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Sample records for allowed outage times

  1. Risk informed decision making for the allowed outage times changes

    International Nuclear Information System (INIS)

    The paper describes the methods for risk informed evaluation of the allowed outage times. Applications of the methods are also provided for the safety related equipment of the J. Bohunice V2 NPP. (author)

  2. Risk informed decision making for the allowed outage times changes

    International Nuclear Information System (INIS)

    The paper describes the methods for risk informed evaluation of the allowed outage times. Applications of the methods are also provided for the safety related equipment of the J.Bohunice V2 NPP. (author)

  3. Risk-Based Allowed Outage Time and Surveillance Test Interval Extensions for Angra 1

    OpenAIRE

    Orlando Gibelli, Sonia M.; e Melo, P. F. Frutuoso; Bogado Leite, Sérgio Q.

    2012-01-01

    In this work, Probabilistic Safety Assessment (PSA) is used to evaluate Allowed Outage Times (AOT) and Surveillance Test Intervals (STI) extensions for three Angra 1 nuclear power plant safety systems. The interest in such an analysis lies on the fact that PSA comprises a risk-based tool for safety evaluation and has been increasingly applied to support both the regulatory and the operational decision-making processes. Regarding Angra 1, among other applications, PSA is meant to be an additio...

  4. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Lee, Byeong Cheol [Seoul Nationl Univ., Seoul (Korea, Republic of)] (and others)

    1996-07-15

    The objectives of this study is the development of methodology by which assessing the optimizes Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korea nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches is performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method.

  5. Risk-based evaluation of Allowed Outage Times (AOTs) considering risk of shutdown

    International Nuclear Information System (INIS)

    When safety systems fail during power operation, Technical Specifications (TS) usually limit the repair within Allowed Outage Time (AOT). If the repair cannot be completed within the AOT, or no AOT is allowed, the plant is required to be shut down for the repair. However, if the capability to remove decay heat is degraded, shutting down the plant with the need to operate the affected decay-heat removal systems may impose a substantial risk compared to continued power operation over a usual repair time. Thus, defining a proper AOT in such situations can be considered as a risk-comparison between the repair in frill power state with a temporarily increased level of risk, and the altemative of shutting down the plant for the repair in zero power state with a specific associated risk. The methodology of the risk-comparison approach, with a due consideration of the shutdown risk, has been further developed and applied to the AOT considerations of residual heat removal and standby service water systems of a boiling water reactor (BWR) plant. Based on the completed work, several improvements to the TS requirements for the systems studied can be suggested

  6. Study on risk-informed determination method of allowed outage time in fast reactor systems

    International Nuclear Information System (INIS)

    The present report describes a study aiming at proposing a method to determine the allowed outage time (AOT) after detecting a failure in the equipment that stands by during fast reactor power operation by taking into account risk information rationally. In the present study, an improved risk estimation model based on the previous study was constructed so as to consider properly that the repaired component was returned to the standby state again when the repair action completed within the range of AOT. Based on the improved model, core damage probability (CDP) per each detection of the failure is expressed as a function depending on the elapsed time after failure detection. In addition, there are the upper and lower bound values of CDP, and the CDP changes monotonously (i.e., either decreases or increases) between a pair of both the bound values. If a target value of CDP that is not lower than the lower bound can be given, it is possible to determine AOT, where the point-estimation value of CDP becomes lower than or equal to the target value because CDP depends on the elapsed time. Finally, we developed the procedure for determining the AOT from the view point of maintaining the total core damage frequency less than or equal to a prescribed target value. (author)

  7. Risk-informed allowed outage time change for Ulchin units 3 and 4

    International Nuclear Information System (INIS)

    In this report, the risk assessment on the change of allowed outage time (AOT) and the on-line maintenance of major safety systems for Ulchin Units 3 and 4 is performed to identify the possibilities of them. The systems for which the risk assessment is performed are High Pressure Safety Injection System (HPSIS), Low Pressure Safety Injection System (LPSIS), Containment Spray System (CSS), Shutdown Cooling System (SCS), Safety Injection Tank (SIT), Component Cooling Water System (CCWS), Essential Service Water System (ESWS), Essential Chilled Water System (ECWS), and Emergency Diesel Generator (EDG). Major measures for risk assessment are core damage frequency and large early release frequency. Comprehensive evaluation results from PSA aspects are as follows: 1) It is expected that present AOT of 3days for EDG can be extended to 10 days, that of 3days for LPSIS, SCS, CSS to 7 days, and that of 1 hour for SIT to 24 hours. 2) The risk on the AOT change can be optimistically estimated without the consideration for the change of common cause failure probabilities and initiating event frequencies. 3) It is expected that on-line preventive maintenance of LPSIS, CSS, SCS, CCWS, ESWS, ECWS, and EDG can be performed without greatly increasing the risk

  8. A study on assessment methodology of surveillance test interval and allowed outage time

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chang Hyun; You, Young Woo; Cho, Jae Seon; Huh, Chang Wook; Kim, Do Hyoung; Kim, Ju Youl; Kim, Yoon Ik; Yang, Hui Chang; Park, Kang Min [Seoul National Univ., Seoul (Korea, Republic of)

    1998-03-15

    The objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Internal(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plant safety. In this study, the survey about the assessment methodologies, modelings and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. The sensitivity analyses about the failure factors of the components are performed in the bases of the and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code. The qualitative assessment for the STI/AOR of RPS/ESFAS assured safety the most important system in the nuclear power plant are performed.

  9. Risk-Based Allowed Outage Time and Surveillance Test Interval Extensions for Angra 1

    Directory of Open Access Journals (Sweden)

    Sonia M. Orlando Gibelli

    2012-01-01

    Full Text Available In this work, Probabilistic Safety Assessment (PSA is used to evaluate Allowed Outage Times (AOT and Surveillance Test Intervals (STI extensions for three Angra 1 nuclear power plant safety systems. The interest in such an analysis lies on the fact that PSA comprises a risk-based tool for safety evaluation and has been increasingly applied to support both the regulatory and the operational decision-making processes. Regarding Angra 1, among other applications, PSA is meant to be an additional method that can be used by the utility to justify Technical Specification relaxation to the Brazilian regulatory body. The risk measure used in this work is the Core Damage Frequency, obtained from the Angra 1 Level 1 PSA study. AOT and STI extensions are evaluated for the Safety Injection, Service Water and Auxiliary Feedwater Systems using the SAPHIRE code. In order to compensate for the risk increase caused by the extensions, compensatory measures as (1 test of redundant train prior to entering maintenance and (2 staggered test strategy are proposed. Results have shown that the proposed AOT extensions are acceptable for two of the systems with the implementation of compensatory measures whereas STI extensions are acceptable for all three systems.

  10. A study on assessment methodology of surveillance test interval and Allowed Outage Time

    Energy Technology Data Exchange (ETDEWEB)

    Che, Moo Seong; Cheong, Chang Hyeon; Ryu, Yeong Woo; Cho, Jae Seon; Heo, Chang Wook; Kim, Do Hyeong; Kim, Joo Yeol; Kim, Yun Ik; Yang, Hei Chang [Seoul National Univ., Seoul (Korea, Republic of)

    1997-07-15

    Objectives of this study is the development of methodology by which assesses the optimization of Surveillance Test Interval(STI) and Allowed Outage Time(AOT) using PSA method that can supplement the current deterministic methods and the improvement of Korean nuclear power plants safety. In the first year of this study, the survey about the assessment methodologies, modeling and results performed by domestic and international researches are performed as the basic step before developing the assessment methodology of this study. The assessment methodology that supplement the revealed problems in many other studies is presented and the application of new methodology into the example system assures the feasibility of this method. In the second year of this study, the sensitivity analyses about the failure factors of the components are performed in the bases of the assessment methodologies of the first study, the interaction modeling of the STI and AOT is quantified. And the reliability assessment methodology about the diesel generator is reviewed and applied to the PSA code.

  11. The determination of allowed outage time using the evaluation of transition risk

    International Nuclear Information System (INIS)

    he objectives of this study are to propose a new evaluation method for transition risk and to determine the AOT using the new method. We review and compare the evaluation methods of transition risk which was previously studied. We also identify important assumptions used in previous studies for the evaluation of transition risk. We select general items required for the development of evaluation method for the transition risk. Based on the items selected, we propose a new evaluation method for transition risk. The new evaluation method for the transition risk is based on following assumptions; 1)For the same time span, the risk occurred from the failure to the completion of component repair during power operation is the same as the total risk including the risk occurred from power operation to specific shutdown/low power operation and the risk from specific shutdown/low power operation to power operation. 2)Shutdown operation and the repair of components are initiated just after the identification of the failure of components. The evaluation of the transition risk is performed to incorporate the characteristics of shutdown operation into Ulchin Units 3 and 4 Level 1 internal PSA for power operation. The application results of the new method to the HPSIS and the LPSIS for Ulchin Units 3 and 4 show that the AOT of HPSIS is properly determined and the AOT of LPSIS can be greatly increased. In this study, the main factors affecting the determination of AOT using the evaluation for transition risk are identified as the time of shutdown operation, the consideration of the change on common cause failure probability, and the risk of shutdown operation. It is expected that the evaluation method for the transition risk proposed in this study will be used for the determination of AOT and for the decision, in the case of the components unavailable, whether power operation is continuously performed or shutdown operation is initiated

  12. Quantification of risk considering external events on the change of allowed outage time and the preventive maintenance during power operation

    International Nuclear Information System (INIS)

    In this study, for the major safety systems of Ulchin Units 3/4, we quantify the risk on the change of AOT and the PM during power operation to identify the effects on the results of external events PSA when nuclear power plant changes such as allowed outage time are requested. The systems for which the risks on the change of allowed outage time are quantified are High Pressure Safety Injection System (HPSIS), Containment Spray System (CSS), and Emergency Diesel Generator (EDG). The systems for which the risks on the PM during power operation are Low Pressure Safety Injection System (LPSIS), CSS, EDG, Essential Service Water System (ESWS). Following conclusions can be obtained through this study: 1)The increase of core damage frequency (ΔCDF) on the change of AOT and the conditional core damage probability (CCDP) on the on-line PM of each system are differently quantified according to the cases of considering only internal events or only external events. . 2)It is expected that the quantification of risk including internal and external events is advantageous for the licensee of NPP if the regulatory acceptance criteria for the technical specification changes are relatively set up. However, it is expected to be disadvantageous for the licensee if the acceptance criteria are absolutely set up. 3)It is expected that the conduction on the quantification of only a fire event is sufficient when the quantification of external events PSA model is required for the plant changes of Korea Standard NPPs. 4)It is expected that the quantification of the increase of core damage frequency and the incremental conditional core damage probability on technical specification changes are not needed if the quantification results of those considering only internal events are below regulatory acceptance criteria and the external events PSA results are not greatly affected by the system availability. However, it is expected that the quantification of risk considering external events on

  13. Risk-based evaluation of allowed outage time and surveillance test interval extensions for nuclear power plants

    International Nuclear Information System (INIS)

    The main goal of this work is, through the use of Probabilistic Safety Analysis (PSA), to evaluate Technical Specification (TS) Allowed Outage Times (AOT) and Surveillance Test Intervals (STI) extensions for Angra 1 nuclear power plant. PSA has been incorporated as an additional tool, required as part of NPP licensing process. The risk measure used in this work is the Core Damage Frequency (CDF), obtained from the Angra 1 PSA Level 1. AOT and STI extensions are calculated for the Safety Injection System (SIS), Service water System (SAS) and Auxiliary Feedwater System (AFS) through the use of SAPHIRE code. In order to compensate for the risk increase caused by the extensions, compensatory measures as test of redundant train prior to entering maintenance and staggered test strategy are proposed. Results have shown that the proposed AOT extensions are acceptable for the SIS and SAS with the implementation of compensatory measures. The proposed AOT extension is not acceptable for the AFS. The STI extensions are acceptable for all three systems. (author)

  14. Assessment of risks associated with the extension of allowed outage times for UCN 3and4 SIT and LPSI

    International Nuclear Information System (INIS)

    As a part of risk-informed application study, assessment of risks associated with extending the allowed outage times (AOT) for the safety injection tank (SIT) and the low pressure safety injection (LPSI) system of UCN 3and4 was performed. Using the UCN 3and4 PSA model along with deterministic and operational considerations, the AOT extensions from 1 hour to 24 hours for one inoperable SIT, and from 3 days to 7 days for a single LIPS subtrain were evaluated from the view poing of various plant risks. The risks evaluated in this study include at-power risk, mode transition risk, and shutdown risk. In the assessment of the at-power risk, the single AOT risks for both corrective and preventive maintenance were independently evaluated based on the conditional CDFs and AOT durations. The mode transition risk, which could be avoided if extended AOT were used, was evaluated by modifying the PSA model based on realistic plant operation during mode transition. Regarding the shutdown risk, the sensitivity of shutdowm risk to the improved LPSI system reliability by preventive maintenance at power was evaluated. In addition, the impact of the AOT change on the plant Large Early Release Frequency (LERF) was also qualitatively assessed. Results of the risk assessment showed that the at-power risks associated with the extended AOT for SIT and LPSI system were negligible and these risks would be offset by a combination of avoided mode transition risk and implementation of appropriate compensatory measures. Several compensatory measures, which can be taken when the extended AOT is utilized, are suggested. (author)

  15. Reducing outage times: a FROG perspective

    International Nuclear Information System (INIS)

    In 1992, the Framatome Owners Group (FROG) was set up. It provides a forum for the members, who are all users of Framatome nuclear steam supply systems, to share and benefit from each others experience. Joint activities have been focused on safety and economic performance. Through effective control of outage duration, the average capability factor for the 60 plus nuclear units operated by the members rose from 74% in 1992 to 81.5% in 1993, while the average unplanned capability loss factor reduced from 9% to 3.5%. The specific measures now being taken by three FROG members to improve these results still further are described. The members concerned are Electrabel of Belgium, Electrite de France and the Korea Electric Power Co. (UK)

  16. Real time organizational effectiveness improvement during a nuclear plant refueling outage

    International Nuclear Information System (INIS)

    At GPU nclear there has been a growing awareness of the impact of corporate culture on organizational effectiveness. Teamwork, continuous improvement and vision have been areas of focus for the company. At the Oyster Creek nuclear plant, pre-outage teambuilding activities have been part of the program for conducting even more effective scheduled refueling outages. These activities have been on-going for the recent scheduled refueling outages. There had been, however, no specific plan or experience with real-time organizational effectiveness improvement during the course of the refueling outage. Such an activity was conducted during the refueling outage spanning late 1992 and early 1993. This paper reports on that experience. (author)

  17. Investigation of Suitability of Cascading Outage Assessment Methods for Real-Time Assessment

    DEFF Research Database (Denmark)

    Petersen, Pauli Fríðheim; Jóhannsson, Hjörtur; Nielsen, Arne Hejde

    This paper investigates the suitability of assessment methods for cascading outages for real-time assessment. A total of ten assessment methods for cascading outages are investigated, and for all of the investigated methods a complexity assessment is performed to assess the suitability...... of the method to real-time assessment. The investigation revealed that two of the methods are of special interest for further study on real-time assessment of cascading outages. These are the betweenness centrality model, based on network topology, and the manchester model, based on AC power flow....

  18. Minimizing maintenance and outage time with an automated tagging system

    International Nuclear Information System (INIS)

    Public Service Electric and Gas Company has developed a computerized ''Tagging Request and Inquiry System'' (TRIS) to support maintenance tagging operations and valve alignment operations at all of its nuclear and fossil power plants. The system was first placed in service in June 1981 at the Salem Nuclear Power Plant. TRIS tracks the operational status of plant components (valves, breakers, etc.). It is a comprehensive system involving six major function menus, 50 data input screens, 35 screen outputs, and 66 reports. By eliminating much of the weakness inherent in manual tagging and alignment procedures, TRIS reduces maintenance outage durations, improves plant safety, and minimizes the possibility of errors

  19. Power Outages

    Science.gov (United States)

    ... Thunderstorms & Lightning Tornadoes Tsunamis Volcanoes Wildfires Main Content Power Outages This page provides basic safety tips and ... during and after a power outage. Before a Power Outage Build or restock your emergency preparedness kit , ...

  20. Power Outages

    Science.gov (United States)

    ... Plants Workplace Plans School Emergency Plans Main Content Power Outages This page provides basic safety tips and ... during and after a power outage. Before a Power Outage Build or restock your emergency preparedness kit , ...

  1. Outage Analysis of Cooperative Transmission with Energy Harvesting Relay: Time Switching versus Power Splitting

    Directory of Open Access Journals (Sweden)

    Guanyao Du

    2015-01-01

    Full Text Available This paper investigates the multiuser transmission network with an energy harvesting (EH cooperative relay, where a source transmits independent information to multiple destinations with the help of an energy constrained relay. The relay can harvest energy from the radio frequency (RF signals transmitted from the source, and it helps the multiuser transmission only by consuming the harvested energy. By adopting the time switching and the power splitting relay receiver architectures, we firstly propose two protocols, the time switching cooperative multiuser transmission (TSCMT protocol and the power splitting cooperative multiuser transmission (PSCMT protocol, to enable the simultaneous information processing and EH at the relay for the system. To evaluate the system performance, we theoretically analyze the system outage probability for the two proposed protocols and then derive explicit expressions for each of them, respectively. Numerical results are provided to demonstrate the accuracy of our analytical results and reveal that compared with traditional noncooperative scheme our proposed protocols are green solutions to offer reliable communication and lower system outage probability without consuming additional energy. In particular, for the same transmit power at the source, the PSCMT protocol is superior to the TSCMT protocol to obtain lower system outage probability.

  2. Paper on outage philosophy

    International Nuclear Information System (INIS)

    After a brief history of outages in the Scottish nuclear power plants, the author comments the different pressures contributing to a change in the management and the organisation of these outages. He comments the outage organisation (in terms of management, use of station work force, company support, open communications, career development), the outage philosophy (in terms of supportive management, teamwork and total quality management, ownership and commitment to safety, good preparation and robust planning, achievable and agreed targets, process analysis and continual improvement), outage achievements (in terms of time between breakers, work efficiency, safety), the future improvements. He identifies the recipe for success

  3. Improvement of availability of PWR nuclear plants through the reduction of the time required for refueling/maintenance outages

    International Nuclear Information System (INIS)

    The objective of the project, conducted by Commonwealth Research Corporation and Westinghouse Electric Corporation, is to identify improvements in procedures and equipment which will reduce the time required for refueling/maintenance outages at PWR nuclear power plants. The outage of Commonwealth Edison Zion Station Unit 1 in March through May of 1976 was evaluated to identify those items which caused delays and those work activities that offer the potential for significant improvements that could reduce the overall duration of the outage and achieve an improvement in the plant's availability for power production. Modifications in procedures have been developed and were evaluated during one or more outages in 1977. Conceptual designs have been developed for equipment modifications to the refueling system that could reduce the time required for the refueling portion of the outage. The purpose of the interim report is to describe those conceptual designs and to assess their impact upon future outages. Recommendations are included for the implementation of these equipment improvements in a continuation of this program as a demonstration of plant availability benefits that can be realized in PWR nuclear plants already in operation or under construction

  4. GUIDELINES FOR IMPLEMENTATION OF AN ADVANCED OUTAGE CONTROL CENTER TO IMPROVE OUTAGE COORDINATION, PROBLEM RESOLUTION, AND OUTAGE RISK MANAGEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn St; Farris, Ronald; Whaley, April M; Medema, Heather; Gertman, David

    2014-09-01

    This research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE) and performed in close collaboration with industry R&D programs that provide the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. The LWRS program serves to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. Managing NPP outages is a complex and difficult task due to the large number of maintenance and repair activities that are accomplished in a short period of time. During an outage, the outage control center (OCC) is the temporary command center for outage managers and provides several critical functions for the successful execution of the outage schedule. Essentially, the OCC functions to facilitate information inflow, assist outage management in processing information, and to facilitate the dissemination of information to stakeholders. Currently, outage management activities primarily rely on telephone communication, face to face reports of status, and periodic briefings in the OCC. It is a difficult task to maintain current the information related to outage progress and discovered conditions. Several advanced communication and collaboration technologies have shown promise for facilitating the information flow into, across, and out of the OCC. The use of these technologies will allow information to be shared electronically, providing greater amounts of real-time information to the decision makers and allowing OCC coordinators to meet with supporting staff remotely. Passively monitoring status electronically through advances in the areas of mobile worker technologies, computer-based procedures, and automated work packages will reduce the current reliance on manually

  5. Outage preparation milestones - A tool to improve planned outage performance

    International Nuclear Information System (INIS)

    Sustainable development of Nuclear Energy depends heavily on excellent performance of the existing fleet which in turn depend heavily on the performance of planned outages. Nuclear Power Plants who have successfully undertaken outage optimization projects have demonstrated than an effective Outage Preparation Milestone program is a key component of their improvement programs. This paper will provide background into the field of 'Outage Optimization' including the philosophy, general approach, and results obtained in the U. S. industry. The significant safety improvements afforded by properly implementing outage improvement programs will be explained. Some specific examples of outage improvements will be given including the adoption of a strong Outage Preparation Milestone Program. The paper will then describe the attributes of an effective Outage Preparation Milestone Program and list a set of specific key milestones. The key milestones are defined and the reasons for each are explained. Suggested due dates for each key milestone relative to the outage start date are provided. Successful implementation of an Outage Preparation Milestone program depends heavily upon the management tools and methods used to assure that the organization meets the milestones on time and in a quality fashion. These include methods to handle cases where milestones are not met - either partially or fully. KHNP is investigating implementing an improved Outage Preparation Milestone program for its fleet of reactors as part of its overall program to improve its performance of planned outages

  6. Integrated planning the key to reducing outage times in the US

    International Nuclear Information System (INIS)

    Start-up and shutdown activities, the carrying out of major modifications, and valve diagnostics/maintenance are among the major causes of unavailability at US Pressurized Water Reactors. If US plant performance is to be lifted to international levels all these will need more attention. However, it may be improved handling of the logistical intricacies of outages which will do more for plant availability in the future. The lengthy (18 or 24 month) operating cycles used by US utilities may complicate plant maintenance; the majority of plants in the world are on 12-month cycles. (author)

  7. Maintenance and Outage Management Assessment (MOMA)

    International Nuclear Information System (INIS)

    The competitive environment has significant implications for nuclear power plant (NPP) operations, which include, inter alia, the need for efficient use of resources and effective management of plant activities of maintenance and outages. The purpose of NPP maintenance and outages is to allow NPPs to use all those functions necessary for safe and reliable power production by keeping them available and adequate maintenance programme is essential. The maintenance programme covers all preventive and remedial measures, both administrative and technical, necessary to identify and mitigate degradation of a functioning system, structure or component, or restore the design functions of a failed system, structure or component to an acceptable level. In response to the needs of MSs, NPES (Nuclear Power Section, Division of Nuclear Power, IAEA) plans to strengthen its services. NPES services will not only continue to provide its 'traditional' products of publications of nuclear industrial best practices and technical implementation of TC projects on plant maintenance and outage management, but also be expanded to deliver, in a timely manner, technical support missions as requested by MSs for NPPs. One of many services is Maintenance and Outage Management Assessment (MOMA). The NPP can obtain support and assistance in assessment and optimisation of its maintenance program and/or outage management. It aims to help the NPP improve its performance of maintenance and outage in a competitive nuclear power business environment. The specific benefits of the assessment are as follows: a) disseminate nuclear industrial best practices on maintenance program and outage management in the world, b) benchmark, evaluate and optimise the approach of maintenance program and outage management and c) identify solutions to known problems at nuclear power plants, if any. MOMA is conducted at the request of NPPs of any IAEA Member States. MOMA consists in a technical mission/visit for 1-3 weeks by

  8. Technology Integration Initiative In Support of Outage Management

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby; David Gertman

    2012-07-01

    Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Often, command and control during outages is maintained in the outage control center where many of the underlying technologies supporting outage control are the same as those used in the 1980’s. This research reports on the use of advanced integrating software technologies and hand held mobile devices as a means by which to reduce cycle time, improve accuracy, and enhance transparency among outage team members. This paper reports on the first phase of research supported by the DOE Light Water Reactor Sustainability (LWRS) Program that is performed in close collaboration with industry to examine the introduction of newly available technology allowing for safe and efficient outage performance. It is thought that this research will result in: improved resource management among various plant stakeholder groups, reduced paper work, and enhanced overall situation awareness for the outage control center management team. A description of field data collection methods, including personnel interview data, success factors, end-user evaluation and integration of hand held devices in achieving an integrated design are also evaluated. Finally, the necessity of obtaining operations cooperation support in field studies and technology evaluation is acknowledged.

  9. Finnish outage management practices to reduce occupational doses and shorten outage duration

    International Nuclear Information System (INIS)

    Two Finnish nuclear power stations, TVO and Loviisa, have been among the world leaders in nuclear power plants. The plants consistently accomplish refueling outages in less than 25 days and outage occupational doses below 50 person-rem per unit. As U.S. utilities enter a deregulated market, cost reduction has become a paramount interest along with safe nuclear plant operations. U.S. attention has focused on European plant experience to better understand the relationship between shorter refueling outages and reduction in occupational dose. This paper summarizes the observations made during a NARTC site visit in October, 1995, to TVO and Loviisa to study health physics management practices to achieve this world class performance. Planning and selection of work is critical to the success of a shorter outage. Planning needs to occur by outage time, in-plant zone and be resource loaded/coordinated. The TVO plant works to a 10-y planning matrix. Only required work is approved at Loviisa; nice to do work is not allowed. Training of Finnish workers occurs in a carefully laid out plan from apprenticeship to journeyman levels. Finnish attitudes about radiation protection and work performance is discussed as also being a key to Finnish successes

  10. Reengineering to reduce outage costs: Spring hanger pinning during outages

    International Nuclear Information System (INIS)

    One of the key steps in the reengineering process requires us to ask the question, open-quotes Is this step in our work process necessary?close quotes This paper describes one such redesign of a maintenance procedure, resulting in significant gains in cost reduction and schedule compression for plant outages. Before draining a water-filled piping system, maintenance procedures at many power plants require pinning of all spring hangers supporting the system. This requirement ensures that piping system components are not overloaded by the spring force that is no longer counteracted by the weight of water in the pipeline. Unfortunately, pinning spring hangers can be a time-consuming and costly endeavor. Because spring hangers quite often are located in congested areas that are inaccessible from floor level, scaffolding must be erected to allow physical access by maintenance personnel. At Clinton power station, the subject power plant for this paper, this activity was costing approximately $250 000 per refueling outage and a personnel radiation exposure of -5 person-rems. In the past, the only alternative to this costly requirement was to perform case-by-case analysis to evaluate the effects of the spring uplift forces on the drained piping and associated components. However, these analyses are costly (approximately $8000 per piping subsystem) and time consuming. Given these rather significant costs, it is highly advantageous to limit or eliminate the spring hanger pinning requirement. This paper presents an overview of an evaluation performed for Clinton power station to address this issue

  11. Mast sipping and MULTIINSPECTION shorten refueling outages

    International Nuclear Information System (INIS)

    Innovative inspection systems from Siemens can significantly contribute towards shortening the time needed for refuelling outages. Mast sipping is a technique which provides fast information on the condition of fuel assemblies scheduled for further use in the reactor core. The system MULTIINSPECTION allows standard inspections of fuel assemblies and other core components to be performed without having to use the refuelling machine all of the time. In addition to these benefits, the new procedures considerably reduce the radiation exposure of operating personnel. These new procedures and the associated equipment can be adapted to power plant operations and equipment to more effectively perform required service activities. (UK)

  12. Multicast Capacity Scaling of Wireless Networks with Multicast Outage

    CERN Document Server

    Liu, Chun-Hung

    2010-01-01

    Multicast transmission has several distinctive traits as opposed to more commonly studied unicast networks. Specially, these include (i) identical packets must be delivered successfully to several nodes, (ii) outage could simultaneously happen at different receivers, and (iii) the multicast rate is dominated by the receiver with the weakest link in order to minimize outage and retransmission. To capture these key traits, we utilize a Poisson cluster process consisting of a distinct Poisson point process (PPP) for the transmitters and receivers, and then define the multicast transmission capacity (MTC) as the maximum achievable multicast rate times the number of multicast clusters per unit volume, accounting for outages and retransmissions. Our main result shows that if $\\tau$ transmission attempts are allowed in a multicast cluster, the MTC is $\\Theta\\left(\\rho k^{x}\\log(k)\\right)$ where $\\rho$ and $x$ are functions of $\\tau$ depending on the network size and density, and $k$ is the average number of the inte...

  13. Nuclear power plant outages

    International Nuclear Information System (INIS)

    The Finnish Radiation and Nuclear Safety Authority (STUK) controls nuclear power plant safety in Finland. In addition to controlling the design, construction and operation of nuclear power plants, STUK also controls refuelling and repair outages at the plants. According to section 9 of the Nuclear Energy Act (990/87), it shall be the licence-holder's obligation to ensure the safety of the use of nuclear energy. Requirements applicable to the licence-holder as regards the assurance of outage safety are presented in this guide. STUK's regulatory control activities pertaining to outages are also described

  14. Progress Report on Alloy 617 Time Dependent Allowables

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Julie Knibloe [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    Time dependent allowable stresses are required in the ASME Boiler and Pressure Vessel Code for design of components in the temperature range where time dependent deformation (i.e., creep) is expected to become significant. There are time dependent allowable stresses in Section IID of the Code for use in the non-nuclear construction codes, however, there are additional criteria that must be considered in developing time dependent allowables for nuclear components. These criteria are specified in Section III NH. St is defined as the lesser of three quantities: 100% of the average stress required to obtain a total (elastic, plastic, primary and secondary creep) strain of 1%; 67% of the minimum stress to cause rupture; and 80% of the minimum stress to cause the initiation of tertiary creep. The values are reported for a range of temperatures and for time increments up to 100,000 hours. These values are determined from uniaxial creep tests, which involve the elevated temperature application of a constant load which is relatively small, resulting in deformation over a long time period prior to rupture. The stress which is the minimum resulting from these criteria is the time dependent allowable stress St. In this report data from a large number of creep and creep-rupture tests on Alloy 617 are analyzed using the ASME Section III NH criteria. Data which are used in the analysis are from the ongoing DOE sponsored high temperature materials program, form Korea Atomic Energy Institute through the Generation IV VHTR Materials Program and historical data from previous HTR research and vendor data generated in developing the alloy. It is found that the tertiary creep criterion determines St at highest temperatures, while the stress to cause 1% total strain controls at low temperatures. The ASME Section III Working Group on Allowable Stress Criteria has recommended that the uncertainties associated with determining the onset of tertiary creep and the lack of significant

  15. Outage Analysis of Spectrum-Sharing over M-Block Fading with Sensing Information

    KAUST Repository

    Alabbasi, Abdulrahman

    2016-07-13

    Future wireless technologies, such as, 5G, are expected to support real-time applications with high data throughput, e.g., holographic meetings. From a bandwidth perspective, cognitive radio is a promising technology to enhance the system’s throughput via sharing the licensed spectrum. From a delay perspective, it is well known that increasing the number of decoding blocks will improve the system robustness against errors, while increasing the delay. Therefore, optimally allocating the resources to determine the tradeoff of tuning the length of decoding blocks while sharing the spectrum is a critical challenge for future wireless systems. In this work, we minimize the targeted outage probability over the block-fading channels while utilizing the spectrum-sharing concept. The secondary user’s outage region and the corresponding optimal power are derived, over twoblocks and M-blocks fading channels. We propose two suboptimal power strategies and derive the associated asymptotic lower and upper bounds on the outage probability with tractable expressions. These bounds allow us to derive the exact diversity order of the secondary user’s outage probability. To further enhance the system’s performance, we also investigate the impact of including the sensing information on the outage problem. The outage problem is then solved via proposing an alternating optimization algorithm, which utilizes the verified strict quasiconvex structure of the problem. Selected numerical results are presented to characterize the system’s behavior and show the improvements of several sharing concepts.

  16. Integrated use of Primavera and ORAM codes in outage 1999 at NPP Krsko

    International Nuclear Information System (INIS)

    The paper deals with the following postulated main goals of outage scheduling with Primavera tool at Krsko NPP: planning and controlling of resources (people, equipment, locations, sources), controlling the safety aspects of an outage and assuring defense-in-depth philosophy (through integrated safety assessment by ORAM code), diversity use of the plan during preparations period and outage progress (MCB, work leaders, management, planning Dept., subcontractors, support, etc.), allowing for optimization of outage duration. A snapshot in Primavera of what actually happened in outage 1999, lessons learned and a new work template is the scope of the next year outage.(author)

  17. Refuelling outage optimization

    International Nuclear Information System (INIS)

    The Teollisuuden Voima Oy (TVO) operates two 710 MW nuclear power plant units in Olkiluoto on the west coast of Finland. TVO I was connected to the national grid in 1978 and TVO II in 1980. The price of the produced electricity is depending on the capacity factor of the plant. In order to avoid unplanned shutdowns and to operate at a high efficiency a good condition monitoring and an effective maintenance are needed. In this paper the development of the main maintenance period of the plant and the refuelling outage are described. (author). 11 figs

  18. Strategies for organizing outages

    International Nuclear Information System (INIS)

    Based on four sociological studies carried out in France and in the United States between 1991 and 1994, this paper aims at presenting different organizational strategies for scheduled outages in nuclear power plants. Some short examples suggest that organizational settings are not equivalent in terms of actors' practices: some organizational designs tend to minimize actors autonomy while others are favouring it. Distinctions can also be made between formal and informal autonomy or between clear delegations of decision making power and implicit ones. The author argues that these differences have major implications for actors' participation inside the organization

  19. Management of planned unit outages

    International Nuclear Information System (INIS)

    Management of planned unit outages at the Bruno Leuschner Nuclear Power Plant is based on the experience gained with Soviet PWR units of the WWER type over a period of more than 50 reactor-years. For PWR units, planned outages concentrate almost exclusively on annual refuellings and major maintenance of the power plant facilities involved. Planning of such major maintenance work is based on a standardized basic network plan and a catalogue of standardized maintenance and inspection measures. From these, an overall maintenance schedule of the unit and partial process plans of the individual main components are derived (manually or by computer) and, in the temporal integration of major maintenance at every unit, fixed starting times and durations are determined. More than 75% of the maintenance work at the Bruno Leuschner Nuclear Power Plant is carried out by the plant's own maintenance personnel. Large-scale maintenance of every unit is controlled by a special project head. He is assisted by commissioners, each of whom is responsible for his own respective item. A daily control report is made. The organizational centre is a central office which works in shifts around the clock. All maintenance orders and reports of completion pass through this office; thus, the overall maintenance schedule can be corrected daily. To enforce the proposed operational strategy, suitable accompanying technical measures are required with respect to effective facility monitoring and technical diagnosis, purposeful improvement of particularly sensitive components and an increase in the effectiveness of maintenance work by special technologies and devices. (author)

  20. Areva: experiences in outage services

    International Nuclear Information System (INIS)

    As the world leader in the nuclear industry, Areva is firmly committed to the safe and reliable operation of the Spanish nuclear power plants. Following this commitment, Areva has established the subsidiary Areva NP Services Spain as a local platform to provide nuclear services for the Spanish nuclear power plants. being integrated and supported by the global Areva Group, Areva NP Services Spain is able to offer services solutions to all customers demands while maintaining close and sustainable relationships with them. This integration also allows the Spanish personnel of Areva to employ their skills by working in multinational teams in international projects. This article will present the capacities, and the most important recent national and international project performed by Areva NP Services Spain in the field of outage services. (Author)

  1. Does it matter when a power outage occurs? - A choice experiment study on the willingness to pay to avoid power outages

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, Fredrik; Martinsson, Peter [Department of Economics, Goeteborg University, Box 640, 405, 30 Goeteborg (Sweden)

    2008-05-15

    Using a choice experiment survey, the marginal willingness to pay (WTP) among Swedish households for reductions in power outages is estimated. The results from the random parameter logit estimation indicate that the marginal WTP increases with the duration of the outages, and is higher if the outages occur during weekends and during winter months. Moreover, the random parameter logit model allows us to estimate a sample distribution of WTP and we find a significant unobserved heterogeneity in some of the outage attributes. Given that households have negative welfare effects from outages, it is important that policy makers consider these negative impacts on household utility when regulating the Swedish electricity market. (author)

  2. Does it matter when a power outage occurs? - A choice experiment study on the willingness to pay to avoid power outages

    International Nuclear Information System (INIS)

    Using a choice experiment survey, the marginal willingness to pay (WTP) among Swedish households for reductions in power outages is estimated. The results from the random parameter logit estimation indicate that the marginal WTP increases with the duration of the outages, and is higher if the outages occur during weekends and during winter months. Moreover, the random parameter logit model allows us to estimate a sample distribution of WTP and we find a significant unobserved heterogeneity in some of the outage attributes. Given that households have negative welfare effects from outages, it is important that policy makers consider these negative impacts on household utility when regulating the Swedish electricity market. (author)

  3. Detecting Power Outages with the VIIRS DNB Images - potentials and challenges

    Science.gov (United States)

    Cao, C.; Uprety, S.; Shao, X.

    2012-12-01

    Power outages after a major storm or hurricane affect millions of people. The launch of the Suomi NPP with the VIIRS significantly enhances our capability to monitor and detect power outages on a daily basis with the Day Night Band (DNB) which outperforms the traditional OSL on DMSP satellites in both spatial and radiometric resolutions. This study explores the use of the DNB for detecting power outages in the Washington DC metropolitan area in June 2012, which was the largest non-hurricane power outage in history for the region with millions of people lost power, and state of emergency declared in some states such as Virginia. The DNB data were analyzed for the period one week before and after the storm. The light loss is estimated through image differencing techniques for spatial patterns, as well as total radiance and irradiance changes as a time series. The effects of cloud absorption and scattering are evaluated using the cloud masks from VIIRS products, and the long wave thermal infrared images are also used to assist the assessment. The results show that the DNB data are very useful for both spatial and radiometric detection of light loss, but also with some challenges due to clouds and the known terminator straylight effect of the instrument for the region during summer solstice. It is expected that further refinements in the methodology will significantly reduce the uncertainties. A VIIRS Data Robotics system is also being developed which will allow the routine detection of power outages for any given location worldwide.

  4. Development of Improved Graphical Displays for an Advanced Outage Control Center, Employing Human Factors Principles for Outage Schedule Management

    Energy Technology Data Exchange (ETDEWEB)

    St Germain, Shawn Walter [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thomas, Kenneth David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The long-term viability of existing nuclear power plants in the United States (U.S.) is dependent upon a number of factors, including maintaining high capacity factors, maintaining nuclear safety, and reducing operating costs, particularly those associated with refueling outages. Refueling outages typically take 20-30 days, and for existing light water NPPs in the U.S., the reactor cannot be in operation during the outage. Furthermore, given that many NPPs generate between $1-1.5 million/day in revenue when in operation, there is considerable interest in shortening the length of refueling outages. Yet refueling outages are highly complex operations, involving multiple concurrent and dependent activities that are somewhat challenging to coordinate; therefore, finding ways to improve refueling outage performance, while maintaining nuclear safety has proven to be difficult. The Advanced Outage Control Center (AOCC) project is a research and development (R&D) demonstration activity under the LWRS Program. LWRS is an R&D program that works closely with industry R&D programs to establish technical foundations for the licensing and managing of long-term, safe, and economical operation of current fleet of NPPs. As such, the LWRS Advanced Outage Control Center project has the goal of improving the management of commercial NPP refueling outages. To accomplish this goal, INL is developing an advanced outage control center (OCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. The overall focus is on developing an AOCC with the following capabilities that enables plant and OCC staff to; Collaborate in real-time to address emergent issues; Effectively communicate outage status to all workers involved in the outage; Effectively communicate discovered conditions in the field to the OCC; Provide real-time work status; Provide automatic pending support notifications

  5. Development of Improved Graphical Displays for an Advanced Outage Control Center, Employing Human Factors Principles for Outage Schedule Management

    International Nuclear Information System (INIS)

    The long-term viability of existing nuclear power plants in the United States (U.S.) is dependent upon a number of factors, including maintaining high capacity factors, maintaining nuclear safety, and reducing operating costs, particularly those associated with refueling outages. Refueling outages typically take 20-30 days, and for existing light water NPPs in the U.S., the reactor cannot be in operation during the outage. Furthermore, given that many NPPs generate between $1-1.5 million/day in revenue when in operation, there is considerable interest in shortening the length of refueling outages. Yet refueling outages are highly complex operations, involving multiple concurrent and dependent activities that are somewhat challenging to coordinate; therefore, finding ways to improve refueling outage performance, while maintaining nuclear safety has proven to be difficult. The Advanced Outage Control Center (AOCC) project is a research and development (R&D) demonstration activity under the LWRS Program. LWRS is an R&D program that works closely with industry R&D programs to establish technical foundations for the licensing and managing of long-term, safe, and economical operation of current fleet of NPPs. As such, the LWRS Advanced Outage Control Center project has the goal of improving the management of commercial NPP refueling outages. To accomplish this goal, INL is developing an advanced outage control center (OCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. The overall focus is on developing an AOCC with the following capabilities that enables plant and OCC staff to; Collaborate in real-time to address emergent issues; Effectively communicate outage status to all workers involved in the outage; Effectively communicate discovered conditions in the field to the OCC; Provide real-time work status; Provide automatic pending support notifications

  6. How individual traces and interactive timelines could support outage execution - Toward an outage historian concept

    International Nuclear Information System (INIS)

    In the context of a project that is designing innovative ICT-based solutions for the organizational concept of outage management, we focus on the informational process of the OCR (Outage Control Room) underlying the execution of the outages. Informational process are based on structured and unstructured documents that have a key role in the collaborative processes and management of the outage. We especially track the structured and unstructured documents, electronically or not, from creation to sharing. Our analysis allows us to consider that the individual traces produced by an individual participant with a specific role could be multi-purpose and support sharing between participants without creating duplication of work. The ultimate goal is to be able to generate an outage historian, that is not just focused on highly structured information, which could be useful to improve the continuity of information between participants. We study the implementation of this approach through web technologies and social media tools to address this issue. We also investigate the issue of data access through interactive visualization timelines coupled with other modality's to assist users in the navigation and exploration of the proposed historian. (authors)

  7. Nuclear Plant Integrated Outage Management

    International Nuclear Information System (INIS)

    This paper is a discussion of an emerging concept for improving nuclear plant outage performance - integrated outage management. The paper begins with an explanation of what the concept encompasses, including a scope definition of the service and descriptions of the organization structure, various team functions, and vendor/customer relationships. The evolvement of traditional base scope services to the integrated outage concept is addressed and includes discussions on changing customer needs, shared risks, and a partnership approach to outages. Experiences with concept implementation from a single service in 1984 to the current volume of integrated outage management presented in this paper. We at Westinghouse believe that the operators of nuclear power plants will continue to be aggressively challenged in the next decade to improve the operating and financial performance of their units. More and more customers in the U. S. are looking towards integrated outage as the way to meet these challenges of the 1990s, an arrangement that is best implemented through a long-term partnering with a single-source supplier of high quality nuclear and turbine generator outage services. This availability, and other important parameters

  8. Pricing power outages in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

    Baarsma, Barbara E.; Hop, J. Peter [SEO Economic Research/University of Amsterdam, Amsterdam (Netherlands)

    2009-09-15

    In most Western countries, the power grid provides electricity more than 99% of the time. To maintain reliability at such high levels, energy companies have to continually invest in electric transmission- and distribution systems. Since customers of electricity cannot switch from one distribution network to another, no economic incentive exists that matches the supplied reliability to customer preferences. Either under- or over-investment in reliability may thus result. In order to introduce market-like incentives, the Dutch Energy Regulator introduced a regulatory system based on the (perceived) costs of power outages. An essential ingredient of the regulation is the cost of a power outage of a particular duration (i.e., 1 minute). This paper measures these outage cost by using conjoint analysis. We find that the social cost of the present Dutch level of reliability - that is, one outage of two hours every four years - is EUR2.80 on average for every household, and EUR33.10 on average for every SME firm. The total costs to Dutch society are almost EUR50 million. (author)

  9. Outage rates and outage durations of opportunistic relaying systems

    CERN Document Server

    Hadzi-Velkov, Zoran; 10.1109/LCOMM.2010.02.091683

    2010-01-01

    Opportunistic relaying is a simple yet efficient cooperation scheme that achieves full diversity and preserves the spectral efficiency among the spatially distributed stations. However, the stations' mobility causes temporal correlation of the system's capacity outage events, which gives rise to its important second-order outage statistical parameters, such as the average outage rate (AOR) and the average outage duration (AOD). This letter presents exact analytical expressions for the AOR and the AOD of an opportunistic relaying system, which employs a mobile source and a mobile destination (without a direct path), and an arbitrary number of (fixed-gain amplify-and-forward or decode-and-forward) mobile relays in Rayleigh fading environment.

  10. 35/30 outage improvement project

    International Nuclear Information System (INIS)

    Outage performance is a significant contributor to the business plan at Bruce Power. A process improvement initiative commenced in 2010-11 to improve outage efficiency and predictability. 12 teams (over 200 people) participated in improvement identification in four areas: Organizational Engagement; Outage Scope; Resources; and, Critical Outage Execution. Out of over 550 initiatives identified, 200 are being incorporated into the Outage Improvement Initiative. Key deliverables include: Development of a long-range 'fleet-level' business strategy to integrate outage duration, outage improvements and unit refurbishments; Development of a 35 day outage schedule template; Determining optimal outage organization to perform outages on an 8-unit site; Improved schedule adherence and productivity; Process to integrate scope needs to support life-cycle and long-range outage needs improvement while meeting near term and regulatory requirements; Consistent methodology in planning of outages to front-end load the high risk work into the outage schedule; Consistent baseline by senior leaders for the expectations of milestone ownership and completion; Consistent framework for milestone compliance and preparation; Communication strategy to educate personnel on the importance of the outage program and nuclear safety, business goals, and budget; and, Suite of metrics based upon industry benchmarks. The Outage Improvement Initiative has a goal of 35 day outages every 30 months. This potentially represents considerable savings to the Bruce Power business plan, both direct revenue savings attributed to reduced outage duration, as well as incremental outage cost savings. Other improvements from the initiative will include personnel radiation exposure and equipment reliability due to decreased outage duration and adherence to scoping, assessing and long lead part milestones. This presentation will describe the outage improvement initiatives to achieve a goal of consistent 35 day outages

  11. 40 CFR 60.4141 - Timing requirements for Hg allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Timing requirements for Hg allowance... Times for Coal-Fired Electric Steam Generating Units Hg Allowance Allocations § 60.4141 Timing requirements for Hg allowance allocations. (a) By November 17, 2006, the permitting authority will submit...

  12. Mast sipping technique optimises refueling outages

    International Nuclear Information System (INIS)

    Innovative inspection systems from FRAMATOME ANP can significantly contribute towards shortening the time needed for refueling outages. Mast sipping is a technique which provides fast information on the condition of fuel assemblies scheduled for further use in the reactor core. FRAMATOME ANP is going to deliver a mast sipping system for Kozloduy 440 VVER units, to identify leaking fuel assemblies. Whereas in some other VVER 440 plants the sipping test has normally been performed to date with a sipping hood placed on the top of the fuel assemblies in the core before unloading them to the spent fuel storage pool, today the sipping test can be performed as the fuel assemblies are being removed from the reactor. This new method can save time and permits the condition of a fuel assembly to be identified at the earliest possible point in time. The mast sipping procedure makes use of the reduction in pressure which occurs when fuel assemblies are lifted out of the reactor pressure vessel, the resulting pressure difference al-lowing water-soluble or gaseous fission products to be released from defective fuel rods. During the movement of the fuel assembly by the refueling machine, water is extracted from the refueling machine mast in the vicinity of the fuel assembly and analyzed for the presence of fission products. Gaseous fission products (xenon and krypton) are separated from the water, dried and routed to a scintillation detector. The measured data are analysed immediately after sampling. A water sample is taken in parallel which can be analysed in the radio-chemical laboratory to provide a reference measurement. The data obtained from the sample measurements are immediately evaluated. The results are displayed on screen and the data stored in a text file. The mast sipping system has been qualified in several German PWR plants during refueling with excellent results. In the mean time Mast Sipping is considered as a standard procedure in nuclear power plants of Germany

  13. Outage management: A case study

    International Nuclear Information System (INIS)

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission's (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study

  14. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Haber, S.B.; Barriere, M.T. (Brookhaven National Lab., Upton, NY (United States)); Roberts, K.H. (California Univ., Berkeley, CA (United States). Walter A. Haas School of Business)

    1992-01-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission's (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  15. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Haber, S.B.; Barriere, M.T. [Brookhaven National Lab., Upton, NY (United States); Roberts, K.H. [California Univ., Berkeley, CA (United States). Walter A. Haas School of Business

    1992-09-01

    Outage management issues identified from a field study conducted at a two-unit commercial pressurized water reactor (PWR), when one unit was in a refueling outage and the other unit was at full power operation, are the focus of this paper. The study was conduced as part of the US Nuclear Regulatory Commission`s (NRC) organizational factors research program, and therefore the issues to be addressed are from an organizational perspective. Topics discussed refer to areas identified by the NRC as critical for safety during shutdown operations, including outage planning and control, personnel stress, and improvements in training and procedures. Specifically, issues in communication, management attention, involvement and oversight, administrative processes, organizational culture, and human resources relevant to each of the areas are highlighted by example from field data collection. Insights regarding future guidance in these areas are presented based upon additional data collection subsequent to the original study.

  16. Improving refueling outages through partnership

    International Nuclear Information System (INIS)

    This paper describes an approach to reduce nuclear plant outage duration and cost through partnership. Partnership is defined as a long-term commitment between the utility and the vendor with the objective of achieving shared business goals by maximizing the effectiveness of each party's resources. The elements of an effective partnership are described. Specific examples are given as to how partnership has worked in the effective performance of refueling outages. To gain the full benefits of a partnership, both parties must agree to share information, define the scope early, communicate goals and expectations, and identify boundaries for technical ownership. (author)

  17. The process of NPP refuelling outage analysis and follow-up

    International Nuclear Information System (INIS)

    Following the outages in 2004 and 2006, the Slovenian Nuclear Safety Administration (SNSA) has started with the practice of independent outage analysis in a form of an internal report. It includes a comparison of performed activities against the planned time schedule of activities, evaluation of design modifications implementation and analysis of significant events. The main result of the outage analysis is a list of recommendations and some open issues that have been identified. These findings are the basis for development of an action plan for SNSA activities until the next outage, aimed at eliminating deficiencies found out during the outage and further improving outage activities. The established system of outage supervision together with the final analysis and long term action plan represents an effective continuous safety supervision process, by which the regulatory body independently contributes to the higher level of safety culture both at the licensee and among its own staff. (author)

  18. Follow up of the PWRs maintenance outages in France

    International Nuclear Information System (INIS)

    This paper describes the general frame of the follow-up of the PWRs maintenance outages by the DRIREs (Regional Directorates for Industry, Research and the Environment) in France, with respect to the enforcement of several regulations (including the quality assurance order of 1984), but also to the compliance with the general operating rules for EDF plants. Maintenance as well as reactor operation activities during outages are considered by the DRIREs, and more particularly the pressure vessel regulation, the equipment important for safety, the outage preparation, the real time follow-up, the completion of outage. A few examples of recent events or incidents, involving human factors and organisation aspects, are given. They stress the importance of safety culture, training as well as experience feedback for the different actors

  19. Multicast Outage Probability and Transmission Capacity of Multihop Wireless Networks

    CERN Document Server

    Liu, Chun-Hung

    2010-01-01

    Multicast transmission, wherein the same packet must be delivered to multiple receivers, is an important aspect of sensor and tactical networks and has several distinctive traits as opposed to more commonly studied unicast networks. Specially, these include (i) identical packets must be delivered successfully to several nodes, (ii) outage at any receiver requires the packet to be retransmitted at least to that receiver, and (iii) the multicast rate is dominated by the receiver with the weakest link in order to minimize outage and retransmission. We utilize a Poisson cluster process consisting of a distinct Poisson point process (PPP) for the transmitters and receivers, and then define the multicast transmission capacity (MTC) as the maximum achievable multicast rate times the number of multicast clusters per unit volume (area for $d=2$), accounting for outages and retransmissions. A multicast cluster is a contiguous volume (area) over which a packet is multicasted, and to reduce outage it can be tessellated i...

  20. Evolution of an outage management organization in a small utility

    International Nuclear Information System (INIS)

    Six refueling outages with a number of major equipment failure outages have taught Rancho Seco management three main items. One is that a dedicated management organization must be formed for the purpose of controlling work functions at Rancho Seco. This dedicated organization must have the experience of the plant and not have the responsibility for the actual maintenance. Second, upper management within a power plant must get directly involved in the outage. Upper management must show their presence, give input, and be available when needed. The third item learned is that the scheduling organization must be adequately staffed. Although Rancho Seco completed a refueling outage in 1978 within only 36 days, additional inspection requirements due to regulatory changes and/or previous equipment failures requiring follow-up actions would place the shortest possible outage today at approx.70 days. The only way an organization can keep this outage time down is with the proper scheduling of the resources and the timely coordination of activities to reduce conflicts

  1. Exceptional outage for Fessenheim-1

    International Nuclear Information System (INIS)

    The article describes the 10-yearly outage maintenance and improvements program during the 191-day shut-down of Fessenheim on the Grand Canal d'Alsace. The program concerns hydraulic and containment testing as well as specialized maintenance operations on heavy-duty components

  2. Development and demonstration of techniques for reducing occupational radiation doses during refueling outages. Tasks 7A/7B. Advanced outage management and radiation exposure control

    International Nuclear Information System (INIS)

    Objectives of Tasks 7A and 7B were to develop and demonstrate computer based systems to assist plant management and staff in utilizing information more effectively to reduce occupational exposures received as a result of refueling outages, and to shorten the duration of the outage. The Advanced Outage Management (AOM) Tool (Task 7A) is an automated outage planning system specifically designed to meet the needs of nuclear plant outage management. The primary objective of the AOM tool is to provide a computerized system that can manipulate the information typically associated with outage planning and scheduling to furnish reports and schedules that more accurately project the future course of the outage. The Radiation Exposure Control (REC) Tool (Task 7B) is a computerized personnel radiation exposure accounting and management system designed to enable nuclear plant management to project and monitor total personnel radiation exposure on a real-time basis. The two systems were designed to operate on the same computer system and interface through a common database that enables information sharing between plant organizations not typically interfaced. This interfacing provides outage planners with a means of incorporating occupational radiation exposure as a factor for making decisions on the course of an outage

  3. Analysis of the Dependence of Power Outages on Lightning Events within the Ijebu Province, Nigeria

    Directory of Open Access Journals (Sweden)

    J.O. Adepitan

    2012-09-01

    Full Text Available The study aimed at developing a model for lightning-induced outages in Nigeria from results obtained on determining the proportion and rate of lightning-induced outages out of the total power outages experienced in Ijebu province of Nigeria. Power outage records for Ijebu province, comprising Ijebu-Ode and Sagamu areas, Ogun state, Nigeria for the years 2002-2006 were collected from Power Holding Company of Nigeria (PHCN. Unintentional stochastic outages were separated from those due to deliberate load shedding. Lightning events records were collected from Nigeria Meteorological Agency for the same period. The two sets of time series were superimposed. Outages with time, t6 min were classified as ‘Others’ (OT. The two sets of data were analyzed in order to determine percentage of lightning-induced outagfes. Also, thunderstorm days and power line parameters were used as input data for modified FLASH 1.7 software (considering tropical region to estimate the rate of lightning induced outages. The five-year period, 2002 to 2006, experienced no significant difference (p<0.05 in the mean of percentage of LI outages for both areas, calculated as 8.6 for Ijebu-Ode and 9.5 for Sagamu. The corresponding values for PLI being 1 and 2%; whereas OT had values 90.4 and 88.5%. Where earth wires were available on the transmission lines, the mafn lightning-induced outage rate was 1/100 km-year. The mean flashover rate for unshielded lines was 22/100 km-year. A linear relationship was established between the annual lightning-induced outages and the annual lightning days for the province. Lightning accounted for approximately 10% of the random outages experienced in Ijebu province. Lightning-induced outages are linearly related to lightning days. Lightning-induced outage rate is much higher over unshielded than shielded transmission lines.

  4. Outage capacity of multicarrier systems

    KAUST Repository

    Yilmaz, Ferkan

    2010-01-01

    The probability density function and the cumulative distribution function of the product of shifted Gamma variates are obtained in terms of the generalized Fox\\'s H function. Using these new results, the exact outage capacity of multi carrier transmission through a slow Nakagami-m fading channel is presented. Moreover, it is shown that analytical and simulation results are in perfect agreement. © 2009 IEEE.

  5. Analysis of Fixed Outage Transmission Schemes: A Finer Look at the Full Multiplexing Point

    CERN Document Server

    Wu, Peng

    2007-01-01

    This paper studies the performance of transmission schemes that have rate that increases with average SNR while maintaining a fixed outage probability. This is in contrast to the classical Zheng-Tse diversity-multiplexing tradeoff (DMT) that focuses on increasing rate and decreasing outage probability. Three different systems are explored: antenna diversity systems, time/frequency diversity systems, and automatic repeat request (ARQ) systems. In order to accurately study performance in the fixed outage setting, it is necesary to go beyond the coarse, asymptotic multiplexing gain metric. In the case of antenna diversity and time/frequency diversity, an affine approximation to high SNR outage capacity (i.e., multiplexing gain plus a power/rate offset) accurately describes performance and shows the very significant benefits of diversity. ARQ is also seen to provide a significant performance advantage, but even an affine approximation to outage capacity is unable to capture this advantage and outage capacity must...

  6. Minimizing forced outage risk in generator bidding

    Science.gov (United States)

    Das, Dibyendu

    Competition in power markets has exposed the participating companies to physical and financial uncertainties. Generator companies bid to supply power in a day-ahead market. Once their bids are accepted by the ISO they are bound to supply power. A random outage after acceptance of bids forces a generator to buy power from the expensive real-time hourly spot market and sell to the ISO at the set day-ahead market clearing price, incurring losses. A risk management technique is developed to assess this financial risk associated with forced outages of generators and then minimize it. This work presents a risk assessment module which measures the financial risk of generators bidding in an open market for different bidding scenarios. The day-ahead power market auction is modeled using a Unit Commitment algorithm and a combination of Normal and Cauchy distributions generate the real time hourly spot market. Risk profiles are derived and VaRs are calculated at 98 percent confidence level as a measure of financial risk. Risk Profiles and VaRs help the generators to analyze the forced outage risk and different factors affecting it. The VaRs and the estimated total earning for different bidding scenarios are used to develop a risk minimization module. This module will develop a bidding strategy of the generator company such that its estimated total earning is maximized keeping the VaR below a tolerable limit. This general framework of a risk management technique for the generating companies bidding in competitive day-ahead market can also help them in decisions related to building new generators.

  7. Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

    Directory of Open Access Journals (Sweden)

    Slavche Pejoski

    2014-01-01

    Full Text Available We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

  8. Darlington Station outage - a maintenance perspective

    International Nuclear Information System (INIS)

    Ontario Hydro's Darlington Nuclear Generating Station (4x881MW(e)net) has carried out its first station outage since full commercial operation. The outage presented challenges to the organization in terms of outage planning, support, management, and safe execution within the constraints of schedule, budget and resources. This paper will focus on the success of the outage maintenance program, identifying the major work programs - a vacuum structure and containment outage, an emergency service water system outage, an emergency coolant injection system outage, intake channel inspections, low pressure service water inspections, and significant outage maintenance work on each of the four reactor units. Planning for the outage was initiated early in anticipation of this important milestone in the station's life. Detailed safety reviews - nuclear, radiation, and conventional - were conducted in support of the planned maintenance program. System lineup and work protection were provided by the Station Operator work group. Work protection permitry was initiated well in advance of the outage. Station maintenance staff resources were bolstered in support of the outage to ensure program execution could be maintained within the schedule. Training programs were in place to ensure that expectations were clear and that high standards would be maintained. Materials management issues in support of maintenance activities were given high priority to ensure no delays to the planned work. Station management review and monitoring in preparation for and during the outage ensured that staff priorities remained focused. Lessons learned from the outage execution are being formalized in maintenance procedures and outage management procedures, and shared with the nuclear community. (author)

  9. Bingham Pump Outage Pits: Environmental information document

    International Nuclear Information System (INIS)

    Seven waste sites known as the Bingham Pump Outage Pits located in areas of the Savannah River Plant (SRP) received solid waste containing an estimated 4 Ci of low-level radioactivity in 1957-1958. These sites were subsequently backfilled and have been inactive since that time. Most of the radioactivity at the Bingham Pump Outage Pits has been eliminated by radioactive decay. A total of approximately 1 Ci of activity (primarily 137Cs and 90Sr) is estimated to remain at the seven sites. The closure options considered for the Bingham Pump Outage Pits are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated. Evaluation indicates that the relative human health risks for all closure options are small. The greatest public risk would occur after the waste site was released to unrestricted public use (assumed to occur in Year 2085) via the groundwater pathway to a well. The cost estimates show that the waste removal and closure option is the most expensive (89.6 million dollars). The cost of the no waste removal and the no action options is $800,000. 35 refs., 26 figs., 47 tabs

  10. Development of Methodologies for Technology Deployment for Advanced Outage Control Centers that Improve Outage Coordination, Problem Resolution and Outage Risk Management

    Energy Technology Data Exchange (ETDEWEB)

    Shawn St. Germain; Ronald Farris; Heather Medeman

    2013-09-01

    schedule depends upon the performance of the outage management organization. During an outage, the outage control center (OCC) is the temporary command center for outage managers and provides several critical functions for the successful execution of the outage schedule. Essentially, the OCC functions to facilitate information inflow, assist outage management in processing information and to facilitate the dissemination of information to stakeholders. Currently, outage management activities primarily rely on telephone communication, face to face reports of status and periodic briefings in the OCC. Much of the information displayed in OCCs is static and out of date requiring an evaluation to determine if it is still valid. Several advanced communication and collaboration technologies have shown promise for facilitating the information flow into, across and out of the OCC. Additionally, advances in the areas of mobile worker technologies, computer based procedures and electronic work packages can be leveraged to improve the availability of real time status to outage managers.

  11. Nuclear power plant outage optimisation strategy

    International Nuclear Information System (INIS)

    Competitive environment for electricity generation has significant implications for nuclear power plant operations, including among others the need of efficient use of resources, effective management of plant activities such as on-line maintenance and outages. Nuclear power plant outage management is a key factor for good, safe and economic nuclear power plant performance which involves many aspects: plant policy, co-ordination of available resources, nuclear safety, regulatory and technical requirements and, all activities and work hazards, before and during the outage. This technical publication aims to communicate these practices in a way they can be used by operators and utilities in the Member States of the IAEA. It intends to give guidance to outage managers, operating staff and to the local industry on planning aspects, as well as examples and strategies experienced from current plants in operation on the optimization of outage period. This report discusses the plant outage strategy and how this strategy is actually implemented. The main areas identified as most important for outage optimization by the utilities and government organizations participating in this report are: organization and management; outage planning and preparation, outage execution, safety outage review, and counter measures to avoid extension of outages and to easier the work in forced outages. This report was based on discussions and findings by the authors of the annexes and the participants of an Advisory Group Meeting on Determinant Causes for Reducing Outage Duration held in June 1999 in Vienna. The report presents the consensus of these experts regarding best common or individual good practices that can be used at nuclear power plants with the aim to optimize

  12. Outage analysis of blind cooperative diversity

    KAUST Repository

    Tourki, Kamel

    2011-06-06

    Mobile users with single antennas can still take advantage of spatial diversity through cooperative space-time-encoded transmission. In this paper, we considered a scheme in which a relay chooses to cooperate only if its source-relay channel is of an acceptable quality, and we evaluate the usefulness of relaying when the source acts blindly and ignores the decision of the relays whether they may cooperate or not. In our study, we consider the regenerative relays in which the decisions to cooperate are based on a targeted end-to-end data rate R. We derived the end-to-end outage probability for a transmission rate R and a code rate ρ and look at a power allocation strategy between the source and the relays in order to minimize the end-to-end outage probability at the destination for high signal-to-noise ratio, by using the golden section search method. Performance results show that the computer simulations-based results coincide with our analytical results. Copyright © 2011 John Wiley & Sons, Ltd.

  13. Achieving outage excellence through partnership in performance

    International Nuclear Information System (INIS)

    This paper discusses the joint efforts of Public Service of New Jersey and Westinghouse aimed at attaining excellence in outage performance. Success in the 1986 outages at Salem Units 1 and 2 was accomplished by joint efforts in detailed initial communication and planning, tough goal setting, communication of objectives, identification of responsibility, incentive structuring, and finally, by hard work by both organizations aimed at working the plan and minimizing impacts where changes were required during the outage

  14. Management strategies for nuclear power plant outages

    International Nuclear Information System (INIS)

    More competitive energy markets have significant implications for nuclear power plant operations, including, among others, the need for more efficient use of resources and effective management of plant activities such as on-line maintenance and outages. Outage management is a key factor for safe, reliable and economic plant performance and involves many aspects: plant policy, coordination of available resources, nuclear safety, regulatory and technical requirements, and all activities and work hazards, before and during the outage. The IAEA has produced this report on nuclear power plant outage management strategies to provide both a summary and an update of a follow-up to a series of technical documents related to practices regarding outage management and cost effective maintenance. The aim of this publication is to identify good practices in outage management: outage planning and preparation, outage execution and post-outage review. As in in the related technical documents, this report aims to communicate these practices in such a way that they can be used by operating organizations and regulatory bodies in Member States. The report was prepared as part of an IAEA project on continuous process improvement. The objective of this project is to increase Member State capabilities in improving plant performance and competitiveness through the utilization of proven engineering and management practices developed and transferred by the IAEA

  15. Nuclear operations branch outage management strategy

    International Nuclear Information System (INIS)

    In 1991, partly in response to declining nuclear performance in Ontario Hydro, six priority areas were chosen where improvement efforts should be focused. Of these, outage management has the greatest potential for increasing near-term electrical generation. Many initiatives are being undertaken to improve performance in this key area. The outage management strategy is intended to focus these improvement efforts, and put outage management at Ontario Hydro's nuclear generating stations on a more predictable and business-like basis. This paper outlines the strategic planning process, and provides an overview of the outage management strategy. 2 refs, 1 tab., 4 figs

  16. Wooden hutch space allowance influences male Holstein calf health, performance, daily lying time, and respiratory immunity.

    Science.gov (United States)

    Calvo-Lorenzo, M S; Hulbert, L E; Fowler, A L; Louie, A; Gershwin, L J; Pinkerton, K E; Ballou, M A; Klasing, K C; Mitloehner, F M

    2016-06-01

    Dairy calves in the western United States are commonly raised individually in wooden hutches with a space allowance of 1.23m(2)/calf. Recent legislative initiatives in California and across the United States were passed regarding concern over space allowance for farm animals. The objective of this study was to determine if rearing male Holstein calves in wooden hutches modified to increase space allowance would influence measures of performance, lying time per day, health, and respiratory immunocompetence. At 4d of age, 60 calves were randomly assigned to 1 of 3housing treatments: (1) conventional housing (CONV; 1.23m(2)/calf), (2) 1.5 × CONV (MOD; 1.85m(2)/calf), or (3) 3 × CONV (MAX; 3.71m(2)/calf). Intakes of milk and solid feed were recorded daily and body weight was measured at 0, 3, 6, 10, and 12 wk of age. For the first 3 wk of the trial, calves were scored daily for fecal consistency, hydration, and hide cleanliness. In addition, calves were scored for respiratory health (i.e., nasal and eye discharge, ear position) until 7 wk of age. The total lying duration per day was recorded using data loggers at 3, 6, and 10 wk of age. Eight clinically healthy calves from each treatment were sensitized with subcutaneous ovalbumin (OVA) and then challenged with aerosolized OVA to assess calf respiratory immunity at 11 wk of age. Bronchoalveolar lavage fluid (BALF) was collected 4d after the OVA challenge and analyzed for leukocyte differentials and OVA-specific IgG, IgG1, IgA, and IgE. Calf average daily gain and body weight were positively associated with space allowance at approximately 3 wk before weaning and throughout postweaning, respectively. A greater space allowance decreased lying time after 46d. Space allowance did not influence fecal consistency, but there was a tendency for MAX calves to take 1d longer to recover from loose feces than MOD calves. The MAX calves had the fewest (%) observations with feces on their body compared with CONV or MOD. At 3 wk of

  17. Underlay Cognitive Radio Systems with Improper Gaussian Signaling: Outage Performance Analysis

    KAUST Repository

    Amin, Osama

    2016-03-29

    Improper Gaussian signaling has the ability over proper (conventional) Gaussian signaling to improve the achievable rate of systems that suffer from interference. In this paper, we study the impact of using improper Gaussian signaling on the performance limits of the underlay cognitive radio system by analyzing the achievable outage probability of both the primary user (PU) and secondary user (SU). We derive the exact outage probability expression of the SU and construct upper and lower bounds of the PU outage probability which results in formulating an approximate expression of the PU outage probability. This allows us to design the SU signal by adjusting its transmitted power and the circularity coefficient to minimize the SU outage probability while maintaining a certain PU quality-of-service. Finally, we evaluate the derived expressions for both the SU and the PU and the corresponding adaptive algorithms by numerical results.

  18. Use of VIIRS DNB Data to Monitor Power Outages and Restoration for Significant Weather Events

    Science.gov (United States)

    Jedlovec, Gary; Molthan, Andrew

    2008-01-01

    NASA fs Short-term Prediction Research and Transition (SPoRT) project operates from NASA's Marshall Space Flight Center in Huntsville, Alabama. The team provides unique satellite data to the National Weather Service (NWS) and other agencies and organizations for weather analysis. While much of its work is focused on improving short-term weather forecasting, the SPoRT team supported damage assessment and response to Hurricane Superstorm Sandy by providing imagery that highlighted regions without power. The team used data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite. The VIIRS low-light sensor, known as the day-night-band (DNB), can detect nighttime light from wildfires, urban and rural communities, and other human activity which emits light. It can also detect moonlight reflected from clouds and surface features. Using real time VIIRS data collected by our collaborative partner at the Space Science and Engineering Center of the University of Wisconsin, the SPoRT team created composite imagery to help detect power outages and restoration. This blackout imagery allowed emergency response teams from a variety of agencies to better plan and marshal resources for recovery efforts. The blackout product identified large-scale outages, offering a comprehensive perspective beyond a patchwork GIS mapping of outages that utility companies provide based on customer complaints. To support the relief efforts, the team provided its imagery to the USGS data portal, which the Federal Emergency Management Agency (FEMA) and other agencies used in their relief efforts. The team fs product helped FEMA, the U.S. Army Corps of Engineers, and U.S. Army monitor regions without power as part of their disaster response activities. Disaster responders used the images to identify possible outages and effectively distribute relief resources. An enhanced product is being developed and integrated into a web

  19. Assessing energy supply security: Outage costs in private households

    International Nuclear Information System (INIS)

    The objective of this paper is to contribute to the topic of energy supply security by proposing a Monte Carlo-based and a survey based model to analyze the costs of power interruptions. Outage cost estimations are particularly important when deciding on investments to improve supply security (e.g. additional transmission lines) in order to compare costs to benefits. But also other policy decisions on measures that have direct or indirect consequences for the supply security (e.g. a phasing out of nuclear energy) need to be based on results from outage cost estimations. The main focus of this paper lies with residential consumers, but the model is applied to commercial, industrial and governmental consumers as well. There are limited studies that have approached the problem of evaluating outage cost. When comparing the results of these studies, they often display a high degree of diversification. As consumers have different needs and dependencies towards the supply of electricity because of varying circumstances and preferences, a great diversity in outage cost is a logical consequence. To take the high degree of uncertainties into account, a Monte Carlo simulation was conducted in this study for the case of private households in Germany. - Highlights: ► A macroeconomic model to assess outage cost is proposed. ► Possibilities for substitution are considered by analyzing individual preferences for the time-use. ► Uncertainties are taken into account by using a Monte Carlo simulation. ► This study reveals the distribution of outage costs to different electricity consumers. ► Implications for energy policy decisions are discussed.

  20. Outage risk reduction at Diablo Canyon

    International Nuclear Information System (INIS)

    A formal risk reduction program was conducted at the Diablo Canyon Nuclear Generating plant as part of EPRI's Outage Risk Assessment and Management Program. The program began with a probabilistic and deterministic assessment of the frequency of core coolant boiling and core uncovery during shutdown operations. This step identified important contributors to risk, periods of high vulnerability, and potential mechanisms for reducing risk. Next, recovery strategies were evaluated and procedures, training, and outage schedules modified. Twelve risk reduction enhancements were developed and implemented. These enhancements and their impact are described in this paper. These enhancements reduced the calculated risk of core uncovery by about a factor of four for a refueling outage without lengthening the outage schedule; increased the outage efficiency, contributing to completing 11 days ahead of schedule; and helped to earn the highest achievable SALP rating from the NRC. (author)

  1. Operation risk analysis and control during ten-year outage program

    International Nuclear Information System (INIS)

    In L101 outage of Ling'ao nuclear power station (the 1st outage on unit 1), containment pressurizing test had been implemented. In L201 outage (the 1st outage on unit 2), primary hydraulic test, pressure vessel in-service inspection and containment pressurizing test were all done, which is the first time for Daya Bay NPS and Ling'ao NPS to complete the characteristic ten-year outage program. It is also the first time for domestic commercial nuclear power station to perform primary hydraulic test. Operations branch studied into the test requirements and possible risks so as to effectively control the operational activities and test during these programs. A complete set of overall operating procedure for ten-year outage programs has been prepared. Operating procedure as the guideline, main blocking, TSD, TCA and permit management are all helpful in the risk control. The interface problem among different test configuration and unit start-up are solved, laying a solid foundation for the success of ten-year outage program. the effectiveness and scientificity of the procedure has been proved in the outage. The success may serve as the valuable reference for two plants and domestic nuclear stations in the future. (authors)

  2. New reconstruction algorithm allows shortened acquisition time for myocardial perfusion SPECT

    International Nuclear Information System (INIS)

    Shortening scan time and/or reducing radiation dose at maintained image quality are the main issues of the current research in radionuclide myocardial perfusion imaging (MPI). We aimed to validate a new iterative reconstruction (IR) algorithm for SPECT MPI allowing shortened acquisition time (HALF time) while maintaining image quality vs. standard full time acquisition (FULL time). In this study, 50 patients, referred for evaluation of known or suspected coronary artery disease by SPECT MPI using 99mTc-Tetrofosmin, underwent 1-day adenosine stress 300 MBq/rest 900 MBq protocol with standard (stress 15 min/rest 15 min FULL time) immediately followed by short emission scan (stress 9 min/rest 7 min HALF time) on a Ventri SPECT camera (GE Healthcare). FULL time scans were processed with IR, short scans were additionally processed with a recently developed software algorithm for HALF time emission scans. All reconstructions were subsequently analyzed using commercially available software (QPS/QGS, Cedars Medical Sinai) with/without X-ray based attenuation correction (AC). Uptake values (percent of maximum) were compared by regression and Bland-Altman (BA) analysis in a 20-segment model. HALF scans yielded a 96% readout and 100% clinical diagnosis concordance compared to FULL. Correlation for uptake in each segment (n = 1,000) was r = 0.87at stress (p < 0.001) and r = 0.89 at rest (p < 0.001) with respective BA limits of agreement of -11% to 10% and -12% to 11%. After AC similar correlation (r = 0.82, rest; r = 0.80, stress, both p < 0.001) and BA limits were found (-12% to 10%; -13% to 12%). With the new IR algorithm, SPECT MPI can be acquired at half of the scan time without compromising image quality, resulting in an excellent agreement with FULL time scans regarding to uptake and clinical conclusion. (orig.)

  3. Seasonal and Local Characteristics of Lightning Outages of Power Distribution Lines in Hokuriku Area

    Science.gov (United States)

    Sugimoto, Hitoshi; Shimasaki, Katsuhiko

    The proportion of the lightning outages in all outages on Japanese 6.6kV distribution lines is high with approximately 20 percent, and then lightning protections are very important for supply reliability of 6.6kV lines. It is effective for the lightning performance to apply countermeasures in order of the area where a large number of the lightning outages occur. Winter lightning occurs in Hokuriku area, therefore it is also important to understand the seasonal characteristics of the lightning outages. In summer 70 percent of the lightning outages on distribution lines in Hokuriku area were due to sparkover, such as power wire breakings and failures of pole-mounted transformers. However, in winter almost half of lightning-damaged equipments were surge arrester failures. The number of the lightning outages per lightning strokes detected by the lightning location system (LLS) in winter was 4.4 times larger than that in summer. The authors have presumed the occurrence of lightning outages from lightning stroke density, 50% value of lightning current and installation rate of lightning protection equipments and overhead ground wire by multiple regression analysis. The presumed results suggest the local difference in the lightning outages.

  4. Use of collaboration software to improve nuclear power plant outage management

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn

    2015-02-01

    Nuclear Power Plant (NPP) refueling outages create some of the most challenging activities the utilities face in both tracking and coordinating thousands of activities in a short period of time. Other challenges, including nuclear safety concerns arising from atypical system configurations and resource allocation issues, can create delays and schedule overruns, driving up outage costs. Today the majority of the outage communication is done using processes that do not take advantage of advances in modern technologies that enable enhanced communication, collaboration and information sharing. Some of the common practices include: runners that deliver paper-based requests for approval, radios, telephones, desktop computers, daily schedule printouts, and static whiteboards that are used to display information. Many gains have been made to reduce the challenges facing outage coordinators; however; new opportunities can be realized by utilizing modern technological advancements in communication and information tools that can enhance the collective situational awareness of plant personnel leading to improved decision-making. Ongoing research as part of the Light Water Reactor Sustainability Program (LWRS) has been targeting NPP outage improvement. As part of this research, various applications of collaborative software have been demonstrated through pilot project utility partnerships. Collaboration software can be utilized as part of the larger concept of Computer-Supported Cooperative Work (CSCW). Collaborative software can be used for emergent issue resolution, Outage Control Center (OCC) displays, and schedule monitoring. Use of collaboration software enables outage staff and subject matter experts (SMEs) to view and update critical outage information from any location on site or off.

  5. Use of collaboration software to improve nuclear power plant outage management

    International Nuclear Information System (INIS)

    Nuclear Power Plant (NPP) refueling outages create some of the most challenging activities the utilities face in both tracking and coordinating thousands of activities in a short period of time. Other challenges, including nuclear safety concerns arising from atypical system configurations and resource allocation issues, can create delays and schedule overruns, driving up outage costs. Today the majority of the outage communication is done using processes that do not take advantage of advances in modern technologies that enable enhanced communication, collaboration and information sharing. Some of the common practices include: runners that deliver paper-based requests for approval, radios, telephones, desktop computers, daily schedule printouts, and static whiteboards that are used to display information. Many gains have been made to reduce the challenges facing outage coordinators; however; new opportunities can be realized by utilizing modern technological advancements in communication and information tools that can enhance the collective situational awareness of plant personnel leading to improved decision-making. Ongoing research as part of the Light Water Reactor Sustainability Program (LWRS) has been targeting NPP outage improvement. As part of this research, various applications of collaborative software have been demonstrated through pilot project utility partnerships. Collaboration software can be utilized as part of the larger concept of Computer-Supported Cooperative Work (CSCW). Collaborative software can be used for emergent issue resolution, Outage Control Center (OCC) displays, and schedule monitoring. Use of collaboration software enables outage staff and subject matter experts (SMEs) to view and update critical outage information from any location on site or off.

  6. Options for shortening nuclear power plant refueling outages

    International Nuclear Information System (INIS)

    Deregulation of the European electricity market on 01.01.1999 forced a large number of electric utilities- especially nuclear power plant operators - to find ways of drastically cutting down their costs in order to be able to compete successfully within the new market environment. Nuclear power plants currently in operation mainly have three potential ways of reducing their power generating costs: by increasing plant availability, reducing fuel costs and cutting down operating costs. The optimization of plant refueling outages offers considerable potential for enhancing plant availability, but also helps bring down operating costs by reducing expenditure on maintenance. In order to optimize an outage in terms of its duration and costs, a variety of approaches are possible - all of which, however, involve certain key factors such as good organization, planning, logistics and control, improvement of equipment and tools, as well as motivation of personnel. Another aspect is the introduction of innovative technologies. In the last few years, such technologies have frequently enabled maintenance effort to be reduced, thus saving considerable time, and have also resulted in a need for fewer personnel to carry out the work, thus reducing radiation exposure. In many instances they have also improved the quality of work and outage performance as a whole. The paper uses recent examples to show how innovative technologies can contribute to-wards reducing nuclear plant maintenance costs and shorten the duration of refueling out-ages. (author)

  7. World class performance: the outage/operating cycle continuum

    International Nuclear Information System (INIS)

    It's all about Performance! Predictable and sustainable high performance is the key to public and stakeholder confidence in the nuclear industry. Why? Because nuclear is unique and safe, reliable operation each and every day is required to keep public trust. What better way to demonstrate this predictability than in breaker to breaker operating runs? Delivering on what was promised is the essence of our OPG accountability model: 'Say it, Do it'. This presentation is drawn from practical experience gained during the most recent planned maintenance outages at Darlington Nuclear. Key elements for outage success that will be discussed include; Human Performance: Ensuring each action is deliberate and executed right the first time; Continuous Learning: Recent examples demonstrating how drawing from lessons learned and operating experience worldwide can dramatically improve outage performance; Teamwork and Partnership: Recognizing our industry is too complex for a single; individual or organization to run on its own; Scope Selection: Darlington currently has an industry leading 0.5% Forced Loss Rate (FLR). If right work is selected and executed at the right time then ultimately the plant speaks and it shows up in low FLR and high Nuclear Performance Index; Planning: Ask and anticipate what can go wrong, what options exist and then pre-decide what path you would take. Some practical tools will be provided which have been recently used to plan out surprises; Oversight: An outage left to run its own course will have a surprise outcome. Strong management oversight is required to meet the goals of outage execution. Tips on how to improve communication and accountability will be discussed. Trust is built on confidence and confidence is built on sustainable performance. World class sustainable performance requires using all the tools available. This discussion will provide insight on these very tools. (author)

  8. The Role of Occupational Health and Safety in Complex Outage Services to NPPs

    International Nuclear Information System (INIS)

    Meeting outage schedules in NPPs which are increasingly demanding, apart from all other aspects, introduces a new perspective on occupational health and safety (OHS). Not only is the OHS a constituent part of a plant's overall outage management, it above all dictates paramount objectives to outage service providers. The paper reviews the impacts of reductions of outage durations on OHS and presents related experience of the leading Slovenian outage services provider, NUMIP d.o.o. over the last ten years. The company is now getting prepared for its 12th outage at Krsko NPP in 2010, and has not have recorded a major injury so far, even though these projects engaged over 450 people at a time on-site. To achieve such results, a lot of emphasis is being put onto OHS management prior to and during outages. A certified OHSAS 18001 system has been established and implemented to further support preparation and execution of NUMIP's outage activities at Krsko NPP, and also for other projects. An effective continuous improvement system is built into the project, providing for implementation of lessons learned from domestic and foreign plants. To illustrate the topic in more detail, a case on a Seismic protection of polar crane project is presented. It took place in the 2009 Outage and has certainly been one of the most demanding projects from the OHS point of view for NUMIP so far. The paper aims at contributing to a better understanding of the role of effective management of OHS on the side of a service provider, and, consequently, in the overall outage success of a plant.(author).

  9. San Onofre - the evolution of outage management

    International Nuclear Information System (INIS)

    With the addition of units 2 and 3 to San Onofre nuclear station in 1983 and 1984, it became evident that a separate group was needed to manage outages. Despite early establishment of a division to handle outages, it was a difficult journey to make the changes to achieve short outages. Early organizational emphasis was on developing an error-free operating environment and work culture. This is difficult for a relatively large organization at a three-unit site. The work processes and decision styles were designed to be very deliberate with many checks and balances. The organization leadership and accountability were focused in the traditional operations, maintenance, and engineering divisions. Later, our organization emphasis shifted to achieving engineering excellence. With a sound foundation of operating and engineering excellence, our organizational focus has turned to achieving quality outages. This means accomplishing the right work in a shorter duration and having the units run until the next refueling

  10. A framework and review of customer outage costs: Integration and analysis of electric utility outage cost surveys

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Leora; Sullivan, Michael; Van Liere, Kent; Katz, Aaron; Eto, Joseph

    2003-11-01

    A clear understanding of the monetary value that customers place on reliability and the factors that give rise to higher and lower values is an essential tool in determining investment in the grid. The recent National Transmission Grid Study recognizes the need for this information as one of growing importance for both public and private decision makers. In response, the U.S. Department of Energy has undertaken this study, as a first step toward addressing the current absence of consistent data needed to support better estimates of the economic value of electricity reliability. Twenty-four studies, conducted by eight electric utilities between 1989 and 2002 representing residential and commercial/industrial (small, medium and large) customer groups, were chosen for analysis. The studies cover virtually all of the Southeast, most of the western United States, including California, rural Washington and Oregon, and the Midwest south and east of Chicago. All variables were standardized to a consistent metric and dollar amounts were adjusted to the 2002 CPI. The data were then incorporated into a meta-database in which each outage scenario (e.g., the lost of electric service for one hour on a weekday summer afternoon) is treated as an independent case or record both to permit comparisons between outage characteristics and to increase the statistical power of analysis results. Unadjusted average outage costs and Tobit models that estimate customer damage functions are presented. The customer damage functions express customer outage costs for a given outage scenario and customer class as a function of location, time of day, consumption, and business type. One can use the damage functions to calculate outage costs for specific customer types. For example, using the customer damage functions, the cost experienced by an ''average'' customer resulting from a 1 hour summer afternoon outage is estimated to be approximately $3 for a residential customer, $1

  11. Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status

    Directory of Open Access Journals (Sweden)

    Luis Gonzaga Santesteban

    2015-06-01

    Full Text Available Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if THz time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years old plant, using a general purpose THz emitter receiver head.Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.

  12. Power Outage, Business Continuity and Businesses' Choices of Power Outage Mitigation Measures

    Directory of Open Access Journals (Sweden)

    Ali Asgary

    2011-01-01

    Full Text Available Problem statement: Power outage has been mentioned as one of the most experienced and perceived risks by various types of businesses and organizations. Thus, reducing the impacts of power outage has become a key agenda in business continuity planning. Back-up or stand-by generators are among the most well known measures taken by power consumers to tackle the power outage problem. Approach: A survey was conducted to understand various aspects of power outage and the impacts of power outrage on businesses. In addition a choice experiment method was used to derive businesses’ preferences for different power outage mitigation measures that would have a range of prices, space requirements, air and noise pollution as well as mobility attributes using a sample of Canadian businesses located in the . Sample was drawn from businesses operating in the Greater Toronto Area (GTA and surrounding communities in Ontario, Canada. Results: It was found that majority of businesses have experienced and unconvinced by power outage and consider it to be a major risk to their operations. Production loss, data loss, damage to equipment and loss of lighting are the most significant sources for inconveniences caused by the power outages. It was found that a considerable number of businesses have not taken appropriate measures to mitigate this risk. Estimations from the responses revealed that sample businesses had a positive willingness to pay for power outage reduction and that businesses prefer power outage mitigation measures that are least costly, have low levels of air and noise pollution and occupy smaller spaces respectively. Conclusion: An uninterrupted power supply is an important element of business continuity in today’s business world. Although many businesses are not fully prepared against power outages, they are willing to pay for low cost and low pollution power outage mitigation measures.

  13. Major outages at nuclear power stations: outage strategy and its implementation

    International Nuclear Information System (INIS)

    In the new era of competition in the recently privatised electricity generating market, the costs of electric power production can be brought down by reducing plant outages to the lowest levels compatible with safety constraints. Some of the management principles used to achieve such low duration outages are described. High plant reliability following the station's return to power must also be ensured. (UK)

  14. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  15. Status Report on the Development of Micro-Scheduling Software for the Advanced Outage Control Center Project

    Energy Technology Data Exchange (ETDEWEB)

    Shawn St. Germain; Kenneth Thomas; Ronald Farris; Jeffrey Joe

    2014-09-01

    The long-term viability of existing nuclear power plants (NPPs) in the United States (U.S.) is dependent upon a number of factors, including maintaining high capacity factors, maintaining nuclear safety, and reducing operating costs, particularly those associated with refueling outages. Refueling outages typically take 20-30 days, and for existing light water NPPs in the U.S., the reactor cannot be in operation during the outage. Furthermore, given that many NPPs generate between $1-1.5 million/day in revenue when in operation, there is considerable interest in shortening the length of refueling outages. Yet, refueling outages are highly complex operations, involving multiple concurrent and dependent activities that are difficult to coordinate. Finding ways to improve refueling outage performance while maintaining nuclear safety has proven to be difficult. The Advanced Outage Control Center project is a research and development (R&D) demonstration activity under the Light Water Reactor Sustainability (LWRS) Program. LWRS is a R&D program which works with industry R&D programs to establish technical foundations for the licensing and managing of long-term, safe, and economical operation of current NPPs. The Advanced Outage Control Center project has the goal of improving the management of commercial NPP refueling outages. To accomplish this goal, this INL R&D project is developing an advanced outage control center (OCC) that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. This report describes specific recent efforts to develop a capability called outage Micro-Scheduling. Micro-Scheduling is the ability to allocate and schedule outage support task resources on a sub-hour basis. Micro-Scheduling is the real-time fine-tuning of the outage schedule to react to the actual progress of the primary outage activities to ensure that support task resources are

  16. Outage management and health physics issue, 2007

    International Nuclear Information System (INIS)

    The focus of the May-June issue is on outage management and health physics. Major articles/reports in this issue include: India: a potential commercial opportunity, a U.S. Department of Commerce Report, by Joe Neuhoff and Justin Rathke; The changing climate for nuclear energy, by Skip Bowman, Nuclear Energy Insitute; Selecting protective clothing, by J. Mark Price, Southern California Edison; and Succssful refurbishment outage, by Sudesh K. Gambhir, Omaha Public Power District. Industry innovation articles in this issue are: Containment radiation monitoring spiking, by Michael W. Lantz and Robert Routolo, Arizona Public Service Company; Improved outage performance, by Michael Powell and Troy Wilfong, Arizona Public Service Company, Palo Verde Nuclear Generating Station; Stop repacking valves and achieve leak-free performance, by Kenneth Hart, PPL Susquehanna LLC; and Head assembly upgrade package, by Timothy Petit, Dominion Nuclear

  17. Ontario-U.S. power outages : impacts on critical infrastructure

    International Nuclear Information System (INIS)

    This paper described the power outage and resulting blackout that occurred on August 14, 2003 and identified how critical infrastructure was directly and interdependently impacted in Canada. The aim of the paper was to assist critical infrastructure protection and emergency management professionals in assessing the potential impacts of large-scale critical infrastructure disruptions. Information for the study was acquired from Canadian and American media reports and cross-sectoral information sharing with provincial and federal governments and the private sector. The blackout impacted most of the sources and means of generating, transmitting and distributing power within the area, which in turn impacted all critical infrastructure sectors. Landline and cellular companies experienced operational difficulties, which meant that emergency responders were impacted. Newspapers and the electronic media struggled to release information to the public. The banking and finance industry experienced an immediate degradation of services. The power outage caused shipping and storage difficulties for commercial retailers and dairy producers. A number of incidents were reported where only partially treated waste water was released into neighbouring waterways. The timing of the blackout coincided with the closures of workplaces and created additional difficulties on transportation networks. Many gas station pumps were inoperable. Police, fire departments and ambulance services experienced a dramatic increase in the volume of calls received, and all branches of the emergency services sector encountered transportation delays and difficulties with communications equipment. Nuclear reactors were also impacted. An estimated 150,000 Government of Canada employees were unable to report to work. Estimates have indicated that the power outage cost Ontario's economy between $1 and $2 billion. The outage negatively impacted 82 per cent of small businesses in Ontario. 170 refs., 3 figs

  18. Benchmark Report on Key Outage Attributes: An Analysis of Outage Improvement Opportunities and Priorities

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn St. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Farris, Ronald [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2014-09-01

    Advanced Outage Control Center (AOCC), is a multi-year pilot project targeted at Nuclear Power Plant (NPP) outage improvement. The purpose of this pilot project is to improve management of NPP outages through the development of an AOCC that is specifically designed to maximize the usefulness of communication and collaboration technologies for outage coordination and problem resolution activities. This report documents the results of a benchmarking effort to evaluate the transferability of technologies demonstrated at Idaho National Laboratory and the primary pilot project partner, Palo Verde Nuclear Generating Station. The initial assumption for this pilot project was that NPPs generally do not take advantage of advanced technology to support outage management activities. Several researchers involved in this pilot project have commercial NPP experience and believed that very little technology has been applied towards outage communication and collaboration. To verify that the technology options researched and demonstrated through this pilot project would in fact have broad application for the US commercial nuclear fleet, and to look for additional outage management best practices, LWRS program researchers visited several additional nuclear facilities.

  19. Residential outage cost estimation: Hong Kong

    International Nuclear Information System (INIS)

    Hong Kong has almost perfect electricity reliability, the result of substantial investments ultimately financed by electricity consumers who may be willing to accept lower reliability in exchange for lower bills. But consumers with high outage costs are likely to reject the reliability reduction. Our ordered-logit regression analysis of the responses by 1876 households to a telephone survey conducted in June 2013 indicates that Hong Kong residents exhibit a statistically-significant preference for their existing service reliability and rate. Moreover, the average residential cost estimate for a 1-h outage is US$45 (HK$350), topping the estimates reported in 10 of the 11 studies published in the last 10 years. The policy implication is that absent additional compelling evidence, Hong Kong should not reduce its service reliability. - Highlights: • Use a contingent valuation survey to obtain residential preferences for reliability. • Use an ordered logit analysis to estimate Hong Kong's residential outage costs. • Find high outage cost estimates that imply high reliability requirements. • Conclude that sans new evidence, Hong Kong should not reduce its reliability

  20. SAMPLE RESULTS FROM MCU SOLIDS OUTAGE

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T.; Washington, A.; Oji, L.; Coleman, C.; Poirier, M.

    2014-09-22

    Savannah River National Laboratory (SRNL) has received several solid and liquid samples from MCU in an effort to understand and recover from the system outage starting on April 6, 2014. SRNL concludes that the presence of solids in the Salt Solution Feed Tank (SSFT) is the likely root cause for the outage, based upon the following discoveries  A solids sample from the extraction contactor #1 proved to be mostly sodium oxalate  A solids sample from the scrub contactor#1 proved to be mostly sodium oxalate  A solids sample from the Salt Solution Feed Tank (SSFT) proved to be mostly sodium oxalate  An archived sample from Tank 49H taken last year was shown to contain a fine precipitate of sodium oxalate  A solids sample from the extraction contactor #1 drain pipe from extraction contactor#1 proved to be mostly sodium aluminosilicate  A liquid sample from the SSFT was shown to have elevated levels of oxalate anion compared to the expected concentration in the feed Visual inspection of the SSFT indicated the presence of precipitated or transferred solids, which were likely also in the Salt Solution Receipt Tank (SSRT). The presence of the solids coupled with agitation performed to maintain feed temperature resulted in oxalate solids migration through the MCU system and caused hydraulic issues that resulted in unplanned phase carryover from the extraction into the scrub, and ultimately the strip contactors. Not only did this carryover result in the Strip Effluent (SE) being pushed out of waste acceptance specification, but it resulted in the deposition of solids into several of the contactors. At the same time, extensive deposits of aluminosilicates were found in the drain tube in the extraction contactor #1. However it is not known at this time how the aluminosilicate solids are related to the oxalate solids. The solids were successfully cleaned out of the MCU system. However, future consideration must be given to the exclusion of oxalate solids into

  1. Real-time quantum trajectories for classically allowed dynamics in strong laser fields

    CERN Document Server

    Plimak, L I

    2015-01-01

    Both the physical picture of the dynamics of atoms and molecules in intense infrared fields and its theoretical description use the concept of electron trajectories. Here we address a key question which arises in this context: Are distinctly quantum features of these trajectories, such as the complex-valued coordinates, physically relevant in the classically allowed region of phase space, and what is their origin? First, we argue that solutions of classical equations of motion can account for quantum effects. To this end, we construct an exact solution to the classical Hamilton-Jacobi equation which accounts for dynamics of the wave packet, and show that this solution is physically correct in the limit $\\hbar \\to 0$. Second, we show that imaginary components of classical trajectories are directly linked to the finite size of the initial wavepacket in momentum space. This way, if the electronic wavepacket produced by optical tunneling in strong infrared fiels is localised both in coordinate and momentum, its m...

  2. Commercial operation and outage experience of ABWR at Kashiwazaki-Kariwa units Nos. 6 and 7

    International Nuclear Information System (INIS)

    Kashiwazaki-Kariwa Nuclear Power Station Units Nos. 6 and 7, the world's first ABWRs (Advanced Boiling Water Reactor), started commercial operation on November 7, 1996 and July 2, 1997, respectively, and continued their commercial operation with a high capacity factor, low occupational radiation exposure and radioactive waste. Units 6 and 7 were in their 3rd cycle operation until 25th April 1999 and 1st November 1999, respectively. Thermal efficiency was 35.4-35.8% (design thermal efficiency: 34.5%) during these period, demonstrating better performance than that of BWR-5 (design thermal efficiency: 33.4%). Nos. 6 and 7 have experienced 2 annual outages. The first outage of unit No. 6 started on November 20, 1997 and was completed within 61 days (including 6 New Year holidays), and the second outage started on March 13, 1999 and was completed within 44 days. The first annual outage of unit No. 7 started on May 27, 1998, earlier than it would normally have been, to avoid an annual outage during the summer, and was completed within 55 days, and the second outage started on September 18th, 1999 and was completed within 45 days, All annual outages were carried out within a very short time period without any severe malfunctions, including newly designed ABWR systems and equipment. As the first outage in Japan, 55 days is a very short period, despite the fact that the Nos. 6 and 7 are the first ABWRs in the world and the largest capacity units in Japan. The total occupational radiation exposure of No. 6 was 300 man-mSv (1st outage) and 331 man-mSv (2nd outage). That of Unit 7 was 153 man-mSv (1st outage) Those of unit No. 6 were at the same level as those of unit No. 3, which is the latest design 1100MW(e) BWR-5. That of unit No. 7 was the lowest ever at Kashiwazaki-Kariwa nuclear power station. The drums of radioactive waste discharged during the annual outage numbered 54 (1st outage) for No. 6 and 62 (1st outage) for No. 7, which was less than the design target of 100

  3. Outages 1999 and 2000, investments in safety and long-term operation of NE Krsko

    International Nuclear Information System (INIS)

    Plant outage is an important part of nuclear power plant operation. During that time the conditions are established for the performance of specific activities, such as refueling, tests, inspections, preventive and corrective maintenance and modifications, that are intended to confirm proper condition and availability of safety and other important components and improve overall plant safety and reliability. It is well know that in Nuclear Power Plant Krsko (Nuklearna elektrarna Krsko NEK) during Outage 2000 new Steam Generators (SGs) will be placed in service, while Outage '99 was used for preparatory works. But the importance of those two outages is even greater, because they are implementing a broad number of improvements and establishing a basis for long-term plant operation. Outage '99 required very detailed planning to assure a good control over the outage activities and operational plant systems necessary for safe shutdown. Numerous activities took place in a relatively narrow space in the Reactor Building. Some of these activities will have a big significance for the future. The article treats the status update and summarizes the specifics and importance of the mentioned activities to long-term plant safe and reliable operation.(author)

  4. Performance Shaping Factors Assessments and Application to PHWR Outages

    International Nuclear Information System (INIS)

    Human reliability analysis is definitely related to the quality of PSA because human errors have been identified as major contributors to PSA. According to NRC's 'Office of analysis and evaluation of operational data (AEOD)',82% of the reactor trips and accident during outage is caused by the events related to human errors. There is, however, no one HRA method universally accepted. Furthermore, HRA during PHWR outages has not been performed around the world yet. HRA during PHWR outages is especially important since manual management of operator is more required during PHWR. In this study, accident scenarios which HYU developed are used to perform a quantification of human error probability. In this study, overall procedures of standard HRA methodology are introduced and follows the quantification of 10 possible selected human actions during PHWR outages based on standard HRA methodology. To see the verification, quantified values were compared with the values from 'Generic CANDU Probabilistic Safety Assessment' and the values estimated by ASEP.Core Damage Frequency was estimated 3.35 x 10-4 more higher than CDF estimated by AECL data. It was considered that the differences between the HEPs for OPAFW and OPECC3 make CDF higher. Therefore, complementary study of reestimating HEP for OPAFW and OPECC3 in detail is required for increasing the qualities of HRA and PSA. Moreover, one of the difficulties in performing human reliability analysis is to evaluate performance shaping factors which represent the characteristics and circumstances. For assessing a specific human action more exactly, it is necessary to consider all of the PSFs at the same time which makes an effect on the human action. Also, it requires the effect comparison among PSFs to minimize the uncertainties which are usually caused by the subjective judgements of HRA analysts. To see the sensitivity, performance shaping factors of each decision rule are changed which resulted in changes of core damage

  5. Real-time quantum trajectories for classically allowed dynamics in strong laser fields

    Science.gov (United States)

    Plimak, L. I.; Ivanov, Misha Yu.

    2015-10-01

    Both the physical picture of the dynamics of atoms and molecules in intense infrared fields and its theoretical description use the concept of electron trajectories. Here, we address a key question which arises in this context: Are distinctly quantum features of these trajectories, such as the complex-valued coordinates, physically relevant in the classically allowed region of phase space, and what is their origin? First, we argue that solutions of classical equations of motion can account for quantum effects. To this end, we construct an exact solution to the classical Hamilton-Jacobi equation which accounts for dynamics of the wave packet, and show that this solution is physically correct in the limit ?. Second, we show that imaginary components of classical trajectories are directly linked to the finite size of the initial wave packet in momentum space. This way, if the electronic wave packet produced by optical tunnelling in strong infrared fields is localised both in coordinate and momentum, its motion after tunnelling ipso facto cannot be described with purely classical trajectories - in contrast to popular models in the literature.

  6. Calculation of failure probability of a redundant system with maximum time allowed for repair: an application

    International Nuclear Information System (INIS)

    The paper illustrates an application of new mathematical formulae to calculate the failure probability of a system when the time for repair is limited to a maximum value. Failure of all redundant sub-systems does not cause instant damage; the system must remain in the failed state for a given finite time T for damage to occur. If repair to any sub-system is completed within T the damage will be averted; otherwise the system will suffer irrepairable damage. The example chosen does not refer to any particular system although the data used are taken from real components. It consists of a vessel accommodating a constant heat source for a period of 6 months. The system failure considered is damage caused by excessive temperature. The probability of exceeding this temperature for the system is calculated and the results are compared with simple unreliability calculations. The effect of different repair conditions on the calculations is also considered. (author)

  7. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    International Nuclear Information System (INIS)

    Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy

  8. Qinshan CANDU NPP outage performance improvement through benchmarking

    International Nuclear Information System (INIS)

    With the increasingly fierce competition in the deregulated Energy Market, the optimization of outage duration has become one of the focal points for the Nuclear Power Plant owners around the world. People are seeking various ways to shorten the outage duration of NPP. Great efforts have been made in the Light Water Reactor (LWR) family with the concept of benchmarking and evaluation, which great reduced the outage duration and improved outage performance. The average capacity factor of LWRs has been greatly improved over the last three decades, which now is close to 90%. CANDU (Pressurized Heavy Water Reactor) stations, with its unique feature of on power refueling, of nuclear fuel remaining in the reactor all through the planned outage, have given raise to more stringent safety requirements during planned outage. In addition, the above feature gives more variations to the critical path of planned outage in different station. In order to benchmarking again the best practices in the CANDU stations, Third Qinshan Nuclear Power Company (TQNPC) have initiated the benchmarking program among the CANDU stations aiming to standardize the outage maintenance windows and optimize the outage duration. The initial benchmarking has resulted the optimization of outage duration in Qinshan CANDU NPP and the formulation of its first long-term outage plan. This paper describes the benchmarking works that have been proven to be useful for optimizing outage duration in Qinshan CANDU NPP, and the vision of further optimize the duration with joint effort from the CANDU community. (authors)

  9. Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks

    CERN Document Server

    Chalhoub, Gerard; Misson, Michel

    2010-01-01

    Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaCARI, a time segmentation protocol that saves energy, improves the overall performance of the network and enables quality of service in terms of guaranteed access to the medium and end-to-end delays. This time segmentation is achieved by synchronizing the activity of nodes using a tree-based beacon propagation and allocating activity periods for each cluster of nodes. The tree-based topology is inspired from the cluster-tree proposed by the ZigBee standard. The efficiency of our protocol is proven analytically, by simulati...

  10. Differential reproductive timing in Echinocardium spp.: the first Mediterranean survey allows interoceanic and interspecific comparisons.

    Science.gov (United States)

    Egea, Emilie; Mérigot, Bastien; Mahé-Bézac, Chantal; Féral, Jean-Pierre; Chenuil, Anne

    2011-01-01

    Echinocardium cordatum had long been considered as cosmopolitan, but molecular data revealed it is a complex of cryptic species, with two non-hybridizing species (B1 & B2) in the Mediterranean Sea living in syntopy with Echinocardium mediterraneum. Histological analyses of the gonads from a 17-month sampling period revealed a statistically significant time lag between the Maturity Indices of E. cordatum and E. mediterraneum. The main environmental stimulus may be different for the two nominal species, possibly seawater temperature for E. cordatum and chlorophyll a concentration for E. mediterraneum. Within the E. cordatum complex, spawning timing and synchrony are different according to major geographic areas (Atlantic/Pacific/Mediterranean) and/or the corresponding genetic subdivision [A/P/(B1 & B2)]. In contrast, the effects of temperature on the reproductive cycle seem rather to mirror the genetic lineages than environmental similarities of the different localities. Between the sister species (B1 & B2) no differences could be detected, maybe due to small sample sizes. PMID:21262482

  11. ESTIMATION MODEL OF RESIDUAL LIFE-TIME OF LOCOMOTIVE FRAME BOGIE WITH ALLOWANCE FOR CREEP

    Directory of Open Access Journals (Sweden)

    V. R. Skalskyi

    2014-12-01

    Full Text Available Purpose. The problem of determining the residual life of frame bogie elements of locomotives is a great importance for predicting their work safely and avoidance potential failures on the track. This especially concern cases when such elements have creep-fatigue cracks which grow under action of cyclic loading with excerpts T1 in the cycle and reach their critical size. Here the question of the propagation of such defects (cracks arises, their kinetics and about the period of subcritical cracks growth. The aim is to develop a calculation model for determination the period of subcritical creep-fatigue cracks growth in the bogies frames of electric locomotive. The model takes into account the basic parameters of load, geometry of the construction element and cracks. Methodology. The calculation model for determination the period of subcritical creep-fatigue cracks growth in structural elements of frame under conditions of variable load time has been formulated. It is based on the first law of thermodynamics concerning to mechanics of solids slow fracture at low temperature creep and variable loadings. It is assumed that the period of unsteady creep dominates here (the first section of the creep curve. Low-temperature creep is creep of materials at temperatures T0 < 0,5Tmp, where Tmp − the melting point of the material. Findings. The analytical formula for the determination of the stress intensity factor of truck bolster with technological hole has been obtained. It is shown that by experimentally established constants of the material using the proposed analytical relations can easily determine residual resource of the bogie frame elements. Originality. The new mathematical model for describing the kinetics of creep-fatigue cracks growth in the frames bogies of electric locomotive under variable in time loadings with various time excerpts and on this base the period determination of subcritical crack growth has been proposed. Practical value

  12. Breath ammonia and trimethylamine allow real-time monitoring of haemodialysis efficacy

    International Nuclear Information System (INIS)

    Non-invasive monitoring of breath ammonia and trimethylamine using Selected-ion-flow-tube mass spectroscopy (SIFT-MS) could provide a real-time alternative to current invasive techniques. Breath ammonia and trimethylamine were monitored by SIFT-MS before, during and after haemodialysis in 20 patients. In 15 patients (41 sessions), breath was collected hourly into Tedlar bags and analysed immediately (group A). During multiple dialyses over 8 days, five patients breathed directly into the SIFT-MS analyser every 30 min (group B). Pre- and post-dialysis direct breath concentrations were compared with urea reduction, Kt/V and creatinine concentrations. Dialysis decreased breath ammonia, but a transient increase occurred mid treatment in some patients. Trimethylamine decreased more rapidly than reported previously. Pre-dialysis breath ammonia correlated with pre-dialysis urea in group B (r2 = 0.71) and with change in urea (group A, r2 = 0.24; group B, r2 = 0.74). In group B, ammonia correlated with change in creatinine (r2 = 0.35), weight (r2 = 0.52) and Kt/V (r2 = 0.30). The ammonia reduction ratio correlated with the urea reduction ratio (URR) (r2 = 0.42) and Kt/V (r2 = 0.38). Pre-dialysis trimethylamine correlated with Kt/V (r2 = 0.21), and the trimethylamine reduction ratio with URR (r2 = 0.49) and Kt/V (r2 = 0.36). Real-time breath analysis revealed previously unmeasurable differences in clearance kinetics of ammonia and trimethylamine. Breath ammonia is potentially useful in assessment of dialysis efficacy

  13. Influence of allowable interruption period on estimates of accelerometer wear time and sedentary time in older adults

    Science.gov (United States)

    Mailey, Emily L.; Gothe, Neha P.; Wójcicki, Thomas R.; Szabo, Amanda N.; Olson, Erin A.; Mullen, Sean P.; Fanning, Jason T.; Motl, Robert W.; McAuley, Edward

    2013-01-01

    The criteria one uses to reduce accelerometer data can profoundly influence the interpretation of research outcomes. The purpose of this study was to examine the influence of three different interruption periods (i.e., 20, 30, and 60 minutes) on the amount of data retained for analyses and estimates of sedentary time among older adults. Older adults (N=311; Mage=71.1) wore an accelerometer for seven days and reported wear time on an accelerometer log. Accelerometer data were downloaded and scored using 20, 30, and 60-minute interruption periods. Estimates of wear time derived using each interruption period were compared to self-reported wear time, and descriptive statistics were used to compare estimates of sedentary time. Results showed a longer interruption period (i.e., 60 minutes) yields the largest sample size and the closest approximation of self-reported wear time. A short interruption period (i.e., 20 minutes) is likely to underestimate sedentary time among older adults. PMID:23752299

  14. Influence of allowable interruption period on estimates of accelerometer wear time and sedentary time in older adults

    OpenAIRE

    Mailey, Emily L; Gothe, Neha P.; Wójcicki, Thomas R.; Szabo, Amanda N.; Olson, Erin A.; Mullen, Sean P.; Fanning, Jason T.; Motl, Robert W.; McAuley, Edward

    2013-01-01

    The criteria one uses to reduce accelerometer data can profoundly influence the interpretation of research outcomes. The purpose of this study was to examine the influence of three different interruption periods (i.e., 20, 30, and 60 minutes) on the amount of data retained for analyses and estimates of sedentary time among older adults. Older adults (N=311; Mage=71.1) wore an accelerometer for seven days and reported wear time on an accelerometer log. Accelerometer data were downloaded and sc...

  15. Nuclear cost control focuses on refueling outages

    International Nuclear Information System (INIS)

    Extending operating cycles and shortening refueling outages are the mainstays of utility efforts to improve the economics of nuclear generation. Here are key management approaches that have contributed to recent successes. Improving operating efficiency remains the byword of nuclear power producers, as they intensify their drive to reduce operation and maintenance (O and M) costs and survive--even thrive--in a competitive environment. Because replacement-power and other costs can incur penalties of $0.5-million or more for each that a nuclear unit is inoperative--and almost $3-million/day, for one utility--refueling outages are an obvious focal point for such efforts, By the same token, the impact on the bottom line is greater and more dramatic here than for other cost-saving activities

  16. Outage management and health physics issue, 2006

    International Nuclear Information System (INIS)

    The focus of the May-June issue is on outage management and health physics. Major articles/reports in this issue include: A design with experience for the U.S., by Michael J. Wallace, Constellation Generation Group; Hope to be among the first, by Randy Hutchinson, Entergy Nuclear; Plans to file COLs in 2008, by Garry Miller, Progress Energy; Evolution of ICRP's recommendations, by Lars-Erik Holm, ICRP; European network on education and training in radiological protection, by Michele Coeck, SCK-CEN, Belgium; Outage managment: an important tool for improving nuclear power plant performance, by Thomas Mazour and Jiri Mandula, IAEA, Austria; and Plant profile: Exploring new paths to excellence, by Anne Thomas, Exelon Nuclear

  17. Outage management and health physics issue, 2009

    International Nuclear Information System (INIS)

    The focus of the May-June issue is on outage management and health physics. Major articles include the following: Planning and scheduling to minimize refueling outage, by Pat McKenna, AmerenUE; Prioritizing safety, quality and schedule, by Tom Sharkey, Dominion; Benchmarking to high standards, by Margie Jepson, Energy Nuclear; Benchmarking against U.S. standards, by Magnox North, United Kingdom; Enabling suppliers for new build activity, by Marcus Harrington, GE Hitachi Nuclear Energy; Identifying, cultivating and qualifying suppliers, by Thomas E. Silva, AREVA NP; Creating new U.S. jobs, by Francois Martineau, Areva NP. Industry innovation articles include: MSL Acoustic source load reduction, by Amir Shahkarami, Exelon Nuclear; Dual Methodology NDE of CRDM nozzles, by Michael Stark, Dominion Nuclear; and Electronic circuit board testing, by James Amundsen, FirstEnergy Nuclear Operating Company. The plant profile article is titled The future is now, by Julia Milstead, Progress Energy Service Company, LLC

  18. Record outage at South Texas Project

    International Nuclear Information System (INIS)

    The outage at South Texas Project's nuclear power plant Unit 2 was completed in 17 days, 14 hours and 10 minutes. Westinghouse was responsible for three critical path activities. Steam generator maintenance and repair including plug inspections and contingency repairs; 100 percent eddy current testing; tube plugging and stabilisation; in-situ tube pressure testing; sludge lancing of the secondary side; and removal and installation of manway covers and nozzle dams. Refueling services included reactor disassembly and reassembly, refueling and dynamic rod worth measurement. Turbine generator inspection included substantial improvements to the end turn bracing system, two feed-pump turbine inspections, extensive main turbine valve change-outs, MSR inspections, lube oil cooler inspection and EH system flush. This paper details the steam generator and refueling portions of the outage program performed by Westinghouse Nuclear Services and the critical preplanning and communications activities coordinated by HLP. (author)

  19. Advanced Outage and Control Center: Strategies for Nuclear Plant Outage Work Status Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby

    2012-05-01

    The research effort is a part of the Light Water Reactor Sustainability (LWRS) Program. LWRS is a research and development program sponsored by the Department of Energy, performed in close collaboration with industry to provide the technical foundations for licensing and managing the long-term, safe and economical operation of current nuclear power plants. The LWRS Program serves to help the US nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The Outage Control Center (OCC) Pilot Project was directed at carrying out the applied research for development and pilot of technology designed to enhance safe outage and maintenance operations, improve human performance and reliability, increase overall operational efficiency, and improve plant status control. Plant outage management is a high priority concern for the nuclear industry from cost and safety perspectives. Unfortunately, many of the underlying technologies supporting outage control are the same as those used in the 1980’s. They depend heavily upon large teams of staff, multiple work and coordination locations, and manual administrative actions that require large amounts of paper. Previous work in human reliability analysis suggests that many repetitive tasks, including paper work tasks, may have a failure rate of 1.0E-3 or higher (Gertman, 1996). With between 10,000 and 45,000 subtasks being performed during an outage (Gomes, 1996), the opportunity for human error of some consequence is a realistic concern. Although a number of factors exist that can make these errors recoverable, reducing and effectively coordinating the sheer number of tasks to be performed, particularly those that are error prone, has the potential to enhance outage efficiency and safety. Additionally, outage management requires precise coordination of work groups that do not always share similar objectives. Outage

  20. Outage Key Safety Functions Configuration risk assessment for a three loops Westinghouse PWR

    International Nuclear Information System (INIS)

    Highlights: • The paper evaluates the use of PSA on the Outage configuration risk management. • A method is proposed based on Risk Criteria to evaluate the OKSFs’ Configurations. • The methodology allows to identify which of the OKSFs can be analyzed using PSA. • The method has been applied to a Pilot real case. The OKSFs procedure is evaluated. - Abstract: The methodology developed provides guidance on the use of Probabilistic Safety Assessment (PSA) for the risk-informed evaluation of Guides which ensure the compliment of Outage Key Safety Functions (OKSFs) in Nuclear Power Plants. The methodology has been applied to the 3rd and 13th Plant Operational States (POSs) as a pilot experience. These POSs are within the Operating Mode 4 (Hot Shutdown) of a three loops Westinghouse Pressurized Water Reactor. The addressed Guide requires the operability of just one charge pump as boric acid supply source. PSA gives a Core Damage Frequency increase (ΔCDF) of 1.19 × 10−6 year−1 for the unavailability of the charge pump in standby, consequently, the maximum exposure time (time for the Increase of Core Damage Probability of the configuration to reach 1.0E−06) for this situation is T = 53.6 h. Given an average time for the POSs of 40 h, it is concluded that the charge pumps requirement is correct. However, it could be improved with the inclusion of an additional inventory replacement function. This would limit the effect on risk of the charge pump unavailability. Furthermore, the need for the external electrical sources to be available during Mode 4 is ratified. The procedure requires the operability of both supply sources during the POSs. The unavailability of one of supply sources them involves a ΔCDF equal to 1.64 × 10−5 year−1 and a maximum exposure time of T = 3.89 h. This requirement is considered appropriate from the risk-informed regulation point of view

  1. International outage coding system for nuclear power plants. Results of a co-ordinated research project

    International Nuclear Information System (INIS)

    The experience obtained in each individual plant constitutes the most relevant source of information for improving its performance. However, experience of the level of the utility, country and worldwide is also extremely valuable, because there are limitations to what can be learned from in-house experience. But learning from the experience of others is admittedly difficult, if the information is not harmonized. Therefore, such systems should be standardized and applicable to all types of reactors satisfying the needs of the broad set of nuclear power plant operators worldwide and allowing experience to be shared internationally. To cope with the considerable amount of information gathered from nuclear power plants worldwide, it is necessary to codify the information facilitating the identification of causes of outages, systems or component failures. Therefore, the IAEA established a sponsored Co-ordinated Research Project (CRP) on the International Outage Coding System to develop a general, internationally applicable system of coding nuclear power plant outages, providing worldwide nuclear utilities with a standardized tool for reporting outage information. This TECDOC summarizes the results of this CRP and provides information for transformation of the historical outage data into the new coding system, taking into consideration the existing systems for coding nuclear power plant events (WANO, IAEA-IRS and IAEA PRIS) but avoiding duplication of efforts to the maximum possible extent

  2. Balance-of-plant outage availability study. Phase I. Extension report

    International Nuclear Information System (INIS)

    After completion of the Phase 1 Refueling Outage Availability Study, Babcock and Wilcox and the U.S. Department of Energy entered into a supplemental agreement to perform a balance-of-plant maintenance, inspection, and test study with the cooperation of Duke Power Company and Arkansas Power and Light Company. The objectives were (1) to expand the Phase 1 data base, including balance-of-plant activities, to reduce outage time and increase plant availability and (2) to conduct an onsite review of plant maintenance, practices to complement the utility efforts in reducing outage time and increasing on-line operational time. Data were obtained from (1) observations during the 1977 refueling outage at Oconee 3, (2) review of maintenance practices during the Arkansas Nuclear One, Unit 1, operational cycle in 1977, and (3) selected observations of the 1978 refueling outage at ANO-1. Accumulated data were then reviewed and analyzed to produce a list of improvement recommendations for Oconee 3 and ANO-1 that can be generically applied to plants of similar design and construction

  3. Outage performance improvement by state of the art reactor stud tensioning

    International Nuclear Information System (INIS)

    Actual methods of reactor closing, i.e. cover to vessel sealing, is based on the creation of an equal load to the sealing circumference by tensioning all reactor studs with an equal force. This method ensures leak tightness through equal compression of the reactor seal in normal circumstances and is largely applied for all types of reactors throughout many generations and designs of nuclear power stations. The tension generated in each reactor stud is controlled indirectly by measuring the reactor stud elongation while under stress. Most studs are designed to measure this elongation easily by conventional or more advanced systems (from individual clock gauge to integrated digital transmission to a computer screen). It is this elongation value, prescribed by the reactor vessel/cover manufacturer which must be respected and demonstrated during all reactor closing operations, weather they take place for initial hydro testing, refuelling operations or periodical hydraulic tests of the primary circuit. Closing (and re-opening) of reactor vessels has become a routine operation as it is required for fuel reloading of the reactor core. This operation is performed on all PWR and BWR type of reactors with a large variety of tooling. As most of the utilities have implemented maintenance optimisation programs, the refuelling outage is reduced to a sequence of activities that allow quick and efficient refuelling of the core. The performance and efficiency of instrumentation and tooling deployed during these essential activities are of the utmost importance to minimise the critical path of the refuelling outage. Today, in support of outage performance, many utilities have invested in new and refurbished tooling to allow quick and efficient opening and closing of the reactor vessel. The features and properties of the most performing multi stud tensioning machines currently in service in nuclear power stations world wide (Africa, Europe, Asia and USA) are presented in the paper

  4. Outage performance improvement by state of the art reactor stud tensioning

    Energy Technology Data Exchange (ETDEWEB)

    Oehler, Horst Werner [Wenutec GmbH, Industriestrasse 1, D-44534 Luenen (Germany); Vervliet, Herman [Wenutec Sarl, 2, Parc des Fontenelles, F-78870 Bailly (France)

    2006-07-01

    Actual methods of reactor closing, i.e. cover to vessel sealing, is based on the creation of an equal load to the sealing circumference by tensioning all reactor studs with an equal force. This method ensures leak tightness through equal compression of the reactor seal in normal circumstances and is largely applied for all types of reactors throughout many generations and designs of nuclear power stations. The tension generated in each reactor stud is controlled indirectly by measuring the reactor stud elongation while under stress. Most studs are designed to measure this elongation easily by conventional or more advanced systems (from individual clock gauge to integrated digital transmission to a computer screen). It is this elongation value, prescribed by the reactor vessel/cover manufacturer which must be respected and demonstrated during all reactor closing operations, weather they take place for initial hydro testing, refuelling operations or periodical hydraulic tests of the primary circuit. Closing (and re-opening) of reactor vessels has become a routine operation as it is required for fuel reloading of the reactor core. This operation is performed on all PWR and BWR type of reactors with a large variety of tooling. As most of the utilities have implemented maintenance optimisation programs, the refuelling outage is reduced to a sequence of activities that allow quick and efficient refuelling of the core. The performance and efficiency of instrumentation and tooling deployed during these essential activities are of the utmost importance to minimise the critical path of the refuelling outage. Today, in support of outage performance, many utilities have invested in new and refurbished tooling to allow quick and efficient opening and closing of the reactor vessel. The features and properties of the most performing multi stud tensioning machines currently in service in nuclear power stations world wide (Africa, Europe, Asia and USA) are presented in the paper

  5. OTRA-THS MAC to reduce Power Outage Data Collection Latency in a smart meter network

    Energy Technology Data Exchange (ETDEWEB)

    Garlapati, Shravan K [ORNL; Kuruganti, Phani Teja [ORNL; Buehrer, Richard M [ORNL; Reed, Jeffrey H [ORNL

    2014-01-01

    The deployment of advanced metering infrastructure by the electric utilities poses unique communication challenges, particularly as the number of meters per aggregator increases. During a power outage, a smart meter tries to report it instantaneously to the electric utility. In a densely populated residential/industrial locality, it is possible that a large number of smart meters simultaneously try to get access to the communication network to report the power outage. If the number of smart meters is very high of the order of tens of thousands (metropolitan areas), the power outage data flooding can lead to Random Access CHannel (RACH) congestion. Several utilities are considering the use of cellular network for smart meter communications. In 3G/4G cellular networks, RACH congestion not only leads to collisions, retransmissions and increased RACH delays, but also has the potential to disrupt the dedicated traffic flow by increasing the interference levels (3G CDMA). In order to overcome this problem, in this paper we propose a Time Hierarchical Scheme (THS) that reduces the intensity of power outage data flooding and power outage reporting delay by 6/7th, and 17/18th when compared to their respective values without THS. Also, we propose an Optimum Transmission Rate Adaptive (OTRA) MAC to optimize the latency in power outage data collection. The analysis and simulation results presented in this paper show that both the OTRA and THS features of the proposed MAC results in a Power Outage Data Collection Latency (PODCL) that is 1/10th of the 4G LTE PODCL.

  6. Empirical Evidence on Time-Varying Hedging Effectiveness of Emissions Allowances under Departures from the Cost-of-Carry Theory

    OpenAIRE

    Kai Chang

    2013-01-01

    Under departures from the cost-of-carry theory, traded spot prices and conditional volatility disturbed from futures market have significant impacts on futures price of emissions allowances, and then we propose time-varying hedge ratios and hedging effectiveness estimation using ECM-GARCH model. Our empirical results show that conditional variance, conditional covariance, and their correlation between between spot and futures prices exhibit time-varying trends. Conditional volatility of spot ...

  7. Design Concepts for an Outage Control Center Information Dashboard

    International Nuclear Information System (INIS)

    The nuclear industry, and the business world in general, is facing a rapidly increasing amount of data to be dealt with on a daily basis. In the last two decades, the steady improvement of data storage devices and means to create and collect data along the way influenced the manner in which we deal with information. Most data is still stored without filtering and refinement for later use. Many functions at a nuclear power plant generate vast amounts of data, with scheduled and unscheduled outages being a prime example of a source of some of the most complex data sets at the plant. To make matters worse, modern information and communications technology is making it possible to collect and store data faster than our ability to use it for making decisions. However, in most applications, especially outages, raw data has no value in itself; instead, managers, engineers and other specialists want to extract the information contained in it. The complexity and sheer volume of data could lead to information overload, resulting in getting lost in data that may be irrelevant to the task at hand, processed in an inappropriate way, or presented in an ineffective way. To prevent information overload, many data sources are ignored so production opportunities are lost because utilities lack the ability to deal with the enormous data volumes properly. Decision-makers are often confronted with large amounts of disparate, conflicting and dynamic information, which are available from multiple heterogeneous sources. Information and communication technologies alone will not solve this problem. Utilities need effective methods to exploit and use the hidden opportunities and knowledge residing in unexplored data resources. Superior performance before, during and after outages depends upon the right information being available at the right time to the right people. Acquisition of raw data is the easy part; instead, it is the ability to use advanced analytical, data processing and data

  8. Design Concepts for an Outage Control Center Information Dashboard

    Energy Technology Data Exchange (ETDEWEB)

    Hugo, Jacques Victor [Idaho National Lab. (INL), Idaho Falls, ID (United States); St Germain, Shawn Walter [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, Cheradan Jo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Whitesides, McKenzie Jo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Farris, Ronald Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-12-01

    The nuclear industry, and the business world in general, is facing a rapidly increasing amount of data to be dealt with on a daily basis. In the last two decades, the steady improvement of data storage devices and means to create and collect data along the way influenced the manner in which we deal with information. Most data is still stored without filtering and refinement for later use. Many functions at a nuclear power plant generate vast amounts of data, with scheduled and unscheduled outages being a prime example of a source of some of the most complex data sets at the plant. To make matters worse, modern information and communications technology is making it possible to collect and store data faster than our ability to use it for making decisions. However, in most applications, especially outages, raw data has no value in itself; instead, managers, engineers and other specialists want to extract the information contained in it. The complexity and sheer volume of data could lead to information overload, resulting in getting lost in data that may be irrelevant to the task at hand, processed in an inappropriate way, or presented in an ineffective way. To prevent information overload, many data sources are ignored so production opportunities are lost because utilities lack the ability to deal with the enormous data volumes properly. Decision-makers are often confronted with large amounts of disparate, conflicting and dynamic information, which are available from multiple heterogeneous sources. Information and communication technologies alone will not solve this problem. Utilities need effective methods to exploit and use the hidden opportunities and knowledge residing in unexplored data resources. Superior performance before, during and after outages depends upon the right information being available at the right time to the right people. Acquisition of raw data is the easy part; instead, it is the ability to use advanced analytical, data processing and data

  9. Indicators for management of planned outages in nuclear power plants

    International Nuclear Information System (INIS)

    The outages considered within the scope of this publication are planned refuelling outages (PWR and BWR nuclear power plants) and planned outages associated with major maintenance, tests and inspections (PHWR and LWGR nuclear power plants). The IAEA has published some valuable reports providing guidance and assistance to operating organizations on outage management. This TECDOC outlines main issues to be considered in outage performance monitoring and provides guidance to operating organizations for the development and implementation of outage programmes which could enhance plant safety, reliability and economics. It also complements the series of reports published by the IAEA on outage management and on previous work related to performance indicators developed for monitoring different areas of plant operation, such as safety, production, reliability and economics. This publication is based upon the information presented at a technical meeting to develop a standardized set of outage indicators for outage optimization, which was organised in Vienna, 6-9 October 2003. At this meeting, case studies and good practices relating to performance indicator utilization in the process of planned outage management were presented and discussed

  10. Distributed Power-Line Outage Detection Based on Wide Area Measurement System

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2014-07-01

    Full Text Available In modern power grids, the fast and reliable detection of power-line outages is an important functionality, which prevents cascading failures and facilitates an accurate state estimation to monitor the real-time conditions of the grids. However, most of the existing approaches for outage detection suffer from two drawbacks, namely: (i high computational complexity; and (ii relying on a centralized means of implementation. The high computational complexity limits the practical usage of outage detection only for the case of single-line or double-line outages. Meanwhile, the centralized means of implementation raises security and privacy issues. Considering these drawbacks, the present paper proposes a distributed framework, which carries out in-network information processing and only shares estimates on boundaries with the neighboring control areas. This novel framework relies on a convex-relaxed formulation of the line outage detection problem and leverages the alternating direction method of multipliers (ADMM for its distributed solution. The proposed framework invokes a low computational complexity, requiring only linear and simple matrix-vector operations. We also extend this framework to incorporate the sparse property of the measurement matrix and employ the LSQRalgorithm to enable a warm start, which further accelerates the algorithm. Analysis and simulation tests validate the correctness and effectiveness of the proposed approaches.

  11. Radiological protection for the ANGRA 1 steam generator replacement outage

    International Nuclear Information System (INIS)

    The Angra 1 Nuclear Power Plant (NPP) is a Westinghouse two-loop plant with net output before its 1P16 Outage of 632 MWe, with the Old Steam Generators (OSG) type model D3, which were replaced by two new Steam Generators with feed water-ring system. Localized in Angra dos Reis, Rio de Janeiro - Brazil, Angra 1 started in commercial operation in 1985 and, from the beginning problems related to corrosion have appeared in the Inconel 600 alloy of the tubes. The corrosion problems indicated the necessity for a strong control of the tubes thicknesses and, after a time, the ELETRONUCLEAR decided to replace the OSG. In 2009, ELETRONUCLEAR initiated in January 24, the actions for the Steam Generators Replacement - SGR. During the SGR process, several controls were applied in field, which made possible to have no radiological accidents, no dose limits exceeded, and permitted to achieve a very good result in terms of Collective Dose. This paper describes the radiological controls applied for the Angra 1 Steam Generator Replacement Outage, the radiological protection team sizing and distribution and the obtained results. (author)

  12. The cost of power outages on Taiwan's industry

    International Nuclear Information System (INIS)

    Information on the costs incurred by electricity customers as a result of power interruptions (total outages) or power curtailments (partial outages) is important for planning the desired capacity level of electricity systems, the efficient and equitable setting of electricity prices and the development of priority service programs. Therefore, evaluation of outage costs is an important issue for many power companies and energy researchers. The purpose of this study is first to distinguish between the various types of power outages and their characteristics. Second, to evaluate the cost of power outages due to shortages in generation capacity in Taiwan. And finally, to determine the implications and limitations imposed by the outage costs in terms of both economics and their role in the decision making process

  13. Effective communication - The key to satisfying outage material requirements

    International Nuclear Information System (INIS)

    Satisfying outage material requirements for a nuclear station can be a frustrating challenge. Utility inventories have been developed based primarily on preventive and corrective maintenance requirements rather than outage maintenance and modification material requirements. Since a significant volume of material procurements is necessary to satisfy outage material requirements, it is crucial to effectively communicate these needs when planning outage activities. At Public Service Electric and Gas (PSE and G) Corporation portions of the management information system (MIS) has been utilized to order, expedite, track and communicate the status of station outage material needs. This communication tool is called the material coordination system (MCS). The MCS has improved success at meeting both routine and crucial outage commitments by having material available when it is needed in the schedule

  14. PMU Placement for Line Outage Identification via Multiclass Logistic Regression

    OpenAIRE

    Kim, Taedong; Wright, Stephen J

    2014-01-01

    We consider the problem of identifying a single line outage in a power grid by using data from phasor measurement units (PMUs). When a line outage occurs, the voltage phasor of each bus node changes in response to the change in network topology. Each individual line outage has a consistent "signature," and a multiclass logistic regression (MLR) classifier can be trained to distinguish between these signatures reliably. We consider first the ideal case in which PMUs are attached to every bus, ...

  15. Outage Performance of Flexible OFDM Schemes in Packet-Switched Transmissions

    Directory of Open Access Journals (Sweden)

    Romain Couillet

    2009-01-01

    Full Text Available α-OFDM, a generalization of the OFDM modulation, is proposed. This new modulation enhances the outage capacity performance of bursty communications. The α-OFDM scheme is easily implementable as it only requires an additional time symbol rotation after the IDFT stage and a subsequent phase rotation of the cyclic prefix. The physical effect of the induced rotation is to slide the DFT window over the frequency spectrum. When successively used with different angles α at the symbol rate, α-OFDM provides frequency diversity in block fading channels. Interestingly, simulation results show a substantial gain in terms of outage capacity and outage BER in comparison with classical OFDM modulation schemes. The framework is extended to multiantenna and multicellular OFDM-based standards. Practical simulations, in the context of 3GPP-LTE, called hereafter α-LTE, sustain our theoretical claims.

  16. Outage capacity and outage rate performance of MIMO free-space optical system over strong turbulence channel

    Science.gov (United States)

    Hasan, Omar M.; Taha, Mohamed; Abu Sharkh, Osama

    2016-06-01

    In this paper, we investigate outage capacity, outage probability, and outage rate performance of multiple-input multiple-output (MIMO) free-space optical system operating over strong turbulence channels. The MIMO optical system employs intensity modulation direct detection with on-off signaling, and equal gain combining technique at the receiver. We derived novel closed-form expressions for three system metrics, namely, outage capacity, outage probability, and outage rate. Expressions derived here are based on the generalized Gamma-Gamma channel model, which is based on scintillation theory that assumes that the irradiance of the received optical wave is modeled as the product of small-scale and large-scale turbulence eddies. The results are evaluated for different values of received signal-to-noise ratios, strong turbulence conditions, and several values of transmit/receive diversity.

  17. Control Room Tasks During Refueling in Ringhals 1 Nuclear Power Plant - Operator performance during refuelling outages

    International Nuclear Information System (INIS)

    This paper discusses the performance and tasks of the operators in the control room during refuelling outages. Analyses of such events have, during the last years, shown that the risk for nuclear accidents is not negligible compared with the risk at higher reactor power levels. Some experts have the opinion that, due to mistakes during an outage, the risk for such accidents during the outage and other accidents later on during power operation is higher than in other plant situations. The high risk level is mainly a result of errors at maintenance actions and supervision of lining up of safety systems. Most of the control rooms in existing NPPs were designed more than 10 years ago. At that time the activities and the tasks for the operators were not very well understood. Procedures for refuelling and other activities during the outages were not described very well. Often the utility organisation for refuelling outages was not established at the start of the control room design. Experience from operation during many years has shown that the performance of operators can be improved in existing plant, and thus risks be reduced, by upgrading the control room. These issues have been studied as a part of the modernisation project for Ringhals 1, an ABB Atom BWR owned by Vattenfall AB in Sweden. The paper will describe the working model for upgrading the control room and important issues to take care of with respect to refuelling outages. The identified issues will be used as the input for improving control room philosophy and the individual technical systems. (authors)

  18. Application of RCM analysis to the optimization of outages

    International Nuclear Information System (INIS)

    Considerations to be made before starting RCM analyses at selected systems of the Dukovany-3 reactor unit are discussed. Such systems should be selected where a shortening of their planned maintenance during outages could affect the total length of the outage period. (P.A.)

  19. Kozloduy NPP units 5 and 6 modernization program. Measures implementation in outages

    International Nuclear Information System (INIS)

    The units 5 and 6 modernization program is a highly demanding program composed by many plant modifications and studies about plant conditions. The program measures implementation during the units outages represents a challenge by the need to compromise shut down duration with the workload related to measures installation. The units shutdown duration should be kept to the planned duration. In parallel, contractors work has to be organized, planned and performed to allow successful measures completion. In accordance with the contract requirements, contractors prepare installation documents which comprise all activities to be performed during the installation and testing of the measures. The subcontractors complement these installation documents with the project organization and execution documents, which include the manpower skills, qualifications, work orders, and other important installation instructions and information. Contractors prepared detailed installation schedules, and these were integrated by Parsons E and C in the Integrated installation schedule. The integrated schedule proved to be useful to identify possible area usage conflicts and manpower overlapping, with appropriate results for electrical, instrumentation and control work, and for the utilization of the polar crane in the containment building. Contractors installation schedules were updated on a weekly basis, showing variances versus the target, and manpower histograms for the resource loading. Organization of contractors work was supported by KNPP plant outage meetings, in which status and problems were addressed, and solution and/or corrective actions defined for further implementation. KNPP meetings were planned on a daily basis for most relevant or critical measures, or on a weekly basis for less intensive measures. KNPP meetings proved to be an excellent communication tool for keeping the measures under control and monitoring KNPP defined personnel responsible for authorizing changes, in

  20. Elimination of maintenance outage and cost reduction by development of outage-free maintenance techniques

    International Nuclear Information System (INIS)

    The development program of KEPCO on outage-free maintenance techniques for distribution line work since 1984 is overviewed. It has succeeded in eliminating maintenance outages since 1989. The original aim was to improve customer satisfaction. However, in all, four benefits were realised through the development. These are cost reduction, securing of worker safety, improvement of customer service, and advancement of distribution techniques and morale in KEPCO. The introduction of robotic techniques for maintenance work and manipulator techniques for repair work is planned for further modernization. These new techniques are helping in both work safety and work efficiency improvement. Cost reduction and advancement of distribution line work techniques is also considered. (R.P.)

  1. Incorporating outage management principles into the advanced light water reactor

    International Nuclear Information System (INIS)

    In the United States there are 110 light water reactor (LWR) plants currently in operation, with a total generating capacity of 102 580 MW(electric). These plants include 37 boiling water reactor (BWR) and 73 pressurized water reactor (PWR) units. Since 1980, more than 40 nuclear power plants have entered service in the United States. However, no new plants have been ordered by utilities and owners groups since 1978. There will come a time in the not-too-distant future that new, large electricity generating units will be needed to supply expected increases in base-load capacity. Will the new advanced LWR (ALWR) designs be able to pass muster and be chosen to help meet that need? With outage management at operating plants improving every year, what can the ALWR designs offer that has not already been incorporated?

  2. Operating plant scorecard: A statistical analysis of plant outage performance

    International Nuclear Information System (INIS)

    The purpose of this paper is to examine the relationship between outage maintenance practices and overall plant performance at domestic nuclear stations with Westinghouse nuclear steam supply systems. While the specific data in this paper reflect only the Westinghouse subset of US nuclear stations, the author feels that the conclusions reached may well be applicable to light water reactor (LWR) systems in general. The trend toward longer fuel cycles at domestic nuclear stations is inevitable from the standpoint of fuel economics and spent-fuel storage considerations. The challenge is to adjust not only maintenance practices but maintenance philosophy as well, so that longer cycle times are not achieved at the expense of unit availability

  3. Oscillation-Driven Spike-Timing Dependent Plasticity Allows Multiple Overlapping Pattern Recognition in Inhibitory Interneuron Networks.

    Science.gov (United States)

    Garrido, Jesús A; Luque, Niceto R; Tolu, Silvia; D'Angelo, Egidio

    2016-08-01

    The majority of operations carried out by the brain require learning complex signal patterns for future recognition, retrieval and reuse. Although learning is thought to depend on multiple forms of long-term synaptic plasticity, the way this latter contributes to pattern recognition is still poorly understood. Here, we have used a simple model of afferent excitatory neurons and interneurons with lateral inhibition, reproducing a network topology found in many brain areas from the cerebellum to cortical columns. When endowed with spike-timing dependent plasticity (STDP) at the excitatory input synapses and at the inhibitory interneuron-interneuron synapses, the interneurons rapidly learned complex input patterns. Interestingly, induction of plasticity required that the network be entrained into theta-frequency band oscillations, setting the internal phase-reference required to drive STDP. Inhibitory plasticity effectively distributed multiple patterns among available interneurons, thus allowing the simultaneous detection of multiple overlapping patterns. The addition of plasticity in intrinsic excitability made the system more robust allowing self-adjustment and rescaling in response to a broad range of input patterns. The combination of plasticity in lateral inhibitory connections and homeostatic mechanisms in the inhibitory interneurons optimized mutual information (MI) transfer. The storage of multiple complex patterns in plastic interneuron networks could be critical for the generation of sparse representations of information in excitatory neuron populations falling under their control. PMID:27079422

  4. Consequences of long-term power outages and high electricity prices lasting for months

    International Nuclear Information System (INIS)

    Several areas in the world have experienced electricity outages for longer periods of time, but the consequences of these are sparsely documented. There is a need for further analysis of the socioeconomic consequences of the outages. In addition to KILE (Quality adjusted revenue framework for un supplied energy) costs one has to take into account that the costs often increase proportionally with the durance of the outage, and that KILE tariffs do not reflect lost consumer's surplus for products that are not produced during an outage. A good example is the public underground transport, where the company's economical loss can be significantly smaller than the loss of utility value for the travellers. If the authorities act with reasonability it is difficult to see that periods with very high prices represent a big problem. The most important problems are related to diffused effects, especially for households with a weak economy. These problems can be solved with improved contractual forms (price guarantees) or by transfers to the households, without weakening the incentives for electricity economising (ml)

  5. Allowance trading

    International Nuclear Information System (INIS)

    This paper reports that Title IV of the Clean Air Act Amendments of 1990 (CAAA) calls for a reduction of 10 million tons of sulfur dioxide (SO2) emissions per year from 1989 levels. Since utilities are the largest single group of emitters of SO2, Title IV concentrates on utilities. Rather than dictate which utilities will reduce emission, the CAAA calls for a system of allowances. Each allowance will permit a utility to emit 1 ton of SO2 in a given calendar year. Utilities will be issued allowances based on their average consumption of fossil fuel in 1985, 1986, and 1987. If a utility is able to reduce emissions below the level at which they are allowed to emit, they may bank, trade, or sell the extra allowances If a utility is unable to reduce emissions to their allowed level, they must buy allowances. new utilities which were not assigned allowances must buy them. In addition to free market trading, EPA will hold auctions and direct sales to provide allowances for utilities unable to obtain them on the open market

  6. Role of shutdown PRA in outage planning

    International Nuclear Information System (INIS)

    As part of the ABWR shutdown risk evaluation, a reliability assessment of the decay heat removal (DHR) function was completed to determine the minimum number of systems that must be kept available during shutdown to ensure that the risks associated with the loss of decay heat removal events are acceptable. The selected criteria for the study is a conditional core damage probability of 1.0E-05. The analysis was carried out by developing probabilistic risk assessment (PRA) models for shutdown conditions. The plant is assumed to be initially shutdown with the decay heat being removed by the residual heat removal (RHR) system in the shutdown cooling mode. Loss of the operating RHR system due to random failure, loss of service water, and loss of offsite power are assumed to be the initiating events. The results of this study provide guidance regarding various combinations of systems that can be kept available during a plant outage, to ensure acceptable risk associated with loss of the DHR systems. This minimum set of systems will give a utility flexibility in scheduling maintenance activities for DHR systems. This PRA-based approach could be easily extended to operating BWR plants using information available from the operating plant IPE

  7. Outage Key Safety Functions Configuration risk assessment for a three loops Westinghouse PWR

    Energy Technology Data Exchange (ETDEWEB)

    Cid, M.M.; Dies, J., E-mail: javier.Dies@Upc.Edu; Tapia, C., E-mail: carlos.Tapia@Upc.Edu; Diaz, P., E-mail: pedro.diaz.bayona@upc.edu

    2015-09-15

    Highlights: • The paper evaluates the use of PSA on the Outage configuration risk management. • A method is proposed based on Risk Criteria to evaluate the OKSFs’ Configurations. • The methodology allows to identify which of the OKSFs can be analyzed using PSA. • The method has been applied to a Pilot real case. The OKSFs procedure is evaluated. - Abstract: The methodology developed provides guidance on the use of Probabilistic Safety Assessment (PSA) for the risk-informed evaluation of Guides which ensure the compliment of Outage Key Safety Functions (OKSFs) in Nuclear Power Plants. The methodology has been applied to the 3rd and 13th Plant Operational States (POSs) as a pilot experience. These POSs are within the Operating Mode 4 (Hot Shutdown) of a three loops Westinghouse Pressurized Water Reactor. The addressed Guide requires the operability of just one charge pump as boric acid supply source. PSA gives a Core Damage Frequency increase (ΔCDF) of 1.19 × 10{sup −6} year{sup −1} for the unavailability of the charge pump in standby, consequently, the maximum exposure time (time for the Increase of Core Damage Probability of the configuration to reach 1.0E−06) for this situation is T = 53.6 h. Given an average time for the POSs of 40 h, it is concluded that the charge pumps requirement is correct. However, it could be improved with the inclusion of an additional inventory replacement function. This would limit the effect on risk of the charge pump unavailability. Furthermore, the need for the external electrical sources to be available during Mode 4 is ratified. The procedure requires the operability of both supply sources during the POSs. The unavailability of one of supply sources them involves a ΔCDF equal to 1.64 × 10{sup −5} year{sup −1} and a maximum exposure time of T = 3.89 h. This requirement is considered appropriate from the risk-informed regulation point of view.

  8. Good practices for outage management in nuclear power plants

    International Nuclear Information System (INIS)

    As a follow-up to an earlier Technical Document on Good Practices for Improved Nuclear Power Plant Performance (IAEA-TECDOC-498), the Agency has produced a more focused technical report on good practices associated with nuclear power plant outage planning and execution. As with the earlier document, the overall aim is that by identifying good practices in the key aspects of outage management, overall world nuclear performance will improve and the gap between excellent performers and operators with developing programmes will be narrowed. This document has been produced through the contribution of numerous operators and government agencies. It aims at minimizing text and focusing on actual good practices in use which can be found in the annexes. While the specific methods used to achieve excellence in maintenance/refuelling outages may differ, the fundamental requirements of outage management are discussed

  9. Outage performance of cognitive radio systems with Improper Gaussian signaling

    KAUST Repository

    Amin, Osama

    2015-06-14

    Improper Gaussian signaling has proved its ability to improve the achievable rate of the systems that suffer from interference compared with proper Gaussian signaling. In this paper, we first study impact of improper Gaussian signaling on the performance of the cognitive radio system by analyzing the outage probability of both the primary user (PU) and the secondary user (SU). We derive exact expression of the SU outage probability and upper and lower bounds for the PU outage probability. Then, we design the SU signal by adjusting its transmitted power and the circularity coefficient to minimize the SU outage probability while maintaining a certain PU quality-of-service. Finally, we evaluate the proposed bounds and adaptive algorithms by numerical results.

  10. Fessenheim makes the most of its ten year outage

    International Nuclear Information System (INIS)

    EdF took advantage of the long shutdown opportunity during its Fessenheim 1 ten year outage (April to October 1989) to carry out a number of tests and modifications additional to normal outage operations. The major activities incorporated in this outage were: both normal outage operations and unscheduled operations carried out in response to problems found after inspections had been carried out; a reactor coolant pressure boundary hydro test, to comply with French regulations; a containment test (a mandatory safety requirement); 147 modifications, carried out as part of the 900MWe series upgrading programme; additional design studies initiated by EdF upon request from the Nuclear Facility Central Surveillance Service (SCSIN). (author)

  11. Trading wireless information and power transfer: Relay selection to minimize the outage probability

    OpenAIRE

    Butt, M. Majid; Nasir, Adnan; Mohamed, Amr; Guizani, Mohsen

    2014-01-01

    This paper studies the outage probability minimization problem for a multiple relay network with energy harvesting constraints. The relays are hybrid nodes used for simultaneous wireless information and power transfer from the source radio frequency (RF) signals. There is a trade-off associated with the amount of time a relay node is used for energy and information transfer. Large intervals of information transfer implies little time for energy harvesting from RF signals and thus, high probab...

  12. CHILD ALLOWANCE

    CERN Multimedia

    Human Resources Division

    2001-01-01

    HR Division wishes to clarify to members of the personnel that the allowance for a dependent child continues to be paid during all training courses ('stages'), apprenticeships, 'contrats de qualification', sandwich courses or other courses of similar nature. Any payment received for these training courses, including apprenticeships, is however deducted from the amount reimbursable as school fees. HR Division would also like to draw the attention of members of the personnel to the fact that any contract of employment will lead to the suppression of the child allowance and of the right to reimbursement of school fees.

  13. OPG's approach of crediting natural circulation in outage heat sinks

    International Nuclear Information System (INIS)

    A review of crediting natural circulation as a backup means of removing the reactor core decay heat during an outage in Ontario Power Generation's nuclear stations was completed in 2000. The objective was to define the configurations and conditions under which natural circulation can be confidently credited as an effective heat transport mechanism for use in shutdown heat sink management. The project was an interdisciplinary program, and involved analyses in the areas of heat transport system thermalhydaulics, fuel and fuel channel thermal and mechanical behaviour, radiation physics, and probabilistic risks. The assessment shows that it is economically acceptable to credit natural circulation as a backup means of removing the core decay heat whenever the no fuel failure criteria are met. The economic risks associated with such a potential use decrease with time after shutdown. The waiting times after shutdown when there would be various levels of risks of damaging the pressure tubes and fuel bundles were derived for use in planning maintenance activities so as to minimize the economic risks. (author)

  14. Psychosocial work strain of maintenance personnel during annual outage and normal operation in a nuclear power plant

    International Nuclear Information System (INIS)

    This paper reports on a study which evaluates psychosocial work demands during the annual outage for a maintenance work group in a nuclear power plant. The study is based on a stress paradigm and it has been asserted that increased work strain would have a negative effect on performance. Nineteen workers, aged 20-55 years, participated in the study. The subjects filled out a questionnaire comparing work strain during annual outage and normal operation. During the outage period a 3-shift 24-hour work schedule, including nightwork, was used (working hours during normal operation was 7-16). Increased demands on concentration and vigilance, increased time pressure and strain on social relations within the group were found to characterize work during annual outage. Interestingly, for specific work tasks an association was found between the risk of making errors and high psychological workload. Increased work strain, shiftwork including nightwork and reduced social support are important psychosocial risk factors that might contribute to human error during the outage period

  15. TOPOLOGY AND CASCADING LINE OUTAGES IN POWER GRIDS

    Institute of Scientific and Technical Information of China (English)

    David L. PEPYNE

    2007-01-01

    Motivated by the small world network research of Watts & Strogatz, this paper studies relationships between topology and cascading line outages in electric power grids. Cascading line outages are a type of cascading collapse that can occur in power grids when the transmission network is congested. It is characterized by a self-sustaining sequence of line outages followed by grid breakup, which generally leads to widespread blackout. The main findings of this work are twofold: On one hand, the work suggests that topologies with more disorder in their interconnection topology tend to be robust with respect to cascading line outages in the sense of being able to support greater generation and demand levels than more regularly interconnected topologies. On the other hand, the work suggests that topologies with more disorder tend to be more fragile in that should a cascade get started, they tend to break apart after fewer outages than more regularly interconnected topologies. Thus, as has been observed in other complex networks, there appears to be a tradeoff between robustness and fragility.These results were established using synthetically generated power grid topologies and verified using the IEEE 57 bus and 188 bus power grid test cases.

  16. Prediction of power system frequency response after generator outages using neural nets

    Energy Technology Data Exchange (ETDEWEB)

    Djukanovic, M.B.; Popovic, D.P. (Electrotechnicki Inst. ' Nikola Tesla' , Belgrade (Yugoslavia)); Sobajic, D.J.; Pao, Y.-H. (Case Western Reserve Univ., Cleveland, OH (United States))

    1993-09-01

    A new methodology is presented for estimating the frequency behaviour of power systems necessary for an indication of under-frequency load shedding in steady-state security assessment. It is well known that large structural disturbances such as generator tripping or load outages can initiate cascading outages, system separation into islands, and even the complete breakup. The approach provides a fairly accurate method of estimating the system average frequency response without making simplifications or neglecting non-linearities and small time constants in the equations of generating units, voltage regulators and turbines. The efficiency of the new procedure is demonstrated using the New England power system model for a series of characteristic perturbations. The validity of the proposed approach is verified by comparison with the simulation of short-term dynamics including effects of control and automatic devices. (author)

  17. Innovation on Energy Power Technology (15)Great Advances in Power System Stabilizing Technology triggered by the Wide-area Outage

    Science.gov (United States)

    Egawa, Masanao

    On July 23, 1987, a very hot day, the largest wide-area power outage occurred in Kanto-Area, Japan. The cause was a voltage collapse on the bulk power network of Tokyo Electric Power Company, due to the abnormal rate of demand rising following resume after lunch break. Aggressive studies on voltage collapse throughout industry and university have led to great advances in power system stability. This essay describes the detail record of the outage, the applied countermeasures, and the inside story when the multiple voltage solutions of power flow on actual power system were found out for the first time.

  18. Outage and Local Throughput and Capacity of Random Wireless Networks

    CERN Document Server

    Haenggi, Martin

    2008-01-01

    Outage probabilities and single-hop throughput are two important performance metrics that have been evaluated for certain specific types of wireless networks. However, there is a lack of comprehensive results for larger classes of networks, and there is no systematic approach that permits the convenient comparison of the performance of networks with different geometries and levels of randomness. The uncertainty cube is introduced to categorize the uncertainty present in a network. The three axes of the cube represent the three main potential sources of uncertainty in interference-limited networks: the node distribution, the channel gains (fading), and the channel access (set of transmitting nodes). For the performance analysis, a new parameter, the so-called {\\em spatial contention}, is defined. It measures the slope of the outage probability in an ALOHA network as a function of the transmit probability $p$ at $p=0$. Outage is defined as the event that the signal-to-interference ratio (SIR) is below a certain...

  19. Outage Risk Assessment and Management (ORAM) thermal-hydraulics toolkit

    International Nuclear Information System (INIS)

    A PC-based thermal-hydraulic toolkit for use in support of outage optimization, management and risk assessment has been developed. This mechanistic toolkit incorporates simple models of key thermal-hydraulic processes which occur during an outage, such as recovery from or mitigation of outage upsets; this includes heat-up of water pools following loss of shutdown cooling, inadvertent drain down of the RCS, boiloff of coolant inventory, heatup of the uncovered core, and reflux cooling. This paper provides a list of key toolkit elements, briefly describes the technical basis and presents illustrative results for RCS transient behavior during reflux cooling, peak clad temperatures for an uncovered core and RCS response to loss of shutdown cooling. (author)

  20. 41 CFR 302-2.110 - Are there time factors that we must consider for allowing an employee to complete all aspects of...

    Science.gov (United States)

    2010-07-01

    ... that we must consider for allowing an employee to complete all aspects of relocation? 302-2.110 Section... Are there time factors that we must consider for allowing an employee to complete all aspects of... travel is approved and inform employees that they must complete all aspects of relocation within a...

  1. Impacts of organization and management on outage performance

    International Nuclear Information System (INIS)

    From probabilistic safety assessments and root cause analyses for incidents/accidents, the risk at refueling outage has recently been recognized to be comparable to (or even more significant than) the commonly evaluated risk at power in a Nuclear Power Plant (NPP). This paper summarizes the major findings in the aspect of 'organization and management', which is identified to have significant impacts on outage performance in the qualitative assessment of a PWR plant. In order to reduce the potential risk arisen from those identified imperfections, the corresponding suggestions are also proposed. (author)

  2. An Isotropic SPPP Mo del for Femto cells Networks with Outage Probability Constraints

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; TIAN Hui

    2015-01-01

    Femtocells have been considered as a cost-eff ective solution to unload traffic from already overbur-dened macrocell networks in 4G cellular networks. The severe interference in spectrum-sharing macro and femto networks may cause User-equipment (UE) to experience outage. We derive an utmost isotropic Spatial Poisson point process (SPPP) density for Femtocell access points (FAPs) under the UEs’ outage constraints. Based on the derived isotropic SPPP density, we propose a distributed transmit probability self-regulation scheme for an FAP to adapt its transmit probability per Transmission time in-terval (TTI). The scheme adjusts the homogeneous dis-tributed FAPs in practice deployment to the proposed isotropic one. Simulation results show that the derived den-sity can fulfill the outage probability constraints of UEs while accommodating the maximum femtocells. The self-regulation scheme can adapt the femtocell transmit prob-abilities to provide reliable downlink service, for even a large number of femtocells per cell site.

  3. Distributions of large-scale power outages : extreme values and the effect of truncation

    Energy Technology Data Exchange (ETDEWEB)

    Zeretzki, R.L. [Tenessee Univ., Knoxville, TN (United States). Dept. of Statistics; Briggs, W.M. [New York Methodist Hospital, Brooklyn, NY (United States); Sterling, M. [Oak Ridge Operations, Oak Ridge, TN (United States). Dept. of Energy; Shankar, M. [Oak Ridge National Laboratory, Oak Ridge, TN (United States). Computational Sciences

    2009-07-01

    Studies using complex systems theories have suggested that many power outages follow a power law distribution over certain time scales. In this study, a North American Electric Reliability Council (NERC) database was used to investigate the distribution of large-scale power outages between 1984 and 2006. The aim of the study was to statistically characterize the distribution of outages. Modern statistical methodologies were used to fit the data with various distributions. The statistical theory of extremes was then used to account for the truncation of smaller values in the reporting criteria. Results of the study were then used to investigate the risk management consequences of various tail behaviors. Techniques were developed to fit the actual distribution of the day including log-log rank plots and novel diagnostic plots. A central limit theorem was applied to the log of results in order to produce normalized data. The study showed that immediate investments to increase the reliability of the transmission and distribution network would be beneficial. 24 refs., 2 tabs., 6 figs.

  4. Oscillation-Driven Spike-Timing Dependent Plasticity Allows Multiple Overlapping Pattern Recognition in Inhibitory Interneuron Networks

    DEFF Research Database (Denmark)

    Garrido, Jesús A.; Luque, Niceto R.; Tolu, Silvia;

    2016-01-01

    The majority of operations carried out by the brain require learning complex signal patterns for future recognition, retrieval and reuse. Although learning is thought to depend on multiple forms of long-term synaptic plasticity, the way this latter contributes to pattern recognition is still poorly...... understood. Here, we have used a simple model of afferent excitatory neurons and interneurons with lateral inhibition, reproducing a network topology found in many brain areas from the cerebellum to cortical columns. When endowed with spike-timing dependent plasticity (STDP) at the excitatory input synapses...... and at the inhibitory interneuron-interneuron synapses, the interneurons rapidly learned complex input patterns. Interestingly, induction of plasticity required that the network be entrained into theta-frequency band oscillations, setting the internal phase-reference required to drive STDP. Inhibitory...

  5. Outage planning: basics are the key to success

    International Nuclear Information System (INIS)

    Northeast Utilities Service Company (NUSCO) services approx.1,126,000 customers in Connecticut and western Massachusetts. The company's operating nuclear facilities include Connecticut Yankee, Millstone Unit 1, and Millstone Unit 2. Although NUSCO's earliest commercial operation of a nuclear plant dates back to January 1968, the cost and scheduling section was not created until 1979. The section was created as a corporate service organization composed of four major units: cost engineering, estimating, backfit/betterment planning, and outage planning. To date, 12 of the 28 nuclear refueling outages have been planned and scheduled by the department. There is now a wealth of outage information available from both company personnel and a historical computer database. Current directions within cost and scheduling have been back to basics. The backfit/betterment planning unit has been working with the in-house engineering and design groups to define their work scopes better, to develop a generic work breakdown structure, and to provide better resource planning. The estimating and cost engineering units are working to utilize this to provide true cost and schedule integration. Outage planning will wait for these developments on projects before discussing possible applications in the field

  6. Practice of fuel management and outage strategy at Paks NPP

    International Nuclear Information System (INIS)

    The Paks Nuclear Power Plant generates almost 40% of Hungarian electricity production at lowest price. In spite of this fact the reduction of operational and maintenance costs is one of the most important goal of the plant management. The proper fuel management and outage strategy can give a considerable influence for this cost reduction. The aim of loading pattern planning is to get the required cycle length with available fuel cassettes and to keep all key parameters of safety analysis under safety limits. Another important point is production at profit, where both the fuel and spent fuel cost are determining. Earlier the conditions given by our only fuel supplier restricted our possibilities, so at the beginning the fuel arrangement changing was the only way to improve efficiency of fuel using. As first step we introduced the low leakage core design. The next step was the 4 years cycle using of some cassettes. By this way nearly half of 3 years cycle old cassettes remained in the core for fourth cycle. In the immediate future we want to use profiled cassettes developed by Russian supplier. Simultaneously we will load new type of WWER cassettes with burnable poison developed by BNFL Company. Hereby we can apply more BNFL cassettes for four years cycle even more. Both cost of fuel and number of spent fuel can be reduced besides keeping parameters under safety limits. The Hungarian in service inspection rules determine that every four year we have to make a complete inspection of reactor vessel. Therefore earlier we had two types of outages. Every 4 years we planned a long outage with 55-65 days duration and normal ones with about 30-35 days duration between the long ones. During the normal outages this way did not give us enough room to utilise the shortest possible critical path determined by works on reactor. Some years ago we changed our outage strategy. Now we plan every 4 years a long outage, and between them one normal and two short ones. As a result the

  7. ALARA database value in future outage work planning and dose management

    International Nuclear Information System (INIS)

    ALARA database encompassing job-specific duration and man-rem plant specific information over three refueling outages represents an invaluable tool for the outage work planner and ALARA engineer. This paper describes dose-management trends emerging based on analysis of three refueling outages at Clinton Power Station. Conclusions reached based on hard data available from a relational database dose-tracking system is a valuable tool for planning of future outage work. The system's ability to identify key problem areas during a refueling outage is improving as more outage comparative data becomes available. Trends over a three outage period are identified in this paper in the categories of number and type of radiation work permits implemented, duration of jobs, projected vs. actual dose rates in work areas, and accuracy of outage person-rem projection. The value of the database in projecting 1 and 5 year station person-rem estimates is discussed

  8. An EOQ model for time-dependent deteriorating items with alternating demand rates allowing shortages by considering time value of money

    Directory of Open Access Journals (Sweden)

    Kundu Antara

    2013-01-01

    Full Text Available The present paper deals with an economic order quantity (EOQ model of an inventory problem with alternating demand rate: (i For a certain period, the demand rate is a non linear function of the instantaneous inventory level. (ii For the rest of the cycle, the demand rate is time dependent. The time at which demand rate changes, may be deterministic or uncertain. The deterioration rate of the item is time dependent. The holding cost and shortage cost are taken as a linear function of time. The total cost function per unit time is obtained. Finally, the model is solved using a gradient based non-linear optimization technique (LINGO and is illustrated by a numerical example.

  9. Outage analysis of opportunistic decode-and-forward relaying

    KAUST Repository

    Tourki, Kamel

    2010-09-01

    In this paper, we investigate a dual-hop opportunistic decode-and-forward relaying scheme where the source may or not be able to communicate directly with the destination. We first derive statistics based on exact probability density function (PDF) of each hop. Then, the PDFs are used to determine closed-form outage probability expression for a transmission rate R. Furthermore, we evaluate the asymptotic outage performance and the diversity order is deduced. Unlike existing works where the analysis focused on high signal-to-noise ratio (SNR) regime, such results are important to enable the designers to take decisions regarding practical systems that operate at low SNR regime. We show that performance simulation results coincide with our analytical results under practical assumption of unbalanced hops. © 2010 IEEE.

  10. Outage Constrained Secrecy Rate Maximization Using Cooperative Jamming

    CERN Document Server

    Luo, Shuangyu; Petropulu, Athina

    2012-01-01

    We consider a Gaussian MISO wiretap channel, where a multi-antenna source communicates with a single-antenna destination in the presence of a single-antenna eavesdropper. The communication is assisted by multi-antenna helpers that act as jammers to the eavesdropper. Each helper independently transmits noise which lies in the null space of the channel to the destination, thus creates no interference to the destination. Under the assumption that there is eavesdropper channel uncertainty, we derive the optimal covariance matrix for the source signal so that the secrecy rate is maximized subject to probability of outage and power constraints. Assuming that the eavesdropper channels follow zero-mean Gaussian model with known covariances, we derive the outage probability in a closed form. Simulation results in support of the analysis are provided.

  11. Outage and BER analysis for ultrawideband-based WPAN in Nakagami-m fading channels

    KAUST Repository

    Mehbodniya, Abolfazl

    2011-09-01

    This paper presents a performance analysis of multiband orthogonal frequency-division multiplexing (MB-OFDM) in ultra wideband (UWB)-based personal area networks (UPANs). A UPAN consists of devices with different UWB technologies at the physical layer. Approximate expressions for the outage probability and average bit error rate (BER) are derived in closed form for the MB-OFDM target receiver, taking into account multi-user interference (MUI), as well as external interference in the form of time-hopping (TH) and direct-sequence (DS) UWB signals. © 2010 IEEE.

  12. Outage analysis of interference-limited systems using STBC with co-channel MIMO interferers

    Institute of Scientific and Technical Information of China (English)

    Yongzhao LI; Leonard J.CIMINI,JR.; Nageen HIMAYAT

    2009-01-01

    The performance of Space-Time Block Coding (STBC) with co-channel MIMO interference is investigated.For an interference-limited environment, the closed-form ex-pressions for the probability density functions of the signal-to-interference ratio are derived and applied to analyze the outage probability with three typical types of co-channel MIMO interferers: STBC, open-loop spatial multiplexing and closed-loop spatial multiplexing. Both theoretical anal-yses and simulation results show that the performance of STBC is independent of the MIMO modes used in the in-terfering links.

  13. Outage probability of distributed beamforming with co-channel interference

    KAUST Repository

    Yang, Liang

    2012-03-01

    In this letter, we consider a distributed beamforming scheme (DBF) in the presence of equal-power co-channel interferers for both amplify-and-forward and decode-and-forward relaying protocols over Rayleigh fading channels. We first derive outage probability expressions for the DBF systems. We then present a performance analysis for a scheme relying on source selection. Numerical results are finally presented to verify our analysis. © 2011 IEEE.

  14. "I Have to Rest All the Time Because You Are Not Allowed to Play": Exploring Children's Perceptions of Autonomy during Sleep-Time in Long Day Care Services

    Science.gov (United States)

    Nothard, Michaela; Irvine, Susan; Theobald, Maryanne; Staton, Sally; Pattinson, Cassandra; Thorpe, Karen

    2015-01-01

    Daytime sleep is a significant part of the daily routine for children attending early childhood education and care (ECEC) services in Australia and many other countries. The practice of sleep-time can account for a substantial portion of the day in ECEC and often involves a mandated sleep/rest period for all children, including older…

  15. Upgrading BWR training simulators for annual outage operation training

    International Nuclear Information System (INIS)

    Based upon the recently developed quality assurance program by the Japanese electric companies, BWR Operator Training Center (BTC) identified the needs to enhance operators' knowledge and skills for operations tasks during annual outage, and started to develop a dedicated operator training course specialized for them. In this paper, we present the total framework of the training course for annual outage operations and the associated typical three functions of our full-scope simulators specially developed and upgraded to conduct the training; namely, (1) Simulation model upgrade for the flow and temperature behavior concerning residual heat removal (RHR) system with shutdown cooling mode, (2) Addition of malfunctions for DC power supply equipment, (3) Simulation model upgrade for water filling operation for reactor pressurization (future development). We have implemented a trial of the training course by using the upgraded 800MW full-scope training simulator with functions (1) and (2) above. As the result of this trial, we are confident that the developed training course is effective for enhancing operators' knowledge and skills for operations tasks during annual outage. (author)

  16. Compound Outage Probability and Capacity of a Class of Fading MIMO Channels with Channel Distribution Uncertainty

    CERN Document Server

    Ioannou, Ioanna; Loyka, Sergey

    2011-01-01

    Outage probability and capacity of a class of block-fading MIMO channels are considered with partial channel distribution information. Specifically, the channel or its distribution are not known but the latter is known to belong to a class of distributions where each member is within a certain distance (uncertainty) from a nominal distribution. Relative entropy is used as a measure of distance between distributions. Compound outage probability defined as min (over the transmit signal distribution) -max (over the channel distribution class) outage probability is introduced and investigated. This generalizes the standard outage probability to the case of partial channel distribution information. Compound outage probability characterization (via one-dimensional convex optimization), its properties and approximations are given. It is shown to have two-regime behavior: when the nominal outage probability decreases (e.g. by increasing the SNR), the compound outage first decreases linearly down to a certain threshol...

  17. Inducement of IGA/SCC in Inconel 600 steam generator tubing during unit outages

    International Nuclear Information System (INIS)

    The degradation of Unit 4 SG tubing by IGA/SCC has limited both the operating period and end of life predictions for Unit 4 since restart in late 2003. The circumferential IGA/SCC has been most significant in SG4 with substantial increases in both initiation and growth rates from 2005 through the spring of 2007. A detailed review of the occurrence of circumferential OD IGA/SCC at the RTZ in the HL TTS region of Bruce 4 steam generator tubes has led a conclusion that it is probable that the IGA/SCC has been the result of attack by partially reduced sulfur species such as tetrathionates and thiosulfates during periods of low temperature exposure. It is believed that attack of this type has mostly likely occurred during startup evolutions following outages as the result the development of aggressive reduced sulfur species in the TTS region during periods when the boilers were fully drained for maintenance activities. The modification of outage practices to limit secondary side oxygen ingress in the spring of 2007 has apparently arrested the degradation and has had significant affects on the allowable operating interval and end of life predictions for the entire unit. (author)

  18. Key issues for the control of refueling outage duration and costs in PWR nuclear power plants

    International Nuclear Information System (INIS)

    For several years, EDF, within the framework of the CIDEM project and in collaboration with some German Utilities, has undertaken a detailed review of the operating experience both of its own NPP and of foreign units, in order to improve the performances of future units under design, particularly the French-German European Pressurized Reactor (EPR) project. This review made it possible to identify the key issues allowing to decrease the duration of refueling and maintenance outages. These key issues can be classified in 3 categories: Design; Maintenance and Logistic Support; Outage Management. Most key issues in the design field and some in the logistic support field have been studied and could be integrated into the design of any future PWR unit, as for the EPR project. Some of them could also be adapted to current plants, provided they are feasible and profitable. The organization must be tailored to each country, utility or period: it widely depends on the power production environment, particularly in a deregulation context. (author)

  19. Overview of Pickering NGS Units 1 and 2 retube outage

    International Nuclear Information System (INIS)

    After the Pickering NGS Unit 2 pressure tube failure in August 1983, a decision was made in March 1984 to replace all the pressure tubes from both Unit 1 and Unit 2. This retubing was accomplished over a three year period, together with a program of inspection, maintenance, and modification on other systems. Equipment was put in a short term mothballed state at the commencement of the outage, and a thorough recommissioning of all systems, both old and new, was carried out during restart. This paper provides an overview of the program, highlighting successes and difficulties, and recommending changes for future retubing projects

  20. Lay-up condition during ENPP refurbishment outage

    International Nuclear Information System (INIS)

    Embalse Nuclear Power Plant (ENPP) is a CANDU® 6 type with 648 MWe output with the First Criticality in 1983, and 100% Power in September 1983. The plant was designed and licensed to operate during 24 Effective Full Power Years (EFPY) As it is getting close to the end of the design life, it was decided to implement the necessary tasks for a Plant Life Extension (PLEX) Project. The PLEX Project includes 3 Phases: Phase I: Prioritization and Analysis, Phase II: Project Engineering, and Phase III: Implementation. (See Figure 1) During Phase III in the PLEX Proyect, many components will be replaced, and many Systems, Structures and Components (SSC) need to be inspected/refurbished (e.g. Reactor Retubing, Steam Generators Cartridge replacement, inspections and maintenance of large components (as pipes, pumps, heat exchangers), station systems configuration will be totally different from normal operating conditions. Even when some Systems have conservation facilities and procedures these are thought for normal maintenance outage. During the refurbishment outage the condition on those components can change and lead the SSC exposed to abnormal aggressive conditions, as an oxidizing atmosphere due to the air ingress to the system (the stressors could be increased). Consequently the Aging Related Degradation Mechanisms (ARDM) can be accelerated limiting the remaining life of these components.Then it is very important to implement an adequate Lay Up Condition Program. During the implementation of a Lay Up refurbished Condition Program a prioritization of systems and / or more relevant components requiring special conservation will be done. Then a review of the chemical specifications to analyze while lay up methods should be applied. From the PLEX phase I, scope definition, it was identified equipment to be replaced or requiring certain inspections during the refurbishment outage, the possible interference and conditions needed for implementation depending on the method

  1. Permanent start-up instrumentation for maintenance outages

    International Nuclear Information System (INIS)

    This paper assesses the need and feasibility of permanent start-up instrumentation detectors to monitor photoneutron flux during maintenance outages. CANDU ion chamber systems were designed to remain on scale for ten weeks after reactor shutdown. A requirement was imposed in the mid-1990s to put the reactor into an overpoisoned guaranteed shutdown state whenever it is shut down and not actively undergoing a restart. Due to the high gadolinium concentration, the ion chamber systems go off scale within three weeks. Operating policies and procedures require the neutron flux and its rate of change to be monitored when fuel is in the reactor. (author)

  2. LIDAR AND INS FUSION IN PERIODS OF GPS OUTAGES FOR MOBILE LASER SCANNING MAPPING SYSTEMS

    Directory of Open Access Journals (Sweden)

    I. Klein

    2012-09-01

    Full Text Available Mobile laser scanning systems are becoming an increasingly popular means to obtain 3D coverage on a large scale. To perform the mapping, the exact position of the vehicle must be known throughout the trajectory. Exact position is achieved via integration of Global Positioning Systems (GPS and Inertial Navigation Systems (INS. Yet, in urban environments, cases of complete or even partial GPS outages may occur leaving the navigation solution to rely only on the INS. The INS navigation solution degrades with time as the Inertial Measurement Unit (IMU measurements contains noise, which permeates into the navigation equations. Degradation of the position determination leads to loss of data in such segments. To circumvent such drift and its effects, we propose fusing INS with lidar data by using building edges. This detection of edges is then translated into position data, which is used as an aiding to the INS. It thereby enables the determination of the vehicle position with a satisfactory level accuracy, sufficient to perform the laser-scanning based mapping in those outage periods.

  3. Cascading Power Outages Propagate Locally in an Influence Graph that is not the Actual Grid Topology

    CERN Document Server

    Hines, Paul D H; Rezaei, Pooya

    2015-01-01

    In a cascading power transmission outage, component outages propagate non-locally; after one component outages, the next failure may be very distant, both topologically and geographically. As a result, simple models of topological contagion do not accurately represent the propagation of cascades in power systems. However, cascading power outages do follow patterns, some of which are useful in understanding and reducing blackout risk. This paper describes a method by which the data from many cascading failure simulations can be transformed into a graph-based model of influences that provides actionable information about the many ways that cascades propagate in a particular system. The resulting "influence graph" model is Markovian, since component outage probabilities depend only on the outages that occurred in the prior generation. To validate the model we compare the distribution of cascade sizes resulting from n-2 contingencies in a 2896 branch test case to cascade sizes in the influence graph. The two dist...

  4. Outage Probability of General Ad Hoc Networks in the High-Reliability Regime

    CERN Document Server

    Giacomelli, Riccardo; Haenggi, Martin

    2010-01-01

    Outage probabilities in wireless networks depend on various factors: the node distribution, the MAC scheme, and the models for path loss, fading and transmission success. In prior work on outage characterization for networks with randomly placed nodes, most of the emphasis was put on networks whose nodes are Poisson distributed and where ALOHA is used as the MAC protocol. In this paper we provide a general framework for the analysis of outage probabilities in the high-reliability regime. The outage probability characterization is based on two parameters: the intrinsic spatial contention $\\gamma$ of the network, introduced in [1], and the coordination level achieved by the MAC as measured by the interference scaling exponent $\\kappa$ introduced in this paper. We study outage probabilities under the signal-to-interference ratio (SIR) model, Rayleigh fading, and power-law path loss, and explain how the two parameters depend on the network model. The main result is that the outage probability approaches $\\gamma\\e...

  5. On Outage Performance of Spectrum-Sharing Communication over M-Block Fading

    KAUST Repository

    Alabbasi, AbdulRahman

    2015-12-06

    In this paper, we consider a cognitive radio system in which a block-fading channel is assumed. Each transmission frame consists of M blocks and each block undergoes a different channel gain. Instantaneous channel state information about the interference links remains unknown to the primary and secondary users. We minimize the secondary user\\'s targeted outage probability over the block-fading channels. To protect the primary user, a statistical constraint on its targeted outage probability is enforced. The secondary user\\'s targeted outage region and the corresponding optimal power are derived. We also propose two sub-optimal power strategies and derive compact expressions for the corresponding outage probabilities. These probabilities are shown to be asymptotic lower and upper bounds on the outage probability. Utilizing these bounds, we derive the exact diversity order of the secondary user outage probability. Selected numerical results are presented to characterize the system\\'s behavior.

  6. Operational Readiness Verification, Phase 3. A Field Study at a Swedish NPP during a Productive Outage (Safety-train Outage)

    International Nuclear Information System (INIS)

    This report describes the results from Phase III of a study on Operational Readiness Verification (ORV) that was carried out from December 2002 to November 2003. The work comprised a field study of ORV activities at a Swedish NPP during a planned productive outage [subavstaellning], which allowed empirical work to be conducted in an appropriate environment with good accessibility to technical staff. One conclusion from Phase I of this project was the need to look more closely at the differences between three levels or types of tests that occur in ORV: object (component) test, system level test and (safety) function test, and to analyse the different steps of testing in order to understand the nontrivial relations between tests and safety. A second conclusion was the need to take a closer look at the organisation's ability to improvise in the sense of adjusting pre-defined plans to the actual conditions under which they are to be carried out. Phase II of the project found that although all three types of test occurred, they were rather used according to need rather than to a predefined arrangement or procedure. The complexity of ORV could be understood and described by using the concepts of Community of Practice, embedding, and Efficiency-Thoroughness Trade-Off. In addition, organisation and the different communities of practice improvise by adjusting pre-defined plans or work orders to the existing conditions. Such improvisations take place both on the levels of individual actions, on the level of communities of practice, and on the organisational level. The ability to improvise is practically a necessity for work to be carried out, but is also a potential risk. Phase III of the project studied how tasks are adapted relative to the different types of embedding and the degree of correspondence between nominal and actual ORV. It also looked further at the different Communities of Practice that are part of maintenance and ORV, focusing on the coordination and

  7. Operational Readiness Verification, Phase 3. A Field Study at a Swedish NPP during a Productive Outage (Safety-train Outage)

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, Erik [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, Vincent; Persson, Bodil [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2004-01-01

    This report describes the results from Phase III of a study on Operational Readiness Verification (ORV) that was carried out from December 2002 to November 2003. The work comprised a field study of ORV activities at a Swedish NPP during a planned productive outage, which allowed empirical work to be conducted in an appropriate environment with good accessibility to technical staff. One conclusion from Phase I of this project was the need to look more closely at the differences between three levels or types of tests that occur in ORV: object (component) test, system level test and (safety) function test, and to analyse the different steps of testing in order to understand the nontrivial relations between tests and safety. A second conclusion was the need to take a closer look at the organisation's ability to improvise in the sense of adjusting pre-defined plans to the actual conditions under which they are to be carried out. Phase II of the project found that although all three types of test occurred, they were rather used according to need rather than to a predefined arrangement or procedure. The complexity of ORV could be understood and described by using the concepts of Community of Practice, embedding, and Efficiency-Thoroughness Trade-Off. In addition, organisation and the different communities of practice improvise by adjusting pre-defined plans or work orders to the existing conditions. Such improvisations take place both on the levels of individual actions, on the level of communities of practice, and on the organisational level. The ability to improvise is practically a necessity for work to be carried out, but is also a potential risk. Phase III of the project studied how tasks are adapted relative to the different types of embedding and the degree of correspondence between nominal and actual ORV. It also looked further at the different Communities of Practice that are part of maintenance and ORV, focusing on the coordination and communication between

  8. Cognitive Proactive and Reactive DF Relaying Schemes under Joint Outage and Peak Transmit Power Constraints

    OpenAIRE

    Tran, Hung; Zepernick, Hans-Jürgen; Phan, Hoc

    2013-01-01

    In this paper, outage performance of cognitive cooperative radio networks using two decode-and-forward (DF) schemes is investigated. Subject to the joint outage constraint of the primary user and the peak transmit power constraint of the secondary user, adaptive power allocation policies for the secondary transmitter and secondary relays are studied. Based on these strategies, expressions for the outage probability of proactive and reactive DF schemes are obtained. Interestingly, our results ...

  9. Operation and maintenance outage experience of reactor internal pump

    International Nuclear Information System (INIS)

    The No.6 unit of Tokyo Electric Power Company's Kashiwazaki-Kariwa Nuclear Power Station (K-6), the first advanced boiling water reactor (ABWR), turned over on November 1996. One of the major design features of ABWR is a reactor internal pump (RIP). Ten RIPs are mounted at the bottom of a reactor pressure vessel (RPV) so as to circulate reactor water directly to the reactor core. All RIPs have been successfully operating through the first and second plant operating cycles. In the first outage, two RIPs among them were maintained according to plan. Two sets of the impeller and shaft were removed in series into the fuel pool and examined at visual tests. Two motors were also removed in series to the maintenance area and disassembled to parts for visual and/or dimensional tests. No harm was found as the results of the tests. Two other spare motors were installed instead of the above two examined motors as the advanced procedure according to plan. All RIPs were operated in high speed condition at the end of the outage. The monitored data of each RIP were confirmed to the good operation in the second cycle. (author)

  10. Availability and outage frequency of repairable parallel unit systems

    International Nuclear Information System (INIS)

    This contribution evolved directly from the application of reliability and maintainability analysis in the design of the Gentilly-2 nuclear power station. This station employs a 600 MWe Candu type pressurized heavy water reactor. During the design stage decisions have to be made regarding the configuration of systems which consists of a number of units in parallel. The criteria used in making these decisions are: safety, economics (capital cost and operating efficiency, reliability and maintainability, which can be expressed numerically as availability and outage frequency). This paper describes a method for analyzing the availability and outage frequency of systems consisting of a number of repairable units in parallel. The method is based on state transition models (a unit, whether it is the operating or the standby unit, can be in either of two states: healthy or in repair; the probability of being in either state is a function of the transition rates between the two states: failure rate and repair rate). The development of computer program Stram is presented, as well as some examples of program output

  11. Long-range outage planning - A strategy for success

    International Nuclear Information System (INIS)

    The nuclear power industry, already beset by reduced demand, environmental concerns, regulatory-initiated modifications, increased operations costs, and other cost-affecting factors, is now entering a new era. Electric utilities in general and the nuclear utilities in particular are facing the specter of competition, until now a facet of the business world they have seldom had to confront in their geographically defined, independent service areas. The force of competition stems not only from other utilities but also from alternative fuels, and from utility customers. In light of this climate of competition, the utilities must seek to control operating costs, to maintain or improve plant availability and reliability, and to assess and schedule the requirements imposed by the US Nuclear Regulatory Commission (NRC) and by needed maintenance activities. In particular, the need to control the many regulatory proposed plant modifications and inspections on a plant-specific basis has prompted the development of the living schedule concept. This paper presents the subject of long-range outage planning as a means of dealing with the futurity of present operating decisions and a method of achieving quality outages

  12. Outage analysis for underlay cognitive networks using incremental regenerative relaying

    KAUST Repository

    Tourki, Kamel

    2013-02-01

    Cooperative relay technology has recently been introduced into cognitive radio (CR) networks to enhance the network capacity, scalability, and reliability of end-to-end communication. In this paper, we investigate an underlay cognitive network where the quality of service (QoS) of the secondary link is maintained by triggering an opportunistic regenerative relaying once it falls under an unacceptable level. Analysis is conducted for two schemes, referred to as the channel-state information (CSI)-based and fault-tolerant schemes, respectively, where different amounts of CSI were considered. We first provide the exact cumulative distribution function (cdf) of the received signal-to-noise ratio (SNR) over each hop with colocated relays. Then, the cdf\\'s are used to determine a very accurate closed-form expression for the outage probability for a transmission rate $R$. In a high-SNR region, a floor of the secondary outage probability occurs, and we derive its corresponding expression. We validate our analysis by showing that the simulation results coincide with our analytical results in Rayleigh fading channels. © 1967-2012 IEEE.

  13. Simultaneous effects of allowed time, teaching method, ability, and student assessment of treatment on achievement in a high school biology course (ISIS)

    Science.gov (United States)

    Burkman, Ernest; Brezin, Michael; Griffin, Patrick

    The simultaneous effects of teaching method (self-directed, group directed, and teacher directed), allowed time for study, and two student variables (academic ability and assessment of treatment implementation) are described for student achievement in a high school biology course (ISIS). The variable student assessment of treatment implementation was viewed as a particularly important variable for two reasons: (1) in research by Stayrook, Corno, and Winne (1978) it has accounted for as much variance in achievement as the assigned treatment; and (2) it provides a means for controlling the range of implementation of teaching methods. A between-student analysis resulted in a description of effects complicated by interactions among all the variables. While the interactions were particularly strong in the student-directed method, it may generally be concluded that as time allowed for study decreased, students who perceived the treatment as being well implemented tended to have higher achievement. Also, it was found that the main effect of ability was quite strong. The results confirmed the importance of student assessment of treatment implementation as a descriptive variable. Additionally, the results suggest a qualification in the conclusion of Cronbach and Snow (1971) that individualized instruction tends to favor high-ability students; that conclusion may need to be modified to situations in which students fully perceive their autonomy.

  14. On the Outage Behavior of Asynchronous OFDM DF and AF Cooperative Networks

    CERN Document Server

    Torbatian, Mehdi

    2009-01-01

    The outage behavior of various relaying protocols over a general one hop asynchronous cooperative network is examined when orthogonal frequency division multiplexing (OFDM) is used to combat synchronization error among the relays. We consider non-orthogonal selection decode-and-forward (NSDF), orthogonal selection decode-and-forward (OSDF), non-orthogonal amplify-and-forward (NAF), and orthogonal amplify-and-forward (OAF) relaying protocols and analyze the diversity multiplexing gain tradeoff (DMT) in all scenarios. The transmitting nodes cooperatively construct an asynchronous OFDM space-time code by re-sending the source messages over a common time interval and a common frequency bandwidth. It is shown that in decode-and-forward (DF) type protocols, the asynchronous network provides a diversity gain greater than or equal to the one of the corresponding synchronous network in the limit of code word length and throughout the range of multiplexing gain. In amplify-and-forward (AF) type protocols, in which the ...

  15. Start-up of Cirus after refurbishment outage and observations during approach to criticality

    International Nuclear Information System (INIS)

    The report presents various physics related aspects of the startup of Cirus reactor after the prolonged refurbishment outage. The special nuclear instrumentation scheme adopted to ensure safe startup of the reactor is described. Salient observations made and physics measurements carried out during various approaches to criticality are covered. One of the significant observations concerned a major reactivity anomaly during the approach to criticality. After due investigations the cause of the anomaly was attributed to the inadvertent wetting of the graphite reflector which houses the reactor regulating and protection system ion chambers. The report also includes salient observations during raising of reactor power to high levels. The wet reflector also resulted in a significant difference measured between the thermal and neutronic power of the reactor. In view of the reactivity anomaly, the core reactivity variation with time was closely followed and compared with computations. As expected the reactivity anomaly reduced gradually with time. (author)

  16. Outage analysis for underlay relay-assisted cognitive networks

    KAUST Repository

    Tourki, Kamel

    2012-12-01

    Cooperative relay technology was recently introduced into cognitive radio networks in order to enhance network capacity, scalability, and reliability of end-to-end communication. In this paper, we investigate an underlay cognitive network where the quality of service of the secondary link is maintained by triggering an opportunistic regenerative relaying once it falls under an unacceptable level. We first provide the exact cumulative density function (CDF) of received signal-to-noise (SNR) over each hop with co-located relays. Then, the CDFs are used to determine very accurate closed-form expression for the outage probability for a transmission rate R. We validate our analysis by showing that simulation results coincide with our analytical results in Rayleigh fading channels. © 2012 IEEE.

  17. Braess's paradox in oscillator networks, desynchronization and power outage

    Science.gov (United States)

    Witthaut, Dirk; Timme, Marc

    2012-08-01

    Robust synchronization is essential to ensure the stable operation of many complex networked systems such as electric power grids. Increasing energy demands and more strongly distributing power sources raise the question of where to add new connection lines to the already existing grid. Here we study how the addition of individual links impacts the emergence of synchrony in oscillator networks that model power grids on coarse scales. We reveal that adding new links may not only promote but also destroy synchrony and link this counter-intuitive phenomenon to Braess's paradox known for traffic networks. We analytically uncover its underlying mechanism in an elementary grid example, trace its origin to geometric frustration in phase oscillators, and show that it generically occurs across a wide range of systems. As an important consequence, upgrading the grid requires particular care when adding new connections because some may destabilize the synchronization of the grid—and thus induce power outages.

  18. Unified Importance Sampling Schemes for Efficient Simulation of Outage Capacity over Generalized Fading Channels

    KAUST Repository

    Ben Rached, Nadhir

    2015-11-13

    The outage capacity (OC) is among the most important performance metrics of communication systems operating over fading channels. Of interest in the present paper is the evaluation of the OC at the output of the Equal Gain Combining (EGC) and the Maximum Ratio Combining (MRC) receivers. In this case, it can be seen that this problem turns out to be that of computing the Cumulative Distribution Function (CDF) for the sum of independent random variables. Since finding a closedform expression for the CDF of the sum distribution is out of reach for a wide class of commonly used distributions, methods based on Monte Carlo (MC) simulations take pride of price. In order to allow for the estimation of the operating range of small outage probabilities, it is of paramount importance to develop fast and efficient estimation methods as naive Monte Carlo (MC) simulations would require high computational complexity. In this line, we propose in this work two unified, yet efficient, hazard rate twisting Importance Sampling (IS) based approaches that efficiently estimate the OC of MRC or EGC diversity techniques over generalized independent fading channels. The first estimator is shown to possess the asymptotic optimality criterion and applies for arbitrary fading models, whereas the second one achieves the well-desired bounded relative error property for the majority of the well-known fading variates. Moreover, the second estimator is shown to achieve the asymptotic optimality property under the particular Log-normal environment. Some selected simulation results are finally provided in order to illustrate the substantial computational gain achieved by the proposed IS schemes over naive MC simulations.

  19. Darlington NGS vacuum building outage: modification to supply post-seismic makeup water to the heat transport system

    International Nuclear Information System (INIS)

    The periodic stationwide outage at Darlington NGS includes removal of the Emergency Coolant Injection System from service to allow for maintenance. As a prerequisite, the station must set up a minimum 2.5 kg/s temporary makeup water supply, to help cool the fuel should a seismic event occur. This modification cannot be commissioned, as commissioning would dilute the heavy water in the Primary Heat Transport System with light water. Therefore, flow analysis is necessary to demonstrate that the required flow rate can be achieved. This paper provides details of the design, and key aspects of the supporting analysis. (author)

  20. Darlington NGS vacuum building outage: modification to supply post-seismic makeup water to the heat transport system

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Dean, B.; Emad, M. [Wardrop Engineering Inc., Energy Div., Pickering, Ontario (Canada)

    2009-07-01

    The periodic stationwide outage at Darlington NGS includes removal of the Emergency Coolant Injection System from service to allow for maintenance. As a prerequisite, the station must set up a minimum 2.5 kg/s temporary makeup water supply, to help cool the fuel should a seismic event occur. This modification cannot be commissioned, as commissioning would dilute the heavy water in the Primary Heat Transport System with light water. Therefore, flow analysis is necessary to demonstrate that the required flow rate can be achieved. This paper provides details of the design, and key aspects of the supporting analysis. (author)

  1. 77 FR 63757 - Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over...

    Science.gov (United States)

    2012-10-17

    ..., regarding Interconnected Voice over Internet Protocol (VoIP) outage reporting rules, published at 77 FR..., and 4.9 published at 77 FR 25088, April 27, 2012, are effective December 16, 2012. FOR FURTHER... COMMISSION 47 CFR Part 4 Extension of the Commission's Rules Regarding Outage Reporting to...

  2. On Error Estimation in terms of Outage for Rician/Rayleigh Fading Environment

    OpenAIRE

    Anjana Shukla Dr. Vineeta Saxena Nigam

    2011-01-01

    In this paper proposes a novel mathematical method to express the outage probability for a desired radio signal received from a mobile transmitter in the presence of multipath interfering signals with rician and Rayleigh fading. New Rician/Rayleigh outage probabilities curves against the normalized reuse distance without lognormal shadowing effect are presented and discussed. The effect of SIR, Protection ratio

  3. Outage probability of opportunistic decode-and-forward relaying over Nakagami-m fading channels

    Institute of Scientific and Technical Information of China (English)

    CHUAI Gang; ZHANG Bao-zhi; LIU Xing-mei; GAO Li

    2009-01-01

    In this article, the outage probability behavior of a relay network over Nakagami-m fading channels is analyzed. Both reactive and proactive opportunistic decode-and-forward (DAF) strategies are considered. The closed-form solutions to the outage probabilities on both opportunistic DAF strategies are derived. Simulation results conf'Lrrn the presented mathematical analysis.

  4. Risk quantification in deterministic procedures: outage key safety functions evaluation using probabilistic risk assessment

    International Nuclear Information System (INIS)

    In 2007 a collaboration agreement between the Nuclear Industry and the Nuclear Engineering Research Group of the Technical University of Catalonia (NERG-UPC) began on the Risk-Informed Operation Decision Management field. A Manual has been created; it provides a guidance of the systematic of using Probabilistic Risk Assessment for the evaluation of guides or procedures which ensure the compliment of Outage Key Safety Functions (OKSF) in nuclear power plants. The evaluation base is probabilistic; the core damage frequencies (CDF) values determine the acceptance of the analyzed guides and encourage suggestions for improvements in the contained procedures. Acceptance criteria from Plants Supervision System are used throw out quantifications. The developed methodology pretends to evaluate the risk associated to the availability system configurations during the outage. The documents used in the development have been: PRA, OKSF procedure and Performance Technical Specifications (PTS) from a 3 loops Westinghouse PWR. As a pilot experience, the methodology has been applied to the 3. and 13. Operational Plant State (OPS), always within the operational mode 4. Some conclusions of the analysis: The analyzed procedure requires the operability of just one charge pump as boric acid supply source. PRA gives a CDF increase (ΔCDF) of 1,19.10-6 year-1 for the pump in standby, consequently, an exposure time T= 53,6 hours. Given an average time for the OPS of 40 hours, it is concluded the correct treatment of the procedure. However, it could be improved with the inclusion of an additional inventory replacement function. This would limit the charge pump unavailability. On the other hand, the availability of the external electrical sources is ratified. The procedure requires the operability of both supplies during the OPS. The unavailability of one of them (transformer fail) involves a ΔCDF equal to 1,64.10-5 year-1 and a T= 3,89 hours. Then, it is considered appropriate the treatment

  5. Home Use Devices: How to Prepare for and Handle Power Outages for Medical Devices That Require Electricity

    Science.gov (United States)

    ... to Prepare for and Handle Power Outages for Medical Devices that Require Electricity Center for De CDRH vices ... to Prepare for and Handle Power Outages for Medical Devices that Require Electricity As a home medical device ...

  6. Observations and insights from the Grand Gulf Low Power and Shutdown Study of POS 5 during a refueling outage

    International Nuclear Information System (INIS)

    With the completion of the documentation of the results from the Grand Gulf Nuclear Power Plant Low Power and Shutdown (LP and S) Project funded by the US Nuclear Regulatory Commission, detailed probabilistic risk assessment (PRA) information from a boiling water reactor for a specific time period in LP and S conditions became available for examination. This paper summarizes why LP and S conditions should be examined and how the particular operational state was selected. It also summarizes observations and insights extracted from an examination of: (1) results in the LP and S documentation, (2) the specific models and assumptions used in the LP and S analyses, (3) selected results from the full power analysis, (4) the experience of the analysts who performed the original LP and S study, and (5) results from sensitivity calculations to help determine the impact that model assumptions and data values had on the results from the original LP and S analysis. Observations and insights on core damage frequency and aggregate risk (early fatalities and total latent cancer fatalities) associated with operations during plant operational state 5 (i.e., basically cold shutdown as defined by Technical Specifications) during a refueling outage for traditional internal events are provided. In addition, a discussion of similarities and differences between full power accidents and accidents during LP and S conditions is provided. As part of this discussion, core damage frequency and risks results are presented on a per hour and per calendar year basis, allowing alternative perspectives on both the core damage frequency and risk associated with these two operational states

  7. Bruce B 2004 vacuum building outage: fiberglass spray header refurbishment program

    International Nuclear Information System (INIS)

    Bruce Power is required to inspect the internals of the containment system Vacuum Building at the Bruce B plant once every 12 years and the previous inspection was carried out in 1992. During the 2004 Bruce B Vacuum Building Outage (VBO) significant inspections and refurbishment were carried out on the dousing water system spray headers which are a key component of the post- LOCA Vacuum Building pressure suppression system. These sixteen headers are made of Fiberglass Reinforced Plastic (FRP) and were manufactured by Tywood Industries in 1980. The company went out of business shortly after supplying the headers and the resin and roving used to manufacture the headers is no longer available. There were several known manufacturing deficiencies with the spray headers and degradation with aging was expected to have occurred. Inconsistent results from laboratory assessments of aged samples created considerable uncertainty as to the current condition of the headers. To remove and replace entire spray headers would be a very complicated and time-consuming process due to the physical access difficulties. Each new header would have to be brought into the vacuum building in pieces and assembled in situ. Header replacement was not considered a viable alternative for the 2004 VBO so plans were put in place to refurbish the headers sufficiently to ensure that they would last at least until the next planned inspection in 2016. This FRP spray header inspection and rehabilitation program was the critical path job for the 2004 VBO. This paper will summarize the technical concerns and uncertainties with the integrity of the FRP spray headers that existed prior to the outage but will primarily focus on the preparations for, execution of, and lessons learned during the actual field execution of the work. (author)

  8. Power Outages, Extreme Events and Health: a Systematic Review of the Literature from 2011-2012

    Science.gov (United States)

    Klinger, Chaamala; Landeg, Owen; Murray, Virginia

    2014-01-01

    Background Extreme events (e.g. flooding) threaten critical infrastructure including power supplies. Many interlinked systems in the modern world depend on a reliable power supply to function effectively. The health sector is no exception, but the impact of power outages on health is poorly understood. Greater understanding is essential so that adverse health impacts can be prevented and/or mitigated. Methods We searched Medline, CINAHL and Scopus for papers about the health impacts of power outages during extreme events published in 2011-2012. A thematic analysis was undertaken on the extracted information. The Public Health England Extreme Events Bulletins between 01/01/2013 - 31/03/2013 were used to identify extreme events that led to power outages during this three-month period. Results We identified 20 relevant articles. Power outages were found to impact health at many levels within diverse settings. Recurrent themes included the difficulties of accessing healthcare, maintaining frontline services and the challenges of community healthcare. We identified 52 power outages in 19 countries that were the direct consequence of extreme events during the first three months of 2013. Conclusions To our knowledge, this is the first review of the health impacts of power outages. We found the current evidence and knowledge base to be poor. With scientific consensus predicting an increase in the frequency and magnitude of extreme events due to climate change, the gaps in knowledge need to be addressed in order to mitigate the impact of power outages on global health. PMID:24459613

  9. Reliabilty worth: Development of a relationship with outage magnitude, duration and frequency

    International Nuclear Information System (INIS)

    British Columbia Hydro's Worth Project Team was founded to determine values for reliability for reference in evaluation of investment and operating decisions. Work to date has produced key preliminary values for specific outages and concepts for the shape of the relationship between value and these determinates of reliability worth, frequency, magnitude and duration. These values and concepts are described. The values are developed through an iterative, trial and refinement approach. The approach incorporates direct input from customers, common sense and judgement, and micro- and macro-economic concepts. Reliability worth values for reduced or prevented outages are presented for residential, commercial, small industrial and mixed sectors and various outage durations. Reliability worth values were obtained through customer surveys. Limitations of the reliability worth value are numerous and are listed. Study of cost vs magnitude of interruption using microeconomic models has shown that costly system improvements to reduce the possibility of widespread outages may not be justified. The case of exceptionally large area outages (blackouts) is examined. The cost vs frequency relationship was examined in terms of the economic concept of utility or satisfaction. Different loss/frequency characteristics are demonstrated for different customer classes. Customer value for reduced outage duration is expressed in a curve with flatter slope than that for eliminated outages. 2 refs., 6 figs

  10. Use of a Computerized Tool (ORAM) to Help Manage Outage Safety and Risk at NPP Krsko

    International Nuclear Information System (INIS)

    Outage Risk Assessment and Management (ORAM) is a computerized methodology developed by the U.S. Electric Power Research Institute (EPRI) to help Nuclear Power Plant personnel manage the risk and safety associated with refueling and forced plant outages. Today, over 60 plants including NPP Krsko are using ORAM during the preparation and performance of plant outages. In fact, many plants are attributing much of the reductions in the duration of refueling outages to the use of ORAM. The success of the ORAM methodology is the capability to provide plant and management personnel with understandable results from both deterministic evaluations of plant safety and quantitative risk assessments. The Nuklearna Elektrarna Krsko (NEK) use of ORAM involves both of these approaches. The deterministic portion of ORAM is used to model the NPP Krsko Shutdown Technical Specifications and administrative considerations. The probabilistic portion of ORAM uses industry and NEK specific initiating events and other risk elements pertaining to shutdown to derive a quantitative risk assessment for various end states, including core damage and RCS boiling. This paper expands on the value of each approach and demonstrates the benefits of combining these elements in the decision-making process. Another key advantage of ORAM is the ability to apply the methodology to specific outages. Since no outage is identical, this provides tremendous benefits to plant personnel for managing the safety and risk of a particular outage. ORAM does this ba organizing all of the various plant configurations and equipment unavailability windows into numerous plant states. Furthermore, ORAM evaluations can be automatedby interfacing with outage scheduling software programs such as Primavera. For each plant state, the deterministic and the probabilistic logic evaluations are applied. This paper will demonstrate the ORAM evaluation for an actual NPP Krsko outage. (author)

  11. Optimal Power Allocation for Fading Channels in Cognitive Radio Networks: Ergodic Capacity and Outage Capacity

    CERN Document Server

    Kang, Xin; Nallanathan, Arumugam; Garg, Hari Krishna; Zhang, Rui

    2008-01-01

    A cognitive radio network (CRN) is formed by either allowing the secondary users (SUs) in a secondary communication network (SCN) to opportunistically operate in the frequency bands originally allocated to a primary communication network (PCN) or by allowing SCN to coexist with the primary users (PUs) in PCN as long as the interference caused by SCN to each PU is properly regulated. In this paper, we consider the latter case, known as spectrum sharing, and study the optimal power allocation strategies to achieve the ergodic capacity and the outage capacity of the SU fading channel under different types of power constraints and fading channel models. In particular, besides the interference power constraint at PU, the transmit power constraint of SU is also considered. Since the transmit power and the interference power can be limited either by a peak or an average constraint, various combinations of power constraints are studied. It is shown that there is a capacity gain for SU under the average over the peak ...

  12. Configuration control during plant outages. A review of operating experience

    International Nuclear Information System (INIS)

    After the occurrence of several significant events in nuclear power plants during shut-down modes of operation in the eighties, and from the results of probabilistic safety assessments completed in the nineties, it was clear that risk from low power and shutdown operational modes could not be neglected and had to be addressed by appropriate safety programs. A comprehensive review of operating experience from the last ten years has been conducted by the Joint Research Centre with the objective of deriving lessons learned and recommendations useful for nuclear regulatory bodies and utilities alike. This paper is focused on one particular challenge that any nuclear plant faces whenever it plans its next outage period: how to manage the configuration of all systems under a complex environment involving numerous concurrent activities, and how to make sure that systems are returned to their valid configuration before the plant resumes power operation. This study highlights the importance of conveying accurate but synthesized information on the status of the plant to the operators in the main control room. Many of the lessons learned are related to the alarm display in the control room and to the use of check lists to control the status of systems. Members of the industry and safety authorities may now use these recommendations and lessons learned to feed their own operating experience feedback programs, and check their applicability for specific sites.

  13. Configuration control during plant outages. A review of operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Peinador Veira, Miguel; El Kanbi, Semir [European Commission Joint Research Centre, Petten (Netherlands). Inst. for Energy and Transport; Stephan, Jean-Luc [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France); Martens, Johannes [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Koeln (Germany)

    2015-03-15

    After the occurrence of several significant events in nuclear power plants during shut-down modes of operation in the eighties, and from the results of probabilistic safety assessments completed in the nineties, it was clear that risk from low power and shutdown operational modes could not be neglected and had to be addressed by appropriate safety programs. A comprehensive review of operating experience from the last ten years has been conducted by the Joint Research Centre with the objective of deriving lessons learned and recommendations useful for nuclear regulatory bodies and utilities alike. This paper is focused on one particular challenge that any nuclear plant faces whenever it plans its next outage period: how to manage the configuration of all systems under a complex environment involving numerous concurrent activities, and how to make sure that systems are returned to their valid configuration before the plant resumes power operation. This study highlights the importance of conveying accurate but synthesized information on the status of the plant to the operators in the main control room. Many of the lessons learned are related to the alarm display in the control room and to the use of check lists to control the status of systems. Members of the industry and safety authorities may now use these recommendations and lessons learned to feed their own operating experience feedback programs, and check their applicability for specific sites.

  14. The Loss of Spent Fuel Pool Cooling Analysis during Plant Outage for OPR1000

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Woo; Huh, Jae Young [KEPCO E-C, Daejeon (Korea, Republic of)

    2014-10-15

    Recently, spent fuels stored in the spent fuel pool (SFP) with a loss of cooling during the refueling of plant outage have been required to maintain their integrity especially after the Fukushima disaster. A thermal-hydraulic analysis of the loss of SFP cooling (LOSFPC) during the plant operating state 8 (POS 8) or refueling period is performed to establish the success criteria for the probabilistic safety assessment (PSA). This paper is to investigate the incipient boiling time in the spent fuel region, time to uncover in the SFP and the time of fuel cladding failure for the Hanul Nuclear Power Plant Units 3 and 4 (HUN 3 and 4) which is the typical optimized power reactor 1000 (OPR1000). The results show that the sufficient time for operator action is available for the LOSFPC during the refueling period for the OPR1000. From a loss of SFP cooling analysis for HUN 3 and 4, RELAP5/MOD3.3 shows reasonable thermal-hydraulic behaviors and is acceptable to establish the success criteria of operator action for the PSA.

  15. Extreme Outages due to Polarization Mode Dispersion Periodic and Quasi-Periodic Compensation Strategies

    CERN Document Server

    Chernyak, V; Kolokolov, I V; Lebedev, V; Chernyak, Vladimir; Chertkov, Michael; Kolokolov, Igor; Lebedev, Vladimir

    2003-01-01

    Effect of birefringent disorder on the Bit Error Rate (BER) in an optical fiber system subject to amplifier noise may lead to extreme outages, related to anomalously large values of BER. We analyze the Probability Distribution Function (PDF) of BER for various strategies of Polarization Mode Dispersion (PMD) compensation. A compensation method capable of more efficient suppression of the extreme outages, and thus of an essential enhancement of the fiber system performance, is proposed.

  16. Estimating the spatial distribution of power outages during hurricanes in the Gulf coast region

    International Nuclear Information System (INIS)

    Hurricanes have caused severe damage to the electric power system throughout the Gulf coast region of the US, and electric power is critical to post-hurricane disaster response as well as to long-term recovery for impacted areas. Managing power outage risk and preparing for post-storm recovery efforts requires accurate methods for estimating the number and location of power outages. This paper builds on past work on statistical power outage estimation models to develop, test, and demonstrate a statistical power outage risk estimation model for the Gulf Coast region of the US. Previous work used binary hurricane-indicator variables representing particular hurricanes in order to achieve a good fit to the past data. To use these models for predicting power outages during future hurricanes, one must implicitly assume that an approaching hurricane is similar to the average of the past hurricanes. The model developed in this paper replaces these indicator variables with physically measurable variables, enabling future predictions to be based on only well-understood characteristics of hurricanes. The models were developed using data about power outages during nine hurricanes in three states served by a large, investor-owned utility company in the Gulf Coast region

  17. The strategy of reducing the annual outage length of Fukushima-II NPS

    International Nuclear Information System (INIS)

    The ninth annual outage inspection of Fukushima-II NPS unit No.3 was executed within 36 days from September 12 to October 17, 1998. The outage length of 36 days is the shortest in our history. The capacity factor will exceed 86% in fiscal 1998. It used to be emphasized the necessity for energy security and safety rather than costs in the nuclear industry. Recently, environment of the electric industry has been becoming more competitive. The nuclear industry had to participate in the competition. The preparations for shortening the annual outage length were begun in 1994. The shortening activities have progressed with the policy which ensure safety and reliability. The outage length has been reduced from mid-80 s to 36 days step by step over 3 years. The most important factor in shortening the outage length is to commit all participants, employees and contractors. Because of the endeavor to shorten the outage length, the capacity factor of Fukushima-II NPS is being maintained at a higher level. Hereafter the capacity factor level of 85% will continue, except unplanned shutdown. (author)

  18. Power Conditioning And Distribution Units For 50V Platforms A Flexible And Modular Concept Allowing To Deal With Time Constraining Programs

    Science.gov (United States)

    Lempereur, V.; Liegeois, B.; Deplus, N.

    2011-10-01

    In the frame of its Power Conditioning and Distribution Unit (PCDU) Medium power product family, Thales Alenia space ETCA is currently developing Power Conditioning Unit (PCU) and PCDU products for 50V platforms applications. These developments are performed in very schedule constraining programs. This challenge can be met thanks to the modular PCDU concept allowing to share a common heritage at mechanical & thermal points of view as well as at electrical functions level. First Medium power PCDU application has been developed for Herschel-Planck PCDU and re-used in several other missions (e.g. GlobalStar2 PCDU for which we are producing more than 26 units). Based on this heritage, a development plan based on Electrical Model (EM) (avoiding Electrical Qualification Model - EQM) can be proposed when the mechanical qualification of the concept covers the environment required in new projects. This first heritage level allows reducing development schedule and activities. In addition, development is also optimized thanks to the re-use of functions designed and qualified in Herschel- PlanckPCDU. This coversinternal TM/TC management inside PCDU based on a centralized scheduler and an internal high speed serial bus. Finally, thanks to common architecture of several 50V platforms based on full regulated bus, S3R (Sequential Shunt Switch Regulator) concept and one (or two) Li- Ion battery(ies), a common PCU/PCDU architecture has allowed the development of modules or functions that are used in several applications. These achievements are discussed with particular emphasis on PCDU architecture trade-offs allowing flexibility of proposed technical solutions (w.r.t. mono/bi-battery configurations, SA inner capacitance value, output power needs...). Pro's and con's of sharing concepts and designs between several applications on 50V platforms are also be discussed.

  19. Stability and Distributed Power Control in MANETs with Outages and Retransmissions

    CERN Document Server

    Giovanidis, Anastasios

    2009-01-01

    In the current work the effects of hop-by-hop packet loss and retransmissions via ARQ protocols are investigated within a Mobile Ad-hoc NET-work (MANET). Errors occur due to outages and a success probability function is related to each link, which can be controlled by power and rate allocation. We first derive the expression for the network's capacity region, where the success function plays a critical role. Properties of the latter as well as the related maximum goodput function are presented and proved. A Network Utility Maximization problem (NUM) with stability constraints is further formulated which decomposes into (a) the input rate control problem and (b) the scheduling problem. Under certain assumptions problem (b) is relaxed to a weighted sum maximization problem with number of summants equal to the number of nodes. This further allows the formulation of a non-cooperative game where each node decides independently over its transmitting power through a chosen link. Use of supermodular game theory sugge...

  20. Foreign Objects Found in Steam Generator 'Cold' Header During Scheduled Maintenance Outage

    International Nuclear Information System (INIS)

    During scheduled maintenance outage on the Unit in the course of TV examination of the 'cold header' on Steam Generator 2 (SG-2) to check for cleanliness and for subsequent pressurization, the following foreign material was found: M4x8 mm stainless steel bolt; 15x2 mm piece of plastic clamp; two 10x10 mm pieces of black-colour reinforced hose; Undetermined particulate. On completion of examination all the above objects were removed from the header. No breach of safe operation limits and conditions occurred. The foreign objects fell into SG-2 'cold' header from a maintenance platform during SG-2 repair works; no requirement for maintenance plugs for header was identified to avoid foreign material intrusion. Contractors and plant personnel were allowed to work unsupervised during the maintenance work. Maintenance documentation did not identify the actions required and risk assessment to avoid foreign material intrusion into the primary circuit during activities performed on depressurized components of the reactor installation. (author)

  1. Does the D.C. Response of Memristors Allow Robotic Short-Term Memory and a Possible Route to Artificial Time Perception?

    OpenAIRE

    Gale, Ella; Costello, Ben de Lacy; Adamatzky, Andrew

    2014-01-01

    Time perception is essential for task switching, and in the mammalian brain appears alongside other processes. Memristors are electronic components used as synapses and as models for neurons. The d.c. response of memristors can be considered as a type of short-term memory. Interactions of the memristor d.c. response within networks of memristors leads to the emergence of oscillatory dynamics and intermittent spike trains, which are similar to neural dynamics. Based on this data, the structure...

  2. Conventional and real-time PCRs for detection of Erwinia piriflorinigrans allow its distinction from the fire blight pathogen, Erwinia amylovora.

    Science.gov (United States)

    Barbé, Silvia; Bertolini, Edson; Roselló, Montserrat; Llop, Pablo; López, María M

    2014-04-01

    Erwinia piriflorinigrans is a new pathogenic species of the bacterial genus Erwinia that has been described recently in Spain. Accurate detection and identification of E. piriflorinigrans are challenging because its symptoms on pear blossoms are similar to those caused by Erwinia amylovora, the causal agent of fire blight. Moreover, these two species share phenotypic and molecular characteristics. Two specific and sensitive conventional and real-time PCR protocols were developed to identify and detect E. piriflorinigrans and to differentiate it from E. amylovora and other species of this genus. These protocols were based on sequences from plasmid pEPIR37, which is present in all strains of E. piriflorinigrans analyzed. After the stability of the plasmid was demonstrated, the specificities of the protocols were confirmed by the amplification of all E. piriflorinigrans strains tested, whereas 304 closely related pathogenic and nonpathogenic Erwinia strains and microbiota from pear trees were not amplified. In sensitivity assays, 10(3) cells/ml extract were detected in spiked plant material by conventional or real-time PCR, and 10(2) cells/ml were detected in DNA extracted from spiked plant material by real-time PCR. The protocols developed here succeeded in detecting E. piriflorinigrans in 102 out of 564 symptomatic and asymptomatic naturally infected pear samples (flowers, cortex stem tissue, leaves, shoots, and fruitlets), in necrotic Pyracantha sp. blossoms, and in necrotic pear and apple tissues infected with both E. amylovora and E. piriflorinigrans. Therefore, these new tools can be used in epidemiological studies that will enhance our understanding of the life cycle of E. piriflorinigrans in different hosts and plant tissues and its interaction with E. amylovora. PMID:24509928

  3. Multi-factorial analysis of occupational outage doses dispersion in the French NPPs 1998-2002

    International Nuclear Information System (INIS)

    Since 1992, many improvements have been achieved at EDF in terms of reducing occupational radiological exposures. Many efforts have been done in several areas, but without knowing what are the factors that have most influenced these results. It would therefore be of interest now to know more about that in order to be able to decide where to invest with an optimal efficiency to further improve occupational radiological protection. The results presented here are just examples of what can be done with such a study both in France and at the international level with ISOE 2 data when fulfilled; they may be considered as preliminary results. Consequently, they must be confirmed and validated. Of course, some variables such as zinc injection have not been studied here, as they were not relevant in France. Some others have not been kept such as biological shielding tons installed during the outage, as the information was not available in the French plants. However that study has pointed out the interest of mixing qualitative and quantitative variables, the interest of mixing descriptive statistical analysis with the analysis of correlations between dose dispersion and other variables dispersions as well as there evolution with time

  4. Complementary system for monitoring and control of neutron flux during a fuel outage and during reactor start up stage

    International Nuclear Information System (INIS)

    The present work is an example for that, how with modern technical instruments is possible to compensate disadvantage and to increase technical resources of the old systems, without a change of given system totally with new one. The system detail design and implementation was possible mostly, due to the international conferences and courses organised by IAEA and technical information provided by the agency. The designed system plays a role of complementary system to the in-situ operational systems for monitoring and control of the reactor core neutron flux, allowing its measurement and control during a fuel outage and during reactor start up stage. Additionally, the system recalculates the reactivity in beta units and according to its value the reactor criticality fixed up reactivity is defined. (author)

  5. The Direct Assessment and Captive Costs Methods for Estimating the Economic Costs of Power Outages among Selected Industries in Nigeria

    Directory of Open Access Journals (Sweden)

    Hachimenum N. Amadi

    2015-05-01

    Full Text Available Due to frequent power outages, the typical Nigerian firm incurs huge costs arising from damaged equipment, lost output, spoiled materials, idle workers and restart costs. This paper developed mathematical models for the computation of the economic costs due to power outages in selected electricity intensive industries from the major industrial areas of Nigeria. This became necessary to optimize investment and operating decisions for adequate power outage mitigation measures.

  6. Operational Readiness Verification, Phase 2: A Field Study at a Swedish NPP during a Productive-Outage

    International Nuclear Information System (INIS)

    This report describes the results from Phase II of a study on Operational Readiness Verification (ORV), and was carried out from October 2001 to September 2002. The work comprised a field study of ORV activities at a Swedish NPP during a planned productive outage, which allowed empirical work to be conducted in an appropriate environment with good accessibility to technical staff. One conclusion from Phase I of this project was the need to look more closely at the differences between three levels or types of tests that occur in ORV: object (component) test, system level test and (safety) function test, and to analyse the different steps of testing in order to understand the nontrivial relations between tests and safety. A second conclusion was the need to take a closer look at the organisation's ability to improvise in the sense of adjusting pre-defined plans to the actual conditions under which they are to be carried out. One outcome of Phase II is that there is no clear distinction between the three types of tests in the way they are carried out, and that they are used according to need rather than according to an internal logic or structure. In order better to understand the complexity of ORV, it was found useful to introduce concepts such as: (1) Community of Practice, defined as a small groups of people who through extensive communication developed a common sense of purpose, work-related knowledge and experience; (2) embedding, which means that all tasks and activities take place in an environment or context that may be physical, social, or historical (cultural); and (3) the Efficiency-Thoroughness Trade-Off (ETTO) principle, which characterises how people try to adjust what they do to the local conditions of work (temporal, physical and organisational). By using these terms to understand the practice of ORV, it becomes easier to understand how actions at times can be carried out in such a manner that the outcomes differ significantly from what was desired. It

  7. Outage performance of reactive cooperation in Nakagami-m fading channels

    KAUST Repository

    Benjillali, Mustapha

    2010-06-01

    In this paper, we investigate the outage performance of Decode-and-Forward with reactive relaying in dual-hop cooperetive Nakagaml-m fading links. The destination, based on the umque knowledge of local second hop channel state information, selects the best relay to increase the chances of cooperation when the direct link is also available. After deriving the exact distribution of the variables of interest, the outage probability of the system - with and without the direct link - is obtained in closed-form, and the ε-outage capacity is derived in the particular c.se wh.ere the channel model is reduced to a Rayleigh fading. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters.

  8. A Simple Scheme for Improved Performance of Fixed Outage Rate Cellular System

    Directory of Open Access Journals (Sweden)

    Hussein M.A. Basi

    2004-01-01

    Full Text Available The traffic characteristic of mobile cellular systems is rather distinct from that of a fixed telephone network. However the system planning and design are still carried out with the tools of conventional traffic theory. In the recent days much work is being done in the performance evaluation of mobile or cellular communication systems in order to develop a system with greater efficiency. The useful parameters to estimate the performance of the system are voice quality, frequency spectrum efficiency and Grade of Service (GOS. The grade of service will be affected due to outage of channels. In this study, a new scheme is proposed to reduce lost calls due to channel outage in the fixed rate outage cellular system. In this proposed scheme the call will never dropped but may be delayed. The system performance is evaluated for different conditions and the results are discussed.

  9. Outage performance of Decode-and-Forward partial selection in Nakagami-m fading channels

    KAUST Repository

    Benjillali, Mustapha

    2010-01-01

    In this paper, we investigate the outage performance of Decode-and-Forward with partial selection relaying in dualhop cooperative Nakagami-m fading links. The source, based on the unique knowledge of local first hop channel state information, selects the best relay to increase the chances of successful decoding and hence the possibility of cooperation when the direct link is also available. After deriving the exact distribution of the sum of two gamma variates with the same shape parameter, the outage probability of the system-with and without the direct link-is obtained in closed-form. We also derive the ε-outage capacity in different particular cases, and the obtained results- when the channel model is reduced to a Rayleigh fading-are either new or correspond to those previously obtained in other works. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters. © 2009 IEEE.

  10. Outage Performance of Decode-and-Forward in Two-Way Relaying with Outdated CSI

    KAUST Repository

    Hyadi, Amal

    2015-01-07

    In this paper, we analyze the outage behavior of decode-and-forward relaying in the context of selective two-way cooperative systems. First, a new relay selection metric is proposed to take into consideration both transmission rates and instantaneous link conditions between cooperating nodes. Afterwards, the outage probability of the proposed system is derived for Nakagami-m fading channels in the case when perfect channel state information is available and then extended to the more realistic scenario where the available channel state information (CSI) is outdated due to fast fading. New expressions for the outage probability are obtained, and the impact of imperfect CSI on the performance is evaluated. Illustrative numerical results, Monte Carlo simulations, and comparisons with similar approaches are presented to assess the accuracy of our analytical derivations and confirm the performance gain of the proposed scheme.

  11. Outage probability analysis of wireless sensor networks in the presence of channel fading and spatial correlation

    KAUST Repository

    Al-Murad, Tamim M.

    2011-07-01

    Evaluating the reliability of wireless sensor networks is becoming more important as theses networks are being used in crucial applications. The outage probability defined as the probability that the error in the system exceeds a maximum acceptable threshold has recently been used as a measure of the reliability of such systems. In this work we find the outage probability of wireless sensor network in different scenarios of distributed sensing where sensors\\' readings are affected by spatial correlation and in the presence of channel fading. © 2011 IEEE.

  12. Integrated head area design of KNGR to reduce refueling outage duration

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Woo Tae; Park, Chi Yong; Kim, In Hwan; Kim, Dae Woong [Korea Electric Power Research Institute, Taejon (Korea, Republic of)

    1997-12-31

    In the design of KNGR (Korea Next Generation Reactor), we believe that economy is one of the most important factors to be considered. Thus, we reviewed and evaluated the consequences of designing the head area into an integrated package from an economical point of view. The refueling outage durations of the nuclear power plants currently in operation in Korea, some having and others not having integrated head package, are compared. This paper discusses the characteristics of head area design and the critical design issues of KNGR head area to evaluate the effect of the head area characteristics on the outage duration. 8 refs., 4 figs. (Author)

  13. Investigation into outages of electric power supply as the result of ice storms

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-01

    The accumulation of large amounts of ice on electric power distribution conductors and on trees surrounding these conductors has resulted in a number of extended customer electric power outages. Commonwealth Associates, Inc. was assigned the task of reviewing six ice-caused electric outages at the following utilities: Long Island Lighting Company; Portland General Electric; Central Illinois Public Service; Central Illinois Light Company; Dallas River Power and Light; and City Water, Light and Power Department of Springfield, Illinois. Weather conditions that result in ice storms are reviewed. Discussions conducted with public officials in the affected communities and states are described and results and recommendations are presented.

  14. The use of success path planning to reduce shutdown risk during a dual unit outage at FPL's Turkey Point Power Plant

    International Nuclear Information System (INIS)

    This paper discusses the merits of using success path planning to direct nuclear power plant operators in their recovery actions from plant transients or equipment malfunctions that occur during plant outages. Florida Power and Light Company (FPL) prepared for an eleven month dual unit outage which involved the electrical distribution system. During different phases of the outage, up to half of the normal power distribution would be out of service. The removal of decay heat from the spent nuclear fuel from both nuclear units became a major planning focus. To reduce the risk of loosing decay heat removal functions. FPL used success path planning to aid the operators in the recovery of decay heat removal functions should an electrical transient occur. A open-quotes success pathclose quotes is the alignment of equipment, valves, piping and electrical power which will restore a plant function which was lost due to a transient or equipment malfunction. There can be more than one success path for a given transient. This method of planning to deal with transients was chosen due to the large amount of equipment that would be out-of-service and tracked according to the plant's Technical Specifications. To decrease the response time to transients, the success paths were proceduralized and included training of the individuals involved with the alignments

  15. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    International Nuclear Information System (INIS)

    continue the study by looking more closely at the differences between three levels, or types, of tests: object test, system test and (safety) function test. This should aim to analyse the different steps of testing in order to understand the non-trivial relations between tests and safety. The study should take place at a single NPP during partial/sub-outages, since these periods allow empirical work to be conducted in an appropriate environment with better accessibility to technical staff than during full outage period

  16. Operational readiness verification, phase 1: A study on safety during outage and restart of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hollnagel, E. [Linkoeping Univ. (Sweden). Dept. of Computer and Information Science; Gauthereau, V. [Linkoeping Univ. (Sweden). Dept. of Industrial Engineering

    2001-06-01

    proposed to continue the study by looking more closely at the differences between three levels, or types, of tests: object test, system test and (safety) function test. This should aim to analyse the different steps of testing in order to understand the non-trivial relations between tests and safety. The study should take place at a single NPP during partial/sub-outages, since these periods allow empirical work to be conducted in an appropriate environment with better accessibility to technical staff than during full outage period.

  17. Reverse Link Outage Probabilities of Multicarrier CDMA Systems with Beamforming in the Presence of Carrier Frequency Offset

    Directory of Open Access Journals (Sweden)

    Xiaoyu Hu

    2007-11-01

    Full Text Available The outage probability of reverse link multicarrier (MC code-division multiple access (CDMA systems with beamforming in the presence of carrier frequency offset (CFO is studied. A conventional uniform linear array (ULA beamformer is utilized. An independent Nakagami fading channel is assumed for each subcarrier of all users. The outage probability is first investigated under a scenario where perfect beamforming is assumed. A closed form expression of the outage probability is derived. The impact of different types of beamforming impairments on the outage probability is then evaluated, including direction-of-arrival (DOA estimation errors, angle spreads, and mutual couplings. Numerical results show that the outage probability improves significantly as the number of antenna elements increases. The effect of CFO on the outage probability is reduced significantly when the beamforming technique is employed. Also, it is seen that small beamforming impairments (DOA estimation errors and angle spreads only affect the outage probability very slightly, and the mutual coupling between adjacent antenna elements does not affect the outage probability noticeably.

  18. Planning maintenance during the first outage and refuelling of Qinshan 300 MW Nuclear Power Unit

    International Nuclear Information System (INIS)

    To take an example in the equipment maintenance of the primary circuit and auxiliary systems, this paper sums up the first outage and refuelling planning maintenance of Qinshan 300 MW Nuclear Power Unit. It concludes the guiding principle and preparatory treatment. Some suggestions are put forward. These suggestions provide active function for improving planning maintenance and management of Qinshan Nuclear Power Plant

  19. Health and maintenance outages in nuclear power plants: an epidemiological survey

    International Nuclear Information System (INIS)

    An epidemiological survey, started in 1989, was carried out at the nuclear power plants in the Loire river valley and at Le Blayais (France). Working conditions, work organisation and their impact on health during annual maintenance outages were studied. The main areas covered in this cross-sectional study were: anxiety and symptoms of depression using the Spielberger and CES-D scales. Comparisons were made during both a scheduled outage and in normal operation on four distinct groups of workers, each individual being his own control. A chi-square test was used for the quantitative variables and a test on differences for the quantitative variables. During a unit outage, more frequent overtime and atypical working hours were reported (p<0.01); working rhythms and safety rules were felt as more restrictive and exposure to radiation higher (p<0.01). Detrimental modifications of anxiety and symptoms of depression were observed on controllers whereas expected on maintenance agents. Similar results were observed when considering the rates of outages. Possible readings are given with reference to qualitative studies carried out on this topic, which implies extending our research with both the quantitative and qualitative approaches. (authors). 10 refs., 6 tabs

  20. Competitive outage lengths when servicing the liquid relief valves of the heat transport system

    International Nuclear Information System (INIS)

    Conservative engineering judgement has been frequently used to decide how early into an outage certain type of maintenance work for key elements of the Heat Transport System (HTS) can be conducted. The immediate consequence of this approach is that the length of the outages is increased unnecessarily because this maintenance work often becomes the critical path and, in an environment of competition such as the up coming open market for electricity in Ontario, short duration outages provide great strategic advantages. This paper presents the work done to relax the 30-day waiting period to block closed the LRVs. A detailed model of the HTS which includes the SDCS and the LCH piping connection to the D2O Storage Tank was developed for the state-of-the-art Two Unequal Fluids (TUF) computer code. The results of the simulations with the TUF code have shown that the LCH can be credited as the overpressure relief path as early as two days after unit shutdown in case of loss of forced circulation (e.g., loss of Class III Power to the SDCS pumps). The financial savings and the additional flexibility in planning outage work due to the reduction of the waiting period by a factor of 15 are apparent. (author)

  1. COG CANDU outage optimization project at Wolsong, Qinshan, Cernavoda, Point Lepreau, Darlington and Pickering

    Energy Technology Data Exchange (ETDEWEB)

    McWilliams, L. [CANDU Owners Group, Toronto, Ontario (Canada)

    2011-07-01

    This COG initiated project objective is to reduce the timeline CANDU power plants are shutdown for planned maintenance outages through knowledge sharing, benchmarking and completion of a Gap Analysis. The following CANDU Nuclear Power Stations/Facilities formed a partnership to achieve the objective: Korean Hydro and Nuclear Power Company (Wolsong), Qinshan, Societatea Nationala 'Nuclearelectrica' (Cernavoda), New Brunswick Power Nuclear (Point Lepreau), Candu Energy Inc. (formerly AECL) and Ontario Power Generation Inc. (Darlington and Pickering). Project participants selected ten focus areas to evaluate and optimize. Benchmarking studies were conducted at each utility. A Gap Analysis was performed between the stations and site specific recommendations have been made considering: Critical path improvement opportunities (Unit Shutdown, RBLRT and Unit Start up); Major work program improvement opportunities (Turbine/Generator, Electrical Maintenance, MOT, SST and the Valve Program); Recommended modifications to reduce outage durations; and, Process Improvements (standardized clearance process). A final report has been issued to each station identifying: Gap Analysis Comparison results; Best Practices for each area studied; Site specific improvement opportunities; Most Effective Process for Outage Preparation; Most Effective Outage Execution Practices; and, Contingency Plan Preparation. Results were discussed during the presentation.

  2. Application of Hybrid Geo-Spatially Granular Fragility Curves to Improve Power Outage Predictions

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Steven J [ORNL; Allen, Melissa R [ORNL; Omitaomu, Olufemi A [ORNL; Walker, Kimberly A [ORNL

    2014-01-01

    Fragility curves depict the relationship between a weather variable (wind speed, gust speed, ice accumulation, precipitation rate) and the observed outages for a targeted infrastructure network. This paper describes an empirical study of the county by county distribution of power outages and one minute weather variables during Hurricane Irene with the objective of comparing 1) as built fragility curves (statistical approach) to engineering as designed (bottom up) fragility curves for skill in forecasting outages during future hurricanes; 2) county specific fragility curves to find examples of significant deviation from average behavior; and 3) the engineering practices of outlier counties to suggest future engineering studies of robustness. Outages in more than 90% of the impacted counties could be anticipated through an average or generic fragility curve. The remaining counties could be identified and handled as exceptions through geographic data sets. The counties with increased or decreased robustness were characterized by terrain more or less susceptible to persistent flooding in areas where above ground poles located their foundations. Land use characteristics of the area served by the power distribution system can suggest trends in the as built power grid vulnerabilities to extreme weather events that would be subjects for site specific studies.

  3. Trading sulfur dioxide allowances

    International Nuclear Information System (INIS)

    The 1990 Clean Air Act is aimed at generators larger than 25 MW, as these are the largest polluters. Market incentives give each source an emissions allocation but also flexibility. If a plant has lower emissions than the target, it can sell the 'surplus' emissions as allowances to plants that fail to meet the target. Only a few trades have occurred to date. Market-based incentives should lower the costs of improving environmental quality significantly. However, currently institutional dificulties hamper implementation

  4. World-class outage performance of the Olkiluoto nuclear power plant

    International Nuclear Information System (INIS)

    The production of the Olkiluoto power plant units covered 17% of the electricity consumption in Finland in 1997; the total share of nuclear energy was 27% of the electricity consumed in the country. Based on Finnish experience, nuclear energy is a safe, environmentally friendly and economic way to produce electricity provided that the plants and their personnel are well taken care of. TVO's policy is to keep the plant units in good condition and technically modern. This requires continuous investments in the plant. In maintenance, attention is paid to monitoring the condition of the plant and to preventive maintenance aiming at avoiding disturbances in production. TVO has chosen continuous development as the operational line develops the plant by annual investments and performs the necessary modifications during planned annual outages trying to avoid long production interruptions. The load factors of the Olkiluoto nuclear power plant have been high. The average load factor during the last decade was over 93%. The most significant single factor in the production deficits is the amount or electricity, which has not been produced because of the annual outages. Due to this, special attention has been paid to the performance of the annual outages. TVO aims at continuous development of the annual outage procedure. A centralized task management system makes it possible to perform simultaneously more tasks than before. The company has also invested in equipment and systems, which ease and speed up servicing. Normal outage length varies between 10 and 16 days. By keeping the plant units as modern as possible and in good condition we facilitate reaching TVO's target, which is also stated in TVO's slogan 'always 40 years lifetime'. (author)

  5. Proceedings of a joint OECD/NEA-IAEA symposium on human factors and organisation in NPP maintenance outages: impact on safety

    International Nuclear Information System (INIS)

    The sessions of this conference dealt with outage strategy and methods (in Sweden, France and United States), the organisation and management of outages (organisation during refuelling shutdowns in France, safety approaches in France, in the USA, in Canada, in the United Kingdom and in Sweden), case studies and lessons learned (in France, Korea, Sweden, UK, USA), regulatory aspects of outages (UK, Germany, Mexico, France), the development of outage techniques

  6. Estimation over MIMO Fading Channels: Outage and Diversity Analysis

    OpenAIRE

    Parseh, Reza

    2016-01-01

    In this thesis, estimation of signals over fading channels for analog uncoded transmission is considered. In communication settings with tight delay requirements, e.g. in real-time control over wireless fading channels and vehicle-to-vehicle communication, the use of efficient and therefore long channel codes for reliability is not possible. Without channel codes, one needs to seek out alternative techniques. One such technique is to send uncompressed discrete-time source samples ...

  7. System reliability time-dependent models

    International Nuclear Information System (INIS)

    A probabilistic methodology for safety system technical specification evaluation was developed. The method for Surveillance Test Interval (S.T.I.) evaluation basically means an optimization of S.T.I. of most important system's periodically tested components. For Allowed Outage Time (A.O.T.) calculations, the method uses system reliability time-dependent models (A computer code called FRANTIC III). A new approximation, which was called Independent Minimal Cut Sets (A.C.I.), to compute system unavailability was also developed. This approximation is better than Rare Event Approximation (A.E.R.) and the extra computing cost is neglectible. A.C.I. was joined to FRANTIC III to replace A.E.R. on future applications. The case study evaluations verified that this methodology provides a useful probabilistic assessment of surveillance test intervals and allowed outage times for many plant components. The studied system is a typical configuration of nuclear power plant safety systems (two of three logic). Because of the good results, these procedures will be used by the Argentine nuclear regulatory authorities in evaluation of technical specification of Atucha I and Embalse nuclear power plant safety systems. (Author)

  8. Effects of the April 1st, 2014 GLONASS Outage on GNSS Receivers

    Science.gov (United States)

    Blume, F.; Berglund, H. T.; Romero, I.; D'Anastasio, E.

    2014-12-01

    The use of multi-constellation GNSS receivers has been assumed as a way to increase system integrity both by increased coverage during normal operations and failover redundancy in the event of a constellation failure. At approximately 21:00 UTC on April 1st the entire GLONASS constellation was disrupted as illegal ephemeris uploaded to each satellite took effect simultaneously. The outage continued for more than 10 hours. While ephemeris were incorrect, pseudoranges were correctly broadcast on both L1 and L2 and carrier phases were not affected; in the best case, GNSS receivers could be expected to continue to track all signals including GLONASS and at the worst to continue to track GPS and other constellations. It became clear to operators of the GeoNet network in New Zealand that the majority of their 79 GLONASS-enabled receivers experienced total tracking failures. Further detailed analysis of data from these and 315 additional GLONASS-enabled stations worldwide showed that receiver tracking behavior was affected for most receiver brands and models, both for GLONASS and GPS. Findings regarding the impacts of the GLONASS outage on receiver behavior will be highlighted. We use data recorded by GLONASS enabled global sites for the days during, preceding and following the outage to evaluate the impact of the outage on tracking and positioning performance. We observe that for some receiver types the onboard receiver autonomous integrity monitoring (RAIM) failed to ignore the incorrect messages, resulting in degraded GLONASS and GPS tracking and in some cases complete tracking failures and significant data loss. In addition, many of the receivers with clock steering enabled showed outliers in their receiver clock bias estimates that also coincided with the outage. Our results show in detail how different brands, configurations, and distributions of receivers were affected to varying extents, but no common factors are apparent. This event shows that many manufacturers

  9. Outage planning in nuclear power plants. A paradigm shift from an external towards an integrated project planning tool

    International Nuclear Information System (INIS)

    Latest demands on nuclear plant inspections are the ongoing actualisation of the outage plan on the basis of the current work progress and current events as well as the permanent access to the current planning status and work process of all people involved in the outage. Modern EAM systems (EAM: Enterprise Application Management) made up ground on established project planning tools with regard to functionalities for scheduling work orders. A shift towards an integrated planning in the EAM system increases the efficiency in the outage planning and improves the communication of current states of planning. (orig.)

  10. Analysis of 58Co activity concentration in the primary coolant during CPR1000 NPP shut down for outage

    International Nuclear Information System (INIS)

    Activated corrosion products which deposit on inner walls of primary coolant are the main radioactive sources in PWR NPPs during outage. A method for estimating the 58Co activity concentration during outage was proposed in this paper. By analysis, we can get that the purification rate and the release rate in the primary coolant are the main factors changes of the 58co activity concentration, and the 58Co activity concentration meet the related requirement of Outage limits in CPR1000 nuclear power plant. (authors)

  11. Power outages in California - could they also happen in Germany?

    International Nuclear Information System (INIS)

    Since the summer of 2000, the U.S. state of California has experienced breakdowns of its electricity supply with considerable impacts on all areas of social life. As a consequence of insufficient generating capacity available, specific large-scale consumers or entire urban districts must be cut off the power grid at times of peak electricity demand. The causes of these structural problems of electricity supply in California are associated closely with the consequences of the (incomplete) deregulation of the electricity market. Deregulation, which was achieved with a lot of regulations, accompanied by extensive environmental protection requirements, resulted in a decline of the generating capacity available. In addition, legal fixing of end user prices has spelt financial disaster for many power utilities. Measures to overcome the crisis are being discussed, but will take effect only on a medium term. A similar situation in Germany must not be expected to arise at short notice because sufficient standby capacity is available at the present time, and electricity consumption is rising only moderately. However, on a medium term, a structural crisis similar to that in California could be brought about by the deregulation of the German electricity market, especially with the present influence exerted by the government through measures not in conformity with the market, such as legislation on renewable energies and on cogeneration schemes. (orig.)

  12. Analysis of Chain of Events in Major Historic Power Outages

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

    Full Text Available Contemporary power systems are facing increasing intricate conditions that have never been considered when initially designing the infrastructure, such as malicious threats, accommodating smart grids, etc. As a consequence, blackouts albeit seldom but stubbornly keep appearing from time to time the world around, and demonstrate their devastating capability to create vast damage on both power systems and the society at large. Patterns of the blackout starting from the first triggering events to the system final status have emerged. A framework of a coding system was proposed in this paper in order to capture the common feature in the system evolution during the development of cascades. Cascades in a blackout can be tracked by a chain of events with the help of the codes. It is facile to adopt the framework to build up a knowledge base of blackouts. By applying the proposed framework to 31 selected historic blackouts, most frequent events, effects and origins are identified; the findings can provide useful information for grid designers and security experts for ranking the most imminent issues in their study.

  13. Recent performance of and plasma outage studies with the SNS H- source

    Science.gov (United States)

    Stockli, M. P.; Han, B.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R.

    2016-02-01

    Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ˜55-kW 2-MHz plasma pulses reflecting ˜90% of the continuous ˜300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H2 gas also increased the H- beam current to ˜55 mA and increased the RFQ transmission by ˜7% (relative).

  14. On the outage capacity of the block fading channel at low-power regime

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

    Outage performance of the M-block fading with additive white Gaussian noise (BF-AWGN) is investigated at low-power regime. We consider delay-constrained constant-rate communications with perfect channel state information (CSI) at both the transmitter and the receiver (CSI-TR), under a short-term power constraint. We show that selection diversity that allocates all the power to the strongest block is asymptotically optimal. Then, we provide a simple characterization of the outage probability in the regime of interest. We quantify the reward due to CSI-TR over the constant-rate constant-power scheme and show that this reward increases with the delay constraint. For instance, for Rayleigh fading, we find that a power gain up to 4.3 dB is achievable. © 2014 IEEE.

  15. Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

    Directory of Open Access Journals (Sweden)

    Wenjie Peng

    2014-01-01

    Full Text Available The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC and selected transmission/maximum ratio combining (ST-MRC schemes are adopted in uplink and downlink, respectively. Then, based on a newly proposed nonuniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis regarding the system performance are proven and illustrated by computer simulations.

  16. Recent Performance of and Plasma Outage Studies with the SNS H- Source

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, Martin P [ORNL; Han, Baoxi [ORNL; Murray Jr, S N [ORNL; Pennisi, Terry R [ORNL; Piller, Chip [ORNL; Santana, Manuel [ORNL; Welton, Robert F [ORNL

    2016-01-01

    SNS ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised RFQ, which requires higher RF power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ~55-kW 2-MHz plasma pulses reflecting ~90% of the continuous ~300W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly-detuned 13-MHz match. Lowering the H2 also increased the H- beam current to ~55 mA, and increased the transmission by ~7%.

  17. Method for estimating power outages and restoration during natural and man-made events

    Energy Technology Data Exchange (ETDEWEB)

    Omitaomu, Olufemi A.; Fernandez, Steven J.

    2016-01-05

    A method of modeling electric supply and demand with a data processor in combination with a recordable medium, and for estimating spatial distribution of electric power outages and affected populations. A geographic area is divided into cells to form a matrix. Within the matrix, supply cells are identified as containing electric substations and demand cells are identified as including electricity customers. Demand cells of the matrix are associated with the supply cells as a function of the capacity of each of the supply cells and the proximity and/or electricity demand of each of the demand cells. The method includes estimating a power outage by applying disaster event prediction information to the matrix, and estimating power restoration using the supply and demand cell information of the matrix and standardized and historical restoration information.

  18. On the Outage Performance of Full-Duplex Selective Decode-and-Forward Relaying

    KAUST Repository

    Khafagy, Mohammad Galal

    2013-02-25

    We evaluate the outage performance in a three-terminal full-duplex relay channel that adopts a selective decode-and-forward protocol, taking relay self-interference into account. Previous work focused on coverage extension scenarios where direct source-destination transmissions are neglected or considered as interference. In this work, we account for the relay self-interference, and exploit the cooperative diversity offered by the independently fading source/relay message replicas that arrive at the destination. We present an approximate, yet accurate, closed-form expression for the end-to-end outage probability that captures their joint effect. With the derived expression in hand, we propose a relay transmit power optimization scheme that only requires the relay knowledge of channel statistics. Finally, we corroborate our analysis with simulations.

  19. Efficient Cooperative Protocols for General Outage-Limited Multihop Wireless Networks

    OpenAIRE

    Maham, Behrouz; Saad, Walid; Debbah, Merouane; Han, Zhu; Hjorungnes, Are

    2010-01-01

    Due to the limited energy supplies of nodes in wire- less networks, achieving energy efficiency is crucial for extending the lifetime of these networks. Thus, we study efficient power allocations and transmission protocols for outage-restricted mul- tihop wireless networks based on cooperative transmission. In such multihop networks, a number of nodes, acting as relays, can assist a source node in the transmission of its messages to a single destination. In this paper, several multihop transm...

  20. Extreme Outages due to Polarization Mode Dispersion First- and Higher- Order Compensations

    CERN Document Server

    Chernyak, V; Kolokolov, I V; Lebedev, V; Chernyak, Vladimir; Chertkov, Michael; Kolokolov, Igor; Lebedev, Vladimir

    2003-01-01

    Joint effect of weak birefringent disorder and amplifier noise on transmission in optical fiber communication systems is properly described in terms of the Probability Distribution Function (PDF) of Bit Error Rate (BER). The PDF tail, correspondent to extreme outages and thus anomalously large values of Bit Error Rate (BER), was analyzed in [1]. In the letter we extend this analysis for the case of the first- and higher-order PMD compensation schemes.

  1. Study on European Nuclear Safety Practices during Planned Outages at Nuclear Power Plants

    International Nuclear Information System (INIS)

    The present project was aimed at providing: a description of the current status of nuclear safety practices during planned outages at nuclear power plants followed in Europe; the criteria for the safety analysis of future reactors at the design stage; proposing a set of recommendations on good practices and criteria leading to the improvement of nuclear safety during those conditions. The work was organised in 3 phases: Collecting data on current practices; Analysis of questionnaire answers and drawing up of safety good practices references and recommendations; Collecting relevant ideas related to the future reactors at design stage (European Pressurised Water Reactor, European Passive Plant project, European Utilities Requirements and Utilities Requirement Document project). The key element of the performed work was the detailed questionnaire, based on bibliographical review, expert experience and outage practices available in the working team. Different safety areas and activities were covered: outage context; nuclear safety; outage strategy, organisation and control; operating feedback; use of Probabilistic Safety Assessment. The questionnaire was answered by 12 European nuclear power plants, representing 9 different European countries and three different types of reactors (Pressurised Water Reactor, Boiling Water Reactor and Water Water Energy Reactor). Conclusions were drawn under the following headers: Organisational survey and generalities Organisational effectiveness Quality of maintenance Quality of operation Engineering support, management of modification Specific aspects Each analysed subject includes the following topics: Questions background with a summary and the aim of the questions. Current status, that describes common practices, as derived from the answers to the questionnaire, and some examples of good specific practices. Identified good practices. (author)

  2. Exact Outage Probability of Cognitive Underlay DF Relay Networks with Best Relay Selection

    Science.gov (United States)

    Bao, Vo Nguyen Quoc; Duong, Trung Quang

    In this letter, we address the performance analysis of underlay selective decode-and-forward (DF) relay networks in Rayleigh fading channels with non-necessarily identical fading parameters. In particular, a novel result on the outage probability of the considered system is presented. Monte Carlo simulations are performed to verify the correctness of our exact closed-form expression. Our proposed analysis can be adopted for various underlay spectrum sharing applications of cognitive DF relay networks.

  3. Final report of MoReMO 2011-2012. Modelling resilience for maintenance and outage

    International Nuclear Information System (INIS)

    The project Modelling Resilience for Maintenance and Outage (MoReMO) represents a two-year joint effort by VTT Technical Research Centre of Finland, Institute for Energy Technology (IFE, Norway) and Vattenfall (Sweden) to develop and test new approaches for safety management. The overall goal of the project was to present concepts on how resilience can be operationalized and built in a safety critical and socio-technical context. Furthermore, the project also aimed at providing guidance for other organizations that strive to develop and improve their safety performance in a business driven industry. We have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. During 2011 and 2012 the MoReMO project team has collected data through field observations, interviews, workshops, and document analysis on the work practices and adjustments in maintenance and outage in Nordic NPPs. The project consisted of two sub-studies, one focused on identifying and assessing adjustments and supporting resilient work practices in maintenance activities, while the other focused on handling performance trade-offs in maintenance and outage, as follows: A. Adjustments in maintenance work in Nordic nuclear power plants (VTT and Vattenfall). B. Handling performance trade-offs - the support of adaptive capacities (IFE and Vattenfall). The historical perspective of maintenance and outage management (Chapter 1.1) was provided by Vattenfall. Together, the two sub-studies have provided valuable insights for understanding the rationale behind work practices and adjustments, their effects on resilience, promoting flexibility and balancing between flexibility and reliability. (Author)

  4. Secrecy Cognitive Gain of Cognitive Radio Sensor Networks with Primary Outage Constraint

    OpenAIRE

    Hongyu Ma; Kai Niu; Weiling Wu; Shengyu Li; Guangqian Chu

    2015-01-01

    This paper studies the physical layer security issue for cognitive radio sensor networks (CRSNs) with primary outage constraint, for which a tractable framework is developed to analyze the secrecy performance for CRSNs related to the random channel characteristics, the spatial distributions of nodes, the nearest neighbour routing protocol, and the aggregate interference. Based on stochastic geometry technique, a novel random analysis method is proposed to derive the closed-form expression of ...

  5. Final report of MoReMO 2011-2012. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Gotcheva, N.; Macchi, L.; Oedewald, P. [Technical Research Centre of Finland (VTT), Espoo (Finland); Eitrheim, M.H.R. [Institute for Energy Technology (IFE) (Norway); Axelsson, C.; Reiman, T.; Pietikaeinen, E. [Ringhals AB (NPP), Vattenfall AB (Sweden)

    2013-04-15

    The project Modelling Resilience for Maintenance and Outage (MoReMO) represents a two-year joint effort by VTT Technical Research Centre of Finland, Institute for Energy Technology (IFE, Norway) and Vattenfall (Sweden) to develop and test new approaches for safety management. The overall goal of the project was to present concepts on how resilience can be operationalized and built in a safety critical and socio-technical context. Furthermore, the project also aimed at providing guidance for other organizations that strive to develop and improve their safety performance in a business driven industry. We have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. During 2011 and 2012 the MoReMO project team has collected data through field observations, interviews, workshops, and document analysis on the work practices and adjustments in maintenance and outage in Nordic NPPs. The project consisted of two sub-studies, one focused on identifying and assessing adjustments and supporting resilient work practices in maintenance activities, while the other focused on handling performance trade-offs in maintenance and outage, as follows: A. Adjustments in maintenance work in Nordic nuclear power plants (VTT and Vattenfall). B. Handling performance trade-offs - the support of adaptive capacities (IFE and Vattenfall). The historical perspective of maintenance and outage management (Chapter 1.1) was provided by Vattenfall. Together, the two sub-studies have provided valuable insights for understanding the rationale behind work practices and adjustments, their effects on resilience, promoting flexibility and balancing between flexibility and reliability. (Author)

  6. Hydro-Quebec's survey on outage cost in industries

    International Nuclear Information System (INIS)

    In 1989 Hydro-Quebec completed a survey on the cost of power interruptions to its industrial customers. A total of 11,000 firms formed the base of the survey, which was reduced to 1,647 for analysis purposes. The questionnaire was designed around the concept of representation of knowledge. The costs of various situations were inferred for every enterprise on the basis of knowledge obtained through the surveys. The results of the survey describe the variation in costs of interruption as a function of time of occurrence, duration and advance notice. These costs are expressed in terms of a reference case by the equivalent hourly cost. The magnitude of the cost of the reference interruption is designated the reference cost of undelivered energy. This paper describes the methodology of the survey but does not include survey results. 4 refs., 2 tabs

  7. Lights out: Impact of the August 2003 power outage on mortality in New York, NY

    Science.gov (United States)

    Anderson, G. Brooke; Bell, Michelle L.

    2012-01-01

    Background Little is known about how power outages affect health. We investigated mortality effects of the largest US blackout to date, August 14–15, 2003 in New York, NY. Methods We estimated mortality risk in New York, NY, using a generalized linear model with data from 1987–2005. We incorporated possible confounders, including weather and long-term and seasonal mortality trends. Results During the blackout, mortality increased for accidental deaths (122% [95% confidence interval = 28%–287%]) and non-accidental (i.e., disease-related) deaths (25% [12%–41%]), resulting in approximately 90 excess deaths. Increased mortality was not from deaths being advanced by a few days; rather, mortality risk remained slightly elevated through August 2003. Discussion To our knowledge, this is the first analysis of power outages and non-accidental mortality. Understanding the impact of power outages on human health is relevant, given that increased energy demand and climate change are likely to put added strain on power grids. PMID:22252408

  8. Ergodic and Outage Performance of Fading Broadcast Channels with 1-Bit Feedback

    CERN Document Server

    Niu, Bo; Somekh, Oren; Haimovich, Alexander M

    2010-01-01

    In this paper, the ergodic sum-rate and outage probability of a downlink single-antenna channel with K users are analyzed in the presence of Rayleigh flat fading, where limited channel state information (CSI) feedback is assumed. Specifically, only 1-bit feedback per fading block per user is available at the base station. We first study the ergodic sum-rate of the 1-bit feedback scheme, and consider the impact of feedback delay on the system. A closed-form expression for the achievable ergodic sum-rate is presented as a function of the fading temporal correlation coefficient. It is proved that the sum-rate scales as loglogK, which is the same scaling law achieved by the optimal non-delayed full CSI feedback scheme. The sum-rate degradation due to outdated CSI is also evaluated in the asymptotic regimes of either large K or low SNR. The outage performance of the 1-bit feedback scheme for both instantaneous and outdated feedback is then investigated. Expressions for the outage probabilities are derived, along w...

  9. Partner cooperation with decode-and-forward: Closed-form outage analysis and comparison

    KAUST Repository

    Benjillali, Mustapha

    2013-01-01

    In this paper, we investigate the outage performance of "partner cooperation" based on opportunistic Decodeand- Forward with constrained partial selection and reactive relaying strategies in dual-hop cooperative Nakagami-m fading links. The source/destination, which is based on the unique knowledge of local channel state information, selects the best relay to increase the chances of cooperation in both uplink and downlink communications when the direct link is also available. After deriving new expressions for the cumulative distribution functions of the variables of interest, the outage probability of the system is obtained in closed-form. We also derive the ε-outage capacity in different particular cases, and the obtained results - when the channel model is reduced to a Rayleigh fading - either are new or correspond to those previously obtained in other works. Simulation results confirm the accuracy of our analysis for a large selection of system and fading parameters and provide a new insight into the design and optimization of cooperative configurations. © 2012 IEEE.

  10. Relay Aided Wireless Multicast Utilizing Network Coding: Outage Behaviour and Diversity Gain

    Directory of Open Access Journals (Sweden)

    Zhi Chen

    2010-01-01

    Full Text Available Broadcast nature of wireless networks can be exploited to provide a flexible transmission, especially in multicast service. The potential relay then is capable to participate in message forwarding. In this paper, we first presents a network coding based cooperative (NCBC multicast scheme exploiting limited feedback, where the source transmits two separate signals to multiple destinations in two successive half slots. The relay may combine the signals if it received two signals correctly and forward it to destinations in the next half slot. The destinations, therefore, can recover signals either from direct transmission or the relay forwarding. The performance analysis on the developed NCBC multicast protocol is given in the viewpoint of physical layer, such as the outage probability and diversity order. It is demonstrated that the NCBC multicast scheme can work better than the source direct multicast in terms of outage probability. Meanwhile, the NCBC multicast scheme can achieve full diversity gain(diversity two for one relay case. Comparing with the known relay schemes, i.e., amplify-andforward (AF and selection decode-and-forward cooperation schemes, it shows that the NCBC multicast scheme achieves almost the same outage performance with relatively less bandwidth and energy consumption.

  11. A novel fusion methodology to bridge GPS outages for land vehicle positioning

    International Nuclear Information System (INIS)

    Many intelligent transportation system applications require accurate, reliable, and continuous vehicle position information whether in open-sky environments or in Global Positioning System (GPS) denied environments. However, there remains a challenging task for land vehicles to achieve such positioning performance using low-cost sensors, especially microelectromechanical system (MEMS) sensors. In this paper, a novel and cost-effective fusion methodology to bridge GPS outages is proposed and applied in the Inertial Navigation System (INS)/GPS/ compass integrated positioning system. In the implementation of the proposed methodology, a key data preprocessing algorithm is first developed to eliminate the noise in inertial sensors in order to provide more accurate information for subsequent modeling. Then, a novel hybrid strategy incorporating the designed autoregressive model (AR model)-based forward estimator (ARFE) with Kalman filter (KF) is presented to predict the INS position errors during GPS outages. To verify the feasibility and effectiveness of the proposed methodology, real road tests with various scenarios were performed. The proposed methodology illustrates significant improvement in positioning accuracy during GPS outages. (paper)

  12. Risk-Based, genetic algorithm approach to optimize outage maintenance schedule

    Energy Technology Data Exchange (ETDEWEB)

    Hadavi, S. Mohammad Hadi [Department of Nuclear Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)], E-mail: smhadihadavi@yahoo.com

    2008-04-15

    A huge number of components are typically scheduled for maintenance when a nuclear power plant is shut down for its planned outage. Among these components, a number of them are risk significant so that their operability as well as reliability is of prime concern. Lack of proper maintenance for such components during the outage would impose substantial risk on the nuclear power plant (NPP) operation. In this paper, a new approach based on genetic algorithm (GA) is presented for the optimization of the NPP maintenance schedule during plant outage/overhaul, and an optimizer is developed accordingly. The developed optimizer, coupled with the suggested risk-cost model, compromises the cost in favor of maintaining the risk imposed by each schedule below regulatory/industry set limits. The suggested cost model consists of two elements, one considering the cost incurred by maintenance activities and the other incorporating the loss of revenues if needed, but unscheduled component maintenance causes further plant shutdown. The optimizer is developed in such a way that any risk and/or cost models the user desires can be applied. The performance of the developed GA/optimizer is evaluated by comparing its predictions with Monte Carlo simulation results. It is shown that the GA/optimizer performs significantly better.

  13. A heuristic model for risk and cost impacts of plant outage maintenance schedule

    Energy Technology Data Exchange (ETDEWEB)

    Mohammad Hadi Hadavi, S. [Energy Research Inc., 6167 Executive Blvd., Rockville, MD 20852 (United States)], E-mail: smhadihadavi@yahoo.com

    2009-07-15

    Cost and risk are two major competing criteria in maintenance optimization problems. If a plant is forced to shutdown because of accident or fear of accident happening, beside loss of revenue, it causes damage to the credibility and reputation of the business operation. In this paper a heuristic model for incorporating three compelling optimization criteria (i.e., risk, cost, and loss) into a single evaluation function is proposed. Such a model could be used in any evaluation engine of outage maintenance schedule optimizer. It is attempted to make the model realistic and to address the ongoing challenges facing a schedule planner in a simple and commonly understandable fashion. Two simple competing schedules for the NPP feedwater system are examined against the model. The results show that while the model successfully addresses the current challenges for outage maintenance optimization, it properly demonstrates the dynamics of schedule in regards to risk, cost, and losses endured by maintenance schedule, particularly when prolonged outage and lack of maintenance for equipments in need of urgent care are of concern.

  14. Important aspects for consideration in minimizing plant outage times. Swiss experience in achieving high availability

    International Nuclear Information System (INIS)

    Operation of Swiss nuclear power plants has not been entirely free of trouble. They have experienced defective fuel elements, steam generator tube damage, excessive vibration of the core components, leakages in the recirculation pump seals and excessive corrosion and erosion in the steam-feedwater plant. Despite these technical problems in the early life of the plants, on overall balance the plants can be considered to have performed exceedingly well. The safety records from more than 40 reactor-years of operation are excellent and, individually and collectively, the capacity factors obtained are among the highest in the world. The problems mentioned have been solved and the plants continue operation with high availabilities. This success can be attributed to the good practices of the utilities with regard to the choice of special design criteria, plant organization, plant operation and plant maintenance, and also to the pragmatic approach of the licensing authorities and their consultants to quality assurance and quality control. The early technical problems encountered, the corresponding solutions adopted and the factors that contributed towards achieving high availabilities in Swiss nuclear power plants are briefly described. (author)

  15. Temporary cooling system for critical loads during Recirculation Cooling Water (RCW) system outage

    International Nuclear Information System (INIS)

    As part of the Point Lepreau Refurbishment Project, Recirculation Cooling Water (RCW) system will be shutdown for maintenance activity. During the RCW outage, alternate cooling flow for critical heat loads such as Spent Fuel Bay (SFB), D2O vapour dryers and Instrument Air Compressor Coolers will be provided through a temporary cooling system to remove approximately 3MW of heat. This paper describes a practical strategy to build in the temporary cooling system for this project. Major equipment involved, piping modifications required and system reliability analysis are also addressed. (author)

  16. Outage performance of two-way DF relaying systems with a new relay selection metric

    KAUST Repository

    Hyadi, Amal

    2012-04-01

    This paper investigates a new constrained relay selection scheme for two-way relaying systems where two end terminals communicate simultaneously via a relay. The introduced technique is based on the maximization of the weighted sum rate of both users. To evaluate the performance of the proposed system, the outage probability is derived in a general case (where an arbitrary channel is considered), and then over independently but not necessarily identically distributed (i.n.i.d.) Rayleigh fading channels. The analytical results are verified through simulations. © 2012 IEEE.

  17. MATCASC: A tool to analyse cascading line outages in power grids

    CERN Document Server

    Koç, Yakup; Araujo, Nuno A M; Warnier, Martijn

    2013-01-01

    Blackouts in power grids typically result from cascading failures. The key importance of the electric power grid to society encourages further research into sustaining power system reliability and developing new methods to manage the risks of cascading blackouts. Adequate software tools are required to better analyze, understand, and assess the consequences of the cascading failures. This paper presents MATCASC, an open source MATLAB based tool to analyse cascading failures in power grids. Cascading effects due to line overload outages are considered. The applicability of the MATCASC tool is demonstrated by assessing the robustness of IEEE test systems and real-world power grids with respect to cascading failures.

  18. Exact outage analysis of incremental decode-and-forward opportunistic relaying

    KAUST Repository

    Tourki, Kamel

    2010-11-01

    In this paper, we investigate a dual-hop decode-andforward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. In our study, we derive exact closed-form expression for the outage probability based on the exact statistics of each hop. Furthermore, we perform asymptotic analysis and we deduce the diversity order of the scheme. We validate our analysis by showing that performance simulation results coincide with our analytical results over different network architectures. © 2010 IEEE.

  19. Algorithms for Estimation of Vehicle Trajectory during GPS Signal Outages Based on Inertial Sensor Data

    Czech Academy of Sciences Publication Activity Database

    Machan, J.; Herda, Z.; Pavelková, Lenka

    Praha: ÚTIA AV ČR, v.v.i, 2011 - (Janžura, M.; Ivánek, J.). s. 19-19 [7th International Workshop on Data - Algorithms - Decision Making. 27.11.2011-29.11.2011, Mariánská] R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : state-space model * ARX model * uniform noise Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2011/AS/pavelkova-algorithms for estimation of vehicle trajectory during gps signal outages based on inertial sensor data.pdf

  20. Electrochemical potential monitoring at the Point Lepreau Generating Station during the 2006 maintenance outage

    International Nuclear Information System (INIS)

    Electrochemical corrosion potential (ECP) probes were installed by the Centre for Nuclear Energy Research in the primary heat transport system sample line of the Point Lepreau Generating Station. The probes provided a realistic estimate of the ECP experienced by the outlet feeder pipes during the 2006 maintenance outage and into the start-up. The results from the installation of the probes indicate that the corrosion potential of the probes, and by extension the feeders, is influenced by temperature, flow velocity and the presence of oxidizing species. Changes in the concentration of oxidizing species were shown to significantly alter the measured potential. (author)

  1. Outage and Capacity Performance Evaluation of Distributed MIMO Systems over a Composite Fading Channel

    OpenAIRE

    2014-01-01

    The exact closed-form expressions regarding the outage probability and capacity of distributed MIMO (DMIMO) systems over a composite fading channel are derived. This is achieved firstly by using a lognormal approximation to a gamma-lognormal distribution when a mobile station (MS) in the cell is in a fixed position, and the so-called maximum ratio transmission/selected combining (MRT-SC) and selected transmission/maximum ratio combining (ST-MRC) schemes are adopted in uplink and downlink, res...

  2. Outage and ser performance of an opportunistic multi-user underlay cognitive network

    KAUST Repository

    Khan, Fahd Ahmed

    2012-10-01

    Consider a multi-user underlay cognitive network where multiple cognitive users concurrently share the spectrum with a primary network and a single secondary user is selected for transmission. The channel is assumed to have independent but not identical Nakagami-m fading. Closed form expressions for the outage performance and the symbol-error-rate performance of the opportunistic multi-user secondary network are derived when a peak interference power constraint is imposed on the secondary network in addition to the limited peak transmit power of each secondary user. © 2012 IEEE.

  3. Cognitive multiple-antenna network in outage-restricted primary system

    DEFF Research Database (Denmark)

    Maham, Behrouz; Popovski, Petar

    2013-01-01

    interference from the downlink MISO cognitive radio, also called secondary system. We derive exact expressions for outage probability of the primary user under Rayleigh fading, when the primary system is exposed to interference from a secondary base station. Moreover, in high-SNR scenario, a closed......In the commons model for the spectrum sharing, cognitive users can access the spectrum as long as the target performance in the legitimate primary system is not violated. In this paper, we consider a downlink primary multiple-input-single-output (MISO) system which operates under a controlled...

  4. Signal Quality Outage Analysis for Ultra-Reliable Communications in Cellular Networks

    DEFF Research Database (Denmark)

    Gerardino, Guillermo Andrés Pocovi; Alvarez, Beatriz Soret; Lauridsen, Mads; Pedersen, Klaus I.; Mogensen, Preben Elgaard

    Ultra-reliable communications over wireless will open the possibility for a wide range of novel use cases and applications. In cellular networks, achieving reliable communication is challenging due to many factors, particularly the fading of the desired signal and the interference. In this regard...... schemes must be complemented with macroscopic diversity as well as interference management techniques in order to ensure the necessary SINR outage performance. Based on the obtained performance results, it is discussed which of the feasible options fulfilling the ultra-reliable criteria are most promising...

  5. Feasibility Study for the K-Area Bingham Pump Outage Pit (643-1G)

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, E.R. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    1997-05-01

    The K-Area Bingham Pump Outage Pit (KBPOP) is one of four BPOP areas at Savannah River Site (SRS), collectively referred to as the BPOP waste unit group. This Feasibility Study (FS) of Remedial Alternatives serves as the lead FS for the BPOP waste unit group. This section identifies the purpose and scope of the FS and presents site background information summarized from the Final Remedial Investigation Report with Baseline Risk Assessment (RI/BRA) WSRC-RP- 95-1555, Rev. 1.2 (WSRC 1997).

  6. Application of time-dependent reliability analysis code ''MARKOV'' to the nuclear power plants

    International Nuclear Information System (INIS)

    This paper provides the calculational model and applications of ''MARKOV'' code. Computer code ''MARKOV'' was developed to estimate the time-dependent reliability/availablity of redundant repairable systems based on a Markov model. The methods of handling transient behaviors due to demand failures and the effect of allowable outage time (AOT) were developed and built in this code, so that more realistic evaluation of the effects such as human errors and long term phased mission probability would be possible compared with the other conventional Markovian approach

  7. Safety assessment of Diablo Canyon risks during shutdown operations. EPRI Outage Risk Assessment and Management (ORAM) program. Final report, June 1993

    International Nuclear Information System (INIS)

    For nuclear power plants, a safety assessment is an essential step toward developing a cost-effective approach to managing safety. This applies to shutdown operations as well as assuring safe operation while at power. This report is a probabilistic and deterministic assessment of the frequency of coolant boiling and core uncovery during shutdown operations of the Diablo Canyon PWRs. The results of the generic PWR shutdown risk assessment (NSAC-176L) are applied for the purposes of validating the generic report and determining results specific to Diablo Canyon. Both forced outages and scheduled outages (for refueling and maintenance) are considered. The emphasis is on loss of decay heat removal and loss of coolant while the fuel is in the reactor vessel, since NSAC-176L found those to be the dominant contributor to core uncovery and possible core damage. Deterministic analyses are performed to determine the expected system response and the time available for remedial action by the plant operators. Probabilistic assessment includes simple event trees and quantification of accident sequences. Vulnerabilities are identified and corrective actions were developed and implemented by Pacific Gas and Electric. (author)

  8. Recent performance of and plasma outage studies with the SNS H{sup −} source

    Energy Technology Data Exchange (ETDEWEB)

    Stockli, M. P., E-mail: stockli@ornl.gov; Han, B.; Murray, S. N.; Pennisi, T. R.; Piller, C.; Santana, M.; Welton, R. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

    2016-02-15

    Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H{sup −} beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ∼55-kW 2-MHz plasma pulses reflecting ∼90% of the continuous ∼300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H{sub 2} gas also increased the H{sup −} beam current to ∼55 mA and increased the RFQ transmission by ∼7% (relative)

  9. Global NDE Best Practice for Technology Improvement, Outage Management, Foreign Material Exclusion and Dose Control

    International Nuclear Information System (INIS)

    Non Destructive Examination (NDE) is a critical element of both Boiling Water and Pressurized Water Reactor outages. Frequently this includes critical path activity so both the utility and the inspection vendor are under intense pressure to perform the work quickly. Concurrent with AREVA's new global organization of NDE resources, AREVA NDE SOLUTIONS, efforts have intensified for global application of lessons learned and best practices. These best practices include new developments as well as continuous improvements to well established tools and NDE techniques. Advancements range from steam generator robots, advanced steam generator deposit characterization sensors and method, new phased array approaches for PWR and BWR reactor vessel examination, new sensors and approaches for RPV head examinations, plus advanced internals examination robots and methods. In addition to specialized tools and techniques, best practice includes numerous management innovations. AREVA's multi-disciplined integrated nuclear worker strategy helps to minimize the total number of personnel deployed to multi-task outages. Specific design and on-site practice has been implemented to minimize or eliminate foreign material from the reactor system and vigorous pursuit of dose management practices keeps our nuclear worker dose as low as reasonably achievable. The industry is moving to much more conservative nuclear worker dose limits. While this is proving to be an issue with many vendors, AREVA has had an internal policy of <2R since 2006. Globalizing the organization also helps AREVA manage peaks and unplanned emergency inspections from an enlarged pool of globally qualified inspection personnel and tools. (Author)

  10. Recent performance of and plasma outage studies with the SNS H⁻ source.

    Science.gov (United States)

    Stockli, M P; Han, B; Murray, S N; Pennisi, T R; Piller, C; Santana, M; Welton, R

    2016-02-01

    Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H(-) beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ∼55-kW 2-MHz plasma pulses reflecting ∼90% of the continuous ∼300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H2 gas also increased the H(-) beam current to ∼55 mA and increased the RFQ transmission by ∼7% (relative). PMID:26932022

  11. On Outage Probability and Diversity-Multiplexing Tradeoff in MIMO Relay Channels

    CERN Document Server

    Loyka, Sergey

    2011-01-01

    Fading MIMO relay channels are studied analytically, when the source and destination are equipped with multiple antennas and the relays have a single one. Compact closed-form expressions are obtained for the outage probability under i.i.d. and correlated Rayleigh-fading links. Low-outage approximations are derived, which reveal a number of insights, including the impact of correlation, of the number of antennas, of relay noise and of relaying protocol. The effect of correlation is shown to be negligible, unless the channel becomes almost fully correlated. The SNR loss of relay fading channels compared to the AWGN channel is quantified. The SNR-asymptotic diversity-multiplexing tradeoff (DMT) is obtained for a broad class of fading distributions, including, as special cases, Rayleigh, Rice, Nakagami, Weibull, which may be non-identical, spatially correlated and/or non-zero mean. The DMT is shown to depend not on a particular fading distribution, but rather on its polynomial behavior near zero, and is the same ...

  12. Process-analysis by use of system-groups to promote outage performance

    International Nuclear Information System (INIS)

    The paper discusses the use of process analysis and user participation in evaluation and promotion of quality. Two case studies are discussed: outage analysis and a project focused on safety culture in maintenance operation. The authors argue that the system group concept (analysis and problem solving in a group setting, with members from a whole process chain, including management) is a useful tool for quality work. The authors describe the methodology used in the outage analysis and some of the major results. The authors argue that quality work, which underestimates the importance of a process perspective, tends to induce a false belief that minor deviations or difficulties can be seen in isolation from each other. A process perspective clearly shows that even small problems must receive strong attention: what may appear as a minor problem in one part of a process may cause bigger problems in another part. In the second case study, a method for promoting awareness of safety for maintenance operation is discussed

  13. Outage performance analysis of underlay cognitive RF and FSO wireless channels

    KAUST Repository

    Ansari, Imran Shafique

    2014-09-01

    In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channel cascaded with a free-space optical (FSO) link is presented. For the RF link, an underlay cognitive network is considered where the secondary users share the spectrum with licensed primary users. Indoor femtocells act as a practical example for such networks. More specifically, it is assumed that the RF link applies power control to maintain the interference at the primary network below a predetermined threshold. While the RF channel is modeled by the Rayleigh fading distribution, the FSO link is modeled by a unified Gamma-Gamma turbulence distribution. The FSO link accounts for pointing errors and both types of detection techniques (i.e. heterodyne detection as well as intensity modulation/direct detection (IM/DD)). With this model, a new exact closed-form expression is derived for the outage probability of the end-To-end signal-To-noise ratio of these systems in terms of the Meijer\\'s G function and the Fox\\'s H functions under fixed amplify-and-forward relay scheme. All new analytical results are verified via computer-based Monte-Carlo simulations and are illustrated by some selected numerical results.

  14. Analysis of heterogeneous boron dilution transients during outages with APROS 3D nodal core model

    International Nuclear Information System (INIS)

    A diluted water plug can form inside the primary coolant circuit if the coolant flow has stopped at least temporarily. The source of the clean water can be external or the fresh water can build up internally during boiling/condensing heat transfer mode, which can occur if the primary coolant inventory has decreased enough during an accident. If the flow restarts in the stagnant primary loop, the diluted water plug can enter the reactor core. During outages after the fresh fuel has been loaded and the temperature of the coolant is low, the dilution potential is the highest because the critical boron concentration is at the maximum. This paper examines the behaviour of the core as clean or diluted water plugs of different sizes enter the core during outages. The analysis were performed with the APROS 3D nodal core model of Loviisa VVER-440, which contains an own flow channel and 10 axial nodes for each fuel assembly. The widerange cross section data was calculated with CASMO-4E. According to the results, the core can withstand even large pure water plugs without fuel failures on natural circulation. The analyses emphasize the importance of the simulation of the backflows inside the core when the reactor is on natural circulation.

  15. Outage Analysis of Practical FSO/RF Hybrid System With Adaptive Combining

    KAUST Repository

    Rakia, Tamer

    2015-08-01

    Hybrid free-space optical (FSO)/radio-frequency (RF) systems have emerged as a promising solution for high-data-rate wireless transmission. We present and analyze a transmission scheme for the hybrid FSO/RF communication system based on adaptive combining. Specifically, only FSO link is active as long as the instantaneous signal-to-noise ratio (SNR) at the FSO receiver is above a certain threshold level. When it falls below this threshold level, the RF link is activated along with the FSO link and the signals from the two links are combined at the receiver using a dual-branch maximal ratio combiner. Novel analytical expression for the cumulative distribution function (CDF) of the received SNR for the proposed hybrid system is obtained. This CDF expression is used to study the system outage performance. Numerical examples are presented to compare the outage performance of the proposed hybrid FSO/RF system with that of the FSO-only and RF-only systems. © 1997-2012 IEEE.

  16. Spatial generalized linear mixed models of electric power outages due to hurricanes and ice storms

    International Nuclear Information System (INIS)

    This paper presents new statistical models that predict the number of hurricane- and ice storm-related electric power outages likely to occur in each 3 kmx3 km grid cell in a region. The models are based on a large database of recent outages experienced by three major East Coast power companies in six hurricanes and eight ice storms. A spatial generalized linear mixed modeling (GLMM) approach was used in which spatial correlation is incorporated through random effects. Models were fitted using a composite likelihood approach and the covariance matrix was estimated empirically. A simulation study was conducted to test the model estimation procedure, and model training, validation, and testing were done to select the best models and assess their predictive power. The final hurricane model includes number of protective devices, maximum gust wind speed, hurricane indicator, and company indicator covariates. The final ice storm model includes number of protective devices, ice thickness, and ice storm indicator covariates. The models should be useful for power companies as they plan for future storms. The statistical modeling approach offers a new way to assess the reliability of electric power and other infrastructure systems in extreme events

  17. Report on Nova Scotia Power Company's transmission system and outages communications

    Energy Technology Data Exchange (ETDEWEB)

    Stright, R.; Cannata, M.D.Jr.; Lautenschlager, M.; Kozlosky, C.K.; Arndt, S.M. [Liberty Consulting Group, Quentin, PA (United States)

    2005-03-04

    A severe storm occurred in Nova Scotia on November 13 and 14, 2004, during which a large portion of Nova Scotia Power Inc. (NSPI) customers were without power. The storm severely damaged sections of Nova Scotia's power transmission and distribution systems. The Nova Scotia Utility and Review Board issued a request for proposals (RFP) for consultants to examine NSPI's communications as well as its transmission system operations, maintenance and planning. The Liberty Consulting Group conducted the study and reported on transmission system maintenance and structure design; transmission system planning and system design; and communications and outage response. The consultant field inspected the adequacy of design criteria and the condition of failed and remaining towers and poles in areas affected by the storm and compared results with areas not affected by the storm. The consultant also evaluated NSPI's maintenance and inspection programs, vegetation management, staffing, replacement structure inventory and lessons learned from previous weather events. The report revealed how the collapse of a small number of transmission towers resulted in such a major outage. Following the review, 74 actions were created, of which more than half are complete. tabs, figs.

  18. Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks

    Science.gov (United States)

    Nasir, Hina; Javaid, Nadeem; Sher, Muhammad; Qasim, Umar; Khan, Zahoor Ali; Alrajeh, Nabil; Niaz, Iftikhar Azim

    2016-01-01

    This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs); performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE) efficient depth based routing and Enhanced-ACE (E-ACE) are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ). E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment. PMID:27420061

  19. Exploiting Outage and Error Probability of Cooperative Incremental Relaying in Underwater Wireless Sensor Networks.

    Science.gov (United States)

    Nasir, Hina; Javaid, Nadeem; Sher, Muhammad; Qasim, Umar; Khan, Zahoor Ali; Alrajeh, Nabil; Niaz, Iftikhar Azim

    2016-01-01

    This paper embeds a bi-fold contribution for Underwater Wireless Sensor Networks (UWSNs); performance analysis of incremental relaying in terms of outage and error probability, and based on the analysis proposition of two new cooperative routing protocols. Subject to the first contribution, a three step procedure is carried out; a system model is presented, the number of available relays are determined, and based on cooperative incremental retransmission methodology, closed-form expressions for outage and error probability are derived. Subject to the second contribution, Adaptive Cooperation in Energy (ACE) efficient depth based routing and Enhanced-ACE (E-ACE) are presented. In the proposed model, feedback mechanism indicates success or failure of data transmission. If direct transmission is successful, there is no need for relaying by cooperative relay nodes. In case of failure, all the available relays retransmit the data one by one till the desired signal quality is achieved at destination. Simulation results show that the ACE and E-ACE significantly improves network performance, i.e., throughput, when compared with other incremental relaying protocols like Cooperative Automatic Repeat reQuest (CARQ). E-ACE and ACE achieve 69% and 63% more throughput respectively as compared to CARQ in hard underwater environment. PMID:27420061

  20. Analytical Tools to Predict Distribution Outage Restoration Load. Final Project Report.

    Energy Technology Data Exchange (ETDEWEB)

    Law, John

    1994-11-14

    The main activity of this project has been twofold: (1) development of a computer model to predict CLPU(Cold Load Pickup) and (2) development of a field measurement and analysis method to obtain the input parameters of the CLPU model. The field measurement and analysis method is called the Step-Voltage-Test (STEPV). The Kootenai Electric Cooperative Appleway 51 feeder in Coeur d`Alene was selected for analysis in this project and STEPV tests were performed in winters of 92 and 93. The STEPV data was analyzed (method and results presented within this report) to obtain the Appleway 51 feeder parameters for prediction by the CLPU model. One only CLPU record was obtained in winter 1994. Unfortunately, the actual CLPU was not dramatic (short outage and moderate temperature) and did not display cyclic restoration current. A predicted Appleway 51 feeder CLPU was generated using the parameters obtained via the STEPV measurement/analysis/algorithm method at the same ambient temperature and outage duration as the measured actual CLPU. The predicted CLPU corresponds reasonably well with the single actual CLPU data obtained in winter 1994 on the Appleway 51 feeder.

  1. 基于滞销补贴策略的价格时变供应链协调研究%Study on Coordination of Price Time-varying Supply Chains Based on Markdown Allowance Strategy

    Institute of Scientific and Technical Information of China (English)

    鄢章华; 白世贞

    2013-01-01

    在分析供应链价格时变特征的基础上,基于销售价格时变、需求和响应时间不确定的假设,分别构建了集中式供应链的决策模型和分散式供应链的决策模型,通过对比说明分散式决策模式下供应链需要进行协调,以实现全局优化,并设计了按比例滞销补贴的契约形式进行分散式供应链的协调.结果表明:通过选择适当的补贴比例,能实现分散式供应链向集中式供应链的协调.最后通过算例验证了该契约协调的有效性.%In this paper,on the basis of an analysis of the time-varying characteristic of supply chain prices as well as an uncertainty hypothesis,we respectively established the centralized and distributed supply chain decision-making model and through comparison demonstrated under the distribution decision model,the supply chain need coordinating to realize global optimization,for which we designed the contract based on proportional markdown allowance.The result indicated a suitably chosen allowance proportion could coordinate the distributed supply chain toward the centralized supply chain.

  2. Outage probability of dual-hop partial relay selection with feedback delay in the presence of interference

    KAUST Repository

    Al-Qahtani, Fawaz S.

    2011-09-01

    In this paper, we investigate the outage performance of a dual-hop relaying systems with partial relay selection and feedback delay. The analysis considers the case of Rayleigh fading channels when the relaying station as well as the destination undergo mutually independent interfering signals. Particularly, we derive the cumulative distribution function (c.d.f.) of a new type of random variable involving sum of multiple independent exponential random variables, based on which, we present closed-form expressions for the exact outage probability of a fixed amplify-and-forward (AF) and decode-and-forward (DF) relaying protocols. Numerical results are provided to illustrate the joint effect of the delayed feedback and co-channel interference on the outage probability. © 2011 IEEE.

  3. Outage performance of opportunistic two-way amplify-and-forward relaying with outdated channel state information

    KAUST Repository

    Hwang, Kyusung

    2013-09-01

    In this paper, we study the outage performance of an amplify-and-forward (AF)-based two-way relaying (TWR) system with multiple relays where a single relay selection is performed based on outdated channel state information (CSI). Specifically, we propose a single relay selection scheme in AF-based TWR system under outdated CSI conditions. With this policy, we offer a statistical analysis of the signal-to-noise ratio per hop and analyze the outage probability with asymmetric outage thresholds based on CSI-assisted AF protocol. Additionally, we provide the exact and asymptotic expressions based on the provided statistical/joint statistical analyses of a dual-hop AF transmission. Finally, we verify our analytical results with some selected computer-based simulation results. © 1972-2012 IEEE.

  4. Development of a Real-Time PCR for a Sensitive One-Step Coprodiagnosis Allowing both the Identification of Carnivore Feces and the Detection of Toxocara spp. and Echinococcus multilocularis.

    Science.gov (United States)

    Knapp, Jenny; Umhang, Gérald; Poulle, Marie-Lazarine; Millon, Laurence

    2016-05-15

    Studying the environmental occurrence of parasites of concern for humans and animals based on coprosamples is an expanding field of work in epidemiology and the ecology of health. Detecting and quantifying Toxocara spp. and Echinococcus multilocularis, two predominant zoonotic helminths circulating in European carnivores, in feces may help to better target measures for prevention. A rapid, sensitive, and one-step quantitative PCR (qPCR) allowing detection of E. multilocularis and Toxocara spp. was developed in the present study, combined with a host fecal test based on the identification of three carnivores (red fox, dog, and cat) involved in the life cycles of these parasites. A total of 68 coprosamples were collected from identified specimens from Vulpes vulpes, Canis lupus familiaris, Canis lupus, Felis silvestris catus, Meles meles, Martes foina, and Martes martes With DNA coprosamples, real-time PCR was performed in duplex with a qPCR inhibitor control specifically designed for this study. All the coprosample host identifications were confirmed by qPCR combined with sequencing, and parasites were detected and confirmed (E. multilocularis in red foxes and Toxocara cati in cats; 16% of samples presented inhibition). By combining parasite detection and quantification, the host fecal test, and a new qPCR inhibitor control, we created a technique with a high sensitivity that may considerably improve environmental studies of pathogens. PMID:26969697

  5. Accurate outage analysis of incremental decode-and-forward opportunistic relaying

    KAUST Repository

    Tourki, Kamel

    2011-04-01

    In this paper, we investigate a dual-hop decode-and-forward opportunistic relaying scheme where the selected relay chooses to cooperate only if the source-destination channel is of an unacceptable quality. We first derive the exact statistics of received signal-to-noise (SNR) over each hop with co-located relays, in terms of probability density function (PDF). Then, the PDFs are used to determine very accurate closed-form expression for the outage probability for a transmission rate R. Furthermore, we perform asymptotic analysis and we deduce the diversity order of the scheme. We validate our analysis by showing that performance simulation results coincide with our analytical results over different network architectures. © 2011 IEEE.

  6. Mathematical model for planning measures to reduce coal face outages in mines

    Energy Technology Data Exchange (ETDEWEB)

    Litvintsev, A.V.

    1987-05-01

    Describes with detailed examples the TISPLAN SUP OZSh computer program which has been developed for use by mine management (supervisors and mechanics) and comprises two main subsets, managerial and mechanical. The full set of causes of coal face outages is determined using the classifiers currently used by the Soviet coal industry (217 causes). This model was assessed in data processing and computer centers belonging to the Donetskugol' and Oktyabr'ugol' associations and its largest drawback was found to be the laboriousness of the preventive measure calculations; this may be corrected by improving the reliability of the primary data in the data base of preventive measures, with objective assessments of their effectiveness and details of the level of staff training. The minimum annual benefit of introducing this computerized calculation system will be 6,000 rubles per mine. 4 refs.

  7. QA's role in the independent verification of plant readiness for startup from planned outages

    International Nuclear Information System (INIS)

    Quality Assurance (QA) personnel at the N Reactor, located near Richland, Washington, USA, perform many activities to independently verify the readiness for startup of the reactor from planned outages. The verifications are performed as inspections, test witnessing, audits, surveillance, and followup on identified corrective action needs. The results of these verifications are used in a formal readiness review process. The formal reviews are administered by a Review Board of representatives from several major components of the Company and are conducted using systematically structured analytical techniques. The N Reactor QA staff includes 26 persons (excluding managers) who are involved in independent verifications of reactor-related work as part or all of their assigned functions

  8. Outage Performance Analysis of Cooperative Diversity with MRC and SC in Correlated Lognormal Channels

    Directory of Open Access Journals (Sweden)

    Skraparlis D

    2009-01-01

    Full Text Available Abstract The study of relaying systems has found renewed interest in the context of cooperative diversity for communication channels suffering from fading. This paper provides analytical expressions for the end-to-end SNR and outage probability of cooperative diversity in correlated lognormal channels, typically found in indoor and specific outdoor environments. The system under consideration utilizes decode-and-forward relaying and Selection Combining or Maximum Ratio Combining at the destination node. The provided expressions are used to evaluate the gains of cooperative diversity compared to noncooperation in correlated lognormal channels, taking into account the spectral and energy efficiency of the protocols and the half-duplex or full-duplex capability of the relay. Our analysis demonstrates that correlation and lognormal variances play a significant role on the performance gain of cooperative diversity against noncooperation.

  9. A unified simulation approach for the fast outage capacity evaluation over generalized fading channels

    KAUST Repository

    Ben Rached, Nadhir

    2015-06-14

    The outage capacity (OC) is among the most important performance metrics of communication systems over fading channels. The evaluation of the OC, when Equal Gain Combining (EGC) or Maximum Ratio Combining (MRC) diversity techniques are employed, boils down to computing the Cumulative Distribution Function (CDF) of the sum of channel envelopes (equivalently amplitudes) for EGC or channel gain (equivalently squared enveloped/amplitudes) for MRC. Closed-form expressions of the CDF of the sum of many generalized fading variates are generally unknown and constitute open problems. In this paper, we develop a unified hazard rate twisting Importance Sampling (IS) based approach to efficiently estimate the CDF of the sum of independent arbitrary variates. The proposed IS estimator is shown to achieve an asymptotic optimality criterion, which clearly guarantees its efficiency. Some selected simulation results are also shown to illustrate the substantial computational gain achieved by the proposed IS scheme over crude Monte-Carlo simulations.

  10. Experience of oil in CANDU® moderator during A831 planned outage at Bruce Power

    International Nuclear Information System (INIS)

    In their address to the Nuclear Plant Chemistry Conference 2009, Bruce Power staff will describe the effects of oil ingress to the moderator of a CANDU® reactor. During the A831 planned outage of Bruce Power Unit 3, an incident of oil ingress into moderator was discovered on Oct 17, 2008. An investigation identified the cause of the oil ingress. Atomic Energy of Canada Ltd. (AECL) assessed operability of the reactor with the oil present and made recommendations with respect to the effect on unit start-up with oil present. The principal concern was the radiolytic generation of deuterium from the breakdown of the oil in-core. Various challenges were presented during start-up which were overcome via innovative approaches. The subsequent actions and consequential effects on moderator chemistry are discussed in this paper. Examination of the plant chemistry data revealed some interesting aspects of moderator system chemistry under upset conditions which will also be presented. (author)

  11. Experience of oil in CANDU moderator during A831 planned outage at Bruce Power

    International Nuclear Information System (INIS)

    In their address to the Nuclear Plant Chemistry Conference 2009, Bruce Power staff will describe the effects of oil ingress to the moderator of a CANDU reactor. During the A831 planned outage of Bruce Power Unit 3, an incident of oil ingress into moderator was discovered on Oct 17, 2008. An investigation identified the cause of the oil ingress. Atomic Energy of Canada Ltd. (AECL) assessed operability of the reactor with the oil present and made recommendations with respect to the effect on unit start-up with oil present. The principal concern was the radiolytic generation of deuterium from the breakdown of the oil in-core. Various challenges were presented during start-up which were overcome via innovative approaches. The subsequent actions and consequential effects on moderator chemistry are discussed in this paper. Examination of the plant chemistry data revealed some interesting aspects of moderator system chemistry under upset conditions which will also be presented. (author)

  12. Assessment of the impact on safety with regard to change in outage interval from 12 to 18 or 24 months at Gentilly-2 Nuclear Generating Station

    Energy Technology Data Exchange (ETDEWEB)

    Vaillancourt, R.; Croteau, M.; Komljenovic, D.; Royer, M. [Hydro-Quebec, Montreal, Quebec (Canada); Bellil, A.; Joober, K. [ENAQ, (Canada); Abdul-Nour, G.; Darragi, M. [Univ. of Quebec in Trois-Rivieres, Trois-Rivieres, Quebec (Canada)

    2003-07-01

    This paper presents the methodology and preliminary results of an impact assessment, concerning safety, resulting from the increase in outage interval from 12 to 18 or 24 months at Gentilly-2 NPP. This change will result in the decrease of the frequency of periodic tests and preventive maintenance performed during planned outages, and modify safety design matrices and reliability studies results and conclusions. (author)

  13. Are Older Adults Prepared to Ensure Food Safety during Extended Power Outages and Other Emergencies?: Findings from a National Survey

    Science.gov (United States)

    Kosa, Katherine M.; Cates, Sheryl C.; Karns, Shawn; Godwin, Sandria L.; Coppings, Richard J.

    2012-01-01

    Natural disasters and other emergencies can cause an increased risk of foodborne illness. We conducted a nationally representative survey to understand consumers' knowledge and use of recommended practices during/after extended power outages and other emergencies. Because older adults are at an increased risk for foodborne illness, this paper…

  14. Olkiluoto 1 and 2 - Plant efficiency improvement and lifetime extension-project (PELE) implemented during outages 2010 and 2011

    International Nuclear Information System (INIS)

    Teollisuuden Voima Oyj (TVO) is a non-listed public company founded in 1969 to produce electricity for its stakeholders. TVO is the operator of the Olkiluoto nuclear power plant. TVO follows the principle of continuous improvement in the operation and maintenance of the Olkiluoto plant units. The PELE project (Plant Efficiency Improvement and Lifetime Extension), mainly completed during the annual outages in 2010 and 2011, and forms one part of the systematic development of Olkiluoto units. TVO maintains a long-term development program that aims at systematically modernizing the plant unit systems and equipment based on the latest technology. According to the program, the Olkiluoto 1 and Olkiluoto 2 plant units are constantly renovated with the intention of keeping them safe and reliable, The aim of the modernization projects is to improve the safety, reliability, and performance of the plant units. PELE project at Olkiluoto 1 was done in 2010 and at Olkiluoto 2 in 2011. The outage length of Olkiluoto 1 was 26 d 12 h 4 min and Olkiluoto 2 outage length was 28 d 23 h 46 min. (Normal service-outage is about 14 days including refueling and refueling-outage length is about seven days. See figure 1) The PELE project consisted of several single projects collected into one for coordinated project management. Some of the main projects were as follows: - Low pressure turbines: rotor, stator vane, casing and turbine instrumentation replacement. - Replacement of Condenser Cooling Water (later called seawater pumps) pumps - Replacement of inner isolation valves on the main steam lines. - Generator and the generator cooling system replacement. - Low voltage switchgear replacement. This project will continue during future outages. PELE was a success. 100 TVO employees and 1500 subcontractor employees participated in the project. The execution of the PELE projects went extremely well during the outages. The replacement of the low pressure turbines and seawater pumps improved the

  15. Guidance Document - Provision of Outage Reserve Capacity for Molybdenum-99 Irradiation Services: Methodology and Economic Analysis

    International Nuclear Information System (INIS)

    In June 2011, the OECD Nuclear Energy Agency's (NEA) High-level Group on the Security of Supply of Medical Radioisotopes (HLG-MR) released its policy approach for ensuring a long-term secure supply of molybdenum-99 (99Mo) and its decay product technetium-99m ('99mTc). This policy approach was developed after two years of extensive examination and analysis of the challenges facing the supply chain, and the provision of a reliable, secure supply of these important medical isotopes. The full policy approach can be found in the OECD/NEA report, The Supply of Medical Radioisotopes: The Path to Reliability (NEA, 2011). One of the key principles in the policy approach relates to the provision of outage reserve capacity (ORC) in the 99Mo/'99mTc supply chain, as defined on page 7: 'Principle 2: Reserve capacity should be sourced and paid for by the supply chain. A common approach should be used to determine the amount of reserve capacity required'. This Principle follows the findings of the OECD/NEA report, The Supply of Medical Radioisotopes: An Economic Study of the Molybdenum-99 Supply Chain (NEA, 2010), which clearly demonstrated the need for excess 99Mo production capacity, relative to demand, as some reactors may have to be shutdown unexpectedly or for extended periods. The Study also demonstrated that the pricing structure from reactors for 99Mo irradiation services prior to the 2009-10 supply shortage was not economically sustainable, including the pricing of ORC, with the cost being subsidised by host nations. These nations have indicated a move away from subsidising production, which often benefits foreign nations or foreign companies, and therefore pricing for irradiation services must recover the full cost of production to ensure economic sustainability and a long-term secure supply. Appropriate pricing would also encourage more efficient use of the product, reducing inefficient use of 99Mo/'99mTc would reduce excess production and the associated radioactive

  16. Improving nuclear utility generation capacity, understanding the sources of forced outage and learning how to prevent them

    International Nuclear Information System (INIS)

    MIT and PECO Energy have completed a detailed examination of the sources of forced outages at the Limerick Generating Station (LGS) Boiling Water Reactor Class IV (BWR IV) site over a five year period and contrasted that information to similar BWR IV utilities in the United States over the same period. Each forced outage was attributed to one system and assigned causal codes of equipment versus human factors and failure attributes such as weak design, poor craftsmanship, and worn parts. It was found that fifty four percent of the lost power at LGS was the result of Balance of Plant failures. Industry wide data identifies fifty nine percent of the lost power as attributed to Balance of Plant failures. Balance of Plant systems are those systems not included in the primary and safety related system category. Considering failure causal factors, forty six percent of the lost power at the utility under study was the result of equipment factors such as weak design or worn parts. Significantly, the study showed a high variance between those systems which caused significant forced outage at the two sister LGS units. This demonstrated the infrequent nature of plant forced outages within a given system. This was supported by the observation that dominant systems attributing to forced outage at LGS were not equally represented in industry data. It is suggested that for individual utilities to dramatically improve unit capability factors with regard to Balance of Plant systems, they must learn from industry wide experiences and develop cooperative means of exchanging lessons learned among similarly designed plants and systems. With the broad knowledge base of system failures, current designs must be frequently assessed and altered until each system poses an acceptable level of risk to generation capacity. (author)

  17. In service inspection of the reactor pressure vessel coolant and moderator nozzles at Atucha 1. 1998/1999 outages

    International Nuclear Information System (INIS)

    During the August 1998 and the August 1999 Atucha 1 outages, two areas were inspected on the Reactor Pressure Vessel: the nozzle inner radii and the nozzle shell welds on all 3 moderator nozzles and all 4 main coolant nozzles. The inspections themselves were carried out by Mitsui Babcock Energy Limited from Scotland. The coordination, maintenance assistant and mounting of the manipulator devices over the nozzles were carried out by NASA personnel. Although it was not the first time the nozzle shell welds were inspected, due to the technologies advances in the ultrasonic field and in the inspection manipulators (magnetic ones), it was possible to inspect more volume than in previous inspections. In the other hand, it was the first time NASA was able to inspect the inner radii. In this last case the mayor problems to inspect them were the nozzles geometry and the small space available to install manipulators. The result of the inspections were: 1) There were no reportable indications at any of the inner radii inspected; 2) The inspection of nozzle to shell welds in main-coolant nozzles R3 and R4 detected flaws (one in each nozzle) which were reported as exceeding the dimensions specified as the acceptance level under Table IWB 3512-1, Section XI of the ASME code. Subsequent analysis requested by NASA and performed by Mitsui Babcock, demonstrated that the flaws were over dimensioned and could be explained as due to 'point' flaws. The analysis was based on theoretical mathematic model and experimental trials. Therefore their dimension were under the acceptance level of the ASME XI code. Although the Mitsui Babcock analysis, and at the same time it was in progress, it was assumed that the flaws were as they were originally presented (exceeding the acceptance level). NASA asked SIEMENS/KWU, the designer of the plant, to perform the fracture assessment according to ASME XI App. A. The assessment shows that the expected crack growth is negligibly small and the safety

  18. Outage and ser performance of spectrum sharing system with TAS/MRC

    KAUST Repository

    Khan, Fahd Ahmed

    2013-06-01

    Capacity of the secondary network degrades due to the interference constraint from the primary network. The secondary network capacity can be enhanced by means of spatial diversity, that can be achieved by adding multiple antennas on the terminals. In this paper, the performance of a multiple-input multiple-output (MIMO) secondary link with transmit antenna selection (TAS) at the transmitter and maximum ratio combining (MRC) at the receiver is analysed. A peak transmit power constraint is considered in addition to the interference power constraint. For a Rayleigh faded channel, closed-form expression for the outage probability of a MIMO cognitive system (MIMO-CS) with TAS/MRC is derived. In addition, closed-form expressions of the moment generating function and the symbol error rate are also obtained. The performance of this system is analyzed for asymptotic regimes and it is shown that TAS/MRC in a MIMO-CS achieves a generalized diversity order of nTnR, where nT and nR are the number of transmit and receive antennas, respectively. Numerical results are also presented to corroborate the derived analytical results. © 2013 IEEE.

  19. The Application of Phasor Measurement Units in Transmission Line Outage Detection Using Support Vector Machine

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-07-01

    Full Text Available Many protection applications are based upon the Phasor Measurement Units (PMUs technology. Therefore, PMUs have been increasingly widespread throughout the power network, and there are several researches have been made to locate the PMUs for complete system observability. This paper introduces an important application of PMUs in power system protection which is the detection of single line outage. In addition, a detection of the out of service line is achieved depending on the variations of phase angles measured at the system buses where the PMUs are located. Hence, a protection scheme from unexpected overloading in the network that may lead to system collapse can be achieved. Such detections are based upon an artificial intelligence technique which is the support Vector Machine (SVM classification tool. To demonstrate the effectiveness of the proposed approach, the algorithm is tested using offline simulation for both the 14-bus IEEE and the 30-bus IEEE systems. Two different kernels of the SVM are tested to select the more appropriate one (i.e. polynomial and Radial Basis Function (RBF kernels are used.

  20. Intermediate report of MoReMo. Modelling resilience for maintenance and outage

    Energy Technology Data Exchange (ETDEWEB)

    Oedewald, P.; Macchi, L. (VTT Technical Research Centre of Finland (Finland)); Axelsson, C. (Ringhals AB, Vattenfall AB (Sweden)); Eitrheim, M.H.R. (Institute for Energy Technology (Norway))

    2012-02-15

    Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

  1. Optimal PMU placement for maintaining full network observability during single outage of lines

    Directory of Open Access Journals (Sweden)

    Fariborz Haghighatdar fesharaki

    2011-05-01

    Full Text Available Nowadays, the optimal application of phasor measurement units (PMUs in power systems is increasing because of their advantages such as the capability for dynamical state estimation and improvements in the speed of control and protection systems. In this paper, a new method is presented using binary integer linear programming for the optimal placement of PMUs to guarantee full observability of a power system. Moreover, the problem of the optimal placement of these units in the case of a single line outage is investigated. In all of the investigations, the effect of zero-injection buses in the power system was considered. The ability of the proposed method in solving any of these problems was demonstrated by applying to the 14-, 30-, 39-, 57- and 118-bus IEEE standard systems, 42-bus transmission network of Esfahan Regional Electric and also two very large-scale systems with 2383 and 2746 buses. The simulation results verified the effective and appropriate performance of the proposed method in comparison with other methods.

  2. A study on maintenance optimization by the automatic planning tool for regular plant outage work in nuclear power plant using the logic programming language 'Prolog'

    International Nuclear Information System (INIS)

    This paper discusses maintenance optimization by the automatic planning tool for regular plant outage work in nuclear power plant using the logic programming language 'Prolog'. As a result of consideration, the following results were obtained. (1) The automatic planning tool for regular plant outage in nuclear power plant was developed. (2) Using this tool, the work plan for BWR primary recirculation system and residual heat removal system was automatically made on the condition of flattening man loading over the plant outage schedule as much as possible. (3) Several points for improving the developed tool were listed. (author)

  3. Exact Outage Probability of Dual-Hop CSI-Assisted AF Relaying Over Nakagami-m Fading Channels

    KAUST Repository

    Xia, Minghua

    2012-10-01

    In this correspondence, considering dual-hop channel state information (CSI)-assisted amplify-and-forward (AF) relaying over Nakagami- m fading channels, the cumulative distribution function (CDF) of the end-to-end signal-to-noise ratio (SNR) is derived. In particular, when the fading shape factors m1 and m2 at consecutive hops take non-integer values, the bivariate H-function and G -function are exploited to obtain an exact analytical expression for the CDF. The obtained CDF is then applied to evaluate the outage performance of the system under study. The analytical results of outage probability coincide exactly with Monte-Carlo simulation results and outperform the previously reported upper bounds in the low and medium SNR regions.

  4. Relevant Explanations: Allowing Disjunctive Assignments

    OpenAIRE

    Shimony, Solomon Eyal

    2013-01-01

    Relevance-based explanation is a scheme in which partial assignments to Bayesian belief network variables are explanations (abductive conclusions). We allow variables to remain unassigned in explanations as long as they are irrelevant to the explanation, where irrelevance is defined in terms of statistical independence. When multiple-valued variables exist in the system, especially when subsets of values correspond to natural types of events, the over specification problem, alleviated by inde...

  5. Control of the risk of exposure to alpha-emitting radionuclides during an outage in a nuclear power plant

    International Nuclear Information System (INIS)

    Control of the risk of external exposure of EDF PWR plant maintenance workers by alpha-emitting radionuclides is based on identification and quantification of the contamination of the systems. Appropriate arrangements are made to ensure protection on the basis of the prior analysis of the risk. In 2001, an experiment carried out at Cattenom Power Plant during a unit outage in the presence of a leaking fuel, based on measurement of alpha-emitting radionuclides, made it possible to determine a realistic factor for the resuspension of particles. On the basis of the experimental results, a resuspension factor of 10-6 m-1 for operational radiological protection was adopted. In the case of this unit outage, an appropriate surveillance system using this resuspension factor for workers was set in place in collaboration with the occupational medicine and radiological protection department. It was based on prior estimation of the level of alpha contamination, and confirmed by swipe measurements, atmospheric surveillance by monitors, and collective analysis by nose blow samples from workers selected on the basis of their workstations, as well as supplementary individual measurements (monitoring of faeces). This surveillance made it possible to validate an appropriate work area monitoring system, as well as the means of individual and collective protection adopted, and to establish that there was no contamination of staff by actinides during the unit outage. (authors)

  6. Spectrum Sharing in an ISM Band: Outage Performance of a Hybrid DS/FH Spread Spectrum System with Beamforming

    Directory of Open Access Journals (Sweden)

    Hanyu Li

    2009-01-01

    Full Text Available This paper investigates spectrum sharing issues in the unlicensed industrial, scientific, and medical (ISM bands. It presents a radio frequency measurement setup and measurement results in 2.4 GHz. It then develops an analytical model to characterize the coexistence interference in the ISM bands, based on radio frequency measurement results in the 2.4 GHz. Outage performance using the interference model is examined for a hybrid direct-sequence frequency-hopping spread spectrum system. The utilization of beamforming techniques in the system is also investigated, and a simplified beamforming model is proposed to analyze the system performance using beamforming. Numerical results show that beamforming significantly improves the system outage performance. The work presented in this paper provides a quantitative evaluation of signal outages in a spectrum sharing environment. It can be used as a tool in the development process for future dynamic spectrum access models as well as engineering designs for applications in unlicensed bands.

  7. Outage Performance Analysis of Relay Selection Schemes in Wireless Energy Harvesting Cooperative Networks over Non-Identical Rayleigh Fading Channels.

    Science.gov (United States)

    Do, Nhu Tri; Bao, Vo Nguyen Quoc; An, Beongku

    2016-01-01

    In this paper, we study relay selection in decode-and-forward wireless energy harvesting cooperative networks. In contrast to conventional cooperative networks, the relays harvest energy from the source's radio-frequency radiation and then use that energy to forward the source information. Considering power splitting receiver architecture used at relays to harvest energy, we are concerned with the performance of two popular relay selection schemes, namely, partial relay selection (PRS) scheme and optimal relay selection (ORS) scheme. In particular, we analyze the system performance in terms of outage probability (OP) over independent and non-identical (i.n.i.d.) Rayleigh fading channels. We derive the closed-form approximations for the system outage probabilities of both schemes and validate the analysis by the Monte-Carlo simulation. The numerical results provide comprehensive performance comparison between the PRS and ORS schemes and reveal the effect of wireless energy harvesting on the outage performances of both schemes. Additionally, we also show the advantages and drawbacks of the wireless energy harvesting cooperative networks and compare to the conventional cooperative networks. PMID:26927119

  8. Outage Analysis of Train-to-Train Communication Model over Nakagami-m Channel in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Pengyu Liu

    2013-01-01

    Full Text Available This paper analyzes the end-to-end outage performance of high-speed-railway train-to-train communication model in high-speed railway over independent identical and nonidentical Nakagami-m channels. The train-to-train communication is inter-train communication without an aid of infrastructure (for base station. Source train uses trains on other rail tracks as relays to transmit signals to destination train on the same track. The mechanism of such communication among trains can be divided into three cases based on occurrence of possible-occurrence relay trains. We first present a new closed form for the sum of squared independent Nakagami-m variates and then derive an expression for the outage probability of the identical and non-identical Nakagami-m channels in three cases. In particular, the problem is improved by the proposed formulation that statistic for sum of squared Nakagami-m variates with identical m tends to be infinite. Numerical analysis indicates that the derived analytic results are reasonable and the outage performance is better over Nakagami-m channel in high-speed railway scenarios.

  9. Emission allowances stall in marketplace

    International Nuclear Information System (INIS)

    Misinformation and public misunderstanding have given emissions trading a bad reputation in the public marketplace, says William F. Malec, executive vice president of the Tennessee Valley Authority (TVA), in Knoxville, Tennessee. Media coverage of a May 1992 emissions-allowance trade between TVA and Wisconsin Power and Light open-quotes focused on the agreement's pollution-trading aspects, not its overall potential economic and environmental benefits,close quotes Malec says. Such negative portrayal of TVA's transaction sparked severe public criticism and charges that emissions trading gives utilities the right to pollute. open-quotes The fact is that TVA sought the emissions-trading agreement as a means to reduce overall emissions in the most cost-effective way,close quotes Malec explains. Emissions trading allows a company with emission levels lower than clean-air standards to earn open-quotes credits.close quotes These credits then may be purchased by a company with emission levels that exceed federal standards. Under this arrangement, the environment is protected and companies that buy credits save money because they do not have to purchase expensive emissions-control devices or reduce their production levels. Malec says TVA decided to enter into the emissions-allowance market, not only to cut costs, but also to publicize the existence and benefits of emissions trading. However, TVA's experience proves that open-quotes people will not accept what they do not understand,close quotes concludes Malec, open-quotes especially when complex environmental issues are involved.close quotes

  10. Survey of PWR plant personnel on shutdown safety practices and risk management needs. EPRI Outage Risk Assessment and Management (ORAM) program. Final report, March 1992

    International Nuclear Information System (INIS)

    Nuclear power plant operating experience has shown that PWRs are susceptible to a variety of events during shutdown conditions. At the request of its member utilities, EPRI initiated a program to develop an integrated technical assistance package for evaluating and managing risk during shutdown operation. This program is called the Outage Risk Assessment and Management (ORAM) Program. One of the tasks of the program was to survey EPRI member utilities to gain insights into existing outage management practices. In June of 1991 a questionnaire was developed and sent to the EPRI member utilities that operate pressurized water reactors to solicit information concerning current outage management practices. The questionnaire covered four main topics 1) general outage management; 2) refueling; 3) risk quantification and 4) operating staff insights. The information obtained from the survey and insights acquired from site interviews were used as input in making generic probabilistic assessments and in developing risk management guidelines. The report contains a summary of the survey responses. (author)

  11. Down-select ion specific media (ISM) utilization in upset and outage conditions

    International Nuclear Information System (INIS)

    This paper presents a process that has been used to help nuclear power plant (NPP) clients resolve some of their more challenging waste water processing issues. These treatment issues may become even more evident during outage conditions, due (in part) to associated decontamination activities that may cause off-normal chemical conditions, which may subsequently change both the peak levels of activities for radionuclides introduced into the collected waste water and also the chemical forms in which they may exist (e.g., formation of colloids or soluble chelates). In one NPP waste processing example, a large proportion of soluble Co-58, which is normally present as a soluble cationic species or an uncharged colloidal solid, was found to behave like an anion; formation of an anionic chelation complex was implicated, possibly due to suspect EDTA, or similar additive, in a proprietary decontamination soap formulation. Antimony 125 (Sb125), normally present as a weakly anionic (Sb(OH)6-) or even neutral (Sb(OH)30) species, was being displaced from previously-loaded media by other, more strongly bound species, causing an unacceptable peak activity in water intended for discharge. A quick resolution of the existing waste processing limitations was required, due to limited waste water holding capacity. Samples of the authentic NPP waste water containing the recalcitrant radionuclides were sent to our licensed off-site laboratory (MCLinc), where small-scale batch-equilibrium testing was used to down-select, from a large number (36) of candidate media (both commercially available and developed internally), those that were relatively effective and economical for use in achieving the required discharge criteria. Batch equilibrium testing is very efficient for use in screening the relative effectiveness of contaminant removal by candidate media in a select waste water composition, and can also provide an estimate of the ultimate contaminant loading capacities on the candidate

  12. Measures for the assessment and extension of the service life time of steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Knyrim, W.D.; Merz, N.; Herrmann, N.; Beck, N. [KSG Kohlenscheidungsgesellschaft GmbH, Vienna (Austria)

    1997-12-31

    In many industrial countries it has become more and more necessary to extend the life time of steam generators to retrofit with environmental protection measures and to adapt to the state of the art. GEC-EVT have introduced a service program for the retrofit of steam generators which is divided into three main phases: Phase 1 Pre-Outage: Documentation of the actual status; Phase 2 Outage: Test and inspection phase; Phase 3 Post-Outage: Evaluation. After phase 3 all technical and economical data are available for the client to decide the following actions. 5 refs., 6 figs.

  13. A fluorescein-labeled AmpC β-lactamase allows rapid characterization of β-lactamase inhibitors by real-time fluorescence monitoring of the β-lactamase-inhibitor interactions.

    Science.gov (United States)

    Tsang, Man-Wah; Chan, Pak-Ho; Liu, Sze-Yan; Wong, Kwok-Yin; Leung, Yun-Chung

    2016-02-01

    Rapid emergence of class C β-lactamases has urged an immediate need for developing class C β-lactamase specific inhibitors for effective clinical treatment. To facilitate the development of effective class C β-lactamase inhibitors, we propose a new approach for a rapid analysis of the interaction of AmpC β-lactamase and its inhibitors using our recently developed V211Cf fluorescent β-lactamase biosensor during drug screening. Since the fluorescein of V211Cf can report the local environment change in the active site of AmpC β-lactamase, fluorescence responses of V211Cf toward its substrates/inhibitors can provide real-time traces of the dynamic change of the interaction of the β-lactamase with its substrates/inhibitors. In this study, we found that V211Cf displayed distinct fluorescence signal patterns toward different kinds of inhibitors (including clavulanic acid, sulbactam, tazobactam and 2-thiopheneboronic acid) due to the differences in their interactions with β-lactamase. V211Cf not only enables a high throughput screening for inhibitors but can also provide a rapid preliminary indication on the inhibitor's potency and stability to β-lactamase's hydrolytic action as well as how the inhibitors interact with the target enzyme, thereby speeding up the drug discovery and development cycle of class C β-lactamase inhibitors. PMID:26250526

  14. Transformation of serum-susceptible Escherichia coli O111 with p16Slux plasmid to allow for real-time monitoring of complement-based inactivation of bacterial growth in bovine milk.

    Science.gov (United States)

    Maye, S; Stanton, C; Fitzgerald, G F; Kelly, P M

    2016-01-01

    Complement activity has only recently been characterized in raw bovine milk. However, the activity of this component of the innate immune system was found to diminish as milk was subjected to heat or partitioning during cream separation. Detection of complement in milk relies on a bactericidal assay. This assay exploits the specific growth susceptibility of Escherichia coli O111 to the presence of complement. Practical application of the assay was demonstrated when a reduction in complement activity was recorded in the case of pasteurized and reduced-fat milks. This presented an opportunity to improve the functionality of the bactericidal assay by incorporating bioluminescence capability into the target organism. Following some adaptation, the strain was transformed by correctly integrating the p16Slux plasmid. Growth properties of the transformed strain of E. coli O111 were unaffected by the modification. The efficacy of the strain adaptation was correlated using the LINEST function analysis [r=0.966; standard error of prediction (SEy)=0.957] bioluminescence with that of bactericidal assay total plate counts within the range of 7.5 to 9.2 log cfu/mL using a combination of raw and processed milk samples. Importantly, the transformed E. coli O111 p16Slux strain could be identified in milk and broth samples using bioluminescence measurement, thus enabling the bactericidal assay-viability test to be monitored in real time throughout incubation. PMID:26585477

  15. 40 CFR 60.4160 - Submission of Hg allowance transfers.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Submission of Hg allowance transfers... Times for Coal-Fired Electric Steam Generating Units Hg Allowance Transfers § 60.4160 Submission of Hg allowance transfers. An Hg authorized account representative seeking recordation of a Hg allowance...

  16. Exact closed form expressions for outage probability of GSC receivers over Rayleigh fading channel subject to self-interference

    KAUST Repository

    Nam, Sungsik

    2010-11-01

    Previous work on performance analyses of generalized selection combining (GSC) RAKE receivers based on the signal to noise ratio focused on the development of methodologies to derive exact closed-form expressions for various performance measures. However, some open problems related to the performance evaluation of GSC RAKE receivers still remain to be solved such that an assessment of the impact of self-interference on the performance of GSC RAKE receivers. To have a full and exact understanding of the performance of GSC RAKE receivers, the outage probability of GSC RAKE receivers needs to be analyzed as closed-form expressions. The major difficulty in this problem is to derive some joint statistics of ordered exponential variates. With this motivation in mind, we capitalize in this paper on some new order statistics results to derive exact closed-form expressions for outage probability of GSC RAKE receivers subject to self-interference over independent and identically distributed Rayleigh fading channels. © 2010 IEEE.

  17. Cooperative AF Relaying in Spectrum-Sharing Systems: Outage Probability Analysis under Co-Channel Interferences and Relay Selection

    KAUST Repository

    Xia, Minghua

    2012-11-01

    For cooperative amplify-and-forward (AF) relaying in spectrum-sharing wireless systems, secondary users share spectrum resources originally licensed to primary users to communicate with each other and, thus, the transmit power of secondary transmitters is strictly limited by the tolerable interference powers at primary receivers. Furthermore, the received signals at a relay and at a secondary receiver are inevitably interfered by the signals from primary transmitters. These co-channel interferences (CCIs) from concurrent primary transmission can significantly degrade the performance of secondary transmission. This paper studies the effect of CCIs on outage probability of the secondary link in a spectrum-sharing environment. In particular, in order to compensate the performance loss due to CCIs, the transmit powers of a secondary transmitter and its relaying node are respectively optimized with respect to both the tolerable interference powers at the primary receivers and the CCIs from the primary transmitters. Moreover, when multiple relays are available, the technique of opportunistic relay selection is exploited to further improve system performance with low implementation complexity. By analyzing lower and upper bounds on the outage probability of the secondary system, this study reveals that it is the tolerable interference powers at primary receivers that dominate the system performance, rather than the CCIs from primary transmitters. System designers will benefit from this result in planning and designing next-generation broadband spectrum-sharing systems.

  18. 76 FR 32340 - Federal Travel Regulation; Temporary Duty (TDY) Travel Allowances (Taxes); Relocation Allowances...

    Science.gov (United States)

    2011-06-06

    ... number of Federal agencies have made the WTA optional to the employee. Nothing in tax law or existing... state and local tax law. At the same time, this rule carries forward from the current 302-17 the... including Social Security tax, if applicable, and Medicare tax. Current law does not allow Federal...

  19. Survey of BWR plant personnel on shutdown safety practices and risk management needs. EPRI Outage Risk Assessment and Management (ORAM) program. Final report, March 1992

    International Nuclear Information System (INIS)

    In response to increasing attention to potential risks during shutdown conditions, nuclear utilities are explicitly addressing safety in their outage planning and management. As part of an integrated package to assist utilities, a survey of BWR utilities was conducted. Detailed interviews with three BWR utilities were supplemented by insights from NRC and BWR Owners Group surveys. The primary objective was to acquire information for use in developing shutdown risk management guidance. Summaries of the interviews and other surveys resulted in thirteen detailed conclusions related to 1) current levels of safety reviews that have a bearing on shutdown operations, 2) the current process for outage planning and management, 3) outage management policies and guidelines that are in use, 4) perceived problems and challenges, and 5) recommendations for future risk management guidance. (author)

  20. Gamma spectrometric characterization of short cooling time nuclear spent fuels using hemispheric CdZnTe detectors

    Science.gov (United States)

    Lebrun, A.; Bignan, G.; Szabo, J. L.; Arenas-Carrasco, J.; Arlt, R.; Dubreuil, A.; Esmailpur Kazerouni, K.

    2000-07-01

    After years of cooling, nuclear spent fuel gamma emissions are mainly due to caesium isotopes which are emitters at 605, 662 and 796-801 keV. Extensive work has been done on such fuels using various CdTe or CdZnTe probes. When fuels have to be measured after short cooling time (during NPP outage) the spectrum is much more complex due to the important contributions of niobium and zirconium in the 700 keV range. For the first time in a nuclear power plant, four spent fuels of the Kozloduy VVER reactor no 4 were measured during outage, 37 days after shutdown of the reactor. In such conditions, good resolution is of particular interest, so a 20 mm 3 hemispheric crystal was used with a resolution better than 7 keV at 662 keV. This paper presents the experimental device and analyzes the results which show that CdZnTe commercially available detectors enabled us to perform a semi-quantitative determination of the burn-up after a short cooling time. In addition, it is discussed how a burn-up evolution code (CESAR) coupled to a gamma transport code (MCNP) allows us to predict and interpret the experimental data from CdZnTe detectors. Particularly, bremsstrahlung contribution to the gamma spectra is suggested and modeled. Calculation results indicate a good agreement between this hypothesis and the present measurements.

  1. 40 CFR 60.4153 - Recordation of Hg allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Recordation of Hg allowance allocations... Times for Coal-Fired Electric Steam Generating Units Hg Allowance Tracking System § 60.4153 Recordation of Hg allowance allocations. (a) By December 1, 2006, the Administrator will record in the Hg...

  2. Material technical regulation on allowable stress

    International Nuclear Information System (INIS)

    It starts with applicability. Next it tell about setting regulation of allowable stress in general examination, allowable stress of steel material and nonferrous metals and allowable stress of blot material. It has three charts of the text.

  3. 46 CFR 154.421 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and...

  4. 46 CFR 154.440 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may...

  5. Power allocation and achievable data rate in spectrum-sharing channels under adaptive primary service outage constraints

    KAUST Repository

    Yang, Yuli

    2012-09-01

    In this paper, we focus on a cognitive radio network where adaptive modulation is adopted in primary links. The gap between the primary user (PU)\\'s received signal-to-noise ratio (SNR) and the lower SNR boundary of the modulation mode that is being used, provides an interference-tolerable zone. Based on this gap, a secondary user (SU) has an increased opportunity to access the licensed spectrum and to determine the transmit power it should use to keep the PU\\'s quality-of-service (QoS) unaffected. However, since the SU cannot obtain perfect information on the PU\\'s received SNR, it has to choose an SNR point between the lower and upper boundaries of the PU\\'s current modulation mode as if this point were the real SNR received by the PU. Considering this issue, in order to quantify the effect of the SU\\'s transmissions on the PU\\'s QoS, we define the PU\\'s service outage probability and obtain its closed-form expressions by taking into account whether the peak transmit power constraint is imposed on the secondary\\'s transmission or not. Subsequently, we derive the SU\\'s achievable data rate in closed form for counterpart scenarios. Numerical results provided here quantify the relation between the PU\\'s service outage probability and the SU\\'s achievable data rate, which further demonstrate that the higher the peak transmit power a secondary transmitter can support, the better performance the cognitive radio network can achieve. © 2012 IEEE.

  6. Reason analysis for contamination of protective clothes during the first outage of unit 1 at Qinshan Nuclear Power Plant phase II

    International Nuclear Information System (INIS)

    More contamination events of protective clothes were occurred during the first outage of Unit 1 at Qinshan Nuclear Power Plant phase II. As a result, contaminated protective clothes were accumulated. This paper describes the amount and conditions of protective clothes analyses and discussies the reason of contamination. The measures for protecting protective clothes agaist contamination were put forward. (authors)

  7. Evaluation of the resilience of a full-scale down-flow hanging sponge reactor to long-term outages at a sewage treatment plant in India.

    Science.gov (United States)

    Onodera, Takashi; Takayama, Daisuke; Ohashi, Akiyoshi; Yamaguchi, Takashi; Uemura, Shigeki; Harada, Hideki

    2016-10-01

    Resilience to process outages is an essential requirement for sustainable wastewater treatment systems in developing countries. In this study, we evaluated the ability of a full-scale down-flow hanging sponge (DHS) reactor to recover after a 10-day outage. The DHS tested in this study uses polyurethane sponge as packing material. This full-scale DHS reactor has been tested over a period of about 4 years in India with a flow rate of 500 m(3)/day. Water was not supplied to the DHS reactor that was subjected to the 10-day outage; however, the biomass did not dry out because the sponge was able to retain enough water. Soon after the reactor was restarted, a small quantity of biomass, amounting to only 0.1% of the total retained biomass, was eluted. The DHS effluent achieved satisfactory removal of suspended solids, chemical oxygen demand, and ammonium nitrogen within 90, 45, and 90 min, respectively. Conversely, fecal coliforms in the DHS effluent did not reach satisfactory levels within 540 min; instead, the normal levels of fecal coliforms were achieved within 3 days. Overall, the tests demonstrated that the DHS reactor was sufficiently robust to withstand long-term outages and achieved steady state soon after restart. This reinforces the suitability of this technology for developing countries. PMID:27450993

  8. Allowance Holdings and Transfers Data Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Allowance Holdings and Transfers Data Inventory contains measured data on holdings and transactions of allowances under the NOx Budget Trading Program (NBP), a...

  9. 46 CFR 154.428 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable...

  10. 46 CFR 154.447 - Allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for...

  11. 77 FR 25088 - Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over...

    Science.gov (United States)

    2012-04-27

    .... Observers in critical infrastructure industries and in government, domestically and abroad, are becoming... carefully studying the record, we will not at this time adopt the proposal in the NPRM to require...

  12. Cluster approach allows budgeting, planning with DRGs.

    Science.gov (United States)

    Grimaldi, P L

    1984-01-01

    Measuring costs and revenues on a diagnosis related group (DRG) basis allows health care managers to define product lines, identify market shares, and examine the effects of case mix and physician behavior on profitability. It also enables public agencies to predict bed needs and evaluate certificate-of-need applications. The large number of DRGs, however, and other managerial considerations may discourage the use of DRG-based budgeting and planning. To save time and enhance data usefulness, financial officers may consolidate the DRGs into fewer groups. Revenue, for example, can be estimated by grouping the DRGs into 23 major diagnostic categories or by clustering them according to cost weight or into one group. Comparisons of payment rates and costs will identify the DRGs that lose money and will determine whether departmental costs are excessive. Strategic planning units formed from the 468 DRGs will help health care managers analyze and project performance. Product lines for this purpose may be clustered according to major diagnostic category, physician specialty, or clinical department. Since a potentially enormous amount of DRG-based clinical and financial information could be generated, hospitals should create data committees to ensure that managers receive only the information they need. PMID:10310693

  13. Reactor vessel cold overpressure event for Kuosheng Nuclear Station Unit 1 during EOC-6 refueling outage

    International Nuclear Information System (INIS)

    On November 22, 1989, Kuosheng Nuclear Power Station Unit 1 (a BWR-6 reactor with Mark-III containment Commercial in December, 1981 with 985 MWE of rated power) was at its final stage of the EOC-6 refueling and the reactor vessel head had been restored and retensioned. The IGSCC weld overlay for the recirculation loop piping was in progress. The welding procedure required that the recirculation pump be aligned, which in turn required the operation of the control rod water driving pump (CRD pump), for the purpose of reducing the welding stresses. With the CRD pump in operation, the cold water was persistently pumped into the reactor vessel resulting in the subsequent system pressurization. The personnel errors further enhanced the pressure excursion until a maximal of 81 kg/cm2 - a level well above the Plant Technical Specifications allowed limit - was reached and the reactor scrammed. Although the post-event safety analysis exihibits no immediate structural concern, yet this event represented one of the important operational lessons for plants at shutdown operating conditions. (author)

  14. 42 CFR 61.8 - Benefits: Stipends; dependency allowances; travel allowances; vacation.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Benefits: Stipends; dependency allowances; travel...; dependency allowances; travel allowances; vacation. Individuals awarded regular fellowships shall be entitled...) Stipend. (b) Dependency allowances. (c) When authorized in advance, separate allowances for travel....

  15. 42 CFR 61.9 - Payments: Stipends; dependency allowances; travel allowances.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Payments: Stipends; dependency allowances; travel allowances. 61.9 Section 61.9 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... allowances; travel allowances. Payments for stipends, dependency allowances, and the travel...

  16. 42 CFR 405.2468 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... to the limit on the all-inclusive rate for allowable costs. (3) Allowable graduate medical education.... (f) Graduate medical education. (1) Effective for that portion of cost reporting periods occurring on... receive direct graduate medical education payment for those residents. (2) Direct graduate...

  17. 27 CFR 28.334 - Credit allowance.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Credit allowance. 28.334... OF THE TREASURY LIQUORS EXPORTATION OF ALCOHOL Action on Claims § 28.334 Credit allowance. Where the credit relates to internal revenue taxes on beer that have been determined but not yet paid by...

  18. 38 CFR 49.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 49.27 Allowable... for State, Local, and Indian Tribal Governments.” The allowability of costs incurred by non-profit organizations is determined in accordance with the provisions of OMB Circular A-122, “Cost Principles for...

  19. 36 CFR 1210.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program... Circular A-87, “Cost Principles for State and Local Governments.” The allowability of costs incurred by non... Principles for Non-Profit Organizations.” The allowability of costs incurred by institutions of...

  20. 22 CFR 226.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... Relations AGENCY FOR INTERNATIONAL DEVELOPMENT ADMINISTRATION OF ASSISTANCE AWARDS TO U.S. NON-GOVERNMENTAL ORGANIZATIONS Post-award Requirements Financial and Program Management § 226.27 Allowable costs. For each kind..., “Cost Principles for State and Local Governments.” The allowability of costs incurred by...

  1. 22 CFR 518.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 518.27 Allowable costs. For each kind of recipient, there is a set of... allowability of costs incurred by non-profit organizations is determined in accordance with the provisions...

  2. 15 CFR 14.27 - Allowable costs.

    Science.gov (United States)

    2010-01-01

    ... GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.27 Allowable costs. For each kind of..., Local and Indian Tribal Governments.” The allowability of costs incurred by non-profit organizations...

  3. 20 CFR 435.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT ORGANIZATIONS, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 435.27 Allowable costs. For each kind..., Local, and Indian Tribal Governments.” (b) Allowability of costs incurred by non-profit organizations...

  4. 45 CFR 2543.27 - Allowable costs.

    Science.gov (United States)

    2010-10-01

    ... GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 2543.27 Allowable costs. For each kind... and Local Governments.” The allowability of costs incurred by non-profit organizations is...

  5. 20 CFR 617.46 - Travel allowance.

    Science.gov (United States)

    2010-04-01

    ... mile at the prevailing mileage rate authorized under the Federal travel regulations (see 41 CFR part... prevailing per diem allowance rate authorized under the Federal travel regulations (see 41 CFR part 101-7... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Travel allowance. 617.46 Section...

  6. 40 CFR 30.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... of appendix E of 45 CFR part 74, “Principles for Determining Costs Applicable to Research and... NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 30.27 Allowable..., “Cost Principles for State and Local Governments.” The allowability of costs incurred by...

  7. 28 CFR 70.27 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ...-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... for State and Local Governments.” The allowability of costs incurred by non-profit organizations is determined in accordance with the provisions of OMB Circular A-122, “Cost Principles for...

  8. Utility allowed returns and market extremes

    International Nuclear Information System (INIS)

    In recent years interest rates have fluctuated from exceptionally high levels in the early 1980s to their current levels, the lowest in two decades. Observers and analysts generally have assumed that allowed returns by regulatory commissions follow the movement of interest rates; indeed some analysts use a risk premium method to estimate the cost of common equity, assuming a constant and linear relationship between interest rates and the cost of common equity. That suggests we could expect a relatively stable relationship between interest rates and allowed returns, as well. However, a simple comparison of allowed returns and interest rates shows that this is not the case in recent years. The relationship between market interest rates and the returns allowed by commissions varies and is obviously a great deal more complicated. Empirically, there appears to be only a narrow range where market interest rates significantly affect the allowed returns on common stock set by state commissions, at least for electric and combination utilities. If rates are at historically low levels, allowed returns based largely on market rates will hasten subsequent rate filings, and commissions appear to look beyond the low rate levels. Conversely, it appears that regulators do not let historically high market rates determine allowed returns either. At either high or low interest levels, caution seems to be the policy

  9. Carbon allowance allocation in the transportation industry

    International Nuclear Information System (INIS)

    This study proposes models for projecting reductions in CO2 emissions of 10%, 20%, 30%, and 40% compared to business as usual (BAU), using a carbon allowance allocation policy and both unimodal and intermodal modes of transportation. The results show that for 10% to 80% decreases in free carbon allowance, the intermodal ratio increased from 1.01% to 53.44%, which led to decreases in carbon emissions and demand ranging from 10.41% to 48.19% and 8.45% to 7.57%, respectively. When free carbon allowances are decreased, the demand for intermodal systems increases accordingly. These results suggest that a carbon allowance allocation policy could mitigate transportation carbon emissions with a relatively small negative impact on economic activity. - Highlights: • This study proposes models for CO2 reduction by using carbon allowance policy. • This study found decreases in carbon allowance allocation, the intermodal ratio increased. • Truck-only transport will be replaced by intermodal transport. • The carbon allowance allocation policy cause small negative impact on economic activity

  10. The impact of fuel cladding failure events on occupational radiation exposures at nuclear power plants: Case study, PWR [pressurized-water reactor] during an outage

    International Nuclear Information System (INIS)

    This report is the second in a series of case studies designed to evaluate the magnitude of increase in occupational radiation exposures at commercial US nuclear power plants resulting from small incidents or abnormal events. The event evaluated is fuel cladding failure, which can result in elevated primary coolant activity and increased radiation exposure rates within a plant. For this case study, radiation measurements were made at a pressurized-water reactor (PWR) during a maintenance and refueling outage. The PWR had been operating for 22 months with fuel cladding failure characterized as 105 pin-hole leakers, the equivalent of 0.21% failed fuel. Gamma spectroscopy measurements, radiation exposure rate determinations, thermoluminescent dosimeter (TLD) assessments, and air sample analyses were made in the plant's radwaste, pipe penetration, and containment buildings. Based on the data collected, evaluations indicate that the relative contributions of activation products and fission products to the total exposure rates were constant over the duration of the outage. This constancy is due to the significant contribution from the longer-lived isotopes of cesium (a fission product) and cobalt (an activation product). For this reason, fuel cladding failure events remain as significant to occupational radiation exposure during an outage as during routine operations. As documented in the previous case study (NUREG/CR-4485 Vol. 1), fuel cladding failure events increased radiation exposure rates an estimated 540% at some locations of the plant during routine operations. Consequently, such events can result in significantly greater radiation exposure rates in many areas of the plant during the maintenance and refueling outages than would have been present under normal fuel conditions

  11. On the Efficient Simulation of the Distribution of the Sum of Gamma-Gamma Variates with Application to the Outage Probability Evaluation Over Fading Channels

    KAUST Repository

    Chaouki Ben Issaid

    2016-06-01

    The Gamma-Gamma distribution has recently emerged in a number of applications ranging from modeling scattering and reverbation in sonar and radar systems to modeling atmospheric turbulence in wireless optical channels. In this respect, assessing the outage probability achieved by some diversity techniques over this kind of channels is of major practical importance. In many circumstances, this is intimately related to the difficult question of analyzing the statistics of a sum of Gamma-Gamma random variables. Answering this question is not a simple matter. This is essentially because outage probabilities encountered in practice are often very small, and hence the use of classical Monte Carlo methods is not a reasonable choice. This lies behind the main motivation of the present work. In particular, this paper proposes a new approach to estimate the left tail of the sum of Gamma-Gamma variates. More specifically, we propose a mean-shift importance sampling scheme that efficiently evaluates the outage probability of L-branch maximum ratio combining diversity receivers over Gamma-Gamma fading channels. The proposed estimator satisfies the well-known bounded relative error criterion, a well-desired property characterizing the robustness of importance sampling schemes, for both identically and non-identically independent distributed cases. We show the accuracy and the efficiency of our approach compared to naive Monte Carlo via some selected numerical simulations.

  12. Outage Performance Analysis of Relay Selection Schemes in Wireless Energy Harvesting Cooperative Networks over Non-Identical Rayleigh Fading Channels †

    Science.gov (United States)

    Do, Nhu Tri; Bao, Vo Nguyen Quoc; An, Beongku

    2016-01-01

    In this paper, we study relay selection in decode-and-forward wireless energy harvesting cooperative networks. In contrast to conventional cooperative networks, the relays harvest energy from the source’s radio-frequency radiation and then use that energy to forward the source information. Considering power splitting receiver architecture used at relays to harvest energy, we are concerned with the performance of two popular relay selection schemes, namely, partial relay selection (PRS) scheme and optimal relay selection (ORS) scheme. In particular, we analyze the system performance in terms of outage probability (OP) over independent and non-identical (i.n.i.d.) Rayleigh fading channels. We derive the closed-form approximations for the system outage probabilities of both schemes and validate the analysis by the Monte-Carlo simulation. The numerical results provide comprehensive performance comparison between the PRS and ORS schemes and reveal the effect of wireless energy harvesting on the outage performances of both schemes. Additionally, we also show the advantages and drawbacks of the wireless energy harvesting cooperative networks and compare to the conventional cooperative networks. PMID:26927119

  13. Presentation to the Canada-US power system outage public forum

    International Nuclear Information System (INIS)

    Solar manufacturers, distributors, retailers, installers, and consultants across Canada are represented by the Canadian Solar Industries Association (CanSIA). The author clarified the solar situation in Canada, noting that Canada has a similar or better solar resource than nations who are currently solar leaders, and that few solar markets in the world today are cost-competitive without the support of government. The reliability of the electrical grid can be increased with the help of solar energy, and it can also increase the diversification of energy sources. Even during winter ice storms, solar buildings can function without an outside source of heat. Similarly, no outside source of electricity is required for such a building to function during summer blackouts. Growth of the global market for solar power exceeds 25 per cent annually. Approximately 1 per cent of Canada's electricity supply could be provided by solar through proper planning, and over 2 per cent by 2025 in Ontario. The author argued that several measures must be implemented in Canada for the country to reach its potential in support of the electrical grid. The measures include a National Renewable Energy Plan, a Renewable Portfolio Standard, net metering, feed in policy, elimination of electric rate subsidies and the introduction of time-of-day metering, and subsidies. 3 tabs

  14. Assessment of customer outage costs due to electric service interruptions - residential sector

    International Nuclear Information System (INIS)

    The assessment of the benefit or the worth of reliability is perceived as being a major contribution in providing the additional detail in the justification of new system facilities and operating reliability levels provided the required information can be obtained in a consistent and coherent manner. The costs incurred by consumers, customer interruption costs (CIC), as a result of interruptions in their electricity supply are considered key indicators of customer expectations and therefore of reliability worth. The assessment of CIC through surveys is considered to yield the most definitive results. The paper is based on extensive surveys conducted at UMIST. It reports on the customer characteristics of the residential respondents and their experience of interruptions, the undesirability of some effects of interruptions and the variation of undesirability of effects with frequency of interruption, season, time of day and weekday/weekend. The customers' ratings of these aspects are also tested for statistical correlation with the customer and experience of interruption variables. Remarkable agreement on the opinions is displayed across the RECs leading to the expectation that the corresponding CIC derived from the studies will be comparable as well. (author)

  15. Sign Patterns That Allow the Given Matrix

    Institute of Scientific and Technical Information of China (English)

    邵燕灵; 孙良

    2003-01-01

    Let P be a property referring to a real matrix. For a sign pattern A, if there exists a real matrix B in the qualitative class of A such that B has property P, then we say A allows P. Three cases that A allows an M-matrix, an inverse M-matrix and a P0-matrix are considered. The complete characterizations are obtained.

  16. FINANCIAL-ACCOUNTING ASPECTS REGARDING FAMILY ALLOWANCES

    OpenAIRE

    Iuliana Cenar

    2010-01-01

    The importance of family and ensuring its social protection are indisputable in any society. It is the reason why in this paper we plan to create an overall picture of how social protection is achieved through family allowances and other social benefits, as well as the role of accounting in this process. Thus, we considered appropriate to present the institutional and legal frameworks for the social protection of the family thorough family allowances and additional social benefits related to ...

  17. Child Allowances, Educational Subsidies and Economic Growth

    OpenAIRE

    Chen, Hung-Ju

    2013-01-01

    This paper examines the effects on economic growth attributable to government policies of child allowances and educational subsidies. We show that multiple steady states may arise under these two policies, with club convergence occurring, and the initial condition being of relevance, if the tax rate is fairly high. Under a policy of child allowances, an increase in the tax rate is found to raise the quantity of children, but lower the quality of adults; however, under a policy of educational ...

  18. Regulatory treatment of allowances and compliance costs

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K. [National Regulatory Research Institute, Columbus, OH (United States)

    1993-07-01

    The Clean Air Act Amendments of 1990 (CAAA) established a national emission allowance trading system, a market-based form of environmental regulation designed to reduce and limit sulfur dioxide emissions. However, the allowance trading system is being applied primarily to an economically regulated electric utility industry. The combining of the new form of environmental regulation and economic regulation of electric utilities has raised a number of questions including what the role should be of the federal and state utility regulating commissions and how those actions will affect the decision making process of the utilities and the allowance market. There are several dimensions to the regulatory problems that commissions face. Allowances and utility compliance expenditures have implications for least-cost/IPR (integrated resource planning), prudence review procedures, holding company and multistate utility regulation and ratemaking treatment. The focus of this paper is on the ratemaking treatment. The following topics are covered: ratemaking treatment of allowances and compliance costs; Traditional cost-recovery mechanisms; limitations to the traditional approach; traditional approach and the allowance trading market; market-based cost recovery mechanisms; methods of determining the benchmark; determining the split between ratepayers and the utility; other regulatory approaches; limitations of incentive mechanisms.

  19. When does unreliable grid supply become unacceptable policy? Costs of power supply and outages in rural India

    International Nuclear Information System (INIS)

    Despite frequent blackouts and brownouts, extension of the central grid remains the Indian government's preferred strategy for the country's rural electrification policy. This study reports an assessment that compares grid extension with distributed generation (DG) alternatives, based on the subsidies they will necessitate, and costs of service interruptions that are appropriate in the rural Indian context. Using cross-sectional household expenditure data and region fixed-effects models, average household demand is estimated. The price elasticity of demand is found to be in the range of −0.3 to −0.4. Interruption costs are estimated based on the loss of consumer surplus due to reduced consumption of electric lighting energy that results from intermittent power supply. Different grid reliability scenarios are simulated. Despite the inclusion of interruption costs, standalone DG does not appear to be competitive with grid extension at distances of less than 17 km. However, backing up unreliable grid service with local DG plants is attractive when reliability is very poor, even in previously electrified villages. Introduction of energy efficient lighting changes these economics, and the threshold for acceptable grid unreliability significantly reduces. A variety of polices to promote accelerated deployment and the wider adoption of improved end-use efficiency, warrant serious consideration. - Highlights: • We question the reliance on conventional grid in rural electricity supply in India. • Alternatives compared through government subsidies and consumer interruption costs. • Interruption costs are estimated based on loss of consumer surplus due to outages. • Augmenting unreliable grid with local biomass or diesel based backups preferable. • With efficient lighting, standalone biomass plants are optimal at very low distances

  20. Outage analysis of selective cooperation in underlay cognitive networks with fixed gain relays and primary interference modeling

    KAUST Repository

    Hussain, Syed Imtiaz

    2012-09-01

    Selective cooperation is a well investigated technique in non-cognitive networks for efficient spectrum utilization and performance improvement. However, it is still a nascent topic for underlay cognitive networks. Recently, it was investigated for underlay networks where the secondary nodes were able to adapt their transmit power to always satisfy the interference threshold to the primary users. This is a valid assumption for cellular networks but many non-cellular devices have fixed transmit powers. In this situation, selective cooperation poses a more challenging problem and performs entirely differently. In this paper, we extend our previous work of selective cooperation based on either hop\\'s signal to noise ratio (SNR) with fixed gain and fixed transmit power relays in an underlay cognitive network. This work lacked in considering the primary interference over the cognitive network and presented a rather idealistic analysis. This paper deals with a more realistic system model and includes the effects of primary interference on the secondary transmission. We first derive end-to-end signal to interference and noise ratio (SINR) expression and the related statistics for a dual-hop relay link using asymptotic and approximate approaches. We then derive the statistics of the selected relay link based on maximum end-to-end SINR among the relays satisfying the interference threshold to the primary user. Using this statistics, we derive closed form asymptotic and approximate expressions for the outage probability of the system. Analytical results are verified through simulations. It is concluded that selective cooperation in underlay cognitive networks performs better only in low to medium SNR regions. © 2012 IEEE.

  1. US utility regulations and allowance trading

    International Nuclear Information System (INIS)

    This paper provides a layman's review of the history of US regulations, including trans-boundary problems between the US and Canada, the philosophy and justification involved in recent actions, the steps being taken to meet present compliance and allowance requirements, and some projections as to the future of emission-control activities in the United States. The total SO2 emissions for all utility power plants have now been mandated to be lowered to about half of recent projected values, and this total cannot be exceeded in the future in spite of possible growth needs. Because anyone wishing to build a coal-fired power plant in the future will probably need some allowances, as even with the best of controls some SO2 may be emitted, the availability of allowances in the future is an important planning consideration

  2. Allowance System: Proposed acid-rain rule

    International Nuclear Information System (INIS)

    The U.S. Environmental Protection Agency (EPA) has proposed four rules containing the core acid rain requirements: the Permits Rule (40 CFR Part 72), the Allowance System Rule (40 CFR Part 73), the Continuous Emission Monitoring Rule (40 CFR Part 75), and the Excess Emissions Rule (40 CFR Part 77). EPA will also propose additional rules at a future date. These rules will include requirements for facilities that elect to opt into the Acid Rain Program (40 CFR Part 74) and for the nitrogen oxide (NOx) control program (40 CFR Part 76). The fact sheet summarizes the key components of EPA's proposed Allowance System

  3. Manpower Training Allowances: Financial Assistance or Investment?

    Science.gov (United States)

    Latour, Georges

    1975-01-01

    The author compares the differing approaches of Germany, Sweden, France, and Australia for providing financial support to adults enrolled in vocational training programs, focusing on training allowances for recurrent education. He concludes that without some governmental maintenance program, it is unlikely that adults can utilize even tuition-free…

  4. 7 CFR 550.25 - Allowable costs.

    Science.gov (United States)

    2010-01-01

    ... at 2 CFR part 225. The allowability of costs incurred by non-profit organizations is determined in... commercial organizations and those non-profit organizations listed in appendix C to Circular A-122 (2 CFR... AGRICULTURE GENERAL ADMINISTRATIVE POLICY FOR NON-ASSISTANCE COOPERATIVE AGREEMENTS Management of...

  5. 29 CFR 1470.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... Financial Administration § 1470.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set...

  6. 24 CFR 85.22 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... Circular A-122 as not subject to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply with cost principles acceptable to the Federal agency. ... TRIBAL GOVERNMENTS Post-Award Requirements Financial Administration § 85.22 Allowable costs....

  7. Allowance trading: Market operations and regulatory response

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.A.; South, D.W.; McDermott, K.A.

    1992-01-01

    The use of the SO[sub 2] allowance system as defined by Title IV of the 1990 Clean Air Act Amendments offers utilities greater compliance flexibility than EPA technology standards, State Implementation Plan (SEP) performance standards, or EPA bubble/offset strategies. Traditional methods at best offered the utility the ability to trade emissions between different units at a particular plant. The SO[sub 2] emissions trading system advocated under Title IV will allow a utility to trade emissions across its utility system, and/or trade emissions between utilities to take advantage of interfirm control cost differences. The use of transferable emission allowances offers utilities greater flexibility in the choice of how to control emissions: the choices include fuel switching, flue gas scrubbing, environmental dispatch, repowering, and even the choice not to control emissions [as long as the New Source Performance Standards (NSPS) and Prevention of Significant Deterioration (PSD) requirements are met]. The added flexibility allows utilities to choose the least cost manner of compliance with Title IV requirements. It is hoped (intended) that pollution control cost-minimization by individual utilities will in turn reduce the cost of controlling SO[sub 2] for the electric utility industry in aggregate. In addition, through the use of NO[sub x] emission averaging, the utility would average NO[sub x] emissions from different point sources in order to comply with the prescribed emission standard.

  8. Allowance trading: Market operations and regulatory response

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, K.A.; South, D.W.; McDermott, K.A.

    1992-12-31

    The use of the SO{sub 2} allowance system as defined by Title IV of the 1990 Clean Air Act Amendments offers utilities greater compliance flexibility than EPA technology standards, State Implementation Plan (SEP) performance standards, or EPA bubble/offset strategies. Traditional methods at best offered the utility the ability to trade emissions between different units at a particular plant. The SO{sub 2} emissions trading system advocated under Title IV will allow a utility to trade emissions across its utility system, and/or trade emissions between utilities to take advantage of interfirm control cost differences. The use of transferable emission allowances offers utilities greater flexibility in the choice of how to control emissions: the choices include fuel switching, flue gas scrubbing, environmental dispatch, repowering, and even the choice not to control emissions [as long as the New Source Performance Standards (NSPS) and Prevention of Significant Deterioration (PSD) requirements are met]. The added flexibility allows utilities to choose the least cost manner of compliance with Title IV requirements. It is hoped (intended) that pollution control cost-minimization by individual utilities will in turn reduce the cost of controlling SO{sub 2} for the electric utility industry in aggregate. In addition, through the use of NO{sub x} emission averaging, the utility would average NO{sub x} emissions from different point sources in order to comply with the prescribed emission standard.

  9. 22 CFR 145.27 - Allowable costs.

    Science.gov (United States)

    2010-04-01

    ... of appendix E of 45 CFR part 74, “Principles for Determining Costs Applicable to Research and..., HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 145..., “Cost Principles for State and Local Governments.” The allowability of costs incurred by...

  10. 40 CFR 31.22 - Allowable costs.

    Science.gov (United States)

    2010-07-01

    ... not subject to that circular 48 CFR part 31, Contract Cost Principles and Procedures, or uniform cost... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Allowable costs. 31.22 Section 31.22 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL ASSISTANCE...

  11. 19 CFR 191.101 - Drawback allowance.

    Science.gov (United States)

    2010-04-01

    ... Preparations (Including Perfumery) Manufactured From Domestic Tax-Paid Alcohol § 191.101 Drawback allowance. (a... perfumery) manufactured or produced in the United States in part from the domestic tax-paid alcohol. (b... tax on flavoring extracts or medicinal or toilet preparations (including perfumery) manufactured...

  12. Power Outage - 16 October

    CERN Multimedia

    2014-01-01

    At 19:03 last night, a fire in an 18kV circuit breaker in building 212 led to a blackout on the Meyrin site. The CERN fire brigade rapidly brought the fire under control and power was restored by 22:25. Many CERN systems were affected and have been brought back in to service overnight, this work will continue through the day.

  13. 76 FR 16629 - Federal Travel Regulation (FTR); Relocation Allowances-Relocation Income Tax Allowance (RITA) Tables

    Science.gov (United States)

    2011-03-24

    ... Register (73 FR 35952) specifying that the General Services Administration (GSA) would no longer publish... ADMINISTRATION Federal Travel Regulation (FTR); Relocation Allowances-- Relocation Income Tax Allowance (RITA...), Office of Travel, Transportation, and Asset Management (MT), General Services Administration at (202)...

  14. Component Repair Times Obtained from MSPI Data

    Energy Technology Data Exchange (ETDEWEB)

    Eide, Steven A. [Curtiss-Wright/Scietech, Ketchum, ID (United States); Cadwallader, Lee [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Information concerning times to repair or restore equipment to service given a failure is valuable to probabilistic risk assessments (PRAs). Examples of such uses in modern PRAs include estimation of the probability of failing to restore a failed component within a specified time period (typically tied to recovering a mitigating system before core damage occurs at nuclear power plants) and the determination of mission times for support system initiating event (SSIE) fault tree models. Information on equipment repair or restoration times applicable to PRA modeling is limited and dated for U.S. commercial nuclear power plants. However, the Mitigating Systems Performance Index (MSPI) program covering all U.S. commercial nuclear power plants provides up-to-date information on restoration times for a limited set of component types. This paper describes the MSPI program data available and analyzes the data to obtain median and mean component restoration times as well as non-restoration cumulative probability curves. The MSPI program provides guidance for monitoring both planned and unplanned outages of trains of selected mitigating systems deemed important to safety. For systems included within the MSPI program, plants monitor both train UA and component unreliability (UR) against baseline values. If the combined system UA and UR increases sufficiently above established baseline results (converted to an estimated change in core damage frequency or CDF), a “white” (or worse) indicator is generated for that system. That in turn results in increased oversight by the US Nuclear Regulatory Commission (NRC) and can impact a plant’s insurance rating. Therefore, there is pressure to return MSPI program components to service as soon as possible after a failure occurs. Three sets of unplanned outages might be used to determine the component repair durations desired in this article: all unplanned outages for the train type that includes the component of interest, only

  15. Probabilistic real-time contingency ranking method

    International Nuclear Information System (INIS)

    This paper describes a real-time contingency method based on a probabilistic index-expected energy not supplied. This way it is possible to take into account the stochastic nature of the electric power system equipment outages. This approach enables more comprehensive ranking of contingencies and it is possible to form reliability cost values that can form the basis for hourly spot price calculations. The electric power system of Serbia is used as an example for the method proposed. (author)

  16. Realization of allowable qeneralized quantum gates

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The most general duality gates were introduced by Long,Liu and Wang and named allowable generalized quantum gates (AGQGs,for short).By definition,an allowable generalized quantum gate has the form of U=YfkjsckUK,where Uk’s are unitary operators on a Hilbert space H and the coefficients ck’s are complex numbers with |Yfijo ck\\ ∧ 1 an d 1ck| <1 for all k=0,1,...,d-1.In this paper,we prove that an AGQG U=YfkZo ck∧k is realizable,i.e.there are two d by d unitary matrices W and V such that ck=W0kVk0 (0

  17. Allowable Differential Settlement of Oil Pipelines

    Directory of Open Access Journals (Sweden)

    Zahra Faeli

    2010-10-01

    Full Text Available Abstract The allowable settlement of pipelines has been mentioned rarely in design references and codes. The present paper studies the effects of differential settlement of pipeline bed on resulted forces and deformations and then determines the allowable differential settlement of pipelines in two conditions as follows: (i heterogeneous soil bed and (ii adjacent to steel tanks. To accomplish the studies, numerical simulation of pipeline is used. The pipeline bed is idealized by Winkler springs and four-element standard viscoelastic Burger model. Also, the use of geosynthetic reinforcement is studied in heterogeneous soil beds and the effect of geosynthetics on decreasing the settlement is investigated. The pipeline-tank joints in two cases of fixed and flexible joints are investigated and the results for two kinds of joints are compared.

  18. Making It Personal: Per Capita Carbon Allowances

    DEFF Research Database (Denmark)

    Fawcett, Tina; Hvelplund, Frede; Meyer, Niels I

    2009-01-01

    The Chapter highligts the importance of introducing new, efficient schemes for mitigation of global warming. One such scheme is Personal Carbon Allowances (PCA), whereby individuals are allotted a tradable ration of CO2 emission per year.This chapter reviews the fundamentals of PCA and analyzes its...... merits and problems. The United Kingdom and Denmark have been chosen as case studies because the energy situation and the institutional setup are quite different between the two countries....

  19. The US SO2 allowance trading program

    International Nuclear Information System (INIS)

    The US SO2 Allowance Trading Program is the world's first large-scale application of a cap-and-trade mechanism for limiting emissions, and it is often cited as an example for the control of other pollutants and of greenhouse gases. Drawing upon experience with this novel approach to omissions control since 1995, this article makes five observations that address common misunderstandings about emissions trading and that are applicable to the control of greenhouse gases. First, emissions trading did not compromise environmental effectiveness, and even enhanced it. Second, the program works because of the simplicity of the compliance requirement, the unavoidably strict accountability of the system, and the complete flexibility given to emitting sources. All three go together to form what may be regarded as a virtuous circle. Third, despite fears to the contrary, allowance markets developed in response to trading opportunities. Fourth, the politics of allowance allocation can be helpful in overcoming objections to emission control measures. Finally, provisions for voluntary accession present problems of moral hazard that must be carefully considered. (author)

  20. Forecasting the market for SO2 emission allowances under uncertainty

    International Nuclear Information System (INIS)

    This paper deals with the effects of uncertainty and risk aversion on market outcomes for SO2 emission allowance prices and on electric utility compliance choices. The 1990 Clean Air Act Amendments (CAAA), which are briefly reviewed here, provide for about twice as many SO2 allowances to be issued per year in Phase 1 (1995--1999) than in Phase 2. Considering the scrubber incentives in Phase 1, there is likely to be substantial emission banking for use in Phase 2. Allowance prices are expected to increase over time at a rate less than the return on alternative investments, so utilities which are risk neutral, or potential speculators in the allowance market, are not expected to bank allowances. The allowances will be banked by utilities that are risk averse. The Argonne Utility Simulation Model (ARGUS2) is being revised to incorporate the provisions of the CAAA acid rain title and to simulate SO2 allowance prices, compliance choices, capacity expansion, system dispatch, fuel use, and emissions using a unit level data base and alternative scenario assumptions. 1 fig

  1. 32 CFR 534.3 - Allowable expenses for witnesses.

    Science.gov (United States)

    2010-07-01

    ... each day's attendance and for the time necessarily occupied in going to and returning from the same... going to and returning from the place of attendance. In lieu of the mileage allowance provided for... continental United States, will be entitled to the actual expenses of travel at the lowest first-class...

  2. Future prices and market for SO2 allowances

    International Nuclear Information System (INIS)

    The expected price of SO2 emission allowances is an important issue in energy and integrated resource planning activities. For example, the expected price of SO2 allowances in needed in order to evaluate alternative strategies for meeting SO2 provisions of the Clean Air Act Amendments of 1990. In addition, the expected SO2 allowance price is important to state public utility regulators who must provide guidance on rate-making issues regarding utility compliance plans which involve allowance trading and direct investment of SO2 control technologies. Last but not the least, the expected SO2 allowance price is an important determinant of the future market for natural gas and low sulfur coal. The paper develops estimates of SO2 allowance prices over time by constructing national supply and demand curves for SO2 reductions. Both the supply and demand for SO2 reductions are based on an analysis of the sulfur content of fuels burned in 1990 by utilities throughout the United States; and on assumptions about plant retirements, the rate of new capacity growth, the types of new and replacement plants constructed, the costs of SO2 reduction measures and legislation by midwest states to maintain the use of high sulfur coal to protect local jobs. The paper shows that SO2 allowance prices will peak around the year 2000 at about $500 per ton, and will eventually fall to zero by about the year 2020. A sensitivity analysis indicates that the price of SO2 allowances is relatively insensitive to assumptions regarding the availability of natural gas or energy demand growth. However, SO2 allowance prices tend to be quite sensitive to assumptions regarding regulations which may force early retirement of existing power plants and possible legislation which may reduce CO2 emissions

  3. Adaptive Space–Time Coding Using ARQ

    KAUST Repository

    Makki, Behrooz

    2015-09-01

    We study the energy-limited outage probability of the block space-time coding (STC)-based systems utilizing automatic repeat request (ARQ) feedback and adaptive power allocation. Taking the ARQ feedback costs into account, we derive closed-form solutions for the energy-limited optimal power allocation and investigate the diversity gain of different STC-ARQ schemes. In addition, sufficient conditions are derived for the usefulness of ARQ in terms of energy-limited outage probability. The results show that, for a large range of feedback costs, the energy efficiency is substantially improved by the combination of ARQ and STC techniques if optimal power allocation is utilized. © 2014 IEEE.

  4. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    Science.gov (United States)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).

  5. 75 FR 14442 - Federal Travel Regulation (FTR); Relocation Allowances-Relocation Income Tax Allowance (RITA) Tables

    Science.gov (United States)

    2010-03-25

    ... Amendment 2008-04 in the Federal Register (73 FR 35952) specifying that GSA would no longer publish the RITA... ADMINISTRATION Federal Travel Regulation (FTR); Relocation Allowances-- Relocation Income Tax Allowance (RITA...: Mr. Ed Davis, Office of Governmentwide Policy (M), Office of Travel, Transportation, and...

  6. 78 FR 26637 - Federal Travel Regulation (FTR); Relocation Allowance-Relocation Income Tax (RIT) Allowable Tables

    Science.gov (United States)

    2013-05-07

    ... June 25, 2008 (73 FR 35952), specifying that GSA would no longer publish the RIT Allowance tables in... From the Federal Register Online via the Government Publishing Office GENERAL SERVICES ADMINISTRATION Federal Travel Regulation (FTR); Relocation Allowance--Relocation Income Tax (RIT)...

  7. 40 CFR 82.8 - Grant of essential use allowances and critical use allowances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Grant of essential use allowances and critical use allowances. 82.8 Section 82.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production and Consumption Controls § 82.8 Grant of essential use...

  8. 计及缺电成本的用户侧蓄电池储能系统容量规划%Capacity Plan of Battery Energy Storage System in User Side Considering Power Outage Cost

    Institute of Scientific and Technical Information of China (English)

    颜志敏; 王承民; 连鸿波; 衣涛; 时志雄; 张宇

    2012-01-01

    Based on the relevant studies, in order to bring the battery energy storage system economical benefits in the user side caused by reducing capacity of user's distribution station and decreasing the power expenses for user, a value model for reducing loss of the transformer and power outage cost is built. In the mean time, considering the investment cost and operation and maintenance cost, the capacity optimization plan model for user' s battery energy storage system is developed and particle swarm optimization algorithm is used to solve it.%在相关研究的基础上,考虑了用户侧电池储能系统在减少用户配电站建设容量和降低购电费用方面为用户带来的经济价值,建立了其降低配电变压器损耗和停电损失的价值模型。同时,考虑蓄电池储能系统的投资成本和运行维护成本,建立了其容量优化规划模型,并用粒子群优化算法进行了求解。

  9. New software rejuvenation strategy based on measurement and time

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Operational software systems often experience an "aging" phenomenon, characterized by progressive performance degradation and a sudden hang/crash failure. Software rejuvenation is a proactive fault-tolerance strategy aimed to prevent unexpected outages due to aging. A new rejuvenation strategy based on measurement and time, and constructs a SRN model to evaluate this strategy. Numerical results show that this strategy outweighs either the purely measurementbased or the purely time-based strategy and can effectively improve system performance.

  10. Online Homework Management Systems: Should We Allow Multiple Attempts?

    OpenAIRE

    Rhodes, M. Taylor; Sarbaum, Jeffrey K.

    2013-01-01

    Conventional pencil and paper wisdom suggests that allowing multiple attempts on homework will lead to more time spent on homework, higher homework grades, and better exam performance. For a variety of reasons, homework is increasingly being auto-administered online. This paper discusses the results of a quasi-experiment designed to evaluate student behavior under single and multiple attempt homework settings using an online homework management system. The paper explores whether multiple atte...

  11. Space-Time Water-Filling for Composite MIMO Fading Channels

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available We analyze the ergodic capacity and channel outage probability for a composite MIMO channel model, which includes both fast fading and shadowing effects. The ergodic capacity and exact channel outage probability with space-time water-filling can be evaluated through numerical integrations, which can be further simplified by using approximated empirical eigenvalue and maximal eigenvalue distribution of MIMO fading channels. We also compare the performance of space-time water-filling with spatial water-filling. For MIMO channels with small shadowing effects, spatial water-filling performs very close to space-time water-filling in terms of ergodic capacity. For MIMO channels with large shadowing effects, however, space-time water-filling achieves significantly higher capacity per antenna than spatial water-filling at low to moderate SNR regimes, but with a much higher channel outage probability. We show that the analytical capacity and outage probability results agree very well with those obtained from Monte Carlo simulations.

  12. Voltage quality and brief power outages in Norway. State of the Realm 1993 -2003; Spenningskvalitet og kortvarige avbrudd i Norge. Rikets tilstand 1993-2003

    Energy Technology Data Exchange (ETDEWEB)

    Seljeseth, Helge

    2004-03-01

    The voltage quality in Norway is well within international norms (CENELEC EN50160 and the IEC 61000-2 series). But the variation in the measured voltage quality is large between the various measurement points. Problems do occur among Norwegian network customers, mostly in sparsely populated regions where the network is very extensive (and overhead) for the small number of customers. Cable networks are usually used in urban regions. Ten years of measurements confirms that on average the voltage quality in Norway is equal to and often better than that in other countries. This varies somewhat between the various types of disturbances. The level of over-harmonic voltages in the Norwegian power network is low by European standards. But we have at least as many brief outages and voltage dips. As the reference for the level of voltage quality in Europe, official material from a series of institutions are used.

  13. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Analysis of core damage frequency from internal events for plant operational state 5 during a refueling outage (Main report, Sections 1--9): Volume 2, Part 1A

    International Nuclear Information System (INIS)

    The program objectives include assessing the risks of severe accidents initiated during plant operational states (POS) other than full power operation and comparing the estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with those accidents initiated during full power operation. The objective of the Phase 1 study was to identify potential vulnerable plant configurations, to characterize the potential core damage accident scenario frequencies, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2 POS 5 (approximately Cold Shutdown) during a refueling outage was selected as the plant configuration to be analyzed. System models applicable for POS 5 conditions on the way down to refueling and on the way back up from refueling were developed and supporting thermal hydraulic analyses were performed to determine both the timing of the accidents and success criteria for systems. Initiating events that may occur during POS 5 were identified and accident sequence event trees were developed and quantified. Surviving sequences were examined for recovery potential, appropriate human recovery actions were incorporated into the sequence cut sets, and the sequences were then requantified. Those sequences surviving this preliminary recovery analysis were then reexamined during a time window analysis. The mean core damage frequency of the Grand Gulf plant due to internal events for POS 5 during a refueling outage is 2.0E-06 per year, and the 5th and 95th percentiles are 4.1E-07 and 5.4E-06 per year, respectively. This compares to the total core damage frequency of 4.0E-06 per year estimated in the NUREG-1150 study of full power operations

  14. Allowable pillar to diameter ratio for strategic petroleum reserve caverns.

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L.; Park, Byoung Yoon

    2011-05-01

    This report compiles 3-D finite element analyses performed to evaluate the stability of Strategic Petroleum Reserve (SPR) caverns over multiple leach cycles. When oil is withdrawn from a cavern in salt using freshwater, the cavern enlarges. As a result, the pillar separating caverns in the SPR fields is reduced over time due to usage of the reserve. The enlarged cavern diameters and smaller pillars reduce underground stability. Advances in geomechanics modeling enable the allowable pillar to diameter ratio (P/D) to be defined. Prior to such modeling capabilities, the allowable P/D was established as 1.78 based on some very limited experience in other cavern fields. While appropriate for 1980, the ratio conservatively limits the allowable number of oil drawdowns and hence limits the overall utility and life of the SPR cavern field. Analyses from all four cavern fields are evaluated along with operating experience gained over the past 30 years to define a new P/D for the reserve. A new ratio of 1.0 is recommended. This ratio is applicable only to existing SPR caverns.

  15. Allocation of CO2 emission allowances. Distribution of emission allowances in a European emissions trading scheme

    Energy Technology Data Exchange (ETDEWEB)

    Harmsen, H.; Van der Kolk, J. [KPMG Sustainability, Amstelveen (Netherlands); Kerssemeeckers, M.; De Beer, J. [Ecofys, Utrecht (Netherlands)

    2002-10-01

    The European Commission has submitted a draft directive on Emissions Trading on 23 October 2001. In this system, each Member State has to submit an allocation plan that describes the allowances that will be distributed, and how these will be distributed among the operators of each participating installation. In this study the possible allocation options and their consequences are investigated; the potential bottlenecks are assessed, which would occur if the Netherlands developed a national allocation plan; the criteria for national allocation plans are assessed (Annex III draft directive); and some possibilities for solutions are presented.

  16. 49 CFR 230.24 - Maximum allowable stress.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the...

  17. 17 CFR 190.07 - Calculation of allowed net equity.

    Science.gov (United States)

    2010-04-01

    ... equity. 190.07 Section 190.07 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION BANKRUPTCY § 190.07 Calculation of allowed net equity. Allowed net equity shall be computed as follows: (a) Allowed claim. The allowed net equity claim of a customer shall be equal to the aggregate of the...

  18. Climate Throughout Geologic Time Was Cooled by Sequences of Explosive Volcanic Eruptions Forming Aerosols That Reflect and Scatter Ultraviolet Solar Radiation and Warmed by Relatively Continuous Extrusion of Basaltic Lava that Depletes Ozone, Allowing More Solar Ultraviolet Radiation to Reach Earth

    Science.gov (United States)

    Ward, P. L.

    2015-12-01

    Active volcanoes of all sizes and eruptive styles, emit chlorine and bromine gases observed to deplete ozone. Effusive, basaltic volcanic eruptions, typical in Hawaii and Iceland, extrude large lava flows, depleting ozone and causing global warming. Major explosive volcanoes also deplete ozone with the same emissions, causing winter warming, but in addition eject megatons of water and sulfur dioxide into the lower stratosphere where they form sulfuric-acid aerosols whose particles grow large enough to reflect and scatter ultraviolet sunlight, causing net global cooling for a few years. The relative amounts of explosive and effusive volcanism are determined by the configuration of tectonic plates moving around Earth's surface. Detailed studies of climate change throughout geologic history, and since 1965, are not well explained by greenhouse-gas theory, but are explained quite clearly at OzoneDepletionTheory.info. Ozone concentrations vary substantially by the minute and show close relationships to weather system highs and lows (as pointed out by Dobson in the 1920s), to the height of the tropopause, and to the strength and location of polar vortices and jet streams. Integrating the effects of volcanism on ozone concentrations and the effects of ozone concentrations on synoptic weather patterns should improve weather forecasting. For example, the volcano Bárðarbunga, in central Iceland, extruded 85 km2 of basaltic lava between August 29, 2014, and February 28, 2015, having a profound effect on weather. Most surprising, more than a week before the March 4 eruption of Eyjafjallajökull in 2010, substantial amounts of ozone were released in the vicinity of the volcano precisely when surface deformation showed that magma first began moving up from sills below 4 km depth. Ozone similarly appears to have been emitted 3.5 months before the Pinatubo eruption in 1991. Readily available daily maps of ozone concentrations may allow early warning of an imminent volcanic

  19. Coal sulfur-premium models for SO2 allowance valuation

    International Nuclear Information System (INIS)

    Clean Air Capital Markets, an investment bank structuring SO2 Allowance transactions, has designed two allowance value models. The first forecasts an equilibrium allowance value based on coal supply and demand. The second estimates the sulfur premium of all reported coal deliveries to utilities. Both models demonstrate that the fundamental allowance value is approximately double current spot market prices for small volumes of off-system allowances

  20. Ratemaking and accounting for allowances and compliance costs

    International Nuclear Information System (INIS)

    The regulatory treatment of compliance costs and allowances will significantly affect both the utility's CAAA compliance decisions and the cost of compliance. Sections in this chapter include ratemaking treatment of allowances, utility buy-ins, the market test of compliance costs and utility incentive, FERC account classification, measuring the value of allowances, inventory methods for allowances, expense recognition of allowances, regulatory-created assets and liabilities, and application of the FERC proposal. 8 refs., 1 tab

  1. Minimization of outage probability of WiMAX link supported by laser link between a high-altitude platform and a satellite.

    Science.gov (United States)

    Arnon, Shlomi

    2009-07-01

    Various technologies for the implementation of a WiMAX (IEEE802.16) base station on board a high-altitude platform (HAP) are currently being researched. The network configuration under consideration includes a satellite, several HAPs, and subscribers on the ground. The WiMAX base station is positioned on the satellite and connects with the HAP via an analog RF over-laser communication (LC) link. The HAPs house a transparent transponder that converts the optic signal to a WiMAX RF signal and the reverse. The LC system consists of a laser transmitter and an optical receiver that need to be strictly aligned to achieve a line-of-sight link. However, mechanical vibration and electronic noise in the control system challenge the transmitter-receiver alignment and cause pointing errors. The outcome of pointing errors is fading of the received signal, which leads to impaired link performance. In this paper, we derive the value of laser transmitter gain that can minimize the outage probability of the WiMAX link. The results indicate that the optimum value of the laser transmitter gain is not a function of the pointing error statistics. PMID:19568289

  2. Evaluation of risk impact of changes to Completion Times addressing model and parameter uncertainties

    International Nuclear Information System (INIS)

    This paper presents an approach and an example of application for the evaluation of risk impact of changes to Completion Times within the License Basis of a Nuclear Power Plant based on the use of the Probabilistic Risk Assessment addressing identification, treatment and analysis of uncertainties in an integrated manner. It allows full development of a three tired approach (Tier 1–3) following the principles of the risk-informed decision-making accounting for uncertainties as proposed by many regulators. Completion Time is the maximum outage time a safety related equipment is allowed to be down, e.g. for corrective maintenance, which is established within the Limiting Conditions for Operation included into Technical Specifications for operation of a Nuclear Power Plant. The case study focuses on a Completion Time change of the Accumulators System of a Nuclear Power Plant using a level 1 PRA. It focuses on several sources of model and parameter uncertainties. The results obtained show the risk impact of the proposed CT change including both types of epistemic uncertainties is small as compared with current safety goals of concern to Tier 1. However, what concerns to Tier 2 and 3, the results obtained show how the use of some traditional and uncertainty importance measures helps in identifying high risky configurations that should be avoided in NPP technical specifications no matter the duration of CT (Tier 2), and other configurations that could take part of a configuration risk management program (Tier 3). - Highlights: • New approach for evaluation of risk impact of changes to Completion Times. • Integrated treatment and analysis of model and parameter uncertainties. • PSA based application to support risk-informed decision-making. • Measures of importance for identification of risky configurations. • Management of important safety issues to accomplish safety goals

  3. Allowing for surface preparation in stress corrosion cracking modelling

    International Nuclear Information System (INIS)

    When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor's primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author)

  4. Vloga Inštituta za kovinske materiale in tehnologije pri remontnih delih v JE Krško: The role of the Institute of metals and technology in the outages of JE Krško:

    OpenAIRE

    Vojvodič-Tuma, Jelena

    1995-01-01

    Institute of metals and technology is an authorised supervising organisation for construction, test operation, start, and operation of nuclear power plant. We present Institute activities needed for releasing expertise on repeated start of reactor after outage 1995 and fuel replacement in Nuclear power plant Krško. Non - destructive methods applied on steam generators and reactor vessel head penetrations are explained, as well as an example of determination of erosion/corrosion and acceptance...

  5. 46 CFR 54.25-5 - Corrosion allowance.

    Science.gov (United States)

    2010-10-01

    ... Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-5 Corrosion allowance. The corrosion allowance must be as required in 46 CFR 54.01-35. ... 46 Shipping 2 2010-10-01 2010-10-01 false Corrosion allowance. 54.25-5 Section 54.25-5...

  6. 46 CFR 154.412 - Cargo tank corrosion allowance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo tank corrosion allowance. 154.412 Section 154.412... Containment Systems § 154.412 Cargo tank corrosion allowance. A cargo tank must be designed with a corrosion...) carries a cargo that corrodes the tank material. Note: Corrosion allowance for independent tank type C...

  7. 5 CFR 180.105 - Claims not allowed.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Claims not allowed. 180.105 Section 180.105 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS EMPLOYEES' PERSONAL PROPERTY CLAIMS § 180.105 Claims not allowed. (a) A claim is not allowable if: (1) The damage...

  8. 46 CFR 64.13 - Allowable stress; tank.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Allowable stress; tank. 64.13 Section 64.13 Shipping... CARGO HANDLING SYSTEMS Standards for an MPT § 64.13 Allowable stress; tank. (a) The calculated stress in... not exceed the allowable stress listed in Division 1 of section VIII of the ASME Code, for a...

  9. 40 CFR 72.95 - Allowance deduction formula.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Allowance deduction formula. 72.95... (CONTINUED) PERMITS REGULATION Compliance Certification § 72.95 Allowance deduction formula. The following formula shall be used to determine the total number of allowances to be deducted for the calendar...

  10. 41 CFR 101-27.503 - Allowable credit.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Allowable credit. 101-27...-Return of GSA Stock Items § 101-27.503 Allowable credit. Allowable credit for activities returning... condition of the material received. (a) Credit will be granted at the rate of 80 percent of the current...

  11. 40 CFR 74.49 - Calculation for deducting allowances.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Calculation for deducting allowances. 74.49 Section 74.49 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR....49 Calculation for deducting allowances. (a) Allowance deduction formula. The following formula...

  12. 32 CFR 842.35 - Depreciation and maximum allowances.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide”...

  13. 45 CFR 1801.43 - Allowance for books.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Allowance for books. 1801.43 Section 1801.43... HARRY S. TRUMAN SCHOLARSHIP PROGRAM Payments to Finalists and Scholars § 1801.43 Allowance for books. The cost allowance for a Scholar's books is $1000 per year, or such higher amount published on...

  14. 42 CFR 61.37 - Stipends, allowances, and benefits.

    Science.gov (United States)

    2010-10-01

    ... fellowship or series of service fellowships. (b) Travel and transportation allowances. Under conditions prescribed by the Secretary, an individual appointed as a service fellow may be authorized personal travel allowances or transportation and per diem, travel allowances or transportation for his or her...

  15. 30 CFR 206.157 - Determination of transportation allowances.

    Science.gov (United States)

    2010-07-01

    ... a rate of return in accordance with paragraph (b)(2)(iv)(B) of this section. Allowable capital costs... salvage value. (B) The MMS shall allow as a cost an amount equal to the allowable initial capital... production month based on the lesser of the volume-weighted average of the rates paid by the third...

  16. 40 CFR 97.42 - NOX allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  17. 40 CFR 96.42 - NOX allowance allocations.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  18. 40 CFR 96.50 - NOX Allowance Tracking System accounts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System accounts... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Tracking System § 96.50 NOX Allowance Tracking System accounts. (a) Nature...

  19. 40 CFR 97.50 - NOX Allowance Tracking System accounts.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX Allowance Tracking System accounts... PROGRAMS (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Tracking System § 97.50 NOX Allowance Tracking System accounts. (a) Nature and function of...

  20. 19 CFR 174.29 - Allowance or denial of protests.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Allowance or denial of protests. 174.29 Section... OF THE TREASURY (CONTINUED) PROTESTS Review and Disposition of Protests § 174.29 Allowance or denial of protests. The port director shall allow or deny in whole or in part a protest filed in...

  1. Naturally occurring allele diversity allows potato cultivation in northern latitudes.

    Science.gov (United States)

    Kloosterman, Bjorn; Abelenda, José A; Gomez, María del Mar Carretero; Oortwijn, Marian; de Boer, Jan M; Kowitwanich, Krissana; Horvath, Beatrix M; van Eck, Herman J; Smaczniak, Cezary; Prat, Salomé; Visser, Richard G F; Bachem, Christian W B

    2013-03-14

    Potato (Solanum tuberosum L.) originates from the Andes and evolved short-day-dependent tuber formation as a vegetative propagation strategy. Here we describe the identification of a central regulator underlying a major-effect quantitative trait locus for plant maturity and initiation of tuber development. We show that this gene belongs to the family of DOF (DNA-binding with one finger) transcription factors and regulates tuberization and plant life cycle length, by acting as a mediator between the circadian clock and the StSP6A mobile tuberization signal. We also show that natural allelic variants evade post-translational light regulation, allowing cultivation outside the geographical centre of origin of potato. Potato is a member of the Solanaceae family and is one of the world's most important food crops. This annual plant originates from the Andean regions of South America. Potato develops tubers from underground stems called stolons. Its equatorial origin makes potato essentially short-day dependent for tuberization and potato will not make tubers in the long-day conditions of spring and summer in the northern latitudes. When introduced in temperate zones, wild material will form tubers in the course of the autumnal shortening of day-length. Thus, one of the first selected traits in potato leading to a European potato type is likely to have been long-day acclimation for tuberization. Potato breeders can exploit the naturally occurring variation in tuberization onset and life cycle length, allowing varietal breeding for different latitudes, harvest times and markets. PMID:23467094

  2. Carbon nanohorns allow acceleration of osteoblast differentiation via macrophage activation

    Science.gov (United States)

    Hirata, Eri; Miyako, Eijiro; Hanagata, Nobutaka; Ushijima, Natsumi; Sakaguchi, Norihito; Russier, Julie; Yudasaka, Masako; Iijima, Sumio; Bianco, Alberto; Yokoyama, Atsuro

    2016-07-01

    Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the proof-of-concept on the osteoblast differentiation capacity by CNHs will allow future studies focused on CNHs as ideal therapeutic materials for bone regeneration.Carbon nanohorns (CNHs), formed by a rolled graphene structure and terminating in a cone, are promising nanomaterials for the development of a variety of biological applications. Here we demonstrate that alkaline phosphatase activity is dramatically increased by coculture of human monocyte derived macrophages (hMDMs) and human mesenchymal stem cells (hMSCs) in the presence of CNHs. CNHs were mainly localized in the lysosome of macrophages more than in hMSCs during coculturing. At the same time, the amount of Oncostatin M (OSM) in the supernatant was also increased during incubation with CNHs. Oncostatin M (OSM) from activated macrophage has been reported to induce osteoblast differentiation and matrix mineralization through STAT3. These results suggest that the macrophages engulfed CNHs and accelerated the differentiation of mesenchymal stem cells into the osteoblast via OSM release. We expect that the

  3. About Time

    OpenAIRE

    Maia, M. D.

    1996-01-01

    The concept of time is discussed in the context of the canonical formulation of the gravitational field. Using a hypersurface orthogonal foliation, the arbitrariness of the lapse function is eliminated and the shift vector vanishes, allowing a consistent definition of time.

  4. Quantum Time

    OpenAIRE

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

    2015-01-01

    We give a consistent quantum description of time, based on Page and Wootters' conditional probabilities mechanism, that overcomes the criticisms that were raised against similar previous proposals. In particular we show how the model allows to reproduce the correct statistics of sequential measurements performed on a system at different times.

  5. Indices allowing early detection of chronic pulmonary emphysema

    International Nuclear Information System (INIS)

    To establish criteria allowing early detection of pathologically significant alterations in pulmonary emphysema caused by smoking, pulmonary-function tests and high-resolution computed tomography were done in 104 subjects categorized into three groups: nonsmoking healthy adults, smokers with a normal FEV1%, and smokers with a low FEV1% (cross-sectional analysis). Fifty-six of the 104 patients underwent pulmonary-function testing and high-resolution computed tomography once per year for 3 years (longitudinal analysis). Cross-sectional and longitudinal analyses showed that abnormalities in functional residual capacity, in single-breath diffusing capacity for carbon monoxide, and in the average tomographic density of sections in the lower lung fields obtained after a deep inspiration could be used to predict whether the disease would reach an advanced stage, even if the patients had no significant symptoms at the time of testing. Relative areas of low-attenuation regions, which were alleged to directly reflect the size of emphysematous areas, appear not to be useful for early detection of pathological emphysema. (author)

  6. ASVCP guidelines: allowable total error guidelines for biochemistry.

    Science.gov (United States)

    Harr, Kendal E; Flatland, Bente; Nabity, Mary; Freeman, Kathleen P

    2013-12-01

    As all laboratory equipment ages and contains components that may degrade with time, initial and periodically scheduled performance assessment is required to verify accurate and precise results over the life of the instrument. As veterinary patients may present to general practitioners and then to referral hospitals (both of which may each perform in-clinic laboratory analyses using different instruments), and given that general practitioners may send samples to reference laboratories, there is a need for comparability of results across instruments and methods. Allowable total error (TEa ) is a simple comparative quality concept used to define acceptable analytical performance. These guidelines are recommendations for determination and interpretation of TEa for commonly measured biochemical analytes in cats, dogs, and horses for equipment commonly used in veterinary diagnostic medicine. TEa values recommended herein are aimed at all veterinary settings, both private in-clinic laboratories using point-of-care analyzers and larger reference laboratories using more complex equipment. They represent the largest TEa possible without generating laboratory variation that would impact clinical decision making. TEa can be used for (1) assessment of an individual instrument's analytical performance, which is of benefit if one uses this information during instrument selection or assessment of in-clinic instrument performance, (2) Quality Control validation, and (3) as a measure of agreement or comparability of results from different laboratories (eg, between the in-clinic analyzer and the reference laboratory). These guidelines define a straightforward approach to assessment of instrument analytical performance. PMID:24320779

  7. Corrosion allowances for sodium heated steam generators: evaluation of effects and extrapolation to component life time

    International Nuclear Information System (INIS)

    Steam generator tubes are subjected to two categories of corrosion; metal/sodium reactions and metal/water-steam interactions. Referring to these environmental conditions the relevant parameters are discussed. The influences of these parameters on the sodium corrosion and water/steam-reactions are evaluated. Extrapolations of corrosion values to steam generator design conditions are performed and discussed in detail. (author)

  8. Time Segmentation Approach Allowing QoS and Energy Saving for Wireless Sensor Networks

    OpenAIRE

    Chalhoub, Gerard; Delobel, François; Misson, Michel

    2010-01-01

    Wireless sensor networks are conceived to monitor a certain application or physical phenomena and are supposed to function for several years without any human intervention for maintenance. Thus, the main issue in sensor networks is often to extend the lifetime of the network by reducing energy consumption. On the other hand, some applications have high priority traffic that needs to be transferred within a bounded end-to-end delay while maintaining an energy efficient behavior. We propose MaC...

  9. [Theoretic evaluation of allowable time for evacuation from occupational zone of accidentally released uranium hexafluoride].

    Science.gov (United States)

    Babenko, S P

    2005-01-01

    Transdermal intake of uranium hexafluoride hydrolysis products is analysed. The authors present calculations of uranium and fluor amounts entering human body, in accordance with duration of stay in hazardous circumstances. PMID:16381480

  10. Essays on the United States sulfur dioxide allowance market

    Science.gov (United States)

    Arimura, Toshihide

    In this thesis, I study the U.S. SO2 allowance market. The first chapter conducts an empirical study of electric utility behavior under the SO2 allowance market. The probit models find that the uncertainty of PUC regulations may have caused them to shun the SO2 allowance market in favor of a strategy of fuel blending/switching while utilities responded to the allowance market efficiently. This implies that the allowance price would have been higher without PUC regulations. Local environmental regulations are also found to be responsible for the unexpectedly low allowance price. However, there is no evidence that the rate of return regulation has affected the fuel switching decision. In chapter 2, a competitive dynamic equilibrium of the SO2 allowance market is characterized and is numerically solved for several policy experiments. First, the competitive dynamic equilibrium with banking is solved. The allowance price is expected to go up to 302.60 dollars at the end of Phase II when the emission decreases to the Phase II target level. Cost savings from direct control is estimated to be 78% (18.1 billion dollars). Next, a competitive dynamic equilibrium of the allowance market without banking is examined. The cost saving from the banking is found to be 780.0 million dollars (13.34% cost saving). Another finding is that the investment behavior in the markets with and without banking are quite different despite the same SO2 emission reduction in the long run.

  11. 基于“站-线-变-户”电网模型的预约停电管理模型设计%Appointment power outage management business model design based on “Station - line - change - households” grid model

    Institute of Scientific and Technical Information of China (English)

    于涛

    2014-01-01

    Based oninformation integration camp with "Station - line - change - households" grid model, appointment blackout that allow customers to participate in the development of power cut scheme will be performed in the power supply enterprise customer information and interaction platform.Establish an appointment outage management model, namely screening appointment blackout customers,select the best service channels to communicate with customers,pooled analysis of customer feedback across channels,and develop optimal algorithm to formulate an optimal power cut scheme.%本文基于营配信息集成“站-线-变-户”电网模型,让客户参与停电计划的制定,在供电企业客服信息与互动平台实行预约停电。建立预约停电管理模型,即筛选预约停电客户群,选择最佳服务渠道与客户进行沟通,汇集分析各渠道客户的意见,通过算法处理制定最优的停电计划。

  12. Telescope sipping impact refuelling outages

    International Nuclear Information System (INIS)

    Based on world wide leading technology in fuel leak detection ABB Nuclear Services developed a new sipping method for Boiling Water Reactors during early nineties, the so called ''TELESCOPE sipping''. The method is today recognised as a reliable and the fastest sipping method and has been used in six BWR sipping projects, where the fuel bundles in the reactor core were tested and all leaking fuel assemblies were identified. Today the TELESCOPE sipping method is also developed for Pressurized Water Reactors as an improvement or replacement alternative of the so called ''INMAST sipping'' method. Patents are pending for both applications. (Author). 3 figs

  13. 26 CFR 1.194-2 - Amount of deduction allowable.

    Science.gov (United States)

    2010-04-01

    ... deduction allowable. (a) General rule. The allowable monthly deduction with respect to reforestation expenditures made in a taxable year is determined by dividing the amount of reforestation expenditures made in... subject to election. A taxpayer may elect to amortize up to $10,000 of qualifying...

  14. 49 CFR 174.86 - Maximum allowable operating speed.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15...

  15. 40 CFR 86.1725-01 - Allowable maintenance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Allowable maintenance. 86.1725-01... Trucks § 86.1725-01 Allowable maintenance. This section includes text that specifies requirements that... are subject to the applicable Otto-cycle or diesel engine maintenance requirements of §...

  16. 19 CFR 159.8 - Allowance for loss, injury, etc.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Allowance for loss, injury, etc. 159.8 Section 159.8 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF..., etc. Allowance in duties for any merchandise which is lost, stolen, destroyed, injured, abandoned,...

  17. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665.127 Section 665.127 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may...

  18. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665.627 Section 665.627 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Island Area Fisheries § 665.627 Allowable gear and gear restrictions. (a) Coral reef ecosystem MUS may...

  19. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665.427 Section 665.427 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS...

  20. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665.227 Section 665.227 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be...

  1. 42 CFR 489.31 - Allowable charges: Blood.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Allowable charges: Blood. 489.31 Section 489.31... Allowable charges: Blood. (a) Limitations on charges. (1) A provider may charge the beneficiary (or other person on his or her behalf) only for the first three pints of blood or units of packed red...

  2. 48 CFR 1652.216-71 - Accounting and Allowable Cost.

    Science.gov (United States)

    2010-10-01

    ... of FEHBP Clauses 1652.216-71 Accounting and Allowable Cost. As prescribed in section 1616.7002, the...). Accounting and Allowable Cost (FEHBAR 1652.216-71) (JAN 2003) (a) Annual Accounting Statements. (1) The... addition, the Carrier must: (i) on request, document and make available accounting support for the cost...

  3. 24 CFR 213.260 - Allowable methods of premium payment.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Allowable methods of premium payment. 213.260 Section 213.260 Housing and Urban Development Regulations Relating to Housing and Urban... Allowable methods of premium payment. Premiums shall be payable in cash or in debentures at par plus...

  4. 46 CFR 64.15 - Allowable stress; framework.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Allowable stress; framework. 64.15 Section 64.15... AND CARGO HANDLING SYSTEMS Standards for an MPT § 64.15 Allowable stress; framework. The calculated stress for the framework must be 80 percent or less of the minimum yield stress of the framework...

  5. 42 CFR 50.504 - Allowable cost of drugs.

    Science.gov (United States)

    2010-10-01

    ... maximum allowable cost (MAC) of the drug, if any, established in accordance with 45 CFR part 19, plus a... in 45 CFR part 74, no separate dispensing fee will be recognized. (b) In determining whether a... 42 Public Health 1 2010-10-01 2010-10-01 false Allowable cost of drugs. 50.504 Section...

  6. 48 CFR 1352.216-70 - Estimated and allowable costs.

    Science.gov (United States)

    2010-10-01

    ... Estimated and allowable costs. As prescribed in 48 CFR 1316.307(a), insert the following clause: Estimated and Allowable Costs (APR 2010) (a) Estimated Costs. The estimated cost of this contract is... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Estimated and...

  7. 40 CFR 35.940-5 - Disputes concerning allowable costs.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Disputes concerning allowable costs. 35.940-5 Section 35.940-5 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER... relating to cost allowability or allocation at its earliest opportunity (if possible, before execution...

  8. Allowance trading: Correcting the past and looking to the future

    International Nuclear Information System (INIS)

    Allowance trading is basic to the Title IV acid rain provisions of the 1990 Clean Air Act Amendments (CAAA) in the United States; the provisions seek to achieve a 10-million-ton reduction in annual sulfur dioxide emissions from the electric power utility industry. Allowance trading, a market-based approach, is conceptually similar to the emissions trading policy of the US Environmental Protection Agency (EPA). An allowance is defined as the authorization to emit, during or after a specified calendar year, one ton of sulfur dioxide. This paper provides an overview of the allowance trading program by summarizing some important features, particularly as they are responsive to limitations and concern as related to the precursor emissions trading program in the early to mid-1980s. Such features include a simple definition of baseline emission levels, encouragements for nationwide trading, disincentives for accumulation of excess allowance,s opportunities for leasing other short-term allowance transfer arrangements, enforcement provisions, and benefits of bonus allowances and early emission reductions. Adherence to implementation protocols for the acid rain provisions of Title IV of the CAAA will provide a good opportunity to evaluate this market-based approach for environmental quality management

  9. Decoherence Allows Model Reduction in Nonadiabatic Dynamics Simulations.

    Science.gov (United States)

    Trivedi, Dhara J; Prezhdo, Oleg V

    2015-08-20

    A nonadiabatic (NA) molecular dynamics (MD) simulation requires calculation of NA coupling matrix elements, the number of which scales as a square of the number of basis states. The basis size can be huge in studies of nanoscale materials, and calculation of the NA couplings can present a significant bottleneck. A quantum-classical approximation, NAMD overestimates coherence in the quantum, electronic subsystem, requiring decoherence correction. Generally, decoherence times decrease with increasing energy separation between pairs of states forming coherent superpositions. Since rapid decoherence stops quantum dynamics, one expects that decoherence-corrected NAMD can eliminate the need for calculation of NA couplings between energetically distant states, notably reducing the computational cost. Considering several types of dynamics in a semiconductor quantum dot, we demonstrate that indeed, decoherence allows one to reduce the number of needed NA coupling matrix elements. If the energy levels are spaced closer than 0.1 eV, one obtains good results while including only three nearest-neighbor couplings, and in some cases even with just the first nearest-neighbor coupling scheme. If the energy levels are spaced by about 0.4 eV, the nearest-neighbor model fails, while three or more nearest-neighbor schemes also provide good results. In comparison, the results of NAMD simulation without decoherence vary continuously with changes in the number of NA couplings. Thus, decoherence effects induced by coupling to a quantum-mechanical environment not only provide the physical mechanism for NAMD trajectory branding and improve the accuracy of NAMD simulations, but also afford significant computational savings. PMID:26221974

  10. Regulatory incentives and the economics of allowance trading

    International Nuclear Information System (INIS)

    This chapter develops an economic model of allowance trading when the output market of affected firms is subject to public utility regulation. Rather than placing a firm's productive enterprise in the background to highlight the effects of environmental policy, the productive and environmental decisions of the firm are placed at the center of the model. This chapter discusses the economics of public utility regulation, a model of rate-of-return regulation with a command-and-control environmental constraint, emission allowance trading without rate-of-return regulation, and emission allowance trading with rate-of-return regulation. 25 refs., 1 fig

  11. 40 CFR 82.20 - Availability of consumption allowances in addition to baseline consumption allowances for class...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of consumption allowances in addition to baseline consumption allowances for class II controlled substances. 82.20 Section 82.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  12. 40 CFR 82.9 - Availability of production allowances in addition to baseline production allowances for class I...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of production allowances in addition to baseline production allowances for class I controlled substances. 82.9 Section 82.9 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  13. 40 CFR 82.10 - Availability of consumption allowances in addition to baseline consumption allowances for class I...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Availability of consumption allowances in addition to baseline consumption allowances for class I controlled substances. 82.10 Section 82.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  14. Seal allows blind assembly and thermal expansion of components

    Science.gov (United States)

    1965-01-01

    The design of a seal consisting of two concentric cylinders with outer and inner threaded elements attached to each side of the system interface withstands large temperature changes and allows for blind assembly.

  15. Economic rationale for an emission allowance trading program

    International Nuclear Information System (INIS)

    The assumption behind the economic model of allowance trading is that managers of firms are better at solving pollution abatement problems than government overseers. This is because firms know more than an environmental regulator about their own operations and because the profit motive, rather than direct government mandate of compliance decisions, may be more effective at minimizing emission control costs. The allowance trading program in the CAAA is designed to provide firms with an incentive to make good choices about how to reduce emissions by allowing the firm to reduce compliance cost and profit from trading. This chapter discusses the benefits of allowance trading and summarizes the economic literature on tradable pollution rights. 17 refs., 2 figs

  16. Prosecutor allowed to infer existence of HIV test in rape.

    Science.gov (United States)

    1999-05-28

    A Texas appeals court held that a prosecutor may make inferences about the emotional distress a rape victim may feel while awaiting HIV results after an attack. The defendant, convicted and sentenced for raping two women, claimed the judge unfairly allowed jurors to consider prosecution statements regarding the victims' HIV tests during the punishment phase of the trial. The appeals court disagreed, and upheld the trial judge's decision to allow reasonable inferences based on the facts at hand. PMID:11367139

  17. How Institutions Affect Outcomes in Laboratory Tradable Fishing Allowance Systems

    OpenAIRE

    Anderson, Christopher M.

    2004-01-01

    The objective of this paper is to illustrate that economic institutions matter, i.e., that different rules of trade present different incentives for bidding, asking, and trading in new markets, and that these different incentives lead to different price discovery patterns, which yield materially different outcomes. In a laboratory tradable fishing allowance system, when trade takes place through a double auction, which parallels an institution common in extant tradable allowance systems, mark...

  18. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1. Volume 5: Analysis of core damage frequency from seismic events for plant operational state 5 during a refueling outage

    International Nuclear Information System (INIS)

    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 Sandia National Laboratories studying a boiling water reactor (Grand Gulf), and the other at Brookhaven National Laboratory studying a pressurized water reactor (Surry Unit 1). Both the Sandia and Brookhaven 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 outage conditions, is complementary to the internal-initiator analyses at Brookhaven and Sandia. This report covers the seismic analysis at Grand Gulf. All of the many systems modeling assumptions, component non-seismic failure rates, and human effort rates that were used in the internal-initiator study at Grand Gulf have been adopted here, so that the results of the study can be as comparable as possible. Both the Sandia study and this study examine only one shutdown plant operating state (POS) at Grand Gulf, namely POS 5 representing cold shutdown during a refueling outage. 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 POS 5. The results of the analysis are that the core-damage frequency for earthquake-initiated accidents during refueling outages in POS 5 is found to be quite low in absolute terms, less than 10-7/year

  19. The Title IV allowance trading program begins to take shape

    International Nuclear Information System (INIS)

    In enacting sweeping amendments to the Clean Air Act in 1990, Congress included provisions for massive reductions of nationwide emissions of sulfur dioxide (SO2) from the electric utility industry. These provisions, commonly referred to as the acid rain program, are set forth in Title IV of both the Amendments and the Act. The 'centerpiece' of the acid rain program is 'an innovative, market-based approach' for bringing about mandated SO2 reductions, which will be embodied in a trading system of fully marketable emission allowances. This paper examines the allowance trading system as it begins to take shape in the latter part of 1991. The statutory commands of Sections 403 (the allowance program) and 416 (reserves, auctions, sales, and guarantees) of the Clean Air Act are reviewed first. There follows a discussion of the important details of the allowance trading program which Congress left for EPA to define in the Part 73 rules, and the principal features of proposed auction and direct sale rules and draft proposed allowance trading rules. At the conclusion is a discussion of several significant questions that remain concerning the development, implementation, and ultimate viability of the allowance trading system

  20. Evaluation of potential severe accidents during low power and shutdown operations at Grand Gulf, Unit 1: Analysis of core damage frequency from internally induced flooding events for Plant Operational State 5 during a refueling outage. Volume 4

    International Nuclear Information System (INIS)

    An estimate of the contribution of internal flooding to the mean core damage frequency at the Grand Gulf Nuclear Station was calculated for Plant Operational State 5 during a refueling outage. Pursuant to this objective, flood zones and sources were identified and flood volumes were calculated. Equipment necessary for the maintenance of plant safety was identified and its vulnerability to flooding was determined. Event trees and fault trees were modified or developed as required, and PRA quantification was performed using the IRRAS code. The mean core damage frequency estimate for GGNS during POS 5 was found to be 2.3 E-8 per year

  1. How far is observation allowed in patients with ectopia lentis?

    Science.gov (United States)

    Matsuo, Toshihiko

    2015-01-01

    Surgical timing for ectopia lentis has not been well described until now. The purpose of this study is to find a benchmark as to how far observation would be allowed in children with ectopia lentis when they and their families are reluctant to go through surgery. Retrospective review was made on 15 consecutive patients (14 children and one adult) with ectopia lentis in both eyes, seen at a referral-based institution in 5 years from April 2008 to March 2013, to survey the reasons for continuing observation or deciding surgical intervention. The diagnoses were Marfan syndrome in six patients, familial ectopia lentis in six, and sporadic ectopia lentis in three. Observation was continued in nine patients with the age at the final visit, ranging from 4 to 17 (median 9) years, because six children had good visual acuity at both near and distant viewing with glasses, and three children had visual acuity of 0.4 at near viewing despites poor visual acuity at distant viewing with glasses. In contrast, lensectomy was determined in six patients (5 children and one adult) with the age at surgery, ranging from 4 to 36 (median 9) years, and the age at the final visit, ranging from 7 to 42 (median 11) years, mainly because of poor visual acuity at near and distant viewing. More specific causes for surgeries in five children were the optical axis to become aphakic due to the progression of ectopia in the course in two children, lens dislocation to the anterior chamber after blunt eye injury in one child, and difficulty in studying at school classes in two children. One adult patient developed cataract in ectopic lenses. Lensectomy, combined with anterior vitrectomy, was done from two limbal side ports with a 25-gauge infusion cannula and vitreous cutter. Two patients at the age of 16 and 36 years, additionally, underwent intraocular lens-suturing in both eyes. In conclusions, observation was continued in children with ectopia lentis who had good visual acuity at near viewing

  2. ACCOUNTING FOR GREENHOUSE GASES EMISSIONS ALLOWANCES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Marius Deac

    2013-02-01

    Full Text Available The present paper tries to analyze the accounting challenges that the implementation of EU Emissions Trading Scheme has risen. On 2 December 2004, IASB has issued an interpretation regarding the accounting of the GHG emissions allowances (IFRIC 3 „Emission Rights”. This interpretation should have been effective for annual periods beginning after 1 March 2005, the first year of the EU Emission Trading Scheme implementation. Less than a year after it was issued, IFRIC has withdrawn IFRIC 3. In December 2007, IASB has started a new project in order to provide guidance on accounting for carbon allowances called Emissions Trading Schemes Project. In the absence of an accounting standard regarding the accounting of these emissions allowances a diversity of accounting practices have been identified. Nowadays, there are three main accounting practices for the recognition of the emissions allowances and the GHG emissions liabilities: IFRIC 3 approach, the government grants approach and the net liability or off balance sheet approach. The accounting treatment of greenhouse gas emissions allowances by Romanian companies resembles the net liability or off balance sheet approach. Finance Ministry Order no. 1118/2012 states that GHG emission certificates should be recognized as fixed assets (if the entity is expecting a profit in the long term or in the category of short term investments (if the entity is expecting a profit in the short term. The accounting of the greenhouse gas emissions allowances described above is applicable mainly to traders of such certificates and not for the installations in the scope of the EU ETS directive, which should recognize GHG emissions off balance sheet, at their nominal value (nil if received for free. The shortfall or excess of allowances will be recognized in the profit or loss as they are bought or sold by the entity (the accounting treatment imposed by Finance Ministry Order no. 3055/2009.

  3. Allowable variance set on left ventricular function parameter

    International Nuclear Information System (INIS)

    Purpose: To evaluate the influence of allowable Variance settings on left ventricular function parameter of the arrhythmia patients during gated myocardial perfusion imaging. Method: 42 patients with evident arrhythmia underwent myocardial perfusion SPECT, 3 different allowable variance with 20%, 60%, 100% would be set before acquisition for every patients,and they will be acquired simultaneously. After reconstruction by Astonish, end-diastole volume(EDV) and end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) would be computed with Quantitative Gated SPECT(QGS). Using SPSS software EDV, ESV, EF values of analysis of variance. Result: there is no statistical difference between three groups. Conclusion: arrhythmia patients undergo Gated myocardial perfusion imaging, Allowable Variance settings on EDV, ESV, EF value does not have a statistical meaning. (authors)

  4. 41 CFR 102-85.105 - How does an agency pay for customer alterations that exceed the TI allowance?

    Science.gov (United States)

    2010-07-01

    ... for customer alterations that exceed the TI allowance? 102-85.105 Section 102-85.105 Public Contracts....105 How does an agency pay for customer alterations that exceed the TI allowance? Amounts exceeding the TI allowance are paid in a one-time lump sum and are not amortized over the term of the...

  5. 75 FR 63184 - Temporary Duty (TDY) Travel Allowances

    Science.gov (United States)

    2010-10-14

    ... ADMINISTRATION Temporary Duty (TDY) Travel Allowances AGENCY: Office of Governmentwide Policy, General Services... of agencies subject to the FTR to enhance travel cost savings and reduce greenhouse gas emissions. This guidance will improve management of agency travel programs, save money on travel costs,...

  6. 47 CFR 32.1191 - Accounts receivable allowance-other.

    Science.gov (United States)

    2010-10-01

    ....1191 Accounts receivable allowance—other. (a) This account shall be credited with amounts charged to..., Other Accounts Receivable. There shall also be credited to this account amounts collected which... 47 Telecommunication 2 2010-10-01 2010-10-01 false Accounts receivable allowance-other....

  7. 47 CFR 32.1171 - Allowance for doubtful accounts.

    Science.gov (United States)

    2010-10-01

    ... uncollectible amounts related to accounts receivable and notes receivable included in Account 1170, Receivables... or directly to Account 6790, Provision for uncollectible notes receivable, as appropriate. (c....1171 Allowance for doubtful accounts. (a) This account shall be credited with amounts charged...

  8. 42 CFR 413.50 - Apportionment of allowable costs.

    Science.gov (United States)

    2010-10-01

    ... MEDICARE PROGRAM PRINCIPLES OF REASONABLE COST REIMBURSEMENT; PAYMENT FOR END-STAGE RENAL DISEASE SERVICES; OPTIONAL PROSPECTIVELY DETERMINED PAYMENT RATES FOR SKILLED NURSING FACILITIES Apportionment § 413.50 Apportionment of allowable costs. (a) Consistent with prevailing practice in which third-party organizations...

  9. 9 CFR 50.14 - Claims not allowed.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Claims not allowed. 50.14 Section 50.14 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... of the requirements of this part: (b) All cattle, bison, and captive cervids 12 months of age or...

  10. 75 FR 78940 - Sales-Based Royalties and Vendor Allowances

    Science.gov (United States)

    2010-12-17

    ... proposed regulations on adjusting the cost of merchandise inventory for an allowance, discount, or price... Services, Inc. v. Commissioner, TC Memo. 2001-324; but see Robinson Knife Manufacturing Company, Inc. v..., discount, or price rebate a taxpayer earns as a result of selling a vendor's merchandise, typically at...

  11. Can preapproval jump-start the allowance market

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, D.J.; Goffman, J.

    1992-06-01

    With compliance deadlines approaching in three years, utility, environmental and financial planners and their regulators are in the process of grappling with the requirements imposed, and opportunities created, by the acid rain program established under Title 4 of the Clean Air Act amendments of 1990. The novel element of the program - emissions or allowance trading through a nationwide allowance market - presents great challenges for utilities and their regulators. Perhaps the foremost challenge is establishing the allowance market. If state utility commissions subject utilities' compliance strategies to traditional after-the-fact prudence reviews, as tradition would impel them to do, the attendant regulatory risks are likely to push utilities toward more conservative compliance schemes that underuse allowance trading (as the exchange at the head of this article demonstrates). If that happens, the market will fail to develop, and its full potential for environmental benefit at least cost will go unrealized. This, in turn, is likely to strengthen the case for non-market regulatory mechanisms - a vicious circle. In this paper, the authors suggest a way out of this.

  12. Mitigation of Global Warming with Focus on Personal Carbon Allowances

    DEFF Research Database (Denmark)

    Meyer, Niels I

    2008-01-01

    The mitigation of global warming requires new efficient systems and methods. The paper presents a new proposal called personal carbon allowances with caps on the CO2 emission from household heating and electricity and on emission from transport in private cars and in personal air flights. Results...

  13. Can preapproval jump-start the allowance market?

    International Nuclear Information System (INIS)

    With compliance deadlines approaching in three years, utility, environmental and financial planners and their regulators are in the process of grappling with the requirements imposed, and opportunities created, by the acid rain program established under Title 4 of the Clean Air Act amendments of 1990. The novel element of the program - emissions or allowance trading through a nationwide allowance market - presents great challenges for utilities and their regulators. Perhaps the foremost challenge is establishing the allowance market. If state utility commissions subject utilities' compliance strategies to traditional after-the-fact prudence reviews, as tradition would impel them to do, the attendant regulatory risks are likely to push utilities toward more conservative compliance schemes that underuse allowance trading (as the exchange at the head of this article demonstrates). If that happens, the market will fail to develop, and its full potential for environmental benefit at least cost will go unrealized. This, in turn, is likely to strengthen the case for non-market regulatory mechanisms - a vicious circle. In this paper, the authors suggest a way out of this

  14. 14 CFR 14.05 - Allowance fees and expenses.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Allowance fees and expenses. 14.05 Section 14.05 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES IMPLEMENTING THE EQUAL ACCESS TO JUSTICE ACT OF 1980 General Provisions § 14.05...

  15. 13 CFR 120.971 - Allowable fees paid by Borrower.

    Science.gov (United States)

    2010-01-01

    ... Development Company Loan Program (504) Fees § 120.971 Allowable fees paid by Borrower. (a) CDC fees. The fees a CDC may charge the Borrower in connection with a 504 loan and Debenture are limited to the... closing fee sufficient to reimburse it for the expenses of its in-house or outside legal counsel,...

  16. 40 CFR 18.8 - Stipends, Allowances, and Benefits.

    Science.gov (United States)

    2010-07-01

    ... such stipend as is authorized by the Administrator or designee. (b) Travel and transportation... Environmental Protection Research fellow may be authorized travel and transportation or relocation allowances... conjunction with travel authorized by the Administrator or designee. Included under this part is travel...

  17. Recording Discounts Allowable on Invoices. Student's Manual and Instructor's Handbook.

    Science.gov (United States)

    Albert, Linda F.

    Supporting performance objective 50 of the V-TECS (Vocational-Technical Education Consortium of States) Bookkeeper Catalog, a set of student materials and an instructor's manual on recording discounts allowable on invoices are included in this module. (This module is the fifth in a set of ten on bookkeeping [CE 019 480-489].) The student materials…

  18. 40 CFR 35.2205 - Maximum allowable project cost.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GRANTS AND OTHER FEDERAL... adjustments for differing site conditions will be exempt, provided the requirements of 40 CFR part 35,...

  19. 40 CFR 310.11 - What costs are allowable?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 27 2010-07-01 2010-07-01 false What costs are allowable? 310.11 Section 310.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY... equipment that you procured for a specific evacuation; and (10) Containerization or packaging cost...

  20. 9 CFR 53.10 - Claims not allowed.

    Science.gov (United States)

    2010-01-01

    ..., RINDERPEST, AND CERTAIN OTHER COMMUNICABLE DISEASES OF LIVESTOCK OR POULTRY § 53.10 Claims not allowed. (a... the introduction into or the dissemination within the United States of any communicable disease of... destruction of fish due to infectious salmon anemia (ISA) unless the claimants have agreed in writing...