WorldWideScience

Sample records for 3mw power level

  1. 2.3-MW Medium-Voltage, Three-Level Wind Energy Inverter Applying a Unique Bus Structure and 4.5-kV Si/SiC Hybrid Isolated Power Modules: Preprint

    Erdman, W.; Keller, J.; Grider, D.; VanBrunt, E.

    2014-11-01

    A high-efficiency, 2.3-MW, medium-voltage, three-level inverter utilizing 4.5-kV Si/SiC (silicon carbide) hybrid modules for wind energy applications is discussed. The inverter addresses recent trends in siting the inverter within the base of multimegawatt turbine towers. A simplified split, three-layer laminated bus structure that maintains low parasitic inductances is introduced along with a low-voltage, high-current test method for determining these inductances. Feed-thru bushings, edge fill methods, and other design features of the laminated bus structure provide voltage isolation that is consistent with the 10.4-kV module isolation levels. Inverter efficiency improvement is a result of the (essential) elimination of the reverse recovery charge present in 4.5-kV Si PIN diodes, which can produce a significant reduction in diode turn-off losses as well as insulated-gate bipolar transistor (IGBT) turn-on losses. The hybrid modules are supplied in industry-standard 140 mm x 130 mm and 190 mm x 130 mm packages to demonstrate direct module substitution into existing inverter designs. A focus on laminated bus/capacitor-bank/module subassembly level switching performance is presented.

  2. Energy Storage System by Means of Improved Thermal Performance of a 3 MW Grid Side Wind Power Converter

    Qin, Zian; Liserre, Marco; Blaabjerg, Frede;

    2013-01-01

    Wind speed variations make the power of wind turbine system to fluctuate, which could increase the thermal stress of the power converter and reduce its lifetime. In order to relieve this problem, short-term energy storage technologies are applied to improve the thermal performance of a 3 MW grid...... side wind power converter. The cost, weight and cycle life of the energy storage technologies are evaluated based on a typical low speed high turbulence wind profile. In detail, a wind turbine system model is established and its control strategy is illustrated, which is followed by the power control...... method of the energy storage system. Then the conventional thermal evaluation approach is simplified for evaluation with long term wind profile. The case studies are done to address the optimal power size and capacity of the energy storage system by comparing the improvement of the thermal performance...

  3. Reliability Estimation with Uncertainties Consideration for High Power IGBTs in 2.3 MW Wind Turbine Converter System

    Kostandyan, Erik; Ma, Ke

    2012-01-01

    This paper investigates the lifetime of high power IGBTs (insulated gate bipolar transistors) used in large wind turbine applications. Since the IGBTs are critical components in a wind turbine power converter, it is of great importance to assess their reliability in the design phase of the turbine....... Minimum, maximum and average junction temperatures profiles for the grid side IGBTs are estimated at each wind speed input values. The selected failure mechanism is the crack propagation in solder joint under the silicon die. Based on junction temperature profiles and physics of failure model, the...... probabilistic and determinist damage models are presented with estimated fatigue lives. Reliably levels were assessed by means of First Order Reliability Method taking into account uncertainties....

  4. The high-power (3-MW) long-pulse (3-s) radio-frequency system for ion cyclotron resonance heating experiments on TEXTOR

    A multimegajoule ion cyclotron resonance heating (ICRH) experiment was installed on the Torus Experiment for Technology-Oriented Research (TEXTOR) tokamak. The system consists of two independent power lines each designed to generate and launch 1.5 MW of radio-frequency (rf) power into the machine during a 3-s period in the 25- to 29-MHz frequency range. Each power line consists of the following items: a 1.5-MW transmitter, a transmission line system, and an interface linking the transmission line to the antenna of the shielded strip-line type placed along the tokamak's hot liner. Details of the line and antenna diagnostics and data acquisition system together with the subsequent impedance characteristic calculations are given. The rf radiation shielding for the ICRH experiment is explained. The control of the rf setup as a TEXTOR sub-system and the generator pulse control and operation modes are outlined. The antenna loading and power limitation in the presence of plasma and the conditioning procedure are discussed. Finally, the new rf system compatible with the toroidal pump limiter Advanced Limiter Test-II is presented

  5. Characteristics and facilities of a 3MW LEU fuelled TRIGA reactor

    A 3 MW TRIGA reactor fuelled with low enriched uranium having 19.7 % U-235 and 20 wt% Uranium and Zirconium Hydride, has been installed and recently made critical at a research laboratory of the Bangladesh Atomic Energy Commission. This paper describes the basic design, low and high power test results and the facilities of the reactor. The details of the core configuration of the initial criticality with 50 elements and the final core with 100 elements at 3 MW power are discussed. The available experimental facilities are also described briefly. (author)

  6. Thermal Hydraulics Analysis for the 3MW TRIGA MARK-II Research Reactor Under Transient Condition

    Some important thermal hydraulic parameters of the 3 MW TRIGA MARK-II research reactor operating under transient condition were investigated using two computer codes PULTRI and TEMPUL. Major transient parameters, such as, peak power and prompt energy released after pulse, maximum fuel and coolant temperature, surface heat flux, time and radial distribution of temperature within fuel element after pulse, fuel, fuel-cladding gap width variation, etc. were computer and compared with the experimental and operational values as reported in the safety Analysis Report (SAR). It was observed that pulsing of the reactor inserting an excess reactivity of $2.00 shoots the reactor power level to 854.353 MW compared to an experimental value of 852 MW; the maximum fuel temperature corresponding to this peak power was found to be 846.76o C which is much less than the limiting maximum value of fuel temperature of 11500 C as reported in SAR. During a pulse if the film boiling occurs for a peak adiabatic fuel temperature of 1000o C, the calculated outer cladding wall temperature was observed to be 702.390 C compared to a value of 760o C reported in SAR under the same condition. The investigated other results were also found to be in good agreement with the values reported in the SAR. 16 refs., 22 figs. (author)

  7. Operation experience with the 3 MW TRIGA Mark-II research reactor of Bangladesh

    The 3 MW TRIGA Mark-II research reactor of Bangladesh Atomic Energy Commission (BAEC) has been operating since September 14, 1986. The reactor is used for radioisotope production (131I, 99mTc, 46Sc), various R and D activities and manpower training. The reactor has been operated successfully since it's commissioning with the exception of a few reportable incidents. Of these, the decay tank leakage incident of 1997 is considered to be the most significant one. As a result of this incident, reactor operation at full power under forced-convection mode remained suspended for about 4 years. During that time, the reactor was operated at a power level of 250 kW so as to carry out experiments that require lower neutron flux. This was made possible by establishing a temporary by pass connection across the decay tank using local technology. The other incident was the contamination of the Dry Central Thimble (DCT) that took place in March 2002 when a pyrex vial containing 50 g of TeO2 powder got melted inside the DCT. The vial was melted due to high heat generation on its surface while the reactor was operated for 8 hours at 3 MW for trial production of Iodine-131 (131I). A Wet Central Thimble (WCT) was used to replace the damaged DCT in June 2002 such that the reactor operation could be resumed. The WCT was again replaced by a new DCT in June 2003 such that radioisotope production could be continued. A total of 873 irradiation requests (IRs) have been catered for different reactor uses. Out of these, 114 IRs were for radioisotope (RI) production and 759 IRs for different experiments. The total amount of RI produced stands at about 2100 GBq. The total amount of burn-up-fuel is about 6158 MWh. Efforts are on to undertake an ADP project so as to convert the analog console and I and C system of the reactor into digital one. The paper summarizes the reactor operation experiences focusing on troubleshooting, rectification, modification, RI production, various R and D activities

  8. Spent Fuel Management Program in the 3MW TRIGA MARK-II Research Reactor of Bangladesh

    Bangladesh Atomic Energy Commission (BAEC) has been operating a 3 MW TRIGA MARK II research reactor since 1986. The reactor was installed in the campus of the Atomic Energy Research Establishment (AERE) at Savar, Dhaka. It is one of the main nuclear research facilities in the country. The reactor uses TRIGA LEU fuel with uranium content of 20% by weight. The enrichment level of the fuel is 19.7%. The reactor has so far been operated for 7834 hours with a total cumulative burn up of 15898 MWh (662.5 MWd). The total burn up life of the present core is 1200 MWd. The main areas of use are: training of man-power for nuclear power plant applications, radioisotope (RI) production, neutron activation analysis (NAA), neutron radiography (NR) and neutron scattering. The government of Bangladesh has taken decision to establish nuclear power programme in the country. There is an ADP (Annual Development Project) to accomplish necessary activities for construction of medium size nuclear power plant (NPP) in the western zone of the country. Now, with regard to the safe management, storage of spent fuel and disposal of radioactive waste arising from operation of the research reactor and also from the proposed NPP expected to be constructed in future, BAEC is drawing up short and long-term plans and programs. At present, there does not exist any spent fuel element in the reactor facility. It is to be mentioned that Bangladesh is aware of the US DOE’s ‘Take Back Program’ in connection with the research reactor spent fuel of US origin, and is very much interested to take part in this program. The paper presents the current status of handling and storage facilities available for spent fuel and strategy for the safe management of spent fuel to be generated from the research reactor in near future. (author)

  9. Plan for the safe decommissioning of the BAEC 3MW TRIGA MARK-II research reactor

    The 3 MW TRIGA Mark-II research reactor of Bangladesh Atomic Energy Commission (BAEC) has been operating since September 14, 1986. The reactor is used for radioisotope production (131I, 99mTc, 46Sc), various R and D activities, and manpower training. The reactor has been operated successfully since it's commissioning with the exception of a few reportable incidents. Of these, the decay tank leakage incident of 1997 is considered to be the most significant one. As a result of this incident, reactor operation at full power remained suspended for about 4 years. However, the reactor operation was continued during this period at a power level of 250 kW to cater the needs of various R and D groups, which required lower neutron flux for their experiments. This was made possible by establishing a temporary by pass connection across the decay tank using local technology. The reactor was made operational again at full power after successful replacement of the damaged decay tank in August 2001. At present the reactor is operated 5 days a week at a full power level of 3 MW for production of I-131 and R and D purposes. Up to December 2005 total burn-up of the core stands at about 358 Megawatt Days (MWDs). BAEC has planned to increase the production of 131I and as such, the core burn-up is expected to be increased very significantly in the years to come. There is a declaration from the US DOE that all US origin research reactor spent fuel generated within 2006 will be taken away to the USA at their own cost within 2009. But the fuel burn up of the BAEC research reactor is about 6%. So the reactor can operate for about 10-20 years more. An initial decommissioning plan for the BAEC TRIGA reactor and relevant facilities should be established as early as possible as recommended in the IAEA Safety Standards Series No.WS-G-2.1 (Decommissioning of Nuclear Power Plants and Research Reactors - Safety Standards Series No.WS-G-2.1, IAEA, Vienna, 1999). During the design and construction

  10. UPGRADING THE SNS COMPRESSOR RING TO 3 MW

    The initial performance goal for the SNS compressor ring is 1.4 MW with 1.0 GeV linac beam. During the design phase many considerations and provisions have been made to allow progressive increase in power level of the ring, ultimately to 3.0 MW and beyond after years of improvements. The most important provision for future higher power operation is an increase in beam energy from 1.0 to 1.3 GeV. Other possible upgrades covered in this report include ion source current, new stripper foil material, injection and extraction systems, transverse damper, barrier cavity, and electron clearing to avoid e-p instability

  11. The 3 MW ECRH/ECCD transmission and launching system on TORE SUPRA

    The ECRH experiment on TORE SUPRA is designed to inject up to 3 MW of power at 118 GHz using an antenna consisting of six fixed spherical mirrors and three mobile steering mirrors. The position of the mobile mirrors can be varied in real time using two stepper motors for each mobile mirror. In addition to controlling the injection angle, the position of the mobile mirrors also affects the polarisation of the injected wave. Accurate formulae to compute, in real time, the stepper motor positions required to obtain the desired beam injection angles have been derived. Formulae to determine the effect on the wave polarisation, of the actual mobile mirror positions have also been determined. These formulae have been verified by precise laser measurements and by comparison of power deposition calculations and experimental results. (authors)

  12. Nuclear research reactor 0.5 to 3 MW

    This nuclear reactor has been designed for radioisotope production, basic and applied research in reactor physics and nuclear engineering, neutron-beam experimentation, irradiation of various materials and training of scientific and technical personnel. It is located in the 'Production Area' of the Nuclear Technology Center. It is equipped with the necessary facilities for large-scale production of radioisotopes to be used in medicine as well as for other scientific and industrial purposes. In addition, it has a Neutronography Facility and the required equipment to perform Neutron-Activation Analysis. It is an open pool-type reactor, moderated and cooled with light water, fuelled with 20% enriched uranium. Its reflector are graphite and water. It has plate-type fuel elements clad in aluminium. The reactor core is located near the bottom of the demineralized water pool. It includes fuel elements, reflector and sample-holding devices for materials to be irradiated. This kind of configuration, which is widely used in research reactors, provides a high degree of safety since it prevents the core from becoming exposed under any circumstance and does not require any cooling system during reactor shutdown. Power output is between 0.5 to 3 MWTH, with a minimum thermal neutron flux of approx, 1013 n/cm2·sec, at irradiation zone almost with no modifications. Heat extraction is achieved by means of a cooling circuit which comprises two circulation pumps and a plate-type heat exchanger. Final heat dissipation to the atmosphere is performed through another cooling circuit which includes two circulation pumps and a cooling tower. Reactor control is accomplished with five neutron-absorbing rods positioned by means of especially designed elements and governed by the reactor's instrumentation and control system. Should an abnormal situation arise, gravity causes the rods to fall automatically, thus extinguishing the nuclear reaction. The reactor building has a ventilation system

  13. Status of spent fuel in the 3MW BAEC MK-II research reactor facility of Bangladesh

    Bangladesh has been operating a 3 MW TRIGA MARK II research reactor since 1986. The reactor is installed in the campus of the Atomic Energy Research Establishment (AERE) at Savar, which is located about 40 km northwest of Dhaka. It is one of the main nuclear research facilities in the country. The reactor uses TRIGA LEU fuel with uranium content of 20% by weight. The enrichment level of the fuel is 19.7%. So far the reactor has been operated for 5624 hours with a total cumulative burnup (BU) of 10 690 MWh (445 MWd). The main areas of use are: training of man-power for research reactor operation and applications, radioisotope (RI) production, neutron activation analysis (NAA), neutron radiography (NR) and neutron scattering. Radioisotopes produced to date are: I-131, Sc-46 and Tc-99m. Bangladesh is a peace loving country with a strong commitment towards nuclear nonproliferation. Accordingly, it has signed several multilateral and bilateral agreements, protocols, treaties, etc. prevailing in the International Nuclear Non-proliferation regime. Bangladesh has also signed a Nuclear Cooperation Agreement with the USA on 17 September 1981, which facilitated export of nuclear technology from the USA to Bangladesh. The research reactor was procured under the provisions of this agreement. In 2003, the tenure of the Agreement was extended up to 2012. At present, there does not exist any spent fuel element in the reactor facility. However, with the recently undertaken RI production enhancement program, it is expected that the reactor will start generating spent fuels from the year 2012. It is to be mentioned that Bangladesh is aware of the US DOE's 'Take Back Program' in connection with the research reactor spent fuel of US origin, and is very much interested to take part in this program. The paper presents the current status of handling and storage facilities available for spent fuel and strategy for the safe management spent fuel to be generated from the research reactor in

  14. Characterization of blade throw from a 2.3MW horizontal axis wind turbine upon failure

    Sarlak, Hamid; Sørensen, Jens Nørkær

    2015-01-01

    The present work concerns aerodynamics of thrown objects from a 2.3 MW Horizontal Axis Wind Turbine (HAWT), as a consequence of blade failure. The governing set of ordinary differential equations for the flying objects are derived and numerically solved using a 4th order Runge-Kutta time advancing...

  15. Race-track coils for a 3 MW HTS ship motor

    Highlights: • Sumitomo Electric manufactured the HTS field coils for a 3 MW HTS ship motor. • The motor was developed and successfully passed the loading test by Kawasaki Heavy. • We tested and obtained the basic data to evaluate the 20-year durability of coils. - Abstract: Since the discovery of high-temperature superconductivity (HTS), Sumitomo Electric has been developing silver-sheathed Bi2223 superconducting wire and products. Ship propulsion motors are one of the most promising applications of HTS. Sumitomo Electric Industries, Ltd. (SEI) has recently manufactured 24 large racetrack coils, using 70 km long DI-BSCCO wires, for use in a 3 MW HTS motor developed by Kawasaki Heavy Industries, Ltd. (KHI). The 3 MW HTS motor, using our newly developed racetrack coils, has successfully passed the loading test. It is particularly important that the HTS field coils used in ship propulsion motors can withstand the expansive forces repeatedly applied to them. As racetrack type coils have straight sections, the support mechanism they require to withstand expansive forces is very different from that of circular coils. Therefore, we ran tests and obtained the basic data to evaluate the 20-year durability of racetrack coils against the repeatedly applied expansive forces expected in domestic ship propulsion motors

  16. Race-track coils for a 3 MW HTS ship motor

    Ueno, E., E-mail: ueno-eisaku@sei.co.jp; Kato, T.; Hayashi, K.

    2014-09-15

    Highlights: • Sumitomo Electric manufactured the HTS field coils for a 3 MW HTS ship motor. • The motor was developed and successfully passed the loading test by Kawasaki Heavy. • We tested and obtained the basic data to evaluate the 20-year durability of coils. - Abstract: Since the discovery of high-temperature superconductivity (HTS), Sumitomo Electric has been developing silver-sheathed Bi2223 superconducting wire and products. Ship propulsion motors are one of the most promising applications of HTS. Sumitomo Electric Industries, Ltd. (SEI) has recently manufactured 24 large racetrack coils, using 70 km long DI-BSCCO wires, for use in a 3 MW HTS motor developed by Kawasaki Heavy Industries, Ltd. (KHI). The 3 MW HTS motor, using our newly developed racetrack coils, has successfully passed the loading test. It is particularly important that the HTS field coils used in ship propulsion motors can withstand the expansive forces repeatedly applied to them. As racetrack type coils have straight sections, the support mechanism they require to withstand expansive forces is very different from that of circular coils. Therefore, we ran tests and obtained the basic data to evaluate the 20-year durability of racetrack coils against the repeatedly applied expansive forces expected in domestic ship propulsion motors.

  17. Thermal-Hydraulic Analysis of the 3-MW TRIGA MARK-II Research Reactor Under Steady-State and Transient Conditions

    Important thermal-hydraulic parameters of the 3-MW TRIGA MARK-II research reactor operating under both steady-state and transient conditions are reported. Neutronic analyses were performed by using the CITATION diffusion code and the MCNP4B2 Monte Carlo code. The output of CITATION and MCNP4B2 were input to the PARET thermal-hydraulic code to study the steady-state and transient thermal-hydraulic behavior of the reactor. To benchmark the PARET model, data were obtained from different measurements performed by thermocouples in the instrumented fuel (IF) rod during the steady-state operation both under forced- and natural-convection mode and compared with the calculation. The mass flow rates needed for input to PARET were taken from the Final Safety Analysis Report for a downward forced coolant flow equivalent to 3500 gal/min. For natural convection cooling of the reactor, the mass flow rate was generated using the NCTRIGA code. Peak fuel temperatures measured by the thermocouples in the IF rods at different power levels of the TRIGA core were compared with the values calculated by PARET. The axial distribution of the temperatures of the fuel centerline, fuel surface, and the cladding surface in the hot channel were calculated for the reactor operating at the full-power level. Fuel surface heat flux and heat transfer coefficients for the hot channel were also calculated for the reactor operating at the full-power level. The investigated results were found to be in good agreement with the experimental and operational values. The testing of the PARET model calculations through benchmarking the available TRIGA experimental and operational data for pulse-mode operations showed that PARET can successfully be used to analyze the transient behavior of the reactor. Major transient parameters, such as peak power and prompt energy released after pulse, full-width at half-maximum of pulse peak, and maximum fuel centerline temperatures for different fuel elements at different

  18. Criticality and safety parameter studies for upgrading 3 MW TRIGA MARK II research reactor and validation of generated cross section library and computational method

    This study deals with the neutronic and thermal hydraulic analysis of the 3MW TRIGA MARK II research reactor to upgrade it to a higher flux. The upgrading will need a major reshuffling and reconfiguration of the current core. To reshuffle the current core configuration, the chain of NJOY94.10 - WIMSD-5A - CITATION - PARET - MCNP4B2 codes has been used for the overall analysis. The computational methods, tools and techniques, customisation of cross section libraries, various models for cells and super cells, and a lot of associated utilities have been standardised and established/validated for the overall core analysis. Analyses using the 4-group and 7-group libraries of macroscopic cross sections generated from the 69-group WIMSD-5 library showed that a 7-group structure is more suitable for TRIGA calculations considering its LEU fuel composition. The MCNP calculations established that the CITATION calculations and the generated cross section library are reasonably good for neutronic analysis of TRIGA reactors. Results obtained from PARET demonstrated that the flux upgrade will not cause the temperature limit on the fuel to be exceeded. Also, the maximum power density remains, by a substantial margin below the level at which the departure from nucleate boiling could occur. A possible core with two additional irradiation channels around the CT is projected where almost identical thermal fluxes as in the CT are obtained. The reconfigured core also shows 7.25% thermal flux increase in the Lazy Susan. (author)

  19. Race-track coils for a 3 MW HTS ship motor

    Ueno, E.; Kato, T.; Hayashi, K.

    2014-09-01

    Since the discovery of high-temperature superconductivity (HTS), Sumitomo Electric has been developing silver-sheathed Bi2223 superconducting wire and products. Ship propulsion motors are one of the most promising applications of HTS. Sumitomo Electric Industries, Ltd. (SEI) has recently manufactured 24 large racetrack coils, using 70 km long DI-BSCCO wires, for use in a 3 MW HTS motor developed by Kawasaki Heavy Industries, Ltd. (KHI). The 3 MW HTS motor, using our newly developed racetrack coils, has successfully passed the loading test. It is particularly important that the HTS field coils used in ship propulsion motors can withstand the expansive forces repeatedly applied to them. As racetrack type coils have straight sections, the support mechanism they require to withstand expansive forces is very different from that of circular coils. Therefore, we ran tests and obtained the basic data to evaluate the 20-year durability of racetrack coils against the repeatedly applied expansive forces expected in domestic ship propulsion motors.

  20. Index and reference levels for Power Quality

    The JWG C4.07 CIGRE/CIRED have the goal in quantification of index and reference levels of general character for being able to carry out analysis of Power Quality in the actual scenario of market liberalization

  1. Design for a 1.3 MW, 13 MeV Beam Dump for an Energy Recovery Linac

    Sinclair, Charles K; Smith, Colin H

    2005-01-01

    The electron beam exiting an Energy Recovery Linac (ERL) is dumped close to the injection energy. This energy is chosen as low as possible while allowing the beam quality specifications to be met. As ERLs are designed for high average beam current, beam dumps are required to handle high beam power at low energy. Low energy electrons have a short range in practical dump materials, requiring the beam size at the dump face be enlarged to give acceptable power densities and heat fluxes. Cornell University is developing a 100 mA average current ERL as a synchrotron radiation source. The 13 MeV optimum injection energy requires a 1.3 MW beam dump. We present a mature design for this dump, using an array of water-cooled extruded copper tubes. This array is mounted in the accelerator vacuum normal to the beam. Fatigue failure resulting from abrupt thermal cycles associated with beam trips is a potential failure mechanism. We report on designs for a 75 kW, 750 keV tube-cooled beryllium plate dump for electron gun test...

  2. LPGC, Levelized Steam Electric Power Generator Cost

    1 - Description of program or function: LPGC is a set of nine microcomputer programs for estimating power generation costs for large steam-electric power plants. These programs permit rapid evaluation using various sets of economic and technical ground rules. The levelized power generation costs calculated may be used to compare the relative economics of nuclear and coal-fired plants based on life-cycle costs. Cost calculations include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. These programs can be used for quick analyses of power generation costs using alternative economic parameters, such as interest rate, escalation rate, inflation rate, plant lead times, capacity factor, fuel prices, etc. The two major types of electric generating plants considered are pressurized-water reactor (PWR) and pulverized coal-fired plants. Data are also provided for the Large Scale Prototype Breeder (LSPB) type liquid metal reactor. Costs for plant having either one or two units may be obtained. 2 - Method of solution: LPGC consists of nine individual menu-driven programs controlled by a driver program, MAINPWR. The individual programs are PLANTCAP, for calculating capital investment costs; NUCLOM, for determining operation and maintenance (O and M) costs for nuclear plants; COALOM, for computing O and M costs for coal-fired plants; NFUEL, for calculating levelized fuel costs for nuclear plants; COALCOST, for determining levelized fuel costs for coal-fired plants; FCRATE, for computing the fixed charge rate on the capital investment; LEVEL, for calculating levelized power generation costs; CAPITAL, for determining capitalized cost from overnight cost; and MASSGEN, for generating, deleting, or changing fuel cycle mass balance data for use with NFUEL. LPGC has three modes of operation. In the first, each individual code can be executed independently to determine one aspect of the total

  3. Initial operation and utilization of the Bangladesh 3 Mw TRIGA reactor

    A 3 Mw TRIGA MK-II pulsing type research reactor fuelled with low enrichment uranium having 19.7% U-235 and 20 wt % Uranium, 0.47% Erbium and Zirconium Hydride, has been installed at the Atomic Energy Research Establishment, savar in the last week of October, 1986. This multi-purpose reactor, capable of both steady-state and pulsing operation, has been put into service in several disciplines since its commissioning and presently in operation without any major problem. The paper describes the initial operating experience and the reactor utilization made in several areas including the operator training conducted for the formation of the initial crew for the reactor. (author)

  4. Experience on the refurbishment of the cooling system of the 3 MW TRIGA Mark II research reactor of Bangladesh and the modernization plan of the reactor control console

    The 3 MW TRIGA Mark II research reactor of the Bangladesh Atomic Energy Commission (BAEC) achieved its first criticality on 14 September 1986. Since then, the reactor has been used for manpower training, radioisotope production, and various R and D activities in the field of neutron activation analysis (NAA), neutron radiography (NR), and neutron scattering. Full power reactor operations remained suspended from 1997-2001 when a corrosion leakage problem in the 16N decay tank threatened the integrity of the primary cooling loop. The new tank was installed in 2001 and some modification and upgrades were carried out in the reactor cooling system such that the operational safety of the reactor could be strengthened. The cooling system upgrade mainly included replacement of the fouled shell and tube-type heat exchanger by a new plate-type one, modification of the cooling system piping layout, installation of isolation valves, installation of a chemical injection system for the secondary cooling system, modification of the Emergency Core Cooling System (ECCS), etc. After successful completion of all these modifications, the reactor was made operational again at full power of 3 MW in August 2001. BAEC, the operating organization, is now implementing a government-funded project to replace the old analogue control console of the research reactor with a digital control console. This paper focuses on the modification of the cooling system as well as the I and C system and the upcoming control console upgrade of the 3 MW TRIGA Mark II research reactor of Bangladesh. It also presents short descriptions of major incidents encountered so far in the reactor facility. (author)

  5. Strengthening operational safety of the 3MW TRIGA MK-II research reactor of Bangladesh Atomic Energy Commission through modification and upgrade of its water system

    The 3 MW TRIGA MK-II Research Reactor of Bangladesh Atomic Energy Commission (BAEC) attained its first criticality on 14 September 1986. Since then it has been operated at different power levels for manpower training, various R and D activities and isotope production. However, operation of the reactor had to be suspended temporarily for a number of times because of different types of problems mainly in the water systems of the reactor. The first problem was encountered in January 1990. It was a leakage problem in the suction line of the emergency core cooling system (ECCS). Then in September 1990 a welding joint of the exi-check valve located at the discharge side of one of the two primary pumps failed. As a result primary water started to leak out of the system at a slow rate. These problems were solved locally. However in July 1997 the 32,000 liter capacity N-16 decay tank (made of Type 6061-T6 aluminium alloy) got damaged due to corrosion. As the tank was found not to be repairable, it was decided to replace it by a new one. It was also strongly felt that the water system of the reactor needed to be upgraded such that operational safety of the reactor is strengthened. Keeping this in mind a contract was signed on 14 Jan. 2000 with the original reactor supplier to supply and install a new decay tank by replacing the old one. Under the contract provisions were also kept to upgrade the cooling system. The upgrading program mainly includes replacement of the fouled tube and shell type heat exchanger by a new plate type one, modification of the layout of the cooling pipes, installation of isolation valves, modification of the old ECCS, etc. It is expected that after completion of all these works by May 2001, operational safety of the BAEC TRIGA research reactor will be strengthened significantly. (author)

  6. 3 MW TRIGA Research Reactor facility of BAEC and its Utilization

    Molla, N.I.; Bhuiyan, S.I.; Wadud Mondal, M.A.; Ahmed, F.U.; Islam, M.N.; Hossain, S.M.; Ahmed, K.; Zulquarnain, A.; Abedin, Z. [Bangladesh Atomic Energy Commission, Atomic Energy Research Establishment, Dhaka (Bangladesh)

    1999-08-01

    The paper briefly describes the Utilisation of 3 MW TRIGA Research Reactor of BAEC for neutron beam research, neutron activation analysis are isotope production. It includes the installation of the triple axis neutron spectrometer at the radial piercing beam port and a neutron radiography set-up at the tangential beam port and their uses for material analysis and condensed matter research and material testing. Nuclear and magnetic structures of some ferrites have been studied in powder diffraction method in the double axis mode. SANS technique with double crystal diffraction known as Bonse and Hart's method has been adopted in an experiment with alumina sample. The neutron radiography set-up and its use in the detection of corrosion in alumina have been reported. Determination of arsenic concentration in drinking water from tube well via Instrumental Neutron Activation Analysis and production of radioiodine-131 by dry distillation method are presented. Our experience on the removal of N-16 decay tank because of the leakage of coolant and bringing the research reactor back to operational by-passing the decay tank have been focussed. A possible reconfiguration of the existing TRIGA core, without exceeding the safety margins, providing additional irradiation channel and upgrading the neutron flux for increased radioisotope production has been attempted. Cross section library ENDF/B-VI and JENDL3.2, code NJOY94.10, WIMSD package, 3-D code CITATION, PARET and Monte Carlo code MCNP4B2 have been employed to achieve the objective. (author)

  7. Neutronic Analysis of the 3 MW TRIGA MARK II Research Reactor, Part I: Monte Carlo Simulation

    This study deals with the neutronic analysis of the current core configuration of a 3 MW TRIGA MARK II research reactor at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh and validation of the results by benchmarking with the experimental, operational and available Final Safety Analysis Report (FSAR) values. The three-dimensional continuous-energy Monte Carlo code MCNP4C was used to develop a versatile and accurate full-core model of the TRIGA core. The model represents in detail all components of the core with literally no physical approximation. All fresh fuel and control elements as well as the vicinity of the core were precisely described. Continuous energy cross-section data from ENDF/B-VI and S(α, β) scattering functions from the ENDF/B-V library were used. The validation of the model against benchmark experimental results is presented. The MCNP predictions and the experimentally determined values are found to be in very good agreement, which indicates that the Monte Carlo model is correctly simulating the TRIGA reactor. (author)

  8. 3 MW TRIGA Research Reactor facility of BAEC and its Utilization

    The paper briefly describes the Utilisation of 3 MW TRIGA Research Reactor of BAEC for neutron beam research, neutron activation analysis are isotope production. It includes the installation of the triple axis neutron spectrometer at the radial piercing beam port and a neutron radiography set-up at the tangential beam port and their uses for material analysis and condensed matter research and material testing. Nuclear and magnetic structures of some ferrites have been studied in powder diffraction method in the double axis mode. SANS technique with double crystal diffraction known as Bonse and Hart's method has been adopted in an experiment with alumina sample. The neutron radiography set-up and its use in the detection of corrosion in alumina have been reported. Determination of arsenic concentration in drinking water from tube well via Instrumental Neutron Activation Analysis and production of radioiodine-131 by dry distillation method are presented. Our experience on the removal of N-16 decay tank because of the leakage of coolant and bringing the research reactor back to operational by-passing the decay tank have been focussed. A possible reconfiguration of the existing TRIGA core, without exceeding the safety margins, providing additional irradiation channel and upgrading the neutron flux for increased radioisotope production has been attempted. Cross section library ENDF/B-VI and JENDL3.2, code NJOY94.10, WIMSD package, 3-D code CITATION, PARET and Monte Carlo code MCNP4B2 have been employed to achieve the objective. (author)

  9. Low Power Design with High-Level Power Estimation and Power-Aware Synthesis

    Ahuja, Sumit; Shukla, Sandeep Kumar

    2012-01-01

    Low-power ASIC/FPGA based designs are important due to the need for extended battery life, reduced form factor, and lower packaging and cooling costs for electronic devices. These products require fast turnaround time because of the increasing demand for handheld electronic devices such as cell-phones, PDAs and high performance machines for data centers. To achieve short time to market, design flows must facilitate a much shortened time-to-product requirement. High-level modeling, architectural exploration and direct synthesis of design from high level description enable this design process. This book presents novel research techniques, algorithms,methodologies and experimental results for high level power estimation and power aware high-level synthesis. Readers will learn to apply such techniques to enable design flows resulting in shorter time to market and successful low power ASIC/FPGA design. Integrates power estimation and reduction for high level synthesis, with low-power, high-level design; Shows spec...

  10. Thermal hydraulic transient study of 3 MW TRIGA Mark-II research reactor of Bangladesh using the EUREKA-2/RR code

    Highlights: ► Reactor power transition time depends on magnitude and form of reactivity. ► This time also depends on existing reactor power during reactivity insertion. ► Pattern of power transition depends on form of reactivity insertion. ► Doppler’s effect is seen for lower reactivity insertion when reactor power is low. ► EUREKA-2/RR code performs well for RIA and LOFA of TRIGA Mark-II research reactor. - Abstract: EUREKA-2/RR code has been used for the analyses of reactivity insertion accident (RIA) and loss of flow accident (LOFA) of 3 MW TRIGA Mark-II research reactor of Bangladesh. Transient characteristics of different parameters such as core power, fuel temperature, clad temperature, departure from nucleate boiling ratio (DNBR) due to the different form and magnitude of reactivity insertion has been focused. It is found from the analysis that the magnitude of insertion reactivity and the reactor operating power during this insertion impose a total effect on the core safety. Also, transient effects on reactor were studied for 15% loss of flow of the primary coolant. Provided the scram system is available, the reactor is found to shutdown safely in both cases. From these two studies in series, it is seen that EUREKA-2/RR is well suited for the analyses of reactor safety parameters with good approximations.

  11. Microgrid Control Techniques at Power Converter Level

    Valouch, Viktor; Šimek, Petr; Škramlík, Jiří; Tlustý, J.

    Ostrava: VŠB - TU Ostrava, 2013, s. 611-616. ISBN 978-80-248-2988-3. [Electric Power Engineering - EPE 2013. Kouty nad Desnou (CZ), 28.05.2013-30.05.2013] Institutional support: RVO:61388998 Keywords : microgrid * power converter * droop control Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  12. Nuclear power and low level radiation hazards

    Even in the future, nuclear power is expected to contribute less than 1/10th of the present total population exposure to man-made radiation. By the best estimates available, the current health risks of nuclear power generation appear to be much less than those associated with the major alternative sources of energy, with the exception of natural gas which is about equally safe. Uncertainties concerning the radiation risks from nuclear power, from medical x-rays and from the effects of reduced ventillation to conserve heat appear to be less than those associated with estimates of risks from the use of coal and various other sources of energy. This is in part because of the large amount of effort devoted to studies of radiation effects. The benefits in terms of current life expectancy associated with any of the conventional or unconventional methods of power production appear to greatly outweigh the associated current health hazards. (author)

  13. Power Analysis in Two-Level Unbalanced Designs

    Konstantopoulos, Spyros

    2010-01-01

    Previous work on statistical power has discussed mainly single-level designs or 2-level balanced designs with random effects. Although balanced experiments are common, in practice balance cannot always be achieved. Work on class size is one example of unbalanced designs. This study provides methods for power analysis in 2-level unbalanced designs…

  14. Criticality and safety parameter studies for upgrading 3MW TRIGA MARK II research reactor and validation of generated cross section library and computational method

    The neutronic and thermal hydraulic analysis of the 3 MW TRIGA MARK II research reactor to upgrade it is presented. The upgrading will need a major reshuffling and reconfiguration of the current core. To realize this objective, the overall strategy followed is: 1.) generation of problem dependent cross section library from basic Evaluated Nuclear Data Files such as ENDF/B-VI, JENDL3.2 with NJOY94.10+, 2.) use WIMSD-5 package to generate cell constants for all of the materials in the core and its immediate neighborhood, 3.) use CITATION to perform 3-D global analysis of the core to study multiplication factor, neutron flux and power distributions, power peaking factors, temperature reactivity coefficients, etc., 4.) couple output of CITATION with PARET to study thermal hydraulic behavior to predict safety margins, 5.) check the validity of the deterministic codes with the Monte Carlo code MCNP4B2 , and 6.) reshuffle the current core configuration to achieve the desired objectives. The computational methods, tools and techniques, customization of cross section libraries, various models for cells and super cells, and a lot of associated utilities have been standardized and established/validated for the overall core analysis

  15. University students' understanding level about words related to nuclear power

    The authors conducted a survey of university students' understanding level about words related to nuclear power before and after Fukushima Daiichi Power Plant accident, and analyzed the difference between before and after the accident. The results show that university students' understanding level improved after the accident, especially in the case of reported words by mass media. Understanding level of some nuclear power security words which were not reported so much by mass media also improved. That may be caused by rising of people's concern about nuclear power generation after the accident, and there is a possibility that the accident motivated people to access such words via internet, journals, etc. (author)

  16. Application of plasma attenuator for microwave power level control

    V. L. Kofanov

    1967-12-01

    Full Text Available Correlations for the calculation of the circuit back coupling time constant of control power level system using filter which removes signal parasitic amplitude modulation are derived. System is described in which coefficient of the stabilization 250—300 is obtained when changing the input power level is 15—25 db.

  17. Rotational Augmentation on a 2.3 MW Rotor Blade with Thick Flatback Airfoil Cross-Sections: Preprint

    Schreck, S.; Fingersh, L.; Siegel, K.; Singh, M.; Medina, P.

    2013-01-01

    Rotational augmentation was analyzed for a 2.3 MW wind turbine, which was equipped with thick flatback airfoils at inboard radial locations and extensively instrumented for acquisition of time varying surface pressures. Mean aerodynamic force and surface pressure data were extracted from an extensive field test database, subject to stringent criteria for wind inflow and turbine operating conditions. Analyses of these data showed pronounced amplification of aerodynamic forces and significant enhancements to surface pressures in response to rotational influences, relative to two-dimensional, stationary conditions. Rotational augmentation occurrence and intensity in the current effort was found to be consistent with that observed in previous research. Notably, elevated airfoil thickness and flatback design did not impede rotational augmentation.

  18. Challenges with Tertiary-Level Mechatronic Fluid Power

    Dransfield, Peter; Conrad, Finn

    1996-01-01

    As authors we take the view that mechatronics, as it relates to fluid power, has three levels which we designate as primary, secondary and tertiary. A brief review of the current status of fluid power, hydraulic and pneumatic, and of electronic control of it is presented and discussed. The focus is...... then on tertiary-level mechatronic fluid power and the challenges to it being applied successfully....

  19. Reactive Power Impact on Lifetime Prediction of Two-level Wind Power Converter

    Zhou, Dao; Blaabjerg, Frede; Lau, M.; Tonnes, M.

    The influence of reactive power injection on the dominating two-level wind power converter is investigated and compared in terms of power loss and thermal behavior. Then the lifetime of both the partial-scale and full-scale power converter is estimated based on the widely used Coffin-Manson model....... It is concluded that the injection of the reactive power could have serious impact on the power loss and thermal profile, especially at lower wind speed. Furthermore, the introduction of the reactive power could also shorten the lifetime of the wind power converter significantly....

  20. Experimental Study of a Multi Level Overtopping Wave Power Device

    Kofoed, Jens Peter; Hald, Tue; Frigaard, Peter Bak

    2002-01-01

    , compared to only one level, has been evaluated experimentally. From the experimental results, and the performed optimizations based on these, it has been found that the efficiency of a wave power device of the overtopping type can be increased by as much as 76 % by using 5 levels instead of 1. However......, using 5 levels introduces practical problems, and is most probably not economically feasible. It is concluded that it is reasonable to use 2 levels (maybe 3), which can increase the efficiency by 25-40 % compared to using a single level.......Results of experimental investigations of a floating wave energy device called Power Pyramid is presented. The Power Pyramid utilizes reservoirs in multiple levels when capturing wave overtopping and converting it into electrical energy. The effect of capturing the overtopping in multiple levels...

  1. Battery Energy Storage System for PV Output Power Leveling

    Rajkiran Singh; Seyedfoad Taghizadeh; Nadia Mei Lin Tan; Jagadeesh Pasupuleti

    2014-01-01

    Fluctuating photovoltaic (PV) output power reduces the reliability in power system when there is a massive penetration of PV generators. Energy storage systems that are connected to the PV generators using bidirectional isolated dc-dc converter can be utilized for compensating the fluctuating PV power. This paper presents a grid connected energy storage system based on a 2 kW full-bridge bidirectional isolated dc-dc converter and a PWM converter for PV output power leveling. This paper propos...

  2. Ultrasonic level and temperature sensor for power reactor applications

    An ultrasonic waveguide employing torsional and extensional acoustic waves has been developed for use as a level and temperature sensor in pressurized and boiling water nuclear power reactors. Features of the device include continuous measurement of level, density, and temperature producing a real-time profile of these parameters along a chosen path through the reactor vessel

  3. Power Consideration for Three-Level Growth Models

    Li, Wei; Konstantopoulos, Spyros

    2016-01-01

    The purpose of this study is extend previous methods by Raudenbush and Liu (2001) and Spybrook et al. (2011), and provide methods for power analysis of tests of treatment effects in studies of polynomial change with two levels of nesting (e.g., students and schools) where the treatment is either at the third level (e.g., school intervention) or at…

  4. User's manual for levelized power generation cost using a microcomputer

    Microcomputer programs for the estimation of levelized electrical power generation costs are described. Procedures for light-water reactor plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, nuclear decommissioning cost, and levelized total generation cost. Programs are written in Pascal and are run on an Apple II Plus microcomputer

  5. Computational Analysis of Nuclear Safety Parameters of 3 MW TRIGA Mark-II Research Reactor Based on Evaluated Nuclear Data Libraries JENDL-3.3 and ENDF/B-VII.0

    Khan, Jahirul Haque [Bangladesh Atomic Energy Commission, Dhaka (Bangladesh)

    2013-07-01

    The objective of this study is to explain the main nuclear safety parameters of 3 MW TRIGA Mark-II Research Reactor at AERE, Savar, Dhaka, Bangladesh from the viewpoint of reactor safety and also reactor operator. The most important nuclear reactor physics safety parameters are power distribution, power peaking factors, shutdown margin, control rod worth, excess reactivity and fuel temperature reactivity coefficient. These parameters are calculated using the chain of the computer codes the SRAC-PIJ for cell calculation based on neutron transport theory and the SRAC-CITATION for core calculation based on neutron diffusion equation. To achieve this objective the TRIGA model is developed by the 3-D diffusion code SRAC-CITATION based on the group constants that come from the collision probability transport code SRAC-PIJ. In this study the evaluated nuclear data libraries JENDL-3.3 and ENDF/B-VII.0 are used. The calculated most important reactor physics parameters are compared to the safety analysis report (SAR) values as well as earlier published MCNP results (numerically benchmark). It was found that the calculated results show a good agreement between the said libraries. Besides, in most cases the calculated results reveal a reasonable agreement with the SAR values (by General Atomic) as well as the MCNP results. In addition, this analysis can be used as the inputs for thermal-hydraulic calculations of the TRIGA fresh core in the steady state and pulse mode operation. Because of power peaking factors, power distributions and temperature reactivity coefficients are the most important reactor safety parameters for normal operation and transient safety analysis in research as well as in power reactors. They form the basis for technical specifications and limitations for reactor operation such as loading pattern limitations for pulse operation (in TRIGA). Therefore, this analysis will be very important to develop the nuclear safety parameters data of 3 MW TRIGA Mark

  6. Computational Analysis of Nuclear Safety Parameters of 3 MW TRIGA Mark-II Research Reactor Based on Evaluated Nuclear Data Libraries JENDL-3.3 and ENDF/B-VII.0

    The objective of this study is to explain the main nuclear safety parameters of 3 MW TRIGA Mark-II Research Reactor at AERE, Savar, Dhaka, Bangladesh from the viewpoint of reactor safety and also reactor operator. The most important nuclear reactor physics safety parameters are power distribution, power peaking factors, shutdown margin, control rod worth, excess reactivity and fuel temperature reactivity coefficient. These parameters are calculated using the chain of the computer codes the SRAC-PIJ for cell calculation based on neutron transport theory and the SRAC-CITATION for core calculation based on neutron diffusion equation. To achieve this objective the TRIGA model is developed by the 3-D diffusion code SRAC-CITATION based on the group constants that come from the collision probability transport code SRAC-PIJ. In this study the evaluated nuclear data libraries JENDL-3.3 and ENDF/B-VII.0 are used. The calculated most important reactor physics parameters are compared to the safety analysis report (SAR) values as well as earlier published MCNP results (numerically benchmark). It was found that the calculated results show a good agreement between the said libraries. Besides, in most cases the calculated results reveal a reasonable agreement with the SAR values (by General Atomic) as well as the MCNP results. In addition, this analysis can be used as the inputs for thermal-hydraulic calculations of the TRIGA fresh core in the steady state and pulse mode operation. Because of power peaking factors, power distributions and temperature reactivity coefficients are the most important reactor safety parameters for normal operation and transient safety analysis in research as well as in power reactors. They form the basis for technical specifications and limitations for reactor operation such as loading pattern limitations for pulse operation (in TRIGA). Therefore, this analysis will be very important to develop the nuclear safety parameters data of 3 MW TRIGA Mark

  7. Graphene induced bifurcation of energy levels at low input power

    Li, Rujiang; Lin, Shisheng; Liu, Xu; Chen, Hongsheng

    2015-01-01

    We study analytically the energy states in the waveguide system of graphene coated dielectric nanowire based on the explicit form of nonlinear surface conductivity of graphene. The energy levels of different plasmonic modes can be tuned by the input power at the order of a few tenths of mW. The self-focusing behavior and self-defocusing behavior are exhibited in the lower and upper bifurcation branches, respectively, which are separated by a saturation of input power. Moreover, due to the nonlinearity of graphene, the dispersion relations for different input powers evolve to an energy band which is in sharp contrast with the discrete energy level in the limit of zero power input.

  8. High-level power analysis and optimization techniques

    Raghunathan, Anand

    1997-12-01

    This thesis combines two ubiquitous trends in the VLSI design world--the move towards designing at higher levels of design abstraction, and the increasing importance of power consumption as a design metric. Power estimation and optimization tools are becoming an increasingly important part of design flows, driven by a variety of requirements such as prolonging battery life in portable computing and communication devices, thermal considerations and system cooling and packaging costs, reliability issues (e.g. electromigration, ground bounce, and I-R drops in the power network), and environmental concerns. This thesis presents a suite of techniques to automatically perform power analysis and optimization for designs at the architecture or register-transfer, and behavior or algorithm levels of the design hierarchy. High-level synthesis refers to the process of synthesizing, from an abstract behavioral description, a register-transfer implementation that satisfies the desired constraints. High-level synthesis tools typically perform one or more of the following tasks: transformations, module selection, clock selection, scheduling, and resource allocation and assignment (also called resource sharing or hardware sharing). High-level synthesis techniques for minimizing the area, maximizing the performance, and enhancing the testability of the synthesized designs have been investigated. This thesis presents high-level synthesis techniques that minimize power consumption in the synthesized data paths. This thesis investigates the effects of resource sharing on the power consumption in the data path, provides techniques to efficiently estimate power consumption during resource sharing, and resource sharing algorithms to minimize power consumption. The RTL circuit that is obtained from the high-level synthesis process can be further optimized for power by applying power-reducing RTL transformations. This thesis presents macro-modeling and estimation techniques for switching

  9. Generation of a library for reactor calculations and some applications in core and safety parameter studies of the 3-MW TRIGA MARK-II research reactor

    This paper reports on a data base of the TRIGAP code that is generated for the 3-MW TRIGA MARK-II research reactor in Bangladesh. The library is created using the WIMS-D/4 code. Cross sections are calculated from zero burnup to 37% of initial 235U in 20 burnup steps. The created TRIGAP library is tested through practical calculations and is compared with experimental values or with values in the safety analysis report (SAR). Excess reactivity of the fresh core configuration is measured and determined to be 10.27 dollars, while a value of 10.267 dollars is obtained using the generated library. By choosing burnup steps of 0, 50, 350, and 750, WM · h, the whole operating history is covered. The calculated temperature defect at 1 and 3 MW is 1.15 and 3.59 dollars compared with the experimental value of 1.02 and 3.64 dollars, respectively. The xenon value obtained at 1 and 3 MW is 2.21 and 3.20 dollars, respectively, compared with 3.57 dollars at 3 MW in the SAR. The TRIGAP code with its new library is used for calculating fast and thermal flux distributions close to values from the SAR

  10. Power Constrained High-Level Synthesis of Battery Powered Digital Systems

    Nielsen, Sune Fallgaard; Madsen, Jan

    2003-01-01

    We present a high-level synthesis algorithm solving the combined scheduling, allocation and binding problem minimizing area under both latency and maximum power per clock-cycle constraints. Our approach eliminates the large power spikes, resulting in an increased battery lifetime, a property of...... utmost importance for battery powered embedded systems. Our approach extends the partial-clique partitioning algorithm by introducing power awareness through a heuristic algorithm which bounds the design space to those of power feasible schedules. We have applied our algorithm on a set of dataflow graphs...

  11. Aerobic Capacity and Anaerobic Power Levels of the University Students

    Taskin, Cengiz

    2016-01-01

    The aim of study was to analyze aerobic capacity and anaerobic power levels of the university students. Total forty university students who is department physical education and department business (age means; 21.15±1.46 years for male and age means; 20.55±1.79 years for female in department physical education), volunteered to participate in this…

  12. Battery Energy Storage System for PV Output Power Leveling

    Rajkiran Singh

    2014-01-01

    Full Text Available Fluctuating photovoltaic (PV output power reduces the reliability in power system when there is a massive penetration of PV generators. Energy storage systems that are connected to the PV generators using bidirectional isolated dc-dc converter can be utilized for compensating the fluctuating PV power. This paper presents a grid connected energy storage system based on a 2 kW full-bridge bidirectional isolated dc-dc converter and a PWM converter for PV output power leveling. This paper proposes two controllers: a current controller using the d-q synchronous reference and a phase-shift controller. The main function of the current controller is to regulate the voltage at the high-side dc, so that the voltage ratio of the high-voltage side (HVS with low-voltage side (LVS is equal to the transformer turns ratio. The phase-shift controller is employed to manage the charging and discharging modes of the battery based on PV output power and battery voltage. With the proposed system, unity power factor and efficient active power injection are achieved. The feasibility of the proposed control system is investigated using PSCAD simulation.

  13. Design of megawatt power level heat pipe reactors

    Mcclure, Patrick Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Poston, David Irvin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dasari, Venkateswara Rao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reid, Robert Stowers [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-12

    An important niche for nuclear energy is the need for power at remote locations removed from a reliable electrical grid. Nuclear energy has potential applications at strategic defense locations, theaters of battle, remote communities, and emergency locations. With proper safeguards, a 1 to 10-MWe (megawatt electric) mobile reactor system could provide robust, self-contained, and long-term power in any environment. Heat pipe-cooled fast-spectrum nuclear reactors have been identified as a candidate for these applications. Heat pipe reactors, using alkali metal heat pipes, are perfectly suited for mobile applications because their nature is inherently simpler, smaller, and more reliable than “traditional” reactors. The goal of this project was to develop a scalable conceptual design for a compact reactor and to identify scaling issues for compact heat pipe cooled reactors in general. Toward this goal two detailed concepts were developed, the first concept with more conventional materials and a power of about 2 MWe and a the second concept with less conventional materials and a power level of about 5 MWe. A series of more qualitative advanced designs were developed (with less detail) that show power levels can be pushed to approximately 30 MWe.

  14. Protoflight photovoltaic power module system-level tests in the space power facility

    Rivera, Juan C.; Kirch, Luke A.

    1989-01-01

    Work Package Four, which includes the NASA-Lewis and Rocketdyne, has selected an approach for the Space Station Freedom Photovoltaic (PV) Power Module flight certification that combines system level qualification and acceptance testing in the thermal vacuum environment: The protoflight vehicle approach. This approach maximizes ground test verification to assure system level performance and to minimize risk of on-orbit failures. The preliminary plans for system level thermal vacuum environmental testing of the protoflight PV Power Module in the NASA-Lewis Space Power Facility (SPF), are addressed. Details of the facility modifications to refurbish SPF, after 13 years of downtime, are briefly discussed. The results of an evaluation of the effectiveness of system level environmental testing in screening out incipient part and workmanship defects and unique failure modes are discussed. Preliminary test objectives, test hardware configurations, test support equipment, and operations are presented.

  15. Refurbishment, Modernization and Ageing Management Program of The 3MW TRIGA Mark-II Research Reactor of Bangladesh

    The 3 MW TRIGA MK-II research reactor of Bangladesh Atomic Energy Commission (BAEC) achieved its first criticality on 14 September 1986. The reactor has been used for manpower training, radioisotope production and various R and D activities in the field of neutron activation analysis, neutron radiography and neutron scattering. Reactor Operation and Maintenance Unit (ROMU) is responsible for operation and maintenance of the research reactor. During the past twenty seven years ROMU carried out several refurbishments, replacement, modification and modernization activities in the reactor facility. The major tasks carried out under refurbishment program were replacement of the corrosion damaged N-16 decay tank by a new one, replacement of the fouled shell and tube type heat exchanger by a plate type one, modification of the shielding arrangements around the N-16 decay tank and ECCS system and solving the radial beam port-1 leakage problem. All of these refurbishment activities were performed under an annual development project (ADP) funded by Bangladesh government. BAEC research reactor (RR) was operated by analogue console system from its commissioning to July, 2011. Old analog based console has been replaced by digital console on June, 2012. Modernization program for the reactor control console due to obsolescence and unavailability of spare parts of I and C system was vital to restore the safe operation of the reactor. Considering these facts, installation of a digital control console and I and C system based on the state-of-the-art digital technology became necessary. Reactor digital console system installation tasks were performed under another ADP funded project by Bangladesh government. Now the reactor is operating with the digital control system. Besides this, the Neutron Radiography (NR) facility has been modernized by the addition of a digital neutron radiography set-up at the tangential beam port. The Neutron Scattering (NS) facility also has been upgraded

  16. Refurbishment, Modernization and Ageing Management Program of The 3MW TRIGA Mark-II Research Reactor of Bangladesh

    Salam, M. A. [Atomic Energy Research Establishment, Dhaka (Bangladesh)

    2013-07-01

    The 3 MW TRIGA MK-II research reactor of Bangladesh Atomic Energy Commission (BAEC) achieved its first criticality on 14 September 1986. The reactor has been used for manpower training, radioisotope production and various R and D activities in the field of neutron activation analysis, neutron radiography and neutron scattering. Reactor Operation and Maintenance Unit (ROMU) is responsible for operation and maintenance of the research reactor. During the past twenty seven years ROMU carried out several refurbishments, replacement, modification and modernization activities in the reactor facility. The major tasks carried out under refurbishment program were replacement of the corrosion damaged N-16 decay tank by a new one, replacement of the fouled shell and tube type heat exchanger by a plate type one, modification of the shielding arrangements around the N-16 decay tank and ECCS system and solving the radial beam port-1 leakage problem. All of these refurbishment activities were performed under an annual development project (ADP) funded by Bangladesh government. BAEC research reactor (RR) was operated by analogue console system from its commissioning to July, 2011. Old analog based console has been replaced by digital console on June, 2012. Modernization program for the reactor control console due to obsolescence and unavailability of spare parts of I and C system was vital to restore the safe operation of the reactor. Considering these facts, installation of a digital control console and I and C system based on the state-of-the-art digital technology became necessary. Reactor digital console system installation tasks were performed under another ADP funded project by Bangladesh government. Now the reactor is operating with the digital control system. Besides this, the Neutron Radiography (NR) facility has been modernized by the addition of a digital neutron radiography set-up at the tangential beam port. The Neutron Scattering (NS) facility also has been upgraded

  17. Piloted Mars mission planning: NEP technology and power levels

    This paper examines the strong interrelationship between assumed technology and mission performance requirements for NEP. Recent systems analysis efforts by NASA, DOE, and various contractors are used to project achievable system performance as a function of technological sophistication for two piloted Mars mission applications. Specific mass regimes for each collection of technologies are presented as a function of power level for piloted applications. Low thrust mission analyses are presented which relate these system performance projections to achievable mission performance. Mission performance ''maps'' are constructed which link prime mission figures-of-merit of time and initial mass with system requirements on power level and specific mass, and hence technology. Both opposition and conjunction class piloted Mars missions are presented for the 2016 opportunity, analogous to those proposed in the ''90-Day Study'' and ''Synthesis'' architecture studies. Mass and time breakdowns are presented for 10 MWe piloted and 5 MWe cargo point designs

  18. Radio frequency plasma nitriding of aluminium at higher power levels

    Nitriding of aluminium 2011 using a radio frequency plasma at higher power levels (500 and 700 W) and lower substrate temperature (500 deg. C) resulted in higher AlN/Al2O3 ratios than obtained at 100 W and 575 deg. C. AlN/Al2O3 ratios derived from X-ray photoelectron spectroscopic analysis (and corroborated by heavy ion elastic recoil time of flight spectrometry) for treatments preformed at 100 (575 deg. C), 500 (500 deg. C) and 700 W (500 deg. C) were 1.0, 1.5 and 3.3, respectively. Scanning electron microscopy revealed that plasma nitrided surfaces obtained at higher power levels exhibited much finer nodular morphology than obtained at 100 W

  19. Criticality and Safety Parameter Studies of a 3-MW TRIGA MARK-II Research Reactor and Validation of the Generated Cross-Section Library and Computational Method

    This study deals with the analysis of some neutronics and safety parameters of the current core of a 3-MW TRIGA MARK-II research reactor and validation of the generated macroscopic cross-section library and calculational techniques by benchmarking with experimental, operational, and available Safety Analysis Report (SAR) values. The overall strategy is: (a) generation of the problem-dependent cross-section library from basic Evaluated Nuclear Data Files such as ENDF/B-VI and JENDL-3.2 with NJOY94.10+, (b) use of the WIMSD-5 package to generate a few-group neutron macroscopic cross section for all of the materials in the core and its immediate neighborhood, (c) use the three-dimensional CITATION code to perform the global analysis of the core, and (d) checking of the validity of the CITATION diffusion code with the MCNP4B2 Monte Carlo code. The ultimate objective is to establish methods for reshuffling the current core configuration to upgrade the thermal flux at irradiation locations for increased isotope production. The computational methods, tools and techniques, customization of cross-section libraries, various models for cells and supercells, and many associated utilities are standardized and established/validated for the overall neutronic analysis. The excess reactivity, neutron flux, power distribution, power peaking factors, determination of the hot spot, and fuel temperature reactivity coefficients αf in the temperature range of 45 to 1000 deg. C are studied. All the analyses are performed using the 4- and 7-group libraries of the macroscopic cross sections generated from the 69-group WIMSD-5 library. The 7-group calculations yield comparatively better agreement with the experimental value of keff and the other core parameters. The CITATION test runs using different cross-section sets based on the different models applied in the WIMSD-5 calculations show a strong influence of those models on the final integral parameter. Some of the cells are specially

  20. A Rotating Speed Controller Design Method for Power Levelling by Means of Inertia Energy in Wind Power Systems

    Qin, Zian; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    frequency domain for power leveling. Moreover, the impact of other parameters on power leveling, including the time constant of maximum power point tracking (MPPT) and the rotor inertia, are also studied. With the proposed optimal design, the power fluctuations are mitigated as much as possible, while the...

  1. Study on emergency action levels for Qinshan Nuclear Power Plant

    Based on Qinshan NPP, the technique scheme and many required considerations in the development of emergency action levels (EALs) for Nuclear Power Plants are discussed in detail, which include the selection of emergency classification systems, the criteria for development of EALs, the determination of initiating conditions (ICs) and EALs, the presentation of EALs (e.g. EALs matrix, emergency classification procedure chart in main control room, etc.), the use of emergency operating procedures (EOPs) and critical safety function status trees (CSFSTs) in emergency classification, etc. (authors)

  2. Low level waste management developments in UK nuclear power stations

    This paper discusses how the UK definition of low-level waste (LLW) as agreed between the Government regulating departments and the nuclear industry differs from that in the US and elsewhere. It is that the material is not suitable for disposal as ordinary refuse and that it has a specific activity level below 12 GBq/te beta-gamma and 4 GBq/te alpha. In other words it generally covers the low activity trash produced by the industry. The LLW produced as a result of power station operations can be grouped as drummable/non-drummable, compactable/non-compactable using low force compaction technology, and as burnable/non-burnable depending on the management practices locally

  3. Technical basis for staffing levels at nuclear power plants

    Shurberg, D.A.; Haber, S.B. [Brookhaven National Lab., Upton, NY (United States); Morisseau, D. [Nuclear Regulatory Commission, Washington, DC (United States)] [and others

    1995-04-01

    The objective of this project is to provide a technical basis for the establishment of criteria for minimum staffing levels of licensed and non-licensed NPP shift personnel. Minimum staffing levels for the purpose of this study, are defined as those necessary for successful accomplishment of all safety and additional functions that must be performed in order for the licensee to meet applicable regulatory requirements. This project involves a multi-faceted approach to the investigation of the issue. Relevant NRC documentation was identified and reviewed. Using the information obtained from this documentation review, a test plan was developed to aid in the collection of further information regarding the adequacy of current shift staffing levels. The test plan addresses three different activities to be conducted to provide information to the NRC for use in the assessment of current minimum staffing levels. The first activity is collection of data related to industry shift staffing practices through site visits to seven nuclear power plants. The second activity is a simulator study, which will use licensed operator crews responding to a simulated event, under two different staffing levels. Finally, workload models will be constructed for both licensed and non-licensed personnel, using a priori knowledge of the simulator scenarios with data resulting from one of the staffing levels studied in the simulator, and the data collected from the site visits. The model will then be validated against the data obtained from the second staffing level studied in the simulator. The validated model can then be used to study the impact of changing staffing-related variables on the plant shift crew`s ability to effectively mitigate an event.

  4. Utilization experience with research reactors of various power levels

    Utilization of research reactor, PARR-1 at the power level of 5 MW, and then at 9 MW, after the up gradation and conversion from highly enriched uranium (HEU) to low enriched uranium (LEU), has been described. In addition, the type of work carried out around a smaller facility, PARR-2, with power rating of 27kW has also been discussed. Utilization of PARR-1 in the area of neutron diffraction, neutron capture studies, radioisotope production, neutron activation analysis, reactor physics, and in reactor controls etc has been illustrated. The benefits derived from the up gradation of the power for neutron diffraction studies, radioisotope production and neutron radiography have been discussed. The problem, which can be handed successfully on PARR-2, include neutron activation analysis, production of short-lived radioisotopes, and experimentation in reactor engineering and physics for training purposes. Suitable methodologies have been developed for the analysis of samples of varied nature using neutron activation technique, and the experience gained has been applied to the analysis of geological, environmental and biological samples and high purity materials. (author)

  5. Experience and challenges on safeguards practices and approaches for BAEC 3 MW TRIGA Mk-II research reactor and other establishment of Bangladesh

    the only establishment in the country where nuclear materials are being used. The 3 MW TRIGA Mark-II research reactor of BAEC has been operating since September 14, 1986. The reactor is used for radioisotope production (131I, 99mTc, 46Sc), various R and D activities, manpower training and education. As a facility and material balance area, AERE facilities have been designated by the Agency (IAEA) as BDA-, BD-A and BDZ- respectively. The facilities at AERE which are of concern from safeguards point of view are the 3MW TRIGA Mk-II research reactor and the radioisotope production laboratory. The reactor facility has fuel elements and fission chambers where nuclear materials are used. Where as the radioisotope production laboratory has isotope transfer cask made from depleted uranium. Accounting of nuclear materials is carried out by maintaining and routinely updating several records as recommended by IAEA and standards prescribed/adopted by the Nuclear Safety and Radiation Control Regulations of BAEC. Nuclear fuel was first imported into the country in 1985. Fuels were loaded into the reactor core on 13 September 1986. IAEA safeguards inspectors visited the facility for the first time in 1986. Since then the facility is inspected regularly on annual basis by two or three inspectors at a time. The inventories of nuclear materials at AERE include several kilograms of 19.7% enriched uranium in the form of TRIGA fuels, several kilograms of depleted uranium in the form of shielding for the radioisotope transfer cask and a few grams of 99.3% enriched uranium in the form of fission chambers. A few of the fuels are still fresh and they have been stored in the fresh fuel storage room. Rest of the fuels is loaded into the reactor core. The facility has not yet generated any spent fuel. According to the safety analysis report (SAR), the initial core loading is capable of producing about 1278 megawatt-days of energy. But as of now, the figure for the total cumulative burn-up stands

  6. Maximum allowable power levels in HANARO fuel channels

    HANARO is a light-water-cooled and heavy-water-reflected research reactor designed and operated at a full power of 30 MWth. The compact core is composed of 23 hexagonal and 16 circular flow channels. Each hexagonal flow channel, formed by a hexagonal flow tube, is loaded with a hexagonal fuel bundle which has 36 fuel elements. The circular flow channel formed by a circular flow tube is loaded with a circular fuel bundle which has 18 fuel elements. In the thermalhydraulic design of the HANARO, the design limit values for the three design parameters were determined using the statistical thermal design method. The design basis is that for the normal operation and the operational occurrences, the physical phenomena like as CHF (Critical Heat Flux) or ONB(Onset of Nucleate Boiling) would not occur with the 95% of probability and the 95% confidence level as illustrated in Figure 1. In this paper, the maximum power levels satisfying the design limits were obtained and the safe operational ranges were made for the four different fuel channels

  7. Management of the high-level nuclear power facilities

    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

  8. Indicators for assessing the safety level of nuclear power plants

    Since the political opening of the states of Central and Eastern Europe roughly one decade ago, Western industrialized countries in particular have been striving to achieve sustainable improvements in the safety of nuclear reactors in those countries. One objective of these efforts is to ensure a high level of nuclear safety and safety culture in line with worldwide endeavors. The enlargement of the European Union in the very near future offers an opportunity for reaching this goal in the participating countries. Existing international framework agreements refer to the appropriate safety guidelines. At EU level, the harmonization of nuclear safety standards has been an important topic for years, with specific constructive activities being initiated, e.g., by the industry and by regulatory authorities. Uniform safety standards should not be the basis of proven reviews conducted by the national licensing and supervisory authorities. The objective should be the development of key requirements as framework conditions, irrespective of their practical implementation. They could be applied to any nuclear power plant in an accession country, but likewise to plants in member states, in order to provide an overview of the current safety status of a nuclear power plant and the rules by which it is run. As deriving uniform safety standards is a very expensive and lengthy procedure, the approach shown here identifies six main areas of review for light water reactors (safety systems; integrity of the safety barriers; risk assessment; radiation exposure of the plant personnel and the environment; plant operations management; plant safety) and the associated safety indicators, with reference criteria formulated as concretely as possible. This proposal also lends itself to international individual evaluations of safety levels and could facilitate the review process already under way for the EU candidate countries. (orig.)

  9. Dynamic evaluation of the levelized cost of wind power generation

    Highlights: • Conventional levelized cost of energy is static and does not consider flexibility. • This paper defines a dynamic version by means of stochastic programming. • A penalty for early exercising is proposed to differentiate static and dynamic. • Results show the effects of feed-in tariff support in low wind sites. • Policy implications are derived on the basis of the static and dynamic measures. - Abstract: This paper discusses an alternative computation method of the levelized cost of energy of distributed wind power generators. Unlike in the conventional procedures, it includes time of commencement as an optimization variable. For that purpose, a methodology from Longstaff and Schwartz’s dynamic program for pricing financial American options is derived, which provides the ability to find the optimum time and value while coping with uncertainty revenues from energy sales and variable capital costs. The results obtained from the analysis of wind records of 50 sites entail that the conventional levelized cost of energy can be broken down into an optimum, minimum (time-dependent) value and a penalty for early exercising, which can be employed to define investment strategies and support policies

  10. Retrieval of Intermediate Level Waste at Trawsfyndd Nuclear Power Station

    Wall, S.; Shaw, I.

    2002-02-25

    In 1996 RWE NUKEM Limited were awarded two contracts by BNFL Magnox Generation as part of the decommissioning programme for the Trawsfynydd power station. From the normal operations of the two Magnox reactors, intermediate level waste (ILW) had accumulated on site, this was Miscellaneous Activated Components (MAC) and Fuel Element Debris (FED). The objective of these projects is retrieval of the waste from storage vaults, monitoring, packaging and immobilization in a form suitable for on site storage in the medium term and eventual disposal to a waste repository. The projects involve the design, supply, commissioning and operation of equipment to retrieve, pack and immobilize the waste, this includes recovery from vaults in both reactor and pond locations and final decommissioning and removal of plant from site after completion of waste recovery.

  11. Temporal variations in Global Seismic Stations ambient noise power levels

    Ringler, A.T.; Gee, L.S.; Hutt, C.R.; McNamara, D.E.

    2010-01-01

    Recent concerns about time-dependent response changes in broadband seismometers have motivated the need for methods to monitor sensor health at Global Seismographic Network (GSN) stations. We present two new methods for monitoring temporal changes in data quality and instrument response transfer functions that are independent of Earth seismic velocity and attenuation models by comparing power levels against different baseline values. Our methods can resolve changes in both horizontal and vertical components in a broad range of periods (∼0.05 to 1,000 seconds) in near real time. In this report, we compare our methods with existing techniques and demonstrate how to resolve instrument response changes in long-period data (>100 seconds) as well as in the microseism bands (5 to 20 seconds).

  12. CEA contribution to power plant operation with high burnup level

    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 Gd2O3 mixed with fuel or with inert element like Al2O3. 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 Gd2O3 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

  13. Experience and challenges on safeguards practices and approaches for BAEC 3 MW TRIGA Mk-II research reactor and other establishment of Bangladesh

    Bangladesh is deeply committed to nuclear non-proliferation signing and accesses to different unilateral protocols, agreements and treaties like Nuclear Non-Proliferation Treaty (NPT), Comprehensive Test Ban Treaty (CTBT), Safeguards Agreements, Nuclear Cooperation Agreements with the USA and other countries etc. are the manifestations of such commitment. The first of such agreements, the NPT was signed in August 1979. NPT is a national commitment that the signatory country will not engage in activities related on nuclear detonations. Subsequently a bilateral agreement entitled 'Safeguards Agreements' was signed with the International Atomic Energy Agency (IAEA) in June 1982. This provides for international verification of facilities and balancing of nuclear materials. 3MW TRIGA Mark-II Research Reactor Facility of Bangladesh Atomic Energy Commission (BAEC) is inspected physically by the IAEA Safeguards Inspectors on an annual basis. For this purpose, a subsidiary arrangement was made with the IAEA, which had defined the scope of such verification. Bangladesh has also signed a Nuclear Cooperation Agreement with the USA on September 17, 1981, which facilitated export of nuclear technology from USA to Bangladesh. Bangladesh also signed another bilateral agreement entitled 'Protocol Additional to the Safeguards Agreements' with the IAEA in March 30, 2001. The main purpose of this agreement is to provide the IAEA with information on 'so called dual-purpose materials and facilities' including the front end and back end of the nuclear fuel cycle. Its enforcement required filing of an initial declaration, draft of which has been sent to the Ministry of Science, Information and Communication Technology (MOSICT) for approval and transmittal to IAEA through the office of the permanent mission in Geneva. This protocol till to-date is the highest level of verification under the nonproliferation regime. The commitment of Bangladesh to non-proliferation is adequately reflected

  14. Analysis and core-life calculation of 3 MW Triga Mark II research reactor including effects of central thimble modification

    The principal objective of this study was to formulate an effective optimal fuel management strategy for TRIGA MARK II research reactor at AERE, Savar. The core management study has been performed by utilizing four basic types of information calculated for the reactor: criticality, power peaking, neutron flux and burnup calculation. Reshuffling at 20,000 MWh step gives the longest core life of the reactor which is 64500 MWh. Central thimble modification altered the shape of the flux which increased the core reactivity by c 12 and the core-life by 500 MWh. Besides, the study gives valuable insight into the behaviour of the reactor

  15. Burnup analysis and in-core fuel management study of the 3 MW TRIGA MARK II research reactor

    The principal objective of this study is to formulate an effective optimal fuel management strategy for the TRIGA MARK II research reactor at AERE, Savar. The core management study has been performed by utilizing four basic types of information calculated for the reactor: criticality, power peaking, neutron flux and burnup calculation. This paper presents the results of the burnup calculations for TRIGA LEU fuel elements. The fuel element burnup for approximately 20 years of operation was calculated using the TRIGAP compute code. The calculation is performed in one-dimensional radial geometry in TRIGAP. Inter-comparison of TRIGAP results with other two calculations performed by MVP-BURN and MCNP4C-ORIGEN2.1 show very good agreement. Reshuffling at 20,000 MWh step provides the highest core lifetime of the reactor, which is 64,500 MWh. Besides, the study gives valuable insight into the behaviour of the reactor and will ensure better utilization and operation of the reactor in future

  16. Estimation of radiological doses due to the failure of a single element of a 3 MW (T) TRIGA Mark-II research reactor

    Radiological doses due to the failure of a single fuel element of a 3 MW (t) TRIGA Mark-II Research Reactor was estimated for both anticipated and design basis releases considering hypothetical accident conditions. The noble gas and halogen fission product inventory has been calculated assuming a burn-up of 2000 MWd occurring in 1.8 calendar years. For both of the releases, one hundred percent of the noble gases in the fuel-cladding gap were assumed to release from the fuel element and subsequently transferred directly to the reactor hall and twenty-five percent of the halogens in the fuel-cladding gap were assumed to release from the fuel element (with the remainder assumed to plat out on the relatively cool cladding). For the removal of the fission product gases from the reactor hall to the environment, two mechanisms were considered. These are: (1) removal by the emergency ventilation system through an activated charcoal trap in the event of a design basis release and (2) removal by the normal ventilation system for anticipated release. For the first removal mechanism, the system has been designed with activated charcoal filters having an efficiency of 0% for noble gases and 99 % for halogens. For both the cases, only the bottom one-fifth of the reactor hall volume was assumed to be involved in the air circulation (i.e., the top four-fifths was considered to be stagnant). The dispersion of the escaped fission products to the environment through the stack of the reactor was estimated using a Gaussian plume model and basing on the design parameters of the TRIGA reactor as well as the meteorological data of the site. Total individual doses in the reactor hall as well as in the environment were calculated applying the methodologies described in the IAEA publications with the assumptions as mentioned above. The total dose was regarded as the doses caused by immersion in the radioactive air plume (for both noble gas and halogen), inhaled halogen and the deposited

  17. Power systems: Carbon negative at the regional level

    Bauer, Nico

    2015-03-01

    Modelling of the power system on the west coast of North America shows that including bioenergy with carbon capture and sequestration technologies could enable the region to be carbon negative by 2050.

  18. Draft emergency action level guidelines for nuclear power plants

    This document is provided for interim use during the initial phases of the NRC effort to promptly improve emergency preparedness at operating nuclear power plants. Changes to the document can be expected as experience is gained in its use and public comments are received. Further, the Commission has initiated a rulemaking procedure, now scheduled for completion in January 1930 in the area of Emergency Planning and Preparedness. Additional requirements are to be expected when rulemaking is completed and some modifications to this document may be necessary. Four classes of Emergency Action Levels are established which replace the classes in Regulatory Guide 1.101, each with associated examples of initiating conditions. The classes are: - Notification of Unusual Event; - Alert; - Site Emergency; - General Emergency. The rationale for the notification and alert classes is to provide early and prompt notification of minor events which could lead to more serious consequences given operator error or equipment failure or which might be indicative of more serious conditions which are not yet fully realized. A gradation is provided to assure fuller response preparations for more serious indicators. The site emergency class reflects conditions where some significant releases are likely or are occurring but where a core melt situation is not indicated based on current information. In this situation full mobilization of emergency personnel in tie :near site environs is indicated as well as dispatch of monitoring teams and associated communications. The general emergency class involves actual or imminent substantial core degradation or malting with the potential for loss of containment. The immediate action for this class is sheltering (staying inside) rather thai evacuation until an assessment can be made that (1) an evacuation is indicated and (2) an evacuation, if indicated, can be completed prior to significant release and transport of radioactive material to the affected

  19. Traction Power System Capacity Limitations at Various Traffic Levels

    Abrahamsson, Lars; Söder, Lennart

    2011-01-01

    The aim, and main contribution, of this paper is to propose a fine-tuned fast approximator, based on neural networks, that uses aggregated traction system information as inputs and outputs. This approximator can be used as an investment planning constraint in the optimization. It considers that there is a limit on the intensity of the train traffic, depending on the strength of the power system. In the numerical examples of this paper, the approximator inputs are the power system configuratio...

  20. Stable level and phase control circuits for high power VHF transmitters for RIB applications

    For most applications it is required that the output power level and insertion phase of a high power transmitter remain unchanged against ambient temperature variation and power supply fluctuations. Design schemes for a stable level controller and a phase controller for use in a VHF transmitter that has been indigenously developed for RIB application at VECC is presented in this paper. (author)

  1. On the Problem of Wireless Scheduling with Linear Power Levels

    Tonoyan, Tigran

    2011-01-01

    In this paper we consider the problem of communication scheduling in wireless networks with respect to the SINR(Signal to Interference plus Noise Ratio) constraint in metric spaces. The nodes are assigned linear powers, i.e. for each sender node the power is constant times the path loss between the sender and corresponding receiver. This is the minimal power for a successful transmission. We present a constant factor deterministic approximation algorithm, which works for at least Euclidean fading metrics. Simultaneously we obtain the approximate value of the optimal schedule length with error at most a constant factor. To give an insight into the complexity of the problem, we show that in some metric spaces the problem is NP-hard and cannot be approximated within a factor less than 1.5.

  2. A High Power Density Three-level Parallel Resonant Converter for Capacitor Charging

    Sheng, Honggang

    2009-01-01

    This dissertation proposes a high-power, high-frequency and high-density three-level parallel resonant converter for capacitor charging. DC-DC pulsed power converters are widely used in military and medical systems, where the power density requirement is often stringent. The primary means for reducing the power converter size has been to reduce loss for reduced cooling systems and to increase the frequency for reduced passive components. Three-level resonant converters, which combine the mer...

  3. The advantages and disadvantages of centralized control of air power at operational level

    Arisoy, Uǧur

    2014-05-01

    People do not want to see and hear a war. In today's world, if war is inevitable, the use of air power is seen as the preferable means of conducting operations instead of financially burdensome land battles which are more likely to cause heavy loss of life. The use of Air Power has gained importance in NATO operations in the Post-Cold War era. For example, air power has undertaken a decisive role from the beginning to the end of the operation in Libya. From this point of view, the most important issue to consider is how to direct air power more effectively at operational level. NATO's Core JFAC (Joint Force Air Command) was established in 2012 to control joint air power at operational level from a single center. US had experienced JFAC aproach in the Operation Desert Storm in 1991. UK, France, Germany, Italy and Spain are also directing their air power from their JFAC structures. Joint air power can be directed from a single center at operational level by means of JFAC. JFAC aproach provides complex planning progress of Air Power to be controled faster in a single center. An Air Power with a large number of aircrafts, long range missiles of cutting-edge technology may have difficulties in achieving results unless directed effectively. In this article, directing air power more effectively at operational level has been studied in the framework of directing air power from a single center carried out by SWOT analysis technique. "Directing Air Power at operational level from a single center similar to JFAC-like structure" is compared with "Directing Air Power at operational level from two centers similar to AC (Air Command) + CAOC (Combined Air Operations Center) structure" As a result of this study, it is assessed that directing air power at operational level from a single center would bring effectiveness to the air campaign. The study examines directing air power at operational level. Developments at political, strategic and tactical levels have been ignored.

  4. 49 CFR 393.94 - Interior noise levels in power units.

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Interior noise levels in power units. 393.94... AND ACCESSORIES NECESSARY FOR SAFE OPERATION Miscellaneous Parts and Accessories § 393.94 Interior noise levels in power units. (a) Applicability of this section. The interior noise level...

  5. A DC-DC Converter Efficiency Model for System Level Analysis in Ultra Low Power Applications

    Benton H. Calhoun; Aatmesh Shrivastava

    2013-01-01

    This paper presents a model of inductor based DC-DC converters that can be used to study the impact of power management techniques such as dynamic voltage and frequency scaling (DVFS). System level power models of low power systems on chip (SoCs) and power management strategies cannot be correctly established without accounting for the associated overhead related to the DC-DC converters that provide regulated power to the system. The proposed model accurately predicts the efficiency of induct...

  6. Design of Oil-Quenching Tank for 3 MW Wind Turbine Main Shaft Bearings%3MW风电主轴轴承淬火油槽设计

    邵阳; 马忠超; 姚艳书

    2015-01-01

    The problems existing in heat treatment for main shaft bearings used in 3MW wind turbines are analyzed.The volume of oil-quenching tank for the bearing rings is calculated,and the structure for oil-quenching tank is rede-signed.The hardness of the bearing rings satisfies standard requirement for secondary quenching cooling process during heat treatment by adopting oil-quenching tank with top plug type and side plug type stirrers.%分析3MW风电主轴轴承热处理中存在的问题,计算轴承套圈淬火油槽的体积,重新设计淬火油槽结构,采用顶插式和侧插式组合搅拌器的淬火油槽,使3MW风电主轴轴承在热处理二次淬火冷却过程中硬度达到标准要求。

  7. Low power level safety management of Finnish BWR

    Good practices in work coordination and safety management have contributed to short refueling outage duration in Finnish BWR plants. Human and organizational factors are considered especially important in the low paper states, which consist of start-up, shut-down and the outage period itself. This originates from the use of external labour during the outage, the number of both contemporary and sequentially linked human actions and the variety of potential ways the personnel can affect the plant state. While the containment barrier does not exist, more organizational and administrative means have to be used in risk management. To promote the safety further, special studies have been carried out. This paper discusses both the low power mode PSA and the studies of work orientation and competence among the operating staff in Olkiluoto BWR plant. An advanced outage control requires also open-minded consideration of potential risks and the means for their reduction. Good results in low power risk management can be reached only by the involvement of both the plant operating and the maintenance staff. A profound safety management is a prerequisite for safe low power states. (author)

  8. Photovoltaic Shading Testbed for Module-Level Power Electronics

    Deline, C.; Meydbray, J.; Donovan, M.; Forrest, J.

    2012-05-01

    This document describes a repeatable test procedure that attempts to simulate shading situations, as would be experienced by typical residential rooftop photovoltaic (PV) systems. This type of shading test is particularly useful to evaluate the impact of different power conversion setups, including microinverters, DC power optimizers and string inverters, on overall system performance. The performance results are weighted based on annual estimates of shade to predict annual performance improvement. A trial run of the test procedure was conducted with a side by side comparison of a string inverter with a microinverter, both operating on identical 8kW solar arrays. Considering three different shade weighting conditions, the microinverter was found to increase production by 3.7% under light shading, 7.8% under moderate shading, and 12.3% under heavy shading, relative to the reference string inverter case. Detail is provided in this document to allow duplication of the test method at different test installations and for different power electronics devices.

  9. Power Analysis for Cross Level Mediation in CRTs

    Kelcey, Ben

    2014-01-01

    A common design in education research for interventions operating at a group or cluster level is a cluster randomized trial (CRT) (Bloom, 2005). In CRTs, intact clusters (e.g., schools) are assigned to treatment conditions rather than individuals (e.g., students) and are frequently an effective way to study interventions because they permit…

  10. Robust model-based steam generator level control in nuclear power plant

    Economic feasibility of a power plant requires smooth and uninterrupted plant operation in the face of varying electrical power demand. The feed-water system in a power plant is a major contributor to plant unavailability. The purpose of this paper is to present a general framework for addressing all aspects of this problem and design, analyze and evaluate a water level controller for Steam Generator (SG) and using robust controller design procedure, Linear Quadratic Gaussian with Loop Transfer Recovery, LQG/LTR for low power and high power range. Simulations show that the proposed controller improves transient response of (SG) water level and demonstrate its superiority to existing conventional PI controllers. (author)

  11. Effect of spatial distribution of dissipated power on modeling of SMR BAW resonators at high power levels.

    Tag, Andreas; Bader, Bernhard; Huck, Christian; Karolewski, Dominik; Pitschi, Maximilian; Weigel, Robert; Hagelauer, Amelie

    2015-10-01

    The modeling of bulk acoustic wave resonators at elevated power levels has been improved by taking the spatial distribution of the dominating loss mechanisms into account. The spatial distribution of the dissipated power enables more accurate modeling of the temperature increase caused by the applied power. Thus, it is also possible to more accurately model the frequency shifts of the resonators' impedance curves resulting from the temperature increase caused by the applied power. Simulation and measurement results for the temperatures and impedances of the resonators with different layerstacks at high power loads are presented. The simulation and measurement results are in good agreement, confirming the presented modeling approach. Furthermore, the de-embedding procedure used to obtain vectorial scattering parameters of the resonators during high power loads, the according measurement setup, and the procedure for measuring absolute temperatures by infrared thermography are discussed. PMID:26470048

  12. Low-level radioactive waste processing at nuclear power plants

    This survey was limited to systems and materials used to process waste liquids contaminated with radionuclides. Since the chemical and radiological character of collected liquids may change dramatically, the survey describes waste and cleanup process streams encountered during normal outage or power production conditions. Influents containing specific organic compounds, salts, or solids common to local sources, and the special techniques developed to remove or concentrate these materials are not detailed in this report. The names and phone numbers of the individuals responsible for investigating and solving these problems, however, provides easy access to data which will save time and expense when facing abnormal processing, purchasing, or engineering challenges. The Liquid Radwaste Source Book contains information collected from 31 of 36 BWR's as well as contact information from all licensed commercial units. Since some sites share common radwaste processing facilities, not all units are represented by individual data sheets

  13. Determination of the acoustic source power levels of wind turbines

    Debruijn, A.; Stam, W. J.; Dewolf, W. B.

    To facilitate Wind Energy Conversin System (WECS) licensing, it is recommended to obtain the immission-relevant sound power from the WECS, since this quantity fits into most recommendations for industrial installations. Measurements on small and medium-scale WECS show that rotor rotation speed is a more important parameter than the wind velocity with regard to the radiated noise. An acoustic telescope was used to identify noise sources on two medium-size wind turbines. The mechanical noise from the nacelle is mostly predominant but the trailing edge aerodynamic noise is not negligible. A prediction model for this type of noise, which leads to good agreement with experimental data was developed. A method to suppress turbulence signals around WECS is a set-up with twin microphones, using correlation techniques on both signals.

  14. User instructions for levelized power generation cost codes using an IBM-type PC

    Coen, J.J.; Delene, J.G.

    1989-01-01

    Programs for the calculation of levelized power generation costs using an IBM or compatible PC are described. Cost calculations for nuclear plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. 7 refs., 36 figs., 4 tabs.

  15. User instructions for levelized power generation cost codes using an IBM-type PC

    Programs for the calculation of levelized power generation costs using an IBM or compatible PC are described. Cost calculations for nuclear plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, decommissioning cost, and total levelized power generation cost. 7 refs., 36 figs., 4 tabs

  16. Analysis of the DNB ratio and the loss-of-flow accident (LOFA) of the 3 MW TRIGA MARK II research reactor

    The PARET code was used to analyze two most important thermal hydraulic design parameters of the 3 MW TRIGA MARK II research reactor. The first design parameters is the DNB (departure from nucleate boiling) ratio, which is defined as the ratio of the critical heat flux to the heat flux achieved in the core and was computed by means of a suitable correlation as defined in PARET code. The reactor core should be designed so as to prevent the DNBR from dropping below a chosen value under a high heat flux transient condition for the most adverse set of mechanical and coolant conditions. Over the length 0.381 m of the hottest channel the DNB ratio varies, starting from 3.8951 to 5.4031, with a minimum of 2.7851. The peak heat flux occurs at the axial center of the fuel elements; therefore the DNB ratio is minimum at this location. The second design parameter is the loss-of-flow accident scenario of the TRIGA reactor. The Bergles-Rohsenow correlation was selected for detecting onset of nucleate boiling, the transition model with the McAdams correlation was included for fully developed two-phase flow, and the Seider-Tate correlation was used for the single-phase forced convection regime. The loss-of-flow transient after a trip time of 4.08 sec at 85% of loss of normal flow for the TRIGA core shows a peak temperature of 709.22 C in the fuel centerline and 131.94 C in the clad and 46.63 C in the coolant exit of the hottest channel. The transient was terminated at 15% of nominal flow after about 48.0 sec. The time at which the reversal of coolant flow starts is about 67.0 sec. (author)

  17. Power levels in office equipment: Measurements of new monitors and personal computers

    Electronic office equipment has proliferated rapidly over the last twenty years and is projected to continue growing in the future. Efforts to reduce the growth in office equipment energy use have focused on power management to reduce power consumption of electronic devices when not being used for their primary purpose. The EPA ENERGY STAR[registered trademark] program has been instrumental in gaining widespread support for power management in office equipment, and accurate information about the energy used by office equipment in all power levels is important to improving program design and evaluation. This paper presents the results of a field study conducted during 2001 to measure the power levels of new monitors and personal computers. We measured off, on, and low-power levels in about 60 units manufactured since July 2000. The paper summarizes power data collected, explores differences within the sample (e.g., between CRT and LCD monitors), and discusses some issues that arise in m etering office equipment. We also present conclusions to help improve the success of future power management programs.Our findings include a trend among monitor manufacturers to provide a single very low low-power level, and the need to standardize methods for measuring monitor on power, to more accurately estimate the annual energy consumption of office equipment, as well as actual and potential energy savings from power management

  18. Nuclear power plant personnel entry level qualifications and training

    This paper summarizes the early results and current status of a research program at ORNL which is intended to provide the methods and technical basis for NRC to initiate the use of the Systems Approach to Training (SAT) in the evaluation of training programs and entry level qualifications for NPP control room personnel. The program is an outgrowth of previous studies of simulator hardware and simulator training requirements under the Safety Related Operator Actions Program which recommended adaptation of a systems methodology to development and evaluation of NPP training programs

  19. Nuclear power plant personnel entry level qualifications and training

    Jorgensen, C.C.; Haas, P.M.; Selby, D.L.; Lowry, J.C.

    1983-01-01

    This paper summarizes the early results and current status of a research program at ORNL which is intended to provide the methods and technical basis for NRC to initiate the use of the Systems Approach to Training (SAT) in the evaluation of training programs and entry level qualifications for NPP control room personnel. The program is an outgrowth of previous studies of simulator hardware and simulator training requirements under the Safety Related Operator Actions Program which recommended adaptation of a systems methodology to development and evaluation of NPP training programs.

  20. Optimum design parameter studies on different power level of the small size SFR

    Core characteristics on different power levels were evaluated for technical support to determine the proper power level of the prototype SFR (Sodium cooled Fast Reactor) in Korea. The initial core will be constructed based on U metal fuel due to the insufficient TRU experiment database, and Uranium fuel will be substituted to TRU fuel. The various uranium cores were designed with same cycle length and the number of batches, and the performances of those cores were evaluated to decide the candidate core for each power levels at first. The selected power levels are 50, 75, 100, 125, 150, and 200 MWe. The fuel cost, irradiation time, and irradiation performance were compared among the candidate cores on different power level. As a different way, the core performance was also estimated by increasing the number of batches to reach the limit of fast neutron fluence at each power level. According to the evaluation of studies, the power capacity of the prototype SFR should not be less than 100 MWe from the neutronics viewpoint because the irradiation performance and the fuel economy became worse rapidly with decreasing power level. (author)

  1. ACCOUNTING OF REACTIVE POWER COMPENSATION LEVEL AT PAYMENT CALCULATION OF TECHNOLOGICAL CONSUMPTION (LOSSES OF ELECTRIC POWER FOR ITS TRANSMISSION IN POWER NETWORK

    E. P. Zabello

    2005-01-01

    Full Text Available The method is proposed to make a correction in payment for consumption of reactive energy and power which is attributed to deviation of actual activation energy losses for reactive power compensation from their standard value. It is recommended to calculate standard loss values for every voltage level and actual loss values are to be determined with the help of application of remote electronic accounting means in the current mode of power consumption.

  2. Modular Multi-level converter based HVDC System for Grid Connection of Offshore Wind Power Plant

    Gnanarathna, U.N.; Chaudhary, Sanjay Kumar; Gole, A.M.; Teodorescu, Remus

    2010-01-01

    This paper explores the application of modular multi-level converters (MMC) as a means for harnessing the power from off-shore wind power plants. The MMC consists of a large number of simple voltage sourced converter (VSC) submodules that can be easily assembled into a converter for high-voltage ......This paper explores the application of modular multi-level converters (MMC) as a means for harnessing the power from off-shore wind power plants. The MMC consists of a large number of simple voltage sourced converter (VSC) submodules that can be easily assembled into a converter for high...

  3. Design and Analysis of Multi Level D-STATCOM to Improve the Power Quality

    Dinesh. Badavath,

    2014-01-01

    Full Text Available In the last decade, the electrical power quality issue has been the main concern of the power companies. Power quality is defined as the index which both the delivery and consumption of electric power affect on the performance of electrical apparatus. From a customer point of view, a power quality problem can be defined as any problem is manifested on voltage, current, or frequency deviation that results in power failure. The power electronics progressive, especially in flexible alternating-current transmission system (FACTS and custom power devices, affects power quality improvement. This paper presents an investigation of seven-Level Cascaded H - bridge (CHB Inverter as Distribution Static Compensator (DSTATCOM in Power System (PS for compensation of reactive power and harmonics. The advantages of CHB inverter are low harmonic distortion, reduced number of switches and suppression of switching losses. The DSTATCOM helps to improve the power factor and eliminate the Total Harmonics Distortion (THD drawn from a Non-Liner Diode Rectifier Load (NLDRL. The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM while Proportional and Integral (PI control is used for capacitor dc voltage regulation. A CHB Inverter is considered for shunt compensation of a 11 Kv distribution system. Finally a level shifted PWM (LSPWM and phase shifted PWM (PSPWM techniques are adopted to investigate the performance of CHB Inverter. The results are obtained through Matlab/Simulink software package.

  4. Effects of lignocellulosic composition and microwave power level on the gaseous product of microwave pyrolysis

    Agricultural residues are abundant resources to produce renewable energy and valuable chemicals. This study focused on the effects of lignocellulosic composition and microwave power level on the gaseous product of microwave pyrolysis of agricultural residues. When agricultural residues were under microwave radiation within 10 min, the maximum temperatures of approximately 320, 420, and 530 °C were achieved at the microwave power levels of 300, 400, and 500 W, respectively. Gas yield increased with increasing microwave power level, whereas solid and liquid yields decreased. Besides, gaseous products with higher H2 content and higher calorific values can be obtained at higher microwave power levels. In addition to microwave power level, lignocellulosic composition was also an important factor. H2 and CO2 yields increased with increasing hemicellulose content, whereas CH4 and CO yields increased with increasing cellulose content. Four empirical equations were derived to present the contributions of lignocellulosic materials to the yields of gaseous components. - Highlights: • About 530 °C was reached within 10 min at a microwave power level of 500 W. • Gas yield increased with increasing microwave power level. • A high correlation between hemicellulose content and either H2 or CO2 yield. • A high correlation between cellulose content and either CH4 or CO yield. • Empirical equations depict contribution of lignocellulosic content to gas yield

  5. Operating the Irish power system with increased levels of wind power

    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...

  6. System-level power optimization for wireless multimedia communication power aware computing

    Karri, Ramesh

    2007-01-01

    List of Figures. List of Tables. Preface. 1. Total Power Optimization for Wireless Multimedia Communication; E. Erkip, Xiaoan Ly, Yao Wang, D. Goodman. 2. Energy-Aware TDMA-Based MAC for Sensor Networks; K. Arisha, M. Youssef, M. Younis. 3. Power Aware Packet Routing Control in ad-hoc Wireless Networks; Qilian Liang, N. Neigus. 4. Optimal Node Scheduling for Effective Energy Usage in Sensor Networks; A. Srivastava, J. Sobaje, M. Potkonjak, M. Sarrafzadeh. 5. Energy-Efficient Data Multicast in Multi-Hop Wireless Networks; J.L. Wong, G. Veltri, M. Potkonjak. 6. Low-Energy Software Optimization f

  7. Procedural justice climate and group power distance: an examination of cross-level interaction effects.

    Yang, Jixia; Mossholder, Kevin W; Peng, T K

    2007-05-01

    In this article, the authors extend research on the cross-level effects of procedural justice climate by theorizing and testing its interaction with group power distance. The results indicated that group power distance moderated the relationships between procedural justice climate and individual-level outcomes (organizational commitment and organization-directed citizenship behavior). More specifically, a larger group power distance was found to attenuate the positive cross-level effects of procedural justice climate. Implications for procedural justice climate research are discussed. PMID:17484550

  8. Atmospheric contamination levels in reactor containments of Chooz, Fessenheim and Tihange power plants

    The levels of atmospheric contamination in the french PWR power plants have been studied with the help of measurements results carried out in the french power plant of Fessenheim and in the franco-belgium power plants of Chooz and Tihange. The reached levels, reactor on normal operation and reactor shut-down, are evaluated for the following forms of contamination: noble gases, iodine, aerosols and tritium. The main causes of variation of these levels are also analysed: variations due to primary water activity increasing, variations when intervention with opening of contaminated circuits

  9. Benchmark tests of JENDL-3.3 and ENDF/B-VI data files using Monte Carlo simulation of the 3 MW TRIGA MARK II research reactor

    The three-dimensional continuous-energy Monte Carlo code MNCP4C was used to develop a versatile and accurate full-core model of the 3 MW TRIGA MARK II research reactor at Atomic Energy Research Establishment, Savar, Dhaka, Bangladesh. The model represents in detail all components of the core with literally no physical approximation. All fresh fuel and control elements as well as the vicinity of the core were precisely described. Validation of the newly generated continuous energy cross section data from JENDL-3.3 was performed against some well-known benchmark lattices using MCNP4C and the results were found to be in very good agreement with the experiment and other evaluations. For TRIGA analysis continuous energy section data from JENDL-3.3 and ENDF/B-VI in combination with the JENDL-3.2 and ENDF/B-V data files (for natZr, natMo, natCr, natFe, natNi, natSi, and natMg) at 300K evaluations were used. Full S(α, β) scattering functions from ENDF/B-V for Zr in ZrH, H in ZrH and water molecule, and for graphite were used in both cases. The validation of the model was performed against the criticality and reactivity benchmark experiments of the reactor. The MNCP calculated values for effective multiplication factor keff underestimated 0.0250%Δk/k and 0.2510%Δk/k for control rods critical positions and overestimated 0.2098%Δk/k and 0.0966%Δk/k for all control rods withdrawn positions using JENDL-3.3 and ENDF/B-VI, respectively. The core multiplication factor differs appreciably (∼3.3%) between the no S(α, β) (when temperature representation for free gas treatment is about 300K) and 300K S(α, β) case. However, there is ∼20.0% decrease of thermal neutron flux occurs when the thermal library is removed. Effect of erbium isotope that is present in the TRIGA fuel over the criticality analysis of the reactor was also studied. In addition to the keff values, the well known integral parameters: δ28, δ25, ρ25, and C were calculated and compared for both JENDL3

  10. Application of Back Propagation Neural Network to Drum Level Control in Thermal Power Plants

    Preeti Manke; Sharad Tembhurne

    2012-01-01

    The paper describes the development and testing of a neural network based drum level controller for sub-critical thermal power plant boilers. Experimental data obtained from an operational coal fired power plant (500MW Thermal Power Station, Korba, India) is used to train the neural network. This model proposes a simple training algorithm for a class of nonlinear systems, which enables the neural network to be trained with the output errors of the controlled plant. The only a priori knowledge...

  11. To Strengthen the Career Management for Middle & High-Level Personnel in Power Enterprises

    Jun Ma; Jiaoyan Ma

    2009-01-01

    With the deepening of the power system reform, the management environment of power enterprises has undergone profound changes as well.  The competition advantages of power enterprises have turned from technology and fund to human resources, especially the core talents of enterprises—the middle & high-level personnel.  It is of strategic importance to employ career management to these people in order to exert their human capital advantages and to enhance the core competitive competence of ...

  12. Bidirectional Five-Level Power Processing Interface for Low Voltage Battery Energy Storage System

    Huang, Jain-Yi; Jou, Hurng-Liahng; Wu, Kuen-Der; Lin, You-Si; Wu, Jinn-Chang

    A bidirectional five-level power processing interface for low voltage battery energy storage system (BESS) is developed in this paper. This BESS consists of a bidirectional five-level DC-AC converter, a bidirectional dual boost/buck DC-DC converter and a battery set. This five-level DC-AC converter includes a bidirectional full-bridge converter and a bidirectional dual buck DC-DC converter. The five-level power processing interface can charge power to the battery set form the utility or discharge the power from the battery set to the utility depending on the demanded operation of user. A hardware prototype is developed to verify the performance of this BESS. Experimental results show the performance of the developed BESS is as expected.

  13. Automatic controller for steam generator water level during low power operation

    This research proposes a new controller which ensures a satisfactory automatic control for the steam generator water level from low power to full power. It is premised that the current analog control loop is replaced with digital computer control thus expanding the range of possible solutions. The proposed approach is to compensate the level measurement for thermal shrink and swell effects which cause complications in level control during low power operation. A non-linear digital predictor is a part of the controller and is used to estimate shrink and swell effects. The predictor is found to be stable and on-line applicable with micro-processors. The controller is evaluated by calculations in which it controls an existing non-linear digital computer model of a steam generator. For a multi-ramp power increase from low power to full power, the proposed controller shows good performances for the entire range. Water level settles down within 3 min after a single ramp increase (5% power increase in a minute) without any stability problem. Even at very low power, the maximum overshoot is judged to be acceptable. (orig.)

  14. Building America Case Study: Photovoltaic Systems with Module-Level Power Electronics

    2015-09-01

    Direct current (DC) power optimizers and microinverters (together known as module-level power electronics, or MLPE) are one of the fastest growing market segments in the solar industry. According to GTM Research in The Global PV Inverter Landscape 2015, over 55% of all residential photovoltaic (PV) installations in the United States used some form of MLPE in 2014.

  15. The Level of Power Quality Measurement and Evaluation in A Stone Crusher Plant

    Mustafa ŞEKKELİ

    2009-03-01

    Full Text Available Both electric utilities and end users of electric power are becoming increasingly concerned about the quality of electric power. Quality of electrical energy in the electrical system that is requested continuous power (uninterrupted power, constant frequency and with constant amplitude can be explained by sinusoidal voltage. Deformation of voltage in the form of sinusoidal waveform is explained as a harmonic. Harmonics are most important factors in decreasing quality of energy in the electrical system. In industrial plants, existence of harmocins and voltage drop, causes serious problems both in plant and network. This problem affects the cost. In this study, a power quality measurements are carried out in stone crusher plant. Harmonics and voltage drop has been measured and evaluated with the power analyzer. In the power quality measurements, harmonic level of the plant is not so bad. However, it is recommended that compensation system with harmonic elimination can be established in plant.

  16. System Level Power Management for Embedded Rtos: An Object Oriented Approach

    Ankur Agarwal

    2009-11-01

    Full Text Available Power management systems for embedded devices can be developed in real-time operating system (RTOS or in applications. If power management policies are applied in operating system (OS, then designers and developers will not have to worry about complex power management algorithms and techniques. They can rather concentrate on application development. The OS contains specific and accurate information about the various tasks being executed. An RTOS further has a comprehensive set of power management application programming interfaces (APIs for both device drivers and applications within a power management component. Therefore, it is logical to place policies and algorithms in the OS that can place components not being used into lower power states. This can significantly reduce the system energy consumption. We present here an abstract model of a system power manager (PM, device power managers, and application power managers. We present relationship and interactions of these managers with each other using Unified Modeling Language (UML class diagrams, sequence diagrams and state charts. We recommend that the PM must be implemented at the OS level in any embedded device. We also recommend the interfaces for interactions between PM and the devices power manager, as well as PM and application power manager. Device driver and application developers can easily use this object oriented approach to make the embedded system more power efficient, easy to maintain, and faster to develop.

  17. Maximum core loading of Kartini Reactor at 250 kW of power level

    Maximum core loading of Kartini Reactor at 250 kW of power level. Reevaluation of the safety aspect of Kartini Reactor is currently being performed, for the purpose of increasing the nominal power from 100 to 250 kW. The results of the evaluations will be used to verify the feasibility of the reactor to operate at the proposed power level. One of the important safety parameters which needs to be reevaluated is related to the shutdown capability of the available control rods, which is normally indicated through the parameter of available Shudown Margin (SDM), which is a function of both power level and Core Loading. This paper presents the methodology and the result of determining the Maximum Core Loading of Kartini Reactor at power level of 250 kW. The result indicates that the maximum core loading of Kartini reactor, for 250 kW of Nominal Power is 82 fuel elements, associated with 3.8 $ of available core excess. It is concluded that the negative reactivity of the available control rods is still sufficient to compensate the amount of reactivity produced by the addition of 11 new fuel elements over the minimum requirement for operation at 250 kW of power level

  18. Low Power at Different levels of VLSI Design an clock Distribution Schemes

    Chetan Sharma

    2011-01-01

    Low power chip requirement in the VLSI industry is main considerable field due to the reduction of chip dimension day by day and environmental factors. In this paper various low power techniques at Gate level, Architecture level and different tradeoffs between different clock distribution schemes like as single driver clock scheme and distributed buffers clock scheme are reviewed. Here it is also tried to showing various effects of particular clock distribution scheme such as clock skew, cloc...

  19. Metal clad active fibres for power scaling and thermal management at kW power levels.

    Daniel, Jae M O; Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John

    2016-08-01

    We present a new approach to high power fibre laser design, consisting of a polymer-free all-glass optical fibre waveguide directly overclad with a high thermal conductivity metal coating. This metal clad active fibre allows a significant reduction in thermal resistance between the active fibre and the laser heat-sink as well as a significant increase in the operating temperature range. In this paper we show the results of a detailed thermal analysis of both polymer and metal coated active fibres under thermal loads typical of kW fibre laser systems. Through several different experiments we present the first demonstration of a cladding pumped aluminium-coated fibre laser and the first demonstration of efficient operation of a cladding-pumped fibre laser at temperatures of greater than 400 °C. Finally, we highlight the versatility of this approach through operation of a passively (radiatively) cooled ytterbium fibre laser head at an output power of 405 W in a compact and ultralight package weighing less than 100 g. PMID:27505822

  20. Performance assessment for the water level control system in steam generator of the nuclear power plant

    Highlights: ► We consider the two PI controller steam generator water level control systems. ► We develop performance assessment methods for plants with stable and unstable zeros. ► The examples show the effectiveness of the proposed method. - Abstract: The steam generator water level control system is the most important components of a nuclear power plant. The operating steam generator water level control system is increasingly recognized as a capital asset that should be routinely maintained and monitored. However, the control loop performance assessment is still an open problem; thus, the performance assessment technology will be brought into the steam generator water level control system in nuclear power plants. Performance assessment methods for the plant with stable and unstable zeros of two PI controller systems are developed at all specific power levels. The numerical examples will demonstrate the effectiveness of the proposed method.

  1. The Level of Difficulty and Discrimination Power of the Basic Knowledge and Skills Examination (EXHCOBA.

    Eduardo Backhoff Escudero

    2000-05-01

    Full Text Available The Basic Knowledge and Skills Examination (EXHCOBA is one of the few great-scale examinations in Mexico which has been publishing its psychometric parameters.  In this paper we describe the  item analysis results, regarding the exam’s difficulty level and discrimination power.  Results show that most of the items have a medium difficulty and a high discrimination power.  They also reveal that the mathematics items have better discrimination power levels than the ones which belong to social science.

  2. A set of fuzzy systems to automate the manual procedures for reactor power level changes

    In this chapter, we describe a set of fuzzy systems which automate the manual part of procedures being used in the reactor operations for PWR-type nuclear power plants. One of the fuzzy systems evaluates the total power defect as a function of the boron concentration and the reactor power level. Others are used to compute the amount of step changes for the control rod as a function of the current rod position and the increment of the total power defect needed for the power level change. Each fuzzy system is either an exact or an approximate representation of the cubic spline interpolation for the corresponding function provided as graphs. The resulting set of fuzzy systems not only improves the efficiency in performing the curve readings but also reduces the interpolation errors involved. (orig.)

  3. Impact of high level penetration of Wind Turbines on Power System Transient Stability

    Kalogiannis, Theodoros; Llano, Enrique Muller; Hoseinzadeh, Bakhtyar;

    2015-01-01

    One of the most relevant aspects in power systems is their reliability and robustness of maintaining the stability under large disturbances. System stability is a crucial aspect to consider when expanding the network, e.g. while increasing the levels of wind power penetration. Wind turbine...... generators differ from the conventional ones in their inertial contribution to the grid, therefore, in most cases the ability of the system to maintain a stable operation is declined. To investigate this, two standard models are designed in PowerFactory software. The first is used to characterize system...... components, the response of the wind turbines and thereupon to validate them, whereas the second is used to estimate the maximum levels of wind power penetration. Those levels mainly depend on the spinning reserve, the inertia of the system and the severity of the event. Rate of change of frequency will...

  4. Plasma Switch for High-Power Active Pulse Compressor

    Hirshfield, Jay L. [Omega-P, Inc.

    2013-11-04

    Results are presented from experiments carried out at the Naval Research Laboratory X-band magnicon facility on a two-channel X-band active RF pulse compressor that employed plasma switches. Experimental evidence is shown to validate the basic goals of the project, which include: simultaneous firing of plasma switches in both channels of the RF circuit, operation of quasi-optical 3-dB hybrid directional coupler coherent superposition of RF compressed pulses from both channels, and operation of the X-band magnicon directly in the RF pulse compressor. For incident 1.2 ?s pulses in the range 0.63 ? 1.35 MW, compressed pulses of peak powers 5.7 ? 11.3 MW were obtained, corresponding to peak power gain ratios of 8.3 ? 9.3. Insufficient bakeout and conditioning of the high-power RF circuit prevented experiments from being conducted at higher RF input power levels.

  5. Optimization of E-DCH channel power ratios to maximize link level efficiency

    Zarco, Carlos Ruben Delgado; Malone, Jaime Tito; Wigard, Jeroen;

    2006-01-01

    For the WCDMA/HSUPA concept, a key to ensuring high spectral efficiency is to correctly adjust the transmission power ratios among the data and control channels. This paper provides optimal values for the power ratio between the Enhanced-Dedicated Physical Data Channel (E-DPDCH) and the Dedicated...... Physical Control Channel (DPCCH) from a Link Efficiency (LE) point of view. LE has been defined as the ratio between the average number of correctly received bits per second and the average total transmitted power. The optimization was carried out by testing different E-DPDCH to DPCCH power ratios in an...... HSUPA link level simulator for different bit rates. This simulator includes Hybrid ARQ (HARQ) and optimal power ratios are extracted for different Retransmission Sequence Number (RSN) targets. For Vehicular-A 30 km/h conditions, the optimal power ratios per code show only minor dependency on the bit...

  6. Scalability of components for kW-level average power few-cycle lasers.

    Hädrich, Steffen; Rothhardt, Jan; Demmler, Stefan; Tschernajew, Maxim; Hoffmann, Armin; Krebs, Manuel; Liem, Andreas; de Vries, Oliver; Plötner, Marco; Fabian, Simone; Schreiber, Thomas; Limpert, Jens; Tünnermann, Andreas

    2016-03-01

    In this paper, the average power scalability of components that can be used for intense few-cycle lasers based on nonlinear compression of modern femtosecond solid-state lasers is investigated. The key components of such a setup, namely, the gas-filled waveguides, laser windows, chirped mirrors for pulse compression and low dispersion mirrors for beam collimation, focusing, and beam steering are tested under high-average-power operation using a kilowatt cw laser. We demonstrate the long-term stable transmission of kW-level average power through a hollow capillary and a Kagome-type photonic crystal fiber. In addition, we show that sapphire substrates significantly improve the average power capability of metal-coated mirrors. Ultimately, ultrabroadband dielectric mirrors show negligible heating up to 1 kW of average power. In summary, a technology for scaling of few-cycle lasers up to 1 kW of average power and beyond is presented. PMID:26974623

  7. User's manual for levelized power generation cost using an IBM PC

    Programs for the estimation of levelized electric power generation costs using the BASIC interpreter on an IBM PC are described. Procedures for light-water reactor plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, nuclear decommissioning cost, and levelized total generation cost

  8. A control strategy for a three-level unified power quality conditioner

    Monteiro, Luís F. C.; Costa, José C. C.; Aredes, Maurício; Afonso, João L.

    2005-01-01

    In this work a control strategy for a three-level Unified Power Quality Conditioner (UPQC) is introduced. Basically, this control strategy is based on the set of active and non-active (reactive) power definitions in the time domain, which have been proposed by Fryze in the 30´s of the last century. The goal of this work consists in expand this control strategy to deal with three-level converters. The use of three-level converters allows a better performance of the equipment, by reducing...

  9. Wafer-level chip-scale packaging analog and power semiconductor applications

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  10. Three-phase power supply, output 60v and 100a, with unit power factor and low RFI level

    João Batista Vieira Júnior

    2003-01-01

    Full Text Available This paper presents a three-phase rectifier, unit power factor, non-dissipative commutation in DC-DC converter and synchronized control in frequency, working with 89% of global efficiency and low level do RFI. The proposed structure allows the operation with high switching frequency. The output voltage is controlled by PWM with a constant frequency. The operation principle, theoretical analysis from DC converter, relevant equations, current balance control technique and experimental results, are shown in this paper.

  11. Nonlinear Power-Level Control of the MHTGR Only with the Feedback Loop of Helium Temperature

    Zhe Dong

    2013-02-01

    Full Text Available Power-level control is a crucial technique for the safe, stable and efficient operation of modular high temperature gas-cooled nuclear reactors (MHTGRs, which have strong inherent safety features and high outlet temperatures. The current power-level controllers of the MHTGRs need measurements of both the nuclear power and the helium temperature, which cannot provide satisfactory control performance and can even induce large oscillations when the neutron sensors are in error. In order to improve the fault tolerance of the control system, it is important to develop a power-level control strategy that only requires the helium temperature. The basis for developing this kind of control law is to give a state-observer of the MHTGR a relationship that only needs the measurement of helium temperature. With this in mind, a novel nonlinear state observer which only needs the measurement of helium temperature is proposed. This observer is globally convergent if there is no disturbance, and has the L2 disturbance attenuation performance if the disturbance is nonzero. The separation principle of this observer is also proven, which denotes that this observer can recover the performance of both globally asymptotic stabilizers and L2 disturbance attenuators. Then, a new dynamic output feedback power-level control strategy is established, which is composed of this observer and the well-built static state-feedback power-level control based upon iterative dissipation assignment (IDA-PLC. Finally, numerical simulation results show the high performance and feasibility of this newly-built dynamic output feedback power-level controller.

  12. US power plant sites at risk of future sea-level rise

    Bierkandt, R.; Auffhammer, M.; Levermann, A.

    2015-12-01

    Unmitigated greenhouse gas emissions may increase global mean sea-level by about 1 meter during this century. Such elevation of the mean sea-level enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation measures are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to sea-level rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If sea-level rise is properly accounted for in future planning, an adaptation to sea-level rise may be costly but possible.

  13. US power plant sites at risk of future sea-level rise

    Unmitigated greenhouse gas emissions may increase global mean sea-level by about 1 meter during this century. Such elevation of the mean sea-level enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation measures are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to sea-level rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If sea-level rise is properly accounted for in future planning, an adaptation to sea-level rise may be costly but possible. (letter)

  14. A DC-DC Converter Efficiency Model for System Level Analysis in Ultra Low Power Applications

    Benton H. Calhoun

    2013-06-01

    Full Text Available This paper presents a model of inductor based DC-DC converters that can be used to study the impact of power management techniques such as dynamic voltage and frequency scaling (DVFS. System level power models of low power systems on chip (SoCs and power management strategies cannot be correctly established without accounting for the associated overhead related to the DC-DC converters that provide regulated power to the system. The proposed model accurately predicts the efficiency of inductor based DC-DC converters with varying topologies and control schemes across a range of output voltage and current loads. It also accounts for the energy and timing overhead associated with the change in the operating condition of the regulator. Since modern SoCs employ power management techniques that vary the voltage and current loads seen by the converter, accurate modeling of the impact on the converter efficiency becomes critical. We use this model to compute the overall cost of two power distribution strategies for a SoC with multiple voltage islands. The proposed model helps us to obtain the energy benefits of a power management technique and can also be used as a basis for comparison between power management techniques or as a tool for design space exploration early in a SoC design cycle.

  15. The management of mixed low-level radioactivewaste in the nuclear power industry

    As a result of investigations sponsored by the nuclear power industry, the definition of mixed low-level radioactive waste (mixed waste) in the industry is clarified. A methodology for estimating the annual generation rate of mixed waste is presented and its application to a typical nuclear power plant is illustrated. Effective management practices to minimize the generation of mixed waste are described and strategies to deal with unavoidable mixed waste are identified

  16. Multi-spacecraft measurement of anisotropic power levels and scaling in solar wind turbulence

    K. T. Osman; Horbury, T. S.

    2009-01-01

    Measurements by the four Cluster spacecraft in the solar wind are used to determine quantitatively the field-aligned anisotropy of magnetohydrodynamic inertial range turbulence power levels and spectral indexes. We find, using time-lagged second order structure functions, that the spectral index is near 2 around the field-parallel direction, which is consistent with a "critical balance" turbulent cascade. Solar wind fluctuations are found to be anisotropic with power mainly ...

  17. Thermal analysis of multi-MW two-level wind power converter

    Zhou, Dao; Blaabjerg, Frede; Mogens, Lau;

    2012-01-01

    In this paper, the multi-MW wind turbine of partial-scale and full-scale two-level power converter with DFIG and direct-drive PMSG are designed and compared in terms of their thermal performance. Simulations of different configurations regarding loss distribution and junction temperature in the...... power device in the whole range of wind speed are presented and analyzed. It is concluded that in both partial-scale and full-scale power converter the most thermal stressed power device in the generator-side converter will have higher mean junction temperature and larger junction temperature...... fluctuation compared to grid-side converter at the rated wind speed. Moreover, the thermal performance of the generator-side converter in the partial-scale power converter becomes crucial around the synchronous operating point and should be considered carefully....

  18. A system-level mathematical model for evaluation of power train performance of load-leveled electric-vehicles

    Purohit, G. P.; Leising, C. J.

    1984-01-01

    The power train performance of load leveled electric vehicles can be compared with that of nonload leveled systems by use of a simple mathematical model. This method of measurement involves a number of parameters including the degree of load leveling and regeneration, the flywheel mechanical to electrical energy fraction, and efficiencies of the motor, generator, flywheel, and transmission. Basic efficiency terms are defined and representative comparisons of a variety of systems are presented. Results of the study indicate that mechanical transfer of energy into and out of the flywheel is more advantageous than electrical transfer. An optimum degree of load leveling may be achieved in terms of the driving cycle, battery characteristics, mode of mechanization, and the efficiency of the components. For state of the art mechanically coupled flyheel systems, load leveling losses can be held to a reasonable 10%; electrically coupled systems can have losses that are up to six times larger. Propulsion system efficiencies for mechanically coupled flywheel systems are predicted to be approximately the 60% achieved on conventional nonload leveled systems.

  19. Estimation of Power Consumption at Behavioral Modeling Level Using SystemC

    Damaševičius Robertas

    2007-01-01

    Full Text Available A successful embedded system design requires thorough domain analysis and design space exploration. The aim is to develop a target system, which implements the prescribed functionality and at the same time meets the design, time, and cost-related constraints. The early evaluation of design characteristics, such as power consumption, allows the user to take advantage of many architectural design options available and to modify the system architecture, if needed. Currently, SystemC is used to model the hardware and software parts of a system at the high level. However, the characteristics of the modeled system are obtained only at the late design stages during physical synthesis. Here, we present a framework for power estimation at the modeling level of a design using macromodels. The SystemC class library is modified and extended with new classes describing the computation of power characteristics of the behavioral-level hardware models.

  20. Architecture-level performance/power tradeoff in network processor design

    CHEN Hong-song; JI Zhen-zhou; HU Ming-zeng

    2007-01-01

    Network processors are used in the core node of network to flexibly process packet streams. With the increase of performance, the power of network processor increases fast, and power and cooling become a bottleneck. Architecture-level power conscious design must go beyond low-level circuit design. Architectural power and performance tradeoff should be considered at the same time. Simulation is an efficient method to design modern network processor before making chip. In order to achieve the tradeoff between performance and power,the processor simulator is used to design the architecture of network processor. Using Netbench, Commubench benchmark and processor simulator-SimpleScalar, the performance and power of network processor are quantitatively evaluated. New performance tradeoff evaluation metric is proposed to analyze the architecture of network processor. Based on the high performance Intel IXP 2800 Network processor configuration, optimized instruction fetch width and speed 、instruction issue width, instruction window size are analyzed and selected. Simulation results show that the tradeoff design method makes the usage of network processor more effectively. The optimal key parameters of network processor are important in architecture-level design. It is meaningful for the next generation network processor design.

  1. Level-one modules library for DSNP: Dynamic Simulator for Nuclear Power-plants

    The Dynamic Simulator for Nuclear Power-plants (DSNP) is a system of programs and data sets by which a nuclear power plant or part thereof can be simulated at different levels of sophistication. The acronym DSNP is used interchangeably for the DSNP language, for the DSNP precompiler, for the DSNP libraries, and for the DSNP document generator. The DSNP language is a set of simple block oriented statements, which together with the appropriate data, comprise a simulation of a nuclear power plant. The majority of the DSNP statements will result in the inclusion of a simulated physical module into the program. FORTRAN statements can be inserted with no restrictions among DSNP statements

  2. Level-one modules library for DSNP: Dynamic Simulator for Nuclear Power-plants

    Saphier, D.

    1978-09-01

    The Dynamic Simulator for Nuclear Power-plants (DSNP) is a system of programs and data sets by which a nuclear power plant or part thereof can be simulated at different levels of sophistication. The acronym DSNP is used interchangeably for the DSNP language, for the DSNP precompiler, for the DSNP libraries, and for the DSNP document generator. The DSNP language is a set of simple block oriented statements, which together with the appropriate data, comprise a simulation of a nuclear power plant. The majority of the DSNP statements will result in the inclusion of a simulated physical module into the program. FORTRAN statements can be inserted with no restrictions among DSNP statements.

  3. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized.

  4. Battery Recharging Issue for a Two-Power-Level Flywheel System

    Janaína Gonçalves de Oliveira

    2010-01-01

    Full Text Available A novel battery recharging system for an all-electric driveline comprising a flywheel with a permanent magnet double wound synchronous machine (motor/generator is presented. The double winding enables two voltage levels and two different power levels. This topology supersedes other all-electric drivelines. The battery operates in a low-power regime supplying the average power whereas the flywheel delivers and absorbs power peaks, which are up to a higher order of magnitude. The topology presents new challenges for the power conversion system, which is the focus of this investigation. The main challenge is the control of the power flow to the battery when the vehicle is parked despite the decay of the flywheel machine voltage; which is dependent on its charge state, that is, rotational speed. The design and simulation of an unidirectional DC/DC buck/boost converter for a variable rotational speed flywheel is presented. Conventional power electronic converters are used in a new application, which can maintain a constant current or voltage on the battery side. Successful PI current control has been implemented and simulated, together with the complete closed loop system.

  5. Dynamic Output Feedback Power-Level Control for the MHTGR Based On Iterative Damping Assignment

    Zhe Dong

    2012-06-01

    Full Text Available Because of its strong inherent safety features and high outlet temperature, the modular high temperature gas-cooled nuclear reactor (MHTGR is already seen as the central part of the next generation of nuclear plants. Such power plants are being considered for industrial applications with a wide range of power levels, and thus power-level control is an important technique for their efficient and stable operation. Stimulated by the high regulation performance provided by nonlinear controllers, a novel dynamic output-feedback nonlinear power-level regulator is developed in this paper based on the technique of iterative damping assignment (IDA. This control strategy can provide the L2 disturbance attenuation performance under modeling uncertainty or exterior disturbance, and can also guarantee the globally asymptotic closed-loop stability without uncertainty and disturbance. This newly built control strategy is then applied to the power-level regulation of the HTR-PM plant, and numerical simulation results show both the feasibility and high performance of this newly-built control strategy. Furthermore, the relationship between the values of the parameters and the performance of this controller is not only illustrated numerically but also analyzed theoretically.

  6. Amendment of standard for procedures of level 1 probabilistic risk assessment of nuclear power plants during power operation

    A standard which is intended to provide requirements and methodologies for conducting level 1 probabilistic risk assessment (PRA) was amended. In this standard, PRA is carried out to evaluate the risk of nuclear power plants by evaluating the core damage frequencies due to internal initiating events during power operation. This standard was approved and published by the Atomic Energy Society of Japan (AESJ) on the deliberations at the Subcommittee on Level 1 PRA under the Risk Technical Committee of the AESJ Standards Committee. AESJ formulated and issued this document after deliberation by the Risk Technical Committee and the Standards Committee. PRA of a nuclear power plant is a probabilistic approach for comprehensively and quantitatively assessing plant risk. This involves quantitative analysis of accident scenarios up to core damage and of the further evolution of events after core damage, with careful attention to events that are related to core or fuel damage, finally to arrive at an estimation of event frequencies and consequences. In Japan, PRA has been implemented to evaluate the validity of Accident Management Strategies and the quantitative safety of nuclear power plants in the Periodic Safety Review. Furthermore, in the regulatory area, the Nuclear Regulation Authority, which is the new regulatory authority founded in 2012, intends to utilize PRA in their new safety regulation positively. As the validity of PRA has come to be accepted, preservation of the quality and transparency of PRA has become important issues. Recognizing that preparation of a standard for PRA procedure is effective in addressing these issues, the AESJ standards committee is preparing a procedures guide for nuclear facilities. As described above, this standard replaces the 2008 issue - A Standard for Procedures of Probabilistic Safety Assessment of Nuclear Power Plants during Power Operation (Level 1 PSA):2008 - of the same standard. We decided to make this amendment because five

  7. Method for Calculating CO2 Emissions from the Power Sector at the Provincial Level in China

    MA Cui-Mei; GE Quan-Sheng

    2014-01-01

    Based on the detailed origins of each province’s electricity consumption, a new method for calculating CO2 emissions from the power sector at the provincial level in China is proposed. With this so-called consumer responsibility method, the emissions embodied in imported electricity are calculated with source-specific emission factors. Using the new method, we estimate CO2 emissions in 2005 and 2010. Compared with those derived from the producer responsibility method, the power exporters’ emissions decreased sharply. The emissions from the power sector in Inner Mongolia, the largest power exporter of China, decreased by 109 Mt in 2010. The value is equivalent to those from Shaanxi’s power production and Canada’s power and heat production. In contrast, the importers’ emissions increased substantially. The emissions from the power sector in Hebei, the largest power importer of China, increased by 74 Mt. Emissions of Beijing, increased by 60 Mt (320%), in 2010. Thus, we suggest that the Chinese government should take the emissions, as calculated from the consumption perspective, into account when formulating and assessing local CO2 emission reduction targets.

  8. Decentralized load frequency control on each power plant. Hatsudensho level ni okeru bunsangata fuka shuhasu seigyo

    Tanaka, E.; Hasegawa, J. (HOkkaido Universtiy, Sapporo (Jpaan))

    1991-02-20

    Because of relatively decreasing hydraulic power plants, it becomes difficult to secure an electric power capacity needed for load frequency control of the electric power system. Accordingly, application is studied of the modern control theory based on a state equation instead of the classic control theory. To improve control characteristic by transmitting as little information as possible, decentralized control on each power plant level is studied and applied to a model. The following is a summarized conclusion: By detecting by an integral compensator and controlling variables which are equal to voltage phase angle deviations, frequency deviations or interchange power deviations can be controlled without information on interconnected-power-line tide deviations or interchange power deviations. Designing and practical operation of this system are easy because the control system is structured by the information including frequency deviations only from each power plant. Moreover, if some state variables are not available, the control system can be designed with a dynamic compensator. 6 refs., 4 figs., 2 tabs.

  9. Optimization of Electric Power Leveling Systems by using Taper-Off-Reflectance Particle Swarm Optimization

    Makino, Yohei; Fujii, Toshinori; Imai, Jun; Funabiki, Shigeyuki

    Recently, it is desired to develop energy control technologies for environmental issues such as global warming and exhaustion of fossil fuel. Power fluctuations in large power consumers may cause the instability of electric power systems and increase the cost of the electric power facility and electricity charges. Developing the electric power-leveling systems (EPLS) to compensate the power fluctuations is necessary for future electric power systems. Now, EPLS with an SMES have been proposed as one of the countermeasures for the electric power quality improvement. The SMES is superior to other energy storage devices in response and storage efficiency. The authors proposed the EPLS based on fussy control with the SMES. For this practical implementation, optimizing control gain and SMES capacity is an important issue. This paper proposes a new optimization method of the EPLS. The proposed algorithm is novel particle swarm optimization based on taper-off reflectance (TRPSO). The proposed TRPSO optimizes the design variables of the EPLS efficiently and effectively.

  10. Quantum cascade laser in a master oscillator power amplifier configuration with Watt-level optical output power.

    Hinkov, Borislav; Beck, Mattias; Gini, Emilio; Faist, Jérôme

    2013-08-12

    We present the design and realization of short-wavelength (λ = 4.53 μm) and buried-heterostructure quantum cascade lasers in a master oscillator power amplifier configuration. Watt-level, singlemode peak optical output power is demonstrated for typical non-tapered 4 μm wide and 5.25 mm long devices. Farfield measurements prove a symmetric, single transverse-mode emission in TM(00)-mode with typical divergences of 25° and 27° in and perpendicular to growth direction, respectively. We demonstrate singlemode tuning over a range of 7.9 cm(-1) for temperatures between 263K and 313K and also singlemode emission for different driving currents. The side mode suppression ratio is measured to be higher than 20 dB. PMID:23938833

  11. A Polymer Optical Fiber Fuel Level Sensor: Application to Paramotoring and Powered Paragliding

    David Sánchez Montero; Carmen Vázquez; Pedro Contreras Lallana

    2012-01-01

    A low-cost intensity-based polymer optical fiber (POF) sensor for fuel level measurements in paramotoring and powered paragliding is presented, exploiting the advantages of the optical fiber sensing technology. Experimental results demonstrate that the best option can be performed by stripping the fiber at the desired discrete points to measure the fuel level as well as with a gauge-shape fiber bending. The prototype has a good linearity, better than 4% full scale (F.S.), and sensitivity arou...

  12. A review of studies on low-level vibrations as a source of electric power generation

    RAHMATİAN, Mohammad Ali; RAHMATİAN, Mohammad Rasoul; RAHİMZADEH, Hamed

    2015-01-01

    Abstract. Recent advances in low power VLSI design, with a low duty cycle has been able to resolve wireless sensor problems. In addition, researchers are looking to generate electrical energy from vibrations. The present paper discusses the low level vibration sources and their use in piezoelectric circuit for the production of electrical energy. The simulation results show that this scheme can convert low-level vibrations in nature, home environment, workplace, etc. into electrical energy.

  13. Design for reliability in power electronics in renewable energy systems – status and future

    Wang, Huai; Blaabjerg, Frede; Ma, Ke;

    2013-01-01

    maintenance costs, and herefore, low Levelized-Cost-of-Energy (LCOE) of renewable energy systems. This paper presents the prior-art Design for Reliability (DFR) process for power converters and addresses the paradigm shift to Physics-of-Failure (PoF) approach and mission profile based analysis. Moreover, the......Advances in power electronics enable efficient and flexible interconnection of renewable sources, loads and electric grids. While targets concerning efficiency of power converters are within reach, recent research endeavors to predict and improve their reliability to ensure high availability, low...... lifetime prediction of reliability-critical components IGBT modules is discussed in a 2.3 MW wind power converter. Finally, the challenges and opportunities to achieve more reliable power electronic converters are discussed....

  14. The natural radioactive level of the coal, coal cinder and slag from power plants

    The -ray spectrometer was used to analyze the natural radioactive level of the coal from Urumqi, Yi li and Ha mi areas; coal cinder and slag from China power plant and state power plant in Urumqi. The average value of and of coal is 5.54, 3.51, 69.15 from Urumqi; 9.59, 4.02, 72.95 from Yi li; 7.42, 4.87, 88.32 from Ha mi; the coal cinder is 29.31, 15.57, 111.39 from China power plant; 24.67, 16.22, 133.98 from state power plant, respectively. The result reveals that the coal cinder's application range has no limit according to national standard. (authors)

  15. Estimating Brand Level Demand Elasticities and Measuring Market Power for Regular Carbonated Soft Drinks

    Langan, Glenn E.; Cotterill, Ronald W.

    1994-01-01

    This paper reports econometric estimation of brand level demand (AIDS) elasticities for regular carbonated soft drinks using Information Resources, Inc. panel data. Own and cross price elasticities are used to measure actual and hypothetical market power that would arise from potential mergers or collusive pricing arrangements.

  16. Prospective Physics Teachers' Level of Understanding Energy, Power and Force Concepts

    Saglam-Arslan, Aysegul; Kurnaz, Mehmet Altan

    2009-01-01

    The aim of this study is to determine prospective physics teachers' level of understanding of the concepts of energy and the related concepts of force and power. The study was carried out with the participation of 56 physics education department students at a university in Karadeniz region. All participants had previously taken an introductory…

  17. Empirical LTE Smartphone Power Model with DRX Operation for System Level Simulations

    Lauridsen, Mads; Noël, Laurent; Mogensen, Preben

    An LTE smartphone power model is presented to enable academia and industry to evaluate users’ battery life on system level. The model is based on empirical measurements on a smartphone using a second generation LTE chipset, and the model includes functions of receive and transmit data rates and...

  18. Review of practicing Level-2 probabilistic safety analysis for Chinese nuclear power plants

    Existing studies about Level-2 PSA (Probabilistic Safety Analysis) in the world, covering NUREG-1150, IAEA-SSG-4, 50-P-8 and Level-2 plant PSA reports for AP1000 and EPR, serve in this paper as the basis of a literature study aimed at determining guidelines to practice Level-2 PSA in Chinese commercial nuclear power plants. We recapitulate the main technical elements composing Level-2 PSA: the familiarization with plant data and systems, interface with Level-1, containment performance analysis, accident progression and containment event tree analysis, source term and release category analysis, sensitivity, importance and uncertainty analysis, and the relationship between them. At last, outcomes of Level-2 PSA are presented. (author)

  19. Improvement of High-Power Three-Level Explosion-Proof Inverters Using Soft Switching Control Based on Optimized Power-Loss Algorithm

    Shi-Zhou Xu

    2015-01-01

    Full Text Available The high-power three-level explosion-proof inverters demand high thermal stability of power devices, and a set of theories and methods is needed to achieve an accurate power-loss calculation of power devices, to establish heat dissipation model, and ultimately to reduce the power loss to improve thermal stability of system. In this paper, the principle of neutral point clamped three-level (NPC3L inverter is elaborated firstly, and a fourth-order RC equivalent circuit of IGBT is derived, on which basis the power-loss model of IGBT and the optimized maternal power-loss thermal model, using an optimized power-loss algorithm, are established. Secondly, in accordance with the optimized maternal power-loss thermal model, the generic formulas of power-loss calculation are deduced to calculate the power-loss modification values of NPC3L and soft switching three-level (S3L inverters, which will be the thermal sources during thermal analysis for maternal power-loss thermal models. Finally, the experiment conducted on the 2.1 MW experimental platform shows that S3L inverter has the same excellent output characteristics with NPC3L inverter, reduces the power loss significantly by 213 W in each half-bridge, and decreases the temperature by 10°C, coinciding with the theoretical calculation, which verifies the accuracy of optimized power-loss algorithm and the effectiveness of the improvement.

  20. Study on gamma radiation levels around Thermal Power Plant and Zindal Steel Plant of Bellary district

    Indoor and outdoor ambient gamma radiation levels have been measured around Thermal Power Plant and Zindal Steel Plant of Bellary district by using Scintillometer (Type SM 141D) manufactured by Electronics Corporation of India Limited (ECIL). All measurements were made 1 m in above the ground level. The arithmetic mean of the readings was taken as representative figure for each location. The exposure rate in μR.h-1 was converted into absorbed dose rate nGyh-1 using the conversion factor of 1μR.h-1 = 8.7 nGy.h-1, which stems from the definition of the Roentgen. The average values of gamma radiation levels in outdoor and indoor atmosphere around Thermal Power Plant and Zindal Steel Plant of Bellary district have been measured using Scintillometer. We have also measured the variation of gamma radiation level in different rooms of same dwelling in different places of the study area. The data shows indoor gamma radiation is higher than outdoor gamma radiation level. The gamma exposure rate in outdoor and indoor atmosphere of the study area found to be varied from 113.1 to 234.6 nGh-1 and 139.2 to 365.2 nGh1-1 with arithmetic mean of 165.3 nGh-1 and 203.6 nGh-1, respectively. The study shows that indoor gamma radiation is higher than outdoor gamma radiation level. Dwelling having granite floorings shows maximum level of gamma radiation when compared to other floorings. Kitchen and bed rooms shows higher radiation level compared to halls. Maximum outdoor gamma radiation level have been observed near the dumps of thermal power plant

  1. Development of a Review Guide for a Level-3 PSA of Nuclear Power Plants

    A probabilistic safety assessment (PSA) provides a systematic analysis to identify and quantify all the risks that a plant imposes to the operators, general public and the environment. The main benefits of a PSA is to provide insights into the safety aspects of a plant design, performance, and the potential environmental impacts of postulated accidents, including the identification of dominant risk contributors, and a comparison of the options for reducing a risk. Among the three levels of a PSA, a Level-3 PSA provides insights into the relative importance of a accident prevention and mitigative measures expressed in terms of the adverse consequences for the health of the public, and the contamination of land, air, water, and foodstuffs. Finally, a Level-3 PSA provides insights into the relative effectiveness of emergency response planning aspects of an off-site accident management, and into the economic impacts. Regulatory bodies are generally responsible for the specification of safety criteria which can be related to PSAs at Level-1, -2, and -3. Examples of these criteria are the frequency of a severe core damage for a Level-1, and the frequency of large releases of radionuclides for a Level-2 PSA. The most commonly used Level-3 related safety criteria are early and cancer fatality risks. The regulatory body in Korea has developed the review guides for the Level-1 and -2 PSA. And the current regulatory structure for the licensing of nuclear power plants is established for an LWR-oriented structure. However, the accomplishment of a Level-3 PSA as well as Level-1 and -2 PSA is necessary in order to establish the risk-informed and performance-based regulatory structure for the licensing of future nuclear power plants. In such a situation, the need for the accomplishment of a Level-3 PSA is increasing. Therefore, the main goal of this study is to develop a review guide for the Level-3 PSA

  2. Reactor core water level monitor system and startup for CPR1000 nuclear power plant

    Reactor core water level monitor system is an important system used in CPR1000 nuclear power plant for monitoring the water level of reactor core after LOCA accident. The level measured by this system is used directly in the accident operation procedure. The principle of the measurement and the component of the system were introduced. According to the startup work of the first project for CPR1000, the goal for the first startup of this system relying on domestic engineering team was achieved. (authors)

  3. Evaluation of safety issues on newly regulated nuclear power plant by tsunami-level 1 PRA

    The tsunami caused by the Great East Japan Earthquake triggered severe accidents involving the units 1 to 4 at the Fukushima Dai-ichi nuclear power station (NPS). In order to re-operate existing nuclear power plants it should be necessary to reduce the core damage frequency on risk by tsunami. In this work, effects of the off-site power supply installation on resuming operation of nuclear power plants were investigated by utilizing the Tsunami-Level 1 Probability Risk Assessment (PRA). Unit 2 of the Onagawa nuclear power station, which resembled units 2 and 3 of Fukushima Dai-ichi, was selected for PRA. First, event-tree was created for the units of the Onagawa nuclear power station with the safety systems such as Emergency Core Cooling System (ECCS), investigating the plant situation at the time of the earthquake and tsunami occurrences. It was assumed that the magnitude of the tsunami was equivalent to the Great East Japan Earthquake. The accident-analytical progression-time was 36 hours, determined from the core-damage occurrence of the unit 3 of Fukushima Dai-ichi nuclear power station. Failure probabilities were calculated by the fault tree, which was created from the elements listed in the event tree. For the calculation, failure rates reported by the NUCIA (NUClear Information Archives) were primarily utilized. Then, obtained failure probabilities were embedded to the event tree. Core damage probabilities were evaluated by calculating success and failure rates for each accidental progression and scenarios. Restoration of the failed equipment and machineries was not considered in the analysis. Installation of the power supply vehicles at the nuclear power plant site reduced the core damage probability from 2.58×10-6 to 8.56×10-7. However, continued addition of the power supply vehicles could not lower the core damage probability further more. In the case of Unit 2 of Onagawa nuclear power station, there could be a limit to lower the core damage probability

  4. Survey of ambient electromagnetic and radio-frequency interference levels in nuclear power plants

    This document reports the results of a survey of ambient electromagnetic conditions in representative nuclear power plants. The U.S. Nuclear Regulatory Commission (NRC) Office of Nuclear Regulatory Research engaged the Oak Ridge National Laboratory (ORNL) to perform these measurements to characterize the electromagnetic interference (EMI) and radio-frequency interference (RFI) levels that can be expected in nuclear power plant environments. This survey is the first of its kind, being based on long-term unattended observations. The data presented in this report were measured at eight different nuclear units and required 14 months to collect. A representative sampling of power plant conditions (reactor type, operating mode, site location) monitored over extended observation periods (up to 5 weeks) were selected to more completely determine the characteristic electromagnetic environment for nuclear power plants. Radiated electric fields were measured over the frequency range of 5 MHz to 8 GHz. Radiated magnetic fields and conducted EMI events were measured over the frequency range of 305 Hz to 5 MHz. Highest strength observations of the electromagnetic ambient environment across all measurement conditions at each site provide frequency-dependent profiles for EMI/RFI levels in nuclear power plants

  5. Application of Back Propagation Neural Network to Drum Level Control in Thermal Power Plants

    Preeti Manke

    2012-03-01

    Full Text Available The paper describes the development and testing of a neural network based drum level controller for sub-critical thermal power plant boilers. Experimental data obtained from an operational coal fired power plant (500MW Thermal Power Station, Korba, India is used to train the neural network. This model proposes a simple training algorithm for a class of nonlinear systems, which enables the neural network to be trained with the output errors of the controlled plant. The only a priori knowledge of the controlled plant is the direction of its output response. Due to its simple structure and algorithm, and good performance, the proposed controller has high potential for handling difficult problems in process-control systems. The Artificial neural networks (ANN modeling can significantly reduce the frequency of deviations and the degree of deviation of the water level in the drum. The ANN model to be applied for the boiler feed system in the power plant will not only increase the efficiency of the system but also shall considerably reduce the tripping of the power plant.

  6. Computer-based control of nuclear power information systems at international level

    In most highly industrialized countries of the world information plays major role in anti-nuclear campaign. Information and discussions on nuclear power need critical and objective analysis before the structured information presentation to the public to avoid bias anti-nuclear information on one side and neglect of great risk in nuclear power. This research is developing a computer-based information system for the control of nuclear power at international level. The system is to provide easy and fast information highways for the followings: (1) Low Regulatory dose and activity limit as level of high danger for individuals and public. (2) Provision of relevant technical or scientific education among the information carriers in the nuclear power countries. The research is on fact oriented investigation about radioactivity. It also deals with fact oriented education about nuclear accidents and safety. A standard procedure for dissemination of latest findings using technical and scientific experts in nuclear technology is developed. The information highway clearly analyzes the factual information about radiation risk and nuclear energy. Radiation cannot be removed from our environment. The necessity of radiation utilizations defines nuclear energy as two-edge sword. It is therefore, possible to use computer-based information system in projecting and dissemination of expert knowledge about nuclear technology positively and also to use it in directing the public on the safety and control of the nuclear energy. The computer-based information highway for nuclear energy technology is to assist in scientific research and technological development at international level. (author)

  7. Improvement of High-Power Three-Level Explosion-Proof Inverters Using Soft Switching Control Based on Optimized Power-Loss Algorithm

    Shi-Zhou Xu; Feng-You He

    2015-01-01

    The high-power three-level explosion-proof inverters demand high thermal stability of power devices, and a set of theories and methods is needed to achieve an accurate power-loss calculation of power devices, to establish heat dissipation model, and ultimately to reduce the power loss to improve thermal stability of system. In this paper, the principle of neutral point clamped three-level (NPC3L) inverter is elaborated firstly, and a fourth-order RC equivalent circuit of IGBT is derived, on w...

  8. A new tool to estimate maximum wind power penetration level: In perspective of frequency response adequacy

    Highlights: • This study proposes a new tool to estimate maximum wind power penetration level. • This tool takes frequency response adequacy into account. • System frequency sensitivity is modelled as a function of inertia and headroom. • A practical power system is investigated as a case study. • Outputs from the proposed tool match with dynamic simulation results. - Abstract: Wind energy is becoming a significant source of generation in many countries because of its zero fuel cost and no air pollution. Due to integration of large-scale wind power in conventional grids, synchronous generators are being economically replaced. Modern wind farms are based on power electronics interface; and unlike synchronous generators, they do not have inherent frequency support capability. So, in a combined synchronous and non-synchronous machine based power system, it has always been a concern for a network operator to maintain system frequency within acceptable limits following a major disturbance. From power system security point of view, wind penetration can be limited by frequency response criteria. Up to now, several methodologies have been proposed to estimate maximum threshold of wind integration. However, none of them recommends how a system operator could be immediately informed about a secured wind penetration limit, as soon as generation profile is known. This paper proposes a new estimation tool of maximum wind penetration level from the frequency response adequacy point of view. Available system information viz. inertia and headroom are used as input parameters in the developed tool. Output of this tool will provide the highest margin of wind power that can be integrated at a particular load condition without violating frequency response constraints. The proposed technique is applied and analysed for a 250 bus, 65 machine Australian electricity network

  9. Photovoltaic Shading Testbed for Module-Level Power Electronics: 2014 Update

    Deline, C.; Meydbray, J.; Donovan, M.

    2014-08-01

    The 2012 NREL report 'Photovoltaic Shading Testbed for Module-Level Power Electronics' provides a standard methodology for estimating the performance benefit of distributed power electronics under partial shading conditions. Since the release of the report, experiments have been conducted for a number of products and for different system configurations. Drawing from these experiences, updates to the test and analysis methods are recommended. Proposed changes in data processing have the benefit of reducing the sensitivity to measurement errors and weather variability, as well as bringing the updated performance score in line with measured and simulated values of the shade recovery benefit of distributed PV power electronics. Also, due to the emergence of new technologies including sub-module embedded power electronics, the shading method has been extended to include power electronics that operate at a finer granularity than the module level. An update to the method is proposed to account for these emerging technologies that respond to shading differently than module-level devices. The partial shading test remains a repeatable test procedure that attempts to simulate shading situations as would be experienced by typical residential or commercial rooftop photovoltaic (PV) systems. Performance data for multiple products tested using this method are discussed, based on equipment from Enphase, Solar Edge, Maxim Integrated and SMA. In general, the annual recovery of shading losses from the module-level electronics evaluated is 25-35%, with the major difference between different trials being related to the number of parallel strings in the test installation rather than differences between the equipment tested.

  10. Multi-spacecraft measurement of anisotropic power levels and scaling in solar wind turbulence

    K. T. Osman

    2009-08-01

    Full Text Available Measurements by the four Cluster spacecraft in the solar wind are used to determine quantitatively the field-aligned anisotropy of magnetohydrodynamic inertial range turbulence power levels and spectral indexes. We find, using time-lagged second order structure functions, that the spectral index is near 2 around the field-parallel direction, which is consistent with a "critical balance" turbulent cascade. Solar wind fluctuations are found to be anisotropic with power mainly in wavevectors perpendicular to the mean field, where the spectral index is around 5/3.

  11. Airborne monitoring of radioactivity level in the regions surrounding Qinshan Nuclear Power Plant and Shanghai city

    The author introduces the monitoring method and main results of environmental γ radioactivity level and surface density of 137Cs and 60Co on the ground in the regions surrounding Qinshan Nuclear Power Plant and Shanghai City, using airborne γspectrometer. The results show that the absorbed dose rate in air (1 m above ground) is lower normal background, the average is 52.7 nGy/h in the regions. No pollution from Nuclear Power Plant had been monitored, but two artificial pollution points at the fertilizer factory of Fengxian County and the refractory material factory of Haiyan County had unexpectly been monitored

  12. Disentangling Bargaining Power from Individual and Household Level to Institutions: Evidence on Women’s Position in Ethiopia

    Staveren, Irene; Mabsout, Ramzi

    2010-01-01

    textabstractSUMMARY Women's bargaining power is generally analyzed only with individual level and household level variables. We add a third level, namely institutional bargaining power. We define this as bargaining power which one party freely derives from unequal social norms. In the bargaining literature there is a common paradoxical finding, namely that more access to and control over individual resources sometimes decreases rather than increases women‟s bargaining outcomes. With household...

  13. Explosive power of lower limbs in rhythmic gymnastics athletes in different competitive levels

    Amanda Batista SANTOS

    2016-03-01

    Full Text Available Abstract The explosive power in Rhythmic Gymnastics shows itself in the great majority of movements and elements performed by the gymnasts, particularly in the jumps, which are essential corporal movements in this sport. The training directed to the development of jumping capacity presents a large quantity of exercises which aim to improve muscular power in the lower limbs and therefore the impulsion capacity. The vertical impulsion is an important measure used to calculate the explosive power of the lower limbs and is directly connected to the success that the gymnast will be able to achieve. Therefore, the aim of this study is to evaluate the height of two jumps in the RG (stag jump and Cossack jump in contact mat Ergojump, which calculates the jump height in connection with the flight timing, executed by national level junior gymnasts and to compare them to the results of the Junior National Team - in total 30 junior gymnasts with 13.73 ± 0.17 years old. Furthermore, to compare the levels of explosive power of preferred lower limb (PLL and non-preferred lower limb (NPLL of all gymnasts in the study, in order to verify eventual functional asymmetries. For the statistical analysis we used Parametric Tests (t Test and Nonparametric (Mann-Whitney Test and Wilcoxon Test. The gymnasts of the National Team achieved superior marks in 33.3% of the tests and 83.3% of the gymnasts of our sample did not present explosive power asymmetries. We conclude that the gymnasts of the National Team did not show the expected superiority in the tests, and the most of gymnasts presented a harmonious development of explosive power for both lower limbs, since they did not show functional asymmetries.

  14. Power optimization of digital baseband WCDMA receiver components on algorithmic and architectural level

    M. Schämann

    2008-05-01

    Full Text Available High data rates combined with high mobility represent a challenge for the design of cellular devices. Advanced algorithms are required which result in higher complexity, more chip area and increased power consumption. However, this contrasts to the limited power supply of mobile devices.

    This presentation discusses the application of an HSDPA receiver which has been optimized regarding power consumption with the focus on the algorithmic and architectural level. On algorithmic level the Rake combiner, Prefilter-Rake equalizer and MMSE equalizer are compared regarding their BER performance. Both equalizer approaches provide a significant increase of performance for high data rates compared to the Rake combiner which is commonly used for lower data rates. For both equalizer approaches several adaptive algorithms are available which differ in complexity and convergence properties. To identify the algorithm which achieves the required performance with the lowest power consumption the algorithms have been investigated using SystemC models regarding their performance and arithmetic complexity. Additionally, for the Prefilter Rake equalizer the power estimations of a modified Griffith (LMS and a Levinson (RLS algorithm have been compared with the tool ORINOCO supplied by ChipVision. The accuracy of this tool has been verified with a scalable architecture of the UMTS channel estimation described both in SystemC and VHDL targeting a 130 nm CMOS standard cell library.

    An architecture combining all three approaches combined with an adaptive control unit is presented. The control unit monitors the current condition of the propagation channel and adjusts parameters for the receiver like filter size and oversampling ratio to minimize the power consumption while maintaining the required performance. The optimization strategies result in a reduction of the number of arithmetic operations up to 70% for single components which leads to an

  15. Habit, custom, and power: a multi-level theory of population health.

    Zimmerman, Frederick J

    2013-03-01

    In multi-level theory, individual behavior flows from cognitive habits, either directly through social referencing, rules of thumb, or automatic behaviors; or indirectly through the shaping of rationality itself by framing or heuristics. Although behavior does not arise from individually rational optimization, it generally appears to be rational, because the cognitive habits that guide behavior evolve toward optimality. However, power imbalances shaped by particular social, political, and economic structures can distort this evolution, leading to individual behavior that fails to maximize individual or social well-being. Replacing the dominant rational-choice paradigm with a multi-level theoretical paradigm involving habit, custom, and power will enable public health to engage in rigorous new areas of research. PMID:23415591

  16. Application of PSA to Assess the Safety Level of Nuclear Power Plants

    This paper reviews the application of PSA in German nuclear power plant regulation. From a fundamental point of view, it has to be mentioned that as stipulated in the corresponding requirements, regulatory decision making in Germany is primarily based on deterministic analyses and evaluations. Therefore, PSA is not used as a stand alone but as a supplementary basis. In this context PSA has developed a valuable tool with continuously growing importance. Level 1+ PSAs are now elaborated for all German nuclear power plants in operation, most of them are already reviewed by the competent supervisory authority and its experts. Current research activities on the federal level primarily concentrate on the further development of the methodology in the areas human factor, common cause failures, accident management measures and reduction of uncertainties in methods and data. (author)

  17. Availability analysis of nuclear power system with performance degradation and multi-level support capacity

    The availability analysis which combines universal generating function (UGF) with Markov state transition theory was proposed to nuclear power system with performance degradation and multi-level support capacity. The system logical model and performance state combination model were constructed by UGF. Furthermore, the computational expression for component state probability based on Markov method was constructed considering performance degradation and multi-level support capacity. And then the model was embedded into the logic model and performance state combination model by UGF. This combined model was used in availability analysis of an actual example with different performance demands, and the influence of maintenance condition to system availability was also analyzed. The results show that this method captures the operational and maintenance characteristics. The obtained results can provide guidance to nuclear power system operation, management, maintenance decision-making and support condition analysis. (authors)

  18. Processing of low-level and intermediate-level radioactive wastes from the nuclear power plant Muehleberg at Mol

    Between October 1986 and April 1987 two contracts were concluded between the nuclear power plant Muehleberg and the German firm Transnuklear GmbH for the processing of low-level and intermediate-level radioactive wastes from Muehleberg in the incineration facility at Mol in Belgium. In the contracts, transport of the wastes to Mol and back was included. According to the contracts the maximum admissible surface dose rate of the containers enclosing the wastes was 3000 mR/h. The actual maximum value of the surface dose rate was 1800 mR/h. On January 8, 1988, Swiss press published a statement to the effect that those wastes having a surface dose rate of more than 200 mR/h cannot be processed at Mol and must be transported back to Switzerland. Three representatives of Muehleberg visited Mol to discuss the conflicting information. The result of their inquiries was that the processing and transport of foreign wastes at Mol are currently suspended due to the irregularities associated with Transnuklear. Neither the safety nor the operation of the Muehleberg facility are jeopardized through the incident

  19. A Transformer-less Partial Power Boost Converter for PV Applications Using a Three-Level Switching Cell

    Agamy, Mohammed; Harfman-Todorovic, Maja; Elasser, Ahmed; Essakiappan, Somasundaram

    2013-03-01

    Photovoltaic architectures with distributed power electronics provide many advantages in terms of energy yield as well as system level optimization. As the power level of the solar farm increases it becomes more beneficial to increase the dc collection network voltage, which requires the use of power devices with higher voltage ratings, and thus making the design of efficient, low cost, distributed power converters more challenging. In this paper a simple partial power converter topology is proposed. The topology is implemented using a three-level switching cell, which allows the use of semiconductor devices with lower voltage rating; thus improving design and performance and reducing converter cost. This makes the converters suitable for use for medium to high power applications where dc-link voltages of 600V~1kV may be needed without the need for high voltage devices. Converter operation and experimental results are presented for two partial power circuit variants using three-level switching cells.

  20. Computational and experimental research of internal combustion engine with spark ignition and quality power level control

    О. П. Домбровский; Р. Ф. Зиннатуллин; Е. Г. Стругова

    2013-01-01

    The article presents the methodology of injection and combustion processes simulation in the internal combustion engine with unified working process. The results of computational study of injection and combustion processes in the combustion chamber of experimental two-stroke engine are presented. The possibility of full-range quality power level control and full fuel-burning is experimentally and computationally shown on two-stroke gasoline engine, the results of study are presented. Reducing...

  1. POPCYCLE: a computer code for calculating nuclear and fossil plant levelized life-cycle power costs

    POPCYCLE, a computer code designed to calculate levelized life-cycle power costs for nuclear and fossil electrical generating plants is described. Included are (1) derivations of the equations and a discussion of the methodology used by POPCYCLE, (2) a description of the input required by the code, (3) a listing of the input for a sample case, and (4) the output for a sample case

  2. Biographical learning in top-level coaching - personal styles and the power of practical sense

    Christensen, Mette Krogh

    : Biographical learning in top-level coaching - personal styles and the power of practical sense. There is a growing body of studies in sports coaching cultures, comprising research focusing on the individual learning processes and life histories of top-level coaches. Even if top-level sport has become...... increasingly professionalized, the role of the top-level coach and the developmental pathways of the coaches differ widely in both areas of experience and amount of experience. In this paper I draw on theories on biographical learning, idiosyncratic learning and development of coaching expertise. This paper...... aspects of coaching expertise: 1) the coaches’ descriptions of their development of expertise as a “personal journey” and a matter of unique pathways, and 2) the coaches’ use of social constructed practical sense in their daily work, particularly in identification and assessment of skillfulness and talent...

  3. A Polymer Optical Fiber Fuel Level Sensor: Application to Paramotoring and Powered Paragliding

    David Sánchez Montero

    2012-05-01

    Full Text Available A low-cost intensity-based polymer optical fiber (POF sensor for fuel level measurements in paramotoring and powered paragliding is presented, exploiting the advantages of the optical fiber sensing technology. Experimental results demonstrate that the best option can be performed by stripping the fiber at the desired discrete points to measure the fuel level as well as with a gauge-shape fiber bending. The prototype has a good linearity, better than 4% full scale (F.S., and sensitivity around 0.5 V per bend are obtained. Hysteresis due to residual fluid at the sensing points is found to be less than 9% F.S.

  4. Modelling and measurement of the absolute level of power radiated by antenna integrated THz UTC photodiodes.

    Natrella, Michele; Liu, Chin-Pang; Graham, Chris; van Dijk, Frederic; Liu, Huiyun; Renaud, Cyril C; Seeds, Alwyn J

    2016-05-30

    We determine the output impedance of uni-travelling carrier (UTC) photodiodes at frequencies up to 400 GHz by performing, for the first time, 3D full-wave modelling of detailed UTC photodiode structures. In addition, we demonstrate the importance of the UTC impedance evaluation, by using it in the prediction of the absolute power radiated by an antenna integrated UTC, over a broad frequency range and confirming the predictions by experimental measurements up to 185 GHz. This is done by means of 3D full-wave modelling and is only possible since the source (UTC) to antenna impedance match is properly taken into account. We also show that, when the UTC-to-antenna coupling efficiency is modelled using the classical junction-capacitance/series-resistance concept, calculated and measured levels of absolute radiated power are in substantial disagreement, and the maximum radiated power is overestimated by a factor of almost 7 dB. The ability to calculate the absolute emitted power correctly enables the radiated power to be maximised through optimisation of the UTC-to-antenna impedance match. PMID:27410104

  5. Quantitative Model and Metrics of Electrical Grids’ Resilience Evaluated at a Power Distribution Level

    Alexis Kwasinski

    2016-02-01

    Full Text Available This paper presents a framework to systematically measure and assess power grids’ resilience with a focus on performance as perceived by customers at the power distribution level. The proposed framework considers an analogous measure of availability as a basic metric for resilience and defines other key resilience-related concepts and metrics, such as resistance and brittleness. This framework also provides a measurement for the degree of functional dependency of loads on power grids and demonstrates how the concepts of resilience and dependency are inherently related. It also discusses the implications of considering human-centered processes as fundamental constituting components of infrastructure systems. Thanks to its quantitative nature, the proposed resilience framework enables the creation of tools to evaluate power grids’ performance as a lifeline and to assess the effects of plans for optimal electrical power infrastructure deployment and operation. The discussion is supported by practical examples and empirical records from field damage assessments conducted after recent notable natural disasters.

  6. Nonlinear Adaptive Dynamic Output-Feedback Power-Level Control of Nuclear Heating Reactors

    Zhe Dong

    2013-01-01

    Full Text Available Due to the high safety performance of small nuclear reactors, there is a promising future for small reactors. Nuclear heating reactor (NHR is a small reactor that has many advanced safety features such as the integrated arrangement, natural circulation at any power levels, self-pressurization, hydraulic control rod driving, and passive residual heating removing and can be applied to the fields of district heating, seawater desalination, and electricity production. Since the NHR dynamics has strong nonlinearity and uncertainty, it is meaningful to develop the nonlinear adaptive power-level control technique. From the idea of physically based control design method, a novel nonlinear adaptive power-level control is given for the NHR in this paper. It is theoretically proved that this newly built controller does not only provide globally asymptotic closed-loop stability but is also adaptive to the system uncertainty. Numerical simulation results show the feasibility of this controller and the relationship between the performance and controller parameters.

  7. Minimizing the Levelized Cost of Energy in Single-Phase Photovoltaic Systems with an Absolute Active Power Control

    Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya;

    2016-01-01

    Countries with considerable PhotoVoltaic (PV) installations are facing a challenge of overloading their power grid during peak-power production hours if the power infrastructure remains the same. To address this, regulations have been imposed on PV systems, where more active power control should...... be flexibly performed. As an advanced control strategy, the Absolute Active Power Control (AAPC) can effectively solve the overloading issues by limiting the maximum possible PV power to a certain level (i.e., the power limitation), and also benefit the inverter reliability due to the reduction in the thermal...... loading of the power devices. However, its feasibility is challenged by the associated energy losses. An increase of the inverter lifetime and a reduction of the energy yield can alter the cost of energy, demanding an optimization of the power limitation. Therefore, aiming at minimizing the Levelized Cost...

  8. A new high-voltage level-shifting circuit for half-bridge power ICs

    In order to reduce the chip area and improve the reliability of HVICs, a new high-voltage level-shifting circuit with an integrated low-voltage power supply, two PMOS active resistors and a current mirror is proposed. The integrated low-voltage power supply not only provides energy for the level-shifting circuit and the logic circuit, but also provides voltage signals for the gates and sources of the PMOS active resistors to ensure that they are normally-on. The normally-on PMOS transistors do not, therefore, need to be fabricated in the depletion process. The current mirror ensures that the level-shifting circuit has a constant current, which can reduce the process error of the high-voltage devices of the circuit. Moreover, an improved RS trigger is also proposed to improve the reliability of the circuit. The proposed level-shifting circuit is analyzed and confirmed by simulation with MEDICI, and the simulation results show that the function is achieved well. (semiconductor integrated circuits)

  9. Fault detection and diagnosis of the deaerator level control system in nuclear power plants

    Kim, Kyung Youn; Lee, Yoon Joon [Cheju National Univ., Cheju (Korea, Republic of)

    2004-02-01

    The deaerator of a power plant is one of feedwater heaters in the secondary system, and it is located above the feedwater pumps. The feedwater pumps take the water from the deaerator storage tank, and the Net Positive Suction Head(NPSH) should always be ensured. To secure the sufficient NPSH, the deaerator tank is equipped with the level control system of which level sensors are critical items. And it is necessary to ascertain the sensor state on-line. For this, a model-based Fault Detection and Diagnosis(FDD) is introduced in this study. The dynamic control model is formulated from the relation of input-output flow rates and liquid-level of the deaerator storage tank. Then an adaptive state estimator is designed for the fault detection and diagnosis of sensors. The performance and effectiveness of the proposed FDD scheme are evaluated by applying the operation data of Yonggwang Units 3 and 4.

  10. Global Sea Level Stabilization-Sand Dune Fixation: A Solar-powered Sahara Seawater Textile Pipeline

    Badescu, Viorel; Bolonkin, Alexander A

    2007-01-01

    Could anthropogenic saturation with pumped seawater of the porous ground of active sand dune fields in major deserts (e.g., the westernmost Sahara) cause a beneficial reduction of global sea level? Seawater extraction from the ocean, and its deposition on deserted sand dune fields in Mauritania and elsewhere via a Solar-powered Seawater Textile Pipeline (SSTP) can thwart the postulated future global sea level. Thus, Macro-engineering offers an additional cure for anticipated coastal change, driven by global sea level rise, that could supplement, or substitute for (1) stabilizing the shoreline with costly defensive public works (armoring macroprojects) and (2) permanent retreat from the existing shoreline (real and capital property abandonment). We propose Macro-engineering use tactical technologies that sculpt and vegetate barren near-coast sand dune fields with seawater, seawater that would otherwise, as commonly postulated, enlarge Earth seascape area! Our Macro-engineering speculation blends eremology with...

  11. Consideration of safety level when a country selects nuclear power plant technology

    Tu, Nguyen Hoang [KAIST, Daejeon (Korea, Republic of); Choi, Young Sung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2012-10-15

    Energy is essential for national development. Nearly every aspect of development requires reliable access to modern energy resources. States may have different reasons for considering starting a nuclear power project to achieve their national energy needs, such as lack of available indigenous energy resources, the desire to reduce dependence upon imported energy, the need to increase the diversity of energy resources and/or mitigation of carbon emission increases. The start of a nuclear power plant project involves several complex and interrelated activities with long duration, typically lasting about 10 to 15 years. The main focus, however, is to ensure that the project is implemented successfully from the views of commercial benefits and, more importantly to ensure the acceptability of the public over long term period, safety level achieved or to be achieved by the project. This paper is aimed at providing consideration on the practical selection of a first nuclear power project in a country to ensure that the project will have enough safety level.

  12. Alternative LEU designs for the FRM-II with power levels of 20-22 MW

    Alternative LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne National Laboratory (ANL) at the request of an FRM-II Expert Commission established by the German Federal Government in January 1999 to evaluate the options for using LEU fuel instead of HEU fuel in cores with power levels of 20 MW. The ANL designs would use the same building structure and maintain as many of the HEU design features as practical. The range of potential LEU fuels was expanded from previous studies to include already-tested silicide fuels with uranium densities up to 6.7 g/cm3 and the new U-Mo fuels that show excellent prospects for achieving uranium densities in the 8-9 g/cm3 range. For each of the LEU cores, the design parameters were chosen to match the 50 day cycle length of the HEU core and to maximize the thermal neutron flux in the Cold Neutron Source and beam tubes. The studies concluded that an LEU core with a diameter of about 29 cm instead of 24 cm in HEU design and operating at a power level of 20 MW would have thermal neutron fluxes that are 0.85-0.86 times that of the HEU design in the Cold Neutron Source. With a potential future upgrade to a power of 22 MW, this ratio would increase to 0.92-0.93. (author)

  13. Alterative LEU designs for the FRM-II with power levels of 20-22 MW

    Alternative LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne National Laboratory (ANL) at the request of an FRM-II Expert Group established by the German Federal Government in January 1999 to evaluate the options for using LEU fuel instead of HEU fuel in cores with power levels of 20 MW. The ANL designs would use the same building structure and maintain as many of the HEU design features as practical. The range of potential LEU fuels was expanded from previous studies to include already-tested silicide fuels with uranium densities up to 6.7 g/cm3 and the new U-Mo fuels that show excellent prospects for achieving uranium densities in the 8-9 g/cm3 range. For each of the LEU cores; the design parameters were chosen to match the 50 day cycle length of the HEU core and to maximize the thermal neutron flux in the Cold Neutron Source and beam tubes. The studies concluded that an LEU core with a diameter of about 29 cm instead of 24 cm in HEU design and operating at a power level of 20 MW would have thermal neutron fluxes that are 0.85 times that of the HEU design at the center of the Cold Neutron Source. With a potential future upgrade to a power of 22 MW, this ratio would increase to 0.93

  14. Reactivity response analyses for the design of automatic power level control system of upgraded JRR-3

    This reports the analytical results of transient responses to inserted reactivities for the design of the automatic power level control system of upgraded JRR-3. The parameters of reactor kinetics, prompt neutron lifetime and effective delayed neutron fraction, have been calculated by neutron diffusion theory and perturbation theory using the SRAC code system. Burn-up processes, reactor temperatures and configurations of control rods have been taken into account in the calculation. The transient responses of the automatic control system to a step reactivity change of +- 7.3 * 10-4 Δk/k and a ramp reactivity change of +- 3.0 * 10-4 Δk/k/sec have been obtained by analogue computer. As the result, when a regulator rod is used for the automatic power control, its driving velocity has been designed to be 30 cm/min. It has been confirmed that this designed control system can quickly respond to the reactivity perturbations and maintain a desired power level. (author)

  15. Assessment of two-level heat pump installations’ power efficiency for heat supply systems

    Аlla Е. Denysova

    2015-06-01

    Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources has essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two-level heat pump installation operating as heat source the Odessa city ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of geothermal heat supply. Calculated are the values of electric energy consumption N by the compressors’ drive, and the heat supply system transformation coefficient µ for a source of geothermal heat from ground waters of Odessa city allowing to estimate efficiency of two-level heat pump installations.

  16. A detector for monitoring the onset of cavitation during therapy-level measurements of ultrasonic power

    Hodnett, M.; Zeqiri, B.

    2004-01-01

    Acoustic cavitation occurring in the water path between a transducer and the target of a radiation force balance can provide a significant source of error during measurements of ultrasonic power. These problems can be particularly acute at physiotherapy levels (>1 W), and low frequencies (leq 1 MHz). The cavitating bubbles can absorb and scatter incident ultrasound, leading to an underestimate in the measured power. For these reasons, International Specification standards demand the use of degassed water. This imposes requirements that may actually be difficult to meet, for example, in the case of hospitals. Also, initially degassed water will rapidly re-gas, increasing the likelihood of cavitation occurring. For these reasons, NPL has developed a device that monitors acoustic emissions generated by bubble activity, for detecting the onset of cavitation during power measurements. A commercially available needle hydrophone is used to detect these emissions. The acoustic signals are then monitored using a Cavitation Detector (CD) unit, comprising an analogue electrical filter that may be tuned to detect frequency components generated by cavitating bubbles, and which provides an indication of when the measured level exceeds a pre-defined threshold. This paper describes studies to establish a suitable detection scheme, the principles of operation of the CD unit, and the performance tests carried out with a range of propagation media.

  17. A detector for monitoring the onset of cavitation during therapy-level measurements of ultrasonic power

    Hodnett, M; Zeqiri, B [National Physical Laboratory, Queens Road, Teddington, Middlesex, TW11 0LW (United Kingdom)

    2004-01-01

    Acoustic cavitation occurring in the water path between a transducer and the target of a radiation force balance can provide a significant source of error during measurements of ultrasonic power. These problems can be particularly acute at physiotherapy levels (>1 W), and low frequencies ({<=} 1 MHz). The cavitating bubbles can absorb and scatter incident ultrasound, leading to an underestimate in the measured power. For these reasons, International Specification standards demand the use of degassed water. This imposes requirements that may actually be difficult to meet, for example, in the case of hospitals. Also, initially degassed water will rapidly re-gas, increasing the likelihood of cavitation occurring. For these reasons, NPL has developed a device that monitors acoustic emissions generated by bubble activity, for detecting the onset of cavitation during power measurements. A commercially available needle hydrophone is used to detect these emissions. The acoustic signals are then monitored using a Cavitation Detector (CD) unit, comprising an analogue electrical filter that may be tuned to detect frequency components generated by cavitating bubbles, and which provides an indication of when the measured level exceeds a pre-defined threshold. This paper describes studies to establish a suitable detection scheme, the principles of operation of the CD unit, and the performance tests carried out with a range of propagation media.

  18. Alterative LEU designs for the FRM-II with power levels of 20-22 MW.

    Hanan, N. A.; Smith, R. S.; Matos, J. E.

    1999-09-27

    Alternative LEU Designs for the FRM-II have been developed by the RERTR Program at Argonne National Laboratory (ANL) at the request of an FRM-II Expert Group established by the German Federal Government in January 1999 to evaluate the options for using LEU fuel instead of HEU fuel in cores with power levels of 20 MW. The ANL designs would use the same building structure and maintain as many of the HEU design features as practical. The range of potential LEU fuels was expanded from previous studies to include already-tested silicide fuels with uranium densities up to 6.7 g/cm{sup 3} and the new U-Mo fuels that show excellent prospects for achieving uranium densities in the 8-9 g/cm{sup 3} range. For each of the LEU cores; the design parameters were chosen to match the 50 day cycle length of the HEU core and to maximize the thermal neutron flux in the Cold Neutron Source and beam tubes. The studies concluded that an LEU core with a diameter of about 29 cm instead of 24 cm in HEU design and operating at a power level of 20 MW would have thermal neutron fluxes that are 0.85 times that of the HEU design at the center of the Cold Neutron Source. With a potential future upgrade to a power of 22 MW, this ratio would increase to 0.93.

  19. Power infrastructure quality and manufacturing productivity in Africa: A firm level analysis

    This study sought to examine the impact of the quality of power infrastructure on productivity in African manufacturing firms using data from the World Bank enterprise surveys. We measured power infrastructure quality using the number of hours per day without electricity and the percentage of output lost due to outages and found these indicators to be negative and significant determinants of productivity. These variables seem to be significant determinants in Uganda, Tanzania and Zambia as well as in the food and agriculture sector. To improve economic growth and encourage employment creation, governments in Africa have to come up with measures to improve the reliability of electricity infrastructure. - Highlights: • Power infrastructure quality indicators are found to have a negative and significant effect. • The power quality indicators have varied effects both at country and sector level. • Owning a generator minimises the negative impact of outages in Uganda, Tanzania and Mauritius. • Other controls like labour, capital, foreign ownership etc. have a positive and significant effect. • The firm age variable is insignificant suggesting that accumulated knowledge does not matter

  20. Power Quality Improvement at Distribution Level for Grid Connected Renewable Energy Sources

    S. Syed Ahmed

    2014-09-01

    Full Text Available The non-linear load current harmonics may result in voltage harmonics and can create a serious PQ problem in the power system network. Active power filters (APF are extensively used to compensate the load current harmonics and load unbalance at distribution level. This results in an additional hardware cost. However, in this project it has incorporated the features of APF in the conventional inverter interfacing renewable with the grid, without any additional hardware cost. Here, the main idea is the maximum utilization of inverter rating which is most of the time underutilized due to intermittent nature of RES. The grid-interfacing inverter can effectively be utilized to perform the four important functions they are to transfer active power harvested from the renewable resources (wind, solar, etc., load reactive power demand support, current harmonics compensation at PCC and current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. The PQ constraints at the PCC can therefore be strictly maintained within the utility standards without additional hardware cost. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. This new control concept is demonstrated with extensive MATLAB/Simulink simulation studies

  1. Minimizing the Levelized Cost of Energy in Single-Phase Photovoltaic Systems with an Absolute Active Power Control

    Yang, Yongheng; Koutroulis, Eftichios; Sangwongwanich, Ariya;

    2015-01-01

    Several countries with considerable PhotoVoltaic (PV) installations are facing a challenge of overloading the power infrastructure during peak-power production hours. Regulations have been imposed on the PV systems, where more active power control should be flexibly performed. As an advanced...... control strategy, the Absolute Active Power Control (AAPC) can effectively solve the overloading issues by limiting the maximum possible PV power to a certain level (i.e., the power limitation), and also benefit the inverter reliability. However, its feasibility is challenged by the energy loss....... An increase of the inverter lifetime and a reduction of the energy yield can alter the cost of energy, demanding an optimization of the power limitation. Therefore, aiming at minimizing the Levelized Cost of Energy (LCOE), the power limit is optimized for the AAPC strategy in this paper. The optimization...

  2. The tensor analyzing power Asub(yy) near s-wave levels

    In the neighborhood of an isolated resonance induced by s-wave particles, the component Asub(yy)(theta) of the tensor analyzing power is independent of the reaction angle theta. The constant value of Asub(yy)(theta) is a function of the level spin J and of the (l',s') configuration in the exit channel of the resonant amplitude. The use of this fact as a diagnostic tool in an analysis of the process is discussed and demonstrated with data available. It is also pointed out that efficient polarimeters can be constructed, which measure the quantity Asub(yy). (Auth.)

  3. Discussions on results of environmental background radiation level investigation for Tianwan Nuclear Power Plant

    The environmental background radiation level investigation surrounding Tianwan Nuclear Power Plant was conducted for 2 years by China Institute for Radiation Protection. The investigation results are all collected in this paper and discussions are made on some results, such as 90Sr and 3H contents in water bodies, 137Cs and 7Be contents in plant, 137Cs and 40K contents in animal and animal products, 137Cs contents in soil, plant and animal, as well as considerations in choosing indicating organism, etc. Main conclusions are presented as well. (author)

  4. Modeling of Busbars in High Power Neutral Point Clamped Three-Level Inverters

    YI Rung; ZHAO Zhengming; ZHONG Yulin

    2008-01-01

    The busbars in high power neutral point clamped three-level inverters are modeled using the Maxwell Q3D Extractor software, which is based on the partial element equivalent circuits method. The equivalent circuits of the busbars and devices model are simulated in the electric simulator PSIM to analyze the effects of the parasitic inductance on the switching characteristics of the integrated gate commutatedthyristor (IGCT) in different topology positions. The simulation results agree well with the measured imped-ance analyzer results and the IGCT test results, which proves the effectiveness of the modeling method for the large, complex busbars.

  5. Radioactivity level of the ambient environment of Anren bone-coal power station

    2002-01-01

    The radioactivity level of the ambient environment of Anren Bonc-coalPower Station (BCPS) was investigated systematically. The γ radiation dose ratelevel in the environment, the content of 238U and 226Ra in the ambient soil and thefarmland in the direction of downwind, the concentrations of 238U, 232Th, 226Ra, 40Kand 222Rn, as well as α potential energy in air, and the concentrations of natural Uand Th in effluent are all higher than the corresponding values of the reference site.The additional annual effective dose equivalent to the residents living in the housesmade of bone-coal cinder brick is 2.7mSv.

  6. Computational analysis of the curvature distribution and power losses of metal strip in tension levellers

    Tension levelling is employed in strip processing lines to minimise residual stresses resp. to improve the strip flatness by inducing small elasto-plastic deformations. To improve the design of such machines, precise calculation models are essential to reliably predict tension losses due to plastic dissipation, power requirements of the driven bridle rolls (located upstream and downstream), reaction forces on levelling rolls as well as strains and stresses in the strip. FEM (Finite Element Method) simulations of the tension levelling process (based on Updated Lagrangian concepts) yield high computational costs due to the necessity of very fine meshes as well as due to the severely non-linear characteristics of contact, material and geometry. In an evaluation process of hierarchical models (models with different modeling levels), the reliability of both 3D and 2D modelling concepts (based on continuum and structural elements) was proved by extensive analyses as well as consistency checks against measurement data from an industrial tension leveller. To exploit the potential of computational cost savings, a customised modelling approach based on the principle of virtual work has been elaborated, which yields a drastic reduction of degrees of freedom compared to simulations by utilising commercial FEM-packages.

  7. A new three-level current-source PWM inverter and its application for grid connected power conditioner

    This paper presents a novel topology of a three-level current-source PWM inverter totally driven by using single gate-drive power supply used for a grid connected inverter. The great feature of the proposed inverter circuit is that all of the power switches are connected on common-source or common-emitter configuration. Using this common-source current-source inverter (CS-CSI) the number of gate-drive power supply can dramatically be reduced into only a single power source without using bootstrap technique or many isolated power supplies. Operation of the proposed new inverter was tested by using computer simulation and experimentally. The simulation and experimental results proved that the inverter works properly generate a three-level output current waveform and inject a sinusoidal current into power grid with unity power factor operation. During grid connected operation, almost all harmonic orders are suppressed by using an additional harmonic suppression technique.

  8. Potential for de-regulated disposal of very low level wastes from nuclear power plants

    The purpose of the study discussed in this paper was to review the characteristics of low level waste streams generated in commercial nuclear power facilities to determine which may be suitable for disposal by methods other than transfer to a facility licensed by the Nuclear Regulatory Commission (NRC) and to evaluate the benefits, risks, and costs of exempting such very low level wastes (VLW) from the disposal requirements of 10 CFR Part 61. Of course, wastes that no longer require regulation of their radiological properties are still subject to the regulatory controls - federal, state, or local - that affect non-radioactive wastes of similar chemical and physical properties and similar origins. This study addressed radiological aspects only, and assumed, in its evaluations, that the wastes can and will be disposed of in accordance with all other applicable requirements. 4 references, 1 figure, 6 tables

  9. Design of LCL-Filter Based Three-level Active Power Filter

    Shilan Chen

    2013-07-01

    Full Text Available This paper proposes an improved design of LCL-Filters for Three-Level Shunt Active power filters (APF. Available design principles are presented to achieve high compensation bandwidth and low switching frequency current. Then, affecitons of different parameters are taken into consideration of constraints on LCL-Filter design with detail analysis of ripple current. A simple and practical design procedure of LCL-Filter for Three-Level APF is subsequently proposed. The first step is to choose the resonant frequency of LCL-Filter according to the highest order harmonic needed to be compensated. Then it is aim to optimize the parameters of the LCL-Filter based on the design principles and constraints. The simulation results verify the effectiveness of the proposed method.

  10. Trending of low level events and near misses to enhance safety performance in nuclear power plants

    The IAEA Safety Fundamentals publication, Safety of Nuclear Installations, Safety Series No. 110, states the need for operating organizations to establish a programme for the collection and analysis of operating experience in nuclear power plants. Such a programme ensures that operating experience is analysed, events important to safety are reviewed in depth, and lessons learned are disseminated to the staff of the organization and to relevant national and international organizations. As a result of the effort to enhance safety in operating organizations, incidents are progressively decreasing in number and significance. This means that in accordance with international reporting requirements the amount of collected data becomes less sufficient to draw meaningful statistical conclusions. This is where the collection and trend analysis of low level events and near misses can prove to be very useful. These trends can show which of the safety barriers are weak or failing more frequently. Evaluation and trending of low level events and near misses will help to prevent major incidents because latent weaknesses have been identified and corrective actions taken to prevent recurrence. This leads to improved safety and production. Low level events and near misses, which may reach several thousand per reactor operating year, need to be treated by the organizations as learning opportunities. A system for capturing these low level events and near misses truly needs to be an organization-wide system in which all levels of the organization, including contractors, participate. It is desirable that the overall operational experience feedback (OEF) process should integrate the lessons learned and the associated data from significant events with those of lower level events and near misses. To be able to effectively implement a process dealing with low level events and near misses, it is necessary that the organization have a well established OEF process for significant events

  11. Comparison of p53 levels in lymphocytes and in blood plasma of nuclear power plant workers

    p53 levels were assessed in lymphocytes and in blood plasma of workers from two Czech nuclear power plants (NPP): 114 subjects working in Temelin and 108 subjects working in Dukovany. Ionizing radiation (IR) exposure data were available for 64 and 59 subjects working in the monitored zones from the NPP in Temelin and Dukovany, respectively. The short-term doses of IR for these subjects were 0.01 and 0.12 mSv, and the long-term doses were 0.46 and 5.68 mSv, in the Temelin and Dukovany NPP, respectively. As a control group, 46 subjects living in Ceske Budejovice, a city nearby the Temelin NPP, were analyzed. The concentration of p53 in lymphocytes was significantly higher in workers from the monitored zone in the Dukovany NPP (median value 6.4 pg/μg protein, P < 0.001) than in workers from the Temelin NPP (3.2 pg/μg) as well as in the control group (3.5 pg/μg). In contrast, plasma levels of p53 were comparable in the control group (median value 116 pg/ml plasma) and workers from the monitored zone of Dukovany NPP (102 pg/ml), but lower in workers from Temelin NPP (5 pg/ml). Other factors affecting p53 levels were studied. Smoking resulted in increased p53 lymphocyte levels. The effect of polymorphisms in metabolic and DNA repair genes on p53 levels was analyzed. The correlation was found between p53 levels in lymphocytes and p53 codon 72 polymorphism in subjects working in NPPs, but not in the control group. The results of measurement p53 levels in lymphocytes suggest that this biomarker could reflect the short-term as well as long-term effects of low doses IR. Its impact on human health should be further explored

  12. Evaluating the level and nature of sustainable development for a geothermal power plant

    The paper provides for an evaluation of the potential level and nature of sustainable development of the Sabalan geothermal power plant in NW Iran, to be operational in 2011. The paper achieves this by applying a mathematical model of sustainable development developed by the author (re: Phillips), in respect to the Environmental Impact Assessment (EIA) conducted by Yousefi et al. using the Rapid Impact Assessment Matrix (RIAM) methodology (re: Pastakia; Pastakia and Jensen). Using a model application methodology developed for the RIAM, the results indicated that the nature of sustainable development for Sabalan was considered to be very weak (S = 0.063). This was due to the imbalance between negative environmental impacts and positive socio-economic impacts deriving from the project. Further, when placed into context with a similar set of results obtained from the EIA of the Tuzla geothermal power plant by Baba also using the RIAM methodology, then the similarities between the results obtained raises some legimate questions as to the sustainable development credentials of geothermal power production. (author)

  13. Allowable Residual Contamination Levels in soil for decommissioning the Shippingport Atomic Power Station site

    As part of decommissioning the Shippingport Atomic Power Station, a fundamental concern is the determination of Allowable Residual Contamination Levels (ARCL) for radionuclides in the soil at the site. The ARCL method described in this report is based on a scenario/exposure-pathway analysis and compliance with an annual dose limit for unrestricted use of the land after decommissioning. In addition to naturally occurring radionuclides and fallout from weapons testing, soil contamination could potentially come from five other sources. These include operation of the Shippingport Station as a pressurized water reactor, operations of the Shippingport Station as a light-water breeder, operation of the nearby Beaver Valley reactors, releases during decommissioning, and operation of other nearby industries, including the Bruce-Mansfield coal-fired power plants. ARCL values are presented for 29 individual radionculides and a worksheet is provided so that ARCL values can be determined for any mixture of the individual radionuclides for any annual dose limit selected. In addition, a worksheet is provided for calculating present time soil concentration value that will decay to the ARCL values after any selected period of time, such as would occur during a period of restricted access. The ARCL results are presented for both unconfined (surface) and confined (subsurface) soil contamination. The ARCL method and results described in this report provide a flexible means of determining unrestricted-use site release conditions after decommissioning the Shippingport Atomic Power Station

  14. What day-ahead reserves are needed in electric grids with high levels of wind power?

    Mauch, Brandon; Apt, Jay; Carvalho, Pedro M. S.; Jaramillo, Paulina

    2013-09-01

    Day-ahead load and wind power forecasts provide useful information for operational decision making, but they are imperfect and forecast errors must be offset with operational reserves and balancing of (real time) energy. Procurement of these reserves is of great operational and financial importance in integrating large-scale wind power. We present a probabilistic method to determine net load forecast uncertainty for day-ahead wind and load forecasts. Our analysis uses data from two different electric grids in the US with similar levels of installed wind capacity but with large differences in wind and load forecast accuracy, due to geographic characteristics. We demonstrate that the day-ahead capacity requirements can be computed based on forecasts of wind and load. For 95% day-ahead reliability, this required capacity ranges from 2100 to 5700 MW for ERCOT, and 1900 to 4500 MW for MISO (with 10 GW of installed wind capacity), depending on the wind and load forecast values. We also show that for each MW of additional wind power capacity for ERCOT, 0.16-0.30 MW of dispatchable capacity will be used to compensate for wind uncertainty based on day-ahead forecasts. For MISO (with its more accurate forecasts), the requirement is 0.07-0.13 MW of dispatchable capacity for each MW of additional wind capacity.

  15. What day-ahead reserves are needed in electric grids with high levels of wind power?

    Day-ahead load and wind power forecasts provide useful information for operational decision making, but they are imperfect and forecast errors must be offset with operational reserves and balancing of (real time) energy. Procurement of these reserves is of great operational and financial importance in integrating large-scale wind power. We present a probabilistic method to determine net load forecast uncertainty for day-ahead wind and load forecasts. Our analysis uses data from two different electric grids in the US with similar levels of installed wind capacity but with large differences in wind and load forecast accuracy, due to geographic characteristics. We demonstrate that the day-ahead capacity requirements can be computed based on forecasts of wind and load. For 95% day-ahead reliability, this required capacity ranges from 2100 to 5700 MW for ERCOT, and 1900 to 4500 MW for MISO (with 10 GW of installed wind capacity), depending on the wind and load forecast values. We also show that for each MW of additional wind power capacity for ERCOT, 0.16–0.30 MW of dispatchable capacity will be used to compensate for wind uncertainty based on day-ahead forecasts. For MISO (with its more accurate forecasts), the requirement is 0.07–0.13 MW of dispatchable capacity for each MW of additional wind capacity. (letter)

  16. High Partial Discharge Levels in Nuclear Power Plant Turbo-Generator

    On-line measurement of partial discharge (PD) is commonly known method for assessment of armature winding condition. Since it can be carried out while the machine is in operation, it is considered by many to be the most realistic one. PD pulses are forwarded to measuring instrument using capacitive couplers connected to machine stator phase winding. Magnitude, polarity and phase angle relative to phase-to-ground voltage are measured for every pulse and further analysed by statistical approach. A number of problems with armature winding can be registered and diagnosed by PD method. The paper presents results of PD measurement and its analysis in case of large synchronous turbo-generator, 812 MVA, 21 kV, cosφ=0.85, 50 Hz, 1500 rpm, manufactured in 1979 and installed in nuclear power plant Krsko, Slovenia. The generator is cooled with hydrogen, with armature winding directly cooled by water. The turbine-generator set's rated power has been increased from original 660 MW twice: in 2000 up to 690 MW and in 2004 up to 730 MW. There have been no modifications on generator regarding the power increase. Paper presents results of PD measurements in NPP Krsko carried out by authors since 2001. Previously measured high PD levels have been verified and monitored after installation of on-line PD monitoring system in 2004. All other performed off-line measurements have not shown any signs of severe deterioration or other problem in generator stator winding insulation. Registered PDs were almost 8 times higher than 95% of typical PDs measured for similar turbo-generators, their magnitude varies with ratio 1:100, their phase distribution lies around 0 degrees and 180 degrees, (indicating that their cause is outside of slots and of mechanical origin), their main source migrates from phase to phase, they are cross-coupling to other phases (indicating that their origin lies in part of generator where all three phases are close) and their phase occurrence varies with constant active

  17. A stationary reference frame current control for a multi-level H-bridge power converter for universal and flexible power management in future electricity network

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, Pericle;

    2008-01-01

    converters for grid connection of renewable sources will be needed. These power converters must be able to provide intelligent power management as well as ancillary services. This paper assesses a control method based on the stationary reference frame with Proportional-Resonant current controllers for a...... multi-level cascaded H-bridges power converter used for grid applications. Harmonic content in the Point of Common Coupling, system response for bidirectional power flow, voltage and frequency excursions as well as voltage unbalances and asymmetries and low voltage ride-though capabilities are studied....

  18. Grid Connection of Wave Power Farm Using an N-Level Cascaded H-Bridge Multilevel Inverter

    Rickard Ekström

    2013-01-01

    Full Text Available An N-level cascaded H-bridge multilevel inverter is proposed for grid connection of large wave power farms. The point-absorber wave energy converters are individually rectified and used as isolated DC-sources. The variable power characteristics of the wave energy converters are discussed, and a method of mitigating this issue is demonstrated. The complete power control system is given in detail and has been experimentally verified for a single-phase setup of the 9-level inverter. Theoretical expressions of the power sharing between multilevel cells are derived and show good correspondence with the experimental results.

  19. Level 1 shutdown and low power operation of Mochovce NPP, Unit 1, Slovakia

    The paper presents general approach, used methods and form of documentation of the results that have been applied within the shutdown and low power PSA (SPSA) study for Mochovce NPP, Unit 1, Slovakia. The SPSA project was realized by VUJE Trnava Inc., Slovakia in 2001-2002 years. The Level 1 SPSA study for Mochovce NPP Unit 1 covers internal events as well as internal (fires, floods and heavy load drop) and external (aircraft crash, extreme meteorological conditions, seismic event and influence of surrounding industry) hazards. Mochovce NPP consists of two operating units equipped with VVER 440/V213 reactors safety upgraded before construction finishing and operation start. 87 safety measures based on VVER 440 operational experience and international mission insights were implemented to enhance its operational and nuclear safety. The SPSA relates to full power PSA (FPSA) as a continuation of the effort to create a harmonized level 1 PSA model for all operational modes of the plant with the goal to use it for further purposes as follows: Real Time Risk Monitor, Maintenance Optimization, Technical Specifications Optimization, Living PSA. (author)

  20. Microwave cytotoxicity: lack of in vitro evidence of nonthermal effects at high power levels

    A unique cylindrical microwave cavity chamber for the exposure of mammalian cells was designed and built. The cavity was used to determine whether or not microwaves (896 or 434-460 MHz) are capable of affecting cellular survival via nonthermal mechanisms other than those resulting from equivalent thermal exposures. Chinese hamster ovary (HA-1) cells or radiation-induced fibrosarcoma (RIF) mouse cells were grown directly on gold-plated copper disks to assure optimum heat dissipation and accurate thermal dosimetry. The temperature was controlled precisely (+/-0.1/sup o/C and was measured continuously during microwave exposures. Microwave power levels of 135 W/cm3 of absorbed power maintained for 30 min caused no discernible decrease in cellular survival of proliferating cells compared to that measured in appropriate heat controls over a temperature range of 12 to 46/sup o/C. In addition, RIF mouse cells were exposed similarly in Hanks' balanaced salt solution (HBSS). Again, no additional decrease in survival beyond that due to heating was observed for microwave exposure in full medium; however, a significant decrease in survival was noted when cells were treated in HBSS which was at pH 6.9-7.2. This phenomenon may have implications in tumors with significant portions of the population at low pH or with low nutrient concentrations. Since these absorbed power levels are at least two orders of magnitude greater than those that will be necessary to hear and maintain tumors at hyperthermic treatment temperatures for cancer therapy, these results suggest that cellular destruction in proliferating cells can be predicted by the heat effect and that any microwave-specific nonthermal effects encountered in vivo will likely be due to problems of thermal dosimetry of physiological factors related to this mode of heat distribution

  1. Evaluation of environmental tritium level in the area of Cernavoda Nuclear Power Plant

    This work is a continuation of the study entitled Evaluation of environmental tritium levels before and after start of a new tritium source for model verification' that commenced two years ago as part of an European research contract having as objective the 'Investigations and Modelling of the Dynamics of Environmental HT/HTO/OBT Levels Resulting from the Tritium Releases'. The aim of this study was to evaluate the environmental tritium level in pre-operational stage of Cernavoda Nuclear Power Plant and the dynamics of variation of tritium concentration in the first operational years of NPP, for determination of site-specific transfer parameters and model validation. Representative samples for Cernavoda area were analyzed; - air humidity; - water from Danube River, Danube-Black Sea Canal and lakes; - drinking, rain and snow water; - HTO concentration in soils at different depths; - tissue free water tritium in vegetal and animal foodstuffs relevant for human diets like cereals (wheat, maize, barley). vegetables (potatoes, tomato, cabbage, onion, bean), grapes and wine. The mean concentration of tritium obtained in 1996 for these types of measurements is presented. The values of tritium concentration in air, water, soil and plants are as low as for areas without contaminating sources. The operation in 1996 of the Cernavoda NPP did not modify the tritium environmental level. (authors)

  2. Design and Analysis of Multi Level D-STATCOM to Improve the Power Quality

    Dinesh. Badavath,; Mr. T. Subramanya Sastry

    2014-01-01

    In the last decade, the electrical power quality issue has been the main concern of the power companies. Power quality is defined as the index which both the delivery and consumption of electric power affect on the performance of electrical apparatus. From a customer point of view, a power quality problem can be defined as any problem is manifested on voltage, current, or frequency deviation that results in power failure. The power electronics progressive, especially in flexib...

  3. Application of Backstepping to the Virtual Flux Direct Power Control of Five-Level Three-Phase Shunt Active Power Filter

    Bouzidi Mansour

    2014-03-01

    Full Text Available This paper proposes a virtual flux direct power control-space vector modulation combined with backstepping control for three-phase five-level neutral point clamped shunt active power filter. The main goal of the proposed active filtering system is to eliminate the unwanted harmonics and compensate fundamental reactive power drawn from the nonlinear loads. In this study, the voltage-balancing control of four split dc capacitors of the five-level active filter is achieved using five-level space vector modulation with balancing strategy based on the effective use of the redundant switching states of the inverter voltage vectors. The obtained results showed that, the proposed multilevel shunt active power filter with backstepping control can produce a sinusoidal supply current with low harmonic distortion and in phase with the line voltage.

  4. Development Efforts Expanded in Ion Propulsion: Ion Thrusters Developed With Higher Power Levels

    Patterson, Michael J.; Rawlin, Vincent K.; Sovey, James S.

    2003-01-01

    The NASA Glenn Research Center was the major contributor of 2-kW-class ion thruster technology to the Deep Space 1 mission, which was successfully completed in early 2002. Recently, NASA s Office of Space Science awarded approximately $21 million to Glenn to develop higher power xenon ion propulsion systems for large flagship missions such as outer planet explorers and sample return missions. The project, referred to as NASA's Evolutionary Xenon Thruster (NEXT), is a logical follow-on to the ion propulsion system demonstrated on Deep Space 1. The propulsion system power level for NEXT is expected to be as high as 25 kW, incorporating multiple ion thrusters, each capable of being throttled over a 1- to 6-kW power range. To date, engineering model thrusters have been developed, and performance and plume diagnostics are now being documented. The project team-Glenn, the Jet Propulsion Laboratory, General Dynamics, Boeing Electron Dynamic Devices, the Applied Physics Laboratory, the University of Michigan, and Colorado State University-is in the process of developing hardware for a ground demonstration of the NEXT propulsion system, which comprises a xenon feed system, controllers, multiple thrusters, and power processors. The development program also will include life assessments by tests and analyses, single-string tests of ion thrusters and power systems, and finally, multistring thruster system tests in calendar year 2005. In addition, NASA's Office of Space Science selected Glenn to lead the development of a 25-kW xenon thruster to enable NASA to conduct future missions to the outer planets of Jupiter and beyond, under the High Power Electric Propulsion (HiPEP) program. The development of a 100-kW-class ion propulsion system and power conversion systems are critical components to enable future nuclear-electric propulsion systems. In fiscal year 2003, a team composed of Glenn, the Boeing Company, General Dynamics, the Applied Physics Laboratory, the Naval Research

  5. A Battery-less Grid Connected Photovoltaic Power generation using Five-Level Common-Emitter Current-Source Inverter

    Suroso Suroso

    2014-12-01

    Full Text Available Renewable power generation using photovoltaic is very interesting to be developed to deal with the problems of conventional energy sources and environmental issues. The photovoltaic power generation can operate both in stand-alone and grid-connected operations. This paper presents an application of the five-level common-emitter current-source inverter (CE-CSI for grid connected photovoltaic system without batteries as energy storage system. In the proposed system, the five-level CE-CSI works generating a sinusoidal output current from photovoltaic system to be injected into the power grid. The transformer is used in the system to step-down the grid voltage to meet the voltage level of the photovoltaic system, and also works as a galvanic insulation between the power grid and the inverter system. Two conditions of the power grid voltage, i.e. a pure sinusoidal and a distorted power grid, are tested through computer simulation using PSIM software. Furthermore, experimental test result of the five-level inverter is also presented. The test results show that the five-level CE-CSI works well injecting a sinusoidal current into the power grid with low harmonic contents, and with unity power factor operation. The results also show that the distorted grid voltage affects the harmonic contents of the current injected by the inverter.

  6. Low Level Event and Near Miss Process for Nuclear Power Plants: Best Practices

    The IAEA programme on the operational safety of nuclear power plants gives priority to the development and promotion of the proper use of IAEA safety standards through the provision of assistance to Member States in the application of safety standards, the performance of safety review missions and the conduct of training activities based on safety standards. A number of IAEA safety standards and nuclear safety publications discuss the processes that need to be put into place for the feedback and analysis of operating experience (OE) at nuclear power plants. These include: Fundamental Safety Principles (IAEA Safety Standards Series No. SF-1), Safety of Nuclear Power Plants: Commissioning and Operation (IAEA Safety Standards Series No. SSR-2/2), Application of the Management System for Facilities and Activities (IAEA Safety Standards Series No. GS-G-3.1) and A System for the Feedback of Experience from Events in Nuclear Installations (IAEA Safety Standards Series No. NS-G-2.11). Additionally, several IAEA TECDOCs cover many aspects of the establishment, conduct and continuous improvement of an OE programme at nuclear power plants, including the consideration of low level events (LLEs) and near misses (NMs). Although these IAEA safety standards and nuclear safety publications have been in existence for several years, 70 per cent of the IAEA Operational Safety Review Team (OSART) missions carried out at nuclear power plants between 2006 and 2010 identified weaknesses in the reporting and analysis process for LLEs and NMs. In fact, this has been one of the recurring issues most often identified in the area of OE during these missions. These weaknesses have been further confirmed by most of the IAEA Peer Review of the Operational Safety Performance Experience (PROSPER) missions that have been conducted to date. Finally, the IAEA International Nuclear Safety Group, in their report entitled Improving the International System for Operating Experience Feedback (INSAG-23

  7. Adaptative control with non-minimum phase system. Application to level control in PWR power plant steam generator

    This thesis presents the proposal for a water control level method likely to improve performance, especially at low power. Particular problems are analyzed in detail. Finally, computerized simulations are presented; they confirm the algorithm performance

  8. A General Framework for Power Analysis to Detect the Moderator Effects in Two- and Three-Level Cluster Randomized Trials

    Dong, Nianbo; Spybrook, Jessaca; Kelcey, Ben

    2016-01-01

    The purpose of this study is to propose a general framework for power analyses to detect the moderator effects in two- and three-level cluster randomized trials (CRTs). The study specifically aims to: (1) develop the statistical formulations for calculating statistical power, minimum detectable effect size (MDES) and its confidence interval to…

  9. Study and Analysis of a Natural Reference Frame Current Controller for a Multi-Level H-Bridge Power Converter

    Ciobotaru, Mihai; Iov, Florin; Zanchetta, P.;

    2008-01-01

    natural reference frame controller, based on proportional-resonant (PR) technique, for a multi-level H-bridge power converter for Universal and Flexible Power Management in Future Electricity Network. The proposed method is tested in terms of harmonic content in the Point of Common Coupling (PCC), voltage...

  10. Several High Level Issues in Reliability Assessment of Safety-Critical Software in Nuclear Power Plants

    Kim, Man Cheol; Jang, Seung Cheol [KAERI, Daejeon (Korea, Republic of)

    2011-08-15

    For the purpose of developing a consensus method for the reliability assessment of safety-critical digital instrumentation and control systems in nuclear power plants, several high level issues in reliability assessment of the safety-critical software based on Bayesian belief network modeling and statistical testing are discussed. Related to the Bayesian belief network modeling, the relation between the assessment approach and the sources of evidence, the relation between qualitative evidence and quantitative evidence, and how to consider qualitative evidence are discussed. Related to the statistical testing, the need of the consideration of context-specific software failure probabilities and the inability to perform a huge number of tests in the real world are discussed. The discussions in this paper are expected to provide a common basis for future discussions on the reliability assessment of safety-critical software.

  11. Managing autonomy levels in the SSM/PMAD testbed. [Space Station Power Management and Distribution

    Ashworth, Barry R.

    1990-01-01

    It is pointed out that when autonomous operations are mixed with those of a manual nature, concepts concerning the boundary of operations and responsibility become clouded. The space station module power management and distribution (SSM/PMAD) automation testbed has the need for such mixed-mode capabilities. The concept of managing the SSM/PMAD testbed in the presence of changing levels of autonomy is examined. A knowledge-based approach to implementing autonomy management in the distributed SSM/PMAD utilizing a centralized planning system is presented. Its knowledge relations and system-wide interactions are discussed, along with the operational nature of the currently functioning SSM/PMAD knowledge-based systems.

  12. Some Comparisons of Measured and Predicted Primary Radiation Levels in the Aagesta Power Plant

    Neutron fluxes and gamma exposure rates in the primary shields of the Aagesta nuclear plant have been measured and the results compared with values predicted during shield design, and with values obtained later by the NRN bulk shielding code. The input data for the problems are given. The radial predictions are conservative by a factor of not more than 2 close to the reactor and by an unknown, higher factor further out. The conservatism is explainable by the differences between the true local conditions and core power distributions and those assumed in the predictions. The axial flux levels based on streaming calculations are found to agree quite well with the estimated values. The conservatism here is not so large and it seems to be necessary to be very careful when handling streaming problems. The experience gained shows that a power plant is less suitable for studying the accuracy of the shield design codes as such, but the practical results from the combined application of massive shield codes and void streaming predictions to complicated problems give information about the true degree of conservatism present

  13. Efficiency at maximum power of a heat engine working with a two-level atomic system.

    Wang, Rui; Wang, Jianhui; He, Jizhou; Ma, Yongli

    2013-04-01

    We consider the finite-time operation of a quantum heat engine whose working substance is composed of a two-level atomic system. The engine cycle, consisting of two quantum adiabatic and two quantum isochoric (constant-frequency) processes and working between two heat reservoirs at temperatures T(h) and T(c)(cycle. By optimizing the power output with respect to two frequencies, we obtain the efficiency at maximum power output (EMP) and analyze numerically the effects of the times taken for two adiabatic and two isochoric processes on the EMP. In the absence of internally dissipative friction, we find that the EMP is bounded from the upper side by a function of the Carnot efficiency η(C), η(+)=η(C)(2)/[η(C)-(1-η(C))ln(1-η(C))], with η(C)=1-T(c)/T(h). This analytic expression is confirmed by our exact numerical result and is identical to the one derived in an engine model based on a mesoscopic or macroscopic system. If the internal friction is included, we find that the EMP decreases as the friction coefficient increases. PMID:23679385

  14. Levelized Cost of Energy Analysis of a Wind Power Generation System at Búrfell in Iceland

    Birgir Freyr Ragnarsson

    2015-09-01

    Full Text Available Wind energy harnessing is a new energy production alternative in Iceland. Current installed wind power in Iceland sums to 1.8 MW, which in contrast is 0.1% of the country’s total electricity production. This article is dedicated to the exploration of the potential cost of wind energy production at Búrfell in the south of Iceland. A levelized cost of energy (LCOE approach was applied to the estimation of the potential cost. Weibull simulation is used to simulate wind data for calculations. A confirmation of the power law is done by comparing real data to calculated values. A modified Weibull simulation is verified by comparing results with actual on-site test wind turbines. A wind farm of 99MWis suggested for the site. Key results were the capacity factor (CF at Búrfell being 38.15% on average and that the LCOE for wind energy was estimated as 0.087–0.088 USD/kWh (assuming 10% weighted average cost of capital (WACC, which classifies Búrfell among the lowest LCOE sites for wind energy in Europe.

  15. A Demonstration of Spectral Level Reconstruction of Intrinsic $B$-mode Power

    Pal, Barun

    2016-01-01

    We investigate the prospects and consequences of the spectral level reconstruction of primordial $B$-mode power by solving the systems of linear equations assuming that the lensing potential together with the lensed polarization spectra are already in hand. We find that this reconstruction technique may be very useful to have an estimate of the amplitude of primordial gravity waves or more specifically the value of tensor to scalar ratio. We also see that one can have cosmic variance limited reconstruction of the intrinsic $B$-mode power up to few hundred multipoles ($\\ell\\sim500$) which is more than sufficient to have an estimate of the tensor to scalar ratio. Since the small scale cosmic microwave background (CMB henceforth) anisotropies are not sourced by the primordial gravity waves generated during inflation. We also find that the impact of instrumental noise may be bypassed within this reconstruction algorithm. A simple demonstration for the nullification of the instrumental noise anticipating COrE like...

  16. Low Power Analysis of Network-Level On-chip communication using Asynchronous AMBA protocol

    E. Sakthivel

    2012-07-01

    Full Text Available Network on-chip (NoC is a novel structuraldesign template, which can be defied for complicatedsystem level on-chip design. NoC has a potential tolimit and present the bus-based communication. In thispaper, the crisis to discuss is Low power consumptionin an Asynchronous Network on-chip (NoC levelcommunication. NoC is implemented using FPGAwhich has less fabrication cost and reduces thecomplexity. An Asynchronous NoC has beenimplemented in Spartan kit using Xilinx FPGA ISEtools and its network interface is AdvancedMicrocontroller Bus Architecture (AMBA whichfeatures numerous bus masters and a sole clock edgeevolution and so on. Here the AMBA highperformance 32-bit AHB bus is employed in which ithas a high clock frequency system and it is the heart ofour bus system. To accomplish low power consumptionby interfacing SoC with AMBA- AHB protocol. TheAHB model and an Asynchronous NoC are employedand executed using VHDL programming module

  17. Determination of 93Zr in medium and low level radioactive wastes from Brazilian nuclear power plants

    The majority of long-lived radionuclides produced in the nuclear power plants can be regarded as difficult-to-measure radionuclides (RDM), hence chemical separation is necessary before the nuclear measurement of them. The zirconium isotope 93Zr is a long-lived pure β-particle-emitting radionuclide produced from 235U fission and from neutron activation of the stable isotope 92Zr and thus occurring as one of the radionuclides found in nuclear reactors. Due to its long half-life, 93Zr is one of the radionuclides of interest for the performance of assessment studies of waste storage or disposal. Two different methodologies based on extractive resins and LSC and ICP-MS techniques that enables the 93Zr determination in medium (ILW) and low level (LLW) radioactive wastes samples from Brazilian nuclear power plants has been developed in our laboratory. Analyzing real samples 65% and 75% chemical yields for 93Zr recovery were achieved for ICP-MS and LSC techniques, respectively. The detection limits were 0.045 μg.L-1 for ICP-MS and 0.05 Bq.L-1 for LSC techniques. (author)

  18. Exergetic optimization of single level combined gas-steam power plants considering different objective functions

    Bracco, Stefano [Department of Turbomachinery, Energy Systems and Transportation, University of Genova, Via Montallegro 1, 16145 Genova (Italy); Siri, Silvia [Department of Communications, Computer and Systems Science, University of Genova, Via Opera Pia 13, 16145 Genova (Italy)

    2010-12-15

    Combined cycle power plants have been studied in this paper with the aim of optimizing the heat recovery steam generator using a first and second law approach. To this end, a mathematical model has been developed for determining the optimal steam pressure in a one pressure level heat recovery steam generator, considering that the gas turbine is known. Different objective functions have been analysed in this study, some of which refer only to the exergy balance of the heat recovery steam generator while others involve the whole bottoming cycle. Some constraints for the operating parameters of the power plant have also been taken into account, regarding for instance the steam quality at the turbine outlet and the steam turbine blade height. Some numerical results have been reported in the paper, comparing the different objective functions for heat recovery steam generators coupled with several gas turbines; the developed parametric analysis has been performed in order to evaluate the influence of some parameters on both the heat recovery steam generator and the whole bottoming cycle. (author)

  19. Management of Low Level Rad-Waste Arising From Nuclear Power Stations in Japan

    In nuclear power stations in Japan, in order to reduce radioactivity release into the environment based on the concept of ALARA, various improvements of the gaseous and liquid waste treatment systems have been made in both aspects of facilities and operations as follows: In order to reduce the release of gaseous waste, the following facilities were introduced: Charcoal bed typed noble gas holdup facility, Clean steam supply system for turbine gland seal, No leak typed valve In order to reduce the release of liquid waste, the following measures were taken: Evaporating floor drain, Evaporating laundry drain;, Demoralizing plant surplus water by a mix bed typed ion exchange resin. As a result of these counter measures, the release of gaseous and liquid radioactivity into the environment has been reduced gradually, and is now virtually 'zero' as shown in Islet. 1. Contrary to reduction in radioactivity release into the environment, residual radioactivity inside nuclear power station has made consequent increase of low level radioactive wastes in the form of solid

  20. INFLUENCES OF THE PURCHASING POWER CHANGE ON THE EVOLUTION OF THE AGROALIMETARY MARKETS ON EUROPEAN UNION LEVEL

    Laura Catalina Timiras

    2013-01-01

    This paper aims to identify the manifested connection between the dynamics of the population purchasing power and the dynamic of agroalimentary markets in general as well as by product types on European Union level. Based on the last data supplied by Eurostat 2013, using the specific methods for studying the correlations, we have detected that increases and decreases of the purchasing power generated similar changes on agroalimentary markets level from the point of view of achieved sales in m...

  1. INFLUENCES OF THE PURCHASING POWER CHANGE ON THE EVOLUTION OF THE AGROALIMETARY MARKETS ON EUROPEAN UNION LEVEL

    Laura Catalina Timiras

    2014-01-01

    This paper aims to identify the manifested connection between the dynamics of the population purchasing power and the dynamic of agroalimentary markets in general as well as by product types on European Union level. Based on the last data supplied by Eurostat 2013, using the specific methods for studying the correlations, we have detected that increases and decreases of the purchasing power generated similar changes on agroalimentary markets level from the point of view of achieved sales in m...

  2. Analysis of SG level control system stability after power uprating at Kori 3 and 4 and Ygn 1 and 2

    Poor control of the steam generator water level in the secondary system of a nuclear power plant after power uprating at Kori Unit 3 and 4 and Younggwang Unit 1 and 2 can lead to frequent reactor shutdowns. Such shutdowns are caused by violation of safety limits on the water level. The performance of steam generator level control system has been evaluated. The purposes of simulation analysis are to provide the expected plant responses as follows; 1) To support training plant operators and engineering personnel in preparation for performing the actual site test. 2) For evaluation to determine appropriate SG level control system setpoints in advance of performing the site startup test

  3. Power

    Bowles, Samuel; Gintis, Herbert

    2007-01-01

    We consider the exercise of power in competitive markets for goods, labour and credit. We offer a definition of power and show that if contracts are incomplete it may be exercised either in Pareto-improving ways or to the disadvantage of those without power. Contrasting conceptions of power including bargaining power, market power, and consumer sovereignty are considered. Because the exercise of power may alter prices and other aspects of exchanges, abstracting from power may miss essential a...

  4. Impacts from a fossil fuel power plant on ozone levels in Memphis, Tennessee

    The Tennessee Valley Authority (TVA) Allen power plant is located on the Mississippi River in the southwest corner of Memphis, Tennessee. Allen has three coal-fired cyclone boilers with a rated capacity of 272 MW each. It is a Phase 2 plant under Title IV of the Clean Air Act and is the largest single source of NOx in the Memphis area. TVA plans to reduce Allen NOx emissions through a combination of burning low-sulfur coal (which has the benefit of reducing NOx emissions while also reducing SO2 emissions) and installing gas re-burn technology. A modeling study using the SAI, Inc., UAM-V photochemical model was conducted to examine the potential impacts of NOx reductions on ozone levels in the Memphis area. A series of four model simulations were made in which different Allen emissions scenarios were examined. The focus period of the photochemical modeling was 11--14 July 1995 when measurements in and near Memphis indicated peak hourly ozone levels of 135--140 ppb. This analysis primarily examined computed impacts within 50 km of Memphis. Allen was computed to contribute as much as 20--30 ppb to ground ozone levels 20-50 km downwind using its NOx emission rate before Title IV compliance. After compliance it was computed to contribute only about 10--20 ppb. At the same time, maximum daily ozone reductions due to Allen NOx titration of ozone were between 30 and 60 ppb. These benefits will be reduced by 30--50% after Title IV compliance, and are expected to occur within 30 km of the plant. More model grid cells indicated dis-benefits (net ground-level ozone increases) than benefits on three of the four episode days using the Title IV compliance emission rate. Significant ozone dis-benefits were expected because of the well-documented NO titration of ozone within plumes having a high ratio of NO to volatile organic compounds

  5. Efficiency improvement of transport service by trolley buses based on the levels of their power demand

    V. V. Aulin

    2014-12-01

    Full Text Available Purpose. Use efficiency improvement of trolley buses in passenger traffic based on power levels of electric energy input and terms adjustment of their maintenance. Methodology. In order to achieve this goal conformance of electric energy input by trolleybus to the transported amount of passengers taking into account characteristics of the route is offered to establish. The major indicators of the trolleybus operation are: speed of a race on lines, number of tractive motor firing, voltage and amperage in the network that were taken with accountants from a dashboard. Research results were tabulated and recorded with DVR. Along with the study of power consumption of electric energy input by a trolleybus passenger count was carried out too. Findings. The directly proportional dependence between the level of energy consumption by a trolleybus and the number of passengers for constant performance route was determined. Originality. As the criteria for evaluating the effectiveness of the trolleybus operation on the route is proposed to use the ratio between electricity consumption and number of passengers for these characteristics of the route. This is confirmed experimentally. The obtained formulas give the possibility to balance the force work and consequently the volume of energy consumption during the trolleybus movement on the rise and the descent. Practical value. The proposed criterion can be used to adjust the terms of maintenance on the individual program, that means individual maintenance (IM. Type of work performed at the IM should be determined on the basis of diagnostic data of the vehicle (V. The principles of IM were formulated: 1 the primary task is planned and preventative strategy to identify and eliminate troubleshooting and technical actions; 2 operational control of the vehicle (V technical condition on the basis of prediction of its state using the proposed criteria, that takes into account the dependence of power consumption to

  6. A RESEARCH TO HIGH-PERFORMANCE MULTI-LEVEL SINGLEPHASE AC/DC POWER FACTOR CORRECT SWITCHING CONVERTER

    Gao Chao

    2008-01-01

    This letter studies and analyzes the working features of main circuit of tri-level boost Power Factor Correct (PFC) converter and the advantages of tri-level switch converter in aspects of bearing high-voltage of power components,overall system loss and magnetic component selection based upon the single-level boost PFC switch converter. Besides,relying on the application of mi-croprocessor in power converter technology and DSP (Digital Signal Processing) chip's strong cal-culating capacity,the letter presents the adoption of modified scheme of tri-level boost PFC converter under the control of predictive control algorithm. Moreover,the operating principle and control method are specified,the results of circuit test and analysis are provided and the advantages of pre-dictive control technology-based multi-level boost PFC converter is verified.

  7. POWER QUALITY ENHANCEMENT USING 7 LEVEL CASCADED H - BRIDGE INVERTER BASED D - STATCOM WITH PQ THEOR Y

    Bhushan P. Kadu

    2015-06-01

    Full Text Available This paper presents an investigation of Seven - Level H – bridge Inverter is used in a Distribution Static Compensator (DSTATCOM in Power System (PS, making use of seven level cascaded inverter benefits of low harmonics distortion, reduced number of switches to achieve the seven - level inverter output over the conventional cascaded seven level inverter and reduced switching losses . In order to improve the power factor, compensate the reactive power and suppress the total harmonics distortion (THD drawn from a Non - Liner Diode Rectifier Load (NLDRL of DSTATCOM, we propose a Level Shift Pulse Width Modulation (LSPWM technique is used as control for the switches of H – bridge Inverter. The PQ theory is used to generate the reference compensating current for DSTATCOM . The proposed system is simulated in the MATLAB environment using simulink and results are discussed

  8. Use of Three-Level Power Converters in Wind-Driven Permanent-Magnet Synchronous Generators with Unbalanced Loads

    Ming-Hung Chen

    2015-01-01

    This paper describes the design and implementation of three-level power converters for wind-driven permanent-magnet synchronous generators with unbalanced loads. To increase voltage stress and reduce current harmonics in the electrical power generated by a wind generator, a three-phase, three-level rectifier is used. Because a synchronous rotating frame is used on the AC-input side, the use of a neutral-point-clamped controller is proposed to increase the power factor to unity and reduce curr...

  9. Measurement and release of low-level contaminated materials from nuclear power plants into environment

    Release of low-level contaminated solid materials originated from the operation or decommissioning of nuclear power plants into the environment for their recycling, reuse or liquidation is one of the main ways for the minimization of radioactive wastes production. Regulated measurement of contamination and quantitative determination of radionuclides in materials to be released are relatively complicated but manageable processes. AllDeco operates 2 measuring devices for materials release. For this purpose measuring chambers of RTM type are used for the determination of total gamma activity of radionuclides in materials. Activities of alpha and beta radionuclides are calculated by statistical results processing based on radionuclide vectors established in the laboratory for samples of similar materials. Possible spatial inhomogeneities of the contamination in measured materials can be identified by the devices software. The measurement of total gamma activity is completed by controlling spectrometric determination of present gamma radionuclides using NaI or Ge detectors. Limits for the release are measured and observed according to assigned accuracy for measuring chambers as authorized official measures. The stipulated reference levels are controlled by selective measurements of the surface alpha and beta activities and by the determination of the ratio of main gamma radionuclides. (authors)

  10. Clearance of very low level radioactive waste in spanish nuclear power plants

    According to present Spanish legislation a radioactive waste is defined as any material or waste product, without any possible planned use, that contains or is contaminated with radionuclides in concentrations or activity levels higher than those established by the Regulatory Authorities. Legally, this situation allows to develop a conventional management of very low level radioactive waste, by checking the negligibility of their radiological impact, and thus obtaining the corresponding Authorization to treat them as conventional waste. This presentation describes the clearance project of contaminated oils from spanish nuclear power plants. The on-site management includes: -) preliminary settling, centrifugation and filtration; -) oil purification; and -) radiological characterization. The off-site management includes the following operations: -) transportation to the facility where treatment is developed (dilution); -) temporary storage (decay); -) transportation to the place where final management is carried out; -) oil burning (dilution); and management of ashes and other combustion products. An annual amount of 70 m3/year (63 MBq) of very low contaminated oil with a specific concentration of 1 Bq/g could be disposed off. (A.C.)