Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations, Main report (Chapters 7--12). Volume 2, Part 1B

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.

1994-06-01

During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this report is to document the approach utilized in the Surry plant and discuss the results obtained. A parallel report for the Grand Gulf plant is prepared by SNL. This study shows that the core-damage frequency during mid-loop operation at the Surry plant is comparable to that of power operation. We recognize that there is very large uncertainty in the human error probabilities in this study. This study identified that only a few procedures are available for mitigating accidents that may occur during shutdown. Procedures written specific shutdown accidents would be useful

Risk analysis of releases from accidents during mid-loop operation at Surry

International Nuclear Information System (INIS)

Jo, J.; Lin, C.C.; Nimnual, S.; Mubayi, V.; Neymotin, L.

1992-11-01

Studies and operating experience suggest that the risk of severe accidents during low power operation and/or shutdown (LP/S) conditions could be a significant fraction of the risk at full power operation. Two studies have begun at the Nuclear Regulatory Commission (NRC) to evaluate the severe accident progression from a risk perspective during these conditions: One at the Brookhaven National Laboratory for the Surry plant, a pressurized water reactor (PWR), and the other at the Sandia National Laboratories for the Grand Gulf plant, a boiling water reactor (BWR). Each of the studies consists of three linked, but distinct, components: a Level I probabilistic risk analysis (PRA) of the initiating events, systems analysis, and accident sequences leading to core damage; a Level 2/3 analysis of accident progression, fuel damage, releases, containment performance, source term and consequences-off-site and on-site; and a detailed Human Reliability Analysis (HRA) of actions relevant to plant conditions during LP/S operations. This paper summarizes the approach taken for the Level 2/3 analysis at Surry and provides preliminary results on the risk of releases and consequences for one plant operating state, mid-loop operation, during shutdown

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations, Appendices E (Sections E.1--E.8). Volume 2, Part 3A

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.

1994-06-01

During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this report is to document the approach utilized in the Surry plant and discuss the results obtained. A parallel report for the Grand Gulf plant is prepared by SNL. This study shows that the core-damage frequency during mid-loop operation at the Surry plant is comparable to that of power operation. The authors recognize that there is very large uncertainty in the human error probabilities in this study. This study identified that only a few procedures are available for mitigating accidents that may occur during shutdown. Procedures written specifically for shutdown accidents would be useful

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations, Main report (Chapters 1--6). Volume 2, Part 1A

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.

1992-06-01

During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this report is to document the approach utilized in the Surry plant and discuss the results obtained. A parallel report for the Grand Gulf plant is prepared by SNL. This study shows that the core-damage frequency during mid-loop operation at the Surry plant is comparable to that of power operation. We recognize that there is very large uncertainty in the human error probabilities in this study. This study identified that only a few procedures are available for mitigating accidents that may occur during shutdown written specifically for shutdown accidents would be useful. This document presents Chapters 1--6 of the report

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1. Volume 5: Analysis of core damage frequency from seismic events during mid-loop operations

International Nuclear Information System (INIS)

Budnitz, R.J.; Davis, P.R.; Ravindra, M.K.; Tong, W.H.

1994-08-01

In 1989 the US Nuclear Regulatory Commission (NRC) initiated an extensive program to examine carefully the potential risks during low-power and shutdown operations. The program included two parallel projects, one at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1) and the other at Sandia National Laboratories studying a boiling water reactor (Grand Gulf). Both the Brookhaven and Sandia projects have examined only accidents initiated by internal plant faults--so-called ''internal initiators.'' This project, which has explored the likelihood of seismic-initiated core damage accidents during refueling shutdown conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Surry Unit 1. All of the many systems modeling assumptions, component non-seismic failure rates, and human error rates that were used in the internal-initiator study at Surry have been adopted here, so that the results of the two studies can be as comparable as possible. Both the Brookhaven study and this study examine only two shutdown plant operating states (POSs) during refueling outages at Surry, called POS 6 and POS 10, which represent mid-loop operation before and after refueling, respectively. This analysis has been limited to work analogous to a level-1 seismic PRA, in which estimates have been developed for the core-damage frequency from seismic events during POSs 6 and 10. The results of the analysis are that the core-damage frequency of earthquake-initiated accidents during refueling outages in POS 6 and POS 10 is found to be low in absolute terms, less than 10 -6 /year

Analysis of core damage frequency: Surry, Unit 1 internal events

International Nuclear Information System (INIS)

Bertucio, R.C.; Julius, J.A.; Cramond, W.R.

1990-04-01

This document contains the accident sequence analysis of internally initiated events for the Surry Nuclear Station, Unit 1. This is one of the five plant analyses conducted as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 documents the risk of a selected group of nuclear power plants. The work performed and described here is an extensive of that published in November 1986 as NUREG/CR-4450, Volume 3. It addresses comments form numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved. The context and detail of this report are directed toward PRA practitioners who need to know how the work was performed and the details for use in further studies. The mean core damage frequency at Surry was calculated to be 4.05-E-5 per year, with a 95% upper bound of 1.34E-4 and 5% lower bound of 6.8E-6 per year. Station blackout type accidents (loss of all AC power) were the largest contributors to the core damage frequency, accounting for approximately 68% of the total. The next type of dominant contributors were Loss of Coolant Accidents (LOCAs). These sequences account for 15% of core damage frequency. No other type of sequence accounts for more than 10% of core damage frequency. 49 refs., 52 figs., 70 tabs

U.S. industry response to surry corrosion event

International Nuclear Information System (INIS)

Chexal, V.K.; Dietrich, E.B.; Torok, R.C.; Randall, G.A.; Shevde, V.C.; Horowitz, J.S.

1990-01-01

On December 9, 1986, a 460 mm (18 inch) diameter carbon steel elbow in the condensate system at Surry Unit-2 failed. The failure occurred as a consequence of thinning of the elbow by erosion-corrosion. Inspections revealed significant thinning of carbon steel sections at numerous locations in the condensate and feedwater piping of both Surry units. The subsequent discovery of thinning at other plants established erosion-corrosion as a generic issue for nuclear and fossil plants. To quickly resolve industry and regulatory concerns associated with single-phase erosion-corrosion, EPRI sought to: (1) find ways to determine where single phase erosion-corrosion is most likely to occur; (2) define accurate and low-cost inspection methods; and (3) identify techniques for preventing further pipe degradation. Erosion-corrosion programs have been conducted in a number of laboratories world-wide. The associated phenomena are complex and depend on the interrelationship of water temperature, water chemistry, component material, flow velocity and the geometry of the flow path (straight, bend, tee, etc.). EPRI supplemented existing data and developed technical products tailored for utility use on the erosion-corrosion issue. This paper describes the U.S. industry response to the Surry event and the related EPRI activities in the corrosion area

Analysis of core damage frequency, Surry, Unit 1 internal events appendices

International Nuclear Information System (INIS)

Bertucio, R.C.; Julius, J.A.; Cramond, W.R.

1990-04-01

This document contains the appendices for the accident sequence analyses of internally initiated events for the Surry Nuclear Station, Unit 1. This is one of the five plant analyses conducted as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 documents the risk of a selected group of nuclear power plants. The work performed is an extensive reanalysis of that published in November 1986 as NUREG/CR-4450, Volume 3. It addresses comments from numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved. The context and detail of this report are directed toward PRA practitioners who need to know how the work was performed and the details for use in further studies. The mean core damage frequency at Surry was calculated to be 4.0E-5 per year, with a 95% upper bound of 1.3E-4 and 5% lower bound of 6.8E-6 per year. Station blackout type accidents (loss of all AC power) were the largest contributors to the core damage frequency, accounting for approximately 68% of the total. The next type of dominant contributors were Loss of Coolant Accidents (LOCAs). These sequences account for 15% of core damage frequency. No other type of sequence accounts for more than 10% of core damage frequency

Approach and results of the PWR low power and shutdown accident frequencies program - Coarse screening analysis for Surry

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Luckas, W.; Wong, S.M.; Fitzpatrick, R.G.

1991-01-01

Traditionally, probabilistic risk analyses of severe accidents in nuclear power plants have limited themselves to consideration of the set of initiating events occurring during full power operation. However, some analyses of accident initiators during low power, shutdown, and other modes of plant operation other than full power have been performed. These studies as well as the Chernobyl accident and recent operating experience at US pressurized water reactors (PWRs) suggested that risks during low power and shutdown could be significant. As such, the analysis of the frequencies, consequences, and risks of these accidents was identified as one task in the Nuclear Regulatory Commission staff's study of the implications of the Chernobyl accident to US commercial nuclear power plants. This program is an ongoing high priority effort at Brookhaven National Laboratory (BNL). The scope includes a Level 1 probabilistic risk assessment (PRA) with internal fire and flood for Surry Unit 1 (PWR). This program is also closely coupled to a parallel project for the Grand Gulf plant (BWWR) being conducted by SNL. The program is being performed in two phases. Phase 1 represents a coarse screening analysis to identify dominant accident scenarios as well as risk dominant plant configurations and plant operating states. In Phase 2, a detailed PRA will be performed for the dominant accident scenarios/operating states identified in Phase 1. The objectives, results and insights of Phase 1 are discussed in the paper

Comparison of CONTAIN and TCE calculations for direct containment heating of Surry

International Nuclear Information System (INIS)

Washington, K.E.; Stuart, D.S.

1996-01-01

This paper presents the results of several CONTAIN code calculations used to model direct containment heating (DCH) loads for the Surry plant. The results of these calculations are compared with the results obtained using the two-cell equilibrium (TCE) model for the same set of initial and boundary conditions. This comparison is important because both models have been favorably validated against the available DCH database, yet there are potentially important modeling differences. The comparisons are to quantitatively assess the impact of these differences. A major conclusion of this study is that, for the accident conditions studied and for a broad range of sensitivity cases, the peak pressures predicted by both TCE and CONTAIN are well below the failure pressure for the Surry containment. (orig.)

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix I, Volume 2, Part 5

Energy Technology Data Exchange (ETDEWEB)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J. [Brookhaven National Lab., Upton, NY (United States); Bley, D.; Johnson, D. [PLG Inc., Newport Beach, CA (United States); Holmes, B. [AEA Technology, Dorset (United Kingdom)] [and others

1994-06-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Lab. (BNL) and Sandia National Labs. (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this volume of the report is to document the approach utilized in the level-1 internal events PRA for the Surry plant, and discuss the results obtained. A phased approach was used in the level-1 program. In phase 1, which was completed in Fall 1991, a coarse screening analysis examining accidents initiated by internal events (including internal fire and flood) was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis.

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix I, Volume 2, Part 5

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Bley, D.; Johnson, D.; Holmes, B.

1994-06-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Lab. (BNL) and Sandia National Labs. (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The objective of this volume of the report is to document the approach utilized in the level-1 internal events PRA for the Surry plant, and discuss the results obtained. A phased approach was used in the level-1 program. In phase 1, which was completed in Fall 1991, a coarse screening analysis examining accidents initiated by internal events (including internal fire and flood) was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis

A pilot application of risk-informed methods to establish inservice inspection priorities for nuclear components at Surry Unit 1 Nuclear Power Station. Revision 1

International Nuclear Information System (INIS)

Vo, T.V.; Phan, H.K.; Gore, B.F.; Simonen, F.A.; Doctor, S.R.

1997-02-01

As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest National Laboratory has developed risk-informed approaches for inservice inspection plans of nuclear power plants. This method uses probabilistic risk assessment (PRA) results to identify and prioritize the most risk-important components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot application of this methodology. This report, which incorporates more recent plant-specific information and improved risk-informed methodology and tools, is Revision 1 of the earlier report (NUREG/CR-6181). The methodology discussed in the original report is no longer current and a preferred methodology is presented in this Revision. This report, NUREG/CR-6181, Rev. 1, therefore supersedes the earlier NUREG/CR-6181 published in August 1994. The specific systems addressed in this report are the auxiliary feedwater, the low-pressure injection, and the reactor coolant systems. The results provide a risk-informed ranking of components within these systems

Socio-economic impacts of nuclear generating stations: Surry case study

International Nuclear Information System (INIS)

Flynn, J.

1982-07-01

This report documents a case study of the socio-economic impacts of the construction and operation of the Surry nuclear power station. It is part of a major post-licensing study of the socio-economic impacts at twelve nuclear power stations. The case study covers the period beginning with the announcement of plans to construct the reactor and ending in the period 1980 to 1981. The case study deals with changes in the economy, population, settlement patterns and housing, local government and public services, social structure, and public response in the study area during the construction/operation of the reactor. A regional modeling approach is used to trace the impact of the construction/operation on the local economy, labor market, and housing market. Emphasis in the study is on the attribution of socio-economic impacts to the reactor or other causal factors. As part of the study of local public response to the construction/operation of the reactor, the effects of the Three Mile Island accident are examined

Fracture mechanics evaluation of feedwater line failure at Surry-2: Final report

International Nuclear Information System (INIS)

Zahoor, A.; Gamble, R.M.

1987-10-01

The purpose of this work was to perform a fracture mechanics evaluation of a failure that occurred in an elbow of the 18-inch suction line to the ''A'' main feed pump at Surry Power Station, Unit 2. The failure occurred during a pressure transient subsequent to a reactor trip, which was initiated by a low-low steam generator level protection signal. Analyses were performed to characterize the crack formation and growth sequence at the estimated failure pressure (550 psi) and normal operating pressure (367 psi); this work included predicting the longitudinal throughwall crack lengths for initial wall breakthrough and failure. A sensitivity study also was performed to assess the effect on the results of variations in several conditions that generally influence failure

Fracture mechanics evaluation of feedwater line failure at Surry-2: Final report

Energy Technology Data Exchange (ETDEWEB)

Zahoor, A.; Gamble, R.M.

1987-10-01

The purpose of this work was to perform a fracture mechanics evaluation of a failure that occurred in an elbow of the 18-inch suction line to the ''A'' main feed pump at Surry Power Station, Unit 2. The failure occurred during a pressure transient subsequent to a reactor trip, which was initiated by a low-low steam generator level protection signal. Analyses were performed to characterize the crack formation and growth sequence at the estimated failure pressure (550 psi) and normal operating pressure (367 psi); this work included predicting the longitudinal throughwall crack lengths for initial wall breakthrough and failure. A sensitivity study also was performed to assess the effect on the results of variations in several conditions that generally influence failure.

CONTAIN calculations of direct containment heating in the Surry plant

International Nuclear Information System (INIS)

Williams, D.C.; Louie, D.L.Y.

1988-01-01

The draft NUREG-1150 risk analysis performed for the Surry plant identified direct containment heating (DCH) as a potentially dominant contributor to the total public risk associated with this plant. At that time, however, detailed mechanistic calculations of DCH loads were unavailable. Subsequently, a series of analyses of DCH scenarios using the CONTAIN-DCH code was performed in order to put the treatment of DCH on a firmer basis in the final draft of NUREG-1150. The present paper describes some of the results obtained for the Surry plant. A developmental model for DCH has been incorporated into CONTAIN code. This model includes mechanistic treatments of reasonably well-understood phenomena (e.g., heat and mass transfer), together with a parametric treatment of poorly understood phenomena for which mechanistic models are unavailable (e.g., debris de-entrainment from the gas stream due to debris-structure interactions). The DCH model was described in an earlier report, but the present version incorporates a number of advances, including treatment of the chemical equilibria involved in the iron-steam reaction

Surry Power Station secondary water chemistry improvement since steam generator replacement and the unit two feedwater pipe rupture

International Nuclear Information System (INIS)

Swindell, E.T.

1988-01-01

Surry Power Station has two Westinghouse-designed three-loop PWRs of 811 MWe design rating. The start of commercial operation was in July, 1972 in No.1 plant, and May, 1973 in No.2 plant. Both plants began the operation using controlled phosphate chemistry for the steam generators. In 1975, both plants were converted to all volatile treatment on the secondary side due to the tube wall thinning corrosion in the steam generators, which was associated with the phosphate sludge that was building up on the tube sheets and created acidic condition. Thereafter, condenser and air leakage and steam generator denting occurred, and after the operation of 8 years 2 month of No.1 plant and 5 years 9 months of No.2 plant, the steam generators were replaced. A major plant improvement program was designed and implemented from 1979 to 1980. The improvement in new steam generators, the modification for preventing corrosion, the addition of a steam generator blowdown recovery system, the reconstruction of condensers, the installation of full flow, deep bed condensate polishers, the addition of Dionex 8,000 on-line ion chromatograph, a long term maintenance agreement with Westinghouse and so on are reported. (Kako, I.)

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal floods during mid-loop operations. Volume 4

International Nuclear Information System (INIS)

Kohut, P.

1994-07-01

The major objective of the Surry internal flood analysis was to provide an improved understanding of the core damage scenarios arising from internal flood-related events. The mean core damage frequency of the Surry plant due to internal flood events during mid-loop operations is 4.8E-06 per year, and the 5th and 95th percentiles are 2.2E-07 and 1.8E-05 per year, respectively. Some limited sensitivity calculations were performed on three plant improvement options. The most significant result involves modifications of intake-level structure on the canal, which reduced core damage frequency contribution from floods in mid-loop by about 75%

Evaluation of potential severe accidents during low power and shutdown operations at Surry: Unit 1, Volume 1

International Nuclear Information System (INIS)

Chu, T.L.; Pratt, W.T.

1995-10-01

This document contains a summarization of the results and insights from the Level 1 accident sequence analyses of internally initiated events, internally initiated fire and flood events, seismically initiated events, and the Level 2/3 risk analysis of internally initiated events (excluding fire and flood) for Surry, Unit 1. The analysis was confined to mid-loop operation, which can occur during three plant operational states (identified as POSs R6 and R10 during a refueling outage, and POS D6 during drained maintenance). The report summarizes the Level 1 information contained in Volumes 2--5 and the Level 2/3 information contained in Volume 6 of NUREG/CR-6144

Evaluation of potential severe accidents during low power and shutdown operations at Surry: Unit 1, Volume 1

Energy Technology Data Exchange (ETDEWEB)

Chu, T.L.; Pratt, W.T. [eds.; Musicki, Z. [Brookhaven National Lab., Upton, NY (United States)

1995-10-01

This document contains a summarization of the results and insights from the Level 1 accident sequence analyses of internally initiated events, internally initiated fire and flood events, seismically initiated events, and the Level 2/3 risk analysis of internally initiated events (excluding fire and flood) for Surry, Unit 1. The analysis was confined to mid-loop operation, which can occur during three plant operational states (identified as POSs R6 and R10 during a refueling outage, and POS D6 during drained maintenance). The report summarizes the Level 1 information contained in Volumes 2--5 and the Level 2/3 information contained in Volume 6 of NUREG/CR-6144.

A pilot application of risk-based methods to establish in-service inspection priorities for nuclear components at Surry Unit 1 Nuclear Power Station

International Nuclear Information System (INIS)

Vo, T.; Gore, B.; Simonen, F.; Doctor, S.

1994-08-01

As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest Laboratory is developing a method that uses risk-based approaches to establish in-service inspection plans for nuclear power plant components. This method uses probabilistic risk assessment (PRA) results and Failure Modes and Effects Analysis (FEMA) techniques to identify and prioritize the most risk-important systems and components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot applications of this method. The specific systems addressed in this report are the reactor pressure vessel, the reactor coolant, the low-pressure injection, and the auxiliary feedwater. The results provide a risk-based ranking of components within these systems and relate the target risk to target failure probability values for individual components. These results will be used to guide the development of improved inspection plans for nuclear power plants. To develop inspection plans, the acceptable level of risk from structural failure for important systems and components will be apportioned as a small fraction (i.e., 5%) of the total PRA-estimated risk for core damage. This process will determine target (acceptable) risk and target failure probability values for individual components. Inspection requirements will be set at levels to assure that acceptable failure probabilistics are maintained

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

Energy Technology Data Exchange (ETDEWEB)

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

1995-04-01

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

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Accident tolerant clad material modeling by MELCOR: Benchmark for SURRY Short Term Station Black Out

International Nuclear Information System (INIS)

Wang, Jun; Mccabe, Mckinleigh; Wu, Lei; Dong, Xiaomeng; Wang, Xianmao; Haskin, Troy Christopher; Corradini, Michael L.

2017-01-01

Highlights: • Thermo-physical and oxidation kinetics properties calculation and analysis of FeCrAl. • Properties modelling of FeCrAl in MELCOR. • Benchmark calculation of Surry nuclear power plant. - Abstract: Accident tolerant fuel and cladding materials are being investigated to provide a greater resistance to fuel degradation, oxidation and melting if long-term cooling is lost in a Light Water Reactor (LWR) following an accident such as a Station Blackout (SBO) or Loss of Coolant Accident (LOCA). Researchers at UW-Madison are analyzing an SBO sequence and examining the effect of a loss of auxiliary feedwater (AFW) with the MELCOR systems code. Our research work considers accident tolerant cladding materials (e.g., FeCrAl alloy) and their effect on the accident behavior. We first gathered the physical properties of this alternative cladding material via literature review and compared it to the usual zirconium alloys used in LWRs. We then developed a model for the Surry reactor for a Short-term SBO sequence and examined the effect of replacing FeCrAl for Zircaloy cladding. The analysis uses MELCOR, Version 1.8.6 YR, which is developed by Idaho National Laboratory in collaboration with MELCOR developers at Sandia National Laboratories. This version allows the user to alter the cladding material considered, and our study examines the behavior of the FeCrAl alloy as a substitute for Zircaloy. Our benchmark comparisons with the Sandia National Laboratory’s analysis of Surry using MELCOR 1.8.6 and the more recent MELCOR 2.1 indicate good overall agreement through the early phases of the accident progression. When FeCrAl is substituted for Zircaloy to examine its performance, we confirmed that FeCrAl slows the accident progression and reduce the amount of hydrogen generated. Our analyses also show that this special version of MELCOR can be used to evaluate other potential ATF cladding materials, e.g., SiC as well as innovative coatings on zirconium cladding

Accident tolerant clad material modeling by MELCOR: Benchmark for SURRY Short Term Station Black Out

Energy Technology Data Exchange (ETDEWEB)

Wang, Jun, E-mail: jwang564@wisc.edu [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Mccabe, Mckinleigh [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Wu, Lei [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Dong, Xiaomeng [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Wang, Xianmao [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Haskin, Troy Christopher [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States); Corradini, Michael L., E-mail: corradini@engr.wisc.edu [College of Engineering, The University of Wisconsin-Madison, Madison 53706 (United States)

2017-03-15

Highlights: • Thermo-physical and oxidation kinetics properties calculation and analysis of FeCrAl. • Properties modelling of FeCrAl in MELCOR. • Benchmark calculation of Surry nuclear power plant. - Abstract: Accident tolerant fuel and cladding materials are being investigated to provide a greater resistance to fuel degradation, oxidation and melting if long-term cooling is lost in a Light Water Reactor (LWR) following an accident such as a Station Blackout (SBO) or Loss of Coolant Accident (LOCA). Researchers at UW-Madison are analyzing an SBO sequence and examining the effect of a loss of auxiliary feedwater (AFW) with the MELCOR systems code. Our research work considers accident tolerant cladding materials (e.g., FeCrAl alloy) and their effect on the accident behavior. We first gathered the physical properties of this alternative cladding material via literature review and compared it to the usual zirconium alloys used in LWRs. We then developed a model for the Surry reactor for a Short-term SBO sequence and examined the effect of replacing FeCrAl for Zircaloy cladding. The analysis uses MELCOR, Version 1.8.6 YR, which is developed by Idaho National Laboratory in collaboration with MELCOR developers at Sandia National Laboratories. This version allows the user to alter the cladding material considered, and our study examines the behavior of the FeCrAl alloy as a substitute for Zircaloy. Our benchmark comparisons with the Sandia National Laboratory’s analysis of Surry using MELCOR 1.8.6 and the more recent MELCOR 2.1 indicate good overall agreement through the early phases of the accident progression. When FeCrAl is substituted for Zircaloy to examine its performance, we confirmed that FeCrAl slows the accident progression and reduce the amount of hydrogen generated. Our analyses also show that this special version of MELCOR can be used to evaluate other potential ATF cladding materials, e.g., SiC as well as innovative coatings on zirconium cladding

Study Of Morphological Changes Of Uterine Horn Of Surri Mouse Depended To Morphine Before Puberty And DuringPuberty

Directory of Open Access Journals (Sweden)

Shadkhast M

2003-11-01

Full Text Available : Morphine is the most important alkaloid of opium family which is found as much as ten percent in opium, and is in two types the sulfate morphine and the hydrochloride morphine."nMaterials and Methods: In this study morphological changes of uterus of surri mice due to oral consumption of sulfate morphine were studied. It was shown that, female surri mice following gradually increasing of morphine to water (0.1 and 0.01 mg/ml were depended to morphine. Female surri mice were classified in two age groups before puberty and depended to morphine during puberty. Each age group took morphine for 21 days. After finishing the period, the mice anesthetizing were weighted, then were anesthetizing and uterus was studied the length, width and apparent features."nResults&ConcIusion: In this study it was distinguished that length and width of uterine horn, between experimental and control groups, were significant (P< 0.01. Morphological changes such as anemia, the thinness and fragitidily walls of uterus and filiformity of uterine horns were observed."n"n"n"n"n"n 

Risk contribution from low power and shutdown of a pressurized water reactor

International Nuclear Information System (INIS)

Chu, T.L.; Pratt, W.T.

1997-01-01

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

Surry steam generator - examination and evaluation

International Nuclear Information System (INIS)

Clark, R.A.; Doctor, P.G.; Ferris, R.H.

1985-10-01

This report summarizes research conducted during the fourth year of the five year Steam Generator Group Project. During this period the project conducted numerous nondestructive examination (NDE) round robin inspections of the original Surry 2A steam generator. They included data acquisition/analysis and analysis-only round robins using multifrequency bobbin coil eddy current tests. In addition, the generator was nondestructively examined by alternate or advanced techniques including ultrasonics, optical fiber, profilometry and special eddy current instrumentation. The round robin interpretation data were compared. To validate the NDE results and for tube integrity testing, a selection of tubing samples, determined to be representative of the generator, was designated for removal. Initial sample removals from the generator included three sections of tube sheet, two sections of support plate and encompassed tubes, and a number of straight and U-bend tubing sections. Metallographic examination of these sections was initiated. Details of significant results are presented in the following paper. 13 figs

Surry steam generator - examination and evaluation

Energy Technology Data Exchange (ETDEWEB)

Clark, R A; Doctor, P G; Ferris, R H

1987-01-01

This report summarizes research conducted during the fourth year of the five year Steam Generator Group Project. During this period the project conducted numerous nondestructive examination (NDE) round robin inspections of the original Surry 2A steam generator. They included data acquisition/analysis and analysis-only round robins using multifrequency bobbin coil eddy current tests. In addition, the generator was nondestructively examined by alternate or advanced techniques including ultrasonics, optical fiber, profilometry and special eddy current instrumentation. The round robin interpretation data were compared. To validate the NDE results and for tube integrity testing, a selection of tubing samples, determined to be representative of the generator, was designated for removal. Initial sample removals from the generator included three sections of tube sheet, two sections of support plate and encompassed tubes, and a number of straight and U-bend tubing sections. Metallographic examination of these sections was initiated. Details of significant results are presented in the following paper.

Recreation Carrying Capacity Facts and Considerations. Report 11. Surry Mountain Lake Project Area.

Science.gov (United States)

1980-07-01

contributions of practical experience and knowledge , along with their assistance in arranging schedules, have made this carrying capacity research effort...This survey obtained six responses from boaters and water- skiers . 29 A~ .~ ~ ~ ~ ~ ~ ~ ~~~~~~~PEEI PAG ... ._DIAN.K+.+.+ 3+ ,.+ -,++ + _-NO FILM...User characteristics Table 17 indicates the characteristics of the boaters and water- skiers surveyed at Surry. The small sample size at

Socioeconomic impacts of nuclear generating stations: Surry case study. Technical report 1 Oct 78-4 Jan 82

International Nuclear Information System (INIS)

Flynn, J.

1982-07-01

The report documents a case study of the socioeconomic impacts of the construction and operation of the Surry nuclear power station. It is part of a major post-licensing study of the socioeconomic impacts at twelve nuclear power stations. The case study covers the period beginning with the announcement of plans to construct the reactor and ending in the period, 1980-81. The case study deals with changes in the economy, population, settlement patterns and housing, local government and public services, social structure, and public response in the study area during the construction/operation of the reactor. A regional modeling approach is used to trace the impact of construction/operation on the local economy, labor market, and housing market. Emphasis in the study is on the attribution of socioeconomic impacts to the reactor or other causal factors. As part of the study of local public response to the construction/operation of the reactor, the effects of the Three Mile Island accident are examined

Virginia Power thermal-hydraulics methods

International Nuclear Information System (INIS)

Anderson, R.C.; Basehore, K.L.; Harrell, J.R.

1987-01-01

Virginia Power's nuclear safety analysis group is responsible for the safety analysis of reload cores for the Surry and North Anna power stations, including the area of core thermal-hydraulics. Postulated accidents are evaluated for potential departure from nucleate boiling violations. In support of these tasks, Virginia Power has employed the COBRA code and the W-3 and WRB-1 DNB correlations. A statistical DNBR methodology has also been developed. The code, correlations and statistical methodology are discussed

Project management for the Virginia power spent fuel storage project

International Nuclear Information System (INIS)

Smith, M.

1992-01-01

Like Duke Power, Virginia Power has been involved in spent fuel storage expansion studies for a long time - possibly a little longer than Duke Power. Virginia Power's initial studies date back to the late 70s and into the early 80s. Large variety of storage techniques are reviewed including reracking and transshipment. Virginia Power also considered construction a new spent fuel pool. This was one of the options that was considered early on since Virginia Power started this process before any dry storage techniques had been proven. Consolidation of spent fuel is something that was also studied. Finally, construction of dry storage facility was determined to be the technology of choice. They looked a large variety of dry storage technologies and eventually selected dry storage in metal casks at Surry. There are many of reasons why a utility may choose one technology over another. In Virginia Power's situation, additional storage was needed at Surry much earlier than at other utilities. Virginia Power was confronted with selecting a storage technique and having to be a leader in that it was the first U.S. utility to implement a dry storage system

Virginia Power's nuclear operations: Leading by example

International Nuclear Information System (INIS)

Kuehn, S.E.

1995-01-01

Success has been a long time coming for Virginia Power's nuclear units, but after a record run and some of the shortest refueling outages ever, the rest of the industry could learn a few things. This article describes the changes made by Virginia Power at its Surry and North Anna plants. Virginia Power's recipe for success called for equal amounts of individual initiative, management savvy, engineering discipline, organization, dedication, perseverance, pride, introspection, motivation, and humility

Human reliability analysis in support of a level 1 PRA for Surry during midloop operations

International Nuclear Information System (INIS)

Lin, J.C.; Bley, D.C.; Chu, T.-L.

2004-01-01

The objectives of this Level 1 probabilistic risk assessment (PRA) are to evaluate the important accident sequences initiated during midloop operations and to compare the qualitative and quantitative results with those for accidents initiated during power operations. The primary types of human actions analyzed in this study involve the dynamic operator actions and recovery actions that take place during the accident sequence following an initiating event. Two parts of the human actions were analyzed: failure to diagnose and failure to perform the action. The scope of the Level 1 PRA for Surry during midloop operations includes internal, fire, and flood initiating events. The major categories of dynamic operator actions taken during the accident sequence following an initiating event are: providing makeup to the reactor coolant system (RCS), restoring residual heat removal (RHR) cooling, establishing steam generator reflux cooling, establishing primary feed and spill, establishing gravity feed from refueling water storage tank (RWST), establishing high pressure recirculation, establishing recirculation spray, and cross-connecting RWSTs. All categories are not applicable to all initiating events and all plant operating states (POS). (author)

Reactor power reduction system and method

International Nuclear Information System (INIS)

Bruno, S.J.; Dunn, S.A.; Raber, M.

1978-01-01

A method of operating a nuclear power reactor is disclosed which enables an accelerated power reduction of the reactor without completely shutting the reactor down. The method includes monitoring the incidents which, upon their occurrence, would require an accelerated power reduction in order to maintain the reactor in a safe operation mode; calculating the power reduction required on the occurrence of such an incident; determining a control rod insertion sequence for the normal operation of the reactor, said sequence being chosen to optimize reactor power capability; selecting the number of control rods necessary to respond to the accelerated power reduction demand, said selection being made according to a priority determined by said control rod insertion sequence; and inserting said selected control rods into the reactor core. 11 claims, 13 figures

Virginia Power's nuclear operations: Leading by example

Energy Technology Data Exchange (ETDEWEB)

Kuehn, S.E.

1995-02-01

Success has been a long time coming for Virginia Power's nuclear units, but after a record run and some of the shortest refueling outages ever, the rest of the industry could learn a few things. This article describes the changes made by Virginia Power at its Surry and North Anna plants. Virginia Power's recipe for success called for equal amounts of individual initiative, management savvy, engineering discipline, organization, dedication, perseverance, pride, introspection, motivation, and humility.

Analyses of natural circulation during a Surry station blackout using SCDAP/RELAP5

International Nuclear Information System (INIS)

Bayless, P.D.

1988-10-01

The effects of reactor coolant system natural circulation on the response of the Surry nuclear power plant during a station blackout transient were investigated. A TMLB' sequence (loss of all ac power, immediate loss of auxillary feedwater) was simulated from transient initiation until after fuel rod relocation had begun. Integral analyses of the system thermal-hydraulics and the core damage behavior were performed using the SCDAP/RELAP5 computer code and several different models of the plant. Three scoping calculations were performed in which the complexity of the plant model was progressively increased to determine the overall effects of in-vessel and hot leg natural circulation flows on the plant response. The natural circulation flows extended the transient, slowing the core heatup and delaying core damage by transferring energy from the core to structures in the upper plenum and coolant loops. Increased temperatures in the ex-core structures indicated that they may fail, however. Nine sensitivity calculations were then performed to investigate the effects of modeling uncertainties on the multidimensional natural circulation flows and the system response. Creep rupture failure of the pressurizer surge line was predicted to occur in eight of the calculations, with the hot leg failing in the ninth. The failure time was fairly insensitive to the parameters varied. The failures occurred near the time that fuel rod relocation began, well before failure of the reactor vessel would be expected. A calculation was also performed in which creep rupture failure of the surge line was modeled. The subsequent blowdown led to rapid accumulator injection and quenching of the entire core. 18 refs., 105 figs., 17 tabs

Virginia power nuclear power station engineer training program

International Nuclear Information System (INIS)

Williams, T.M.; Haberstroh-Timpano, S.

1987-01-01

In response to the Institute of Nuclear Power Operations (INPO) accreditation requirements for technical staff and manager, Virginia Power developed the Nuclear Power Station Engineer Training Programs (NPSETP). The NPSETP is directed toward enhancing the specific knowledge and skills of company engineers, especially newly hired engineers. The specific goals of the program are to promote safe and reliable plant operation by providing engineers and appropriate engineering technicians with (1) station-specific basic skills; (2) station-specific specialized skills in the areas of surveillance and test, plant engineering, nuclear safety, and in-service inspection. The training is designed to develop, maintain, and document through demonstration the required knowledge and skills of the engineers in the identified groups at North Anna and Surry Power Stations. The program responds to American National Standards Institute, INPO, and US Nuclear Regulatory Commission standards

Summary of MELCOR 1.8.2 calculations for three LOCA sequences (AG, S2D, and S3D) at the Surry Plant

International Nuclear Information System (INIS)

Kmetyk, L.; Smith, L.

1994-03-01

Activities involving regulatory implementation of updated source term information were pursued. These activities include the identification of the source term, the identification of the chemical form of iodine in the source term, and the timing of the source term's entrance into containment. These activities are intended to support a more realistic source term for licensing nuclear power plants than the current TID-14844 source term and current licensing assumptions. MELCOR calculations were performed to support the technical basis for the updated source term. This report presents the results from three MELCOR calculations of nuclear power plant accident sequences and presents comparisons with Source Term code Package (STCP) calculations for the same sequences. The three low-pressure sequences were analyzed to identify the materials which enter containment (source terms) and are available for release to the environment, and to obtain timing of sequence events. The source terms include fission products and other materials such as those generated by core-concrete interactions. All three calculations, for both MELCOR and STCP, analyzed the Surry plant, a pressurized water reactor (PWR) with a subatmospheric containment design

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Evaluation of severe accident risk during mid-loop operations. Main report. Volume 6. Part 1

Energy Technology Data Exchange (ETDEWEB)

Jo, J.; Lin, C.C.; Neymotin, L. [Brookhaven National Lab., Upton, NY (United States)] [and others

1995-05-01

During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. A phased approach was used in the level-1 program. In phase 1 which was completed in Fall 1991, a coarse screening analysis including internal fire and flood was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The results of the phase 2 level 2/3 study are the subject of this volume of NUREG/CR-6144, Volume 6.

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Evaluation of severe accident risk during mid-loop operations. Main report. Volume 6. Part 1

International Nuclear Information System (INIS)

Jo, J.; Lin, C.C.; Neymotin, L.

1995-05-01

During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by Brookhaven National Laboratory (BNL) and Sandia National Laboratories (SNL). Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. A phased approach was used in the level-1 program. In phase 1 which was completed in Fall 1991, a coarse screening analysis including internal fire and flood was performed for all plant operational states (POSs). The objective of the phase 1 study was to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenarios, and to provide a foundation for a detailed phase 2 analysis. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The results of the phase 2 level 2/3 study are the subject of this volume of NUREG/CR-6144, Volume 6

Power fluctuation reduction methodology for the grid-connected renewable power systems

Science.gov (United States)

Aula, Fadhil T.; Lee, Samuel C.

2013-04-01

This paper presents a new methodology for eliminating the influence of the power fluctuations of the renewable power systems. The renewable energy, which is to be considered an uncertain and uncontrollable resource, can only provide irregular electrical power to the power grid. This irregularity creates fluctuations of the generated power from the renewable power systems. These fluctuations cause instability to the power system and influence the operation of conventional power plants. Overall, the power system is vulnerable to collapse if necessary actions are not taken to reduce the impact of these fluctuations. This methodology aims at reducing these fluctuations and makes the generated power capability for covering the power consumption. This requires a prediction tool for estimating the generated power in advance to provide the range and the time of occurrence of the fluctuations. Since most of the renewable energies are weather based, as a result a weather forecast technique will be used for predicting the generated power. The reduction of the fluctuation also requires stabilizing facilities to maintain the output power at a desired level. In this study, a wind farm and a photovoltaic array as renewable power systems and a pumped-storage and batteries as stabilizing facilities are used, since they are best suitable for compensating the fluctuations of these types of power suppliers. As an illustrative example, a model of wind and photovoltaic power systems with battery energy and pumped hydro storage facilities for power fluctuation reduction is included, and its power fluctuation reduction is verified through simulation.

Intervention in independent spent fuel storage facility license application proceedings for storage on the power plant site

International Nuclear Information System (INIS)

Jordan, J.

1992-01-01

This presentation summarizes the intervention in the Nuclear Regulatory Commission (NRC) licensing process for currently operating Independent Spent fuel Storage Installation (ISFSI) projects at Carolina Power and Light's Company's H.B. Robinson, Duke Power Company's Oconee, and Virginia Power Company's Surry. In addition, intervention at dry storage facilities that are currently under development are also described. The utilities and reactors include Baltimore Gas and Electric Company's Calvert Cliffs, Public Service Company of Colorado's Fort St. Vrain plant, Northern States Power Company's Prairie Island, Wisconsin Electric Power Company's Point Beach, and Consumers Power Company's Palisades

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit-1: Analysis of core damage frequency from internal events during mid-loop operations. Appendices F-H, Volume 2, Part 4

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Bley, D.; Johnson, D.; Holmes, B.

1994-06-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis

MELCOR 1.8.2 assessment: Surry PWR TMLB' (with a DCH study)

International Nuclear Information System (INIS)

Kmetyk, L.N.; Cole, R.K. Jr.; Smith, R.C.; Summers, R.M.; Thompson, S.L.

1994-02-01

MELCOR is a fully integrated, engineering-level computer code, being developed at Sandia National Laboratories for the USNRC. This code models the entire spectrum of severe accident phenomena in a unified framework for both BWRs and PWRs. As part of an ongoing assessment program, the MELCOR computer code has been used to analyze a station blackout transient in Surry, a three-loop Westinghouse PWR. Basecase results obtained with MELCOR 1.8.2 are presented, and compared to earlier results for the same transient calculated using MELCOR 1.8.1. The effects of new models added in MELCOR 1.8.2 (in particular, hydrodynamic interfacial momentum exchange, core debris radial relocation and core material eutectics, CORSOR-Booth fission product release, high-pressure melt ejection and direct containment heating) are investigated individually in sensitivity studies. The progress in reducing numeric effects in MELCOR 1.8.2, compared to MELCOR 1.8.1, is evaluated in both machine-dependency and time-step studies; some remaining sources of numeric dependencies (valve cycling, material relocation and hydrogen burn) are identified

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Dose reduction at nuclear power plants

International Nuclear Information System (INIS)

Baum, J.W.; Dionne, B.J.

1983-01-01

The collective dose equivalent at nuclear power plants increased from 1250 rem in 1969 to nearly 54,000 rem in 1980. This rise is attributable primarily to an increase in nuclear generated power from 1289 MW-y to 29,155 MW-y; and secondly, to increased average plant age. However, considerable variation in exposure occurs from plant to plant depending on plant type, refueling, maintenance, etc. In order to understand the factors influencing these differences, an investigation was initiated to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at light water plants. Objectives are to: identify high-dose maintenance tasks and related dose-reduction techniques; investigate utilization of high-reliability, low-maintenance equipment; recommend improved radioactive waste handling equipment and procedures; examine incentives for dose reduction; and compile an ALARA handbook

Conformance to Regulatory Guide 1.97 Slurry Power Station, Unit Nos. 1 and 2 (Docket Nos. 50-280 and 50-281)

International Nuclear Information System (INIS)

Stoffel, J.W.

1985-09-01

This EG and G Idaho, Inc., report reviews the submittals for Regulatory Guide 1.97, Revision 3, for Unit Nos. 1 and 2 of the Surry Power Station and identifies areas of nonconformance to the regulatory guide. Exceptions to Regulatory Guide 1.97 are evaluated and those areas where sufficient basis for acceptability is not provided are identified

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix E (Sections E.9-E.16), Volume 2, Part 3B

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Wong, S.M.; Bley, D.; Johnson, D.

1994-06-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis

Evaluation of potential severe accidents during low power and shutdown operations at Surry, Unit 1: Analysis of core damage frequency from internal events during mid-loop operations. Appendix E (Sections E.9-E.16), Volume 2, Part 3B

Energy Technology Data Exchange (ETDEWEB)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Wong, S.M. [Brookhaven National Lab., Upton, NY (United States); Bley, D.; Johnson, D. [PLG Inc., Newport Beach, CA (United States)] [and others

1994-06-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analyses that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. In phase 2, mid-loop operation was selected as the plant configuration to be analyzed based on the results of the phase 1 study. The objective of the phase 2 study is to perform a detailed analysis of the potential accident scenarios that may occur during mid-loop operation, and compare the results with those of NUREG-1150. The scope of the level-1 study includes plant damage state analysis, and uncertainty analysis. Volume 1 summarizes the results of the study. Internal events analysis is documented in Volume 2. It also contains an appendix that documents the part of the phase 1 study that has to do with POSs other than mid-loop operation. Internal fire and internal flood analyses are documented in Volumes 3 and 4. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. Volume 6 documents the accident progression, source terms, and consequence analysis.

Virginia Power's vision of lower costs

International Nuclear Information System (INIS)

Anon.

1997-01-01

The top two positions in the 1996 annual league table of US nuclear production costs were taken by Surry at $11.45/MWh generated and North Anna at $12.64. Both are PWR plants operated by Virginia Power. This is part of a consistent pattern of good performance in recent years. In the late 1980s, however, the performance of these plants was very poor. The management changes which have brought about the transformation are examined. They include: setting goals; better teamwork; increased accountability of senior management for budgets; development and monitoring of performance indicators; running the nuclear division as a separate business; more effective maintenance and reduced outage costs. (UK)

EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

Directory of Open Access Journals (Sweden)

V. N. Radkevich

2016-01-01

Full Text Available The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6�

Risk contribution from low power and shutdown of a pressurized water reactor

International Nuclear Information System (INIS)

Chu, T.L.; Pratt, W.T.

1997-01-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power operation and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 PRA for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. 12 refs., 7 tabs

Level 1 probabilistic risk assessment of low power and shutdown operations at a PWR: Phase 2 results

International Nuclear Information System (INIS)

Chu, T.L.; Bozoki, G.; Kohut, P.; Musicki, Z.; Wong, S.M.; Yang, J.; Hsu, C.J.; Diamond, D.J.; Su, R.F.; Holmes, B.; Siu, N.; Bley, D.; Lin, J.

1992-01-01

As a result of the Chernobyl accident and other precursor events (e.g., Diablo Canyon), the US Nuclear Regulatory Commission's (NRC's) Office of Nuclear Regulatory Research (RES) initiated an extensive project during 1989 to carefully examine the potential risks during Low Power and Shutdown (LP ampersand S) operations. Shortly after the program began, an event occurred at the Vogtle plant during shutdown, which further intensified the effort of the LP ampersand S program. In the LP ampersand S program, one pressurized water reactor (PWR), Surry, and one boiling water reactor (BWR), Grand Gulf, were selected, mainly because they were previously analyzed in the NUREG-1150 Study. The Level-1 Program is being performed in two phases. Phase 1 was dedicated to performing a coarse screening level-1 analysis including internal fire and flood. A draft report was completed in November, 1991. In the phase 2 study, mid-loop operations at the Surry plant were analyzed in detail. The objective of this paper is to present the approach of the phase 2 study and the preliminary results and insights

PowerFilm PowerShade Fixed Site Solar System Cost Reduction Plan

Science.gov (United States)

2014-07-31

system was designed which adds capability of grid tie connection to the standalone function. This battery operating system has built-in intelligence...goal concerning alternative conductive grid inks was to reduce the cost of the silver ink layer without a reduction in PV power with experimentation... system . To overcome this loss, a new BOS unit with higher power transfer efficiency has been developed. This system also has grid tie

Coal-Fired Power Plant Heat Rate Reductions

Science.gov (United States)

View a report that identifies systems and equipment in coal-fired power plants where efficiency improvements can be realized, and provides estimates of the resulting net plant heat rate reductions and costs for implementation.

Dry cask storage: a Vepco/DOE/EPRI cooperative demonstration program

International Nuclear Information System (INIS)

Smith, M.L.

1984-01-01

In response to a Department of Energy (DOE) Solicitation for Cooperative Agreement Proposal, Virginia Electric and Power Company (Vepco) proposed to participate in a spent fuel storage demonstration program utilizing the dry cask storage technology. This proposed program includes dry cask storage at Vepco's Surry Nuclear Power Station and research and development activities at a DOE site in support of the licensed program at Surry. Phase I of Vepco's two-phase program involves a demonstration of the licensed dry cask storage of spent fuel in an inert atmosphere at the Surry Power Station site. Phase II of Vepco's proposed program will involve the demonstration of storing unconsolidated and consolidated spent fuel in dry casks filled only with air. This phase of the program will involve DOE site testing similar to Phase I and is expected to require an additional (fourth) cask to demonstrate storage of unconsolidated spent fuel in air-filled casks

Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization

Directory of Open Access Journals (Sweden)

Zhou G Tong

2007-01-01

Full Text Available Many modern communication signal formats, such as orthogonal frequency-division multiplexing (OFDM and code-division multiple access (CDMA, have high peak-to-average power ratios (PARs. A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers (PAs, but also leads to low transmission power efficiency. Selected mapping (SLM and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach.

Reactive power compensation and loss reduction in large industrial enterprises

Energy Technology Data Exchange (ETDEWEB)

Jovanovic, S; Gajic, B; Mijailovic, S [Institute Nikola Tesla, Beograd (Yugoslavia)

1991-12-01

This paper considers the reactive power compensation and the active power and energy loss reduction of large radial power networks in the Serbian mine and smelting industry. It gives an efficient optimization procedure for positioning and sizing capacitors in large industrial systems integrated with a simple network analysis method. (Author).

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

International Nuclear Information System (INIS)

1975-01-01

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

Assessment of the potential for high-pressure melt ejection resulting from a Surry station blackout transient

International Nuclear Information System (INIS)

Knudson, D.L.; Dobbe, C.A.

1993-11-01

Containment integrity could be challenged by direct heating associated with a high pressure melt ejection (HPME) of core materials following reactor vessel breach during certain severe accidents. Intentional reactor coolant system (RCS) depressurization, where operators latch pressurizer relief valves open, has been proposed as an accident management strategy to reduce risks by mitigating the severity of HPME. However, decay heat levels, valve capacities, and other plant-specific characteristics determine whether the required operator action will be effective. Without operator action, natural circulation flows could heat ex-vessel RCS pressure boundaries (surge line and hot leg piping, steam generator tubes, etc.) to the point of failure before vessel breach, providing an alternate mechanism for RCS depressurization and HPME mitigation. This report contains an assessment of the potential for HPME during a Surry station blackout transient without operator action and without recovery. The assessment included a detailed transient analysis using the SCDAP/RELAP5/MOD3 computer code to calculate the plant response with and without hot leg countercurrent natural circulation, with and without reactor coolant pump seal leakage, and with variations on selected core damage progression parameters. RCS depressurization-related probabilities were also evaluated, primarily based on the code results

NOx reduction in Opole power plant

International Nuclear Information System (INIS)

Higgins, B.; Gong, B.; Pozzobon, E.; Kinal, E.; Pilipionek, J.

2010-01-01

In 2008 PGE Elektrownia Opole ordered a 'turn-key' retrofit execution of the combustion system to reduce NO x emission at BP-1150 boiler. The project includes modifications of burners as a first stage, and then ROFA system installation for combustion optimization and primary reduction of NO x , and Rotamix system installation for the further, secondary NO x reduction. The condition to install ROFA and Rotamix systems was keeping the same parameters of the power unit operation, in particular CO emission level, fly ash LOI and bottom ash LOI, ammonia slip, ambient noise, boiler availability and efficiency, material wastage rate, steam flow rate and temperature, as well as consumption of urea, water, electricity and compressed air. The work for this project was performed by a consortium that included Nalco Mobotec, Remak-Rozruch (a Consortium Leader) and SEFAKO

Power flow prediction in vibrating systems via model reduction

Science.gov (United States)

Li, Xianhui

This dissertation focuses on power flow prediction in vibrating systems. Reduced order models (ROMs) are built based on rational Krylov model reduction which preserve power flow information in the original systems over a specified frequency band. Stiffness and mass matrices of the ROMs are obtained by projecting the original system matrices onto the subspaces spanned by forced responses. A matrix-free algorithm is designed to construct ROMs directly from the power quantities at selected interpolation frequencies. Strategies for parallel implementation of the algorithm via message passing interface are proposed. The quality of ROMs is iteratively refined according to the error estimate based on residual norms. Band capacity is proposed to provide a priori estimate of the sizes of good quality ROMs. Frequency averaging is recast as ensemble averaging and Cauchy distribution is used to simplify the computation. Besides model reduction for deterministic systems, details of constructing ROMs for parametric and nonparametric random systems are also presented. Case studies have been conducted on testbeds from Harwell-Boeing collections. Input and coupling power flow are computed for the original systems and the ROMs. Good agreement is observed in all cases.

Maintenance of fire systems and equipment at Virginia Power

International Nuclear Information System (INIS)

Doubrely, E.B. Jr.

1989-01-01

The basics of fire protection systems maintenance are well codified and documented in the National Fire Codes published by the National Fire Protection Association. In addition, Insurers often promulgate minimum standards for fire protection systems design and maintenance to which they attach conditions of insurability. Regulatory agencies and even in-house corporate policies can impact the maintenance of fire protection systems and equipment. This presentation will focus on the various methods and alternate ways of performing system maintenance, whether required by code, insurer, or by some regulatory commitment at Virginia Powers North Anna and Surry nuclear power stations. The approach to performing similar work is handled differently at each station. This difference can be attributed to proximity to outside assistance as well as plant philosophy. In addition to station maintenance practices, a discussion of in-house servicing of portable fire suppression equipment is offered. 1 tab

An Optimization Mechanism Intended for Static Power Reduction Using Dual-thTechnique

Directory of Open Access Journals (Sweden)

Rodolfo P. Santos

2012-01-01

Full Text Available Power consumption reduction is a challenge nowadays. Techniques for dynamic and static power minimization have been proposed, but most of them are very time consuming. This work proposes an algorithm for reducing static power, which can be perfectly inserted in the conventional design flow for integrated systems considering an open source environment (open access infrastructure. The proposed approach, based on a Dual-Threshold technique, replaces part of the cells of the circuit by cells with a higher threshold voltage without resulting in timing violations in the circuit. The decision to replace a cell is based on timing estimates of the circuit modeling with the cell replacement, before it is actually replaced. The fact that only some cells are replaced every iteration results in a reduction of the runtime of the algorithm. Additionally, results showed a reduction in static power up to 39.28%, when applying the proposed approach in the ISCAS85 benchmark circuits.

Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

Science.gov (United States)

Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

2014-01-01

This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

Engine-propeller power plant aircraft community noise reduction key methods

Science.gov (United States)

Moshkov P., A.; Samokhin V., F.; Yakovlev A., A.

2018-04-01

Basic methods of aircraft-type flying vehicle engine-propeller power plant noise reduction were considered including single different-structure-and-arrangement propellers and piston engines. On the basis of a semiempirical model the expressions for blade diameter and number effect evaluation upon propeller noise tone components under thrust constancy condition were proposed. Acoustic tests performed at Moscow Aviation institute airfield on the whole qualitatively proved the obtained ratios. As an example of noise and detectability reduction provision a design-and-experimental estimation of propeller diameter effect upon unmanned aircraft audibility boundaries was performed. Future investigation ways were stated to solve a low-noise power plant design problem for light aircraft and unmanned aerial vehicles.

Assessment of the potential for HPME during a station blackout in the Surry and Zion PWRS

International Nuclear Information System (INIS)

Knudson, D.L.; Bayless, P.D.; Dobbe, C.A.; Odar, F.

1994-01-01

The integrity of a PWR (pressurized water reactor) containment structure could be challenged by direct heating associated with a HPME (high pressure melt ejection) of core materials following reactor vessel lower head breach during certain severe accidents. Structural failure resulting from direct containment heating is a contributor to the risk of operating a PWR. Intentional RCS (reactor coolant system) depressurization, where operators latch pressurizer relief valves open, has been proposed as an accident management strategy to reduce those risks by mitigating the severity of the HPME. However, decay heat levels, valve capacities, and other plant-specific characteristics determine whether the required operator action will be effective. Without operator action, natural circulation flows could heat ex-vessel RCS pressure boundaries (surge line and hot leg piping, steam generator tubes, etc.) to the point of failure before failure of the lower head providing an unintentional mechanism for depressurization and HPME mitigation. This paper summarizes an assessment of RCS depressurization with respect to the potential for HPME during a station blackout in the Surry and Zion PWRs. The assessment included a detailed transient analysis using the SCDAP/RELAP5/MOD3 computer code and an evaluation of RCS depressurization-related probabilities primarily based on the code results

Cost reduction potentials in the German market for balancing power

International Nuclear Information System (INIS)

Flinkerbusch, Kai; Heuterkes, Michael

2010-01-01

This article examines potential cost reductions in the market for balancing power by pooling all four German control areas. In a united control area both the procurement and the production of balancing power may be more efficient than in four separated control areas. Our data contain bids on energy procurement as well as balancing power flows in the period from December 2007 to November 2008. A reference scenario simulates the market results for secondary and tertiary balancing power. Subsequently, we simulate a united control area. We show that in the period under review the total costs of balancing power are reduced by 17%. (author)

EMISSIONS REDUCTION DATA FOR GRID-CONNECTED PHOTOVOLTAIC POWER SYSTEMS

Science.gov (United States)

This study measured the pollutant emission reduction potential of 29 photovoltaic (PV) systems installed on residential and commercial building rooftops across the U.S. from 1993 through 1997. The U.S. Environmental Protection Agency (EPA) and 21 electric power companies sponsor...

Dynamic model reduction: An overview of available techniques with application to power systems

Directory of Open Access Journals (Sweden)

Đukić Savo D.

2012-01-01

Full Text Available This paper summarises the model reduction techniques used for the reduction of large-scale linear and nonlinear dynamic models, described by the differential and algebraic equations that are commonly used in control theory. The groups of methods discussed in this paper for reduction of the linear dynamic model are based on singular perturbation analysis, modal analysis, singular value decomposition, moment matching and methods based on a combination of singular value decomposition and moment matching. Among the nonlinear dynamic model reduction methods, proper orthogonal decomposition, the trajectory piecewise linear method, balancing-based methods, reduction by optimising system matrices and projection from a linearised model, are described. Part of the paper is devoted to the techniques commonly used for reduction (equivalencing of large-scale power systems, which are based on coherency, synchrony, singular perturbation analysis, modal analysis and identification. Two (most interesting of the described techniques are applied to the reduction of the commonly used New England 10-generator, 39-bus test power system.

Quantitative assessment of aquatic impacts of power plants

Energy Technology Data Exchange (ETDEWEB)

McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

1979-08-01

Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers.

Quantitative assessment of aquatic impacts of power plants

International Nuclear Information System (INIS)

McKenzie, D.H.; Arnold, E.M.; Skalski, J.R.; Fickeisen, D.H.; Baker, K.S.

1979-08-01

Progress is reported in a continuing study of the design and analysis of aquatic environmental monitoring programs for assessing the impacts of nuclear power plants. Analysis of data from Calvert Cliffs, Pilgrim, and San Onofre nuclear power plants confirmed the generic applicability of the control-treatment pairing design suggested by McKenzie et al. (1977). Substantial progress was made on the simulation model evaluation task. A process notebook was compiled in which each model equation was translated into a standardized notation. Individual model testing and evaluating was started. The Aquatic Generalized Environmental Impact Simulator (AGEIS) was developed and will be tested using data from Lake Keowee, South Carolina. Further work is required to test the various models and perfect AGEIS for impact analyses at actual power plant sites. Efforts on the hydrologic modeling task resulted in a compendium of models commonly applied to nuclear power plants and the application of two well-received hydrodynamic models to data from the Surry Nuclear Power Plant in Virginia. Conclusions from the study of these models indicate that slight inaccuracies of boundary data have little influence on mass conservation and accurate bathymetry data are necessary for conservation of mass through the model calculations. The hydrologic modeling task provides valuable reference information for model users and monitoring program designers

Time and dose assessment of barge shipment and at-reactor handling of a CASTOR V/21 spent fuel storage cask

Energy Technology Data Exchange (ETDEWEB)

Hostick, C.J. (Pacific Northwest Lab., Richland, WA (United States)); Lavender, J.C. (Westinghouse Hanford Co., Richland, WA (United States)); Wakeman, B.H. (Virginia Electric and Power Co., Richmond, VA (United States))

1992-04-01

This report contains the results of a time/motion analysis and a radiation dose assessment made during the receipt from barge transport and the loading of CAst iron cask for Storage and Transport Of Radioactive material (CASTOR) V/21 storage casks with spent nuclear fuel at the Surry Power Station in Virginia during 1987. The study was a cooperative effort between Pacific Northwest Laboratory (PNL) and Virginia Electric and Power Company (Virginia Power), and was funded by the US Department of Energy (DOE) Transportation Program Office. In this study, cask handling activities were tracked at the Surry Power Station, tracing the transfer of the empty spent fuel storage cask from an ocean-going vessel to a barge for river transport through the activities required to place the loaded storage cask at an at-reactor storage location.

Minimum load reduction for once-through boiler power plants

International Nuclear Information System (INIS)

Colombo, P.; Godina, G.; Manganelli, R.

2001-01-01

In Italy the liberalization process of energy market is giving particular importance to the optimization of power plants performances; especially for those that will be called to satisfy grid peak demands. On those plants some techniques have been experimented for the reduction of minimum load; these techniques, investigated and tested by an engineering dynamic simulator, have been sequentially tested on plant. The minimum load for up 320 MW of Tavazzano power plants has been diminished from 140 down to 80 MW without plant modification [it

Standing phase angle reduction for power system restoration

Energy Technology Data Exchange (ETDEWEB)

Hazarika, D. [Assam Engineering College (India). Electrical Engineering Dept.; Sinha, A.K. [IIT Khargpur (India). Electrical Engineering Dept.

1998-01-01

The paper describes a methodology for the reduction of standing phase angle (SPA) difference between two buses of a power system, which is essential before interconnecting a line between two buses. This problem is encountered normally during restoration operations of a power system. For this purpose, the standing phase angle difference between two specific buses is represented in terms of sensitivity factors associated with the change in real power injections at the buses. To arrive at the desired standing phase angle difference between two buses, the modified contribution at generation/load buses have been evaluated based on 'higher the sensitivity higher the participation' logic. This methodology acts as a direct help to reduce excessive SPA difference between two buses to an acceptable limit, which otherwise requires regulation of various generation levels on a trial and error basis. (author)

Experimental study on using a high-temperature superconducting inductor for power loss reduction in an active power filter

International Nuclear Information System (INIS)

Chao, C; To, H P; Grantham, C; Rahman, M F

2006-01-01

An active power filter improves the electric power quality through the compensation of harmonics in the power network. A current-source active power filter using a conventional copper inductor for its energy storage has a significant power loss. The loss in the copper inductor can be substantially reduced by using a high-temperature superconducting (HTS) inductor instead. Experiments have been conducted on a prototype current-source active power filter for studying the power loss reduction effect and harmonics compensation performance of the active power filter using a HTS inductor. Experimental results are analysed and discussed in this paper

Virginia Power and Department of Energy spent fuel transportation experience

International Nuclear Information System (INIS)

Ruska, M.D.; Schoonen, D.H.

1986-12-01

Spent fuel assemblies for the Spent Fuel Storage Cask Testing Program conducted by EG and G Idaho, Inc., at the Idaho National Engineering Laboratory (INEL) were transported to the INEL. A total of 69 spent fuel assemblies (23 shipments) were shipped from Virginia Power's nuclear power plant at Surry, Virginia, to the INEL between July 1985 and June 1986 to fill and test three spent fuel storage casks. The shipments were made over the highway system in Transnuclear, Inc., TN-8L shipping casks on specially constructed trailers. The shipments were moved by diesel tractors owned and operated by Tri-State Motor Transit Company of Joplin, Missouri. The gross vehicle weight for each shipment was 112,000 lb, which was a major consideration when selecting routes for the shipments. Cooperative negotiations with officials for the 17 states involved obtained authorization to transport through their states. The shipping campaign was successfully completed through close communication and cooperation and careful planning and operation by all organizations involved

Conformance to Generic Letter 83-28, Items 3.1.3 and 3.2.3, Beaver Valley, Unit No. 1, North Anna, Unit Nos. 1 and 2, Surry Unit Nos. 1 and 2 (Docket Nos. 50-334, 50-338, 50-339, 50-280, and 50-281)

International Nuclear Information System (INIS)

Haroldsen, R.

1985-09-01

This report provides a review of the submittals for Beaver Valley, Unit No. 1, North Anna, Unit Nos. 1 and 2, and Surry, Unit Nos. 1 and 2, for conformance to Generic Letter 83-28, Items 3.1.3 and 3.2.3. The specific plants selected were reviewed as a group because of similarity in type and applicability of review items

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

are subject to decreasing productivity manifested in the form of decreasing production fluid temperature, flow rate, or both during the life span of the associated power generation project. The impacts of geothermal production fluid temperature decline on power plant performance can be significant; a reduction in heat input to a power plant not only decreases the thermal energy available for conversion to electrical power, but also adversely impacts the power plant efficiency. The impact of resource productivity decline on power generation project economics can be equally detrimental. The reduction in power generation is directly correlated to a reduction in revenues from power sales. Further, projects with Power Purchase Agreement (PPA) contracts in place may be subject to significant economic penalties if power generation falls below a specified default level. While the magnitude of PPA penalties varies on a case-by-case basis, it is not unrealistic for these penalties to be on the order of the value of the deficit power sales such that the utility may purchase the power elsewhere. This report evaluates the use of geothermal/solar-thermal hybrid plant technology for mitigation of resource productivity decline, which has not been a primary topic of investigation in previous analyses in the open literature.

Current status of waste power generation in Japan and its impact on carbon dioxide reduction

International Nuclear Information System (INIS)

Takaoka, Masaki; Takeda, Nobuo; Yamagata, Naruo; Masuda, Takahiro

2010-01-01

In this research, we discuss current status of waste power generation (WPG) in Japan and various scenarios about the indirect reduction of carbon dioxide by WPG. The numbers of WPG facilities are 291 domestically as of 2006. Power generation capacity achieves 1584 MW and power generation amount is 7179 G Wh/ year. When we consider to reduce the used electricity for operation and office by WPG and emission coefficient of electricity for operation and office is to be 0.555 kg-CO 2 / kWh in default value, then carbon dioxide reduction amount is calculated to 3.9 million tons, which is equivalent to 26.7 % of 14.6 million tons of carbon dioxide emitted by municipal solid waste incinerator (MSWI) in 2005. Using various existing technological options, it finds that the efficiency of power generation will achieve more than 20 % in MSWI with the power generation efficiency of 20% as a feasible assumption, the total power generation amount and the carbon dioxide reduction amount will become 16540 G Wh/ year and 9.18 million tons, respectively. So, it is equivalent to 62.7% of carbon dioxide emitted by MSWI. Also, the ratio of additional reduction amount of carbon dioxide by WPG to total additional reduction amount in Japan during the first commitment period is 26.3%, which suggests that the promotion of WPG in MSWI is one of effective options for prevention of global warming. (author)

Erosion/corrosion-induced pipe wall thinning in US Nuclear Power Plants

International Nuclear Information System (INIS)

Wu, P.C.

1989-04-01

Erosion/corrosion in single-phase piping systems was not clearly recognized as a potential safety issue before the pipe rupture incident at the Surry Power Station in December 1986. This incident reminded the nuclear industry and the regulators that neither the US Nuclear Regulatory Commission (NRC) nor Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code require utilities to monitor erosion/corrosion in the secondary systems of nuclear power plants. This report provides a brief review of the erosion/corrosion phenomenon and its major occurrence in nuclear power plants. In addition, efforts by the NRC, the industry, and the ASME Section XI Committee to address this issue are described. Finally, results of the survey and plant audits conducted by the NRC to assess the extent of erosion/corrosion-induced piping degradation and the status of program implementation regarding erosion/corrosion monitoring are discussed. This report will support a staff recommendation for an additional regulatory requirement concerning erosion/corrosion monitoring. 21 refs., 3 tabs

Cost-Effectiveness of Emission Reduction for the Indonesian Coal-Fired Power Plants

NARCIS (Netherlands)

Handayani, Kamia; Krozer, Yoram

2014-01-01

This paper presents the result of research on the cost-effectiveness of emission reduction in the selected coal-fired power plants (CFPPs) in Indonesia. The background of this research is the trend of more stringent environmental regulation regarding air emission from coal-fired power plants (CFPPs)

Strategies for emission reduction from thermal power plants.

Science.gov (United States)

Prisyazhniuk, Vitaly A

2006-07-01

Major polluters of man's environment are thermal power stations (TPS) and power plants, which discharge into the atmosphere the basic product of carbon fuel combustion, CO2, which results in a build-up of the greenhouse effect and global warm-up of our planet's climate. This paper is intended to show that the way to attain environmental safety of the TPS and to abide by the decisions of the Kyoto Protocol lies in raising the efficiency of the heat power stations and reducing their fuel consumption by using nonconventional thermal cycles. Certain equations have been derived to define the quantitative interrelationship between the growth of efficiency of the TPS, decrease in fuel consumption and reduction of discharge of dust, fuel combustion gases, and heat into the environment. New ideas and new technological approaches that result in raising the efficiency of the TPS are briefly covered: magneto-hydrodynamic resonance, the Kalina cycle, and utilizing the ambient heat by using, as the working medium, low-boiling substances.

Emission reduction trading - a power marketer`s perspective

Energy Technology Data Exchange (ETDEWEB)

Stewart, M. [Powerex Inc., Vancouver, BC (Canada)

1999-10-01

The current situation , and the short-term and long-term outlook in emission reduction trading are reviewed from the point of view of a power marketer. The author`s view is that while the concept of emission reduction credit (ERC) is easy enough to understand, i.e. a series of measures to reduce carbon dioxide production and enhance carbon sequestration, there is no standard definition, although there are a number of models under consideration. What is being sought is clear ownership and title, a clear understanding of what qualifies as a credit, credit for early action, commodity specifications and the ability to hedge. The author predicts that in the short-tem, industry will experiment with different types of transactions to gain experience and seek partners who are willing to share risk and development cost. In the longer-term, emission reduction credits will be bought and sold as commodities and traded, swapped or exchanged as part of a portfolio in bilateral trade transactions, and used in hedging against future liabilities.

Data base on dose reduction research projects for nuclear power plants

International Nuclear Information System (INIS)

Khan, T.A.; Yu, C.K.; Roecklein, A.K.

1994-05-01

This is the fifth volume in a series of reports that provide information on dose reduction research and health physics technology or nuclear power plants. The information is taken from two of several databases maintained by Brookhaven National Laboratory's ALARA Center for the Nuclear Regulatory Commission. The research section of the report covers dose reduction projects that are in the experimental or developmental phase. It includes topics such as steam generator degradation, decontamination, robotics, improvements in reactor materials, and inspection techniques. The section on health physics technology discusses dose reduction efforts that are in place or in the process of being implemented at nuclear power plants. A total of 105 new or updated projects are described. All project abstracts from this report are available to nuclear industry professionals with access to a fax machine through the ACEFAX system or a computer with a modem and the proper communications software through the ACE system. Detailed descriptions of how to access all the databases electronically are in the appendices of the report

Occupational dose reduction developments and data collected at nuclear power plants

International Nuclear Information System (INIS)

Dionne, B.J.; Baum, J.W.

1984-01-01

Occupational dose reduction developments and data collected at nuclear power plants have been described. Written descriptions of repetitive high dose jobs, their collective dose equivalent ranges and list of dose reduction techniques will aid in reducing collective dose equivalents from these dose-reduction targets. Knowing which components contribute to high maintenance or repair dose will aid in reducing routine maintenance collective dose equivalents. The radwaste dose reduction improvements will aid in reducing radwaste operations collective dose equivalent and reduce the number of radwaste workers who exceed their administrative dose limits. The identification and rating of managers' and workers' ALARA incentives will provide the basis for recommendations to improve dose reduction incentives. Lastly, the identification and rating of the key components of an ALARA program will aid in the development and coordination of the nuclear station ALARA programs

A Hybrid Data Compression Scheme for Power Reduction in Wireless Sensors for IoT.

Science.gov (United States)

Deepu, Chacko John; Heng, Chun-Huat; Lian, Yong

2017-04-01

This paper presents a novel data compression and transmission scheme for power reduction in Internet-of-Things (IoT) enabled wireless sensors. In the proposed scheme, data is compressed with both lossy and lossless techniques, so as to enable hybrid transmission mode, support adaptive data rate selection and save power in wireless transmission. Applying the method to electrocardiogram (ECG), the data is first compressed using a lossy compression technique with a high compression ratio (CR). The residual error between the original data and the decompressed lossy data is preserved using entropy coding, enabling a lossless restoration of the original data when required. Average CR of 2.1 × and 7.8 × were achieved for lossless and lossy compression respectively with MIT/BIH database. The power reduction is demonstrated using a Bluetooth transceiver and is found to be reduced to 18% for lossy and 53% for lossless transmission respectively. Options for hybrid transmission mode, adaptive rate selection and system level power reduction make the proposed scheme attractive for IoT wireless sensors in healthcare applications.

A system dynamics model of China's electric power structure adjustment with constraints of PM10 emission reduction.

Science.gov (United States)

Guo, Xiaopeng; Ren, Dongfang; Guo, Xiaodan

2018-06-01

Recently, Chinese state environmental protection administration has brought out several PM10 reduction policies to control the coal consumption strictly and promote the adjustment of power structure. Under this new policy environment, a suitable analysis method is required to simulate the upcoming major shift of China's electric power structure. Firstly, a complete system dynamics model is built to simulate China's evolution path of power structure with constraints of PM10 reduction considering both technical and economical factors. Secondly, scenario analyses are conducted under different clean-power capacity growth rates to seek applicable policy guidance for PM10 reduction. The results suggest the following conclusions. (1) The proportion of thermal power installed capacity will decrease to 67% in 2018 with a dropping speed, and there will be an accelerated decline in 2023-2032. (2) The system dynamics model can effectively simulate the implementation of the policy, for example, the proportion of coal consumption in the forecast model is 63.3% (the accuracy rate is 95.2%), below policy target 65% in 2017. (3) China should promote clean power generation such as nuclear power to meet PM10 reduction target.

Greenhouse Gas reduction for scenarios of power sources development of the Republic of Moldova

Directory of Open Access Journals (Sweden)

Comendant I.

2010-04-01

Full Text Available For the new power market conditions, Moldova power sources development options up to 2033 are evaluated, and for the six scenarios selected the greenhouse gas reduction impact is determined.

Human engineering considerations in the design of New Virginia Power Radwaste facilities

International Nuclear Information System (INIS)

Bankley, A.V.; Morris, L.L.; Lippard, D.W.

1988-01-01

Human engineering principles were considered by Virginia Power in the recent design of new radwaste facilities (NRFs) for both the Surry and North Anna power stations. Virginia Power recognized that the rigorous application of human engineering principles to the NRF design was essential to the ultimate success or failure of the facilities. Success of the NRF should not only be measured in the volume of radwaste processed but also by other factors such as (a) availability and maintainability of preferred equipment, (b) as-low-as-reasonably-achievable considerations, (c) actual release rates versus achievable release rates, and (d) flexibility to deal with varying circumstances. Each of these success criteria would suffer as the result of operator/human inefficiencies or error. Therefore, human engineering should be applied to the maximum practical extent to minimize such inefficiencies or errors. No method is ever going to ensure a perfectly human-engineered facility design. Virginia Power believes, however, that significant strides have been made in efforts to design and construct a successful radwaste processing facility, a facility where operating success rests with the ability of the human operators to perform their jobs in an efficient and reliable fashion

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Main report and appendices, Volume 6, Part 1

International Nuclear Information System (INIS)

Brown, T.D.; Kmetyk, L.N.; Whitehead, D.; Miller, L.; Forester, J.; Johnson, J.

1995-03-01

Traditionally, probabilistic risk assessments (PRAS) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Recent studies and operational experience have, however, implied that accidents during low power and shutdown could be significant contributors to risk. In response to this concern, in 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The program consists of two parallel projects being performed by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf). The program objectives include assessing the risks of severe accidents initiated during plant operational states other than full power operation and comparing the estimated risks with the risk associated with accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program is that of a Level-3 PRA. The subject of this report is the PRA of the Grand Gulf Nuclear Station, Unit 1. The Grand Gulf plant utilizes a 3833 MWt BUR-6 boiling water reactor housed in a Mark III containment. The Grand Gulf plant is located near Port Gibson, Mississippi. The regime of shutdown analyzed in this study was plant operational state (POS) 5 during a refueling outage, which is approximately Cold Shutdown as defined by Grand Gulf Technical Specifications. The entire PRA of POS 5 is documented in a multi-volume NUREG report (NUREG/CR-6143). The internal events accident sequence analysis (Level 1) is documented in Volume 2. The Level 1 internal fire and internal flood analyses are documented in Vols 3 and 4, respectively

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Main report and appendices, Volume 6, Part 1

Energy Technology Data Exchange (ETDEWEB)

Brown, T.D.; Kmetyk, L.N.; Whitehead, D.; Miller, L. [Sandia National Labs., Albuquerque, NM (United States); Forester, J. [Science Applications International Corp., Albuquerque, NM (United States); Johnson, J. [GRAM, Inc., Albuquerque, NM (United States)

1995-03-01

Traditionally, probabilistic risk assessments (PRAS) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Recent studies and operational experience have, however, implied that accidents during low power and shutdown could be significant contributors to risk. In response to this concern, in 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The program consists of two parallel projects being performed by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf). The program objectives include assessing the risks of severe accidents initiated during plant operational states other than full power operation and comparing the estimated risks with the risk associated with accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program is that of a Level-3 PRA. The subject of this report is the PRA of the Grand Gulf Nuclear Station, Unit 1. The Grand Gulf plant utilizes a 3833 MWt BUR-6 boiling water reactor housed in a Mark III containment. The Grand Gulf plant is located near Port Gibson, Mississippi. The regime of shutdown analyzed in this study was plant operational state (POS) 5 during a refueling outage, which is approximately Cold Shutdown as defined by Grand Gulf Technical Specifications. The entire PRA of POS 5 is documented in a multi-volume NUREG report (NUREG/CR-6143). The internal events accident sequence analysis (Level 1) is documented in Volume 2. The Level 1 internal fire and internal flood analyses are documented in Vols 3 and 4, respectively.

Cost reduction potentials of offshore wind power in Germany

International Nuclear Information System (INIS)

Hobohm, Jens; Krampe, Leonard; Peter, Frank

2014-01-01

Offshore wind power is a major hope for the German energy turnaround. However, it will only be possible to tap its cost reduction potentials if industry, the political leadership and the administrative authorities join forces to create the necessary preconditions. An important requirement for this capital-intensive technology are stable legal and political framework conditions. A recent study on the future shows what needs to be done.

Change in CANDU-6 reactivity following a power reduction at low PHT purity

International Nuclear Information System (INIS)

Whitlock, J.J.; Soulard, M.R.; Baudouin, A.

1995-01-01

The reactivity effect of a power reduction in CANDU-6 is examined using a three-dimensional, steady-state, coupled neutronics/thermalhydraulics methodology, starting from a global irradiation distribution matched to site data. The power reduction is sufficient to suppress coolant boiling in the fuel channels, and thus the significant parameters affecting reactivity are an increase in coolant density and a decrease in fuel temperature. These individual components are estimated using infinite-lattice-cell methodology. The effect of using newer methodology, particularly for the thermalhydraulic analysis, is examined by comparison with previous simulations. (author). 10 refs., 7 tabs., 1 fig

Reduction of capital costs of nuclear power plants. NEA-report

International Nuclear Information System (INIS)

2000-01-01

Since the the mid-1980s, the declining real prices of fossil fuels and the significant improvements in thermal efficiencies of combined cycle power plants have eroded the economic competitiveness of nuclear power plants in most OECD countries. In order for nuclear power to remain a viable option for the next millennium, the cost of electricity from nuclear power plant must be greatly reduced to be competitive with alternative sources. Of the three major components of nuclear generation cost - capital, O and M and fuel - the capital cost component makes up approximately 60 per cent of the total. Therefore, identification of the means to reduce the capital costs of nuclear power plants is a high priority activity toward keeping nuclear power competitive. Among a number of capital cost reduction measures, the principal ones were agreed by the expert group as follows: Increased plant size, improved construction methods, reduced construction schedule, design improvement, improved procurement, organisation and contractual aspects, standardisation and construction in series, multiple unit construction, regulatory and policy reform. (orig.)

The role of nuclear power in the reduction of greenhouse gas emissions

International Nuclear Information System (INIS)

Baratta, A.J.

2010-01-01

Nuclear energy is a low greenhouse gas emitter and is capable of providing large amounts of power using proven technology. In the immediate future, it can contribute to greenhouse gas reduction but only on a modest scale, replacing a portion of the electricity produced by coal fired power plants. While it has the potential to do more, there are significant resource issues that must be addressed if nuclear power is to replace coal or natural gas as a source of electricity

Data base on nuclear power plant dose reduction research projects

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Baum, J.W.

1986-10-01

Staff at the ALARA Center of Brookhaven National Laboratory have established a data base of information about current research that is likely to result in lower radiation doses to workers. The data base, concerned primarily with nuclear power generation, is part of a project that the ALARA Center is carrying out for the Nuclear Regulatory Commission. This report describes its current status. A substantial amount of research on reducing occupational exposure is being done in the US and abroad. This research is beginning to have an impact on the collective dose expenditures at nuclear power plants. The collective radiation doses in Europe, Japan, and North America all show downward trends. A large part of the research in the US is either sponsored by the nuclear industry through joint industry organizations such as EPRI and ESEERCO or is done by individual corporations. There is also significant participation by smaller companies. The main emphasis of the research on dose reduction is on engineering approaches aimed at reducing radiation fields or keeping people out of high-exposure areas by using robotics. Effective ALARA programs are also underway at a large number of nuclear plants. Additional attention should be given to non-engineering approaches to dose reduction, which are potentially very useful and cost effective but require quantitative study and analysis based on data from nuclear power plants. 9 refs., 1 fig.

Cost-effectiveness analysis of risk reduction at nuclear power plants

International Nuclear Information System (INIS)

Lochard, J.; Maccia, C.; Pages, P.

1985-01-01

Cost-effectiveness analysis of risk reduction is now widely accepted as a rational analytical framework to consistently address the resource allocation problem underlying any risk management process. This paper presents how this technique can be usefully applied to complex systems such as the management of radioactive releases from nuclear power plants into the environment. (orig.) [de

Emission reduction trading - a power marketer's perspective

Energy Technology Data Exchange (ETDEWEB)

Stewart, M. (Powerex Inc., Vancouver, BC (Canada))

1999-01-01

The current situation , and the short-term and long-term outlook in emission reduction trading are reviewed from the point of view of a power marketer. The author's view is that while the concept of emission reduction credit (ERC) is easy enough to understand, i.e. a series of measures to reduce carbon dioxide production and enhance carbon sequestration, there is no standard definition, although there are a number of models under consideration. What is being sought is clear ownership and title, a clear understanding of what qualifies as a credit, credit for early action, commodity specifications and the ability to hedge. The author predicts that in the short-tem, industry will experiment with different types of transactions to gain experience and seek partners who are willing to share risk and development cost. In the longer-term, emission reduction credits will be bought and sold as commodities and traded, swapped or exchanged as part of a portfolio in bilateral trade transactions, and used in hedging against future liabilities.

State of the art review of radioactive waste volume reduction techniques for commercial nuclear power plants

International Nuclear Information System (INIS)

1980-04-01

A review is made of the state of the art of volume reduction techniques for low level liquid and solid radioactive wastes produced as a result of: (1) operation of commercial nuclear power plants, (2) storage of spent fuel in away-from-reactor facilities, and (3) decontamination/decommissioning of commercial nuclear power plants. The types of wastes and their chemical, physical, and radiological characteristics are identified. Methods used by industry for processing radioactive wastes are reviewed and compared to the new techniques for processing and reducing the volume of radioactive wastes. A detailed system description and report on operating experiences follow for each of the new volume reduction techniques. In addition, descriptions of volume reduction methods presently under development are provided. The Appendix records data collected during site surveys of vendor facilities and operating power plants. A Bibliography is provided for each of the various volume reduction techniques discussed in the report

CPICOR{trademark}: Clean power from integrated coal-ore reduction

Energy Technology Data Exchange (ETDEWEB)

Wintrell, R.; Miller, R.N.; Harbison, E.J.; LeFevre, M.O.; England, K.S.

1997-12-31

The US steel industry, in order to maintain its basic iron production, is thus moving to lower coke requirements and to the cokeless or direct production of iron. The US Department of Energy (DOE), in its Clean Coal Technology programs, has encouraged the move to new coal-based technology. The steel industry, in its search for alternative direct iron processes, has been limited to a single process, COREX{reg_sign}. The COREX{reg_sign} process, though offering commercial and environmental acceptance, produces a copious volume of offgas which must be effectively utilized to ensure an economical process. This volume, which normally exceeds the internal needs of a single steel company, offers a highly acceptable fuel for power generation. The utility companies seeking to offset future natural gas cost increases are interested in this clean fuel. The COREX{reg_sign} smelting process, when integrated with a combined cycle power generation facility (CCPG) and a cryogenic air separation unit (ASU), is an outstanding example of a new generation of environmentally compatible and highly energy efficient Clean Coal Technologies. This combination of highly integrated electric power and hot metal coproduction, has been designated CPICOR{trademark}, Clean Power from Integrated Coal/Ore Reduction.

Descriptive statistics of occupational employment in nuclear power utilities. Final working paper

International Nuclear Information System (INIS)

Little, J.R.; Johnson, R.C.

1982-10-01

The Institute of Nuclear Power Operations conducted a survey of its 58 member utilities during the Spring of 1982. This was the second such survey performed to identify employment trends and to project needs for trained personnel in the industry to 1991. The first was performed in 1981. The 1982 employment survey consisted of four questionnaires, asking for information on: (1) on-site employment; (2) on-site turnover; (3) off-site employment; and (4) off-site turnover. The survey instruments were designed to reflect approaches used by the utilities to meet the labor requirements for operation of nuclear power plants through off-site support personnel, contractors, and holding company personnel, as well as utility employees working at the plant site. On-site information was received from all 83 plants at the 58 utilities. However, employment information from Surry of VEPCO arrived too late to be included in the analysis. Therefore, their numbers are reflected in the adjusted totals. Responses to requests for off-site employment information were received from 55 of the 58 utilities

Experimental analysis of flexibility change with different levels of power reduction by demand response activation on thermostat controlled loads

DEFF Research Database (Denmark)

Lakshmanan, Venkatachalam; Marinelli, Mattia; Hu, Junjie

2017-01-01

This paper studies the flexibility available with thermostatically controlled loads (TCLs) to provide power system services by demand response (DR) activation. Although the DR activation on TCLs can provide power system ancillary services, it is important to know how long such services can...... be provided for when different levels of power reduction are imposed. The flexibility change with different levels of power reduction is tested experimentally with domestic fridges used by real customers with unknown user interaction. The investigation quantifies the flexibility of household fridges...... and the impact of DR activation in terms of deviation in the average temperature. The maximum possible power reduction with the cluster of refrigerators is 67% and the available flexibility with the cluster of refrigerators is 10%. The resulting deviation in the average temperature is 14%....

The German risk study for nuclear power plants

International Nuclear Information System (INIS)

Birkhofer, A.

1980-01-01

In August 1979 results of the ''German Risk Study for Nuclear Power Plants'' were published. The Main Report, in which approach and results of the study are documented, has been available since the end of 1979. It was the charter of the study - which was performed on behalf of the Minister of Research and Technology of the Federal Republic of Germany - to apply as far as possible the methods of the US Reactor Safety Study (WASH-1400) to German plant and site conditions. A direct transfer of the results was not deemed justified, mainly for the following reasons: There is quite a number of differences between the design of the reference plants of WASH-1400 (Surry-1, Peach Bottom-2) and German nuclear power plants. The mean population density in the Federal Republic of Germany is more than ten times of the United States. In the vicinity of nuclear power plants the ratio is about 3:1. To calculate the collective risk resulting from reactor accidents, a total of 25 plants at 19 different sites in the Federal Republic of Germany were considered. This included all plants with 600 MW or more electrical output, which were in operation, under construction or in licensing process by July 1, 1977. As an approximation to the real situation, it has been assumed that all 25 plants are technically identical to the reference plant

Data base on dose reduction research projects for nuclear power plants. Volume 5

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Yu, C.K.; Roecklein, A.K. [Brookhaven National Lab., Upton, NY (United States)

1994-05-01

This is the fifth volume in a series of reports that provide information on dose reduction research and health physics technology or nuclear power plants. The information is taken from two of several databases maintained by Brookhaven National Laboratory`s ALARA Center for the Nuclear Regulatory Commission. The research section of the report covers dose reduction projects that are in the experimental or developmental phase. It includes topics such as steam generator degradation, decontamination, robotics, improvements in reactor materials, and inspection techniques. The section on health physics technology discusses dose reduction efforts that are in place or in the process of being implemented at nuclear power plants. A total of 105 new or updated projects are described. All project abstracts from this report are available to nuclear industry professionals with access to a fax machine through the ACEFAX system or a computer with a modem and the proper communications software through the ACE system. Detailed descriptions of how to access all the databases electronically are in the appendices of the report.

Economic Performance and Emission Reduction of Supply Chains in Different Power Structures: Perspective of Sustainable Investment

Directory of Open Access Journals (Sweden)

Xiutian Shi

2018-04-01

Full Text Available Environmental issues have increasingly received attention in both industry and academia. Many firms have started to make sustainable investments, such as adopting the pollution-abatement technologies, to reduce carbon emissions. To investigate the impacts of the sustainable investment on firms’ profit and emission reduction, we consider supply chains with uncertain demand in different power structures. Specifically, we examine the sustainable investment problem in three supply chain power structures, i.e., manufacturer Stackelberg (MS power structure, vertical Nash (VN power structure and retailer Stackelberg (RS power structure. We first derive the optimal decisions for both the retailer and manufacturer in each power structure. Then, by comparing the results in the three power structures, we find that the manufacturer gets benefits from making the sustainable investment, especially in unequal power structures. When the average market size is large (small enough, both of the supply chain members obtain more profits in the MS (RS power structure. From an environmental perspective, we find that the emission reduction is more significant in sequential games (i.e., MS and RS power structures than that in a simultaneous game (i.e., VN power structure. In addition, we conduct some numerical studies and discuss more managerial insights in the paper.

Cost effective snubber reduction program for nuclear power plants

International Nuclear Information System (INIS)

Adams, T.M.; Antaki, G.A.; Chang, K.C.

1985-01-01

Due to the stringent seismic requirements imposed on nuclear power plants, piping engineers have resorted to the extensive use of snubbers to support nuclear piping systems. The advantage of snubbers is that they provide dynamic restraint while allowing free thermal growth of the pipe. Unfortunately, as more plants go into operation, utilities have to face the costs of strict in-service inspection requirements and risks of unscheduled or extended plant outages associated with snubber failures. The snubber inspection requirements, defined in plant Technical Specifications, require periodic visual inspections of all snubbers and functional tests of a percentage of the plant snubbers, during refueling outages. For a typical 1000 Mw unit this represents from 50 to several hundred snubbers to be functionally tested at each refueling outage. Should failures occur during testing, the sample size must be further increased. Very quickly the costs and risks of extended shutdowns have led the industry to consider, and in many cases implement, snubber reduction programs. At the same time several changes in seismic design criteria have greatly facilitated the reduction of snubbers, making snubber elimination economically and technically attractive. In this paper we examine the costs and benefits of snubber reduction programs and propose a method for evaluating their cost benefits

An algorithm for reduction of extracted power from photovoltaic strings in grid-tied photovoltaic power plants during voltage sags

DEFF Research Database (Denmark)

Tafti, Hossein Dehghani; Maswood, Ali Iftekhar; Pou, Josep

2016-01-01

strings should be reduced during voltage sags. In this paper, an algorithm is proposed for determining the reference voltage of the PV string which results in a reduction of the output power to a certain amount. The proposed algorithm calculates the reference voltage for the dc/dc converter controller......, based on the characteristics of the power-voltage curve of the PV string and therefore, no modification is required in the the controller of the dc/dc converter. Simulation results on a 50-kW PV string verified the effectiveness of the proposed algorithm in reducing the power from PV strings under......Due to the high penetration of the installed distributed generation units in the power system, the injection of reactive power is required for the medium-scale and large-scale grid-connected photovoltaic power plants (PVPPs). Because of the current limitation of the grid-connected inverter...

Effect of plasma power on reduction of printable graphene oxide thin films on flexible substrates

Science.gov (United States)

Banerjee, Indrani; Mahapatra, Santosh K.; Pal, Chandana; Sharma, Ashwani K.; Ray, Asim K.

2018-05-01

Room temperature hydrogen plasma treatment on solution processed 300 nm graphene oxide (GO) films on flexible indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates has been performed by varying the plasma power between 20 W and 60 W at a constant exposure time of 30 min with a view to examining the effect of plasma power on reduction of GO. X-ray powder diffraction (XRD) and Raman spectroscopic studies show that high energy hydrogen species generated in the plasma assist fast exfoliation of the oxygenated functional groups present in the GO samples. Significant decrease in the optical band gap is observed from 4.1 eV for untreated samples to 0.5 eV for 60 W plasma treated samples. The conductivity of the films treated with 60 W plasma power is estimated to be six orders of magnitude greater than untreated GO films and this enhancement of conductivity on plasma reduction has been interpreted in terms of UV-visible absorption spectra and density functional based first principle computational calculations. Plasma reduction of GO/ITO/PET structures can be used for efficiently tuning the electrical and optical properties of reduced graphene oxide (rGO) for flexible electronics applications.

Power-to-heat in adiabatic compressed air energy storage power plants for cost reduction and increased flexibility

Science.gov (United States)

Dreißigacker, Volker

2018-04-01

The development of new technologies for large-scale electricity storage is a key element in future flexible electricity transmission systems. Electricity storage in adiabatic compressed air energy storage (A-CAES) power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. For further improvements in cost efficiencies and flexibility, system modifications are necessary. Therefore, a novel concept regarding the integration of an electrical heating component is investigated. This modification allows increased power plant flexibilities and decreasing component sizes due to the generated high temperature heat with simultaneously decreasing total round trip efficiencies. For an exemplarily A-CAES case simulation studies regarding the electrical heating power and thermal energy storage sizes were conducted to identify the potentials in cost reduction of the central power plant components and the loss in round trip efficiency.

Trend of collective dose and dose reduction measures of Mitsubishi Electric Corporation workers in nuclear power plants

International Nuclear Information System (INIS)

Yamato, I.; Nakayama, T.; Shimokawa, F.; Yamamoto, T.

1996-01-01

MELCO has supplied the reactor instrumentation control system, reactor coolant pump motors, turbine generator and central control system for the pressurized water type nuclear power plant. For the legal periodical inspection and repair work, MELCO has also received orders for the periodical inspection for 23 power plants (including 4 plants under construction) of 5 electric power companies, and executed the inspection work from the view point of preventive maintenance. The annual dose for MELCO's workers is liable to be decreased in spite of increased number of plants. The dose for new plant in particular is 50, or less as compared with that for conventional plant. This is because the measures taken for the conventional plant against the dose reduction is reflected upon the new plant. The dose reduction measures are taken for each system for which order was received. Such measures are mainly intended to improve the work procedures and equipment for reduction of work time in the radioactive area and to arrange the working process, so as to perform the work in such period when the dose level at the working environment is low. To enhance the workers' consciousness for reduction of dose, MELCO provided the workers with dose predictive training, and let them aware of such items known at the tool box briefing (TBX), which could realize the dose reduction for workers. MELCO has been positively promoting the activity to arrange the desirable work environment for extermination of 3Ks (giken, gitsui, titanai) or 3Ds (dangerous, difficult, dirty) including protection against radiation in corporation with electric power companies. (author)

Parallelizing Compiler Framework and API for Power Reduction and Software Productivity of Real-Time Heterogeneous Multicores

Science.gov (United States)

Hayashi, Akihiro; Wada, Yasutaka; Watanabe, Takeshi; Sekiguchi, Takeshi; Mase, Masayoshi; Shirako, Jun; Kimura, Keiji; Kasahara, Hironori

Heterogeneous multicores have been attracting much attention to attain high performance keeping power consumption low in wide spread of areas. However, heterogeneous multicores force programmers very difficult programming. The long application program development period lowers product competitiveness. In order to overcome such a situation, this paper proposes a compilation framework which bridges a gap between programmers and heterogeneous multicores. In particular, this paper describes the compilation framework based on OSCAR compiler. It realizes coarse grain task parallel processing, data transfer using a DMA controller, power reduction control from user programs with DVFS and clock gating on various heterogeneous multicores from different vendors. This paper also evaluates processing performance and the power reduction by the proposed framework on a newly developed 15 core heterogeneous multicore chip named RP-X integrating 8 general purpose processor cores and 3 types of accelerator cores which was developed by Renesas Electronics, Hitachi, Tokyo Institute of Technology and Waseda University. The framework attains speedups up to 32x for an optical flow program with eight general purpose processor cores and four DRP(Dynamically Reconfigurable Processor) accelerator cores against sequential execution by a single processor core and 80% of power reduction for the real-time AAC encoding.

Calculation and reduction of the sound emissions of overhead power lines

International Nuclear Information System (INIS)

Straumann, U.

2007-01-01

In this dissertation, Ulrich Straumann of the Swiss Federal Institute of Technology in Zurich, Switzerland, discusses the reduction of sound emissions from overhead power lines. Corona-discharges occur during wet weather or when foggy or icing conditions prevail. Apart from these wide-band crackling noises, low-frequency, tonal emissions also occur. The CONOR (Corona Noise Reduction) project examined these emissions at a frequency of twice the mains frequency and looked for economically feasible solutions to the problems caused by them. The source of these emissions and the mechanisms causing them are discussed. Also, ways of calculating their strength are presented. The effects of varying cable geometry and construction are discussed, as are hydrophilic coatings that could be used to reduce sound emissions.

Possibilities for Carbon Dioxide Emission Reduction Resulting from Nuclear Power Use

International Nuclear Information System (INIS)

Bozicevic, M.; Tomsic, Z.; Kovacevic, T.

1998-01-01

Each energy resource is connected to certain environmental impacts and risks which must be taken into account. In recent years attention has been focused on the climate change effects of the burning fossil fuels, especially coal, due to the carbon dioxide which this releases into the atmosphere. If the electric energy produced in nuclear power plants were produced in coal-fired plants, global CO 2 emissions would rise for more than 2000 million tons, a significant value in comparison with 4000 million tons which is recommended as a target for emission reduction by the year 2005 at the Toronto Conference on the Changing Atmosphere. Possibilities for carbon dioxide emission reduction which would be the result of the nuclear option acceptance are discussed in this paper. (author)

Distributed Reactive Power Control based Conservation Voltage Reduction in Active Distribution Systems

Directory of Open Access Journals (Sweden)

EMIROGLU, S.

2017-11-01

Full Text Available This paper proposes a distributed reactive power control based approach to deploy Volt/VAr optimization (VVO / Conservation Voltage Reduction (CVR algorithm in a distribution network with distributed generations (DG units and distribution static synchronous compensators (D-STATCOM. A three-phase VVO/CVR problem is formulated and the reactive power references of D-STATCOMs and DGs are determined in a distributed way by decomposing the VVO/CVR problem into voltage and reactive power control. The main purpose is to determine the coordination between voltage regulator (VR and reactive power sources (Capacitors, D-STATCOMs and DGs based on VVO/CVR. The study shows that the reactive power injection capability of DG units may play an important role in VVO/CVR. In addition, it is shown that the coordination of VR and reactive power sources does not only save more energy and power but also reduces the power losses. Moreover, the proposed VVO/CVR algorithm reduces the computational burden and finds fast solutions. To illustrate the effectiveness of the proposed method, the VVO/CVR is performed on the IEEE 13-node test system feeder considering unbalanced loading and line configurations. The tests are performed taking the practical voltage-dependent load modeling and different customer types into consideration to improve accuracy.

Modeling the economic consequences of LWR accidents

International Nuclear Information System (INIS)

Burke, R.P.; Aldrich, D.C.; Rasmussen, N.C.

1984-01-01

Models to be used for analyses of economic risks from events which may occur during LWR plant operation are developed in this study. The models include capabilities to estimate both onsite and offsite costs of LWR events ranging from routine plant outages to severe core-melt accidents resulting in large releases of radioactive material to the environment. The models can be used by both the nuclear power industry and regulatory agencies in cost-benefit analyses for decisionmaking purposes. The newly developed economic consequence models are applied in an example to estimate the economic risks from operation of the Surry Unit 2 plant. The analyses indicate that economic risks from US LWR operation, in contrast to public health risks, are dominated by relatively high-frequency forced outage events. Even for severe (e.g., core-melt) accidents, expected offsite costs are less than expected onsite costs for the Surry site. The implications of these conclusions for nuclear power plant operation and regulation are discussed

Impact of plant transient response on fuel management strategy at Virginia Power

International Nuclear Information System (INIS)

Bucheit, D.M.; Smith, N.A.

1987-01-01

Virginia Power has been performing in-house reload core design and safety analysis for several years. These analyses have been in support of North Anna units 1 and 2 and Surry units 1 and 2, all of which are three-loop pressurized water reactor plants designed and built by Westinghouse. Historically, Virginia Power first developed the capability to design and optimize its own core loading patterns in the early 1970's. This development effort was driven by the need to establish in-house control of the fuel management process, thereby ensuring that energy generation requirements are met in an economically optimum fashion. It soon became obvious that reload design and safety analysis processes are so integrally coupled that in order to perform the fuel management function in an effective manner, in-house capability in both areas needed to be developed. After reviewing the spectrum of economic, safety and operational constraints which affect the reload design and analysis process, an integrated model of the process is presented in flow chart format. This is followed by several specific examples which illustrate the interplay between sound fuel management practice and the assurance of plant safety using in-house analysis techniques

Data base on dose reduction research projects for nuclear power plants: Volume 3

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Baum, J.W.

1989-05-01

This is the third volume in a series of reports that provide information on dose-reduction research and health physics technology for nuclear power plants. The information is taken from data base maintained by Brookhaven National Laboratory's ALARA Center for the Nuclear Regulatory Commission. This report presents information on 80 new projects, covering a wide area of activities. Projects on steam generator degradation, decontamination, robotics, improvement in reactor materials, and inspection techniques, among others, are described in the research section. The section on health physics technology includes some simple and very cost-effective projects to reduce radiation exposures. Collective dose data from the United States and other countries are also presented. In the conclusion, we suggest that although new advanced reactor design technology will eventually reduce radiation exposures at nuclear power plants to levels below serious concern, in the interim an aggressive approach to dose reduction remains necessary. 20 refs.

Transient reduction of tinnitus intensity is marked by concomitant reductions of delta band power

Directory of Open Access Journals (Sweden)

Weisz Nathan

2008-01-01

Full Text Available Abstract Background Tinnitus is an auditory phantom phenomenon characterized by the sensation of sounds without objectively identifiable sound sources. To date, its causes are not well understood. Previous research found altered patterns of spontaneous brain activity in chronic tinnitus sufferers compared to healthy controls, yet it is unknown whether these abnormal oscillatory patterns are causally related to the tinnitus sensation. Partial support for this notion comes from a neurofeedback approach developed by our group, in which significant reductions in tinnitus loudness could be achieved in patients who successfully normalized their patterns of spontaneous brain activity. The current work attempts to complement these studies by scrutinizing how modulations of tinnitus intensity alter ongoing oscillatory activity. Results In the present study the relation between tinnitus sensation and spontaneous brain activity was investigated using residual inhibition (RI to reduce tinnitus intensity and source-space projected magnetencephalographic (MEG data to index brain activity. RI is the sustained reduction (criteria: 50% for at least 30 s in tinnitus loudness after cessation of a tonal tinnitus masker. A pilot study (n = 38 identified 10 patients who showed RI. A significant reduction of power in the delta (1.3–4.0 Hz frequency band was observed in temporal regions during RI (p ≤ 0.001. Conclusion The current results suggest that changes of tinnitus intensity induced by RI are mediated by alterations in the pathological patterns of spontaneous brain activity, specifically a reduction of delta activity. Delta activity is a characteristic oscillatory activity generated by deafferented/deprived neuronal networks. This implies that RI effects might reflect the transient reestablishment of balance between excitatory and inhibitory neuronal assemblies, via reafferentation, that have been perturbed (in most tinnitus individuals by hearing damage. As

Anode-cathode power distribution systems and methods of using the same for electrochemical reduction

Science.gov (United States)

Koehl, Eugene R; Barnes, Laurel A; Wiedmeyer, Stanley G; Williamson, Mark A; Willit, James L

2014-01-28

Power distribution systems are useable in electrolytic reduction systems and include several cathode and anode assembly electrical contacts that permit flexible modular assembly numbers and placement in standardized connection configurations. Electrical contacts may be arranged at any position where assembly contact is desired. Electrical power may be provided via power cables attached to seating assemblies of the electrical contacts. Cathode and anode assembly electrical contacts may provide electrical power at any desired levels. Pairs of anode and cathode assembly electrical contacts may provide equal and opposite electrical power; different cathode assembly electrical contacts may provide different levels of electrical power to a same or different modular cathode assembly. Electrical systems may be used with an electrolyte container into which the modular cathode and anode assemblies extend and are supported above, with the modular cathode and anode assemblies mechanically and electrically connecting to the respective contacts in power distribution systems.

NPPs Secondary Circuit Piping Wall-Thinning Management in China

International Nuclear Information System (INIS)

Zhong Zhimin; Li Jinsong; Zheng Hui

2012-01-01

Since 1980s, secondary circuit piping wall-thinning incidents happened in nuclear power plants (NPPs) worldwide. Particularly Surry 2 and Mihama 3 accidents resulted from flow-accelerated corrosion (FAC), unplanned outage, huge fatalities and economic loss pushed whole industry to pay more attention on the wall-thinning problem.

IR and UV gas absorption measurements during NOx reduction on an industrial natural gas fired power plant

DEFF Research Database (Denmark)

Stamate, Eugen; Chen, Weifeng; Jørgensen, L.

2010-01-01

NOx reduction of flue gas by plasma-generated ozone was investigated in pilot test experiments on an industrial power plant running on natural gas. Reduction rates higher than 95% have been achieved for a molar ratio O3:NOx slightly below two. Fourier transform infrared and ultraviolet absorption...... spectroscopy were used for spatial measurements of stable molecules and radicals along the reduction reactor. Reactions of O3 injected in the flue gas in the reduction reactor were also modeled. Experiments are in good agreement with numerical simulations. The operation costs for NOx reduction were estimated...

Cost reduction and safety design features of new nuclear power plants in India. Annex 13

International Nuclear Information System (INIS)

Sharma, V.K.

2002-01-01

Indian Nuclear Power Programme is designed to exploit limited reserves of uranium and extensive resource of thorium. Pressurised heavy water reactors are found most suitable and form the main stay of the first stage of the programme. Thorium utilisation is achieved in the second and third stages. Today India has total installed capacity of 2720 MWe of PHWRs which are operating with high plant load factors of over 80%. Rich experience of construction and operation of over 150 reactor years is being utilised in effecting cost reduction and safety improvements. Standardisation and reduction in gestation period by preproject activities, advance procurement and work packages of engineer, procure, construct and commission are some of the techniques being adopted for cost reduction in the new projects. But the cost of safety is rising. Design basis event of double ended guillotine rupture of primary pressure boundary needs a relook based on current knowledge of material behaviour. This event appears improbable. Similarly some of the safety related systems like closed loop cooling water operating at low temperature and pressure, and low usage factors may be designed as per standard codes without invoking special nuclear requirements. The paper will address these issues and highlight the possible areas for cost reduction both in operating and safety systems. Modern construction and project management techniques are being employed. Gestation period of 5 years and cost of less than US $1400 per KWe are the present targets. In Indian environment nuclear power is found to be competitive with thermal power plants at distances of about 800 Kms from the coal mines. (author)

Extension of cycle 8 of Angra-1 reactor, optimization of electric power generation reduction

International Nuclear Information System (INIS)

Miranda, Anselmo Ferreira; Moreira, Francisco Jose; Valladares, Gastao Lommez

2000-01-01

The main objective of extending fuel cycle length of Angra-1 reactor, is in fact of that each normal refueling are changed about 40 fuel elements of the reactor core. Considering that these elements do not return for the reactor core, this procedure has became possible a more gain of energy of these elements. The extension consists in, after power generation corresponding to a cycle burnup of 13700 MWD/TMU or 363.3 days, to use the reactivity gain by reduction of power and temperature of primary system for power generation in a low energy patamar

Aircraft panel with sensorless active sound power reduction capabilities through virtual mechanical impedances

Science.gov (United States)

Boulandet, R.; Michau, M.; Micheau, P.; Berry, A.

2016-01-01

This paper deals with an active structural acoustic control approach to reduce the transmission of tonal noise in aircraft cabins. The focus is on the practical implementation of the virtual mechanical impedances method by using sensoriactuators instead of conventional control units composed of separate sensors and actuators. The experimental setup includes two sensoriactuators developed from the electrodynamic inertial exciter and distributed over an aircraft trim panel which is subject to a time-harmonic diffuse sound field. The target mechanical impedances are first defined by solving a linear optimization problem from sound power measurements before being applied to the test panel using a complex envelope controller. Measured data are compared to results obtained with sensor-actuator pairs consisting of an accelerometer and an inertial exciter, particularly as regards sound power reduction. It is shown that the two types of control unit provide similar performance, and that here virtual impedance control stands apart from conventional active damping. In particular, it is clear from this study that extra vibrational energy must be provided by the actuators for optimal sound power reduction, mainly due to the high structural damping in the aircraft trim panel. Concluding remarks on the benefits of using these electrodynamic sensoriactuators to control tonal disturbances are also provided.

Reduction of wind power induced reserve requirements by advanced shortest-term forecasts and prediction intervals

Energy Technology Data Exchange (ETDEWEB)

Dobschinski, Jan; Wessel, Arne; Lange, Bernhard; Bremen, Lueder von [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany)

2009-07-01

In electricity systems with large penetration of wind power, the limited predictability of the wind power generation leads to an increase in reserve and balancing requirements. At first the present study concentrates on the capability of dynamic day-ahead prediction intervals to reduce the wind power induced reserve and balancing requirements. Alternatively the reduction of large forecast errors of the German wind power generation by using advanced shortest-term predictions has been evaluated in a second approach. With focus on the allocation of minute reserve power the aim is to estimate the maximal remaining uncertainty after trading activities on the intraday market. Finally both approaches were used in a case study concerning the reserve requirements induced by the total German wind power expansion in 2007. (orig.)

The cost of operating with failed fuel at Virginia power

International Nuclear Information System (INIS)

Ford, C.A.

1988-01-01

Virginia Power has completed a study of the costs incurred due to fuel failures in its pressurized water reactors. This study was prompted by histories of high primary coolant activity and subsequent fuel inspections at the North Anna and Surry power stations. The study included an evaluation of the total costs of fuel failures as well as an evaluation of the economics of postirradiation fuel inspections. The major costs of fuel failures included personnel radiation exposure, permanently discharged failed fuel, radwaste generation, increased labor requirements, containment entry delays due to airborne radioactivity, and ramp rate restrictions. Although fuel failures affect a utility in several other areas, the items evaluated in the study were thought to be the most significant of the costs. The study indicated that performing a postirradiation failed fuel examination can be economically justified at tramp-corrected 131 I levels of > 0.015 μCi/g. The savings to the utility can be on the order of several million dollars. Additionally, the cost penalty of performing a fuel inspection at lower iodine levels is generally in the range of $200,000. This economic penalty is expected to be outweighed by the intangible benefits of operating with a defect-free core

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Summary of results. Volume 1

International Nuclear Information System (INIS)

Whitehead, D.W.; Staple, B.D.; Daniel, S.L.

1995-07-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to examine the potential risks during low power and shutdown operations. Two plants, Surry and Grand Gulf, were selected as the plants to be studied by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf). This report documents the work performed during the analysis of the Grand Gulf plant. A phased approach was used for the overall study. In Phase 1, the objectives were to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenario frequencies and risks, and to provide a foundation for a detailed Phase 2 analysis. It was in Phase 1 that the concept of plant operational states (POSs) was developed to allow the analysts to better represent the plant as it transitions from power operation to nonpower operation than was possible with the traditional technical specification divisions of modes of operation. This phase consisted of a coarse screening analysis performed for all POSs, including seismic and internal fire and flood for some POSs. In Phase 2, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected as the plant configuration to be analyzed based on the results of the Phase 1 study. The scope of the Level 1 study includes plant damage state analysis and uncertainty analysis and is documented in a multi-volume NUREG/CR report (i.e., NUREG/CR-6143). The internal events analysis is documented in Volume 2. Internal fire and internal flood analyses are documented in Volumes 3 and 4, respectively. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. The Level 2/3 study of the traditional internal events is documented in Volume 6, and a summary of the results for all analyses is documented in Volume 1

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Summary of results. Volume 1

Energy Technology Data Exchange (ETDEWEB)

Whitehead, D.W. [ed.; Staple, B.D.; Daniel, S.L. [and others

1995-07-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to examine the potential risks during low power and shutdown operations. Two plants, Surry and Grand Gulf, were selected as the plants to be studied by Brookhaven National Laboratory (Surry) and Sandia National Laboratories (Grand Gulf). This report documents the work performed during the analysis of the Grand Gulf plant. A phased approach was used for the overall study. In Phase 1, the objectives were to identify potential vulnerable plant configurations, to characterize (on a high, medium, or low basis) the potential core damage accident scenario frequencies and risks, and to provide a foundation for a detailed Phase 2 analysis. It was in Phase 1 that the concept of plant operational states (POSs) was developed to allow the analysts to better represent the plant as it transitions from power operation to nonpower operation than was possible with the traditional technical specification divisions of modes of operation. This phase consisted of a coarse screening analysis performed for all POSs, including seismic and internal fire and flood for some POSs. In Phase 2, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected as the plant configuration to be analyzed based on the results of the Phase 1 study. The scope of the Level 1 study includes plant damage state analysis and uncertainty analysis and is documented in a multi-volume NUREG/CR report (i.e., NUREG/CR-6143). The internal events analysis is documented in Volume 2. Internal fire and internal flood analyses are documented in Volumes 3 and 4, respectively. A separate study on seismic analysis, documented in Volume 5, was performed for the NRC by Future Resources Associates, Inc. The Level 2/3 study of the traditional internal events is documented in Volume 6, and a summary of the results for all analyses is documented in Volume 1.

Review of staff training plans Licensed Benchmarking on task analysis and selection of learning environments

International Nuclear Information System (INIS)

Iglesias Moran, J.

2013-01-01

The purpose of this paper is to present the findings and possible improvement actions taken after a work of technical exchange with U.S. Surry nuclear power plant. The visit focused on the study of the methodology for the analysis and design of training programs according to the standards of INPO.

Optimization of Power Generation Rights Under the Requirements of Energy Conservation and Emission Reduction

Science.gov (United States)

Hu-ping, YANY; Chong-wei, ZHONG; Fei-fei, YAN; Cheng-yi, TANG

2018-03-01

In recent years, the energy crisis and greenhouse effect problem have caused wide public concern, if these issues cannot be resolved quickly, they will bring troubles to people’s lives.In response, many countries around the world have implemented policies to reduce energy consumption and greenhouse gas emissions. In our country, the electric power industry has made great contribution to the daily life of people and the development of industry, but it is also an industry of high consumption and high emission.In order to realize the sustainable development of society, it is necessary to make energy conservation and emission reduction in the power industry as an important part of the realization of this goal.In this context, power generation trade has become a hot topic in energy conservation and emission reduction.Through the electricity consumption of the units with different power efficiency and coal consumption rate,it can achieve the target of reducing coal consumption, reducing network loss, reducing greenhouse gas emission, and increasing social benefit,and so on. This article put forward a optimal energy model on the basis of guaranteeing safety and environmental protection.In this paper, they used the IEEE30, IEEE39, IEEE57 and IEEE118 node system as an example, and set up the control groups to prove the practicality of the presented model.The solving method of this model was interior-point method.

Comprehensive Report to Congress Clean Coal Technology Program: Clean power from integrated coal/ore reduction

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-10-01

This report describes a clean coal program in which an iron making technology is paired with combined cycle power generation to produce 3300 tons per day of hot metal and 195 MWe of electricity. The COREX technology consists of a metal-pyrolyzer connected to a reduction shaft, in which the reducing gas comes directly from coal pyrolysis. The offgas is utilized to fuel a combined cycle power plant.

Comprehensive evaluation and study on energy saving and emission reduction of nuclear power based on the osculation value method

International Nuclear Information System (INIS)

Liu Zhihui; Wei Fangxin; Liu Xiaomin

2014-01-01

By means of osculation value method, several provinces are selected to study the energy saving and emission reduction effect of nuclear power from provincial range according to the statistic data in 2010. Theoretically, nuclear power effect is reducing the consumption of non-renewable energy such as coal and reducing the release of pollutants such as CO 2 . The result shows that the comprehensive evaluation of energy saving and emission reduction effect in Zhejiang and Jiangsu provinces are the best. In comparison, Guangdong province falls behind Hubei and Fujian provinces. Total consumption of coal per unit of GDP in Guangdong, Zhejiang, and Jiangsu provinces is apparently lower than that of Hebei, Shanxi, Liaoning, and Hubei provinces. However, total release of SO 2 and NOx, etc. is apparently reduced in provinces with nuclear power, compared with provinces without nuclear power. But total release of CO 2 from thermal power generation (coal) per unit of GDP is not apparently reduced in provinces with nuclear power than those without. (authors)

Radionuclide release calculations for selected severe accident scenarios

International Nuclear Information System (INIS)

Denning, R.S.; Leonard, M.T.; Cybulskis, P.; Lee, K.W.; Kelly, R.F.; Jordan, H.; Schumacher, P.M.; Curtis, L.A.

1990-08-01

This report provides the results of source term calculations that were performed in support of the NUREG-1150 study. ''Severe Accident Risks: An Assessment for Five US Nuclear Power Plants.'' This is the sixth volume of a series of reports. It supplements results presented in the earlier volumes. Analyses were performed for three of the NUREG-1150 plants: Peach Bottom, a Mark I, boiling water reactor; Surry, a subatmospheric containment, pressurized water reactor; and Sequoyah, an ice condenser containment, pressurized water reactor. Complete source term results are presented for the following sequences: short term station blackout with failure of the ADS system in the Peach Bottom plant; station blackout with a pump seal LOCA for the Surry plant; station blackout with a pump seal LOCA in the Sequoyah plant; and a very small break with loss of ECC and spray recirculation in the Sequoyah plant. In addition, some partial analyses were performed which did not require running all of the modules of the Source Term Code Package. A series of MARCH3 analyses were performed for the Surry and Sequoyah plants to evaluate the effects of alternative emergency operating procedures involving primary and secondary depressurization on the progress of the accident. Only thermal-hydraulic results are provided for these analyses. In addition, three accident sequences were analyzed for the Surry plant for accident-induced failure of steam generator tubes. In these analyses, only the transport of radionuclides within the primary system and failed steam generator were examined. The release of radionuclides to the environment is presented for the phase of the accident preceding vessel meltthrough. 17 refs., 176 figs., 113 tabs

Fiscal 1998 research report on the total electric power loss reduction project for Myanmer; 1998 nendo Myanmer koku denryoku soshitsu sogo teigen project chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

As a part of Japanese clean development mechanism, study was made on reduction of greenhouse effect gas emission from thermal power plants by reduction of power transmission and distribution losses of power systems in Myanmer. Study was made on technical power transmission and distribution losses for the national grid transmission system, 33kV sub- transmission system of Thaketa substation in Yangong city, and 6.6kV and 400V distribution systems of Latha and Lanmadaw townships in the downtown area of Yangong. Countermeasures for power loss reduction were considered on the basis of the study result. The loss reduction project plan includes a construction cost of 5,134,000US$, loss reduction of 7,726kW, and loss reduction of 33,213,000kWh. The project feasibility and profitability were evaluated by comparison between a financial internal rate of return (FIRR) and an opportunity cost assuming that a discount rate is the opportunity cost. As a result, FIRR was 17.36% and the discount rate was 8.89% in Myanmer. (NEDO)

Worldwide activities on the reduction of occupational exposure at nuclear power plants

International Nuclear Information System (INIS)

Kahn, T.A.; Baum, J.W.

1988-06-01

This report is based on analysis of an informational data base set up at the Brookhaven National Laboratory ALARA Center. It is part of a project sponsored by the US Nuclear Regulatory Commission to monitor and evaluate research on dose reduction at nuclear power plants in the US and abroad. The main benefits to be expected from reducing occupational exposures are highlighted in the report, the chief causes of elevated doses are identified, and effective approaches to minimize radiation exposures are proposed. A wide range of research activity is covered, including plant chemistry, cobalt reduction techniques, stress corrosion cracking, decontamination, remote tools and devices, and robotics. Advanced reactors, which are designed for low radiation exposures, are examined, and health physics technology programs which have been effective in reducing occupational exposure at various utilities are discussed. The highlights of the programs on dose reduction conducted by a number of countries are described, and comparisons are made of the collective occupational radiation dose equivalents for selected countries. The short and long term trends such studies are pointing to are evaluated. It is concluded that the efforts to improve dose reduction, both in the US and abroad, remain in a healthy state but require continuing encouragement and further development

Cost-effectiveness analysis of risk reduction at nuclear power plants: What have we learned from experience

International Nuclear Information System (INIS)

Lochard, J.; Pages, P.

1984-01-01

Within the field of risk management techniques, cost-effectiveness analysis of risk reduction is now recognized as an adequate method for evaluating and defining the optimal allocation of protection and safety resources within large industrial systems. The paper considers some of the issues that arise in connection with cost-effectiveness analysis of risk reduction at nuclear power stations. Particular attention is called to both the interdependence between criteria that characterize risk reduction problems and the resulting aggregation and weighting procedures needed when the multidimensionality of criteria is explicitly taken into account. The discussion of these problems is illustrated with results of case studies on both public and occupational risk reduction at French PWRs during normal operation. (author)

Experiences of occupational dose reduction at the Fugen nuclear power station

International Nuclear Information System (INIS)

Suzuki, Kazuya; Nakao, Hiromi; Naoi, Yohsuke; Takei, Hiroaki

1992-01-01

Occupational radiation dose has been effectively suppressed by efforts against both internal and external exposure in the Fugen nuclear power station. The tritium internal dose is completely suppressed by developments of high sensitivity tritium monitors with hollow fiber radon filters, comfortable tritium protection suits, and established working procedure for equipment maintenance of the heavy water system. The internal occupational dose has been suppressed to a negligible level comparing to the external dose. The external occupational dose had increased with dose rates of the primary cooling system. Establishment of radiation work procedure for maintenance works and development of chemical decontamination has been effectively saving the external occupational dose. The chemical decontaminations carried out in 1989 and 1991 are the first applications to the whole primary cooling system of operating power stations in Japan. This paper describes these efforts and effects on occupational dose reduction in Fugen. (author)

Evaluation of environmental impact predictions

International Nuclear Information System (INIS)

Cunningham, P.A.; Adams, S.M.; Kumar, K.D.

1977-01-01

An analysis and evaluation of the ecological monitoring program at the Surry Nuclear Power Plant showed that predictions of potential environmental impact made in the Final Environmental Statement (FES), which were based on generally accepted ecological principles, were not completely substantiated by environmental monitoring data. The Surry Nuclear Power Plant (Units 1 and 2) was chosen for study because of the facility's relatively continuous operating history and the availability of environmental data adequate for analysis. Preoperational and operational fish monitoring data were used to assess the validity of the FES prediction that fish would congregate in the thermal plume during winter months and would avoid the plume during summer months. Analysis of monitoring data showed that fish catch per unit effort (CPE) was generally high in the thermal plume during winter months; however, the highest fish catches occurred in the plume during the summer. Possible explanations for differences between the FES prediction and results observed in analysis of monitoring data are discussed, and general recommendations are outlined for improving impact assessment predictions

Second-Order Harmonic Reduction Technique for Photovoltaic Power Conditioning Systems Using a Proportional-Resonant Controller

Directory of Open Access Journals (Sweden)

Hae-Gwang Jeong

2013-01-01

Full Text Available This paper proposes a second-order harmonic reduction technique using a proportional-resonant (PR controller for a photovoltaic (PV power conditioning system (PCS. In a grid-connected single-phase system, inverters create a second-order harmonic at twice the fundamental frequency. A ripple component unsettles the operating points of the PV array and deteriorates the operation of the maximum power point tracking (MPPT technique. The second-order harmonic component in PV PCS is analyzed using an equivalent circuit of the DC/DC converter and the DC/AC inverter. A new feed-forward compensation technique using a PR controller for ripple reduction is proposed. The proposed algorithm is advantageous in that additional devices are not required and complex calculations are unnecessary. Therefore, this method is cost-effective and simple to implement. The proposed feed-forward compensation technique is verified by simulation and experimental results.

Risk-based inspection of nuclear power plants

International Nuclear Information System (INIS)

Masopust, R.

1995-01-01

A multidiscipline research programme was developed in the USA to establish risk-based inspections for NPP structures and equipment components. Based on this US research effort, the risk-based procedure for developing inspection guidelines for NPPs is described. The procedure includes the definition of systems, qualitative risk assessment, qualitative risk analysis and development of the inspection programme. The method, when adopted and modified, is recommended also for risk-based inspections of structures and equipment of WWER-type NPPs. A pilot application of the method to unit 1 of the Surry NPP is summarized. (Z.S.) 1 tab., 1 fig., 5 refs

Reduction of radiation exposure in Japanese BWR Nuclear Power Plants

International Nuclear Information System (INIS)

Morikawa, Yoshitake

1995-01-01

The reduction of occupational exposure to radiation during the annual inspection and maintenance outages of Japanese boiling water reactors (BWR) is one of the most important objectives for stable and reliable operation. It was shown that this radiation exposure is caused by radionuclides, such as Co-60, Co-58 and Mn-54 which are produced from the metal elements Co, Ni, and Fe present in the corrosion products of structural materials that had been irradiated by neutrons. Therefore, to reduce radiation sources and exposures in Japanese BWRs, attempts have been reinforced to remove corrosion products and activated corrosion products from the primary coolant system. This paper describes the progress of the application of these measures to Japanese BWRs. Most Japanese BWR-4 and BWR-5 type nuclear power plants started their commercial operations during the 1970s. With the elapse of time during operations, a problem came to the forefront, namely that occupational radiation exposure during plant outages gradually increased, which obstructed the smooth running of inspections and maintenance work. To overcome this problem, extensive studies to derive effective countermeasures for radiation exposure reduction were undertaken, based on the evaluation of the plants operation data

Reduction of radiation exposure in Japanese BWR Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Morikawa, Yoshitake [ISOGO Nuclear Engineering Center, Yokohama (Japan)

1995-03-01

The reduction of occupational exposure to radiation during the annual inspection and maintenance outages of Japanese boiling water reactors (BWR) is one of the most important objectives for stable and reliable operation. It was shown that this radiation exposure is caused by radionuclides, such as Co-60, Co-58 and Mn-54 which are produced from the metal elements Co, Ni, and Fe present in the corrosion products of structural materials that had been irradiated by neutrons. Therefore, to reduce radiation sources and exposures in Japanese BWRs, attempts have been reinforced to remove corrosion products and activated corrosion products from the primary coolant system. This paper describes the progress of the application of these measures to Japanese BWRs. Most Japanese BWR-4 and BWR-5 type nuclear power plants started their commercial operations during the 1970s. With the elapse of time during operations, a problem came to the forefront, namely that occupational radiation exposure during plant outages gradually increased, which obstructed the smooth running of inspections and maintenance work. To overcome this problem, extensive studies to derive effective countermeasures for radiation exposure reduction were undertaken, based on the evaluation of the plants operation data.

Experiments to investigate direct containment heating phenomena with scaled models of the Surry Nuclear Power Plant

International Nuclear Information System (INIS)

Blanchat, T.K.; Allen, M.D.; Pilch, M.M.

1994-01-01

The Containment Technology Test Facility (CTTF) and the Surtsey Test Facility at Sandia National Laboratories (SNL) are used to perform scaled experiments for the Nuclear Regulatory Commission (NRC) that simulate High Pressure Melt Ejection (HPME) accidents in a nuclear power plant (NPP). These experiments are designed to investigate the effects of direct containment heating (DCH) phenomena on the containment load. High-temperature, chemically reactive melt is ejected by high-pressure steam into a scale model of a reactor cavity. Debris is entrained by the steam blowdown into a containment model where specific phenomena, such as the effect of subcompartment structures, prototypic atmospheres, and hydrogen generation and combustion, can be studied

Results and insights of a level-1 internal event PRA of a PWR during mid-loop operations

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.; Yang, J.; Bozoki, G.; Hsu, C.J.; Diamond, D.J.; Wong, S.M.; Holmes, B.; Su, R.F.; Dang, V.; Siu, N.; Bley, D.; Johnson, D.; Lin, J.

1994-01-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analysis that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. During 1989, the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. The program includes two parallel projects being performed by BNL and SNL. Two plants, Surry (pressurized water reactor) and Grand Gulf (boiling water reactor), were selected as the plants to be studied. The objectives of the program are to assess the risks of severe accidents initiated during plant operational states other than full power operation and to compare the estimated core damage frequencies, important accident sequences and other qualitative and quantitative results with those accidents initiated during full power operation as assessed in NUREG-1150. The scope of the program includes that of a level-3 PRA. The objective of this paper is to present the approach utilized in the level-1 PRA for the Surry plant, and discuss the results obtained. A comparison of the results with those of other shutdown studies is provided. Relevant safety issues such as plant and hardware configurations, operator training, and instrumentation and control is discussed

Effects of wind intermittency on reduction of CO2 emissions: The case of the Spanish power system

International Nuclear Information System (INIS)

Gutiérrez-Martín, F.; Da Silva-Álvarez, R.A.; Montoro-Pintado, P.

2013-01-01

Renewable energy sources are believed to reduce drastically greenhouse gas emissions that would otherwise be generated from fossil fuels used to generate electricity. This implies that a unit of renewable energy will replace a unit of fossil-fuel, with its CO 2 emissions, on an equivalent basis – with no other effects on the grid. But, the fuel economy and emissions in the existing power systems are not proportional with the electricity production of intermittent sources due to cycling of the fossil-fuel plants that make up the balance of the grid (i.e. changing the power output makes thermal units to operate less efficiently). This study focuses in the interactions between wind generation and thermal plants cycling, by establishing the levels of extra fuel use caused by decreased efficiencies of fossil back-up for wind electricity in Spain. We analyze the production of all thermal plants in 2011, studying scenarios where wind penetration causes major deviations in programming and we define a procedure for quantifying CO 2 reductions using emission factors and efficiency curves from existing installations; the objective is to discuss the real contribution of renewable energy to the environmental targets: the results show that CO 2 reductions are still relevant at high wind penetration, whilst we also suggest alternatives to improve reliability of the power system. - Highlights: ► Comprehensive analysis of interactions of wind and fuel utilities in the power system. ► Fuel economy is not proportional with wind generation due to cycling of fossil plants. ► The results show that CO 2 reductions are still relevant even at high wind penetration. ► Alternatives to improve reliability of future power systems are also pointed out

Data base on nuclear power plant dose reduction research projects

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Dionne, B.J.; Baum, J.W.

1985-12-01

This report contains project information on the research and development activities of the nuclear power industry in the area of dose reduction. It is based on a data base of information set up at the ALARA Center of Brookhaven National Laboratory. One purpose of this report is to draw attention to work in progress and to enable researchers and subscribers to obtain further information from the investigators and project managers. Information is provided on 180 projects, divided according to whether they are oriented to Engineering Research or to Health Physics Technology. The report contains indices on main category, project manager, principal investigator, sponsoring organization, contracting organization, and subject. This is an initial report. It is intended that periodic updates be issued whenever sufficient material has been accumulated.

Data base on nuclear power plant dose reduction research projects

International Nuclear Information System (INIS)

Khan, T.A.; Dionne, B.J.; Baum, J.W.

1985-12-01

This report contains project information on the research and development activities of the nuclear power industry in the area of dose reduction. It is based on a data base of information set up at the ALARA Center of Brookhaven National Laboratory. One purpose of this report is to draw attention to work in progress and to enable researchers and subscribers to obtain further information from the investigators and project managers. Information is provided on 180 projects, divided according to whether they are oriented to Engineering Research or to Health Physics Technology. The report contains indices on main category, project manager, principal investigator, sponsoring organization, contracting organization, and subject. This is an initial report. It is intended that periodic updates be issued whenever sufficient material has been accumulated

Dose-reduction techniques for high-dose worker groups in nuclear power plants

International Nuclear Information System (INIS)

Khan, T.A.; Baum, J.W.; Dionne, B.J.

1991-03-01

This report summarizes the main findings of a study of the extent of radiation dose received by special work groups in the nuclear power industry. Work groups which chronically get large doses were investigated, using information provided by the industry. The tasks that give high doses to these work groups were examined and techniques described that were found to be particularly successful in reducing dose. Quantitative information on the extent of radiation doses to various work groups shows that significant numbers of workers in several critical groups receive doses greater than 1 and even 2 rem per year, particularly contract personnel and workers at BWR-type plants. The number of radiation workers whose lifetime dose is greater than their age is much less. Although the techniques presented would go some way in reducing dose, it is likely that a sizeable reduction to the high-dose work groups may require development of new dose-reduction techniques as well as major changes in procedures. 10 refs., 26 tabs

Pollution from the electric power sector in Japan and efficient pollution reduction

International Nuclear Information System (INIS)

Matsushita, Kyohei; Yamane, Fumihiro

2012-01-01

Under the scheme of the Kyoto Protocol, there are plans for the efficient reduction of carbon dioxide emissions. In the electric power sector, nuclear power generation, which emits no carbon dioxide in the process of generating electricity, has come under scrutiny. However, this energy produces a new environmental issue: the disposal of radioactive waste. First, we derive shadow prices of carbon dioxide and low-level waste as marginal abatement costs in the case of the electric power sector in Japan, employing a directional output distance function. It is found that the shadow prices are US$39 per tonne for carbon dioxide and US$1531 per liter for low-level waste. Secondly, we calculate the indirect Morishima elasticity between carbon dioxide and low-level waste in order to identify their substitutability, and it is found that the substitution of low-level waste for carbon dioxide is easier than the reverse. This result suggests that, with the amount of generated electricity fixed, carbon dioxide can be substituted more easily by low-level waste when the relative price of carbon dioxide increases, for example, as a result of implementation of a carbon dioxide tax or an emissions trading system.

The power sector in China and India: greenhouse gas emissions reduction potential and scenarios for 1990-2020

International Nuclear Information System (INIS)

Kroeze, Carolien; Vlasblom, Jaklien; Gupta, Joyeeta; Boudri, Christiaan; Blok, Kornelis

2004-01-01

Emissions of greenhouse gases from China and India are expected to increase in the coming two decades. The objectives of this study are two-fold: (1) to quantify the technical potential of various options to reduce emissions of greenhouse gases from the electricity sector in China and India in the year 2020, and (2) to evaluate a business-as-usual (BAU) scenario plus a number of best practice technology (BPT) scenarios for emission reduction of greenhouse gases from electricity production in China and India up to the year 2020. Options to reduce emissions include end use efficiency improvement, fuel switches, and efficiency improvement of existing and new power plants. For China, we calculated that the individual options analysed have technical potentials to reduce 2020 emissions ranging from 1% to 43% (relative to 2020 unabated emissions) and for India from 4% to 45%. Relatively large reduction potentials are calculated for end use efficiency improvement (43% for China and 45% for India), replacement of coal by renewable energy (23% for China and 14% for India) and natural gas (11% for China and 14% for India). Reducing electricity losses during transmission and distribution would reduce emissions by 7% (China) and 6% (India) and electrical efficiency improvement of power plants by 9% in both countries. The reduction options differ with respect to their feasibility. In the BAU scenario, emissions increase considerably between 1990 and 2020. Next, we present results for three BPT scenarios, which reflect the combined technical potential of selected options to reduce emissions. Our calculations indicate that all three scenarios have a potential to reduce emissions to about half the 2020 BAU level. The three scenarios are very different in their assumptions on reduction options, indicating that there are different strategies possible for realising relatively large emission reductions in China and India. We conclude that end use efficiency improvement may be one of

Novel Power Reduction Technique for ReRAM with Automatic Avoidance Circuit for Wasteful Overwrite

Directory of Open Access Journals (Sweden)

Takaya Handa

2012-01-01

Full Text Available Low-power operations can be great advantageous for ReRAM devices. However, wasteful overwriting such as the SET operation to low-resistance state (LRS device and the RESET operation to high-resistance state (HRS device causes not only an increase in power but also the degradation of the write cycles due to repeatedly rewriting. Thus, in this paper, we proposed a novel automatic avoidance circuit for dealing with wasteful overwriting that uses a sense amplifier and estimated the energy consumption reduction rate by conducting a circuit simulation. As a result, this circuit helped to reliably avoid the wasteful overwriting operation to reduce about 99% and 97% of wasteful energy using VSRC and CSRC, respectively.

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

Science.gov (United States)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-11-01

This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Volume reduction of dry active waste by use of a waste sorting table at the Brunswick nuclear power plant

International Nuclear Information System (INIS)

Snead, P.B.

1988-01-01

Carolina Power and Light Company's Brunswick nuclear power plant has been using a National Nuclear Corporation Model WST-18 Waste Sorting Table to monitor and sort dry active waste for segregating uncontaminated material as a means of low-level waste volume reduction. The WST-18 features 18 large-area, solid scintillation detectors arranged in a 3 x 6 array underneath a sorting/monitoring surface that is shielded from background radiation. An 11-week study at Brunswick showed that the use of the waste sorting table resulted in dramatic improvements in both productivity (man-hours expended per cubic foot of waste processed) and monitoring quality over the previous hand-probe frisking method. Use of the sorting table since the study has confirmed its effectiveness in volume reduction. The waste sorting table paid for its operation in volume reduction savings alone, without accounting for the additional savings from recovering reusable items

Options for greenhouse emission reduction by using a module for combined heat and power generation

International Nuclear Information System (INIS)

Stankov, Nikola; Ivanov, Bozhidar

2009-01-01

This report contains example of CO 2 emission reduction assessment when using module for combined heat and power generation that is fueled by natural gas. Environmental benefits are related to the type of fuel that is used and the increased efficiency of the combined production process. Choosing of the CHP unit and the assessment scheme are also presented

Peak-to-average power ratio reduction in interleaved OFDMA systems

KAUST Repository

Al-Shuhail, Shamael; Ali, Anum; Al-Naffouri, Tareq Y.

2015-01-01

Orthogonal frequency division multiple access (OFDMA) systems suffer from several impairments, and communication system engineers use powerful signal processing tools to combat these impairments and to keep up with the capacity/rate demands. One of these impairments is high peak-to-average power ratio (PAPR) and clipping is the simplest peak reduction scheme. However, in general, when multiple users are subjected to clipping, frequency domain clipping distortions spread over the spectrum of all users. This results in compromised performance and hence clipping distortions need to be mitigated at the receiver. Mitigating these distortions in multiuser case is not simple and requires complex clipping mitigation procedures at the receiver. However, it was observed that interleaved OFDMA presents a special structure that results in only self-inflicted clipping distortions (i.e., the distortions of a particular user do not interfere with other users). In this work, we prove analytically that distortions do not spread over multiple users (while utilizing interleaved carrier assignment in OFDMA) and construct a compressed sensing system that utilizes the sparsity of the clipping distortions and recovers it on each user. We provide numerical results that validate our analysis and show promising performance for the proposed clipping recovery scheme.

Peak-to-average power ratio reduction in interleaved OFDMA systems

KAUST Repository

Al-Shuhail, Shamael

2015-12-07

Orthogonal frequency division multiple access (OFDMA) systems suffer from several impairments, and communication system engineers use powerful signal processing tools to combat these impairments and to keep up with the capacity/rate demands. One of these impairments is high peak-to-average power ratio (PAPR) and clipping is the simplest peak reduction scheme. However, in general, when multiple users are subjected to clipping, frequency domain clipping distortions spread over the spectrum of all users. This results in compromised performance and hence clipping distortions need to be mitigated at the receiver. Mitigating these distortions in multiuser case is not simple and requires complex clipping mitigation procedures at the receiver. However, it was observed that interleaved OFDMA presents a special structure that results in only self-inflicted clipping distortions (i.e., the distortions of a particular user do not interfere with other users). In this work, we prove analytically that distortions do not spread over multiple users (while utilizing interleaved carrier assignment in OFDMA) and construct a compressed sensing system that utilizes the sparsity of the clipping distortions and recovers it on each user. We provide numerical results that validate our analysis and show promising performance for the proposed clipping recovery scheme.

Status of US storage efforts

International Nuclear Information System (INIS)

Leasburg, R.H.

1984-01-01

Tasks involved in the implementation of the Nuclear Waste Policy Act are discussed. The need for speedy action on applications to deal with spent fuel storage problems is stressed. The problems faced by the Virginia Electric and Power Company, where full core discharge capability at the 1600-megawatt Surry power station is expected to be reached in early 1986, are reviewed. It is pointed out that although the Nuclear Waste Policy Act does not apply in this case, the problems illustrate the situation that may be faced after the Act is implemented. Problems involved in intro-utility transhipments and dry cask storage of spent fuel from Surry, including transportation ordinances at state and local levels and approval for the use of dry casks for storage, are reported. The suggestion that dry casks be used for interim storage and eventual transport to monitored retrievable storage facilities or permanent storage sites is considered. It is pointed out that data from a proposed 3-utility demonstration program of dry cask storage of consolidated fuels and the storage of fuels in air should give information applicable to the timely implementation of the Nuclear Waste Policy Act

Probabilistic safety criteria for improvement of Nuclear Power Plant design and operation

Energy Technology Data Exchange (ETDEWEB)

Cho, Nam Jin; Chung, Woo Sick; Park, Moon Kyu [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1991-12-15

The procedure of this study is to : research on the status of IAEA(International Atomic Energy Agency) member states about the policy of safety goals, study figures of merit and demerit that inherently exist in the existing methodology for reliability allocation, develop an efficient methodology for allocating reliability from top-level safety goals to intermediate and low-level PSC, write a computer code on the basis of the methodology proposed in the study, and apply the methodology to Surry Unit 1 that is the type of PWR.

Operating experience feedback report: Progress in scram reduction: Commercial power reactors

International Nuclear Information System (INIS)

Bell, L.G.; O'Reilly, P.D.

1989-03-01

This report documents the results of a trends and patterns analysis of unplanned reactor scrams at commercial US nuclear power reactors from January 1, 1984 to January 1, 1988. Major objectives of this report prepared by the Nuclear Regulatory Commission's (NRC's) Office for Analysis and Evaluation of Operational Data (AEOD) are to: (1) provide feedback of operational experience regarding reactor scram trends in support of the Commission's Strategic Goals, (2) examine the causes of unplanned scrams, and (3) examine the relationship between the causes of unplanned scrams and industry initiatives undertaken to reduce the frequency of unplanned scrams, especially with a view to the potential for future scram rate reduction. 31 refs., 14 figs., 49 tabs

An integrated framework for effective reduction of occupational radiation exposure in a nuclear power plant

International Nuclear Information System (INIS)

Joo, Hyun Moon; Hak, Soo Kim; Young, Ho Cho; Chang, Sun Kang

1998-01-01

For effective reduction of occupational radiation exposure in a nuclear power plant, it is necessary to identify repetitive high radiation jobs during maintenance and refueling operation and comprehensively assess them. An integrated framework for effective reduction of occupational radiation exposure is proposed in this study. The framework consists of three parts; data collection, statistical analysis, and ALARA findings. A PC-based database program, INSTORE, is used for data collection and reduction, and the Rank Sum Method is used in identifying high radiation jobs. As a case study, the data accumulated in Kori Units 3 and 4 have been analyzed. The results of this study show that the radiation job classifications of SG related work have much effect on annual ORE collective dose in Kori Units 3 and 4. As an example of ALARA findings, hence, the improvements for the radiation job classifications of SG related work are summarized

Transient reduction in theta power caused by interictal spikes in human temporal lobe epilepsy.

Science.gov (United States)

Manling Ge; Jundan Guo; Yangyang Xing; Zhiguo Feng; Weide Lu; Xinxin Ma; Yuehua Geng; Xin Zhang

2017-07-01

The inhibitory impacts of spikes on LFP theta rhythms(4-8Hz) are investigated around sporadic spikes(SSs) based on intracerebral EEG of 4 REM sleep patients with temporal lobe epilepsy(TLE) under the pre-surgical monitoring. Sequential interictal spikes in both genesis area and extended propagation pathway are collected, that, SSs genesis only in anterior hippocampus(aH)(possible propagation pathway in Entorhinal cortex(EC)), only in EC(possible propagation pathway in aH), and in both aH and EC synchronously. Instantaneous theta power was estimated by using Gabor wavelet transform, and theta power level was estimated by averaged over time and frequency before SSs(350ms pre-spike) and after SSs(350ms post-spike). The inhibitory effect around spikes was evaluated by the ratio of theta power level difference between pre-spike and post-spike to pre-spike theta power level. The findings were that theta power level was reduced across SSs, and the effects were more sever in the case of SSs in both aH and EC synchronously than either SSs only in EC or SSs only in aH. It is concluded that interictal spikes impair LFP theta rhythms transiently and directly. The work suggests that the reduction of theta power after the interictal spike might be an evaluation indicator of damage of epilepsy to human cognitive rhythms.

Performance analysis of ORC power generation system with low-temperature waste heat of aluminum reduction cell

Science.gov (United States)

Wang, Zhiqi; Zhou, Naijun; Jing, Guo

Performance of organic Rankine cycle (ORC) system to recover low-temperature waste heat from aluminum reduction cell was analyzed. The temperature of waste heat is 80°C-200°C and the flow rate is 3×105m3/h. The pinch temperature difference between waste heat and working fluids is 10°C. The results show that there is optimal evaporating temperature for maximum net power under the same pinch point. For heat source temperature range of 80°C-140°C and 150°C-170°C, the working fluid given biggest net power is R227ea and R236fa, respectively. When the temperature is higher than 180°C, R236ea generates the biggest net power. The variation of heat source temperature has important effect on net power. When the temperature decreases 10%, the net power will deviate 30% from the maximum value.

Dominant superiority of nuclear power in the reduction of CO2 emissions. Part 2

International Nuclear Information System (INIS)

Kase, Susumu

2011-01-01

Soon after the oil crisis in 1973, then French president Giscard d'Estaing and his administration very strongly persuaded the French people to make the nation's electrical power consist mainly of nuclear power. As a result, by the beginning of 1990's, as high as 80% of electric power generated in France became nuclear (30% in Japan). Add the share 9% of hydroelectric power, 89% of electric power generated in France is now free of fossil fuel, and emission of green house gases per capita in France is now 42% less than in Japan. What Japan should do first of all in the coming future is to emulate the French experience. That should result in a 35% reduction in green house gas emission by 2030 at an acceptable cost. To put that in practice we first must overcome the now considerably weakened but still stubbornly remaining national sentiment against nuclear power. It will take a very strong top to bottom persuasion by the leading sector of the society. As to this matter the author stressed in a separate paper that mankind, like in the instinctive language capability, possesses a born instinctive way of life to believe in and live by the dominant spirit of the time. And unfortunately the current spirit of the time still is tainted with irrational dislike of nuclear power which can be weakened by strong and persistent persuasion. (author)

POTENTIAL HEALTH RISK REDUCTION ARISING FROM REDUCED MERCURY EMISSIONS FROM COAL FIRED POWER PLANTS.

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T. M.; Lipfert, F. W.; Morris, S. C.; Moskowitz, P. D.

2001-09-01

The U.S. Environmental Protection Agency (EPA) has announced plans to regulate mercury (Hg) emissions from coal-fired power plants. EPA has not prepared a quantitative assessment of the reduction in risk that could be achieved through reduction in coal plant emissions of Hg. To address this issue, Brookhaven National Laboratory (BNL) with support from the U.S. Department of Energy Office of Fossil Energy (DOE FE) prepared a quantitative assessment of the reduction in human health risk that could be achieved through reduction in coal plant emissions of Hg. The primary pathway for Hg exposure is through consumption of fish. The most susceptible population to Hg exposure is the fetus. Therefore the risk assessment focused on consumption of fish by women of child-bearing age. Dose response factors were generated from studies on loss of cognitive abilities (language skills, motor skills, etc.) by young children whose mothers consumed large amounts of fish with high Hg levels. Population risks were estimated for the general population in three regions of the country, (the Midwest, Northeast, and Southeast) that were identified by EPA as being heavily impacted by coal emissions. Three scenarios for reducing Hg emissions from coal plants were considered: (1) A base case using current conditions; (2) A 50% reduction; and, (3) A 90% reduction. These reductions in emissions were assumed to translate linearly into a reduction in fish Hg levels of 8.6% and 15.5%, respectively. Population risk estimates were also calculated for two subsistence fisher populations. These groups of people consume substantially more fish than the general public and, depending on location, the fish may contain higher Hg levels than average. Risk estimates for these groups were calculated for the three Hg levels used for the general population analyses. Analysis shows that the general population risks for exposure of the fetus to Hg are small. Estimated risks under current conditions (i.e., no

Trading our health: Ontario Power Generation's plan to violate its air pollution reduction commitment

International Nuclear Information System (INIS)

Gibbons, J.; Bjorkquist, S.

1999-01-01

Amid growing concerns about nitrogen oxide (Nox) emissions, the Ontario Clean Air Alliance is recommending in this report that the Ontario government restrict Nox emissions from Ontario Power Generation (OPG) in the year 2000 and not let the corporation meet its emissions cap by on a net basis by retiring Pilot Emission Reduction Trading (PERT) Nox emission reduction credits. Instead the alliance believes the Ontario government should require OPG to achieve emissions compliance by curtailing coal-fired electricity exports, purchasing renewable and natural-gas electricity and promoting energy efficiency. OPG's inventory of PERT Nox reduction credits are assessed against whether they will cause an increase in the year 2000 as a result of trading. Ontario Power Generation's Nox emissions are a central chemical component of acid rain and smog and are produced from its coal-fired electricity generators. The utility would like to achieve Nox reductions by establishing demand management programs which would reduce the demand for electricity by 5200 megawatts (MW), by purchasing 3100 MW of non-utility generation and by undertaking combustion process modifications at its Lambton and Nanticoke coal-fired generating stations. It has not met its 2000 demand management and non-utility generation targets, and specifically, as of December 31, 1998, Ontario Hydro's successor companies demand management programs have only reduced electricity demand by approximately 1300 MW. Furthermore, the successor companies will have only approximately 1700 MW of non-utility generation capacity under contract by December 31, 1999. The report describes the criteria for ensuring that Nox emissions trading will not lead to a net increase in Ontario's emissions in any given year, and a description is included of why the 'Draft Rules for Emission Trading in Ontario' rules do not meet these criteria. Permitting OPG to use its PERT credits to meet its Nox cap, will allow them to increase coal

Reduction of CO2 emission by INCAM model in Malaysia biomass power plants during the year 2016.

Science.gov (United States)

Amin, Nor Aishah Saidina; Talebian-Kiakalaieh, Amin

2018-03-01

As the world's second largest palm oil producer and exporter, Malaysia could capitalize on its oil palm biomass waste for power generation. The emission factors from this renewable energy source are far lower than that of fossil fuels. This study applies an integrated carbon accounting and mitigation (INCAM) model to calculate the amount of CO 2 emissions from two biomass thermal power plants. The CO 2 emissions released from biomass plants utilizing empty fruit bunch (EFB) and palm oil mill effluent (POME), as alternative fuels for powering steam and gas turbines, were determined using the INCAM model. Each section emitting CO 2 in the power plant, known as the carbon accounting center (CAC), was measured for its carbon profile (CP) and carbon index (CI). The carbon performance indicator (CPI) included electricity, fuel and water consumption, solid waste and waste-water generation. The carbon emission index (CEI) and carbon emission profile (CEP), based on the total monthly carbon production, were determined across the CPI. Various innovative strategies resulted in a 20%-90% reduction of CO 2 emissions. The implementation of reduction strategies significantly reduced the CO 2 emission levels. Based on the model, utilization of EFB and POME in the facilities could significantly reduce the CO 2 emissions and increase the potential for waste to energy initiatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA: Volume 4

International Nuclear Information System (INIS)

Khan, T.A.; Baum, J.W.

1989-06-01

This report is the fourth in the series of bibliographies supporting the efforts at the Brookhaven National Laboratory on dose reduction at nuclear power plants. Abstracts for this bibliography were selected from proceedings of technical meetings, journals, research reports and searches of the DOE's Energy Data Base. The abstracts included in this report to operational health physics as well as other subjects which have a bearing on dose reduction at nuclear power plants, such as stress corrosion, cracking, plant chemistry, use of robotics and remote devices, etc. Material on improved design, materials selection, planning and other topics which are related to dose reduction efforts are also included. The report contains 327 abstracts as well as subject and author indices. All information in the current volume is also available from the ALARA Center's bulletin board service which is accessible by personal computers with the help of a modem. The last section of the report explains the features of the bulletin board. The bulletin board will be kept up-to-date with new information and should be of help in keeping people current in the area of dose reduction

Reduction of sulphur dioxide emissions by pyrolysis reduction of the burning sulfur of coal, applied in the power station 'Maritsa-East 3'

International Nuclear Information System (INIS)

Lyutskanov, L.; Dushanov, D.

1999-01-01

A study for applying of the new method for reduction of the sulfur content in solid fuel reported at the Energy Forum '98 has been carried out. The calculations for using this method at the power station 'Maritsa-East 3' were made. The advantages compared to the conventional methods for removing of SO 2 from flue gases are reported. The application of this method reduces the emissions of SO 2 with 83-85%. The heat saved is equal to the heat from 13.8% of the coal. The tar obtained after removing of sulfur can be used as fuel. The expenses for transport and treatment of limestone and of obtained gypsum (needed at the conventional methods for removing the sulfur) are eliminated. The capital investments needed are smaller because of the 25-30 times smaller volume of the equipment for sulfur reduction

Experimental evidence of oxygen thermo-migration in PWR UO{sub 2} fuels during power ramps using in-situ oxido-reduction indicators

Energy Technology Data Exchange (ETDEWEB)

Riglet-Martial, Ch., E-mail: chantal.martial@cea.fr; Sercombe, J.; Lamontagne, J.; Noirot, J.; Roure, I.; Blay, T.; Desgranges, L.

2016-11-15

The present study describes the in-situ electrochemical modifications which affect irradiated PWR UO{sub 2} fuels in the course of a power ramp, by means of in-situ oxido-reduction indicators such as chromium or neo-formed chemical phases. It is shown that irradiated fuels (of nominal stoichiometry close to 2.000) under temperature gradient such as that occurring during high power transients are submitted to strong oxido-reduction perturbations, owing to radial migration of oxygen from the hot center to the cold periphery of the pellet. The oxygen redistribution, similar to that encountered in Sodium Fast Reactors fuels, induces a massive reduction/precipitation of the fission products Mo, Ru, Tc and Cr (if present) in the high temperature pellet section and the formation of highly oxidized neo-formed grey phases of U{sub 4}O{sub 9} type in its cold section, of lower temperature. The parameters governing the oxidation states of UO{sub 2} fuels under power ramps are finally debated from a cross-analysis of our results and other published information. The potential chemical benefits brought by oxido-reductive additives in UO{sub 2} fuel such as chromium oxide, in connection with their oxygen buffering properties, are discussed.

Reduction of occupational exposures in PWR power plants - actions undertaken

International Nuclear Information System (INIS)

Jeanson, P.

1983-01-01

The reduction of doses to nuclear power plant workers is a permanent aim of Electricite de France. Many actions are undertaken simultaneously some of them jointly with the Commissariat a l'Energie Atomique. The theoretical studies bear mainly on the formation and transfer of corrosion and fission products in the primary circuit of PWRs and on the procedures to lower the deposited activity. The practical studies bear on the design of materials and buildings and the rules of installation as well as on the chemical conditioning of the primary fluid. They also bear on the conditions of maintenance of all the components; for the main ones, special tools are designed. Finally, operating a daily dosimetry makes it possible to know the distribution of collective doses better and therefore to judiciously direct the actions to be undertaken [fr

Energy-Efficiency Analysis of Per-Subcarrier Antenna Selection with Peak-Power Reduction in MIMO-OFDM Wireless Systems

Directory of Open Access Journals (Sweden)

Ngoc Phuc Le

2014-01-01

Full Text Available The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability. However, the implementation of the conventional per-subcarrier selection scheme may result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation. This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna permutations. For analysis, we derive the CCDF (complementary cumulative distribution function of the power efficiency as well as the analytical expressions of the average power efficiency. It is proved from the power-efficiency perspective that the proposed allocation scheme outperforms the conventional scheme. We also show that the improvement in the power efficiency translates into an improved capacity and, in turn, increases energy efficiency of the proposed system. Simulation results are provided to validate our analyses.

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

Energy Technology Data Exchange (ETDEWEB)

Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jung, Seungmin [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of); Cho, Yoonsung [Department of Electric and Energy Engineering, Catholic University of Daegu, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-702 (Korea, Republic of); Yoon, Donghee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of)

2013-11-15

Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

International Nuclear Information System (INIS)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-01-01

Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed

Cost reduction potentials of offshore wind power in Germany; Kostensenkungspotenziale der Offshore-Windenergie in Deutschland

Energy Technology Data Exchange (ETDEWEB)

Hobohm, Jens; Krampe, Leonard; Peter, Frank [Prognos AG, Berlin (Germany). Bereich Energiewirtschaft

2014-01-15

Offshore wind power is a major hope for the German energy turnaround. However, it will only be possible to tap its cost reduction potentials if industry, the political leadership and the administrative authorities join forces to create the necessary preconditions. An important requirement for this capital-intensive technology are stable legal and political framework conditions. A recent study on the future shows what needs to be done.

Regional reductions in sleep electroencephalography power in obstructive sleep apnea: a high-density EEG study.

Science.gov (United States)

Jones, Stephanie G; Riedner, Brady A; Smith, Richard F; Ferrarelli, Fabio; Tononi, Giulio; Davidson, Richard J; Benca, Ruth M

2014-02-01

Obstructive sleep apnea (OSA) is associated with significant alterations in neuronal integrity resulting from either hypoxemia and/or sleep loss. A large body of imaging research supports reductions in gray matter volume, alterations in white matter integrity and resting state activity, and functional abnormalities in response to cognitive challenge in various brain regions in patients with OSA. In this study, we used high-density electroencephalography (hdEEG), a functional imaging tool that could potentially be used during routine clinical care, to examine the regional distribution of neural activity in a non-clinical sample of untreated men and women with moderate/severe OSA. Sleep was recorded with 256-channel EEG in relatively healthy subjects with apnea-hypopnea index (AHI) > 10, as well as age-, sex-, and body mass index-matched controls selected from a research population initially recruited for a study on sleep and meditation. Sleep laboratory. Nine subjects with AHI > 10 and nine matched controls. N/A. Topographic analysis of hdEEG data revealed a broadband reduction in EEG power in a circumscribed region overlying the parietal cortex in OSA subjects. This parietal reduction in neural activity was present, to some extent, across all frequency bands in all stages and episodes of nonrapid eye movement sleep. This investigation suggests that regional deficits in electroencephalography (EEG) power generation may be a useful clinical marker for neural disruption in obstructive sleep apnea, and that high-density EEG may have the sensitivity to detect pathological cortical changes early in the disease process.

Power plant emissions reduction

Science.gov (United States)

Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy

2015-10-20

A system for improved emissions performance of a power plant generally includes an exhaust gas recirculation system having an exhaust gas compressor disposed downstream from the combustor, a condensation collection system at least partially disposed upstream from the exhaust gas compressor, and a mixing chamber in fluid communication with the exhaust gas compressor and the condensation collection system, where the mixing chamber is in fluid communication with the combustor.

A Real-Coded Genetic Algorithm with System Reduction and Restoration for Rapid and Reliable Power Flow Solution of Power Systems

Directory of Open Access Journals (Sweden)

Hassan Abdullah Kubba

2015-05-01

Full Text Available The paper presents a highly accurate power flow solution, reducing the possibility of ending at local minima, by using Real-Coded Genetic Algorithm (RCGA with system reduction and restoration. The proposed method (RCGA is modified to reduce the total computing time by reducing the system in size to that of the generator buses, which, for any realistic system, will be smaller in number, and the load buses are eliminated. Then solving the power flow problem for the generator buses only by real-coded GA to calculate the voltage phase angles, whereas the voltage magnitudes are specified resulted in reduced computation time for the solution. Then the system is restored by calculating the voltages of the load buses in terms of the calculated voltages of the generator buses, after a derivation of equations for calculating the voltages of the load busbars. The proposed method was demonstrated on 14-bus IEEE test systems and the practical system 362-busbar IRAQI NATIONAL GRID (ING. The proposed method has reliable convergence, a highly accurate solution and less computing time for on-line applications. The method can conveniently be applied for on-line analysis and planning studies of large power systems.

The trip status and the reduction countermeasure in Kori nuclear power plant unit 1 and 2

International Nuclear Information System (INIS)

Kim, Jung-Soo

1991-01-01

Nuclear power account for 36% of Korea's total electric capacity and provided over 50% of the net electric power supply by June 1991. These plants supply US with the cheapest and most stable electric supply available. However each units capacity is very large and a plant trip due to failure of a component or a human error has a great influence on the nations electric power supply and drastically decreases the reserve margin. This report will analyze the trip causes and measure the trip frequency from the first commercial operation of Kori unit 1 and 2 to the end of June 1991, reflect to the plant operation, management and facility modification, etc. This will minimize the number of trips or urgent power reductions and thus contribute to an increase in plant capacity factor and safety, and stabilize the electric power demand and supply. The safety and the economy of nuclear power plant have to be secured and raised respectably by increasing the capacity factor. Since the prevention of trips plays an important role in the plant safety and economy, we have to do our best to prevent the unexpected trip

Greenhouse gas and air pollutant emission reduction potentials of renewable energy--case studies on photovoltaic and wind power introduction considering interactions among technologies in Taiwan.

Science.gov (United States)

Kuo, Yu-Ming; Fukushima, Yasuhiro

2009-03-01

To achieve higher energy security and lower emission of greenhouse gases (GHGs) and pollutants, the development of renewable energy has attracted much attention in Taiwan. In addition to its contribution to the enhancement of reliable indigenous resources, the introduction of renewable energy such as photovoltaic (PV) and wind power systems reduces the emission of GHGs and air pollutants by substituting a part of the carbon- and pollutant-intensive power with power generated by methods that are cleaner and less carbon-intensive. To evaluate the reduction potentials, consequential changes in the operation of different types of existing power plants have to be taken into account. In this study, a linear mathematical programming model is constructed to simulate a power mix for a given power demand in a power market sharing a cost-minimization objective. By applying the model, the emission reduction potentials of capacity extension case studies, including the enhancement of PV and wind power introduction at different scales, were assessed. In particular, the consequences of power mix changes in carbon dioxide, nitrogen oxides, sulfur oxides, and particulates were discussed. Seasonally varying power demand levels, solar irradiation, and wind strength were taken into account. In this study, we have found that the synergetic reduction of carbon dioxide emission induced by PV and wind power introduction occurs under a certain level of additional installed capacity. Investigation of a greater variety of case studies on scenario development with emerging power sources becomes possible by applying the model developed in this study.

CPU time reduction strategies for the Lambda modes calculation of a nuclear power reactor

Energy Technology Data Exchange (ETDEWEB)

Vidal, V.; Garayoa, J.; Hernandez, V. [Universidad Politecnica de Valencia (Spain). Dept. de Sistemas Informaticos y Computacion; Navarro, J.; Verdu, G.; Munoz-Cobo, J.L. [Universidad Politecnica de Valencia (Spain). Dept. de Ingenieria Quimica y Nuclear; Ginestar, D. [Universidad Politecnica de Valencia (Spain). Dept. de Matematica Aplicada

1997-12-01

In this paper, we present two strategies to reduce the CPU time spent in the lambda modes calculation for a realistic nuclear power reactor.The discretization of the multigroup neutron diffusion equation has been made using a nodal collocation method, solving the associated eigenvalue problem with two different techniques: the Subspace Iteration Method and Arnoldi`s Method. CPU time reduction is based on a coarse grain parallelization approach together with a multistep algorithm to initialize adequately the solution. (author). 9 refs., 6 tabs.

Oxidation of mercury across selective catalytic reduction catalysts in coal-fired power plants

Energy Technology Data Exchange (ETDEWEB)

Constance L. Senior [Reaction Engineering International, Salt Lake City, UT (United States)

2006-01-15

A kinetic model for predicting the amount of mercury (Hg) oxidation across selective catalytic reduction (SCR) systems in coal-fired power plants was developed and tested. The model incorporated the effects of diffusion within the porous SCR catalyst and the competition between ammonia and Hg for active sites on the catalyst. Laboratory data on Hg oxidation in simulated flue gas and slipstream data on Hg oxidation in flue gas from power plants were modeled. The model provided good fits to the data for eight different catalysts, both plate and monolith, across a temperature range of 280-420{sup o}C, with space velocities varying from 1900 to 5000 hr{sup -1}. Space velocity, temperature, hydrochloric acid content of the flue gas, ratio of ammonia to nitric oxide, and catalyst design all affected Hg oxidation across the SCR catalyst. The model can be used to predict the impact of coal properties, catalyst design, and operating conditions on Hg oxidation across SCRs. 20 refs., 9 figs., 2 tabs.

Reduction of wind powered generator cost by use of a one bladed rotor

Energy Technology Data Exchange (ETDEWEB)

Pruyn, R R; Wiesner, W; Ljungstroem, O [ed.

1976-01-01

Cost analysis supported by preliminary design studies of one and two bladed wind powered generator units shows that a 30% reduction in acquisition cost can be achieved with a one bladed design. Designs studied were sized for an output power of 1000 kilowatts. The one bladed design has the potential for reducing acquisition cost to $680 per available kilowatt if the unit is located in a region with mean surface winds of 15 mph. Vibratory loads of the one bladed design are significant and will require considerable design attention. The one per rev Coriolis torque caused by blade flapping is the most significant problem. The major source of blade flapping will be the velocity gradient of the ground boundary layer. A torsional vibration isolating coupling may be required in the generator drive to reduce the loads due to this vibratory torque. An inclined flapping hinge also is desirable to cause pitch-flap coupling that will suppress blade flap motions.

Estimation of power production potential from natural gas pressure reduction stations in pakistan using aspen hysys

International Nuclear Information System (INIS)

Unar, I.N.; Aftab, A.

2015-01-01

Pakistan is a gas rich but power poor country. It consumes approximately 1, 559 Billion cubic feet of natural gas annually. Gas is transported around the country in a system of pressurized transmission pipelines under a pressure-range of 600-1 000 psig exclusively operated by two state owned companies i.e. SNGPL (Sui Northern Gas Pipelines Limited) and SSGCL (Sui Southern Gas Company Limited). The gas is distributed by reducing from the transmission pressure into distribution pressure up to maximum level of 150 psig at the city gate stations normally called SMS (Sales Metering Station). As a normal practice gas pressure reduction at those SMSs is accomplished in pressure regulators (PCVs or in of natural gas is an untapped energy resource which is currently wasted by its throttling. This pressure reduction at SMS (pressure drop through SMS) may also be achieved by expansion of natural gas in TE, which converts its pressure into the mechanical energy, which can be transmitted any loading device for example electric generator. The aim of present paper is to explore the expected power production potential of various Sales Metering Stations of SSGCL company in Pakistan. The model of sales metering station was developed in a standard flow sheeting software Aspen HYSYS at the rate 7.1 to calculate power and study other parameters when an expansion turbine is used instead of throttling valves. It was observed from the simulation results that a significant power (more than 140 KW) can be produced at pressure reducing stations of SSGC network with gas flows more than 2.2 MMSCFD and pressure ration more than 1.3. (author)

Reduction of greenhouse gas in power industry by emission trading system

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun Myung; Lee, Kee Hoon [Korea Energy Economics Institute, Euiwang (Korea)

1999-04-01

The rules governing their implementation and operation for implementing the Kyoto Protocol including emissions permit trading, project-based credit trading and the Clean Development Mechanism are to be decided at future talks. How these policies are eventually designed will determine the effectiveness of the Protocol. However, it has been passive and insufficient to deal with the Kyoto Protocol since there is no obligation on reduction of greenhouse gas emissions. Therefore, the issues on emissions permit trading are analyzed and the strategies for utilizing the Kyoto mechanism effectively are presented through reviewing the existing negotiation strategies. Moreover, how to use emissions permit trading in the power industry, the largest greenhouse gas emissions industry, is examined by dividing into two sections, domestic and abroad. (author). 62 refs., 2 figs., 42 tabs.

Energy conservation and emission reduction policies for the electric power industry in China

International Nuclear Information System (INIS)

Li Li; Tan Zhongfu; Wang Jianhui; Xu Jun; Cai Chengkai; Hou Yong

2011-01-01

Because of China's increasingly limited energy supplies and serious environmental pollution, much attention has been paid to conserving energy and reducing emissions to help the country's economy achieve sustainable development. As the electric power industry is the largest consumer of coal resources in China and also emits high levels of air pollutants each year, the Chinese government has enacted many technical and economic policies for energy conservation and emission reduction in the last few years. These policies are summarized in this paper, along with relevant laws and medium- and long-term plans, all of which address ideas such as adjusting the power generation mix, promoting demand-side management, introducing energy-efficient scheduling, and installing desulfurization units. The paper also assesses the results of these policies by analyzing several key indicators of energy consumption and emissions. The analysis shows that although some progress has been made in conserving energy and reducing emissions, substantial work is still required for China to catch up with developed countries. Some suggestions for future work are provided. - Highlights: → China has made many policies for reducing the power industries' energy consumption and emissions. → Progress has been made in conserving energy and reducing emission of the electric power industry. → Substantial works need to be done for China to catch up with the level of developed country. → Market mechanisms for conserving energy and reducing emission should be constructed in the future.

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA

International Nuclear Information System (INIS)

Kaurin, D.G.; Khan, T.A.; Sullivan, S.G.; Baum, J.W.

1993-07-01

The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in the continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This is volume 7 of the series. The abstracts in this bibliography were selected from proceedings of technical meetings and conferences, journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to radiation protection and dose reduction, and ranges from use of robotics to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 7 contains 293 abstract, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 7. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes

Energy consumption reduction in existing HVAC-R systems via a power law controlling kit

International Nuclear Information System (INIS)

Pinnola, C.F.; Vargas, J.V.C.; Buiar, C.L.; Ordonez, J.C.

2015-01-01

This paper presents an alternative solution for reducing energy consumption in heating, ventilation, air conditioning and refrigeration (HVAC-R) systems. For that, an existing typical commercial refrigeration system was equipped with a novel control system based on a power law, using a frequency inverter and a programmable logic controller (PLC). Hence, it was possible to compare the operation and energy consumption of the system with the power law control and with the on-off system, quantifying the obtained gains. The experimental unit consisted of a cooling chamber, an enclosing chamber (antechamber), and a vapor compression refrigeration system, i.e., an example of a practical commercial cooling system. A set of graphs shows the experimental measurements performed with the two systems. In this way, the measured temperatures in some selected points of the two systems, as well as the consumption in kWh for a period of 6 h and 10 min were compared in the tests. The main conclusions of this work are: i) The system operating with the power law control with respect to the conventional on-off control, showed energy consumption savings of up to 31% in a test period of 6 h and 10 min, and ii) The system compressor cycling frequency in the system operating with the power law control is smaller than with the traditional on-off system. Therefore, the study shows that the developed power law control kit has potential to be installed in any existing system with immediate significant energy savings with no need for HVAC-R hardware changes. - Highlights: • An energy consumption reduction strategy for HVAC-R systems is presented. • Power law and on-off control actions are experimentally compared. • Energy savings of 31% were obtained with power law control. • Compressor cycling frequency is smaller with power law control. • Power law control kit has potential to be installed in any existing system

Estimation of Power Production Potential from Natural Gas Pressure Reduction Stations in Pakistan Using ASPEN HYSYS

Directory of Open Access Journals (Sweden)

Imran Nazir Unar

2015-07-01

Full Text Available Pakistan is a gas rich but power poor country. It consumes approximately 1, 559 Billion cubic feet of natural gas annually. Gas is transported around the country in a system of pressurized transmission pipelines under a pressure range of 600-1000 psig exclusively operated by two state owned companies i.e. SNGPL (Sui Northern Gas Pipelines Limited and SSGCL (Sui Southern Gas Company Limited. The gas is distributed by reducing from the transmission pressure into distribution pressure up to maximum level of 150 psig at the city gate stations normally called SMS (Sales Metering Station. As a normal practice gas pressure reduction at those SMSs is accomplished in pressure regulators (PCVs or in throttle valves where isenthalpic expansion takes place without producing any energy. Pressure potential of natural gas is an untapped energy resource which is currently wasted by its throttling. This pressure reduction at SMS (pressure drop through SMS may also be achieved by expansion of natural gas in TE, which converts its pressure into the mechanical energy, which can be transmitted any loading device for example electric generator. The aim of present paper is to explore the expected power production potential of various Sales Metering Stations of SSGCL company in Pakistan. The model of sales metering station was developed in a standard flow sheeting software Aspen HYSYS®7.1 to calculate power and study other parameters when an expansion turbine is used instead of throttling valves. It was observed from the simulation results that a significant power (more than 140 KW can be produced at pressure reducing stations of SSGC network with gas flows more than 2.2 MMSCFD and pressure ration more than 1.3.

Benchmark calculations of power distribution within fuel assemblies. Phase 2: comparison of data reduction and power reconstruction methods in production codes

International Nuclear Information System (INIS)

2000-01-01

Systems loaded with plutonium in the form of mixed-oxide (MOX) fuel show somewhat different neutronic characteristics compared with those using conventional uranium fuels. In order to maintain adequate safety standards, it is essential to accurately predict the characteristics of MOX-fuelled systems and to further validate both the nuclear data and the computation methods used. A computation benchmark on power distribution within fuel assemblies to compare different techniques used in production codes for fine flux prediction in systems partially loaded with MOX fuel was carried out at an international level. It addressed first the numerical schemes for pin power reconstruction, then investigated the global performance including cross-section data reduction methods. This report provides the detailed results of this second phase of the benchmark. The analysis of the results revealed that basic data still need to be improved, primarily for higher plutonium isotopes and minor actinides. (author)

Substantial reductions of input energy and peak power requirements in targets for heavy ion fusion

International Nuclear Information System (INIS)

Mark, J.W.K.; Pan, Y.L.

1986-01-01

Two ways of reducing the requirements of the heavy ion driver for inertial confinement fusion (ICF) target implosion are described. Compared to estimates of target gain not using these methods, the target input energy and peak power may be reduced by about a factor of two with the use of the hybrid-implosion concept. Another factor of two reduction in input energy may be obtained with the use of spin-polarized DT fuel in the ICF target

In vitro study of heat production during power reduction of equine mandibular teeth.

Science.gov (United States)

Allen, Martin L; Baker, Gordon J; Freeman, David E; Holmes, Kenneth R; Marretta, Sandra Manfra; Scoggins, R Dean; Constable, Peter

2004-04-01

To measure the amount of heat generated during 3 methods of equine dental reduction with power instruments. In vitro study. 30 premolar and molar teeth removed from mandibles of 8 equine heads collected at an abbatoir. 38-gauge copper-constantan thermocouples were inserted into the lingual side of each tooth 15 mm (proximal) and 25 mm (distal) from the occlusal surface, at a depth of 5 mm, which placed the tip close to the pulp chamber. Group-NC1 (n = 10) teeth were ground for 1 minute without coolant, group-NC2 (10) teeth were ground for 2 minutes without coolant, and group-C2 (10) teeth were ground for 2 minutes with water for coolant. Mean temperature increase was 1.2 degrees C at the distal thermocouple and 6.6 degrees C at the proximal thermocouple for group-NC1 teeth, 4.1 degrees C at the distal thermocouple and 24.3 degrees C at the proximal thermocouple for group-NC2 teeth, and 0.8 degrees C at the distal thermocouple and -0.1 degrees C at the proximal thermocouple for group-C2 teeth. In general, an increase of 5 degrees C in human teeth is considered the maximum increase before there is permanent damage to tooth pulp. In group-NC2 teeth, temperature increased above this limit by several degrees, whereas in group-C2 teeth, there was little or no temperature increase. Our results suggest that major reduction of equine teeth by use of power instruments causes thermal changes that may cause irreversible pulp damage unless water cooling is used.

Reduction - competitive tomorrow

International Nuclear Information System (INIS)

Worley, L.; Bargerstock, S.

1995-01-01

Inventory reduction is one of the few initiatives that represent significant cost-reduction potential that does not result in personnel reduction. Centerior Energy's Perry nuclear power plant has embarked on an aggressive program to reduce inventory while maintaining plant material availability. Material availability to the plant was above 98%, but at an unacceptable 1994 inventory book value of $47 million with inventory carrying costs calculated at 30% annually

LWR design decision methodology: Phase II. Final report

International Nuclear Information System (INIS)

1981-01-01

Techniques were identified to augment existing design process at the component and system level in order to optimize cost and safety between alternative system designs. The method was demonstrated using the Surry Low Pressure Injection System (LPIS). Three possible backfit options were analyzed for the Surry LPIS, assessing the safety level of each option and estimating the acquisition and installation costs for each

Evaluating the CO 2 emissions reduction potential and cost of power sector re-dispatch

Energy Technology Data Exchange (ETDEWEB)

Steinberg, Daniel C.; Bielen, David A.; Townsend, Aaron

2018-01-01

Prior studies of the U.S. electricity sector have recognized the potential to reduce carbon dioxide (CO2) emissions by substituting generation from coal-fired units with generation from under-utilized and lower-emitting natural gas-fired units; in fact, this type of 're-dispatch' was invoked as one of the three building blocks used to set the emissions targets under the Environmental Protection Agency's Clean Power Plan. Despite the existence of surplus natural gas capacity in the U.S., power system operational constraints not often considered in power sector policy analyses, such as transmission congestion, generator ramping constraints, minimum generation constraints, planned and unplanned generator outages, and ancillary service requirements, could limit the potential and increase the cost of coal-to-gas re-dispatch. Using a highly detailed power system unit commitment and dispatch model, we estimate the maximum potential for re-dispatch in the Eastern Interconnection, which accounts for the majority of coal capacity and generation in the U.S. Under our reference assumptions, we find that maximizing coal-to-gas re-dispatch yields emissions reductions of 230 million metric tons (Mt), or 13% of power sector emissions in the Eastern Interconnection, with a corresponding average abatement cost of $15-$44 per metric ton of CO2, depending on the assumed supply elasticity of natural gas.

Potential for greenhouse gas reduction in industry through increased heat recovery and/or integration of combined heat and power

International Nuclear Information System (INIS)

Axelsson, H.; Harvey, S.; Aasblad, A.; Berntsson, T.

2003-01-01

The potential for greenhouse gas (GHG) reduction in industry through process integration measures depends to a great extent on prevailing technical and economic conditions. A step-wise methodology developed at the author's department based on pinch technology was used to analyse how various parameters influence the cost-optimal configuration for the plant's energy system, and the opportunities for cost-effective GHG emissions reduction compared to this solution. The potential for reduction of GHG emissions from a given plant depends primarily on the design of the industrial process and its energy system (internal factors) and on the electricity-to-fuel price ratio and the specific GHG emissions from the national power generation system (external factors)

PRA for emergency planning: assessing the risk profile of a 3-loop PWR on the basis of US and German risk studies

International Nuclear Information System (INIS)

Chakraborty, S.; Fuchs, H.; Gubler, R.; Landolt, J.; Miteff, L.

1985-01-01

Emergency planning around nuclear power plants should be based on a realistic assessment of their risk profile. Since the results of the Rasmussen study (WASH-1400) and later of the German risk study (Phase A) were not judged to be fully representative for NPP's in Switzerland, an investigation was started to transfer applicable US and German results to a Swiss 3-loop PWR (Goesgen) and to assess the impact of differences in plant design compared to Surry-1 and Biblis-B. The core melt probability for Goesgen was calculated to be more than a factor of ten smaller than for the US and German studies. This is mainly due to more redundancy/better separation (especially in the emergency feedwater) and to partial automation of cooldown after a small break. The results were instrumental in limiting the release categories to be used as reference cases for emergency planning. Further reduction of postulated accidental releases is expected from the current source term research

Effects of sprint interval training and body weight reduction on power to weight ratio in experienced cyclists.

Science.gov (United States)

Lunn, William R; Finn, Joan A; Axtell, Robert S

2009-07-01

The purpose of this study was to determine the effect of supramaximal sprint interval training (SIT), body weight reduction, and a combination of both treatments on peak and average anaerobic power to weight ratio (PPOan:Wt, APOan:Wt) by manipulating peak and average anaerobic power output (PPOan, APOan) and body weight (BW) in experienced cyclists. Participants (N = 34, age = 38.0 +/- 7.1 years) were assigned to 4 groups for a 10-week study. One group performed twice-weekly SIT sessions on a cycle ergometer while maintaining body weight (SIT). A second group did not perform SIT but intentionally reduced body weight (WR). A third group simultaneously performed SIT sessions and reduced body weight (SIT+WR). A control group cycled in their normal routine and maintained body weight (CON). The 30-second Wingate Test assessed pretest and posttest POan:Wt scores. There was a significant mean increase (p weight (kg) decreased significantly in WR and SIT + WR (80.3 +/- 13.7 to 75.3 +/- 11.9 and 78.9 +/- 10.8 to 73.4 +/- 10.8, respectively). The results demonstrate that cyclists can use SIT sessions and body weight reduction as singular training interventions to effect significant increases in anaerobic power to weight ratio, which has been correlated to enhanced aerobic cycling performance. However, the treatments were not effective as combined interventions, as there was no significant change in either PPOan:Wt or APOan:Wt in SIT + WR.

A dual mode operated boost inverter and its control strategy for ripple current reduction in single-phase uninterruptible power supplies

DEFF Research Database (Denmark)

Tang, Y.; Yao, W.; Blaabjerg, Frede

2015-01-01

In single-phase uninterruptible power supply (UPS) applications, it is well known that the AC side instantaneous power is not constant by nature. The resulting input current from the DC source side will inevitably contain low frequency ripple components that may largely deteriorate the system...... as active power conversion, while its CM operation is controlled in such a way that the low frequency ripple current on the DC side can be maintained in a minimum level. The proposed ripple current reduction method may not only work with linear loads, but also nonlinear loads, where more sophisticated...

Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low wind power potentials

Science.gov (United States)

Miller, Lee; Kleidon, Axel

2017-04-01

Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power potentials that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m-2) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m-2) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m-2 of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.

LWR design decision methodology: Phase II. Final report

Energy Technology Data Exchange (ETDEWEB)

None

1981-01-01

Techniques were identified to augment existing design process at the component and system level in order to optimize cost and safety between alternative system designs. The method was demonstrated using the Surry Low Pressure Injection System (LPIS). Three possible backfit options were analyzed for the Surry LPIS, assessing the safety level of each option and estimating the acquisition and installation costs for each. (DLC)

Efficiency potentials of heat pumps with combined heat and power. For maximum reduction of CO2 emissions and for electricity generation from fossil fuels with CO2 reduction in Switzerland

International Nuclear Information System (INIS)

Rognon, F.

2005-06-01

This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at how the efficiency potential of heat pumps together with combined heat and power systems can help provide a maximum reduction of CO 2 emissions and provide electricity generation from fossil fuel in Switzerland together with reductions in CO 2 emissions. In Switzerland, approximately 80% of the low-temperature heat required for space-heating and for the heating-up of hot water is produced by burning combustibles. Around a million gas and oil boilers were in use in Switzerland in 2000, and these accounted for approximately half the country's 41.1 million tonnes of CO 2 emissions. The authors state that there is a more efficient solution with lower CO 2 emissions: the heat pump. With the enormous potential of our environment it would be possible to replace half the total number of boilers in use today with heat pumps. This would be equivalent to 90 PJ p.a. of useful heat, or 500,000 systems. The power source for heat pumps should come from the substitution of electric heating systems (electric resistor-based systems) and from the replacement of boilers. This should be done by using combined heat and power systems with full heat utilisation. This means, according to the authors, that the entire required power source can be provided without the need to construct new electricity production plants. The paper examines and discusses the theoretical, technical, market and realisable potentials

Potential reduction of carbon dioxide emissions from the use of electric energy storage on a power generation unit/organic Rankine system

International Nuclear Information System (INIS)

Mago, Pedro J.; Luck, Rogelio

2017-01-01

Highlights: • A power generation organic Rankine cycle with electric energy storage is evaluated. • The potential carbon dioxide emissions reduction of the system is evaluated. • The system performance is evaluated for a building in different climate zones. • The system emissions and cost are compared with those of conventional systems. • Use of carbon emissions cap and trade programs on the system is evaluated. - Abstract: This paper evaluates the potential carbon dioxide emissions reduction from the implementation of electric energy storage to a combined power generation unit and an organic Rankine cycle relative to a conventional system that uses utility gas for heating and utility electricity for electricity needs. Results indicate that carbon dioxide emission reductions from the operation of the proposed system are directly correlated to the ratio of the carbon dioxide emission conversion factor for electricity to that of the fuel. The location where the system is installed also has a strong influence on the potential of the proposed system to save carbon dioxide emissions. Finally, it is shown that by using carbon emissions cap and trade programs, it is possible to establish a frame of reference to compare/exchange operational cost gains with carbon dioxide emission reductions/gains.

The impacts of electricity dispatch protocols on the emission reductions due to wind power and carbon tax.

Science.gov (United States)

Yu, Yang; Rajagopal, Ram

2015-02-17

Two dispatch protocols have been adopted by electricity markets to deal with the uncertainty of wind power but the effects of the selection between the dispatch protocols have not been comprehensively analyzed. We establish a framework to compare the impacts of adopting different dispatch protocols on the efficacy of using wind power and implementing a carbon tax to reduce emissions. We suggest that a market has high potential to achieve greater emission reduction by adopting the stochastic dispatch protocol instead of the static protocol when the wind energy in the market is highly uncertain or the market has enough adjustable generators, such as gas-fired combustion generators. Furthermore, the carbon-tax policy is more cost-efficient for reducing CO2 emission when the market operates according to the stochastic protocol rather than the static protocol. An empirical study, which is calibrated according to the data from the Electric Reliability Council of Texas market, confirms that using wind energy in the Texas market results in a 12% CO2 emission reduction when the market uses the stochastic dispatch protocol instead of the 8% emission reduction associated with the static protocol. In addition, if a 6$/ton carbon tax is implemented in the Texas market operated according to the stochastic protocol, the CO2 emission is similar to the emission level from the same market with a 16$/ton carbon tax operated according to the static protocol. Correspondingly, the 16$/ton carbon tax associated with the static protocol costs 42.6% more than the 6$/ton carbon tax associated with the stochastic protocol.

Surry Power Station, Units 1 and 2. Annual operating report for 1976, section 2: core performance and startup physics test reports

International Nuclear Information System (INIS)

1977-01-01

The analyses of four core performance indicators including burnup distribution, reactivity depletion, power distribution, and primary coolant activity are discussed. Information is presented concerning fuel densification monitoring; start-up physics testing; and James River temperature, salinity, fish, biota, and plankton entrainment monitoring

CONTROLLING THE SPEED OF ROLLING CUTS IN CONDITIONS OF REDUCTION OF BRAKE POWER OF CAR RETARDERS

Directory of Open Access Journals (Sweden)

D. M. Kozachenko

2016-06-01

Full Text Available Purpose. The study aims to develop the requirements for organization of the marshalling process in the conditions when the power of retarder positions is less than the nominal one. Methodology. The research is carried out using the train traffic safety theory and mathematical modelling of hump processes. Findings. The current technical standard documents regulating the operational performance of humps do not contain direct instructions on how to proceed in the event of brake power loss by car retarders, thus creating threats to the traffic safety. This problem is quite acute for the Ukrainian railways in connection with a chronic shortage of funds for the repair and renewal of technical equipment, including the humps. At the same time, a significant drop in the volume of work leads to the fact that the hump required processing capacity can be provided in case of partial failure of retarders as well. Herewith the most important task is to ensure the breaking-up safety in conditions of parametric failures of retarders. The analysis of dangerous situations, the occurrence of which is possible at humps, as well as the modelling of cut rolling, allowed establishing the connection between the value of retarder tire pressing force on the car wheels and the breaking-up modes, providing the safety of marshalling process. The paper sets the application areas of such measures as the breaking-up speed reduction, breaking-up termination, the use of additional braking by block hangers. Originality. The originality of the work lies in the fact that it first obtained the complex of dependencies that determine the performance requirements for the power of hump retarders and allow the staff to enter the appropriate limits for breaking-up modes to ensure the marshalling process safety. Practical value. The results of the research can be used to supplement the «Instruction on the maintenance of facilities of mechanized and automated humps» in order to determine

Synthesis of high intrinsic loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid-assisted hydrothermal-reduction route

International Nuclear Information System (INIS)

Behdadfar, Behshid; Kermanpur, Ahmad; Sadeghi-Aliabadi, Hojjat; Morales, Maria del Puerto; Mozaffari, Morteza

2012-01-01

Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated intrinsic loss power (ILP) was 9.4 nHm 2 /kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: ► Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. ► Citric acid acted as reducing agent and surfactant in the route. ► This is a facile, low energy and environmental friendly route. ► The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. ► The calculated intrinsic loss power of the synthesized ferrofluids was very high.

Power system coherency and model reduction

CERN Document Server

Chow, Joe H

2014-01-01

This book provides a comprehensive treatment for understanding interarea modes in large power systems and obtaining reduced-order models using the coherency concept and selective modal analysis method.

FY 2000 report on the results of the development of the stand-by consumption power reduction technology. R and D of the stand-by consumption power reduction technology in relation to machine tools; 2000 nendo taikiji shohi denryoku sakugen gijutsu kaihatsu seika hokokusho. Kosaku kiki ni kanrensuru taikiji shohi denryoku sakugen gijutsu no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

In relation to machine tools, a method was studied for reducing consumption power at the time of standing-by, keeping the present processing accuracy, processing efficiency and operability, and the results of the study were as follows. As to the chip conveyer, the stand-by consumption power was reduced by approximately 75% by reducing the motor capacity by reviewing the effective operation method and the structure. Concerning the mist collector, a reduction of approximately 85% was confirmed by adopting the efficient operation method and high-efficient motor. Relating to the oil controller, an experiment was made on the frame thermal circulation system and the self-forced air cooling system. In terms of the rise in temperature, the controller is lower than the existing one, but it was found out that the consumption power could be reduced by about 14% and about 98%, respectively. About the coolant pump, the optimum inclination angle/necessary minimum flow rate of oil pan were confirmed, and a reduction of 47% was confirmed. As to the hydraulic pump, study was made of a method to substitute other power source for oil pressure and the intermittent operation of hydraulic unit, and effects of each were confirmed. Further studies were made of the control disc, reduction in air consumption, etc. (NEDO)

Experiments to investigate direct containment heating phenomena with scaled models of the Calvert Cliffs Nuclear Power Plant

International Nuclear Information System (INIS)

Blanchat, T.K.; Pilch, M.M.; Allen, M.D.

1997-02-01

The Surtsey Test Facility is used to perform scaled experiments simulating High Pressure Melt Ejection accidents in a nuclear power plant (NPP). The experiments investigate the effects of direct containment heating (DCH) on the containment load. The results from Zion and Surry experiments can be extrapolated to other Westinghouse plants, but predicted containment loads cannot be generalized to all Combustion Engineering (CE) plants. Five CE plants have melt dispersal flow paths which circumvent the main mitigation of containment compartmentalization in most Westinghouse PWRs. Calvert Cliff-like plant geometries and the impact of codispersed water were addressed as part of the DCH issue resolution. Integral effects tests were performed with a scale model of the Calvert Cliffs NPP inside the Surtsey test vessel. The experiments investigated the effects of codispersal of water, steam, and molten core stimulant materials on DCH loads under prototypic accident conditions and plant configurations. The results indicated that large amounts of coejected water reduced the DCH load by a small amount. Large amounts of debris were dispersed from the cavity to the upper dome (via the annular gap). 22 refs., 84 figs., 30 tabs

Long-term outcomes in medial flap inferior turbinoplasty are superior to submucosal electrocautery and submucosal powered turbinate reduction.

Science.gov (United States)

Barham, Henry P; Thornton, Mona A; Knisely, Anna; Marcells, George N; Harvey, Richard J; Sacks, Raymond

2016-02-01

Techniques for inferior turbinate reduction vary from complete turbinectomy to limited cauterization. Surgical methods differ on the degree of tissue reduction and reliance on surgical tissue removal vs tissue ablation. The outcome and morbidity from 3 different turbinate techniques are compared. A randomized double-blinded study was performed. Patient nasal cavities were randomized to different interventions on each side within the same patient. One group had a combination of submucosal powered turbinate reduction (designated "submucosal") and submucosal electrocautery (designated "electrocautery"); and the second group had a combination of submucosal powered turbinate reduction (designated "submucosal") and medial flap turbinoplasty (designated "turbinoplasty"). Patient-scored nasal obstruction and rhinorrhoea (1 to 5) along with blindly assessed nasal airway patency ratings (1 to 4) was done at 12 and 60 months postoperatively. Pain requiring additional analgesia, crusting, bleeding (needing review), and revision were documented. A total of 100 patients were recruited (age 32.79 ± 13.58 years; 39% female). This represented 200 nasal airway surgeries with 100 submucosal procedures, 50 electrocautery and 50 medial flap turbinoplasties. No patients complained of worsening of their obstruction. At 60 months patients in the turbinoplasty group had greater outcomes, with 90.2% having occasional or no decongestant use (Kendall's tau B p electrocautery (15.8%) and submucosal (37.8%). Fewer turbinoplasty patients had a revision procedure (12%, χ(2) = 20.08, p electrocautery (54%) and submucosal (40%). Crusting was more common in the electrocautery group (58% vs submucosal 2% and turbinoplasty 0%; χ(2) = 92.04; p < 0.001). The medial flap turbinoplasty provided consistent, robust results. Long-term relief of obstructive symptoms without additional risk of complication was observed in the turbinoplasty group. © 2015 ARS-AAOA, LLC.

Dose reduction and optimization studies (ALARA) at nuclear power facilities

International Nuclear Information System (INIS)

Baum, J.W.; Meinhold, C.B.

1983-01-01

Brookhaven National Laboratory (BNL) has been commissioned by the Nuclear Regulatory Commission (NRC) to study dose-reduction techniques and effectiveness of as low as reasonably achievable (ALARA) planning at LWR plants. These studies have the following objectives: identify high-dose maintenance tasks; identify dose-reduction techniques; examine incentives for dose reduction; evaluate cost-effectiveness and optimization of dose-reduction techniques; and compile an ALARA handbook on data, engineering modifications, cost-effectiveness calculations, and other information of interest to ALARA practioners

Reduction of electric power consumption in relation to household appliances. Elbesparelser ved husholdningsapparater; Forprojekt

Energy Technology Data Exchange (ETDEWEB)

Gydesen, A.

1989-07-15

Possibilities were investigated for the reduction of electric power consumption in relation to household appliances, and for cooperation with manufacturers in this respect. It is suggested that in the cases of washing-up machines, and washing and drying machines, hot water from the tap could be utilized. This would mean that the energy consumption would then shift to domestic heating equipment, dual-purpose power plants and district heating plants. Ovens, drying machines, washing machines and washing-up machines could use natural gas, especially in areas where this fuel could be conveyed to each household via pipes. Cooperation with manufacturers seems feasible, especially with regard to electric ovens, saucepans for use in combination with the latter, and water beds. Considering future developments, it is reasonable to expect that ultra sound will be utilized in connection with washing-up and washing machines, moreover it is likely that the use of enzymes in washing powders will mean that washing machines will be able to run on cold water. (AB) 21 refs.

Is There a Future for Nuclear Power? Wind and Emission Reduction Targets in Fossil-Fuel Alberta.

Science.gov (United States)

van Kooten, G Cornelis; Duan, Jun; Lynch, Rachel

2016-01-01

This paper explores the viability of relying on wind power to replace upwards of 60% of electricity generation in Alberta that would be lost if coal-fired generation is phased out. Using hourly wind data from 17 locations across Alberta, we are able to simulate the potential wind power output available to the Alberta grid when modern, 3.5 MW-capacity wind turbines are spread across the province. Using wind regimes for the years 2006 through 2015, we find that available wind power is less than 60% of installed capacity 98% of the time, and below 30% of capacity 74% of the time. There is only a small amount of correlation between wind speeds at different locations, but yet it remains necessary to rely on fossil fuel generation. Then, based on the results from a grid allocation model, we find that CO2 emissions can be reduced by about 30%, but only through a combination of investment in wind energy and reliance on purchases of hydropower from British Columbia. Only if nuclear energy is permitted into the generation mix would Alberta be able to meet its CO2-emissions reduction target in the electricity sector. With nuclear power, emissions can be reduced by upwards of 85%.

Is There a Future for Nuclear Power? Wind and Emission Reduction Targets in Fossil-Fuel Alberta

Science.gov (United States)

Duan, Jun; Lynch, Rachel

2016-01-01

This paper explores the viability of relying on wind power to replace upwards of 60% of electricity generation in Alberta that would be lost if coal-fired generation is phased out. Using hourly wind data from 17 locations across Alberta, we are able to simulate the potential wind power output available to the Alberta grid when modern, 3.5 MW-capacity wind turbines are spread across the province. Using wind regimes for the years 2006 through 2015, we find that available wind power is less than 60% of installed capacity 98% of the time, and below 30% of capacity 74% of the time. There is only a small amount of correlation between wind speeds at different locations, but yet it remains necessary to rely on fossil fuel generation. Then, based on the results from a grid allocation model, we find that CO2 emissions can be reduced by about 30%, but only through a combination of investment in wind energy and reliance on purchases of hydropower from British Columbia. Only if nuclear energy is permitted into the generation mix would Alberta be able to meet its CO2-emissions reduction target in the electricity sector. With nuclear power, emissions can be reduced by upwards of 85%. PMID:27902712

Confluence reduction for Markov automata

NARCIS (Netherlands)

Timmer, Mark; Katoen, Joost P.; van de Pol, Jaco; Stoelinga, Mariëlle Ida Antoinette

2016-01-01

Markov automata are a novel formalism for specifying systems exhibiting nondeterminism, probabilistic choices and Markovian rates. As expected, the state space explosion threatens the analysability of these models. We therefore introduce confluence reduction for Markov automata, a powerful reduction

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA. Volume 7

Energy Technology Data Exchange (ETDEWEB)

Kaurin, D.G.; Khan, T.A.; Sullivan, S.G.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States)

1993-07-01

The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in the continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This is volume 7 of the series. The abstracts in this bibliography were selected from proceedings of technical meetings and conferences, journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to radiation protection and dose reduction, and ranges from use of robotics to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 7 contains 293 abstract, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 7. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes.

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA. Volume 8

Energy Technology Data Exchange (ETDEWEB)

Sullivan, S.G.; Khan, T.A.; Xie, J.W. [Brookhaven National Lab., Upton, NY (United States)

1995-05-01

The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in a continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This volume 8 of the series. The abstracts in this bibliography were selected form proceedings of technical meetings and conference journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to the many aspects of radiation protection and dose reduction, and ranges form use of robotics, to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 8 contains 232 abstracts, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 8. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes.

A randomized 3-month clinical comparison of a power toothbrush to a manual toothbrush in the reduction of gingivitis.

Science.gov (United States)

Li, Zhen; He, Tao; Li, Chun; Sun, Lily; Chang, Jinlan; He, Yanyan; Zhao, Jizhi; Ji, Ning

2016-08-01

To compare the anti-gingivitis effect of a power toothbrush relative to a manual toothbrush control. This was a 3-month, randomized and controlled, single-center, parallel group, examiner-blinded clinical study. 123 Chinese adults in good general health and with at least 15 gingival bleeding sites, as measured by the Gingival Bleeding Index, were enrolled into the study. At baseline, pre-treatment gingivitis levels were assessed using the Mazza Bleeding Index. Subjects were then randomly assigned to receive either an oscillating-rotating power toothbrush [Oral-B Professional Care 7000 (D17u/EB17)] or a flat-trim manual toothbrush with tapered filaments (Lion Dentor Systema). Subjects brushed at home twice-daily with their assigned toothbrush and a marketed sodium fluoride dentifrice (Crest Cavity Protection dentifrice), and were reevaluated at Months 1, 2, and 3. 113 evaluable subjects completed the study. Both groups showed significant reductions in gingivitis from baseline for all time points measured (Pgingivitis reductions of 7.11%, 9.20% and 8.47%, respectively, than the manual toothbrush (Pgingivitis compared with a manual toothbrush at Months 1, 2 and 3.

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA. Volume 8

International Nuclear Information System (INIS)

Sullivan, S.G.; Khan, T.A.; Xie, J.W.

1995-05-01

The ALARA Center at Brookhaven National Laboratory publishes a series of bibliographies of selected readings in radiation protection and ALARA in a continuing effort to collect and disseminate information on radiation dose reduction at nuclear power plants. This volume 8 of the series. The abstracts in this bibliography were selected form proceedings of technical meetings and conference journals, research reports, and searches of the Energy Science and Technology database of the US Department of Energy. The subject material of these abstracts relates to the many aspects of radiation protection and dose reduction, and ranges form use of robotics, to operational health physics, to water chemistry. Material on the design, planning, and management of nuclear power stations is included, as well as information on decommissioning and safe storage efforts. Volume 8 contains 232 abstracts, an author index, and a subject index. The author index is specific for this volume. The subject index is cumulative and lists all abstract numbers from volumes 1 to 8. The numbers in boldface indicate the abstracts in this volume; the numbers not in boldface represent abstracts in previous volumes

Viability of LPG use in low-power outboard engines for reduction in consumption and pollutant emissions

International Nuclear Information System (INIS)

Murillo, S.; Miguez, J.L.; Porteiro, J.; Hernandez, J.J.; Lopez-Gonzalez, L.M.

2003-01-01

This study presents the viability of the use of liquefied petroleum gases (LPG) dosage systems in order to solve the fuel supply in four-stroke outboard engines in compliance with regulations concerning emissions of immediate application pollutants. Results obtained show an important decrease in specific fuel consumption (nearly 20%) provoking a small power loss (about 5%), with an extra saving when making use of bottled fuel, which does not suffer spills in the bunkers and maintenance operations. Laboratory tests have been carried out on 8 and 15 HP Yamaha outboard engines, obtaining reductions in pollutants (CO, HC and NO x ) of 60% and of 95% for each power, respectively. These trials have been contrasted with tests carried out in the Vigo estuary and the river Milno waterways, both located in the South of Galicia (Spain). (Author)

A Study on the Risk Reduction Effect by MLCS (Mid-loop Level Control System) of EUAPR using the Low-Power and Shutdown PSA Result

International Nuclear Information System (INIS)

Lee, Keunsung; Choi, Sunmi; Kim, Eden

2016-01-01

The EU-APR design has been developed in order to expand and diversify the global nuclear power market of APR1400. For the improvement of shutdown risk for the EUAPR, the mid-loop level control system (MLCS) is considered during mid-loop operation for the EU-APR, which is not incorporated into SKN 3 and 4 (APR1400 Type) in Korea. Commonly, the risk associated with the NPP can be identified through the PSA. Thus, this paper discusses the low power and shutdown (LPSD) risk reduction effect by MLCS using the Low-Power and Shutdown PSA Result. LPSD level 1 PSA models for EU-APR have been developed. The risk reduction effect by MLCS is discussed. Because the loss of shutdown cooling function during mid-loop is one of the most vulnerable events, the MLCS have a significant influence on CDF in LPSD PSA. The shutdown risk of domestic power plants would likely be reduced if the MLCS is adopted in all operating NPPs in Korea during the mid-loop operation. It is expected that this work will contribute to reduce shutdown risk of domestic power plants

Results and insights of a level-1 internal event PRA of a PWR during mid-loop operations

International Nuclear Information System (INIS)

Chu, T.L.; Musicki, Z.; Kohut, P.

1993-01-01

Traditionally, probabilistic risk assessments (PRA) of severe accidents in nuclear power plants have considered initiating events potentially occurring only during full power operation. Some previous screening analysis that were performed for other modes of operation suggested that risks during those modes were small relative to full power operation. However, more recent studies and operational experience have implied that accidents during low power and shutdown could be significant contributors to risk. The objective of this paper is to present the approach utilized in the level-1 PRA for the Surry plant, and discuss the results obtained. A comparison of the results with those of other shutdown studies is provided. Relevant safety issues such as plant and hardware configurations, operator training, and instrumentation and control is discussed

Risk impact of two accident management strategies

International Nuclear Information System (INIS)

Dingman, S.; Camp, A.

1992-01-01

This report probabilistic Risk Assessment is used to evaluate two accident management strategies: intentionally depressurizing the reactor coolant system of a pressurized water reactor to prevent containment-pressurization during high pressure melt ejection, and flooding the containment of a boiling water reactor to prevent or delay vessel breach. Sensitivity studies indicated that intentional depressurization would not provide a significant risk reduction at Surry. A preliminary evaluation of the containment flooding strategy indicated that it might prove beneficial for some plants, but that further strategy development would be needed to fully evaluate the strategy-

Radionuclide release calculations for selected severe accident scenarios. Volume 3. PWR, subatmospheric containment design

International Nuclear Information System (INIS)

Denning, R.S.; Gieseke, J.A.; Cybulskis, P.; Lee, K.W.; Jordan, H.; Curtis, L.A.; Kelly, R.F.; Kogan, V.; Schumacher, P.M.

1986-07-01

This report presents results of analyses of the enviromental releases of fission products (source terms) for severe accident scenarios in a pressurized water reactor with a subatmospheric containment design. The analyses were performed to support the Severe Accident Risk Reduction/Risk Rebaselining Program (SARRP) which is being undertaken for the US Nuclear Regulatory Commission by Sandia National Laboratories. In the SARRP program, risk estimates are being generated for a number of reference plant designs. the Surry plant has been used in this study as the reference plant for a subatmospheric design

Reduction of coupling parameters and duality

International Nuclear Information System (INIS)

Oehme, R.; Max-Planck-Institut fuer Physik, Muenchen

2000-01-01

The general method of the reduction in the number of coupling parameters is discussed. Using renormalization group invariance, theories with several independent couplings are related to a set of theories with a single coupling parameter. The reduced theories may have particular symmetries, or they may not be related to any known symmetry. The method is more general than the imposition of invariance properties. Usually, there are only a few reduced theories with an asymptotic power series expansion corresponding to a renormalizable Lagrangian. There also exist 'general' solutions containing non-integer powers and sometimes logarithmic factors. As an example for the use of the reduction method, the dual magnetic theories associated with certain supersymmetric gauge theories are discussed. They have a superpotential with a Yukawa coupling parameter. This parameter is expressed as a function of the gauge coupling. Given some standard conditions, a unique, isolated power series solution of the reduction equations is obtained. After reparameterization, the Yukawa coupling is proportional to the square of the gauge coupling parameter. The coefficient is given explicitly in terms of the numbers of colors and flavors. 'General' solutions with non-integer powers are also discussed. A brief list is given of other applications of the reduction method. (orig.)

Reduction technique of drop voltage and power losses to improve power quality using ETAP Power Station simulation model

Science.gov (United States)

Satrio, Reza Indra; Subiyanto

2018-03-01

The effect of electric loads growth emerged direct impact in power systems distribution. Drop voltage and power losses one of the important things in power systems distribution. This paper presents modelling approach used to restructrure electrical network configuration, reduce drop voltage, reduce power losses and add new distribution transformer to enhance reliability of power systems distribution. Restructrure electrical network was aimed to analyse and investigate electric loads of a distribution transformer. Measurement of real voltage and real current were finished two times for each consumer, that were morning period and night period or when peak load. Design and simulation were conduct by using ETAP Power Station Software. Based on result of simulation and real measurement precentage of drop voltage and total power losses were mismatch with SPLN (Standard PLN) 72:1987. After added a new distribution transformer and restructrured electricity network configuration, the result of simulation could reduce drop voltage from 1.3 % - 31.3 % to 8.1 % - 9.6 % and power losses from 646.7 watt to 233.29 watt. Result showed, restructrure electricity network configuration and added new distribution transformer can be applied as an effective method to reduce drop voltage and reduce power losses.

Reduction of impurity contamination in a working gas for closed-cycle MHD power generation

International Nuclear Information System (INIS)

Endo, N.; Yoshikawa, K.; Shioda, S.

1989-01-01

The reduction of impurity contamination in a working inert gas for closed-cycle MHD power generation is examined. A conceptual operation system of regenerative heat exchangers is proposed for minimizing the amount of combustion gas which mixes in the working inert gas. Experiments have shown that this mixing can be reduced significantly by evacuating and flushing the heat exchangers after being heated by combustion gas. Calculations have shown that, among the main molecular contaminants in the working inert gas, CO 2 , H 2 O and O 2 can be removed as compounds with the seed material, while N 2 and H 2 can be reduced by a partial purification of the circulating working inert gas. (author)

The BOS-X approach: achieving drastic cost reduction in CPV through holistic power plant level innovation

Science.gov (United States)

Plesniak, A.; Garboushian, V.

2012-10-01

In 2011, the Amonix Advanced Technology Group was awarded DOE SunShot funding in the amount of 4.5M to design a new Balance of System (BOS) architecture utilizing Amonix MegaModules™ focused on reaching the SunShot goal of 0.06-$0.08/kWhr LCOE. The project proposal presented a comprehensive re-evaluation of the cost components of a utility scale CPV plant and identified critical areas of focus where innovation is needed to achieve cost reduction. As the world's premier manufacturer and most experienced installer of CPV power plants, Amonix is uniquely qualified to lead a rethinking of BOS architecture for CPV. The presentation will focus on the structure of the BOS-X approach, which looks for the next wave of cost reduction in CPV through evaluation of non-module subsystems and the interaction between subsystems during the lifecycle of a solar power plant. Innovation around nonmodule components is minimal to date because CPV companies are just now getting enough practice through completion of large projects to create ideas and tests on how to improve baseline designs and processes. As CPV companies increase their installed capacity, they can utilize an approach similar to the methodology of BOS-X to increase the competitiveness of their product. Through partnership with DOE, this holistic approach is expected to define a path for CPV well aligned with the goals of the SunShot Initiative.

Reduction of U3O8 to U by a metallic reductant, Li

International Nuclear Information System (INIS)

Jin-Mok Hur; Sun-Seok Hong; Hansoo Lee

2010-01-01

Reduction of U 3 O 8 was investigated for the recycling of spent oxide fuel from a commercial nuclear power plant. The possible reduction methods were proposed and compared. Based on the thermodynamic analysis, Li metal was selected as a reductant. The optimum reaction temperature for the reduction of U 3 O 8 was investigated at the wider reaction temperature range. The adverse oxidation of U metal by Li 2 O at 1,000 deg C was experimentally verified. Ellingham diagram was constructed to investigate the extent of the uranium oxides reduction when the reaction was carried out above melting point of U metal. (author)

Reduction in adipose tissue volume using a new high-power radiofrequency technology combined with infrared light and mechanical manipulation for body contouring.

Science.gov (United States)

Adatto, Maurice A; Adatto-Neilson, Robyn M; Morren, Grietje

2014-09-01

A growing patient demand for a youthful skin appearance with a favorable body shape has led to the recent development of new noninvasive body contouring techniques. We have previously demonstrated that the combination of bipolar radiofrequency (RF) and optical energies with tissue manipulation is an efficient reshaping modality. Here, we investigated the efficacy and safety of a new high-power version of this combined technology, in terms of adipose tissue reduction and skin tightening. Thirty-five patients received one treatment per week over 6 weeks to their abdomen/flank, buttock, or thigh areas and were followed up to 3 months post completion of the treatment protocol. This new device has an increased power in the bipolar RF, as this parameter appears to be the most important energy modality for volume reduction. Patient circumferences were measured and comparisons of baseline and post treatment outcomes were made. Diagnostic ultrasound (US) measurements were performed in 12 patients to evaluate the reduction in adipose tissue volume, and a cutometer device was used to assess improvements in skin tightening. We observed a gradual decline in patient circumferences from baseline to post six treatments. The overall body shaping effect was accompanied with improvement in skin tightening and was clearly noticeable in the comparison of the before and after treatment clinical photographs. These findings correlated with measurements of adipose tissue volume and skin firmness/elasticity using diagnostic US and cutometer, respectively. The thickness of the fat layer showed on average a 29% reduction between baseline and the 1-month follow up. The average reduction in the circumference of the abdomen/flanks, buttocks, and thighs from baseline to the 3-month follow-up was 1.4, 0.5, and 1.2 cm, respectively, and 93% of study participants demonstrated a 1-60% change in fat layer thickness. Patients subjectively described comfort and satisfaction from treatment, and 97% of

Dynamic Voltage and Frequency Scaling and Adaptive Body Biasing for Active and Leakage Power Reduction in MPSoC: a Literature Overview

OpenAIRE

Milutinovic, A.; Molnos, Anca; Goossens, Kees; Smit, Gerardus Johannes Maria

2009-01-01

Power is an important design constraint for all nomadic and tethered devices as mobile phones or media-boxes today. This is mainly because it limits their operational time or because of the required operational thermal conditions. In order to keep the pace with increasing number of use-cases while increasing the lifetime, power reduction is enforced to all parts of a device, thus also for the embedded chipset. For this and other reasons like cost and size, the whole chipset has been integrate...

76 FR 66090 - Facility Operating License Amendment From Virginia Electric and Power Company, Surry Power...

Science.gov (United States)

2011-10-25

... process, thermal expansion mismatch between the tube and tubesheet, and from the differential pressure... staff at 1- 800-397-4209, 301-415-4737, or by e-mail to [email protected] . The application for... attachment to the application, dated July 28, 2011, contains SUNSI and, accordingly, this portion is being...

Low power interconnect design

CERN Document Server

Saini, Sandeep

2015-01-01

This book provides practical solutions for delay and power reduction for on-chip interconnects and buses.  It provides an in depth description of the problem of signal delay and extra power consumption, possible solutions for delay and glitch removal, while considering the power reduction of the total system.  Coverage focuses on use of the Schmitt Trigger as an alternative approach to buffer insertion for delay and power reduction in VLSI interconnects. In the last section of the book, various bus coding techniques are discussed to minimize delay and power in address and data buses.   ·         Provides practical solutions for delay and power reduction for on-chip interconnects and buses; ·         Focuses on Deep Sub micron technology devices and interconnects; ·         Offers in depth analysis of delay, including details regarding crosstalk and parasitics;  ·         Describes use of the Schmitt Trigger as a versatile alternative approach to buffer insertion for del...

Research on PM2.5 emission reduction path of China ‘s electric power industry based on DEA model

Science.gov (United States)

Jin, Yanming; Yang, Fan; Liu, Jun

2018-02-01

Based on the theory of data envelopment analysis, this study constructs the environmental performance evaluation model of the power industry, analyzes the performance of development of clean energy, the implementation of electricity replacement, and the development of coal-fired energy-saving and emission-reducing measures. Put forward technology path to reduce emission in the future. The results show that (1) improving the proportion of coal for power generation, speeding up the replacement of electricity is the key to solve the haze in China. (2) With the photovoltaic and other new energy power generation costs gradually reduced and less limit from thermal energy, by final of “thirteenth five-years plan”, the economy of clean energy will surpass thermal energy-saving emission reduction. (3) After 2025, the economy of the electricity replacement will be able to show.

Risk assessment for the intentional depressurization strategy in PWRs

International Nuclear Information System (INIS)

Dingman, S.E.

1994-03-01

An accident management strategy has been proposed in which the reactor coolant system is intentionally depressurized during an accident. The aim is to reduce the containment pressurization that would result from high pressure ejection of molten debris at vessel breach. Probabilistic risk assessment (PRA) methods were used to evaluate this strategy for the Surry nuclear power plant. Sensitivity studies were conducted using event trees that were developed for the NUREG-1150 study. It was found that depressurization (intentional or unintentional) had minimal impact on the containment failure probability at vessel breach for Surry because the containment loads assessed for NUREG-1150 were not a great threat to the containment survivability. An updated evaluation of the impact of intentional depressurization on the probability of having a high pressure melt ejection was then made that reflected analyses that have been performed since NUREG-1150 was completed. The updated evaluation confirmed the sensitivity study conclusions that intentional depressurization has minimal impact on the probability of a high pressure melt ejection. The updated evaluation did show a slight benefit from depressurization because depressurization delayed core melting, which led to a higher probability of recovering emergency core coolant injection, thereby arresting the core damage

A Modeled Carbon Emission Analysis Of Rampal Power Plant In Bangladesh And A Review Of Carbon Reduction Technologies

Directory of Open Access Journals (Sweden)

Gour Chand Mazumder

2015-08-01

Full Text Available todays most important concern of Bangladesh is power generation. Government has planned a 1320 MW coal-fired power station at Rampal near Sundarbans. Environmentalists have indicated that this plant will face environmental issues. So we tried finding the capability of Sundarbans to face carbon emissions. We figured out approximate carbon emission of that power plant using an arbitrary operational model. We found 3.16MKg of carbon emission daily. We used mangroves carbon sequestration rate to calculate the carbon tolerance level of Sundarbans and found approximately 4.2 MKg of carbon per day.The amount of emission we found here is marginal with the ability of Sundarbans as it is already contributing to sequester carbon from other sources. We studied and showed technology wise carbon reductions. It is possible to reduce 90 to 95 carbon emissioby using these technologies. We recommend these advanced technologies to ensure sundarbans environmental safety.

Thermoelectric Properties of Silicon Germanium: An Investigation of the Reduction of Lattice Thermal Conductivity and Enhancement of Power Factor

Science.gov (United States)

Lahwal, Ali Sadek

Thermoelectric materials are of technological interest owing to their ability of direct thermal-to-electrical energy conversion. In thermoelectricity, thermal gradients can be used to generate an electrical power output. Recent efforts in thermoelectrics are focused on developing higher efficient power generation materials. In this dissertation, the overall goal is to investigate both the n-type and p-type of the state of the art thermoelectric material, silicon germanium (SiGe), for high temperature power generation. Further improvement of thermoelectric performance of Si-Ge alloys hinges upon how to significantly reduce the as yet large lattice thermal conductivity, and optimizing the thermoelectric power factor PF. Our methods, in this thesis, will be into two different approaches as follow: The first approach is manipulating the lattice thermal conductivity of n and p-type SiGe alloys via direct nanoparticle inclusion into the n-type SiGe matrix and, in a different process, using a core shell method for the p-type SiGe. This approach is in line with the process of in-situ nanocomposites. Nanocomposites have become a new paradigm for thermoelectric research in recent years and have resulted in the reduction of thermal conductivity via the nano-inclusion and grain boundary scattering of heat-carrying phonons. To this end, a promising choice of nano-particle to include by direct mixing into a SiGe matrix would be Yttria Stabilized Zirconia ( YSZ). In this work we report the preparation and thermoelectric study of n-type SiGe + YSZ nanocomposites prepared by direct mechanical mixing followed by Spark Plasma Sintering (SPS) processing. Specifically, we experimentally investigated the reduction of lattice thermal conductivity (kappaL) in the temperature range (30--800K) of n-type Si 80Ge20P2 alloys with the incorporation of YSZ nanoparticles (20 ˜ 40 nm diameter) into the Si-Ge matrix. These samples synthesized by SPS were found to have densities > 95% of the

National environmental targets and international emission reduction instruments

International Nuclear Information System (INIS)

Morthorst, P.E.

2003-01-01

According to the agreed burden sharing within the European Union the overall EU emission reduction target as agreed by in the Kyoto protocol is converted into national greenhouse gas reduction-targets for each of the member states. In parallel with national emission reduction initiatives common EU policies for emission reductions are considered. Currently discussed is the introduction of a market for tradable permits for CO 2 -emissions to achieve emission reductions within the power industry and other energy intensive industries. In parallel with this markets for green certificates to deploy renewable energy technologies seem to be appearing in a number of countries, among these Denmark, Italy, Sweden, Belgium (Flanders), England and Australia. Although these national initiatives for a green certificate market are fairly different, they could be a starting point for establishing a common EU certificate market. But interactions between national targets for greenhouse gas emissions and these international instruments for emission reduction are not a trivial matter, especially not seen in relation to the possible contributions of these instruments in achieving national GHG-reduction targets. The paper is split into three parts all taking a liberalised power market as starting point: The first part discusses the consequences of a general deployment of renewable energy technologies, using planning initiatives or national promotion schemes (feed-in tariffs). In the second part an international green certificate market is introduced into the liberalised power market context, substituting other national promotion schemes. Finally, in the third part a combination of an international green certificate market (TGC) and an international emission-trading scheme for CO 2 is analysed within the liberalised international power market set-up. The main conclusion is that neither the use of national renewable support schemes nor the introduction of a TGC-market into a liberalised

Occupational dose reduction at nuclear power plants: Annotated bibliography of selected readings in radiation protection and ALARA

International Nuclear Information System (INIS)

Baum, J.W.; Khan, T.A.

1986-10-01

This report is the third in a series of bibliographies supporting the efforts at Brookhaven National Laboratory on dose reduction at nuclear power plants. Abstracts for this report were selected from papers presented at recent technical meetings, journals and research reports reviewed at the BNL ALARA Center, and searches of the DOE/RECON data base on energy-related publications. The references selected for inclusion in the bibliography relate not only to operational health physics topics but also to plant chemistry, stress corrosion cracking, and other aspects of plant operation which have important impacts on occupational exposure. Also included are references to improved design, planning, materials selection and other topics related to what might be called ALARA engineering. Thus, an attempt has been made to cover a broad spectrum of topics related directly or indirectly to occupational exposure reduction. The report contains 252 abstracts and both author and subject indices

Graphite anode surface modification with controlled reduction of specific aryl diazonium salts for improved microbial fuel cells power output.

Science.gov (United States)

Picot, Matthieu; Lapinsonnière, Laure; Rothballer, Michael; Barrière, Frédéric

2011-10-15

Graphite electrodes were modified with reduction of aryl diazonium salts and implemented as anodes in microbial fuel cells. First, reduction of 4-aminophenyl diazonium is considered using increased coulombic charge density from 16.5 to 200 mC/cm(2). This procedure introduced aryl amine functionalities at the surface which are neutral at neutral pH. These electrodes were implemented as anodes in "H" type microbial fuel cells inoculated with waste water, acetate as the substrate and using ferricyanide reduction at the cathode and a 1000 Ω external resistance. When the microbial anode had developed, the performances of the microbial fuel cells were measured under acetate saturation conditions and compared with those of control microbial fuel cells having an unmodified graphite anode. We found that the maximum power density of microbial fuel cell first increased as a function of the extent of modification, reaching an optimum after which it decreased for higher degree of surface modification, becoming even less performing than the control microbial fuel cell. Then, the effect of the introduction of charged groups at the surface was investigated at a low degree of surface modification. It was found that negatively charged groups at the surface (carboxylate) decreased microbial fuel cell power output while the introduction of positively charged groups doubled the power output. Scanning electron microscopy revealed that the microbial anode modified with positively charged groups was covered by a dense and homogeneous biofilm. Fluorescence in situ hybridization analyses showed that this biofilm consisted to a large extent of bacteria from the known electroactive Geobacter genus. In summary, the extent of modification of the anode was found to be critical for the microbial fuel cell performance. The nature of the chemical group introduced at the electrode surface was also found to significantly affect the performance of the microbial fuel cells. The method used for

Reduction of field emission in superconducting cavities with high power pulsed RF

International Nuclear Information System (INIS)

Graber, J.; Crawford, C.; Kirchgessner, J.; Padamsee, H.; Rubin, D.; Schmueser, P.

1994-01-01

A systematic study is presented of the effects of pulsed high power RF processing (HPP) as a method of reducing field emission (FE) in superconducting radio frequency (SRF) cavities to reach higher accelerating gradients for future particle accelerators. The processing apparatus was built to provide up to 150 kW peak RF power to 3 GHz cavities, for pulse lengths from 200 μs to 1 ms. Single-cell and nine-cell cavities were tested extensively. The thermal conductivity of the niobium for these cavities was made as high as possible to ensure stability against thermal breakdown of superconductivity. HPP proves to be a highly successful method of reducing FE loading in nine-cell SRF cavities. Attainable continuous wave (CW) fields increase by as much as 80% from their pre-HPP limits. The CW accelerating field achieved with nine-cell cavities improved from 8-15 MV/m with HPP to 14-20 MV/m. The benefits are stable with subsequent exposure to dust-free air. More importantly, HPP also proves effective against new field emission subsequently introduced by cold and warm vacuum ''accidents'' which admitted ''dirty'' air into the cavities. Clear correlations are obtained linking FE reduction with the maximum surface electric field attained during processing. In single cells the maximums reached were E peak =72 MV/m and H peak =1660 Oe. Thermal breakdown, initiated by accompanying high surface magnetic fields is the dominant limitation on the attainable fields for pulsed processing, as well as for final CW and long pulse operation. To prove that the surface magnetic field rather than the surface electric fields is the limitation to HPP effectiveness, a special two-cell cavity with a reduced magnetic to electric field ratio is successfully tested. During HPP, pulsed fields reach E peak =113 MV/m (H peak =1600 Oe) and subsequent CW low power measurement reached E peak =100 MV/m, the highest CW field ever measured in a superconducting accelerator cavity. ((orig.))

Fuel consumption reduction in urban buses by using power split transmissions

International Nuclear Information System (INIS)

Macor, Alarico; Rossetti, Antonio

2013-01-01

Highlights: • Fuel consumption is highly influenced by transmission layout and control. • Continuous Variable Transmission allows control of the working point of the engine. • Hydromechanical CVT was numerically tested and compared with usual mechanical solutions. • CVT solution proved to reduce fuel consumption, improving the I.C.E. mean efficiency. • Results obtained from standard emission test cycles: New York and Manhattan Buses. - Abstract: The reduction of fuel consumption of urban vehicles is one of the challenges of the society today. Many promising technologies such as hybrid electric vehicles and fuel cells are the focus of a lot of research and investments, but high costs prevent their development on a large scale, especially in heavy duty vehicles. Simpler solutions, such as continuously variable transmissions, are then interesting alternatives: they preserve some of the advantages of hybrid solutions significantly reducing the overall cost of the system. Since these technologies allow the decoupling of the engine’s velocity from that of the wheels, optimised management of the engine becomes feasible, leading to lower fuel consumption than that of traditional solutions. This work compares the hydromechanical transmission with a traditional power shift in an application where efficiency and comfort are required: a city bus. The performance of a vehicle with a dual stage hydromechanical transmission has been investigated by means of a model implemented in the AMESim environment. A second model of a vehicle with a power shift transmission has been taken as reference solution. During the simulation of two standard test cycles, the first vehicle showed the lower fuel consumption, due to its better engine management, and to the operation of the torque converter during starts, which lowers the efficiency of the reference vehicle

Data base on dose reduction research projects for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Vulin, D.S.; Liang, H.; Baum, J.W. (Brookhaven National Lab., Upton, NY (United States))

1992-08-01

This is the fourth volume in a series of reports that provide information on dose reduction research and health physics technology for nuclear power plants. The information is taken from a data base maintained by Brookhaven National Laboratory's ALARA Center for the Nuclear Regulatory Commission. This report presents information on 118 new or updated projects, covering a wide range of activities. Projects including steam generator degradation, decontamination, robotics, improvement in reactor materials, and inspection techniques, among others, are described in the research section of the report. The section on health physics technology includes some simple and very cost-effective projects to reduce radiation exposures. Included in this volume is a detailed description of how to access the BNL data bases which store this information. All project abstracts from this report, as well as many other useful documents, can be accessed, with permission, through our on-line system, ACE. A computer equipped with a modem, or a fax machine is all that is required to connect to ACE. Many features of ACE, including software, hardware, and communications specifics, are explained in this report.

Energy saving and consumption reducing evaluation of thermal power plant

Science.gov (United States)

Tan, Xiu; Han, Miaomiao

2018-03-01

At present, energy saving and consumption reduction require energy saving and consumption reduction measures for thermal power plant, establishing an evaluation system for energy conservation and consumption reduction is instructive for the whole energy saving work of thermal power plant. By analysing the existing evaluation system of energy conservation and consumption reduction, this paper points out that in addition to the technical indicators of power plant, market activities should also be introduced in the evaluation of energy saving and consumption reduction in power plant. Ttherefore, a new evaluation index of energy saving and consumption reduction is set up and the example power plant is calculated in this paper. Rresults show that after introducing the new evaluation index of energy saving and consumption reduction, the energy saving effect of the power plant can be judged more comprehensively, so as to better guide the work of energy saving and consumption reduction in power plant.

Potential of plug-in hybrid electric vehicle for reduction of CO2 emission and role of non-fossil power plant

International Nuclear Information System (INIS)

Hiwatari, R.; Okano, K.; Yamamoto, H.

2009-01-01

A method to analyze the demand of electricity and the reduction of CO 2 emission and oil consumption by PHEV is established. Using the performance of PHEV optimized by EPRI and an estimation on the pattern of driving and charging in Japan, the following results are obtained. The electric demand for PHEV60(which has 60mile EV range) and PHEV20(which has 20mile EV range) is evaluated at 79.3 billion kWh and 41.2 billion kWh, respectively, in case that all vehicles in Japan (80 million cars) would be replaced by PHEV. The load leveling effect on the Japanese grid, which is hypothetically considered as one electric grid system, is evaluated at about 30 million kW, in case that all vehicles in Japan are replaced by PHEV60 and charged in the midnight. However, when the charge of PHEVs starts in the evening, that effect is not obtained. The reduction of CO 2 emission results in 64 million ton by the averaged CO 2 emissions intensity (emissions per unit of user end electricity) in Japan, and 98 million ton by electricity from the non-fossil power plant such as nuclear energy or renewable one. Those values are equivalent to 25% and 38% of CO 2 emission from the transport sector in Japan in 2003. Hence, non-fossil power plant enhances the reduction of CO 2 emission by the PHEV introduction. (author)

Design of a Low-Power VLSI Macrocell for Nonlinear Adaptive Video Noise Reduction

Directory of Open Access Journals (Sweden)

Sergio Saponara

2004-09-01

Full Text Available A VLSI macrocell for edge-preserving video noise reduction is proposed in the paper. It is based on a nonlinear rational filter enhanced by a noise estimator for blind and dynamic adaptation of the filtering parameters to the input signal statistics. The VLSI filter features a modular architecture allowing the extension of both mask size and filtering directions. Both spatial and spatiotemporal algorithms are supported. Simulation results with monochrome test videos prove its efficiency for many noise distributions with PSNR improvements up to 3.8 dB with respect to a nonadaptive solution. The VLSI macrocell has been realized in a 0.18 μm CMOS technology using a standard-cells library; it allows for real-time processing of main video formats, up to 30 fps (frames per second 4CIF, with a power consumption in the order of few mW.

Efficacy of an electrically active sonic toothbrush and an oscillating/rotating powered toothbrush in the reduction of plaque and gingivitis: A comparative clinical trial

Directory of Open Access Journals (Sweden)

Himanshu Dadlani

2010-01-01

Full Text Available Objectives: The purpose of the present study was to clinically evaluate and compare the efficacy of an electrically active sonic toothbrush and an oscillating/rotating powered toothbrush in the reduction of plaque and gingivitis. Material and Methods: For this study, 40 healthy student volunteers (20 males, 20 females were selected. The subjects were randomly assigned into two groups by a second examiner; one group used a current producing sonic toothbrush and the other group used a battery powered toothbrush. Plaque Index, Modified Gingival Index and Gingival Bleeding Index were assessed at baseline, 15 th day, 30 th day, 45 th day and 60 th day. Results: All the baseline indices appeared to be well balanced. At the end of the study, reduction in plaque index, modified gingival index and gingival bleeding index were statistically highly significant during each interval for both the toothbrushes. The difference in reduction of clinical parameters between the two toothbrushes was statistically non significant. Conclusion: Both the toothbrushes used in this study were clinically effective in removing plaque and improving gingival health.

Photovoltaic Impact Assessment of Smart Inverter Volt-VAR Control on Distribution System Conservation Voltage Reduction and Power Quality

Energy Technology Data Exchange (ETDEWEB)

Ding, Fei [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nagarajan, Adarsh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baggu, Murali [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nguyen, Andu [SolarCity, San Mateo, CA (United States); Walinga, Sarah [SolarCity, San Mateo, CA (United States); McCarty, Michael [SolarCity, San Mateo, CA (United States); Bell, Frances [SolarCity, San Mateo, CA (United States)

2016-12-01

This report presents an impact assessment study of distributed photovoltaic (PV) with smart inverter Volt-VAR control on conservation voltage reduction (CVR) energy savings and distribution system power quality. CVR is a methodology of flattening and lowering a distribution system voltage profile in order to conserve energy. Traditional CVR relies on operating utility voltage regulators and switched capacitors. However, with the increased penetration of distributed PV systems, smart inverters provide the new opportunity to control local voltage and power factor by regulating the reactive power output, leading to a potential increase in CVR energy savings. This report proposes a methodology to implement CVR scheme by operating voltage regulators, capacitors, and autonomous smart inverter Volt-VAR control in order to achieve increased CVR benefit. Power quality is an important consideration when operating a distribution system, especially when implementing CVR. It is easy to measure the individual components that make up power quality, but a comprehensive method to incorporate all of these values into a single score has yet to be undertaken. As a result, this report proposes a power quality scoring mechanism to measure the relative power quality of distribution systems using a single number, which is aptly named the 'power quality score' (PQS). Both the CVR and PQS methodologies were applied to two distribution system models, one obtained from the Hawaiian Electric Company (HECO) and another obtained from Pacific Gas and Electric (PG&E). These two models were converted to the OpenDSS platform using previous model conversion tools that were developed by NREL. Multiple scenarios including various PV penetration levels and smart inverter densities were simulated to analyze the impact of smart inverter Volt-VAR support on CVR energy savings and feeder power quality. In order to analyze the CVR benefit and PQS, an annual simulation was conducted for each

PEAK-TO-AVERAGE POWER RATIO REDUCTION USING CODING AND HYBRID TECHNIQUES FOR OFDM SYSTEM

Directory of Open Access Journals (Sweden)

Bahubali K. Shiragapur

2016-03-01

Full Text Available In this article, the research work investigated is based on an error correction coding techniques are used to reduce the undesirable Peak-to-Average Power Ratio (PAPR quantity. The Golay Code (24, 12, Reed-Muller code (16, 11, Hamming code (7, 4 and Hybrid technique (Combination of Signal Scrambling and Signal Distortion proposed by us are used as proposed coding techniques, the simulation results shows that performance of Hybrid technique, reduces PAPR significantly as compared to Conventional and Modified Selective mapping techniques. The simulation results are validated through statistical properties, for proposed technique’s autocorrelation value is maximum shows reduction in PAPR. The symbol preference is the key idea to reduce PAPR based on Hamming distance. The simulation results are discussed in detail, in this article.

Coherency Identification of Generators Using a PAM Algorithm for Dynamic Reduction of Power Systems

Directory of Open Access Journals (Sweden)

Seung-Il Moon

2012-11-01

Full Text Available This paper presents a new coherency identification method for dynamic reduction of a power system. To achieve dynamic reduction, coherency-based equivalence techniques divide generators into groups according to coherency, and then aggregate them. In order to minimize the changes in the dynamic response of the reduced equivalent system, coherency identification of the generators should be clearly defined. The objective of the proposed coherency identification method is to determine the optimal coherent groups of generators with respect to the dynamic response, using the Partitioning Around Medoids (PAM algorithm. For this purpose, the coherency between generators is first evaluated from the dynamic simulation time response, and in the proposed method this result is then used to define a dissimilarity index. Based on the PAM algorithm, the coherent generator groups are then determined so that the sum of the index in each group is minimized. This approach ensures that the dynamic characteristics of the original system are preserved, by providing the optimized coherency identification. To validate the effectiveness of the technique, simulated cases with an IEEE 39-bus test system are evaluated using PSS/E. The proposed method is compared with an existing coherency identification method, which uses the K-means algorithm, and is found to provide a better estimate of the original system. 

Investigation of greenhouse gas reduction potential and change in technological selection in Indian power sector

International Nuclear Information System (INIS)

Mathur, Jyotirmay; Bansal, Narendra Kumar; Wagner, H.-J.

2003-01-01

Due to the growing energy needs along with increasing concerns towards control of greenhouse gas emissions, most developing countries are under pressure to find alternative methods for energy conversion and policies to make these technologies economically viable. One of the instruments that have been adopted by many industrial countries is that of the carbon tax. The rate of introducing carbon taxes however, depends upon the local economic conditions and market forces. The case of Indian power sector has been examined by using MARKAL model for introduction of carbon taxes at four different trajectories. Their implications on the power generation choices have been investigated for a time span of 25 years from the year 2000. In general large hydropower plants have emerged as the first choice followed by wind energy systems. However, cheaper availability of coal in India keeps scope of use of coal based technologies for which pressurised fluidised bed combustion technology has been found to be the balanced choice among fossil technologies. There exists a potential of reduction of greenhouse gas emissions by about 25% as compared to the 'business-as-usual' case in presence of high carbon tax rates

Electronic DC transformer with high power density

NARCIS (Netherlands)

Pavlovský, M.

2006-01-01

This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

Risk-based technical specifications: Development and application of an approach to the generation of a plant specific real-time risk model

International Nuclear Information System (INIS)

Puglia, B.; Gallagher, D.; Amico, P.; Atefi, B.

1992-10-01

This report describes a process developed to convert an existing PRA into a model amenable to real time, risk-based technical specification calculations. In earlier studies (culminating in NUREG/CR-5742), several risk-based approaches to technical specification were evaluated. A real-time approach using a plant specific PRA capable of modeling plant configurations as they change was identified as the most comprehensive approach to control plant risk. A master fault tree logic model representative of-all of the core damage sequences was developed. Portions of the system fault trees were modularized and supercomponents comprised of component failures with similar effects were developed to reduce the size of the model and, quantification times. Modifications to the master fault tree logic were made to properly model the effect of maintenance and recovery actions. Fault trees representing several actuation systems not modeled in detail in the existing PRA were added to the master fault tree logic. This process was applied to the Surry NUREG-1150 Level 1 PRA. The master logic mode was confirmed. The model was then used to evaluate frequency associated with several plant configurations using the IRRAS code. For all cases analyzed computational time was less than three minutes. This document Volume 2, contains appendices A, B, and C. These provide, respectively: Surry Technical Specifications Model Database, Surry Technical Specifications Model, and a list of supercomponents used in the Surry Technical Specifications Model

Neutronics design of accelerator-driven system for power flattening and beam current reduction

International Nuclear Information System (INIS)

Nishihara, Kenji; Iwanaga, Kohei; Tsujimoto, Kazufumi; Kurata, Yuji; Oigawa, Hiroyuki; Iwasaki, Tomohiko

2008-01-01

In the present neutronics design of the Accelerator-Driven System (ADS) cooled by lead-bismuth eutectic (LBE), we investigated several methods to reduce the power peak and beam current, and estimated the temperature reductions of the cladding tube and beam window from the conventional design. The methods are adjustment of inert matrix ratio in fuel in each burn-up cycle, multiregion design in terms of pin radius or inert matrix content, and modification of the level of the beam window position and the height of the central fuel assemblies. As a result, we optimized the ADS combined with the adjustment of the inert matrix ratio in each burn-up cycle, multiregion design in terms of inert matrix content and deepened window level. The maximum temperatures of the optimized ADS at the surface of the cladding tube and the beam window were reduced by 91 and 38degC, respectively. The maximum beam current was improved from 20.3 to 15.6 mA. (author)

76 FR 58844 - Virginia Electric and Power Company, Surry Power Station, Units 1 and 2; Exemption

Science.gov (United States)

2011-09-22

... effectively addressed through staff augmentation that can only be practically achieved through the use of work... quality of the human environment published in the Federal Register on August 31, 2011 (76 FR 54259). This...

Proceedings of an international workshop on historic dose experience and dose reduction (ALARA) at nuclear power plants

International Nuclear Information System (INIS)

Horan, J.R.; Baum, J.W.; Dionne, B.J.

1985-06-01

Dose reduction data and experience from 28 foreign and 10 US nuclear power plants was examined to determine causes for the wide variations in occupational dose from country to country. Major topics discussed were: steam generator and refueling maintenance problems; utility and supplier ALARA programs; effectiveness of dose-reduction modifications; attitudes and training; current and future dose-reduction research. While many parameters contribute to differences of occupational doses between plants from different nations, it is clear that most US plants have higher collective dose equivalent per reactor per megawatt-year than most other countries, even for plants of similar size and age. Worldwide, Finnish and Swedish plants, both PWR and BWR, have achieved the lowest values. Major factors which contribute to low doses include: (1) minimization of cobalt in primary system components exposed to water; (2) careful plant design, layout and component segregation and shielding; (3) plant standardization; (4) selection of components and systems for increased reliability; (5) management interest and commitment; (6) minimum number of workers and in-depth worker training; (7) careful control of primary system oxygen and pH; (8) good primary system water purity to minimize corrosion product formation; (9) use of special tools and robotics; (10) decontamination and passivation of primary systems and components; and (11) extent of backfitting and mandated inspections

Emissions from the Polish power industry

International Nuclear Information System (INIS)

Uliasz-Bochenczyk, Alicja; Mokrzycki, Eugeniusz

2007-01-01

Poland is a country where power and heat energy production is based on conventional fuel combustion, above all hard coal and lignite. In power plants and combined heat and power plants, fossil fuel combustion results in emitting to the atmosphere first of all SO 2 , NO x , CO, particulate matter, greenhouse gases for instance N 2 O and CO 2 . For many years the Polish power industry has tried to reduce the emission of air contaminants to the atmosphere. The reduction is feasible on account of various methods of emission reduction, which have been advanced and applied for many years. The paper presents conventional fuels used in the Polish professional power industry, as well as the principal emission types occurring there for the last 10 years and the undertaken reduction measures

Time/motion observations and dose analysis of reactor loading, transportation, and dry unloading of an overweight truck spent fuel shipment

International Nuclear Information System (INIS)

Hostick, C.J.; Lavender, J.C.; Wakeman, B.H.

1992-04-01

This document presents observed activity durations and radiation dose analyses for an overweight truck shipment of pressurized water reactor (PWR) spent fuel from the Surry Power Station in Virginia to the Idaho National Engineering Laboratory. The shipment consisted of a TN-8L shipping cask carrying three 9-year-old PWR spent fuel assemblies. Handling times and dose analyses for at-reactor activities were completed by Virginia Electric and Power Company (Virginia Power) personnel. Observations of in-transit and unloading activities were made by Pacific Northwest Laboratory (PNL) personnel, who followed the shipment for approximately 2800 miles and observed cask unloading activities. In-transit dose estimates were calculated using dose rate maps provided by Virginia Power for a fully loaded TN-8L shipping cask. The dose analysis for the cask unloading operations is based on the observations of PNL personnel

Reduction of capital costs of nuclear power plants

International Nuclear Information System (INIS)

2000-01-01

The competitiveness of nuclear power plants depends largely on their capital costs represent some 60 per cent of their total generation costs. Reviewing and analysing ways and means to reduce capital costs of nuclear power plants are essential to enhance the economic viability of the nuclear option. The report is based upon cost information and data provided by experts from NEA Member countries. It investigates the efficiency of alternative methods for reducing capital costs of nuclear units. It will provide stakeholders from the industry and governmental agencies with relevant elements in support of policy making. (author)

Proposition of primary methods for nitrogen oxides emissions reduction at coal-fired 200 MW power unit (Yugoslavia)

International Nuclear Information System (INIS)

Repic, B.; Mladenovic, R.; Crnomarkovic, N.

1997-01-01

The combustion of coal is followed by increased pollution of the environment with toxic products. Together with the generation of other pollutants, the emission of nitrogen oxides (NO x ) represents, due to its high toxicity, a great environmental risk. Appropriate measures must be taken for lowering NO x emission, both on new facilities and those already in operation. Basic technologies (primary reduction methods) of several generations, developed until now and used in practice, are presented in the paper. The technologies applicable on domestic facilities and adjusted to domestic coals have been given particular consideration. Proposition of primary methods for NO x emission reduction at coal-fired 200 MW power unit at TPS 'Nikola Tesla' is analyzed. The following methods have been considered in detail: flue gases recirculation, multi-stage combustion, low-NO x burners, additional over-fire air, multi-stage air intake into the furnace, staged fuel injection, grinding fineness increase, etc. Considerations were performed according to existing constructive characteristics of the furnace and the burners, and characteristics of used fuels, i. e. lignites from Kolubara pit. (Author)

UNEP Demonstrations of Mercury Emission Reduction at Two Coal-fired Power Plants in Russia

Directory of Open Access Journals (Sweden)

Jozewicz W.

2013-04-01

Full Text Available The United Nations Environment Programme (UNEP partnership area “Mercury releases from coal combustion” (The UNEP Coal Partnership has initiated demonstrations of mercury air emission reduction at two coal-fired power plants in Russia. The first project has modified the wet particulate matter (PM scrubber installed in Toliatti thermal plant to allow for addition of chemical reagents (oxidants into the closedloop liquid spray system. The addition of oxidant resulted in significant improvement of mercury capture from 20% total mercury removal (without the additive up to 60% removal (with the additive. It demonstrates the effectiveness of sorbent injection technologies in conjunction with an electrostatic precipitator (ESP. ESPs are installed at 60%, while wet PM scrubbers are installed at 30% of total coal-fired capacity in Russia. Thus, the two UNEP Coal Partnership projects address the majority of PM emission control configurations occurring in Russia.

CO2 emission reduction potential of large-scale energy efficiency measures in power generation from fossil fuels in China, India, Brazil, Indonesia and South Africa

OpenAIRE

Boehme, Benn J.; Krey, Matthias

2005-01-01

We quantify the theoretical potential for energy-efficiency CDM projects using best available technology in coal, natural gas or oil fuelled power generation in China, India, Brazil, Indonesia and South Africa, looking at new power plants or retrofit measures. We then discuss the likelihood of the potential emission reductions materialising under CDM. Our results are very sensitive to choices of baseline and project efficiencies and the level of electricity generation from potential emission ...

Probabilistic risk assessment (PRA) on the effectiveness of a core rescue system (SSN) for PWRs

International Nuclear Information System (INIS)

Petrangeli, G.; Valeri, A.

1983-01-01

Safety systems for the prevention of LWR core severe damage have recently been studied, which are based on automatic primary system depressurization and on borated water injection by low pressure accumulators. These systems have been named Core Rescue System (SSN). The present study evaluates the reduction in core melt probability brought about by the installation of a SSN system on the RSS (WASH 1400) PWR plant (Surry 1). The calculated result is a core melt probability reduction factor of about 250. Taking into account the possible effect of external or internal unknown events of negligible, yet undefined, probability it is concluded that a SSN system can make a plant ten times safer. The first part of a review report by Prof. N.C.Rasmussen, MIT, dealing with general comment, is attached

The lure of disarmament and arms reduction; Le leurre du desarmement et de la reduction des armements

Energy Technology Data Exchange (ETDEWEB)

Paris, H.

2011-03-15

Nuclear disarmament and arms reduction do not have the same aims. Confusing their definitions means misunderstanding the logic which currently drives the power calculations of yesterday's Great Powers, and their associated approaches to the new strategic actor: China. The author knows the subject well from personal experience. (author)

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Supporting MELCOR calculations, Volume 6, Part 2

International Nuclear Information System (INIS)

Kmetyk, L.N.; Brown, T.D.

1995-03-01

To gain a better understanding of the risk significance of low power and shutdown modes of operation, the Office of Nuclear Regulatory Research at the NRC established programs to investigate the likelihood and severity of postulated accidents that could occur during low power and shutdown (LP ampersand S) modes of operation at commercial nuclear power plants. To investigate the likelihood of severe core damage accidents during off power conditions, probabilistic risk assessments (PRAs) were performed for two nuclear plants: Unit 1 of the Grand Gulf Nuclear Station, which is a BWR-6 Mark III boiling water reactor (BWR), and Unit 1 of the Surry Power Station, which is a three-loop, subatmospheric, pressurized water reactor (PWR). The analysis of the BWR was conducted at Sandia National Laboratories while the analysis of the PWR was performed at Brookhaven National Laboratory. This multi-volume report presents and discusses the results of the BWR analysis. The subject of this part presents the deterministic code calculations, performed with the MELCOR code, that were used to support the development and quantification of the PRA models. The background for the work documented in this report is summarized, including how deterministic codes are used in PRAS, why the MELCOR code is used, what the capabilities and features of MELCOR are, and how the code has been used by others in the past. Brief descriptions of the Grand Gulf plant and its configuration during LP ampersand S operation and of the MELCOR input model developed for the Grand Gulf plant in its LP ampersand S configuration are given

Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Evaluation of severe accident risks for plant operational state 5 during a refueling outage. Supporting MELCOR calculations, Volume 6, Part 2

Energy Technology Data Exchange (ETDEWEB)

Kmetyk, L.N.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States)

1995-03-01

To gain a better understanding of the risk significance of low power and shutdown modes of operation, the Office of Nuclear Regulatory Research at the NRC established programs to investigate the likelihood and severity of postulated accidents that could occur during low power and shutdown (LP&S) modes of operation at commercial nuclear power plants. To investigate the likelihood of severe core damage accidents during off power conditions, probabilistic risk assessments (PRAs) were performed for two nuclear plants: Unit 1 of the Grand Gulf Nuclear Station, which is a BWR-6 Mark III boiling water reactor (BWR), and Unit 1 of the Surry Power Station, which is a three-loop, subatmospheric, pressurized water reactor (PWR). The analysis of the BWR was conducted at Sandia National Laboratories while the analysis of the PWR was performed at Brookhaven National Laboratory. This multi-volume report presents and discusses the results of the BWR analysis. The subject of this part presents the deterministic code calculations, performed with the MELCOR code, that were used to support the development and quantification of the PRA models. The background for the work documented in this report is summarized, including how deterministic codes are used in PRAS, why the MELCOR code is used, what the capabilities and features of MELCOR are, and how the code has been used by others in the past. Brief descriptions of the Grand Gulf plant and its configuration during LP&S operation and of the MELCOR input model developed for the Grand Gulf plant in its LP&S configuration are given.

Operational experience on reduction of feedwater iron and liquid radwaste input for Kuosheng Nuclear Power Plant

International Nuclear Information System (INIS)

Wen, T.J.; Huang, Theresa Chen; Liu, Wen Tsung; Liu, T.C.; Shyur, Tzu Sheng; Shen, S.C.

1998-01-01

Other than cobalt alloys, or low cobalt materials, feedwater iron content plays an important role in crud activation and transport causing the growth of out-of-core radiation fields and associated with radwaste generation. Before installing prefilter in the upstream of condensate deep-bed demineralizer, increasing demand for suspended solid removal required new backwash and regeneration technique in Kuosheng Nuclear Power Plant. At steady state full power operation, the average iron concentration in condensate demineralizer influent was 8-15 ppb. Considering both the necessity of backwash and reduction of liquid radwaste input, several actions had been taken to promote the crud removal capabilities without using ultrasonic resin cleaner and controlled feedwater iron content between 0.5 and 2.0 ppb. This modified resin backwash technique would also generate minimum liquid radwaste. Meanwhile, significant efforts have been made to promote the quality of waste water by carefully control input streams as well as backwash modification to reduce liquid radwaste generation. The daily quantity of liquid radwaste has decreased dramatically in the past two years and is effectively controlled under the expected average daily input of design basis. (author)

Low activation material design methodology for reduction of radio-active wastes of nuclear power plant

International Nuclear Information System (INIS)

Hasegawa, A.; Satou, M.; Nogami, S.; Kakinuma, N.; Kinno, M.; Hayashi, K.

2007-01-01

Most of the concrete shielding walls and pipes around a reactor pressure vessel of a light water reactor become low level radioactive waste at decommission phase because they contain radioactive nuclides by thermal-neutron irradiation during its operation. The radioactivity of some low level radioactive wastes is close to the clearance level. It is very desirable in terms of life cycle cost reduction that the radioactivity of those low level radioactive wastes is decreased below clearance level. In case of light water reactors, however, methodology of low activation design of a nuclear plant has not been established yet because the reactor is a large-scale facility and has various structural materials. The Objectives of this work are to develop low activation material design methodology and material fabrication for reduction of radio-active wastes of nuclear power plant such as reinforced concrete. To realize fabrication of reduced radioactive concrete, it is necessary to develop (1) the database of the chemical composition of raw materials to select low activation materials, (2) the tool for calculation of the neutron flux and the spectrum distribution of nuclear plants to evaluate radioactivity of reactor components, (3) optimization of material process conditions to produce the low activation cement and the low activation steels. Results of the data base development, calculation tools and trial production of low activation cements will be presented. (authors)

75 FR 76495 - Virginia Electric and Power Company North Anna Power Station, Unit Nos. 1 and 2 Surry Power...

Science.gov (United States)

2010-12-08

..., Supplement 1 and 2, ``Use of Nuclear Energy Institute (NEI) 99-01, Methodology for Development of Emergency.... Environmental Impacts of the Proposed Action The NRC has completed its environmental assessment of the proposed... NRC concludes that there are no significant environmental impacts associated with the proposed action...

78 FR 46616 - Virginia Electric and Power Company; North Anna Power Station, Units 1 and 2; Surry Power Station...

Science.gov (United States)

2013-08-01

... Nuclear Energy Institute (NEI) 99-01, Methodology for Development of Emergency Action Levels.'' The... readily accessible means available in the Control Room. Environmental Impacts of the Proposed Action The... that there are no significant environmental impacts associated with the proposed action. Environmental...

Data base on dose reduction research projects for nuclear power plants. Volume 4

Energy Technology Data Exchange (ETDEWEB)

Khan, T.A.; Vulin, D.S.; Liang, H.; Baum, J.W. [Brookhaven National Lab., Upton, NY (United States)

1992-08-01

This is the fourth volume in a series of reports that provide information on dose reduction research and health physics technology for nuclear power plants. The information is taken from a data base maintained by Brookhaven National Laboratory`s ALARA Center for the Nuclear Regulatory Commission. This report presents information on 118 new or updated projects, covering a wide range of activities. Projects including steam generator degradation, decontamination, robotics, improvement in reactor materials, and inspection techniques, among others, are described in the research section of the report. The section on health physics technology includes some simple and very cost-effective projects to reduce radiation exposures. Included in this volume is a detailed description of how to access the BNL data bases which store this information. All project abstracts from this report, as well as many other useful documents, can be accessed, with permission, through our on-line system, ACE. A computer equipped with a modem, or a fax machine is all that is required to connect to ACE. Many features of ACE, including software, hardware, and communications specifics, are explained in this report.

Randomised controlled trial and economic analysis of an internet-based weight management programme: POWeR+ (Positive Online Weight Reduction).

Science.gov (United States)

Little, Paul; Stuart, Beth; Hobbs, Fd Richard; Kelly, Jo; Smith, Emily R; Bradbury, Katherine J; Hughes, Stephanie; Smith, Peter Wf; Moore, Michael V; Lean, Mike Ej; Margetts, Barrie M; Byrne, Christopher D; Griffin, Simon; Davoudianfar, Mina; Hooper, Julie; Yao, Guiqing; Zhu, Shihua; Raftery, James; Yardley, Lucy

2017-01-01

Behavioural counselling with intensive follow-up for obesity is effective, but in resource-constrained primary care settings briefer approaches are needed. To estimate the clinical effectiveness and cost-effectiveness of an internet-based behavioural intervention with regular face-to-face or remote support in primary care, compared with brief advice. Individually randomised three-arm parallel trial with health economic evaluation and nested qualitative interviews. Primary care general practices in the UK. Patients with a body mass index of ≥ 30 kg/m 2 (or ≥ 28 kg/m 2 with risk factors) identified from general practice records, recruited by postal invitation. Positive Online Weight Reduction (POWeR+) is a 24-session, web-based weight management intervention completed over 6 months. Following online registration, the website randomly allocated participants using computer-generated random numbers to (1) the control intervention ( n  = 279), which had previously been demonstrated to be clinically effective (brief web-based information that minimised pressure to cut down foods, instead encouraging swaps to healthier choices and increasing fruit and vegetables, plus 6-monthly nurse weighing); (2) POWeR+F ( n  = 269), POWeR+ supplemented by face-to-face nurse support (up to seven contacts); or (3) POWeR+R ( n  = 270), POWeR+ supplemented by remote nurse support (up to five e-mails or brief telephone calls). The primary outcome was a modelled estimate of average weight reduction over 12 months, assessed blind to group where possible, using multiple imputation for missing data. The secondary outcome was the number of participants maintaining a 5% weight reduction at 12 months. A total of 818 eligible individuals were randomised using computer-generated random numbers. Weight change, averaged over 12 months, was documented in 666 out of 818 participants (81%; control, n  = 227; POWeR+F, n  = 221; POWeR+R, n  = 218). The control group

Evaluation of measures for greenhouse gas emissions reduction in energy supply sector

International Nuclear Information System (INIS)

Khristov, Kh.; Todorova, S.; Vasilev, Kh.; Simeonova, K.

1996-01-01

This study performed by the Energoproekt Company, Sofia (BG) is aimed at estimating the economic costs of CO 2 emissions reduction in the electricity supply system for the period 2000-2020. The specific capital investment and cost price of the following technical options have been compared: reduction of electricity and heat loss; gas and steam cycle power plants; micro hydro potential; renewable sources; extension of nuclear power installations; gas steam turbine equipment; combined cycle power plants. The evaluation is made according to requirements of a baseline scenario - to develop an import-independent energy supply policy and an economic growth without sharp structural changes. A 25-year-operation of a hypothetical energy supply system is modelled by the ENPEP code (ANL, US). The three least-cost options identified are: power loss reduction; gas and steam cycle PPs and hydroelectric objects. An optimal combination of measures, so called ' aggregated scenario' is proposed. It would allow for CO 2 reduction by 23,7 mill tons and prime cost reduction by $19,83 per ton reduced emissions. 3 refs., 2 tabs

Fiscal 1999 basic survey report for promotion of joint implementation. Project for overall loss reduction in Myanmar for thermoelectric power during transmission and distribution; 1999 nendo Myanmar koku karyoku sohaiden denryoku sonshitsu sogo teigen project hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

With connection to the clean development mechanism (CDM) taken into consideration, a study is made about achieving greenhouse gas reduction in Myanmar through power generation facility heat efficiency improvement and power loss reduction. Taken up in the study are the Shwedaung power plant, the Mann power plant, and the power transmission system in the Mandalay District. The profitability of thermoelectric power facility improvement is calculated using the financial internal rate of return (FIRR), derivable from the cost of thermoelectric power facility improvement and the convenience to be created thereby, and using the opportunity cost in Myanmar. The result is then subjected to a feasibility study. Most effective for CO2 reduction is the addition or installation of advanced compound cycle power generation facilities which are also excellent in heat efficiency and power generation cost. The FIRR of thermoelectric power facility improvement is 9.4-12.8%, which means the effort is worth investment. Measures for decreasing power loss during transmission include the use of higher voltages, laying of new lines, employment of conductors thicker in size, and the installation of phase modifiers. The economic internal rate of return (EIRR) and FIRR are calculated for the study of feasibility. An analysis covering a 10-year period results in a 20.41% EIRR (exceeding the socially accepted discount rate of 10%) and a 17.56% FIRR (exceeding the general loan interest of 15%), which means that there is feasibility. (NEDO)

Lifetime estimation for the power semiconductors considering mission profiles in wind power converter

OpenAIRE

Ma, Ke; Liserre, Marco; Blaabjerg, Frede

2013-01-01

As a key component in the wind turbine system, power electronic converter and its power semiconductors suffer from adverse power loadings related to environment, and are proven to have certain failure rates. Therefore, correct lifetime estimation of wind power converter is crucial for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power...

Threshold reduction through photon recycling in semiconductor lasers

Energy Technology Data Exchange (ETDEWEB)

Gigase, Y.B.; Harder, C.S.; Kesler, M.P.; Meier, H.P. (IBM Research Division, Zurich Research Laboratory, CH-8803 Rueschlikon (Switzerland)); Van Zeghbroeck, B. (University of Colorado, Boulder, CO (USA))

1990-09-24

The threshold pump power of an AlGaAs-GaAs ridge quantum well laser diode has been reduced by 42% by recycling the spontaneous emission. An integrated photodiode absorbs the spontaneous radiation emitted by the laser diode and converts it back into electrical power. The recycling of this power results in a reduction of the electrical power required to reach the lasing threshold.

CO{sub 2}-mitigation measures through reduction of fossil fuel burning in power utilities. Which road to go?

Energy Technology Data Exchange (ETDEWEB)

Kaupp, A. [Energetica International Inc., Suva (Fiji)

1996-12-31

Five conditions, at minimum, should be examined in the comparative analysis of CO{sub 2}-mitigation options for the power sector. Under the continuing constraint of scarce financial resources for any private or public investment in the power sector, the following combination of requirements characterise a successful CO{sub 2}-mitigation project: (1) Financial attractiveness for private or public investors. (2) Low, or even negative, long range marginal costs per ton of `CO{sub 2} saved`. (3) High impact on CO{sub 2}-mitigation, which indicates a large market potential for the measure. (4) The number of individual investments required to achieve the impact is relatively small. In other words, logistical difficulties in project implementation are minimised. (5) The projects are `socially fair` and have minimal negative impact on any segment of the society. This paper deals with options to reduce carbonaceous fuel burning in the power sector. Part I explains how projects should be selected and classified. Part II describes the technical options. Since reduction of carbonaceous fuel burning may be achieved through Demand Side Management (DSM) and Supply Side Management (SSM) both are treated. Within the context of this paper SSM does not mean to expand power supply as demand grows. It means to economically generate and distribute power as efficiently as possible. In too many instances DSM has degenerated into efficient lighting programs and utility managed incentives and rebate programs. To what extent this is a desirable situation for utilities in Developing Countries that face totally different problems as their counterparts in highly industrialised countries remains to be seen. Which road to go is the topic of this paper.

Regulations on allocating the sums of money regarding of development of radiation exposure reduction technology for nuclear power facilities

International Nuclear Information System (INIS)

1984-01-01

The regulations provide for the sums of money regarding research and development of radiation exposure reduction technology for nuclear power facilities and evaluation of the results. Expenses cover the purchase of equipment, personnel expenditures, travelling expenses, communication, etc. The contents are as follows: the application for subsidy allocations, determination of subsidy allocations, withdrawal of applications, a report on the work proceedings, a report on the results, approval of alterations in the plans, withdrawal of the decision for a subsidy allocation, patent rights, utilization etc. of the results, management of the properties, etc. (Mori, K.)

Optimal reduction of flexible dynamic system

International Nuclear Information System (INIS)

Jankovic, J.

1994-01-01

Dynamic system reduction is basic procedure in various problems of active control synthesis of flexible structures. In this paper is presented direct method for system reduction by explicit extraction of modes included in reduced model form. Criterion for optimal system discrete approximation in synthesis reduced dynamic model is also presented. Subjected method of system decomposition is discussed in relation to the Schur method of solving matrix algebraic Riccati equation as condition for system reduction. By using exposed method procedure of flexible system reduction in addition with corresponding example is presented. Shown procedure is powerful in problems of active control synthesis of flexible system vibrations

The lure of disarmament and arms reduction

International Nuclear Information System (INIS)

Paris, H.

2011-01-01

Nuclear disarmament and arms reduction do not have the same aims. Confusing their definitions means misunderstanding the logic which currently drives the power calculations of yesterday's Great Powers, and their associated approaches to the new strategic actor: China. The author knows the subject well from personal experience. (author)

U.S. electric power sector transitions required to achieve 80% reductions in economy-wide greenhouse gas emissions: Results based on a state-level model of the U.S. energy system

Energy Technology Data Exchange (ETDEWEB)

Iyer, Gokul C.; Clarke, Leon E.; Edmonds, James A.; Kyle, Gordon P.; Ledna, Catherine M.; McJeon, Haewon C.; Wise, M. A.

2017-05-01

The United States has articulated a deep decarbonization strategy for achieving a reduction in economy-wide greenhouse gas (GHG) emissions of 80% below 2005 levels by 2050. Achieving such deep emissions reductions will entail a major transformation of the energy system and of the electric power sector in particular. , This study uses a detailed state-level model of the U.S. energy system embedded within a global integrated assessment model (GCAM-USA) to demonstrate pathways for the evolution of the U.S. electric power sector that achieve 80% economy-wide reductions in GHG emissions by 2050. The pathways presented in this report are based on feedback received during a workshop of experts organized by the U.S. Department of Energy’s Office of Energy Policy and Systems Analysis. Our analysis demonstrates that achieving deep decarbonization by 2050 will require substantial decarbonization of the electric power sector resulting in an increase in the deployment of zero-carbon and low-carbon technologies such as renewables and carbon capture utilization and storage. The present results also show that the degree to which the electric power sector will need to decarbonize and low-carbon technologies will need to deploy depends on the nature of technological advances in the energy sector, the ability of end-use sectors to electrify and level of electricity demand.

A State-of-the-Art Report on Technologies of Volume Reduction and Self-Disposal for Large Metal Wastes including the Steam Generator of Nuclear Power Plants

International Nuclear Information System (INIS)

Lee, Kune Woo; Choi, W. K.; Kim, G. Y.

2009-06-01

This report focuses on technologies of volume reduction and self-disposal for large metal wastes including the steam generator of nuclear power plants. This report consists of the cases of treatments and foreign and domestic technologies for steam generator replacement

Variable-Width Datapath for On-Chip Network Static Power Reduction

Energy Technology Data Exchange (ETDEWEB)

Michelogiannakis, George; Shalf, John

2013-11-13

With the tight power budgets in modern large-scale chips and the unpredictability of application traffic, on-chip network designers are faced with the dilemma of designing for worst- case bandwidth demands and incurring high static power overheads, or designing for an average traffic pattern and risk degrading performance. This paper proposes adaptive bandwidth networks (ABNs) which divide channels and switches into lanes such that the network provides just the bandwidth necessary in each hop. ABNs also activate input virtual channels (VCs) individually and take advantage of drowsy SRAM cells to eliminate false VC activations. In addition, ABNs readily apply to silicon defect tolerance with just the extra cost for detecting faults. For application traffic, ABNs reduce total power consumption by an average of 45percent with comparable performance compared to single-lane power-gated networks, and 33percent compared to multi-network designs.

Fiscal 1999 basic study for promotion of joint implementation. Study of greenhouse gas reduction by modifying the power generation system of a power station in the Republic of Kazakhstan; 1999 nendo Kazakhstan ni okeru hatsudensho no hatsuden system kaishu ni yoru onshitsu koka gas sakugen ni kansuru chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

A feasibility study is conducted aiming to reduce greenhouse gas emissions by refurbishing obsolete power stations in Shymkent City, the Republic of Kazakhstan. The clean development mechanism is also discussed. Aircraft engine-derived 20MW-class gas turbine cogenerators will be introduced, one each into a 1st and 2nd power stations. A simple-cycle model of the same will also be introduced into the 1st power station. The facility costs will be US$61.279 million for the 1st power station and US$33.590 million for the 2nd power station. The amount of fuel to be saved will be 238.6-thousand tons/year in terms of oil, totalling 5,964-thousand tons in a 25-year period. As for the reduction of greenhouse gas emissions, there will be a 737.9-thousand tons/year reduction in terms of CO2, meaning a total reduction of 18.448-thousand ton in a 25-year period. An FIRRROI (Financial Internal Rate of Return on Investment) is tentatively calculated using power and heat prices presented by the other party. The result of calculation shows that the net cash flow before and after tax stays negative throughout the whole operating period, which means a total lack of cost effectiveness. This is attributed to the low power and heat unit prices set by the other party, extremely lower than the internationally accepted prices. The FIRRROI after tax will turn positive when the unit prices are 1.5 times higher and the total investment is reduced by 20%. (NEDO)

The reduction of retinal autofluorescence caused by light exposure.

Science.gov (United States)

Morgan, Jessica I W; Hunter, Jennifer J; Merigan, William H; Williams, David R

2009-12-01

A prior study showed that long exposure to 568-nm light at levels below the maximum permissible exposure safety limit produces retinal damage preceded by a transient reduction in the autofluorescence of retinal pigment epithelial (RPE) cells in vivo. The present study shows how the effects of exposure power and duration combine to produce this autofluorescence reduction and find the minimum exposure causing a detectable autofluorescence reduction. Macaque retinas were imaged using a fluorescence adaptive optics scanning laser ophthalmoscope to resolve individual RPE cells in vivo. The retina was exposed to 568-nm light over a square subtending 0.5 degrees with energies ranging from 1 to 788 J/cm(2), where power and duration were independently varied. In vivo exposures of 5 J/cm(2) and higher caused an immediate decrease in autofluorescence followed by either full autofluorescence recovery (exposures or= 247 J/cm(2)). No significant autofluorescence reduction was observed for exposures of 2 J/cm(2) and lower. Reciprocity of exposure power and duration held for the exposures tested, implying that the total energy delivered to the retina, rather than its distribution in time, determines the amount of autofluorescence reduction. That reciprocity held is consistent with a photochemical origin, which may or may not cause retinal degeneration. The implementation of safe methods for delivering light to the retina requires a better understanding of the mechanism causing autofluorescence reduction. Finally, RPE imaging was demonstrated using light levels that do not cause a detectable reduction in autofluorescence.

75 FR 9618 - Virginia Electric and Power Company Surry Power Station, Unit Nos. 1 and 2 Environmental...

Science.gov (United States)

2010-03-03

... change to radioactive effluents that effect radiation exposures to plant workers and members of the.... There would be no impact to socioeconomic resources. Therefore, no changes to or different types of non...

Fiscal 1999 achievement report. Development of technology for reducing power consumption during standby (Research and development of technologies for application of standby power reduction to domestic and office-automation appliances); 1999 nendo taikiji shohi denryoku sakugen gijutsu kaihatsu seika hokokusho. Kaden oyobi OA kiki no taiki denryoku sakugen jitsuyoka gijutsu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-05-01

Efforts are exerted to develop power-efficient modules to be built into electrical products for reduction in power consumption in the standby state for domestic and office-automation appliances. In this study, television sets, audio sets, and air conditioners were selected out of domestic appliances and, out of office-automation appliances, notebook-size and desktop personal computers were selected. The standby power consumption is to be reduced to 3mW for domestic appliances, to 0.2W for notebook-size personal computers, and to 1/10-1/200 of the level being currently consumed in the case of desktop personal computers. For domestic appliances, a power efficient module not insulated from the AC power line was developed, to be built into a CPU-aided appliance to be turned on and off by remote control for the reduction of its standby power to 3mW. For notebook-size personal computers, a power-efficient power source insulated from the AC power line was developed, which consumes but 0.2W of standby power. It was built into a marketed notebook-size personal computer and tested for performance. For desktop personal computers, a 25mW power source insulated from the AC power line was fabricated, and tested for performance. (NEDO)

Global implications of standby power use

Energy Technology Data Exchange (ETDEWEB)

Lebot, Benoit; Meier, Alan; Anglade, Alain

2000-05-01

Separate studies indicate that standby power is responsible for 20-60 W per home in developed countries. Standby power is responsible for about 2% of OECD countries total electricity consumption and the related power generation generates almost 1% of their carbon emissions. Replacement of existing appliances with those appliances having the lowest standby would reduce total standby power consumption by over 70%. The resulting reductions in carbon emissions would meet over 3% of OECD's total Kyoto commitments. Other strategies may cut more carbon emissions, but standby power is unique in that the reductions are best accomplished through international collaboration and whose costs and large benefits would be spread over all countries.

Results of comparative assessment of US and foreign nuclear power plant dose experience and dose reduction programs

International Nuclear Information System (INIS)

Baum, J.W.; Horan, J.R.; Dionne, B.J.

1985-01-01

The objectives of this study were to determine how collective dose equivalents at US nuclear power plants compare to those of other technically advanced countries, and to evaluate factors that contribute to the differences. Fifty Health Physicists and nuclear engineers from 10 countries met at BNL May 29 - June 1, 1984 to exchange information and hold discussions on ''Historical Dose Experience and Dose Reduction (ALARA) at Nuclear Power Plants''. Results of evaluation of data from this meeting and other data from recent publications are summarized. Based on data evaluated to date it is clear that US plants have higher collective dose equivalents per reactor and per MW-yr generated than most other countries. Factors which contribute to low doses include: 1) minimization of cobalt in primary system components exposed to water, 2) careful control of primary system oxygen and pH, 3) good primary system water purity to minimize corrosion product formation, 4) careful plant design, layout and component segregation and shielding, 5) management interest and commitment, 6) minimum number of workers and in-depth worker training, 7) use of special tools, and 8) plant standardization

An investigation of the reduction of carbon dioxide in a silent electric discharge

Science.gov (United States)

Luce, R. S.; Greenough, B. (Editor)

1978-01-01

The reduction of CO2 to O2 and CO in a silent electric discharge was studied. It was found that current alone (in the ionized plasma induced by the silent electric discharge) was reponsible for the CO2 reduction process. Voltage and frequency were important only in so far as they induced current in the plasma. Pressure and temperature were of minimum influence in the process. The large power consumption in the process was recognized as resulting from the low power factor of the reactor vessel which electrically behaved like a capacitor. The power factor was subsequently improved by adding an inductive element to make the reactor vessel capacitance part of a resonant circuit. It was found that the CO2 reduction process was most efficient in terms of power vs reduction rate when a voltage was employed that was only slightly higher than that needed to induce the plasma.

Study on reactor power change and ambiguous control of third Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Wang Gongzhan

2006-01-01

The phenomenon of the average power reduction during long term full power operating in Third Qinshan nuclear power plant is analyzed . According to the basic conclusions of reactor power fluctuating derived by probability statistic and calculation the corresponding ambiguous control project is proposed. The operating performance could be achieved by the present controlling project is predicted additionally. (authors)

Report of year 2000 version on basic survey for promotion of joint execution. Study on reduction of greenhouse effect gas by means of rehabilitation of power generation systems of power plants in Kazakhstan

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

A feasibility study investigation was performed to renew old power plants in the city of Shymkent in the Republic of Kazakhstan to achieve reduction in greenhouse effect gas emission. The Clean Development Mechanism will also participate in the consultation. One each cogeneration power plant using gas turbines of 20 MW class diverted from aircraft use will be introduced into the first and second power plants. The first power plant will also be introduced with one generator of simple cycle of the same type. The facility cost will amount to US$61,279 million for the first power plant, and US$33,590 million for the second power plant. Fuel conservation will amount to 2,386,000 toe/year, and in cumulative total of 25 years, 5,964,000 toeCO2. Electric power and heat prices provided by the Kazakhstan side were used to calculate the finance internal return rate of return on investment (FIRRROI). The net cash flow was found to be in negative figures for both of before and after tax throughout the whole operation period, indicating no economic benefit whatsoever. This is because the electric power and heat unit price set for the calculation is extremely low compared to the international price. If the unit price is raised to 1.5 times, and the total calculation amount is reduced by 20%, the FIRRROI after tax will be ub a positive figure. (NEDO)

Air pollution reduction in thermoelectric power stations - case study: Iquitos power plant; Reducao do impacto da poluicao do ar em usinas termeletricas - estudo de caso: usina termeletrica Iquitos

Energy Technology Data Exchange (ETDEWEB)

Dondero, Luz [Sao Paulo Univ., SP (Brazil). Inst. de Energia e Eletrotecnica. Programa Interunidades de Pos-graduacao em Energia]. E-mail: luz@iee.usp.br

2000-07-01

This work studies the environmental impacts of atmospheric emissions sent out by the Iquito's thermoelectric power station in Peru. Initially, we compute the quantitative flows (in g/s) of major gas pollutants (SO{sub 2}, SO{sub 3}, NOx, CO, CO{sub 2} and MP) emitted by the power plant. Then, we calculate the station's emission rates per kWh generated (in kilogram of pollutant /kWh). Having those inputs, we adopt EPA's SCREEN3.0 dispersion model to simulate the SO{sub 2} and NOx into the local atmosphere. We also forecast the future evolution of SO{sub 2} emissions considering the potential growth of electricity generation in the power plant. Since the Iquito's power station is located within the city's urban area, with gas emissions having direct impacts upon the local population, we study different strategies for emissions reduction from the plant. Firstly, we consider the upgrading of the existing plant with additional equipment for a more strict emission control. Then, we analyze the option of shutting down the most critical machine (in terms of atmospheric emission) in the old plant, and its substitution by a new and more efficient machine. We concluded that, although the addition of more strict control equipment is more efficient on reducing total emission, the strategy of exchanging machines is less costly and should be consider as the preferable option. (author)

Reduction of particulate emission in two coal-fired power plants; Reduccion de la Emisiones de Particulas Solidas en Centrales Termicas de Carbon Existentes Mediante Acondicionamiento Integral (Fisico y Quimico) de Gases de Combustion

Energy Technology Data Exchange (ETDEWEB)

1999-09-01

Escucha and Cercs are two coal-fired power stations, each with a capacity of 160MW, which belong to FECSA. Tehy came into operation in 1970 and 1971. Their boilers are of the once-through type and both have similar configurations, although they use different types of coal. The power station at Cercs uses a mixture of local lignite, rich in calcium, together with 40% of South African coal, while that of Escucha uses local lignite, the ashes of which are predominantly silicon and aluminium oxides, together with 20% of South African coal. At both power stations, the local lignite has changes during the life of the power stations and presently its quality is clearly inferior th that when the power stations were designed. This change in quality has produced two consequences, on one hand, the characteristics of the ash have changed in that the resistivity of the fly ash produced at present is much higher than when the power stations were designed. On the other hand, the temperature of the gases at the boiler outlet has increased and reaches values of up to 200 degree centigree, which has also led to an increase in resistivity. These two facts have produced, as a consequence, a significant increase in the emission of particulate matter. In order to reduce the emission of particulate matter, two stategies were implantes at both power stations; a reduction in the temperature of the flue gases and a reduction of the resistivity of the fly ash. This was an innovative approach to the problem, as generally either one or the other of these strategies is employed but rarely both of them at the same time. A reduction of flue gas temperature was achieved by modifying the last three tube banks of the boiler by adding another 2500 m``2 of heat exchanging surface. As a result, the temperature of the flue gases decreased to a value of 140 degree centigree, which in turn produced a notable effect on the resistivity of the ash. Furthermore, an increase in the performance of the boiler

Regulations on the allocating of subsidies to promote the development of radiation exposure reduction technology for nuclear power facilities

International Nuclear Information System (INIS)

1984-01-01

The regulations provide for subsidies for the research and development of radiation exposure reduction technology for nuclear power facilities and evaluation of the results. The subsidies are for purchase of equipment, materials, etc. and other expendures approved. The contents are as follows: applications for subsidies, determination of subsidy allocations, withdrawal of applications, a report on the work proceedings, a report on the results, confirmation on the sum of the subsidies, payment of subsidies, approval of alterations in the plans, withdrawal of the decision for subsidies, patent rights, payment of the earnings, management of the properties, etc. (Mori, K.)

Transmutation of radioactive wastes from nuclear power plants. A contribution to the reduction of the final repository problem; Transmutation radioaktiver Reststoffe aus Kernkraftwerken. Ein Beitrag zur Verringerung der Endlagerproblematik

Energy Technology Data Exchange (ETDEWEB)

Mach, Manfred [Technische Univ. Berlin (Germany). Inst. fuer Technologie und Management

2015-07-01

The brochure on transmutation of radioactive wastes from nuclear power plants - a contribution to the reduction of the final repository problem covers the following issues: What is transmutation? Nuclear power in Germany; energy density of fuels; time span of energy resources; CO{sub 2} emissions from different energy sources; types of nuclear power plants in Germany; cost of German electricity generation plants; nuclear power plants worldwide; wastes from nuclear electricity production; radiation from fission products; radiation effects on humans, the nuclear fuel cycle, direct final disposal of radioactive wastes; risk assessment of the direct final disposal; partitioning of actinides; transmutation of actinides.

Electrochemical Reduction Process for Pyroprocessing

Energy Technology Data Exchange (ETDEWEB)

Choi, Eun-Young; Hong, Sun-Seok; Park, Wooshin; Im, Hun Suk; Oh, Seung-Chul; Won, Chan Yeon; Cha, Ju-Sun; Hur, Jin-Mok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-06-15

Nuclear energy is expected to meet the growing energy demand while avoiding CO{sub 2} emission. However, the problem of accumulating spent fuel from current nuclear power plants which is mainly composed of uranium oxides should be addressed. One of the most practical solutions is to reduce the spent oxide fuel and recycle it. Next-generation fuel cycles demand innovative features such as a reduction of the environmental load, improved safety, efficient recycling of resources, and feasible economics. Pyroprocessing based on molten salt electrolysis is one of the key technologies for reducing the amount of spent nuclear fuel and destroying toxic waste products, such as the long-life fission products. The oxide reduction process based on the electrochemical reduction in a LiCl-Li{sub 2}O electrolyte has been developed for the volume reduction of PWR (Pressurized Water Reactor) spent fuels and for providing metal feeds for the electrorefining process. To speed up the electrochemical reduction process, the influences of the feed form for the cathode and the type of anode shroud on the reduction rate were investigated.

Incentive aspects of point implementation of greenhouse gas reduction

International Nuclear Information System (INIS)

Michaelowa, A.

1996-01-01

The costs of a national climate policy instruments can be reduced if a reduction of greenhouse gas emission achieved abroad can be credited to a national target. Reductions carried through by agents of one country in another country are called Joint Implementation and have been a major topic in the negotiations on the UN Framework Convention on Climate Change. The first Conference of the parties in Berlin decided that the concept should be tested in a pilot phase without crediting. To induce private investments in Joint Implementation projects, primary instruments such as emission taxes, subsidies, tradeable emission rights or regulation are a necessary condition. Tax concessions, subsidies, additional emission rights or relaxation of regulation act as incentives. These must be proportional to the emission reduction achieved through the projects. Tax concessions and subsidies are preferable to other instruments for efficiency reasons. Examples are given for calculating tax concessions on a range of projects, including the installation of new boilers at a foreign power plant, the building of a new lignite power plant abroad, and the replacement of a coal-fired power plant with a hydroelectric power plant. 18 refs., 7 figs., 1 tab

Research on faults data processing and attributes reduction arithmetic based on data mining for nuclear power plants

International Nuclear Information System (INIS)

Liu Yongkuo; Xie Chunli; Xia Hong

2010-01-01

A distance standardized method is proposed considering the features of fault data of nuclear power plants and based on the knowledge discovery function of the data mining method, to standardize the data under different condition and of different order magnitudes. According to the characteristics of parameters, the parameters are dispersed using the alarm values, as a reference for the choice of the break points of the discrete data.The data are reduced using the concept lattice attribute reduction method, and thus the core attributes, relative necessary attributes and unnecessary attributes for fault diagnosis are obtained. The data in literature are calculated and the attributes are classified accurately. When the formal context is affirmatory, the fault can be diagnosed exactly using the core attributes. (authors)

Marginal CO2 reduction cost in ENERGY 2000 development. A socio-economic evaluation of the marginal cost for the alternative reduction methods

International Nuclear Information System (INIS)

Maeng, H.

1995-01-01

The official Danish environmental plan involves a reduction of CO 2 within the next 30-50 years. This report describes the analysis of socio-economic cost/consequences of marginal CO 2 reduction by means of various technical solution models. Calculations by means of the special program subroutine SAMFOKO are based on energy balance in annual, monthly, daily and hourly scale. Heat and power savings as well as the development of decentralized power plants are considered in the supply model. Socio-economic consequences in form of charges and cost are discussed. (EG)

Power quality enhancement at distribution level utilizing the unified power quality conditioner (UPQC)

Science.gov (United States)

Khadkikar, Vinod

The present doctoral work is based on the philosophy of optimal utilization of the available resources in a most effective and efficient way to improve the product efficiency and to reduce the overall cost. This work proposes a novel control philosophy termed as power angle control (PAC), in which both the series and shunt inverters share the load reactive power in co-ordination with each other without affecting the basic UPQC compensation capabilities. This eventually results in a better utilization of the series inverter, reduction in the shunt inverter rating to some extent and ultimately in the reduction of the overall cost of UPQC. Moreover, in this thesis work several other control approaches are also proposed, such as, unit vector template generation, quadrature voltage injection, generalized single-phase p-q theory and novel current unbalance compensation approach. All the developed concepts are successfully validated through digital simulation as well as extensive experimental investigations. Keywords. power quality, active power filter, unified power quality conditioner, reactive power compensation, harmonics compensation.

A simplified approach to analyze the effectiveness of NO2 and SO2 emission reduction of coal-fired power plant from OMI retrievals

Science.gov (United States)

Bai, Yang; Wu, Lixin; Zhou, Yuan; Li, Ding

2017-04-01

Nitrogen oxides (NOX) and sulfur dioxide (SO2) emissions from coal combustion, which is oxidized quickly in the atmosphere resulting in secondary aerosol formation and acid deposition, are the main resource causing China's regional fog-haze pollution. Extensive literature has estimated quantitatively the lifetimes and emissions of NO2 and SO2 for large point sources such as coal-fired power plants and cities using satellite measurements. However, rare of these methods is suitable for sources located in a heterogeneously polluted background. In this work, we present a simplified emission effective radius extraction model for point source to study the NO2 and SO2 reduction trend in China with complex polluted sources. First, to find out the time range during which actual emissions could be derived from satellite observations, the spatial distribution characteristics of mean daily, monthly, seasonal and annual concentration of OMI NO2 and SO2 around a single power plant were analyzed and compared. Then, a 100 km × 100 km geographical grid with a 1 km step was established around the source and the mean concentration of all satellite pixels covered in each grid point is calculated by the area weight pixel-averaging approach. The emission effective radius is defined by the concentration gradient values near the power plant. Finally, the developed model is employed to investigate the characteristic and evolution of NO2 and SO2 emissions and verify the effectiveness of flue gas desulfurization (FGD) and selective catalytic reduction (SCR) devices applied in coal-fired power plants during the period of 10 years from 2006 to 2015. It can be observed that the the spatial distribution pattern of NO2 and SO2 concentration in the vicinity of large coal-burning source was not only affected by the emission of coal-burning itself, but also closely related to the process of pollutant transmission and diffusion caused by meteorological factors in different seasons. Our proposed

Reduction in adipose tissue volume using a new high-power radiofrequency technology combined with infrared light and mechanical manipulation for body contouring

OpenAIRE

Adatto, Maurice A.; Adatto-Neilson, Robyn M.; Morren, Grietje

2014-01-01

A growing patient demand for a youthful skin appearance with a favorable body shape has led to the recent development of new noninvasive body contouring techniques. We have previously demonstrated that the combination of bipolar radiofrequency (RF) and optical energies with tissue manipulation is an efficient reshaping modality. Here, we investigated the efficacy and safety of a new high-power version of this combined technology, in terms of adipose tissue reduction and skin tightening. Thirt...

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

CERN Document Server

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...

Effect of selective catalytic reduction (SCR) on fine particle emission from two coal-fired power plants in China

Science.gov (United States)

Li, Zhen; Jiang, Jingkun; Ma, Zizhen; Wang, Shuxiao; Duan, Lei

2015-11-01

Nitrogen oxides (NOx) emission abatement of coal-fired power plants (CFPPs) requires large-scaled installation of selective catalytic reduction (SCR), which would reduce secondary fine particulate matter (PM2.5) (by reducing nitrate aerosol) in the atmosphere. However, our field measurement of two CFPPs equipped with SCR indicates a significant increase of SO42- and NH4+ emission in primary PM2.5, due to catalytic enhancement of SO2 oxidation to SO3 and introducing of NH3 as reducing agent. The subsequent formation of (NH4)2SO4 or NH4HSO4 aerosol is commonly concentrated in sub-micrometer particulate matter (PM1) with a bimodal pattern. The measurement at the inlet of stack also showed doubled primary PM2.5 emission by SCR operation. This effect should therefore be considered when updating emission inventory of CFPPs. By rough estimation, the enhanced primary PM2.5 emission from CFPPs by SCR operation would offset 12% of the ambient PM2.5 concentration reduction in cities as the benefit of national NOx emission abatement, which should draw attention of policy-makers for air pollution control.

Potential for greenhouse gas emission reductions using surplus electricity in hydrogen, methane and methanol production via electrolysis

International Nuclear Information System (INIS)

Uusitalo, Ville; Väisänen, Sanni; Inkeri, Eero; Soukka, Risto

2017-01-01

Highlights: • Greenhouse gas emission reductions using power-to-x processes are studied using life cycle assessment. • Surplus electricity use led to greenhouse gas emission reductions in all studied cases. • Highest reductions can be achieved by using hydrogen to replace fossil based hydrogen. • High reductions are also achieved when fossil transportation fuels are replaced. - Abstract: Using a life cycle perspective, potentials for greenhouse gas emission reductions using various power-to-x processes via electrolysis have been compared. Because of increasing renewable electricity production, occasionally surplus renewable electricity is produced, which leads to situations where the price of electricity approach zero. This surplus electricity can be used in hydrogen, methane and methanol production via electrolysis and other additional processes. Life cycle assessments have been utilized to compare these options in terms of greenhouse gas emission reductions. All of the power-to-x options studied lead to greenhouse gas emission reductions as compared to conventional production processes based on fossil fuels. The highest greenhouse gas emission reductions can be gained when hydrogen from steam reforming is replaced by hydrogen from the power-to-x process. High greenhouse gas emission reductions can also be achieved when power-to-x products are utilized as an energy source for transportation, replacing fossil transportation fuels. A third option with high greenhouse gas emission reduction potential is methane production, storing and electricity conversion in gas engines during peak consumption hours. It is concluded that the power-to-x processes provide a good potential solution for reducing greenhouse gas emissions in various sectors.

PowerGen plc report and accounts 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

Detailed financial results are presented for the United Kingdom power generation company PowerGen for the year ended 2 April 1995. A review is given of operating and financial performance. Significant reductions in operating costs and improvements in productivity have been achieved. Diversity of fuels and plant portfolio has been enhanced by building 3000 MW of gas fired CCGT plant. Investment in coal import facilities has increased access to international coal markets. Environmental performance has improved with further reductions in SO{sub 2}, NO{sub x} and CO{sub 2} emissions. Overseas projects include construction of 990 MW CCGT power station in Portugal and a contract to build the 1200 MW Paiton 2 coal-fired power station in Indonesia. Investment in lignite mining and power generation assets of MIBRAG in Germany is contributing to profits. PowerGen`s five year contract for coal supply was assigned to RJB Mining (UK) Ltd. during the year. Stocks of coal fell during the year and further reductions are expected during 1995/96.

The European Power System. Decarbonization and Cost Reduction: Lost in Transmissions?

International Nuclear Information System (INIS)

Jaureguy-Naudin, Maite

2012-01-01

Europe's energy policy is commonly defined by three axes of equal importance: security of supplies, competitiveness and sustainable development. The European Commission is mandated to develop the policy tools that allow the implementation of this common policy. Early on, challenges arose from the trade-offs to be made not only between these three pillars but also between a common European policy and national approaches. The European Commission has always had to struggle in attempting to keep a balanced line. Over the past twenty years, the EU has been engaged in the liberalization of the electricity and gas sector. For a long time, liberalization was the main objective of European energy policy. Liberalization of the electricity sector was supposed to bring many benefits. Foremost, these included the more efficient allocation of generation and transmission capacities, and the enhancement of the competitiveness of the European economy as a whole, through lower energy costs. The trading of electricity output between countries was part of this strategy. Interconnections are vital to facilitating electricity trade between Member States. It is in this context that interest in cross-border interconnections has increased. However, new constraints have emerged and have put climate change at the top of European agenda. In December 2008, as part of the fight against climate change, the European Union adopted its Energy and Climate package endorsing three objectives for 2020: i) a 20% increase in energy efficiency, ii) a 20% reduction in GHG emissions (compared to 1990), and iii) a 20% share of renewable energy sources in final energy consumption. A direct consequence of the later objective is that renewable energy sources (RES) in electricity generation are expected to expand from 20.3% of electricity output in 2010, to around 33%, in order to meet the objective set by the European Commission. Hydroelectric power has limited additional potential due to geographical

Power decoupling techniques for single-phase power electronics systems — An overview

DEFF Research Database (Denmark)

Tang, Yi; Blaabjerg, Frede

2015-01-01

. In this paper, recently proposed state-of-the-art power decoupling techniques for ripple power reduction in these systems are presented and classified into different groups for performance comparison. The pros and cons of these techniques are discussed and identified, and the conclusions drawn will be useful...

A cooperative power trading system based on satisfaction space technology

International Nuclear Information System (INIS)

Matsumoto, K.; Maruo, T.; Mori, N.

2006-01-01

This paper proposed a new power trading system model designed to ensure customer cooperation with power suppliers. Designed as an Internet application, the cooperative power trading system modelled power markets using a satisfaction space technology A network model of electric power trading systems was developed to create a communication network system that consisted of suppliers, customers, and auctioneers. When demand exceeded supply, the auctioneer in the trading system requested power reductions from customers. Rewards were paid to maintain the degree of satisfaction of the customers. The supplier's evaluation function was defined as a function of market price and power supply. A power reducing method was developed using a combinatorial optimization technique. Suppliers and customers submitted bids for initial power trading quantities, while the auctioneer decided a market price based on bidding values. After receiving the market price, suppliers and customers submitted a second set of bids for expected power trading quantities. A power reduction plan was then developed by the auctioneer to balance the amount of power supply and demand. The system can be applied to customers whose evaluation functions cannot be estimated beforehand, as the auctioneer was able to choose the most efficient power reduction point selected by consumers using a maximum steep slope method. Simulations conducted to validate the trading system demonstrated that the system is capable of choosing efficient energy reduction plans. 6 refs., 4 tabs., 3 figs

Power Control in Wireless Sensor Networks with Variable Interference

Directory of Open Access Journals (Sweden)

Michele Chincoli

2016-01-01

Full Text Available Adaptive transmission power control schemes have been introduced in wireless sensor networks to adjust energy consumption under different network conditions. This is a crucial goal, given the constraints under which sensor communications operate. Power reduction may however have counterproductive effects to network performance. Yet, indiscriminate power boosting may detrimentally affect interference. We are interested in understanding the conditions under which coordinated power reduction may lead to better spectrum efficiency and interference mitigation and, thus, have beneficial effects on network performance. Through simulations, we analyze the performance of sensor nodes in an environment with variable interference. Then we study the relation between transmission power and communication efficiency, particularly in the context of Adaptive and Robust Topology (ART control, showing how appropriate power reduction can benefit both energy and spectrum efficiency. We also identify critical limitations in ART, discussing the potential of more cooperative power control approaches.

Plant evaluation activities and O and M cost reduction in U.S

International Nuclear Information System (INIS)

Itoh, Takeshi

1998-01-01

Although some nuclear power plants face the possibility of premature retirement, most nuclear power plants have achieved substantial reductions in costs, mainly in O and M costs, and appear to be competitive with new gas and coal fired power plants. Improving competitiveness of existing nuclear power plants in the United States has primarily been driven by the electric utility self assessment activities. However, the background of this activity has been provided by the activities of NRC, INPO, NEI, EUCG and other activities being conducted for improvement of the nuclear power industry as a whole. Utility companies that are in the forefront of this activity have already achieved the reductions in staffing and outage time that are generally known to be effective for reducing O and M costs and are moving forward with rationalization and cost reductions in other areas. However, these electric utility companies are also achieving high safety and reliability. The staff of these electric utility companies have a high degree of autonomy, self motivation and self critical attitude and the staffing of these companies is a numerically small elite. This culture is supported by the self evaluation activity established by each company and is nurtured and supported by the management system. This appears to be one of the major elements in cost reduction. As this is based on U.S. information, differences in the system, society and culture in other nations mean that these findings may not be directly applicable. However, from the point of view of the prospects of nuclear power, these findings have an important meaning. This meaning is that the achievements in the United States of cost reduction activities centering on O and M costs are an important experience for other countries including Japan in reestablishing the economic competitiveness of nuclear power. (author)

An Eight-Week Clinical Evaluation of an Oscillating-Rotating Power Toothbrush with a Brush Head Utilizing Angled Bristles Compared with a Sonic Toothbrush in the Reduction of Gingivitis and Plaque.

Science.gov (United States)

Ccahuana-Vasquez, Renzo A; Conde, Erinn; Grender, Julie M; Cunningham, Pamela; Qaqish, Jimmy; Goyal, C Ram

2015-01-01

To evaluate and compare the efficacy of an oscillating-rotating (O-R) power toothbrush with a brush head utilizing angled bristles to a marketed sonic toothbrush in the reduction of plaque and gingivitis over an eight-week period. This study used a randomized, examiner-blind, single-center, two-treatment, parallel group, eight-week design. Subjects with mild-to-moderate plaque and gingivitis were evaluated for baseline whole mouth, gingival margin, and approximal plaque, gingivitis, and gingival bleeding. Clinical assessments were performed using the Modified Gingival Index, Gingival Bleeding Index, and the Rustogi Modified Navy Plaque Index. Subjects received either the O-R brush (Oral-B Professional Care 1000 [D16u] with Oral-B CrossAction brush head [EB50]) or the sonic brush (Sonicare DiamondClean with the standard DiamondClean brush head). Subjects brushed twice daily for two minutes per brushing with the assigned brush and a standard fluoride dentifrice for eight weeks before returning for plaque and gingivitis evaluations using the same methods. Prior to baseline and Week 8 measurements, participants abstained from oral hygiene for 12 hours. One hundred and forty-eight subjects completed the study; 75 in the O-R group and 73 in the sonic group. Both brushes demonstrated statistically significant reductions in plaque and gingivitis over the eight-week study period (p gingivitis than the sonic brush. Whole mouth, gingival margin, and approximal plaque reductions were 27.7%, 46.8%, and 29.3% greater, respectively, compared with the sonic brush, while the reductions in gingivitis, gingival bleeding, and number of bleeding sites were 34.6%, 36.4%, and 36.1% greater, respectively, for the O-R brush than for the sonic brush (p gingivitis reductions for the O-R power brush incorporating the angled-bristled brush head were significantly greater than for the sonic power brush.

Lifetime estimation for the power semiconductors considering mission profiles in wind power converter

DEFF Research Database (Denmark)

Ma, Ke; Liserre, Marco; Blaabjerg, Frede

2013-01-01

for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included......As a key component in the wind turbine system, power electronic converter and its power semiconductors suffer from adverse power loadings related to environment, and are proven to have certain failure rates. Therefore, correct lifetime estimation of wind power converter is crucial...... estimation, more detailed information for the reliability performance of wind power converter can be obtained....

Occupational dose control in Nuclear Power Plants

International Nuclear Information System (INIS)

Viktorsson, C.; Lochard, J.; Benedittini, M.; Baum, J.; Khan, T.A.

1990-01-01

Reduction in occupational exposure at nuclear power plants is desirable not only in the interest of the health and safety of plant personnel, but also because it enhances the safety and reliability of the plants. This report summarises the current trends of doses to workers at nuclear power plants and the achievements and developments regarding methods for their reduction

Risk reduction by filtered venting in PWR large dry-containments

International Nuclear Information System (INIS)

Gazzillo, F.; Kastenberg, W.E.

1984-01-01

The potential risk reduction associated with a Filtered-Vented Containment System is evaluated. A low-volume venting strategy has been considered and data referring to the Zion power plant, along with the results of the Zion Probabilistic Safety Study, have been used. An estimate of the reduction factor is first made for a single core melt accident sequence whose containment failure mode is late overpressure. The result, interpreted as a reduction factor applicable to the release category associated with containment late overpressure is then used for the estimation of the overall risk reduction factor. In particular, the case of internal and external risk for the Zion power plant are considered. Because the contribution from seismic events dominates the overall risk, the importance of different assumptions for seismic fragility is also assessed. Finally an uncertainty analysis of the risk reduction factor for a single accident sequence is performed. An estimate is also obtained on the level of confidence with which certain required values of risk reduction can be achieved. (orig.)

Integrated Off-Line Power Converter

DEFF Research Database (Denmark)

Fan, Lin

The miniaturization trend of industrial and consumer electronics continuously drives the demand of reductions in size, weight, and cost of power supplies. The examples of such applications considered in this research are light-emitting diode (LED) drivers for intelligent lighting systems and inte......The miniaturization trend of industrial and consumer electronics continuously drives the demand of reductions in size, weight, and cost of power supplies. The examples of such applications considered in this research are light-emitting diode (LED) drivers for intelligent lighting systems......-resistances) of these devices are jointly determined by the device, layout, package, and PCB parasitic properties. The research highly contributes to the development towards Power Supply on Chip (PwrSoC) regardless of topologies and switching technologies. First, parasitic capacitances of power semiconductors are a part...

Stirling engine with hydraulic power output for powering artificial hearts

International Nuclear Information System (INIS)

Johnston, R.P.; Noble, J.E.; Emigh, S.G.; White, M.A.; Griffith, W.R.; Perrone, R.E.

1975-01-01

The DWDL heart power source combines the high efficiency of Stirling engines with the reliability, efficiency, and flexibility of hydraulic power transfer and control to ensure long system life and physiological effectiveness. Extended life testing has already been achieved with an engine module; animal in-vivo tests with an assist heart have consistently demonstrated required performance by biological synchronization and effective ventricle relief. The present System 5 can reliably meet near-term thousand-hour animal in-vivo test goals as far as the durability and efficacy of the power source are concerned. Carefully planned development of System 6 has produced major reductions in size and required input power. Research engine tests have provided the basis for achieving performance goals and the approach for further improvement is well established. The near term goal is 33 W heat input with 16 W input projected for normal physical activity. The goal of reduction of engine module volume to 0.9 liter has been achieved. Demonstrated reliability of 292 d for the engine and 35 d for the full system, as well as effectiveness of the artificial heart power source in short-term in-vivo tests indicate that life-limiting problems are now blood pump reliability and the machine-animal interface

Energy saving and emission reduction of China's urban district heating

International Nuclear Information System (INIS)

Chen, Xia; Wang, Li; Tong, Lige; Sun, Shufeng; Yue, Xianfang; Yin, Shaowu; Zheng, Lifang

2013-01-01

China's carbon dioxide (CO 2 ) emission ranks highest in the world. China is committed to reduce its CO 2 emission by 40% to 45% from the 2005 levels by 2020. To fulfill the target, China's CO 2 emission reduction must exceed 6995 million tons. Energy consumption and CO 2 emission of China's urban district heating (UDH) are increasing. The current policy implemented to improve UDH focuses on replacing coal with natural gas to reduce energy consumption and CO 2 emission to some extent. This paper proposes that heat pump heating (HPH) could serve as a replacement for UDH to help realize energy-saving and emission-reduction goals to a greater extent. The paper also analyzes the impact of this replacement on the heating and power generation sectors. The results show that replacing coal-based UDH with HPH decreases energy consumption and CO 2 emission by 43% in the heating sector. In the power generation sector, the efficiency of power generation at the valley electricity time increases by 0.512%, and the ratio of peak–valley difference decreases by 16.5%. The decreases in CO 2 emission from the heating and power generation sectors cumulatively account for 5.55% of China's total CO 2 emission reduction target in 2020. - Highlights: ► Replacing urban district heating with heat pump heating. ► Impact of heat pump heating on heating and power generation sectors. ► Potential of energy saving and emission reduction for heat pump heating. ► China should adjust current urban heating strategy

Current status and future potential for advanced volume reduction technologies

International Nuclear Information System (INIS)

Rutland, L.; Naughton, M.D.; Papaiya, N.C.

1984-01-01

With escalating costs for disposal of low-level radioactive waste (LLW) from nuclear power plants, and the possibility of unavailability of disposal space, some nuclear power utilities responded by commiting to implementing advanced volume reduction (VR) systems. This paper presents recent experience to implement advanced volume reduction technologies; their performance and typical operating and capital costs. This experience in the light of current economic conditions may enable us to predict the direction that future advanced VR technology commitments is taking

Static power reduction for midpoint-terminated busses

Science.gov (United States)

Coteus, Paul W [Yorktown Heights, NY; Takken, Todd [Brewster, NY

2011-01-18

A memory system is disclosed which is comprised of a memory controller and addressable memory devices such as DRAMs. The invention provides a programmable register to control the high vs. low drive state of each bit of a memory system address and control bus during periods of bus inactivity. In this way, termination voltage supply current can be minimized, while permitting selected bus bits to be driven to a required state. This minimizes termination power dissipation while not affecting memory system performance. The technique can be extended to work for other high-speed busses as well.

Verifications of ES-DCPD method for piping wall thickness monitoring in the SFASL

International Nuclear Information System (INIS)

Ryu, Kyung Ha; Kim, Ji Hak; Hwang, Il Soon

2009-01-01

Although various monitoring systems, algorithm and the concept of redundant systems were developed for nuclear power plant's (NPP) aged components, accidents in NPPs have been reported continuously such as Surry unit-2 flow accelerated corrosion (FAC) accident and Mihama unit-3 FAC accident. We developed a new piping wall loss monitoring system using equipotential switching direct current potential drop (ES-DCPD) method. This method can be used as a screening method with high speed, thus can also be used as a precise online monitoring method. This method has been developed and planned for a demonstration to a NPP's secondary side piping system in Korea

Speeding Up Maximal Causality Reduction with Static Dependency Analysis

OpenAIRE

Huang, Shiyou; Huang, Jeff

2017-01-01

Stateless Model Checking (SMC) offers a powerful approach to verifying multithreaded programs but suffers from the state-space explosion problem caused by the huge thread interleaving space. The pioneering reduction technique Partial Order Reduction (POR) mitigates this problem by pruning equivalent interleavings from the state space. However, limited by the happens-before relation, POR still explores redundant executions. The recent advance, Maximal Causality Reduction (MCR), shows a promisi...

Dependent Space and Attribute Reduction on Fuzzy Information System

Directory of Open Access Journals (Sweden)

Shu Chang

2017-01-01

Full Text Available From equivalence relation RBδ on discourse domain U, we can derive equivalence relation Rδ on the attribute set A. From equivalence relation Rδ on discourse domain A, we can derive a congruence relation on the attribute power set P(A and establish an object dependent space. And then,we discuss the reduction method of fuzzy information system on object dependent space. At last ,the example in this paper demonstrates the feasibility and effectiveness of the reduction method based on the congruence relation Tδ providing an insight into the link between equivalence relation and congruence relation of dependent spaces in the rough set. In this way, the paper can provide powerful theoritical support to the combined using of reduction method, so it is of certain practical value.

Cost-effectiveness of reduction of off-site dose

International Nuclear Information System (INIS)

McGrath, J.J.; Macphee, R.; Arbeau, N.; Miskin, J.; Scott, C.K.; Winters, E.

1988-03-01

Since the early 1970's, nuclear power plants have been designed and operated with a target of not releasing more than one percent of the licensed limits (derived emission limits) in liquid and gaseous effluents. The AECB initiated this study of the cost-effectiveness of the reduction of off-site doses as part of a review to determine if further measures to reduce off-site doses might be reasonably achievable. Atlantic Nuclear has estimated the cost of existing technology options that can be applied for a further reduction of radioactive effluents from future CANDU nuclear power plants. Detritiation, filtration, ion exchange and evaporation are included in the assessment. The costs are presented in 1987 Canadian dollars, and include capital and operating costs for a reference 50 year plant life. Darlington NGS and Point Lepreau NGS are the reference nuclear power plant types and locations. The effect resulting from the hypothetical application of each technology has been calculated as the resulting reduction in world collective radiation dose detriment. The CSA N288.1 procedure was used for local pathway analysis and the global dispersion model developed by the NEA (OECD) group of experts was used for dose calculations. The reduction in the 'collective effective dose equivalent commitment' was assumed to exist for 10,000 years, the expected life-span of solid waste repositories. No attempt was made to model world population dynamics. The collective dose reductions were calculated for a nominal world population of 10 billion persons. The estimated cost and effect of applying the technology options are summarized in a tabular form for input to further consideration of 'reasonably achievable off-site dose levels'

Assessment of CPPF Reduction After Adapting Our Own Power Distribution Prediction Method

International Nuclear Information System (INIS)

Kim, Sung-min; Park, Joong-woo; Kho, Dae-hack; Seo, Hyung-beom; Han, Bong-gyun

2006-01-01

CANDU reactor which uses natural Uranium as a fuel requires daily on-power refueling due to its insufficient excess reactivity. So its power distribution changes unceasingly. Reactor physicists identify the change twice a week using RFSP (Reactor Fuelling Simulation Program) code, and check if it is operated within power limitation (380 channels and 4560 bundles). We also calculate ROP (Regional Overpower Protection trip system) detector calibration target value (DC, Detector Calibration) and determine refueling channels and their order. DC is composed of CPPF (Channel Power Peaking Factor), Plant ageing penalty and the factor considering PHT (Primary Heat Transport system) condition, etc. The lower CPPF means the lower DC, and the lower DC means the larger operating margin. If the reactor is not operated in full power state as Wolsong Unit no. 1, the additional operating margin can be converted to the additional operating power directly

GHG emission scenarios in Asia and the world: The key technologies for significant reduction

International Nuclear Information System (INIS)

Akashi, Osamu; Hijioka, Yasuaki; Masui, Toshihiko; Hanaoka, Tatsuya; Kainuma, Mikiko

2012-01-01

In this paper, we explore GHG emission scenarios up to 2050 in Asia and the world as part of the Asian Modeling Exercise and assess technology options for meeting a 2.6 W/m 2 radiative forcing target using AIM/Enduse[Global] and AIM/Impact[Policy]. Global GHG emissions in 2050 are required to be reduced by 72% relative to a reference scenario, which corresponds to a 57% reduction from the 2005 level, in order to meet the above target. Energy intensity improvement contributes a lot to curbing CO 2 emission in the short-term. Meanwhile, carbon intensity reduction and CO 2 capture play a large role for further emission reduction in the mid to long-term. The top five key technologies in terms of reduction amount are CCS, solar power generation, wind power generation, biomass power generation and biofuel, which, in total, account for about 60% of global GHG emissions reduction in 2050. We implement additional model runs, each of which enforced limited availability of one of the key technology. The result shows that the 2.6 W/m 2 target up to 2050 is achievable even if availability of any one of the key technologies is limited to half the level achieved in the default simulation. However, if the use of CCS or biomass is limited, the cumulative GHG abatement cost until 2050 increases considerably. Therefore CCS and biomass have a vital role in curbing costs to achieve significant emission reductions. - Highlights: ► We explore GHG emission scenarios up to 2050 in Asia and the world. ► Significant GHG emission reduction is required to limit radiative forcing at low level. ► We assess technology options for achieving significant GHG emission reduction. ► CCS, solar power, wind power, and biomass are the key technologies for reduction. ► Especially, CCS and biomass play a vital role in curbing costs to achieve significant emission reductions.

Multidisciplinary Modelling Tools for Power Electronic Circuits

DEFF Research Database (Denmark)

Bahman, Amir Sajjad

in reliability assessment of power modules, a three-dimensional lumped thermal network is proposed to be used for fast, accurate and detailed temperature estimation of power module in dynamic operation and different boundary conditions. Since an important issue in the reliability of power electronics...... environment to be used for optimization of cooling system layout with respect to thermal resistance and pressure drop reductions. Finally extraction of electrical parasitics in the multi-chip power modules will be investigated. As the switching frequency of power devices increases, the size of passive...... components are reduced considerably that leads to increase of power density and cost reduction. However, electrical parasitics become more challenging with increasing the switching frequency and paralleled chips in the integrated and denser packages. Therefore, electrical parasitic models are analyzed based...

Interferometric crosstalk reduction by phase scrambling

NARCIS (Netherlands)

Tafur Monroy, I.; Tangdiongga, E.; Jonker, R.J.W.; Waardt, de H.

2000-01-01

Interferometric crosstalk, arising from the detection of undesired signals at the same nominal wavelength, may introduce large power penalties and bit-error rate (BER) floor significantly restricting the scalability of optical networks. In this paper, interferometric crosstalk reduction in optical

Cost reductions for offshore wind power. Exploring the balance between scaling, learning and R and D

International Nuclear Information System (INIS)

Van der Zwaan, B.; Rivera-Tinoco, R.; Lensink, S.; Van den Oosterkamp, P.

2012-01-01

Offshore wind electricity generation is prospected to increase substantially in the near future at a number of locations, like in the Baltic, Irish and North Sea, and emerge at several others. The global growth of offshore wind technology is likely to be accompanied by reductions in wind park construction costs, both as a result of scaling and learning effects. Since 2005, however, significant cost increases have been observed. A recent surge in commodity prices proves to constitute one of the main drivers of these cost increases. This observation begs the question whether wind turbine manufacturers should return to the laboratory for undertaking R and D that explores the use of alternative materials and bring offshore wind energy closer to competitiveness. It is demonstrated that if one abstracts from material price fluctuations, in particular for metals such as copper and steel, turbine production plus installation cost data publicly available for a series of offshore wind park projects (realized in several European countries since the 1990's) show a cost reduction trend. Hence various other sources of cost increases, such as due to the progressively larger distances from the shore (and correspondingly greater depths at sea) at which wind parks have been (and will be) built, are outshadowed by cost reduction effects. When one expresses the overall cost development for offshore wind energy capacity as an experience curve, a learning rate is found of 3%, which reflects a mixture of economies-of-scale and learning-by-doing mechanisms. Also the impact is quantified on offshore wind power construction costs from the recent tightness in the market for turbine manufacturing and installation services: without the demand-supply response inertia at the origin of this tightness it is estimated that the learning rate would be 5%. Since these learning rates are relatively low - in comparison to those observed for other technologies, and in view of the high current capacity

Leakage current minimisation and power reduction techniques using sub-threshold design

CSIR Research Space (South Africa)

Tsague, HD

2015-11-01

Full Text Available Low power IC solutions are in great demand with the rapid advancement of handheld devices, wearables, smart cards and radio frequency identification bringing a massive amount of new products to market that all have the same primary need: Powering...

Guidance of reactor operators and TSC personnel with the severe accident management guidance under shutdown and low power conditions

International Nuclear Information System (INIS)

Van Haesendonck, M.F.; Prior, R.P.

2000-01-01

The Westinghouse Owners Group Severe Accident Management Guidance (WOG SAMG) was developed between 1991 and 1994. The primary goals for severe accident management that form the basis of the WOG SAMG are to terminate any radioactive releases to the environment; to prevent failure of any containment fission product boundary and to return the plant to a controlled stable condition. The WOG SAMG is primarily a TSC tool for mitigation of low probability core damage events. The philosophy is that control room operators should remain focused on the prevention of core damage, whereas the TSC personnel should concentrate on the mitigation of the severe accident. The symptom based package is built up as a structured process for choosing appropriate actions based on actual plant conditions. No detailed knowledge of severe accident phenomena is required. The scope of the WOG SAMG is limited to severe accidents resulting from initiating events occurring during full power operation. However, a number of studies such as the EdF EPS 1300 Probabilistic Safety Assessment (PSA), the shutdown Probabilistic Risk Assessment (PRA) for Surry, the BERA shutdown PRA for Beznau, the EPRI/ Westinghouse ORAM methodology etc. have shown that the frequency of core damage (a severe accident) during shutdown and low power operation can be of the same order of magnitude as for full power operation. The at-power SAMG is viewed as the resolution of the severe accident issue. Similarly, it is expected that as shutdown PRAs mature, the final resolution of the severe accident issue will lie in SAMG for low power and shutdown operation. Therefore in resolution of this issue, Westinghouse has developed the Shutdown Severe Accident Management Guidance (SSAMG) which gives guidance for both control room and TSC personnel to mitigate a severe accident under shutdown or low power conditions. In the last few years, many LWR plants have been implementing SAMG. In the US, all plants have developed SAMG, and many

Did the electric power consumption in Norway really go down?

International Nuclear Information System (INIS)

2003-01-01

Information about how the high prices in the Nordic power market have affected the power consumption in the North is important for the assessment of the ability of the power market to deal with shortage situations. The market has reacted less than expected, and some of the reduction of consumption is due to other factors than high prices. Energy intensive industry has cut its power consumption considerably, but some of this reduction is due to decline in economic activity. In the boiler market there has also been a strong reduction, but not as much as had been expected. Consumption has gone down in general, but with a considerable lag.

Fiscal 1999 research report. Development of ultralow- loss power device technology (Survey on next-generation practical power semiconductor devices); 1999 nendo choteisonshitsu denryoku soshi gijutsu kaihatsu seika hokokusho. Jisedai power handotai device jitsuyoka chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

This research proposes the clear developmental policy and target for 'Development project of ultralow-loss power device technology' through the research on power electronics or advanced power semiconductor devices as key technology of conversion loss reduction for various power applications and power supply systems. Main research issues are as follows. A bidirectional current switch using P-MOS FETs is promising as an ace of power system interconnection control equipment. IEGT as MOS gate high-power device will be substituted for GTO gradually. SiC devices will play the leading part of low- loss power devices for inverters of power converters, power systems of electric vehicles, Shinkansen and maglev railways, power systems of information and communication systems, and DC power systems. Size and cost reduction of low-noise soft switching as application technology of power devices are possible by using active circuits. Development of high- efficiency low-noise compact inexpensive inverters is an important issue. Countermeasures against various losses of inverters are also described. (NEDO)

Low power constant fraction discriminator

International Nuclear Information System (INIS)

Krishnan, Shanti; Raut, S.M.; Mukhopadhyay, P.K.

2001-01-01

This paper describes the design of a low power ultrafast constant fraction discriminator, which significantly reduces the power consumption. A conventional fast discriminator consumes about 1250 MW of power whereas this low power version consumes about 440 MW. In a multi detector system, where the number of discriminators is very large, reduction of power is of utmost importance. This low power discriminator is being designed for GRACE (Gamma Ray Atmospheric Cerenkov Experiments) telescope where 1000 channels of discriminators are required. A novel method of decreasing power consumption has been described. (author)

Transient voltage control of a DFIG-based wind power plant for suppressing overvoltage using a reactive current reduction loop

Directory of Open Access Journals (Sweden)

Geon Park

2016-01-01

Full Text Available This paper proposes a transient voltage control scheme of a doubly fed induction generator (DFIG-based wind power plant (WPP using a reactive current reduction loop to suppress the overvoltage at a point of interconnection (POI and DFIG terminal after a fault clearance. The change of terminal voltage of a DFIG is monitored at every predefined time period to detect the fault clearance. If the voltage change exceeds a set value, then the reactive current reduction loop reduces the reactive current reference in the DFIG controller using the step function. The reactive current injection of DFIGs in a WPP is rapidly reduced, and a WPP can rapidly suppress the overvoltage at a fault clearance because the reactive current reference is reduced. Using an electromagnetic transients program–released version (EMTP–RV simulator, the performance of the proposed scheme was validated for a model system comprising 20 units of a 5-MW DFIG considering various scenarios, such as fault and wind conditions. Test results show that the proposed scheme enables a WPP to suppress the overvoltage at the POI and DFIG terminal within a short time under grid fault conditions.

FLOODPLAIN, Surry COUNTY, VA

Data.gov (United States)

Federal Emergency Management Agency, Department of Homeland Security — The Floodplain Mapping/Redelineation study deliverables depict and quantify the flood risks for the study area. The primary risk classifications used are the...

Military power requirements and backup power considerations

International Nuclear Information System (INIS)

Botts, T.E.

1986-01-01

All US Air Force (USAF) facilities have certain critical power requirements that must be met in order to carry out their mission successfully. Internal USAF studies have shown that the mission can degrade precipitously as the available power decreases below the mission critical level. Now, more than ever before, the military and private industry are finding that certain functions, such as automated data processing and automated process control, respond catastrophically to power reductions. Furthermore, increased reliance on electrical power means, in the case of the Air Force, that critical power requirements are anticipated to increase by half over the next 15 yr. For these reasons and others, the USAF is investigating several means of improving the availability of electric power under adverse conditions above that which can be provided by an off-base supplier. Among the approaches to this problem being pursued at this time are a program to improve all sorts of generator sets on a service-wide basis and the Multimegawatt Terrestrial Power (MTP) Program, which is pursuing the design and testing of a small dedicated nuclear power source to provide critical mission power. The purpose of this paper is to provide some insight into some of the issues associated with USAF power programs

Applicabilities of ship emission reduction methods

Energy Technology Data Exchange (ETDEWEB)

Guleryuz, Adem [ARGEMAN Research Group, Marine Division (Turkey)], email: ademg@argeman.org; Kilic, Alper [Istanbul Technical University, Maritime Faculty, Marine Engineering Department (Turkey)], email: enviromarineacademic@yahoo.com

2011-07-01

Ships, with their high consumption of fossil fuels to power their engines, are significant air polluters. Emission reduction methods therefore need to be implemented and the aim of this paper is to assess the advantages and disadvantages of each emissions reduction method. Benefits of the different methods are compared, with their disadvantages and requirements, to determine the applicability of such solutions. The methods studied herein are direct water injection, humid air motor, sea water scrubbing, diesel particulate filter, selected catalytic reduction, design of engine components, exhaust gas recirculation and engine replacement. Results of the study showed that the usefulness of each emissions reduction method depends on the particular case and that an evaluation should be carried out for each ship. This study pointed out that methods to reduce ship emissions are available but that their applicability depends on each case.

Duke Power's liquid radwaste processing improvement efforts

International Nuclear Information System (INIS)

Baker, R.E. Jr.; Bramblett, J.W.

1995-01-01

The rising cost of processing liquid radwaste and industry efforts to reduce offsite isotopic contributions has drawn greater attention to the liquid radwaste area. Because of economic pressures to reduce cost and simultaneously improve performance, Duke Power has undertaken a wide ranging effort to cost effectively achieve improvements in the liquid radwaste processing area. Duke Power has achieved significant reductions over recent years in the release of curies to the environment from the Liquid Radwaste Treatmentt systems at its Catawba, McGuire, and Oconee stations. System wide site curie reductions of 78% have been achieved in a 3 year period. These curie reductions have been achieved while simultaneously reducing the amount of media used to accomplish treatment. The curie and media usage reductions have been achieved at low capital cost expenditures. A large number of approaches and projects have been used to achieve these curie and media usage reductions. This paper will describe the various projects and the associated results for Duke Power's processing improvement efforts. The subjects/projects which will be described include: (1) Cooperative philosophy between stations (2) Source Control (3) Processing Improvements (4) Technology Testing

Modular Power Electronic Converters in the Power Range 1 to 10 kW

DEFF Research Database (Denmark)

Klimczak, Pawel

Thanks to CO2 emission reduction policies and increasing prices of fossil fuels a significant growth in field of sustainable energy sources (SES) is being observed during last decade. A government support and take-off projects in Europe and US shall ensure an increasing trend in future too. Some...... of SES based plants , like hydro-, geothermal-, biofuel-plants, use synchronous generators directly connected to the grid. But some other SES technologies, like fuel cell or photovoltaic, require a power electronic converter between the energy source and the load or the grid. Work presented...... in this thesis concentrates on dc-dc non-isolated converters suitable for high voltage gain applications, like uninterruptible power supply (UPS) and some of sustainable energy sources. A special attention is on reduction of power losses and efficiency improvements in non-isolated dc-dc step-up converters...

ALARA at nuclear power plants

International Nuclear Information System (INIS)

Baum, J.W.

1991-01-01

Implementation of the ALARA principle at nuclear power plants presents a continuing challenge for health physicists at utility corporate and plant levels, for plant designers, and for regulatory agencies. The relatively large collective doses at some plants are being addressed through a variety of dose reduction techniques. Initiatives by the ICRP, NCRP, NRC, INPO, EPRI, and BNL ALARA Center have all contributed to a heightened interest and emphasis on dose reduction. The NCRP has formed Scientific Committee 46-9 which is developing a report on ALARA at Nuclear Power Plants. It is planned that this report will include material on historical aspects, management, valuation of dose reduction ($/person-Sv), quantitative and qualitative aspects of optimization, design, operational considerations, and training. The status of this work is summarized in this report

CBA main magnet power supply ripple reduction

International Nuclear Information System (INIS)

Bagley, G.; Edwards, R.J.

1983-01-01

The preliminary results of a development program to minimize beam perturbation resulting from ripple current generated by the CBA Main Magnet Power Supply are presented. The assessment of the magnitude and causes of the ripple generated led to a modification of the SCR Gate Driver and the addition of a bandpass amplifier correction loop which gave significant improvement. A description of the changes made and the results obtained are included. A second design approach was developed in which the timing of the SCR gate pulses is directly determined by a VCO. The results reported with this VCO Loop indicate superior performance particularly at frequencies below 60 Hz. A shunt transistor regulator design is proposed to minimize higher SCR switching frequency harmonics

Snubber reduction

International Nuclear Information System (INIS)

Olson, D.E.; Singh, A.K.

1986-01-01

Many safety-related piping systems in nuclear power plants have been oversupported. Since snubbers make up a large percentage of the pipe supports or restraints used in a plant, a plant's snubber population is much larger than required to adequately restrain the piping. This has resulted in operating problems and unnecessary expenses for maintenance and inservice inspections (ISIs) of snubbers. This paper presents an overview of snubber reduction, including: the incentives for removing snubbers, a historical perspective on how piping became oversupported, why it is possible to remove snubbers, and the costs and benefits of doing so

Improved availability through reduction in rework

International Nuclear Information System (INIS)

Grosswald, M.; Lowman, J.

1985-01-01

The Florida Power and Light Company Quality Improvement Rework Identification Program is discussed. Establishment of the Quality Improvement Rework Identification Task Team, goals, and methods of the program are noted. Resulting from the program are reductions in failure frequency and positive incentives from a teamwork approach

Prediction and attendance of Angra 2 nuclear power plant cycle extension

International Nuclear Information System (INIS)

Dias, Amory; Ferreira Junior, Decio Brandes M.; Morgado, Mario Monteiro; Santos, Barbara Oliveira dos; Oliveira, Monica Georgia Nunes

2007-01-01

The Report Project Nuclear and Thermohydraulic (RPNT) of the Nuclear Power Plant Angra 2 previews extension of the cycle, using a feedback of core reactor reactivity, through the reduction of the moderator average temperature and power. In this phase, the reactor power remains almost invariable. Furthermore, the extension of cycle can be stretch after the limit of the temperature reduction has been reached, through of reactor power fall until the determined date for the end cycle and the start outage for the next cycle. The proposal of this work is to show the Power Plant results during the phase of moderator temperature reduction and to compare with the predict values obtained from reactivity balance calculation methodology used for the Reactor Physics. In general, the results of this work can collaborate for the extension behavior evaluation of the cycles of the Nuclear Power Plant 2, being used the procedure of cooling reduction average temperature, as well as, it will also collaborate for methodology qualification applied for the Reactor Physics during the reactivity balance calculation. (author)

Report on the survey in fiscal 1998. Survey on CO{sub 2} reduction at coal fired thermal power plants in Russia; 1998 nendo chosa hokokusho. Roshia sekitan karyoku hatsudensho CO{sub 2} sakugen chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

Russia was selected as a candidate for the joint project implementation based on COP3, and coal fired thermal power plants in the country were surveyed. From among power plants having generation capacity of 200 GW, 600 thermal power plants account for 70%. Two-third of them are using natural gas as fuel, with the remaining plants using coal, which are noticeably overaged, having facility renewal as a pressing problem. Therefore, they can be the good targets for reducing carbon dioxide emission by modernizing the facilities. Promising projects with large cost effect of CO2 reduction were extracted in the Far Eastern and Siberian regions, where weight of coal fired thermal power plants is high. These projects include five plants including Amursk No. 1 and Kabarovsk No. 1 in the Far Eastern region, and five plants including Irkutsk Nos. 6, 10 and 11 in the Siberian region. From among 48 projects proposed to Japan by RAOEES 'ROSSII' in 1998, nine projects were surveyed individually as the objects of case study. Based on the survey and the consultation with the counterpart, draft proposals were prepared for each power plant, and CO2 reduction effect was evaluated. The Dogobuzh, Cherpet and Troitsk power plants were identified as having a promising potential. (NEDO)

Electronic Power Transformer for Power Distribution Networks

Directory of Open Access Journals (Sweden)

Ermuraсhi Iu.V.

2017-12-01

Full Text Available Reducing losses in electricity distribution networks is a current technical problem. This issue also has social and environmental aspects. As a promising solution one can examine the direct distribution from the medium voltage power network using new equipment based on the use of power electronics. The aim of the paper is to propose and argue an innovative technical solution for the realization of the Solid State Transformer (SST in order to decrease the number of energy transformation stages compared to the known solutions, simplifying the topology of the functional scheme with the reduction of production costs and the loss of energy in transformers used in electrical distribution networks. It is proposed the solution of simplifying the topology of the AC/AC electronic transformer by reducing the number of passive electronic components (resistors, inductors, capacitors and active (transistors. The inverter of the SST transformer ensures the switching mode of the transistors, using for this purpose the inductance of the magnetic leakage flux of the high frequency transformer. The robustness of the laboratory sample of the SST 10 / 0.22 kV transformer with the power of 20 kW was manufactured and tested. Testing of the laboratory sample confirmed the functionality of the proposed scheme and the possibility of switching of the transistors to at zero current (ZCS mode with the reduction of the energy losses. In the proposed converter a single high-frequency transformer with a simplified construction with two windings is used, which reduces its mass and the cost of making the transformer. The reduction in the manufacturing cost of the converter is also due to the decrease in the number of links between the functional elements.

Risk Reduction Methods for Managing the Development of Regional Electric Power Industry

Directory of Open Access Journals (Sweden)

Mikhail Kozhevnikov

2017-11-01

Full Text Available The development of the regional electric power industry has come to the forefront due to the changing scale, quality, and configuration of electric power infrastructure, and the spread of distributed generation. This gives rise to more stringent requirements regarding the reliability, safety, and environmental impact of electric power supply. This article aims to justify a package of methods that make it possible to identify and minimize investment, production, financial, and environmental risks in order to ensure sustainable development of the regional electric power industry that performs anti-crisis functions, and of individual energy companies. The key method to be employed is integrated resource planning (IRP. As a part of the method, energy conservation, renewable energy sources, and combined heat and power production are considered as equally valid ways of meeting future demand. The authors have designed a methodology for taking into account uncertainty and risk when implementing IRP. The methodology includes analysis of scenarios and decision making processes by calculating past and projected values of profit indicators. When conducting the environmental and economic assessment of an investment project in the electric power industry, the authors suggest using an aggregate indicator of environmental and economic effectiveness that is calculated on the basis of a combination of locally significant positive and negative environmental and economic impacts of the project. The authors formulate conceptual provisions that serve as the foundation for a promising model of the regional electric power industry and which contain recommendations for managing the development of the industry while minimizing organizational, market, and technological risks.

Congestion management of deregulated power systems by optimal setting of Interline Power Flow Controller using Gravitational Search algorithm

Directory of Open Access Journals (Sweden)

Akanksha Mishra

2017-05-01

Full Text Available In a deregulated electricity market it may at times become difficult to dispatch all the required power that is scheduled to flow due to congestion in transmission lines. An Interline Power Flow Controller (IPFC can be used to reduce the system loss and power flow in the heavily loaded line, improve stability and loadability of the system. This paper proposes a Disparity Line Utilization Factor for the optimal placement and Gravitational Search algorithm based optimal tuning of IPFC to control the congestion in transmission lines. DLUF ranks the transmission lines in terms of relative line congestion. The IPFC is accordingly placed in the most congested and the least congested line connected to the same bus. Optimal sizing of IPFC is carried using Gravitational Search algorithm. A multi-objective function has been chosen for tuning the parameters of the IPFC. The proposed method is implemented on an IEEE-30 bus test system. Graphical representations have been included in the paper showing reduction in LUF of the transmission lines after the placement of an IPFC. A reduction in active power and reactive power loss of the system by about 6% is observed after an optimally tuned IPFC has been included in the power system. The effectiveness of the proposed tuning method has also been shown in the paper through the reduction in the values of the objective functions.

Microbial desalination cell with sulfonated sodium poly(ether ether ketone) as cation exchange membranes for enhancing power generation and salt reduction.

Science.gov (United States)

Moruno, Francisco Lopez; Rubio, Juan E; Atanassov, Plamen; Cerrato, José M; Arges, Christopher G; Santoro, Carlo

2018-06-01

Microbial desalination cell (MDC) is a bioelectrochemical system capable of oxidizing organics, generating electricity, while reducing the salinity content of brine streams. As it is designed, anion and cation exchange membranes play an important role on the selective removal of ions from the desalination chamber. In this work, sulfonated sodium (Na + ) poly(ether ether ketone) (SPEEK) cation exchange membranes (CEM) were tested in combination with quaternary ammonium chloride poly(2,6-dimethyl 1,4-phenylene oxide) (QAPPO) anion exchange membrane (AEM). Non-patterned and patterned (varying topographical features) CEMs were investigated and assessed in this work. The results were contrasted against a commercially available CEM. This work used real seawater from the Pacific Ocean in the desalination chamber. The results displayed a high desalination rate and power generation for all the membranes, with a maximum of 78.6±2.0% in salinity reduction and 235±7mWm -2 in power generation for the MDCs with the SPEEK CEM. Desalination rate and power generation achieved are higher with synthesized SPEEK membranes when compared with an available commercial CEM. An optimized combination of these types of membranes substantially improves the performances of MDC, making the system more suitable for real applications. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Power quality in electric distribution systems

International Nuclear Information System (INIS)

Mohamed, A.A.S.

2005-01-01

the power quality of the electric system is defined by the constant values of the voltage and frequency, the good value of the power factor close to unity, and balanced three phase voltages and currents. capacitors are widely installed in distribution systems for reactive power compensation to achieve power and energy loss reduction, voltage regulation and system capacity release. the extent of these benefits depends greatly on low the capacitors are placed on the system . the problem of how to place capacitors on the system such that these benefits are achieved and / or maximized against the cost associated with the capacitor placement is termed the general capacitor placement problem.the presented mathematical model has been developed to determine the size, number, and location of fixed capacitor banks that will maximize the saving derived from reduction in peak power and energy loss, and that will minimize the capital and installation costs of capacitors

TQC works in newly-built nuclear power plant and main electric power system plannings

International Nuclear Information System (INIS)

Akiyama, Yoshihisa; Kawakatsu, Tadashi; Hashimoto, Yasuo

1985-01-01

In the Kansai Electric Power Co., Inc., TQC has been introduced to solve such major problems in nuclear power generation as the securing of nuclear power reliability, the suppression of rises in the costs, the reduction in long periods of power failure and the promotion in siting of nuclear power plants. It is thus employed as a means of the ''creation of a slim and tough business constitution''. The state of activities in Kansai Electric are described in quality assurance of a newly-built nuclear power plant and in raising the reliability of the main electric power system to distribute the generated nuclear power and further the future prospects are explained. (Mori, K.)

COGNITIONS AND BEHAVIOR IN A HIERARCHY - MULDERS POWER THEORY REVISITED

NARCIS (Netherlands)

WILKE, HAM

1992-01-01

In this study, Mulder's power theory consisting of the power distance reduction tendency (PDR) of less powerful group members towards more powerful others, and the power distance enlargement tendency (PDE) of more powerful group members towards less powerful others, is investigated. In particular,

The economics of transition in the power sector

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-07-01

The power sector carries a considerably great burden of the CO2 emission reductions required to address climate change, a feature common to many scenarios of emissions abatement. These reductions will only be possible if existing plants are replaced with more efficient and less-emitting types of plants over the coming decades. This report identifies the investments needed in the power sector, and their related risk factors.

An ultralow power wireless intraocular pressure monitoring system

International Nuclear Information System (INIS)

Liu Demeng; Mei Niansong; Zhang Zhaofeng

2014-01-01

This paper describes an ultralow power wireless intraocular pressure (IOP) monitoring system that is dedicated to sensing and transferring intraocular pressure of glaucoma patients. Our system is comprised of a capacitive pressure sensor, an application-specific integrated circuit, which is designed on the SMIC 180 nm process, and a dipole antenna. The system is wirelessly powered and demonstrates a power consumption of 7.56 μW at 1.24 V during continuous monitoring, a significant reduction in active power dissipation compared to existing work. The input RF sensitivity is −13 dBm. A significant reduction in input RF sensitivity results from the reduction of mismatch time of the ASK modulation caused by FM0 encoding. The system exhibits an average error of ± 1.5 mmHg in measured pressure. Finally, a complete IOP system is demonstrated in the real biological environment, showing a successful reading of the pressure of an eye. (semiconductor integrated circuits)

Outage reduction of Hamaoka NPS

International Nuclear Information System (INIS)

Hida, Shigeru; Anma, Minoru

1999-01-01

In the Hamaoka nuclear power plant, we have worked on the outage reduction since 1993. In those days, the outage length in Hamaoka was 80 days or more, and was largely far apart from excellent results of European and American plants about the 30days. A concrete strategy to achieve the reduction process is the extension of working hours, the changing work schedule control unit for every hour, the equipment improvements, and the improvements of work environments, etc. We executed them one by one reflecting results. As a result, we achieved the outage for 57 days in 1995. Starting from this, we acquired the further outage reduction one by one and achieved the outage for 38 days in 1997 while maintaining safety and reliability of the plant. We advance these strategies further and we will aim at the achievement of the 30·35 days outage in the future. (author)

Power gating of VLSI circuits using MEMS switches in low power applications

KAUST Repository

Shobak, Hosam

2011-12-01

Power dissipation poses a great challenge for VLSI designers. With the intense down-scaling of technology, the total power consumption of the chip is made up primarily of leakage power dissipation. This paper proposes combining a custom-designed MEMS switch to power gate VLSI circuits, such that leakage power is efficiently reduced while accounting for performance and reliability. The designed MEMS switch is characterized by an 0.1876 ? ON resistance and requires 4.5 V to switch. As a result of implementing this novel power gating technique, a standby leakage power reduction of 99% and energy savings of 33.3% are achieved. Finally the possible effects of surge currents and ground bounce noise are studied. These findings allow longer operation times for battery-operated systems characterized by long standby periods. © 2011 IEEE.

Severe measures for the reduction of the SO2 emissions, applicable to the thermal power plants in Romania

International Nuclear Information System (INIS)

Pop, Ovidiu

2006-01-01

The accession of Romania to EU imposes the observance of the environment community regulations and the international conventions to which Romania is a party, as well. The legislative framework was adapted to the of the community regulations by conditioning the operation of the Large Burning Units, LBU, (of thermal power larger than 50 MW) that belong to the thermal power plants. The control of the LBU operation is not limited to the technological problems but goes further to issues related to the protection of the environment where the severity of the measures adopted imposes equally the control of the Emission Limit Values, ELV. To reduce the pollutant emissions, Romania must observe the ELVs for sulfur dioxide, nitrogen oxides and aerosols for each of the existing LBU, and also to prepare a National Plant for the Reduction of the Pollutant Emissions within a transition period, thus ensuring a strict compliance with the EU regulations by January 1, 2008. The power plants for which the transition period was awarded are requested to prevent the pollution especially through the application of the best available techniques what assumes the implementation of some important investment programs. In order to have a clear image on what the observance of the community regulations mean in the domain of the sulfur dioxide emission from the LBU, a few self-evident figures are shown. The paper tackles the following issues: EU Accession Requirements; The efforts of the conforming; The best available techniques (BAT); Severe Measures for the Reduction of the Sulfur Emissions; Wet Desulfurization Procedures; Desulfurization dry/semidry procedures. Since the fuels used by the LBUs in Romania have much sulfur one concludes that they cannot be fired without the desulfurization of the flue gases. Even the mandatory utilization of the fuel oil with sulfur contents less than 1% starting by January 1, 2007 cannot solve the problem; it reduces to a certain extent the SO 2 emissions but

Thermal electric power production

International Nuclear Information System (INIS)

Boehmer, S.

2001-01-01

The basic principle of a thermal power plant is to heat up water in the pipe system of a boiler to generate steam, which exits the boiler with high pressure and releases its energy to a tandem-arranged turbine. This energy is transmitted to a generator over a common shaft. The generated electricity is fed into the power supply system. The processed steam is condensed to water by means of a condenser and transferred back into the pipe system of the boiler (feed water circuit). In general the following techniques are applied for the combustion of solid, liquid and gaseous fuels: dry bottom boiler, wet bottom boiler, grate firing, fluidized bed combustion, gasification systems - integrated gasification combined cycle (IGCC), oil firing technique, gas firing technique. Residues from power plants are generated by the following processes and emission reduction measures: separation of bottom ash or boiler slag in the boiler; separation of fly ash (particulate matter) by means of filters or electric precipitators; desulphurization through lime additive processes, dry sorption or spray absorption processes and lime scrubbing processes; desulphurization according to Wellmann-Lord and to the Walther process; reduction of NO x emissions by selective catalytic reduction (SCR). In this case spent catalyst results as a waste unless it is recycled. No residues are generated by the following measures to reduce NO x emissions: minimization of nitrogen by selective non-catalytic reduction (SNCR); adaptations of the firing technology to avoid emissions - primary measures (low-NO x burners, CO reduction). However, this may change the quality of fly ash by increasing unburnt carbon. Combustion of fossil fuels (with the exception of gaseous fuels) and biomass generates large quantities of residues - with coal being the greatest contributor - either from the fuel itself in the form of ashes, or from flue gas cleaning measures. In coal-fired power plants huge amounts of inorganic residues

Emissions reduction and economic implications of renewable energy market penetration of power generation for residential consumption in the MENA region

International Nuclear Information System (INIS)

El Fadel, M.; Rachid, G.; El-Samra, R.; Bou Boutros, G.; Hashisho, J.

2013-01-01

This paper examines the implications of renewable energy (RE) deployment in power generation for residential consumption in the Middle East and North Africa (MENA) region under various RE penetration targets. A comparative assessment revealed a great heterogeneity among countries with Turkey dominating as the highest emitter. At the sub-regional level, the Middle East sub-region contributes more than double the GHG emissions estimated for the Gulf and North Africa sub-regions with all sub-regions achieving reductions in the range of 6–38% depending on the RE target penetration and promising up to 54% savings on investment excluding positive externalities associated with the offset of greenhouse gas (GHG) emissions savings. - Highlights: ► Heterogeneity in GHG emissions in MENA region with Turkey contributing the most. ► Average regional GHG tCO 2 e/capita of 0.42 decreases to 0.17 with RE penetration. ► GHG emissions regional reduction reaches 8–36% depending on RE target penetration. ► Return on investment in RE promises up to 54% savings excluding positive externalities. ► Carbon credits offer economic incentives rendering RE investment more attractive.

Low power predictable memory and processing architectures

OpenAIRE

Chen, Jiaoyan

2013-01-01

Great demand in power optimized devices shows promising economic potential and draws lots of attention in industry and research area. Due to the continuously shrinking CMOS process, not only dynamic power but also static power has emerged as a big concern in power reduction. Other than power optimization, average-case power estimation is quite significant for power budget allocation but also challenging in terms of time and effort. In this thesis, we will introduce a methodology to support mo...

Study on severe accident induced by large break loss of coolant accident for pressureized water reactor

International Nuclear Information System (INIS)

Zhang Longfei; Zhang Dafa; Wang Shaoming

2007-01-01

Using the best estimate computer code SCDAP/RELAP5/MOD3.2 and taking US Westinghouse corporation Surry nuclear power plant as the reference object, a typical three-loop pressurized water reactor severe accident calculation model was established and 25 cm large break loss of coolant accident (LBLOCA) in cold and hot leg of primary loop induced core melt accident was analyzed. The calculated results show that core melt progression is fast and most of the core material melt and relocated to the lower plenum. The lower head of reactor pressure vessel failed at an early time and the cold leg break is more severe than the hot leg break in primary loop during LBLOCA. (authors)

Advanced Radioisotope Power Systems Segmented Thermoelectric Research

Science.gov (United States)

Caillat, Thierry

2004-01-01

Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

Customer value in green power purchases

International Nuclear Information System (INIS)

Welsh, L.

1998-01-01

A discussion about generating electricity from renewable energy sources was presented. The Environment Canada/ENMAX green power contract stipulates that in order for electricity to quality as green power it must be generated by renewable energy sources such as wind, solar, combustion of sustainably produced biomass, or run-of-the-river hydroelectricity. The contract also includes emissions reduction credit (ERC) ownership for greenhouse gases, sulphur dioxide, nitrogen oxides, particulates, and toxics. By using green power in some of its own facilities the government demonstrates its support for renewable energy sources, and provides the initial market for the industry to build up its capacity to service larger markets. The emission reduction credits 'earned' could be added to the government inventories as environmental assets

Molecular characterization of three common olive (Olea europaea L.) cultivars in Palestine, using simple sequence repeat (SSR) markers.

Science.gov (United States)

Obaid, Ramiz; Abu-Qaoud, Hassan; Arafeh, Rami

2014-09-03

Eight accessions of olive trees from three common varieties in Palestine, Nabali Baladi, Nabali Mohassan and Surri, were genetically evaluated using five simple sequence repeat (SSR) markers. A total of 17 alleles from 5 loci were observed in which 15 (88.2%) were polymorphic and 2 (11.8%) were monomorphic. An average of 3.4 alleles per locus was found ranging from 2.0 alleles with the primers GAPU-103 and DCA-9 to 5.0 alleles with U9932 and DCA-16. The smallest amplicon size observed was 50 bp with the primer DCA-16, whereas the largest one (450 bp) with the primer U9932. Cluster analysis with the unweighted pair group method with arithmetic average (UPGMA) showed three clusters: a cluster with four accessions from the 'Nabali Baladi' cultivar, another cluster with three accessions that represents the 'Nabali Mohassen' cultivar and finally the 'Surri' cultivar. The similarity coefficient for the eight olive tree samples ranged from a maximum of 100% between two accessions from Nabali Baladi and also in two other samples from Nabali Mohassan, to a minimum similarity coefficient (0.315) between the Surri and two Nabali Baladi accessions. The results in this investigation clearly highlight the genetic dissimilarity between the three main olive cultivars that have been misidentified and mixed up in the past, based on conventional morphological characters.

The role and significance of nuclear power in China in response to climate change

International Nuclear Information System (INIS)

Hou Huiqun; Wu Jin; Bai Yunsheng

2010-01-01

This paper analyzes international climate negotiations and the domestic situation. In accordance with the development goal of 2020, the emission reduction of nuclear power is measured as compared with thermal power from the sector of power generation and nuclear power chain respectively. It emphasized that nuclear power can play a significant role in the emission reduction with corresponding policy recommendations. (authors)

Evaluating the risk-reduction benefits of wind energy

Energy Technology Data Exchange (ETDEWEB)

Brower, M.C. [Brower & Company, Andover, MA (United States); Bell, K. [Convergence Research, Seattle, WA (United States); Bernow, S.; Duckworth, M. [Tellus Inst., Boston, MA (United States); Spinney P. [Charles River Associates, Boston, MA (United States)

1996-12-31

This paper presents preliminary results of a study to evaluate the risk-reduction benefits of wind power for a case study utility system using decision analysis techniques. The costs and risks of two alternative decisions-whether to build a 400 MW gas-fired combined cycle plant or a 1600 MW wind plant in 2003-were compared through computer simulations as fuel prices, environmental regulatory costs, wind and conventional power plant availability, and load growth were allowed to vary. Three different market scenarios were examined: traditional regulation, a short-term power pool, and fixed-price contracts of varying duration. The study concludes that, from the perspective of ratepayers, wind energy provides a net levelized risk-reduction benefit of $3.4 to $7.8/MWh under traditional regulation, and less in the other scenarios. From the perspective of the utility plant owners, wind provides a significant risk benefit in the unregulated market scenarios but none in a regulated market. The methodology and findings should help inform utility resource planning and industry restructuring efforts. 2 figs., 3 tabs.

Thermal Loading and Lifetime Estimation for Power Device Considering Mission Profiles in Wind Power Converter

DEFF Research Database (Denmark)

Ma, Ke; Liserre, Marco; Blaabjerg, Frede

2015-01-01

for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included......As a key component in the wind turbine system, the power electronic converter and its power semiconductors suffer from complicated power loadings related to environment, and are proven to have high failure rates. Therefore, correct lifetime estimation of wind power converter is crucial...... devices, more detailed information of the lifetime-related performance in wind power converter can be obtained. Some experimental results are also included to validate the thermal behavior of power device under different mission profiles....

Implications of the recent reductions in natural gas prices for emissions of CO2 from the US power sector.

Science.gov (United States)

Lu, Xi; Salovaara, Jackson; McElroy, Michael B

2012-03-06

CO(2) emissions from the US power sector decreased by 8.76% in 2009 relative to 2008 contributing to a decrease over this period of 6.59% in overall US emissions of greenhouse gases. An econometric model, tuned to data reported for regional generation of US electricity, is used to diagnose factors responsible for the 2009 decrease. More than half of the reduction is attributed to a shift from generation of power using coal to gas driven by a recent decrease in gas prices in response to the increase in production from shale. An important result of the model is that, when the cost differential for generation using gas rather than coal falls below 2-3 cents/kWh, less efficient coal fired plants are displaced by more efficient natural gas combined cycle (NGCC) generation alternatives. Costs for generation using NGCC decreased by close to 4 cents/kWh in 2009 relative to 2008 ensuring that generation of electricity using gas was competitive with coal in 2009 in contrast to the situation in 2008 when gas prices were much higher. A modest price on carbon could contribute to additional switching from coal to gas with further savings in CO(2) emissions.

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

Science.gov (United States)

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Skylab technology electrical power system

Science.gov (United States)

Woosley, A. P.; Smith, O. B.; Nassen, H. S.

1974-01-01

The solar array/battery power systems for the Skylab vehicle were designed to operate in a solar inertial pointing mode to provide power continuously to the Skylab. Questions of power management are considered, taking into account difficulties caused by the reduction in power system performance due to the effects of structural failure occurring during the launching process. The performance of the solar array of the Apollo Telescope Mount Power System is discussed along with the Orbital Workshop solar array performance and the Airlock Module power conditioning group performance. A list is presented of a number of items which have been identified during mission monitoring and are recommended for electrical power system concepts, designs, and operation for future spacecraft.

Evaluation of a fast power demand response strategy using active and passive building cold storages for smart grid applications

International Nuclear Information System (INIS)

Cui, Borui; Wang, Shengwei; Yan, Chengchu; Xue, Xue

2015-01-01

Highlights: • A fast power demand response strategy is developed for smart grid applications. • The developed strategy can provide immediate and stepped power demand reduction. • The demand reduction and building indoor temperature can be predicted accurately. • The demand reduction during the DR event is stable. - Abstract: Smart grid is considered as a promising solution in improving the power reliability and sustainability where demand response is one important ingredient. Demand response (DR) is a set of demand-side activities to reduce or shift electricity use to improve the electric grid efficiency and reliability. This paper presents the investigations on the power demand alternation potential for buildings involving both active and passive cold storages to support the demand response of buildings connected to smart grids. A control strategy is developed to provide immediate and stepped power demand reduction through shutting chiller(s) down when requested. The primary control objective of the developed control strategy is to restrain the building indoor temperature rise as to maintain indoor thermal comfort within certain level during the DR event. The chiller power reduction is also controlled under certain power reduction set-point. The results show that stepped and significant power reduction can be achieved through shutting chiller(s) down when requested. The power demand reduction and indoor temperature during the DR event can be also predicted accurately. The power demand reduction is stable which is predictable for the system operators

Instrumentation and control for reactor power setback in PFBR

International Nuclear Information System (INIS)

Upadhyay, Chandra Kant; Vasal, Tanmay; Nagaraj, C.P.; Madhusoodanan, K.

2013-01-01

In Prototype Fast Breeder Reactor (PFBR), a 500 MWe plant, Reactor Power Setback is a special operation envisaged for bulk power reduction on occurrence of certain events in Balance of Plant. The bulk power reduction requires a large negative reactivity perturbation if reactor is operating on nominal power. This necessitates a reliable monitoring system with fault tolerant I and C architecture in order to inhibit reactor SCRAM on negative reactivity trip signal. The impact of above events on the process is described. Design of a functional prototype module to carry out RPSB logic operation and its interface with other instruments has been discussed. (author)

CO2 reduction potential of future coal gasification based power generation technologies

International Nuclear Information System (INIS)

Jansen, D.; Oudhuis, A.B.J.; Van Veen, H.M.

1992-03-01

Assessment studies are carried out on coal gasification power plants integrated with gas turbines (IGCC) or molten carbonate fuel cells (MCFC) without and with CO 2 -removal. System elements include coal gasification, high-temperature gas-cleaning, molten carbonate fuel cells or gas turbines, CO shift, membrane separation, CO 2 recovery and a bottoming cycle. Various system configurations are evaluated on the basis of thermodynamic computations. The energy balances of the various system configurations clearly indicate that integrated coal gasification MCFC power plants (IGMCFC) with CO 2 removal have high efficiencies (42-47% LHV) compared to IGCC power plants with CO 2 -removal (33-38% LHV) and that the CO 2 -removal is simplified due to the specific properties of the molten carbonate fuel cells. IGMCFC is therefore an option with future prospective in the light of clean coal technologies for power generation with high energy efficiencies and low emissions. 2 figs., 3 tabs., 10 refs

Excessive price reduction and extreme volatility in wind dominant electricity markets; solutions and emerging challenges

DEFF Research Database (Denmark)

Farashbashi-Astaneh, Seyed-Mostafa; Chen, Zhe; Mousavi, Omid Alizadeh

2013-01-01

High intermittency in the nature of wind power emphasize conceptual revising in the mechanisms of electricity markets with high wind power penetration levels. This paper introduces overmuch price reduction and high price volatility as two adverse consequences in future wind dominant electricity...... is developed. The paper indicates discriminatory pricing approach can be beneficial in high penetration of wind power because it alleviates high price variations and spikiness in one hand and prevents overmuch price reduction in wind dominant electricity markets on the other hand....... markets. While high price volatility imposes elevated risk levels for both electricity suppliers and consumers, excessive price reduction of electricity is a disincentive for investment in new generation capacity and might jeopardizes system adequacy in long term. A comparative study between marginal...

Compendium of cost-effectiveness evaluations of modifications for dose reduction at nuclear power plants

International Nuclear Information System (INIS)

Baum, J.W.; Matthews, G.R.

1985-12-01

This report summarizes available information on cost effectiveness of engineering modifications potentially valuable for dose reduction at nuclear power plants. Data were gathered from several US utilities, published literature, equipment and service suppliers, and recent technical meetings. Five simplified econometric models were employed to evaluate data and arrive at a value for cost effectiveness expressed in either (a) dollars/rem, or (b) total dollar savings calculated using a nominal value of $1000/rem. Models employed were: a basic model with no consideration given to the time value of money; two models in which discounting was used to evaluate costs and savings in terms of present values; and two models in which income taxes and revenue requirements were considered. Results from different models varied by as much as a factor of 10, and were generally lowest for the basic model and highest for the before-tax revenue requirements model. Results for 151 evaluations employing different assumptions concerning number of plants per site and outage impacts were tabulated in order of decreasing cost effectiveness. Twenty-five evaluations were identified as exceptionally cost effective since both costs and dose were saved. Forty evaluations indicated highly cost-effective changes based on costs below $1000/rem saved using results of the present-worth model that included discounting of future dose savings

Hydrogen risk reduction in Nuclear power plant

International Nuclear Information System (INIS)

Movahed, M.A.; Travis, J.R.

1999-01-01

In case of a severe accident in a nuclear power plant with core melt and hydrogen production, the hydrogen risk is one of the main concerns. It may jeopardize the containment integrity due to violent deflagration that can lead to DDT (Deflagration Detonation Transient) or even detonation of proper hydrogen mitigation means are not available. The design of the EPR (European Pressurized water Reactor) Hydrogen mitigation and control system is based on the lumped parameter code WAVCO and the 3D code GASFLOW. The concept consists of recombiners and igniters to cope with all scenarios including those without steam. The system has been checked to avoid DDT by the 7λ criteria that's implemented in GASFLOW. Future analysis could deal with determining dynamic pressure loads, if appropriate, and some sensitivity studies to check the hydrogen control measures with respect to different source locations and mass flow rates. Also a conditional criterion for determining the likelihood of fast deflagration should be developed. (author)

PMBLDC motor drive with power factor correction controller

DEFF Research Database (Denmark)

George, G.J.; Ramachandran, Rakesh; Arun, N.

2012-01-01

reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase...

Comparisons of receive array interference reduction techniques under erroneous generalized transmit beamforming

KAUST Repository

Radaydeh, Redha Mahmoud

2014-02-01

This paper studies generalized single-stream transmit beamforming employing receive array co-channel interference reduction algorithms under slow and flat fading multiuser wireless systems. The impact of imperfect prediction of channel state information for the desired user spatially uncorrelated transmit channels on the effectiveness of transmit beamforming for different interference reduction techniques is investigated. The case of over-loaded receive array with closely-spaced elements is considered, wherein it can be configured to specified interfering sources. Both dominant interference reduction and adaptive interference reduction techniques for statistically ordered and unordered interferers powers, respectively, are thoroughly studied. The effect of outdated statistical ordering of the interferers powers on the efficiency of dominant interference reduction is studied and then compared against the adaptive interference reduction. For the system models described above, new analytical formulations for the statistics of combined signal-to-interference-plus-noise ratio are presented, from which results for conventional maximum ratio transmission and single-antenna best transmit selection can be directly deduced as limiting cases. These results are then utilized to obtain quantitative measures for various performance metrics. They are also used to compare the achieved performance of various configuration models under consideration. © 1972-2012 IEEE.

Estimate of Possible CO2 Emission Reduction in Slovenia

International Nuclear Information System (INIS)

Plavcak, V.-P.; Jevsek, F.; Tirsek, A.

1998-01-01

The first estimation of possible CO 2 emission reduction, according to the obligations from Kyoto Protocol, is prepared. The results show that the required 8% reduction of greenhouses gases in Slovenia in the period from 2008 to 2012 with regard to year 1986 will require a through analytical treatment not only in electric power sector but also in transport and industry sectors, which are the main pollutants. (author)

A Visualization Tool to Analyse Usage of Web-Based Interventions: The Example of Positive Online Weight Reduction (POWeR)

Science.gov (United States)

Smith, Emily; Bradbury, Katherine; Morrison, Leanne; Dennison, Laura; Michaelides, Danius; Yardley, Lucy

2015-01-01

Background Attrition is a significant problem in Web-based interventions. Consequently, this research aims to identify the relation between Web usage and benefit from such interventions. A visualization tool has been developed that enables researchers to more easily examine large datasets on intervention usage that can be difficult to make sense of using traditional descriptive or statistical techniques alone. Objective This paper demonstrates how the visualization tool was used to explore patterns in participants’ use of a Web-based weight management intervention, termed "positive online weight reduction (POWeR)." We also demonstrate how the visualization tool can be used to perform subsequent statistical analyses of the association between usage patterns, participant characteristics, and intervention outcome. Methods The visualization tool was used to analyze data from 132 participants who had accessed at least one session of the POWeR intervention. Results There was a drop in usage of optional sessions after participants had accessed the initial, core POWeR sessions, but many users nevertheless continued to complete goal and weight reviews. The POWeR tools relating to the food diary and steps diary were reused most often. Differences in participant characteristics and usage of other intervention components were identified between participants who did and did not choose to access optional POWeR sessions (in addition to the initial core sessions) or reuse the food and steps diaries. Reuse of the steps diary and the getting support tools was associated with greater weight loss. Conclusions The visualization tool provided a quick and efficient method for exploring patterns of Web usage, which enabled further analyses of whether different usage patterns were associated with participant characteristics or differences in intervention outcome. Further usage of visualization techniques is recommended to (1) make sense of large datasets more quickly and efficiently; (2

Clean fossil-fuelled power generation

International Nuclear Information System (INIS)

Oliver, Tony

2008-01-01

Using fossil fuels is likely to remain the dominant means of producing electricity in 2030 and even 2050, partly because power stations have long lives. There are two main ways of reducing CO 2 emissions from fossil-fuelled power plants. These are carbon capture and storage (CCS), which can produce near-zero CO 2 emissions, and increases in plant efficiency, which can give rise to significant reductions in CO 2 emissions and to reduced costs. If a typical UK coal-fired plant was replaced by today's best available technology, it would lead to reductions of around 25% in emissions of CO 2 per MW h of electricity produced. Future technologies are targeting even larger reductions in emissions, as well as providing a route, with CCS, to zero emissions. These two routes are linked and they are both essential activities on the pathway to zero emissions. This paper focuses on the second route and also covers an additional third route for reducing emissions, the use of biomass. It discusses the current status of the science and technologies for fossil-fuelled power generation and outlines likely future technologies, development targets and timescales. This is followed by a description of the scientific and technological developments that are needed to meet these challenges. Once built, a power plant can last for over 40 years, so the ability to upgrade and retrofit a plant during its lifetime is important

Mathematical optimization techniques for managing selective catalytic reduction for a fleet of coal-fired power plants

Science.gov (United States)

Alanis Pena, Antonio Alejandro

Major commercial electricity generation is done by burning fossil fuels out of which coal-fired power plants produce a substantial quantity of electricity worldwide. The United States has large reserves of coal, and it is cheaply available, making it a good choice for the generation of electricity on a large scale. However, one major problem associated with using coal for combustion is that it produces a group of pollutants known as nitrogen oxides (NO x). NOx are strong oxidizers and contribute to ozone formation and respiratory illness. The Environmental Protection Agency (EPA) regulates the quantity of NOx emitted to the atmosphere in the United States. One technique coal-fired power plants use to reduce NOx emissions is Selective Catalytic Reduction (SCR). SCR uses layers of catalyst that need to be added or changed to maintain the required performance. Power plants do add or change catalyst layers during temporary shutdowns, but it is expensive. However, many companies do not have only one power plant, but instead they can have a fleet of coal-fired power plants. A fleet of power plants can use EPA cap and trade programs to have an outlet NOx emission below the allowances for the fleet. For that reason, the main aim of this research is to develop an SCR management mathematical optimization methods that, with a given set of scheduled outages for a fleet of power plants, minimizes the total cost of the entire fleet of power plants and also maintain outlet NO x below the desired target for the entire fleet. We use a multi commodity network flow problem (MCFP) that creates edges that represent all the SCR catalyst layers for each plant. This MCFP is relaxed because it does not consider average daily NOx constraint, and it is solved by a binary integer program. After that, we add the average daily NOx constraint to the model with a schedule elimination constraint (MCFPwSEC). The MCFPwSEC eliminates, one by one, the solutions that do not satisfy the average daily

AAEC nuclear power projections

International Nuclear Information System (INIS)

Khoe, G.; Fredsall, J.; Scurr, I.; Plotnikoff, W.

1981-01-01

The nuclear power capacity projections developed in the May-June period of 1981 by the AAEC are presented. There have been downward revisions for nearly all countries with centrally planned economies. Projections for the year 2000 for the Western World have decreased in aggregate by 4.7% (27Gw) compared to those of 1980. However, this reduction is less than the previous estimate reduction and there appears to have been a stabilisation in the projection

Voltage regulation and power losses reduction in a wind farm integrated MV distribution network

Science.gov (United States)

Fandi, Ghaeth; Igbinovia, Famous Omar; Tlusty, Josef; Mahmoud, Rateb

2018-01-01

A medium-voltage (MV) wind production system is proposed in this paper. The system applies a medium-voltage permanent magnet synchronous generator (PMSG) as well as MV interconnection and distribution networks. The simulation scheme of an existing commercial electric-power system (Case A) and a proposed wind farm with a gearless PMSG insulated gate bipolar transistor (IGBT) power electronics converter scheme (Case B) is compared. The analyses carried out in MATLAB/Simulink environment shows an enhanced voltage profile and reduced power losses, thus, efficiency in installed IGBT power electronics devices in the wind farm. The resulting wind energy transformation scheme is a simple and controllable medium voltage application since it is not restrained by the IGBT power electronics voltage source converter (VSC) arrangement. Active and reactive power control is made possible with the aid of the gearless PMSG IGBT power converters.

Global outlook for nuclear power

International Nuclear Information System (INIS)

Southworth, F.H.

2010-01-01

'Full text:' The global nuclear power forecast, the North American outlook and the effect of nuclear power growth on greenhouse gas emissions in North America will be discussed. The construction of Generation III reactors will replace aging power plants and, further, add capacity that is environmentally sustainable. The outlook for Generation IV reactors also may significantly improve the environmental balance after 2030, both in electrical markets, waste reduction, and in non-traditional markets such as process heat. (author)

Ethical aspects of nuclear power

International Nuclear Information System (INIS)

Streithofen, H.B.

1989-01-01

The nuclear controversy comprises many ethical aspects, e.g. the waste disposal problem. Nuclear opponents should not neglect the environmental protection aspect; for example, the use of nuclear power alone brought about an 8% reduction of the CO 2 burden in 1987. Our responsibility towards nature and humans in the Third World leaves us no alternative to nuclear power. On the other hand, the nuclear power debate should not become a matter of religious beliefs. (DG) [de

Direct plasma NO_x reduction using single surface dielectric barrier discharge

DEFF Research Database (Denmark)

Kroushawi, Feisal; Stamate, Eugen

2014-01-01

NOx reduction using direct atmospheric barrier discharge in air-NO mixture at different voltages and flow rates is inversigated. Reduction rate of 80% is achieved at 3.18 W/cm2 power density and gas mixture of 20 slm air and 0.006 slm NO. The ozone for NO reduction is produced by a honeycomb stru...

Potentiality Prediction of Electric Power Replacement Based on Power Market Development Strategy

Science.gov (United States)

Miao, Bo; Yang, Shuo; Liu, Qiang; Lin, Jingyi; Zhao, Le; Liu, Chang; Li, Bin

2017-05-01

The application of electric power replacement plays an important role in promoting the development of energy conservation and emission reduction in our country. To exploit the potentiality of regional electric power replacement, the regional GDP (gross domestic product) and energy consumption are taken as potentiality evaluation indicators. The principal component factors are extracted with PCA (principal component analysis), and the integral potentiality analysis is made to the potentiality of electric power replacement in the national various regions; a region is taken as a research object, and the potentiality of electric power replacement is defined and quantified. The analytical model for the potentiality of multi-scenario electric power replacement is developed, and prediction is made to the energy consumption with the grey prediction model. The relevant theoretical research is utilized to realize prediction analysis on the potentiality amount of multi-scenario electric power replacement.

Optimized Envelope Tracking Power Supply for Tetra2 Base Station RF Power Amplifier

DEFF Research Database (Denmark)

Høyerby, Mikkel Christian Wendelboe; Andersen, Michael Andreas E.

2008-01-01

An ultra-fast tracking power supply (UFTPS) for envelope tracking in a 50kHz 64-QAM Tetra2 base station power amplification system is demonstrated. A simple method for optimizing the step response of the PID+PD sliding-mode control system is presented and demonstrated, along with a PLL-based scheme...... application. Also demonstrated is the effect of non-zero UFTPS output impedance on envelope tracking performance. At 13W average (156W peak) RF output, a reduction of DC input power consumption from 93W (14% efficiency) to 54W (24% efficiency) is obtained by moving from a fixed RF power amplifier supply...

MEASUREMENTS OF ABSORPTION, EMISSIVITY REDUCTION, AND LOCAL SUPPRESSION OF SOLAR ACOUSTIC WAVES IN SUNSPOTS

International Nuclear Information System (INIS)

Chou, D.-Y.; Liang, Z.-C.; Yang, M.-H.; Zhao Hui; Sun, M.-T.

2009-01-01

The power of solar acoustic waves in magnetic regions is lower relative to the quiet Sun. Absorption, emissivity reduction, and local suppression of acoustic waves contribute to the observed power reduction in magnetic regions. We propose a model for the energy budget of acoustic waves propagating through a sunspot in terms of the coefficients of absorption, emissivity reduction, and local suppression of the sunspot. Using the property that the waves emitted along the wave path between two points have no correlation with the signal at the starting point, we can separate the effects of these three mechanisms. Applying this method to helioseismic data filtered with direction and phase-velocity filters, we measure the fraction of the contribution of each mechanism to the power deficit in the umbra of the leading sunspot of NOAA 9057. The contribution from absorption is 23.3 ± 1.3%, emissivity reduction 8.2 ± 1.4%, and local suppression 68.5 ± 1.5%, for a wave packet corresponding to a phase velocity of 6.98 x 10 -5 rad s -1 .

Development of robots for nuclear power plants

International Nuclear Information System (INIS)

Sasaki, Masayoshi

1982-01-01

In nuclear power plants, the reduction of maintenance time, the reduction of radiation exposure and man-power saving are increasingly required. To achieve these purposes, various remote-controlled devices, such as robots in a broad sense, have been earnestly developed. Of these, three machines for replacing, four devices for inspection, two systems for cleaning, and two equipment for processing are tabulated in this paper. Typical eight machines or equipment are briefly introduced, mainly describing their features or characteristics. Those are: a remotely handling machine for control rod drive mechanism, an automatic refueling machine, an automatic ultrasonic flaw detection system replacing for a manually operated testing system for the welded parts of primary cooling system, an automatic cask washing machine for decontamination, a floor-type remote inspection vehicle for various devices operating inside power plants, a monorail-type remote inspection vehicle for inspection in spaces where floor space is short, and a remote-controlled automatic pipe welding machine for welding operations in a radioactive environment such as replacing the piping of primary cooling system. Most of these devices serves for radiation exposure reduction at the same time. Existing nuclear power plant design assumes direct manual maintenance, which limits the introduction of robots. Future nuclear power plants should be designed on the assumption of automatic remote-controlled tools and devices being used in maintenance work. (Wakatsuki, Y.)

BP volume reduction equipment

International Nuclear Information System (INIS)

Kitamura, Yoshinori; Muroo, Yoji; Hamanaka, Isao

2003-01-01

A new type of burnable poison (BP) volume reduction system is currently being developed. Many BP rods, a subcomponent of spent fuel assemblies are discharged from nuclear power reactors. This new system reduces the overall volume of BP rods. The main system consists of BP rod cutting equipment, equipment for the recovery of BP cut pieces, and special transport equipment for the cut rods. The equipment is all operated by hydraulic press cylinders in water to reduce operator exposure to radioactivity. (author)

GROUNDING THE REDUCTION OF POWER OF THE HYDRAULIC DRIVE ELECTRIC MOTOR BY EQUIVALENT POWER METHOD

Directory of Open Access Journals (Sweden)

O. Hrygorov

2017-06-01

Full Text Available The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is justified.

Optimization in the scale of nuclear power generation and the economy of nuclear power

International Nuclear Information System (INIS)

Suzuki, Toshiharu

1983-01-01

In the not too distant future, the economy of nuclear power will have to be restudied. Various conditions and circumstances supporting this economy of nuclear power tend to change, such as the decrease in power demand and supply, the diversification in base load supply sources, etc. The fragility in the economic advantage of nuclear power may thus be revealed. In the above connection, on the basis of the future outlook of the scale of nuclear power generation, that is, the further reduction of the current nuclear power program, and of the corresponding supply and demand of nuclear fuel cycle quantities, the aspect of the economic advantage of nuclear power was examined, for the purpose of optimizing the future scale of nuclear power generation (the downward revision of the scale, the establishment of the schedule of nuclear fuel cycle the stagnation of power demand and nuclear power generation costs). (Mori, K.)

Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

Science.gov (United States)

Johnson, Dexter; Brown, Gerald V.

2005-01-01

Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

Combining Power and Data using Powerline Communication for Harness Simplification and Mass Reduction

Data.gov (United States)

National Aeronautics and Space Administration — The challenge of this task is to eliminate dedicated communication wires to powered instruments and electronic devices. It will demonstrate realistic data and power...

Improved 64-bit Radix-16 Booth Multiplier Based on Partial Product Array Height Reduction

DEFF Research Database (Denmark)

Antelo, Elisardo; Montuschi, Paolo; Nannarelli, Alberto

2016-01-01

, a reduction of one unit in the maximum height is achieved. This reduction may add flexibility during the design of the pipelined multiplier to meet the design goals, it may allow further optimizations of the partial product array reduction stage in terms of area/delay/power and/or may allow additional addends...

Factors influencing CO2 emissions in China's power industry: Co-integration analysis

International Nuclear Information System (INIS)

Zhao, Xiaoli; Ma, Qian; Yang, Rui

2013-01-01

More than 40% of China's total CO 2 emissions originate from the power industry. The realization of energy saving and emission reduction within China's power industry is therefore crucial in order to achieve CO 2 emissions reduction in this country. This paper applies the autoregressive-distributed lag (ARDL) co-integration model to study the major factors which have influenced CO 2 emissions within China's power industry from 1980 to 2010. Results have shown that CO 2 emissions from China's power industry have been increasing rapidly. From 1980 to 2010, the average annual growth rate was 8.5%, and the average growth rate since 2002 has amounted to 10.5%. Secondly, the equipment utilization hour (as an indicator of the power demand) has the greatest influence on CO 2 emissions within China's power industry. In addition, the impact of the industrial added value of the power sector on CO 2 emissions is also positive from a short-term perspective. Thirdly, the Granger causality results imply that one of the important motivators behind China's technological progress, within the power industry, originates from the pressures created by a desire for CO 2 emissions reduction. Finally, this paper provides policy recommendations for energy saving and emission reduction for China's power industry. - Highlights: ► We study the major factors influencing China's power industry CO 2 emissions. ► The average annual growth rate of CO 2 emission from power industry is calculated. ► Installed capacity has the greatest influence on power industry CO 2 emission. ► The Granger causality between CO 2 emission and its effecting factors is analyzed

Assessing the impact of primary measures for NOx reduction on the thermal power plant steam boiler

International Nuclear Information System (INIS)

Stupar, Goran; Tucaković, Dragan; Živanović, Titoslav; Belošević, Srdjan

2015-01-01

The European normatives prescribe content of 200 mg/Nm 3 NO x for pulverized coal combusting power plants. In order to reduce content of NO x in Serbian thermal power plant (TPP) 'Kostolac B' it's necessary to implement particular measures until 2016. The mathematical model of lignite combustion in the steam boiler furnace is defined and applied to analyze the possibility of implementing certain primary measures for reducing nitrogen oxides and their effects on the steam boiler operation. This model includes processes in the coal-fired furnace and defines radiating reactive two-phase turbulent flow. The model of turbulent flow also contains sub-model of fuel and thermal NO x formation and destruction. This complex mathematical model is related to thermal and aerodynamic calculations of the steam boiler within a unified calculation system in order to analyze the steam boiler overall work. This system provides calculations with a number of influential parameters. The steam boiler calculations for unit 1 (350 MWe) of TPP 'Kostolac B' are implemented for existing and modified combustion system in order to achieve effective, reliable and ecological facility work. The paper presents the influence analysis of large number of parameters on the steam boiler operation with an accepted concept of primary measures. Presented system of calculations is verified against measurements in TPP 'Kostolac B'. - Highlights: • Modern steam boilers need to operate according to ecological standards. • Possibility of applying some of the primary measures of NO x reduction. • Conventional calculations have no possibility to estimate sub-stoichiometric combustion. • Develop a new method of connecting the calculations. • Analysis shows the most favorable operation boiler regime (efficiency and ecology)

Projections of US GHG reductions from nuclear power new capacity based on historic levels of investment

International Nuclear Information System (INIS)

Besmann, Theodore M.

2010-01-01

Historical rates of capital investment in nuclear plant construction were used as a guide to estimate the potential rate of future capacity introduction. The total linear rate of capital expenditure over the entire period of historical construction from 1964 to 1990 was determined to equal $11.5 billion/yr, and that for the period of peak construction from 1973 to 1985 was computed as $17.9 billion/yr, all in 2004$. These values were used with a variety of current capital cost estimates for nuclear construction to obtain several scenarios for possible future nuclear capacity additions. These values were used to obtain the effect of projected nuclear generating capacity on GHG emissions assuming nuclear would directly replace coal-fired generation. It was concluded that actual reductions in emissions would not be experienced until 2038, yet growth in emissions from electrical production would be slowed through that period. Due to the significant time to introduce large-scale changes in the utility sector, nuclear energy cannot have a dramatic short-term effect on emissions. Nuclear power, however, can have a major positive longer term impact, particularly under more favorable cost and investment conditions.

Economic evaluation of environmental externalities in China’s coal-fired power generation

International Nuclear Information System (INIS)

Zhao, Xiaoli; Cai, Qiong; Ma, Chunbo; Hu, Yanan; Luo, Kaiyan; Li, William

2017-01-01

Serious environmental externalities exist in China’s power industry. Environmental economics theory suggests that the evaluation of environmental externality is the basis of designing an efficient regulation. The purposes of this study are: (1) to identify Chinese respondents’ preferences for green development of electric power industry and the socio-economic characteristics behind them; (2) to investigate the different attitudes of the respondents towards pollution and CO_2 reduction; (3) to quantitatively evaluate the environmental cost of China’s coal-fired power generation. Based on the method of choice experiments (CE) and the 411 questionnaires with 2466 data points, we found that Chinese respondents prefer PM2.5, SO_2 and NO_x reduction to CO_2 reduction and that the environment cost of coal-fired power plants in China is 0.30 yuan per kWh. In addition, we found that the socio-economic characteristics of income, education, gender, and environmental awareness have significant impacts on respondents’ choices. These findings indicate that the environmental cost of coal-fired power generation is a significant factor that requires great consideration in the formulation of electric power development policies. In addition, importance should also be attached to the implementation of green power price policy and enhancement of environmental protection awareness. - Highlights: • Chinese respondents have willingness to pay premium for green development. • The environment cost of coal-fired power plants in China is 0.30 yuan/kwh. • Chinese respondents prefer PM2.5, SO_2 and NO_x reduction to CO_2 reduction. • Environmental awareness has significant impacts on respondents’ preferences. • Income, education and gender affect the evaluation results.

Feasibility study on Bobovdol thermal power plant upgrading project

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

A survey has been made in relation with the improvement project intended of energy conservation, and reduction of global warming gas emission at the Bobovdol thermal power plant located in the suburb of Sofia, the capital of the Republic of Bulgaria. The existing Bobovdol power plant having a total capacity of 630 MW with three generators is a coal burning thermal power plant having been used already for 23 to 27 years, hence over-aged. The survey has discussed an improvement project of scrap-and-build type to make the plant a high-efficiency gas combined cycle power plant using gas turbines. The project calls for building 210-MW gas combined power generation facilities having 70-MW gas turbines, one each in three stages in 2007, 2012 and 2017. As a result of the discussions, the fuel consumption reducing rate was found to reach 37.99%, whereas the cumulative energy saving quantity in 41 years will reach 16.37 million tons of fuel oil equivalent. In addition, the reduction rate of global warming gas emission is 57.75%, and the cumulative reduction quantity in 41 years is 105.18 million tons. (NEDO)

Method research of fault diagnosis based on rough set for nuclear power plant

International Nuclear Information System (INIS)

Chen Zhihui; Xia Hong

2005-01-01

Nuclear power equipment fault feature is complicated and uncertain. Rough set theory can express and deal with vagueness and uncertainty, so that it can be introduced nuclear power fault diagnosis to analyze and process historical data to find rule of fault feature. Rough set theory treatment step: Data preprocessing, attribute reduction, attribute value reduction, rule generation. According to discernibility matrix definition and nature, we can utilize discernibility matrix in reduction algorithm that make attribute and attribute value reduction, so that it can minish algorithmic complication and simplify programming. This algorithm is applied to the nuclear power fault diagnosis to generate rules of diagnosis. Using these rules, we have diagnosed five kinds of model faults correctly. (authors)

Mercury emissions from South Africa’s coal-fired power stations

Directory of Open Access Journals (Sweden)

Belinda L. Garnham

2016-12-01

Full Text Available Mercury is a persistent and toxic substance that can be bio-accumulated in the food chain. Natural and anthropogenic sources contribute to the mercury emitted in the atmosphere. Eskom’s coal-fired power stations in South Africa contributed just under 93% of the total electricity produced in 2015 (Eskom 2016. Trace amounts of mercury can be found in coal, mostly combined with sulphur, and can be released into the atmosphere upon combustion. Coal-fired electricity generation plants are the highest contributors to mercury emissions in South Africa. A major factor affecting the amount of mercury emitted into the atmosphere is the type and efficiency of emission abatement equipment at a power station. Eskom employs particulate emission control technology at all its coal-fired power stations, and new power stations will also have sulphur dioxide abatement technology. A co-beneficial reduction of mercury emissions exists as a result of emission control technology. The amount of mercury emitted from each of Eskom’s coal-fired power stations is calculated, based on the amount of coal burnt and the mercury content in the coal. Emission Reduction Factors (ERF’s from two sources are taken into consideration to reflect the co-benefit received from the emission control technologies at the stations. Between 17 and 23 tons of mercury is calculated to have been emitted from Eskom’s coal-fired power stations in 2015. On completion of Eskom’s emission reduction plan, which includes fabric filter plant retrofits at two and a half stations and a flue gas desulphurisation retrofit at one power station, total mercury emissions from the fleet will potentially be reduced by 6-13% by 2026 relative to the baseline. Mercury emission reduction is perhaps currently not the most pressing air quality problem in South Africa. While the focus should then be on reducing emissions of other pollutants which have a greater impact on human health, mercury emission reduction

Risk analysis local grids. Mapping and reduction of risks in electric power grids; Riskanalysmetod lokalnaet. Kartlaeggning och reduktion av risker i elnaet

Energy Technology Data Exchange (ETDEWEB)

Kylefors, Martin; Fredholm, Lotta; Sandstroem, Cecilia

2007-11-15

The objective of the project has been to contribute to development of risk analysis applications that correspond to the need of investments as an effect of new regulation. The aim has been to develop a method for screening and assessing risks, and for ranking risk reducing measures in order of priority. Phase 1 has consisted of an overview of methods, selection of appropriate methods, and development of principles regarding application suitable for power distribution companies. Phase 2 has consisted of adjustments and tests of the method. The method focuses on risks associated with power failures, with a duration exceeding 12 hours, in medium voltage local networks. Stations are excluded. The suggested method is based on principles of Preliminary Hazard Analysis and Cost-Benefit Analysis. Risks are suggested to be assessed based on three main factors (load, exposure and alternative supply). The quota between the highest and lowest value is 20 for each factor. Each factor is assessed by underlying factors such as type of cable/wire, number of customers and average power consumption. By multiplying the factors a resulting risk level is obtained in the range of 0.05 to 400. The level determines the need for further investments. Appropriate risk reducing measure is selected by putting the risk reduction (benefit) in relation to the total costs for investment and maintenance, for each alternative measure. There is a further need for development of a method for stations. There is also a further need for development of a priority model in city networks where power failures less than 12 hours are taken into account. Finally there is a need to turn the functional requirement (no power failures exceeding 24 hours) into an acceptable risk level

International power plant business

Energy Technology Data Exchange (ETDEWEB)

Grohe, R.

1986-03-03

At the Brown Boveri press seminar 'Energy' in Baden-Baden Rainer Grohe, member of the Brown Boveri board, Mannheim, gave a survey of the activities on the international power plant market in recent years. He showed the vacuities which must be taken into account in this sector today. The drastic escalation of demands on power plant suppliers has lead not to a reduction of protagonists but to an increase. (orig.).

Simulation of decreasing reactor power level with BWR simulator

International Nuclear Information System (INIS)

Suwoto; Zuhair; Rivai, Abu Khalid

2002-01-01

Study on characteristic of BWR using Desktop PC Based Simulator Program was analysed. This simulator is more efficient and cheaper for analyzing of characteristic and dynamic respond than full scope simulator for decreasing power level of BW. Dynamic responses of BWR reactor was investigated during the power level reduction from 100% FP (Full Power) which is 3926 MWth to 0% FP with 25% steps and 1 % FP/sec rate. The overall results for core flow rate, reactor steam flow, feed-water flow and turbine-generator power show tendency proportional to reduction of reactor power. This results show that reactor power control in BWR could be done by control of re-circulation flow that alter the density of water used as coolant and moderator. Decreasing the re-circulation flow rate will decrease void density which has negative reactivity and also affect the position of control rods

Residue Derived Fuels as an Alternative Fuel for the Hellenic Power Generation Sector and their Potential for Emissions ReductionConstantinos S. Psomopoulos

Directory of Open Access Journals (Sweden)

Constantinos S. Psomopoulos

2014-09-01

Full Text Available The European Union Landfill Directive (1999/31 EC promotes more environmental friendly waste management options, by reducing the amount of wastes and more specific of biodegradable wastes, disposed of in landfills. The EU member states are adopting the mechanical-biological treatment process for municipal solid waste and non-hazardous industrial wastes to comply with the abovementioned Directive's targets on landfill diversion, and produce waste derived fuels such as refuse derived fuel and solid recovered fuel. Waste derived fuels present high calorific values depending on their synthesis and are being used both in dedicated waste-to-energy plants and as fuel substitutes in industrial processes. In this paper the refuse derived fuel and solid recovered fuel production and utilisation options in European Union are presented, and the possibilities in Greece based on the waste production and National Plan for Waste Management of the Ministry of Environment is attempted. The existing and ongoing studies on co-combustion and co-gasification with brown coal support the use of refuse derived fuel and solid recovered fuel as fuel on Hellenic Power Sector, adopting in the existing lignite power plants adequate Air Pollution Control systems. If the co-combustion or co-gasification of these alternative fuels is adopted from the Hellenic Power Sector a reduction on emissions is expected that cannot be neglected.

Beta and gamma dose calculations for PWR and BWR containments

International Nuclear Information System (INIS)

King, D.B.

1989-07-01

Analyses of gamma and beta dose in selected regions in PWR and BWR containment buildings have been performed for a range of fission product releases from selected severe accidents. The objective of this study was to determine the radiation dose that safety-related equipment could experience during the selected severe accident sequences. The resulting dose calculations demonstrate the extent to which design basis accident qualified equipment could also be qualified for the severe accident environments. Surry was chosen as the representative PWR plant while Peach Bottom was selected to represent BWRs. Battelle Columbus Laboratory performed the source term release analyses. The AB epsilon scenario (an intermediate to large LOCA with failure to recover onsite or offsite electrical power) was selected as the base case Surry accident, and the AE scenario (a large break LOCA with one initiating event and a combination of failures in two emergency cooling systems) was selected as the base case Peach Bottom accident. Radionuclide release was bounded for both scenarios by including spray operation and arrested sequences as variations of the base scenarios. Sandia National Laboratories used the source terms to calculate dose to selected containment regions. Scenarios with sprays operational resulted in a total dose comparable to that (2.20 x 10 8 rads) used in current equipment qualification testing. The base case scenarios resulted in some calculated doses roughly an order of magnitude above the current 2.20 x 10 8 rad equipment qualification test region. 8 refs., 23 figs., 12 tabs

Industrial power takes new directions

International Nuclear Information System (INIS)

Smith, D.J.

1992-01-01

The line between industrial power producers, non-utility power producers, and more specifically cogenerators, is no longer clear. Some industrials still own and operate their own power plants; others have become equity partners in third-party plants. Many industrial complexes have their steam and electrical power requirements supplied by third-party cogeneration plants. This paper reports that one of the major reasons industrial plants choose third-party cogeneration over self-generation is economics. Rather than spend capital on non-revenue projects such as power plants, manufacturers prefer to invest in profit-making ventures. Responding to the recent environmental awareness of many communities, industrial power plants are now collaborating with electric utilities to address environmental concerns. One way this is being accomplished is the dispatching of power plants for localized NO x reduction

A master system for power system fault phenomena

Energy Technology Data Exchange (ETDEWEB)

Yoo, Myung Ho; Jang, Sang Ho; Hong, Joon Hee; Min, Wan Ki; Yoo, Chang Hwan [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center

1995-12-31

This report includes as follows - Real time digital simulator - Remote measuring, analyzing and reproducing system of power system fault data -Power system reduction method program using EMTP -Test system for protection device. (author). 22 refs., 38 figs.

Power Flow Distribution Strategy for Improved Power Electronics Energy Efficiency in Battery Storage Systems: Development and Implementation in a Utility-Scale System

Directory of Open Access Journals (Sweden)

Michael Schimpe

2018-03-01

Full Text Available Utility-scale battery storage systems typically consist of multiple smaller units contributing to the overall power dispatch of the system. Herein, the power distribution among these units is analyzed and optimized to operate the system with increased energy efficiency. To improve the real-life storage operation, a holistic system model for battery storage systems has been developed that enables a calculation of the energy efficiency. A utility-scale Second-Life battery storage system with a capacity of 3.3 MWh/3 MW is operated and evaluated in this work. The system is in operation for the provision of primary control reserve in combination with intraday trading for controlling the battery state of charge. The simulation model is parameterized with the system data. Results show that losses in power electronics dominate. An operational strategy improving the energy efficiency through an optimized power flow distribution within the storage system is developed. The power flow distribution strategy is based on the reduction of the power electronics losses at no-load/partial-load by minimizing their in-operation time. The simulation derived power flow distribution strategy is implemented in the real-life storage system. Field-test measurements and analysis prove the functionality of the power flow distribution strategy and reveal the reduction of the energy throughput of the units by 7%, as well as a significant reduction of energy losses in the units by 24%. The cost savings for electricity over the system’s lifetime are approximated to 4.4% of its investment cost.

Analysis and Countermeasures of Wind Power Accommodation by Aluminum Electrolysis Pot-Lines in China

Science.gov (United States)

Zhang, Hongliang; Ran, Ling; He, Guixiong; Wang, Zhenyu; Li, Jie

2017-10-01

The unit energy consumption and its price have become the main obstacles for the future development of the aluminum electrolysis industry in China. Meanwhile, wind power is widely being abandoned because of its instability. In this study, a novel idea for wind power accommodation is proposed to achieve a win-win situation: the idea is for nearby aluminum electrolysis plants to absorb the wind power. The features of the wind power distribution and aluminum electrolysis industry are first summarized, and the concept of wind power accommodation by the aluminum industry is introduced. Then, based on the characteristics of aluminum reduction cells, the key problems, including the bus-bar status, thermal balance, and magnetohydrodynamics instabilities, are analyzed. In addition, a whole accommodation implementation plan for wind power by aluminum reduction is introduced to explain the theoretical value of accommodation, evaluation of the reduction cells, and the industrial experiment scheme. A numerical simulation of a typical scenario proves that there is large accommodation potential for the aluminum reduction cells. Aluminum electrolysis can accommodate wind power and remain stable under the proper technique and accommodation scheme, which will provide promising benefits for the aluminum plant and the wind energy plant.

Selection of highway routes for the shipment of radioactive materials within the Commonwealth of Virginia

International Nuclear Information System (INIS)

Hobeika, A.G.; Jamei, B.; Santoso, I.B.

1986-01-01

In this study Virginia Electric and Power Company proposed to ship limited quantities of irradiated nuclear fuel from Surry to North Anna in Virginia. Eight routes were considered as candidate routes for shipment. The objectives of this study are: To minimize the accidental-release radiation risk to people and property; and to maximize the community preparedness in terms of emergency response and evacuation capability. To determine the ''Preferred'' route and the alternative route for highway shipments of radioactive material, a conceptual approach was developed, based on the following three principles: Feasibility; Evaluation; and Choice. The feasibility of a candidate route is first established. Then all feasible routes are evaluated under the same criteria, which would lead to the choice of the best feasible route

Reactor coolant pump transportation incident

International Nuclear Information System (INIS)

Noce, D.

1992-01-01

This paper reports on an incident, which occurred on August 27, 1991, in which a Reactor Coolant Pump motor en route from Surry Power Station to Westinghouse repair facilities struck the overpass at the junction of Interstate 64 and Jefferson Avenue in Newport News, Virginia. The transport container that housed the reactor coolant pump motor failed to clear the overpass. The force of the impact dislodged the container and motor from the truck bed, and it landed on the acceleration land and road shoulder. Upon impact, the container broke open and exposed the reactor coolant pump motor. Incidental radioactively contaminated water that remained in the motor coolers drained onto the road, contaminating the aggregate as well as the underlying gravel

Predictors of relationship power among drug-involved women.

Science.gov (United States)

Campbell, Aimee N C; Tross, Susan; Hu, Mei-chen; Pavlicova, Martina; Nunes, Edward V

2012-08-01

Gender-based relationship power is frequently linked to women's capacity to reduce sexual risk behaviors. This study offers an exploration of predictors of relationship power, as measured by the multidimensional and theoretically grounded sexual relationship power scale, among women in outpatient substance abuse treatment. Linear models were used to test nine predictors (age, race/ethnicity, education, time in treatment, economic dependence, substance use, sexual concurrency, partner abuse, and sex role orientation) of relationship power among 513 women participating in a multi-site HIV risk reduction intervention study. Significant predictors of relationship control included having a non-abusive male partner, only one male partner, and endorsing traditional masculine (or both masculine and feminine) sex role attributes. Predictors of decision-making dominance were interrelated, with substance use × partner abuse and age × sex role orientation interactions. Results contribute to the understanding of factors which may influence relationship power and to their potential role in HIV sexual risk reduction interventions.

Isostable reduction with applications to time-dependent partial differential equations.

Science.gov (United States)

Wilson, Dan; Moehlis, Jeff

2016-07-01

Isostables and isostable reduction, analogous to isochrons and phase reduction for oscillatory systems, are useful in the study of nonlinear equations which asymptotically approach a stationary solution. In this work, we present a general method for isostable reduction of partial differential equations, with the potential power to reduce the dimensionality of a nonlinear system from infinity to 1. We illustrate the utility of this reduction by applying it to two different models with biological relevance. In the first example, isostable reduction of the Fokker-Planck equation provides the necessary framework to design a simple control strategy to desynchronize a population of pathologically synchronized oscillatory neurons, as might be relevant to Parkinson's disease. Another example analyzes a nonlinear reaction-diffusion equation with relevance to action potential propagation in a cardiac system.

Green Power Procurement Library | Energy Analysis | NREL

Science.gov (United States)

., and E.S. Brown. 2006. Utility-Marketer Partnerships: An Effective Strategy for Marketing Green Power Reduction Programs. Local Government Climate and Energy Strategy Series. EPA 430-R-09-045. Green Power Developing New Renewable Energy Projects. NREL/TP-6A20-51904. July. Natural Marketing Institute. 2011

Development of the Ukrainian power sector taking into account the environmental impact of power facilities

International Nuclear Information System (INIS)

Dyakova, E.; Krymskaya, L.

1997-01-01

This paper concentrates on the following problems: Evaluation of total environmental impacts from all kinds of power plants on the whole territory of Ukraine; evaluation of environmental impacts in selected regions due to uneven power facilities distribution. Analysis of the environmental situation in Ukraine was conducted using the IMPACTS module of the ENPEP package with account to the Ukrainian energy requirements in perspective. Some recommendations concerning the development of power facilities and reduction of air emissions are also given. (author). 7 figs, 5 tabs

Development of the Ukrainian power sector taking into account the environmental impact of power facilities

Energy Technology Data Exchange (ETDEWEB)

Dyakova, E; Krymskaya, L [Institute for Nuclear Research, National Academy of Science, Kiev (Ukraine)

1997-09-01

This paper concentrates on the following problems: Evaluation of total environmental impacts from all kinds of power plants on the whole territory of Ukraine; evaluation of environmental impacts in selected regions due to uneven power facilities distribution. Analysis of the environmental situation in Ukraine was conducted using the IMPACTS module of the ENPEP package with account to the Ukrainian energy requirements in perspective. Some recommendations concerning the development of power facilities and reduction of air emissions are also given. (author). 7 figs, 5 tabs.

Investigation on wind energy-compressed air power system.

Science.gov (United States)

Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

2004-03-01

Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

Power Consumption Reduction for Wireless Sensor Networks Using A Fuzzy Approach

Directory of Open Access Journals (Sweden)

Giovanni Pau

2016-01-01

Full Text Available The increasing complexity of Wireless Sensor Networks (WSNs is leading towards the deployment of complex networked systems and the optimal design of WSNs can be a very difficult task because several constraints and requirements must be considered, among all the power consumption. This paper proposes a novel fuzzy logic based mechanism that according to the battery level and to the ratio of Throughput to Workload determines the sleeping time of sensor devices in a Wireless Sensor Network for environmental monitoring based on the IEEE 802.15.4 protocol. The main aim here is to find an effective solution that achieves the target while avoiding complex and computationally expensive solutions, which would not be appropriate for the problem at hand and would impair the practical applicability of the approach in real scenarios. The results of several real test-bed scenarios show that the proposed system outperforms other solutions, significantly reducing the whole power consumption while maintaining good performance in terms of the ratio of throughput to workload. An implementation on off-the-shelf devices proves that the proposed controller does not require powerful hardware and can be easily implemented on a low-cost device, thus paving the way for extensive usage in practice.

Solar Powered Remediation and pH Control

Science.gov (United States)

2017-04-13

zone. The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar panels...polarity of the proton reduction system can be periodically alternated (i.e., the anode becomes a cathode) to increase the size of the treatment area, to...PRT System The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar

Engineering development in nuclear power plant construction

International Nuclear Information System (INIS)

Guenther, P.

1979-01-01

Proceeding from the up-to-now experience in the erection of nuclear power stations, especially of the first and second unit of the Greifswald nuclear power plant, the following essential aspects of the development of constructional engineering are discussed: (1) constructional features and criteria, (2) organizational management, (3) current status and problems in prelimary operations, and (4) possibilities of further expenditure reductions in constructing nuclear power stations

Surry Power Station, Units 1 and 2. Annual operating report: January--December 1977, volume I--introduction, summary of operating experience; changes, tests, experiments, and safety-related maintenance; effluent releases; data tabulations