Optical Diagnostic Characterization of High-Power Hall Thruster Wear and Operation

Science.gov (United States)

Williams, George J., Jr.; Soulas, George C.; Kamhawi, Hani

2012-01-01

Optical emission spectroscopy is employed to correlate BN insulator erosion with high-power Hall thruster operation. Specifically, actinometry leveraging excited xenon states is used to normalize the emission spectra of ground state boron as a function of thruster operating condition. Trends in the strength of the boron signal are correlated with thruster power, discharge voltage, and discharge current. In addition, the technique is demonstrated on metallic coupons embedded in the walls of the HiVHAc EM thruster. The OES technique captured the overall trend in the erosion of the coupons which boosts credibility in the method since there are no data to which to calibrate the erosion rates of high-power Hall thrusters. The boron signals are shown to trend linearly with discharge voltage for a fixed discharge current as expected. However, the boron signals of the higher-power NASA 300M and NASA 457Mv2 trend with discharge current and show an unexpectedly weak to inverse dependence on discharge voltage. Electron temperatures measured optically in the near-field plume of the thruster agree well with Langmuir probe data. However, the optical technique used to determine Te showed unacceptable sensitivity to the emission intensities. Near-field, single-frequency imaging of the xenon neutrals is also presented as a function of operating condition for the NASA 457 Mv2.

Generic study on the design and operation of high power targets

Directory of Open Access Journals (Sweden)

A. Ahmad

2014-02-01

Full Text Available With the move towards beam power in the range of 1–10 MW, a thorough understanding of the response of target materials and auxiliary systems to high power densities and intense radiation fields is required. This paper provides insight into three major aspects related to the design and operation of high power solid targets: thermal stresses, coolant performance, and radiation damage. Where appropriate, a figure-of-merit approach is followed to facilitate the comparison between different target or coolant candidates. The section on radiation damage reports total and spatial variations of displacement-per-atom and helium production levels in different target materials.

High-power 355 nm ultraviolet lasers operating at ultrahigh repetition rate

International Nuclear Information System (INIS)

Chen, H; Liu, Q; Yan, P; Gong, M

2013-01-01

In this letter, we demonstrate a novel 355 nm ultraviolet (UV) laser operating at ultrahigh repetition rate from 300 kHz to 1 MHz. The hybrid fiber-MOPA–bulk amplifiers based IR source exhibits a high average power of 105 W with near-diffraction-limited beam quality, narrow linewidth and high polarization extinction ratio. Two-cascaded LBO crystals are employed for high efficiency frequency tripling, and a maximum 43.7 W of average UV power is achieved at 400 kHz, corresponding to a conversion efficiency as high as 41.6%. The pulse duration of the UV pulse can be tuned from 5 to 10 ns with good pulse peak stability (better than 2.2% (RMS)). (letter)

CERN-group conceptual design of a fast neutron operated high power energy amplifier

International Nuclear Information System (INIS)

Rubbia, C.; Rubio, J.A.; Buono, S.

1997-01-01

The practical feasibility of an Energy Amplifier (EA) with power and power density which are comparable to the ones of the present generation of large PWR is discussed in this paper. This is only possible with fast neutrons. Schemes are described which offer a high gain, a large maximum power density and an extended burn-up, well in excess of 100 GW x d/t corresponding to about five years at full power operation with no intervention on the fuel core. The following topics are discussed: physics considerations and parameter definition, the accelerator complex, the energy amplifier unit, computer simulated operation, and fuel cycle closing

CERN-group conceptual design of a fast neutron operated high power energy amplifier

Energy Technology Data Exchange (ETDEWEB)

Rubbia, C; Rubio, J A [European Organization for Nuclear Research, CERN, Geneva (Switzerland); Buono, S [Laboratoire du Cyclotron, Nice (France); and others

1997-11-01

The practical feasibility of an Energy Amplifier (EA) with power and power density which are comparable to the ones of the present generation of large PWR is discussed in this paper. This is only possible with fast neutrons. Schemes are described which offer a high gain, a large maximum power density and an extended burn-up, well in excess of 100 GW x d/t corresponding to about five years at full power operation with no intervention on the fuel core. The following topics are discussed: physics considerations and parameter definition, the accelerator complex, the energy amplifier unit, computer simulated operation, and fuel cycle closing. 84 refs, figs, tabs.

Facing the challenges of distribution systems operation with high wind power penetration

DEFF Research Database (Denmark)

Das, Kaushik; Altin, Müfit; Hansen, Anca Daniela

2017-01-01

power flow in 60kV distribution networks through controlling the ability of wind power plants (WPPs) to generate or absorb reactive power. This paper aims to understand the characteristics of a distribution network with high penetration of distributed generation. A detailed analysis of the active...... and reactive power flows in a real distribution network under different wind and load conditions based on actual measurements is performed in order to understand the correlation between the consumption, wind power production, and the network losses. Conclusive remarks are presented, briefly expressing......This paper addresses the challenges associated with the operation of a distribution system with high penetration of wind power. The paper presents some preliminary investigations of an ongoing Danish research work, which has as main objective to reduce the network losses by optimizing the reactive...

Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

DEFF Research Database (Denmark)

Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

2008-01-01

In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive...... vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible economical incentives for the vehicle owners will be shown. By control of EDV charging through a price...... signal from the day ahead market the economical incentives for an EDV-owner will be small. If the EDV's can participate in the regulation of the grid through ancillary services the incentives will be increased to an attractive level....

Durability of Low Platinum Fuel Cells Operating at High Power Density

Energy Technology Data Exchange (ETDEWEB)

Polevaya, Olga [Nuvera Fuel Cells Inc.; Blanchet, Scott [Nuvera Fuel Cells Inc.; Ahluwalia, Rajesh [Argonne National Lab; Borup, Rod [Los-Alamos National Lab; Mukundan, Rangachary [Los-Alamos National Lab

2014-03-19

Understanding and improving the durability of cost-competitive fuel cell stacks is imperative to successful deployment of the technology. Stacks will need to operate well beyond today’s state-of-the-art rated power density with very low platinum loading in order to achieve the cost targets set forth by DOE ($15/kW) and ultimately be competitive with incumbent technologies. An accelerated cost-reduction path presented by Nuvera focused on substantially increasing power density to address non-PGM material costs as well as platinum. The study developed a practical understanding of the degradation mechanisms impacting durability of fuel cells with low platinum loading (≤0.2mg/cm2) operating at high power density (≥1.0W/cm2) and worked out approaches for improving the durability of low-loaded, high-power stack designs. Of specific interest is the impact of combining low platinum loading with high power density operation, as this offers the best chance of achieving long-term cost targets. A design-of-experiments approach was utilized to reveal and quantify the sensitivity of durability-critical material properties to high current density at two levels of platinum loading (the more conventional 0.45 mgPt.cm–1 and the much lower 0.2 mgPt.cm–2) across several cell architectures. We studied the relevance of selected component accelerated stress tests (AST) to fuel cell operation in power producing mode. New stress tests (NST) were designed to investigate the sensitivity to the addition of electrical current on the ASTs, along with combined humidity and load cycles and, eventually, relate to the combined city/highway drive cycle. Changes in the cathode electrochemical surface area (ECSA) and average oxygen partial pressure on the catalyst layer with aging under AST and NST protocols were compared based on the number of completed cycles. Studies showed elevated sensitivity of Pt growth to the potential limits and the initial particle size distribution. The ECSA loss

Operating experiences since rise-to-power test in high temperature engineering test reactor (HTTR)

International Nuclear Information System (INIS)

Tochio, Daisuke; Watanabe, Shuji; Motegi, Toshihiro; Kawano, Shuichi; Kameyama, Yasuhiko; Sekita, Kenji; Kawasaki, Kozo

2007-03-01

The rise-to-power test of the High Temperature Engineering Test Reactor (HTTR) was actually started in April 2000. The rated thermal power of 30MW and the rated reactor outlet coolant temperature of 850degC were achieved in the middle of Dec. 2001. After that, the reactor thermal power of 30MW and the reactor outlet coolant temperature of 950degC were achieved in the final rise-to-power test in April 2004. After receiving the operation licensing at 850degC, the safety demonstration tests have conducted to demonstrate inherent safety features of the HTGRs as well as to obtain the core and plant transient data for validation of safety analysis codes and for establishment of safety design and evaluation technologies. This paper summarizes the HTTR operating experiences for six years from start of the rise-to-power test that are categorized into (1) Operating experiences related to advanced gas-cooled reactor design, (2) Operating experiences for improvement of the performance, (3) Operating experiences due to fail of system and components. (author)

Decision Optimization for Power Grid Operating Conditions with High- and Low-Voltage Parallel Loops

Directory of Open Access Journals (Sweden)

Dong Yang

2017-05-01

Full Text Available With the development of higher-voltage power grids, the high- and low-voltage parallel loops are emerging, which lead to energy losses and even threaten the security and stability of power systems. The multi-infeed high-voltage direct current (HVDC configurations widely appearing in AC/DC interconnected power systems make this situation even worse. Aimed at energy saving and system security, a decision optimization method for power grid operating conditions with high- and low-voltage parallel loops is proposed in this paper. Firstly, considering hub substation distribution and power grid structure, parallel loop opening schemes are generated with GN (Girvan-Newman algorithms. Then, candidate opening schemes are preliminarily selected from all these generated schemes based on a filtering index. Finally, with the influence on power system security, stability and operation economy in consideration, an evaluation model for candidate opening schemes is founded based on analytic hierarchy process (AHP. And a fuzzy evaluation algorithm is used to find the optimal scheme. Simulation results of a New England 39-bus system and an actual power system validate the effectiveness and superiority of this proposed method.

Demand side resource operation on the Irish power system with high wind power penetration

International Nuclear Information System (INIS)

Keane, A.; Tuohy, A.; Meibom, P.; Denny, E.; Flynn, D.; Mullane, A.; O'Malley, M.

2011-01-01

The utilisation of demand side resources is set to increase over the coming years with the advent of advanced metering infrastructure, home area networks and the promotion of increased energy efficiency. Demand side resources are proposed as an energy resource that, through aggregation, can form part of the power system plant mix and contribute to the flexible operation of a power system. A model for demand side resources is proposed here that captures its key characteristics for commitment and dispatch calculations. The model is tested on the all island Irish power system, and the operation of the model is simulated over one year in both a stochastic and deterministic mode, to illustrate the impact of wind and load uncertainty. The results illustrate that demand side resources can contribute to the efficient, flexible operation of systems with high penetrations of wind by replacing some of the functions of conventional peaking plant. Demand side resources are also shown to be capable of improving the reliability of the system, with reserve capability identified as a key requirement in this respect. - Highlights: → Demand side resource model presented for use in unit commitment and dispatch calculations. → Benefits of demand side aggregation demonstrated specifically as a peaking unit and provider of reserve. → Potential to displace or defer construction of conventional peaking units.

The impact of hybrid energy storage on power quality, when high power pulsed DC loads are operated on a microgrid testbed

Science.gov (United States)

Kelley, Jay Paul

As the Navy's demands for high power transient loads evolves, so too does the need for alternative energy sources to back-up the more traditional power generation. Such applications in need of support include electrical grid backup and directed energy weapon systems such as electromagnetic launchers, laser systems, and high power microwave generators, among others. Among the alternative generation sources receiving considerable attention are energy storage devices such as rechargeable electrochemical batteries and capacitors. In such applications as those mentioned above, these energy storage devices offer the ability to serve a dual role as both a power source to the various loads as well high power loads themselves to the continual generation when the high power transient loads are in periods of downtime. With the recent developments in electrochemical energy storage, lithium-ion batteries (LIBs) seem like the obvious choice, but previous research has shown that the elevated rates of charging can be detrimental to both the cycle life and the operational life span of the device. In order to preserve the batteries, their charge rate must be limited. One proposed method to accomplish the dual role task mentioned above, while preserving the life of the batteries, is by combining high energy density LIBs with high power density electric double layer capacitors (EDLCs) or lithium-ion capacitors (LICs) using controllable power electronics to adjust the flow of power to and from each device. Such a configuration is typically referred to as hybrid energy storage module (HESM). While shipboard generators start up, the combined high energy density and high power density of the HESM provides the capability to source critical loads for an extended period of time at the high rates they demand. Once the generator is operationally efficient, the HESM can act as a high energy reservoir to harvest the energy from the generator while the loads are in short periods of inactivity

Emission properties of diode laser bars during pulsed high-power operation

International Nuclear Information System (INIS)

Hempel, Martin; Tomm, Jens W; Elsaesser, Thomas; Hennig, Petra

2011-01-01

High-power diode laser bars (cm-bars) are subjected to single pulse step tests carried out up to and beyond their ultimate limits of operation. Laser nearfields and thermal behaviour are monitored for pulse widths in the 10–100 µs range with streak- and thermo-cameras, respectively. Thresholds of catastrophic optical damage are determined, and their dependence on the length of the injected current pulses is explained qualitatively. This approach permits testing the hardness of facet coatings of cm-bars with or without consideration of accidental single pre-damaged emitter failure effects and thermal crosstalk between the emitters. This allows for the optimization of pulsed operation parameters, helps limiting sudden degradation and provides insight into the mechanisms governing the device emission behaviour at ultimate output powers. (fast track communication)

High-power and long-pulse operation of TE{sub 31,11} mode gyrotron

Energy Technology Data Exchange (ETDEWEB)

Ikeda, Ryosuke, E-mail: ikeda.ryosuke@jaea.go.jp; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Sakamoto, Keishi

2015-10-15

Highlights: • We are under development of TE{sub 31,11} mode gyrotron to aim ITER specification. • HE{sub 11} mode purity reached 96% of ITER specification. • Mode competition was suppressed in initial phase of oscillation by anode voltage control. • Maximum output power of 1.2 MW was achieved. • Steady state operation of 500 MJ was achieved. - Abstract: The ITER electron cyclotron system is designed to inject a 20 MW RF beam by using twenty-four 170 GHz/1 MW gyrotrons. JAEA is currently developing a gyrotron having a high-order mode (TE{sub 31,11}) to reduce the heat load in the cavity resonator and achieve an output power greater than 1 MW. The measured radiation profile at the front of the diamond window agreed with the results of the calculation. In order to suppress RF loss in the equatorial and upper port launchers, a high-quality HE{sub 11} mode is required at the exit of the matching optics unit (MOU). An HE{sub 11} mode purity of 96% was achieved by finely adjusting the two mirrors in the MOU. During the oscillation start-up phase, mode competition with counter-rotating TE{sub 29,12} mode was observed on the higher magnetic field side which caused arcing and pressure increase in the gyrotron. To avoid the counter-rotating TE{sub 29,12} mode from being excited, a start-up scenario that controls the voltage between the anode and cathode electrodes at the initial phase of operation was introduced, which was able to achieve a stable start-up of TE{sub 31,11} mode. A 1.2 MW output power having a total electric efficiency of 43% was obtained in high-power experiments. In steady-state operation, a 1000 s oscillation length and output power of 0.51 MW was achieved.

Tendencies in operating power reactors

International Nuclear Information System (INIS)

Brinckmann, H.F.

1987-01-01

A survey is given about new tendencies in operating power reactors. In order to meet the high demands for control and monitoring of power reactors modern procedures are applicated such as the incore-neutron flux detection by means of electron emission detectors and multi-component activation probes, the noise diagnostics as well as high-efficient automation systems

CEA contribution to power plant operation with high burnup level

International Nuclear Information System (INIS)

1981-03-01

High level burnup in PWR leads to investigate again the choices carried out in the field of fuel management. French CEA has studied the economic importance of reshuffling technique, cycle length, discharge burnup, and non-operation period between two cycles. Power plants operators wish to work with increased length cycles of 18 months instead of 12. That leads to control problems because the core reactivity cannot be controlled with the only soluble boron: moderator temperature coefficient must be negative. With such cycles, it is necessary to use burnable poisons and for economic reasons with a low penalty in end of cycle. CEA has studied the use of Gd 2 O 3 mixed with fuel or with inert element like Al 2 O 3 . Parametric studies of specific weights, efficacities relatively to the fuel burnup and the fuel enrichment have been carried out. Particular studies of 1 month cycles with Gd 2 O 3 have shown the possibility to control power distribution with a very low reactivity penalty in EOC. In the same time, in the 100 MW PWR-CAP, control reactivity has been made with large use of gadolinia in parallel with soluble boron for the two first cycles

Organizing nuclear power plant operation

International Nuclear Information System (INIS)

Adams, H.W.; Rekittke, K.

1987-01-01

With the preliminary culmination in the convoy plants of the high standard of engineered safeguards in German nuclear power plants developed over the past twenty years, the interest of operators has now increasingly turned to problems which had not been in the focus of attention before. One of these problems is the organization of nuclear power plant operation. In order to enlarge the basis of knowledge, which is documented also in the rules published by the Kerntechnischer Ausschuss (Nuclear Technology Committee), the German Federal Minister of the Interior has commissioned a study of the organizational structures of nuclear power plants. The findings of that study are covered in the article. Two representative nuclear power plants in the Federal Republic of Germany were selected for the study, one of them a single-unit plant run by an independent operating company in the form of a private company under German law (GmbH), the other a dual-unit plant operated as a dependent unit of a utility. The two enterprises have different structures of organization. (orig.) [de

Role of check operators in achieving operational excellence at Virginia Power's nuclear stations

International Nuclear Information System (INIS)

Shriver, B.L.; Williams, T.M.; Stewart, W.L.

1987-01-01

Virginia Power has implemented a Check Operator Program as a part of its commitment to excellence in the operation of the North Anna and Surry nuclear power stations. The Check Operator Program utilizes highly qualified licensed personnel to independently evaluate the performance of licensed operators and senior operators during normal, abnormal and simulated emergency conditions. Emphasis is placed upon individual and team performance as well as the procedures and training which support the operators. The check operators report to line management to ensure that their recommendations are implemented into the overall operations philosophy of the power station

Transverse mode instabilities in burst operation of high-power fiber laser systems

Science.gov (United States)

Jauregui, Cesar; Stihler, Christoph; Tünnermann, Andreas; Limpert, Jens

2018-02-01

We propose, to the best of our knowledge, the first mitigation strategy for TMI based on controlling the phase shift between the thermally-induced index grating and the modal intensity pattern. In particular, in this work we present a study of transverse mode instabilities in burst operation in a high-power fiber laser system. It is shown that, with a careful choice of the parameters, this operation regime can potentially lead to the mitigation of TMI by forcing an energy transfer from the higher-order-modes into the fundamental mode during the burst.

Radiological Environmental Protection for LCLS-II High Power Operation

Science.gov (United States)

Liu, James; Blaha, Jan; Cimeno, Maranda; Mao, Stan; Nicolas, Ludovic; Rokni, Sayed; Santana, Mario; Tran, Henry

2017-09-01

The LCLS-II superconducting electron accelerator at SLAC plans to operate at up to 4 GeV and 240 kW average power, which would create higher radiological impacts particularly near the beam loss points such as beam dumps and halo collimators. The main hazards to the public and environment include direct or skyshine radiation, effluent of radioactive air such as 13N, 15O and 41Ar, and activation of groundwater creating tritium. These hazards were evaluated using analytic methods and FLUKA Monte Carlo code. The controls (mainly extensive bulk shielding and local shielding around high loss points) and monitoring (neutron/photon detectors with detection capabilities below natural background at site boundary, site-wide radioactive air monitors, and groundwater wells) were designed to meet the U.S. DOE and EPA, as well as SLAC requirements. The radiological design and controls for the LCW systems [including concrete housing shielding for 15O and 11C circulating in LCW, 7Be and erosion/corrosion products (22Na, 54Mn, 60Co, 65Zn, etc.) captured in resin and filters, leak detection and containment of LCW with 3H and its waste water discharge; explosion from H2 build-up in surge tank and release of radionuclides] associated with the high power beam dumps are also presented.

Cohering power of quantum operations

Energy Technology Data Exchange (ETDEWEB)

Bu, Kaifeng, E-mail: bkf@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China); Kumar, Asutosh, E-mail: asukumar@hri.res.in [Harish-Chandra Research Institute, Chhatnag Road, Jhunsi, Allahabad 211019 (India); Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094 (India); Zhang, Lin, E-mail: linyz@zju.edu.cn [Institute of Mathematics, Hangzhou Dianzi University, Hangzhou 310018 (China); Wu, Junde, E-mail: wjd@zju.edu.cn [School of Mathematical Sciences, Zhejiang University, Hangzhou 310027 (China)

2017-05-18

Highlights: • Quantum coherence. • Cohering power: production of quantum coherence by quantum operations. • Study of cohering power and generalized cohering power, and their comparison for differentmeasures of quantum coherence. • Operational interpretation of cohering power. • Bound on cohering power of a generic quantum operation. - Abstract: Quantum coherence and entanglement, which play a crucial role in quantum information processing tasks, are usually fragile under decoherence. Therefore, the production of quantum coherence by quantum operations is important to preserve quantum correlations including entanglement. In this paper, we study cohering power–the ability of quantum operations to produce coherence. First, we provide an operational interpretation of cohering power. Then, we decompose a generic quantum operation into three basic operations, namely, unitary, appending and dismissal operations, and show that the cohering power of any quantum operation is upper bounded by the corresponding unitary operation. Furthermore, we compare cohering power and generalized cohering power of quantum operations for different measures of coherence.

Design and development of high voltage high power operational ...

Indian Academy of Sciences (India)

address this challenge, a) Designing a discrete power opamp with high .... the use of high-impedance feedback networks, thus minimizing their output loading ... Spice simulation is done for the circuit and results are given in figures 4a–c.

An online Vce measurement and temperature estimation method for high power IGBT module in normal PWM operation

DEFF Research Database (Denmark)

Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

2014-01-01

An on-state collector-emitter voltage (Vce) measurement and thereby an estimation of average temperature in space for high power IGBT module is presented while power converter is in operation. The proposed measurement circuit is able to measure both high and low side IGBT and anti parallel diode...

Preparation and practice for nuclear power plant operation

International Nuclear Information System (INIS)

Wu Xuesong; Lu Tiezhong

2015-01-01

The operational preparation of the nuclear power plant is an important work in nuclear power plant production preparation. Due to the construction period of nuclear power plant from starting construction to production is as long as five years, the professional requirements of nuclear power operation are very strict, and the requirements for nuclear safety are also extremely high. Especially after the Fukushima accident, higher requirements for the safe operation of nuclear power plant are posed by competent authorities of the national level, regulatory authorities and each nuclear power groups. Based on the characteristics of the construction phase of nuclear power plant and in combination with engineering practice, this paper expounds the system established in the field of nuclear power plant operation and generally analyses the related management innovation. (authors)

Radiological Environmental Protection for LCLS-II High Power Operation

Directory of Open Access Journals (Sweden)

Liu James

2017-01-01

Full Text Available The LCLS-II superconducting electron accelerator at SLAC plans to operate at up to 4 GeV and 240 kW average power, which would create higher radiological impacts particularly near the beam loss points such as beam dumps and halo collimators. The main hazards to the public and environment include direct or skyshine radiation, effluent of radioactive air such as 13N, 15O and 41Ar, and activation of groundwater creating tritium. These hazards were evaluated using analytic methods and FLUKA Monte Carlo code. The controls (mainly extensive bulk shielding and local shielding around high loss points and monitoring (neutron/photon detectors with detection capabilities below natural background at site boundary, site-wide radioactive air monitors, and groundwater wells were designed to meet the U.S. DOE and EPA, as well as SLAC requirements. The radiological design and controls for the LCW systems [including concrete housing shielding for 15O and 11C circulating in LCW, 7Be and erosion/corrosion products (22Na, 54Mn, 60Co, 65Zn, etc. captured in resin and filters, leak detection and containment of LCW with 3H and its waste water discharge; explosion from H2 build-up in surge tank and release of radionuclides] associated with the high power beam dumps are also presented.

A battery-powered high-current power supply for superconductors

CERN Document Server

Wake, M; Suda, K

2002-01-01

Since superconductors do not require voltages, a high-current power supply could run with low power if the voltage is sufficiently reduced. Even a battery-powered power supply could give as much as 2,000A for a superconductor. To demonstrate this hypothesis, a battery-powered 2,000A power supply was constructed. It uses an IGBT chopper and Schottky diode together with a specially arranged transformer to produce a high current with low voltage. Testing of 2,000A operation was performed for about 1.5 hr using 10 car batteries. Charging time for this operation was 8 hr. Ramping control was smooth and caused no trouble. Although the IGBT frequency ripple of 16.6 kHz was easily removed using a passive filter, spike noise remained in the output voltage. This ripple did not cause any trouble in operating a pancake-type inductive superconducting load. (author)

Optics assembly for high power laser tools

Science.gov (United States)

Fraze, Jason D.; Faircloth, Brian O.; Zediker, Mark S.

2016-06-07

There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

Operation and control of high power Gyrotrons for ECRH systems in SST-1 and Aditya

Energy Technology Data Exchange (ETDEWEB)

Shukla, B.K., E-mail: shukla@ipr.res.in; Bora, D.; Jha, R.; Patel, Jatin; Patel, Harshida; Babu, Rajan; Dhorajiya, Pragnesh; Dalakoti, Shefali; Purohit, Dharmesh

2016-11-15

Highlights: • Operation and control of high power Gyrotrons. • Data acquisition and control (DAQ) for Gyrotron system. • Ignitron based crowbar protection. • VME and PXI based systems. - Abstract: The Electron Cyclotron Resonance Heating (ECRH) system is an important heating system for the reliable start-up of tokamak. The 42 GHz and 82.6 GHz ECRH systems are used in tokamaks SST-1 and Aditya to carry out ECRH related experiments. The Gyrotrons are high power microwave tubes used as a source for ECRH systems. The Gyrotron is a delicate microwave tube, which deliver megawatt level power at very high voltage ∼40–50 kV with the current requirement ∼10 A–50 A. The Gyrotrons are associated with the subsystems like: High voltage power supplies (Beam voltage and anode voltage), dedicated crowbar system, magnet, filament and ion pump power supplies, cooling, interlocks and a dedicated data acquisition & control (DAC) system. There are two levels of interlocks used for the protection of Gyrotron: fast interlocks (arcing, beam over current, dI/dt, anode voltage and anode over current etc.) operate within 10 μs and slow interlocks (cooling, filament, silence of Gyrotron, ion pump and magnet currents) operate within 100 ms. Two Gyrotrons (42 GHz/500 kW/500 ms and 82.6 GHz/200 kW/1000 s) have been commissioned on dummy load for full parameters. The 42 GHz ECRH system has been integrated with SST-1 & Aditya tokamak and various experiments have been carried out related to ECRH assisted breakdown and start-up of tokamak at fundamental and second harmonic. These Gyrotrons are operated with VME based data acquisition and control (DAC) system. The DAC system is capable to acquire 64 digital and 32 analog signals. The system is used to monitor & acquire the data and also used for slow interlocks for the protection of Gyrotron. The data acquired from the system are stored online on VME system and after the shot stored in a file in binary format. The MDSPlus, a set of

Operator support system for nuclear power plants

International Nuclear Information System (INIS)

Mori, Nobuyuki; Tai, Ichiro; Sudo, Osamu; Naito, Norio.

1987-01-01

The nuclear power generation in Japan maintains the high capacity factor, and its proportion taken in the total generated electric power exceeded 1/4, thus it has become the indispensable energy source. Recently moreover, the nuclear power plants which are harmonious with operators and easy to operate are demanded. For realizing this, the technical development such as the heightening of operation watching performance, the adoption of automation, and the improvement of various man-machine systems for reducing the burden of operators has been advanced by utilizing electronic techniques. In this paper, the trend of the man-machine systems in nuclear power plants, the positioning of operation support system, the support in the aspects of information, action and knowledge, the example of a new central control board, the operation support system using a computer, an operation support expert system and the problems hereafter are described. As the development of the man-machine system in nuclear power plants, the upgrading from a present new central control board system PODIA through A-PODIA, in which the operational function to deal with various phenomena arising in plants and safety control function are added, to 1-PODIA, in which knowledge engineering technology is adopted, is expected. (Kako, I.)

Method to operate power reactors with light water cooling

International Nuclear Information System (INIS)

Aleite, W.; Bock, H.W.

1976-01-01

The invention provides a possibility to 'condition' the fuel of a power plant used in base load operation, i.e. to bring it to such a high power density level that the local excesses arising with the occasional total power changes, remain below the power densities reached in normal operation (conditioning level). (orig./RW) [de

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

Energy Technology Data Exchange (ETDEWEB)

Hillairet, Julien, E-mail: julien.hillairet@cea.fr; Mollard, Patrick; Bernard, Jean-Michel; Argouarch, Arnaud; Berger-By, Gilles; Charabot, Nicolas; Colas, Laurent; Delaplanche, Jean-Marc; Ekedahl, Annika; Fedorczak, Nicolas; Ferlay, Fabien; Goniche, Marc; Hatchressian, Jean-Claude; Helou, Walid; Jacquot, Jonathan; Joffrin, Emmanuel; Litaudon, Xavier; Lombard, Gilles; Magne, Roland; Patterlini, Jean-Claude [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France); and others

2015-12-10

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

High-intensity power-resolved radiation imaging of an operational nuclear reactor.

Science.gov (United States)

Beaumont, Jonathan S; Mellor, Matthew P; Villa, Mario; Joyce, Malcolm J

2015-10-09

Knowledge of the neutron distribution in a nuclear reactor is necessary to ensure the safe and efficient burnup of reactor fuel. Currently these measurements are performed by in-core systems in what are extremely hostile environments and in most reactor accident scenarios it is likely that these systems would be damaged. Here we present a compact and portable radiation imaging system with the ability to image high-intensity fast-neutron and gamma-ray fields simultaneously. This system has been deployed to image radiation fields emitted during the operation of a TRIGA test reactor allowing a spatial visualization of the internal reactor conditions to be obtained. The imaged flux in each case is found to scale linearly with reactor power indicating that this method may be used for power-resolved reactor monitoring and for the assay of ongoing nuclear criticalities in damaged nuclear reactors.

The characterization of secondary lithium-ion battery degradation when operating complex, ultra-high power pulsed loads

Science.gov (United States)

Wong, Derek N.

The US Navy is actively developing all electric fleets, raising serious questions about what is required of onboard power supplies in order to properly power the ship's electrical systems. This is especially relevant when choosing a viable power source to drive high power propulsion and electric weapon systems in addition to the conventional loads deployed aboard these types of vessels. Especially when high pulsed power loads are supplied, the issue of maintaining power quality becomes important and increasingly complex. Conventionally, a vessel's electrical power is generated using gas turbine or diesel driven motor-generator sets that are very inefficient when they are used outside of their most efficient load condition. What this means is that if the generator is not being utilized continuously at its most efficient load capacity, the quality of the output power may also be effected and fall outside of the acceptable power quality limits imposed through military standards. As a solution to this potential problem, the Navy has proposed using electrochemical storage devices since they are able to buffer conventional generators when the load is operating below the generator's most efficient power level or able to efficiently augment a generator when the load is operating in excess of the generator's most efficient power rating. Specifically, the US Navy is interested in using commercial off-the-shelf (COTS) lithium-ion batteries within an intelligently controlled energy storage module that could act as either a prime power supply for on-board pulsed power systems or as a backup generator to other shipboard power systems. Due to the unique load profile of high-rate pulsed power systems, the implementation of lithium-ion batteries within these complex systems requires them to be operated at very high rates and the effects these things have on cell degradation has been an area of focus. There is very little published research into the effects that high power transient

High-power LED light sources for optical measurement systems operated in continuous and overdriven pulsed modes

Science.gov (United States)

Stasicki, Bolesław; Schröder, Andreas; Boden, Fritz; Ludwikowski, Krzysztof

2017-06-01

The rapid progress of light emitting diode (LED) technology has recently resulted in the availability of high power devices with unprecedented light emission intensities comparable to those of visible laser light sources. On this basis two versatile devices have been developed, constructed and tested. The first one is a high-power, single-LED illuminator equipped with exchangeable projection lenses providing a homogenous light spot of defined diameter. The second device is a multi-LED illuminator array consisting of a number of high-power LEDs, each integrated with a separate collimating lens. These devices can emit R, G, CG, B, UV or white light and can be operated in pulsed or continuous wave (CW) mode. Using an external trigger signal they can be easily synchronized with cameras or other devices. The mode of operation and all parameters can be controlled by software. Various experiments have shown that these devices have become a versatile and competitive alternative to laser and xenon lamp based light sources. The principle, design, achieved performances and application examples are given in this paper.

Modeling Control Situations in Power System Operations

DEFF Research Database (Denmark)

Saleem, Arshad; Lind, Morten; Singh, Sri Niwas

2010-01-01

for intelligent operation and control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack...... of explicit principles for model construction. This paper presents a work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents. An example of power system......Increased interconnection and loading of the power system along with deregulation has brought new challenges for electric power system operation, control and automation. Traditional power system models used in intelligent operation and control are highly dependent on the task purpose. Thus, a model...

Nuclear power plant operation experience - a feedback programme

International Nuclear Information System (INIS)

Banica, I.; Sociu, F.; Margaritescu, C.

1994-01-01

An effective high quality maintenance programme is required for the safe reliable operation of a nuclear power plant. To achieve the objectives of such a programme, both plant management and staff must be highly dedicated and motivated to perform high quality work at all levels. Operating and maintenance experience data collections and analysis are necessary in order to enhance the safety of the plant and reliability of the structures systems and components throughout their operating life. Significant events, but also minor incident, may reveal important deficiencies or negative trends adverse to safety. Therefore, a computer processing system for collecting, classifying and evaluating abnormal events or findings concerning operating-maintenance and for feeding back the results of the lessons learned from experience into the design and the operation of our nuclear power plant is considered to be of paramount importance. (Author)

Novel packaging for CW and QCW diode laser modules for operation with high power and duty cycles

Science.gov (United States)

Fassbender, Wilhelm; Lotz, Jens; Kissel, Heiko; Biesenbach, Jens

2018-02-01

Continuous wave (CW) and quasi-continuous wave (QCW) operated diode laser bars and arrays have found a wide range of industrial, medical, scientific, military and space applications with a broad variety in wavelength, pulse energy, pulse duration and beam quality. Recent applications require even higher power, duty cycles and power density. The heat loss will be dissipated by conductive cooling or liquid cooling close to the bars. We present the latest performance and reliability data of two novel high-brightness CW and QCW arrays of customized and mass-production modules, in compact and robust industry design for operation with high power and high duty cycles. All designs are based on single diode packages consisting of 10mm laser bars, soft or hard soldered between expansion matched submounts. The modular components cover a wide span of designs which differ basically in water/conduction (active/passive) cooled, single, linear (horizontal and vertical) arranged designs, as well as housed and unhoused modules. The different assembling technologies of active and passive cooled base plates affect the heat dissipation and therefore the reachable power at different QCW operating conditions, as well as the lifetime. As an example, a package consisting of 8 laser diodes, connected to a 28.8*13.5*7.0mm3 DCB (direct copper bonded) submount, passively or actively cooled is considered. This design is of particular interest for mobile applications seamless module to module building system, with an infinite number of laser bars at 1.7mm pitch. Using 940nm bars we can reach an optical output power per bar of 450W at 25°C base plate temperature with 10Hz, 1.2% duty cycle and 1.2ms pulse duration. As an additional example, micro channel coolers can be vertically stacked up to 50 diodes with a 1,15mm pitch. This design is suitable for all applications, demanding also compactness and light weight and high power density. Using near infrared bars and others, we can reach an optical

Pulsed operation of high-power light emitting diodes for imaging flow velocimetry

International Nuclear Information System (INIS)

Willert, C; Klinner, J; Moessner, S; Stasicki, B

2010-01-01

High-powered light emitting diodes (LED) are investigated for possible uses as light sources in flow diagnostics, in particular, as an alternative to laser-based illumination in particle imaging flow velocimetry in side-scatter imaging arrangements. Recent developments in solid state illumination resulted in mass-produced LEDs that provide average radiant power in excess of 10 W. By operating these LEDs with short duration, pulsed currents that are considerably beyond their continuous current damage threshold, light pulses can be generated that are sufficient to illuminate and image micron-sized particles in flow velocimetry. Time-resolved PIV measurements in water at a framing rate of 2kHz are presented. The feasibility of LED-based PIV measurements in air is also demonstrated

High-power klystrons

Science.gov (United States)

Siambis, John G.; True, Richard B.; Symons, R. S.

1994-05-01

Novel emerging applications in advanced linear collider accelerators, ionospheric and atmospheric sensing and modification and a wide spectrum of industrial processing applications, have resulted in microwave tube requirements that call for further development of high power klystrons in the range from S-band to X-band. In the present paper we review recent progress in high power klystron development and discuss some of the issues and scaling laws for successful design. We also discuss recent progress in electron guns with potential grading electrodes for high voltage with short and long pulse operation via computer simulations obtained from the code DEMEOS, as well as preliminary experimental results. We present designs for high power beam collectors.

High-power semiconductor RSD-based switch

Energy Technology Data Exchange (ETDEWEB)

Bezuglov, V G; Galakhov, I V; Grusin, I A [All-Russian Scientific Research Inst. of Experimental Physics, Sarov (Russian Federation); and others

1997-12-31

The operating principle and test results of a high-power semiconductor RSD-based switch with the following operating parameters is described: operating voltage 25 kV, peak operating current 200 kA, maximum transferred charge 70 C. The switch is intended for use by high-power capacitor banks of state-of-the-art research facilities. The switch was evaluated for applicability in commercial pulsed systems. The possibility of increasing the peak operating current to 500 kA is demonstrated. (author). 4 figs., 2 refs.

High Power Density Power Electronic Converters for Large Wind Turbines

DEFF Research Database (Denmark)

Senturk, Osman Selcuk

. For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

Centralized operation and monitoring system for nuclear power plants

International Nuclear Information System (INIS)

Kudo, Mitsuru; Sato, Hideyuki; Murata, Fumio

1988-01-01

According to the prospect of long term energy demand, in 2000, the nuclear power generation facilities in Japan are expected to take 15.9% of the total energy demand. From this fact, it is an important subject to supply nuclear power more stably, and in the field of instrumentation and control, many researches and developments and the incessant effort of improvement have been continued. In the central operation and monitoring system which is the center of the stable operation of nuclear power plants, the man-machine technology aiding operators by electronic and computer application technologies has been positively developed and applied. It is considered that hereafter, for the purpose of rationally heightening the operation reliability of the plants, the high quality man-machine system freely using the most advanced technologies such as high reliability digital technology, optical information transmission, knowledge engineering and so on is developed and applied. The technical trend of operation and monitoring system, the concept of heightening operation and monitoring capability, the upgrading of operation and monitoring system, and the latest operation, monitoring and control systems for nuclear power plants and waste treatment facilities are described. (K.I.)

High average power solid state laser power conditioning system

International Nuclear Information System (INIS)

Steinkraus, R.F.

1987-01-01

The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers

Improving Reliability of High Power Quasi-CW Laser Diode Arrays Operating in Long Pulse Mode

Science.gov (United States)

Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.

2006-01-01

Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data of the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.

Tianwan nuclear power plant operation and management practices

International Nuclear Information System (INIS)

Gu Yingbing

2010-01-01

Tianwan Nuclear Power Station is a high-tech cooperation project in nuclear sector in the spirit of promoting the political relationship, economic trading and international strategic partnership between China and Russia. It was listed as one of the key nuclear projects to be constructed during the 'Ninth Five-Year' Plan. In this article the author summarizes and feedbacks the practices of operation management in Tianwan Nuclear Power Station in 7 aspects of safety culture construction, operation team building, daily operation management, operation document management, plant chemistry control and management, solid, liquid and gaseous waste management and control of operation performance indicators. (author)

Ferrite-free high power electrodeless fluorescent lamp operated at a frequency of 160-1000 kHz

International Nuclear Information System (INIS)

Popov, Oleg A; Chandler, Robert

2002-01-01

An electrodeless ferrite-free fluorescent lamp of a closed-loop type ('tokamak') was studied at a driving frequency, f = 160-1000 kHz, and power of 100-250 W. The inductive discharge was ignited in the mercury-argon mixture with the help of an induction coil of several (7-15) turns made from multiple-strand (Litz) wire. The discharge parameters - current, resistance, and electric field - were calculated using the transformer model of an RF inductive discharge. They were found to be close to those measured in a plasma of a 'tokamak'-type lamp operated at the same frequency and RF power but with the use of the ferrite cores. The ferrite-free lamp had high luminous efficacy as high as 85 LPW at a frequency, f>200 kHz, and power of 100-200 W. Such a high efficacy is attributed to low coil power losses ( 90%

14 CFR 27.695 - Power boost and power-operated control system.

Science.gov (United States)

2010-01-01

... Systems § 27.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

14 CFR 29.695 - Power boost and power-operated control system.

Science.gov (United States)

2010-01-01

... Systems § 29.695 Power boost and power-operated control system. (a) If a power boost or power-operated... failure of all engines. (b) Each alternate system may be a duplicate power portion or a manually operated... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Power boost and power-operated control...

Integrated operation and management system for a 700MW combined cycle power plant

Energy Technology Data Exchange (ETDEWEB)

Shiroumaru, I. (Yanai Power Plant Construction Office, Chugoku Electric Power Co., Inc., 1575-5 Yanai-Miyamoto-Shiohama, Yanai-shi, Yamaguchi-ken (JP)); Iwamiya, T. (Omika Works, Hitachi, Ltd., 5-2-1 Omika-cho, Hitachi-shi, Ibaraki-ken (JP)); Fukai, M. (Hitachi Works, Hitachi, Ltd., 3-1-1 Saiwai-cho, Hitachi-shi, Ibaraki-ken (JP))

1992-03-01

Yanai Power Plant of the Chugoku Electric Power Co., Inc. (Yamaguchi Pref., Japan) is in the process of constructing a 1400MW state-of-the-art combined cycle power plant. The first phase, a 350MW power plant, started operation on a commercial basis in November, 1990. This power plant has achieved high efficiency and high operability, major features of a combined cycle power plant. The integrated operation and management system of the power plant takes care of operation, maintenance, control of general business, etc., and was built using the latest computer and digital control and communication technologies. This paper reports that it is expected that this system will enhance efficient operation and management for the power plant.

Operator training simulator for BWR nuclear power plant

International Nuclear Information System (INIS)

Watanabe, Tadasu

1988-01-01

For the operation management of nuclear power stations with high reliability and safety, the role played by operators is very important. The effort of improving the man-machine interface in the central control rooms of nuclear power stations is energetically advanced, but the importance of the role of operators does not change. For the training of the operators of nuclear power stations, simulators have been used from the early stage. As the simulator facilities for operator training, there are the full scope simulator simulating faithfully the central control room of an actual plant and the small simulator mainly aiming at learning the plant functions. For BWR nuclear power stations, two full scope simulators are installed in the BWR Operator Training Center, and the training has been carried out since 1974. The plant function learning simulators have been installed in respective electric power companies as the education and training facilities in the companies. The role of simulators in operator training, the BTC No.1 simulator of a BWR-4 of 780 MWe and the BTC No.2 simulator of a BWR-5 of 1,100 MWe, plant function learning simulators, and the design of the BTC No.2 simulator and plant function learning simulators are reported. (K.I.)

Applications of high power microwaves

International Nuclear Information System (INIS)

Benford, J.; Swegle, J.

1993-01-01

The authors address a number of applications for HPM technology. There is a strong symbiotic relationship between a developing technology and its emerging applications. New technologies can generate new applications. Conversely, applications can demand development of new technological capability. High-power microwave generating systems come with size and weight penalties and problems associated with the x-radiation and collection of the electron beam. Acceptance of these difficulties requires the identification of a set of applications for which high-power operation is either demanded or results in significant improvements in peRFormance. The authors identify the following applications, and discuss their requirements and operational issues: (1) High-energy RF acceleration; (2) Atmospheric modification (both to produce artificial ionospheric mirrors for radio waves and to save the ozone layer); (3) Radar; (4) Electronic warfare; and (5) Laser pumping. In addition, they discuss several applications requiring high average power than border on HPM, power beaming and plasma heating

High-field, high-density tokamak power reactor

International Nuclear Information System (INIS)

Cohn, D.R.; Cook, D.L.; Hay, R.D.; Kaplan, D.; Kreischer, K.; Lidskii, L.M.; Stephany, W.; Williams, J.E.C.; Jassby, D.L.; Okabayashi, M.

1977-11-01

A conceptual design of a compact (R 0 = 6.0 m) high power density (average P/sub f/ = 7.7 MW/m 3 ) tokamak demonstration power reactor has been developed. High magnetic field (B/sub t/ = 7.4 T) and moderate elongation (b/a = 1.6) permit operation at the high density (n(0) approximately 5 x 10 14 cm -3 ) needed for ignition in a relatively small plasma, with a spatially-averaged toroidal beta of only 4%. A unique design for the Nb 3 Sn toroidal-field magnet system reduces the stress in the high-field trunk region, and allows modularization for simpler disassembly. The modest value of toroidal beta permits a simple, modularized plasma-shaping coil system, located inside the TF coil trunk. Heating of the dense central plasma is attained by the use of ripple-assisted injection of 120-keV D 0 beams. The ripple-coil system also affords dynamic control of the plasma temperature during the burn period. A FLIBE-lithium blanket is designed especially for high-power-density operation in a high-field environment, and gives an overall tritium breeding ratio of 1.05 in the slowly pumped lithium

Nuclear power plant operator licensing

International Nuclear Information System (INIS)

1997-01-01

The guide applies to the nuclear power plant operator licensing procedure referred to the section 128 of the Finnish Nuclear Energy Degree. The licensing procedure applies to shift supervisors and those operators of the shift teams of nuclear power plant units who manipulate the controls of nuclear power plants systems in the main control room. The qualification requirements presented in the guide also apply to nuclear safety engineers who work in the main control room and provide support to the shift supervisors, operation engineers who are the immediate superiors of shift supervisors, heads of the operational planning units and simulator instructors. The operator licensing procedure for other nuclear facilities are decided case by case. The requirements for the basic education, work experience and the initial, refresher and complementary training of nuclear power plant operating personnel are presented in the YVL guide 1.7. (2 refs.)

High power CW linac in PNC

International Nuclear Information System (INIS)

Toyama, S.; Wang, Y.L.; Emoto, T.

1994-01-01

Power Reactor and Nuclear Fuel Development Corporation (PNC) is developing a high power electron linac for various applications. The electron beam is accelerated in CW operation to get maximum beam current of 100 mA and energy of 10 MeV. Crucial components such as a high power L-band klystron and a high power traveling wave resonant ring (TWRR) accelerator guides were designed and manufactured and their performance were examined. These design and results from the recent high power RF tests were described in this paper. (author)

CW operation of high-power blue laser diodes with polished facets on semi-polar ( 20 2 ¯ 1 ¯ ) GaN substrates

KAUST Repository

Pourhashemi, A.

2016-10-11

Continuous wave (CW) operation of high-power blue laser diodes (LDs) with polished facets on semi-polar (202̅1̅) gallium nitride (GaN) substrates is demonstrated. Ridge waveguide LDs were fabricated using indium GaN waveguiding layers and GaN cladding layers. At a lasing wavelength of 452 nm, the peak two-facet CW output power from an LD with uncoated facets was 1.71 W at a current of 3 A, corresponding to an optical power density of 32.04 MW/cm2 on each facet. The dependence of output power on current did not change with repeated CW measurements, indicating that the polished facets did not degrade under high-power CW operation. These results show that polished facets are a viable alternative to cleaved or etched facets for high-power CW semi-polar LDs.

CW operation of high-power blue laser diodes with polished facets on semi-polar ( 20 2 ¯ 1 ¯ ) GaN substrates

KAUST Repository

Pourhashemi, A.; Farrell, R.M.; Cohen, D.A.; Becerra, D.L.; DenBaars, S.P.; Nakamura, S.

2016-01-01

Continuous wave (CW) operation of high-power blue laser diodes (LDs) with polished facets on semi-polar (202̅1̅) gallium nitride (GaN) substrates is demonstrated. Ridge waveguide LDs were fabricated using indium GaN waveguiding layers and GaN cladding layers. At a lasing wavelength of 452 nm, the peak two-facet CW output power from an LD with uncoated facets was 1.71 W at a current of 3 A, corresponding to an optical power density of 32.04 MW/cm2 on each facet. The dependence of output power on current did not change with repeated CW measurements, indicating that the polished facets did not degrade under high-power CW operation. These results show that polished facets are a viable alternative to cleaved or etched facets for high-power CW semi-polar LDs.

CALCULATION OF OPERATING PARAMETERS OF HIGH-VOLTAGE POWER TAKE-OFF SYSTEM FOR THE PHOTOVOLTAIC FACILITY

Directory of Open Access Journals (Sweden)

R.V. Zaitsev

2016-09-01

Full Text Available Purpose. To ensure maximum production of electric power by photovoltaic vacilities, in addition to using highly efficient photovoltaic modules equipped with solar radiation concentrators must use a highly effective power take-off system. This paper is inscribed to solving the problem of a highly efficient and economic power take-off system development. Methodology. To solving the problem, we implemented three stages. On the first stage examines the dependence of electrical power from the intensity of the incident solar radiation. Based on this, the second stage is calculated the DC-DC converter resonant circuit and its working parameters, and developed circuit diagram of DC-DC converter. On the third stage, we carry out an analysis of power take-off system with step up DC-DC converter working. Results. In this paper, we carry out the analysis of working efficiency for photovoltaic facility power take-off system with step-up boost converter. The result of such analysis show that the efficiency of such system in a wide range of photovoltaic energy module illumination power is at 0.92, whereas the efficiency of classic power take-off systems does not exceed 0.70. Achieved results allow designing a circuit scheme of a controlled bridge resonant step-up converter with digital control. Proposed scheme will ensure reliable operation, fast and accurate location point of maximum power and conversion efficiency up to 0.96. Originality. Novelty of proposed power take-off system solution constitute in implementation of circuit with DC-DC converters, which as it shown by results of carrying out modeling is the most effective. Practical value. Practical implementation of proposed power take-off system design will allow reducing losses in connective wires and increasing the efficiency of such a system up to 92.5% in wide range of photovoltaic energy modules illumination.

Advanced High Voltage Power Device Concepts

CERN Document Server

Baliga, B Jayant

2012-01-01

Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

High-feedback Operation of Power Electronic Converters

DEFF Research Database (Denmark)

Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Andriyanov, Alexey I.

2013-01-01

The purpose of this review is to provide a survey of some of the most important bifurcation phenomena that one can observe in pulse-modulated converter systems when operating with high corrector gain factors. Like other systems with switching control, electronic converter systems belong...... to the class of piecewise-smooth dynamical systems. A characteristic feature of such systems is that the trajectory is “sewed” together from subsequent discrete parts. Moreover, the transitions between different modes of operation in response to a parameter variation are often qualitatively different from...

Atomic power plant and its operation method

International Nuclear Information System (INIS)

Yamamoto, Fumiaki; Higashio, Satoru.

1986-01-01

Purpose: To improve operation performance by partially restraining local over power in the axial power distribution of the reactor core by properly controlling the reactor pressure and furthermore by smoothly and properly performing reactor start-up operation in a short time while maintaining fuel integrity. Method: With the reactor pressure input to the pressure controller from the pressure detector, the valve opening of the main steam adjusting valve is adjusted so that the pressure will decrease when the reactor is started up. Also the adjusting valve is controlled so that the pressure will be lower than the set value of rated pressure, thus changing the axial distribution of void. In the meantime, with the stored state of xenon stored along with the increase of reactor power taken into consideration, the reactor pressure is increased as high as the rated value until the reactor power reaches to the rated power, thereby alleviating the local increase of reactor power without changing the whole reactor power and also enabling substantial reduction of reactor start-up time while maintaining reactor integrity. (Horiuchi, T.)

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2001-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

Aiding operator performance at low power feedwater control

International Nuclear Information System (INIS)

Woods, D.D.

1986-01-01

Control of the feedwater system during low power operations (approximately 2% to 30% power) is a difficult task where poor performance (excessive trips) has a high cost to utilities. This paper describes several efforts in the human factors aspects of this task that are underway to improve feedwater control. A variety of knowledge acquisition techniques have been used to understand the details of what makes feedwater control at low power difficult and what knowledge and skill distinguishes expert operators at this task from less experienced ones. The results indicate that there are multiple factors that contribute to task difficulty

47 CFR 73.751 - Operating power.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Operating power. 73.751 Section 73.751... International Broadcast Stations § 73.751 Operating power. No international broadcast station shall be authorized to install, or be licensed for operation of, transmitter equipment with: (a) A rated carrier power...

Overview on the high power excimer laser technology

Science.gov (United States)

Liu, Jingru

2013-05-01

High power excimer laser has essential applications in the fields of high energy density physics, inertial fusion energy and industry owing to its advantages such as short wavelength, high gain, wide bandwidth, energy scalable and repetition operating ability. This overview is aimed at an introduction and evaluation of enormous endeavor of the international high power excimer laser community in the last 30 years. The main technologies of high power excimer laser are reviewed, which include the pumping source technology, angular multiplexing and pulse compressing, beam-smoothing and homogenous irradiation, high efficiency and repetitive operation et al. A high power XeCl laser system developed in NINT of China is described in detail.

Efficient high power operation of erbium 3 µm fibre laser diode-pumped at 975 nm

NARCIS (Netherlands)

Jackson, S.D.; King, T.A.; Pollnau, Markus

2000-01-01

Efficient CW operation of a 2.71 um Er,Pr:ZBLAN double-clad fibre laser pumped with a single diode laser operating at a wavelength of 975 nm is described. A maximum output power of 0.5 W and a slope efficiency of 25% (with respect to the launched pump power) were obtained. Threshold pump powers of <

The operating staff of nuclear power plants

International Nuclear Information System (INIS)

Schlegel, G.; Christ, W.

1988-01-01

The training of its staff is one of the pillars of the safe and economical operation of a power plant. This is why power plant owners began to systematically train their staff already in the 50s, and why they created central training facilities. Staff members who have undergone this training make an indispensable contribution to the acceptedly high safety and availability of German power plants. The substantial cost of creating training facilities and of schooling plant staff is considered to be an investment for the future. Low labour turnover permits careful observation and development of staff and leads to a high standard of knowledge and experience. (orig./HSCH) [de

Licensing operators for commercial nuclear power plants

International Nuclear Information System (INIS)

Hannon, J.N.

1988-01-01

The human element in the operation of commercial nuclear power plants is of utmost importance. Not only must the operators be technically competent in the execution of numerous complicated tasks, they must be capable of working together as a team to diagnose dynamic plant conditions to ensure that their plants are operated safely. The significance of human interaction skills and crew communications has been demonstrated most vividly in TMI and Chernobyl. It follows that the NRC must retain its high standards for licensing operators. This paper discusses activities and initiatives being employed by the NRC to enhance the reliability of its licensing examinations, and to build a highly qualified examiner work force

Operation of a CW high power RFQ test cavity: The CRNL 'sparkers'

International Nuclear Information System (INIS)

Hutcheon, R.M.; Schriber, S.O.; Brown, J.C.; Clements, D.W.; Campbell, H.F.; McMichael, G.E.; De Jong, M.S.

1984-01-01

A 270 MHz RFQ structure with 365 mm long unmodulated vanes and a 2.5 mm minimum vane-to-vane gap was used to study cw operation at surface fields in excess of 30 MV/m. The brazed OFHC solid copper structure is flood cooled and couples rf power by a drive 100p at the centre of one quadrant. Surface electric fields equivalent to twice the Kilpatrick limit were obtained at 39 kW power. The structure was rapidly conditioned with alternating periods of pulsed and cw operation to levels above 45 kW. Bremsstrahlung end point energies were used as a measure of peak vane-to-vane voltage. Several interesting observations have been made. Glowing pinpoints of light were seen near the vane tips, some extinguishing with time, others appearing - but their number and intensity increasing with rf power. Microdischarges were seen, consisting of very small localized flashes of light between the vane tips, usually accompanied by a complete collapse and re-establishment of the structure rf field over a 20 μs interval. The frequency of field collapses varied with power but was independent of gas pressure and species up to 4x10 -3 Pa. As structure power was increased above the conditioned level, a rapid succession of microdischarges would occur, increasing the reflected power beyond the fast trip level. (orig.)

The 77 K operation of a multi-resonant power converter

Science.gov (United States)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

The liquid-nitrogen temperature (77 K) operation of a 55 W, 200 kHz, 48/28 V zero-voltage switching multi-resonant dc/dc converter designed with commercially available components is reported. Upon dipping the complete converter (power and control circuits) into liquid-nitrogen, the converter performance improved as compared to the room-temperature operation. The switching frequency, resonant frequency, and the characteristic impedance did not change significantly. Accordingly, the zero-voltage switching was maintained from no-load to full-load for the specified line variations. Cryoelectronics can provide high density power converters, especially for high power applications.

Thermal power plant design and operation

CERN Document Server

Sarkar, Dipak

2015-01-01

Thermal Power Plant: Design and Operation deals with various aspects of a thermal power plant, providing a new dimension to the subject, with focus on operating practices and troubleshooting, as well as technology and design. Its author has a 40-long association with thermal power plants in design as well as field engineering, sharing his experience with professional engineers under various training capacities, such as training programs for graduate engineers and operating personnel. Thermal Power Plant presents practical content on coal-, gas-, oil-, peat- and biomass-fueled thermal power

Research & Implementation of AC - DC Converter with High Power Factor & High Efficiency

Directory of Open Access Journals (Sweden)

Hsiou-Hsian Nien

2014-05-01

Full Text Available In this paper, we design and develop a high power factor, high efficiency two-stage AC - DC power converter. This paper proposes a two-stage AC - DC power converter. The first stage is boost active power factor correction circuit. The latter stage is near constant frequency LLC resonant converter. In addition to traditional LLC high efficiency advantages, light-load conversion efficiency of this power converter can be improved. And it possesses high power factor and near constant frequency operating characteristics, can significantly reduce the electromagnetic interference. This paper first discusses the main structure and control manner of power factor correction circuit. And then by the LLC resonant converter equivalent model proceed to circuit analysis to determine the important parameters of the converter circuit elements. Then design a variable frequency resonant tank. The resonant frequency can change automatically on the basis of the load to reach near constant frequency operation and a purpose of high efficiency. Finally, actually design and produce an AC – DC power converter with output of 190W to verify the characteristics and feasibility of this converter. The experimental results show that in a very light load (9.5 W the efficiency is as high as 81%, the highest efficiency of 88% (90 W. Full load efficiency is 87%. At 19 W ~ 190 W power changes, the operating frequency change is only 0.4 kHz (AC 110 V and 0.3 kHz (AC 220 V.

Suppression of multipacting in high power RF couplers operating with superconducting cavities

Energy Technology Data Exchange (ETDEWEB)

Ostroumov, P.N., E-mail: ostroumov@frib.msu.edu [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States); Kazakov, S. [Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Morris, D.; Larter, T.; Plastun, A.S.; Popielarski, J.; Wei, J.; Xu, T. [Facility for Rare Isotope Beams (FRIB), Michigan State University, East Lansing, MI 48824 (United States)

2017-06-01

Capacitive input couplers based on a 50 Ω coaxial transmission line are frequently used to transmit RF power to superconducting (SC) resonators operating in CW mode. It is well known that coaxial transmission lines are prone to multipacting phenomenon in a wide range of RF power level and operating frequency. The Facility for Rare Isotope Beams (FRIB) being constructed at Michigan State University includes two types of quarter wave SC resonators (QWR) operating at 80.5 MHz and two types of half wave SC resonators (HWR) operating at 322 MHz. As was reported in ref. [1] a capacitive input coupler used with HWRs was experiencing strong multipacting that resulted in a long conditioning time prior the cavity testing at design levels of accelerating fields. We have developed an insert into 50 Ω coaxial transmission line that provides opportunity to bias the RF coupler antenna and protect the amplifier from the bias potential in the case of breakdown in DC isolation. Two of such devices have been built and are currently used for the off-line testing of 8 HWRs installed in the cryomodule.

Review of Power System Stability with High Wind Power Penetration

DEFF Research Database (Denmark)

Hu, Rui; Hu, Weihao; Chen, Zhe

2015-01-01

analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

HIGH AVERAGE POWER OPTICAL FEL AMPLIFIERS

International Nuclear Information System (INIS)

2005-01-01

Historically, the first demonstration of the optical FEL was in an amplifier configuration at Stanford University [l]. There were other notable instances of amplifying a seed laser, such as the LLNL PALADIN amplifier [2] and the BNL ATF High-Gain Harmonic Generation FEL [3]. However, for the most part FELs are operated as oscillators or self amplified spontaneous emission devices. Yet, in wavelength regimes where a conventional laser seed can be used, the FEL can be used as an amplifier. One promising application is for very high average power generation, for instance FEL's with average power of 100 kW or more. The high electron beam power, high brightness and high efficiency that can be achieved with photoinjectors and superconducting Energy Recovery Linacs (ERL) combine well with the high-gain FEL amplifier to produce unprecedented average power FELs. This combination has a number of advantages. In particular, we show that for a given FEL power, an FEL amplifier can introduce lower energy spread in the beam as compared to a traditional oscillator. This properly gives the ERL based FEL amplifier a great wall-plug to optical power efficiency advantage. The optics for an amplifier is simple and compact. In addition to the general features of the high average power FEL amplifier, we will look at a 100 kW class FEL amplifier is being designed to operate on the 0.5 ampere Energy Recovery Linac which is under construction at Brookhaven National Laboratory's Collider-Accelerator Department

Technical support for nuclear power operations

International Nuclear Information System (INIS)

1999-04-01

This report prepared by the group of senior experts from nuclear operating organizations in Member states, addresses the problem of improving the operating performance of nuclear power plants. Safe and reliable operation is essential for strengthening the viability of nuclear power in the increasingly competitive market of electric power. Basic principles and requirements concerning technical procedures and developed practices are discussed. Report reflects the best current international practices and presents those management initiatives that go beyond the mandated regulatory compliance and could lead to enhancement od operational safety and improved plant performance. By correlating experiences and presenting collective effective practices it is meant to assist nuclear power plant managers in achieving improvement in operation through the contribution of effective technical support

High power tests of an electroforming cavity operating at 11.424 GHz

Science.gov (United States)

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

2016-03-01

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

The NASA CSTI High Capacity Power Project

International Nuclear Information System (INIS)

Winter, J.; Dudenhoefer, J.; Juhasz, A.; Schwarze, G.; Patterson, R.; Ferguson, D.; Schmitz, P.; Vandersande, J.

1992-01-01

This paper describes the elements of NASA's CSTI High Capacity Power Project which include Systems Analysis, Stirling Power Conversion, Thermoelectric Power Conversion, Thermal Management, Power Management, Systems Diagnostics, Environmental Interactions, and Material/Structural Development. Technology advancement in all elements is required to provide the growth capability, high reliability and 7 to 10 year lifetime demanded for future space nuclear power systems. The overall project will develop and demonstrate the technology base required to provide a wide range of modular power systems compatible with the SP-100 reactor which facilitates operation during lunar and planetary day/night cycles as well as allowing spacecraft operation at any attitude or distance from the sun. Significant accomplishments in all of the project elements will be presented, along with revised goals and project timeliness recently developed

Application of parallel connected power-MOSFET elements to high current d.c. power supply

International Nuclear Information System (INIS)

Matsukawa, Tatsuya; Shioyama, Masanori; Shimada, Katsuhiro; Takaku, Taku; Neumeyer, Charles; Tsuji-Iio, Shunji; Shimada, Ryuichi

2001-01-01

The low aspect ratio spherical torus (ST), which has single turn toroidal field coil, requires the extremely high d.c. current like as 20 MA to energize the coil. Considering the ratings of such extremely high current and low voltage, power-MOSFET element is employed as the switching device for the a.c./d.c. converter of power supply. One of the advantages of power-MOSFET element is low on-state resistance, which is to meet the high current and low voltage operation. Recently, the capacity of power-MOSFET element has been increased and its on-state resistance has been decreased, so that the possibility of construction of high current and low voltage a.c./d.c. converter with parallel connected power-MOSFET elements has been growing. With the aim of developing the high current d.c. power supply using power-MOSFET, the basic characteristics of parallel operation with power-MOSFET elements are experimentally investigated. And, the synchronous rectifier type and the bi-directional self commutated type a.c./d.c. converters using parallel connected power-MOSFET elements are proposed

Inertial Fusion Power Plant Concept of Operations and Maintenance

Energy Technology Data Exchange (ETDEWEB)

Anklam, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Knutson, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunne, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kasper, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sheehan, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lang, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mau, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2015-01-15

Parsons and LLNL scientists and engineers performed design and engineering work for power plant pre-conceptual designs based on the anticipated laser fusion demonstrations at the National Ignition Facility (NIF). Work included identifying concepts of operations and maintenance (O&M) and associated requirements relevant to fusion power plant systems analysis. A laser fusion power plant would incorporate a large process and power conversion facility with a laser system and fusion engine serving as the heat source, based in part on some of the systems and technologies advanced at NIF. Process operations would be similar in scope to those used in chemical, oil refinery, and nuclear waste processing facilities, while power conversion operations would be similar to those used in commercial thermal power plants. While some aspects of the tritium fuel cycle can be based on existing technologies, many aspects of a laser fusion power plant presents several important and unique O&M requirements that demand new solutions. For example, onsite recovery of tritium; unique remote material handling systems for use in areas with high radiation, radioactive materials, or high temperatures; a five-year fusion engine target chamber replacement cycle with other annual and multi-year cycles anticipated for major maintenance of other systems, structures, and components (SSC); and unique SSC for fusion target waste recycling streams. This paper describes fusion power plant O&M concepts and requirements, how O&M requirements could be met in design, and how basic organizational and planning issues can be addressed for a safe, reliable, economic, and feasible fusion power plant.

Control system for high power laser drilling workover and completion unit

Science.gov (United States)

Zediker, Mark S; Makki, Siamak; Faircloth, Brian O; DeWitt, Ronald A; Allen, Erik C; Underwood, Lance D

2015-05-12

A control and monitoring system controls and monitors a high power laser system for performing high power laser operations. The control and monitoring system is configured to perform high power laser operation on, and in, remote and difficult to access locations.

Optimization of power system operation

CERN Document Server

Zhu, Jizhong

2015-01-01

This book applies the latest applications of new technologies topower system operation and analysis, including new and importantareas that are not covered in the previous edition. Optimization of Power System Operation covers both traditional andmodern technologies, including power flow analysis, steady-statesecurity region analysis, security constrained economic dispatch,multi-area system economic dispatch, unit commitment, optimal powerflow, smart grid operation, optimal load shed, optimalreconfiguration of distribution network, power system uncertaintyanalysis, power system sensitivity analysis, analytic hierarchicalprocess, neural network, fuzzy theory, genetic algorithm,evolutionary programming, and particle swarm optimization, amongothers. New topics such as the wheeling model, multi-areawheeling, the total transfer capability computation in multipleareas, are also addressed. The new edition of this book continues to provide engineers andac demics with a complete picture of the optimization of techn...

Operation of nuclear power plants

International Nuclear Information System (INIS)

Severa, P.

1988-04-01

The textbook for training nuclear power plant personnel is centred on the most important aspects of operating modes of WWER-440 reactors. Attention is devoted to the steady state operation of the unit, shutdown, overhaul with refuelling, physical and power start-up. Also given are the regulations of shift operation and the duties of individual categories of personnel during the shift and during the change of shifts. (Z.M.). 3 figs., 1 tab

Method for Prediction of the Power Output from Photovoltaic Power Plant under Actual Operating Conditions

Science.gov (United States)

Obukhov, S. G.; Plotnikov, I. A.; Surzhikova, O. A.; Savkin, K. D.

2017-04-01

Solar photovoltaic technology is one of the most rapidly growing renewable sources of electricity that has practical application in various fields of human activity due to its high availability, huge potential and environmental compatibility. The original simulation model of the photovoltaic power plant has been developed to simulate and investigate the plant operating modes under actual operating conditions. The proposed model considers the impact of the external climatic factors on the solar panel energy characteristics that improves accuracy in the power output prediction. The data obtained through the photovoltaic power plant operation simulation enable a well-reasoned choice of the required capacity for storage devices and determination of the rational algorithms to control the energy complex.

High-frequency high-voltage high-power DC-to-DC converters

Science.gov (United States)

Wilson, T. G.; Owen, H. A.; Wilson, P. M.

1982-09-01

A simple analysis of the current and voltage waveshapes associated with the power transistor and the power diode in an example current-or-voltage step-up (buck-boost) converter is presented. The purpose of the analysis is to provide an overview of the problems and design trade-offs which must be addressed as high-power high-voltage converters are operated at switching frequencies in the range of 100 kHz and beyond. Although the analysis focuses on the current-or-voltage step-up converter as the vehicle for discussion, the basic principles presented are applicable to other converter topologies as well.

Operational experience, availability and reliability of nuclear power plants

International Nuclear Information System (INIS)

Kueffer, K.

1980-01-01

This lecture - presents a survey on nuclear power production and plant performance in the Western World covering all reactor types and light-water reactors in particular and discusses key parameters such as load factors and non-availability analysis. - outlines the main reasons for the reliable performance of Swiss nuclear power plants - quality equipment - operator qualification and training - engineering know how on site - maintenance philosophy and outage planning - information system and feedback of experience - explains the management functions as applied at the Beznau Nuclear Power Station to ensure high power productivity and reliability - improvement - a feedback control system - analysis of production losses - optimization in shut-down planning - minimizing disturbances during plant operation - optimizing personnel qualification and efficiency. (orig.)

Training of power plant operating personnel

International Nuclear Information System (INIS)

Kraftwerksschule, E.V.

1986-01-01

In Germany, professional training of power plant operating personnel became an important issue in the fifties, when power plant parameters as well as complexity of instrumentation and control increased considerably. Working Groups of VGB Technische Vereiningung der Grosskraftwerketreiber e.v. (Association of Large Power Plant Operators) developed a professional career for power plant operating personnel and defined pre-requisites, scope and objectives of training. In 1957 the German utilities founded KRAFTWERKSSCHULE E.V. (kws) as a school for theoretical training and for guidance of practical training in the power plants. KWS is a non-profit organisation and independent of authorities. Today KWS has 127 members in Germany and in 6 other countries. The objectives of KWS include the training of: -Kraftwerker (control room operators; - Kraftwerksmesiter (shift supervisors); and - shift engineers; according the guidelines of the VGB

Distributed Optimization of Sustainable Power Dispatch and Flexible Consumer Loads for Resilient Power Grid Operations

Science.gov (United States)

Srikantha, Pirathayini

Today's electric grid is rapidly evolving to provision for heterogeneous system components (e.g. intermittent generation, electric vehicles, storage devices, etc.) while catering to diverse consumer power demand patterns. In order to accommodate this changing landscape, the widespread integration of cyber communication with physical components can be witnessed in all tenets of the modern power grid. This ubiquitous connectivity provides an elevated level of awareness and decision-making ability to system operators. Moreover, devices that were typically passive in the traditional grid are now `smarter' as these can respond to remote signals, learn about local conditions and even make their own actuation decisions if necessary. These advantages can be leveraged to reap unprecedented long-term benefits that include sustainable, efficient and economical power grid operations. Furthermore, challenges introduced by emerging trends in the grid such as high penetration of distributed energy sources, rising power demands, deregulations and cyber-security concerns due to vulnerabilities in standard communication protocols can be overcome by tapping onto the active nature of modern power grid components. In this thesis, distributed constructs in optimization and game theory are utilized to design the seamless real-time integration of a large number of heterogeneous power components such as distributed energy sources with highly fluctuating generation capacities and flexible power consumers with varying demand patterns to achieve optimal operations across multiple levels of hierarchy in the power grid. Specifically, advanced data acquisition, cloud analytics (such as prediction), control and storage systems are leveraged to promote sustainable and economical grid operations while ensuring that physical network, generation and consumer comfort requirements are met. Moreover, privacy and security considerations are incorporated into the core of the proposed designs and these

High power diode-pumped continuous wave and Q-switch operation of Tm,Ho:YVO4 laser

International Nuclear Information System (INIS)

Yao, B Q; Li, G; Meng, P B; Zhu, G L; Ju, Y L; Wang, Y Z

2010-01-01

High power diode-pumped continuous wave (CW) and Q-switch operation of Tm,Ho:YVO 4 laser is reported. Using two Tm,Ho:YVO 4 rods in a single cavity, up to 20.2 W of CW output lasing at 2054.7 nm was obtained under cryogenic temperature of 77 K with an optical to optical conversion efficiency of 32.9%. For Q-switch operation, up to 19.4 W of output was obtained under 15 kHz pulse repetition frequency (PRF) with a minimum pulse width of 24.2 ns. In addition, different pulse repetition frequencies of Q-switch operation with 10.0 kHz, 12.5 kHz and 15.0 kHz were investigated comparatively

Management of the high-level nuclear power facilities

International Nuclear Information System (INIS)

Preda, Marin

2003-05-01

This thesis approaches current issues in the management of the high power nuclear facilities and as such it appears to be important particularly for nuclear power plant operation topics. Of special interest are the failure events entailing possible catastrophic situations. The contents is structured onto ten chapters. The first chapter describes the operation regimes of the nuclear high power facilities. Highlighted here are the thesis scope and the original features of the work. The second chapter deals with operational policies developed in order to ensure the preventive maintenance of the nuclear installations. Also managing structures are described devoted to practical warranting the equipment safety function of non-classical power stations. In the third chapter cases of nuclear accidents are analyzed especially stressing the probabilistic risk and the operation regimes having in view the elimination of catastrophic events. In the fourth and fifth chapters the control of nuclear radiation emission is treated focusing the quality issue of nuclear installations required to avoid hazardous effects at level of nuclear reactor operation stage. At the same time set of operational measures is given here for preventing risks, catastrophes and chaotic situations. The chapter five presents both theoretical and practical approaches of the nuclear reactor core management concerning particularly the fuel testing, the water primary system and the quality of the involved equipment. In the sixth and seventh chapters issues of risk-quality correlations are approached as well as the structure of expert systems for monitoring the operational regimes of nuclear facilities. The efficiency of the power systems with nuclear injection is discussed and some original ideas developed in this work are evidenced in the eighth and ninth chapters. Presented are here both the operational principles and models of raising the efficiency of the interconnected nuclear stations and prices' policy

Fractional power operation of tokamak reactors

International Nuclear Information System (INIS)

Mau, T.K.; Vold, E.L.; Conn, R.W.

1986-01-01

Methods to operate a tokamak fusion reactor at fractions of its rated power, identify the more effective control knobs and assess the impact of the requirements of fractional power operation on full power reactor design are explored. In particular, the role of burn control in maintaining the plasma at thermal equilibrium throughout these operations is studied. As a prerequisite to this task, the critical physics issues relevant to reactor performance predictions are examined and some insight into their impact on fractional power operation is offered. The basic tool of analysis consists of a zero-dimensional (0-D) time-dependent plasma power balance code which incorporates the most advanced data base and models in transport and burn plasma physics relevant to tokamaks. Because the plasma power balance is dominated by the transport loss and given the large uncertainty in the confinement model, the authors have studied the problem for a wide range of energy confinement scalings. The results of this analysis form the basis for studying the temporal behavior of the plasma under various thermal control mechanisms. Scenarios of thermally stable full and fractional power operations have been determined for a variety of transport models, with either passive or active feedback burn control. Important power control parameters, such as gas fueling rate, auxiliary power and other plasma quantities that affect transport losses, have also been identified. The results of these studies vary with the individual transport scaling used and, in particular, with respect to the effect of alpha heating power on confinement

High average-power induction linacs

International Nuclear Information System (INIS)

Prono, D.S.; Barrett, D.; Bowles, E.

1989-01-01

Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of /approximately/ 50-ns duration pulses to > 100 MeV. In this paper we report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs

Assuring human operator alertness at night in power plants

International Nuclear Information System (INIS)

Moore-Ede, M.C.

1988-01-01

The human body is not designed for peak alertness and performance at night, nor is it well-equipped to cope with the frequent day-night inversions required by rotating shift work schedules. As a result, the human operator can become the weak link in a complex technological operation such as a nuclear power plant. The high degree of dependence on human operator vigilance, decision-making ability and performance that is required in nuclear power plant operations can conflict with the human sleepiness and error-proneness which naturally occur during the night shift or after extended periods without adequate sleep. An opportunity to address these problems has come from a series of major research advances in basic circadian physiology

Operating US power reactors

International Nuclear Information System (INIS)

Silver, E.G.

1988-01-01

This update, which appears regularly in each issue of Nuclear Safety, surveys the operations of those power reactors in the US which have been issued operating licenses. Table 1 shows the number of such reactors and their net capacities as of September 30, 1987, the end of the three-month period covered in this report. Table 2 lists the unit capacity and forced outage rate for each licensed reactor for each of the three months (July, August, and September 1987) covered in this report and the cumulative values of these parameters since the beginning of commercial operation. In addition to the tabular data, this article discusses other significant occurrences and developments that affected licensed US power reactors during this reporting period. Status changes at Braidwood Unit 1, Nine Mile Point 2, and Beaver Valley 2 are discussed. Other occurrences discussed are: retraining of control-room operators at Peach Bottom; a request for 25% power for Shoreham, problems at Fermi 2 which delayed the request to go to 75% power; the results of a safety study of the N Reactor at Hanford; a proposed merger of Pacific Gas and Electric with Sacramento Municipal Utility District which would result in the decommissioning of Rancho Seco; the ordered shutdown of Oyster Creek; a minor radioactivity release caused by a steam generator tube rupture at North Anna 1; and 13 fines levied by the NRC on reactor licensees

High-thrust and low-power operation of a 30-cm-diameter mercury ion thruster

Science.gov (United States)

Beattie, J. R.; Kami, S.

1981-01-01

An investigation of a 30-cm-diameter mercury ion thruster designed for high-thrust and low-power operation is described. Experimental results are presented which indicate that good performance and long lifetime are achieved by using a boundary magnetic field arrangement to confine the ionizing electrons. Details of advanced ion-optics designs are discussed, and performance measurements obtained with an advanced two-grid ion-optics assembly are presented. Scaling of the state-of-the-art hollow cathode for higher emission-current capability is described, and performance and lifetime measurements are presented for the scaled cathode.

Towards high-power long-pulse operation on Tore Supra

International Nuclear Information System (INIS)

2000-01-01

The Tore Supra tokamak was given the main mission to investigate the route towards long pulse plasma discharges. This includes the problem of heat exhaust and particle control (via the development of high-performance plasma facing components), and in parallel the physics of fully non inductive discharges and its optimization with respect to the confinement. Tore Supra is thus equipped with a superconducting toroidal magnet (maximum magnetic field on axis 4.5T), a full set of actively cooled plasma facing components (PFC), and a heating and current drive capability based on high power RIF systems connected to actively cooled antennas. The encouraging results already obtained, as well as recent progress in PFC, allowed us to envisage a significant improvement in the heat exhaust capability of Tore Supra. The so-called CIEL-project consists in a complete upgrade of the inner chamber of Tore Supra, planned to be installed during the year 2000. The present paper deals with the experimental and modeling activity linked to the preparation of the long-pulse high-power discharges using the present Tore Supra equipment: heating and current drive scenarios, power coupling, confinement and transport studies, discharge control... An overview of the results obtained in that field is presented, as well as the progress required in the coming years, and the expected performance, for the CIEL phase, in terms of current drive and confinement. (author)

High average-power induction linacs

International Nuclear Information System (INIS)

Prono, D.S.; Barrett, D.; Bowles, E.; Caporaso, G.J.; Chen, Yu-Jiuan; Clark, J.C.; Coffield, F.; Newton, M.A.; Nexsen, W.; Ravenscroft, D.; Turner, W.C.; Watson, J.A.

1989-01-01

Induction linear accelerators (LIAs) are inherently capable of accelerating several thousand amperes of ∼ 50-ns duration pulses to > 100 MeV. In this paper the authors report progress and status in the areas of duty factor and stray power management. These technologies are vital if LIAs are to attain high average power operation. 13 figs

Chaos in high-power high-frequency gyrotrons

International Nuclear Information System (INIS)

Airila, M.

2004-01-01

Gyrotron interaction is a complex nonlinear dynamical process, which may turn chaotic in certain circumstances. The emergence of chaos renders dynamical systems unpredictable and causes bandwidth broadening of signals. Such effects would jeopardize the prospect of advanced gyrotrons in fusion. Therefore, it is important to be aware of the possibility of chaos in gyrotrons. There are three different chaos scenarios closely related to the development of high-power gyrotrons: First, the onset of chaos in electron trajectories would lead to difficulties in the design and efficient operation of depressed potential collectors, which are used for efficiency enhancement. Second, the radio-frequency signal could turn chaotic, decreasing the output power and the spectral purity of the output signal. As a result, mode conversion, transmission, and absorption efficiencies would be reduced. Third, spatio-temporal chaos in the resonator field structure can set a limit for the use of large-diameter interaction cavities and high-order TE modes (large azimuthal index) allowing higher generated power. In this thesis, the issues above are addressed with numerical modeling. It is found that chaos in electron residual energies is practically absent in the parameter region corresponding to high efficiency. Accordingly, depressed collectors are a feasible solution also in advanced high-power gyrotrons. A new method is presented for straightforward numerical solution of the one-dimensional self-consistent time-dependent gyrotron equations, and the method is generalized to two dimensions. In 1D, a chart of gyrotron oscillations is calculated. It is shown that the regions of stationary oscillations, automodulation, and chaos have a complicated topology in the plane of generalized gyrotron variables. The threshold current for chaotic oscillations exceeds typical operating currents by a factor of ten. However, reflection of the output signal may significantly lower the threshold. 2D

High-power and steady-state operation of ICRF heating in the large helical device

Energy Technology Data Exchange (ETDEWEB)

Mutoh, T., E-mail: mutoh@nifs.ac.jp; Seki, T.; Saito, K.; Kasahara, H.; Seki, R.; Kamio, S.; Kumazawa, R.; Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Ii, T.; Makino, R.; Nagaoka, K.; Nomura, G. [National Institute for Fusion Science, 322-6, Oroshi-cho, Toki, Gifu, 509-5292 (Japan); Shinya, T. [The University of Tokyo, Kashiwa 2777-8561 (Japan)

2015-12-10

Recent progress in an ion cyclotron range of frequencies (ICRF) heating system and experiment results in a Large Helical Device (LHD) are reported. Three kinds of ICRF antenna pairs were installed in the LHD, and the operation power regimes were extended up to 4.5 MW; also, the steady-state operation was extended for more than 45 min in LHD at a MW power level. We studied ICRF heating physics in heliotron configuration using a Hand Shake type (HAS) antenna, Field Aligned Impedance Transforming (FAIT) antenna, and Poloidal Array (PA) antenna, and established the optimum minority-ion heating scenario in an LHD. The FAIT antenna having a novel impedance transformer inside the vacuum chamber could reduce the VSWR and successfully injected a higher power to plasma. We tested the PA antennas completely removing the Faraday-shield pipes to avoid breakdown and to increase the plasma coupling. The heating performance was almost the same as other antennas; however, the heating efficiency was degraded when the gap between the antenna and plasma surface was large. Using these three kinds of antennas, ICRF heating could contribute to raising the plasma beta with the second- and third-harmonic cyclotron heating mode, and also to raising the ion temperature as discharge cleaning tools. In 2014, steady-state operation plasma with a line-averaged electron density of 1.2 × 10{sup 19} m{sup −3}, ion and electron temperature of 2 keV, and plasma sustainment time of 48 min was achieved with ICH and ECH heating power of 1.2 MW for majority helium with minority hydrogen. In 2015, the higher-power steady-state operation with a heating power of up to 3 MW was tested with higher density of 3 × 10{sup 19} m{sup −3}.

Issues of integrating high-tech concepts into nuclear power plant operation

International Nuclear Information System (INIS)

Kisner, R.A.; Carter, R.J.; Lindsay, R.W.

1990-01-01

The stockpile of new ideas continues to grow for monitoring nuclear power plant parameters, characteristics, and vital signs and for controlling systems, subsystems, and components. This wide selection of monitoring and control software increases the difficulty of designing an integrated control room. As plant control room operators increase their reliance on computerized systems, including real-time plant data and data base systems, the integration of monitoring, diagnostics, and control software into uniform and seamless environment becomes imperative. A systematic approach to evaluating the usefulness of such high-tech control concepts is needed. This paper concentrates on methods to evaluate control concepts by assessing factors that determine a system's potential effectiveness within the context of the overall environment, including both human and machine components. Although not an in-depth study, this paper serves to outline several measures of utility. 21 refs., 3 figs., 2 tabs

Optimization Criteria of Power Transformer Operation

Directory of Open Access Journals (Sweden)

A. A. Gonchar

2006-01-01

Full Text Available It has been shown that minimum losses in active power of a power transformer do not correspond to its maximum efficiency. For a transformer being operated there are no so called «zones of its economical operation». In this case strictly specified value of active power losses corresponds to a particular current of the winding.

High-Temperature, Wirebondless, Ultracompact Wide Bandgap Power Semiconductor Modules

Science.gov (United States)

Elmes, John

2015-01-01

Silicon carbide (SiC) and other wide bandgap semiconductors offer great promise of high power rating, high operating temperature, simple thermal management, and ultrahigh power density for both space and commercial power electronic systems. However, this great potential is seriously limited by the lack of reliable high-temperature device packaging technology. This Phase II project developed an ultracompact hybrid power module packaging technology based on the use of double lead frames and direct lead frame-to-chip transient liquid phase (TLP) bonding that allows device operation up to 450 degC. The new power module will have a very small form factor with 3-5X reduction in size and weight from the prior art, and it will be capable of operating from 450 degC to -125 degC. This technology will have a profound impact on power electronics and energy conversion technologies and help to conserve energy and the environment as well as reduce the nation's dependence on fossil fuels.

ANALYSIS OF OPTIMUM OPERATING MODES OF POWER TRANSFORMERS UNDER OPERATING CONDITIONS

Directory of Open Access Journals (Sweden)

I. V. Khomenko

2016-12-01

Full Text Available Purpose. The study of parallel operation optimal modes of transformer equipment for a variety of operating conditions: same or different types of transformers, with or without reactive power flows. Methodology. Losses of energy in transformers make 30 % of all losses. Therefore the choice of the economically justified parallel operation of transformers is effective action to reduce losses. Typically, in the calculations of reactive power flows in the transformers are not taken into account. It is interesting to analyze the optimal operating conditions of transformers with and without reactive power flows. Results. Calculations for transformers in distribution networks showed that the inclusion of reactive power flows in transformers significant impact on the calculated optimum regimes of transformers.

Analysis of transistor and snubber turn-off dynamics in high-frequency high-voltage high-power converters

Science.gov (United States)

Wilson, P. M.; Wilson, T. G.; Owen, H. A., Jr.

Dc to dc converters which operate reliably and efficiently at switching frequencies high enough to effect substantial reductions in the size and weight of converter energy storage elements are studied. A two winding current or voltage stepup (buck boost) dc-to-dc converter power stage submodule designed to operate in the 2.5-kW range, with an input voltage range of 110 to 180 V dc, and an output voltage of 250 V dc is emphasized. In order to assess the limitations of present day component and circuit technologies, a design goal switching frequency of 10 kHz was maintained. The converter design requirements represent a unique combination of high frequency, high voltage, and high power operation. The turn off dynamics of the primary circuit power switching transistor and its associated turn off snubber circuitry are investigated.

Operation management of thermal power plant. Karyoku plant no unten kanri

Energy Technology Data Exchange (ETDEWEB)

1994-06-15

Nowadays, thermal power plants are getting bigger and bigger in capacity. At the same time, high reliability to the frequent start and stop due to the demand change as well as effective economy. This paper describes the total operation management system. It included the start and stop, normal operation, specified operation, water quality, operation management involving the environmental problems, protection of machinery and equipment in case of emergency, measures against the failure, and the measures against the disaster. The outline of the normal operation is as follows: from the cost economical point of view, the kind of fuel is changed according to the load; i.e., coal for basic operation, LNG for basic to medium operation, and oil for medium to peak operation. The change in demand cannot be followed by the hydroelectric power. The adjustment of the power depending on the load change can be achieved by the thermal power generation. The automatic frequency control, economical load distribution control are also done. In the nighttime, the minimum load operation is required. The voltage change operation below the rated value or the phase-advancing operation is also done depending on the load conditions. 21 figs., 6 tabs.

The reactor plasma physics of tandem mirror startup and fractional power operation

International Nuclear Information System (INIS)

Kantrowitz, F.D.; Firestone, M.A.; Guebel, D.M.; Mau, T.K.

1984-01-01

Plasma behavior and the performance of plasma technologies are studied during the startup and fractional power operation of tandem mirrors. Five phases of machine operation are identified, some of which require plasma. The plasma phases include plasma initiation and heating, a standby phase with plasma at the density and temperature characteristics of full design performance in reactors, a deuterium-tritium fractional power operating phase in which the fusion plasma undergoes staged power increases to full power, and rated power operating phase. Plasma initiation and heating uses electron cyclotron resonance heating preionization of background gas in the plug and ion cyclotron resonance heating in the central cell. Operation of the radio-frequency systems, the neutral beams, and the direct converter are studied to determine constraints affecting plasma operation. Studies of fractional power operation, carried out using a quasi-steady-state analysis, show that the plasma Q value can be made remarkably insensitive to the level of fusion power by controlling the plasma radius. Copper insert coils used to increase the maximum choke field require considerable power and cause the recirculating power fraction to increase sharply as the fusion power is reduced. Moreover, when an efficient drift pumping scheme is used, achieved improvements in plasma Q by using high-field choke coils must be weighed against their power consumption and other technological difficulties

Economic Justification of Concentrating Solar Power in High Renewable Energy Penetrated Power Systems

Energy Technology Data Exchange (ETDEWEB)

Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kroposki, Benjamin D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Du, Ershun [Tsinghua University; Zhang, Ning [Tsinghua University; Kang, Chongqing [Tsinghua University; Xia, Qing [Tsinghua University

2018-04-24

Concentrating solar power (CSP) plants are able to provide both renewable energy and operational flexibility at the same time due to its thermal energy storage (TES). It is ideal generation to power systems lacking in flexibility to accommodate variable renewable energy (VRE) generation such as wind power and photovoltaics. However, its investment cost currently is too high to justify its benefit in terms of providing renewable energy only. In this paper we evaluate the economic benefit of CSP in high renewable energy penetrated power systems from two aspects: generating renewable energy and providing operational flexibility to help accommodating VRE. In order to keep the same renewable energy penetration level during evaluation, we compare the economic costs between the system with a high share of VRE and another in which some part of the VRE generation is replaced by CSP generation. The generation cost of a power system is analyzed through chronological operation simulation over a whole year. The benefit of CSP is quantified into two parts: (1) energy benefit - the saving investment of substituted VRE generation and (2) flexibility benefit - the reduction in operating cost due to substituting VRE with CSP. The break-even investment cost of CSP is further discussed. The methodology is tested on a modified IEEE RTS-79 system. The economic justifications of CSP are demonstrated in two practical provincial power systems with high penetration of renewable energy in northwestern China, Qinghai and Gansu, where the former province has massive inflexible thermal power plants but later one has high share of flexible hydro power. The results suggest that the CSP is more beneficial in Gansu system than in Qinghai. The levelized benefit of CSP, including both energy benefit and flexibility benefit, is about 0.177-0.191 $/kWh in Qinghai and about 0.238-0.300 $/kWh in Gansu, when replacing 5-20% VRE generation with CSP generation.

High power laser downhole cutting tools and systems

Science.gov (United States)

Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

2015-01-20

Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

Operational characteristics of nuclear power plants - modelling of operational safety

International Nuclear Information System (INIS)

Studovic, M.

1984-01-01

By operational experience of nuclear power plants and realize dlevel of availability of plant, systems and componenst reliabiliuty, operational safety and public protection, as a source on nature of distrurbances in power plant systems and lessons drawn by the TMI-2, in th epaper are discussed: examination of design safety for ultimate ensuring of safe operational conditions of the nuclear power plant; significance of the adequate action for keeping proess parameters in prescribed limits and reactor cooling rquirements; developed systems for measurements detection and monitoring all critical parameters in the nuclear steam supply system; contents of theoretical investigation and mathematical modeling of the physical phenomena and process in nuclear power plant system and components as software, supporting for ensuring of operational safety and new access in staff education process; program and progress of the investigation of some physical phenomena and mathematical modeling of nuclear plant transients, prepared at faculty of mechanical Engineering in Belgrade. (author)

Operation Modeling of Power Systems Integrated with Large-Scale New Energy Power Sources

Directory of Open Access Journals (Sweden)

Hui Li

2016-10-01

Full Text Available In the most current methods of probabilistic power system production simulation, the output characteristics of new energy power generation (NEPG has not been comprehensively considered. In this paper, the power output characteristics of wind power generation and photovoltaic power generation are firstly analyzed based on statistical methods according to their historical operating data. Then the characteristic indexes and the filtering principle of the NEPG historical output scenarios are introduced with the confidence level, and the calculation model of NEPG’s credible capacity is proposed. Based on this, taking the minimum production costs or the best energy-saving and emission-reduction effect as the optimization objective, the power system operation model with large-scale integration of new energy power generation (NEPG is established considering the power balance, the electricity balance and the peak balance. Besides, the constraints of the operating characteristics of different power generation types, the maintenance schedule, the load reservation, the emergency reservation, the water abandonment and the transmitting capacity between different areas are also considered. With the proposed power system operation model, the operation simulations are carried out based on the actual Northwest power grid of China, which resolves the new energy power accommodations considering different system operating conditions. The simulation results well verify the validity of the proposed power system operation model in the accommodation analysis for the power system which is penetrated with large scale NEPG.

Operating Experience with Power Reactors. Proceedings of the Conference on Operating Experience with Power Reactors. Vol. I

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-10-15

At the beginning of 1963 nuclear power plants produced some 3 500 000kW of electrical power to different distribution grids around the world. Much significant operating experience has been gained with these power reactors, but this experience is often not collected in such a way as to make it easily available. The International Atomic Energy Agency convened a Conference on Operating Experience with Power Reactors in Vienna from 4-8 June 1963 which was attended by 240 participants representing 27 of the Agency's Member States and six international organizations. At the Conference, 42 papers giving detailed experience with more than 20 nuclear power stations were discussed. Although similar meetings on a national or regional scale have been held earlier in various countries, this is the first arranged by the Agency on a world-wide basis. Some of the detailed material may have been given earlier but for the most part it represents new and recently acquired experience, and for the first time it has been possible to compile in one place such extensive material on the operating experience with power reactors. The Conference discussed the experience gained both generally in the context of national and international nuclear power development programmes, and more specifically in the detailed operating experience with different power reactor stations. In addition, various plant components, fuel cycles, staffing of nuclear plants and licensing of such staff were treated. It is hoped that these Proceedings will be of interest not only to nuclear plant designers and operators who daily encounter problems similar to those discussed by the Conference, but also to those guiding the planning and implementation of power development programmes.

Operating Experience with Power Reactors. Proceedings of the Conference on Operating Experience with Power Reactors. Vol. II

Energy Technology Data Exchange (ETDEWEB)

NONE

1963-10-15

At the beginning of 1963 nuclear power plants produced some 3 500 000 kW of electrical power to different distribution grids around the world. Much significant operating experience has been gained with these power reactors, but this experience is often not collected in such a way as to make it easily available. The International Atomic Energy Agency convened a Conference on Operating Experience with Power Reactors in Vienna from 4 -8 June 1963 which was attended by 240 participants representing 27 of the Agency's Member States and six international organizations. At the Conference, 42 papers giving detailed experience with more than 20 nuclear power stations were discussed. Although similar meetings on a national or regional scale have been held earlier in various countries, this is the first arranged by the Agency on a world-wide basis. Some of the detailed material may have been given earlier but for the most part it represents new and recently acquired experience, and for the first time it has been possible to compile in one place such extensive material on the operating experience with power reactors. The Conference discussed the experience gained both generally in the context of national and international nuclear power development programmes, and more specifically in the detailed operating experience with different power reactor stations. In addition, various plant components, fuel cycles, staffing of nuclear plants and licensing of such staff were treated. It is hoped that these Proceedings will be of interest not only to nuclear , plant designers and operators who daily encounter problems similar to those discussed by the Conference, but also to those guiding the planning and implementation of power development programmes.

Supervision functions - Secure operation of sustainable power systems

DEFF Research Database (Denmark)

Morais, Hugo; Zhang, Xinxin; Lind, Morten

2013-01-01

of power systems operation control. The use of PMUs allows more penetration of DG mainly, with technologies based on renewable resources with intermittent and unpredictable operation such a wind power. This paper introduces the Secure Operation of Sustainable Power Systems (SOSPO) project. The SOSPO...... project tries to respond to the question "How to ensure a secure operation of the future power system where the operating point is heavily is fluctuating?" focusing in the Supervision module architecture and in the power system operation states. The main goal of Supervision module is to determine...... the power system operation state based on new stability and security parameters derived from PMUs measurement and coordinate the use of automatic and manual control actions. The coordination of the control action is based not only in the static indicators but also in the performance evaluation of control...

Information needs in nuclear power plants during low power operation modes

Energy Technology Data Exchange (ETDEWEB)

Tommila, Teemu; Fantoni, Paolo F.; Zander, Ralf M.

1998-02-01

During the past few years an increasing attention has been paid to the safety of shutdown and refuelling operations. It has turned out that the risks during shutdown may be comparable to the risks of power operation. The goal of this report is to identify information requirements related to low power operating modes of nuclear power plants. These include, for example, warm and cold shutdowns, refuelling and maintenance, as well as related state transitions such as start-up and shut-down. The focus of the report is on planned refuelling outages and the role of the control room in managing the outage activities. As a starting point, the basic terminology and characteristics of low power operation are discussed. The current situation at nuclear power plants and some recent developments in information technology are reviewed. End-users' requirements and enabling technologies are combined in order to identify the opportunities for new information technology tools in low power operation. The required features of process control systems and maintenance information systems are described. Common plant modelling techniques, open software architectures and functional structuring of the process control system are suggested to be the key issues in the long-term development of operator support systems. On a shorter time scale, new tools solving limited practical problems should be developed and evaluated. This would provide a basis for the features needed for low power operation, including for example, outage planning, on-line risk monitoring, management of outage tasks, adaptive alarm handling, computerised procedures and task-oriented human interfaces. (author)

Post-Mortem Analysis after High-Power Operation of the TD24_R05 Tested in Xbox_1

CERN Document Server

Degiovanni, Alberto; Mouriz Irazabal, Nerea; Aicheler, Markus

2016-01-01

The CLIC prototype structure TD24_R05 has been high power tested in Xbox_1 in 2013. This report summarizes all examinations conducted after the high power test including bead-pull measurements, structure cutting, metrology and SEM observations. A synthesis of the various results is then made. The structure developed a hot cell progressively during operation and detuning was observed after the test was complete. The post mortem examination clearly showed a developed standing wave pattern which was explained by the physical deformation of one of the coupler iris. An elevated breakdown count through SEM imaging in the suspected hot cell however could not be confirmed. Neither any particular feature offering an explanation for the observed longitudinal breakdown distribution could be detected.

Knowledge base for power plant operation and its application to operation guide

International Nuclear Information System (INIS)

Doi, Atsushi; Sakaguchi, Toshiaki

1986-01-01

The present study is aimed at constructing a knowledge base for supervisory control operation in power plants and developing an operation guidance by using it. Examination is made to provide dignosis procedures on the basis of an existing alarm system. An operation guidance procedure for diagnosis is proposed which is to be followed when several alarms are sounded simultaneously in a power plant, and application of the procedure to an existing plant is examined. The operation manual for the plant includes 75 description items for six alarms. It is shown that the number of items related to these alarms can be reduced by 70 % by rearranging them according to the procedure. Another investigation is conducted to provide an operation manual for diagnosis to be used when one alarm is sounded in a plant. The quality of the manual developed is on nearly the same level with that for the existing plant examined. When a knowledge base is to be constructed from an existing operation manual, the processing operation generally requires a certain level of linguistic comprehension ability, such as for judgment of synonyms. It is demonstrated that the procedure proposed here is able to develop a high-quality knowledge base with standardized terminology. The procedure can also serve to construct operation manuals for plants in other industrial fields. (Nogami, K.)

A high-power versatile wireless power transfer for biomedical implants.

Science.gov (United States)

Jiang, Hao; Zhang, Jun Min; Liou, Shy Shenq; Fechter, Richard; Hirose, Shinjiro; Harrison, Michael; Roy, Shuvo

2010-01-01

Implantable biomedical actuators are highly desired in modern medicine. However, how to power up these biomedical implants remains a challenge since most of them need more than several hundreds mW of power. The air-core based radio-frequency transformer (two face-to-face inductive coils) has been the only non-toxic and non-invasive power source for implants for the last three decades [1]. For various technical constraints, the maximum delivered power is limited by this approach. The highest delivered power reported is 275 mW over 1 cm distance [2]. Also, the delivered power is highly vulnerable to the coils' geometrical arrangement and the electrical property of the medium around them. In this paper, a novel rotating-magnets based wireless power transfer that can deliver ∼10 W over 1 cm is demonstrated. The delivered power is significantly higher than the existing start-of-art. Further, the new method is versatile since there is no need to have the impedance matching networks that are highly susceptible to the operating frequency, the coil arrangement and the environment.

The high-power iodine laser

Science.gov (United States)

Brederlow, G.; Fill, E.; Witte, K. J.

The book provides a description of the present state of the art concerning the iodine laser, giving particular attention to the design and operation of pulsed high-power iodine lasers. The basic features of the laser are examined, taking into account aspects of spontaneous emission lifetime, hyperfine structure, line broadening and line shifts, stimulated emission cross sections, the influence of magnetic fields, sublevel relaxation, the photodissociation of alkyl iodides, flashlamp technology, excitation in a direct discharge, chemical excitation, and questions regarding the chemical kinetics of the photodissociation iodine laser. The principles of high-power operation are considered along with aspects of beam quality and losses, the design and layout of an iodine laser system, the scalability and prospects of the iodine laser, and the design of the single-beam Asterix III laser.

The Jefferson Lab High Power Light Source

Energy Technology Data Exchange (ETDEWEB)

James R. Boyce

2006-01-01

Jefferson Lab has designed, built and operated two high average power free-electron lasers (FEL) using superconducting RF (SRF) technology and energy recovery techniques. Between 1999-2001 Jefferson Lab operated the IR Demo FEL. This device produced over 2 kW in the mid-infrared, in addition to producing world record average powers in the visible (50 W), ultraviolet (10 W) and terahertz range (50 W) for tunable, short-pulse (< ps) light. This FEL was the first high power demonstration of an accelerator configuration that is being exploited for a number of new accelerator-driven light source facilities that are currently under design or construction. The driver accelerator for the IR Demo FEL uses an Energy Recovered Linac (ERL) configuration that improves the energy efficiency and lowers both the capital and operating cost of such devices by recovering most of the power in the spent electron beam after optical power is extracted from the beam. The IR Demo FEL was de-commissioned in late 2001 for an upgraded FEL for extending the IR power to over 10 kW and the ultraviolet power to over 1 kW. The FEL Upgrade achieved 10 kW of average power in the mid-IR (6 microns) in July of 2004, and its IR operation currently is being extended down to 1 micron. In addition, we have demonstrated the capability of on/off cycling and recovering over a megawatt of electron beam power without diminishing machine performance. A complementary UV FEL will come on-line within the next year. This paper presents a summary of the FEL characteristics, user community accomplishments with the IR Demo, and planned user experiments.

Change-management. From commercial power operation to post power operation and decommissioning

International Nuclear Information System (INIS)

Wasinger, Karl

2015-01-01

Transition from power generation to decommissioning challenges utilities. Power generation is mainly characterized by a stable working environment and constant workload, decommissioning and dismantling, however, by transformation and change. Also, changing requirements for the workforce's skills challenge the organization and its senior management. Ensuring effective and efficient performance, while maintaining motivation of staff, requires adjustment of management processes as well as of operational organization and human resources management. AREVA has more than 20 years of experience in decommissioning of own nuclear fuel cycle plants in France, as well as of other large plants and power reactors in Germany, the United Kingdom and the US. Therefore, the group has developed and successfully implemented integrated change management processes. The implementation of well-established and proven methods, developed by the productive industry and adjusted to the nuclear regulatory requirements, significantly improves the performance and efficiency of means and methods in use. The AREVA Performance Improvement Process defines concrete approaches to identify and improve potential deficits of productivity in six main areas (decommissioning scenarios and stra-tegies, waste treatment and logistics, operations management, supply chain, regulatory monitoring and controls as well as dismantling operation). Nuclear plant and facility owners around the world benefit from AREVA experts well experienced in execution of large and complex decommissioning projects.

Development and application of nuclear power operation database

International Nuclear Information System (INIS)

Shao Juying; Fang Zhaoxia

1996-01-01

The article describes the development of the Nuclear Power Operation Database which include Domestic and Overseas Nuclear Event Scale Database, Overseas Nuclear Power Operation Abnormal Event Database, Overseas Nuclear Power Operation General Reliability Database and Qinshan Nuclear Power Operation Abnormal Event Database. The development includes data collection and analysis, database construction and code design, database management system selection. The application of the database to provide support to the safety analysis of the NPPs which have been in commercial operation is also introduced

Advances in Very High Frequency Power Conversion

DEFF Research Database (Denmark)

Kovacevic, Milovan

Resonant and quasi-resonant converters operated at frequencies above 30 MHz have attracted special attention in the last two decades. Compared to conventional converters operated at ~100 kHz, they offer significant advantages: smaller volume and weight, lower cost, and faster transient performance....... Excellent performance and small size of magnetic components and capacitors at very high frequencies, along with constant advances in performance of power semiconductor devices, suggests a sizable shift in consumer power supplies market into this area in the near future. To operate dc-dc converter power...... method provides low complexity and low gate loss simultaneously. A direct design synthesis method is provided for resonant SEPIC converters employing this technique. Most experimental prototypes were developed using low cost, commercially available power semiconductors. Due to very fast transient...

Operation of SST-1 TF power supply during SST-1 campaigns

International Nuclear Information System (INIS)

Sharma, Dinesh Kumar; Vora, Murtuza M.; Ojha, Amit; Singh, Akhilesh Kumar; Bhavsar, Chirag

2015-01-01

Highlights: • SST-1 TF power supply is 12 pulse SCR converter circuit. • TF power supply protection, measurement and control scheme are explained. • Quench, emergency and normal shot process is explained and results of SST-1 campaigns are shown. • Dynamic control of TF current. • The paper shows the results of last ten SST-1 campaigns. - Abstract: SST-1 TF power supply provides the direct current for the required magnetic field of TF coil. TF power supply includes transformer, 12-pulse converter, bus bar, water-cooled cable, protection and measuring equipments, and isolator, VME DAC system and GUI software. TF power supply is operated through GUI software built in TCL/Tk. VME DAC system monitors the parameters, provides On/Off commands, voltage and current references and initiates predefined reference to emergency shutdown. The emergency shutdown is hardwired to TF power supply from central control. During quench power supply converter opens DCCB and dump resistor is connected in the circuit and VME DAC system acquires bus bar voltage, dump voltage and dump current. Operation of TF power supply also requires monitoring of SCR and transformer temperature and water flow rate of water-cooled cable during high current long pulse shot. Before start up of TF power supply a quench simulation is performed to check the readiness of protection. This paper describes pre startup operation, normal shot operation, emergency and quench process, dynamic control and complete shutdown operation of TF power supply.

Operation of SST-1 TF power supply during SST-1 campaigns

Energy Technology Data Exchange (ETDEWEB)

Sharma, Dinesh Kumar, E-mail: dinesh@ipr.res.in; Vora, Murtuza M.; Ojha, Amit; Singh, Akhilesh Kumar; Bhavsar, Chirag

2015-10-15

Highlights: • SST-1 TF power supply is 12 pulse SCR converter circuit. • TF power supply protection, measurement and control scheme are explained. • Quench, emergency and normal shot process is explained and results of SST-1 campaigns are shown. • Dynamic control of TF current. • The paper shows the results of last ten SST-1 campaigns. - Abstract: SST-1 TF power supply provides the direct current for the required magnetic field of TF coil. TF power supply includes transformer, 12-pulse converter, bus bar, water-cooled cable, protection and measuring equipments, and isolator, VME DAC system and GUI software. TF power supply is operated through GUI software built in TCL/Tk. VME DAC system monitors the parameters, provides On/Off commands, voltage and current references and initiates predefined reference to emergency shutdown. The emergency shutdown is hardwired to TF power supply from central control. During quench power supply converter opens DCCB and dump resistor is connected in the circuit and VME DAC system acquires bus bar voltage, dump voltage and dump current. Operation of TF power supply also requires monitoring of SCR and transformer temperature and water flow rate of water-cooled cable during high current long pulse shot. Before start up of TF power supply a quench simulation is performed to check the readiness of protection. This paper describes pre startup operation, normal shot operation, emergency and quench process, dynamic control and complete shutdown operation of TF power supply.

33 CFR 209.141 - Coordination of hydroelectric power operations with power marketing agencies.

Science.gov (United States)

2010-07-01

... Commanders will develop, in coordination with their respective power marketing agency, a system for exchanging operating information. The system will include general operating information and information on... power operations with power marketing agencies. 209.141 Section 209.141 Navigation and Navigable Waters...

Operation and maintenance of nuclear power plants

International Nuclear Information System (INIS)

Ackermann, G.

1987-01-01

This textbook gives a systematic introduction into the operational and maintenance activities in nuclear power plants with pressurized water reactors. Subjects: (1) Setup and operational behaviour of power reactors, (2) setup of nuclear power plants, (3) radiation protection and nuclear safety, (4) nuclear fuel, (5) constructional layout of nuclear power plants, (6) management, and (7) maintenance. 158 figs., 56 tabs

Development of new S-band RF window for stable high-power operation in linear accelerator RF system

Science.gov (United States)

Joo, Youngdo; Lee, Byung-Joon; Kim, Seung-Hwan; Kong, Hyung-Sup; Hwang, Woonha; Roh, Sungjoo; Ryu, Jiwan

2017-09-01

For stable high-power operation, a new RF window is developed in the S-band linear accelerator (Linac) RF systems of the Pohang Light Source-II (PLS-II) and the Pohang Accelerator Laboratory X-ray Free-Electron Laser (PAL-XFEL). The new RF window is designed to mitigate the strength of the electric field at the ceramic disk and also at the waveguide-cavity coupling structure of the conventional RF window. By replacing the pill-box type cavity in the conventional RF window with an overmoded cavity, the electric field component perpendicular to the ceramic disk that caused most of the multipacting breakdowns in the ceramic disk was reduced by an order of magnitude. The reduced electric field at the ceramic disk eliminated the Ti-N coating process on the ceramic surface in the fabrication procedure of the new RF window, preventing the incomplete coating from spoiling the RF transmission and lowering the fabrication cost. The overmoded cavity was coupled with input and output waveguides through dual side-wall coupling irises to reduce the electric field strength at the waveguide-cavity coupling structure and the possibility of mode competitions in the overmoded cavity. A prototype of the new RF window was fabricated and fully tested with the Klystron peak input power, pulse duration and pulse repetition rate of 75 MW, 4.5 μs and 10 Hz, respectively, at the high-power test stand. The first mass-produced new RF window installed in the PLS-II Linac is running in normal operation mode. No fault is reported to date. Plans are being made to install the new RF window to all S-band accelerator RF modules of the PLS-II and PAL-XFEL Linacs. This new RF window may be applied to the output windows of S-band power sources like Klystron as wells as the waveguide windows of accelerator facilities which operate in S-band.

Training device for nuclear power plant operators

International Nuclear Information System (INIS)

Schoessow, G. J.

1985-01-01

A simulated nuclear energy power plant system with visible internal working components comprising a reactor adapted to contain a liquid with heating elements submerged in the liquid and capable of heating the liquid to an elevated temperature, a steam generator containing water and a heat exchanger means to receive the liquid at an elevated temperature, transform the water to steam, and return the spent liquid to the reactor; a steam turbine receiving high energy steam to drive the turbine and discharging low energy steam to a condenser where the low energy steam is condensed to water which is returned to the steam generator; an electric generator driven by the turbine; indicating means to identify the physical status of the reactor and its contents; and manual and automatic controls to selectively establish normal or abnormal operating conditions in the reactor, steam generator, pressurizer, turbine, electric generator, condenser, and pumps; and to be selectively adjusted to bring the reactor to acceptable operating condition after being placed in an abnormal operation. This device is particularly useful as an education device in demonstrating nuclear reactor operations and in training operating personnel for nuclear reactor systems and also as a device for conducting research on various safety systems to improve the safety of nuclear power plants

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

Science.gov (United States)

Mason, Lee S.

2003-01-01

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

Error analysis of nuclear power plant operator cognitive behavior

International Nuclear Information System (INIS)

He Xuhong; Zhao Bingquan; Chen Yulong

2001-01-01

Nuclear power plant is a complex human-machine system integrated with many advanced machines, electron devices and automatic controls. It demands operators to have high cognitive ability and correct analysis skill. The author divides operator's cognitive process into five stages to analysis. With this cognitive model, operator's cognitive error is analysed to get the root causes and stages that error happens. The results of the analysis serve as a basis in design of control rooms and training and evaluation of operators

Transactive control: a framework for operating power systems characterized by high penetration of distributed energy resources

DEFF Research Database (Denmark)

Hu, Junjie; Yang, Guangya; Kok, Koen

2016-01-01

The increasing number of distributed energy resources connected to power systems raises operational challenges for the network operator, such as introducing grid congestion and voltage deviations in the distribution network level, as well as increasing balancing needs at the whole system level......, followed by a literature review and demonstration projects that apply to transactive control. Cases are then presented to illustrate the transactive control framework. At the end, discussions and research directions are presented, for applying transactive control to operating power systems, characterized...

Unmanned operation of Hydro Power Plants

International Nuclear Information System (INIS)

Regula, E.

2008-01-01

Intentions to launch unmanned operation are no news, the very first occurred in Hydro Power Plants (HPP) at the time when the first computer technology was implemented into process of power generation, i.e. no later than in 1960 s . ENEL entering Slovenske elektrarne not only revived but significantly accelerated the implementation process of unmanned operation. Experience of ENEL says that unmanned operation means better reliability of the HPP and this is the priority. (author)

Super high field ohmically heated tokamak operation

International Nuclear Information System (INIS)

Cohn, D.R.; Bromberg, L.; Leclaire, R.J.; Potok, R.E.; Jassby, D.L.

1986-01-01

The authors discuss a super high field mode of tokamak operation that uses ohmic heating or near ohmic heating to ignition. The super high field mode of operation uses very high values of Β/sup 2/α, where Β is the magnetic field and a is the minor radius (Β/sup 2/α > 100 T/sup 2/m). We analyze copper magnet devices with major radii from 1.7 to 3.0 meters. Minimizing or eliminating the need for auxiliary heating has the potential advantages of reducing uncertainty in extrapolating the energy confinement time of current tokamak devices, and reducing engineering problems associated with large auxiliary heating requirements. It may be possible to heat relatively short pulse, inertially cooled tokamaks to ignition with ohmic power alone. However, there may be advantages in using a very small amount of auxiliary power (less than the ohmic heating power) to boost the ohmic heating and provide a faster start-up, expecially in relatively compact devices

Ergonomics and risk management in high risk organizations: nuclear power plant operator decision making

International Nuclear Information System (INIS)

Carvalho, Paulo Victor Rodrigues de

2003-08-01

Nuclear power plants are high hazard environments where emergency situations can have devastating effects. The operator crew has the ultimate responsibility to control the energy production process with safety. The outcome of a crisis is consequently dependent on the crew's judgement, decision making and situation awareness. In such way we should know how operators make their decisions in order to develop safety strategies. The aim of this thesis is to examine the cognitive processes through which operators make decisions when dealing with micro incidents during their actual work, and to determine whether they use a naturalistic or normative decision making strategy. That is, do they try to recognize the micro incident as familiar and base decisions on condition-action rules (naturalistic), or do they need to concurrently compare and contrast options before selecting the best possible (normative). The method employed for data collection was the Cognitive Task Analysis (CTA) and Ergonomic Work Analysis (EWA). The main findings of this thesis were that decision making is primarily based on naturalistic strategies, such as condition-action rules and recognition. In new situations rules are created ad hoc. These rules appear derived from experience and training rather than from Standard Operating Procedures and contrast normative competence standards used by nuclear industry. (author)

Permanent cessation of Tokai power plant's operation

International Nuclear Information System (INIS)

Satoh, T.

1998-01-01

Tokai power plant (166MWe, Magnox type: GCR) is the first commercial reactor in Japan and has been kept operating stable since its commissioning in July 1996. During this period it has produced electricity of approximately 27.7 billion KWh (as of March 1997) and its stable operation has contributed greatly to the stable supply of electricity in Japan. Furthermore, technologies in various fields have been developed, demonstrated and accumulated through the construction and operation of Tokai power plant. It also contributes to training for many nuclear engineers, and constructions and operations of nuclear power stations by other Japanese power companies. As a pioneer, it has been achieved to develop and popularize Japanese nuclear power generation. On the other hand, Tokai power plant has small capacity in its electric power output, even though the size of the reactor and heat exchangers are rather bigger than those of LWR due to the characteristics of GCR. Therefore, the generation cost is higher than the LWR. Since there is no plant whose reactor type is the same as that of Tokai power plant, the costs for maintenance and fuel cycle are relatively higher than that of LWR. Finally we concluded that the longer we operate it, the less we can take advantage of it economically. As a result of the evaluation for the future operation of Tokai power plant including the current status for supply of electricity by the Japanese utilities and study of decommissioning by Japanese government, we decided to have a plan of stopping its commercial operation of Tokai power plant in the end of March, 1998, when we completely consume its fuel that we possess. From now on, we set about performing necessary studies and researches on the field of plant characterization, remote-cutting, waste disposal for carrying out the decommissioning of Tokai power plant safely and economically. We are going to prepare the decommissioning planning for Tokai power plant in a few years based on the

Compact high voltage, high peak power, high frequency transformer for converter type modulator applications.

Science.gov (United States)

Reghu, T; Mandloi, V; Shrivastava, Purushottam

2016-04-01

The design and development of a compact high voltage, high peak power, high frequency transformer for a converter type modulator of klystron amplifiers is presented. The transformer has been designed to operate at a frequency of 20 kHz and at a flux swing of ±0.6 T. Iron (Fe) based nanocrystalline material has been selected as a core for the construction of the transformer. The transformer employs a specially designed solid Teflon bobbin having 120 kV insulation for winding the high voltage secondary windings. The flux swing of the core has been experimentally found by plotting the hysteresis loop at actual operating conditions. Based on the design, a prototype transformer has been built which is per se a unique combination of high voltage, high frequency, and peak power specifications. The transformer was able to provide 58 kV (pk-pk) at the secondary with a peak power handling capability of 700 kVA. The transformation ratio was 1:17. The performance of the transformer is also presented and discussed.

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1991-08-01

In the Quarterly Reports on the operation of the Finnish nuclear power plants such events and observations are described relating to nuclear and radiation safety which the Finnish Centre for Radiation and Nuclear Safety considers safety significant. Also other events of general interest are reported. The report also includes a summary of the radiation safety of the plants' workers and the environment, as well as tabulated data on the production and load factors of the plants. The Finnish nuclear power plant units Loviisa 1 and 2 as well as TVO I and II were in commercial operation during the whole first quarter of 1991. The load factor average was 99.1 %. Failures have been detected in the uppermost spacing lattices of nuclear fuel bundles removed from the Loviisa nuclear reactors. Further investigations into the significance of the failures have been initiated. In this quarter, renewed cooling systems for the instrumentation area were introduced at Loviisa 1. The modifications made in the systems serve to ensure reliable cooling of the area even during the hottest summer months when the possibility exists that the temperature of the automation equipment could rise too high causing malfunctions which could endanger plant safety. Occupational radiation doses and external releases of radioactivity were below prescribed limits in this quarter. Only small amounts of radioactive substances originating in nuclear power plants were detected in samples taken in the vicinity of nuclear power plants

Entropic cohering power in quantum operations

Science.gov (United States)

Xi, Zhengjun; Hu, Ming-Liang; Li, Yongming; Fan, Heng

2018-02-01

Coherence is a basic feature of quantum systems and a common necessary condition for quantum correlations. It is also an important physical resource in quantum information processing. In this paper, using relative entropy, we consider a more general definition of the cohering power of quantum operations. First, we calculate the cohering power of unitary quantum operations and show that the amount of distributed coherence caused by non-unitary quantum operations cannot exceed the quantum-incoherent relative entropy between system of interest and its environment. We then find that the difference between the distributed coherence and the cohering power is larger than the quantum-incoherent relative entropy. As an application, we consider the distributed coherence caused by purification.

Effect of increased renewables generation on operation of thermal power plants

International Nuclear Information System (INIS)

Eser, Patrick; Singh, Antriksh; Chokani, Ndaona; Abhari, Reza S.

2016-01-01

Highlights: • Impacts of increased renewables in central European transmission system are assessed. • Individual transmission lines and power plants of transmission system are modelled. • Starts and ramps of thermal power plants significantly increase with increased renewables. • Impact of renewables on thermal power plants is highly dependent on location. - Abstract: High spatial and temporal resolution optimal power flow simulations of the 2013 and 2020 interconnected grid in Central Western and Eastern Europe regions are undertaken to assess the impact of an increased penetration of renewables on thermal power plants. In contrast to prior studies, the present work models each individual transmission line and power plant within the two regions. Furthermore, for conventional plants, electricity costs are determined with respect to fuel type, nameplate capacity, operating condition and geographic location; cycling costs are modeled as function of the recent operational history. For renewable power plants, costs and available power are determined using mesoscale weather simulations and hydrology models. Countrywide validation of the simulations shows that all renewable and most conventional power production is predicted with less than 10% error. It is shown that the increased penetration of renewables in 2020 will induce a 4–23% increase in the number of starts of conventional plants. The number of load ramps significantly increases by 63–181%, which underlines the necessity for equipment manufacturers and utilities to adapt to scenarios of high penetration of renewables. The increased cycling operation of coal plants is shown to depend strongly on the power plant’s location and is mainly observed in Germany and the Czech Republic. Austrian coal plants are cycled less because they supply more base load power to southern Germany, where several nuclear power plants will be phased out by 2020. Thus there is a need for more transmission capacity along

Small high cooling power space cooler

Energy Technology Data Exchange (ETDEWEB)

Nguyen, T. V.; Raab, J.; Durand, D.; Tward, E. [Northrop Grumman Aerospace Systems Redondo Beach, Ca, 90278 (United States)

2014-01-29

The small High Efficiency pulse tube Cooler (HEC) cooler, that has been produced and flown on a number of space infrared instruments, was originally designed to provide cooling of 10 W @ 95 K. It achieved its goal with >50% margin when limited by the 180 W output ac power of its flight electronics. It has also been produced in 2 stage configurations, typically for simultaneously cooling of focal planes to temperatures as low as 35 K and optics at higher temperatures. The need for even higher cooling power in such a low mass cryocooler is motivated by the advent of large focal plane arrays. With the current availability at NGAS of much larger power cryocooler flight electronics, reliable long term operation in space with much larger cooling powers is now possible with the flight proven 4 kg HEC mechanical cooler. Even though the single stage cooler design can be re-qualified for those larger input powers without design change, we redesigned both the linear and coaxial version passive pulse tube cold heads to re-optimize them for high power cooling at temperatures above 130 K while rejecting heat to 300 K. Small changes to the regenerator packing, the re-optimization of the tuned inertance and no change to the compressor resulted in the increased performance at 150 K. The cooler operating at 290 W input power achieves 35 W@ 150 K corresponding to a specific cooling power at 150 K of 8.25 W/W and a very high specific power of 72.5 W/Kg. At these powers the cooler still maintains large stroke, thermal and current margins. In this paper we will present the measured data and the changes to this flight proven cooler that were made to achieve this increased performance.

Corrective economic dispatch and operational cycles for probabilistic unit commitment with demand response and high wind power

International Nuclear Information System (INIS)

Azizipanah-Abarghooee, Rasoul; Golestaneh, Faranak; Gooi, Hoay Beng; Lin, Jeremy; Bavafa, Farhad; Terzija, Vladimir

2016-01-01

Highlights: • Suggesting a new UC mixing a probabilistic security and incentive demand response. • Investigating the effects of uncertainty on UC using chance-constraint programming. • Proposing an efficient spinning reserve satisfaction based on a new ED correction. • Presenting a new operational cycles way to convert binary variable to discrete one. - Abstract: We propose a probabilistic unit commitment problem with incentive-based demand response and high level of wind power. Our novel formulation provides an optimal allocation of up/down spinning reserve. A more efficient unit commitment algorithm based on operational cycles is developed. A multi-period elastic residual demand economic model based on the self- and cross-price elasticities and customers’ benefit function is used. In the proposed scheme, the probability of residual demand falling within the up/down spinning reserve imposed by n − 1 security criterion is considered as a stochastic constraint. A chance-constrained method, with a new iterative economic dispatch correction, wind power curtailment, and commitment of cheaper units, is applied to guarantee that the probability of loss of load is lower than a pre-defined risk level. The developed architecture builds upon an improved Jaya algorithm to generate feasible, robust and optimal solutions corresponding to the operational cost. The proposed framework is applied to a small test system with 10 units and also to the IEEE 118-bus system to illustrate its advantages in efficient scheduling of generation in the power systems.

Using management of aging in German nuclear power plants - aspects of KTA 1403 pertaining to residual power operation, post-shutdown operation and residual operation

International Nuclear Information System (INIS)

Barreiro, Pablo; Bever, Thomas; Brast, Gerhard; Elsche, Bjoern; Reese, Sven H.; Grossmann, Patrick; Widera, Martin; Huettner, Frank; Linnemann, Thomas; Smit, Swen-Olaf; Zander, Ralf-Michael

2013-01-01

Management of aging in nuclear power plants originated in the United States of America and became a topic of debate in Germany from the late 1990s onward. On the basis of the existing plant-specific measures practiced comprehensively, KTA 1403, ''Management of Aging in Nuclear Power Plants'', was drafted and finalized in 2010. This publication first presents the context of AM with regard to German nuclear power plants, including references to national and international historical developments. Against this backdrop, the difference between management of aging and lifetime management is discussed next. This is followed by a description of the status of the AM process in nuclear power plants currently in operation, especially organizational plant-specific implementation. As a consequence of the decision by the German federal government to discontinue the peaceful use of nuclear power in Germany and the associated 13th amendment to the Atomic Energy Act of July 31, 2011, a considerable part of the German nuclear power plant park already lost its right of power operation. In this situation, aspects of AM are discussed for plants in the no-power, post-operation and residual operation phases. Finally, experience accumulated in plant-specific execution of the AM process on the basis of KTA 1403 is considered and summarized.

Study on the identification of main drivers affecting the performance of human operators during low power and shutdown operation

International Nuclear Information System (INIS)

Kim, Ar Ryum; Park, Jinkyun; Kim, Ji Tae; Kim, Jaewhan; Seong, Poong Hyun

2016-01-01

Highlights: • The performance of human operator during LPSD operation is significantly important. • Human performance is affected by drivers such as procedure, training, and etc. • Main drivers during LPSD operation at domestic NPPs were suggested. • It is expected that it will be used for estimating human reliability during LPSD operation. - Abstract: In the past, many researchers believed that a reactor during low power and shutdown operation was sufficiently safe. This belief has been changed by the number of accidents during such types of operation, which is significantly high. Also, it was pointed out that one of the main differences between low power and shutdown operation and full power operation is the significance of human action because there are huge amounts of human actions due to extensive maintenance and testing while automatic control and safety functions may be disabled and procedures are insufficient or incomplete. This paper suggests the main drivers in performing human reliability analysis. For this study, we reviewed eight reports relating to human performance during low power and shutdown operation and applied a root cause analysis method for 53 human or human-related events at domestic nuclear power plants to derive the main drivers that affect the occurrence of those events. As a result, several main drivers were derived, such as procedures, training, experience of personnel, and workload/stress. It is expected that these main drivers will be used to perform human reliability analysis for low power and shutdown operation.

Meteorological safeguarding of nuclear power plant operation in Czechoslovakia

International Nuclear Information System (INIS)

Rak, J.; Skulec, S.

1976-01-01

A meteorological tower 200 m high has to be built for meteorological control of the operation of the A-1 nuclear power plant at Jaslovske Bohunice. This meteorological station will measure the physical properties of the lower layers of the atmosphere, carry out experimental verifications of the models of air pollution, investigate the effects of waste heat and waste water from the nuclear power plant on the microclimate, provide the theoretical processing of measured data with the aim of selecting the most favourable model for conditions prevailing in the Czechoslovak Socialist Republic, perform basic research of the physical properties of the ground and boundary layers of the atmosphere and the coordination of state-wide plans in the field of securing the operation of nuclear power plants with regard to meteorology. (Z.M.)

Modifications at operating nuclear power plants

International Nuclear Information System (INIS)

Duffy, T.J.; Gazda, P.A.

1985-01-01

Modifications at operating nuclear power plants offer the structural engineer many challenges in the areas of scheduling of work, field adjustments, and engineering staff planning. The scheduling of structural modification work for operating nuclear power plants is normally closely tied to planned or unplanned outages of the plant. Coordination between the structural engineering effort, the operating plant staff, and the contractor who will be performing the modifications is essential to ensure that all work can be completed within the allotted time. Due to the inaccessibility of some areas in operating nuclear power plants or the short time available to perform the structural engineering in the case of an unscheduled outrage, field verification of a design is not always possible prior to initiating the construction of the modification. This requires the structural engineer to work closely with the contractor to promptly resolve problems due to unanticipated interferences or material procurement problems that may arise during the course of construction. The engineering staff planning for structural modifications at an operating nuclear power plant must be flexible enough to permit rapid response to the common ''fire drills,'' but controlled enough to ensure technically correct designs and to minimize the expenditure of man-hours and the resulting engineering cost

Plant Operation Station for HTR-PM Low Power and Shutdown operation Probabilistic safety analysis

International Nuclear Information System (INIS)

Liu Tao; Tong Jiejuan

2014-01-01

Full range Probabilistic safety analysis (PSA) is one of key conditions for nuclear power plant (NPP) licensing according to the requirement of nuclear safety regulatory authority. High Temperature Gas Cooled Reactor Pebble-bed Module (HTR-PM) has developed construction design and prepared for the charging license application. So after the normal power operation PSA submitted for review, the Low power and Shutdown operation Probabilistic safety analysis (LSPSA) also begin. The results of LSPSA will together with prior normal power PSA results to demonstrate the safety level of HTR-PM NPP Plant Operation Station (POS) is one of important terms in LSPSA. The definition of POS lays the foundation for LSPSA modeling. POS provides initial and boundary conditions for the following event tree and fault tree model development. The aim of this paper is to describe the state-of-the-art of POS definition for HTR-PM LSPSA. As for the first attempt to the high temperature gas cooled reactor module plant, the methodology and procedure of POS definition refers to the LWR LSPSA guidance, and adds to plant initial status analysis due to the HTR-PM characteristics. A specific set of POS grouping vectors is investigate and suggested for HTR-PM NPP, which reflects the characteristics of plant modularization and on-line refueling. As a result, seven POSs are given according to the grouping vectors at the end of the paper. They will be used to the LSPSA modelling and adjusted if necessary. The papers ’work may provide reference to the analogous NPP LSPSA. (author)

High-power CO laser and its potential applications

International Nuclear Information System (INIS)

Sato, Shunichi; Takahashi, Kunimitsu; Shimamoto, Kojiro; Takashima, Yoichi; Matsuda, Keiichi; Kuribayashi, Shizuma; Noda, Osamu; Imatake, Shigenori; Kondo, Motoe.

1995-01-01

The R and D program for the development of a high-power CO laser and its application technologies is described. Based on a self-sustained discharge excitation scheme, the available laser output has been successfully scaled to over 20 kW. The CO laser cutting experiments for thick metals have been performed in association with the decommissioning technologies development. Other potential applications, which include those based on photo chemical process, are reviewed. Recently demonstrated high-power tunable operation and room-temperature operation are also reported. (author)

Independent System Operators and Biomass Power

International Nuclear Information System (INIS)

Porter, Kevin L.

1999-01-01

Since the Federal Energy Regulatory Commission issued its landmark open access transmission rule in 1996, the idea of creating and establishing independent system operators (ISOs) has gained momentum. ISOs may help combine individual utility transmission systems into more regional transmission networks, which ultimately will allow biomass companies to transmit power over longer distances while paying a single transmission rate. To the extent that ISOs are combined or operated with power exchanges, however, biomass companies will likely face even more competitive market pressures. Few operators have experience with ISOs and power exchanges, but preliminary results show that short-term electricity market prices are probably too low for most biomass companies to compete against. Without policy measures, biomass companies may have to pursue strategic opportunities with short-term, spot-market sales; direct bilateral sales to customers; alternative power exchanges; and perhaps a ''green'' power market and sales to ancillary service markets. In addition, prices will likely be more volatile in a restructured market so biomass generators should be selling during those times

Volume Bragg grating narrowed high-power and highly efficient cladding-pumped Raman fiber laser.

Science.gov (United States)

Liu, Jun; Yao, Weichao; Zhao, Chujun; Shen, Deyuan; Fan, Dianyuan

2014-12-10

High-power and highly efficient operation of a single-mode cladding-pumped Raman fiber laser with narrow lasing bandwidth is demonstrated. The spectral narrowing was realized by an external cavity containing a volume Bragg grating with a center wavelength of 1658 nm. A maximum output power of 10.4 W at 1658.3 nm with a spectral linewidth (FWHM) of ∼0.1  nm was obtained for the launched pump power of 18.4 W, corresponding to a slope efficiency of 109% with respect to the launched pump power. Lasing characteristics of free-running operation are also evaluated and discussed.

Operator training simulator for nuclear power plant

International Nuclear Information System (INIS)

Shiozuka, Hiromi

1977-01-01

In nuclear power plants, training of the operators is important. In Japan, presently there are two training centers, one is BWR operation training center at Okuma-cho, Fukushima Prefecture, and another the nuclear power generation training center in Tsuruga City, Fukui Prefecture, where the operators of PWR nuclear power plants are trained. This report describes the BWR operation training center briefly. Operation of a nuclear power plant is divided into three stages of start-up, steady state operation, and shut down. Start-up is divided into the cold-state start-up after the shut down for prolonged period due to periodical inspection or others and the hot-state start-up from stand-by condition after the shut down for a short time. In the cold-state start-up, the correction of reactivity change and the heating-up control to avoid excessive thermal stress to the primary system components are important. The BWR operation training center offers the next three courses, namely beginner's course, retraining course and specific training course. The training period is 12 weeks and the number of trainees is eight/course in the beginner's course. The simulator was manufactured by modeling No. 3 plant of Fukushima First Nuclear Power Station, Tokyo Electric Power Co. The simulator is composed of the mimic central control panel and the digital computer. The software system comprises the monitor to supervise the whole program execution, the logic model simulating the plant interlock system and the dynamic model simulating the plant physical phenomena. (Wakatsuki, Y.)

Integrated approach to optimize operation and maintenance costs for operating nuclear power plants

International Nuclear Information System (INIS)

2006-06-01

In the context of increasingly open electricity markets and the 'unbundling' of generating companies from former utility monopolies, an area of major concern is the economic performance of the existing fleet of nuclear power plants. Nuclear power, inevitably, must compete directly with other electricity generation sources. Coping with this competitive pressure is a challenge that the nuclear industry should meet if the nuclear option is to remain a viable one. This competitive environment has significant implications for nuclear plant operations, including, among others, the need for the more cost effective management of plant activities, and the greater use of analytical tools to balance the costs and benefits of proposed activities, in order to optimize operation and maintenance costs, and thus insure the economic competitiveness of existing nuclear power plants. In the framework of the activities on Nuclear Economic Performance Information System (NEPIS), the IAEA embarked in developing guidance on optimization of operation and maintenance costs for nuclear power plants. The report was prepared building on the fundamental that optimization of operation and maintenance costs of a nuclear power plant is a key component of a broader integrated business strategic planning process, having as overall result achievement of organization's business objectives. It provides advice on optimization of O and M costs in the framework of strategic business planning, with additional details on operational planning and controlling. This TECDOC was elaborated in 2004-2005 in the framework of the IAEA's programme on Nuclear Power Plant Operating Performance and Life Cycle Management, with the support of two consultants meetings and one technical meeting and based on contributions provided by participants. It can serve as a useful reference for the management and operation staff within utilities, nuclear power plant operators and regulators and other organizations involved in

Method of operating BWR type power plants

International Nuclear Information System (INIS)

Koyama, Kazuaki.

1981-01-01

Purpose: To improve the operation efficiency of BWR type reactors by reducing the time from the start-up of the reactor to the start-up of the turbine and electrical generator, as well as decrease the pressure difference in each of the sections of the pressure vessel to thereby extend its life span. Method: The operation comprises switching the nuclear reactor from the shutdown mode to the start-up mode, increasing the reactor power to a predetermined level lower than a rated power while maintaining the reactor pressure to a predetermined level lower than a rated pressure, starting up a turbine and an electrical generator in the state of the predetermined reactor pressure and the reactor power to connect the electrical generator to the power transmission system and, thereafter, increasing the reactor pressure and the reactor power to the predetermined rated pressure and rated power respectively. This can shorten the time from the start-up of the reactor to the start of the power transmission system, whereby the operation efficiency of the power plant can be improved. (Moriyama, K.)

The armenian power system operation stability investigation accounting putting new power systems into operation

International Nuclear Information System (INIS)

Yeghiazaryan, L.V.; Hakobyan, S.G.; Gharibyan, G.V.; Harutyunyan, G.S.; Galstyan, G.H.

2010-01-01

The description of the power systems operation stability failure caused by the system significant emergency states occurred during the last working period in Armenian and USA power systems is performed. With the use of PSSTME-31 software portfolio of Siemens Firm a design model is developed and transient electromechanical process calculations for Armenian power system are performed. The accuracy of the model is checked by comparing real-time transient state parameters and their reproduction calculation results.The Armenia - Iran current power transmission lines permissible limit under the condition of the static and dynamic stability requirements and in case of the new thermal power units maintenance are defined

Institute of Nuclear Power Operations (INPO)

International Nuclear Information System (INIS)

Pack, R.W.

1980-01-01

The electric utility industry established the Institute of Nuclear Power Operations, or INPO, the purpose of which is to ensure the highest quality of operations in nuclear power plants. INPO will be an industry self-help instrument focusing on human factors. From top management to the operator trainee, it will measure utility performance against benchmarks of excellence and help utilities reach those benchmarks throughout training and operating programs. INPO will see that the utilities ferret out lessons for all from the abnormal operating experiences of any. It will do everything possible to assist utilities in meeting its certification requirements, but will have the clout to see that those requirements are met. INPO is also managing the nationwide system of utility emergency response capability

Power System Operation with Large Scale Wind Power Integration

DEFF Research Database (Denmark)

Suwannarat, A.; Bak-Jensen, B.; Chen, Z.

2007-01-01

to the uncertain nature of wind power. In this paper, proposed models of generations and control system are presented which analyze the deviation of power exchange at the western Danish-German border, taking into account the fluctuating nature of wind power. The performance of the secondary control of the thermal......The Danish power system starts to face problems of integrating thousands megawatts of wind power, which produce in a stochastic behavior due to natural wind fluctuations. With wind power capacities increasing, the Danish Transmission System Operator (TSO) is faced with new challenges related...... power plants and the spinning reserves control from the Combined Heat and Power (CHP) units to achieve active power balance with the increased wind power penetration is presented....

Risk contribution from low power, shutdown, and other operational modes beyond full power

Energy Technology Data Exchange (ETDEWEB)

Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

1995-04-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

Risk contribution from low power, shutdown, and other operational modes beyond full power

International Nuclear Information System (INIS)

Whitehead, D.W.; Brown, T.D.; Chu, T.L.; Pratt, W.T.

1995-01-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented

Radiation monitoring data on the power-up test of HTTR. Results up to 20 MW operation

International Nuclear Information System (INIS)

Ashikagaya, Yoshinobu; Nakazawa, Takashi; Yoshino, Toshiaki; Yasu, Katsuji

2002-01-01

The High Temperature Engineering Test Reactor (HTTR) have completed the Power-up test of 9 MW (the single and parallel loaded operation) in the rated operation mode. After that the Power-up test in the rated operation mode and the high-temperature test operation mode with a thermal output of 20 MW (the single and parallel loaded operation) were performed between January 16, 2001 and June 10, 2001. This report describes the radiation monitoring data carried out during the HTTR Power-up test in the rated operation mode and the high-temperature test operation mode with a thermal output of 20 MW. The followings were concluded from these radiation monitoring data. The monitoring of radioactive gaseous effluents and the radiation protection for the works will be easy to do and the exposure dose of the workers will be kept the low level. (author)

Power reactors operational diagnosis

International Nuclear Information System (INIS)

Dach, K.; Pecinka, L.

1976-01-01

The definition of reactor operational diagnostics is presented and the fundamental trends of research are determined. The possible sources of power reactor malfunctions, the methods of defect detection, the data evaluation and the analysis of the results are discussed in detail. In view of scarcity of a theoretical basis and of insufficient in-core instrumentation, operational diagnostics cannot be as yet incorporated in a computer-aided reactor control system. (author)

Resonant High Power Combiners

CERN Document Server

Langlois, Michel; Peillex-Delphe, Guy

2005-01-01

Particle accelerators need radio frequency sources. Above 300 MHz, the amplifiers mostly used high power klystrons developed for this sole purpose. As for military equipment, users are drawn to buy "off the shelf" components rather than dedicated devices. IOTs have replaced most klystrons in TV transmitters and find their way in particle accelerators. They are less bulky, easier to replace, more efficient at reduced power. They are also far less powerful. What is the benefit of very compact sources if huge 3 dB couplers are needed to combine the power? To alleviate this drawback, we investigated a resonant combiner, operating in TM010 mode, able to combine 3 to 5 IOTs. Our IOTs being able to deliver 80 kW C.W. apiece, combined power would reach 400 kW minus the minor insertion loss. Values for matching and insertion loss are given. The behavior of the system in case of IOT failure is analyzed.

Operating modes and practical power flow analysis of bidirectional isolated power interface for distributed power systems

International Nuclear Information System (INIS)

Wen, Huiqing; Su, Bin

2016-01-01

Highlights: • Four operating modes of Dual-Phase-Shift control for Dual Active Bridge converter are presented. • Effects of “minor parameters” such as the deadtime and power device voltage drops are analyzed. • Accurate power flow models with Dual-Phase-Shift control are developed and verified with experimental results. • Optimal operating mode is determined with respect to the efficiency improvement. • Measured efficiency of the Dual Active Bridge converter is improved up to 14%. - Abstract: Due to the intermittent nature of the renewable energy sources including photovoltaic and wind energy, the energy storage systems are essential to stabilize dc bus voltage. Considering the discharge depth of super-capacitors and energy-storage batteries, the bidirectional isolated power interface will operate for a wide range of voltage and power. This study focuses on in-depth analysis of the dual-active-bridge dc–dc converter that is controlled by the dual-phase-shift scheme to improve the conversion efficiency in distributed power system. The power flow of each operating mode with dual-phase-shift control is characterized based on a detailed analysis of the effects of “minor parameters”, including the deadtime and power device voltage drops. The complete output power plane of the dual-active-bridge converter with dual-phase-shift control is obtained and compared with experimental results. The optimal operating mode is determined according to the practical output power range and the power flow characteristics. Experimental evaluation shows the effectiveness of the proposed power flow model with dual-phase-shift control and significant efficiency improvement using the optimal mode of dual-phase-shift compared with the conventional phase shift control.

Experimental progress on virtual-cathode very high power microwave source development

International Nuclear Information System (INIS)

Fazio, M.V.; Hoeberling, R.F.

1987-01-01

The evolution of rf accelerator technology toward high-power, high-current, low-emittance beams produces an ever-increasing demand for efficient, very high power microwave sources. The present klystron technology has performed very well but is not expected to produce reliable gigawatt peak-power units in the 1- to 10-GHz regime. Further major advancements must involve other types of sources. The reflexing electron sources can produce microwave powers at the gigawatt level and have demonstrated operation from 800 MHz to 40 GHz. Pulse length appears to be limited by electron-beam diode closure, and reflexing electron devices have been operated in a repetitively pulsed mode. An experiment is under way to investigate concepts to stabilize the frequency of the virtual cathode source. If one can successfully frequency and phase lock this source to an external signal, then this source can operate as a very high power microwave amplifier making it practical for accelerator applications. The progress on an experiment to test these concepts will be discussed

Recruitment training and licensing of operating personnel for nuclear power plants

International Nuclear Information System (INIS)

Palabrica, R.J.

1979-01-01

This article covers the step-by-step and most rigid recruitment, training, and licensing procedures undertaken in the selection for personnel involved in nuclear power plant operations. These procedures are true to all countries. However, for developing countries such as the Philippines, a bachelor's degree may be required as compared with the U.S. wherein a high school diploma is the minimum requirement. Because of the complexity of a nuclear facility, the work will require highly capable individuals with mature judgement who can render correct decisions even under highly stressed conditions. Thus during the selection and recruitment of applicants for the operator position, they are not only given aptitude tests but are also subjected to a series of psychological examintions. Once they are accepted, they are made to undergo a comprehensive and in-depth training to ensure that they will be capable of operating the nuclear power plant safely and effectively. Finally, those prospective operators have to pass licensing examinations in order to prove their competence and skills. Retraining programs follow after their training to maintain their skills. (RTD)

Power ramping/cycling experience and operational recommendations in KWU power plants

International Nuclear Information System (INIS)

Jan, R. von; Wunderlich, F.; Holzer, R.

1980-01-01

The power cycling and ramping experience of KWU is based on experiments in test and commercial reactors, and on evaluation of plant operation (PHWR, PWR and BWR). Power cycling of fuel rods have never lead to PCI failures. In ramping experiments, for fast ramps PCI failure thresholds of 480/420 W/cm are obtained at 12/23 GWd/t(U) burn-up for pressurized PWR fuel. No failures occurred during limited exceedance of the threshold with reduced ramp rate. Operational recommendations used by KWU are derived from experiments and plant experience. The effects of ramping considerations on plant operation is discussed. No rate restrictions are required for start-ups during an operating cycle or load follow operation within set limits for the distortion of the local power distribution. In a few situations, e.g. start-up after refueling, ramp rates of 1 to 5 %/h are recommended depending on plant and fuel design

China’s Nuclear Power Plants in Operation

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

Qinshan Plant Phase I Located in Haiyan,Zhejiang Province,Qinshan Nuclear Power Plant Phase I is t he first 300-megawatt pressurized water reactor (PWR) nuclear power plant independently designed,constructed,operated and managed by China.The plant came into commercial operation in April 1994.

Power grid operation risk management: V2G deployment for sustainable development

Science.gov (United States)

Haddadian, Ghazale J.

The production, transmission, and delivery of cost--efficient energy to supply ever-increasing peak loads along with a quest for developing a low-carbon economy require significant evolutions in the power grid operations. Lower prices of vast natural gas resources in the United States, Fukushima nuclear disaster, higher and more intense energy consumptions in China and India, issues related to energy security, and recent Middle East conflicts, have urged decisions makers throughout the world to look into other means of generating electricity locally. As the world look to combat climate changes, a shift from carbon-based fuels to non-carbon based fuels is inevitable. However, the variability of distributed generation assets in the electricity grid has introduced major reliability challenges for power grid operators. While spearheading sustainable and reliable power grid operations, this dissertation develops a multi-stakeholder approach to power grid operation design; aiming to address economic, security, and environmental challenges of the constrained electricity generation. It investigates the role of Electric Vehicle (EV) fleets integration, as distributed and mobile storage assets to support high penetrations of renewable energy sources, in the power grid. The vehicle-to-grid (V2G) concept is considered to demonstrate the bidirectional role of EV fleets both as a provider and consumer of energy in securing a sustainable power grid operation. The proposed optimization modeling is the application of Mixed-Integer Linear Programing (MILP) to large-scale systems to solve the hourly security-constrained unit commitment (SCUC) -- an optimal scheduling concept in the economic operation of electric power systems. The Monte Carlo scenario-based approach is utilized to evaluate different scenarios concerning the uncertainties in the operation of power grid system. Further, in order to expedite the real-time solution of the proposed approach for large-scale power systems

Use of wind power forecasting in operational decisions.

Energy Technology Data Exchange (ETDEWEB)

Botterud, A.; Zhi, Z.; Wang, J.; Bessa, R.J.; Keko, H.; Mendes, J.; Sumaili, J.; Miranda, V. (Decision and Information Sciences); (INESC Porto)

2011-11-29

The rapid expansion of wind power gives rise to a number of challenges for power system operators and electricity market participants. The key operational challenge is to efficiently handle the uncertainty and variability of wind power when balancing supply and demand in ths system. In this report, we analyze how wind power forecasting can serve as an efficient tool toward this end. We discuss the current status of wind power forecasting in U.S. electricity markets and develop several methodologies and modeling tools for the use of wind power forecasting in operational decisions, from the perspectives of the system operator as well as the wind power producer. In particular, we focus on the use of probabilistic forecasts in operational decisions. Driven by increasing prices for fossil fuels and concerns about greenhouse gas (GHG) emissions, wind power, as a renewable and clean source of energy, is rapidly being introduced into the existing electricity supply portfolio in many parts of the world. The U.S. Department of Energy (DOE) has analyzed a scenario in which wind power meets 20% of the U.S. electricity demand by 2030, which means that the U.S. wind power capacity would have to reach more than 300 gigawatts (GW). The European Union is pursuing a target of 20/20/20, which aims to reduce greenhouse gas (GHG) emissions by 20%, increase the amount of renewable energy to 20% of the energy supply, and improve energy efficiency by 20% by 2020 as compared to 1990. Meanwhile, China is the leading country in terms of installed wind capacity, and had 45 GW of installed wind power capacity out of about 200 GW on a global level at the end of 2010. The rapid increase in the penetration of wind power into power systems introduces more variability and uncertainty in the electricity generation portfolio, and these factors are the key challenges when it comes to integrating wind power into the electric power grid. Wind power forecasting (WPF) is an important tool to help

Application of expert system to nuclear power plant operation and guidance system

International Nuclear Information System (INIS)

Goto, M.; Takada, Y.

1990-01-01

For a nuclear power plant, it is important that an expert system supplies useful information to the operator to meet the increasing demand for high-level plant operation. It is difficult to build a user-friendly expert system that supplies useful information in real time using existing general-purpose expert system shells. Therefore a domain-specific expert system shell with a useful knowledge representation for problem-solving in nuclear power plant operation was selected. The Plant Table (P/T) representation format was developed for description of a production system for nuclear power plant operation knowledge. The P/T consists of plant condition representation designed to process multiple inputs and single output. A large number of operation inputs for several plant conditions are divided into 'timing conditions', 'preconditions' and 'completion conditions' to facilitate knowledge-base build-up. An expert system for a Nuclear Power Plant Operation and Guidance System utilizing the P/T was developed to assist automatic plant operation and surveillance test operation. In these systems, automatic plant operation signals to the plant equipment and operation guidance messages to the operators are both output based on the processing and assessment of plant operation conditions by the P/T. A surveillance test procedure guide for major safety-related systems, such as those for emergency core cooling systems, is displayed on a CRT (Cathode Ray Tube) and test results are printed out. The expert system for a Nuclear Power Plant Operation and Guidance System has already been successfully applied to Japanese BWR plants

Two-year experience of the Loviisa-1 nuclear power plant operation in Finland

International Nuclear Information System (INIS)

Palmgren, A.; Simola, P.; Skyutta, P.; Malkov, Yu.V.; Mal'tsev, B.K.; Shasharin, G.A.

1979-01-01

The description of experience of creation and operation of the Loviisa-1 nuclear power plant in Finland is presented. The main stages of power block development were the following: functional tests of systems and equipment, hydraulic tests of the reactor and primary circuit, inspection of equipment, hot testing, testing of protective envelope, second inspection, reactor assembling and fuel loading, physical and power start-up of the reactor, testing of the plant as a whole. Tests of the APP operation on load were particularly extensive. These tests were carried out on the 5, 15, 30, 50, 75 and 92 % thermal power levels of the reactor and covered: physical reactor tests, electric and dynamic tests of the power unit, tests with failures in equipment operation, chemical tests, studies of shielding effectiveness, thermal and guarantee tests. The positive experience of the Loviisa-1 nuclear power plant operation, reactor reliability, fuel element tightness, high efficiency (33.9 %) and satisfactory operation of turbo-generator confirm the success of the Loviisa-1 NPP project

Multi-objective design and operation of Solid Oxide Fuel Cell (SOFC) Triple Combined-cycle Power Generation systems: Integrating energy efficiency and operational safety

International Nuclear Information System (INIS)

Sharifzadeh, Mahdi; Meghdari, Mojtaba; Rashtchian, Davood

2017-01-01

Highlights: • Integrating Solid Oxide Fuel Cells with thermal power plants enhance overall energy efficiency. • However, the high degree of process integration in hybrid power plants limits the operating window. • Multi-objective optimization was applied for integrated design and operation. • The Pareto optimal solutions demonstrated strong trade-off between energy efficiency and operational safety. - Abstract: Energy efficiency is one of the main pathways for energy security and environmental protection. In fact, the International Energy Agency asserts that without energy efficiency, 70% of targeted emission reductions are not achievable. Despite this clarity, enhancing the energy efficiency introduce significant challenge toward process operation. The reason is that the methods applied for energy-saving pose the process operation at the intersection of safety constraints. The present research aims at uncovering the trade-off between safe operation and energy efficiency; an optimization framework is developed that ensures process safety and simultaneously optimizes energy-efficiency, quantified in economic terms. The developed optimization framework is demonstrated for a solid oxide fuel cell (SOFC) power generation system. The significance of this industrial application is that SOFC power plants apply a highly degree of process integration resulting in very narrow operating windows. However, they are subject to significant uncertainties in power demand. The results demonstrate a strong trade-off between the competing objectives. It was observed that highly energy-efficient designs feature a very narrow operating window and limited flexibility. For instance, expanding the safe operating window by 100% will incur almost 47% more annualized costs. Establishing such a trade-off is essential for realizing energy-saving.

Toward High-Power Klystrons With RF Power Conversion Efficiency on the Order of 90%

CERN Document Server

Baikov, Andrey Yu; Syratchev, Igor

2015-01-01

The increase in efficiency of RF power generation for future large accelerators is considered a high priority issue. The vast majority of the existing commercial high-power RF klystrons operates in the electronic efficiency range between 40% and 55%. Only a few klystrons available on the market are capable of operating with 65% efficiency or above. In this paper, a new method to achieve 90% RF power conversion efficiency in a klystron amplifier is presented. The essential part of this method is a new bunching technique - bunching with bunch core oscillations. Computer simulations confirm that the RF production efficiency above 90% can be reached with this new bunching method. The results of a preliminary study of an L-band, 20-MW peak RF power multibeam klystron for Compact Linear Collider with the efficiency above 85% are presented.

Very High Frequency Galvanic Isolated Offline Power Supply

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf

During the last decades many researchers have turned their attention to raising the operation frequency of power converters to the very high frequency (VHF) range going from 30 MHz to 300 MHz. Increasing the operating frequency of a power converter leads to smaller energy storing components...... inverters with a single combined rectifier. The converter designed to deliver 9 W to a 60 V LED load and is achieving an efficiency of 89.4% and a power density of 2.14 W3 . The development of this converter proof that offline VHF converter can be implemented with high efficiencies even for low power applications...... are described together with the possibility of using capacitors as the power galvanic isolation, both methods of creating galvanic isolation are implemented in converters. Regarding EMC a series of converters with different filter implementations are examined. The results from the conducted mea-surement from 150...

Design of Instantaneous High Power Supply System with power distribution management for portable military devices

Science.gov (United States)

Kwak, Kiho; Kwak, Dongmin; Yoon, Joohong

2015-08-01

A design of an Instantaneous High Power Supply System (IHPSS) with a power distribution management (PDM) for portable military devices is newly addressed. The system includes a power board and a hybrid battery that can not only supply instantaneous high power but also maintain stable operation at critical low temperature (-30 °C). The power leakage and battery overcharge are effectively prevented by the optimal PDM. The performance of the proposed system under the required pulse loads and the operating conditions of a Korean Advanced Combat Rifle employed in the battlefield is modeled with simulations and verified experimentally. The system with the IHPSS charged the fuse setter with 1.7 times higher voltage (8.6 V) than the one without (5.4 V) under the pulse discharging rate (1 A at 0.5 duty, 1 ms) for 500 ms.

A high frequency, high power CARM proposal for the DEMO ECRH system

International Nuclear Information System (INIS)

Mirizzi, Francesco; Spassovsky, Ivan; Ceccuzzi, Silvio; Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero; Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca; Sabia, Elio; Tuccillo, Angelo Antonio; Zito, Pietro

2015-01-01

Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

A high frequency, high power CARM proposal for the DEMO ECRH system

Energy Technology Data Exchange (ETDEWEB)

Mirizzi, Francesco, E-mail: francesco.mirizzi@enea.it [Consorzio CREATE, Via Claudio 21, I-80125 Napoli (Italy); Spassovsky, Ivan [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Ceccuzzi, Silvio [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Dattoli, Giuseppe; Di Palma, Emanuele; Doria, Andrea; Gallerano, Gianpiero [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Lampasi, Alessandro; Maffia, Giuseppe; Ravera, GianLuca [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Sabia, Elio [Unità Tecnica Applicazioni delle Radiazioni – ENEA, C.R. Frascati, via E. Fermi 45, I-00044 Frascati (Italy); Tuccillo, Angelo Antonio; Zito, Pietro [Unità Tecnica Fusione – ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy)

2015-10-15

Highlights: • ECRH system for DEMO. • Cyclotron Auto-Resonance Maser (CARM) devices. • Relativistic electron beams. • Bragg reflectors. • High voltage pulse modulators. - Abstract: ECRH&CD systems are extensively used on tokamak plasmas due to their capability of highly tailored power deposition, allowing very localised heating and non-inductive current drive, useful for MHD and profiles control. The high electron temperatures expected in DEMO will require ECRH systems with operating frequency in the 200–300 GHz range, equipped with a reasonable number of high power (P ≥ 1 MW) CW RF sources, for allowing central RF power deposition. In this frame the ENEA Fusion Department (Frascati) is coordinating a task force aimed at the study and realisation of a suitable high power, high frequency reliable source.

Safety of Nuclear Power Plants: Commissioning and Operation

International Nuclear Information System (INIS)

2011-01-01

The safety of a nuclear power plant is ensured by means of proper site selection, design, construction and commissioning, and the evaluation of these, followed by proper management, operation and maintenance of the plant. In a later phase, a proper transition to decommissioning is required. The organization and management of plant operations ensures that a high level of safety is achieved through the effective management and control of operational activities. This publication is a revision of the Safety Requirements publication Safety of Nuclear Power Plants: Operation, which was issued in 2000 as IAEA Safety Standards Series No. NS-R-2. The purpose of this revision was to restructure Safety Standards Series No. NS-R-2 in the light of new operating experience and new trends in the nuclear industry; to introduce new requirements that were not included in Safety Standards Series No. NS-R-2 on the operation of nuclear power plants; and to reflect current practices, new concepts and technical developments. This update also reflects feedback on the use of the standards, both from Member States and from the IAEA's safety related activities. The publication is presented in the new format for Safety Requirements publications. The present publication reflects the safety principles of the Fundamental Safety Principles. It has been harmonized with IAEA Safety Standards Series No. GS-R-3 on The Management System for Facilities and Activities. Guidance on the fulfilment of the safety requirements is provided in supporting Safety Guides. The terminology used in this publication is defined and explained in the IAEA Safety Glossary. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the safety objective and safety principles that are established in the Fundamental Safety Principles. This

High voltage power supplies for INDUS-2 RF system

International Nuclear Information System (INIS)

Badapanda, M.K.; Hannurkar, P.R.

2003-01-01

The RF system of Indus-2 employs klystron amplifiers operating at 505.812 MHz. A precession controlled high voltage DC supply of appropriate rating is needed for each klystron amplifier, as its bias supply. Since internal flashover and arcing are common with the operation of these klystrons and stored energies beyond particular limit inside its bias power supply is detrimental to this device, a properly designed crowbar is incorporated between each klystron and its power supply. This crowbar bypass these stored energies and helps protecting klystron under any of these unfavorable conditions. In either case, power supply sees a near short circuit across its load. So, its power circuit is designed to reduce the fault current level and its various components are also designed to withstand these fault currents, as and when it appears. Finally, operation of these high voltage power supplies (HVPS) generates lot of harmonics on the source side, which distort the input waveform substantially and reduces the input power factor also. Source multiplication between two power supplies are planned to improve upon above parameters and suitable detuned line filters are incorporated to keep the input voltage total harmonics distortion (THD) below 5 % and input power factor (IFF) near unity. (author)

Design of 120 MW beam power electron gun for high power klystron

International Nuclear Information System (INIS)

Zhou Zusheng; Dong Dong

2005-01-01

An electron gun was designed and the beam optics for a China-made 50 MW klystron was simulated. The electron gun ceramic cylinder was designed and optimized. The China-made cathode was replaced with an imported one to lessen evaporation and arcing. The high voltage (320 kV) of the cathode was increased to meet the klystron output power demand and a low electric field strength (22.1 kV/mm) electron gun was designed to avoid the high power operation which damaged the ceramic cylinder. The klystron output power was increased and life span extended. (authors)

High speed and high functional inverter power supplies for plasma generation and control, and their performance

International Nuclear Information System (INIS)

Uesugi, Yoshihiko; Razzak, Mohammad A.; Kondo, Kenji; Kikuchi, Yusuke; Takamura, Shuichi; Imai, Takahiro; Toyoda, Mitsuhiro

2003-01-01

The Rapid development of high power and high speed semiconductor switching devices has led to their various applications in related plasma fields. Especially, a high speed inverter power supply can be used as an RF power source instead of conventional linear amplifiers and a power supply to control the magnetic field in a fusion plasma device. In this paper, RF thermal plasma production and plasma heating experiments are described emphasis placed on using a static induction transistor inverter at a frequency range between 200 kHz and 2.5 MHz as an RF power supply. Efficient thermal plasma production is achieved experimentally by using a flexible and easily operated high power semiconductor inverter power supply. Insulated gate bipolar transistor (IGBT) inverter power supplies driven by a high speed digital signal processor are applied as tokamak joule coil and vertical coil power supplies to control plasma current waveform and plasma equilibrium. Output characteristics, such as the arbitrary bipolar waveform generation of a pulse width modulation (PWM) inverter using digital signal processor (DSP) can be successfully applied to tokamak power supplies for flexible plasma current operation and fast position control of a small tokamak. (author)

High power infrared QCLs: advances and applications

Science.gov (United States)

Patel, C. Kumar N.

2012-01-01

QCLs are becoming the most important sources of laser radiation in the midwave infrared (MWIR) and longwave infrared (LWIR) regions because of their size, weight, power and reliability advantages over other laser sources in the same spectral regions. The availability of multiwatt RT operation QCLs from 3.5 μm to >16 μm with wall plug efficiency of 10% or higher is hastening the replacement of traditional sources such as OPOs and OPSELs in many applications. QCLs can replace CO2 lasers in many low power applications. Of the two leading groups in improvements in QCL performance, Pranalytica is the commercial organization that has been supplying the highest performance QCLs to various customers for over four year. Using a new QCL design concept, the non-resonant extraction [1], we have achieved CW/RT power of >4.7 W and WPE of >17% in the 4.4 μm - 5.0 μm region. In the LWIR region, we have recently demonstrated QCLs with CW/RT power exceeding 1 W with WPE of nearly 10 % in the 7.0 μm-10.0 μm region. In general, the high power CW/RT operation requires use of TECs to maintain QCLs at appropriate operating temperatures. However, TECs consume additional electrical power, which is not desirable for handheld, battery-operated applications, where system power conversion efficiency is more important than just the QCL chip level power conversion efficiency. In high duty cycle pulsed (quasi-CW) mode, the QCLs can be operated without TECs and have produced nearly the same average power as that available in CW mode with TECs. Multiwatt average powers are obtained even in ambient T>70°C, with true efficiency of electrical power-to-optical power conversion being above 10%. Because of the availability of QCLs with multiwatt power outputs and wavelength range covering a spectral region from ~3.5 μm to >16 μm, the QCLs have found instantaneous acceptance for insertion into multitude of defense and homeland security applications, including laser sources for infrared

Helium turbomachinery operating experience from gas turbine power plants and test facilities

International Nuclear Information System (INIS)

McDonald, Colin F.

2012-01-01

The closed-cycle gas turbine, pioneered and deployed in Europe, is not well known in the USA. Since nuclear power plant studies currently being conducted in several countries involve the coupling of a high temperature gas-cooled nuclear reactor with a helium closed-cycle gas turbine power conversion system, the experience gained from operated helium turbomachinery is the focus of this paper. A study done as early as 1945 foresaw the use of a helium closed-cycle gas turbine coupled with a high temperature gas-cooled nuclear reactor, and some two decades later this was investigated but not implemented because of lack of technology readiness. However, the first practical use of helium as a gas turbine working fluid was recognized for cryogenic processes, and the first two small fossil-fired helium gas turbines to operate were in the USA for air liquefaction and nitrogen production facilities. In the 1970's a larger helium gas turbine plant and helium test facilities were built and operated in Germany to establish technology bases for a projected future high efficiency large nuclear gas turbine power plant concept. This review paper covers the experience gained, and the lessons learned from the operation of helium gas turbine plants and related test facilities, and puts these into perspective since over three decades have passed since they were deployed. An understanding of the many unexpected events encountered, and how the problems, some of them serious, were resolved is important to avoid them being replicated in future helium turbomachines. The valuable lessons learned in the past, in many cases the hard way, particularly from the operation in Germany of the Oberhausen II 50 MWe helium gas turbine plant, and the technical know-how gained from the formidable HHV helium turbine test facility, are viewed as being germane in the context of current helium turbomachine design work being done for future high efficiency nuclear gas turbine plant concepts. - Highlights: �

Nuclear power plant operating experience, 1976

International Nuclear Information System (INIS)

1977-11-01

This report is the third in a series of reports issued annually that summarize the operating experience of U.S. nuclear power plants in commercial operation. Power generation statistics, plant outages, reportable occurrences, fuel element performance, occupational radiation exposure and radioactive effluents for each plant are presented. Summary highlights of these areas are discussed. The report includes 1976 data from 55 plants--23 boiling water reactor plants and 32 pressurized water reactor plants

High Power RF Test Facility at the SNS

CERN Document Server

Kang, Yoon W; Campisi, Isidoro E; Champion, Mark; Crofford, Mark; Davis, Kirk; Drury, Michael A; Fuja, Ray E; Gurd, Pamela; Kasemir, Kay-Uwe; McCarthy, Michael P; Powers, Tom; Shajedul Hasan, S M; Stirbet, Mircea; Stout, Daniel; Tang, Johnny Y; Vassioutchenko, Alexandre V; Wezensky, Mark

2005-01-01

RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavitites have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducti...

Experiments on high power EB evaporation of niobium

International Nuclear Information System (INIS)

Kandaswamy, E.; Bhardwaj, R.L.; Ram Gopal; Ray, A.K.; Kulgod, S.V.

2002-01-01

Full text: The versatility of electron beam evaporation makes the deposition of many new and unusual materials possible. This technique offers freedom from contamination and precise control. High power electron guns are especially used for obtaining high evaporation rates for large area coatings. This paper deals with the coating experiments carried out on an indigenously developed high power strip electron gun with niobium as evaporant at 40 kW on S.S. substrate. The practical problems of conditioning the gun and venting the vacuum system after the high power operation are also discussed. The coating rate was calculated by weight difference method

Pre and post-operational radioecological studies around Kaiga Nuclear Power Station

International Nuclear Information System (INIS)

Karunakara, N.

2018-01-01

Four PHWR rectors of 220 MWe each are operating at Kaiga. The Centre for Advanced Research in Environmental Radioactivity (CARER), Mangalore University is engaged in frontline research studies on different aspects of environmental radioactivity and radioecology studies around Kaiga and West Coast of India for the last 30 years. Extensive studies were carried out on radiation levels, radionuclides distribution, and transfer of radionuclides through terrestrial, aquatic and atmospheric pathways in the environment of West Coast of India including the Kaiga nuclear power plant. The baseline studies on radioactivity levels around Kaiga region was carried out well before the nuclear power plant became operational and the data generated under these studies are considered to be highly valuable for impact assessments. The nuclear power plant became operational in the year 1999 and since then extensive studies were carried out on radiological impact assessments, through collaboration with Bhabha Atomic Research Centre (BARC) and Nuclear Power Corporation of India (NPCIL)

High-power fiber-coupled pump lasers for fiber lasers

Science.gov (United States)

Kasai, Yohei; Aizawa, Takuya; Tanaka, Daiichiro

2018-02-01

We present high-power fiber-coupled pump modules utilized effectively for ultra-high power single-mode (SM) fiber lasers. Maximum output power of 392 W was achieved at 23 A for 915 nm pump, and 394 W for 976 nm pump. Fiber core diameter is 118 μm and case temperature is 25deg. C. Polarization multiplexing technique was newly applied to our optical system. High-reliability of the laser diodes (LD) at high-power operation has been demonstrated by aging tests. Advanced package structure was developed that manages uncoupled light around input end of the fiber. 800 hours continuous drive with uncoupled light power of 100 W has been achieved.

Ensuring the operational safety of nuclear power plants with WWER reactors

International Nuclear Information System (INIS)

Shasharin, G.A.; Veretennikov, G.A.; Abagyan, A.A.; Lesnoj, S.A.

1984-01-01

At the start of 1983, 27 nuclear power producing units with reactor facilities of the WWER type were in operation in the Soviet Union and other countries. In 1982 the average load factor for nuclear power plants with WWER reactors was 73 per cent. There was not a single nuclear accident or even damage with any significant radiation consequences in the WWER reactors during the entire period of their operation. The most modern nuclear power plants with WWER-440 and WWER-1000 reactors meet all present-day international requirements. Safe operation of the plants is achieved by a variety of measures, the most important of which include: procedures for increasing the reliability of plant equipment and systems; ensuring exact compliance with plant operating instructions; ensuring reliable operation of plant safety systems; action directed towards maintaining the skills of plant personnel at a level adequate to ensure the taking of proper action during transient processes and accident situations. The paper discusses concrete steps for ensuring safe nuclear power plant operation along these lines. In particular, measures such as the following are described: the use of a system for collecting and processing information on equipment failures and defects; the development and introduction of methods of early defect diagnosis; the performance of complex testing of safety systems; the training of highly skilled personnel for nuclear power plants at educational combines and at teaching and training centres making use of simulators; arranging accident-prevention training and special instruction for personnel. (author)

High-power, format-flexible, 885-nm vertical-cavity surface-emitting laser arrays

Science.gov (United States)

Wang, Chad; Talantov, Fedor; Garrett, Henry; Berdin, Glen; Cardellino, Terri; Millenheft, David; Geske, Jonathan

2013-03-01

High-power, format flexible, 885 nm vertical-cavity surface-emitting laser (VCSEL) arrays have been developed for solid-state pumping and illumination applications. In this approach, a common VCSEL size format was designed to enable tiling into flexible formats and operating configurations. The fabrication of a common chip size on ceramic submount enables low-cost volume manufacturing of high-power VCSEL arrays. This base VCSEL chip was designed to be 5x3.33 mm2, and produced up to 50 Watts of peak continuous wave (CW) power. To scale to higher powers, multiple chips can be tiled into a combination of series or parallel configurations tailored to the application driver conditions. In actively cooled CW operation, the VCSEL array chips were packaged onto a single water channel cooler, and we have demonstrated 0.5x1, 1x1, and 1x3 cm2 formats, producing 150, 250, and 500 Watts of peak power, respectively, in under 130 A operating current. In QCW operation, the 1x3 cm2 VCSEL module, which contains 18 VCSEL array chips packaged on a single water cooler, produced over 1.3 kW of peak power. In passively cooled packages, multiple chip configurations have been developed for illumination applications, producing over 300 Watts of peak power in QCW operating conditions. These VCSEL chips use a substrate-removed structure to allow for efficient thermal heatsinking to enable high-power operation. This scalable, format flexible VCSEL architecture can be applied to wavelengths ranging from 800 to 1100 nm, and can be used to tailor emission spectral widths and build high-power hyperspectral sources.

Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

Science.gov (United States)

Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

2016-02-23

A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

High Input Voltage, Silicon Carbide Power Processing Unit Performance Demonstration

Science.gov (United States)

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

2015-01-01

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

Recent developments in high average power driver technology

International Nuclear Information System (INIS)

Prestwich, K.R.; Buttram, M.T.; Rohwein, G.J.

1979-01-01

Inertial confinement fusion (ICF) reactors will require driver systems operating with tens to hundreds of megawatts of average power. The pulse power technology that will be required to build such drivers is in a primitive state of development. Recent developments in repetitive pulse power are discussed. A high-voltage transformer has been developed and operated at 3 MV in a single pulse experiment and is being tested at 1.5 MV, 5 kj and 10 pps. A low-loss, 1 MV, 10 kj, 10 pps Marx generator is being tested. Test results from gas-dynamic spark gaps that operate both in the 100 kV and 700 kV range are reported. A 250 kV, 1.5 kA/cm 2 , 30 ns electron beam diode has operated stably for 1.6 x 10 5 pulses

An analyser for power plant operations

International Nuclear Information System (INIS)

Rogers, A.E.; Wulff, W.

1990-01-01

Safe and reliable operation of power plants is essential. Power plant operators need a forecast of what the plant will do when its current state is disturbed. The in-line plant analyser provides precisely this information at relatively low cost. The plant analyser scheme uses a mathematical model of the dynamic behaviour of the plant to establish a numerical simulation. Over a period of time, the simulation is calibrated with measurements from the particular plant in which it is used. The analyser then provides a reference against which to evaluate the plant's current behaviour. It can be used to alert the operator to any atypical excursions or combinations of readings that indicate malfunction or off-normal conditions that, as the Three Mile Island event suggests, are not easily recognised by operators. In a look-ahead mode, it can forecast the behaviour resulting from an intended change in settings or operating conditions. Then, when such changes are made, the plant's behaviour can be tracked against the forecast in order to assure that the plant is behaving as expected. It can be used to investigate malfunctions that have occurred and test possible adjustments in operating procedures. Finally, it can be used to consider how far from the limits of performance the elements of the plant are operating. Then by adjusting settings, the required power can be generated with as little stress as possible on the equipment. (6 figures) (Author)

Automation system for operation of nuclear power plant

International Nuclear Information System (INIS)

Kinoshita, Mitsuo; Fukuzaki, Koji; Kato, Kanji

1991-01-01

The automation system comprises a general monitor control device incorporating a plurality of emergency operation plannings concerning an automatic processing, and judging whether the operation is to be conducted or not depending on the plannings based on the data planed by a plant, a control device for controlling the plant in accordance with the planning when monitor control device judges that the operation should be done due to the emergency operation plannings and an operation planning device aiding the formation of the operation plannings. When the state of the power plant exceeds a normal control region, the reactor power is lowered automatically by so much as a predetermined value or to a predetermined level, to automatically return the plant state to the normal control region. In this way, the plant operation efficiency can be improved. Further, after automatic operation, since operation plannings for recovering original operation plannings are prepared efficiently and recovered operation plannings are started in a short period of time, the operators' burden can be mitigated and power saving can be attained. (N.H.)

High-Power Ion Thruster Technology

Science.gov (United States)

Beattie, J. R.; Matossian, J. N.

1996-01-01

Performance data are presented for the NASA/Hughes 30-cm-diam 'common' thruster operated over the power range from 600 W to 4.6 kW. At the 4.6-kW power level, the thruster produces 172 mN of thrust at a specific impulse of just under 4000 s. Xenon pressure and temperature measurements are presented for a 6.4-mm-diam hollow cathode operated at emission currents ranging from 5 to 30 A and flow rates of 4 sccm and 8 sccm. Highly reproducible results show that the cathode temperature is a linear function of emission current, ranging from approx. 1000 C to 1150 C over this same current range. Laser-induced fluorescence (LIF) measurements obtained from a 30-cm-diam thruster are presented, suggesting that LIF could be a valuable diagnostic for real-time assessment of accelerator-arid erosion. Calibration results of laminar-thin-film (LTF) erosion badges with bulk molybdenum are presented for 300-eV xenon, krypton, and argon sputtering ions. Facility-pressure effects on the charge-exchange ion current collected by 8-cm-diam and 30-cm-diam thrusters operated on xenon propellant are presented to show that accel current is nearly independent of facility pressure at low pressures, but increases rapidly under high-background-pressure conditions.

Small Horizontal Axis Wind Turbine under High Speed Operation: Study of Power Evaluation

Science.gov (United States)

Moh. M. Saad, Magedi; Mohd, Sofian Bin; Zulkafli, Mohd Fadhli Bin; Abdullah, Aslam Bin; Rahim, Mohammad Zulafif Bin; Subari, Zulkhairi Bin; Rosly, Nurhayati Binti

2017-10-01

Mechanical energy is produced through the rotation of wind turbine blades by air that convert the mechanical energy into electrical energy. Wind turbines are usually designed to be use for particular applications and design characteristics may vary depending on the area of use. The variety of applications is reflected on the size of turbines and their infrastructures, however, performance enhancement of wind turbine may start by analyzing the small horizontal axis wind turbine (SHAWT) under high wind speed operation. This paper analyzes the implementations of SHAWT turbines and investigates their performance in both simulation and real life. Depending on the real structure of the rotor geometry and aerodynamic test, the power performance of the SHAWT was simulated using ANSYS-FLUENT software at different wind speed up to 33.33 m/s (120km/h) in order to numerically investigate the actual turbine operation. Dynamic mesh and user define function (UDF) was used for revolving the rotor turbine via wind. Simulation results were further validated by experimental data and hence good matching was yielded. And for reducing the energy producing cost, car alternator was formed to be used as a small horizontal wind turbine. As a result, alternator-based turbine system was found to be a low-cost solution for exploitation of wind energy.

An analysis of nuclear power plant operating costs

International Nuclear Information System (INIS)

1988-01-01

This report presents the results of a statistical analysis of nonfuel operating costs for nuclear power plants. Most studies of the economic costs of nuclear power have focused on the rapid escalation in the cost of constructing a nuclear power plant. The present analysis found that there has also been substantial escalation in real (inflation-adjusted) nonfuel operating costs. It is important to determine the factors contributing to the escalation in operating costs, not only to understand what has occurred but also to gain insights about future trends in operating costs. There are two types of nonfuel operating costs. The first is routine operating and maintenance expenditures (O and M costs), and the second is large postoperational capital expenditures, or what is typically called ''capital additions.'' O and M costs consist mainly of expenditures on labor, and according to one recently completed study, the majoriy of employees at a nuclear power plant perform maintenance activities. It is generally thought that capital additions costs consist of large maintenance expenditures needed to keep the plants operational, and to make plant modifications (backfits) required by the Nuclear Regulatory Commission (NRC). Many discussions of nuclear power plant operating costs have not considered these capital additions costs, and a major finding of the present study is that these costs are substantial. The objective of this study was to determine why nonfuel operating costs have increased over the past decade. The statistical analysis examined a number of factors that have influenced the escalation in real nonfuel operating costs and these are discussed in this report. 4 figs, 19 tabs

Review of the total system related to operation of nuclear-powered ship

International Nuclear Information System (INIS)

Takamasa, Tomoji; Miyashita, Kunio

2000-01-01

establishment of laws and standards related to the operation of a nuclear-powered ship, were discussed. The group evaluated shipping costs for nuclear-powered container ships using the MRX (Marine Reactor X, as currently designed by JAERI), sailing the North Pacific route. The cost report focused on whether large, high-speed container ships with the MRX, carrying a varying number of containers (4000, 6000, and 8000 TEU) and sailing at varying ship speeds (25, 30, and 34 knots) could compete economically with diesel ships. Comparing transportation costs for diesel container ships and nuclear-powered ships operated on the Pacific Ocean, we found that the latter had an advantage over the former when ship speed was over 30 knots. (author)

Operation manual for the core flow test loop zone power-supply controller

Energy Technology Data Exchange (ETDEWEB)

Harper, R.E.

1981-11-01

The core flow test loop, which is part of the Gas-Cooled Fast Breeder Reactor Program (GCFR) at ORNL, is a high-pressure, high-temperature, out-of-reactor helium circulation system that is being constructed to permit study of the performance at steady-state and transient conditions of simulated segments of core assemblies for a GCFR demonstration plant. The simulated core segments, which are divided into zones, contain electrical heating elements to simulate the heat generated by fission. To control the power which is applied to a zone, a novel multitapped transformer and zone power control system have been designed and built which satisfy stringent design criteria. The controller can match power output to demand to within better than +-1% over a 900:1 dynamic range and perform full-power transients within 1 s. The power is applied in such a way as to minimize the electromagnetic interference at the bandwidth of the loop instrumentation, and the controller incorporates several error detection techniques, making it inherently fail-safe. The operation manual describes the specifications, operating instructions, error detection capabilities, error recovery, troubleshooting, calibration and QA procedures, and maintenance requirements. Also included are sections on the theory of operation, circuitry description, and a complete set of schematics.

Higher operational safety of nuclear power plants by evaluating the behaviour of operating personnel

International Nuclear Information System (INIS)

Mertins, M.; Glasner, P.

1990-01-01

In the GDR power reactors have been operated since 1966. Since that time operational experiences of 73 cumulative reactor years have been collected. The behaviour of operating personnel is an essential factor to guarantee the safety of operation of the nuclear power plant. Therefore a continuous analysis of the behaviour of operating personnel has been introduced at the GDR nuclear power plants. In the paper the overall system of the selection, preparation and control of the behaviour of nuclear power plant operating personnel is presented. The methods concerned are based on recording all errors of operating personnel and on analyzing them in order to find out the reasons. The aim of the analysis of reasons is to reduce the number of errors. By a feedback of experiences the nuclear safety of the nuclear power plant can be increased. All data necessary for the evaluation of errors are recorded and evaluated by a computer program. This method is explained thoroughly in the paper. Selected results of error analysis are presented. It is explained how the activities of the personnel are made safer by means of this analysis. Comparisons with other methods are made. (author). 3 refs, 4 figs

High Power RF Transmitters for ICRF Applications on EAST

International Nuclear Information System (INIS)

Mao Yuzhou; Yuan Shuai; Zhao Yanping; Zhang Xinjun; Chen Gen; Cheng Yan; Wang Lei; Ju Songqing; Deng Xu; Qin Chengming; Yang Lei; Kumazawa, R.

2013-01-01

An Ion Cyclotron Range of Frequency (ICRF) system with a radio frequency (RF) power of 4 × 1.5 MW was developed for the Experimental Advanced Superconducting Tokamak (EAST). High RF power transmitters were designed as a part of the research and development (R and D) for an ICRF system with long pulse operation at megawatt levels in a frequency range of 25 MHz to 70 MHz. Studies presented in this paper cover the following parts of the high power transmitter: the three staged high power amplifier, which is composed of a 5 kW wideband solid state amplifier, a 100 kW tetrode drive stage amplifier and a 1.5 MW tetrode final stage amplifier, and the DC high voltage power supply (HVPS). Based on engineering design and static examinations, the RF transmitters were tested using a matched dummy load where an RF output power of 1.5 MW was achieved. The transmitters provide 6 MW RF power in primary phase and will reach a level up to 12 MW after a later upgrade. The transmitters performed successfully in stable operations in EAST and HT-7 devices. Up to 1.8 MW of RF power was injected into plasmas in EAST ICRF heating experiments during the 2010 autumn campaign and plasma performance was greatly improved.

Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

Energy Technology Data Exchange (ETDEWEB)

Gevorgian, V.; Singh, M.; Muljadi, E.

2011-12-01

In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmission requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.

High-power pulsed lasers

International Nuclear Information System (INIS)

Holzrichter, J.F.

1980-01-01

The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization

HEMP emergency planning and operating procedures for electric power systems. Power Systems Technology Program

Energy Technology Data Exchange (ETDEWEB)

Reddoch, T.W.; Markel, L.C. [Electrotek Concepts, Inc., Knoxville, TN (United States)

1991-12-31

Investigations of the impact of high-altitude electromagnetic pulse (HEMP) on electric power systems and electrical equipment have revealed that HEMP creates both misoperation and failures. These events result from both the early time E{sub 1} (steep-front pulse) component and the late time E{sub 3} (geomagnetic perturbations) component of HEMP. In this report a HEMP event is viewed in terms of its marginal impact over classical power system disturbances by considering the unique properties and consequences of HEMP. This report focuses on system-wide electrical component failures and their potential consequences from HEMP. In particular, the effectiveness of planning and operating procedures for electric systems is evaluated while under the influence of HEMP. This assessment relies on published data and characterizes utilities using the North American Electric Reliability Council`s regions and guidelines to model electric power system planning and operations. Key issues addressed by the report include how electric power systems are affected by HEMP and what actions electric utilities can initiate to reduce the consequences of HEMP. The report also reviews the salient features of earlier HEMP studies and projects, examines technology trends in the electric power industry which are affected by HEMP, characterizes the vulnerability of power systems to HEMP, and explores the capability of electric systems to recover from a HEMP event.

State of the art of High Temperature Power Electronics

OpenAIRE

Buttay , Cyril; Planson , Dominique; Allard , Bruno; Bergogne , Dominique; Bevilacqua , Pascal; Joubert , Charles; Lazar , Mihai; Martin , Christian; Morel , Hervé; Tournier , Dominique; Raynaud , Christophe

2009-01-01

International audience; High temperature power electronics has become possible with the recent availability of silicon carbide devices. This material, as other wide-bandgap semiconductors, can operate at temperatures above 500°C, whereas silicon is limited to 150-200°C. Applications such as transportation or deep oil and gas wells drilling can benefit. A few converters operating above 200°C have been demonstrated, but work is still ongoing to design and build a power system able to operate in...

A Multiagent System for Autonomous Operation of Islanded Microgrids Based on a Power Market Environment

Directory of Open Access Journals (Sweden)

Myong-Chul Shin

2010-12-01

Full Text Available One of the most important requirements of microgrid operation is to maintain a constant frequency such as 50 Hz or 60 Hz, which is closely related to a power balance between supply and demand. In general, microgrids are connected to power grids and surplus/shortage power of microgrids is traded with power grids. Since islanded microgrids are isolated from any power grids, the decrease in generation or load-shedding can be used to maintain the frequency when a power imbalance between supply and demand occurs. The power imbalance restricts the electricity use of consumers in the case of supply shortage and the power supply of suppliers in the case of supply surplus. Therefore, the islanded microgrid should be operated to reduce power imbalance conditions. Meanwhile, the microgrid is a small-scale power system and the employment of skillful operators for effective operation of its components requires high costs. Therefore, automatic operation of the components is effective realistically. In addition, the components are distributed in the microgrid and their operation should consider their owners’ profits. For these reasons, a multiagent system application can be a good alternative for microgrid operation. In this paper, we present a multiagent system for autonomous operation of the islanded microgrid on a power market environment. The proposed multiagent system is designed based on a cooperative operation scheme. We show the functionality and the feasibility of the proposed multiagent system through several tests.

A multiagent system for autonomous operation of islanded microgrids based on a power market environment

Energy Technology Data Exchange (ETDEWEB)

Kim, H.-M. [Department of Electrical Engineering, University of Incheon/12-1, Sondo-dong, Yeonsu-gu, Incheon, 406-840 (Korea, Republic of); Kinoshita, T. [Graduate School of Information Science, Tohoku University/2-1-1, Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Shin, M.-Ch. [School of Information and Communication Engineering, Sungkyunkwan University/300, Cheoncheon-dong, Jangan-gu, Suwon, Gyeonggi-do, 440-746 (Korea, Republic of)

2010-12-15

One of the most important requirements of microgrid operation is to maintain a constant frequency such as 50 Hz or 60 Hz, which is closely related to a power balance between supply and demand. In general, microgrids are connected to power grids and surplus/shortage power of microgrids is traded with power grids. Since islanded microgrids are isolated from any power grids, the decrease in generation or load-shedding can be used to maintain the frequency when a power imbalance between supply and demand occurs. The power imbalance restricts the electricity use of consumers in the case of supply shortage and the power supply of suppliers in the case of supply surplus. Therefore, the islanded microgrid should be operated to reduce power imbalance conditions. Meanwhile, the microgrid is a small-scale power system and the employment of skillful operators for effective operation of its components requires high costs. Therefore, automatic operation of the components is effective realistically. In addition, the components are distributed in the microgrid and their operation should consider their owners' profits. For these reasons, a multiagent system application can be a good alternative for microgrid operation. In this paper, we present a multiagent system for autonomous operation of the islanded microgrid on a power market environment. The proposed multiagent system is designed based on a cooperative operation scheme. We show the functionality and the feasibility of the proposed multiagent system through several tests. (authors)

High-Performance Constant Power Generation in Grid-Connected PV Systems

DEFF Research Database (Denmark)

Sangwongwanich, Ariya; Yang, Yongheng; Blaabjerg, Frede

2016-01-01

An advanced power control strategy by limiting the maximum feed-in power of PV systems has been proposed, which can ensure a fast and smooth transition between maximum power point tracking and Constant Power Generation (CPG). Regardless of the solar irradiance levels, high-performance and stable...... operation are always achieved by the proposed control strategy. It can regulate the PV output power according to any set-point, and force the PV systems to operate at the left side of the maximum power point without stability problems. Experimental results have verified the effectiveness of the proposed CPG...

Low carbon technologies as providers of operational flexibility in future power systems

International Nuclear Information System (INIS)

Pavić, Ivan; Capuder, Tomislav; Kuzle, Igor

2016-01-01

Highlights: • Mixed integer linear programming model for provision of multiple services from EV. • EV energy and reserve services provision effects on power system operation. • Impacts of conventional unit’s decommission on system’s operation and flexibility. • Assessment of power system’s flexibility under different wind generation polices. - Abstract: The paper presents a unit commitment model, based on mixed integer linear programming, capable of assessing the impact of electric vehicles (EV) on provision of ancillary services in power systems with high share of renewable energy sources (RES). The analyses show how role of different conventional units changes with integration of variable and uncertain RES and how introducing a flexible sources on the demand side, in this case EV, impact the traditional provision of spinning/contingency reserve services. In addition, technical constraints of conventional units, such as nuclear, gas or coal, limit the inherit flexibility of the system which results in curtailing clean renewable sources and inefficient operation. Following on that, sensitivity analyses of operational cost and wind curtailment shows which techno-economic constraints impact the flexibility of the high RES systems the most and how integration of more flexible units or decommission of conventional nuclear, coal and gas driven power plants would impact the system’s operation. Finally, two different wind generation polices (wind penalization and wind turbines as reserve providers) have been analysed in terms of operational flexibility through different stages of conventional unit’s decommission and compared with the same analyses when EV were used as reserve providers.

Test setup for accelerated test of high power IGBT modules with online monitoring of Vce and Vf voltage during converter operation

DEFF Research Database (Denmark)

de Vega, Angel Ruiz; Ghimire, Pramod; Pedersen, Kristian Bonderup

2014-01-01

Several accelerated test methods exist in order to study the failures mechanisms of the high power IGBT modules like temperature cycling test or power cycles based on DC current pulses. The main drawback is that the test conditions do not represent the real performance and stress conditions...... of the device in real application. The hypothesis is that ageing of power modules closer to real environment including cooling system, full dc-link voltage and continuous PWM operation could lead to more accurate study of failure mechanism. A new type of test setup is proposed, which can create different real...... load conditions like in the field. Furthermore, collector-emitter voltage (Vce) has been used as indicator of the wear-out of the high power IGBT module. The innovative monitoring system implemented in the test setup is capable of measure the Vce and forward voltage of the antiparallel diode (Vf...

High-power density miniscale power generation and energy harvesting systems

International Nuclear Information System (INIS)

Lyshevski, Sergey Edward

2011-01-01

This paper reports design, analysis, evaluations and characterization of miniscale self-sustained power generation systems. Our ultimate objective is to guarantee highly-efficient mechanical-to-electrical energy conversion, ensure premier wind- or hydro-energy harvesting capabilities, enable electric machinery and power electronics solutions, stabilize output voltage, etc. By performing the advanced scalable power generation system design, we enable miniscale energy sources and energy harvesting technologies. The proposed systems integrate: (1) turbine which rotates a radial- or axial-topology permanent-magnet synchronous generator at variable angular velocity depending on flow rate, speed and load, and, (2) power electronic module with controllable rectifier, soft-switching converter and energy storage stages. These scalable energy systems can be utilized as miniscale auxiliary and self-sustained power units in various applications, such as, aerospace, automotive, biotechnology, biomedical, and marine. The proposed systems uniquely suit various submersible and harsh environment applications. Due to operation in dynamic rapidly-changing envelopes (variable speed, load changes, etc.), sound solutions are researched, proposed and verified. We focus on enabling system organizations utilizing advanced developments for various components, such as generators, converters, and energy storage. Basic, applied and experimental findings are reported. The prototypes of integrated power generation systems were tested, characterized and evaluated. It is documented that high-power density, high efficiency, robustness and other enabling capabilities are achieved. The results and solutions are scalable from micro (∼100 μW) to medium (∼100 kW) and heavy-duty (sub-megawatt) auxiliary and power systems.

Spanish Power Exchange Market Concepts and Operating Experience

International Nuclear Information System (INIS)

Gonzalez, J. J.; Gamito, C.

2000-01-01

On January, 1st, 1998, the Spanish Electricity Market started operations. All generators, distributors, commercialization companies, and final consumers negotiate al power exchanges either through the spot market or using bilateral contracts. The Spanish Power Exchange Market Operator (Compania Operadora del Mercado Espanol de electricidad, OMEL) is responsible for the management of the market and for the economic settlement and billing of a transactions on the Power Exchange market, and the technical operational process handled by the System Operator. This paper describes in detail the Spanish market principles and the experience gathered through the design, installation and first two years of market operation. The paper presents also the Spanish market results from January 1998 up to December 1999 indicating each specific market results and aggregate statistics. (Author)

Research of the Power Plant Operational Modes

Directory of Open Access Journals (Sweden)

Koismynina Nina M.

2017-01-01

Full Text Available In this article the algorithm of the power plant operational modes research is offered. According to this algorithm the program for the modes analysis and connection power transformers choice is developed. The program can be used as educational means for studying of the power plant electric part, at the same time basic data are provided. Also the program can be used for the analysis of the working power plants modes. Checks of the entered data completeness and a choice correctness of the operational modes are provided in the program; in all cases of a deviation from the correct decisions to the user the relevant information is given.

Improving operator quality at Genkai Nuclear Power Plant

International Nuclear Information System (INIS)

Kuwano, Takeshi.

1989-01-01

Improvement in operator quality, or improvement in an operator's skill and professional knowledge, is of prime importance because of its great influence on safe and steady plant operation. This paper describes the education and training of reactor operators at the Genkai pressurized water reactor nuclear power plant with respect to the following topics: organization of Genkai power plant; education and training program management; training at the Nuclear Training Center; training and education on-site including emergency procedures training, normal operating procedures training, informational study of emergency conditions in existing plants, and all-around training of operators; qualifying tests for supervisors; and operator motivation

Mobile Hybrid Power System Theory of Operation

OpenAIRE

Pierce, Timothy M. Jr.

2016-01-01

Efficiency is a driving constraint for electrical power systems as global energy demands are ever increasing. Followed by the introduction of diesel generators, electricity has become available in more locations than ever. However, operating a diesel generator on its own is not the most energy efficient. This is because the high crest factor loads, of many applications, decrease the fuel efficiency of a hydrocarbon generator. To understand this, we need to understand how an electrical load af...

Innovation of nuclear power operation in KHNP

International Nuclear Information System (INIS)

Lee, Byung Sik

2007-01-01

KHNP has operated the nuclear plants with two major functional areas, operation and maintenance very similar to fossil plant operation. KHNP has recently sent engineers to high performing nuclear power plants in usa and canada for training and familiarization with the engineering organization operation, processes and programs. KHNP has also established a system engineering section at each plant since July 2003. However the system engineering section has not achieved desired results because of a lack of understanding to implement the engineering function and processes. This indicates poor change management preparedness and implementation at KHNP. In September 2005. K SET/(KHNP Special Engineering Task Force Team) was established to enhance KHNP's engineering capability: especially the System Engineering function. The team consists of 13 members: 9 KHNP engineers (including one team manager) who have more than one year's experience working or training in USA or Canada, and 4 foreign engineers who have a wide range of experience and knowledge of engineering areas in Nuclear Power Plants of USA. The team first performed a gap analysis comparing performance and work behavior of 2 nd plant to those of world best practice. this was done by interviewing employees and reviewing relevant document. The team identified 26 significant performance gaps among 120 function areas, prioritized the 26 gape, and verified the effectiveness of the selection of gaps by comparing it to SNPM(standard nuclear performance model) developed by NEI

Anomalous dimension of subleading-power N-jet operators

Science.gov (United States)

Beneke, Martin; Garny, Mathias; Szafron, Robert; Wang, Jian

2018-03-01

We begin a systematic investigation of the anomalous dimension of subleading power N-jet operators in view of resummation of logarithmically enhanced terms in partonic cross sections beyond leading power. We provide an explicit result at the one-loop order for fermion-number two N-jet operators at the second order in the power expansion parameter of soft-collinear effective theory.

Fatigue assessments in operating nuclear power plants

International Nuclear Information System (INIS)

Gosselin, S.R.; Deardorff, A.F.; Peltola, D.W.

1994-01-01

In November 1991, the ASME Section XI Task Group on Operating Plant Fatigue Assessment was formed to develop criteria and evaluation methodology for evaluating the effects of cyclic operation in operating nuclear power plants. The objective was to develop guidelines for inclusion in Section XI that could be used by plant operators in evaluating fatigue concerns and their impact on serviceability. This paper discusses the work performed by the Task Group. It explores the concept of ''Fatigue Design Basis'' versus ''Fatigue Operating Basis'' by examining the roles of ASME Section III and ASME Section XI in the design and operation of the nuclear power plants. Guidelines are summarized that may help plant operators perform effective design transient cycle evaluations and optimize cycle counting and fatigue usage tracking. The alternative fatigue evaluation approach using flaw tolerance is also introduced

A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

DEFF Research Database (Denmark)

Hu, Rui; Hu, Weihao; Li, Pengfei

2016-01-01

and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close to its...... stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the restoration....... In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified IEEE 30 Buses...

Automatic Learning of Fine Operating Rules for Online Power System Security Control.

Science.gov (United States)

Sun, Hongbin; Zhao, Feng; Wang, Hao; Wang, Kang; Jiang, Weiyong; Guo, Qinglai; Zhang, Boming; Wehenkel, Louis

2016-08-01

Fine operating rules for security control and an automatic system for their online discovery were developed to adapt to the development of smart grids. The automatic system uses the real-time system state to determine critical flowgates, and then a continuation power flow-based security analysis is used to compute the initial transfer capability of critical flowgates. Next, the system applies the Monte Carlo simulations to expected short-term operating condition changes, feature selection, and a linear least squares fitting of the fine operating rules. The proposed system was validated both on an academic test system and on a provincial power system in China. The results indicated that the derived rules provide accuracy and good interpretability and are suitable for real-time power system security control. The use of high-performance computing systems enables these fine operating rules to be refreshed online every 15 min.

Fort St. Vrain reactor performance and operation to full power

International Nuclear Information System (INIS)

Simon, W.A.; Bramblett, G.C.

1982-01-01

The Fort St. Vrain Nuclear Generating Station, powered by a high-temperature gas-cooled reactor (HTGR), has now been tested to full thermal power. Testing was conducted for the dual purposes of demonstrating component and system capability as a part of the rise-to-power program and determining core fluctuation/redistribution behavior under full power conditions. Both objectives were met. Full power performance of all major components and the achievement of nearly all design objectives has been verified. In addition, the tests showed that the fluctuation phenomenon has been corrected. Core region outlet temperature redistributions have been characterized, related to a physical mechanism, and shown to be inconsequential for overall plant operation

DIII-D ICRF high voltage power supply regulator upgrade

International Nuclear Information System (INIS)

Cary, W.P.; Burley, B.L.; Grosnickle, W.H.

1997-11-01

For reliable operation and component protection, of the 2 MW 30--120 MHz ICRF Amplifier System on DIII-D, it is desirable for the amplifier to respond to high VSWR conditions as rapidly as possible. This requires a rapid change in power which also means a rapid change in the high voltage power supply current demands. An analysis of the power supply's regulator dynamics was needed to verify its expected operation during such conditions. Based on this information it was found that a new regulator with a larger dynamic range and some anticipation capability would be required. This paper will discuss the system requirements, the as-delivered regulator performance, and the improved performance after installation of the new regulator system. It will also be shown how this improvement has made the amplifier perform at higher power levels more reliably

Shutdown and low-power operation at commercial nuclear power plants in the United States

International Nuclear Information System (INIS)

1993-09-01

The report contains the results of the NRC Staff's evaluation of shutdown and low-power operations at US commercial nuclear power plants. The report describes studies conducted by the staff in the following areas: Operating experience related to shutdown and low-power operations, probabilistic risk assessment of shutdown and low-power conditions and utility programs for planning and conducting activities during periods the plant is shut down. The report also documents evaluations of a number of technical issues regarding shutdown and low-power operations performed by the staff, including the principal findings and conclusions. Potential new regulatory requirements are discussed, as well as potential changes in NRC programs. A draft report was issued for comment in February 1992. This report is the final version and includes the responses to the comments along with the staff regulatory analysis of potential new requirements

Highly-stabilized power supply for synchrotron accelerators. High speed, low ripple power supply

Energy Technology Data Exchange (ETDEWEB)

Sato, Kenji [Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics; Kumada, Masayuki; Fukami, Kenji; Koseki, Shoichiro; Kubo, Hiroshi; Kanazawa, Toru

1997-02-01

In synchrotron accelerators, in order to utilize high energy beam effectively, those are operated by repeating acceleration and taking-out at short period. In order to accelerate by maintaining beam track stable, the tracking performance with the error less than 10{sup -3} in the follow-up of current is required for the power supply. Further, in order to maintain the intensity and uniformity of beam when it is taken out, very low ripple is required for output current. The power supply having such characteristics has been developed, and applied to the HIMAC and the SPring-8. As the examples of the application of synchrotrons, the accelerators for medical treatment and the generation of synchrotron radiation are described. As to the power supply for the deflection magnets and quadrupole magnets of synchrotron accelerators, the specifications of the main power supply, the method of reducing ripple, the method of improving tracking, and active filter control are reported. As to the test results, the measurement of current ripple and tracking error is shown. The lowering of ripple was enabled by common mode filter and the symmetrical connection of electromagnets, and high speed response was realized by the compensation for delay with active filter. (K.I.)

Experiences of operation for Ikata Nuclear Power Station

International Nuclear Information System (INIS)

Kashimoto, Shigeyuki

1979-01-01

No. 1 plant in the Ikata Nuclear Power Station, Shikoku Electric Power Co., Inc., is a two-loop PWR unit with electric output of 566 MW, and it began the commercial operation on September 30, 1977, as the first nuclear power station in Shikoku. It is the 13th LWR and 7th PWR in Japan. The period of construction was 52 months since it had been started in June, 1973. During the period, it became the object of the first administrative litigation to seek the cancellation of permission to install the reactor, and it was subjected to the influence of the violent economical variation due to the oil shock, but it was completed as scheduled. After the start of operation, it continued the satisfactory operation, and generated about 2.35 billion KWh for 4300 operation hours. It achieved the rate of utilization of 96.7%. Since March 28, 1978, the first periodical inspection was carried out, and abnormality was not found in the reactor, the steam generator and the fuel at all. The period of inspection was 79 days and shorter than expected. The commercial operation was started again on June 14. The outline of the Ikata Nuclear Power Station, its state of operation, and the periodical inspection are reported. Very good results were able to be reported on the operation for one year, thanks to the valuable experiences offered by other electric power companies. (Kako, I.)

Load following operation of nuclear power plants for meeting power system requirements

International Nuclear Information System (INIS)

Isoda, Hachiro

1987-01-01

This paper describes a calculating program on the availability factors of nuclear, thermal and pumed storage hydro power stations and some calculated results for typical three load factors, 55 %, 60 % and 71 %, are provided when the share of the nuclea power station in the generation facilities is increased. The load following requirement of the nuclear power station is also provided. Load following requirement: If there is a 10 % pumped storage hydro power station, the nuclear power station enables to be operated with its rated output up to 30 % - 35 % of its share. Its daily load following operation for 40 % and 50 % nuclear power station needs every weekend and every day respectively. Availability factor: The availability factor of the nuclear power station manages to get 80 % (maximum availability factor of the nuclear power station in this study) up to 30 % share of it with 10 % pumpued storage hydro power station. When the nuclear power station shares 40 % and 50 %, its availability factor decreases down 1 % and 5 % respectively. (author)

Qualification of nuclear power plant operations personnel

International Nuclear Information System (INIS)

1984-01-01

With the ultimate aim of reducing the possibility of human error in nuclear power plant operations, the Guidebook discusses the organizational aspects, the staffing requirements, the educational systems and qualifications, the competence requirements, the ways to establish, preserve and verify competence, the specific aspects of personnel management and training for nuclear power plant operations, and finally the particular situations and difficulties to be overcome by utilities starting their first nuclear power plant. An important aspect presented in the Guidebook is the experience in training and qualification of nuclear power plant personnel in various countries: Argentina, Belgium, Canada, Czechoslovakia, France, Federal Republic of Germany, Spain, Sweden, United Kingdom and United States of America

Experimental studies for improvement of thermal effects in a high-power fiber-coupled diode laser module operating at 808 nm

Science.gov (United States)

El-Sherif, Ashraf F.; Hussein, Khalid; Hassan, Mahmoud F.; Talat, Mahmoud M.

2012-03-01

High power diode laser module operating at 808 nm is required for different applications, such as developing an efficient high power Nd3+-doped solid state laser and Tm3+ -doped silica fiber laser, industrial, medical and military applications. Optical and thermal images characterization for a fiber-coupled high power diode laser module is presented experimentally for 6.6 Watt output optical power .An external temperature controller system was designed, which stabilizes the central wavelength at 808 nm at 25°C over a wide range of diode laser driving current from 1A to 6 A. without this cooling system, the wavelength changes by 0.35nm/°C for temperature changes from 20°C to 40°C at the same range of the driving current. In this paper we have present a methodology for temperature reduction of a 808 nm high power diode laser module, based on dynamically thermal control, which is known as dynamic thermal management. Stabilization of the output wavelength has been done by using proportional speed control (PSC) of a CPU cooling fan with certain scheme of straight fins heat sink. Two electronic circuits based on pulse width modulation (PWM) in microcontroller and comparators IC have been used. This technique can be considered as an effective mechanism for reducing temperature and power dissipation to make stabilization of the diode laser output wavelength by preventing heat accumulation from the thermo electric cooling (TEC) inside the diode laser module confirmed by thermal images.

A Systematic Multi-Time Scale Solution for Regional Power Grid Operation

Science.gov (United States)

Zhu, W. J.; Liu, Z. G.; Cheng, T.; Hu, B. Q.; Liu, X. Z.; Zhou, Y. F.

2017-10-01

Many aspects need to be taken into consideration in a regional grid while making schedule plans. In this paper, a systematic multi-time scale solution for regional power grid operation considering large scale renewable energy integration and Ultra High Voltage (UHV) power transmission is proposed. In the time scale aspect, we discuss the problem from month, week, day-ahead, within-day to day-behind, and the system also contains multiple generator types including thermal units, hydro-plants, wind turbines and pumped storage stations. The 9 subsystems of the scheduling system are described, and their functions and relationships are elaborated. The proposed system has been constructed in a provincial power grid in Central China, and the operation results further verified the effectiveness of the system.

Operational safety of nuclear power plants

International Nuclear Information System (INIS)

Tanguy, P.

1987-01-01

The operational safety of nuclear power plants has become an important safety issue since the Chernobyl accident. A description is given of the various aspects of operational safety, including the importance of human factors, responsibility, the role and training of the operator, the operator-machine interface, commissioning and operating procedures, experience feedback, and maintenance. The lessons to be learnt from Chernobyl are considered with respect to operator errors and the management of severe accidents. Training of personnel, operating experience feedback, actions to be taken in case of severe accidents, and international cooperation in the field of operational safety, are also discussed. (U.K.)

Hardware and software system for monitoring oil pump operation in power high-voltage transformers

Directory of Open Access Journals (Sweden)

Михайло Дмитрович Дяченко

2017-07-01

Full Text Available The article considers the basic prerequisites for the creation of an automated monitoring system for oil pumps of high-voltage transformers. This is due to the fact that the long operation of oil pumps results in deterioration and destruction of bearings, rubbing of the rotor, breakage and damage to the impeller, leakage, etc., which inevitably causes a significant decrease in the insulating properties of the transformer oil and leads to expenditures for its further recovery. False triggerings of gas protection sometimes occur. Continuous operation of the electric motor also requires additional equipment to protect the motor itself from various emergency situations, such as a short in the stator winding, a housing breakdown, an incomplete phase mode, etc. The use of stationary systems provides: diagnosing defects at an early stage of their development, increasing the reliability and longevity of the equipment components, increasing the overhaul period, decreasing the number of emergency stops, and adjusting the schedule of preventative maintenance. The basic principles of identification of the damaged part of the oil pump are given, the hardware and algorithmic solutions are considered in the work. The full-scale tests of the model sample on the power transformer of the high-voltage substation confirmed the assumption of the possibility of detecting the damaged unit separating it from the rest connected in one mechanical structure. A detailed analysis of the operation of each of the units is carried out by means of the general substation switchboard and displayed as graphs, diagrams and text messages. When the limit values of vibration are reached, faults in the operation of the unit are detected, the overlimit current values, a warning alarm is activated, and the command to disconnect the damaged unit is issued. The optimal solution for the organization of the information collection system using the principle of sensor networks, but combined

Stable operation of a high-power piezoelectric transformer comprising two identical bolt-clamped Langevin-type transducers and a stepped horn

Science.gov (United States)

Adachi, Kazunari; Suzuki, Kohei; Shibamata, Yuki

2018-06-01

We previously developed a 100 W piezoelectric transformer comprising two identical bolt-clamped Langevin-type transducers (BLTs) and a stepped horn whose cross-sectional area ratio determines the specified step-up voltage transformation ratio. Unlike conventional piezoelectric transformers, this transformer is driven at a frequency quite near its mechanical resonance, and thus can be mechanically held firmly at its clearly identified vibratory node without mechanical energy loss. However, it has been revealed that the high-power operation of the transformer often becomes very unstable owing to the “jumping and dropping” phenomena first found by Takahashi and Hirose [Jpn. J. Appl. Phys. 31, 3055 (1992)]. To avoid this instability, we have investigated the peculiar phenomena, and found that they can be attributed to a heavily distorted electric field inside the piezoelectric ceramic disks of the BLT on the primary side of the transformer being driven by a low-impedance voltage source near the mechanical resonance. The resultant concentration of the electric field leads to the local reversal of piezoelectric polarization in every half period of the vibration, viz., the instability. Consequently, we have developed a scheme for the steady high-power operation of this type of piezoelectric transformer and examined its validity experimentally. The method has eventually improved the linearity and power transfer efficiency of the transformer significantly.

Decontamination of operational nuclear power plants

International Nuclear Information System (INIS)

1981-06-01

In order to reduce the radiation fields around nuclear power plants, and, consequently, to limit the radiation exposure of and dose commitments to the operating and maintenance personnel, the contamination build-up should be kept to a minimum. The most fruitful approach, from the point of view of economics and efficiency, is to tackle the problems of contamination and decontamination in the design and construction phases of the reactor. To do this, knowledge gained from the operation of existing power reactors should be used to make improvements in new designs. New structural materials with low corrosion rates or whose constituents are not activated by neutrons should also be used. For older reactors, in most cases it is already too late to incorporate design changes without extensive and expensive modifications. For these plants, decontamination remains the most efficient way to reduce radiation fields. The aim of this report is to deal with the different decontamination methods that may be applied to nuclear power plant circuits and equipment during operation. The factors that have to be considered in determining the type and the extent of the methods used are the engineering and the planning of the decontamination operation and the treatment of the resulting waste generated during the process are also discussed

Training and qualification of nuclear power plant operators

International Nuclear Information System (INIS)

Ohsuga, Y.

2008-01-01

Based on training experiences of the nuclear power plant operators of pressurized water reactors (PWR) at the Nuclear Power Training Center Ltd. (NTC) in Japan, training programs were reviewed referring to US training programs. A systematic approach is deployed to them, which mainly consist of on-the-job training and the NTC training courses to meet the needs of all operators from beginners to experienced veterans according to their experiences and objectives. The NTC training is conducted using the simulators that simulate the nuclear power plant dynamics through the use of computers. The operators trained at the NTC work in the central control room of every PWR power plant. The NTC also carries out the qualification examinations for the shift managers. (T. Tanaka)

Cascade: a high-efficiency ICF power reactor

International Nuclear Information System (INIS)

Pitts, J.H.

1985-01-01

Cascade attains a net power-plant efficiency of 49% and its cost is competitive with high-temperature gas-cooled reactor, pressurized-water reactor, and coal-fired power plants. The Cascade reactor and blanket are made of ceramic materials and activation is 6 times less than that of the MARS Tandem Mirror Reactor operating at comparable power. Hands-on maintenance of the heat exchangers is possible one day after shutdown. Essentially all tritium is recovered in the vacuum system, with the remainder recovered from the helium power conversion loop. Tritium leakage external to the vacuum system and power conversion loop is only 0.03 Ci/d

High-power density miniscale power generation and energy harvesting systems

Energy Technology Data Exchange (ETDEWEB)

Lyshevski, Sergey Edward [Department of Electrical and Microelectronics Engineering, Rochester Institute of Technology, Rochester, NY 14623-5603 (United States)

2011-01-15

This paper reports design, analysis, evaluations and characterization of miniscale self-sustained power generation systems. Our ultimate objective is to guarantee highly-efficient mechanical-to-electrical energy conversion, ensure premier wind- or hydro-energy harvesting capabilities, enable electric machinery and power electronics solutions, stabilize output voltage, etc. By performing the advanced scalable power generation system design, we enable miniscale energy sources and energy harvesting technologies. The proposed systems integrate: (1) turbine which rotates a radial- or axial-topology permanent-magnet synchronous generator at variable angular velocity depending on flow rate, speed and load, and, (2) power electronic module with controllable rectifier, soft-switching converter and energy storage stages. These scalable energy systems can be utilized as miniscale auxiliary and self-sustained power units in various applications, such as, aerospace, automotive, biotechnology, biomedical, and marine. The proposed systems uniquely suit various submersible and harsh environment applications. Due to operation in dynamic rapidly-changing envelopes (variable speed, load changes, etc.), sound solutions are researched, proposed and verified. We focus on enabling system organizations utilizing advanced developments for various components, such as generators, converters, and energy storage. Basic, applied and experimental findings are reported. The prototypes of integrated power generation systems were tested, characterized and evaluated. It is documented that high-power density, high efficiency, robustness and other enabling capabilities are achieved. The results and solutions are scalable from micro ({proportional_to}100 {mu}W) to medium ({proportional_to}100 kW) and heavy-duty (sub-megawatt) auxiliary and power systems. (author)

Optimal Operation of Energy Storage in Power Transmission and Distribution

Science.gov (United States)

Akhavan Hejazi, Seyed Hossein

In this thesis, we investigate optimal operation of energy storage units in power transmission and distribution grids. At transmission level, we investigate the problem where an investor-owned independently-operated energy storage system seeks to offer energy and ancillary services in the day-ahead and real-time markets. We specifically consider the case where a significant portion of the power generated in the grid is from renewable energy resources and there exists significant uncertainty in system operation. In this regard, we formulate a stochastic programming framework to choose optimal energy and reserve bids for the storage units that takes into account the fluctuating nature of the market prices due to the randomness in the renewable power generation availability. At distribution level, we develop a comprehensive data set to model various stochastic factors on power distribution networks, with focus on networks that have high penetration of electric vehicle charging load and distributed renewable generation. Furthermore, we develop a data-driven stochastic model for energy storage operation at distribution level, where the distribution of nodal voltage and line power flow are modelled as stochastic functions of the energy storage unit's charge and discharge schedules. In particular, we develop new closed-form stochastic models for such key operational parameters in the system. Our approach is analytical and allows formulating tractable optimization problems. Yet, it does not involve any restricting assumption on the distribution of random parameters, hence, it results in accurate modeling of uncertainties. By considering the specific characteristics of random variables, such as their statistical dependencies and often irregularly-shaped probability distributions, we propose a non-parametric chance-constrained optimization approach to operate and plan energy storage units in power distribution girds. In the proposed stochastic optimization, we consider

Quality assurance during operation of nuclear power plants

International Nuclear Information System (INIS)

1981-01-01

This Safety Guide provides requirements and recommendations for the establishment and implementation of quality assurance for activities important to safety during commissioning, operation and decommissioning of a nuclear power plant, hereinafter referred to in this Guide as the operation phase or operation. It applies to activities such as: operating, inspecting, testing, commissioning, refuelling, maintaining, repairing, modifying and eventual shut-down and decommissioning of nuclear power plants. It applies also to associated activities related to safety, such as environmental monitoring and responses to emergencies

Operation reports of nuclear power plants

International Nuclear Information System (INIS)

1983-01-01

The requirements aiming to standardize the program of nuclear power plant operation report, required by Brazilian Energy Commission - CNEN - to evaluate the activities related to the nuclear technical safety and to the radiation protection during the units operational phase, are showed. (E.G.) [pt

Improved Collectors for High Power Gyrotrons

International Nuclear Information System (INIS)

Ives, R. Lawrence; Singh, Amarjit; Read, Michael; Borchard, Philipp; Neilson, Jeff

2009-01-01

High power gyrotrons are used for electron cyclotron heating, current drive and parasitic mode suppression in tokamaks for fusion energy research. These devices are crucial for successful operation of many research programs around the world, including the ITER program currently being constructed in France. Recent gyrotron failures resulted from cyclic fatigue of the copper material used to fabricated the collectors. The techniques used to collect the spent beam power is common in many gyrotrons produced around the world. There is serious concern that these tubes may also be at risk from cyclic fatigue. This program addresses the cause of the collector failure. The Phase I program successfully demonstrated feasibility of a mode of operation that eliminates the cyclic operation that caused the failure. It also demonstrated that new material can provide increased lifetime under cyclic operation that could increase the lifetime by more than on order of magnitude. The Phase II program will complete that research and develop a collector that eliminates the fatigue failures. Such a design would find application around the world.

Annual report on nuclear power station operational management, 1984

International Nuclear Information System (INIS)

1985-09-01

As of the end of fiscal year 1984, 28 nuclear power plants were in operation in Japan, the total power output of which was 20.56 million kW, equivalent to 22.9 % of the total generated electric power in Japan. Now nuclear power generation bears a very important role in the stable supply and cost stabilization of electric power. The result of the capacity factor in fiscal year 1984 was 73.9 %, which showed that the nuclear power generation and safety management technologies in Japan are at the top level in the world. However, in order that nuclear power generation accomplishes the role as main power source sufficiently hereafter by increasing the number of plants, the reliability and economical efficiency must be further improved, and especially the safety management and operational management become important. For the purpose, the operational experience accumulated so far must be effectively utilized. In this book, the outline of the administration on the safety regulation of nuclear power generation, the state of operation of nuclear power plants, the state of accidents and failures, the state of regular inspections and so on are summarized. Also the state of radioactive waste management and the radiation control for workers are reported. (Kako, I.)

Operating experience at Scottish Nuclear's power stations

International Nuclear Information System (INIS)

Blackburn, P.

1991-01-01

A brief history is presented of the design and operation of the four Scottish nuclear power stations currently run by Scottish Nuclear, namely Hunterston 'A' and 'B' and the Torness reactors. A design flaw in the Magnox reactor at Hunterston 'A' led to it being operated at lower than optimal temperature and hence producing less power. For Hunterston 'B' reactor the Advanced Gas Cooled design prototype was used. Operating setbacks and successes are noted. The design chosen for Torness embraced all the good points of Hunterston 'B' but sought to eliminate its faults. After 26 years of successful operation Hunterston 'A' is now being decommissioned, while the other three stations continue to generate electricity successfully. (UK)

Operational results in the Onagawa Nuclear Power Station

International Nuclear Information System (INIS)

Hasegawa, Kanichi; Kato, Katsuya; Terada, Hideo; Kamata, Takakage; Kaimura, Yoshiharu

1986-01-01

In the Onagawa Nuclear Power Station, Unit 1 (BWR type, with electric output 524 MW) started operation in June 1, 1984. The power plant has then continued non-stop operation up to April 2, 1985, thus exhibiting its base load plant. In fiscal 1984, the continuous operation is for 342 days; the capacity factor is about 96.1 %, which is the world's top. During the period, the radioactivity releases to the environment in both liquid and gaseous wastes are below the detection limits. The collective exposure dose for plant personnel is merely 6 man-rem. Subsequently, its 1st periodical inspection was started on April 3, 1985, and finished in July the same year. So, the power plant is now again in operation. (Mori, K.)

Statistical operation of nuclear power plants

International Nuclear Information System (INIS)

Gauzit, Maurice; Wilmart, Yves

1976-01-01

A comparison of the statistical operating results of nuclear power stations as issued in the literature shows that the values given for availability and the load factor often differ considerably from each other. This may be due to different definitions given to these terms or even to a poor translation from one language into another. A critical analysis of these terms as well as the choice of a parameter from which it is possible to have a quantitative idea of the actual quality of the operation obtained is proposed. The second section gives, on an homogenous basis and from the results supplied by 83 nuclear power stations now in operation, a statistical analysis of their operating results: in particular, the two light water lines, during 1975, as well as the evolution in terms of age, of the units or the starting conditions of the units during their first two operating years. Test values thus obtained are compared also to those taken 'a priori' as hypothesis in some economic studies [fr

Operator psychological selection system for nuclear power plant

International Nuclear Information System (INIS)

He Xuhong; Huang Xiangrui

2004-01-01

Based on a detailed job analysis of nuclear power plant operator including operation procedures analysis, interview with personnel familiar with operator job, and 9 events happened in the past in the plant involved operator error analysis, several operator work characteristics and performance influence factors are obtained. According to these specific characteristics and factors, referring to the psychological selection research results in the other related critical occupational fields, a full psychological selection system of nuclear power plant operator is forwarded in this paper, including 21 dimensions in 3 facets as general psychological ability, personality and psychological healthy. Practical measurement methods for the proposed selection dimensions are discussed in the end

Nuclear electric power safety, operation, and control aspects

CERN Document Server

Knowles, J Brian

2013-01-01

Assesses the engineering of renewable sources for commercial power generation and discusses the safety, operation, and control aspects of nuclear electric power From an expert who advised the European Commission and UK government in the aftermath of Three Mile Island and Chernobyl comes a book that contains experienced engineering assessments of the options for replacing the existing, aged, fossil-fired power stations with renewable, gas-fired, or nuclear plants. From geothermal, solar, and wind to tidal and hydro generation, Nuclear Electric Power: Safety, Operation, and Control Aspects ass

Operating experience of Fugen Nuclear Power Station

International Nuclear Information System (INIS)

Ohteru, Shigeru; Kaneko, Jun; Kawahara, Toshio; Matsumoto, Mitsuo

1987-01-01

The prototype ATR 'Fugen' developed as one of the national project has verified the performance and reliability of the advanced thermal reactor system through the operation for about eight years since 1979, and the elucidation of the characteristics in plutonium utilization and the development and verification of the tuilizing techniques have been advanced. Besides, the operational results and the achievement of the technical development are successively reflected to the design of a demonstration reactor. In this paper, the outline of Fugan and the operational results are reported. The ATR Fugen Power Station is that of the prototype reactor of heavy water moderated, boiling light water cooled, pressure tube type, having the electric output of 165 MW. It started the full scale operation on March 20, 1979, and as of January, 1987, the total generated electric power reached about 7 billion kWh, the time of power generation was about 43,000 h, and the average capacity factor was 60.6 %. Plutonium utilization techniques, the flow characteristics and the dynamic plant characteristics of a pressure tube type reactor, the operational characteristics of a heavy water system and the techniques of handling heavy water containing tritium, and the operational reliability and maintainability of the machinery and equipment installed have been studied. (Kako, I.)

Operating Experience at the Aagesta Nuclear Power Station

Energy Technology Data Exchange (ETDEWEB)

Sandstroem, S [ed.

1966-09-15

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW{sub t}) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965.

Operating Experience at the Aagesta Nuclear Power Station

International Nuclear Information System (INIS)

Sandstroem, S.

1966-09-01

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW t ) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965

Operating Experience at the Aagesta Nuclear Power Station

Energy Technology Data Exchange (ETDEWEB)

Sandstroem, S. (ed.)

1966-09-15

Sweden's first nuclear power reactor Agesta, achieved criticality on July 17, 1963. Full power (65 MW{sub t}) was attained on March 20, 1964. Aagesta is a heavy water cooled and moderated pressure vessel reactor used for production of electricity as well as for district heating. The design, assembly and construction etc, of the reactor was described in detail in a staff report by AB Atomenergi, 'The Aagesta Nuclear Power Station' edited by B McHugh, which was published in September, 1964. In the book experiences from the commissioning and the first operation of the reactor were reported as well as findings from the extensive reactor physics studies made during this period. The report now presented is written by members of the operating team at Aagesta since its start. It reflects in general the experiences up to the end of 1965. The Aagesta Log, however, covers the period up to the normal summer stop 1966. The reactor has hitherto produced 506,000 MWh power of which 48,700 MWh have been electric power. In July 1965 the responsibility for the reactor operation was taken over by the Swedish State Power Board from AB Atomenergi, which company had started the reactor and operated it until the summer break 1965.

High field, low current operation of engineering test reactors

International Nuclear Information System (INIS)

Schwartz, J.; Cohn, D.R.; Bromberg, L.; Williams, J.E.C.

1987-06-01

Steady state engineering test reactors with high field, low current operation are investigated and compared to high current, lower field concepts. Illustrative high field ETR parameters are R = 3 m, α ∼ 0.5 m, B ∼ 10 T, β = 2.2% and I = 4 MA. For similar wall loading the fusion power of an illustrative high field, low current concept could be about 50% that of a lower field device like TIBER II. This reduction could lead to a 50% decrease in tritium consumption, resulting in a substantial decrease in operating cost. Furthermore, high field operation could lead to substantially reduced current drive requirements and cost. A reduction in current drive source power on the order of 40 to 50 MW may be attainable relative to a lower field, high current design like TIBER II implying a possible cost savings on the order of $200 M. If current drive is less efficient than assumed, the savings could be even greater. Through larger β/sub p/ and aspect ratio, greater prospects for bootstrap current operation also exist. Further savings would be obtained from the reduced size of the first wall/blanket/shield system. The effects of high fields on magnet costs are very dependent on technological assumptions. Further improvements in the future may lie with advances in superconducting and structural materials

Fuel cell/electrochemical capacitor hybrid for intermittent high power applications

Energy Technology Data Exchange (ETDEWEB)

Jarvis, L P; Atwater, T B; Cygan, P J [Army Communications-Electronics Command (CECOM), Fort Monmouth, NJ (United States). Research and Development Center

1999-05-01

A hybrid power source was demonstrated to successfully power a simulated power load encountered in portable military electronics and communications equipment. The hybrid system consisted of a 25 W proton exchange membrane fuel cell (PEMFC) stack connected in parallel with a 70 F capacitor bank. The cyclic regime of 18.0 W for 2 min followed by 2.5 W for 18 min was chosen as the baseline for the simulation of power load. The operating potential cut-off voltage for pass/failure was set to 3.0 V. At room temperature (23-25 C), the PEMFC alone could not handle the described baseline regime with the PEMFC operating potential dropping below the cut-off voltage within 10 s. The hybrid, however, continuously powered the same regime for 25 h. Its operating potential never reached the voltage cut-off point, not even during the high load of 18.0 W. The tests with hybrid configuration were aborted after 25 h of operation with no signs of output degradation, suggesting that further extended operation was possible. (orig.)

47 CFR 73.664 - Determining operating power.

Science.gov (United States)

2010-10-01

... BROADCAST SERVICES Television Broadcast Stations § 73.664 Determining operating power. (a) The operating... substantially zero reactance and a resistance equal to the transmission line characteristic impedance. During...

High power light gas helicon plasma source for VASIMR

International Nuclear Information System (INIS)

Squire, Jared P.; Chang-Diaz, Franklin R.; Glover, Timothy W.; Jacobson, Verlin T.; McCaskill, Greg E.; Winter, D. Scott; Baity, F. Wally; Carter, Mark D.; Goulding, Richard H.

2006-01-01

In the Advanced Space Propulsion Laboratory (ASPL) helicon experiment (VX-10) we have measured a plasma flux to input gas rate ratio near 100% for both helium and deuterium at power levels up to 10 kW. Recent results at Oak Ridge National Laboratory (ORNL) show enhanced efficiency operation with a high power density, over 5 kW in a 5 cm diameter tube. Our helicon is presently 9 cm in diameter and operates up to 10 kW of input power. The data here uses a Boswell double-saddle antenna design with a magnetic cusp just upstream of the antenna. Similar to ORNL, for deuterium at near 10 kW, we find an enhanced performance of operation at magnetic fields above the lower hybrid matching condition

Powersail High Power Propulsion System Design Study

Science.gov (United States)

Gulczinski, Frank S., III

2000-11-01

A desire by the United States Air Force to exploit the space environment has led to a need for increased on-orbit electrical power availability. To enable this, the Air Force Research Laboratory Space Vehicles Directorate (AFRL/ VS) is developing Powersail: a two-phased program to demonstrate high power (100 kW to 1 MW) capability in space using a deployable, flexible solar array connected to the host spacecraft using a slack umbilical. The first phase will be a proof-of-concept demonstration at 50 kW, followed by the second phase, an operational system at full power. In support of this program, the AFRL propulsion Directorate's Spacecraft Propulsion Branch (AFRL/PRS ) at Edwards AFB has commissioned a design study of the Powersail High Power Propulsion System. The purpose of this study, the results of which are summarized in this paper, is to perform mission and design trades to identify potential full-power applications (both near-Earth and interplanetary) and the corresponding propulsion system requirements and design. The design study shall farther identify a suitable low power demonstration flight that maximizes risk reduction for the fully operational system. This propulsion system is expected to be threefold: (1) primary propulsion for moving the entire vehicle, (2) a propulsion unit that maintains the solar array position relative to the host spacecraft, and (3) control propulsion for maintaining proper orientation for the flexible solar array.

Nuclear power plant operational data compilation system

International Nuclear Information System (INIS)

Silberberg, S.

1980-01-01

Electricite de France R and D Division has set up a nuclear power plant operational data compilation system. This data bank, created through American documents allows results about plant operation and operational material behaviour to be given. At present, French units at commercial operation are taken into account. Results obtained after five years of data bank operation are given. (author)

Increase of hydroelectric power plant operation reliability

International Nuclear Information System (INIS)

Koshumbaev, M.B.

2006-01-01

The new design of the turbine of hydroelectric power plant (HPP) is executed in the form of a pipe with plates. Proposed solution allows increasing the hydroelectric power plant capacity at existing head and water flow. At that time the HPP turbine reliability is increase, its operation performances are improving. Design efficiency is effective mostly for small-scale and micro-HPP due to reliable operation, low-end technology, and harmless ecological application. (author)

Analysis and Research on the effect of the Operation of Small Hydropower in the Regional Power Grid

Science.gov (United States)

Ang, Fu; Guangde, Dong; Xiaojun, Zhu; Ruimiao, Wang; Shengyi, Zhu

2018-03-01

The analysis of reactive power balance and voltage of power network not only affects the system voltage quality, but also affects the economic operation of power grid. In the calculation of reactive power balance and voltage analysis in the past, the problem of low power and low system voltage has been the concern of people. When small hydropower stations in the wet period of low load, the analysis of reactive power surplus and high voltage for the system, if small hydropower unit the capability of running in phase is considered, it can effectively solve the system low operation voltage of the key point on the high side.

Optimum operation of a small power production facility

Energy Technology Data Exchange (ETDEWEB)

Capehart, B.L.; Mahoney, J.F.; Sivazlian, B.D.

1983-09-01

To help reduce the U.S.A.'s dependence on imported oil for electrical power generation, the 1978 National Energy Act established regulations to promote construction and operation of cogeneration and small power production facilities. Many of these facilities are presently under construction, with a great number planned. This paper examines the operation of a small power production facility with on-site generation and storage, on-site use, and connection to an electric utility grid system for the purpose of both selling excess power and buying power. It is assumed that the buying and selling price of electricity varies frequently during the day and that the relevant price and demand data may be accurately projected into the near future. With this system description, a mathematical model is formulated and solved by linear programming to obtain a series of periodic buy and sell decisions so as to maximize the profit from operating the small power production facility. Results are presented to illustrate the methodology for determining potential profits.

Analysis and Solution for Operations of Overcurrent Relay in Wind Power System

Directory of Open Access Journals (Sweden)

Yeonho Ok

2016-06-01

Full Text Available Wind power systems are being integrated increasingly into the power grid because of their large capacity and easy access to the transmission grid. The reliability of wind power plants is very important and the elimination of protective relay’s malfunctions is essential to the mitigation of power quality problems due to the frequent starts and stops of high capacity wind generators. In this study, the problem of frequent false operations of the protective relays are analyzed using real data as line voltages, line currents, and wind speed. A new re-coordination of the overcurrent relay (OCR based on the wind speed is proposed to avoid frequent operations of relays and tested for a grid-connected wind farm. This study verifies that the false actions by the OCRs that are not accompanied by actual electrical faults in the power grid or wind power system can be solved by the appropriate re-coordination of the OCR.

Design of EAST LHCD high power supply feedback control system based on PLC

International Nuclear Information System (INIS)

Hu Huaichuan; Shan Jiafang

2009-01-01

Design of EAST LHCD -35kV/5.6MW high power supply feedback control system based on PLC is described. Industrial computer and PLC are used to control high power supply in the system. PID arithmetic is adopted to achieve the feedback control of voltage of high power supply. Operating system is base on real-time operating system of QNX. Good controlling properties and reliable protective properties of the feedback control system are proved by the experiment results. (authors)

Advances in high voltage power switching with GTOs

International Nuclear Information System (INIS)

Podlesak, T.F.

1990-01-01

The control of high voltage at high power, particularly opening switches, has been difficult in the past. Using gate turnoff thyristors (GTOs) arranged in series enables large currents to be switched at high voltage. The authors report a high voltage opening switch has been successfully demonstrated. This switch uses GTOs in series and successfully operates at voltages higher than the rated voltage of the individual devices. It is believed that this is the first time this has been successfully demonstrated, in that GTOs have been operated in series before, but always in a manner as to not exceed the voltage capability of the individual devices. In short, the devices have not worked together, sharing the voltage, but one device has been operated using several backup devices. Of particular interest is how well the individual devices share the voltage applied to them. Equal voltage sharing between devices is absolutely essential, in order to not exceed the voltage rating of any of the devices in the series chain. This is accomplished at high (microsecond) switching speeds. Thus, the system is useful for high frequency applications as well as high power, making for a flexible circuit system element. This demonstration system is rated at 5 KV and uses 1 KV devices. A larger 24 KV system is under design and will use 4.5 KV devices. In order to design the 24 KV switch, the safe operating area of the large devices must be known thoroughly

Operating experience from Swedish nuclear power plants 2002

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

The total production of electricity from Swedish nuclear power plants was 65.6 TWh during 2002, which is a decrease compared to 2001. The energy capability factor for the 11 Swedish reactors averaged 80.8%. The PWRs at Ringhals averaged 87.6%, while the BWRs, not counting Oskarshamn 1, reached 89.2%. No events, which in accordance to conventions should be reported to IAEA, have occurred during 2002. Operational statistics are presented for each Swedish reactor. The hydroelectric power was 66 TWh, 16% lower than 2000. Wind power contributed 0.5 TWh, and remaining production sources, mainly from solid fuel plants combined with district heating, contributed 10.9 TWh. The electricity generation totalled 143 TWh, considerably less than the record high 2001 figure of 158.7 TWh. The preliminary figures for export were 14.8 TWh and and for import 20.1 TWh.

High-Feedback Operation of Power Electronic Converters

Directory of Open Access Journals (Sweden)

Gennady Y. Mikhal'chenko

2013-03-01

Full Text Available The purpose of this review is to provide a survey of some of the most important bifurcation phenomena that one can observe in pulse-modulated converter systems when operating with high corrector gain factors. Like other systems with switching control, electronic converter systems belong to the class of piecewise-smooth dynamical systems. A characteristic feature of such systems is that the trajectory is “sewed” together from subsequent discrete parts. Moreover, the transitions between different modes of operation in response to a parameter variation are often qualitatively different from the bifurcations we know for smooth systems. The review starts with an introduction to the concept of border-collision bifurcations and also demonstrates the approach by which the full dynamics of the piecewise-linear, time-continuous system can be reduced to the dynamics of a piecewise-smooth map. We describe the main bifurcation structures that one observes in three different types of converter systems: (1 a DC/DC converter; (2 a multi-level DC/DC converter; and (3 a DC/AC converter. Our focus will be on the bifurcations by which the regular switching dynamics becomes unstable and is replaced by ergodic or resonant periodic dynamics on the surface of a two-dimensional torus. This transition occurs when the feedback gain is increased beyond a certain threshold, for instance in Electronics 2013, 2 114 order to improve the speed and accuracy of the output voltage regulation. For each of the three converter types, we discuss a number of additional bifurcation phenomena, including the formation and reconstruction of multi-layered tori and the appearance of phase-synchronized quasiperiodicity. Our numerical simulations are compared with experimentally observed waveforms.

Power operation, measurement and methods of calculation of power distribution

International Nuclear Information System (INIS)

Lindahl, S.O.; Bernander, O.; Olsson, S.

1982-01-01

During the initial fuel loading of a BWR core, extensive checks and measurements of the fuel are performed. The measurements are designed to verify that the reactor can always be safely operated in compliance with the regulatory constraints. The power distribution within the reactor core is evaluated by means of instrumentation and elaborate computer calculations. The power distribution forms the basis for the evaluation of thermal limits. The behaviour of the reactor during the ordinary modes of operation as well as during transients shall be well understood and such that the integrity of the fuel and the reactor systems is always well preserved. (author)

CRISP. Dependable ICT Support of Power Grid Operations

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, R.; Mellstrand, P.; Tornqvist, B. [Blekinge Institute of Technology BTH, Karlskrona (Sweden); Akkermans, H. [EnerSearch, Malmoe (Sweden)

2005-03-15

This deliverable D2.4 Dependable ICT support 0f Power Grid Operations is a link between deliverable D1.6 Information security models and their economics and planned activities in WP III, that is, Implementation, Experiments and Tests. Background CRISP material includes deliverables of D2.2 Design document and multi-agent simulation tool for distributed demand-supply matching and D2.3 Design document and simulation tool for diagnostics of high-DG power networks. Furthermore there are links between this document and the deliverable D1.7 Report on distributed network architectures and D1.8 Reports on case study simulations and results. In short, this document specifies and extends the general background on security models and dependability models of deliverable D1.6 with CRISP specific material of D2.2 and D2.4 towards the experiments and tests of WP III. The focus of this deliverable is on dependable ICT support of power grid operation. By recasting the three CRISP experiments into three Scenarios in Chapter 2 we claim that we have a good description of benefits and challenges related to future virtual utilities. Among the challenges are securing trustworthy operation from a technical operation side (avoid disturbances such as blackouts) as wee as from a user-centric business point of view (value added power related services). Our investigation on proper means to safeguard operations of future virtual utilities begins with an assessment of lessons learned from recent (2003) big blackouts worldwide in Chapter 3. We propose an accident diagnosis and repair model (STAMP in Section 3.2) suitable for the complex socio-technical system we envisage for future cell-based virtual utilities. From this analysis and the background material from deliverable D1.6 Information security models and their economics, we then reassess the dependability concerns related to the CRISP related scenarios of Chapter 2. The deliverable provides some novel ideas and models that we claim are

CRISP. Dependable ICT Support of Power Grid Operations

International Nuclear Information System (INIS)

Gustavsson, R.; Mellstrand, P.; Tornqvist, B.; Akkermans, H.

2005-03-01

This deliverable D2.4 Dependable ICT support 0f Power Grid Operations is a link between deliverable D1.6 Information security models and their economics and planned activities in WP III, that is, Implementation, Experiments and Tests. Background CRISP material includes deliverables of D2.2 Design document and multi-agent simulation tool for distributed demand-supply matching and D2.3 Design document and simulation tool for diagnostics of high-DG power networks. Furthermore there are links between this document and the deliverable D1.7 Report on distributed network architectures and D1.8 Reports on case study simulations and results. In short, this document specifies and extends the general background on security models and dependability models of deliverable D1.6 with CRISP specific material of D2.2 and D2.4 towards the experiments and tests of WP III. The focus of this deliverable is on dependable ICT support of power grid operation. By recasting the three CRISP experiments into three Scenarios in Chapter 2 we claim that we have a good description of benefits and challenges related to future virtual utilities. Among the challenges are securing trustworthy operation from a technical operation side (avoid disturbances such as blackouts) as wee as from a user-centric business point of view (value added power related services). Our investigation on proper means to safeguard operations of future virtual utilities begins with an assessment of lessons learned from recent (2003) big blackouts worldwide in Chapter 3. We propose an accident diagnosis and repair model (STAMP in Section 3.2) suitable for the complex socio-technical system we envisage for future cell-based virtual utilities. From this analysis and the background material from deliverable D1.6 Information security models and their economics, we then reassess the dependability concerns related to the CRISP related scenarios of Chapter 2. The deliverable provides some novel ideas and models that we claim are

High-Temperature, Wirebondless, Ultra-Compact Wide Bandgap Power Semiconductor Modules for Space Power Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Silicon carbide (SiC) and other wide band-gap semiconductors offer great promise of high power rating, high operating temperature, simple thermal management, and...

Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

DEFF Research Database (Denmark)

Vlachogiannis, Ioannis (John)

2009-01-01

grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control......In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and "intelligent" components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power...... capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also...

Performance evaluation of a high power DC-DC boost converter for PV applications using SiC power devices

Science.gov (United States)

Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

2016-09-01

The development of Wide band gap (WBG) power devices has been attracted by many commercial companies to be available in the market because of their enormous advantages over the traditional Si power devices. An example of WBG material is SiC, which offers a number of advantages over Si material. For example, SiC has the ability of blocking higher voltages, reducing switching and conduction losses and supports high switching frequency. Consequently, SiC power devices have become the affordable choice for high frequency and power application. The goal of this paper is to study the performance of 4.5 kW, 200 kHz, 600V DC-DC boost converter operating in continuous conduction mode (CCM) for PV applications. The switching behavior and turn on and turn off losses of different switching power devices such as SiC MOSFET, SiC normally ON JFET and Si MOSFET are investigated and analyzed. Moreover, a detailed comparison is provided to show the overall efficiency of the DC-DC boost converter with different switching power devices. It is found that the efficiency of SiC power switching devices are higher than the efficiency of Si-based switching devices due to low switching and conduction losses when operating at high frequencies. According to the result, the performance of SiC switching power devices dominate the conventional Si power devices in terms of low losses, high efficiency and high power density. Accordingly, SiC power switching devices are more appropriate for PV applications where a converter of smaller size with high efficiency, and cost effective is required.

Operating reliability of valves in French pressurized water nuclear power plants

International Nuclear Information System (INIS)

Conte

1986-10-01

Taking into account the large numbers of valves (about 10000) of a PWR nuclear power plant, the importance of some valves in the safety functions and the cost resulting from their unavailability, the individual operability of these equipments has to be ensured at a high reliability level. This assurance can be obtained by means of an effort at all the stages which contribute to the quality of the product: design, qualification tests, fabrication, tests at the start-up stage, maintenance and tests during the power plant operation, experience feedback. This paper emphasizes more particularly on the tests carried out on loops of qualification [fr

Performance and reliability of TPE-2 device with pulsed high power source

International Nuclear Information System (INIS)

Sato, Y.; Takeda, S.; Kiyama, S.

1987-01-01

The performance and the reliability of TPE-2 device with pulsed high power sources are described. To obtain the stable high beta plasma, the reproducibility and the reliability of the pulsed power sources must be maintained. A new power crowbar system with high efficiency and the switches with low jitter time are adopted to the bank system. A monitor system which always watches the operational states of the switches is developed too, and applied for the fast rising capacitor banks of TPE-2 device. The reliable operation for the bank has been realized, based on the data of switch monitor system

High Efficiency Power Converter for Low Voltage High Power Applications

DEFF Research Database (Denmark)

Nymand, Morten

The topic of this thesis is the design of high efficiency power electronic dc-to-dc converters for high-power, low-input-voltage to high-output-voltage applications. These converters are increasingly required for emerging sustainable energy systems such as fuel cell, battery or photo voltaic based......, and remote power generation for light towers, camper vans, boats, beacons, and buoys etc. A review of current state-of-the-art is presented. The best performing converters achieve moderately high peak efficiencies at high input voltage and medium power level. However, system dimensioning and cost are often...

Measurement uncertainty recapture (MUR) power uprates operation at Kuosheng Nuclear Power Station

International Nuclear Information System (INIS)

Chang Chinjang; Wang Tunglu; Lin Chihpao

2009-01-01

Measurement Uncertainty Recapture PowerUprates (MUR PU) are achieved through the use of state-of-the-art feedwater flow measurement devices, i.e., ultrasonic flow meters (UFMs), that reduce the degree of uncertainty associated with feedwater flow measurement and in turn provide for a more accurate calculation of thermal power. The Institute of Nuclear Energy Research (INER) teamed with Sargent and Lundy, LLC (S and L), Pacific Engineers and Constructors, Ltd (PECL), and AREVA to develop a program and plan for the Kuosheng Nuclear Power Station (KNPS) MUR PU Engineering Service Project and for the assistance to Kuosheng MUR PU operation. After regulator's approval of the licensing requests, KSNPS conducted the power ascension test and switchover to the new rated thermal power for Unit 2 and Unit 1 on 7/7/2007 and 11/30/2007, respectively. From then on, KNPS became the first nuclear power plant implementing MUR PU operation in Taiwan and in Asia. (author)

Short-Term and Medium-Term Reliability Evaluation for Power Systems With High Penetration of Wind Power

DEFF Research Database (Denmark)

Ding, Yi; Singh, Chanan; Goel, Lalit

2014-01-01

reliability evaluation techniques for power systems are well developed. These techniques are more focused on steady-state (time-independent) reliability evaluation and have been successfully applied in power system planning and expansion. In the operational phase, however, they may be too rough......The expanding share of the fluctuating and less predictable wind power generation can introduce complexities in power system reliability evaluation and management. This entails a need for the system operator to assess the system status more accurately for securing real-time balancing. The existing...... an approximation of the time-varying behavior of power systems with high penetration of wind power. This paper proposes a time-varying reliability assessment technique. Time-varying reliability models for wind farms, conventional generating units, and rapid start-up generating units are developed and represented...

ICC Experiment Performance Improvement through Advanced Feedback Controllers for High-Power Low-Cost Switching Power Amplifiers

International Nuclear Information System (INIS)

Nelson, Brian A.

2006-01-01

Limited resources force most smaller fusion energy research experiments to have little or no feedback control of their operational parameters, preventing achievement of their full operational potential. Recent breakthroughs in high-power switching technologies have greatly reduced feedback-controlled power supply costs, primarily those classified as switching power amplifiers. However, inexpensive and flexible controllers for these power supplies have not been developed. A uClinux-based micro-controller (Analog Devices Blackfin BF537) was identified as having the capabilities to form the base of a digital control system for switching power amplifiers. A control algorithm was created, and a Linux character device driver was written to realize the algorithm. The software and algorithm were successfully tested on a switching power amplifier and magnetic field coil using University of Washington (subcontractor) resources

Evaluation of nuclear power plant operator's ability

International Nuclear Information System (INIS)

Wei Li; He Xuhong; Zhao Bingquan

2004-01-01

Based on the quantitative research on nuclear power plant (NPP) operator's psychological characteristics and performance, the Borda's method of fuzzy mathematics combined with the character of operator's task is used to evaluate their abilities. The result provides the reference for operator's reliability research and psychological evaluation. (author)

High-power laser diodes with high polarization purity

Science.gov (United States)

Rosenkrantz, Etai; Yanson, Dan; Peleg, Ophir; Blonder, Moshe; Rappaport, Noam; Klumel, Genady

2017-02-01

Fiber-coupled laser diode modules employ power scaling of single emitters for fiber laser pumping. To this end, techniques such as geometrical, spectral and polarization beam combining (PBC) are used. For PBC, linear polarization with high degree of purity is important, as any non-perfectly polarized light leads to losses and heating. Furthermore, PBC is typically performed in a collimated portion of the beams, which also cancels the angular dependence of the PBC element, e.g., beam-splitter. However, we discovered that single emitters have variable degrees of polarization, which depends both on the operating current and far-field divergence. We present data to show angle-resolved polarization measurements that correlate with the ignition of high-order modes in the slow-axis emission of the emitter. We demonstrate that the ultimate laser brightness includes not only the standard parameters such as power, emitting area and beam divergence, but also the degree of polarization (DoP), which is a strong function of the latter. Improved slow-axis divergence, therefore, contributes not only to high brightness but also high beam combining efficiency through polarization.

Island operation - modelling of a small hydro power system

Energy Technology Data Exchange (ETDEWEB)

Skarp, Stefan

2000-02-01

Simulation is a useful tool for investigating a system behaviour. It is a way to examine operating situations without having to perform them in reality. If someone for example wants to test an operating situation where the system possibly will demolish, a computer simulation could be a both cheaper and safer way than to do the test in reality. This master thesis performs and analyses a simulation, modelling an electronic power system. The system consists of a minor hydro power station, a wood refining industry, and interconnecting power system components. In the simulation situation the system works in a so called island operation. The thesis aims at making a capacity analysis of the current system. Above all, the goal is to find restrictions in load power profile of the consumer, under given circumstances. The computer software used in simulations is Matlab and its additional program PSB (Power System Blockset). The work has been carried out in co-operation with the power supplier Skellefteaa Kraft, where the problem formulation of this master thesis was founded.

Very High Frequency Switch-Mode Power Supplies

DEFF Research Database (Denmark)

Madsen, Mickey Pierre

The importance of technology and electronics in our daily life is constantly increasing. At the same time portability and energy efficiency are currently some of the hottest topics. This creates a huge need for power converters in a compact form factor and with high efficiency, which can supply...... these electronic devices. This calls for new technologies in order to miniaturize the power electronics of today. One way to do this is by increasing the switching frequency dramatically and develop very high frequency switch mode power supplies. If these converters can be designed to operate efficiently, a huge...... size, weight and cost reduction can be achieved due to the smaller energy storing elements needed at these frequencies. The research presented in this thesis focuses on exactly this. First various technologies for miniaturization of power supplies are studied, e.g. piezo electric transformers, wide...

Operational costs induced by fluctuating wind power production in Germany and Scandinavia

Energy Technology Data Exchange (ETDEWEB)

Meibom, P. [Risoe National Lab., DTU, System Analysis Dept., Roskilde (Denmark); Weber, C. [Univ. Duisburg-Essen, Chai og Energy Management (Germany); Barth, R.; Brand, H. [Univ. of Stuttgart, Inst. of Energy Economics and the Rational Use of Energy (Germany)

2007-05-15

Adding wind power generation in a power system changes the operational patterns of the existing units due to the variability and unpredictability of wind power production. For large amounts of wind power production the expectation is that the operational costs of the other power plants will increase due to more operation time in part-load and more start-ups. The change in operational costs induced by the wind power production can only be calculated by comparing the operational costs in two power system configurations: with wind power production and with alternative production having properties like conventional production, i.e. being predictable and less variable. The choice of the characteristics of the alternative production is not straight forward and will therefore influence the operational costs induced by wind power production. This paper presents a method for calculating the change in operational costs due to wind power production using a stochastic optimization model covering the power systems in Germany and the Nordic countries. Two cases of alternative production are used to calculate the change in operational costs namely perfectly predictable wind power production enabling calculation of the costs connected to unpredictability, and constant wind power production enabling calculation of the operational costs connected to variability of wind power production. A 2010 case with three different wind power production penetration levels is analysed in the paper. (au)

Low power consumption and high temperature durability for radiation sensor

International Nuclear Information System (INIS)

Matsumoto, Yoshinori; Ueno, Hiroto

2015-01-01

Low power consumption and high temperature operation are important in an environmental monitoring system. The power consumption of 3 mW is achieved for the radiation sensor using low voltage operational amplifier and comparator in the signal processing circuit. The leakage reverse current of photodiode causes the charge amplifier saturation over 50degC. High temperature durability was improved by optimizing the circuit configuration and the values of feedback resistance and capacitance in the charge amplifier. The pulse response of the radiation sensor was measured up to 55degC. The custom detection circuit was designed by 0.6 μm CMOS process at 5-V supply voltage. The operation temperature was improved up to 65degC. (author)

Energy Storage in Power System Operation: The Power Nodes Modeling Framework

DEFF Research Database (Denmark)

Heussen, Kai; Koch, Stephan; Ulbig, Andreas

2010-01-01

for designing operation strategies for power systems based on ubiquitous energy storage, for example to buer non-dispatchable generation, as well as for the evaluation of the operational performance in terms of energy eciency, reliability and cost. After introducing the modeling approach and a categorization......In this paper, a novel concept for the description of energy storage in power systems with dispatchable and non-dispatchable generators and loads is presented. It is based on a system-perspective consideration of energy storage, generation and consumption. This means that grid-relevant aspects...

High Flux Isotope Reactor power upgrade status

International Nuclear Information System (INIS)

Rothrock, R.B.; Hale, R.E.; Cheverton, R.D.

1997-01-01

A return to 100-MW operation is being planned for the High Flux Isotope Reactor (HFIR). Recent improvements in fuel element manufacturing procedures and inspection equipment will be exploited to reduce hot spot and hot streak factors sufficiently to permit the power upgrade without an increase in primary coolant pressure. Fresh fuel elements already fabricated for future use are being evaluated individually for power upgrade potential based on their measured coolant channel dimensions

Decomposing Objectives and Functions in Power System Operation and Control

DEFF Research Database (Denmark)

Heussen, Kai; Lind, Morten

2009-01-01

mix of challenges posed by renewable energy sources, demand response technologies and smartgrid concepts, affecting all areas of power system operation. Both, new control modes and changes in market design are required. This paper presents a mean-ends perspective to the analysis of the control......The introduction of many new energy solutions requires the adaptation of classical operation paradigms in power systems. In the standard paradigm, a power system is some equivalent of a synchronous generators, a power line and an uncontrollable load. This paradigm has been challenged by a diverse...... structures and operation paradigms in present power systems. In a top-down approach, traditional frequency- and area-control mechanisms are formalized. It is demonstrated that future power system operation paradigms with different generation control modes and controllable demand can be modeled in a coherent...

Quality assurance during operation of nuclear power plants

International Nuclear Information System (INIS)

1994-01-01

The general requirements applicable to the quality assurance of the Finnish nuclear power plants are presented in the Council of State Decision (395/91) and in the guide YVL 1.4. This guide specifies the quality assurance requirements to be applied during the operation of the nuclear power plants as well as of the other nuclear facilities. Quality assurance applies to all the activities and organizations with a bearing on the safe operation of the nuclear power plants. (5 refs.)

Coal-fired power plants and the causes of high temperature corrosion

Energy Technology Data Exchange (ETDEWEB)

Oakey, J E; Simms, N J [British Coal Corporation, Coal Technology Development Div., Cheltenham, Glos (United Kingdom); Tomkings, A B [ERA Technology Ltd., Leatherhead, Surrey (United Kingdom)

1996-12-01

The heat exchangers in all types of coal-fired power plant operate in aggressive, high temperature environments where high temperature corrosion can severely limit their service lives. The extent of this corrosion is governed by the combined effects of the operating conditions of the heat exchanger and the presence of corrosive species released from the coal during operation. This paper reviews the coal-related factors, such as ash deposition, which influence the operating environments of heat exchangers in three types of coal-fired power plant - conventional pulverized coal boilers, fluidized bed boilers and coal gasification systems. The effects on the performance of the materials used for these heat exchangers are then compared. (au) 35 refs.

Communication Characteristics of Faulted Overhead High Voltage Power Lines at Low Radio Frequencies

Directory of Open Access Journals (Sweden)

Nermin Suljanović

2017-11-01

Full Text Available This paper derives a model of high-voltage overhead power line under fault conditions at low radio frequencies. The derived model is essential for design of communication systems to reliably transfer information over high voltage power lines. In addition, the model can also benefit advanced systems for power-line fault detection and classification exploiting the phenomenon of changed conditions on faulted power line, resulting in change of low radio frequency signal propagation. The methodology used in the paper is based on the multiconductor system analysis and propagation of electromagnetic waves over the power lines. The model for the high voltage power line under normal operation is validated using actual measurements obtained on 400 kV power line. The proposed model of faulted power lines extends the validated power-line model under normal operation. Simulation results are provided for typical power line faults and typical fault locations. Results clearly indicate sensitivity of power-line frequency response on different fault types.

Economic evaluation of nuclear reactor operation utilizing power effect

International Nuclear Information System (INIS)

Budinsky, M.; Mydliar, J.

1988-01-01

The operation of a reactor at the so-called power effect may substantially increase the burnup of fuel to be removed. The aim of the evaluation of such reactor operation is the optimal determination of the time over which the yield of the higher use of fuel exceeds economic losses resulting from the increased share of constant expenditure of the price of generated kWh of electric power which ensues from such operation. A mathematical model is presented for such evaluation of reactor operation with regard to benefits for the national economy which is the basis of the ESTER 2 computer program. The calculations show that the prices of generated and delivered kWh are minimally 2% less than the prices of generated power without the power effect use. The minimum ranges in the interval of 30 to 50 days. The dependence of the price of generated and delivered kWh from the point of view of the operator of the power plant as well as the component of fuel price of generated kWh will not reach the minimum even after 50 days of operation. From the operating and physical points of view the duration of power effect is not expected to exceed 20 to 30 days which means that from the point of view of the national economy the price of generated and delivered kWh will be 1.6 to 2% less and the fuel component of the price of the generated kWh will be 3 to 4.5% lower. (Z.M.). 5 figs., 3 refs

Annual report on operational management of nuclear power stations, 1979-1980

International Nuclear Information System (INIS)

1981-04-01

This report was compiled by the Agency of Natural Resoures and Energy. The commercial nuclear power stations in Japan started the operation in 1966 for the first time, and as of the end of March, 1981, 22 plants with more than 15.5 million kW capacity were in operation. Nuclear power generation is regarded as the top-rated substitute energy for petroleum, and the target of its development in 1990 is about 52 million kW. The government and the people are exerting utmost efforts to attain the target. The result of the rate of operation of nuclear power stations reached 60.8% in 1980, but it is important to maintain the good, stable state of operation by perfecting the operational management hereafter in order to establish the position of LWRs. At present, the operational management officers of the government stay in nationwide power stations, and supervise the state of operations, thus the system of operational management was strengthened after the Three Mile Island accident in the U.S., and the improvement in the rate of operation is expected. A table shows the nuclear power stations in operation and under construction. The state of operations of individual nuclear power plants in 1979 and 1980, the accidents and failures occurred in nuclear power plants from 1966 to 1980, the minor troubles, the conditions in the regular inspections of individual nuclear power plants, radioactive waste management and the radiation exposure of workers are reported. (Kako, I.)

High-power single-mode cw dye ring laser

Energy Technology Data Exchange (ETDEWEB)

Schroeder, H W; Stein, L; Froelich, D; Fugger, B; Welling, H [Technische Univ. Hannover (Germany, F.R.). Inst. fuer Angewandte Physik

1977-12-01

Due to spatial hole burning, standing-wave dye lasers require a large amount of selectivity inside the cavity for single-mode operation. The output power of these lasers is limited by losses caused by the frequency selecting elements. In a travelling-wave laser, on the other hand, spatial hole burning does not exist, thereby eliminating the need for high selectivity. A travelling-wave cw dye laser was realized by unidirectional operation of a ring laser, yielding single mode output powers of 1.2 W at 595 nm and of 55 mW in the UV-region with intracavity frequency doubling.

High temperature degradation in power plants and refineries

Directory of Open Access Journals (Sweden)

Furtado Heloisa Cunha

2004-01-01

Full Text Available Thermal power plants and refineries around the world share many of the same problems, namely aging equipment, high costs of replacement, and the need to produce more efficiently while being increasingly concerned with issues of safety and reliability. For equipment operating at high temperature, there are many different mechanisms of degradation, some of which interact, and the rate of accumulation of damage is not simple to predict. The paper discusses the mechanisms of degradation at high temperature and methods of assessment of such damage and of the remaining safe life for operation.

Conduct of Operations at Nuclear Power Plants. Safety Guide (Spanish Edition)

International Nuclear Information System (INIS)

2012-01-01

This Safety Guide identifies the main responsibilities and practices of nuclear power plant (NPP) operations departments in relation to their responsibility for the safe functioning of the plant. The guide presents the factors to be considered in structuring the operations department of an NPP; setting high standards of performance; making safety related decisions in an effective manner; conducting control room and field activities in a thorough and professional manner; and maintaining an NPP within established operational limits and conditions. Contents: 1. Introduction; 2. Management and organization of plant operations; 3. Shift complement and functions; 4. Shift routines and operating practices; 5. Control of equipment and plant status; 6. Operations equipment and operator aids; 7. Work control and authorization.

Designing for Wide-Area Situation Awareness in Future Power Grid Operations

Science.gov (United States)

Tran, Fiona F.

Power grid operation uncertainty and complexity continue to increase with the rise of electricity market deregulation, renewable generation, and interconnectedness between multiple jurisdictions. Human operators need appropriate wide-area visualizations to help them monitor system status to ensure reliable operation of the interconnected power grid. We observed transmission operations at a control centre, conducted critical incident interviews, and led focus group sessions with operators. The results informed a Work Domain Analysis of power grid operations, which in turn informed an Ecological Interface Design concept for wide-area monitoring. I validated design concepts through tabletop discussions and a usability evaluation with operators, earning a mean System Usability Scale score of 77 out of 90. The design concepts aim to support an operator's complete and accurate understanding of the power grid state, which operators increasingly require due to the critical nature of power grid infrastructure and growing sources of system uncertainty.

High-Power Electron Accelerators for Space (and other) Applications

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewellen, John W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-05-23

This is a presentation on high-power electron accelerators for space and other applications. The main points covered are: electron beams for space applications, new designs of RF accelerators, high-power high-electron mobility transistors (HEMT) testing, and Li-ion battery design. In summary, the authors have considered a concept of 1-MeV electron accelerator that can operate up to several seconds. This concept can be extended to higher energy to produce higher beam power. Going to higher beam energy requires adding more cavities and solid-state HEMT RF power devices. The commercial HEMT have been tested for frequency response and RF output power (up to 420 W). Finally, the authors are testing these HEMT into a resonant load and planning for an electron beam test in FY17.

Results of the SLAC LCLS Gun High-Power RF Tests

International Nuclear Information System (INIS)

Dowell, D.H.; Jongewaard, E.; Limborg-Deprey, C.; Schmerge, J.F.; Li, Z.; Xiao, L.; Wang, J.; Lewandowski, J.; Vlieks, A.

2007-01-01

The beam quality and operational requirements for the Linac Coherent Light Source (LCLS) currently being constructed at SLAC are exceptional, requiring the design of a new RF photocathode gun for the electron source. Based on operational experience at SLAC's GTF and SDL and ATF at BNL as well as other laboratories, the 1.6cell s-band (2856MHz) gun was chosen to be the best electron source for the LCLS, however a significant redesign was necessary to achieve the challenging parameters. Detailed 3-D analysis and design was used to produce near-perfect rotationally symmetric rf fields to achieve the emittance requirement. In addition, the thermo-mechanical design allows the gun to operate at 120Hz and a 140MV/m cathode field, or to an average power dissipation of 4kW. Both average and pulsed heating issues are addressed in the LCLS gun design. The first LCLS gun is now fabricated and has been operated with high-power RF. The results of these high-power tests are presented and discussed

A high power, tunable free electron maser for fusion

Energy Technology Data Exchange (ETDEWEB)

Urbanus, W.H.; Bratman, V.L.; Bongers, W.A.; Caplan, M.; Denisov, G.G.; Geer, C.A.J. van der; Manintveld, P.; Militsyn, B.; Oomens, A.A.M.; Poelman, A.J.; Plomp, J.; Pluygers, J.; Savilov, A.V.; Smeets, P.H.M.; Sterk, A.B.; Verhoeven, A.G.A

2001-01-01

The Fusion-FEM experiment, a high-power, electrostatic free-electron maser being built at the FOM-Institute for Plasma Physics 'Rijnhuizen', is operated at various frequencies. So far, experiments were done without a depressed collector, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current, and cavity settings such as the feedback coefficient. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.4 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. The next step of the FEM experiment is to reach a pulse length of 100 ms. The major part of the beam line, the high voltage systems, and the collector have been completed. The undulator and mm-wave cavity are now at high voltage (2 MV). The new mm-wave transmission line, which transports the mm-wave output power from the high-voltage terminal to ground and outside the pressure tank, has been tested at low power.

Interactive videodisc training for power plant operations

International Nuclear Information System (INIS)

Nolan, R.; Nolan, J.; Campos, M.; Haukom, R.; Quentin, G.

1990-01-01

During the last several years, professionals in the personal computer and video fields have seen their two technologies coming together. This merging has created a new medium called multimedia. Multimedia provides the user with the interactivity of the personal computer and the realism of live-action television. It appears to be a perfect marriage for education, training and selling applications. As multimedia productions continue to be produced and tested with high marks, business and industry are becoming interested. The Interactive Videodisc Trainer (IVT) is a demonstration of how multimedia technology can be used by the electric power industry for operator training. Although the subject for this pilot program is the Claus sulfur recovery unit at the Cool Water Integrated Gasification Combined Cycle plant, similar courseware can be put to use for training at any type of power plant. The goal is to show many of the features and capabilities inherent in this powerful new training tool, so that utilities can begin to see how it could work for them

A high-power two stage traveling-wave tube amplifier

International Nuclear Information System (INIS)

Shiffler, D.; Nation, J.A.; Schachter, L.; Ivers, J.D.; Kerslick, G.S.

1991-01-01

Results are presented on the development of a two stage high-efficiency, high-power 8.76-GHz traveling-wave tube amplifier. The work presented augments previously reported data on a single stage amplifier and presents new data on the operational characteristics of two identical amplifiers operated in series and separated from each other by a sever. Peak powers of 410 MW have been obtained over the complete pulse duration of the device, with a conversion efficiency from the electron beam to microwave energy of 45%. In all operating conditions the severed amplifier showed a ''sideband''-like structure in the frequency spectrum of the microwave radiation. A similar structure was apparent at output powers in excess of 70 MW in the single stage device. The frequencies of the ''sidebands'' are not symmetric with respect to the center frequency. The maximum, single frequency, average output power was 210 MW corresponding to an amplifier efficiency of 24%. Simulation data is also presented that indicates that the short amplifiers used in this work exhibit significant differences in behavior from conventional low-power amplifiers. These include finite length effects on the gain characteristics, which may account for the observed narrow bandwidth of the amplifiers and for the appearance of the sidebands. It is also found that the bunching length for the beam may be a significant fraction of the total amplifier length

Radiation and High Temperature Tolerant GaN Power Electronics, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Power electronic components with high operating voltages are desirable in NASA Power Management and Distribution (PMAD) systems since they can lead to reduced mass...

High-average-power diode-pumped Yb: YAG lasers

International Nuclear Information System (INIS)

Avizonis, P V; Beach, R; Bibeau, C M; Emanuel, M A; Harris, D G; Honea, E C; Monroe, R S; Payne, S A; Skidmore, J A; Sutton, S B

1999-01-01

A scaleable diode end-pumping technology for high-average-power slab and rod lasers has been under development for the past several years at Lawrence Livermore National Laboratory (LLNL). This technology has particular application to high average power Yb:YAG lasers that utilize a rod configured gain element. Previously, this rod configured approach has achieved average output powers in a single 5 cm long by 2 mm diameter Yb:YAG rod of 430 W cw and 280 W q-switched. High beam quality (M(sup 2)= 2.4) q-switched operation has also been demonstrated at over 180 W of average output power. More recently, using a dual rod configuration consisting of two, 5 cm long by 2 mm diameter laser rods with birefringence compensation, we have achieved 1080 W of cw output with an M(sup 2) value of 13.5 at an optical-to-optical conversion efficiency of 27.5%. With the same dual rod laser operated in a q-switched mode, we have also demonstrated 532 W of average power with an M(sup 2) and lt; 2.5 at 17% optical-to-optical conversion efficiency. These q-switched results were obtained at a 10 kHz repetition rate and resulted in 77 nsec pulse durations. These improved levels of operational performance have been achieved as a result of technology advancements made in several areas that will be covered in this manuscript. These enhancements to our architecture include: (1) Hollow lens ducts that enable the use of advanced cavity architectures permitting birefringence compensation and the ability to run in large aperture-filling near-diffraction-limited modes. (2) Compound laser rods with flanged-nonabsorbing-endcaps fabricated by diffusion bonding. (3) Techniques for suppressing amplified spontaneous emission (ASE) and parasitics in the polished barrel rods

The Chooz power station: ten years of operation

International Nuclear Information System (INIS)

Teste du Bailler, Andre

1977-01-01

The switching into actual service of the Chooz plant, the first pressurized water reactor ever built in France, occurred on 3rd april 1967. Ten years later, one can establish a highly positive balance schedule of plant's operation whose availability is satisfactory, except the mechanical failure which occurred during the startup. The behavior of the equipment, in particular of the components of the primary loop, was satisfactory in its whole since it allowed the gradual increase in capacity by 15% with respect to the initial design. It allowed also the achievment of noticeable progress in the design of equipment intended for the new power stations. Interesting results have also been obtained in radioprotection, working conditions of the staff and environment protection fields. Finally, the training of the operating teams has been closely followed, whether it concerned the operators directly affected by plant operation or the trainees gathered in a school specially organized for this purpose and transferred since to a training Center [fr

Implementation of superconducting fault current limiter for flexible operation in the power substation

Energy Technology Data Exchange (ETDEWEB)

Song, Chong Suk, E-mail: chong_suk@korea.ac.kr [School of Electrical Engineering, Korea University, Anam dong, Seonbukgu, Seoul 136-713 (Korea, Republic of); Lee, Hansang [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Cho, Yoon-sung [Department of Electric and Energy Engineering, Catholic University of Daegu, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-702 (Korea, Republic of); Suh, Jaewan [School of Electrical Engineering, Korea University, Anam dong, Seonbukgu, Seoul 136-713 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam dong, Seonbukgu, Seoul 136-713 (Korea, Republic of)

2014-09-15

Highlights: • The power load concentrated in load centers results in high levels of fault current. • This paper introduces a fault current reduction scheme using SFCLs in substations. • The SFCL is connected in parallel to the bus tie between the two busbars. • The fault current mitigation using SFCLs is verified through PSS/e simulations. - Abstract: The concentration of large-scale power loads located in the metropolitan areas have resulted in high fault current levels during a fault thereby requiring the substation to operate in the double busbar configuration mode. However, the double busbar configuration mode results in deterioration of power system reliability and unbalanced power flow in the adjacent transmission lines which may result in issues such as overloading of lines. This paper proposes the implementation of the superconducting fault current limiter (SFCL) to be installed between the two substation busbars for a more efficient and flexible operation of the substation enabling both single and double busbar configurations depending on the system conditions for guaranteeing power system reliability as well as fault current limitations. Case studies are being performed for the effectiveness of the SFCL installation and results are compared for the cases where the substation is operating in single and double busbar mode and with and without the installation of the SFCL for fault current mitigation.

Embedded control system for high power RF amplifiers

International Nuclear Information System (INIS)

Sharma, Deepak Kumar; Gupta, Alok Kumar; Jain, Akhilesh; Hannurkar, P.R.

2011-01-01

RF power devices are usually very sensitive to overheat and reflected RF power; hence a protective interlock system is required to be embedded with high power solid state RF amplifiers. The solid state RF amplifiers have salient features of graceful degradation and very low mean time to repair (MTTR). In order to exploit these features in favour of lowest system downtime, a real-time control system is embedded with high power RF amplifiers. The control system is developed with the features of monitoring, measurement and network publishing of various parameters, historical data logging, alarm generation, displaying data to the operator and tripping the system in case of any interlock failure. This paper discusses the design philosophy, features, functions and implementation details of the embedded control system. (author)

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1994-03-01

In the third quarter of 1993, all of Finland's four nuclear power plant units were in power operation, with the exception of the annual maintenance outages of the Loviisa units. The load factor average of the plant units was 83.6 %. None of the events which occurred during this annual quarter had any bearing on nuclear or radiation safety. (4 figs., 5 tabs.)

HEMP emergency planning and operating procedures for electric power systems

Energy Technology Data Exchange (ETDEWEB)

Reddoch, T.W.; Markel, L.C. (Electrotek Concepts, Inc., Knoxville, TN (United States))

1991-01-01

Investigations of the impact of high-altitude electromagnetic pulse (HEMP) on electric power systems and electrical equipment have revealed that HEMP creates both misoperation and failures. These events result from both the early time E[sub 1] (steep-front pulse) component and the late time E[sub 3] (geomagnetic perturbations) component of HEMP. In this report a HEMP event is viewed in terms of its marginal impact over classical power system disturbances by considering the unique properties and consequences of HEMP. This report focuses on system-wide electrical component failures and their potential consequences from HEMP. In particular, the effectiveness of planning and operating procedures for electric systems is evaluated while under the influence of HEMP. This assessment relies on published data and characterizes utilities using the North American Electric Reliability Council's regions and guidelines to model electric power system planning and operations. Key issues addressed by the report include how electric power systems are affected by HEMP and what actions electric utilities can initiate to reduce the consequences of HEMP. The report also reviews the salient features of earlier HEMP studies and projects, examines technology trends in the electric power industry which are affected by HEMP, characterizes the vulnerability of power systems to HEMP, and explores the capability of electric systems to recover from a HEMP event.

Liquid Nitrogen Temperature Operation of a Switching Power Converter

Science.gov (United States)

Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

1995-01-01

The performance of a 42/28 V, 175 W, 50 kHz pulse-width modulated buck dc/dc switching power converter at liquid nitrogen temperature (LNT) is compared with room temperature operation. The power circuit as well as the control circuit of the converter, designed with commercially available components, were operated at LNT and resulted in a slight improvement in converter efficiency. The improvement in power MOSFET operation was offset by deteriorating performance of the output diode rectifier at LNT. Performance of the converter could be further improved at low temperatures by using only power MOSFET's as switches. The use of a resonant topology will further improve the circuit performance by reducing the switching noise and loss.

An ultra low-power off-line APDM-based switchmode power supply with very high conversion efficiency

DEFF Research Database (Denmark)

Nielsen, Nils

2001-01-01

This article describes the results from the research work on design of a ultra low power off-line power supply with very high conversion efficiency. The input voltage is 230 VAC nominal and output voltage is 5 VDC. By ultra low power levels, an output power level in the area ranging from 50 m......W and up to 1000 mW is meant. The small power supply is intended for use as a standby power supply in mains operated equipment, which requires a small amount of power in standby mode....

Use of computer codes to improve nuclear power plant operation

International Nuclear Information System (INIS)

Misak, J.; Polak, V.; Filo, J.; Gatas, J.

1985-01-01

For safety and economic reasons, the scope for carrying out experiments on operational nuclear power plants (NPPs) is very limited and any changes in technical equipment and operating parameters or conditions have to be supported by theoretical calculations. In the Nuclear Power Plant Scientific Research Institute (NIIAEhS), computer codes are systematically used to analyse actual operating events, assess safety aspects of changes in equipment and operating conditions, optimize the conditions, preparation and analysis of NPP startup trials and review and amend operating instructions. In addition, calculation codes are gradually being introduced into power plant computer systems to perform real time processing of the parameters being measured. The paper describes a number of specific examples of the use of calculation codes for the thermohydraulic analysis of operating and accident conditions aimed at improving the operation of WWER-440 units at the Jaslovske Bohunice V-1 and V-2 nuclear power plants. These examples confirm that computer calculations are an effective way of solving operating problems and of further increasing the level of safety and economic efficiency of NPP operation. (author)

A high-power laser system for thermonuclear fusion experiments

International Nuclear Information System (INIS)

Azizov, Eh.A.; Ignat'ev, L.P.; Koval'skij, N.G.; Kolesnikov, Yu.A.; Mamzer, A.F.; Pergament, M.I.; Rudnitskij, Yu.P.; Smirnov, G.V.; Yagnov, V.A.; Nikolaevskij, V.G.

1976-01-01

A high-power laser system has been designed for an energy output of approximately 3X10 4 J. Neodymium glass was selected based on the level of technical progress, operating experience and the availability of components. The operating performance that has been achieved to date is described. (author)

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Lehtinen, Pekka

1987-05-01

These general reviews of the operation of the Finnish nuclear power plants concentrate on such events and discoveries related to reactor and radiation safety that the regulatory body, the Finnish Centre for Radiation and Nuclear Safety, regards as noteworthy. The report also includes a summary of the radiation safety of the personnel and the environment, as well as tabulated data on the production and load factors of the plants. In the report period, no event essentially degraded plant safety nor posed a radiation hazard to the perssonnel or the environment. For remedying certain defects found in the administrative procedures concerning plant operation and maintenance, the Loviisa power plant was shut down for several days

MMIC for High-Efficiency Ka-BAnd GaN Power Amplifiers (2007043), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This proposal addresses the need for high-efficiency, high-output power amplifiers operating in the Ka-band frequencies. For space communications, the power...

Application of high performance asynchronous socket communication in power distribution automation

Science.gov (United States)

Wang, Ziyu

2017-05-01

With the development of information technology and Internet technology, and the growing demand for electricity, the stability and the reliable operation of power system have been the goal of power grid workers. With the advent of the era of big data, the power data will gradually become an important breakthrough to guarantee the safe and reliable operation of the power grid. So, in the electric power industry, how to efficiently and robustly receive the data transmitted by the data acquisition device, make the power distribution automation system be able to execute scientific decision quickly, which is the pursuit direction in power grid. In this paper, some existing problems in the power system communication are analysed, and with the help of the network technology, a set of solutions called Asynchronous Socket Technology to the problem in network communication which meets the high concurrency and the high throughput is proposed. Besides, the paper also looks forward to the development direction of power distribution automation in the era of big data and artificial intelligence.

High power density yeast catalyzed microbial fuel cells

Science.gov (United States)

Ganguli, Rahul

Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

Operating the Irish power system with increased levels of wind power

DEFF Research Database (Denmark)

Tuohy, A.; Denny, E.; Meibom, Peter

2008-01-01

This paper summarises some of the main impacts of large amounts of wind power installed in the island of Ireland. Using results from various studies performed on this system, it is shown that wind power will impact on all time frames, from seconds to daily planning of the system operation. Results...... from studies examining operation of the system with up to approximately 40% of electricity provided by wind show that some of the most important aspects to be considered include the type of wind turbine technology, the provision of reserve to accommodate wind forecasting error and the method used...

Computerized operation manual (COM) of nuclear power plants

International Nuclear Information System (INIS)

Szegi, Z.

1985-01-01

This paper is to be presented at the International Seminar on Diagnoses of and Response to Abnormal Occurrences at Nuclear Power Plants organized by the International Atomic Energy Agency. The topic of presentation is the Computerized Operational Manual. This system supports the operator at disturbance situations by displaying quickly and unambiguously the operational instructions and the relevant information without mistakes. By the computerized manual the operator can determine the instruction-subsystem which reflects the real state of the power unit. From this point the system guides the operator on how to drive the unit to another determined state by providing the operational instructions at any time. A data bank is also included which contains information concerning rules restricting on maintenance and repair. The system will be realized at Paks NPP. (author)

Repetitive plasma opening switch for powerful high-voltage pulse generators

International Nuclear Information System (INIS)

Dolgachev, G.I.; Zakatov, L.P.; Nitishinskii, M.S.; Ushakov, A.G.

1998-01-01

Results are presented of experimental studies of plasma opening switches that serve to sharpen the pulses of inductive microsecond high-voltage pulse generators. It is demonstrated that repetitive plasma opening switches can be used to create super-powerful generators operating in a quasi-continuous regime. An erosion switching mechanism and the problem of magnetic insulation in repetitive switches are considered. Achieving super-high peak power in plasma switches makes it possible to develop new types of high-power generators of electron beams and X radiation. Possible implementations and the efficiency of these generators are discussed

A Family of L-band SRF Cavities for High Power Proton Driver Applications

International Nuclear Information System (INIS)

Rimmer, Robert; Marhauser, Frank

2009-01-01

Recent global interest in high duty factor or CW superconducting linacs with high average beam power highlights the need for robust and reliable SRF structures capable of delivering high average RF power to the beam with moderate HOM damping, low interception of halo and good efficiency. Potential applications include proton or H- drivers for spallation neutron sources, neutrino physics, waste transmutation, subcritical reactors, and high-intensity high-energy physics experiments. We describe a family of SRF cavities with a range of Betas capable of transporting beam currents in excess of 10 mA CW with large irises for minimal interception of halo and HOM and power couplers capable of supporting high average power operation. Goals include an efficient cell shape, high packing factor for efficient real-estate gradient and strong HOM damping to ensure stable beam operation,

Operating experience with BWR nuclear power

International Nuclear Information System (INIS)

Bonsdorf, Magnus von.

1986-01-01

The two-unit nuclear power station in Olkiluoto on the western coast of Finland produces about 20 per cent of the electricity consumption of the country. The first unit, TVO-I was first connected to the national grid in September 1978 and TVO-II in February 1980. The original rated power output of each unit was 660 MWe, corresponding to the thermal power of 2000 MW from the reactor. Technical modifications allowed the power to be uprated by 8%. The operating statistics (load factors etc.) are given and the outage experience discussed. The radiological history shows very low radioactivity and dose levels have been maintained at the plant. (UK)

BR3/Vulcain Nuclear Power Station. Construction and Operational Experience

Energy Technology Data Exchange (ETDEWEB)

Storrer, J. [Belgonucleaire, S.A., Brussels (Belgium)

1968-04-15

power density of 41 MW(th)t U. The expected average fuel burnup and core life are 25 000 MWd/t U and 620 equivalent full-power days, respectively. These characteristics have been achieved without taking advantage of various improvements - such as the possibility of flattening the power distribution in the core by the use of two or more fuel enrichments - which are planned for more advanced Vulcain cores. The successful construction and operation of BR3/Vulcain will have demonstrated that components and techniques are available to build and operate simple, compact reactors in the small to medium power range, using long-life, high-power density cores and variable moderation. From the analyses carried out so far this concept competes well with other reactor concepts, while market surveys have indicated that there is a world market for small to medium power stations at prices within reach of those currently mentioned for the Vulcain design. (author)

Simplified reactive power management strategy for complex power grids under stochastic operation and incomplete information

International Nuclear Information System (INIS)

Vlachogiannis, John G.

2009-01-01

In the current released energy market, the large-scale complex transmission networks and the distribution ones with dispersed energy sources and 'intelligent' components operate under uncertainties, stochastic and prior incomplete information. A safe and reliable operation of such complex power grids is a major issue for system operators. Under these circumstances an online reactive power management strategy with minimum risk concerning all uncertain and stochastic parameters is proposed. Therefore, new concepts such as reactive power-weighted node-to-node linking and reactive power control capability are introduced. A distributed and interconnected stochastic learning automata system is implemented to manage, in a unified and unique way, the reactive power in complex power grids with stochastic reactive power demand and detect the vulnerable part. The proposed simplified strategy can also consider more stochastic aspects such as variable grid's topology. Results of the proposed strategy obtained on the networks of IEEE 30-bus and IEEE 118-bus systems demonstrate the effectiveness of the proposed strategy.

14 CFR 29.672 - Stability augmentation, automatic, and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 29.672 Section 29.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 29.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated system is necessary to show...

14 CFR 27.672 - Stability augmentation, automatic, and power-operated systems.

Science.gov (United States)

2010-01-01

... power-operated systems. 27.672 Section 27.672 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION... Construction Control Systems § 27.672 Stability augmentation, automatic, and power-operated systems. If the functioning of stability augmentation or other automatic or power-operated systems is necessary to show...

A High Power Boost Converter for PV Systems Operating up to 300 kHz using SiC Devices

DEFF Research Database (Denmark)

Anthon, Alexander; Zhang, Zhe; Andersen, Michael A. E.

2014-01-01

In this paper, a 3kW boost converter for PV applications using SiC devices is introduced. Main focus is to operate the converter over a wide range of switching frequency and to analyze the main loss distributors as well as the efficiency. The switching element is a recently introduced normally...... be operated at full power for a switching frequency of 100 kHz using natural cooling. At 200 kHz the boost converter is capable of operating at full power when forced air cooling is applied having a JFET case temperature of less than 90 C. The case temperature of the JFET increases up to 110 C at a switching...

Reliability research to nuclear power plant operators based on several methods

International Nuclear Information System (INIS)

Fang Xiang; Li Fu; Zhao Bingquan

2009-01-01

The paper utilizes many kinds of international reliability research methods, and summarizes the review of reliability research of Chinese nuclear power plant operators in past over ten years based on the simulator platform of nuclear power plant. The paper shows the necessity and feasibility of the research to nuclear power plant operators from many angles including human cognition reliability, fuzzy mathematics model and psychological research model, etc. It will be good to the safe operation of nuclear power plant based on many kinds of research methods to the reliability research of nuclear power plant operators. (authors)

Wind Power Forecasting Error Frequency Analyses for Operational Power System Studies: Preprint

Energy Technology Data Exchange (ETDEWEB)

Florita, A.; Hodge, B. M.; Milligan, M.

2012-08-01

The examination of wind power forecasting errors is crucial for optimal unit commitment and economic dispatch of power systems with significant wind power penetrations. This scheduling process includes both renewable and nonrenewable generators, and the incorporation of wind power forecasts will become increasingly important as wind fleets constitute a larger portion of generation portfolios. This research considers the Western Wind and Solar Integration Study database of wind power forecasts and numerical actualizations. This database comprises more than 30,000 locations spread over the western United States, with a total wind power capacity of 960 GW. Error analyses for individual sites and for specific balancing areas are performed using the database, quantifying the fit to theoretical distributions through goodness-of-fit metrics. Insights into wind-power forecasting error distributions are established for various levels of temporal and spatial resolution, contrasts made among the frequency distribution alternatives, and recommendations put forth for harnessing the results. Empirical data are used to produce more realistic site-level forecasts than previously employed, such that higher resolution operational studies are possible. This research feeds into a larger work of renewable integration through the links wind power forecasting has with various operational issues, such as stochastic unit commitment and flexible reserve level determination.

Thermionic integrated circuit technology for high power space applications

International Nuclear Information System (INIS)

Yadavalli, S.R.

1984-01-01

Thermionic triode and integrated circuit technology is in its infancy and it is emerging. The Thermionic triode can operate at relatively high voltages (up to 2000V) and at least tens of amperes. These devices, including their use in integrated circuitry, operate at high temperatures (800 0 C) and are very tolerant to nuclear and other radiations. These properties can be very useful in large space power applications such as that represented by the SP-100 system which uses a nuclear reactor. This paper presents an assessment of the application of thermionic integrated circuitry with space nuclear power system technology. A comparison is made with conventional semiconductor circuitry considering a dissipative shunt regulator for SP-100 type nuclear power system rated at 100 kW. The particular advantages of thermionic circuitry are significant reductions in size and mass of heat dissipation and radiation shield subsystems

The control of operational risk in nuclear power plant operations - Some cross-cultural perspectives

International Nuclear Information System (INIS)

Suchard, A.; Rochlin, G.

1992-01-01

The operation of nuclear power plants requires the management of a complex technology under exacting performance and safety criteria. Organizations operating nuclear power plants are faced with the challenge of simultaneously meeting technical, organizational, and social demands, striving toward perfection in a situation where learning by trial and error can be too costly. In this process, they interact with regulatory bodies who seek to help minimize operational risk by imposing and upholding safety standards. The character of this interaction differs in various countries, as does the larger cultural setting. The study generally pursued the question of how organizations operating complex and demanding technologies adapt to such requirements and circumstances, and how they can succeed in delivering nearly error-free performance. One aspect of this study includes the comparison of organizational and cultural environments for nuclear power plant operations in the US, France, Germany, Sweden, and Switzerland. The research involved in-depth, continuous observations on location and interviews with plant personnel, especially control operators, at one plant in each country

Operating history of U.S. nuclear power reactors

International Nuclear Information System (INIS)

1974-01-01

The operating history of U. S. nuclear power plants through December 31, 1974 has been collected. Included are those nuclear reactor facilities which produce electricity, even if in token amounts, or which are part of a development program concerned with the generation of electricity through the use of a nuclear reactor as a heat source. The information is based on data furnished by facility operators. The charts are plotted in terms of cumulative thermal energy as a function of time. Since only those shutdowns of five days or more are shown, the charts do not give a detailed history of plant operation. They do, however, give an overview of the operating history of a variety of developmental and experimental nuclear power reactors. The data show the yearly gross generation of electricity for each U. S. nuclear plant and, for civilian power plants, information on reactor availability and plant capacity factor. (U.S.)

Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2000-01-01

This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

Operational costs induced by fluctuating wind power production in Germany and Scandinavia

DEFF Research Database (Denmark)

Meibom, Peter; Weber, C.; Barth, R.

2009-01-01

Adding wind power generation in a power system changes the operational patterns of the existing units due to the variability and partial predictability of wind power production. For large amounts of wind power production, the expectation is that the specific operational costs (fuel costs, start......-up costs, variable operation and maintenance costs, costs of consuming CO2 emission permits) of the other power plants will increase due to more operation time in part-load and more start-ups. The change in operational costs induced by the wind power production can only be calculated by comparing...... the operational costs in two power system configurations: with wind power production and with alternative wind production having properties such as conventional production, that is, being predictable and less variable. The choice of the characteristics of the alternative production is not straightforward...

Wind power bidding in electricity markets with high wind penetration

International Nuclear Information System (INIS)

Vilim, Michael; Botterud, Audun

2014-01-01

Highlights: • We analyze the pricing systems and wind power trading in electricity markets. • We propose a model that captures the relation between market prices and wind power. • A probabilistic bidding model can increase profits for wind power producers. • Profit maximizing bidding strategies carry risks for power system operators. • We conclude that modifications of current market designs may be needed. - Abstract: Objective: The optimal day-ahead bidding strategy is studied for a wind power producer operating in an electricity market with high wind penetration. Methods: A generalized electricity market is studied with minimal assumptions about the structure of the production, bidding, or consumption of electricity. Two electricity imbalance pricing schemes are investigated, the one price and the two price scheme. A stochastic market model is created to capture the price effects of wind power production and consumption. A bidding algorithm called SCOPES (Supply Curve One Price Estimation Strategy) is developed for the one price system. A bidding algorithm called MIMICS (Multivariate Interdependence Minimizing Imbalance Cost Strategy) is developed for the two price system. Results: Both bidding strategies are shown to have advantages over the assumed “default” bidding strategy, the point forecast. Conclusion: The success of these strategies even in the case of high deviation penalties in a one price system and the implicit deviation penalties of the two price system has substantial implications for power producers and system operators in electricity markets with a high level of wind penetration. Practice implications: From an electricity market design perspective, the results indicate that further penalties or regulations may be needed to reduce system imbalance

High power RF transmission line component development

International Nuclear Information System (INIS)

Hong, B. G.; Hwang, C. K.; Bae, Y. D.; Yoon, J. S.; Wang, S. J.; Gu, S. H.; Yang, J. R.; Hahm, Y. S.; Oh, G. S.; Lee, J. R.; Lee, W. I.; Park, S. H.; Kang, M. S.; Oh, S. H.; Lee, W.I.

1999-12-01

We developed the liquid stub and phase shifter which are the key high RF power transmission line components. They show reliable operation characteristics and increased insulation capability, and reduced the size by using liquid (silicon oil, dielectric constant ε=2.72) instead of gas for insulating dielectric material. They do not have finger stock for the electric contact so the local temperature rise due to irregular contact and RF breakdown due to scratch in conductor are prevented. They can be utilized in broadcasting, radar facility which require high RF power transmission. Moreover, they are key components in RF heating system for fusion reactor. (author)

High power RF transmission line component development

Energy Technology Data Exchange (ETDEWEB)

Hong, B. G.; Hwang, C. K.; Bae, Y. D.; Yoon, J. S.; Wang, S. J.; Gu, S. H.; Yang, J. R.; Hahm, Y. S.; Oh, G. S.; Lee, J. R.; Lee, W. I.; Park, S. H.; Kang, M. S.; Oh, S. H.; Lee, W.I

1999-12-01

We developed the liquid stub and phase shifter which are the key high RF power transmission line components. They show reliable operation characteristics and increased insulation capability, and reduced the size by using liquid (silicon oil, dielectric constant {epsilon}=2.72) instead of gas for insulating dielectric material. They do not have finger stock for the electric contact so the local temperature rise due to irregular contact and RF breakdown due to scratch in conductor are prevented. They can be utilized in broadcasting, radar facility which require high RF power transmission. Moreover, they are key components in RF heating system for fusion reactor. (author)