results.In this paper, in order to improve the Transient Stability margin further series FACTS device has been implemented. A fuzzy controlled Thyristor Controlled Series Compensation (TCSC) device has been used here and the results highlight the effectiveness of the application of a TCSC in improving the transient stability of a power system.In this paper, Trajectory sensitivity analysis (TSA) has been used to measure the transient stability condition of the system. The TCSC is modeled by a variable capacitor, the value of which changes with the firing angle. It is shown that TSA can be used in the design of the controller. The optimal locations of the TCSC-controller for different fault conditions can also be identified with

  8. Analysis of transient flow and starting pressure gradient of power-law fluid in fractal porous media

    NASA Astrophysics Data System (ADS)

    Tan, Xiao-Hua; Li, Xiao-Ping; Zhang, Lie-Hui; Liu, Jian-Yi; Cai, Jianchao

    2015-09-01

    A transient flow model for power-law fluid in fractal porous media is derived by combining transient flow theory with the fractal properties of tortuous capillaries. Pressure changes of transient flow for power-law fluid in fractal porous media are related to pore fractal dimension, tortuosity fractal dimension and the power-law index. Additionally, the starting pressure gradient model of power-law fluid in fractal porous media is established. Good agreement between the predictions of the present model and that of the traditional empirical model is obtained, the sensitive parameters that influence the starting pressure gradient are specified and their effects on the starting pressure gradient are discussed.

  9. Distributed Multi-Agent-Based Protection Scheme for Transient Stability Enhancement in Power Systems

    NASA Astrophysics Data System (ADS)

    Rahman, M. S.; Mahmud, M. A.; Pota, H. R.; Hossain, M. J.; Orchi, T. F.

    2015-04-01

    This paper presents a new distributed agent-based scheme to enhance the transient stability of power systems by maintaining phase angle cohesiveness of interconnected generators through proper relay coordination with critical clearing time (CCT) information. In this distributed multi-agent infrastructure, intelligent agents represent various physical device models to provide dynamic information and energy flow among different physical processes of power systems. The agents can communicate with each other in a distributed manner with a final aim to control circuit breakers (CBs) with CCT information as this is the key issue for maintaining and enhancing the transient stability of power systems. The performance of the proposed scheme is evaluated on a standard IEEE 39-bus New England benchmark system under different large disturbances such as three-phase short-circuit faults and changes in loads within the systems. From the simulation results, it is found that the proposed scheme significantly enhances the transient stability of power systems as compared to a conventional scheme of static CB operation.

  10. Modeling Reactor Coolant Systems Thermal-Hydraulic Transients

    Energy Science and Technology Software Center (ESTSC)

    1999-10-05

    RELAP5/MOD3.2* is used to model reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents and operational transients such as anticipated transients without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling approach is used that permits simulating a variety of thermal-hydraulic systems. Control system and secondary system components are included to allow modeling of themore » plant controls, turbines, condensers, and secondary feedwater systems.« less

  11. Contribution of Anticipated Transients Without Scram (ATWS) to core melt at United States nuclear power plants

    SciTech Connect

    Giachetti, R.T. , Ann Arbor, MI )

    1989-09-01

    This report looks at WASH-1400 and several other Probabilistic Risk Assessments (PRAs) and Probabilistic Safety Studies (PSSs) to determine the contribution of Anticipated Transients Without Scram (ATWS) events to the total core melt probability at eight nuclear power plants in the United States. After considering each plant individually, the results are compared from plant to plant to see if any generic conclusions regarding ATWS, or core melt in general, can be made. 8 refs., 34 tabs.

  12. An artificial intelligence framework for on-line transient stability assessment of power systems

    SciTech Connect

    Wehenkel, L.; VanCutsem, T.; Ribbens-Pavella, M.

    1989-05-01

    A new framework is proposed to tackle the on-line transient stability problem of power systems. Based on artificial intelligence, it successively makes use of an inductive inference method to automatically build decision rules, and a deductive inference method to apply them on-line. This paper attempts to lay the foundations of an inductive inference method, where the rules explicitly relate a system's stability with relevant static parameters of it. A simple but realistic power system is treated to illustrate important features of the method and to suggest how the derived decision rules could be used on-line.

  13. 47 CFR 54.637 - Off-site data centers and off-site administrative offices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... connections and network equipment associated with off-site data centers and off-site administrative offices... care provider's computer systems, associated components, and data, including (but not limited to... center and the public Internet or another network, (v) An off-site administrative office and the...

  14. 47 CFR 54.637 - Off-site data centers and off-site administrative offices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... connections and network equipment associated with off-site data centers and off-site administrative offices... care provider's computer systems, associated components, and data, including (but not limited to... center and the public Internet or another network, (v) An off-site administrative office and the...

  15. Theoretical foundations for finite-time transient stability and sensitivity analysis of power systems

    NASA Astrophysics Data System (ADS)

    Dasgupta, Sambarta

    Transient stability and sensitivity analysis of power systems are problems of enormous academic and practical interest. These classical problems have received renewed interest, because of the advancement in sensor technology in the form of phasor measurement units (PMUs). The advancement in sensor technology has provided unique opportunity for the development of real-time stability monitoring and sensitivity analysis tools. Transient stability problem in power system is inherently a problem of stability analysis of the non-equilibrium dynamics, because for a short time period following a fault or disturbance the system trajectory moves away from the equilibrium point. The real-time stability decision has to be made over this short time period. However, the existing stability definitions and hence analysis tools for transient stability are asymptotic in nature. In this thesis, we discover theoretical foundations for the short-term transient stability analysis of power systems, based on the theory of normally hyperbolic invariant manifolds and finite time Lyapunov exponents, adopted from geometric theory of dynamical systems. The theory of normally hyperbolic surfaces allows us to characterize the rate of expansion and contraction of co-dimension one material surfaces in the phase space. The expansion and contraction rates of these material surfaces can be computed in finite time. We prove that the expansion and contraction rates can be used as finite time transient stability certificates. Furthermore, material surfaces with maximum expansion and contraction rate are identified with the stability boundaries. These stability boundaries are used for computation of stability margin. We have used the theoretical framework for the development of model-based and model-free real-time stability monitoring methods. Both the model-based and model-free approaches rely on the availability of high resolution time series data from the PMUs for stability prediction. The problem of

  16. Transient Stability Improvement of Multi-Machine Power System with Large-Capacity Battery Systems

    NASA Astrophysics Data System (ADS)

    Kawabe, Ken-Ichi; Yokoyama, Akihiko

    An emergency control has been applied to power systems to avoid cascading outages by making the best use of existing equipment under severe fault conditions. Battery energy storage system (BESS) is one of the attractive equipment for the emergency control according to its growing installed capacity in the current grid. This paper investigates an effective use of BESS for transient stability improvement, and proposes a novel control scheme using wide-area information. The proposed control scheme adopts two stability indices, the energy function and rotor speed of the critical machine, to make it applicable to multi-machine power systems. Besides, it can control active and reactive power injection of the BESS coordinately to make the best use of its converter capacity for the stability enhancement. Digital simulations are conducted on the 32-machine meshed system with multiple BESSs. The results demonstrate that the BESSs controlled by the proposed method can improve the first swing stability and the system damping, and it is made clear how they improve the transient stability of the multi-machine power system. In addition, an impact of the reactive power control on the bus voltages around the installation sites is investigated to discuss a preferable way of their installation.

  17. Transient power supply voltage (v{sub DDT}) analysis for detecting IC defects

    SciTech Connect

    Cole, E.I. Jr.; Soden, J.M.; Beegle, R.W.

    1997-04-01

    Transient power supply voltage (V{sub DDT}) analysis is a new testing technique demonstrated as a powerful alternative and complement to I{sub DDQ} testing. V{sub DDT} takes advantage of the limited response time of a voltage supply to the changing power demands of an IC during operation. Changes in the V{sub DD} response time are used to detect increases in power demand with resolutions of 100 nA at 100 kHz, 1 {mu}A at 1 MHz, and 2.5 {mu}A at 1.5 MHz. These current sensitivities have been shown for ICs with quiescent currents < 0.1 {mu}A and > 300 {mu}A. The V{sub DDT} signal acquisition protocols, frequency versus sensitivity tradeoffs, hardware considerations and limitations, data examples, and areas for future research are described.

  18. Optical Transients Powered by Magnetars: Dynamics, Light Curves, and Transition to the Nebular Phase

    NASA Astrophysics Data System (ADS)

    Wang, Ling-Jun; Wang, S. Q.; Dai, Z. G.; Xu, Dong; Han, Yan-Hui; Wu, X. F.; Wei, Jian-Yan

    2016-04-01

    Millisecond magnetars can be formed via several channels: core collapse of massive stars, accretion-induced collapse of white dwarfs (WDs), double WD mergers, double neutron star (NS) mergers, and WD-NS mergers. Because the mass of ejecta from these channels could be quite different, their light curves are also expected to be diverse. We evaluate the dynamic evolution of optical transients powered by millisecond magnetars. We find that the magnetar with a short spin-down timescale converts its rotational energy mostly into the kinetic energy of the transient, while the energy of a magnetar with a long spin-down timescale goes into radiation of the transient. This leads us to speculate that hypernovae could be powered by magnetars with short spin-down timescales. At late times the optical transients will gradually evolve into a nebular phase because of the photospheric recession. We treat the photosphere and nebula separately because their radiation mechanisms are different. In some cases the ejecta could be light enough that the magnetar can accelerate it to a relativistic speed. It is well known that the peak luminosity of a supernova (SN) occurs when the luminosity is equal to the instantaneous energy input rate, as shown by Arnett. We show that photospheric recession and relativistic motion can modify this law. The photospheric recession always leads to a delay of the peak time {t}{pk} relative to the time {t}× at which the SN luminosity equals the instantaneous energy input rate. Relativistic motion, however, may change this result significantly.

  19. Numerical simulation of the operation of a MHD generator in transient regimes in MHD power stations

    SciTech Connect

    Bityurin, V.A.; Ivanov, P.P.; Koryagina, G.M.; Lyubimov, G.A.; Medin, S.A.; Morozov, G.N.; Prokop, A.S.

    1982-09-01

    Transient regimes of a MHD generator operating in combination with equipment in a MHD power station are analzyed with the help of a numerical model. The MHD generator, whose flow-through part consists of a nozzle, a channel, and a diffuser, is regulated by changing the flow rate and the load. Three types of MHD channels are studied: Faraday supersonic and subsonic, and diagonal supersonic. Their characteristics are presented and the efficiency of the MHD power station under nonrated regimes is determined. It is established that a MHD generator and the MHD power station as a whole admit quite efficient and deep regulation of the change in the flow rate of the working body.

  20. Statistical interpretation of transient current power-law decay in colloidal quantum dot arrays

    NASA Astrophysics Data System (ADS)

    Sibatov, R. T.

    2011-08-01

    A new statistical model of the charge transport in colloidal quantum dot arrays is proposed. It takes into account Coulomb blockade forbidding multiple occupancy of nanocrystals and the influence of energetic disorder of interdot space. The model explains power-law current transients and the presence of the memory effect. The fractional differential analogue of the Ohm law is found phenomenologically for nanocrystal arrays. The model combines ideas that were considered as conflicting by other authors: the Scher-Montroll idea about the power-law distribution of waiting times in localized states for disordered semiconductors is applied taking into account Coulomb blockade; Novikov's condition about the asymptotic power-law distribution of time intervals between successful current pulses in conduction channels is fulfilled; and the carrier injection blocking predicted by Ginger and Greenham (2000 J. Appl. Phys. 87 1361) takes place.

  1. Transient analysis of a molten salt central receiver (MSCR) in a solar power plant

    NASA Astrophysics Data System (ADS)

    Joshi, A.; Wang, C.; Akinjiola, O.; Lou, X.; Neuschaefer, C.; Quinn, J.

    2016-05-01

    Alstom is developing solar power tower plants utilizing molten salt as the working fluid. In solar power tower, the molten salt central receiver (MSCR) atop of the tower is constructed of banks of tubes arranged in panels creating a heat transfer surface exposed to the solar irradiation from the heliostat field. The molten salt heat transfer fluid (HTF), in this case 60/40%wt NaNO3-KNO3, flows in serpentine flow through the surface collecting sensible heat thus raising the HTF temperature from 290°C to 565°C. The hot molten salt is stored and dispatched to produce superheated steam in a steam generator, which in turn produces electricity in the steam turbine generator. The MSCR based power plant with a thermal energy storage system (TESS) is a fully dispatchable renewable power plant with a number of opportunities for operational and economic optimization. This paper presents operation and controls challenges to the MSCR and the overall power plant, and the use of dynamic model computer simulation based transient analyses applied to molten salt based solar thermal power plant. This study presents the evaluation of the current MSCR design, using a dynamic model, with emphasis on severe events affecting critical process response, such as MS temperature deviations, and recommend MSCR control design improvements based on the results. Cloud events are the scope of the transient analysis presented in this paper. The paper presents results from a comparative study to examine impacts or effects on key process variables related to controls and operation of the MSCR plant.

  2. Modeling of transient nonequilibrium phenomena in an inductively coupled plasma under pulsed power conditions

    SciTech Connect

    Ye, R.; Ishigaki, T.

    2005-06-15

    A time-dependent two-temperature model is developed to simulate the behavior of an argon radio frequency plasma under transient nonequilibrium conditions, with emphasis to shed light on the temporal and spatial evolution of the nonequilibrium phenomena occurring in pulsed power plasmas. The results show that the effects of changes in input power on the thermal nonequilibrium and the ionization nonequilibrium are most noticeable at the early stages of pulse on and off. The observed deviation from thermal equilibrium during pulsation is more pronounced in the fringes of the plasma and near the wall of the torch. In the central region, the influence is less significant and the plasma remains in a quasilocal thermal equilibrium state. The temporal evolution of the ionization nonequilibrium does not keep pace with that of the thermal nonequilibrium, and the relaxation process of the electron number density is slower and smoother. The effects of operating conditions on the transient behavior of the nonequilibrium situations under pulsed power conditions are also examined. It indicates that, for materials processing, a pulse duration between 2 and 10 ms is adequate for rf plasmas operated in pulse-modulated modes.

  3. Transient liquid phase diffusion bonding of Udimet 720 for Stirling power converter applications

    NASA Technical Reports Server (NTRS)

    Mittendorf, Donald L.; Baggenstoss, William G.

    1992-01-01

    Udimet 720 has been selected for use on Stirling power converters for space applications. Because Udimet 720 is generally considered susceptible to strain age cracking if traditional fusion welding is used, other joining methods are being considered. A process for transient liquid phase diffusion bonding of Udimet 720 has been theoretically developed in an effort to eliminate the strain age crack concern. This development has taken into account such variables as final grain size, joint homogenization, joint efficiency related to bonding aid material, bonding aid material application method, and thermal cycle.

  4. Influence of a voltage compensation type active superconducting fault current limiter on the transient stability of power system

    NASA Astrophysics Data System (ADS)

    Chen, L.; Tang, Y. J.; Shi, J.; Chen, N.; Song, M.; Cheng, S. J.; Hu, Y.; Chen, X. S.

    2009-10-01

    We have proposed a voltage compensation type active superconducting fault current limiter (SFCL). In this paper, the influence of the SFCL on the transient stability of power system is investigated. For the typical one-machine infinite-bus system, the power-angle characteristics of generator with SFCL are studied in different working conditions, and the transient physical process is analyzed. Using MATLAB SIMULINK, the power-angle swing curves are simulated under different current-limiting modes, fault types and fault clearance times. The results show that the proposed SFCL can effectively reduce the transient swing amplitude of rotor and extend the critical clearance time under mode 1, compared with mode 2 and mode 3 having few effects on enhancing the transient stability.

  5. Black Hole Spin via Continuum Fitting and the Role of Spin in Powering Transient Jets

    NASA Astrophysics Data System (ADS)

    McClintock, Jeffrey E.; Narayan, Ramesh; Steiner, James F.

    2014-09-01

    The spins of ten stellar black holes have been measured using the continuum-fitting method. These black holes are located in two distinct classes of X-ray binary systems, one that is persistently X-ray bright and another that is transient. Both the persistent and transient black holes remain for long periods in a state where their spectra are dominated by a thermal accretion disk component. The spin of a black hole of known mass and distance can be measured by fitting this thermal continuum spectrum to the thin-disk model of Novikov and Thorne; the key fit parameter is the radius of the inner edge of the black hole's accretion disk. Strong observational and theoretical evidence links the inner-disk radius to the radius of the innermost stable circular orbit, which is trivially related to the dimensionless spin parameter a ∗ of the black hole (| a ∗|<1). The ten spins that have so far been measured by this continuum-fitting method range widely from a ∗≈0 to a ∗>0.95. The robustness of the method is demonstrated by the dozens or hundreds of independent and consistent measurements of spin that have been obtained for several black holes, and through careful consideration of many sources of systematic error. Among the results discussed is a dichotomy between the transient and persistent black holes; the latter have higher spins and larger masses. Also discussed is recently discovered evidence in the transient sources for a correlation between the power of ballistic jets and black hole spin.

  6. Transient Stability Enhancement of Power Systems by Lyapunov-Based Recurrent Neural Networks UPFC Controllers

    NASA Astrophysics Data System (ADS)

    Chu, Chia-Chi; Tsai, Hung-Chi; Chang, Wei-Neng

    A Lyapunov-based recurrent neural networks unified power flow controller (UPFC) is developed for improving transient stability of power systems. First, a simple UPFC dynamical model, composed of a controllable shunt susceptance on the shunt side and an ideal complex transformer on the series side, is utilized to analyze UPFC dynamical characteristics. Secondly, we study the control configuration of the UPFC with two major blocks: the primary control, and the supplementary control. The primary control is implemented by standard PI techniques when the power system is operated in a normal condition. The supplementary control will be effective only when the power system is subjected by large disturbances. We propose a new Lyapunov-based UPFC controller of the classical single-machine-infinite-bus system for damping enhancement. In order to consider more complicated detailed generator models, we also propose a Lyapunov-based adaptive recurrent neural network controller to deal with such model uncertainties. This controller can be treated as neural network approximations of Lyapunov control actions. In addition, this controller also provides online learning ability to adjust the corresponding weights with the back propagation algorithm built in the hidden layer. The proposed control scheme has been tested on two simple power systems. Simulation results demonstrate that the proposed control strategy is very effective for suppressing power swing even under severe system conditions.

  7. Distributed Hierarchical Control Architecture for Transient Dynamics Improvement in Power Systems

    SciTech Connect

    Marinovici, Laurentiu D.; Lian, Jianming; Kalsi, Karanjit; Du, Pengwei; Elizondo, Marcelo A.

    2013-08-24

    In this paper, a novel distributed hierarchical coordinated control architecture is proposed for large scale power systems. The newly considered architecture facilitates frequency restoration and power balancing functions to be decoupled and implemented at different levels. At the local level, decentralized robust generator controllers are designed to quickly restore frequency after large faults and disturbances in the system. The controllers presented herein are shown to improve transient stability performance, as compared to conventional governor and excitation control. At the area level, Automatic Generation Control (AGC) is modified and coordinates with the decentralized robust controllers to reach the interchange schedule in the tie lines. The interaction of local and zonal controllers is validated through detailed simulations.

  8. Single Event Transients in Voltage Regulators for FPGA Power Supply Applications

    NASA Technical Reports Server (NTRS)

    Poivey, Christian; Sanders, Anthony; Kim, Hak; Phan, Anthony; Forney, Jim; LaBel, Kenneth A.; Karsh, Jeremy; Pursley, Scott; Kleyner, Igor; Katz, Richard

    2006-01-01

    As with other bipolar analog devices, voltage regulators are known to be sensitive to single event transients (SET). In typical applications, large output capacitors are used to provide noise immunity. Therefore, since SET amplitude and duration are generally small, they are often of secondary importance due to this capacitance filtering. In low voltage applications, however, even small SET are a concern. Over-voltages may cause destructive conditions. Under-voltages may cause functional interrupts and may also trigger electrical latchup conditions. In addition, internal protection circuits which are affected by load as well as internal thermal effects can also be triggered from heavy ions, causing dropouts or shutdown ranging from milliseconds to seconds. In the case of FPGA power supplies applications, SETS are critical. For example, in the case of Actel FPGA RTAX family, core power supply voltage is 1.5V. Manufacturer specifies an absolute maximum rating of 1.6V and recommended operating conditions between 1.425V and 1.575V. Therefore, according to the manufacturer, any transient of amplitude greater than 75 mV can disrupt normal circuit functions, and overvoltages greater than 100 mV may damage the FPGA. We tested five low dropout voltage regulators for SET sensitivity under a large range of circuit application conditions.

  9. An Inductive Power and Data Telemetry Subsystem With Fast Transient Low Dropout Regulator for Biomedical Implants.

    PubMed

    Lin, Yu-Po; Tang, Kea-Tiong

    2016-04-01

    This paper presents a capacitorless low-dropout (LDO) regulator with fast transient response and data reverse telemetry circuit for fully implantable wireless transmission applications. We propose a novel hybrid feedback structure using high-frequency compensation technology to achieve a rapid transient response for the LDO regulator. To reduce the size of the implant and transmit neural recordings through the same coil without interfering with power transmission, the load-shift-key (LSK) modulation technique is adopted for back data telemetry. The proposed implantable chip, fabricated using commercial 0.18 μm complementary metal oxide semiconductor technology, yielded an output power of 15 mW. Under 1.15 V operation voltage, the maximum overshoot and undershoot voltages were less than 45 mV and 55 mV, respectively, for a 15 mA full-load current whose rising and falling time were less than 100 ns. The proposed LSK transceiver uses a digitized demodulator to improve bandwidth efficiency for low carrier frequency operation. PMID:26285218

  10. Digital computer study of nuclear reactor thermal transients during startup of 60-kWe Brayton power conversion system

    NASA Technical Reports Server (NTRS)

    Jefferies, K. S.; Tew, R. C.

    1974-01-01

    A digital computer study was made of reactor thermal transients during startup of the Brayton power conversion loop of a 60-kWe reactor Brayton power system. A startup procedure requiring the least Brayton system complication was tried first; this procedure caused violations of design limits on key reactor variables. Several modifications of this procedure were then found which caused no design limit violations. These modifications involved: (1) using a slower rate of increase in gas flow; (2) increasing the initial reactor power level to make the reactor respond faster; and (3) appropriate reactor control drum manipulation during the startup transient.

  11. Limitations of power conversion systems under transient loads and impact on the pulsed tokamak power reactor

    NASA Astrophysics Data System (ADS)

    Sager, G. T.; Wong, C. P. C.; Kapich, D. D.; McDonald, C. F.; Schleicher, R. W.

    1993-11-01

    The impact of cyclic loading of the power conversion system of a helium-cooled, pulsed tokamak power plant is assessed. Design limits of key components of heat transport systems employing Rankine and Brayton thermodynamic cycles are quantified based on experience in gas-cooled fission reactor design and operation. Cyclic loads due to pulsed tokamak operation are estimated. Expected performance of the steam generator is shown to be incompatible with pulsed tokamak operation without load leveling thermal energy storage. The close cycle gas turbine is evaluated qualitatively based on performance of existing industrial and aeroderivative gas turbines. Advances in key technologies which significantly improve prospects for operation with tokamak fusion plants are reviewed.

  12. Switching transients in high-frequency high-power converters using power MOSFET's

    NASA Technical Reports Server (NTRS)

    Sloane, T. H.; Owen, H. A., Jr.; Wilson, T. G.

    1979-01-01

    The use of MOSFETs in a high-frequency high-power dc-to-dc converter is investigated. Consideration is given to the phenomena associated with the paralleling of MOSFETs and to the effect of stray circuit inductances on the converter circuit performance. Analytical relationships between various time constants during the turning-on and turning-off intervals are derived which provide estimates of plateau and peak levels during these intervals.

  13. Neural-network-based adaptive UPFC for improving transient stability performance of power system.

    PubMed

    Mishra, Sukumar

    2006-03-01

    This paper uses the recently proposed H(infinity)-learning method, for updating the parameter of the radial basis function neural network (RBFNN) used as a control scheme for the unified power flow controller (UPFC) to improve the transient stability performance of a multimachine power system. The RBFNN uses a single neuron architecture whose input is proportional to the difference in error and the updating of its parameters is carried via a proportional value of the error. Also, the coefficients of the difference of error, error, and auxiliary signal used for improving damping performance are depicted by a genetic algorithm. The performance of the newly designed controller is evaluated in a four-machine power system subjected to different types of disturbances. The newly designed single-neuron RBFNN-based UPFC exhibits better damping performance compared to the conventional PID as well as the extended Kalman filter (EKF) updating-based RBFNN scheme, making the unstable cases stable. Its simple architecture reduces the computational burden, thereby making it attractive for real-time implementation. Also, all the machines are being equipped with the conventional power system stabilizer (PSS) to study the coordinated effect of UPFC and PSS in the system. PMID:16566472

  14. Adaptive Evolutionary Programming Incorporating Neural Network for Transient Stability Constrained Optimal Power Flow

    NASA Astrophysics Data System (ADS)

    Tangpatiphan, Kritsana; Yokoyama, Akihiko

    This paper presents an adaptive evolutionary programming incorporating neural network for solving transient stability constrained optimal power flow (TSCOPF). The proposed AEP method is an evolutionary programming (EP)-based algorithm, which adjusts its population size automatically during an optimization process. The artificial neural network, which classifies the AEP individual based on its stability degrees, is embedded into the search template to reduce the computational load caused by transient stability constraints. The fuel cost minimization is selected as the objective function of TSCOPF. The proposed method is tested on the IEEE 30-bus system with two types of the fuel cost functions, i.e. the conventional quadratic function and the quadratic function superimposed by sine component to model the cost curves without and with valve-point loading effect respectively. The numerical examples show that AEP is more effective than conventional EP in terms of computational speed, and when the neural network is incorporated into AEP, it can significantly reduce the computational time of TSCOPF. A study of the architecture of the neural network is also conducted and discussed. In addition, the effectiveness of the proposed method for solving TSCOPF with the consideration of multiple contingencies is manifested.

  15. Thermomechanical Response of a Gas to Spatially Resolved Power Deposition Transients

    NASA Astrophysics Data System (ADS)

    Kassoy, David R.

    2015-11-01

    Liquid propellant rocket engine (LPRE) instability is characterized by growing pressure oscillations that affect the integrity and performance of the system. Modeling and prediction have been topics of intense interest to designers for more than 60 years. LPRE combustion provides a wonderful opportunity to employ thermomechanical concepts and mathematical methodologies to quantify the response of combustion chamber gases to spatially distributed, transient thermal energy deposition. Nondimensional Euler equations, including a power deposition term in the energy equation are used to identify crucial parameters, time and length scales, as well as levels of energy deposition, relevant to LPRE performance. The objective is to provide first principles explanations of physical phenomena responsible for mechanical disturbances observed in operating LPRE's.

  16. Transient analysis of an FHR coupled to a helium Brayton power cycle

    SciTech Connect

    Chen, Minghui; Kim, In Hun; Sun, Xiaodong; Christensen, Richard; Utgikar, Vivek; Sabharwall, Piyush

    2015-08-01

    The Fluoride salt-cooled High-temperature Reactor (FHR) features a passive decay heat removal system and a high-efficiency Brayton cycle for electricity generation. It typically employs an intermediate loop, consisting of an intermediate heat exchanger (IHX) and a secondary heat exchanger (SHX), to couple the primary system with the power conversion unit (PCU). In this study, a preliminary dynamic system model is developed to simulate transient characteristics of a prototypic 20-MWth Fluoride salt-cooled High-temperature Test Reactor (FHTR). The model consists of a series of differential conservation equations that are numerically solved using the MATLAB platform. For the reactor, a point neutron kinetics model is adopted. For the IHX and SHX, a fluted tube heat exchanger and an offset strip-fin heat exchanger are selected, respectively. Detailed geometric parameters of each component in the FHTR are determined based on the FHTR nominal steady-state operating conditions. Three initiating events are simulated in this study, including a positive reactivity insertion, a step increase in the mass flow rate of the PCU helium flow, and a step increase in the PCU helium inlet temperature to the SHX. The simulation results show that the reactor has inherent safety features for those three simulated scenarios. It is observed that the increase in the temperatures of the fuel pebbles and primary coolant is mitigated by the decrease in the reactor power due to negative temperature feedbacks. The results also indicate that the intermediate loop with the two heat exchangers plays a significant role in the transient progression of the integral reactor system.

  17. Robust transient stabilisation problem for a synchronous generator in a power network

    NASA Astrophysics Data System (ADS)

    Verrelli, C. M.; Damm, G.

    2010-04-01

    The robust transient stabilisation problem (with stability proof€) of a synchronous generator in an uncertain power network with transfer conductances is rigorously formulated and solved. The generator angular speed and electrical power are required to be kept close, when mechanical and electrical perturbations occur, to the synchronous speed and mechanical input power, respectively, while the generator terminal voltage is to be regulated, when perturbations are removed, to its pre-fault reference constant value. A robust adaptive nonlinear feedback control algorithm is designed on the basis of a third-order model of the synchronous machine: only two system parameters (synchronous machine damping and inertia constants) along with upper and lower bounds on the remaining uncertain ones are supposed to be known. The conditions to be satisfied by the remote network dynamics for guaranteeing ℒ2 and ℒ∞ robustness and asymptotic relative speed and voltage regulation to zero are weaker than those required by the single machine-infinite bus approximation: dynamic interactions between the local deviations of the generator states from the corresponding equilibrium values and the remote generators states are allowed.

  18. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems.

    PubMed

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a "normal" state where the motors' mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a "stalled" state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors' mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases. PMID:23848724

  19. Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems

    NASA Astrophysics Data System (ADS)

    Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

    2013-06-01

    The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a “normal” state where the motors’ mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a “stalled” state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors’ mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

  20. Assessment of RELAP5/MOD2 against a main feedwater turbopump trip transient in the Vandellos II Nuclear Power Plant

    SciTech Connect

    Llopis, C.; Casals, A.; Perez, J.; Mendizabal, R.

    1993-12-01

    The Consejo de Seguridad Nuclear (CSN) and the Asociacion Nuclear Vandellos (ANV) have developed a model of Vandellos II Nuclear Power Plant. The ANV collaboration consisted in the supply of design and actual data, the cooperation in the simulation of the control systems and other model components, as well as in the results analysis. The obtained model has been assessed against the following transients occurred in plant: A trip from the 100% power level (CSN); a load rejection from 100% to 50% (CSN); a load rejection from 75% to 65% (ANV); and, a feedwater turbopump trip (ANV). This copy is a report of the feedwater turbopump trip transient simulation. This transient actually occurred in the plant on June 19, 1989.

  1. Application of a combined superconducting fault current limiter and STATCOM to enhancement of power system transient stability

    NASA Astrophysics Data System (ADS)

    Mahdad, Belkacem; Srairi, K.

    2013-12-01

    Stable and reliable operation of the power system network is dependent on the dynamic equilibrium between energy production and power demand under large disturbance such as short circuit or important line tripping. This paper investigates the use of combined model based superconducting fault current limiter (SFCL) and shunt FACTS Controller (STATCOM) for assessing the transient stability of a power system considering the automatic voltage regulator. The combined model located at a specified branch based on voltage stability index using continuation power flow. The main role of the proposed combined model is to achieve simultaneously a flexible control of reactive power using STATCOM Controller and to reduce fault current using superconducting technology based SFCL. The proposed combined model has been successfully adapted within the transient stability program and applied to enhance the transient power system stability of the WSCC9-Bus system. Critical clearing time (CCT) has been used as an index to evaluate and validate the contribution of the proposed coordinated Controller. Simulation results confirm the effectiveness and perspective of this combined Controller to enhance the dynamic power system performances.

  2. Transient and steady-state tests of the space power research engine with resistive and motor loads

    NASA Astrophysics Data System (ADS)

    Rauch, Jeffrey S.; Kankam, M. David

    1995-01-01

    The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

  3. Transient and Steady-state Tests of the Space Power Research Engine with Resistive and Motor Loads

    NASA Technical Reports Server (NTRS)

    Rauch, Jeffrey S.; Kankam, M. David

    1995-01-01

    The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

  4. 29 CFR 1908.4 - Offsite consultation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Offsite consultation. 1908.4 Section 1908.4 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... on occupational safety and health issues by telephone and correspondence, and at locations other...

  5. 29 CFR 1908.4 - Offsite consultation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Offsite consultation. 1908.4 Section 1908.4 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR... on occupational safety and health issues by telephone and correspondence, and at locations other...

  6. User's Guide for RESRAD-OFFSITE

    SciTech Connect

    Gnanapragasam, E.; Yu, C.

    2015-04-01

    The RESRAD-OFFSITE code can be used to model the radiological dose or risk to an offsite receptor. This User’s Guide for RESRAD-OFFSITE Version 3.1 is an update of the User’s Guide for RESRAD-OFFSITE Version 2 contained in the Appendix A of the User’s Manual for RESRAD-OFFSITE Version 2 (ANL/EVS/TM/07-1, DOE/HS-0005, NUREG/CR-6937). This user’s guide presents the basic information necessary to use Version 3.1 of the code. It also points to the help file and other documents that provide more detailed information about the inputs, the input forms and features/tools in the code; two of the features (overriding the source term and computing area factors) are discussed in the appendices to this guide. Section 2 describes how to download and install the code and then verify the installation of the code. Section 3 shows ways to navigate through the input screens to simulate various exposure scenarios and to view the results in graphics and text reports. Section 4 has screen shots of each input form in the code and provides basic information about each parameter to increase the user’s understanding of the code. Section 5 outlines the contents of all the text reports and the graphical output. It also describes the commands in the two output viewers. Section 6 deals with the probabilistic and sensitivity analysis tools available in the code. Section 7 details the various ways of obtaining help in the code.

  7. A Physically Transient Form of Silicon Electronics, With Integrated Sensors, Actuators and Power Supply

    PubMed Central

    Hwang, Suk-Won; Tao, Hu; Kim, Dae-Hyeong; Cheng, Huanyu; Song, Jun-Kyul; Rill, Elliott; Brenckle, Mark A.; Panilaitis, Bruce; Won, Sang Min; Kim, Yun-Soung; Yu, Ki Jun; Ameen, Abid; Li, Rui; Su, Yewang; Yang, Miaomiao; Kaplan, David L.; Zakin, Mitchell R.; Slepian, Marvin J.; Huang, Yonggang; Omenetto, Fiorenzo G.; Rogers, John A.

    2013-01-01

    A remarkable feature of modern silicon electronics is its ability to remain functionally and physically invariant, almost indefinitely for many practical purposes. Here, we introduce a silicon-based technology that offers the opposite behavior: it gradually vanishes over time, in a well-controlled, programmed manner. Devices that are ‘transient’ in this sense create application possibilities that cannot be addressed with conventional electronics, such as active implants that exist for medically useful timeframes, but then completely dissolve and disappear via resorption by the body. We report a comprehensive set of materials, manufacturing schemes, device components and theoretical design tools for a complementary metal oxide semiconductor (CMOS) electronics of this type, together with four different classes of sensors and actuators in addressable arrays, two options for power supply and a wireless control strategy. A transient silicon device capable of delivering thermal therapy in an implantable mode and its demonstration in animal models illustrate a system-level example of this technology. PMID:23019646

  8. Neural network recognition of nuclear power plant transients. Final report, April 15, 1992--April 15, 1995

    SciTech Connect

    Bartlett, E.B.

    1995-05-15

    The objective of this report is to describe results obtained during the second year of funding that will lead to the development of an artificial neural network (A.N.N) fault diagnostic system for the real-time classification of operational transients at nuclear power plants. The ultimate goal of this three-year project is to design, build, and test a prototype diagnostic adviser for use in the control room or technical support center at Duane Arnold Energy Center (DAEC); such a prototype could be integrated into the plant process computer or safety-parameter display system. The adviser could then warn and inform plant operators and engineers of plant component failures in a timely manner. This report describes the work accomplished in the second of three scheduled years for the project. Included herein is a summary of the second year`s results as well as descriptions of each of the major topics undertaken by the researchers. Also included are reprints of the articles written under this funding as well as those that were published during the funded period.

  9. New transient absorption observed in the spectrum of colloidal CdSe nanoparticles pumped with high-power femtosecond pulses

    SciTech Connect

    Burda, C.; Link, S.; Green, T.C.; El-Sayed, M.A.

    1999-12-09

    The power dependence of the transient absorption spectrum of CdSe nanoparticle colloids with size distribution of 4.0 {+-} 0.4 nm diameter is studied with femtosecond pump-probe techniques. At the lowest pump laser power, the absorption bleaching (negative spectrum) characteristic of the exciton spectrum is observed with maxima at 560 and 480 nm. As the pump laser power increases, two new transient absorptions at 510 and 590 nm with unresolved fast rise (<100 fs) and long decay times ({much{underscore}gt}150 ps) are observed. The energy of each of the positive absorption is red shifted from that of the bleach bands by {approximately}120 MeV. The origin of this shift is discussed in terms of the effect of the internal electric field of the many electron-hole pairs formed within the quantum dot at the high pump intensity, absorption from a metastable excited state or the formation of biexcitons.

  10. A decision tree-based on-line preventive control strategy for power system transient instability prevention

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Dong, Zhao Yang; Zhang, Rui; Wong, Kit Po

    2014-02-01

    Maintaining transient stability is a basic requirement for secure power system operations. Preventive control deals with modifying the system operating point to withstand probable contingencies. In this article, a decision tree (DT)-based on-line preventive control strategy is proposed for transient instability prevention of power systems. Given a stability database, a distance-based feature estimation algorithm is first applied to identify the critical generators, which are then used as features to develop a DT. By interpreting the splitting rules of DT, preventive control is realised by formulating the rules in a standard optimal power flow model and solving it. The proposed method is transparent in control mechanism, on-line computation compatible and convenient to deal with multi-contingency. The effectiveness and efficiency of the method has been verified on New England 10-machine 39-bus test system.

  11. Power transient analyses of experimental in-reflector devices during safety shutdown in Jules Horowitz Reactor (JHR)

    SciTech Connect

    Camprini, P. C.; Sumini, M.; Artioli, C.; Gonnier, C.; Pouchin, B.; Bourdon, S.

    2012-07-01

    The Jules Horowitz Reactor (JHR) is designed to be a 100 MW material testing reactor (MTR) and it is expected to become the reference facility in the framework of European nuclear research activity. As the core neutron spectrum is quite fast, several experimental devices concerning fuel studies have been conceived to be placed in the reflector in order to exploit a proper thermal neutron flux irradiation. Since the core power is relatively high, the neutronic coupling between the reactor core and the reflector devices has to be taken into account for different rod insertions. In fact the thermal power produced within the fuel samples is considerable. Heat removal during shutdown is a main topic in nuclear safety and it is worth to analyse thermal power transients in fuel samples as well. Here a thermal hydraulic model for JHR core is proposed aiming at a simple and representative description as far as reactivity feedbacks are concerned. Then it is coupled with a neutronic pointwise kinetics analysis by means of the DULCINEE code to compute core power transient calculations. Moreover, some reflector-core coupling evaluations are performed through Monte Carlo method using the TRIPOLI 4.7 code. The JHR equilibrium cycle is considered with respect to four fuel compositions namely Beginning of Cycle (BOC), Xenon Saturation Point (XSP), Middle of Cycle (MOC) and End of Cycle (EOC). Then thermal power transients in the experimental reflector devices are evaluated during safety shutdowns and they are verified for all these cycle steps. (authors)

  12. Temporal dependence of transient dark counts in an avalanche photodiode: A solution for power-law behavior of afterpulsing

    NASA Astrophysics Data System (ADS)

    Akiba, M.; Tsujino, K.

    2016-08-01

    This paper offers a theoretical explanation of the temperature and temporal dependencies of transient dark count rates (DCRs) measured for a linear-mode silicon avalanche photodiode (APD) and the dependencies of afterpulsing that were measured in Geiger-mode Si and InGaAs/InP APDs. The temporal dependencies exhibit power-law behavior, at least to some extent. For the transient DCR, the value of the DCR for a given time period increases with decreases in temperature, while the power-law behavior remains unchanged. The transient DCR is attributed to electron emissions from traps in the multiplication layer of the APD with a high electric field, and its temporal dependence is explained by a continuous change in the electron emission rate as a function of the electric field strength. The electron emission rate is calculated using a quantum model for phonon-assisted tunnel emission. We applied the theory to the temporal dependence of afterpulsing that was measured for Si and InGaAs/InP APDs. The power-law temporal dependence is attributed to the power-law function of the electron emission rate from the traps as a function of their position across the p-n junction of the APD. Deviations from the power-law temporal dependence can be derived from the upper and lower limits of the electric field strength.

  13. Transient liquid phase bonding as a joining technique for high-temperature power electronics

    NASA Astrophysics Data System (ADS)

    Bosco, Nicholas Seth

    Fundamental aspects of transient liquid phase (TLP) bonding in the Cu-Sn system have been studied, with the objective of assessing the utility of the bonding technique in joining high-temperature SiC devices to direct bond copper (DBC) substrates in power electronic packages. This technique can be implemented at relatively low temperatures (in comparison to the melting point of Cu), yet provide bonds that have composition and properties that are similar to those of Cu. The bonding parameters of time, temperature, and interlayer thickness were probed. Additionally, two methods for the introduction of the interlayer were used: one based on the use of foils and the other based on electron beam deposition. The resulting microstructures were characterized using scanning electron microscopy and energy dispersive X-ray analysis. Microstructures consisting of the phases Cu6Sn5, Cu3Sn, Cu 41Sn11, and (Cu) were produced. The time required to form a bond with the targeted microstructure, notably that of (Cu), was found to be dominated by the consumption of intermediate phases, as dictated by diffusion, and thus scaled quadratically with initial interlayer thickness. Two types of bonding defects were obtained: one due to surface contamination and the other caused by the consumption of Sn through the formation of the Cu 6Sn5 intermetallic in the solid state during heating. The successful production of samples devoid of such defects was via electron beam deposition of the interlayer material, with sufficient thickness to ensure ample material for the formation of the transient liquid phase following solid state intermetallic formation. The mechanical properties of these bonds were measured and compared with those made with Sn foil. The toughness of the bonds in samples where the Sn interlayer was introduced by electron beam deposition was greater than that of samples that used an interlayer of Sn foil. The difference was attributed to the higher level of porosity and defects in

  14. Health technology assessment: Off-site sterilization

    PubMed Central

    Dehnavieh, Reza; Mirshekari, Nadia; Ghasemi, Sara; Goudarzi, Reza; Haghdoost, AliAkbar; Mehrolhassani, Mohammad Hossain; Moshkani, Zahra; Noori Hekmat, Somayeh

    2016-01-01

    Background: Every year millions of dollars are expended to equip and maintain the hospital sterilization centers, and our country is not an exception of this matter. According to this, it is important to use more effective technologies and methods in health system in order to reach more effectiveness and saving in costs. This study was conducted with the aim of evaluating the technology of regional sterilization centers. Methods: This study was done in four steps. At the first step, safety and effectiveness of technology was studied via systematic study of evidence. The next step was done to evaluate the economical aspect of off-site sterilization technology using gathered data from systematic review of the texts which were related to the technology and costs of off-site and in-site hospital sterilization. Third step was conducted to collect experiences of using technology in some selected hospitals around the world. And in the last step different aspects of acceptance and use of this technology in Iran were evaluated. Results: Review of the selected articles indicated that efficacy and effectiveness of this technology is Confirmed. The results also showed that using this method is not economical in Iran. Conclusion: According to the revealed evidences and also cost analysis, due to shortage of necessary substructures and economical aspect, installing the off-site sterilization health technology in hospitals is not possible currently. But this method can be used to provide sterilization services for clinics and outpatients centers. PMID:27390714

  15. Stability, Transient Response, Control, and Safety of a High-Power Electric Grid for Turboelectric Propulsion of Aircraft

    NASA Technical Reports Server (NTRS)

    Armstrong, Michael; Ross, Christine; Phillips, Danny; Blackwelder, Mark

    2013-01-01

    This document contains the deliverables for the NASA Research and Technology for Aerospace Propulsion Systems (RTAPS) regarding the stability, transient response, control, and safety study for a high power cryogenic turboelectric distributed propulsion (TeDP) system. The objective of this research effort is to enumerate, characterize, and evaluate the critical issues facing the development of the N3-X concept aircraft. This includes the proposal of electrical grid architecture concepts and an evaluation of any needs for energy storage.

  16. Operational, control and protective system transient analyses of the closed-cycle GT-HTGR power plant

    NASA Astrophysics Data System (ADS)

    Openshaw, F. L.; Chan, T. W.

    1980-11-01

    This paper presents a description of the analyses of the control/protective system preliminary designs for the gas turbine high-temperature gas-cooled reactor (GT-HTGR) power plant. The purpose of these systems is the control and safe operation of the plant in accordance with utility practice for large nuclear generation stations, and in the event of an abnormal or accident condition to shut the plant down in an orderly manner and maintain it in a safe shutdown condition. Several unique characteristics inherent in the operation of the closed-cycle multiple-loop GT-HTGR design have presented special modeling and/or control design requirements or resulted in unusual conditions. The GT-HTGR dynamic modeling, control/protective system design, and transient analyses are illustrated in this paper through discussion of a few selected transient events and the special modeling and control operation for these events.

  17. Evidence that aerodynamic effects, including dynamic stall, dictate HAWT structural loads and power generation in highly transient time frames

    NASA Astrophysics Data System (ADS)

    Shipley, D. E.; Miller, M. S.; Robinson, M. C.; Luttges, M. W.; Simms, D. A.

    1994-08-01

    Aerodynamic data collected from the National Renewable Energy Laboratory's Combined Experiment have shown three distinct performance regimes when the turbine is operated under relatively steady flow conditions. Operating at blade angles of attack below static stall, excellent agreement is achieved with two-dimensional wind tunnel data. Around the static stall angle, the cycle average normal force produced is greater than the static test data. Span locations near the hub produce extremely large values of normal force coefficient, well in excess of the two-dimensional data results. These performance regimes have been shown to be a function of the three-dimensional flow structure and cycle averaged dynamic stall effects. Power generation and root bending moments have also been shown to be directly dependent on the inflow wind velocity. Aerodynamic data, including episodes of dynamic stall, have been correlated on a cycle by cycle basis with the structural and power generation characteristics of a horizontal axis wind turbine. Instantaneous unsteady forces and resultant power generation indicate that peak transient levels can significantly exceed cycle averaged values. Strong coupling between transient aerodynamic and resonant response of the turbine was also observed. These results provide some initial insight into the contribution of unsteady aerodynamics on undesirable turbine structural response and fatigue life.

  18. Transient suppression of broadband gamma power in the default-mode network is correlated with task complexity and subject performance.

    PubMed

    Ossandón, Tomas; Jerbi, Karim; Vidal, Juan R; Bayle, Dimitri J; Henaff, Marie-Anne; Jung, Julien; Minotti, Lorella; Bertrand, Olivier; Kahane, Philippe; Lachaux, Jean-Philippe

    2011-10-12

    Task performance is associated with increased brain metabolism but also with prominent deactivation in specific brain structures known as the default-mode network (DMN). The role of DMN deactivation remains enigmatic in part because its electrophysiological correlates, temporal dynamics, and link to behavior are poorly understood. Using extensive depth electrode recordings in humans, we provide first electrophysiological evidence for a direct correlation between the dynamics of power decreases in the DMN and individual subject behavior. We found that all DMN areas displayed transient suppressions of broadband gamma (60-140 Hz) power during performance of a visual search task and, critically, we show for the first time that the millisecond range duration and extent of the transient gamma suppressions are correlated with task complexity and subject performance. In addition, trial-by-trial correlations revealed that spatially distributed gamma power increases and decreases formed distinct anticorrelated large-scale networks. Beyond unraveling the electrophysiological basis of DMN dynamics, our results suggest that, rather than indicating a mere switch to a global exteroceptive mode, DMN deactivation encodes the extent and efficiency of our engagement with the external world. Furthermore, our findings reveal a pivotal role for broadband gamma modulations in the interplay between task-positive and task-negative networks mediating efficient goal-directed behavior and facilitate our understanding of the relationship between electrophysiology and neuroimaging studies of intrinsic brain networks. PMID:21994368

  19. Evidence that aerodynamic effects, including dynamic stall, dictate HAWT structural loads and power generation in highly transient time frames

    SciTech Connect

    Shipley, D.E.; Miller, M.S.; Robinson, M.C.; Luttges, M.W.; Simms, D.A.

    1994-08-01

    Aerodynamic data collected from the National Renewable Energy Laboratory`s Combined Experiment have shown three distinct performance regimes when the turbine is operated under relatively steady flow conditions. Operating at blade angles of attack below static stall, excellent agreement is achieved with two-dimensional wind tunnel data. Around the static stall angle, the cycle average normal force produced is greater than the static test data. Span locations near the hub produce extremely large values of normal force coefficient, well in excess of the two-dimensional data results. These performance regimes have been shown to be a function of the three-dimensional flow structure and cycle averaged dynamic stall effects. Power generation and root bending moments have also been shown to be directly dependent on the inflow wind velocity. Aerodynamic data, including episodes of dynamic stall, have been correlated on a cycle by cycle basis with the structural and power generation characteristics of a horizontal axis wind turbine. Instantaneous unsteady forces and resultant power generation indicate that peak transient levels can significantly exceed cycle averaged values. Strong coupling between transient aerodynamic and resonant response of the turbine was also observed. These results provide some initial insight into the contribution of unsteady aerodynamics on undesirable turbine structural response and fatigue life.

  20. Transient responses of phosphoric acid fuel cell power plant system. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lu, Cheng-Yi

    1983-01-01

    An analytical and computerized study of the steady state and transient response of a phosphoric acid fuel cell (PAFC) system was completed. Parametric studies and sensitivity analyses of the PAFC system's operation were accomplished. Four non-linear dynamic models of the fuel cell stack, reformer, shift converters, and heat exchangers were developed based on nonhomogeneous non-linear partial differential equations, which include the material, component, energy balance, and electrochemical kinetic features. Due to a lack of experimental data for the dynamic response of the components only the steady state results were compared with data from other sources, indicating reasonably good agreement. A steady state simulation of the entire system was developed using, nonlinear ordinary differential equations. The finite difference method and trial-and-error procedures were used to obtain a solution. Using the model, a PAFC system, that was developed under NASA Grant, NCC3-17, was improved through the optimization of the heat exchanger network. Three types of cooling configurations for cell plates were evaluated to obtain the best current density and temperature distributions. The steady state solutions were used as the initial conditions in the dynamic model. The transient response of a simplified PAFC system, which included all of the major components, subjected to a load change was obtained. Due to the length of the computation time for the transient response calculations, analysis on a real-time computer was not possible. A simulation of the real-time calculations was developed on a batch type computer. The transient response characteristics are needed for the optimization of the design and control of the whole PAFC system. All of the models, procedures and simulations were programmed in Fortran and run on IBM 370 computers at Cleveland State University and the NASA Lewis Research Center.

  1. INITIAL ANALYSIS OF TRANSIENT POWER TIME LAG DUE TO HETEROGENEITY WITHIN THE TREAT FUEL MATRIX.

    SciTech Connect

    D.M. Wachs; A.X. Zabriskie, W.R. Marcum

    2014-06-01

    The topic Nuclear Safety encompasses a broad spectrum of focal areas within the nuclear industry; one specific aspect centers on the performance and integrity of nuclear fuel during a reactivity insertion accident (RIA). This specific accident has proven to be fundamentally difficult to theoretically characterize due to the numerous empirically driven characteristics that quantify the fuel and reactor performance. The Transient Reactor Test (TREAT) facility was designed and operated to better understand fuel behavior under extreme (i.e. accident) conditions; it was shutdown in 1994. Recently, efforts have been underway to commission the TREAT facility to continue testing of advanced accident tolerant fuels (i.e. recently developed fuel concepts). To aid in the restart effort, new simulation tools are being used to investigate the behavior of nuclear fuels during facility’s transient events. This study focuses specifically on the characterizing modeled effects of fuel particles within the fuel matrix of the TREAT. The objective of this study was to (1) identify the impact of modeled heterogeneity within the fuel matrix during a transient event, and (2) demonstrate acceptable modeling processes for the purpose of TREAT safety analyses, specific to fuel matrix and particle size. Hypothetically, a fuel that is dominantly heterogeneous will demonstrate a clearly different temporal heating response to that of a modeled homogeneous fuel. This time difference is a result of the uniqueness of the thermal diffusivity within the fuel particle and fuel matrix. Using MOOSE/BISON to simulate the temperature time-lag effect of fuel particle diameter during a transient event, a comparison of the average graphite moderator temperature surrounding a spherical particle of fuel was made for both types of fuel simulations. This comparison showed that at a given time and with a specific fuel particle diameter, the fuel particle (heterogeneous) simulation and the homogeneous simulation

  2. A Comprehensive 3D Finite Element Model of a Thermoelectric Module Used in a Power Generator: A Transient Performance Perspective

    NASA Astrophysics Data System (ADS)

    Wu, Guangxi; Yu, Xiong

    2015-06-01

    Thermoelectric power generator has potential for small-scale and distributed power generation because of its high durability and scalability. It is very important to realize that the transient behavior of thermoelectric modules (TEM) affects a thermoelectric generator's response to dynamic working environments. Traditionally, researchers have used simplified models to describe the behavior of thermoelectric modules. In this paper we propose a comprehensive mathematical model that considers the effect of variations of chemical potential and carrier density, which are ignored by traditional models. Finite element models based on this new model are used to simulate the transient behavior of a thermoelectric module subjected to rapid changes in boundary temperature or working load. Simulation results show that transition times of thermoelectric modules affected by temperature change are much longer than those of modules affected by changes in electrical load resistance. Sudden changes in working temperature cause voltage overshoot of the TEM output, which, however, is not observed in responses to sudden changes of load resistance. Comparisons also show there are significant differences between the behavior of TEM predicted by use of this new comprehensive model and that predicted by use of traditional models, particularly for the high-temperature intrinsic ionization region and the low-temperature weak ionization region. This implies that chemical potential and carrier density variations, which are taken into account by this new model but ignored by traditional models, have major effects on the performance of TEM.

  3. Analysis of offsite emergency planning zones project

    SciTech Connect

    Petrocchi, A.J.; Armstrong, C.E. . Rocky Flats Plant); McKinney, J.M.; Verholek, M.G.; Fraser, P.J.; Dalfonso, P.H. )

    1991-07-18

    The Rocky Flats Plant maintains and uses significant nonradioactive chemically hazardous material (HAZMAT) inventories. Some of these materials are used in sufficient quantities to represent a credible risk to the offsite public in the event of an emergency at the facility. In Phase 2 of this project, the EG G Rocky Flats, Inc. and TENERA, L.P. Task Team (Task Team) produced an initial screening-level modeling analysis study and an Emergency Planning Zone (EPZ) encompassing the Vulnerable Zones (VZs) for hazardous materials stored at the facility. The screening-level analysis will be supplemented with more refined evaluations during subsequent phases of the project. The existence of these chemicals in the Rocky Flats Plant Occupational Health Information System (OHIS) chemical inventory database was verified. All liquid and gaseous chemicals were considered as potential hazardous material source terms for further screening analysis. Hazards associated with solid substances were not considered in this phase of the project. 2 figs., 13 tabs.

  4. 40 CFR 68.165 - Offsite consequence analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Offsite consequence analysis. 68.165... (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.165 Offsite consequence analysis. (a) The owner or operator shall submit in the RMP information: (1) One worst-case...

  5. 40 CFR 68.165 - Offsite consequence analysis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Offsite consequence analysis. 68.165... (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.165 Offsite consequence analysis. (a) The owner or operator shall submit in the RMP information: (1) One worst-case...

  6. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Offsite consequence analysis parameters. 68.22 Section 68.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Hazard Assessment § 68.22 Offsite consequence analysis parameters. (a) Endpoints....

  7. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Offsite consequence analysis... analysis parameters. (a) Endpoints. For analyses of offsite consequences, the following endpoints shall be.... (b) Wind speed/atmospheric stability class. For the worst-case release analysis, the owner...

  8. Numerical and field tests of hydraulic transients at Piva power plant

    NASA Astrophysics Data System (ADS)

    Giljen, Z.

    2014-03-01

    In 2009, a sophisticated field investigation was undertaken and later, in 2011, numerical tests were completed, on all three turbine units at the Piva hydroelectric power plant. These tests were made in order to assist in making decisions about the necessary scope of the reconstruction and modernisation of the Piva hydroelectric power plant, a plant originally constructed in the mid-1970s. More specifically, the investigation included several hydraulic conditions including both the start-up and stopping of each unit, load rejection under governor control from different initial powers, as well as emergency shut-down. Numerical results were obtained using the method of characteristics in a representation that included the full flow system and the characteristics of each associated Francis turbine. The impact of load rejection and emergency shut-down on the penstock pressure and turbine speed changes are reported and numerical and experimental results are compared, showing close agreement.

  9. Numerical Simulation of Transient and Steady State Nonlinear Beam-Cavity Dynamics in High Power Klystrons.

    NASA Astrophysics Data System (ADS)

    Zambre, Yadunath Bhagvantrao

    1988-03-01

    A 2-1over2 dimensional analysis of klystrons, assuming cylindrical space symmetry but retaining all velocity effects, is presented. The model handles all relativistic, electromagnetic, and non-linear effects. The klystron geometry is viewed as a conducting cylinder (the tube) to which are attached a number of resonant cavities at various locations. Within this tube, particle in cell plasma simulation techniques are used to model the electron beam dynamics and electromagnetic fields. The effects of the cavities are then "patched in" by the use of eigenmode expansions over the cavity geometries. These expansions reduce the effects of the cavity fields into relatively simple time varying boundary conditions on the tube. The plasma simulation in the tube is carried out using a number of "macroparticles," each representing many electrons and each obeying the equations of motion for an electron. A time centered cycloid fitting algorithm is used to move the particles. A time centered spectral method using Fourier series in z and Chebyschev polynomials in r is used to advance the fields. A non-uniform grid permits the use of FFT's to carry out the Chebyschev expansions. A method for finding time periodic solutions is also presented. This method will compute a qualitatively correct transient solution and yield a quantitatively correct steady state solution.

  10. Transient stability enhancement of wind farms using power electronics and facts controllers

    NASA Astrophysics Data System (ADS)

    Mohammadpour, Hossein Ali

    Nowadays, it is well-understood that the burning of fossil fuels in electric power station has a significant influence on the global climate due to greenhouse gases. In many countries, the use of cost-effective and reliable low-carbon electricity energy sources is becoming an important energy policy. Among different kinds of clean energy resources- such as solar power, hydro-power, ocean wave power and so on, wind power is the fastest-growing form of renewable energy at the present time. Moreover, adjustable speed generator wind turbines (ASGWT) has key advantages over the fixed-speed generator wind turbines (FSGWT) in terms of less mechanical stress, improved power quality, high system efficiency, and reduced acoustic noise. One important class of ASGWT is the doubly-fed induction generator (DFIG), which has gained a significant attention of the electric power industry due to their advantages over the other class of ASGWT, i.e. fully rated converter-based wind turbines. Because of increased integration of DFIG-based wind farms into electric power grids, it is necessary to transmit the generated power from wind farms to the existing grids via transmission networks without congestion. Series capacitive compensation of DFIG-based wind farm is an economical way to increase the power transfer capability of the transmission line connecting wind farm to the grid. For example, a study performed by ABB reveals that increasing the power transfer capability of an existing transmission line from 1300 MW to 2000 MW using series compensation is 90% less than the cost of building a new transmission line. However, a factor hindering the extensive use of series capacitive compensation is the potential risk of sub- synchronous resonance (SSR). The SSR is a condition where the wind farm exchanges energy with the electric network, to which it is connected, at one or more natural frequencies of the electric or mechanical part of the combined system, comprising the wind farm and the

  11. Transient stability and control of renewable generators based on Hamiltonian surface shaping and power flow control. Part II, analysis.

    SciTech Connect

    Robinett, Rush D., III; Wilson, David Gerald

    2010-11-01

    The swing equations for renewable generators connected to the grid are developed and a wind turbine is used as an example. The swing equations for the renewable generators are formulated as a natural Hamiltonian system with externally applied non-conservative forces. A two-step process referred to as Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) is used to analyze and design feedback controllers for the renewable generators system. This formulation extends previous results on the analytical verification of the Potential Energy Boundary Surface (PEBS) method to nonlinear control analysis and design and justifies the decomposition of the system into conservative and non-conservative systems to enable a two-step, serial analysis and design procedure. The first step is to analyze the system as a conservative natural Hamiltonian system with no externally applied non-conservative forces. The Hamiltonian surface of the swing equations is related to the Equal-Area Criterion and the PEBS method to formulate the nonlinear transient stability problem. This formulation demonstrates the effectiveness of proportional feedback control to expand the stability region. The second step is to analyze the system as natural Hamiltonian system with externally applied non-conservative forces. The time derivative of the Hamiltonian produces the work/rate (power flow) equation which is used to ensure balanced power flows from the renewable generators to the loads. The Second Law of Thermodynamics is applied to the power flow equations to determine the stability boundaries (limit cycles) of the renewable generators system and enable design of feedback controllers that meet stability requirements while maximizing the power generation and flow to the load. Necessary and sufficient conditions for stability of renewable generators systems are determined based on the concepts of Hamiltonian systems, power flow, exergy (the maximum work that can be extracted from an energy flow) rate

  12. Evaluation of the transient stability of power systems based on the area method

    NASA Astrophysics Data System (ADS)

    Lizalek, N. N.; Ladnova, A. N.; Tonyshev, V. F.; Popova, E. Yu.; Vtorushin, A. S.

    2013-12-01

    The prerequisites and algorithms for the analysis of stability of complex power systems by the area method are considered. Its application is based on the energy relations for the possible trajectories of the oscillatory motion of subsystems isolated for each emergency.

  13. Offsite Shipment Campaign Readiness Assessment (OSCRA): A tool for offsite shipment campaigns

    SciTech Connect

    Michelhaugh, R.D.; Pope, R.B.; Bisaria, A.

    1995-12-31

    The Offsite Shipment Campaign Readiness Assessment (OSCRA) tool is designed to assist program managers in identifying, implementing, and verifying applicable transportation and disposal regulatory requirements for specific shipment campaigns. OSCRA addresses these issues and provides the program manager with a tool to support planning for safe and compliant transportation of waste and other regulated materials. Waste transportation and disposal requirements must be identified and addressed in the planning phase of a waste management project. In the past, in some cases, transportation and disposal requirements have not been included in overall project plans. These planning deficiencies have led to substantial delays and cost impacts. Additionally, some transportation regulatory requirements have not been properly implemented, resulting in substantial fines and public embarrassment for the U.S. Department of Energy (DOE). If a material has been processed and packaged for onsite storage (prior to offsite disposal) in a package that does not meet transportation requirements, it must be repackaged in U.S. Department of Transportation (DOT)-compliant packaging for transport. This repackaging can result in additional cost, time, and personnel radiation exposure. The original OSCRA concept was developed during the Pond Waste Project at the K-25 Site in Oak Ridge, Tennessee. The continued development of OSCRA as a user-friendly tool was funded in 1995 by the DOE Office of Environmental Management, Transportation Management Division (TMD). OSCRA is designed to support waste management managers, site remediation managers, and transportation personnel in defining applicable regulatory transportation and disposal requirements for offsite shipment of hazardous waste and other regulated materials. The need for this tool stems from increasing demands imposed on DOE and the need to demonstrate and document safe and compliant packaging and shipment of wastes from various DOE sites.

  14. Use of neural networks to identify transient operating conditions in nuclear power plants

    SciTech Connect

    Uhrig, R.E.; Guo, Z.

    1989-01-01

    A technique using neural networks as a means of diagnosing specific abnormal conditions or problems in nuclear power plants is investigated and found to be feasible. The technique is based on the fact that each physical state of the plant can be represented by a unique pattern of instrument readings, which can be related to the condition of the plant. Neural networks are used to relate this pattern to the fault or problem. 3 refs., 2 figs., 4 tabs.

  15. Receiving Basin for Offsite Fuels and the Resin Regeneration Facility Safety Analysis Report, Executive Summary

    SciTech Connect

    Shedrow, C.B.

    1999-11-29

    The Safety Analysis Report documents the safety authorization basis for the Receiving Basin for Offsite Fuels (RBOF) and the Resin Regeneration Facility (RRF) at the Savannah River Site (SRS). The present mission of the RBOF and RRF is to continue in providing a facility for the safe receipt, storage, handling, and shipping of spent nuclear fuel assemblies from power and research reactors in the United States, fuel from SRS and other Department of Energy (DOE) reactors, and foreign research reactors fuel, in support of the nonproliferation policy. The RBOF and RRF provide the capability to handle, separate, and transfer wastes generated from nuclear fuel element storage. The DOE and Westinghouse Savannah River Company, the prime operating contractor, are committed to managing these activities in such a manner that the health and safety of the offsite general public, the site worker, the facility worker, and the environment are protected.

  16. Modelling and optimization of transient processes in line focusing power plants with single-phase heat transfer medium

    NASA Astrophysics Data System (ADS)

    Noureldin, K.; González-Escalada, L. M.; Hirsch, T.; Nouri, B.; Pitz-Paal, R.

    2016-05-01

    A large number of commercial and research line focusing solar power plants are in operation and under development. Such plants include parabolic trough collectors (PTC) or linear Fresnel using thermal oil or molten salt as the heat transfer medium (HTM). However, the continuously varying and dynamic solar condition represent a big challenge for the plant control in order to optimize its power production and to keep the operation safe. A better understanding of the behaviour of such power plants under transient conditions will help reduce defocusing instances, improve field control, and hence, increase the energy yield and confidence in this new technology. Computational methods are very powerful and cost-effective tools to gain such understanding. However, most simulation models described in literature assume equal mass flow distributions among the parallel loops in the field or totally decouple the flow and thermal conditions. In this paper, a new numerical model to simulate a whole solar field with single-phase HTM is described. The proposed model consists of a hydraulic part and a thermal part that are coupled to account for the effect of the thermal condition of the field on the flow distribution among the parallel loops. The model is specifically designed for large line-focusing solar fields offering a high degree of flexibility in terms of layout, condition of the mirrors, and spatially resolved DNI data. Moreover, the model results have been compared to other simulation tools, as well as experimental and plant data, and the results show very good agreement. The model can provide more precise data to the control algorithms to improve the plant control. In addition, short-term and accurate spatially discretized DNI forecasts can be used as input to predict the field behaviour in-advance. In this paper, the hydraulic and thermal parts, as well as the coupling procedure, are described and some validation results and results of simulating an example field are

  17. Offsite radiological consequence analysis for the waste transfer leak

    SciTech Connect

    ZIMMERMAN, B.D.

    2003-03-21

    This document quantifies the offsite radiological/consequence of the bounding waste transfer leak accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding waste transfer leak accident is a fine spray leak into the air. The calculation applies reasonably conservative input parameters in accordance with DOE-STD-3009, Appendix A, guidance. The calculated offsite dose of 0.7 rem does not challenge the Evaluation Guideline.

  18. An Introduction to System-Level, Steady-State and Transient Modeling and Optimization of High-Power-Density Thermoelectric Generator Devices Made of Segmented Thermoelectric Elements

    NASA Astrophysics Data System (ADS)

    Crane, D. T.

    2011-05-01

    High-power-density, segmented, thermoelectric (TE) elements have been intimately integrated into heat exchangers, eliminating many of the loss mechanisms of conventional TE assemblies, including the ceramic electrical isolation layer. Numerical models comprising simultaneously solved, nonlinear, energy balance equations have been created to simulate these novel architectures. Both steady-state and transient models have been created in a MATLAB/Simulink environment. The models predict data from experiments in various configurations and applications over a broad range of temperature, flow, and current conditions for power produced, efficiency, and a variety of other important outputs. Using the validated models, devices and systems are optimized using advanced multiparameter optimization techniques. Devices optimized for particular steady-state operating conditions can then be dynamically simulated in a transient operating model. The transient model can simulate a variety of operating conditions including automotive and truck drive cycles.

  19. Assessment of RELAP5/MOD2 against a 10% load rejection transient from 75% steady state in the Vandellos II Nuclear Power Plant

    SciTech Connect

    Llopis, C.; Casals, A.; Perez, J.; Mendizabal, R.

    1993-05-01

    The Consejo de Seguridad Nuclear (CSN) and the Asociacion Nuclear Vandellos have developed a model of Vandellos II Nuclear Power Plant. The ANV collaboration consisted in the supply of design and actual data, the cooperation in the simulation of the control systems and other model components, as well as in the results analysis. The obtained model has been assessed against the following transients occurred in plant: A trip from the 100% power level (CSN); A load rejection from 100% to 50% (CSN); A load rejection from 75% to 65% (ANV); A feedwater turbopump trip (ANV). This copy is a report of the load rejection from 75% to 65% transient simulation. This transient was one of the tests carried out in Vandellos II NPP during the startup tests.

  20. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers

    SciTech Connect

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer program is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional conservation of mass. momentum, and energy equations on the tube side, and the proper accounting for the thermal interaction between shell and tube side through the porous medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient three-dimensional analysis of fluid flow with heat transfer in a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification. it can be used to analyze processes in any heat exchanger or other single-phase engineering applications.

  1. Simultaneous transient operation of a high head hydro power plant and a storage pumping station in the same hydraulic scheme

    NASA Astrophysics Data System (ADS)

    Bucur, D. M.; Dunca, G.; Cervantes, M. J.; Cǎlinoiu, C.; Isbǎşoiu, E. C.

    2014-03-01

    This paper presents an on-site experimental analysis of a high head hydro power plant and a storage pumping station, in an interconnected complex hydraulic scheme during simultaneous transient operation. The investigated hydropower site has a unique structure as the pumping station discharges the water into the hydropower plant penstock. The operation regimes were chosen for critical scenarios such as sudden load rejections of the turbines as well as start-ups and stops with different combinations of the hydraulic turbines and pumps operation. Several parameters were simultaneously measured such as the pumped water discharge, the pressure at the inlet pump section, at the outlet of the pumps and at the vane house of the hydraulic power plant surge tank. The results showed the dependence of the turbines and the pumps operation. Simultaneous operation of the turbines and the pumps is possible in safe conditions, without endangering the machines or the structures. Furthermore, simultaneous operation of the pumping station together with the hydropower plant increases the overall hydraulic efficiency of the site since shortening the discharge circuit of the pumps.

  2. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers

    SciTech Connect

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User's Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions.

  3. State of offsite construction in India-Drivers and barriers

    NASA Astrophysics Data System (ADS)

    Arif, M.; Bendi, D.; Sawhney, A.; Iyer, K. C.

    2012-05-01

    The rapid growth of the construction industry in India has influenced key players in the industry to adopt alternative technologies addressing time, cost and quality. The rising demand in housing, infrastructure and other facilities have further highlighted the need for the construction industry to look at adopting alternate building technologies. Offsite construction has evolved as a panacea to dealing with the under-supply and poor quality in the current age construction industry. Several offsite techniques have been adopted by the construction sector. Although, different forms of offsite techniques have been around for a while but their uptake has been low in the Indian context. This paper presents the perceptions about offsite construction in India and highlights some of the barriers and drivers facing the Indian construction industry. The data was gathered through a survey of 17 high level managers from some of the largest stakeholder organizations of the construction sector in India. The influence of time and cost has been highlighted as a major factor fuelling the adoption of offsite construction. However, the influence of current planning systems and the need for a paradigm shift are some of the prominent barriers towards the adoption of offsite techniques.

  4. Benchmarking of RESRAD-OFFSITE : transition from RESRAD (onsite) toRESRAD-OFFSITE and comparison of the RESRAD-OFFSITE predictions with peercodes.

    SciTech Connect

    Yu, C.; Gnanapragasam, E.; Cheng, J.-J.; Biwer, B.

    2006-05-22

    The main purpose of this report is to document the benchmarking results and verification of the RESRAD-OFFSITE code as part of the quality assurance requirements of the RESRAD development program. This documentation will enable the U.S. Department of Energy (DOE) and its contractors, and the U.S. Nuclear Regulatory Commission (NRC) and its licensees and other stakeholders to use the quality-assured version of the code to perform dose analysis in a risk-informed and technically defensible manner to demonstrate compliance with the NRC's License Termination Rule, Title 10, Part 20, Subpart E, of the Code of Federal Regulations (10 CFR Part 20, Subpart E); DOE's 10 CFR Part 834, Order 5400.5, ''Radiation Protection of the Public and the Environment''; and other Federal and State regulatory requirements as appropriate. The other purpose of this report is to document the differences and similarities between the RESRAD (onsite) and RESRAD-OFFSITE codes so that users (dose analysts and risk assessors) can make a smooth transition from use of the RESRAD (onsite) code to use of the RESRAD-OFFSITE code for performing both onsite and offsite dose analyses. The evolution of the RESRAD-OFFSITE code from the RESRAD (onsite) code is described in Chapter 1 to help the dose analyst and risk assessor make a smooth conceptual transition from the use of one code to that of the other. Chapter 2 provides a comparison of the predictions of RESRAD (onsite) and RESRAD-OFFSITE for an onsite exposure scenario. Chapter 3 documents the results of benchmarking RESRAD-OFFSITE's atmospheric transport and dispersion submodel against the U.S. Environmental Protection Agency's (EPA's) CAP88-PC (Clean Air Act Assessment Package-1988) and ISCLT3 (Industrial Source Complex-Long Term) models. Chapter 4 documents the comparison results of the predictions of the RESRAD-OFFSITE code and its submodels with the predictions of peer models. This report was prepared by Argonne National Laboratory's (Argonne

  5. Electromechanical systems with transient high power response operating from a resonant ac link

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant ac link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control all four operating quadrants. Incorporating the ac link allows the converter in these systems to switch at the zero crossing of every half cycle of the ac waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed under contract to NASA.

  6. Electromechanical systems with transient high power response operating from a resonant AC link

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD).

  7. Transient solution for a plane-strain fracture driven by a shear-thinning, power-law fluid

    NASA Astrophysics Data System (ADS)

    Garagash, D. I.

    2006-12-01

    This paper analyses the problem of a fluid-driven fracture propagating in an impermeable, linear elastic rock with finite toughness. The fracture is driven by injection of an incompressible viscous fluid with power-law rheology. The relation between the fracture opening and the internal fluid pressure and the fracture propagation in mobile equilibrium are described by equations of linear elastic fracture mechanics (LEFM), and the flow of fluid inside the fracture is governed by the lubrication theory. It is shown that for shear-thinning fracturing fluids, the fracture propagation regime evolves in time from the toughness- to the viscosity-dominated regime. In the former, dissipation in the viscous fluid flow is negligible compared to the dissipation in extending the fracture in the rock, and in the later, the opposite holds. Corresponding self-similar asymptotic solutions are given by the zero-viscosity and zero-toughness (J. Numer. Anal. Meth. Geomech. 2002; 26:579-604) solutions, respectively. A transient solution in terms of the crack length, the fracture opening, and the net fluid pressure, which describes the fracture evolution from the early-time (toughness-dominated) to the large-time (viscosity-dominated) asymptote is presented and some of the implications for the practical range of parameters are discussed. Copyright

  8. Neural network recognition of nuclear power plant transients. First annual report, April 15, 1992--April 15, 1993, Revision 1

    SciTech Connect

    Bartlett, E.B.; Danofsky, R.; Adams, J.; AlJundi, T.; Basu, A.; Dhanwada, C.; Kerr, J.; Kim, K.; Lanc, T.

    1993-02-23

    The objective of this report is to describe results obtained during the first year of funding that will lead to the development of an artificial neural network (ANN) fault - diagnostic system for the real - time classification of operational transients at nuclear power plants. The ultimate goal of this three-year project is to design, build, and test a prototype diagnostic adviser for use in the control room or technical support center at Duane Arnold Energy Center (DAEC); such a prototype could be integrated into the plant process computer or safety - parameter display system. The adviser could then warn and inform plant operators and engineers of plant component failures in a timely manner. This report describes the work accomplished in the first of three scheduled years for the project. Included herein is a summary of the first year`s results as, well as individual descriptions of each of the major topics undertaken by the researchers. Also included are reprints of the articles written under this funding as well as those that were published during the funded period.

  9. User's Manual for RESRAD-OFFSITE Version 2.

    SciTech Connect

    Yu, C.; Gnanapragasam, E.; Biwer, B. M.; Kamboj, S.; Cheng, J. -J.; Klett, T.; LePoire, D.; Zielen, A. J.; Chen, S. Y.; Williams, W. A.; Wallo, A.; Domotor, S.; Mo, T.; Schwartzman, A.; Environmental Science Division; DOE; NRC

    2007-09-05

    The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code, which has been widely used for calculating doses and risks from exposure to radioactively contaminated soils. The development of RESRAD-OFFSITE started more than 10 years ago, but new models and methodologies have been developed, tested, and incorporated since then. Some of the new models have been benchmarked against other independently developed (international) models. The databases used have also expanded to include all the radionuclides (more than 830) contained in the International Commission on Radiological Protection (ICRP) 38 database. This manual provides detailed information on the design and application of the RESRAD-OFFSITE code. It describes in detail the new models used in the code, such as the three-dimensional dispersion groundwater flow and radionuclide transport model, the Gaussian plume model for atmospheric dispersion, and the deposition model used to estimate the accumulation of radionuclides in offsite locations and in foods. Potential exposure pathways and exposure scenarios that can be modeled by the RESRAD-OFFSITE code are also discussed. A user's guide is included in Appendix A of this manual. The default parameter values and parameter distributions are presented in Appendix B, along with a discussion on the statistical distributions for probabilistic analysis. A detailed discussion on how to reduce run time, especially when conducting probabilistic (uncertainty) analysis, is presented in Appendix C of this manual.

  10. Development of Fuel Cell Co-generation System with Heat-pump System in Consideration of Transient Response of Electric Power

    NASA Astrophysics Data System (ADS)

    Obara, Shinya; Kudo, Kazuhiko

    The transient response characteristics of electric power output of the fuel cell system for individual houses were investigated, and relation between system control parameters and transient response characteristics were clarified. Furthermore, the transient response characteristics of coefficient of performance (COP) and electric power output of the system which makes heat pump an auxiliary heat source were investigated. Moreover, the relation between COP of heat pump and the transient response characteristics of the system were considered. Analysis of operation cost of system components and annual operation cost balance was performed supposing introducing a fuel cell co-generation system installs to individual house in Sapporo and Tokyo. Relation between COP of heat pump and operation cost, relation of reformer time-constant and operation cost, operation cost of the system with town gas boiler instead of heat pump, were investigated. The fuel cell cogeneration system introduced into Tokyo does not have the necessity of using heat pump and boiler, and it is thought that energy demand is filled with installing a thermal storage tank of small capacity. Moreover, it is more advantageous for operation cost to introduce a town gas boiler rather than introduces about COP=2. 0 heat pump into Sapporo.

  11. EFFECT OF A HIGH OPACITY ON THE LIGHT CURVES OF RADIOACTIVELY POWERED TRANSIENTS FROM COMPACT OBJECT MERGERS

    SciTech Connect

    Barnes, Jennifer; Kasen, Daniel

    2013-09-20

    The coalescence of compact objects is a promising astrophysical source of detectable gravitational wave signals. The ejection of r-process material from such mergers may lead to a radioactively powered electromagnetic counterpart signal which, if discovered, would enhance the science returns. As very little is known about the optical properties of heavy r-process elements, previous light-curve models have adopted opacities similar to those of iron group elements. Here we consider the effect of heavier elements, particularly the lanthanides, which increase the ejecta opacity by several orders of magnitude. We include these higher opacities in time-dependent, multi-wavelength radiative transport calculations to predict the broadband light curves of one-dimensional models over a range of parameters (ejecta masses {approx}10{sup -3}-10{sup -1} M{sub Sun} and velocities {approx}0.1-0.3 c). We find that the higher opacities lead to much longer duration light curves which can last a week or more. The emission is shifted toward the infrared bands due to strong optical line blanketing, and the colors at later times are representative of a blackbody near the recombination temperature of the lanthanides (T {approx} 2500 K). We further consider the case in which a second mass outflow, composed of {sup 56}Ni, is ejected from a disk wind, and show that the net result is a distinctive two component spectral energy distribution, with a bright optical peak due to {sup 56}Ni and an infrared peak due to r-process ejecta. We briefly consider the prospects for detection and identification of these transients.

  12. Off-Site Trip Leaders: Selecting Appropriate Staff.

    ERIC Educational Resources Information Center

    Evans, Will

    1996-01-01

    Well-trained off-site trip leaders can turn a trip into a positive educational lesson. American Camping Association standards are referenced, and some personality traits are suggested as criteria for determining the suitability of staff to act responsibly "in loco director." Discusses factors that determine counselor-to-camper ratios, medical…

  13. 40 CFR 279.24 - Off-site shipments.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) STANDARDS FOR THE MANAGEMENT OF USED OIL Standards for Used Oil Generators § 279.24 Off-site shipments... oil is transported only by transporters who have obtained EPA identification numbers. (a) Self... identification number, used oil that is generated at the generator's site and used oil collected from...

  14. 40 CFR 279.24 - Off-site shipments.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) STANDARDS FOR THE MANAGEMENT OF USED OIL Standards for Used Oil Generators § 279.24 Off-site shipments. Except as provided in paragraphs (a) through (c) of this section, generators must ensure that their used...-transportation of small amounts to approved collection centers. Generators may transport, without an...

  15. Evaluation of groundwater monitoring at offsite nuclear test areas

    SciTech Connect

    Chapman, J.B.; Hokett, S.L.

    1991-03-01

    Groundwater quality has been monitored at nuclear test sites distant from the Nevada Test Site as part of the Long-Term Hydrologic Monitoring Program (LTHMP) since 1972. Separate reports describing the monitoring programs recommended by the US Department of Energy (DOE) Hydrologic Program Advisory Group were issued by the DOE for most of the offsite areas during the early 1980s, and the analytical results from the LTHMP have been regularly reported by the US Environmental Protection Agency (EPA), but there has been little else published about the program. The LTHMP has continued to demonstrate the safety of drinking water supplies near the offsite areas and there have been very few modifications to the program initially mandated by the DOE in 1972. During this time, however, there have been many changes in the fields of hydrogeology and environmental monitoring. In 1988, the DOE requested the Desert Research Institute to perform a critical review of the LTHMP in light of the many technical and regulatory advances in groundwater monitoring in recent years. This report presents an evaluation of the offsite groundwater monitoring program and evaluations specific to the monitoring networks at each of the eight offsite test areas. Discussion of the overall program is presented first, followed by site-specific recommendations. References follow each section for the convenience of readers interested in particular sites. 63 refs., 27 figs., 1 tab.

  16. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... analysis parameters. (a) Endpoints. For analyses of offsite consequences, the following endpoints shall be used: (1) Toxics. The toxic endpoints provided in appendix A of this part. (2) Flammables. The endpoints for flammables vary according to the scenarios studied: (i) Explosion. An overpressure of 1...

  17. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... analysis parameters. (a) Endpoints. For analyses of offsite consequences, the following endpoints shall be used: (1) Toxics. The toxic endpoints provided in appendix A of this part. (2) Flammables. The endpoints for flammables vary according to the scenarios studied: (i) Explosion. An overpressure of 1...

  18. 40 CFR 68.22 - Offsite consequence analysis parameters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... analysis parameters. (a) Endpoints. For analyses of offsite consequences, the following endpoints shall be used: (1) Toxics. The toxic endpoints provided in appendix A of this part. (2) Flammables. The endpoints for flammables vary according to the scenarios studied: (i) Explosion. An overpressure of 1...

  19. Off-Site Faculty: Perspectives on Online Experiences

    ERIC Educational Resources Information Center

    Stewart, Barbara L.; Goodson, Carole; Miertschin, Susan L.

    2010-01-01

    This report presents a cross case analysis involving faculty teaching online from off-site international and interstate locations. The study yielded enabling factors, benefits, communication systems, and challenges in the areas of administration, curriculum, communications, and faculty characteristics. The benefits included the opportunity to be…

  20. 40 CFR 68.30 - Defining offsite impacts-population.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  1. 40 CFR 68.30 - Defining offsite impacts-population.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  2. 40 CFR 68.30 - Defining offsite impacts-population.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  3. 40 CFR 68.30 - Defining offsite impacts-population.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  4. 40 CFR 68.30 - Defining offsite impacts-population.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Defining offsite impacts-population... impacts—population. (a) The owner or operator shall estimate in the RMP the population within a circle... defined in § 68.22(a). (b) Population to be defined. Population shall include residential population....

  5. 40 CFR 279.24 - Off-site shipments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) STANDARDS FOR THE MANAGEMENT OF USED OIL Standards for Used Oil Generators § 279.24 Off-site shipments. Except as provided in paragraphs (a) through (c) of this section, generators must ensure that their used...-transportation of small amounts to approved collection centers. Generators may transport, without an...

  6. 40 CFR 273.55 - Off-site shipments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... materials under 49 CFR 171.8, the shipment must be properly described on a shipping paper in accordance with the applicable Department of Transportation regulations under 49 CFR part 172. ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Off-site shipments. 273.55 Section...

  7. 40 CFR 273.61 - Off-site shipments.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... destination facility rejects a shipment or a portion of a shipment, he must contact the shipper to notify him... facility must: (1) Send the shipment back to the original shipper, or (2) If agreed to by both the shipper... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Off-site shipments. 273.61 Section...

  8. 40 CFR 68.33 - Defining offsite impacts-environment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 16 2012-07-01 2012-07-01 false Defining offsite impacts-environment. 68.33 Section 68.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... impacts—environment. (a) The owner or operator shall list in the RMP environmental receptors within...

  9. 40 CFR 68.33 - Defining offsite impacts-environment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 16 2013-07-01 2013-07-01 false Defining offsite impacts-environment. 68.33 Section 68.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... impacts—environment. (a) The owner or operator shall list in the RMP environmental receptors within...

  10. 40 CFR 68.33 - Defining offsite impacts-environment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 16 2014-07-01 2014-07-01 false Defining offsite impacts-environment. 68.33 Section 68.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... impacts—environment. (a) The owner or operator shall list in the RMP environmental receptors within...

  11. 40 CFR 68.33 - Defining offsite impacts-environment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Defining offsite impacts-environment. 68.33 Section 68.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... impacts—environment. (a) The owner or operator shall list in the RMP environmental receptors within...

  12. 40 CFR 68.33 - Defining offsite impacts-environment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Defining offsite impacts-environment. 68.33 Section 68.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... impacts—environment. (a) The owner or operator shall list in the RMP environmental receptors within...

  13. RACLETTE: a model for evaluating the thermal response of plasma facing components to slow high power plasma transients. Part II: Analysis of ITER plasma facing components

    NASA Astrophysics Data System (ADS)

    Federici, Gianfranco; Raffray, A. René

    1997-04-01

    The transient thermal model RACLETTE (acronym of Rate Analysis Code for pLasma Energy Transfer Transient Evaluation) described in part I of this paper is applied here to analyse the heat transfer and erosion effects of various slow (100 ms-10 s) high power energy transients on the actively cooled plasma facing components (PFCs) of the International Thermonuclear Experimental Reactor (ITER). These have a strong bearing on the PFC design and need careful analysis. The relevant parameters affecting the heat transfer during the plasma excursions are established. The temperature variation with time and space is evaluated together with the extent of vaporisation and melting (the latter only for metals) for the different candidate armour materials considered for the design (i.e., Be for the primary first wall, Be and CFCs for the limiter, Be, W, and CFCs for the divertor plates) and including for certain cases low-density vapour shielding effects. The critical heat flux, the change of the coolant parameters and the possible severe degradation of the coolant heat removal capability that could result under certain conditions during these transients, for example for the limiter, are also evaluated. Based on the results, the design implications on the heat removal performance and erosion damage of the variuos ITER PFCs are critically discussed and some recommendations are made for the selection of the most adequate protection materials and optimum armour thickness.

  14. RACLETTE: a model for evaluating the thermal response of plasma facing components to slow high power plasma transients. Part I: Theory and description of model capabilities

    NASA Astrophysics Data System (ADS)

    Raffray, A. René; Federici, Gianfranco

    1997-04-01

    RACLETTE (Rate Analysis Code for pLasma Energy Transfer Transient Evaluation), a comprehensive but relatively simple and versatile model, was developed to help in the design analysis of plasma facing components (PFCs) under 'slow' high power transients, such as those associated with plasma vertical displacement events. The model includes all the key surface heat transfer processes such as evaporation, melting, and radiation, and their interaction with the PFC block thermal response and the coolant behaviour. This paper represents part I of two sister and complementary papers. It covers the model description, calibration and validation, and presents a number of parametric analyses shedding light on and identifying trends in the PFC armour block response to high plasma energy deposition transients. Parameters investigated include the plasma energy density and deposition time, the armour thickness and the presence of vapour shielding effects. Part II of the paper focuses on specific design analyses of ITER plasma facing components (divertor, limiter, primary first wall and baffle), including improvements in the thermal-hydraulic modeling required for better understanding the consequences of high energy deposition transients in particular for the ITER limiter case.

  15. 38 CFR 36.4364 - Documentation and related requirements-flexible condominiums and condominiums with offsite...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... requirements-flexible condominiums and condominiums with offsite facilities. 36.4364 Section 36.4364 Pensions...—flexible condominiums and condominiums with offsite facilities. (a) Expandable condominiums. The following...) Other flexible condominiums. Condominiums containing withdrawable real estate (contractable...

  16. 38 CFR 36.4364 - Documentation and related requirements-flexible condominiums and condominiums with offsite...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements-flexible condominiums and condominiums with offsite facilities. 36.4364 Section 36.4364 Pensions...—flexible condominiums and condominiums with offsite facilities. (a) Expandable condominiums. The following...) Other flexible condominiums. Condominiums containing withdrawable real estate (contractable...

  17. 38 CFR 36.4364 - Documentation and related requirements-flexible condominiums and condominiums with offsite...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements-flexible condominiums and condominiums with offsite facilities. 36.4364 Section 36.4364 Pensions...—flexible condominiums and condominiums with offsite facilities. (a) Expandable condominiums. The following...) Other flexible condominiums. Condominiums containing withdrawable real estate (contractable...

  18. 38 CFR 36.4364 - Documentation and related requirements-flexible condominiums and condominiums with offsite...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirements-flexible condominiums and condominiums with offsite facilities. 36.4364 Section 36.4364 Pensions...—flexible condominiums and condominiums with offsite facilities. (a) Expandable condominiums. The following...) Other flexible condominiums. Condominiums containing withdrawable real estate (contractable...

  19. 38 CFR 36.4364 - Documentation and related requirements-flexible condominiums and condominiums with offsite...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... requirements-flexible condominiums and condominiums with offsite facilities. 36.4364 Section 36.4364 Pensions...—flexible condominiums and condominiums with offsite facilities. (a) Expandable condominiums. The following...) Other flexible condominiums. Condominiums containing withdrawable real estate (contractable...

  20. Discovery of the correlation between peak episodic jet power and X-ray peak luminosity of the soft state in black hole transients

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Yu, W.

    2015-08-01

    Episodic jets are usually observed in the intermediate state of black hole transients during their X-ray outbursts. Here we report the discovery of a strong positive correlation between the peak radio power of the episodic jet Pjet and the corresponding peak X-ray luminosity Lx of the soft state (in Eddington units) in a complete sample of the outbursts of black hole transients observed during the RXTE era of which data are available, which follows the relation log Pjet = (2.2 ± 0.3) + (1.6 ± 0.2) × log Lx. The transient ultraluminous X-ray source in M31 and HLX-1 in EXO 243-49 fall on the relation if they contain stellar-mass black hole and either stellar-mass black hole or intermediate-mass black hole, respectively. Besides, a significant correlation between the peak power of the episodic jet and the rate of increase of the X-ray luminosity dLx/dt during the rising phase of those outbursts is also found, following log Pjet = (2.0 ± 0.4) + (0.7 ± 0.2) × log dLx/dt. In GX 339-4 and H 1743-322 in which data for two outbursts are available, measurements of the peak radio power of the episodic jet and the X-ray peak luminosity (and its rate of change) shows similar positive correlations between outbursts, which demonstrate the dominant role of accretion over black hole spin in generating episodic jet power. On the other hand, no significant difference is seen among the systems with different measured black hole spin in current sample. This implies that the power of the episodic jet is strongly affected by non-stationary accretion instead of black hole spin characterized primarily by the rate of change of the mass accretion rate.

  1. Radiative power and electron cooling rates for oxygen in steady-state and transient plasmas at densities beyond the coronal limit

    SciTech Connect

    Keane, C.; Skinner, C.H.

    1986-01-01

    We have developed a time-dependent, collisional-radiative model to calculate radiative power and electron cooling rates for oxygen at intermediate densities (10/sup 16/ cm/sup -3/ less than or equal to n/sub e/ less than or equal to 10/sup 20/ cm/sup -3/) where the usual coronal approximation is not valid. Large differences from coronal values are predicted. The behavior of the steady-state radiative power loss coefficient, L/sub Z, is investigated as the electron density is increased. Generalized power loss coefficients applicable to transient plasmas are derived and applied to ionizing and recombining oxygen plasmas. Time-dependent effects are found to play a large role both in terms of the total radiated power and the net electron energy loss rate. 41 refs., 11 figs.

  2. 40 CFR 279.58 - Off-site shipments of used oil.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Off-site shipments of used oil. 279.58....58 Off-site shipments of used oil. Used oil processors/re-refiners who initiate shipments of used oil off-site must ship the used oil using a used oil transporter who has obtained an EPA...

  3. 13 CFR 120.1025 - Off-site reviews and monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Off-site reviews and monitoring... Risk-Based Lender Oversight Supervision § 120.1025 Off-site reviews and monitoring. SBA may conduct off-site reviews and monitoring of SBA Lenders, Intermediaries, and NTAPs, including SBA...

  4. 13 CFR 120.1025 - Off-site reviews and monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Off-site reviews and monitoring... Risk-Based Lender Oversight Supervision § 120.1025 Off-site reviews and monitoring. SBA may conduct off-site reviews and monitoring of SBA Lenders, Intermediaries, and NTAPs, including SBA...

  5. 13 CFR 120.1025 - Off-site reviews and monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Off-site reviews and monitoring. 120.1025 Section 120.1025 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Supervision § 120.1025 Off-site reviews and monitoring. SBA may conduct off-site reviews and monitoring of SBA...

  6. 13 CFR 120.1025 - Off-site reviews and monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Off-site reviews and monitoring... Risk-Based Lender Oversight Supervision § 120.1025 Off-site reviews and monitoring. SBA may conduct off-site reviews and monitoring of SBA Lenders, Intermediaries, and NTAPs, including SBA...

  7. CLASSIFICATION OF THE MGR OFF-SITE UTILITIES SYSTEM

    SciTech Connect

    J.A. Ziegler

    1999-08-31

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) offsite utilities system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998).

  8. Offsite Radiological Consequence Analysis for the Bounding Flammable Gas Accident

    SciTech Connect

    CARRO, C.A.

    2003-07-30

    This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a single-shell tank The calculation applies reasonably conservation input parameters in accordance with DOE-STD-3009, Appendix A, guidance. Revision 1 incorporates comments received from Office of River Protection.

  9. Transient Stability Study of One-Machine-to-Infinite-Bus Power System under Large Penetration of PV Generation

    NASA Astrophysics Data System (ADS)

    Sakamoto, Naoya; Taniguchi, Haruhito; Ota, Yutaka; Nakajima, Tatsuhito; Chinuki, Tomoyuki

    Large penetration of PV may affect transient stability when fault occurs on a transmission line. Classical model for a synchronous generator, a constant current source model for PV and a constant impedance model for load are applied to the one-machine-to-infinite-bus model. The critical clearing time is calculated by using equal area criterion and Y method simulation. As a result, a case with larger PV penetration has longer CCT than the case without PV penetration and this result does not depend on the reduction of synchronous generator capacity according to PV output.

  10. Maximally exposed offsite individual location determination for NESHAPS compliance

    SciTech Connect

    Simpkins, A.A.

    2000-03-13

    The Environmental Protection Agency (EPA) requires the use of the computer program CAP88 for demonstrating compliance with the National Emission Standard for Hazardous Air Pollutants (NESHAPS.) One of the inputs required for CAP88 is the location of the maximally exposed individual (MEI) by sector and distance. Distances to the MEI have been determined for 15 different potential release locations at SRS. These locations were compared with previous work and differences were analyzed. Additionally, SREL Conference Center was included as a potential offsite location since in the future it may be used as a dormitory. Worst sectors were then determined based on the distances.

  11. 13 CFR 109.510 - On-site and off-site reviews.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false On-site and off-site reviews. 109.510 Section 109.510 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION INTERMEDIARY LENDING PILOT PROGRAM Oversight § 109.510 On-site and off-site reviews. (a) General. SBA may conduct off-site reviews and monitoring of ILP...

  12. OFFSITE RADIOLOGICAL CONSEQUENCE ANALYSIS FOR THE BOUNDING FLAMMABLE GAS ACCIDENT

    SciTech Connect

    KRIPPS, L.J.

    2005-02-18

    This document quantifies the offsite radiological consequences of the bounding flammable gas accident for comparison with the 25 rem Evaluation Guideline established in DOE-STD-3009, Appendix A. The bounding flammable gas accident is a detonation in a SST. The calculation applies reasonably conservative input parameters in accordance with guidance in DOE-STD-3009, Appendix A. The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for US. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety-class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST). A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. A detonation in an SST versus a double-shell tank (DST) was selected as the bounding accident because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes.

  13. Transient performance

    NASA Astrophysics Data System (ADS)

    Curnock, Barry

    Gas turbine engine transient behavior, that which is concerned with the changes in engine parameters during acceleration or decceleration of an engine from one steady state point to a different steady state point, is considered. An engine can also experience cyclic aerodynamic phenomena which occur at a nominally steady condition; examples are compressor rotator stall and intake or afterburner buzz. The following are discussed: certification requirements; mechanism of acceleration; compressor working lines and surge; and some important factors (pressure level, moment of inertia, heat soakage, clearances, measurement of transients, thrust reversal, and transient maneuvers which involve significant changes to the shaft speeds of the engine). A set of graphics illustrating transient performance is presented.

  14. Determinations of TSD facility acceptability under the CERCLA Off-Site Rule

    SciTech Connect

    1997-06-01

    On September 22, 1993, the US Environmental Protection Agency (EPA) published the ``Off-Site Rule`` to implement section 121(d)(3) of the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). CERCLA {section}121(d)(3) requires that wastes generated as a result of remediation activities taken under CERCLA authority and transferred off-site be managed only at facilities that comply with the Resource Conservation and Recovery Act. In 1994, the DOE`s Office of Environmental Policy and Assistance (OEPA), RCRA/CERCLA Division (EH-413) published a CERCLA Information Brief titled ``The Off-Site Rule`` which describes the content of the Off-Site Rule and clarifies some of its implications for DOE remedial actions under CERCLA. Additionally, EH-413 published the Guide on Selecting Compliant Off-Site Hazardous Waste Treatment, Storage and Disposal Facilities which provides a regulatory roadmap for accomplishing off-site transfers of environmental restoration and process hazardous waste at DOE facilities in a manner compliant with the Off-Site Rule and other relevant Federal regulations. Those guidance documents concentrate primarily on DOE`s perspective as a hazardous waste generator. The purpose of this Information Brief is to address the implications of the Off-Site Rule for DOE-owned hazardous waste treatment, storage or disposal facilities that accept CERCLA remediation wastes from off-site locations.

  15. Transient and state modulation of beta power in human subthalamic nucleus during speech production and finger movement.

    PubMed

    Hebb, A O; Darvas, F; Miller, K J

    2012-01-27

    Signs of Parkinson's disease (PD) are augmented by speech and repetitive motor tasks. The neurophysiological basis for this phenomenon is unknown, but may involve augmentation of β (13-30 Hz) oscillations within the subthalamic nucleus (STN). We hypothesized that speech and motor tasks increase β power in STN and propose a mechanism for clinical observations of worsening motor state during such behaviors. Subjects undergoing deep brain stimulation (DBS) surgery performed tasks while STN local field potential (LFP) data were collected. Power in the β frequency range was analyzed across the entire recording to observe slow shifts related to block design and during time epochs synchronized to behavior to evaluate immediate fluctuations related to task execution. Bilaterally symmetric β event related desynchronization was observed in analysis time-locked to subject motor and speech tasks. We also observed slow shifts of β power associated with blocks of tasks. Repetitive combined speech and motor, and isolated motor blocks were associated with the highest bilateral β power state. Overt speech alone and imagined speech were associated with a low bilateral β power state. Thus, changing behavioral tasks is associated with bilateral switching of β power states. This offers a potential neurophysiologic correlate of worsened PD motor signs experienced during clinical examination with provocative tasks: switching into a high β power state may be responsible for worsening motor states in PD patients when performing unilateral repetitive motor tasks and combined speech and motor tasks. Beta state changes could be chronically measured and potentially used to control closed loop neuromodulatory devices in the future. PMID:22173017

  16. Scale Model Test and Transient Analysis of Steam Injector Driven Passive Core Injection System for Innovative-Simplified Nuclear Power Plant

    NASA Astrophysics Data System (ADS)

    Ohmori, Shuichi; Narabayashi, Tadashi; Mori, Michitsugu

    A steam injector (SI) is a simple, compact and passive pump and also acts as a high-performance direct-contact compact heater. This provides SI with capability to serve also as a direct-contact feed-water heater that heats up feed-water by using extracted steam from turbine. Our technology development aims to significantly simplify equipment and reduce physical quantities by applying "high-efficiency SI", which are applicable to a wide range of operation regimes beyond the performance and applicable range of existing SIs and enables unprecedented multistage and parallel operation, to the low-pressure feed-water heaters and emergency core cooling system of nuclear power plants, as well as achieve high inherent safety to prevent severe accidents by keeping the core covered with water (a severe accident-free concept). This paper describes the results of the scale model test, and the transient analysis of SI-driven passive core injection system (PCIS).

  17. Reactor System Transient Code.

    Energy Science and Technology Software Center (ESTSC)

    1999-07-14

    RELAP3B describes the behavior of water-cooled nuclear reactors during postulated accidents or power transients, such as large reactivity excursions, coolant losses or pump failures. The program calculates flows, mass and energy inventories, pressures, temperatures, and steam qualities along with variables associated with reactor power, reactor heat transfer, or control systems. Its versatility allows one to describe simple hydraulic systems as well as complex reactor systems.

  18. PLANETSYS, a Computer Program for the Steady State and Transient Thermal Analysis of a Planetary Power Transmission System: User's Manual

    NASA Technical Reports Server (NTRS)

    Hadden, G. B.; Kleckner, R. J.; Ragen, M. A.; Dyba, G. J.; Sheynin, L.

    1981-01-01

    The material presented is structured to guide the user in the practical and correct implementation of PLANETSYS which is capable of simulating the thermomechanical performance of a multistage planetary power transmission. In this version of PLANETSYS, the user can select either SKF or NASA models in calculating lubricant film thickness and traction forces.

  19. Analytical Analysis and Case Study of Transient Behavior of Inrush Current in Power Transformer for Designing of Efficient Circuit Breakers

    NASA Astrophysics Data System (ADS)

    Harmanpreet, Singh, Sukhwinder; Kumar, Ashok; Kaur, Parneet

    2010-11-01

    Stability & security are main aspects in electrical power systems. Transformer protection is major issue of concern to system operation. There are many mall-trip cases of transformer protection are caused by inrush current problems. The phenomenon of transformer inrush current has been discussed in many papers since 1958. In this paper analytical analysis of inrush current in a transformer switched on dc and ac supply has been done. This analysis will help in design aspects of circuit breakers for better performance.

  20. Analysis of offsite Emergency Planning Zones for Rocky Flats Plant

    SciTech Connect

    Inger, J.R. ); Brown-Strattan, M.A. . Rocky Flats Plant)

    1991-01-01

    The purpose of this quality assurance program was to ensure the quality and technical adequacy of Phase 2 of the Analysis of Offsite Emergency Planning Zones (EPZ) for the Rocky Flats Plant project. Quality assurance was accomplished by managing and controlling the processes in the development of the product. The quality assurance task team conducted audits, reviews, and surveillances of project and related activities. This process contributed to identifying areas where the quality assurance plan was not fully implemented, areas needing improvement, and/or corrective actions resulting in a improved product. During the reviews and audits, several key areas were identified where quality assurance plan implementation needed to be improved. These areas included maintaining adequate documentation, reviewing technical results, making inputs traceable to technical results, and understanding that all personnel are responsible for quality.

  1. Program enhancements resulting from the off-site contamination event

    SciTech Connect

    Jarvis, J.S.; Meiners, S.E.

    1993-12-31

    This paper provides information relating to an offsite contamination event at the Paducah Gaseous Diffusion Plant and describes some of the general program enhancements resulting both directly and indirectly from that incident. Workers not routinely assigned to the facility, but certified to operate the facility, received contamination on their skin, and on company issued clothing. The contamination was carried to other areas of the building into non-radiological areas and eventually contaminated a few items of personal clothing, although the levels were below allowable release limits. Underlying causes of the contamination included personnel who performed the required frisking upon exit from the radiological area, but did not recognize or acknowledge the alarm monitor while frisking. In general, the workers had a poor understanding of radiological controls and their application. Worker attitude was no appropriate and inadequate training was also a contributing factor, related to worker attitudes. Immediately following the incident numerous compensatory measures took place.

  2. 13 CFR 120.1025 - Off-site reviews and monitoring.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Off-site reviews and monitoring. 120.1025 Section 120.1025 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION BUSINESS LOANS Risk-Based Lender Oversight Supervision § 120.1025 Off-site reviews and monitoring. SBA may conduct...

  3. 24 CFR 242.50 - Funds and finances: off-site utilities and streets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Funds and finances: off-site utilities and streets. 242.50 Section 242.50 Housing and Urban Development Regulations Relating to Housing... finances: off-site utilities and streets. The Commissioner shall require assurance of completion of...

  4. 24 CFR 242.50 - Funds and finances: off-site utilities and streets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Funds and finances: off-site utilities and streets. 242.50 Section 242.50 Housing and Urban Development Regulations Relating to Housing... finances: off-site utilities and streets. The Commissioner shall require assurance of completion of...

  5. 40 CFR 1400.5 - Internet access to certain off-site consequence analysis data elements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 33 2011-07-01 2011-07-01 false Internet access to certain off-site... DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Public Access § 1400.5 Internet access to certain off... elements in the risk management plan database available on the Internet: (a) The concentration of...

  6. 14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... landing aids; and offsite work. 151.95 Section 151.95 Aeronautics and Space FEDERAL AVIATION... Standards § 151.95 Fences; distance markers; navigational and landing aids; and offsite work. (a) Boundary... navigational aids is eligible for inclusion in a proj- ect whenever necessitated by development on the...

  7. 14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... landing aids; and offsite work. 151.95 Section 151.95 Aeronautics and Space FEDERAL AVIATION... Standards § 151.95 Fences; distance markers; navigational and landing aids; and offsite work. (a) Boundary... navigational aids is eligible for inclusion in a proj- ect whenever necessitated by development on the...

  8. 14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... landing aids; and offsite work. 151.95 Section 151.95 Aeronautics and Space FEDERAL AVIATION... Standards § 151.95 Fences; distance markers; navigational and landing aids; and offsite work. (a) Boundary... navigational aids is eligible for inclusion in a proj- ect whenever necessitated by development on the...

  9. 14 CFR 151.95 - Fences; distance markers; navigational and landing aids; and offsite work.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... landing aids; and offsite work. 151.95 Section 151.95 Aeronautics and Space FEDERAL AVIATION... Standards § 151.95 Fences; distance markers; navigational and landing aids; and offsite work. (a) Boundary... navigational aids is eligible for inclusion in a proj- ect whenever necessitated by development on the...

  10. 40 CFR 1400.5 - Internet access to certain off-site consequence analysis data elements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Internet access to certain off-site... DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Public Access § 1400.5 Internet access to certain off... elements in the risk management plan database available on the Internet: (a) The concentration of...

  11. 40 CFR 1400.5 - Internet access to certain off-site consequence analysis data elements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Internet access to certain off-site... DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Public Access § 1400.5 Internet access to certain off... elements in the risk management plan database available on the Internet: (a) The concentration of...

  12. 40 CFR 1400.5 - Internet access to certain off-site consequence analysis data elements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Internet access to certain off-site... DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Public Access § 1400.5 Internet access to certain off... elements in the risk management plan database available on the Internet: (a) The concentration of...

  13. 40 CFR 1400.5 - Internet access to certain off-site consequence analysis data elements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Internet access to certain off-site... DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Public Access § 1400.5 Internet access to certain off... elements in the risk management plan database available on the Internet: (a) The concentration of...

  14. 24 CFR 242.50 - Funds and finances: off-site utilities and streets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Funds and finances: off-site utilities and streets. 242.50 Section 242.50 Housing and Urban Development Regulations Relating to Housing... finances: off-site utilities and streets. The Commissioner shall require assurance of completion of...

  15. 24 CFR 242.50 - Funds and finances: off-site utilities and streets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Funds and finances: off-site utilities and streets. 242.50 Section 242.50 Housing and Urban Development Regulations Relating to Housing... finances: off-site utilities and streets. The Commissioner shall require assurance of completion of...

  16. 24 CFR 242.50 - Funds and finances: off-site utilities and streets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Funds and finances: off-site utilities and streets. 242.50 Section 242.50 Housing and Urban Development Regulations Relating to Housing... finances: off-site utilities and streets. The Commissioner shall require assurance of completion of...

  17. 24 CFR 242.47 - Insured advances for building components stored off-site.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (d) Advances. (1) Before an advance for a building component stored off-site is insured: (i) The... for building components stored off-site. (a) Building components. In insured advances for building..., if the components are stored at a location approved by the mortgagee and HUD. (2) Each...

  18. A synthesis method for one-port and multi-port equivalent networks for analysis of power system transients

    SciTech Connect

    Do, V.Q.; Gavrilovic, M.M.

    1986-04-01

    Equivalent networks can be used in power system simulation to equipment or computer time and memory space. In this paper, an interative method is developed for synthesizing one-port equivalent networks by the removal of poles corresponding to resonances of the driving-point impedance or admittance function. This results in networks formed by the series or parallel connection of modular RLC circuits. The RLC values are calculated using a parameter-optimization technique. Multi-port equivalent networks are first configured as ..pi.. or T form composed of one-port network branches and the latters are then synthesized by the proposed method for one-port equivalent networks.

  19. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 2, User`s guide and manual

    SciTech Connect

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer program is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional conservation of mass. momentum, and energy equations on the tube side, and the proper accounting for the thermal interaction between shell and tube side through the porous medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient three-dimensional analysis of fluid flow with heat transfer in a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification. it can be used to analyze processes in any heat exchanger or other single-phase engineering applications.

  20. COMMIX-PPC: A three-dimensional transient multicomponent computer program for analyzing performance of power plant condensers. Volume 1, Equations and numerics

    SciTech Connect

    Chien, T.H.; Domanus, H.M.; Sha, W.T.

    1993-02-01

    The COMMIX-PPC computer pregrain is an extended and improved version of earlier COMMIX codes and is specifically designed for evaluating the thermal performance of power plant condensers. The COMMIX codes are general-purpose computer programs for the analysis of fluid flow and heat transfer in complex Industrial systems. In COMMIX-PPC, two major features have been added to previously published COMMIX codes. One feature is the incorporation of one-dimensional equations of conservation of mass, momentum, and energy on the tube stile and the proper accounting for the thermal interaction between shell and tube side through the porous-medium approach. The other added feature is the extension of the three-dimensional conservation equations for shell-side flow to treat the flow of a multicomponent medium. COMMIX-PPC is designed to perform steady-state and transient. Three-dimensional analysis of fluid flow with heat transfer tn a power plant condenser. However, the code is designed in a generalized fashion so that, with some modification, it can be used to analyze processes in any heat exchanger or other single-phase engineering applications. Volume I (Equations and Numerics) of this report describes in detail the basic equations, formulation, solution procedures, and models for a phenomena. Volume II (User`s Guide and Manual) contains the input instruction, flow charts, sample problems, and descriptions of available options and boundary conditions.

  1. Simulation of the transient condensation process in steam pipes during start up of a steam power plant

    NASA Astrophysics Data System (ADS)

    Botsch, T. W.; Stumpmeier, S.; Ganser, J.

    2010-11-01

    This paper introduces a model predicting the unsteady conditions in vertical pipes of a steam power station during start up of the plant. Knowing the time depending variation in the rate of condensation in the pipe is helpful for optimizing the design of the drainage system, which removes the condensate collected from the pipes. At present this system is designed on the basis of the total amount of condensate produced in a particular pipe during start up of the power plant. The model presented will provide a design based on the true maximum flow rate during said period. The paper describes the mass and energy balances for the gas and the condensate as well as the energy balance for the wall. All equations are transformed into a set of differential and algebraic equations and solved at once. The model was subsequently applied on genuine industrial scenarios. The results obtained from the model are discussed in detail and compared with experimental data. In all situations considered, the maximum condensate flow rate calculated was less than 50% of the estimated value using standard design methods.

  2. Experimental and analytical study of loss-of-flow transients in EBR-II occurring at decay power levels

    SciTech Connect

    Chang, L.K.; Mohr, D.; Feldman, E.E.; Betten, P.R.; Planchon, H.P.

    1985-01-01

    A series of eight loss-of-flow (LOF) tests have been conducted in EBR-II to study the transition between forced and natural convective flows following a variety of loss-of-primary-pumping power conditions from decay heat levels. Comparisons of measurements and pretest/posttest predictions were made on a selected test. Good agreements between measurements and predictions was found prior to and just after the flow reaching its minimum, but the agreement is not as good after that point. The temperatures are consistent with the flow response and the assumed decay power. The measured results indicate that the flows of driver and the instrumented subassemblies are too much in the analytical model in the natural convective region. Although a parametric study on secondary flow, turbulent-laminar flow transition, heat transfer ability of the intermediate heat exchange at low flow and flow mixing in the primary tank has been performed to determine their effects on the flow, the cause of the discrepancy at very low flow level is still unknown.

  3. Stochastic simulation of fission product activity in primary coolant due to fuel rod failures in typical PWRs under power transients

    NASA Astrophysics Data System (ADS)

    Javed Iqbal, M.; Mirza, Nasir M.; Mirza, Sikander M.

    2008-01-01

    During normal operation of PWRs, routine fuel rods failures result in release of radioactive fission products (RFPs) in the primary coolant of PWRs. In this work, a stochastic model has been developed for simulation of failure time sequences and release rates for the estimation of fission product activity in primary coolant of a typical PWR under power perturbations. In the first part, a stochastic approach is developed, based on generation of fuel failure event sequences by sampling the time dependent intensity functions. Then a three-stage model based deterministic methodology of the FPCART code has been extended to include failure sequences and random release rates in a computer code FPCART-ST, which uses state-of-the-art LEOPARD and ODMUG codes as its subroutines. The value of the 131I activity in primary coolant predicted by FPCART-ST code has been found in good agreement with the corresponding values measured at ANGRA-1 nuclear power plant. The predictions of FPCART-ST code with constant release option have also been found to have good agreement with corresponding experimental values for time dependent 135I, 135Xe and 89Kr concentrations in primary coolant measured during EDITHMOX-1 experiments.

  4. Decentralized control of large transient in power systems: theory and application. Final report, January 1981-August 1983

    SciTech Connect

    DeCarlo, R.; Hawley, P.; Sebok, D.

    1983-08-01

    Chapter 1 describes a continuation algorithm to construct decentralized state feedback gains which place the natural frequencies (natural modes of vibration or eigenvalues) of a linearized power system at desired locations. Chapter 2 and 3 address the problem of designing a decentralized dither control for linearly interconnected synchronous machines, each of which is nonlinear. In Chapter 2, the theory finds application to the nonlinear third order model of a single machine infinite bus system where the primary control is via an ac-dc converter. Similarly Chapter 3 considers a two machine system with individual machine converters acting as the primary control. Computer simulations of the control action given various system perturbations are found in both Chapters 2 and 3.

  5. Advanced PFBC transient analysis

    SciTech Connect

    White, J.S.; Bonk, D.L.

    1997-05-01

    Transient modeling and analysis of advanced Pressurized Fluidized Bed Combustion (PFBC) systems is a research area that is currently under investigation by the US Department of Energy`s Federal Energy Technology Center (FETC). The object of the effort is to identify key operating parameters that affect plant performance and then quantify the basic response of major sub-systems to changes in operating conditions. PC-TRAX{trademark}, a commercially available dynamic software program, was chosen and applied in this modeling and analysis effort. This paper describes the development of a series of TRAX-based transient models of advanced PFBC power plants. These power plants burn coal or other suitable fuel in a PFBC, and the high temperature flue gas supports low-Btu fuel gas or natural gas combustion in a gas turbine topping combustor. When it is utilized, the low-Btu fuel gas is produced in a bubbling bed carbonizer. High temperature, high pressure combustion products exiting the topping combustor are expanded in a modified gas turbine to generate electrical power. Waste heat from the system is used to raise and superheat steam for a reheat steam turbine bottoming cycle that generates additional electrical power. Basic control/instrumentation models were developed and modeled in PC-TRAX and used to investigate off-design plant performance. System performance for various transient conditions and control philosophies was studied.

  6. Elevated Ca2+ transients and increased myofibrillar power generation cause cardiac hypercontractility in a model of Noonan syndrome with multiple lentigines

    PubMed Central

    Clay, Sarah A.; Domeier, Timothy L.; Hanft, Laurin M.; McDonald, Kerry S.

    2015-01-01

    Noonan syndrome with multiple lentigines (NSML) is primarily caused by mutations in the nonreceptor protein tyrosine phosphatase SHP2 and associated with congenital heart disease in the form of pulmonary valve stenosis and hypertrophic cardiomyopathy (HCM). Our goal was to elucidate the cellular mechanisms underlying the development of HCM caused by the Q510E mutation in SHP2. NSML patients carrying this mutation suffer from a particularly severe form of HCM. Drawing parallels to other, more common forms of HCM, we hypothesized that altered Ca2+ homeostasis and/or sarcomeric mechanical properties play key roles in the pathomechanism. We used transgenic mice with cardiomyocyte-specific expression of Q510E-SHP2 starting before birth. Mice develop neonatal onset HCM with increased ejection fraction and fractional shortening at 4–6 wk of age. To assess Ca2+ handling, isolated cardiomyocytes were loaded with fluo-4. Q510E-SHP2 expression increased Ca2+ transient amplitudes during excitation-contraction coupling and increased sarcoplasmic reticulum Ca2+ content concurrent with increased expression of sarco(endo)plasmic reticulum Ca2+-ATPase. In skinned cardiomyocyte preparations from Q510E-SHP2 mice, force-velocity relationships and power-load curves were shifted upward. The peak power-generating capacity was increased approximately twofold. Transmission electron microscopy revealed that the relative intracellular area occupied by sarcomeres was increased in Q510E-SHP2 cardiomyocytes. Triton X-100-based myofiber purification showed that Q510E-SHP2 increased the amount of sarcomeric proteins assembled into myofibers. In summary, Q510E-SHP2 expression leads to enhanced contractile performance early in disease progression by augmenting intracellular Ca2+ cycling and increasing the number of power-generating sarcomeres. This gives important new insights into the cellular pathomechanisms of Q510E-SHP2-associated HCM. PMID:25724491

  7. Robust adaptive transient damping in power systems. Volume 1, System identification and decentralized adaptive control with applications to power systems: Final report

    SciTech Connect

    Pierre, D.A.; Sadighi, I.; Trudnowski, D.J.; Smith, J.R.; Nehrir, M.H.

    1992-09-01

    This Volume 1 of the final report on RP2665-1 contains two parts. part 1 consists of the following: (1) a literature review of real-time parameter identification algorithms which may be used in self-tuning adaptive control; (2) a description of mathematical discrete-time models that are linear in the parameters and that are useful for self-tuning adaptive control; (3) detailed descriptions of several variations of recursive-least-squares algorithms (RLS algorithms) and a unified representation of some of these algorithms; (4) a new variation of RLS called Corrector Least Squares (CLS); (5) a set of practical issues that need to be addressed in the implementation of RLS-based algorithms; (6) a set of simulation examples that illustrate properties of the identification methods; and (7) appendices With FORTRAN listings of several identification codes. Part 2 of this volume addresses the problem of damping electromechanical oscillations in power systems using advanced control theory. Two control strategies are developed. Controllers are then applied to a power system as power system stabilizer (PSS) units. The primary strategy is a decentralized indirect adaptive control scheme where multiple self-tuning adaptive controllers are coordinated. This adaptive scheme is presented in a general format and the stabilizing properties are demonstrated using examples. Both the adaptive and the conventional strategies are applied to a 17-machine computer-simulated power system. PSS units are applied to four generators in the system. Detailed simulation results are presented that show the feasibility and properties of both control schemes. FORTRAN codes for the control simulations are given in appendices of Part 2, as also are FORTRAN codes for the Prony identification method.

  8. Idaho Habitat Evaluation for Off-Site Mitigation Record : Annual Report 1988.

    SciTech Connect

    Idaho. Dept. of Fish and Game.

    1990-03-01

    The Idaho Department of Fish and Game (IDFG) has been monitoring and evaluating existing and proposed habitat improvement projects for steelhead and chinook in the Clearwater and Salmon subbasins since 1984. Projects included in the monitoring are funded by, or proposed for funding by, the Bonneville Power Administration (BPA) under the Northwest Power Planning Act as off-site mitigation for downstream hydropower development on the Snake and Columbia Rivers. This monitoring project is also funded under the same authority. A mitigation record is being developed to use actual and potential increases in smolt production as the best measures of benefit from a habitat improvement project. This project is divided into two subprojects: general and intensive monitoring. Primary objectives of the general monitoring subproject are to determine natural production increases due to habitat improvement projects in terms of parr production and to determine natural production status and trends in Idaho. The second objective is accomplished by combining parr density from monitoring and evaluation of BPA habitat projects and from other IDFG management and research activities. The primary objective of the intensive monitoring subproject is to determine the relationships between spawning escapement, parr production, and smolt production in two Idaho streams; the upper Salmon River and Crooked River. Results of the intensive monitoring will be used to estimate mitigation benefits in terms of smolt production and to interpret natural production monitoring in Idaho. 30 refs., 19 figs., 34 tabs.

  9. On-site or off-site treatment of medical waste: a challenge.

    PubMed

    Taghipour, Hassan; Mohammadyarei, Taher; Asghari Jafarabadi, Mohamad; Asl Hashemi, Ahmad

    2014-01-01

    Treating hazardous-infectious medical waste can be carried out on-site or off-site of health-care establishments. Nevertheless, the selection between on-site and off-site locations for treating medical waste sometimes is a controversial subject. Currently in Iran, due to policies of Health Ministry, the hospitals have selected on-site-treating method as the preferred treatment. The objectives of this study were to assess the current condition of on-site medical waste treatment facilities, compare on-site medical waste treatment facilities with off-site systems and find the best location of medical waste treatment. To assess the current on-site facilities, four provinces (and 40 active hospitals) were selected to participate in the survey. For comparison of on-site and off-site facilities (due to non availability of an installed off-site facility) Analytical Hierarchy Process (AHP) was employed. The result indicated that most on-site medical waste treating systems have problems in financing, planning, determining capacity of installations, operation and maintenance. AHP synthesis (with inconsistency ratio of 0.01 < 0.1) revealed that, in total, the off-site treatment of medical waste was in much higher priority than the on-site treatment (64.1% versus 35.9%). According to the results of study it was concluded that the off-site central treatment can be considered as an alternative. An amendment could be made to Iran's current medical waste regulations to have infectious-hazardous waste sent to a central off-site installation for treatment. To begin and test this plan and also receive the official approval, a central off-site can be put into practice, at least as a pilot in one province. Next, if it was practically successful, it could be expanded to other provinces and cities. PMID:24739145

  10. Wireless remote control of clinical image workflow: using a PDA for off-site distribution and disaster recovery.

    PubMed

    Documet, Jorge; Liu, Brent J; Documet, Luis; Huang, H K

    2006-07-01

    This paper describes a picture archiving and communication system (PACS) tool based on Web technology that remotely manages medical images between a PACS archive and remote destinations. Successfully implemented in a clinical environment and also demonstrated for the past 3 years at the conferences of various organizations, including the Radiological Society of North America, this tool provides a very practical and simple way to manage a PACS, including off-site image distribution and disaster recovery. The application is robust and flexible and can be used on a standard PC workstation or a Tablet PC, but more important, it can be used with a personal digital assistant (PDA). With a PDA, the Web application becomes a powerful wireless and mobile image management tool. The application's quick and easy-to-use features allow users to perform Digital Imaging and Communications in Medicine (DICOM) queries and retrievals with a single interface, without having to worry about the underlying configuration of DICOM nodes. In addition, this frees up dedicated PACS workstations to perform their specialized roles within the PACS workflow. This tool has been used at Saint John's Health Center in Santa Monica, California, for 2 years. The average number of queries per month is 2,021, with 816 C-MOVE retrieve requests. Clinical staff members can use PDAs to manage image workflow and PACS examination distribution conveniently for off-site consultations by referring physicians and radiologists and for disaster recovery. This solution also improves radiologists' effectiveness and efficiency in health care delivery both within radiology departments and for off-site clinical coverage. PMID:17412116

  11. Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment

    NASA Astrophysics Data System (ADS)

    Li, J. F.; Agyakwa, P. A.; Johnson, C. M.

    2014-04-01

    Real Si insulated gate bipolar transistors with conventional Ni/Ag metallization and dummy Si chips with thickened Ni/Ag metallization have both been bonded, at 250°C for 0 min, 40 min, and 640 min, to Ag foil electroplated with 2.7 µm and 6.8 µm thick Sn as an interlayer. On the basis of characterization of the microstructure of the resulting joints, suitable thicknesses are suggested for the Ag base metal and the Sn interlayer for Ag/Sn/Ag transient liquid-phase (TLP) joints used for power die attachment. The diffusivities of Ag and Sn in the ξAg phase were also obtained. In combination with the kinetic constants of Ag3Sn growth and diffusivities of Ag and Sn in Ag reported in the literature, the diffusivities of Ag and Sn in the ξAg phase were also used to simulate and predict diffusion-controlled growth and evolution of the phases in Ag/Sn/Ag TLP joints during extended bonding and in service.

  12. ON DETECTING TRANSIENT PHENOMENA

    SciTech Connect

    Belanger, G.

    2013-08-10

    Transient phenomena are interesting and potentially highly revealing of details about the processes under observation and study that could otherwise go unnoticed. It is therefore important to maximize the sensitivity of the method used to identify such events. In this article, we present a general procedure based on the use of the likelihood function for identifying transients which is particularly suited for real-time applications because it requires no grouping or pre-processing of the data. The method makes use of all the information that is available in the data throughout the statistical decision-making process, and is suitable for a wide range of applications. Here we consider those most common in astrophysics, which involve searching for transient sources, events or features in images, time series, energy spectra, and power spectra, and demonstrate the use of the method in the case of a weak X-ray flare in a time series and a short-lived quasi-periodic oscillation in a power spectrum. We derive a fit statistic that is ideal for fitting arbitrarily shaped models to a power density distribution, which is of general interest in all applications involving periodogram analysis.

  13. Savannah River Site radioiodine atmospheric releases and offsite maximum doses

    SciTech Connect

    Marter, W.L.

    1990-11-01

    Radioisotopes of iodine have been released to the atmosphere from the Savannah River Site since 1955. The releases, mostly from the 200-F and 200-H Chemical Separations areas, consist of the isotopes, I-129 and 1-131. Small amounts of 1-131 and 1-133 have also been released from reactor facilities and the Savannah River Laboratory. This reference memorandum was issued to summarize our current knowledge of releases of radioiodines and resultant maximum offsite doses. This memorandum supplements the reference memorandum by providing more detailed supporting technical information. Doses reported in this memorandum from consumption of the milk containing the highest I-131 concentration following the 1961 1-131 release incident are about 1% higher than reported in the reference memorandum. This is the result of using unrounded 1-131 concentrations of I-131 in milk in this memo. It is emphasized here that this technical report does not constitute a dose reconstruction in the same sense as the dose reconstruction effort currently underway at Hanford. This report uses existing published data for radioiodine releases and existing transport and dosimetry models.

  14. Fluid management plan for the Project Shoal Area Offsites Subproject

    SciTech Connect

    1996-08-01

    The US Department of Energy, Nevada Operations Office (DOE/NV) has initiated the Offsites Subproject to characterize the hazards posed to human health and the environment as a result of underground nuclear testing activities at facilities other than the Nevada Test Site (NTS). A primary Subproject objective is to gather adequate data to characterize the various Subproject sites through the collection of surface and subsurface soil samples and by drilling several wells for the collection of groundwater data. The Project Shoal Area (PSA) is one of the Subproject`s Nevada sites and is subject to the requirements set forth in the Federal Facility Compliance Agreement and Consent Order (FFACO) (DOE, 1996a). In accordance with the FFACO, a Corrective Action Investigation Plan (CAIP) has been developed for work at the PSA (designated as Corrective Action Unit Number 416). This Fluid Management Plan (FMP) provides guidance for the management of fluids generated from wells constructed at the PSA. Long-term monitoring and future activities at the site, if required, will be set forth in additional documents as required by the FFACO. The ultimate method for disposition of fluids generated by site operations depends upon sample analysis and process knowledge in relation to fluid management criteria. Section 2 describes well site operations; Section 3 discusses fluid management criteria; Section 4 includes the fluid monitoring program; Section 5 presents the fluid management strategy; Section 6 provides for fluid management during routine well monitoring; and Section 7 contains reporting criteria.

  15. Evaluating off-site disposal of low-level waste at LANL-9498

    SciTech Connect

    Hargis, Kenneth M; French, Sean B; Boyance, Julien A

    2009-01-01

    Los Alamos National Laboratory generates a wide range of waste types, including solid low-level radioactive waste (LL W), in conducting its national security mission and other science and technology activities. Although most ofLANL's LLW has been disposed on-site, limitations on expansion, stakeholder concerns, and the potential for significant volumes from environmental remediation and decontamination and demolition (D&D) have led LANL to evaluate the feasibility of increasing off-site disposal. It appears that most of the LL W generated at LANL would meet the Waste Acceptance Criteria at the Nevada Test Site or the available commercial LL W disposal site. Some waste is considered to be problematic to transport to off-site disposal even though it could meet the off-site Waste Acceptance Criteria. Cost estimates for off-site disposal are being evaluated for comparison to estimated costs under the current plans for continued on-site disposal.

  16. Code System for Calculating Early Offsite Consequences from Nuclear Reactor Accidents.

    Energy Science and Technology Software Center (ESTSC)

    1992-06-10

    SMART calculates early offsite consequences from nuclear reactor accidents. Once the air and ground concentrations of the radionuclide are estimated, the early dose to an individual is calculated via three pathways: cloudshine, short-term groundshine, and inhalation.

  17. 40 CFR 279.58 - Off-site shipments of used oil.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) STANDARDS FOR THE MANAGEMENT OF USED OIL Standards for Used Oil Processors and Re-Refiners § 279.58 Off-site shipments of used oil. Used oil processors/re-refiners who initiate shipments of used...

  18. 24 CFR 242.47 - Insured advances for building components stored off-site.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... mortgagor shall: (A) Obtain a bill of sale for the component; (B) Give the mortgagee a security agreement... only for components stored off-site in a quantity required to permit uninterrupted installation at...

  19. 77 FR 59001 - Fee for Services To Support FEMA's Offsite Radiological Emergency Preparedness Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-25

    ... SECURITY Federal Emergency Management Agency Fee for Services To Support FEMA's Offsite Radiological Emergency Preparedness Program AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: The Federal Emergency Management Agency (FEMA) is establishing a fiscal year (FY) 2014 hourly rate...

  20. 75 FR 19985 - Fee for Services To Support FEMA's Offsite Radiological Emergency Preparedness Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ... SECURITY Federal Emergency Management Agency Fee for Services To Support FEMA's Offsite Radiological Emergency Preparedness Program AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: The Federal Emergency Management Agency (FEMA) has established a fiscal year (FY) 2010 hourly rate...

  1. 40 CFR 279.58 - Off-site shipments of used oil.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) STANDARDS FOR THE MANAGEMENT OF USED OIL Standards for Used Oil Processors and Re-Refiners § 279.58 Off-site shipments of used oil. Used oil processors/re-refiners who initiate shipments of used...

  2. Overview of the Department of Energy's Off-Site Radiation Exposure Review Project (ORERP).

    PubMed

    Church, B W; Wheeler, D L; Campbell, C M; Nutley, R V; Anspaugh, L R

    1990-11-01

    The Off-Site Radiation Exposure Review Project (ORERP) was established by the U.S. Department of Energy to (1) collect, preserve, and disseminate historical data related to radioactive fallout and health effects from nuclear testing, and (2) reconstrut, insofar as possible, the exposures to the off-site public from nuclear testing at the Nevada Test Site and doses to individuals resulting from these exposures. The goals, methods, and example results of the ORERP are presented. PMID:2211109

  3. Overview of the Department of Energy's Off-Site Radiation Exposure Review Project (ORERP)

    SciTech Connect

    Church, B.W.; Wheeler, D.L.; Campbell, C.M.; Nutley, R.V.; Anspaugh, L.R. )

    1990-11-01

    The Off-Site Radiation Exposure Review Project (ORERP) was established by the U.S. Department of Energy to (1) collect, preserve, and disseminate historical data related to radioactive fallout and health effects from nuclear testing, and (2) reconstruct, insofar as possible, the exposures to the off-site public from nuclear testing at the Nevada Test Site and doses to individuals resulting from these exposures. The goals, methods, and example results of the ORERP are presented.

  4. Reconstructing ancient sustainability: a comparison of onsite and offsite data

    NASA Astrophysics Data System (ADS)

    Lubos, Carolin; Dreibrodt, Stefan; Horejs, Barbara

    2013-04-01

    With the onset of sedentism humans started to convert their surroundings. Whereas reconstructions of geochemical traces of settlement activity (e.g. Arrhenius, 1931) or man's pressure on the soils of landscapes (e.g. van Andel et al., 1990; Bork, 1998) were carried out at many sites holistic approaches questioning the sustainability of ancient societies are missing so far. A new approach, applied to the multi layered settlement mound "Cukurici Höyük" (western Anatolia, Turkey) aims at comparing land use intensity and settlement intensity. Land use intensity of the former settlers will be described by determining slope instability phases and quantifying slope deposits at hills adjacent to the settlement. Geochemical and physical properties as well as bio remains will be analysed of the dated debris layers onsite and quantified as matter fluxes. Matter accumulation onsite, being an indicator for settlement intensities, is compared to slope instability phases offsite, describing the impact of former settlers on their environment. The approach aims at quantifying historical settlement pressure over several settlement phases and might shed light on different phases of sustainability in ancient Times. The planned project is imbedded within the archaeological project (ERC Project / Austrian Archaeological Institute) which investigates alternating societal systems in a changing environment between 7000 and 3000 BC. Focus is laid on architectural research, archaeobotany, archaeozoology, lithics, metallurgy, and ore deposit. In a first geoarchaeological field campaign differentiable slope deposits could be proved. These contained datable organic material as well as pottery sherds dating to different historical phases. A well-established archaeological chronosequence of settlement layers will provide the onsite framework for this new project. The paper presents preliminary results of the outlined approach. Additionally several geochemical methodologies applied to the debris

  5. Idaho Habitat Evaluation for Off-Site Mitigation Record : Annual Report 1987.

    SciTech Connect

    Petrosky, Charles E.; Holubetz, Terry B.

    1988-04-01

    The Idaho Department of Fish and Game has been monitoring and evaluating existing and proposed habitat improvement projects for steelhead (Salmo gairdneri) and chinook salmon (Oncorhynchus tshawytscha) in the Clearwater and Salmon River drainages over the last four years. Projects included in the evaluation are funded by, or proposed for funding by, the Bonneville Power Administration (BPA) under the Northwest Power Planning Act as off-site mitigation for downstream hydropower development on the Snake and Columbia rivers. A mitigation record is being developed to use increased smolt production at full seeding as the best measure of benefit from a habitat enhancement project. Determination of full benefit from a project depends on presence of adequate numbers of fish to document actual increases in fish production. The depressed nature of upriver anadromous stocks have precluded attainment of full benefit of any habitat project in Idaho. Partial benefit will be credited to the mitigation record in the interim period of run restoration. According to the BPA Work Plan, project implementors have the primary responsibility for measuring physical habitat and estimating habitat change. To date, Idaho habitat projects have been implemented primarily by the US Forest Service (USFS). The Shoshone-Bannock Tribes (SBT) have sponsored three projects (Bear Valley Mine, Yankee Fork, and the proposed East Fork Salmon River projects). IDFG implemented two barrier-removal projects (Johnson Creek and Boulder Creek) that the USFS was unable to sponsor at that time. The role of IDFG in physical habitat monitoring is primarily to link habitat quality and habitat change to changes in actual, or potential, fish production. Individual papers were processed separately for the data base.

  6. Preliminary Transient Performance Data for Afterburner Operation of Westinghouse Electronic Power Regulator on XJ34-WE-32 Turbojet Engine in Altitude Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Vasu, George; Schwent, Glennon V.; Ketchum, James R.

    1951-01-01

    At the request of the Bureau of Aeronautics, Department of the Navy, an investigation of the Westinghouse XJ34-WE-32 turbojet engine is being conducted in the NACA Lewis altitude wind tunnel to determine the steady-state and transient operating characteristics of the controlled and uncontrolled engine at various altitudes and ram pressure ratios. As part of this program, transient performance data that illustrate the operation of the engine is obtained in the form of oscillographic traces. Similar data for engine operation i n the afterburning range, covering a range of throttle settings from the minimum value giving rated speed (throttle position, 72 degrees) to full afterburning (throttle position, ll0 degrees), is presented herein. These data thus serve to indicate the transient characteristics of the engine when the throttle is advance into, withdrawn from, and moved within the afterburning range in a stepwise manner, as well as the steady-state stability of the engine during afterburning .

  7. Assessment of a pressurizer spray valve faulty opening transient at Asco Nuclear Power Plant with RELAP5/MOD2. International Agreement Report

    SciTech Connect

    Reventos, F.; Baptista, J.S.; Navas, A.P.; Moreno, P.

    1993-12-01

    The Asociacion Nuclear Asco has prepared a model of Asco NPP using RELAP5/MOD2. This model, which include thermalhydraulics, kinetics and protection and controls, has been qualified in previous calculations of several actual plant transients. One of the transients of the qualification process is a ``Pressurizer spray valve faulty opening`` presented in this report. It consists in a primary coolant depressurization that causes the reactor trip by overtemperature and later on the actuation of the safety injection. The results are in close agreement with plant data.

  8. Using RFID to Enhance Security in Off-Site Data Storage

    PubMed Central

    Lopez-Carmona, Miguel A.; Marsa-Maestre, Ivan; de la Hoz, Enrique; Velasco, Juan R.

    2010-01-01

    Off-site data storage is one of the most widely used strategies in enterprises of all sizes to improve business continuity. In medium-to-large size enterprises, the off-site data storage processes are usually outsourced to specialized providers. However, outsourcing the storage of critical business information assets raises serious security considerations, some of which are usually either disregarded or incorrectly addressed by service providers. This article reviews these security considerations and presents a radio frequency identification (RFID)-based, off-site, data storage management system specifically designed to address security issues. The system relies on a set of security mechanisms or controls that are arranged in security layers or tiers to balance security requirements with usability and costs. The system has been successfully implemented, deployed and put into production. In addition, an experimental comparison with classical bar-code-based systems is provided, demonstrating the system’s benefits in terms of efficiency and failure prevention. PMID:22163638

  9. Incorporation of HVDC and SVC models in the Northern State Power Co. (NSP) network for on-line implementation of direct transient stability assessment

    SciTech Connect

    Jing, C.; Vittal, V.; Ejebe, G.C.; Irisarri, G.D.

    1995-05-01

    In this paper the authors discuss the incorporation of the 4 dc systems and 2 SVCs in the NSP network for on-line implementation of direct transient stability assessment. The dc and SVC models used are more complicated than those used in the existing AC-DC-SVC Transient Energy Function (TEF) literature. In this new approach, the commutation failure of the HVDC is also considered. It is necessary to use these complicated dc and SVC models because in the NSP network they are located in an area where the transient stability is of great concern. The dc and SVC systems are treated as part of the ac network and their effect on the transient energy function is included. The effect of dc and SVC on the calculation of the potential energy is reflected in the ac network solution. The equivalent models and the proposed procedure developed is tested on a NSP equivalent network of 273 generators and 2,217 buses. The result obtained are in excellent agreement with those obtained by time domain simulation using EPRI ETMSP V3.0.

  10. Wireless remote control clinical image workflow: utilizing a PDA for offsite distribution

    NASA Astrophysics Data System (ADS)

    Liu, Brent J.; Documet, Luis; Documet, Jorge; Huang, H. K.; Muldoon, Jean

    2004-04-01

    Last year we presented in RSNA an application to perform wireless remote control of PACS image distribution utilizing a handheld device such as a Personal Digital Assistant (PDA). This paper describes the clinical experiences including workflow scenarios of implementing the PDA application to route exams from the clinical PACS archive server to various locations for offsite distribution of clinical PACS exams. By utilizing this remote control application, radiologists can manage image workflow distribution with a single wireless handheld device without impacting their clinical workflow on diagnostic PACS workstations. A PDA application was designed and developed to perform DICOM Query and C-Move requests by a physician from a clinical PACS Archive to a CD-burning device for automatic burning of PACS data for the distribution to offsite. In addition, it was also used for convenient routing of historical PACS exams to the local web server, local workstations, and teleradiology systems. The application was evaluated by radiologists as well as other clinical staff who need to distribute PACS exams to offsite referring physician"s offices and offsite radiologists. An application for image workflow management utilizing wireless technology was implemented in a clinical environment and evaluated. A PDA application was successfully utilized to perform DICOM Query and C-Move requests from the clinical PACS archive to various offsite exam distribution devices. Clinical staff can utilize the PDA to manage image workflow and PACS exam distribution conveniently for offsite consultations by referring physicians and radiologists. This solution allows the radiologist to expand their effectiveness in health care delivery both within the radiology department as well as offisite by improving their clinical workflow.

  11. Security assessment of power systems including energy storage and with the integration of wind energy. Volume I. Digital transient simulation effort consulting Agreement No. 1. Final report

    SciTech Connect

    Anderson, P. M.

    1982-06-30

    The purpose of the effort reported has been to adapt the MOD-2 simulation models for implementation on a digital transient stability program. This has involved: selection of an appropriate host program, examination of the host program interface, analysis of the analog models for digital implementation, FORTRAN coding of the model equations, installation and debugging on the host program, and final model verification. Synchronous machine equations are analyzed, with particular emphasis on numerical solution. (LEW)

  12. 75 FR 69470 - Tele Atlas North America, Inc., Currently Doing Business as Tom Tom Including Off-Site Workers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-12

    ... published in the Federal Register on January 25, 2010 (75 FR 3938). At the request of the state, the... Including Off-Site Workers Reporting to This Location, Lebanon, NH; Tele Atlas North America, Inc. Currently..., applicable to workers of Tele Atlas North America, Inc. in Lebanon, New Hampshire and off-site...

  13. 40 CFR 1400.9 - Access to off-site consequence analysis information by State and local government officials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... analysis information by State and local government officials. 1400.9 Section 1400.9 Protection of... REQUIREMENTS; RISK MANAGEMENT PROGRAMS UNDER THE CLEAN AIR ACT SECTION 112(r)(7); DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Access to...

  14. 40 CFR 1400.9 - Access to off-site consequence analysis information by State and local government officials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... analysis information by State and local government officials. 1400.9 Section 1400.9 Protection of... REQUIREMENTS; RISK MANAGEMENT PROGRAMS UNDER THE CLEAN AIR ACT SECTION 112(r)(7); DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Access to...

  15. 40 CFR 1400.9 - Access to off-site consequence analysis information by State and local government officials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... analysis information by State and local government officials. 1400.9 Section 1400.9 Protection of... REQUIREMENTS; RISK MANAGEMENT PROGRAMS UNDER THE CLEAN AIR ACT SECTION 112(r)(7); DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Access to...

  16. 10 CFR 840.4 - Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...—Offsite property 2 Column 2—Other offsite property Alpha emission from transuranic isotopes 3.5 microcuries per square meter 0.35 microcuries per square meter. Alpha emission from isotopes other than transuranic isotopes 35 microcuries per square meter 3.5 microcuries per square meter. Beta or gamma...

  17. 10 CFR 840.4 - Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...—Offsite property 2 Column 2—Other offsite property Alpha emission from transuranic isotopes 3.5 microcuries per square meter 0.35 microcuries per square meter. Alpha emission from isotopes other than transuranic isotopes 35 microcuries per square meter 3.5 microcuries per square meter. Beta or gamma...

  18. 10 CFR 840.4 - Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...—Offsite property 2 Column 2—Other offsite property Alpha emission from transuranic isotopes 3.5 microcuries per square meter 0.35 microcuries per square meter. Alpha emission from isotopes other than transuranic isotopes 35 microcuries per square meter 3.5 microcuries per square meter. Beta or gamma...

  19. 10 CFR 840.4 - Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...—Offsite property 2 Column 2—Other offsite property Alpha emission from transuranic isotopes 3.5 microcuries per square meter 0.35 microcuries per square meter. Alpha emission from isotopes other than transuranic isotopes 35 microcuries per square meter 3.5 microcuries per square meter. Beta or gamma...

  20. 10 CFR 840.4 - Criterion I-Substantial discharge of radioactive material or substantial radiation levels offsite.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...—Offsite property 2 Column 2—Other offsite property Alpha emission from transuranic isotopes 3.5 microcuries per square meter 0.35 microcuries per square meter. Alpha emission from isotopes other than transuranic isotopes 35 microcuries per square meter 3.5 microcuries per square meter. Beta or gamma...

  1. 40 CFR 1400.9 - Access to off-site consequence analysis information by State and local government officials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... analysis information by State and local government officials. 1400.9 Section 1400.9 Protection of... REQUIREMENTS; RISK MANAGEMENT PROGRAMS UNDER THE CLEAN AIR ACT SECTION 112(r)(7); DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Access to...

  2. 40 CFR 1400.9 - Access to off-site consequence analysis information by State and local government officials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... analysis information by State and local government officials. 1400.9 Section 1400.9 Protection of... REQUIREMENTS; RISK MANAGEMENT PROGRAMS UNDER THE CLEAN AIR ACT SECTION 112(r)(7); DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION DISTRIBUTION OF OFF-SITE CONSEQUENCE ANALYSIS INFORMATION Access to...

  3. Offsite environmental monitoring report. Radiation monitoring around United States nuclear test areas, calendar year 1982

    SciTech Connect

    Black, S. C.; Grossman, R. F.; Mullen, A. A.; Potter, G. D.; Smith, D. D.

    1983-07-01

    A principal activity of the Offsite Radiological Safety Program is routine environmental monitoring for radioactive materials in various media and for radiation in areas which may be affected by nuclear tests. It is conducted to document compliance with standards, to identify trends, and to provide information to the public. This report summarizes these activities for CY 1982.

  4. RESRAD-OFFSITE - a new member of the RESRAD family of codes.

    SciTech Connect

    Yu, C.; Gnanapragasam, E.; Biwer, B.; Cheng, J.-J.; Kamboj, S.; Klett, T.; Zielen, A.; Williams, W.A.; Domotor, S.; Wallo, A.; Environmental Science Division; USDOE

    2009-06-01

    The RESRAD-OFFSITE code provides expanded state-of-the art, cost-effective, and user-friendly methods for evaluating the radiological consequences to a receptor located onsite or outside the area of primary contamination. It calculates radiological dose and excess lifetime cancer risk with the predicted radionuclide concentrations in the environment, and derives soil cleanup guidelines corresponding to a specified dose limit. The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code, which has been widely used for calculating doses and risks from exposure to radioactively contaminated soils. The development of RESRAD-OFFSITE started more than 10 years ago, but new models and methodologies have been developed, tested, and incorporated since then. Some of the new models have been benchmarked against other independently developed (international) models. The databases used have also expanded to include all the radionuclides (more than 830) contained in the International Commission on Radiological Protection (ICRP) 38 database. Detailed information on the design and application of the RESRAD-OFFSITE code is presented in its recently published User's Manual.

  5. Off-Site Supervision in Social Work Education: What Makes It Work?

    ERIC Educational Resources Information Center

    Maynard, Sarah P.; Mertz, Linda K. P.; Fortune, Anne E.

    2015-01-01

    The field practicum is the signature pedagogy of the social work profession, yet field directors struggle to find adequate field placements--both in quantity and quality. To accommodate more students with a dwindling pool of practicum sites, creative models of field supervision have emerged. This article considers off-site supervision and its…

  6. Incineration of DOE offsite mixed waste at the Idaho National Engineering and Environmental Laboratory

    SciTech Connect

    Harris, J.D.; Harvego, L.A.; Jacobs, A.M.; Willcox, M.V.

    1998-01-01

    The Waste Experimental Reduction Facility (WERF) incinerator at the Idaho National Engineering and Environmental Laboratory (INEEL) is one of three incinerators in the US Department of Energy (DOE) Complex capable of incinerating mixed low-level waste (MLLW). WERF has received MLLW from offsite generators and is scheduled to receive more. The State of Idaho supports receipt of offsite MLLW waste at the WERF incinerator within the requirements established in the (INEEL) Site Treatment Plan (STP). The incinerator is operating as a Resource Conservation and Recovery Act (RCRA) Interim Status Facility, with a RCRA Part B permit application currently being reviewed by the State of Idaho. Offsite MLLW received from other DOE facilities are currently being incinerated at WERF at no charge to the generator. Residues associated with the incineration of offsite MLLW waste that meet the Envirocare of Utah waste acceptance criteria are sent to that facility for treatment and/or disposal. WERF is contributing to the treatment and reduction of MLLW in the DOE Complex.

  7. OFFSITE ENVIRONMENTAL MONITORING REPORT: RADIATION MONITORING AROUND UNITED STATES NUCLEAR TEST AREAS, CALENDAR YEAR 1980

    EPA Science Inventory

    The U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory in Las Vegas continued its Offsite Radiological Safety Program for the Nevada Test Site (NTS) and other sites of past underground nuclear tests. For each test, the Laboratory provided airborne ...

  8. 40 CFR 62.15140 - What if all the certified operators must be temporarily offsite?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false What if all the certified operators must be temporarily offsite? 62.15140 Section 62.15140 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF STATE PLANS...

  9. 24 CFR 242.47 - Insured advances for building components stored off-site.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Insured advances for building components stored off-site. 242.47 Section 242.47 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND...

  10. 40 CFR 280.51 - Investigation due to off-site impacts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Investigation due to off-site impacts. 280.51 Section 280.51 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID... UNDERGROUND STORAGE TANKS (UST) Release Reporting, Investigation, and Confirmation § 280.51 Investigation...