WorldWideScience

Sample records for operating experience feedback

  1. Reviewing operational experience feedback

    International Nuclear Information System (INIS)

    1991-04-01

    The purpose of this document is to provide detailed supplementary guidance to OSART experts to aid in the evaluation of operational experience feedback (OEF) programmes at nuclear power plants. The document begins by describing the objectives of an OEF programme. It goes on to indicate preparatory work and investigatory guidance for the expert. Section 5 describes attributes of an excellent OEF programme. Appended to these guidelines are examples of OEF documents from various plants. These are intended to help the expert by demonstrating the actual implementation of OEF in practice. These guidelines are in no way intended to conflict with existing national regulations and rules. A comprehensive OEF programme, as described in Section 2, would be impossible to evaluated in detail in the amount of time typically allocated for assessing OEF in an OSART review. The expert must use his or her time wisely by concentrating on those areas that appear to be the weakest

  2. Operating experience feedback

    International Nuclear Information System (INIS)

    Cimesa, S.

    2007-01-01

    Slovenian Nuclear Safety Administration (SNSA) has developed its own system for tracking, screening and evaluating the operating experiences of the nuclear installations. The SNSA staff regularly tracks the operating experiences throughout the world and screens them on the bases of applicability for the Slovenian nuclear facilities. The operating experiences, which pass the screening, are thoroughly evaluated and also recent operational events in these facilities are taken into account. If needed, more information is gathered to evaluate the conditions of the Slovenian facilities and appropriate corrective actions are considered. The result might be the identification of the need for modification at the licensee, the need for modification of internal procedures in the SNSA or even the proposal for the modification of regulations. Information system helps everybody to track the process of evaluation and proper logging of activities. (author)

  3. Operating experience feedback in TVO

    Energy Technology Data Exchange (ETDEWEB)

    Piirto, A [Teollisuuden Voima Oy (Finland)

    1997-12-31

    TVO is a power company operating with two 710 MW BWR units at Olkiluoto. For operating experience feedback TVO has not established a separate organizational unit but rather relies on a group of persons representing various technical disciplines. The ``Operating Experience Group`` meets at about three-week intervals to handle the reports of events (in plant and external) which have been selected for handling by an engineer responsible for experience feedback. 7 charts.

  4. Operating experience feedback program at Olkiluoto NPP

    International Nuclear Information System (INIS)

    Kosonen, Mikko

    2002-01-01

    Recent review and development of the operating experience feedback program will be described. The development of the program has been based on several reviews by outside organizations. Main conclusions from these review reports and from the self assessment of safety performance, safety problems and safety culture on the basis of the operational events made by ASSET-method will be described. An approach to gather and analyze small events - so-called near misses - will be described. The operating experience program has been divided into internal and external operating experience. ASSET-methodology and a computer program assisting the analysis are used for the internal operating experience events. Noteworthy incidents occurred during outage are analyzed also by ASSET-method. Screening and pre analysis of the external operating experience relies on co-operation with ERFATOM, an organization of Nordic utilities for the exchange of nuclear industry experience. A short presentation on the performance of the Olkiluoto units will conclude the presentation. (author)

  5. Operational experience feedback with precursor analysis

    International Nuclear Information System (INIS)

    Koncar, M.; Ferjancic, M.; Muehleisen, A.; Vojnovic, D.

    2003-01-01

    Experience of practical operation is a valuable source of information for improving the safety and reliability of nuclear power plants. Operational experience feedback (Olef) system manages this aspect of NPP operation. The traditional ways of investigating operational events, such as the root cause analysis (RCA), are predominantly qualitative. RCA as a part of the Olef system provides technical guidance and management expectations in the conduct of assessing the root cause to prevent recurrence, covering the following areas: conditions preceding the event, sequence of events, equipment performance and system response, human performance considerations, equipment failures, precursors to the event, plant response and follow-up, radiological considerations, regulatory process considerations and safety significance. The root cause of event is recognized when there is no known answer on question 'why has it happened?' regarding relevant condition that may have affected the event. At that point the Olef is proceeding by actions taken in response to events, utilization, dissemination and exchange of operating experience information and at the end reviewing the effectiveness of the Olef. Analysis of the event and the selection of recommended corrective/preventive actions for implementation and prioritization can be enhanced by taking into account the information and insights derived from Pasa-based analysis. A Pasa based method, called probabilistic precursor event analysis (PPE A) provides a complement to the RCA approach by focusing on how an event might have developed adversely, and implies the mapping of an operational event on a probabilistic risk model of the plant in order to obtain a quantitative assessment of the safety significance of the event PSA based event analysis provides, due to its quantitative nature, appropriate prioritization of corrective actions. PPEA defines requirements for PSA model and code, identifies input requirements and elaborates following

  6. Proposed Reactor Operating Experience Feedback System Development

    International Nuclear Information System (INIS)

    Ahn, Seung Hoon; Kim, Min Chul; Huh, Chang Wook; Lee, Durk Hun; Bae, Koo Hyun

    2006-01-01

    Most events occurring in nuclear power plants are not individually significant, and prevented from progressing to accident conditions by a series of barriers against core damage and radioactive releases. Significant events, if occur, are almost always a breach of these multiple barriers. As illustrated in the 'Swiss cheese' model, the individual layers of defense or 'cheese slices' have weakness or 'holes.' These weaknesses are inconstant, i.e., the holes are open or close at random. When by chance all the holes are aligned, a hazard causes the significant event of concern. Elements of low significant events, inattention to detail, time or economic pressure, uncorrected poor practices/habits, marginal maintenance and equipment care, etc., make holes in the layers of defense; some elements may make more holes in different layers, incurring more chances to be aligned. An effective reduction of the holes, therefore, is gained through better knowledge or awareness of increasing trends of the event elements, followed by appropriate actions. According to the Swiss cheese metaphor, attention to the Operating Experience (OE) feedback system, as opposed to the individual and to randomness, is drawn from a viewpoint of reactor safety

  7. Feedback of operating experience in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    The feedback of operating experience of nuclear facilities to the designers, manufacturers, operators and regulators is one important means of maintaining and improving safety. The Atomic Energy Control Board`s Advisory Committee on Nuclear Safety examined the means for feedback currently being employed, how effective they are and what improvements are advisable. The review found that the need for feedback of operating experience is well recognized within those institutions contributing to the safety of CANDU power reactors, and that the existing procedures are generally effective. Some recommendations, however, are submitted for improvement in the process.

  8. Feedback of operating experience in nuclear power plants

    International Nuclear Information System (INIS)

    1995-06-01

    The feedback of operating experience of nuclear facilities to the designers, manufacturers, operators and regulators is one important means of maintaining and improving safety. The Atomic Energy Control Board's Advisory Committee on Nuclear Safety examined the means for feedback currently being employed, how effective they are and what improvements are advisable. The review found that the need for feedback of operating experience is well recognized within those institutions contributing to the safety of CANDU power reactors, and that the existing procedures are generally effective. Some recommendations, however, are submitted for improvement in the process

  9. Feedback of safety - related operational experience: Lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Elias, D [Commonwealth Edison Co. (United States)

    1997-09-01

    The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues.

  10. Feedback of safety - related operational experience: Lessons learned

    International Nuclear Information System (INIS)

    Elias, D.

    1997-01-01

    The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues

  11. Operating experience feedback report - Air systems problems

    International Nuclear Information System (INIS)

    Ornstein, H.L.

    1987-12-01

    This report highlights significant operating events involving observed or potential failures of safety-related systems in U.S. plants that resulted from degraded or malfunctioning non-safety grade air systems. Based upon the evaluation of these events, the Office for Analysis and Evaluation of Operational Data (AEOD) concludes that the issue of air systems problems is an important one which requires additional NRC and industry attention. This report also provides AEOD's recommendations for corrective actions to deal with the issue. (author)

  12. ETSON proposal on the European operational experience feedback system

    International Nuclear Information System (INIS)

    Maqua, Michael; Bertrand, Remy; Gelder, Pieter de

    2007-01-01

    The new IAEA Safety Fundamentals states regarding the operating experience feedback: The feedback of operating experience from facilities and activities - and, where relevant, from elsewhere - is a key means of enhancing safety. Processes must be put in place for the feedback and analysis of operating experience, including initiating events, accident precursors, near misses, accidents and unauthorized acts, so that lessons may be learned, shared and acted upon. This presentation deals with the proposal of the ETSON (European TSO Network) to optimize the European operating experiences feedback (OEF). It is generally recognized that the efficiency of nuclear safety supervision by public authorities is based on two key requirements: - the existence of a competent authority at national level, benefiting from an appropriate legislative and regulatory basis, from adequate (quantitatively and qualitatively) human resources, particularly for inspection purposes, - the availability of resources devoted to highly specialised independent technical expertise, in order to provide competent authorities with pertinent technical opinions on: -- the safety files provided by operators, for the purpose of licensing corresponding activities, -- the exploitation for regulatory purposes of the operating experience feed back from licensed nuclear installations. There are two worldwide systems intended to learn lessons from experience: the WANO (World Association of Nuclear Operators) system established by the licensees with access restricted to operating organizations and the IRS system jointly operated by IAEA and OECD/NEA accessible to regulators and to some other users nominated by the regulators in their countries. The IRS itself is dedicated to the analysis of safety significant operating events. NEA/CNRA runs a permanent working group on operating experience (WGOE). WGOE provides among other things also generic reports on safety concerns related to operating experiences and

  13. Lessons from feedback of safety operating experience for reactor physics

    International Nuclear Information System (INIS)

    Suchomel, J.; Rapavy, S.

    1999-01-01

    Analyses of events in WWER operations as a part of safety experience feedback provide a valuable source of lessons for reactor physics. Examples of events from Bohunice operation will be shown such as events with inadequate approach to criticality, positive reactivity insertions, expulsion of a control rod from shut-down reactor, problems with reactor protection system and control rods. (Authors)

  14. Operational experiences feedback in Bohunice NPP

    Energy Technology Data Exchange (ETDEWEB)

    Betak, A [NPP Bohunice (Slovakia)

    1997-10-01

    The presentation reviews the following issues: OEF team in Bohunice NPP - structure; training and qualification: ASSET seminars on Prevention of incidents - INES manual handling, NRA-NRC the training on event investigation methods, NU - the training on HPES; legislation - documentation prepared in the frame of QA programme; results of OEF team activities; ASSET mission Dukovany - Experiences; the perspective activities.

  15. Operational safety experience feedback by means of unusual event reports

    International Nuclear Information System (INIS)

    1996-07-01

    Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ''Systems for Reporting Unusual Events in Nuclear Power Plants'' (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs

  16. Operational safety experience feedback by means of unusual event reports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ``Systems for Reporting Unusual Events in Nuclear Power Plants`` (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs.

  17. Operating experience feedback from safety significant events at research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Shokr, A.M. [Atomic Energy Authority, Abouzabal (Egypt). Egypt Second Research Reactor; Rao, D. [Bhabha Atomic Research Centre, Mumbai (India)

    2015-05-15

    Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

  18. Operating experience feedback from safety significant events at research reactors

    International Nuclear Information System (INIS)

    Shokr, A.M.

    2015-01-01

    Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

  19. The Clearing House on Operating Experience Feedback (CH-OEF)

    International Nuclear Information System (INIS)

    Tanarro Colodron, J.

    2016-01-01

    Full text: The Clearing House on Operating Experience Feedback (CH-OEF) is an online information system that contains three technical databases available only to registered users: 1) Operating Experience Feedback (OEF) records, containing information about events occurred at Nuclear Power Plants; 2) Nuclear Power Plant (NPP) records, containing technical details about NPPs; 3) Documents about operating experience, such as the Topical Operating Experience Reports (TOERs) and the quarterly reports on nuclear power plant events. The main objective of the information system is to develop communication, cooperation and sharing of operating experience amongst the national nuclear regulatory authorities participating in EU Clearinghouse network. The CH-OEF is essential for the preparation and dissemination of the quarterly reports on NPP events. These reports are published every three months and are intended to be complementary to other international reporting systems, containing mainly recent information publicly available. Only events that are considered to be likely to have lessons applicable to EU NPPs or with a real or potential impact on nuclear safety are addressed in the reports. The CH-OEF is a fundamental tool for their preparation, providing specific features for a more efficient sharing of information as well as for facilitating the related discussion and decision making. (author

  20. European Clearinghouse for Nuclear Power Plants Operational Experience Feedback

    International Nuclear Information System (INIS)

    Martin Ramos, M.; Noel, M.

    2010-01-01

    In the European Union, in order to support the Community activities on operational experience, a centralized regional network on nuclear power plants operational experience feedback (European Clearinghouse on Operational Experience Feedback for Nuclear Power Plants) was established in 2008 at the EC JRC-IE, Petten (The Netherlands) on request of nuclear Safety Authorities of several Member States. Its main goal is to improve the communication and information sharing on OEF, to promote regional collaboration on analyses of operational experience and dissemination of the lessons learned. The enlarged EU Clearinghouse was launched in April 2010, and it is currently gathering the Regulatory Authorities of Finland, Hungary, Lithuania, the Netherlands, Romania, Slovenia, Switzerland, Bulgaria, Czec Republic, France, Germany, Slovak Republic, and Spain (these last six countries as observers). The OECD Nuclear Energy Agency, the IAEA, the EC Directorates General of the JRC and ENER are also part of the network. Recently, collaboration between some European Technical Support Organizations (such IRSN and GRS) and the EU Clearinghouse has been initiated. This paper explains in detail the objectives and organization of the EU Clearinghouse, as well as the most relevant activities carried out, like research work in trend analysis of events ocurred in NPP, topical reports on particular events, dissemination of the results, quarterly reports on events reported publicly and operational experience support to the members of the EU Clearinghouse. (Author)

  1. European clearinghouse on nuclear power plants operational experience feedback

    International Nuclear Information System (INIS)

    Ranguelova, Vesselina; Bruynooghe, Christiane; Noel, Marc

    2010-01-01

    Learning from operational experience and applying this knowledge promptly and intelligently is one of the ways to improve the safety of Nuclear Power Plant (NPP). Recent reviews of the effectiveness of Operational Experience Feedback (OEF) systems have pointed to the need for further improvement, with importance being placed on tailoring the information to the needs of the regulators. In 2007, at the request of a number of nuclear safety regulatory authorities in Europe, the Institute for Energy of the European Commission's Joint Research Centre (EC JRC) initiated a project on Nuclear Power Plant operational experience feedback, which adopts an integrated approach to the research needed to strengthen the European capabilities for assessment of NPP operational events and to promote the development of tools and mechanisms for the improved application of the lessons learned. Consequently, a so-called ''European Clearinghouse'' on NPP OEF was established, which includes scientific officers from the EC JRC, a number of European nuclear safety regulatory authorities and some of their Technical Support Organizations (TSOs). The paper discusses the activities implemented in 2008 within the framework of the European Clearinghouse on NPP OEF (hereinafter called the European NPP Clearinghouse) and provides an overview of the main conclusions drawn from the safety studies performed. Outlook of the activities carried out in 2009 are given. (orig.)

  2. Operating experience feedback report - Solenoid-operated valve problems

    International Nuclear Information System (INIS)

    Ornstein, H.L.

    1991-02-01

    This report highlights significant operating events involving observed or potential common-mode failures of solenoid-operated valves (SOVs) in US plants. These events resulted in degradation or malfunction of multiple trains of safety systems as well as of multiple safety systems. On the basis of the evaluation of these events, the Office for Analysis and Evaluation of Operational Data (AEOD) of the US Nuclear Regulatory Commission (NRC) concludes that the problems with solenoid-operated valves are an important issue that needs additional NRC and industry attention. This report also provides AEOD's recommendations for actions to reduce the occurrence of SOV common-mode failures. 115 refs., 7 figs., 2 tabs

  3. Nuclear power plant operation experience - a feedback programme

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  4. Self-assessment on nuclear power plants operational experience feedback process

    International Nuclear Information System (INIS)

    Li Hongtao; Ding Ying

    2005-01-01

    This paper introduces the purpose and function of self-assessment conducted by the responsible organizations of nuclear power plants, and describes the methods and requirements of self-assessment on operational experience feedback process to give a example. (authors)

  5. Operational experience feedback in the World Association of Nuclear Operators (WANO)

    International Nuclear Information System (INIS)

    Revuelta, Ramon

    2004-01-01

    Operators in high-risk industries need to be learning organisations, learning from themselves and from the others. This presentation will describe how the nuclear industry is dealing in an integrated manner with the feedback of operating experience (OE), both internal and external, to increase the safety and reliability of power plants; it will describe how it: - investigates events; - reports events and analyses trends; - shares information to prevent recurrence; - performs corrective action and training; - performs assessments to verify effectiveness. The plants have achieved great improvements in performance overall, and to improve further, the industry is evolving. Instead of just learning from past events (reactive) it is now focusing on lower level indications of problems (precursors) through low level events reporting, trending and analysis. A hallmark of the industry is its desire to be self-critical. Emphasis is placed on improving the bottom quartile performing plants

  6. Operating experience feedback report: Technical specifications: Commercial power reactors

    International Nuclear Information System (INIS)

    O'Reilly, P.D.; Plumlee, G.L. III.

    1989-03-01

    This report documents a trends and patterns analysis of technical specification (TS)-related licensee event reports (LERs) conducted by the Nuclear Regulatory Commission's (NRC's) Office for Analysis and Evaluation of Operational Data (AEOD). The objectives of this analysis were (1) to identify and catalog technical specification-related LERs, (2) to categorize and evaluate the events reported in these a LERs, (3) to identify any issues arising from the evaluation which appear to have generic safety significance, or which relate to the on-going Technical Specification Improvement Program, and (4) to trend the results obtained from the analysis of the data obtained in (1) through (3). 9 refs., 9 figs., 22 tabs

  7. Application of ASSET methodology and operational experience feedback of NPPs in China

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Ziyong [The National Nuclear Safety Administration, Beijing (China)

    1997-10-01

    The introductive presentation of ASSET methodology to China started in March 1992, 3 experts from the IAEA held the ASSET Seminar in Wuhan, China. Three years later, an IAEA seminar on ASSET Method and Operational Experience Feedback proceeded in Beijing on 20-24 March 1995. Another ASSET seminar on Self-Assessment and Operational Experience Feedback was held at Guangdong NPP site on 2-6 December 1996, The NNSA and the GNPP hosted the seminar, 2 IAEA experts, 55 participants from the NPPs, research institutes, the regulatory body (NNSA) and its regional offices attended the seminar. 3 figs, 5 tabs.

  8. Application of ASSET methodology and operational experience feedback of NPPs in China

    International Nuclear Information System (INIS)

    Ziyong Lan

    1997-01-01

    The introductive presentation of ASSET methodology to China started in March 1992, 3 experts from the IAEA held the ASSET Seminar in Wuhan, China. Three years later, an IAEA seminar on ASSET Method and Operational Experience Feedback proceeded in Beijing on 20-24 March 1995. Another ASSET seminar on Self-Assessment and Operational Experience Feedback was held at Guangdong NPP site on 2-6 December 1996, The NNSA and the GNPP hosted the seminar, 2 IAEA experts, 55 participants from the NPPs, research institutes, the regulatory body (NNSA) and its regional offices attended the seminar. 3 figs, 5 tabs

  9. Experience feedback of operation events in Ling'ao phase Ⅱ nuclear power plant

    International Nuclear Information System (INIS)

    Xiao Zhi; Tao Shusheng; Sun Guochen; Zhang Zengqing

    2012-01-01

    As a new operating nuclear power plant, Ling'ao Phase Ⅱ occurred 20 pieces of operational events in one year of first cycle. By analyzing the events in this paper, the causes of the events are mainly concentrated in three aspects: interface between commissioning and operating, DCS system and the management of human factors. Finally, author gives some suggestions on experience feedback, as a reference to other similar nuclear power plants. (authors)

  10. Velocity Feedback Experiments

    Directory of Open Access Journals (Sweden)

    Chiu Choi

    2017-02-01

    Full Text Available Transient response such as ringing in a control system can be reduced or removed by velocity feedback. It is a useful control technique that should be covered in the relevant engineering laboratory courses. We developed velocity feedback experiments using two different low cost technologies, viz., operational amplifiers and microcontrollers. These experiments can be easily integrated into laboratory courses on feedback control systems or microcontroller applications. The intent of developing these experiments was to illustrate the ringing problem and to offer effective, low cost solutions for removing such problem. In this paper the pedagogical approach for these velocity feedback experiments was described. The advantages and disadvantages of the two different implementation of velocity feedback were discussed also.

  11. Experience feedback of an operation event during the experiment of feed-water pump switch

    International Nuclear Information System (INIS)

    Sun Shuhai; Li Huasheng; Zhang Hao

    2012-01-01

    In this paper an event is summarized and analyzed, which caused the quit of the high-pressure heaters and the nuclear power rising, during the experiment of the driven feed-water pump switch. The good experience feedback on this event is brought out through gathering related information of domestic nuclear plants. (authors)

  12. The importance for nuclear safety of efficient feedback of operational experience

    International Nuclear Information System (INIS)

    1987-09-01

    Experience of practical operation is a valuable source of information for improving and optimizing the safety and reliability of nuclear power plants. Therefore it is essential to collect information on abnormal events occurring at plants during operation and on all deviations from normal performance by systems and personnel that could be precursors of accidents. For this purpose it is necessary to establish hierarchical systems to feedback operational safety experience at utility, national and international levels and to make these systems as effective as possible. The present report attempts to identify the safety objectives of these systems, to analyse the difficulties presently encountered and to suggest possible improvements

  13. Feedback of operation and maintenance experience into evolutionary plant design (HWRs)

    International Nuclear Information System (INIS)

    Hedges, K.R.; Sanatkumar, A.; Kwon, Oh-Cheol

    1999-01-01

    The process of feeding back operation and maintenance information into the CANDU plant design process has been in constant evolution since the beginning of the CANDU program. The commissioning and operation experience from the first commercial reactors at Pickering A and Bruce A was used extensively in the design of the first generation CANDU 6 Plants. These units have been in operation for 15 years, producing electricity at an average lifetime capacity factor of about 85%. In further advancing the CANDU 6 and 9 design, greater emphasis is placed on enhancements that can reduce operational costs and further improve plant performance by reducing the planned outage time. The plant design has been improved to facilitate maintenance scheduling, equipment isolation, maintenance and post maintenance testing. Individual tasks have been analyzed as well as the interaction between tasks during outages to reduce the down time required and simplify the execution of the work. This results in shorter outages, reduced radioactive dose and reduced costs. The Utilities have continued to play an important role in CANDU 6 Evolution. Specifically; the Korea Utility KEPCO has one of the original four CANDU 6 Plants and three of the most modem. Their feedback to the designers has been very helpful. One of the most important feedback processes is through the CANDU Owners Group, which provides information exchange between members. In India eight PHWRs of 220 MWe capacity are in operation. Four reactors, also of 220 MWe capacity are in advanced stages of construction. Site construction work of two units of 500 MWe PHWRs at Tarapur will be taken up shortly. Over the years, during construction and operation of these power stations, a large amount of experience has been accumulated. Operation and maintenance experience is shared with operating stations by intensive participation of design engineers in Station Operation Review meetings, trouble shooting and root cause analysis of problems

  14. Life management and operational experience feedback - tools to enhance safety and reliability of the NPP

    International Nuclear Information System (INIS)

    Mach, P.

    1997-01-01

    Preparation has started of the Temelin power plant centralized equipment database. Principles of reliability centered maintenance are studied, and use of these activities will be made in the Plant Ageing Management Programme. The aims of the Programme are as follows: selection of important components subject to ageing, data collection, determination of dominant stressors, development, selection and validation of ageing evaluation methods, setup of experience feedback, determination of responsibilities, methodologies and strategy, elaboration of programme procedures and documentation, and maintenance of programme flexibility. Pilot studies of component ageing are under way: for the reactor pressure vessel, steam generator, pressurizer, piping, ECCS and cables. The organizational structure of the Operational Experience Feedback system is described, as are the responsibility of staff and sources of information. (M.D.)

  15. The continuation training of operators and feedback of operational experience in the Royal Navy's nuclear submarine programme

    International Nuclear Information System (INIS)

    Manson, R.P.

    1983-01-01

    Naval continuation training has relied heavily on the use of realistic simulators for over ten years, and this has been proved to be a cost-effective and efficient method of training. The type of simulator used, the selection and qualification of simulator instructors, and the method of training experienced operators is described. Also, the assessment of operator performance, the use of simulators during the final stages of operator qualification, and their use for training operators on plant operation whilst shut-down are covered. The Navy also pays great attention to the feedback of operating experience from sea into both continuation and basic training. This is accomplished using Incident Reports, which are rendered whenever the plant is operated outside the approved Operating Documentation, or when any other unusual circumstance arises. Each Report is individually assessed and replied to by a qualified operator, and those incidents of more general interest are published in a wider circulation document available to all plant operators. In addition, each crew is given an annual lecture on recent operating experiences. Important lessons are fed forward into new plant design, and the incident reports are also used as a source of information for plant reliability data. (author)

  16. Contributions of the European Operating Experience Feedback Project to Support Regulatory Bodies

    International Nuclear Information System (INIS)

    Heitsch, M.

    2016-01-01

    Operating Experience Feedback (OEF) is one of the ways of improving the nuclear safety of operating nuclear power plants. The EC-Clearinghouse initiative was set up in 2008 to support nuclear regulatory authorities of EU Member States, but also Technical Support Organizations, international organizations and the broader nuclear community, to enhance nuclear safety. The differing regulatory regimes in the EU member countries and a significant diversity of the nuclear power plant (NPP) designs have been a challenge in the establishment of the European Clearinghouse. The European Clearinghouse is organized as a Network operated by a Central Office located at the Institute for Energy and Transport (IET) which is part of Joint Research Centre (JRC) of the European Commission. It gathers 17 European regulatory authorities and 3 major European Technical Support organizations (TSO). The Clearinghouse aims at providing lessons learned, recommendations and best practices from operational experience of NPPs based on support and commitment from the EU nuclear regulatory authorities. One of the objectives of the European Clearinghouse is to establish European best practices for the assessment of unusual events in NPPs. The paper will present the main activities of the European Clearinghouse. These include: • Topical studies providing in-depth assessment of selected topics important for the safe operation of NPPs. Statistical tools help to identify interesting subjects for these studies; • Quarterly reports on operating experience; • Training courses in the field of root cause analysis and event investigation; • Development, maintenance and population of a database for storage of operating experience related information; • Collaboration with international organizations such as IAEA and OECD/NEA on all aspects of OEF. All activities of the Clearinghouse initiative focus on providing an added value for nuclear regulation. (author)

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

    International Nuclear Information System (INIS)

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

    1989-03-01

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

  18. Programmable DSP-based multi-bunch feedback--operational experience from six installations

    International Nuclear Information System (INIS)

    Fox, J.; Prabhakar, S.; Teytelman, D.; Young, A.; Stover, G.; Drago, A.; Serio, M.; Khan, S.; Knuth, T.; Kim, Y.; Park, M.

    2000-01-01

    A longitudinal instability control system, originally developed for the PEP-II, DAΦNE and ALS machines has in the last two years been commissioned for use at the PLS and BESSY-II light sources. All of the installations are running identical hardware and use a common software distribution package. This common structure is beneficial in sharing expertise among the labs, and allows rapid commissioning of each new installation based on well-understood diagnostic and operational techniques. While the installations share the common instability control system, there are significant differences in machine dynamics between the various colliders and light sources. These differences require careful specification of the feedback algorithm and system configuration at each installation to achieve good instability control and useful operational margins. This paper highlights some of the operational experience at each installation, using measurements from each facility to illustrate the challenges unique to each machine. Our experience on the opportunities and headaches of sharing development and operational expertise among labs on three continents is also offered

  19. Experience feedback of operational events of the control rod assembly and its drive mechanism in nuclear power plants

    International Nuclear Information System (INIS)

    Zhou Hong; Xiao Zhi; Tao Shusheng; Zheng Lixin; Chen Zhaolin

    2013-01-01

    Seventeen operational events of the control rod assembly and its drive mechanism are collected from 1992 to 2012 important nuclear operational events and feedback in referred nuclear power plants. After investigated and classified, several important issues, such as the impact of control rod swell and fuel assembly distortion, control rod drive mechanism leakage, and the control system reliability of control rod, are emphatically analyzed. Some suggestions of experience feedback are proposed. (authors)

  20. The role of the regulator in promoting and evaluating safety culture. Operating experience feedback programme approach

    International Nuclear Information System (INIS)

    Perez, S.

    2002-01-01

    Promoting and Evaluating Safety Culture (S.C.) in Operating Organizations must be one of the main Nuclear Regulator goals to achieve. This can be possible only if each and every one of the regulatory activities inherently involves S.C. It can be seen throughout attitudes, values, uses and practices in both individuals and the whole regulatory organization. One among all the regulatory tools commonly used by regulators to promote and evaluate the commitment of the licensees with safety culture as a whole involves organizational factors and particular attention is directed to the operating organization. This entailed a wide range of activities, including all those related with management of safety performance. Operating Experience Feedback Programme as a tool to enhance safety operation is particularly useful for regulators in the evaluation of the role of S.C. in operating organization. Safety Culture is recognized as a subset of the wider Organizational Culture. Practices that improve organizational effectiveness can also contribute to enhance safety. An effective event investigation methodology is a specific practice, which contributes to a healthy Safety Culture. (author)

  1. Feedback of operating experience into development of the advanced pressurized water reactor (APWR)

    International Nuclear Information System (INIS)

    Shimoda, S.; Venne, T. van de.

    1989-01-01

    The APWR development, which was successfully completed in 1987 with complete satisfaction of the design objectives, is one of the good examples of the successful international cooperative development. The successful completion of the development through management could be attributed to the following: Sophisticated implementation of development which consists of clear definition of performance goals, review and feedback of operating experience and consideration for reliable design through such development activities as detailed design evaluation, design reviews and verification by testings. Project organization and contractual arrangement which includes program director, project manager and engineering manager, and introduction of lead party/support party concept. Good oversea communication by means of high speed facsimile machine, electronic mail system and telephone conference, and frequent face-to-face meetings. Good communication with the utility companies at progress status and design decision meetings

  2. China: EDF's feedback experience of reactor operating is essential to win international markets

    International Nuclear Information System (INIS)

    Maillart, H.

    2016-01-01

    The main assets of EDF on the Chinese nuclear power market is first, its very important feedback experience of reactor operations (EDF cumulates one year of reactor operations every week due to its fleet of 58 reactors), secondly the cooperation with China allowed China to enter nuclear energy in 1983 with the construction of the Daya Bay plant and now to develop its own technology: the CPR-1000 reactor. China is the world leader in terms of nuclear market dynamism with 30 reactors in operation, 24 reactors being built and 40 others planned. A new stage in the Franco-China cooperation would be to share relevant good practices in the managing of both French and Chinese fleets of reactors. EDF has upgraded its commercial international offer, it now proposes to cover all the stages of the nuclear power plant from site selection to plant deconstruction via construction, operation, maintenance and waste management which constitutes a commitment over a 100 year period. (A.C.)

  3. Links between operating experience feedback of industrial accidents and nuclear safety

    International Nuclear Information System (INIS)

    Eury, S.P.

    2012-01-01

    Since 1992, the bureau for analysis of industrial risks and pollutions (BARPI) collects, analyzes and publishes information on industrial accidents. The ARIA database lists over 40.000 accidents or incidents, most of which occurred in French classified facilities (ICPE). Events occurring in nuclear facilities are rarely reported in ARIA because they are reported in other databases. This paper describes the process of selection, characterization and review of these accidents, as well as the following consultation with industry trade groups. It is essential to publicize widely the lessons learned from analyzing industrial accidents. To this end, a web site (www.aria.developpement-durable.gouv.fr) gives free access to the accidents summaries, detailed sheets, studies, etc. to professionals and the general public. In addition, the accidents descriptions and characteristics serve as inputs to new regulation projects or risk analyses. Finally, the question of the links between operating experience feedback of industrial accidents and nuclear safety is explored: if the rigorous and well-documented methods of experience feedback in the nuclear field certainly set an example for other activities, nuclear safety can also benefit from inputs coming from the vast diversity of accidents arisen into industrial facilities because of common grounds. Among these common grounds we can find: -) the fuel cycle facilities use many chemicals and chemical processes that are also used by chemical industries; -) the problems resulting from the ageing of equipment affect both heavy and nuclear industries; -) the risk of hydrogen explosion; -) the risk of ammonia, ammonia is a gas used by nuclear power plants as an ingredient in the onsite production of mono-chloramine and ammonia is involved in numerous accidents in the industry: at least 900 entries can be found in the ARIA database. The paper is followed by the slides of the presentation

  4. Requirements and Possibilities for Operational Experience Feedback from the Plant's Manufacturer's Point of View

    International Nuclear Information System (INIS)

    Schimann, P.

    2010-01-01

    corresponding projects. A special aspect concerning this matter is the resulting operational experience feedback related to events in nuclear power plants in operation inland and abroad. Hereby the issue of learning from mistakes made by others is addressed. Therefore improvements can already be implemented in the planning stage of new plants while also defects and failure events in operating plants can be avoided sustainable. Therefore smaller countries or countries that want to build their first nuclear power plant, participate more notably. AREVA carries the operational experience feedback out for both its own product portfolio, in the frame of know-how and know-why transfers and for stipulations with nuclear power plants organized in the VGB PowerTech (Technical Association of power and heat generators). The focus of the following discussion lies on the presentation of the volume and the returns of such a stipulation in daily business.(author).

  5. Recurring events, and the Possible Need to Reinforce Operating Experience Feedback Programs

    International Nuclear Information System (INIS)

    Ross, Denwood

    1999-09-01

    A nuclear power plant is designed for a spectrum of incidents and accidents, ranging from a reactor trip without other complications to more serious events such as pipe ruptures. Certain portions of the plant are designed for even more significant events such as severe accidents. Several thousand reactor years of experience have been recorded and many postulated events have in fact occurred. In some instances the same or similar event has occurred more than once within a single country or among several nations. Such cases are referred to as recurring events. One way to reduce the likelihood, or severity (or both) of recurrence is to maintain and utilize a system for reporting of events, both at the national and the international levels. The international system is referred as the Incident Reporting System. Events to be reported to IRS include: - The event itself is serious or important in terms of safety due to an actual or potential reduction in the plant's defense in depth; - The event reveals important lessons learned that will help the international community to prevent its recurrence as a safety significant event under aggravated conditions or to avoid the occurrence of a serious or important event in terms of safety; - The event is a repetition of a similar event previously reported to IRS, but highlights new important lessons learned for the international community. National systems for reporting of events vary in scope; there is guidance on systems for feedback of experience from events in nuclear power plants. Further, the Nuclear Safety Convention, Article 19 - Operation - provides (section vii) that each Contracting Party shall take the appropriate steps to ensure that 'programmes to collect and analyse operating experience are established, the results obtained and the conclusions drawn are acted upon and that existing mechanisms are used to share important experience with international bodies and with other operating organizations and regulatory bodies

  6. Operating experience feedback report -- turbine-generator overspeed protection systems: Commercial power reactors. Volume 11

    International Nuclear Information System (INIS)

    Ornstein, H.L.

    1995-04-01

    This report presents the results of the US Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) review of operating experience of main turbine-generator overspeed and overspeed protection systems. It includes an indepth examination of the turbine overspeed event which occurred on November 9, 1991, at the Salem Unit 2 Nuclear Power Plant. It also provides information concerning actions taken by other utilities and the turbine manufacturers as a result of the Salem overspeed event. AEOD's study reviewed operating procedures and plant practices. It noted differences between turbine manufacturer designs and recommendations for operations, maintenance, and testing, and also identified significant variations in the manner that individual plants maintain and test their turbine overspeed protection systems. AEOD's study provides insight into the shortcomings in the design, operation, maintenance, testing, and human factors associated with turbine overspeed protection systems. Operating experience indicates that the frequency of turbine overspeed events is higher than previously thought and that the bases for demonstrating compliance with NRC's General Design Criterion (GDC) 4, Environmental and dynamic effects design bases, may be nonconservative with respect to the assumed frequency

  7. PROSPER guidelines: Guidelines for peer review and for plant self-assessment of operational experience feedback process

    International Nuclear Information System (INIS)

    2003-01-01

    Effective use of operational performance information is an important element in any plant operator's arrangements for enhancing the operational safety of a nuclear power plant (NPP). This has been recognized in the IAEA Safety Fundamental, The Safety of Nuclear Installations (Safety Series No. 110). Under the technical aspects of safety, one of the principles of operation and maintenance is that the operating organization and the regulatory body shall establish complementary programmes to analyse operating experience to ensure that lessons are learned and acted upon. Such experience shall be shared with relevant national and international bodies. The Convention on Nuclear Safety, which entered into force in July 1996, also recognized the importance of operational experience feedback as a tool of high importance for the safety of nuclear plant operation and its further enhancement. It follows that the arrangements and results achieved under the operation experience feedback process in Member States will be covered by the national report under the Convention and will be subject to periodical review. These principles are further expanded in the IAEA Safety Standards Safety of Nuclear Power Plants: Operation (Safety Standard Series No. NS-R-2, year 2000) under the Feedback of The IAEA-led Peer Review of the effectiveness of the Operational Safety Performance Experience Review process (PROSPER) and associated guidelines have been developed to provide advice and assistance to utilities or individual power plants to strengthen and enhance the effectiveness of operational experience programmes in achieving these fundamental objectives. The objectives of the former IAEA Assessment of Significant Safety Events Team (ASSET) service have been expanded to include an evaluation of the effective use of all operating performance information available to the plant (e.g. external operating experience, internal low-level and near miss event reports and other relevant operating

  8. Improving the international system for operating experience feedback. INSAG-23. A report by the International Nuclear Safety Group

    International Nuclear Information System (INIS)

    2008-01-01

    The operational safety performance of nuclear facilities has, in general, improved notably over time throughout the world. This has been achieved, in part, through operating experience feedback (OEF) and the introduction of new technology. While the continued strong safety performance by operators is encouraging, safety significant events continue to recur in nuclear installations. This indicates that operators are not learning and applying the lessons that experience can teach us. This report focuses on systems that are operated by intergovernmental organizations with close contacts to national regulatory authorities. These systems provide an alternative network to the worldwide system employed by the operators of nuclear facilities known as the World Association of Nuclear Operators (WANO). The WANO system is restricted to its members, who have concluded that keeping the information exchanged confidential improves its usefulness. INSAG recognizes the merits of this approach, particularly in light of the primary responsibility of licensed operators for the safety of their facilities. Nevertheless, INSAG encourages WANO to share key safety lessons with national regulatory authorities and intergovernmental organization

  9. Report of the peer review mission of national operational safety experience feedback process to the Ukraine 11-15 November 1996 Kiev

    International Nuclear Information System (INIS)

    1996-01-01

    At the invitation of the Nuclear Regulatory Administration of Ukraine (NRA), the IAEA carried out a Peer review mission of national operational safety experience feedback process at Kiev from 11 to 15 November 1996. The objective of this mission was to provide the host country, represented by the regulatory body, with independent and comprehensive review of current status of operational safety experience feedback (OSEF) process with respect to the IAEA's recommendations and international practices. The mission concluded that principal arrangements of operational feedback process in Ukraine are, at present, in force and brought positive results since their introduction. The mission also noted several good practices in these activities. 1 tab

  10. Belgian class II nuclear facilities such as irradiators and accelerators. Regulatory Body attention points and operating experience feedback

    Energy Technology Data Exchange (ETDEWEB)

    Minne, Etienne; Peters, Christelle; Mommaert, Chantal; Kennes, Christian; Cortenbosch, Geert; Schmitz, Frederic; Haesendonck, Michel van [Bel V, Brussels (Belgium); Carlier, Pascal; Schrayen, Virginie; Wertelaers, An [Federal Agency for Nuclear Control, Brussels (Belgium)

    2016-11-15

    The aim of this paper is to present the Regulatory Body attention points and the operating experience feedback from Belgian ''class IIA'' facilities such as industrial and research irradiators, bulk radionuclides producers and conditioners. Reinforcement of the nuclear safety and radiation protection has been promoted by the Federal Agency for Nuclear Control (FANC) since 2009. This paper is clearly a continuation of the former paper [1] presenting the evolution in the regulatory framework relative to the creation of Bel V, the subsidiary of the FANC, and to the new ''class IIA'' covering heavy installations such as those mentioned above. Some lessons learnt are extracted from the operating experience feedback based on the events declared to the authorities. Even though a real willingness to meet the new safety requirements is observed among the ''class IIA'' licensees, promoting the safety culture, the nuclear safety and radiation protection remains an endless challenge for the Regulatory Body.

  11. Operating experience feedback report: Experience with pump seals installed in reactor coolant pumps manufactured by Byron Jackson

    International Nuclear Information System (INIS)

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

    1992-09-01

    This report examines the reactor coolant pump (RCP) seal operating experience through August 1990 at plants with Byron Jackson (B-J) RCPs. ne operating experience examined in this analysis included a review of the practice of continuing operation with a degraded seal. Plants with B-J RCPs that have had relatively good experience with their RCP seals attribute this success to a combination of different factors, including: enhanced seal QA efforts, modified/new seal designs, improved maintenance procedures and training, attention to detail, improved seal operating procedures, knowledgeable personnel involved in seal maintenance and operation, reduction in frequency of transients that stress the seals, seal handling and installation equipment designed to the appropriate precision, and maintenance of a clean seal cooling water system. As more plants have implemented corrective measures such as these, the number of B-J RCP seal failures experienced has tended to decrease. This study included a review of the practice of continued operation with a degraded seal in the case of PWR plants with Byron Jackson reactor coolant pumps. Specific factors were identified which should be addressed in order to safety manage operation of a reactor coolant pump with indications of a degrading seal

  12. Zinc injection on the EDF pressurized light water reactors. Current results and operating experience feedback

    International Nuclear Information System (INIS)

    Piana, Olivier; Duval, Arnaud; Moleiro, Edgar; Benfarah, Moez; Bretelle, Jean-Luc; Chaigne, Guy

    2014-01-01

    Nowadays, zinc injection, as well as pH management and hydrogen control, is increasingly considered as an essential element of PWR Primary Water Chemistry worldwide. After a first implementation of zinc injection at Bugey 2 since 2004 and Bugey 4 since 2006, EDF decided to extend this practice, which constitutes a modification of primary circuit chemical conditioning, to other units of its fleet. Currently, 15 among the 58 reactors of the French fleet are injecting depleted zinc acetate into the primary coolant water. Three main goals were identified at the beginning of this program. Indeed, the expected benefits of zinc injection were: Reduction of the rate of generalized corrosion and mitigation of stress corrosion cracking initiation on nickel based alloys (Material goal). Curative or preventive reduction of radiation sources to which workers are exposed (Radiation fields' goal). Mitigation of the AOA or CIPS risks by reduction of corrosion products releases and mitigation of crud deposition (Fuel protection goal). To monitor the zinc addition, EDF has defined a complete survey program concerning: chemistry and radiochemistry responses (primary coolant monitoring of corrosion and fission products and calculation of zinc injected, zinc removed and zinc incorporated in RCS surfaces) ; radiation fields (dose rates and deposited activities measurements) ; materials (statistical analysis of SG tube cracks) ; fuel (oxide thickness measurements and visual exams) ; effluents (corrosion products releases and isotopic distribution follow up) ; wastes (radiochemical characterization of filters). This paper will detail the present results of this monitoring program. It appears that the expected benefits of zinc injection have yet to be fully realized; further operating experience will be required in order to fully evaluate its impact. (author)

  13. Use of safety experience feedback to design new nuclear units

    International Nuclear Information System (INIS)

    Lange, D.; Crochon, J.P.

    1985-06-01

    For the designer, and about safety, the experience feedback can take place in 3 fields: the operating experience feedback (incidents analysis), the ''study'' experience feedback (improvement of justification and evolution of safety considerations), and the fabrication experience feedback. Some examples are presented for each field [fr

  14. Operating experience feedback report: Assessment of spent fuel cooling. Volume 12

    International Nuclear Information System (INIS)

    Ibarra, J.G.; Jones, W.R.; Lanik, G.F.; Ornstein, H.L.; Pullani, S.V.

    1997-02-01

    This report documents the results of an independent assessment by a team from the Office of Analysis and Evaluation of Operational Data of spent-fuel-pool (SFP) cooling in operating nuclear power plants. The team assessed the likelihood and consequences of an extended loss of SFP cooling and suggested corrective actions, based on their findings

  15. Operating experience feedback report -- Pressure locking and thermal binding of gate valves

    International Nuclear Information System (INIS)

    Hsu, C.

    1993-03-01

    The potential for valve inoperability caused by pressure locking and thermal binding has been known for many years in the nuclear industry. Pressure locking or thermal binding is a common-mode failure mechanism that can prevent a gate valve from opening, and could render redundant trains of safety systems or multiple safety systems inoperable. In spite of numerous generic communications issued in the past by the Nuclear Regulatory Commission (NRC) and industry, pressure locking and thermal binding continues to occur to gate valves installed in safety-related systems of both boding water reactors (BWRs) and pressurized water reactors (PWRs). The generic communications to date have not led to effective industry action to fully identify, evaluate, and correct the problem. This report provides a review of operating events involving these failure mechanisms. As a result of this review this report: (1) identifies conditions when the failure mechanisms have occurred, (2) identifies the spectrum of safety systems that have been subjected to the failure mechanisms, and (3) identifies conditions that may introduce the failure mechanisms under both normal and accident conditions. On the basis of the evaluation of the operating events, the Office for Analysis and Evaluation of Operational Data (AEOD) of the NRC concludes that the binding problems with gate valves are an important safety issue that needs priority NRC and industry attention. This report also provides AEOD's recommendation for actions to effectively prevent the occurrence of valve binding failures

  16. Learning lessons from accidents with a human and organisational factors perspective: deficiencies and failures of operating experience feedback systems

    International Nuclear Information System (INIS)

    Dechy, N.; Rousseau, J.M.; Jeffroy, F.

    2012-01-01

    This paper aims at reminding the failures of operating experience feedback (OEF) systems through the lessons of accidents and provides a framework for improving the efficiency of OEF processes. The risk is for example to miss lessons from other companies and industrial sectors, or to miss the implementation of adequate corrective actions with the risk to repeat accidents. Most of major accidents have been caused by a learning failure or other organisational factors as a contributing cause among several root causes. Some of the recurring organisational factors are: -) poor recognition of critical components, of critical activities or deficiency in anticipation and detection of errors, -) excessive production pressure, -) deficiency of communication or lack of quality of dialogue, -) Excessive formalism, -) organisational complexity, -) learning deficiencies (OEF, closing feedback loops, lack of listening of whistle-blowers). Some major accidents occurred in the nuclear industry. Although the Three Mile Island accident has multiple causes, in particular, an inappropriate design of the man-machine interface, it is a striking example of the loss of external lessons from incidents. As for Fukushima it is too early to have established evidence on learning failures. The systematic study and organisational analysis of OEF failures in industrial accidents whatever their sector has enabled us to provide a framework for OEF improvements. Five key OEF issues to improve in priority: 1) human and organisational factors analysis of the root causes of the events, 2) listening to the field staff, dissenting voices and whistle-blowers, 3) monitoring of the external events that provide generic lessons, 4) building an alive memory through a culture of accidents with people who become experiences pillars, and 5) the setting of external audit or organisational analysis of the OEF system by independent experts. The paper is followed by the slides of the presentation

  17. Operating experience feedback report: Service water system failures and degradations: Volume 3

    International Nuclear Information System (INIS)

    Lam, P.; Leeds, E.

    1988-11-01

    A comprehensive review and evaluation of service water system failures and degradations observed in operating events in light water reactors from 1980 to 1987 has been conducted. The review and evaluation focused on the identification of causes of system failures and degradations, the adequacy of corrective actions implemented and planned, and the safety significance of the operating events. The results of this review and evaluation indicate that the service water system failures and degradations have significant safety implications. These system failures and degradations are attributable to a great variety of causes, and have adverse impact on a large number of safety-related systems and components which are required to mitigate reactor accidents. Specifically, the causes of failures and degradations include various fouling mechanisms (sediment deposition, biofouling, corrosion and erosion, pipe coating failure, calcium carbonate, foreign material and debris intrusion); single failures and other design deficiencies; flooding; multiple equipment failures; personnel and procedural errors; and seismic deficiencies. Systems and components adversely impacted by a service water system failure or degradation include the component cooling water system, emergency diesel generators, emergency core cooling system pumps and heat exchangers, the residual heat removal system, containment spray and fan coolers, control room chillers, and reactor building cooling units. 44 refs., 10 figs., 5 tabs

  18. Feedback of experience as a contribution to safety - an operator's duty

    International Nuclear Information System (INIS)

    Micklinghoff, M.; Pamme, H.; Raetzke, C.

    2007-01-01

    Exchanges of information about events and reliability problems make important contributions to nuclear power plant safety. In an article in the last but one issue of atw, journalist Timm Kraegenow proposed that the operators of nuclear power plants model their attitude towards this subject, and their flows of information, on the example of civil aviation. In particular, vendors should be made the nodes of information exchange. However, in-depth comparison shows that the two areas, civil aviation and nuclear power, have fundamentally different structures. The safety of aircraft designs continues to be the vendor's responsibility throughout the service life of that aircraft, and it is the vendor who holds the type certification. When a deficit becomes apparent, the vendor is the partner to be contacted by the competent authority, and it is the vendor's duty to elaborate solutions. In the case of nuclear power plants, however, responsibility for safety after plant commissioning rests with the operator, i.e. the licensee. The licensee initiates improvements in safety and is also the addressee of instructions by the authorities. This fundamental difference in responsibility for safety is in the nature of things. It is bound to affect also exchanges of information as a module of safety. Although comparison with civil aviation is interesting, it becomes apparent in the end that the way in which flows of information are designed cannot be transferred to the nuclear sector. (orig.)

  19. Operating experience feedback on lose of offsite power supply for nuclear power plant

    International Nuclear Information System (INIS)

    Jiao Feng; Hou Qinmai; Che Shuwei

    2013-01-01

    The function of the service power system of a nuclear power plant is to provide safe and reliable power supply for the nuclear power plant facilities. The safety of nuclear power plant power supply is essential for nuclear safety. The serious accident of Fukushima Daiichi nuclear power plant occurred due to loss of service power and the ultimate heat sink. The service power system has two independent offsite power supplies as working power and auxiliary power. This article collected events of loss of offsite power supply in operating nuclear power plants at home and abroad, and analyzed the plant status and cause of loss of offsite power supply events, and proposed improvement measures for dealing with loss of offsite power supply. (authors)

  20. Design of the control room of the N4-type PWR: main features and feedback operating experience

    International Nuclear Information System (INIS)

    Peyrouton, J.M.; Guillas, J.; Nougaret, Ch.

    2004-01-01

    This article presents the design, specificities and innovating features of the control room of the N4-type PWR. A brief description of control rooms of previous 900 MW and 1300 MW -type PWR allows us to assess the change. The design of the first control room dates back to 1972, at that time 2 considerations were taken into account: first the design has to be similar to that of control rooms for thermal plants because plant operators were satisfied with it and secondly the normal operating situation has to be privileged to the prejudice of accidental situations just as it was in a thermal plant. The turning point was the TMI accident that showed the weight of human factor in accidental situations in terms of pilot team, training, procedures and the ergonomics of the work station. The impact of TMI can be seen in the design of 1300 MW-type PWR. In the beginning of the eighties EDF decided to launch a study for a complete overhaul of the control room concept, the aim was to continue reducing the human factor risk and to provide a better quality of piloting the plant in any situation. The result is the control room of the N4-type PWR. Today the cumulated feedback experience of N4 control rooms represents more than 20 years over a wide range of situations from normal to incidental, a survey shows that the N4 design has fulfilled its aims. (A.C.)

  1. Feedback of operation and maintenance experience into evolutionary LWR designs in the USA

    International Nuclear Information System (INIS)

    Machiels, A.J.; Rumble, E.T.; Mulford, T.J.

    1999-01-01

    US utilities, with extensive support and participation from several international companies, have led an industry-wide effort in close cooperation of the US Department of Energy (DOE), to establish a technical foundation for designing the next generation of light water reactors, referred to as Advanced Light Water Reactors (ALWRs). The cornerstone of this effort is the ALWR Utility Requirements Document (URD). ALWR requirements are driven by utilities, but with broad industry participation, including US nuclear steam supply vendors, as well as engineering service, consulting, architect-engineer, and construction companies. Thus, there is essentially a consensus of the industry as to those features to be sought in the next generation of plants, based on the information and lessons learned from over 35 years of operating over 100 LWRs in the US, and many more internationally. The URD addresses the entire plant, including nuclear steam supply system and balance of plant. The requirements are intended to provide improved, standardized versions of ALWRs, which eliminate most of the issues and inefficiencies associated with some of the existing designs; assure a simpler, more forgiving plant design that is excellent in all respects, including safety, performance, constructability, and economics. The US Nuclear Regulatory Commission (NRC) is directly involved with the URD and has published a Safety Evaluation Report on the requirements for each type of ALWR. Through the NRC review, the URD supports improved stability in the regulatory basis for ALWRs by including agreements on the outstanding licensing and severe accident issues. Looking forward, the URD provides a set of utility technical requirements, which can be used in an ALWR investor bid package for the detailed design, licensing and construction. The resulting bid package will provide a basis for investor confidence in implementing an ALWR. (author)

  2. Learning from experience. Feedback to design

    International Nuclear Information System (INIS)

    Hopwood, J.M.; Shalaby, B.A.; Keil, H.

    1997-01-01

    AECL has been the designer of 25 commercial scale CANDU reactors now in operation, with more under construction. AECL has taken the evolutionary approach in developing its current designs, the CANDU 6 and CANDU 9 Nuclear Power Plants. An integral part of this approach is to emphasize feedback of experience to the designers, in a continuous improvement process. AECL has implemented a formal process of gathering and responding to feedback from: NPP operation, construction and commissioning; regulatory input; R and D results: as well as paying close attention to market input. A number of recent examples of design improvement via this feedback process are described

  3. Learning from experience: feedback to CANDU design

    International Nuclear Information System (INIS)

    Allen, P.J.; Hopwood, J.M.; Rousseau, G.P.

    1998-01-01

    AECL's main product line is based on two single unit CANDU nuclear power plant designs; CANDU 6 and CANDU 9, each of which is based on successfully operating CANDU plants. AECL's CANDU development program is based upon evolutionary improvement. The evolutionary design approach ensures the maximum degree of operational provenness. It also allows successful features of today's plants to be retained while incorporating improvements as they develop to the appropriate level of design maturity. A key component of this evolutionary development is a formal process of gathering and responding to feedback from: NPP operation, construction and commissioning; regulatory input; equipment supplier input; R and D results; market input. The progresses for gathering and implementing the experience feedback and a number of recent examples of design improvements from this feedback process are described in the paper. (author)

  4. Reactor operation feed-back in France

    International Nuclear Information System (INIS)

    Feltin, C.; Fourest, B.; Libmann, J.

    1982-09-01

    The Nuclear Safety Department (DSN), technical support of French Safety Authorities, is, in particular, in charge of the analysis of reactor operation and of measures taken consequently to incidents. It proposed the criteria used to select significant incidents; it analyzes such incidents. DSN also analyzes the operating experience of each plant, several years after starting. It examines foreign incidents to assess in what extent lessons learned can be applied to french reactors. The examples presented show that to improve the safety of units operation, the experience feed-back leads to make arrangements, or modifications concerning not only circuits or materials but often procedures. Moreover they show the importance of procedures concerning the operations carried out during reactor shutdown

  5. Operating experience

    International Nuclear Information System (INIS)

    McRae, L.P.; Six, D.E.

    1991-01-01

    In 1987, Westinghouse Hanford Company began operating a first-generation integrated safeguards system in the Plutonium Finishing Plant storage vaults. This Vault Safety and Inventory System is designed to integrate data into a computer-based nuclear material inventory monitoring system. The system gathers, in real time, measured physical parameters that generate nuclear material inventory status data for thousands of stored items and sends tailored report to the appropriate users. These data include canister temperature an bulge data reported to Plant Operations and Material Control and Accountability personnel, item presence and identification data reported to Material Control and Accountability personnel, and unauthorized item movement data reported to Security response forces and Material Control and Accountability personnel. The Westinghouse Hanford Company's experience and operational benefits in using this system for reduce radiation exposure, increase protection against insider threat, and real-time inventory control are discussed in this paper

  6. Making the Most of the Operating Experience Feedback: Design of a Computerized Data Base Related to NPP Component Behavior

    International Nuclear Information System (INIS)

    Degrave, C.; Martin-Onraet, M.

    1998-01-01

    Electricite de France carries out several analyses on NPP component behavior every year. However, these analyses are conducted separately by specialists of only the kind of component and regardless of the time factor. Seven years ago, a working group from the Nuclear Operation Division completed a detailed examination of component behavior of the 50 NPP then in operation, over a ten-years period (from 1980 to 1990). These analyses have been centered on main components only. Today, another working group will integrate this operating experience in a computerized process to facilitate access to all the information contained in the data base. This system will be based on a site server allowing a user-friendly connection, and updated periodically. (author)

  7. Clad failure detection in G 3 - operational feedback; Detection de rupture de gaines G 3 - experience d'exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Plisson, J [CEA Marcoule, Centre de Production de Plutonium, 30 (France)

    1964-07-01

    After briefly reviewing the role and the principles of clad failure detection, the author describes the working conditions and the conclusions reached after 4 years operation of this installation on the reactor G 3. He mentions also the modifications made to the original installation as well as the tests carried out and the experiments under way. (author) [French] Apres un rappel succinct du role et des principes de la detection de rupture de gaines, l'auteur fait un expose des conditions de fonctionnement et de l'experience tiree de 4 annees d'exploitation de cette installation sur le reacteur G 3. Il signale au passage les modifications apportees a l'installation d'origine, ainsi que les essais effectues, et les experiences en cours.

  8. Feedback analysis of transimpedance operational amplifier circuits

    DEFF Research Database (Denmark)

    Bruun, Erik

    1993-01-01

    The transimpedance or current feedback operational amplifier (CFB op-amp) is reviewed and compared to a conventional voltage mode op-amp using an analysis emphasizing the basic feedback characteristics of the circuit. With this approach the paradox of the constant bandwidth obtained from CFB op...

  9. Feedback of experience and customer benefit

    International Nuclear Information System (INIS)

    Knecht, K.; Purucker, B.

    1993-01-01

    To ensure reliable and economic reactor operation, nuclear power plant operators expect fuel element service to contribute to avoiding product failures. This challenge within the overall fuel element system is met by making full use of the resources inherent in qualified and experienced personnel, comprehensive knowledge of the fuel element technologies of pressurized water and boiling water reactors, and the world-wide feedback of experience into the development of new fuel element designs and their components and the advanced development of existing ones. (orig.) [de

  10. Track 5: safety in engineering, construction, operations, and maintenance. Reactor physics design, validation, and operating experience. 5. A Negative Reactivity Feedback Device for Actinide Burner Cores

    International Nuclear Information System (INIS)

    Driscoll, M.J.; Hejzlar, P.

    2001-01-01

    Lead-bismuth eutectic (LBE) cooled reactors are of considerable interest because they may be useful for destruction of actinides in a cost-effective manner, particularly cores fueled predominantly with minor actinides, which gain reactivity with burnup. However, they also pose several design challenges: 1. a small (and perhaps even slightly positive) Doppler feedback; 2. small effective delayed neutron yield; 3. a small negative feedback from axial fuel expansion; 4. positive coolant void and temperature coefficients for conventional designs. This has motivated a search for palliative measures, leading to conceptualization of the reactivity feedback device (RFD). The RFD consists of an in-core flask containing helium gas, tungsten wool, and a small reservoir of LBE that communicates with vertical tubes housing neutron absorber floats. The upper part of these guide tubes contains helium gas that is vented into a separate, cooler ex-core helium gas plenum. The principle of operation is as follows: 1. The tungsten wool, hence the helium gas in the in-core plenum, is heated by gammas and loses heat to the walls by convection and conduction (radiation is feeble for monatomic gases and, in any event, intercepted by the tungsten wool). An energy balance determines the gas temperature, hence, pressure, which is 10 atm here. The energy loss rate can be adjusted by using xenon or a gas mixture in place of helium. The tungsten wool mass, which is 1 vol% wool here, can also be increased to increase gamma heating and further retard convection; alternatively, a Dewar flask could be used in place of the additional wool. 2. An increase in core power causes a virtually instantaneous increase in gamma flux, hence, gas heatup: The thermal time constant of the tungsten filaments and their surrounding gas film is ∼40 μs. 3. The increased gas temperature is associated with an increased gas pressure, which forces more liquid metal into the float guide tubes: LBE will rise ∼100 cm

  11. Operation of PEP longitudinal feedback system

    International Nuclear Information System (INIS)

    Allen, M.A.; Karvonen, L.G.; McConnell, R.A.; Schwarz, H.

    1981-03-01

    In order to suppress longitudinal coupled-bunch oscillations which might limit the capabilities of PEP, the 18 GeV e + e - storage ring at SLAC, a longitudinal feedback system is utilized. A frequency domain feedback system was chosen with the frequency spectrum of the stored beam being sampled close to a symmetry point in the ring where the feedback cavity itself is also located. The symmetry point chosen is symmetry point 5 which lies half-way between interaction regions 4 and 6. The system has been installed in PEP and is now operational. However, at stored currents up to the maximum stored in PEP to date at 14.5 GeV (approximately 40 mA in 6 bunches), the ring has been stable to all modes of longitudinal coupled-bunch oscillations both barycentric and the other fundamental modes. By deliberately detuning the main accelerating cavities, small multibunch oscillations can be introduced which, in turn, can be damped by the feedback system. Under optimized beam conditions the feedback system could be adjusted to positive feedback and excite oscillations with relatively small power to the feedback cavity. This will be described along with other details of the system

  12. IAEA/NEA incident reporting system (IRS). Reporting guidelines. Feedback from safety related operating experience for nuclear power plants

    International Nuclear Information System (INIS)

    1998-01-01

    The Incident Reporting System (IRS) is an international system jointly operated by the International Atomic Energy Agency (IAEA) and the Nuclear Energy Agency of the Organisation for Economic Cooperation and Development (OECD/NEA). The fundamental objective of the IRS is to contribute to improving the safety of commercial nuclear power plants (NPPs) which are operated worldwide. This objective can be achieved by providing timely and detailed information on both technical and human factors related to events of safety significance which occur at these plants. The purpose of these guidelines, which supersede the previous IAEA Safety Series No. 93 (Part II) and the NEA IRS guidelines, is to describe the system and to give users the necessary background and guidance to enable them to produce IRS reports meeting a high standard of quality while retaining the high efficiency of the system expected by all Member States operating nuclear power plants. These guidelines have been jointly developed and approved by the NEA/IAEA

  13. Operation of the PEP transverse beam feedback

    International Nuclear Information System (INIS)

    Olson, C.W.; Paterson, J.M.; Pellegrin, J.L.; Rees, J.R.

    1981-02-01

    The PEP Storage Ring has been equipped with a wide band beam feedback system capable of damping the vertical and horizontal motion of six bunches. The oscillation detection is done at a symmetry point on the Storage Ring and feedback is applied at the same location one orbital period later. The signal is synchronously gated and the system appears as twelve independent feedback loops, operating on the two coordinates of each of the six bunches. Two beam deflection electrodes are driven each by a low-Q push-pull amplifier which is tuned at the 72nd harmonic of the revolution frequency and suppressed-carrier modulation is generated by a sequence of the detected bunch oscillations. The design parameters are reviewed as well as the salient features of the hardware, and the impact of this system on the machine operation is evaluated in the light of experimental results

  14. PNRA Process for Utilizing Experience Feedback for Enhancing Nuclear Safety

    International Nuclear Information System (INIS)

    Shah, Z.H.

    2016-01-01

    One of the elements essential for any organization to become a learning organization is to learn from its own and others experience. The importance of utilizing experience feedback for enhancing operational safety is highlighted in nuclear industry again and again and this has resulted in establishment of several national and international forums. In addition, IAEA action plan on nuclear safety issued after Fukushima accident further highlighted the importance of experience sharing among nuclear community to enhance global nuclear safety regime. PNRA utilizes operating experience feedback gathered through different sources in order to improve its regulatory processes. During the review of licensing submissions, special emphasis is given to utilize the lessons learnt from experience feedback relating to nuclear industry within and outside the country. This emphasis has gradually resulted in various safety improvements in the facilities and processes. Accordingly, PNRA has developed a systematic process of evaluation of international operating experience feedback with the aim to create safety conscious approach. This process includes collecting information from different international forums such as IAEA, regulatory bodies of other countries and useful feedback of past accidents followed by its screening, evaluation and suggesting recommendations both for PNRA and its licensees. As a result of this process, several improvements concerning regulatory inspection plans of PNRA as well as in regulatory decision making and operational practices of licensees have been highlighted. This paper will present PNRA approach for utilizing experience feedback in its regulatory processes for enhancing / improving nuclear safety. (author)

  15. Experience feedback examination in PWR type reactors operating for the 1997-1999 period; Examen du retour d'experience en exploitation des reacteurs a eau sous pression pour la periode 1997-1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    The present report is relative to the examination that the permanent group has made on the experience feedback in operation for PWR type reactors for the period 1997-1999 that was on eleven themes chosen by the Nuclear Safety and Radiation Protection Authority. It used analysis reports made by I.R.S.N. in support of four meetings of the permanent group devoted to this examination from April 2001 to June 2002. The different themes were operating uncertainties, machining to vibrations, analysis of incidents and gaseous releases, circuits, human factors, behaviour of electric batteries, risk of cold source loss. (N.C.)

  16. Experiments with positive, negative and topical relevance feedback

    NARCIS (Netherlands)

    Kaptein, R.; Kamps, J.; Li, R.; Hiemstra, D.

    2008-01-01

    This document contains a description of experiments for the 2008 Relevance Feedback track. We experiment with different amounts of feedback, including negative relevance feedback. Feedback is implemented using massive weighted query expansion. Parsimonious query expansion using Dirichlet smoothing

  17. Experience feedback from nuclear cogeneration - 15369

    International Nuclear Information System (INIS)

    Auriault, C.; Fuetterer, M.A.; Baudrand, O.

    2015-01-01

    A consortium of 20 companies currently runs the NC2I-R (Nuclear Cogeneration Industrial Initiative - Research) project as part of the European Union's 7. Framework Programme. The project supports the development of an industrial initiative to demonstrate nuclear cogeneration of heat and power as an effective low-carbon technology for industrial market applications. As part of this project, operational feedback was collected from previous, existing and planned nuclear cogeneration projects in a number of countries with the aim of identifying a most complete set of boundary conditions which led to successful projects in the past. Stakeholders consulted include in particular utilities and end users. The scope encompassed technical and non-technical information (organizational structure, financial aspects, public relations, etc.) and specifically experience in licensing gained from these projects. The information was collected by a questionnaire and additional face-to-face interviews. The questionnaire was formulated to cover 9 categories of in total 56 questions for 36 identified projects: Motivation and initiative, Role of key players, Organizational structure, Technical aspects, Safety and licensing, Financial aspects, Timing, Public relations, General experience feedback. From the 36 identified projects worldwide, 23 from 10 countries have provided feedback on a variety of applications such as district heating, seawater desalination, paper and pulp industry, petrochemical industry, coal gasification or salt processing. This is a surprisingly positive response considering that several of these projects date back to the 1980's and many of them were performed outside Europe. This paper summarizes and analyzes the received information and deduces from there which boundary conditions are favorable for the construction of new nuclear cogeneration projects. (authors)

  18. Nuclear training and experience feedback in Sweden

    International Nuclear Information System (INIS)

    Olofsson, B.G.

    1987-01-01

    There are several different ways of educating and training the personnel at the Swedish nuclear power plants: centralized training in full-scale and part-task simulators; centralized education in the form of technical academic courses where computerized teaching is also used; extensive decentralized training out at the nuclear power plants, where compact simulators are also used; and experience feedback forms an important part of the training. Five performance indicators will be identified and the results will be presented. The excellent results are a good indication of the fact that well-executed education and training and smoothly functioning experience feedback give results

  19. Orbit Feedback Operation with RCBX (MD 1209)

    CERN Document Server

    Wenninger, Jorg; Nisbet, David; Ponce, Laurette; Louro Alves, Diogo Miguel; CERN. Geneva. ATS Department

    2017-01-01

    The LHC Orbit Feedback (OFB) is able to drive any orbit corrector circuit (COD) to steer the LHC orbit. But during the first feedback tests in 2010, all attempts to use the common triplet orbit correctors (MCBX) failed because the QPS system installed to protect those magnets triggered power aborts as soon as the OFB steered the beam with those CODs. The reason was most likely the violation of the RCBX circuit acceleration limits. For this reason the MCBX orbit correctors were never driven by the OFB in regular operation. Although the performance of the OFB is generally excellent, the quality of the beam steering around IRs could be improved if the OFB could correct the orbit with the MCBX to counteract locally triplet quadrupole movements. The aim of this MD was to make a new attempt to use the MCBX in the OFB. The test was successful at injection (no circuit trip) and failed during the ramp (QPS power abort). The PC voltages and QPS Ures signals revealed the presence of voltage spikes with a period of 10~s...

  20. Microcontroller-based Feedback Control Laboratory Experiments

    Directory of Open Access Journals (Sweden)

    Chiu Choi

    2014-06-01

    Full Text Available this paper is a result of the implementation of the recommendations on enhancing hands-on experience of control engineering education using single chip, small scale computers such as microcontrollers. A set of microcontroller-based feedback control experiments was developed for the Electrical Engineering curriculum at the University of North Florida. These experiments provided hands-on techniques that students can utilize in the development of complete solutions for a number of servo control problems. Significant effort was devoted to software development of feedback controllers and the associated signal conditioning circuits interfacing between the microcontroller and the physical plant. These experiments have stimulated the interest of our students in control engineering.

  1. Current feedback operational amplifiers and their applications

    CERN Document Server

    Senani, Raj; Singh, A K; Singh, V K

    2013-01-01

    This book describes a variety of current feedback operational amplifier (CFOA) architectures and their applications in analog signal processing/generation. Coverage includes a comprehensive survey of commercially available, off-the-shelf integrated circuit CFOAs, as well as recent advances made on the design of CFOAs, including design innovations for bipolar and CMOS CFOAs.  This book serves as a single-source reference to the topic, as well as a catalog of over 200 application circuits which would be useful not only for students, educators and researchers in apprising them about the recent developments in the area but would also serve as a comprehensive repertoire of useful circuits for practicing engineers who might be interested in choosing an appropriate CFOA-based topology for use in a given application.

  2. Experience feedback of computerized controlled nuclear power plants

    International Nuclear Information System (INIS)

    Poizat, F.

    2004-01-01

    The N4 step of French PWR-type nuclear power plants is characterized by an instrumentation and control system entirely computerized (operation procedures including normal and accidental operation). Four power plants of this type (Chooz and Civaux sites) of 1450 MWe each were connected to the power grid between August 1996 and December 1999. The achievement of this program make it possible and necessary to carry out an experience feedback about the development, successes and difficulties encountered in order to draw out some lessons for future realizations. This is the aim of this article: 1 - usefulness and difficulties of such an experience feedback: evolution of instrumentation and control systems, necessary cautions; 2 - a successful computerized control: checking of systems operation, advantages, expectations; 3 - efficiency of computerized systems: demonstration of operation safety, profitability; 4 - conclusions and interrogations: system approach instead of 'micro-software' approach, commercial or 'made to measure' products, contract agreement with a supplier, when and how upgrading. (J.S.)

  3. Operating Experience at NPP Krsko

    International Nuclear Information System (INIS)

    Kavsek, D.; Bach, B.

    1998-01-01

    Systematic analysis of operational experience by assessment of internal and industry events and the feedback of lessons learned is one of the essential activities in the improvement of the operational safety and reliability of the nuclear power plant. At NPP Krsko we have developed a document called ''Operating Experience Assessment Program''. Its purpose is to establish administrative guidance for the processing of operating events including on-site and industry events. Assessment of internal events is based on the following methods: Event and Causal Factor Charting, Change Analysis, Barrier Analysis, MORT (Management Oversight and Risk Tree Analysis) and Human Performance Evaluation. The operating experience group has developed a sophisticated program entitled ''Operating experience tracking system'' (OETS) in response to the need for a more efficient way of processing internal and industry operating experience information. The Operating Experience Tracking System is used to initiate and track operational events including recommended actions follow up. Six screens of the system contain diverse essential information which allows tracking of operational events and enables different kinds of browsing. OETS is a part of the NPP Krsko nuclear network system and can be easily accessed by all plant personnel. (author)

  4. Design of the control room of the N4-type PWR: main features and feedback operating experience; La salle de commande du palier N4: principales caracteristiques et retour d'experience d'exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Peyrouton, J.M.; Guillas, J.; Nougaret, Ch. [Electricite de France (EDF/DPN/CAPE), 93 - Saint-Denis (France)

    2004-07-01

    This article presents the design, specificities and innovating features of the control room of the N4-type PWR. A brief description of control rooms of previous 900 MW and 1300 MW -type PWR allows us to assess the change. The design of the first control room dates back to 1972, at that time 2 considerations were taken into account: first the design has to be similar to that of control rooms for thermal plants because plant operators were satisfied with it and secondly the normal operating situation has to be privileged to the prejudice of accidental situations just as it was in a thermal plant. The turning point was the TMI accident that showed the weight of human factor in accidental situations in terms of pilot team, training, procedures and the ergonomics of the work station. The impact of TMI can be seen in the design of 1300 MW-type PWR. In the beginning of the eighties EDF decided to launch a study for a complete overhaul of the control room concept, the aim was to continue reducing the human factor risk and to provide a better quality of piloting the plant in any situation. The result is the control room of the N4-type PWR. Today the cumulated feedback experience of N4 control rooms represents more than 20 years over a wide range of situations from normal to incidental, a survey shows that the N4 design has fulfilled its aims. (A.C.)

  5. Operational status of the transverse multibunch feedback system at Diamond

    International Nuclear Information System (INIS)

    Uzun, I.; Abbott, M.; Heron, M.T.; Morgan, A.F.D.; Rehm, G.

    2012-01-01

    A transverse multibunch feedback (TMBF) system is in operation at Diamond Light Source to damp coupled-bunch instabilities up to 250 MHz in both the vertical and horizontal planes. It comprises an in-house designed and built analogue front end combined with a Libera Bunch-by-Bunch feedback processor and output stripline kickers. FPGA-based feedback electronics is used to implement several diagnostic features in addition to the basic feedback functionality. This paper reports on the current operational status of the TMBF system along with its characteristics. Also discussed are operational diagnostic functionalities including continuous measurement of the betatron tune and chromaticity. (authors)

  6. Magnet operating experience review for fusion applications

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1991-11-01

    This report presents a review of magnet operating experiences for normal-conducting and superconducting magnets from fusion, particle accelerator, medical technology, and magnetohydrodynamics research areas. Safety relevant magnet operating experiences are presented to provide feedback on field performance of existing designs and to point out the operational safety concerns. Quantitative estimates of magnet component failure rates and accident event frequencies are also presented, based on field experience and on performance of similar components in other industries

  7. Operating nuclear plant feedback to ASME and French codes

    International Nuclear Information System (INIS)

    Journet, J.; O'Donnell, W.J.

    1996-01-01

    The French have an advantage in nuclear plant operating experience feedback due to the highly centralized nature of their nuclear industry. There is only one utility in charge of design as well as operations (EDF) and only one reactor vendor (Framatome). The ASME Code has played a key role in resolving technical issues in the design and operation of nuclear plants since the inception of nuclear power. The committee structure of the Code brings an ideal combination of senior technical people with both broad and specialized experience to bear on complex how safe is safe enough technical issues. The authors now see an even greater role for the ASME Code in a proposed new regulatory era for the US nuclear industry. The current legalistic confrontational regulatory era has been quite destructive. There now appears to be a real opportunity to begin a new era of technical consensus as the primary means for resolving safety issues. This change can quickly be brought about by having the industry take operating plant problems and regulatory technical issues directly to the ASME Code for timely resolution. Surprisingly, there is no institution in the US nuclear industry with such a mandate. In fact, the industry is organized to feedback through the Nuclear Regulatory Commission issues which could be far better resolved through the ASME Code. Major regulatory benefits can be achieved by closing this loop and providing systematic interaction with the ASME Code. The essential elements of a new regulatory era and ideas for organizing US institutional industry responsibilities, taken from the French experience, are described in this paper

  8. Vibrotactile Feedback for Brain-Computer Interface Operation

    Directory of Open Access Journals (Sweden)

    Febo Cincotti

    2007-01-01

    Full Text Available To be correctly mastered, brain-computer interfaces (BCIs need an uninterrupted flow of feedback to the user. This feedback is usually delivered through the visual channel. Our aim was to explore the benefits of vibrotactile feedback during users' training and control of EEG-based BCI applications. A protocol for delivering vibrotactile feedback, including specific hardware and software arrangements, was specified. In three studies with 33 subjects (including 3 with spinal cord injury, we compared vibrotactile and visual feedback, addressing: (I the feasibility of subjects' training to master their EEG rhythms using tactile feedback; (II the compatibility of this form of feedback in presence of a visual distracter; (III the performance in presence of a complex visual task on the same (visual or different (tactile sensory channel. The stimulation protocol we developed supports a general usage of the tactors; preliminary experimentations. All studies indicated that the vibrotactile channel can function as a valuable feedback modality with reliability comparable to the classical visual feedback. Advantages of using a vibrotactile feedback emerged when the visual channel was highly loaded by a complex task. In all experiments, vibrotactile feedback felt, after some training, more natural for both controls and SCI users.

  9. CANDU operating experience

    International Nuclear Information System (INIS)

    McConnell, L.G.; Woodhead, L.W.; Fanjoy, G.R.; Thurygill, E.W.

    1980-05-01

    The CANDU-PHW program is based upon 38 years of heavy water reactor experience with 35 years of operating experience. Canada has had 72 reactor years of nuclear-electric operations experience with 10 nuclear units in 4 generating stations during a period of 18 years. All objectives have been met with outstanding performance: worker safety, public safety, environmental emissions, reliable electricity production, and low electricity cost. The achievement has been realized through total teamwork involving all scientific disciplines and all project functions (research, design, manufacturing, construction, and operation). (auth)

  10. CANDU operating experience

    International Nuclear Information System (INIS)

    McConnell, L.G.; Woodhead, L.W.; Fanjoy, G.R.

    1982-03-01

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This paper highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components and nuclear safety considerations both to the workers and the public

  11. Design of casks: incorporating operational feedback from maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bimet, F.; Hartenstein, M. [COGEMA Logistics, Saint Quentin (France)

    2004-07-01

    Casks are designed to conform to regulations and to client specifications. Essential areas such as easy operation, low costs of maintenance, low operation and maintenance doses, limited waste, are not explicitly covered. Notwithstanding, COGEMA LOGISTICS uses all feedback available, so that casks are designed to be easy, safe and economical to operate and maintain. Maintenance is an activity where you do spot items that old-time designers could have made better, and things that users should not have done. Thanks to quality assurance, there are a number of data available, waiting to be collected and exploited; they have to be identified, located, retrieved, and analysed. Using information such as wear, damage, use of spare parts, access problems helps to make casks ever better. It leads to more efficient concepts, and to upgrades on existing designs; it also allows to integrate environmental considerations, inter alia in the choice of materials and in maintenance methods. It is necessary for the designer to interact with the users, the cask owners, the maintenance providers, in order to gather all relevant information and events. This is made easier when all these actors are ''under one roof'', or have very close ties. This paper presents COGEMA LOGISTICS methods for collecting and analysing all these experiences waiting to be used. It explains our process for analysing data, preparing yearly reports that are made available to our designers. It describes how each new design is subject to a maintainability study, using this feedback, so that the cask safety is always assured, that radiological doses are kept to a minimum, and that operating and maintenance costs will remain as low as possible.

  12. Design of casks: incorporating operational feedback from maintenance

    International Nuclear Information System (INIS)

    Bimet, F.; Hartenstein, M.

    2004-01-01

    Casks are designed to conform to regulations and to client specifications. Essential areas such as easy operation, low costs of maintenance, low operation and maintenance doses, limited waste, are not explicitly covered. Notwithstanding, COGEMA LOGISTICS uses all feedback available, so that casks are designed to be easy, safe and economical to operate and maintain. Maintenance is an activity where you do spot items that old-time designers could have made better, and things that users should not have done. Thanks to quality assurance, there are a number of data available, waiting to be collected and exploited; they have to be identified, located, retrieved, and analysed. Using information such as wear, damage, use of spare parts, access problems helps to make casks ever better. It leads to more efficient concepts, and to upgrades on existing designs; it also allows to integrate environmental considerations, inter alia in the choice of materials and in maintenance methods. It is necessary for the designer to interact with the users, the cask owners, the maintenance providers, in order to gather all relevant information and events. This is made easier when all these actors are ''under one roof'', or have very close ties. This paper presents COGEMA LOGISTICS methods for collecting and analysing all these experiences waiting to be used. It explains our process for analysing data, preparing yearly reports that are made available to our designers. It describes how each new design is subject to a maintainability study, using this feedback, so that the cask safety is always assured, that radiological doses are kept to a minimum, and that operating and maintenance costs will remain as low as possible

  13. Operating experience with snubbers

    International Nuclear Information System (INIS)

    Levin, H.; Cudlin, R.

    1978-06-01

    Recent operating experience with hydraulic and mechanical snubbers has indicated that there is a need to evaluate current practice in the industry associated with snubber qualification testing programs, design and analysis procedures, selection and specification criteria, and the preservice inspection and inservice surveillance programs. The report provides a summary of operational experiences that represent problems that are generic throughout the industry. Generic Task A-13 is part of the NRC Program for the Resolution of Generic Issues Related to Nuclear Power Plants described in NUREG-0410. The report is based upon a rather large amount of data that have become available in the past four years. These data have been evaluated by the Division of Operating Reactors to develop a data base for use in connection with several NRC activities including Category A, Technical Activity A-13 (Snubbers); the Standard Review Plan; future Regulatory Guides; ASME Code Provisions; and various technical specifications of operating nuclear power plants

  14. Maintenance analysis method and operational feedback: a comprehensive maintenance management

    International Nuclear Information System (INIS)

    Mathieu Riou; Victor Planchon

    2006-01-01

    Full text of publication follows: Current periodic inspections program carried out on the COGEMA LOGISTICS casks is required by regulations and approved by the competent Authority. Thus, Safety and casks conformity to the according certificate of approval are guaranteed. Nonetheless, based on experience it appeared that some maintenance operations did not seem relevant or were redundant. Then, it was decided to rethink completely our maintenance program to reach the following objectives: - Set up the 'a minima' required inspection operations required to guarantee Safety and conformity to the certificate of approval, - Optimize criteria and periodicities of inspections taking into account: operational feedback, routine inspections carried out for each transport, regulations, environmental impact (ALARA, waste reduction,...), cost-effectiveness (reduction of cask's immobilization period,...). - Set up a maintenance program in Safety Analysis Reports that: stands alone (no need to check the specification or the certificate of approval to have the complete list of inspections mandatory to guarantee Safety), gives objectives instead of means of controls. This approach needs then to be re-evaluated by the competent Authority. Study's scope has been limited to the TN TM 12 cask family which is intensely used. COGEMA LOGISTICS has a high operational feedback on these casks. After Authority agreement, and in accordance with its requirements, study will then be extended to the other casks belonging to the COGEMA LOGISTICS cask fleet. Actually, the term 'maintenance' is linked to 'Base maintenance' and 'Main maintenance' and implicitly means that the cask is immobilized for a given period. To emphasize the modifications, the term 'maintenance' is no longer used and is substituted by 'periodic upkeep'. By changing the name, COGEMA LOGISTICS wants to emphasize that: some operations can for instance be realized while the cask is unloaded, periodicities are thought in terms of

  15. Operating experience: safety perspective

    International Nuclear Information System (INIS)

    Piplani, Vivek; Krishnamurthy, P.R.; Kumar, Neeraj; Upadhyay, Devendra

    2015-01-01

    Operating Experience (OE) provides valuable information for improving NPP safety. This may include events, precursors, deviations, deficiencies, problems, new insights to safety, good practices, lessons and corrective actions. As per INSAG-10, an OE program caters as a fundamental means for enhancing the defence-in-depth at NPPs and hence should be viewed as ‘Continuous Safety Performance Improvement Tool’. The ‘Convention on Nuclear Safety’ also recognizes the OE as a tool of high importance for enhancing the NPP safety and its Article 19 mandates each contracting party to establish an effective OE program at operating NPPs. The lessons drawn from major accidents at Three Mile Island, Chernobyl and Fukushima Daiichi NPPs had prompted nuclear stalwarts to change their safety perspective towards NPPs and to frame sound policies on issues like safety culture, severe accident prevention and mitigation. An effective OE program, besides correcting current/potential problems, help in proactively improving the NPP design, operating and maintenance procedures, practices, training, etc., and thus plays vital role in ensuring safe and efficient operation of NPPs. Further it enhances knowledge with regard to equipment operating characteristics, system performance trends and provides data for quantitative and qualitative safety analysis. Besides all above, an OE program inculcates a learning culture in the organisation and thus helps in continuously enhancing the expertise, technical competency and knowledge base of its staff. Nuclear and Radiation Facilities in India are regulated by Atomic Energy Regulatory Board (AERB). Operating Plants Safety Division (OPSD) of AERB is involved in managing operating experience activities. This paper provides insights about the operating experience program of OPSD, AERB (including its on-line data base namely OPSD STAR) and its utilisation in improving the regulations and safety at Indian NPPs/projects. (author)

  16. Experience feedback learned from commissioning and operation of the fully computerized I and C system of the French N4 series

    International Nuclear Information System (INIS)

    Maillart, H.

    1999-01-01

    The I and C system of new N4 series of French Nuclear Power Plant, has a fully computerized multilevel architecture from process to technical management. This I and C system includes a computerized control room, which allows seated operation from compact computerized workstations in the control room in the full range of operation situations. This architecture makes a deep use of diversification and redundancy at each level. A CAD tool ensures management, quality and consistency of the data in the different systems of the architecture. Major companies have participated in this project : FRAMATOME together with SCHNEIDER ELECTRIC (Reactor Protection and Control Systems Vendor) and SEMA GROUP together with BAILEY-SEREG HARTMANN and BRAUN (General Automation and Central Data Processing Systems Vendor). The assessment of project performance and the first months of operation of the N4 I and C system that can be established as of now is completely positive: firstly, it confirms the ability of a fully computerized I and C system to meet the reliability, dependability and operation constraints necessary for the control of a nuclear plant unit, secondly, it confirms the validity of the technical choices made by EDF and its suppliers, lastly, this period of operation allows the validation of the choices made for the organization and architecture of the CAD chain upstream of the system. (author)

  17. ATLAS IBL operational experience

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00237659; The ATLAS collaboration

    2017-01-01

    The Insertable B-Layer (IBL) is the inner most pixel layer in the ATLAS experiment, which was installed at 3.3 cm radius from the beam axis in 2014 to improve the tracking performance. To cope with the high radiation and hit occupancy due to proximity to the interaction point, a new read-out chip and two different silicon sensor technologies (planar and 3D) have been developed for the IBL. After the long shut-down period over 2013 and 2014, the ATLAS experiment started data-taking in May 2015 for Run-2 of the Large Hadron Collider (LHC). The IBL has been operated successfully since the beginning of Run-2 and shows excellent performance with the low dead module fraction, high data-taking efficiency and improved tracking capability. The experience and challenges in the operation of the IBL is described as well as its performance.

  18. Operation feedback of hydrogen filling station

    International Nuclear Information System (INIS)

    Pregassame, S.; Barral, K.; Allidieres, L.; Charbonneau, T.; Lacombe, Y.

    2004-01-01

    One of the technical challenges of hydrogen technology is the development of hydrogen infrastructures which satisfy either safety requirements and reliability of filling processes. AIR LIQUIDE realized an hydrogen filling station in Sassenage (France) operational since September 2003. This station is able to fill 3 buses a day up to 350bar by equilibrium with high pressure buffers. In parallel with commercial stations, the group wanted to create a testing ground in real conditions running with several objectives: validate on a full scale bench a simulation tool able to predict the temperature of both gas and cylinder's materials during filling processes; define the best filling procedures in order to reach mass, temperature and filling time targets; analyse the temperature distribution and evolution inside the cylinder; get a general knowledge about hydrogen stations from safety and reliability point of view; operate the first full scale refuelling station in France. The station is also up-graded for 700bar filling from either a liquid hydrogen source or a gas booster, with cold filling possibility. This paper presents the results concerning 350bar filling : thermal effects, optimal filling procedures and influence of parameters such as climatic conditions are discussed. (author)

  19. Vandellos 1 NPP decommissioning feedback experience

    International Nuclear Information System (INIS)

    Fernandez, Rodriguez A.

    2003-01-01

    The Vandellos 1 Nuclear Power Plant (CNV1) is located on the Mediterranean coast in the province of Tarragona (Spain). The Plant is of the European Natural Uranium Graphite-Gas type. The thermal power of the plant amounts to 1,670 MWt, its electrical output being 500 Mwe. The Plant started-up commercial service in May 1972; its final shutdown, due to a fire in the turbines, occurred in October 1989, after 17 years of operation with an accumulated energy production of 55,647 GWh. The option of decommissioning accepted by the Ministry of Industry, consists of first removing the spent fuel and conditioning the operating radioactive wastes, and then undertaking dismantling of almost all the structures and components located outside the reactor vessel, except those ensuring confinement of the vessel itself and the safety and surveillance of the facility and site. No action will be taken with respect to the vessel, in which the reactor will remain confined without nuclear fuel and with its internal components intact until completion of the waiting (dormancy) period. The site itself will be kept under surveillance during dormancy phase, following partial clearance, the remaining installations being left within the new site perimeter in a situation of monitored confinement. Following the dormancy period, which will last some 30 years, total dismantling of the remaining installations will be undertaken, this implying subsequent complete clearance of the site. The project was started in November of 1992, and the works on site began in 1998. The safe enclosure consists only in the reactor pressure vessel, which will be left on site. The activity content of the vessel is about 100 000 Ci, mostly Co 60. Part of the Stage 2 concept is the total static isolation of this vessel. The vessel has 1 700 penetrations, the pipes of which were cut, seal-welded and inspected. After five years of works in Vandellos 1 NPP decommissioning, ENRESA has an experience and knowledge, that is

  20. FFTF operational experience

    International Nuclear Information System (INIS)

    Newland, D.J.; Krupar, J.J.

    1984-01-01

    In April 1982, the FFTF began its first nominally 100 day irradiation cycle. Since that time the plant has operated very well with steadily increasing plant capacity factors during its first four cycles. One hundred fifty fuel assemblies (eighty of which are experiments) and over 32,000 individual fuel pins have been irradiated, some in excess of 100 MWd/Kg burnup. Specialized equipment and systems unique to sodium cooled reactor plants have performed well

  1. A Feedback Model for Data-Rich Learning Experiences

    Science.gov (United States)

    Pardo, Abelardo

    2018-01-01

    Feedback has been identified as one of the factors with the largest potential for a positive impact in a learning experience. There is a significant body of knowledge studying feedback and providing guidelines for its implementation in learning environments. In parallel, the areas of learning analytics or educational data mining have emerged to…

  2. Data analysis method for plant experience feedback data bank

    International Nuclear Information System (INIS)

    Ployart, R.; Lannoy, A.

    1988-01-01

    French pressurized water reactors (PWRs) represent at the moment about fifty units, among which the oldest have been in operation for ten years. Furthermore, these PWRs developed according to a growth strategy of standardized plants and with a single plant operator are quite homogeneous in their design as well as in their operating and maintenance procedures. Lastly, the improvements brought about are usually passed on to the whole of the concerned standardized plant. In this context, the operating plant experience feedback data banks hold valuable information that starts being statistically significant. The reliability oriented methods are rather well known; the ones that enable to read out some information on performance and availability, susceptible to guide the plant operator in the decision making are less tested. It concerns changes of operating or maintenance procedure, or technical changes which could be decided from an assessment of the effects of previous changes, or by observing and explaining a posteriori natural evolutions in the behaviour of components. The method used within the framework of this report leads to reveal and explain singularities, correlations, regroupings and trends in the behaviour of the french PWRs

  3. Operating experience in reprocessing

    International Nuclear Information System (INIS)

    Schueller, W.

    1983-01-01

    Since 1953, reprocessing has accumulated 180 years of operating experience in ten plants, six of them with 41 years of operation in reprocessing oxide fuel from light water reactors. After abortive, premature attempts at what is called commercial reprocessing, which had been oriented towards the market value of recoverable uranium and plutonium, non-military reprocessing technologies have proved their technical feasibility, since 1966 on a pilot scale and since 1976 on an industrial scale. Reprocessing experience obtained on uranium metal fuel with low and medium burnups can now certainly be extrapolated to oxide fuel with high burnup and from pilot plants to industrial scale plants using the same technologies. The perspectives of waste management of the nuclear power plants operated in the Federal Republic of Germany should be viewed realistically. The technical problems still to be solved are in a balanced relationship to the benefit arising to the national economy out of nuclear power generation and can be solved in time, provided there are clearcut political boundary conditions. (orig.) [de

  4. GNF2 Operating Experience

    International Nuclear Information System (INIS)

    Schardt, John

    2007-01-01

    GNF's latest generation fuel product, GNF2, is designed to deliver improved nuclear efficiency, higher bundle and cycle energy capability, and more operational flexibility. But along with high performance, our customers face a growing need for absolute fuel reliability. This is driven by a general sense in the industry that LWR fuel reliability has plateaued. Too many plants are operating with fuel leakers, and the impact on plant operations and operator focus is unacceptable. The industry has responded by implementing an INPO-coordinated program aimed at achieving leaker-free reliability by 2010. One focus area of the program is the relationship between fuel performance (i.e., duty) and reliability. The industry recognizes that the right balance between performance and problem-free fuel reliability is critical. In the development of GNF2, GNF understood the requirement for a balanced solution and utilized a product development and introduction strategy that specifically addressed reliability: evolutionary design features supported by an extensive experience base; thoroughly tested components; and defense-in-depth mitigation of all identified failure mechanisms. The final proof test that the balance has been achieved is the application of the design, initially through lead use assemblies (LUAs), in a variety of plants that reflect the diversity of the BWR fleet. Regular detailed surveillance of these bundles provides the verification that the proper balance between performance and reliability has been achieved. GNF currently has GNF2 lead use assemblies operating in five plants. Included are plants that have implemented extended power up-rates, plants on one and two-year operating cycles, and plants with and without NobleChem TM and zinc injection. The leading plant has undergone three pool-side inspections outages to date. This paper reviews the actions taken to insure GNF2's reliability, and the lead use assembly surveillance data accumulated to date to validate

  5. CANDU 9 Design improvements based on experience feedback

    International Nuclear Information System (INIS)

    Yu, S. K. W.; Bonechi, M.; Snell, V. G.

    2000-01-01

    An evolutionary approach utilizing advance technologies has been implenented for the enhancement introduced in the CANDU 9 Nuclear Power Plant (NPP) design. The design of these systems and associated equipment has also benfited from experience feedback from operating CANDU stations and from including advanced products from CANDU engineering and research programs. This paper highlights the design features that contribute to the safety improvements of the CANDU 9 design, summarizes the analysis results which demonstrate the improved performance and also emphasizes design features which reduce operation and maintenance (Q and M) costs. The safety design features highlighted include the increased use of passive devices and heat sinks to achieve extensive system simplification; this also improves reliability and reduces maintenance workloads. System features that contribute to improved operability are also described. The CANDU 9 Control Center provides plant staff with enhanced operating, maintenance and diagnostics features which significantly improve operability, testing and maintainability due to the integration of human factors engineering with a systematic design process. (author)

  6. Vandellos 1 NPP decommissioning feedback experience

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Rodriguez A. [Empresa Nacional de Residuos Radioactivos, ENPRESA, Madrid (Spain)

    2003-07-01

    The Vandellos 1 Nuclear Power Plant (CNV1) is located on the Mediterranean coast in the province of Tarragona (Spain). The Plant is of the European Natural Uranium Graphite-Gas type. The thermal power of the plant amounts to 1,670 MWt, its electrical output being 500 Mwe. The Plant started-up commercial service in May 1972; its final shutdown, due to a fire in the turbines, occurred in October 1989, after 17 years of operation with an accumulated energy production of 55,647 GWh. The option of decommissioning accepted by the Ministry of Industry, consists of first removing the spent fuel and conditioning the operating radioactive wastes, and then undertaking dismantling of almost all the structures and components located outside the reactor vessel, except those ensuring confinement of the vessel itself and the safety and surveillance of the facility and site. No action will be taken with respect to the vessel, in which the reactor will remain confined without nuclear fuel and with its internal components intact until completion of the waiting (dormancy) period. The site itself will be kept under surveillance during dormancy phase, following partial clearance, the remaining installations being left within the new site perimeter in a situation of monitored confinement. Following the dormancy period, which will last some 30 years, total dismantling of the remaining installations will be undertaken, this implying subsequent complete clearance of the site. The project was started in November of 1992, and the works on site began in 1998. The safe enclosure consists only in the reactor pressure vessel, which will be left on site. The activity content of the vessel is about 100 000 Ci, mostly Co 60. Part of the Stage 2 concept is the total static isolation of this vessel. The vessel has 1 700 penetrations, the pipes of which were cut, seal-welded and inspected. After five years of works in Vandellos 1 NPP decommissioning, ENRESA has an experience and knowledge, that is

  7. Feedback stabilization experiments using l = 2 equilibrium windings in Scyllac

    International Nuclear Information System (INIS)

    Bartsch, R.R.; Cantrell, E.L.; Gribble, R.F.; Freese, K.B.; Handy, L.E.; Kristal, R.; Miller, G.; Quinn, W.E.

    1977-01-01

    The confinement time in the Scyllac Sector Feedback Experiment has been extended with a pre-programmed equilibrium compensation force. This force was produced by driving a current with a flexible waveform in an additional set of l = 2 windings

  8. Contribution of operating feedback to probabilistic safety studies

    International Nuclear Information System (INIS)

    Guio, J.M. de; Lannoy, A.

    1992-03-01

    This paper presents the method used for PWR unit operation feedback analysis and its contribution to probabilistic safety studies. The targets were as follows: - use of failure data banks to assess reliability parameters, - use of event data banks to identify and quantify main system initiating events, - determination of a standard operating profile. These studies, performed in the context of nuclear power plant safety programs, prove useful not only to safety engineers but also to equipment experts, designers, operators and maintenance specialists. They constitute basic data for studies in all these areas or the departure point for new investigations. (authors). 3 figs., 3 tabs., 3 refs

  9. Operating experience at CEBAF

    International Nuclear Information System (INIS)

    Legg, R.

    1996-01-01

    CEBAF, the Continuous Electron Beam Accelerator Facility, is a 5-pass, recirculating, superconducting rf linac designed to provide exceptional beam quality at 4 GeV up to 200 μA CW. It is made up of an injector, two 400-MeV linacs, and 9 recirculation arcs having a total beamline length of more than 4.5 km. On Nov. 5, 1995, CEBAF delivered a 4 GeV, 25-μA CW electron beam to the first of 3 experimental halls and the experimental physics program was started 10 days later. Accelerator availability during the first month of the experimental run exceeded 75%. Beam properties measured in the experimental hall to date are a one sigma momentum spread of 5x10 -5 and an rms emittance of 0.2 nanometer-radians, better than design specification. CW beam has been provided from all 5 passes at 800 MeV intervals. Outstanding performance of the superconducting linacs suggests a machine energy upgrade to 6 GeV in the near term with eventual machine operation at 8-10 GeV. Results from commissioning and operations experience since the last conference are presented

  10. Plasma experiments on staged theta pinch, implosion heating experiment and Scyllac feedback-sector experiment

    International Nuclear Information System (INIS)

    Bartsch, R.R.; Buchenauer, C.J.; Cantrell, E.L.

    1977-01-01

    Results of the Los Alamos theta-pinch program in three areas of investigation are summarized: 1) In the Staged Theta Pinch, results are reported on the effects of magnetic field amplitude and time history of plasma formation. 2) In the Implosion Heating Experiment, density, internal-magnetic field and neutron measurements yield a consistent picture of the implosion which agrees with kinetic computations and with a simple dynamic model of the ions and magnetic piston. 3) In the Scyllac Feedback-Sector Experiment, the l=1, 0 equilibrium plasma parameters have been adjusted to accommodate the feedback stabilization system. With a uniform toroidal discharge tube the m=1 instability is feedback-stabilized in the vertical direction, and confinement in the toroidal direction is extended by feedback control. Results with a helical discharge tube are also reported. (author)

  11. Understanding Arts and Humanities Students' Experiences of Assessment and Feedback

    Science.gov (United States)

    Adams, Joelle; McNab, Nicole

    2013-01-01

    This article examines how undergraduate students on arts and humanities courses experience assessment and feedback. The research uses a detailed audit, a specially devised questionnaire (the Assessment Experience Questionnaire), and student focus group data, and the article examines results from 19 programmes, comparing those from "arts and…

  12. Feedback-Assisted Extension of the Tokamak Operating Space to Low Safety Factor

    Science.gov (United States)

    Hanson, J. M.

    2013-10-01

    Recent DIII-D experiments have demonstrated stable operation at very low edge safety factor, q95 instability. The performance of tokamak fusion devices may benefit from increased plasma current, and thus, decreased q. However, disruptive stability limits are commonly encountered in experiments at qedge ~ 2 (limited plasmas) and q95 ~ 2 (diverted plasmas), limiting exploration of low q regimes. In the recent DIII-D experiments, the impact and control of key disruptive instabilities was studied. Locked n = 1 modes with exponential growth times on the order of the wall eddy current decay timescale τw preceded disruptions at q95 = 2 . The instabilities have a poloidal structure that is consistent with VALEN simulations of the RWM mode structure at q95 = 2 . Applying proportional gain magnetic feedback control of the n = 1 mode resulted in stabilized operation with q95 reaching 1.9, and an extension of the discharge lifetime for > 100τw . Loss of feedback control was accompanied by power supply saturation, followed by a rapidly growing n = 1 mode and disruption. Comparisons of the feedback dynamics with VALEN simulations will be presented. The DIII-D results complement and will be discussed alongside recent RFX-MOD demonstrations of RWM control using magnetic feedback in limited tokamak discharges with qedge economical fusion power production. Supported by the US Department of Energy under DE-FG02-04ER54761 and DE-FC02-04ER54698.

  13. Tevatron operational experiences

    International Nuclear Information System (INIS)

    Norris, B.L.; Theilacker, J.C.

    1989-02-01

    Fermilabs superconducting accelerator, the Tevatron has been operational for nearly six years. The history of its operation is presented. Several long shutdowns for superconducting dipole repairs are discussed. The dominant factor influencing the repair was conductor motion which fatigued the cable in the magnet ends. Borescoping and x-raying techniques were used to determine which magnet ends required repair. Detailed downtime logs were kept for each of the running periods. A discussion of the sources of downtime and a comparison for different operating modes is presented

  14. Land-Atmosphere Feedback Experiment (LAFE) Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    Wulfmeyer, Volker [University of Hohenheim; Turner, David [NOAA National Severe Storms Laboratory

    2016-07-01

    lower troposphere, including the interfacial layer of the CBL. The optimal azimuth is to the ENE of the SGP central facility, which takes advantage of both changes in the surface elevation and different crop types planted along that path. 3) The University of Wisconsin Space Science and Engineering Center Portable Atmospheric Research Center (SPARC) and the University of Oklahoma Collaborative Lower Atmospheric Mobile Profiling System (CLAMPS) operating two vertically pointing atmospheric emitted radiance interferometers (AERIs) and two Doppler lidar (DL) systems scanning cross track to the central RHI for determining the surface friction velocity and the horizontal variability of temperature, moisture, and wind. Thus, both the variability of surface fluxes and CBL dynamics and thermodynamics over the SGP site will be studied for the first time. The combination of these three components will enable us to estimate both the divergence of the latent heat profile and the advection of moisture. Thus, the moisture budget in the SGP domain can be studied. Furthermore, the simultaneous measurements of surface and entrainment fluxes as well as the daily cycle of the CBL thermodynamic state will provide a unique data set for characterizing LSA interaction in dependence of large-scale and local conditions such as soil moisture and the state of the vegetation. The measurements will also be applied for the development of improved parameterizations of surface fluxes and turbulence in the CBL. The latter is possible because mean profiles, gradients, higher-order moments, and fluxes are measured simultaneously. The results will be used for the verification of simulations of LSA feedback in large-eddy simulation (LES) and mesoscale models, which are planned for the SGP site. Due to the strong connection between the pre-convective state of the CBL and the formation of clouds and precipitation, this new generation of experiments will strongly contribute to the improvement of their

  15. Moderator purification and design modifications based on operation feedback

    Energy Technology Data Exchange (ETDEWEB)

    Das, S; Chakrabarti, A K; Shirolkar, K M; Sharma, V K [Nuclear Power Corporation, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    Heavy water is used as a moderator in the Pressurized Heavy Water Reactors using natural uranium as a fissile fuel. The purification system is provided to maintain the purity of moderator heavy water so as to minimise the radiolytic decomposition of heavy water due to nuclear radiation which otherwise would lead to hazardous concentration of deuterium in the moderator cover gas. The presence of dissolved impurity in the moderator increases the radiolysis rate by impeding the reverse reaction and hence these must be removed. The purification system in general controls the chemistry of moderator by minimizing the corrosion of piping in the circuit and along with the liquid poison injection system adjusts the concentration of the poisons in the moderator. This paper describes the evolution of the purification system for the 500 MWe PHWRs based on various operating requirements and feedback from the operating stations. (author). 2 refs., 3 figs., 1 tab.

  16. Moderator purification and design modifications based on operation feedback

    International Nuclear Information System (INIS)

    Das, S.; Chakrabarti, A.K.; Shirolkar, K.M.; Sharma, V.K.

    1994-01-01

    Heavy water is used as a moderator in the Pressurized Heavy Water Reactors using natural uranium as a fissile fuel. The purification system is provided to maintain the purity of moderator heavy water so as to minimise the radiolytic decomposition of heavy water due to nuclear radiation which otherwise would lead to hazardous concentration of deuterium in the moderator cover gas. The presence of dissolved impurity in the moderator increases the radiolysis rate by impeding the reverse reaction and hence these must be removed. The purification system in general controls the chemistry of moderator by minimizing the corrosion of piping in the circuit and along with the liquid poison injection system adjusts the concentration of the poisons in the moderator. This paper describes the evolution of the purification system for the 500 MWe PHWRs based on various operating requirements and feedback from the operating stations. (author)

  17. TRIGA reactor operating experience

    International Nuclear Information System (INIS)

    Anderson, T.V.

    1970-01-01

    The Oregon State TRIGA Reactor (OSTR) has been in operation 3 years. Last August it was upgraded from 250 kW to 1000 kW. This was accomplished with little difficulty. During the 3 years of operation no major problems have been experienced. Most of the problems have been minor in nature and easily corrected. They came from lazy susan (dry bearing), Westronics Recorder (dead spots in the range), The Reg Rod Magnet Lead-in Circuit (a new type lead-in wire that does not require the lead-in cord to coil during rod withdrawal hss been delivered, much better than the original) and other small corrections

  18. Stabilizing operation point technique based on the tunable distributed feedback laser for interferometric sensors

    Science.gov (United States)

    Mao, Xuefeng; Zhou, Xinlei; Yu, Qingxu

    2016-02-01

    We describe a stabilizing operation point technique based on the tunable Distributed Feedback (DFB) laser for quadrature demodulation of interferometric sensors. By introducing automatic lock quadrature point and wavelength periodically tuning compensation into an interferometric system, the operation point of interferometric system is stabilized when the system suffers various environmental perturbations. To demonstrate the feasibility of this stabilizing operation point technique, experiments have been performed using a tunable-DFB-laser as light source to interrogate an extrinsic Fabry-Perot interferometric vibration sensor and a diaphragm-based acoustic sensor. Experimental results show that good tracing of Q-point was effectively realized.

  19. Trust and automation: the influence of automation malfunctions and system feedback on operator trust

    International Nuclear Information System (INIS)

    Strand, Stine

    2001-10-01

    Level of operator trust in an automatic system, which is not in accordance with the reliability of the system, might impose serious threats concerning issues of safety, productivity and the well being of the operator. Operator trust is therefore regarded as an important variable in man-machine interaction. The focus of this study was the influence of automatic malfunctions and amount of feedback provided by the automatic system on level of operator trust. The study was conducted in conjunction with the Human Centred Automation 2000-experiment. Two questionnaires attempting to measure operator trust were developed, designed to reflect the dimensions of predictability, dependability and faith. Analysis of the questionnaires demonstrated that they were reliable tools for measurement of operator trust. Factor analysis did not completely confirm the theoretical dimensions of trust, but indicated partial support. Operator trust correlated negatively with workload across situations, and positively with performance in complex situations. The results of the hypotheses tests demonstrated that operator trust gradually decreased after introduction of malfunctions. The effect of different malfunctions was however the opposite of what was expected, with obvious malfunctions reducing trust more than more camouflaged and safety critical malfunctions. Trust in the automatic system in general was lower than trust in specific malfunctioning components. Different interfaces providing different amount of feedback to the operator did not significantly influence level of operator trust. (Author)

  20. Enhanced operator perception through 3D vision and haptic feedback

    Science.gov (United States)

    Edmondson, Richard; Light, Kenneth; Bodenhamer, Andrew; Bosscher, Paul; Wilkinson, Loren

    2012-06-01

    Polaris Sensor Technologies (PST) has developed a stereo vision upgrade kit for TALON® robot systems comprised of a replacement gripper camera and a replacement mast zoom camera on the robot, and a replacement display in the Operator Control Unit (OCU). Harris Corporation has developed a haptic manipulation upgrade for TALON® robot systems comprised of a replacement arm and gripper and an OCU that provides haptic (force) feedback. PST and Harris have recently collaborated to integrate the 3D vision system with the haptic manipulation system. In multiple studies done at Fort Leonard Wood, Missouri it has been shown that 3D vision and haptics provide more intuitive perception of complicated scenery and improved robot arm control, allowing for improved mission performance and the potential for reduced time on target. This paper discusses the potential benefits of these enhancements to robotic systems used for the domestic homeland security mission.

  1. Transverse feedback: high intensity operation, AGC, IGC, lessons for 2012

    CERN Document Server

    Höfle, W

    2012-01-01

    The transverse damper system (ADT) plays an important role in the preservation of the beam transverse emittance and for damping of oscillations driven by the coupled bunch instability. An overview of the ADT system will be presented with an emphasis on the important feedback loop parameters as they change from injection through the ramp into collision. The dedicated setting - up procedure required for the different bunch intensities and bunch spacings will be explained. During the 2011 run the injection and abort gap cleaning became operational at injection energy. Preparations for cleaning at 3.5 TeV as well as batch selective transverse blow - up were completed and preliminarily tested. Plans for 2012 include study and potential improvement of the system impulse response to improve the 'selectivity' of the cleaning and blow - up facility. The ADT also provides bunch - by - bunch observation, which was extensively used during the run and MDs, and will be further upgraded during the next year.

  2. Vibrotactile Feedback for Brain-Computer Interface Operation

    OpenAIRE

    Cincotti, Febo; Kauhanen, Laura; Aloise, Fabio; Palomäki, Tapio; Caporusso, Nicholas; Jylänki, Pasi; Mattia, Donatella; Babiloni, Fabio; Vanacker, Gerolf; Nuttin, Marnix; Marciani, Maria Grazia; Millán, José del R.

    2007-01-01

    To be correctly mastered, brain-computer interfaces (BCIs) need an uninterrupted flow of feedback to the user. This feedback is usually delivered through the visual channel. Our aim was to explore the benefits of vibrotactile feedback during users' training and control of EEG-based BCI applications. A protocol for delivering vibrotactile feedback, including specific hardware and software arrangements, was specified. In three studies with 33 subjects (i...

  3. NPD Operating Experience

    Energy Technology Data Exchange (ETDEWEB)

    Horton, E. P. [Hydro-Electric Power Commission of Ontario, Rolphton, ON (Canada)

    1968-04-15

    NPD has demonstrated high-capacity factor operation and for the past three years has achieved an average net capacity factor of 98% for the ''winter-peak'' period. The net capacity factor for the year 1966 was 88% and for the period from the end of commissioning (October 1962) to the end of 1966 was 71%. The output of the station has been stretched from 22 MW(e) gross to 25 MW(e) gross. This was aided by the installation of an internal steam separator in the turbine but no basic modifications to the reactor-boiler systems were required. The turbine has also been modified by the installation of chrome steel diaphragms as a solution to an erosion problem. The station also continues as a test facility to develop new components and techniques. This includes the recent successful replacement of two reactor pressure tubes and the conversion of the reactor vault ventilation system to a ''dry'' atmosphere using a molecular sieve to collect heavy-water leakage and control the concentration of acidic oxides of nitrogen. Fuel performance has been excellent and the average burn-up in the core is now 84 MWh/kg U which is slightly above the equilibrium design value. Only three fuel bundles have been found with sheath failures and none of these was due to a deficiency in the fuel but was as a result of handling problems with the refuelling equipment. In spite of undesirably high maintenance time, the fuelling machines have now inserted over 1000 fuel bundles into the reactor ''on power''. Heavy-water loss rates have been acceptable and are improving. The average loss rate from leaks during 1966 was 210 g/h. A proposal to modify the NPD heavy-water heat transport system to allow boiling is under consideration. (author)

  4. Project and feedback experience on nuclear facility decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Santiago, J.L. [ENRESA (Spain); Benest, T.G. [United Kingdom Atomic Energy Authority, Windscale, Cumbria (United Kingdom); Tardy, F.; Lefevre, Ph. [Electricite de France (EDF/CIDEN), 69 - Villeurbanne (France); Willis, A. [VT Nuclear Services (United Kingdom); Gilis, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R. [Belgoprocess (Belgium); Jeanjacques, M. [CEA Saclay, 91 - Gif sur Yvette (France); Bohar, M.P.; Bremond, M.P.; Poyau, C.; Mandard, L.; Boissonneau, J.F.; Fouquereau, A.; Pichereau, E.; Binet, C. [CEA Fontenay aux Roses, 92 (France); Fontana, Ph.; Fraize, G. [CEA Marcoule 30 (France); Seurat, Ph. [AREVA NC, 75 - Paris (France); Chesnokov, A.V.; Fadin, S.Y.; Ivanov, O.P.; Kolyadin, V.I.; Lemus, A.V.; Pavlenko, V.I.; Semenov, S.G.; Shisha, A.D.; Volkov, V.G.; Zverkov, Y.A. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    2008-11-15

    This series of 6 short articles presents the feedback experience that has been drawn from various nuclear facility dismantling and presents 3 decommissioning projects: first, the WAGR project that is the UK demonstration project for power reactor decommissioning (a review of the tools used to dismantle the reactor core); secondly, the dismantling project of the Bugey-1 UNGG reactor for which the dismantling works of the reactor internals is planned to be done underwater; and thirdly, the decommissioning project of the MR reactor in the Kurchatov Institute. The feedback experience described concerns nuclear facilities in Spain (Vandellos-1 and the CIEMAT research center), in Belgium (the Eurochemic reprocessing plant), and in France (the decommissioning of nuclear premises inside the Fontenay-aux-roses Cea center and the decommissioning of the UP1 spent fuel reprocessing plant at the Marcoule site). (A.C.)

  5. Project and feedback experience on nuclear facility decommissioning

    International Nuclear Information System (INIS)

    Santiago, J.L.; Benest, T.G.; Tardy, F.; Lefevre, Ph.; Willis, A.; Gilis, R.; Lewandowski, P.; Ooms, B.; Reusen, N.; Van Laer, W.; Walthery, R.; Jeanjacques, M.; Bohar, M.P.; Bremond, M.P.; Poyau, C.; Mandard, L.; Boissonneau, J.F.; Fouquereau, A.; Pichereau, E.; Binet, C.; Fontana, Ph.; Fraize, G.; Seurat, Ph.; Chesnokov, A.V.; Fadin, S.Y.; Ivanov, O.P.; Kolyadin, V.I.; Lemus, A.V.; Pavlenko, V.I.; Semenov, S.G.; Shisha, A.D.; Volkov, V.G.; Zverkov, Y.A.

    2008-01-01

    This series of 6 short articles presents the feedback experience that has been drawn from various nuclear facility dismantling and presents 3 decommissioning projects: first, the WAGR project that is the UK demonstration project for power reactor decommissioning (a review of the tools used to dismantle the reactor core); secondly, the dismantling project of the Bugey-1 UNGG reactor for which the dismantling works of the reactor internals is planned to be done underwater; and thirdly, the decommissioning project of the MR reactor in the Kurchatov Institute. The feedback experience described concerns nuclear facilities in Spain (Vandellos-1 and the CIEMAT research center), in Belgium (the Eurochemic reprocessing plant), and in France (the decommissioning of nuclear premises inside the Fontenay-aux-roses Cea center and the decommissioning of the UP1 spent fuel reprocessing plant at the Marcoule site). (A.C.)

  6. Operation of the transverse feedback system at the CERN SPS

    International Nuclear Information System (INIS)

    Bossart, R.; Louwerse, R.; Mourier, J.; Vos, L.

    1987-01-01

    To prevent transverse instabilities at high beam intensity in the SPS, the transverse feedback system for damping the betatron oscillations has been upgraded for larger damping decrements and for increased system's bandwidth. The feedback loop now contains a digital delay line cancellor, so that the damper works with a velocity feedback Δx/Δt, unaffected by the closed orbit position x at the pick-up station. The digital processing of the feedback signal facilitates nonlinear feedback techniques such as antidamping and ''band-bang'' feedback. The ''bang-bang'' feedback provides the maximum possible damping rate of the injection oscillations in the SPS-collider, in order to minimize the emittance increase caused by filamentation. The antidamping nonlinearity provides small continuous beam oscillations of 50 μm amplitude for tracking the machine tune Q with a phase locked loop

  7. Feedback from practical experience with large sodium fire accidents

    International Nuclear Information System (INIS)

    Luster, V.P.; Freudenstein, K.F.

    1996-01-01

    The paper reviews the important feedback from the practical experience from two large sodium fires; the first at ALMERIA in Spain and the second in the Na laboratories at Bensberg, Germany. One of the most important sodium fire accidents was the ALMERIA spray fire accident. The origin of this accident was the repair of a valve when about 14 t of sodium was spilled in the plant room over a period of 1/2 hour. The event has been reported (IAEA/IWGFR meeting in 1988) and this presentation gives a short review of important feedback. The Almeria accident was one of the reasons that from that time spray fires had to be taken into account in the safety analyses of nuclear power plants. Due to the fact that spray fire codes were not available in a sufficiently validated state, safety analyses were provisionally based on the feedback from sodium fire tests and also from the Almeria accident itself. The behaviour of spray fires showed that severe destruction, up to melting of metallic structures may occur, but even with a large spray fire is limited roughly within the spray fire zone itself. This could be subsequently be predicted by codes like NABRAND in Germany and FEUMIX in France. Almeria accident has accelerated R and D and code development with respect to spray fires. As example for a code validation some figures are given for the NABRAND code. Another large sodium fire accident happened in 1992 in the test facility at Bensberg in Germany (ILONA). This accident occurred during preheating of a sodium filled vessel which was provisionally installed in the basement of the ILONA test facility at Bensberg. Due to failure of a pressure relief valve the pressure in the vessel increased. As a consequence the plug in a dip tube for draining the vessel failed and about 4,5 t of sodium leaked slowly from the vessel. The plant room was not cladded with steel liners or collecting pans (it was not designed for permanent sodium plant operation). So leaking sodium came directly in

  8. Experience feedback from the transportation of Framatome fuel assemblies

    International Nuclear Information System (INIS)

    Robin, M.E.; Gaillard, G.; Aubin, C.

    1998-01-01

    Framatome, the foremost world nuclear fuel manufacturer, has for 25 years been delivering fuel elements from its three factories (Dessel, Romans, Pierrelatte) to the various sites in France and abroad (Germany, Sweden, Belgium, China, Korea, South Africa, Switzerland). During this period, Framatome has built up experience and expertise in fuel element transportation by road, rail and sea. In this filed, the range of constraints is very wide: safety and environmental protection constraints; constraints arising from the control and protection of nuclear materials, contractual and financial constraints, media watchdogs. Through the experience feedback from the transportation of FRAMATOME assemblies, this paper addresses all the phases in the transportation of fresh fuel assemblies. (authors)

  9. Clad failure detection in G 3 - operational feedback

    International Nuclear Information System (INIS)

    Plisson, J.

    1964-01-01

    After briefly reviewing the role and the principles of clad failure detection, the author describes the working conditions and the conclusions reached after 4 years operation of this installation on the reactor G 3. He mentions also the modifications made to the original installation as well as the tests carried out and the experiments under way. (author) [fr

  10. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    Jackson, H.A.; Woodhead, L.W.; Fanjoy, G.R.

    1984-03-01

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on the operating performance and costs, reliability of system components and nuclear safety considerations for the workers and the public

  11. Ontario Hydro CANDU operating experience

    International Nuclear Information System (INIS)

    Bartholomew, R.W.; Woodhead, L.W.; Horton, E.P.; Nichols, M.J.; Daly, I.N.

    1987-01-01

    The CANDU Pressurized Heavy Water (CANDU-PHW) type of nuclear-electric generating station has been developed jointly by Atomic Energy of Canada Limited and Ontario Hydro. This report highlights Ontario Hydro's operating experience using the CANDU-PHW system, with a focus on worker and public safety, operating performance and costs, and reliability of system components

  12. High-Feedback Operation of Power Electronic Converters

    Directory of Open Access Journals (Sweden)

    Gennady Y. Mikhal'chenko

    2013-03-01

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

  13. Understanding Surgical Resident and Fellow Perspectives on Their Operative Performance Feedback Needs: A Qualitative Study.

    Science.gov (United States)

    Bello, Ricardo J; Sarmiento, Samuel; Meyer, Meredith L; Rosson, Gedge D; Cooney, Damon S; Lifchez, Scott D; Cooney, Carisa M

    2018-04-20

    Operative performance feedback is essential for surgical training. We aimed to understand surgical trainees' views on their operative performance feedback needs and to characterize feedback to elucidate factors affecting its value from the resident perspective. Using a qualitative research approach, 2 research fellows conducted semistructured, one-on-one interviews with surgical trainees. We analyzed recurring themes generated during interviews related to feedback characteristics, as well as the extent to which performance rating tools can help meet trainees' operative feedback needs. Departments or divisions of general or plastic surgery at 9 US academic institutions. Surgical residents and clinical fellows in general or plastic surgery. We conducted 30 interviews with 9 junior residents, 14 senior residents, and 7 clinical fellows. Eighteen (60%) participants were in plastic and 12 (40%) were in general surgery. Twenty-four participants (80%) reported feedback as very or extremely important during surgical training. All trainees stated that verbal, face-to-face feedback is the most valuable, especially if occurring during (92%) or immediately after (65%) cases. Of those trainees using performance rating tools (74%), most (57%) expressed positive views about them but wanted the tools to complement and not replace verbal feedback in surgical education. Trainees value feedback more if received within 1 week or the case. Verbal, face-to-face feedback is very or extremely important to surgical trainees. Residents and fellows prefer to receive feedback during or immediately after a case and continue to value feedback if received within 1 week of the event. Performance rating tools can be useful for providing formative feedback and documentation but should not replace verbal, face-to-face feedback. Considering trainee views on feedback may help reduce perceived gaps in feedback demand-versus-supply in surgical training, which may be essential to overcoming current

  14. SPIN. First Digital Protection System Feedback of experience ... ... after 30 years

    International Nuclear Information System (INIS)

    Kosicki, M.; Pacuta, J.; Kamga, J.; Burel, J.-P.

    2010-01-01

    In this lecture Mr Burel presents experience with the software SPIN - the first digital protection system feedback. After thirty years of operation, the results are positive: - System is in correct operation and still maintained with spare parts available; - No spurious trip or actuation due to the system itself. A project for modernization is prepared to replace the digital part with a new digital technology designed with today's: - Components (SPINLINE 3); - methods and tools (Software development); - Standards (EMI/RFI - qualification), in order to allow customer to add some new functional needs and to keep the system in operation for thirty more years.

  15. Presurized water reactor safety approach and analysis. From conception to experience feedback

    International Nuclear Information System (INIS)

    Libmann, J.

    1987-04-01

    This report deals in ten chapters, with the following subjects: 1. Safety approach methods; 2. Study of accidents; 3. Safety analysis; 4. Study of internal aggressions or those involved by the site; 5. Consideration of complementary situations; 6. Three Mile Island accident; 7. Safety during operation and experience feedback; 8. An example of analysis: steam generator closure plug; 9. Probabilistic safety evaluation; 10. Chernobyl accident. 30 refs [fr

  16. Exploring Occupational Therapy Students' Meaning of Feedback during Fieldwork Experiences

    Science.gov (United States)

    Rathgeber, Karen Lynne

    2014-01-01

    Researchers have revealed that students' confidence and performance improve after they receive feedback from clinical supervisors regarding the delivery of quality patient care. Multiple studies of feedback have focused on the provision and acceptance of feedback; however, it was not known if or how students internalized feedback to promote…

  17. Operating practical experience at Argentina

    International Nuclear Information System (INIS)

    Quihillalt, Oscar

    1997-01-01

    Operating experiences of Atucha-1 and Embalse Nuclear Power Plants were discussed in this work. The technical and economic aspects, such as reliability, availability, personnel training, operating costs, prices and market, which exercise influence upon Argentina nuclear energy policy, mainly on the power electric generation by nuclear power plants were considered. Finally the current status of the nucleoelectric sector in Argentina and forecasting were analysed

  18. Auto-control experiments on DIDO using discontinuous feedback

    International Nuclear Information System (INIS)

    Lawrence, L.A.J.

    1959-12-01

    Experiments on auto-controlling the reactor DIDO are described and the equipment design discussed in some detail. The experiments are carried out to show the suitability of an on/off type of control for the maintenance of: (a) a constant flux level in the presence of noise. (b) constant period during power change. The controlling signals stem from measurement of neutron flux computed to give deviation from demanded power, and period respectively. These signals are fed to a D.C. amplifier with variable deadbang whose output is used to control relays, these in turn control the coarse control arms by means of three-phase motors. The system is designed on the basis of locus diagrams, a conventional non-linear technique being used to handle the relay performance. Calculation of the reactor transfer function at high and low power respectively shows that the stability margin is not appreciably affected by the inherent thermodynamic feedback in the reactor core. (author)

  19. International feedback experience on the cutting of reactor internal components

    International Nuclear Information System (INIS)

    Boucau, J.

    2014-01-01

    Westinghouse capitalizes more than 30 years of experience in the cutting of internal components of reactor and their packaging in view of their storage. Westinghouse has developed and validated different methods for cutting: plasma torch cutting, high pressure abrasive water jet cutting, electric discharge cutting and mechanical cutting. A long feedback experience has enabled Westinghouse to list the pros and cons of each cutting technology. The plasma torch cutting is fast but rises dosimetry concerns linked to the control of the cuttings and the clarity of water. Abrasive water jet cutting requires the installation of costly safety devices and of an equipment for filtering water but this technology allows accurate cuttings in hard-to-reach zones. Mechanical cutting is the most favourable technology in terms of wastes generation and of the clarity of water but the cutting speed is low. (A.C.)

  20. Fort Saint Vrain operational experience

    International Nuclear Information System (INIS)

    Fuller, C.H.

    1989-01-01

    Fort St. Vrain (FSV), on the system of the Public Service Company of Colorado, is the only high temperature gas-cooled (HTGR) power reactor in the United States. The plant features a helium-cooled reactor with a uranium-thorium fuel cycle. The paper describes the experience made during its operation. (author). 2 refs, 4 figs, 2 tabs

  1. Comparing PRAs with operating experience

    International Nuclear Information System (INIS)

    Picard, R.R.; Martz, H.F.

    1998-01-01

    Probabilistic Risk Assessment is widely used to estimate the frequencies of rare events, such as nuclear power plant accidents. An obvious question concerns the extent to which PRAs conform to operating experience--that is, do PRAs agree with reality? The authors discuss a formal methodology to address this issue and examine its performance using plant-specific data

  2. ERB-II operating experience

    International Nuclear Information System (INIS)

    Smith, R.N.; Cissel, D.W.; Smith, R.R.

    1977-01-01

    As originally designed and operated, EBR-II successfully demonstrated the concept of a sodium-cooled fast breeder power plant with a closed fuel reprocessing cycle (mini-nuclear park). Subsequent operation has been as an irradiation facility, a role which will continue into the foreseeable future. Since the beginning of operation in 1961, operating experience of EBR-II has been very satisfactory. Most of the components and systems have performed well. In particular, the mechanical performance of heat-removal systems has been excellent. A review of the operating experience reveals that all the original design objectives have been successfully demonstrated. To date, no failures or incidents resulting in serious in-core or out-of-core consequences have occurred. No water-to-sodium leaks have been detected over the life of the plant. At the present time, the facility is operating very well and continuously except for short shutdowns required by maintenance, refueling, modification, and minor repair. A plant factor of 76.9% was achieved for the calendar year 1976

  3. Emergency planning and operating experience

    International Nuclear Information System (INIS)

    Halpern, O.; Breniere, J.

    1984-01-01

    The purpose of this paper is to derive lessons from operating experience for the planning of emergency measures. This operating experience has two facets: it is obtained not only from the various incidents and accidents which have occurred in countries with nuclear power programmes and from the resulting application of emergency plans but also from the different exercises and simulations carried out in France and in other countries. Experience generally confirms the main approaches selected for emergency plans. The lessons to be derived are of three types: first, it appears necessary to set forth precisely the responsibilities of each person involved in order to prevent a watering-down of decisions in the event of an accident; secondly, considerable improvements need to be made in the different communication networks to be used; and thirdly, small accidents with minor radiological consequences deserve as systematic and thorough an approach as large and more improbable accidents. (author)

  4. Construction of experience feedback system for equipment supervision in nuclear engineering

    International Nuclear Information System (INIS)

    Zou Pingguo; Zhang Liying; Zhang Wenzhong

    2009-01-01

    Based on the analysis of the experience sources on equipment supervision in nuclear engineering, the details of the organization principle, working flow, and report requirement for the experience feedback system are introduced. The function range and its roll in the experience feedback system of the nuclear authority, nuclear power plant owners and equipment supervision organizations are illustrated. The standardization working requirements in the information gathering, analyzing, feedback and tracking process, and the characteristics and form of the incident report and feedback report are proposed. It emphasizes that the method for combined analysis of one significant incident and the whole incidents shall be adopted in the information analysis, and the experience feedback shall be considered in the development of equipment supervision technique and the equipment manufacturing, thus to maximize the use of experience feedback information to improve the pertinency and effectiveness of the experience feedback system. (authors)

  5. Influence of Force and Torque Feedback on Operator Performance in a VR-Based Suturing Task

    Directory of Open Access Journals (Sweden)

    L. Santos-Carreras

    2010-01-01

    Full Text Available The introduction of Minimally Invasive Surgery (MIS has revolutionised surgical care, considerably improving the quality of many surgical procedures. Technological advances, particularly in robotic surgery systems, have reduced the complexity of such an approach, paving the way for even less invasive surgical trends. However, the fact that haptic feedback has been progressively lost through this transition is an issue that to date has not been solved. Whereas traditional open surgery provides full haptic feedback, the introduction of MIS has eliminated the possibility of direct palpation and tactile exploration. Nevertheless, these procedures still provide a certain amount of force feedback through the rigid laparoscopic tool. Many of the current telemanipulated robotic surgical systems in return do not provide full haptic feedback, which to a certain extent can be explained by the requirement of force sensors integrated into the tools of the slave robot and actuators in the surgeon’s master console. In view of the increased complexity and cost, the benefit of haptic feedback is open to dispute. Nevertheless, studies have shown the importance of haptic feedback, especially when visual feedback is unreliable or absent. In order to explore the importance of haptic feedback for the surgeon’s master console of a novel teleoperated robotic surgical system, we have identified a typical surgical task where performance could potentially be improved by haptic feedback, and investigate performance with and without this feedback. Two rounds of experiments are performed with 10 subjects, six of them with a medical background. Results show that feedback conditions, including force feedback, significantly improve task performance independently of the operator’s suturing experience. There is, however, no further significant improvement when torque feedback is added. Consequently, it is deduced that force feedback in translations improves subject

  6. The use of SIPA 2 simulator for safety studies experience feedbacks and future developments

    International Nuclear Information System (INIS)

    Dumas, J.M.; Leteinturier, D.

    1999-01-01

    SIPA 2 experience feedbacks from the beginning of its use at IPSN in 1991 and trends for the next five years are presented. The simulator has been used for three applications: training of engineers working in safety analysis, preparation of national crisis drills, safety studies. In each application, experience feedbacks are analysed to show encountered advantages and difficulties. Trends for the next five years are: extension of the engineer training program (new training courses about normal operating conditions or about beyond design basis accidents), improvements in the validation of simulation configurations (in particular comparison with Cathare 2 new version results) increase of the simulation scope in connection with the SCAR project (taking into account the current power plant datapackage, the improvement of thermalhydraulic models, the extent of the system representation, new neutronic models and description of severe accident conditions). For each trend above, a detail of the planned actions is given. (author)

  7. Local beam position feedback experiments on the ESRF storage ring

    International Nuclear Information System (INIS)

    Chung, Y.; Kahana, E.; Kirchman, J.

    1995-01-01

    This paper describes the results of local beam position feedback experiments conducted on the ESRF storage ring using digital signal processing (DSP) under the trilateral agreement of collaboration among ESRF, APS, and SPring-8. Two rf beam position monitors (BPMS) in the, upstream and downstream of the insertion device (ID) and two x-ray BPMs in the sixth cell were used to monitor the electron beam and the x-ray beam emitted from the ID, respectively. The local bump coefficients were obtained using the technique of singular value decomposition (SVD) on the global response matrix for the bump magnets and all the available BPMs outside the local bump. The local response matrix was then obtained between the two three-magnet bumps and the position monitors. The data sampling frequency was 4 kHz and a proportional, integral, and derivative (PID) controller was used. The result indicates the closed-loop feedback bandwidth close to 100 Hz and clear attenuation (∼ -40 dB) of the 7-Hz beam motion due to girder vibration resonance. Comparison of the results using the rf BPMs and x-ray BPMs will be also discussed

  8. Enhancing audiovisual experience with haptic feedback: a survey on HAV.

    Science.gov (United States)

    Danieau, F; Lecuyer, A; Guillotel, P; Fleureau, J; Mollet, N; Christie, M

    2013-01-01

    Haptic technology has been widely employed in applications ranging from teleoperation and medical simulation to art and design, including entertainment, flight simulation, and virtual reality. Today there is a growing interest among researchers in integrating haptic feedback into audiovisual systems. A new medium emerges from this effort: haptic-audiovisual (HAV) content. This paper presents the techniques, formalisms, and key results pertinent to this medium. We first review the three main stages of the HAV workflow: the production, distribution, and rendering of haptic effects. We then highlight the pressing necessity for evaluation techniques in this context and discuss the key challenges in the field. By building on existing technologies and tackling the specific challenges of the enhancement of audiovisual experience with haptics, we believe the field presents exciting research perspectives whose financial and societal stakes are significant.

  9. Reliability in mechanics: the application of experience feedback

    International Nuclear Information System (INIS)

    Coudray, R.

    1994-01-01

    After a short overview of the available methods for statistical multi-dimensional studies, an application of these methods is described using the experience feedback of French nuclear reactors. The material studied is the RCV (chemical and volumetric control system) pump of the 900 MW PWR type reactors for which data used in the study are explained. The aim of the study is to show the pertinency of the rate of failures as an indicator of the material aging. This aging is illustrated by the most significant characteristics with an indication of their significance level. The method used combines the results from a mixed classification and those from a multiple correspondences analysis in several steps or evolutions. (J.S.). 8 refs., 6 figs., 3 tabs

  10. Using GoPro to Give Video-Assisted Operative Feedback for Surgery Residents: A Feasibility and Utility Assessment.

    Science.gov (United States)

    Moore, Maureen D; Abelson, Jonathan S; O'Mahoney, Paul; Bagautdinov, Iskander; Yeo, Heather; Watkins, Anthony C

    this tool to include additional procedures. Although there has been progress toward improving operative feedback, room for further improvement remains. The use of a head-mounted GoPro is a dynamic tool that provides high-quality video for operative review and has the potential to augment the training experience of GS residents. Future studies exploring a wide array of open procedures involving a greater number of trainees will be needed to further define the use of this resource. Copyright © 2017. Published by Elsevier Inc.

  11. MELOX fuel fabrication plant: Operational feedback and future prospects

    International Nuclear Information System (INIS)

    Hugelmann, D.; Greneche, D.

    2000-01-01

    As of December 1, 1998, 32 Europeans LWRs are loaded with MOX fuel. It clearly means that plutonium recycling in MOX fuels is a mature industry, with successful operational experience in fabrication plants in some European countries, especially in France. Indeed, the recycling of plutonium generated in LWRs is one of the objectives of the full Reprocessing-Conditioning-Recycling (RCR) strategy chosen by France in the 70's. The most impressive results of this strategy, is the fact that 31 of the 32 reactors are loaded with MOX fuels supplied by the COGEMA Group from the same efficient fabrication process, the MIMAS process, improved for the MELOX plant to become the A-MIMAS process. In France, 17 reactors are already loaded and 11 additional reactors are technically suited to do so. Indeed, the EDF MOX program plans to use MOX in 28 of its 57 reactors. An EDF 900 MWe reactor core contains 157 assemblies of 264 rods each. 52 fuel assemblies per year are necessary for a 'UO 2 3-batches-MOX 3-batches' core management. In this case, a third of the UO 2 and a third of the MOX assemblies are replaced yearly, that means 36 UO 2 fuel assemblies and 16 MOX fuel assemblies. Some MOX fuelled reactors have now switched from the previously described core management to a so-called 'hybrid core management'. In this case, a quarter of UO 2 assemblies is replaced yearly. The first EDF reactor loaded with MOX fuel was Saint-Laurent B1, in 1987. The in-core experience, based on several hundred assemblies loaded, with reloading on a 1/3 cycle basis, shows that there is no operational difference between UO 2 and MOX fuels, both in terms of performance and safety. MOX fueling of 900 MWe EDF's PWRs, with a limited in-core MOX ratio of 30%, has needed only minor adaptations, such as addition of control rods, modification of the boron concentration in the cooling system and precaution against radiation exposure, easy to set up (optimisation of the fresh MOX fuel handling process, remote

  12. Operation experience at the UWTF

    International Nuclear Information System (INIS)

    Ueno, Kazuhiro; Inada, Kameji; Ohmori, Kouji; Usui, Kazuya; Irinouchi, Sigenori; Asami, Makoto; Tohchi, Katsunori

    2003-01-01

    This report describes the operation experience on the volume reduction of metal wastes and used air filters contaminated with uranium at the Uranium contaminated Waste Treatment Facility (UWTF) in JNC Tokai Works. The UWTF consists of the metal waste treatment system and the filter-waste treatment system. The former treats metal wastes, the latter treats used air filters. Metal wastes are unpacked from drums, cut, and then compacted. Used air filters are separated into filter media and frames. Then the filter media are compacted and the frames are crushed. The operation of the UWTF was started in June 1998. The following volumes of wastes had been treated at the UWTF from the beginning of the operation to March 2003 (for about 5 years). (1) 1,524 drums of the metal wastes had been reduced to 410 drums. The volume reduction factor was 3.7. (2) 372 drums of the used air filters had been reduced to 39 drums. The volume reduction factor was 9.5. These systems have been operated without trouble for 5 years and have demonstrated to be able to reduce the volumes of the wastes to designed values. The volume reduction technologies for metal wastes and used air filters contaminated with uranium were successfully demonstrated at the UWTF. (author)

  13. ATLAS Pixel Detector Operational Experience

    CERN Document Server

    Di Girolamo, B; The ATLAS collaboration

    2011-01-01

    The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this talk, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: 96.9% of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, an...

  14. New Quartz Crystal Oscillators Using the Current-Feedback Operational Amplifier

    OpenAIRE

    Muhammad Taher Abuelma'atti; Ahmad Al-Ghazwani

    2000-01-01

    New crystal oscillators using the current-feedback operational-amplifier (CFOA) are presented. Each circuit uses one CFOA, a crystal and, at most, five externally connected passive elements. Experimental results are included.

  15. Stack Monitor Operating Experience Review

    International Nuclear Information System (INIS)

    Cadwallader, L.C.; Bruyere, S.A.

    2009-01-01

    Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative 'all modes' failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

  16. Feedback-assisted extension of the tokamak operating space to low safety factor

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, J. M., E-mail: jmh2130@columbia.edu; Bialek, J. M.; Navratil, G. A.; Olofsson, K. E. J.; Shiraki, D.; Turco, F. [Department of Applied Mathematics and Applied Physics, Columbia University, New York, New York 10027-6900 (United States); Baruzzo, M.; Bolzonella, T.; Marrelli, L.; Martin, P.; Piovesan, P.; Piron, C.; Piron, L.; Terranova, D.; Zanca, P. [Consorzio RFX, Corso Stati Uniti 4, 35127 Padova (Italy); Hyatt, A. W.; Jackson, G. L.; La Haye, R. J.; Lanctot, M. J.; Strait, E. J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); and others

    2014-07-15

    Recent DIII-D and RFX-mod experiments have demonstrated stable tokamak operation at very low values of the edge safety factor q(a) near and below 2. The onset of n = 1 resistive wall mode (RWM) kink instabilities leads to a disruptive stability limit, encountered at q(a) = 2 (limiter plasmas) and q{sub 95} = 2 (divertor plasmas). However, passively stable operation can be attained for q(a) and q{sub 95} values as low as 2.2. RWM damping in the q(a) = 2 regime was measured using active MHD spectroscopy. Although consistent with theoretical predictions, the amplitude of the damped response does not increase significantly as the q(a) = 2 limit is approached, in contrast with damping measurements made approaching the pressure-driven RWM limit. Applying proportional gain magnetic feedback control of the n = 1 modes has resulted in stabilized operation with q{sub 95} values reaching as low as 1.9 in DIII-D and q(a) reaching 1.55 in RFX-mod. In addition to being consistent with the q(a) = 2 external kink mode stability limit, the unstable modes have growth rates on the order of the characteristic wall eddy-current decay timescale in both devices, and a dominant m = 2 poloidal structure that is consistent with ideal MHD predictions. The experiments contribute to validating MHD stability theory and demonstrate that a key tokamak stability limit can be overcome with feedback.

  17. Feedback-assisted extension of the tokamak operating space to low safety factor

    International Nuclear Information System (INIS)

    Hanson, J. M.; Bialek, J. M.; Navratil, G. A.; Olofsson, K. E. J.; Shiraki, D.; Turco, F.; Baruzzo, M.; Bolzonella, T.; Marrelli, L.; Martin, P.; Piovesan, P.; Piron, C.; Piron, L.; Terranova, D.; Zanca, P.; Hyatt, A. W.; Jackson, G. L.; La Haye, R. J.; Lanctot, M. J.; Strait, E. J.

    2014-01-01

    Recent DIII-D and RFX-mod experiments have demonstrated stable tokamak operation at very low values of the edge safety factor q(a) near and below 2. The onset of n = 1 resistive wall mode (RWM) kink instabilities leads to a disruptive stability limit, encountered at q(a) = 2 (limiter plasmas) and q 95  = 2 (divertor plasmas). However, passively stable operation can be attained for q(a) and q 95 values as low as 2.2. RWM damping in the q(a) = 2 regime was measured using active MHD spectroscopy. Although consistent with theoretical predictions, the amplitude of the damped response does not increase significantly as the q(a) = 2 limit is approached, in contrast with damping measurements made approaching the pressure-driven RWM limit. Applying proportional gain magnetic feedback control of the n = 1 modes has resulted in stabilized operation with q 95 values reaching as low as 1.9 in DIII-D and q(a) reaching 1.55 in RFX-mod. In addition to being consistent with the q(a) = 2 external kink mode stability limit, the unstable modes have growth rates on the order of the characteristic wall eddy-current decay timescale in both devices, and a dominant m = 2 poloidal structure that is consistent with ideal MHD predictions. The experiments contribute to validating MHD stability theory and demonstrate that a key tokamak stability limit can be overcome with feedback

  18. Nuclear Power Plant Operating Experience from the IAEA/NEA International Reporting System for Operating Experience 2012-2014

    International Nuclear Information System (INIS)

    2018-03-01

    The International Reporting System for Operating Experience (IRS) is an essential element of the international operating experience feedback system for nuclear power plants. Its fundamental objective is to contribute to improving safety of commercial nuclear power plants which are operated worldwide. IRS reports contain information on events of safety significance with important lessons learned which assist in reducing recurrence of events at other plants. This sixth publication, covering the period 2012 - 2014, follows the structure of the previous editions. It highlights important lessons based on a review of the approximately 240 event reports received from the participating countries over this period.

  19. Operation experience with elevated ammonia

    International Nuclear Information System (INIS)

    Vankova, Katerina; Kysela, Jan; Malac, Miroslav; Petrecky, Igor; Svarc, Vladimir

    2011-01-01

    The 10 VVER units in the Czech and Slovak Republics are all in very good water chemistry and radiation condition, yet questions have arisen regarding the optimization of cycle chemistry and improved operation in these units. To address these issues, a comprehensive experimental program for different water chemistries of the primary circuit was carried out at the Rez Nuclear Research Institute, Czech Republic, with the goal of judging the influence of various water chemistries on radiation build-up. Four types of water chemistries were compared: standard VVER water chemistry (in common use), direct hydrogen dosing without ammonia, standard VVER water chemistry with elevated ammonia levels, and zinc dosing to standard VVER water chemistry. The test results showed that the types of water chemistry other than the common one have benefits for the operation of the nuclear power plant (NPP) primary circuit. Operation experience with elevated ammonia at NPP Dukovany Units 3 and 4 is presented which validates the experimental results, demonstrating improved corrosion product volume activity. (orig.)

  20. Experience feedback from incidents: methodological and cultural aspects

    International Nuclear Information System (INIS)

    Perinet, R.

    2007-01-01

    EdF has designed some provisions to improve the reliability of human interventions: an increased number of training simulators, management of the quality of interventions, implementation of human factor consultants on each site, improvement in user documentation, development of communication practices, etc. However, despite efforts made in the right direction, the complexity of human behaviour and organisations make it obligatory to follow up the efficacy of these provisions over time in order to ensure that they produce the expected results on work practices. The in-depth analysis by IRSN of events that are significant for safety shows that experience feedback from incidents constitutes a real opportunity to ensure this follow-up. It also highlights the difficulty for licensees to define the temporal context of investigations to carry out, analysing errors committed more in depth and identifying ensuing problems. This article shows that these difficulties are the result of inappropriate methodologies and a lack of skills and availability to carry out the analysis. Finally, it shows that the incident leads to defensive behaviour among those participating in the system that blocks the compilation of information and limits the relevance of analyses. (author)

  1. Creating Feedback Channels With Optical Communications For Information Operations (IO)

    Science.gov (United States)

    2016-06-01

    amphibious operations. Optical communications technologies, direct marketing principles , and current IO shortfalls are explored to determine whether...technology. First, these concepts are applied to show covert amphibious operations. Optical communications technologies, direct marketing principles , and...power, as per Appendix A. A major portion of the marketing campaign comes in the form of advertising. The correlating principles of advertising in

  2. Decommissioning project feedback experience in the Japan Atomic Energy Research Institut

    International Nuclear Information System (INIS)

    Yanagihara, S.; Tachibana, M.; Miyajima, K.

    2003-01-01

    Since starting the research and development program for peaceful use of nuclear energy in 1950's, various research and demonstration facilities have been constructed in research organizations, universities and commercial sectors in Japan. Some of the nuclear facilities constructed in the early stage of research and development have been retired to be decommissioned because of completion of the initial objectives in the Japan Atomic Energy Research Institute (JAERI). On the other hand, since the first commercial operation of nuclear power plant (1968), the number of nuclear power plants has increased up to 52 plants operating as of August 2003 in Japan. The shear of nuclear energy accounts approximately for 35% of electricity generation in total at present time. However, several nuclear power plants have been operated for more than 25 years and two nuclear power plants are expected to be finally shutdown by 2010 to be eventually decommissioned. The Tokai Power Station, the oldest Japanese nuclear power plant operated by the Japan Atomic Power Company, was permanently shutdown from March 1998 and it is in decommissioning stage at this time. The Fugen, which is advanced thermal reactor operated by the Japan Nuclear Cycle Development Institute (JNC), was finally shutdown on March, 2003 after 25 years operation to be decommissioned. In addition, relating to planned unification between JAERI and JNC in 2005, the studies have been in progress on decommissioning and radioactive waste treatment and disposal; the cost was estimated to be 10 to 30 billion Japanese yens per year during 80 years for decommissioning of nearly 200 nuclear facilities. Decommissioning of nuclear facilities is thus getting to be one of important issues in Japan. Decommissioning of nuclear facilities might be possible using conventional and/or partially improved technology. However, reviewing project feedback experience on decommissioning and decontamination might contribute to solve various issues

  3. Experience with feedback and feedforward for plasma control in ASDEX

    International Nuclear Information System (INIS)

    Schneider, F.

    1983-01-01

    Experimental results of vertical and radial position feedback are shown and discussed. In particular, stability problems of vertical position control are studied in detail. A feedforward procedure for the process computer is described and proved by measurements. (author)

  4. Feedback for Thought: Examining the Influence of Feedback Constituents on Learning Experience

    Science.gov (United States)

    Aoun, Chadi; Vatanasakdakul, Savanid; Ang, Karyne

    2018-01-01

    Reflective teaching practice is often heralded as a pillar of effective tuition. However, the perceptions of multiple forms of feedback among learners and their contributions to reflective learning is yet to attract significant attention, particularly in the Information Systems (IS) context. This research investigates the antecedent constituents…

  5. Performance evaluation of a robot-assisted catheter operating system with haptic feedback.

    Science.gov (United States)

    Song, Yu; Guo, Shuxiang; Yin, Xuanchun; Zhang, Linshuai; Hirata, Hideyuki; Ishihara, Hidenori; Tamiya, Takashi

    2018-06-20

    In this paper, a novel robot-assisted catheter operating system (RCOS) has been proposed as a method to reduce physical stress and X-ray exposure time to physicians during endovascular procedures. The unique design of this system allows the physician to apply conventional bedside catheterization skills (advance, retreat and rotate) to an input catheter, which is placed at the master side to control another patient catheter placed at the slave side. For this purpose, a magnetorheological (MR) fluids-based master haptic interface has been developed to measure the axial and radial motions of an input catheter, as well as to provide the haptic feedback to the physician during the operation. In order to achieve a quick response of the haptic force in the master haptic interface, a hall sensor-based closed-loop control strategy is employed. In slave side, a catheter manipulator is presented to deliver the patient catheter, according to position commands received from the master haptic interface. The contact forces between the patient catheter and blood vessel system can be measured by designed force sensor unit of catheter manipulator. Four levels of haptic force are provided to make the operator aware of the resistance encountered by the patient catheter during the insertion procedure. The catheter manipulator was evaluated for precision positioning. The time lag from the sensed motion to replicated motion is tested. To verify the efficacy of the proposed haptic feedback method, the evaluation experiments in vitro are carried out. The results demonstrate that the proposed system has the ability to enable decreasing the contact forces between the catheter and vasculature.

  6. Regulatory challenges in using nuclear operating experience

    International Nuclear Information System (INIS)

    2006-01-01

    There can be no doubt that the systematic evaluation of operating experience by the operator and the regulator is essential for continued safe operation of nuclear power plants. Recent concerns have been voiced that the operating experience information and insights are not being used effectively to promote safety. If these concerns foreshadow a real trend in OECD countries toward complacency in reporting and analysing operating events and taking corrective actions, then past experience suggests that similar or even more serious events will recur. This report discusses how the regulator can take actions to assure that operators have effective programmes to collect and analyse operating experience and, just as important, for taking steps to follow up with actions to prevent the events and conditions from recurring. These regulatory actions include special inspections of an operator operating experience programme and discussion with senior plant managers to emphasize the importance of having an effective operating experience programme. In addition to overseeing the operator programmes, the regulator has the broader responsibility for assuring that industry-wide trends, both national and international are monitored. To meet these responsibilities, the regulatory body must have its own operating experience programme, and this report discusses the important attributes of such regulatory programmes. It is especially important for the regulator to have the capability for assessing the full scope of operating experience issues, including those that may not be included in an operator operating experience programme, such as new research results, international operating experience, and broad industry trend information. (author)

  7. [Experience feedback committee: a method for patient safety improvement].

    Science.gov (United States)

    François, P; Sellier, E; Imburchia, F; Mallaret, M-R

    2013-04-01

    An experience feedback committee (CREX, Comité de Retour d'EXpérience) is a method which contributes to the management of safety of care in a medical unit. Originally used for security systems of civil aviation, the method has been adapted to health care facilities and successfully implemented in radiotherapy units and in other specialties. We performed a brief review of the literature for studies reporting data on CREX established in hospitals. The review was performed using the main bibliographic databases and Google search results. The CREX is designed to analyse incidents reported by professionals. The method includes monthly meetings of a multi-professional committee that reviews the reported incidents, chooses a priority incident and designates a "pilot" responsible for investigating the incident. The investigation of the incident involves a systemic analysis method and a written synthesis presented at the next meeting of the committee. The committee agrees on actions for improvement that are suggested by the analysis and follows their implementation. Systems for the management of health care, including reporting systems, are organized into three levels: the medical unit, the hospital and the country as a triple loop learning process. The CREX is located in the base level, short loop of risk management and allows direct involvement of care professionals in patient safety. Safety of care has become a priority of health systems. In this context, the CREX can be a useful vehicle for the implementation of a safety culture in medical units. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  8. Operation and performance of a longitudinal feedback system using digital signal processing

    International Nuclear Information System (INIS)

    Teytelman, D.; Fox, J.; Hindi, H.

    1994-01-01

    A programmable longitudinal feedback system using a parallel array of AT ampersand T 1610 digital signal processors has been developed as a component of the PEP-II R ampersand D program. This system has been installed at the Advanced Light Source (LBL) and implements full speed bunch by bunch signal processing for storage rings with bunch spacing of 4ns. Open and closed loop results showing the action of the feedback system are presented, and the system is shown to damp coupled-bunch instabilities in the ALS. A unified PC-based software environment for the feedback system operation is also described

  9. Experience in operation and maintenance of PWRs

    International Nuclear Information System (INIS)

    Broecker, H.; Schomer, E.

    1987-01-01

    At present there are 10 PWRs in operation, most of them built on turnkey basis by KWU. The availability of West German PWRs amounted to 84.7% on average for the period from 1982-86. The good operating results are attributable to the following: 1. Sophiticated design and layout of the plant with good accessibility to the primary system even during operation. 2. Reliable performance of plant and components as result of extensive quality assurance. 3. Well-organized and highly qualified operating personnel. 4. Inservice inspection and preventive maintenance. 5. Good information feedback system. (Liu)

  10. Nine Years of XMM-Newton Pipeline: Experience and Feedback

    Science.gov (United States)

    Michel, Laurent; Motch, Christian

    2009-05-01

    The Strasbourg Astronomical Observatory is member of the Survey Science Centre (SSC) of the XMM-Newton satellite. Among other responsibilities, we provide a database access to the 2XMMi catalogue and run the part of the data processing pipeline performing the cross-correlation of EPIC sources with archival catalogs. These tasks were all developed in Strasbourg. Pipeline processing is flawlessly in operation since 1999. We describe here the work load and infrastructure setup in Strasbourg to support SSC activities. Our nine year long SSC experience could be used in the framework of the Simbol-X ground segment.

  11. Nine Years of XMM-Newton Pipeline: Experience and Feedback

    International Nuclear Information System (INIS)

    Michel, Laurent; Motch, Christian

    2009-01-01

    The Strasbourg Astronomical Observatory is member of the Survey Science Centre (SSC) of the XMM-Newton satellite. Among other responsibilities, we provide a database access to the 2XMMi catalogue and run the part of the data processing pipeline performing the cross-correlation of EPIC sources with archival catalogs. These tasks were all developed in Strasbourg. Pipeline processing is flawlessly in operation since 1999. We describe here the work load and infrastructure setup in Strasbourg to support SSC activities. Our nine year long SSC experience could be used in the framework of the Simbol-X ground segment.

  12. High-feedback Operation of Power Electronic Converters

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  13. International experience feedback on fatigue monitoring systems for nuclear power plants

    International Nuclear Information System (INIS)

    Morilhat, P.

    1997-01-01

    From the very beginning of electro-nuclear programmes the need has become internationally obvious to develop systems aiming at automation and improvement of monitoring of the transients stressing the main mechanical components of nuclear units, by checking the conservativeness of the design no longer from a comparison of causes (temperature and pressure variations) but by directly assessing the results (stresses and linked damage). Prototypes of such systems have appeared since the middle of the 1980's mainly in France, the USA and Germany, and manufacturing them has since continued. Several years of development and on site testing of prototypes of fatigue measuring devices designed by the R and D Direction have enabled contacts with the developers of similar systems to be established and, in some cases, comparisons to be made. The experience accumulated in the use of such systems, both in France and abroad from now on makes a first experience feedback possible. The fatigue measuring device concept is based on a succession of elementary modules which enable the information received from the unit to be processed, first in the form of transient counting (transient meters), then in the form of mechanical diagnosis (fatigue monitoring systems). Among the systems in operation some provide actually only the transient meter part while others link transient meters and fatigue meters (EDF, EPRI and MITSUBISHI systems and some versions of the SIEMENS system). Moreover, numerous systems require, in addition to unit operation instrumentation, specific instrumentation located in monitored areas. The number of devices in operation has not stopped growing since the middle of the 80's to reach 53 systems working in 1996. The biggest developers are EPRI and its consultant Structural Integrity Associates (FatiguePro system), SIEMENS (FAMOS system) and EDF whose gradual implementation of SYSFAC from '96 is going to make its share particularly increase. Technical experience feedback

  14. Auditory display as feedback for a novel eye-tracking system for sterile operating room interaction.

    Science.gov (United States)

    Black, David; Unger, Michael; Fischer, Nele; Kikinis, Ron; Hahn, Horst; Neumuth, Thomas; Glaser, Bernhard

    2018-01-01

    The growing number of technical systems in the operating room has increased attention on developing touchless interaction methods for sterile conditions. However, touchless interaction paradigms lack the tactile feedback found in common input devices such as mice and keyboards. We propose a novel touchless eye-tracking interaction system with auditory display as a feedback method for completing typical operating room tasks. Auditory display provides feedback concerning the selected input into the eye-tracking system as well as a confirmation of the system response. An eye-tracking system with a novel auditory display using both earcons and parameter-mapping sonification was developed to allow touchless interaction for six typical scrub nurse tasks. An evaluation with novice participants compared auditory display with visual display with respect to reaction time and a series of subjective measures. When using auditory display to substitute for the lost tactile feedback during eye-tracking interaction, participants exhibit reduced reaction time compared to using visual-only display. In addition, the auditory feedback led to lower subjective workload and higher usefulness and system acceptance ratings. Due to the absence of tactile feedback for eye-tracking and other touchless interaction methods, auditory display is shown to be a useful and necessary addition to new interaction concepts for the sterile operating room, reducing reaction times while improving subjective measures, including usefulness, user satisfaction, and cognitive workload.

  15. Feedback control of plasma density and heating power for steady state operation in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Kamio, Shuji, E-mail: kamio@nifs.ac.jp; Kasahara, Hiroshi; Seki, Tetsuo; Saito, Kenji; Seki, Ryosuke; Nomura, Goro; Mutoh, Takashi

    2015-12-15

    Highlights: • We upgraded a control system for steady state operation in LHD. • This system contains gas fueling system and ICRF power control system. • Automatic power boost system is also attached for stable operation. • As a result, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. - Abstract: For steady state operation, the feedback control of plasma density and heating power system was developed in the Large Helical Device (LHD). In order to achieve a record of the long pulse discharge, stable plasma density and heating power are needed. This system contains the radio frequency (RF) heating power control, interlocks, gas fueling, automatic RF phase control, ion cyclotron range of frequency (ICRF) antenna position control, and graphical user interface (GUI). Using the density control system, the electron density was controlled to the target density and using the RF heating power control system, the RF power injection could be stable. As a result of using this system, we achieved the long pulse up to 48 min in the electron density of more than 1 × 10{sup 19} m{sup −3}. Further, the ICRF hardware experienced no critical accidents during the 17th LHD experiment campaign in 2013.

  16. Achievement of radiative feedback control for long-pulse operation on EAST

    Science.gov (United States)

    Wu, K.; Yuan, Q. P.; Xiao, B. J.; Wang, L.; Duan, Y. M.; Chen, J. B.; Zheng, X. W.; Liu, X. J.; Zhang, B.; Xu, J. C.; Luo, Z. P.; Zang, Q.; Li, Y. Y.; Feng, W.; Wu, J. H.; Yang, Z. S.; Zhang, L.; Luo, G.-N.; Gong, X. Z.; Hu, L. Q.; Hu, J. S.; Li, J.

    2018-05-01

    The active feedback control of radiated power to prevent divertor target plates overheating during long-pulse operation has been developed and implemented on EAST. The radiation control algorithm, with impurity seeding via a supersonic molecular beam injection (SMBI) system, has shown great success in both reliability and stability. By seeding a sequence of short neon (Ne) impurity pulses with the SMBI from the outer mid-plane, the radiated power of the bulk plasma can be well controlled, and the duration of radiative control (feedforward and feedback) is 4.5 s during a discharge of 10 s. Reliable control of the total radiated power of bulk plasma has been successfully achieved in long-pulse upper single null (USN) discharges with a tungsten divertor. The achieved control range of {{f}rad} is 20%–30% in L-mode regimes and 18%–36% in H-mode regimes. The temperature of the divertor target plates was maintained at a low level during the radiative control phase. The peak particle flux on the divertor target was decreased by feedforward Ne injection in the L-mode discharges, while the Ne pulses from the SMBI had no influence on the peak particle flux because of the very small injecting volume. It is shown that although the radiated power increased, no serious reduction of plasma-stored energy or confinement was observed during the control phase. The success of the radiation control algorithm and current experiments in radiated power control represents a significant advance for steady-state divertor radiation and heat flux control on EAST for near-future long-pulse operation.

  17. Optimal feedback control successfully explains changes in neural modulations during experiments with brain-machine interfaces

    Directory of Open Access Journals (Sweden)

    Miriam eZacksenhouse

    2015-05-01

    Full Text Available Recent experiments with brain-machine-interfaces (BMIs indicate that the extent of neural modulations increased abruptly upon starting to operate the interface, and especially after the monkey stopped moving its hand. In contrast, neural modulations that are correlated with the kinematics of the movement remained relatively unchanged. Here we demonstrate that similar changes are produced by simulated neurons that encode the relevant signals generated by an optimal feedback controller during simulated BMI experiments. The optimal feedback controller relies on state estimation that integrates both visual and proprioceptive feedback with prior estimations from an internal model. The processing required for optimal state estimation and control were conducted in the state-space, and neural recording was simulated by modeling two populations of neurons that encode either only the estimated state or also the control signal. Spike counts were generated as realizations of doubly stochastic Poisson processes with linear tuning curves. The model successfully reconstructs the main features of the kinematics and neural activity during regular reaching movements. Most importantly, the activity of the simulated neurons successfully reproduces the observed changes in neural modulations upon switching to brain control. Further theoretical analysis and simulations indicate that increasing the process noise during normal reaching movement results in similar changes in neural modulations. Thus we conclude that the observed changes in neural modulations during BMI experiments can be attributed to increasing process noise associated with the imperfect BMI filter, and, more directly, to the resulting increase in the variance of the encoded signals associated with state estimation and the required control signal.

  18. Optimal feedback control successfully explains changes in neural modulations during experiments with brain-machine interfaces.

    Science.gov (United States)

    Benyamini, Miri; Zacksenhouse, Miriam

    2015-01-01

    Recent experiments with brain-machine-interfaces (BMIs) indicate that the extent of neural modulations increased abruptly upon starting to operate the interface, and especially after the monkey stopped moving its hand. In contrast, neural modulations that are correlated with the kinematics of the movement remained relatively unchanged. Here we demonstrate that similar changes are produced by simulated neurons that encode the relevant signals generated by an optimal feedback controller during simulated BMI experiments. The optimal feedback controller relies on state estimation that integrates both visual and proprioceptive feedback with prior estimations from an internal model. The processing required for optimal state estimation and control were conducted in the state-space, and neural recording was simulated by modeling two populations of neurons that encode either only the estimated state or also the control signal. Spike counts were generated as realizations of doubly stochastic Poisson processes with linear tuning curves. The model successfully reconstructs the main features of the kinematics and neural activity during regular reaching movements. Most importantly, the activity of the simulated neurons successfully reproduces the observed changes in neural modulations upon switching to brain control. Further theoretical analysis and simulations indicate that increasing the process noise during normal reaching movement results in similar changes in neural modulations. Thus, we conclude that the observed changes in neural modulations during BMI experiments can be attributed to increasing process noise associated with the imperfect BMI filter, and, more directly, to the resulting increase in the variance of the encoded signals associated with state estimation and the required control signal.

  19. Providing feedback on emotional experiences and decision making

    NARCIS (Netherlands)

    Machajdik, J.; Stöttinger, J.; Danelova, E.; Pongratz, M.; Kavicky, L.; Valenti, R.; Hanbury, A.

    2011-01-01

    We present a novel lifelog system concept created to provide a human user with feedback on their conscious and unconscious emotional reactions and encourage the process of self-reflection by looking into an affective mirror. The emotion of the user is deduced from biometric data and enhanced by

  20. Final installation and testing of the feedback power amplifier for the Scyllac feedback experiment

    International Nuclear Information System (INIS)

    Kutac, K.J.; Kewish, R.W. Jr.; Gribble, R.F.; Rawcliffe, A.S.; Miller, G.; Kemp, E.L.; Bartsch, R.R.

    1975-01-01

    The Scyllac feedback system consists of eight subsystems. The installation and testing of the many components and eight subsystems are described. The eight subsystems are: (1) ML-8618 power amplifiers; (2) dc plate and bias power supplies; (3) ac filament power supplies; (4) position detector and signal processor (intermediate amplifier); (5) l = 0 and l = 2 output load coils; (6) control system and interlock system; (7) computer controlled analog-to-digital transient recorders; and (8) cable distribution and cooling-water supply system

  1. Current feedback operational amplifiers as fast charge sensitive preamplifiers for photomultiplier read out

    Energy Technology Data Exchange (ETDEWEB)

    Giachero, A; Gotti, C; Maino, M; Pessina, G, E-mail: claudio.gotti@mib.infn.it [INFN - Sezione di Milano-Bicocca, I-20126, Milano (Italy)

    2011-05-01

    Fast charge sensitive preamplifiers were built using commercial current feedback operational amplifiers for fast read out of charge pulses from a photomultiplier tube. Current feedback opamps prove to be particularly well suited for this application where the charge from the detector is large, of the order of one million electrons, and high timing resolution is required. A proper circuit arrangement allows very fast signals, with rise times down to one nanosecond, while keeping the amplifier stable. After a review of current feedback circuit topology and stability constraints, we provide a 'recipe' to build stable and very fast charge sensitive preamplifiers from any current feedback opamp by adding just a few external components. The noise performance of the circuit topology has been evaluated and is reported in terms of equivalent noise charge.

  2. Operational experience, availability and reliability of nuclear power plants

    International Nuclear Information System (INIS)

    Kueffer, K.

    1980-01-01

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

  3. Plant operator performance evaluation based on cognitive process analysis experiment

    International Nuclear Information System (INIS)

    Ujita, H.; Fukuda, M.

    1990-01-01

    This paper reports on an experiment to clarify plant operators' cognitive processes that has been performed, to improve the man-machine interface which supports their diagnoses and decisions. The cognitive processes under abnormal conditions were evaluated by protocol analyses interviews, etc. in the experiment using a plant training simulator. A cognitive process model is represented by a stochastic network, based on Rasmussen's decision making model. Each node of the network corresponds to an element of the cognitive process, such as observation, interpretation, execution, etc. Some observations were obtained as follows, by comparison of Monte Carlo simulation results with the experiment results: A process to reconfirm the plant parameters after execution of a task and feedback paths from this process to the observation and the task definition of next task were observed. The feedback probability average and standard deviation should be determined for each incident type to explain correctly the individual differences in the cognitive processes. The tendency for the operator's cognitive level to change from skill-based to knowledge-based via rule-based behavior was observed during the feedback process

  4. Simulation and design of feedback control on resistive wall modes in Keda Torus eXperiment

    International Nuclear Information System (INIS)

    Li, Chenguang; Liu, Wandong; Li, Hong

    2014-01-01

    The feedback control of resistive wall modes (RWMs) in Keda Torus eXperiment (KTX) (Liu et al., Plasma Phys. Controlled Fusion 56, 094009 (2014)) is investigated by simulation. A linear model is built to describe the growth of the unstable modes in the absence of feedback and the resulting mode suppression due to feedback, given the typical reversed field pinch plasma equilibrium. The layout of KTX with two shell structures (the vacuum vessel and the stabilizing shell) is taken into account. The feedback performance is explored both in the scheme of “clean mode control” (Zanca et al., Nucl. Fusion 47, 1425 (2007)) and “raw mode control.” The discrete time control model with specific characteristic times will mimic the real feedback control action and lead to the favored control cycle. Moreover, the conceptual design of feedback control system is also presented, targeting on both RWMs and tearing modes

  5. Recent U.S. reactor operating experience

    International Nuclear Information System (INIS)

    Stello, V. Jr.

    1977-01-01

    A qualitative assessment of U.S. and foreign reactor operating experience is provided. Recent operating occurrences having potentially significant safety impacts on power operation are described. An evaluation of the seriousness of each of these issues and the plans for resolution is discussed. A quantitative report on U.S. reactor operational experience is included. The details of the NRC program for evaluating and applying operating reactor experience in the regulatory process is discussed. A review is made of the adequacy of operating reactor safety and environmental margins based on actual operating experience. The Regulatory response philosophy to operating reactor experiences is detailed. This discussion indicates the NRC emphasis on the importance of a balanced action plan to provide for the protection of public safety in the national interest

  6. Commissioning experience from PEP-II HER longitudinal feedback

    International Nuclear Information System (INIS)

    Prabhakar, S.; Teytelman, D.; Fox, J.; Young, A.; Corredoura, P.; Tighe, R.

    1998-06-01

    The DSP-based bunch-by-bunch feedback system installed in the PEP-II HER has been used to damp HOM-induced instabilities at beam currents up to 6-5 mA during commissioning. Beam pseudospectra calcualted from feedback system data indicate the presence of coupled bunch modes that oincide with the 0-M-2 cavity HOM. Bunch current and synchronous phase measurements are also extracted from the data. These measurements reveal the impedance seen by the beam at revolution harmonics. The impedance peak at 3*frev indicates incorrect parking of the idle cavities, and explains the observed instability of mode 3. Bunch synchrotron tunes are calculated from lorentzian fits to the data. Bunch-to-bunch time variation due to the cavity transient is shown to be large enough to result in Landau damping of coupled bunch modes

  7. BWR and ABWR operating experience

    International Nuclear Information System (INIS)

    Nagai, Kimio; Takayama, Yoshito; Shimizu, Shunichi

    1998-01-01

    The first commercial operation of a nuclear power plant in Japan was in 1969. At present, there are 52 nuclear power plants operating in the country, accounting for about 35% of the total electricity generated and about 20 % of the total capacity of electricity generation facilities in Japan. Moreover, Japan has had the highest facility utilization rate, which is an indicator of operational safety, among the top four nuclear-generation countries (U.S.A., France, Germany, and Japan) every year since 1993, and has maintained a utilization rate of more than 80% since 1995. Toshiba has supported plant operation and maintenance in 19 nuclear power plants. The overall facility utilization rate of these plants attained a record of 86.4% in fiscal 1996. Furthermore, the averaged rates over the past three fiscal years from 1995 to 1997 have been the highest in the world among plant constructors such as GE, WH, and Siemens. (author)

  8. Feedback experience from the decommissioning of Spanish nuclear facilities

    International Nuclear Information System (INIS)

    Santiago, J.L.

    2008-01-01

    The Spain has accumulated significant experience in the field of decommissioning of nuclear and radioactive facilities. Relevant projects include the remediation of uranium mills and mines, the decommissioning of research reactors and nuclear research facilities and the decommissioning of gas-graphite nuclear power plants. The decommissioning of nuclear facilities in Spain is undertaken by ENRESA, who is also responsible for the management of radioactive wastes. The two most notable projects are the decommissioning of the Vandellos I nuclear power plant and the decommissioning of the CIEMAT nuclear research centre. The Vandellos I power plant was decommissioned in about five years to what is known as level 2. During this period, the reactor vessel was confined, most plant systems and components were dismantled, the facility was prepared for a period of latency and a large part of the site was restored for subsequent release. In 2005 the facility entered into the phase of dormancy, with minimum operating requirements. Only surveillance and maintenance activities are performed, among which special mention should be made to the five-year check of the leak tightness of the reactor vessel. After the dormancy period (25 - 30 years), level 3 of decommissioning will be initiated including the total dismantling of the remaining parts of the plant and the release of the whole site for subsequent uses. The decommissioning of the CIEMAT Research Centre includes the dismantling of obsolete facilities such as the research reactor JEN-1, a pilot reprocessing plant, a fuel fabrication facility, a conditioning plant for liquid and a liquid waste storage facility which were shutdown in the early eighties. Dismantling works have started in 2006 and will be completed by 2009. On the basis of the experience gained in the above mentioned sites, this paper describes the approaches adopted by ENRESA for large decommissioning projects. (author)

  9. Nuclear units operating improvement by using operating experience

    International Nuclear Information System (INIS)

    Rotaru, I.; Bilegan, I.C.

    1997-01-01

    The paper presents how the information experience can be used to improve the operation of nuclear units. This areas include the following items: conservative decision making; supervisory oversight; teamwork; control room distraction; communications; expectations and standards; operator training and fundamental knowledge, procedure quality and adherence; plant status awareness. For each of these topics, the information illustrate which are the principles, the lessons learned from operating experience and the most appropriate exemplifying documents. (authors)

  10. Operational experience with superconducting synchrotron magnets

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-03-01

    The operational experience with the Fermilab Tevatron is presented, with emphasis on reliability and failure modes. Comprisons are made between the operating efficiencies for the superconducting machine and for he conventional Main Ring

  11. Operational experience with superconducting synchrotron magnets

    International Nuclear Information System (INIS)

    Martin, P.S.

    1987-01-01

    The operational experience with the Fermilab Tevatron is presented, with emphasis on reliability and failure modes. Comparisons are made between the operating efficiencies for the superconducting machine and for the conventional Main Ring

  12. EBR-II operating experience

    International Nuclear Information System (INIS)

    Smith, C.R.F.

    1978-07-01

    Operation of the EBR-2 reactor is presented concerning the performance of the heat removal system; reactor materials; fuel handling system; sodium purification and sampling system; cover-gas purification; plant diagnostics and instrumentation; recent improvements in identifying fission product sources in EBR-2; and EBR-2 safety

  13. Reactor operator screening test experiences

    International Nuclear Information System (INIS)

    O'Brien, W.J.; Penkala, J.L.; Witzig, W.F.

    1976-01-01

    When it became apparent to Duquesne Light Company of Pittsburgh, Pennsylvania, that the throughput of their candidate selection-Phase I training-reactor operator certification sequence was something short of acceptable, the utility decided to ask consultants to make recommendations with respect to candidate selection procedures. The recommendation implemented was to create a Nuclear Training Test that would predict the success of a candidate in completing Phase I training and subsequently qualify for reactor operator certification. The mechanics involved in developing and calibrating the Nuclear Training Test are described. An arbitration decision that resulted when a number of International Brotherhood of Electrical Workers union employees filed a grievance alleging that the selection examination was unfair, invalid, not job related, inappropriate, and discriminatorily evaluated is also discussed. The arbitration decision favored the use of the Nuclear Training Test

  14. Experiences of an operating association

    International Nuclear Information System (INIS)

    Zefferer, H.

    1994-01-01

    The Austrian Draukraftwerke operate a coal power station with a capacity 110 MW el at St. Andraein Kaernten. In 1989, the first stage of a scheme for supplying the town St. Andraewith long-distance energy was started from this power station. To provide for the intermittent downtimes between the plant's operating times, which total an annual 2000 hours, a substitute aggregate was designed consisting of two biomass (chiefly bark)-fueled grate-firing boilers (4 MW th and 2.5 MW th ). The problems that arose during the first years in the areas of biomass storage, conveyor systems, slagging, emission values, and ash removal have meanwhile been solved satisfactorily. Moreover, the Draukraftwerke intend to use biomass for electricity generation in their coal power stations. (orig.) [de

  15. The Wonderland of Operating the ALICE Experiment

    CERN Document Server

    Augustinus, A; Pinazza, O; Rosinský, P; Lechman, M; Jirdén, L; Chochula, P

    2011-01-01

    ALICE is one of the experiments at the Large Hadron Collider (LHC), CERN, Geneva, Switzerland. Composed of 18 sub-detectors each with numerous subsystems that need to be controlled and operated in a safe and efficient way. The Detector Control System (DCS) is the key to this and has been used by detector experts with success during the commissioning of the individual detectors. During the transition from commissioning to operation, more and more tasks were transferred from detector experts to central operators. By the end of the 2010 datataking campaign, the ALICE experiment was run by a small crew of central operators, with only a single controls operator. The transition from expert to non-expert operation constituted a real challenge in terms of tools, documentation and training. A relatively high turnover and diversity in the operator crew that is specific to the HEP experiment environment (as opposed to the more stable operation crews for accelerators) made this challenge even bigger. Thi...

  16. Influence of a new generation of operations support systems on current spacecraft operations philosophy: The users feedback

    Science.gov (United States)

    Darroy, Jean Michel

    1993-01-01

    Current trends in the spacecraft mission operations area (spacecraft & mission complexity, project duration, required flexibility are requiring a breakthrough for what concerns philosophy, organization, and support tools. A major evolution is related to space operations 'informationalization', i.e adding to existing operations support & data processing systems a new generation of tools based on advanced information technologies (object-oriented programming, artificial intelligence, data bases, hypertext) that automate, at least partially, operations tasks that used be performed manually (mission & project planning/scheduling, operations procedures elaboration & execution, data analysis & failure diagnosis). All the major facets of this 'informationalization' are addressed at MATRA MARCONI SPACE, operational applications were fielded and generic products are becoming available. These various applications have generated a significant feedback from the users (at ESA, CNES, ARIANESPACE, MATRA MARCONI SPACE), which is now allowing us to precisely measure how the deployment of this new generation of tools, that we called OPSWARE, can 'reengineer' current spacecraft mission operations philosophy, how it can make space operations faster, better, and cheaper. This paper can be considered as an update of the keynote address 'Knowledge-Based Systems for Spacecraft Control' presented during the first 'Ground Data Systems for Spacecraft Control' conference in Darmstadt, June 1990, with a special emphasis on these last two years users feedback.

  17. The Effects of Active Videogame Feedback and Practicing Experience on Children's Physical Activity Intensity and Enjoyment.

    Science.gov (United States)

    Chen, Han; Sun, Haichun

    2017-08-01

    The study aims to explore the effects of receiving active videogame (AVG) feedback and playing experience on individuals' moderate-to-vigorous physical activity (MVPA) and perceived enjoyment. This was a within-subject design study. The participants included 36 (n = 15 and 21 for boys and girls, respectively) fourth graders enrolled in a rural elementary school in southern Georgia area. The experiment lasted for 6 weeks with each week including three sessions. The participants were assigned in either front row (sensor feedback) or back row (no sensor feedback) during practice, which was alternated in different sessions. Two different dance games were played during the study with each game implemented for 3 weeks. The MVPA was measured with GT3X+ accelerometers. Physical activity (PA) enjoyment was assessed after the completion of the first two and last two sessions of each game. A repeated one-way ANOVA (analysis of variance) was used to examine the effects of AVG feedback and game on MVPA. A repeated one-way MANOVA (multivariate analysis of variance) was conducted for each game to examine the effects of experience and AVG feedback on enjoyment and MVPA. No effects of AVG feedback were found for MVPA or enjoyment (P > 0.05). The effects of experience on MVPA were found for Just Dance Kids 2014 with experience decreased MVPA (P < 0.05). Students who practiced dance AVG without receiving feedback still demonstrated positive affection and accumulated similar MVPA than when practicing while receiving feedback. Experience for certain dance games tends to decrease PA intensity.

  18. Operational experience in underwater photogrammetry

    Science.gov (United States)

    Leatherdale, John D.; John Turner, D.

    Underwater photogrammetry has become established as a cost-effective technique for inspection and maintenance of platforms and pipelines for the offshore oil industry. A commercial service based in Scotland operates in the North Sea, USA, Brazil, West Africa and Australia. 70 mm cameras and flash units are built for the purpose and analytical plotters and computer graphics systems are used for photogrammetric measurement and analysis of damage, corrosion, weld failures and redesign of underwater structures. Users are seeking simple, low-cost systems for photogrammetric analysis which their engineers can use themselves.

  19. US remote monitoring operational experience

    International Nuclear Information System (INIS)

    Dupree, S.A.; Sonnier, C.S.

    1997-01-01

    Under international partnerships and bilateral agreements with the U.S. Department of Energy, Sandia National Laboratories, other national laboratories, and international partner organizations have emplaced remote monitoring systems in nuclear facilities and laboratories in various parts of the world for the purpose of conducting field trials of remote monitoring. The purpose of the present report is to review the results from these field trials and draw general conclusions regarding the trials. Many thousands of hours of sensor and system operation have been logged, and data have been retrieved from many locations. In virtually all cases the system components have functioned as intended and data have been successfully collected and transmitted for review. Comparisons between front-end-triggered video and time-lapse video have shown that the triggered record has captured all relevant monitored operations at the various nuclear facilities included in the field trials. We believe the utility and functional reliability of remote monitoring for international safeguards has been shown. However, it should be kept in mind that openness and transparency, including some form of short-notice inspections, are likely to be prerequisites to the safeguards implementation of remote monitoring in any State

  20. Practice of knowledge management for institutes--take the construction of experience feedback system as the example

    International Nuclear Information System (INIS)

    Wu Kaiping

    2014-01-01

    The construction of experience feedback system is an important part and breakthrough point of institutes' knowledge management. It is significant for institutes' design, management, development and innovation. This article introduces the concept of experience feedback for institutes. It also goes details of the content of experience feedback system construction for institutes, including the founding of experience feedback organizational mechanism, the development of experience feedback system, construction of knowledge database system, the construction of knowledge resources, and the appraisal of experience feedback's performance. Furthermore, the recognition and support of leaders, understanding and cooperation of relative departments, and corporation's culture of encouraging knowledge sharing, also are the important guarantees for the good effects of institutes' experience feedback work. (author)

  1. Feedback from operational experience in front-end transportation

    International Nuclear Information System (INIS)

    Mondonel, J.L.; Parison, C.

    1998-01-01

    Transport forms an integral part of the nuclear fuel cycle, representing the strategic link between each stage of the cycle. In a way there is a transport cycle that parallels the nuclear fuel cycle. This concerns particularly the front-end of the cycle whose steps - mining conversion, enrichment and fuel fabrication - require numerous transports. Back-end shipments involve a handful of countries, but front-end transports involve all five continents, and many exotic countries. All over Europe such transports are routinely performed with an excellent safety track record. Transnucleaire dominates the French nuclear transportation market and carries out both front and back-end transports. For instance in 1996 more than 28,400 front-end packages were transported as well as more than 3,600 back-end packages. However front-end transport is now a business undergoing much change. A nuclear transportation company must now cope with an evolving picture including new technical requirements, new transportation schemes and new business conditions. This paper describes the latest evolutions in terms of front-end transportation and the way this activity is carried out by Transnucleaire, and goes on to discuss future prospects. (authors)

  2. Improving Hospital Services Based on Patient Experience Data: Current Feedback Practices and Future Opportunities.

    Science.gov (United States)

    Kaipio, Johanna; Stenhammar, Hanna; Immonen, Susanna; Litovuo, Lauri; Axelsson, Minja; Lantto, Minna; Lahdenne, Pekka

    2018-01-01

    Patient feedback is considered important for healthcare organizations. However, measurement and analysis of patient reported data is useful only if gathered insights are transformed into actions. This article focuses on gathering and utilization of patient experience data at hospitals with the aim of supporting the development of patient-centered services. The study was designed to explore both current practices of collecting and utilizing patient feedback at hospitals as well as future feedback-related opportunities. Nine people working at different hierarchical levels of three university hospitals in Finland participated in in-depth interviews. Findings indicate that current feedback processes are poorly planned and inflexible. Some feedback data are gathered, but not systematically utilized. Currently, it is difficult to obtain a comprehensive picture of the situation. One future hope was to increase the amount of patient feedback to be able to better generalize and utilize the data. Based on the findings the following recommendations are given: attention to both patients' and healthcare staff's perspectives when collecting feedback, employing a coordinated approach for collecting and utilizing patient feedback, and organizational transformation towards a patient-centric culture.

  3. Fast digital transverse feedback system for bunch train operation in CESR

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J T; Billing, M G; Dobbins, J A [Cornell Univ., Ithaca, NY (United States). Lab. of Nuclear Studies; and others

    1996-08-01

    We have developed a time domain transverse feedback system with the high bandwidth needed to control transverse instabilities when the CESR e{sup +}e{sup -} collider is filled with trains of closely spaced bunches. This system is based on parallel digital processors and a stripline driver. It is capable of acting on arbitrary patterns of bunches having a minimum spacing of 14 ns. Several simplifying features have been introduced. A single shorted stripline kicker driven by one power amplifier is used to control both counter-rotating beams. The desired feedback phase is achieved by sampling the bunch position at a single location on two independently selectable beam revolutions. The system adapts to changes in the betatron tune, bunch pattern, or desired damping rate through the loading of new parameters into the digital processors via the CESR control system. The feedback system also functions as a fast gated bunch current monitor. Both vertical and horizontal loops are now used in CESR operation. The measured betatron damping rates with the transverse feedback system in operation are in agreement with the analytical prediction and a computer simulation developed in connection with this work. (author)

  4. Fast digital transverse feedback system for bunch train operation in CESR

    International Nuclear Information System (INIS)

    Rogers, J.T.; Billing, M.G.; Dobbins, J.A.

    1996-01-01

    We have developed a time domain transverse feedback system with the high bandwidth needed to control transverse instabilities when the CESR e + e - collider is filled with trains of closely spaced bunches. This system is based on parallel digital processors and a stripline driver. It is capable of acting on arbitrary patterns of bunches having a minimum spacing of 14 ns. Several simplifying features have been introduced. A single shorted stripline kicker driven by one power amplifier is used to control both counter-rotating beams. The desired feedback phase is achieved by sampling the bunch position at a single location on two independently selectable beam revolutions. The system adapts to changes in the betatron tune, bunch pattern, or desired damping rate through the loading of new parameters into the digital processors via the CESR control system. The feedback system also functions as a fast gated bunch current monitor. Both vertical and horizontal loops are now used in CESR operation. The measured betatron damping rates with the transverse feedback system in operation are in agreement with the analytical prediction and a computer simulation developed in connection with this work. (author)

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

    International Nuclear Information System (INIS)

    Nelson, Brian A.

    2006-01-01

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

  6. Final analysis of the engineering data on the scyllac feedback stabilization experiment

    International Nuclear Information System (INIS)

    Kutac, K.J.; Kewish, R.W.; Miller, G.; Gribble, R.F.

    1977-01-01

    The feedback stabilization system consists of four basic components: plasma position detectors, a signal processor or mode analyzer driven by the position detector signals, power amplifiers which are driven by the mode analyzer, and feedback load coils driven by the power amplifiers. A short description of each of the four components of the system is presented. The location of the components in the experiment is shown

  7. Operator training and the training simulator experience

    International Nuclear Information System (INIS)

    Mills, D.

    The author outlines the approach used by Ontario Hydro to train operators from the day they are hired as Operators-in-Training until they are Authorized Unit First Operators. He describes in detail the use of the simulator in the final year of the authorization program, drawing on experience with the Pickering NGS A simulator. Simulators, he concludes, are important aids to training but by no means all that is required to guarantee capable First Operators

  8. Industry Operating Experience Process at Krsko NPP

    International Nuclear Information System (INIS)

    Bach, B.; Bozin, B.; Cizmek, R.

    2012-01-01

    Experience has shown that number of minor events and near misses, usually without immediate or significant impact to plant safety and reliability, are precursors of significant or severe events due to the same or similar root or apparent cause(s). It is therefore desirable to identify and analyze weaknesses of the precursor problems (events) in order to prevent occurrence of significant events. Theoretically, significant events could be prevented from occurring if the root cause(s) of these precursor problems could be identified and eliminated. The Operating Experience Program identifies such event precursors and by reporting them to the industry, plant specific corrective actions can be taken to prevent events at other operational plants. The intent of the Operating Experience Program is therefore to improve nuclear power plant safety and reliability of the operating nuclear power plants. Each plant develops its own Operating Experience Program in order to learn from the in-house operating experience as well as from the world community of nuclear plants. The effective use of operating experience includes analyzing both plant and industry events in order to identify fundamental weaknesses and then determining appropriate plant-specific actions that will minimize the likelihood of similar events. Learning and applying the lessons from operating experience is an integral part of station safety culture and is encouraged by managers throughout the top plant administrative programs and procedures. Krsko NPP is developed it own Operating Experience Program by using the most relevant INPO/WANO/IAEA guidelines as well as its own knowledge, skills an operating practice. The Operating Experience Program is a part of the Corrective Action Program, which is among top management programs, thus program is strongly encouraged by top management. The purpose of Operating Experience Program is to provide guidance for using, sharing, and evaluating operating experience information

  9. Operating wind turbines in strong wind conditions by using feedforward-feedback control

    International Nuclear Information System (INIS)

    Feng, Ju; Sheng, Wen Zhong

    2014-01-01

    Due to the increasing penetration of wind energy into power systems, it becomes critical to reduce the impact of wind energy on the stability and reliability of the overall power system. In precedent works, Shen and his co-workers developed a re-designed operation schema to run wind turbines in strong wind conditions based on optimization method and standard PI feedback control, which can prevent the typical shutdowns of wind turbines when reaching the cut-out wind speed. In this paper, a new control strategy combing the standard PI feedback control with feedforward controls using the optimization results is investigated for the operation of variable-speed pitch-regulated wind turbines in strong wind conditions. It is shown that the developed control strategy is capable of smoothening the power output of wind turbine and avoiding its sudden showdown at high wind speeds without worsening the loads on rotor and blades

  10. A Current-Mode Common-Mode Feedback Circuit (CMFB) with Rail-to-Rail Operation

    Science.gov (United States)

    Suadet, Apirak; Kasemsuwan, Varakorn

    2011-03-01

    This paper presents a current-mode common-mode feedback (CMFB) circuit with rail-to-rail operation. The CMFB is a stand-alone circuit, which can be connected to any low voltage transconductor without changing or upsetting the existing circuit. The proposed CMFB employs current mirrors, operating as common-mode detector and current amplifier to enhance the loop gain of the CMFB. The circuit employs positive feedback to enhance the output impedance and gain. The circuit has been designed using a 0.18 μm CMOS technology under 1V supply and analyzed using HSPICE with BSIM3V3 device models. A pseudo-differential amplifier using two common sources and the proposed CMFB shows rail to rail output swing (± 0.7 V) with low common-mode gain (-36 dB) and power dissipation of 390 μW.

  11. Non destructive examinations and degradations: the use of feedback experience to improve maintenance policy

    International Nuclear Information System (INIS)

    Champigny, F.

    2007-01-01

    In France, since 1995, 58 pressurized water reactors have been operating to produce electricity. These reactors were built from 1975 to the beginning of nineties and are ranked in 4 standardized series, 900 MWe CP0 types, 900 MWe CPY types, 1300 MWe types and 1400 MWe types. The plants have undergone evolutions taking into account the feedback experience for manufacturing and construction, net power growth but also maintenance operations. In 1977 the first maintenance programs were based upon the American experience using ASME section XI code. As and when required, they have been modified with the events appeared during the operation. First of them concerned the steam generator tubes with the discover of the first primary water stress corrosion cracking at the end of the seventies then the under-clad cracking phenomenon in the 900 MWe pressure vessel nozzles. At the beginning of years 2000, the new departmental order dedicated to operation required to check and modify, if necessary, the maintenance policy to better take into account the possible damages, fast fracture studies for primary and secondary systems and, last but not least, qualification processes for non destructive examinations. These new requirements have induced a rewriting of the maintenance policies and inspection programs in the way to be more consistent with the need of an improved availability of the plants while keeping a high safety level. Through few examples, we show how the approaches and the practices have been modified in terms of non-destructive examination (NDE) and particularly the impact of the NDE qualification results. In addition, examples of the important choices between in-service inspection and repair policy are also described. (author)

  12. The Tore Supra toroidal pump limiter: experience feedback of HHF elements series manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Cordier, J.J.; Bayetti, P.; Chappuis, P.; Durocher, A.; Escourbiac, F.; Grosman, A.; Lipa, M.; Mitteau, R.; Schlosser, J.; Van Houtte, D

    2003-07-01

    Since 1992, reliable High Heat Flux PFCs based on copper alloy heat sink structures and a CFC armour, have been developed. The final result is an actively cooled high heat flux element that is capable of removing up to 10 MW.m{sup -2} in stationary operating conditions. About 600 of these high performance individual components have then been manufactured and assembled in order to equip a Toroidal Pump Limiter (TPL). The final deliveries was successfully achieved end of 2001. The paper deals with the experience feedback built-up along the four years duration of the TPL components manufacture. We will show where issues were encountered, how solutions were found to achieve the fabrication of components and will highlight what are the main technical lessons to be learned: acceptance criteria, choice of materials, margins of processes. Finally a proposal of an alternative optimised design is presented, fruit of the experience gained from this up to now, unique series manufacture of actively cooled plasma facing HHF components. We believe that such experience will certainly be of use to ITER as well as to Wendelstein 7-X as far as PFC is concerned. (authors)

  13. Regulatory challenges in using nuclear operating experience

    International Nuclear Information System (INIS)

    2006-01-01

    The fundamental objective of all nuclear safety regulatory bodies is to ensure that nuclear utilities operate their plants in an acceptably safe manner at all times. Learning from experience has been a key element in meeting this objective. It is therefore very important for nuclear power plant operators to have an active programme for collecting, analysing and acting on the lessons of operating experience that could affect the safety of their plants. NEA experts have noted that almost all of the recent, significant events reported at international meetings have occurred earlier in one form or another. Counteractions are usually well-known, but information does not always seem to reach end users, or corrective action programmes are not always rigorously applied. Thus, one of the challenges that needs to be met in order to maintain good operational safety performance is to ensure that operating experience is promptly reported to established reporting systems, preferably international in order to benefit from a larger base of experience, and that the lessons from operating experience are actually used to promote safety. This report focuses on how regulatory bodies can ensure that operating experience is used effectively to promote the safety of nuclear power plants. While directed at nuclear power plants, the principles in this report may apply to other nuclear facilities as well. (author)

  14. PPOOLEX experiments on dynamic loading with pressure feedback

    International Nuclear Information System (INIS)

    Puustinen, M.; Laine, J.; Raesaenen, A.

    2011-01-01

    This report summarizes the results of the dynamic loading experiments (DYN series) carried out with the scaled down, two compartment PPOOLEX test facility designed and constructed at LUT. Steam was blown into the dry well compartment and from there through the DN200 vertical blowdown pipe to the condensation pool filled with sub-cooled water. The main purpose of the experiments was to study dynamic loads caused by different condensation modes. Particularly, the effect of counterpressure on loads due to pressure oscillations induced by chugging was of interest. Before the experiments the condensation pool was filled with isothermal water so that the blowdown pipe outlet was submerged by 1.03-1.11 m. The initial temperature of the pool water varied from 11 deg. C to 63 deg. C, the steam flow rate from 290 g/s to 1220 g/s and the temperature of incoming steam from 132 deg. C to 182 deg. C. Non-condensables were pushed from the dry well into the gas space of the wet well with a short discharge of steam before the recorded period of the experiments. As a result of this procedure, the system pressure was at an elevated level in the beginning of the actual experiments. An increased counterpressure was used in the last experiment of the series. The diminishing effect of increased system pressure on chugging intensity and on measured loads is evident from the results of the last experiment. The highest pressure pulses both inside the blowdown pipe and in the condensation pool were about half of those measured with a lower system pressure but otherwise with similar test parameters. The experiments on dynamic loading gave expected results. The loads experienced by pool structures depended strongly on the steam mass flow rate, pool water temperature and system pressure. The DYN experiments indicated that chugging and condensation within the blowdown pipe cause significant dynamic loads in case of strongly sub-cooled pool water. The level of pool water temperature is decisive

  15. PPOOLEX experiments on dynamic loading with pressure feedback

    Energy Technology Data Exchange (ETDEWEB)

    Puustinen, M.; Laine, J.; Raesaenen, A. (Lappeenranta Univ. of Technology, Nuclear Safety Research Unit (Finland))

    2011-01-15

    This report summarizes the results of the dynamic loading experiments (DYN series) carried out with the scaled down, two compartment PPOOLEX test facility designed and constructed at LUT. Steam was blown into the dry well compartment and from there through the DN200 vertical blowdown pipe to the condensation pool filled with sub-cooled water. The main purpose of the experiments was to study dynamic loads caused by different condensation modes. Particularly, the effect of counterpressure on loads due to pressure oscillations induced by chugging was of interest. Before the experiments the condensation pool was filled with isothermal water so that the blowdown pipe outlet was submerged by 1.03-1.11 m. The initial temperature of the pool water varied from 11 deg. C to 63 deg. C, the steam flow rate from 290 g/s to 1220 g/s and the temperature of incoming steam from 132 deg. C to 182 deg. C. Non-condensables were pushed from the dry well into the gas space of the wet well with a short discharge of steam before the recorded period of the experiments. As a result of this procedure, the system pressure was at an elevated level in the beginning of the actual experiments. An increased counterpressure was used in the last experiment of the series. The diminishing effect of increased system pressure on chugging intensity and on measured loads is evident from the results of the last experiment. The highest pressure pulses both inside the blowdown pipe and in the condensation pool were about half of those measured with a lower system pressure but otherwise with similar test parameters. The experiments on dynamic loading gave expected results. The loads experienced by pool structures depended strongly on the steam mass flow rate, pool water temperature and system pressure. The DYN experiments indicated that chugging and condensation within the blowdown pipe cause significant dynamic loads in case of strongly sub-cooled pool water. The level of pool water temperature is decisive

  16. Simulator experiments: effects of NPP operator experience on performance

    International Nuclear Information System (INIS)

    Beare, A.N.; Gray, L.H.

    1985-01-01

    Experiments are being conducted on nuclear power plant (NPP) control room training simulators by the Oak Ridge National Laboratory, its subcontractor, General Physics Corporation, and participating utilities. The experiments are sponsored by the Nuclear Regulatory Commission's (NRC) Human Factors and Safeguards Branch, Division of Risk Analysis and Operations, and are a continuation of prior research using simulators, supported by field data collection, to provide a technical basis for NRC human factors regulatory issues concerned with the operational safety of nuclear power plants. During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE boiling water reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of (a) senior reactor operator (SRO) experience, (b) operating crew augmentation with an STA and (c) practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator. Methodology and results to date are reported

  17. A virtual reality-based method of decreasing transmission time of visual feedback for a tele-operative robotic catheter operating system.

    Science.gov (United States)

    Guo, Jin; Guo, Shuxiang; Tamiya, Takashi; Hirata, Hideyuki; Ishihara, Hidenori

    2016-03-01

    An Internet-based tele-operative robotic catheter operating system was designed for vascular interventional surgery, to afford unskilled surgeons the opportunity to learn basic catheter/guidewire skills, while allowing experienced physicians to perform surgeries cooperatively. Remote surgical procedures, limited by variable transmission times for visual feedback, have been associated with deterioration in operability and vascular wall damage during surgery. At the patient's location, the catheter shape/position was detected in real time and converted into three-dimensional coordinates in a world coordinate system. At the operation location, the catheter shape was reconstructed in a virtual-reality environment, based on the coordinates received. The data volume reduction significantly reduced visual feedback transmission times. Remote transmission experiments, conducted over inter-country distances, demonstrated the improved performance of the proposed prototype. The maximum error for the catheter shape reconstruction was 0.93 mm and the transmission time was reduced considerably. The results were positive and demonstrate the feasibility of remote surgery using conventional network infrastructures. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Feasibility of international data collection and feedback on post-operative pain data: proof of concept.

    Science.gov (United States)

    Zaslansky, R; Chapman, C R; Rothaug, J; Bäckström, R; Brill, S; Davidson, E; Elessi, K; Fletcher, D; Fodor, L; Karanja, E; Konrad, C; Kopf, A; Leykin, Y; Lipman, A; Puig, M; Rawal, N; Schug, S; Ullrich, K; Volk, T; Meissner, W

    2012-03-01

    Post-operative pain exacts a high toll from patients, families, healthcare professionals and healthcare systems worldwide. PAIN-OUT is a research project funded by the European Union's 7th Framework Program designed to develop effective, evidence-based approaches to improve pain management after surgery, including creating a registry for feedback, benchmarking and decision support. In preparation for PAIN-OUT, we conducted a pilot study to evaluate the feasibility of international data collection with feedback to participating sites. Adult orthopaedic or general surgery patients consented to participate between May and October 2008 at 14 collaborating hospitals in 13 countries. Project staff collected patient-reported outcomes and process data from 688 patients and entered the data into an online database. Project staff in 10 institutions met the enrolment criteria of collecting data from at least 50 patients. The completeness and quality of the data, as assessed by rate of missing data, were acceptable; only 2% of process data and 0.06% of patient-reported outcome data were missing. Participating institutions received access to select items as Web-based feedback comparing their outcomes to those of the other sites, presented anonymously. We achieved proof of concept because staff and patients in all 14 sites cooperated well despite marked differences in cultures, nationalities and languages, and a central database management team was able to provide valuable feedback to all. © 2011 European Federation of International Association for the Study of Pain Chapters.

  19. Operational experience with the Daresbury accelerator tube

    International Nuclear Information System (INIS)

    Aitken, T.W.; Eastham, D.A.; Joy, T.; Leese, J.M.; Tait, N.R.S.; Thorn, R.

    1986-01-01

    Operational experience with the Daresbury MKI accelerator tube is reviewed with particular attention to conditioning and high voltage performance. The effects of surges and transients on the tube are described and lines of future development are discussed. (orig.)

  20. Evaluating Effectiveness of Modeling Motion System Feedback in the Enhanced Hess Structural Model of the Human Operator

    Science.gov (United States)

    Zaychik, Kirill; Cardullo, Frank; George, Gary; Kelly, Lon C.

    2009-01-01

    In order to use the Hess Structural Model to predict the need for certain cueing systems, George and Cardullo significantly expanded it by adding motion feedback to the model and incorporating models of the motion system dynamics, motion cueing algorithm and a vestibular system. This paper proposes a methodology to evaluate effectiveness of these innovations by performing a comparison analysis of the model performance with and without the expanded motion feedback. The proposed methodology is composed of two stages. The first stage involves fine-tuning parameters of the original Hess structural model in order to match the actual control behavior recorded during the experiments at NASA Visual Motion Simulator (VMS) facility. The parameter tuning procedure utilizes a new automated parameter identification technique, which was developed at the Man-Machine Systems Lab at SUNY Binghamton. In the second stage of the proposed methodology, an expanded motion feedback is added to the structural model. The resulting performance of the model is then compared to that of the original one. As proposed by Hess, metrics to evaluate the performance of the models include comparison against the crossover models standards imposed on the crossover frequency and phase margin of the overall man-machine system. Preliminary results indicate the advantage of having the model of the motion system and motion cueing incorporated into the model of the human operator. It is also demonstrated that the crossover frequency and the phase margin of the expanded model are well within the limits imposed by the crossover model.

  1. Combining risk analysis and operating experience

    International Nuclear Information System (INIS)

    1986-10-01

    In recent years there has been an increasing interest in the systematic utilization of operating experience in the decision making process concerning large industrial facilities. Even before the advent of Probabilistic Safety Assessment (PSA), operating experience had always played an important role in such decisions. Of course, operating experience has always been an input to PSA also; however, as PSA becomes more mature and the quality and quantity of operating experience improve, greater emphasis is now being placed on the use of operating experience to update and validate PSA and thereby provide a more rational basis for decision making. This report outlines the ways in which data are collected, processed using mathematical techniques and utilized in decision making. It is not intended to provide details of the methods and procedures to be used in these areas, but is rather intended as an introduction to these topics and some of the relevant literature. The meeting presentations were divided into three sessions devoted to the following topics: evaluation of nuclear power plants operational experience (5 papers); uncertainties (2 papers); probabilistic safety assessment studies in Member States (7 papers). A separate abstract was prepared for each of these papers

  2. Operational experience of the Marcoule reactors

    International Nuclear Information System (INIS)

    Conte, F.

    1963-01-01

    The results obtaining from three years operation of the reactors G-2, G-3 have made it possible to accumulate a considerable amount of operational experience of these reactors. The main original points: - the pre-stressed concrete casing - the possibility of loading while under power - automatic temperature control have been perfectly justified by the results of operation. The author confirms the importance of these original solutions and draws conclusions concerning the study of future nuclear power stations. (author) [fr

  3. MIT January Operational Internship Experience 2011

    Science.gov (United States)

    DeLatte, Danielle; Furhmann, Adam; Habib, Manal; Joujon-Roche, Cecily; Opara, Nnaemeka; Pasterski, Sabrina Gonzalez; Powell, Christina; Wimmer, Andrew

    2011-01-01

    This slide presentation reviews the 2011 January Operational Internship experience (JOIE) program which allows students to study operational aspects of spaceflight, how design affects operations and systems engineering in practice for 3 weeks. Topics include: (1) Systems Engineering (2) NASA Organization (3) Workforce Core Values (4) Human Factors (5) Safety (6) Lean Engineering (7) NASA Now (8) Press, Media, and Outreach and (9) Future of Spaceflight.

  4. Operating manual for the critical experiments facility

    International Nuclear Information System (INIS)

    1986-01-01

    The operation of the Critical Experiments Facility (CEF) requires careful attention to procedures in order that all safety precautions are observed. Since an accident could release large amounts of radioactivity, careful operation and strict enforcement of procedures are necessary. To provide for safe operation, detailed procedures have been written for all phases of the operation of this facility. The CEF operating procedures are not to be construed to constitute a part ofthe Technical Specifications. In the event of any discrepancy between the information given herein and the Technical Specifications, limits set forth in the Technical Specifications apply. All normal and most emergency operation conditions are covered by procedures presented in this manual. These procedures are designed to be followed by the operating personnel. Strict adherence to these procedures is expected for the following reasons. (1) To provide a standard, safe method of performing all operations, the procedures were written by reactor engineers experienced in supervising the operation of reactors and were reviewed by an organization with over 30 years of reactor operating experience. (2) To have an up-to-date description of operating techniques available at all times for reference and review, it is necessary that the procedures be written

  5. Operating manual for the critical experiments facility

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    The operation of the Critical Experiments Facility (CEF) requires careful attention to procedures in order that all safety precautions are observed. Since an accident could release large amounts of radioactivity, careful operation and strict enforcement of procedures are necessary. To provide for safe operation, detailed procedures have been written for all phases of the operation of this facility. The CEF operating procedures are not to be construed to constitute a part ofthe Technical Specifications. In the event of any discrepancy between the information given herein and the Technical Specifications, limits set forth in the Technical Specifications apply. All normal and most emergency operation conditions are covered by procedures presented in this manual. These procedures are designed to be followed by the operating personnel. Strict adherence to these procedures is expected for the following reasons. (1) To provide a standard, safe method of performing all operations, the procedures were written by reactor engineers experienced in supervising the operation of reactors and were reviewed by an organization with over 30 years of reactor operating experience. (2) To have an up-to-date description of operating techniques available at all times for reference and review, it is necessary that the procedures be written.

  6. 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.

  7. Operating Experience from Events Reported to the IAEA Incident Reporting System for Research Reactors

    International Nuclear Information System (INIS)

    2015-03-01

    Operating experience feedback is an effective mechanism in providing lessons learned from events and the associated corrective actions to prevent them, helping to improve safety at nuclear installations. The Incident Reporting System for Research Reactors (IRSRR), which is operated by the IAEA, is an important tool for international exchange of operating experience feedback for research reactors. The IRSRR reports contain information on events of safety significance with their root causes and lessons learned which help in reducing the occurrence of similar events at research reactors. To improve the effectiveness of the system, it is essential that national organizations demonstrate an appropriate interest for the timely reporting of events important to safety and share the information in the IRSRR database. At their biennial technical meetings, the IRSRR national coordinators recommended collecting the operating experience from the events reported to the IRSRR and disseminating it in an IAEA publication. This publication highlights the root causes, safety significance, lessons learned, corrective actions and the causal factors for the events reported to the IRSRR up to September 2014. The publication also contains relevant summary information on research reactor events from sources other than the IRSRR, operating experience feedback from the International Reporting System for Operating Experience considered relevant to research reactors, and a description of the elements of an operating experience programme as established by the IAEA safety standards. This publication will be of use to research reactor operating organizations, regulators and designers, and any other organizations or individuals involved in the safety of research reactors

  8. Experience feedback from event reports: the human contribution

    International Nuclear Information System (INIS)

    Swaton, E.; Tolstykh, V.

    1990-01-01

    Analysis of reported events reveals that in a large number of areas human intervention contributed to the initiation and/or development of these events. Since an accident at any nuclear power plant can have a world-wide effect on public acceptance, the need for attentive and reliable human behavior assumes an even greater significance. The identification of areas where human interaction can have an impact on safe operation is mainly relying on the analysis of events reported to the nuclear community. Any substantial compilation of safety significant operational events such as contained in the IAEA-IRS (Incident Reporting System) is bound to provide valuable and factual insights into problem areas, their origin, development, impact and some remedial actions. Thus a systematic analysis has been carried out on over 200 events where a human contribution could be identified. Some events of particular interest will be discussed and furthermore generic lessons will be presented. In addition the Assessment of Safety Significant Event Technique (ASSET) developed within IAEA which provides a structured methodology to identify not only the direct cause explaining why an individual failed but more important, insights on the root causes explaining why this latent deficiency was not detected earlier through the plant surveillance programme was applied. (author)

  9. Simulator experiments: effects of NPP operator experience on performance

    International Nuclear Information System (INIS)

    Beare, A.N.; Gray, L.H.

    1984-01-01

    During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE Boiling Water Reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of senior reactor operator (SRO) experience, operating crew augmentation with an STA and practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. Sixteen two-man crews of licensed operators were employed in a 2 x 2 factorial design. The SROs leading the crews were split into high and low experience groups on the basis of their years of experience as an SRO. One half of the high- and low-SRO experience groups were assisted by an STA. The crews responded to four simulated plant casualties. A five-variable set of content-referenced performance measures was derived from task analyses of the procedurally correct responses to the four casualties. System parameters and control manipulations were recorded by the computer controlling the simulator. Data on communications and procedure use were obtained from analysis of videotapes of the exercises. Questionnaires were used to collect subject biographical information and data on subjective workload during each simulated casualty. For four of the five performance measures, no significant differences were found between groups led by high (25 to 114 months) and low (1 to 17 months as an SRO) experience SROs. However, crews led by low experience SROs tended to have significantly shorter task performance times than crews led by high experience SROs. The presence of the STA had no significant effect on overall team performance in responding to the four simulated casualties. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator

  10. An evaluation of the feedback loops in the poverty focus of world bank operations.

    Science.gov (United States)

    Fardoust, Shahrokh; Kanbur, Ravi; Luo, Xubei; Sundberg, Mark

    2018-04-01

    The World Bank Group in 2013 made the elimination of extreme poverty by 2030 a central institutional focus and purpose. This paper, based on an evaluation conducted by the Independent Evaluation Group of the World Bank Group, examines how, and how well, the Bank uses feedback loops to enhance the poverty focus of its operations. Feedback loops are important for every element of the results chain running from data, to diagnostics, to strategy formulation and finally to strategy implementation. The evaluation uses a range of instruments, including surveys of stakeholders and World Bank staff, focus group meetings, country case studies and systematic reviews of Bank lending and non-lending operations. We find that while the Bank generates useful information on poverty reduction from its projects and programs, the feedback loops - from outcomes to data analysis to diagnostics to strategy formulation and implementation - have generally been weak, with sizable variation across countries. Copyright © 2017 The World Bank. Published by Elsevier Ltd.. All rights reserved.

  11. Kayenta advanced series compensation operational experience

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-01

    The world's first three-phase, thyristor-controlled series compensation scheme with continuously variable impedance has been introduced into a transmission system. Energized and dedicated in September 1992, the installation was placed into commercial operation in January 1993 and has provided over one year of operating experience. This paper describes the 230 kV, 330 MVAr (60 Hz) advanced series compensation (ASC) project, located in north-eastern Arizona at Kayenta Substation on the 320 km Glen Canyon-Shiprock transmission line. The paper describes operating experiences, coordination with phase shifting transformer, phase shifter failure, platform power, system disturbances, and future plans.

  12. Interrater reliability of quantitative ultrasound using force feedback among examiners with varied levels of experience

    Directory of Open Access Journals (Sweden)

    Michael O. Harris-Love

    2016-06-01

    Full Text Available Background. Quantitative ultrasound measures are influenced by multiple external factors including examiner scanning force. Force feedback may foster the acquisition of reliable morphometry measures under a variety of scanning conditions. The purpose of this study was to determine the reliability of force-feedback image acquisition and morphometry over a range of examiner-generated forces using a muscle tissue-mimicking ultrasound phantom. Methods. Sixty material thickness measures were acquired from a muscle tissue mimicking phantom using B-mode ultrasound scanning by six examiners with varied experience levels (i.e., experienced, intermediate, and novice. Estimates of interrater reliability and measurement error with force feedback scanning were determined for the examiners. In addition, criterion-based reliability was determined using material deformation values across a range of examiner scanning forces (1–10 Newtons via automated and manually acquired image capture methods using force feedback. Results. All examiners demonstrated acceptable interrater reliability (intraclass correlation coefficient, ICC = .98, p .90, p < .001, independent of their level of experience. The measurement error among all examiners was 1.5%–2.9% across all applied stress conditions. Conclusion. Manual image capture with force feedback may aid the reliability of morphometry measures across a range of examiner scanning forces, and allow for consistent performance among examiners with differing levels of experience.

  13. A System for the Feedback of Experience from Events in Nuclear Installations. Safety Guide (Spanish Edition); Un sistema de retroinformacion sobre la experiencia derivada de sucesos ocurridos en establecimientos nucleares. Guia de seguridad

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-15

    This Safety Guide provides recommendations on all the main components of operating experience feedback systems, utilizing relevant information on events and abnormal conditions that have occurred at nuclear installations around the world. It focuses on the interaction between the different systems for using operating experience feedback and constitutes an update and an extension of Part I, A National System, of Systems for Reporting Unusual Events in Nuclear Power Plants (IAEA Safety Series No. 93). Contents: 1. Introduction; 2. Main elements of a national system for the feedback of operational experience; 3. Screening of events; 4. Investigation and analysis of events; 5. Corrective actions; 6. Trending and review to recognize emergent problems; 7. Utilization, dissemination and exchange of information on operating experience; 8. Reviewing the effectiveness of the process for feedback of operational experience; 9. Quality assurance; 10. Reporting of safety related events; Appendix I: Reporting criteria and categories; Appendix II: Types of event report, timing, format and content; Appendix III: Investigation and analysis of events; Appendix IV: Approval and implementation of corrective actions; Annex I: Data management for the feedback of operating experience; Annex II: Example of elements of a national feedback system for operating experience.

  14. Operating experience and TPA: the Italian perspective

    International Nuclear Information System (INIS)

    Grimaldi, G.

    1990-01-01

    Collection and analysis of operating experience from the Italian plants and utilization of abroad data both to plants in operation and in construction are presented. Some results are also referred, aimed to evidence the role of the international cooperation to safe operation of nuclear plants. The approach to the Trend and Pattern analyses is described as well, and the use of computerized techniques of analysis on personal computer. Finally on going activities are introduced, specifically application of operating experience of plants in operation to small sized reactors and to ones with more intrinsic safety characteristics; review of the reporting system for future application and comparative analysis of the different realization of selected safety systems

  15. Experience in operation of heavy water reactors

    International Nuclear Information System (INIS)

    Rotaru, Ion; Bilegan, Iosif; Ghitescu, Petre

    1999-01-01

    The paper presents the main topics of the CANDU owners group (COG) meeting held in Mangalia, Romania on 7-10 September 1998. These meetings are part of the IAEA program for exchange of information related mainly to CANDU reactor operation safety. The first meeting for PHWR reactors took place in Vienna in 1989, followed by those in Argentina (1991), India (1994) and Korea (1996). The topics discussed at the meeting in Romania were: operation experience and recent major events, performances of CANDU reactors and safe operation, nuclear safety and operation procedures of PHWR, programs and strategies of lifetime management of installations and components of NPPs, developments and updates

  16. Manufacture and Erection of SFR Components: Feedback from PFBR Experience

    International Nuclear Information System (INIS)

    Chellapandi, P.

    2013-01-01

    Unique Features of SFR Components: • Large diameter thin walled shell and slender structures calling for stringent tolerances posing challenges in manufacturing, handling and erection. • Single side welds are unavoidable at some difficult locations. • In-service inspection is difficult. • Residual stresses should be minimum calling for robust heat treatment strategy. • Minimum number of materials to be used from reliability point of view (but not preferred from economic considerations). • Mainly austenitic stainless steels calling for careful considerations for welding without significant weld repairs and distortions. • Reactor assembly components decide the project time schedule (large manufacturing, assembly and erection time). • Leak tightness is very important in view of resulting sodium leaks. • Limited experience on manufacturing and erection of components. • Design and manufacturing codes still evolvingPFBR Reactor Assembly – Major Lessons: • Grid plate Large number of sleeves, posing difficulty in assembly, hard facing of large diameter plates and heavy flange construction. • Roof slab Large box type structure with many penetrations – complicated manufacturing process, time consuming and difficulty to overcome lamellar tearing problems. • Inclined Fuel Transfer Machine Complex manufacturing processes leading to large time and extensive qualification tests. • Increase of number of primary pipes – essential for enhancing safety. • Integration of components manufactured by different industries took unduly long time

  17. Fuel failure assessments based on radiochemistry. Experience feedback and challenges

    International Nuclear Information System (INIS)

    Petit, C.; Ziabletsev, D.; Zeh, P.

    2015-01-01

    Significant improvements have been observed in LWR nuclear fuel reliability over the past years. As a result, the number of fuel failures in PWRs and BWRs has recently dramatically decreased. Nevertheless, a few remaining challenges still exist. One of them is that the industry has recently started seeing a relatively new type of fuel failure, so-called 'weak leak failures', which could be characterized by a very small release of gaseous fission products and essentially almost zero release of iodines or any other soluble fission products in the reactor coolant. Correspondingly, the behavior of these weak leakers does not follow typical behavior of a conventional leaker characterized by a proportionality of the amount of released Xe 133 related to the failed rod power. Instead, for a weak leaker, the activity of Xe 133 is directly correlated to the size of the cladding defects of the leaker. The presence of undetected weak leaker in the core may lead to carryover of a leaker into the subsequent cycle. Even if the presence of weak leaker in the core is suspected, it typically requires more effort to identify the leaker which could result in extended duration of the outage and ultimately to economic losses to the utility operating the reactor. To effectively deal with this issue the industry has been facing, several changes have been recently realized, which are different from the methodology of dealing with conventional leaker. These changes include new assessment methods, the need for improved sipping techniques to better identify low release leakers, and correspondingly better equipment to be able to locate small clad defects associated with weak leaker, such as sensitive localization device of failed rods, sensitive eddy current coil for the failed rod, ultra high definition cameras for the failed rod examination and experienced fuel reliability engineers performing cause of failure and rood cause research and analyses. Ultimately, the destructive

  18. STUDENTS’ PERCEPTIONS OF THEIR REFLECTIVE ESSAY WRITING EXPERIENCE AND TEACHER FEEDBACK COMMENTS

    Directory of Open Access Journals (Sweden)

    Asiah Mohd Sharif

    2017-01-01

    Full Text Available Reflection which encompasses critical and analytical capabilities is a critical 21st century skill for students to develop. To ensure students are equipped with this skill, reflective writing has been identified as a possible tool. Teacher feedback on students’ written output therefore plays a role in developing students’ reflective skills. This study asks two questions: How do students perceive their experience writing reflective essays? What is the nature of the teacher’s feedback comments on students’ reflective essays and how do students perceive them? To answer these questions, nineteen ESL students in an entry-level Medical programme completed a questionnaire concerning their experiences writing reflective essays and perceptions of teacher feedback on these essays. Interviews were conducted with two students to follow-up on questionnaire responses. The content analysis showed that the students believed reflective writing played a small contribution to their language learning. Further investigation into the students’ perspectives of their teachers’ feedback comments suggests that even though the teachers’ feedback was positive, the students also referred to the comments as inadequate and ineffective. Pedagogical implications and suggestions for future research are discussed.

  19. Experiment feedbacks in micromechanics modeling of thermomechanical behaviors of SMA polycrystals

    International Nuclear Information System (INIS)

    Sittner, P.; Novak, V.

    2004-01-01

    Simulations of pseudoelastic deformation of NiTi and CuAlZnMn polycrystals using an earlier developed micromechanics model are presented. Advantages of having multiple feedbacks established between the model and in situ neutron diffraction experiment as well as doing modeling and experimentation simultaneously are discussed

  20. Changing Teacher Morale: An Experiment in Feedback of Identified Problems of Teachers and Principals. Final Report.

    Science.gov (United States)

    Bentley, Ralph R.; Rempel, Averno M.

    This 2-year study attempted to determine whether feedback to teachers and principals about problems and tensions existing in their schools can be effective in changing morale for (1) teachers generally, (2) vocational teachers, (3) and nonvocational teachers. Relationships between teacher morale and such factors as age, sex, teaching experience,…

  1. Are Success and Failure Experiences Equally Motivational? An Investigation of Regulatory Focus and Feedback

    Science.gov (United States)

    Shu, Tse-Mei; Lam, Shui-fong

    2011-01-01

    The present study extended regulatory focus theory (Idson & Higgins, 2000) to an educational setting and attempted to identify individuals with high motivation after both success and failure feedback. College students in Hong Kong (N = 180) participated in an experiment with a 2 promotion focus (high vs. low) x 2 prevention focus (high vs.…

  2. Management of a radiological emergency. Experience feedback and post-accident management

    International Nuclear Information System (INIS)

    Dubiau, Ph.

    2007-01-01

    In France, the organization of crisis situations and the management of radiological emergency situations are regularly tested through simulation exercises for a continuous improvement. Past severe accidents represent experience feedback resources of prime importance which have led to deep changes in crisis organizations. However, the management of the post-accident phase is still the object of considerations and reflections between the public authorities and the intervening parties. This document presents, first, the nuclear crisis exercises organized in France, then, the experience feedback of past accidents and exercises, and finally, the main aspects to consider for the post-accident management of such events: 1 - Crisis exercises: objectives, types (local, national and international exercises), principles and progress, limits; 2 - Experience feedback: real crises (major accidents, other recent accidental situations or incidents), crisis exercises (experience feedback organization, improvements); 3 - post-accident management: environmental contamination and people exposure, management of contaminated territories, management of populations (additional protection, living conditions, medical-psychological follow up), indemnification, organization during the post-accident phase; 4 - conclusion and perspectives. (J.S.)

  3. A Dataset of Three Educational Technology Experiments on Differentiation, Formative Testing and Feedback

    Science.gov (United States)

    Haelermans, Carla; Ghysels, Joris; Prince, Fernao

    2015-01-01

    This paper describes a dataset with data from three individually randomized educational technology experiments on differentiation, formative testing and feedback during one school year for a group of 8th grade students in the Netherlands, using administrative data and the online motivation questionnaire of Boekaerts. The dataset consists of pre-…

  4. Age vs. experience : evaluation of a video feedback intervention for newly licensed teen drivers.

    Science.gov (United States)

    2013-02-06

    This project examines the effects of age, experience, and video-based feedback on the rate and type of safety-relevant events captured on video event : recorders in the vehicles of three groups of newly licensed young drivers: : 1. 14.5- to 15.5-year...

  5. Rapid Integration of Artificial Sensory Feedback during Operant Conditioning of Motor Cortex Neurons.

    Science.gov (United States)

    Prsa, Mario; Galiñanes, Gregorio L; Huber, Daniel

    2017-02-22

    Neuronal motor commands, whether generating real or neuroprosthetic movements, are shaped by ongoing sensory feedback from the displacement being produced. Here we asked if cortical stimulation could provide artificial feedback during operant conditioning of cortical neurons. Simultaneous two-photon imaging and real-time optogenetic stimulation were used to train mice to activate a single neuron in motor cortex (M1), while continuous feedback of its activity level was provided by proportionally stimulating somatosensory cortex. This artificial signal was necessary to rapidly learn to increase the conditioned activity, detect correct performance, and maintain the learned behavior. Population imaging in M1 revealed that learning-related activity changes are observed in the conditioned cell only, which highlights the functional potential of individual neurons in the neocortex. Our findings demonstrate the capacity of animals to use an artificially induced cortical channel in a behaviorally relevant way and reveal the remarkable speed and specificity at which this can occur. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Feedback stabilization initiative

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-01

    Much progress has been made in attaining high confinement regimes in magnetic confinement devices. These operating modes tend to be transient, however, due to the onset of MHD instabilities, and their stabilization is critical for improved performance at steady state. This report describes the Feedback Stabilization Initiative (FSI), a broad-based, multi-institutional effort to develop and implement methods for raising the achievable plasma betas through active MHD feedback stabilization. A key element in this proposed effort is the Feedback Stabilization Experiment (FSX), a medium-sized, national facility that would be specifically dedicated to demonstrating beta improvement in reactor relevant plasmas by using a variety of MHD feedback stabilization schemes.

  7. Feedback stabilization initiative

    International Nuclear Information System (INIS)

    1997-06-01

    Much progress has been made in attaining high confinement regimes in magnetic confinement devices. These operating modes tend to be transient, however, due to the onset of MHD instabilities, and their stabilization is critical for improved performance at steady state. This report describes the Feedback Stabilization Initiative (FSI), a broad-based, multi-institutional effort to develop and implement methods for raising the achievable plasma betas through active MHD feedback stabilization. A key element in this proposed effort is the Feedback Stabilization Experiment (FSX), a medium-sized, national facility that would be specifically dedicated to demonstrating beta improvement in reactor relevant plasmas by using a variety of MHD feedback stabilization schemes

  8. Operating experience insights supporting ageing assessments

    International Nuclear Information System (INIS)

    Nitoi, M.

    2013-01-01

    Be effective in ageing management means looking at the right aspects, with the right techniques, and one of the most effective tool which could be used for that purpose is the analysis of operating experience. The paper has as objective to perform a review of available operating experience, with the aim to provide a better picture about the impact of ageing effects. The IAEA International Reporting System and NRC Licensee Event Reports were chosen as reference databases, both databases being internationally recognized as important sources of information about events occurrences in the nuclear power plants. The ageing related events identified in the selected time window were analyzed in detail, and the contributions of each major degradation mechanisms that have induced the ageing related events (specific to each defined group of components) was represented and discussed. The paper demonstrates the possibility to use operating experience insights in highlighting the ageing effects. (authors)

  9. Design of a Hardware-Implemented Phase Calculating System for Feedback Control in the LHCD Experiments on EAST

    International Nuclear Information System (INIS)

    Liu Qiang; Liang Hao; Zhou Yongzhao

    2009-01-01

    A fully hardware-implemented phase calculating system for the feedback control in the lower-hybrid current drive (LHCD) experiments is presented in this paper. By taking advantages of field programmable gate array (FPGA) chips with embedded digital signal processing (DSP) cores and the Matlab-aided design method, the phase calculating algorithm with a square root operation and parallel process are efficiently implemented in a single FPGA chip to complete the calculation of phase differences fast and accurately in the lower-hybrid wave (LHW) system on EAST. (fusion engineering)

  10. The SM and MIR reactors operation experience

    International Nuclear Information System (INIS)

    Kuprienko, V.A.; Klinov, A.V.; Svyatkin, M.N.; Shamardin, V.K.

    1995-01-01

    The SM and MIR operation experience show that continuous work on the problem of ageing, in all its aspects, allows for prolongation of the research plant life cycle by several folds as compared to the initial project. The redesigned SM-3 reactor will operate for another 20 years. The similar result is expected from the MIR planned reconstruction which scope will be the topic of future presentations. (orig.)

  11. Nuclear power plant operating experience, 1976

    International Nuclear Information System (INIS)

    1977-11-01

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

  12. Operational experience with SLAC's beam containment electronics

    International Nuclear Information System (INIS)

    Constant, T.N.; Crook, K.; Heggie, D.

    1977-03-01

    Considerable operating experience was accumulated at SLAC with an extensive electronic system for the containment of high power accelerated beams. Average beam power at SLAC can approach 900 kilowatts with the potential for burning through beam stoppers, protection collimators, and other power absorbers within a few seconds. Fast, reliable, and redundant electronic monitoring circuits have been employed to provide some of the safeguards necessary for minimizing the risk to personnel. The electronic systems are described, and the design philosophy and operating experience are discussed

  13. LOFT instrumented fuel design and operating experience

    International Nuclear Information System (INIS)

    Russell, M.L.

    1979-01-01

    A summary description of the Loss-of-Fluid Test (LOFT) system instrumented core construction details and operating experience through reactor startup and loss-of-coolant experiment (LOCE) operations performed to date are discussed. The discussion includes details of the test instrumentation attachment to the fuel assembly, the structural response of the fuel modules to the forces generated by a double-ended break of a pressurized water reactor (PWR) coolant pipe at the inlet to the reactor vessel, the durability of the LOFT fuel and test instrumentation, and the plans for incorporation of improved fuel assembly test instrumentation features in the LOFT core

  14. Case study of feedbacks and synergisms in a double CO2 experiment

    International Nuclear Information System (INIS)

    Mitchell, C.S.; Potter, G.L.; Ellsaesser, H.W.; Walton, J.J.

    1981-01-01

    A method is described for analyzing the feedback and synergistic comtributions of temperature water vapor, cloud cover, surface albedo and CO 2 to the change in the radiation balance at the top of the atmosphere due to a perturbation in an annual-averaged zonal atmospheric climate model. The method is illustrated through analysis of a double CO 2 experiment with the Lawrence Livermore National Laboratory Statistical Dynamical Model (LLNL SDM). The method provides insight into the sensitivity of the model to feedback changes in individual parameters and how each parameter influences the effects of the others

  15. Nuclear power plant operating experiences from the IAEA / Nea incident reporting system 2002-2005

    International Nuclear Information System (INIS)

    2006-01-01

    The Incident Reporting System (IRS) is an essential element of the international operating experience feedback system for nuclear power plants. The IRS is jointly operated and managed by the Nuclear Energy Agency (NEA), a semi-autonomous body within the Organisation for Economic Co-operation and Development (OECD), and the International Atomic Energy Agency (IAEA), a specialized agency within the United Nations System. (author)

  16. Accelerator/Experiment operations - FY 2006

    Energy Technology Data Exchange (ETDEWEB)

    Brice, S.; Conrad, J.; Denisov, D.; Ginther, G.; Holmes, S.; James, C.; Lee, W.; Louis, W.; Moore, C.; Plunkett, R.; Raja, R.; /Fermilab

    2006-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and experiment operations for FY 2006. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2006 Run II at the Tevatron Collider, the MiniBooNE experiments running in the Booster Neutrino Beam in neutrino and antineutrino modes, MINOS using the Main Injector Neutrino Beam (NuMI), and SY 120 activities.

  17. Feedback control and stabilization experiments on the Texas Experimental Tokamak (TEXT)

    International Nuclear Information System (INIS)

    Uckan, T.; Richards, B.; Wootton, A.J.; Bengtson, R.D.; Bravenec, R.; Carreras, B.A.; Li, G.X.; Hurwitz, P.; Phillips, P.E.; Rowan, W.L.; Tsui, H.Y.W.; Uglum, J.R.; Wen, Y.; Winslow, D.

    1995-01-01

    Plasma edge feedback experiments on the Texas Experimental Tokamak (TEXT) have been successful in controlling the edge plasma potential fluctuation level. The feedback wave-launcher is driven by the local edge potential fluctuations. The edge potential fluctuations are modified in a broad frequency band. Moreover, the potential fluctuations can be reduced (≤100 kHz) without enhancing other modes, or excited (10 to 12 kHz), depending on the phase difference between the driver and the launcher signal, and gain of the system. This turbulence modification is achieved not only locally but also halfway around the torus and has about 2 cm of poloidal extent. The local plasma parameters at the edge and the estimated fluctuation-induced radial particle flux are somewhat affected by the edge feedback. ((orig.))

  18. Investigating the Role of Auditory Feedback in a Multimodal Biking Experience

    DEFF Research Database (Denmark)

    Bruun-Pedersen, Jon Ram; Grani, Francesco; Serafin, Stefania

    2017-01-01

    In this paper, we investigate the role of auditory feedback in affecting perception of effort while biking in a virtual environment. Subjects were biking on a stationary chair bike, while exposed to 3D renditions of a recumbent bike inside a virtual environment (VE). The VE simulated a park...... and was created in the Unity5 engine. While biking, subjects were exposed to 9 kinds of auditory feedback (3 amplitude levels with three different filters) which were continuously triggered corresponding to pedal speed, representing the sound of the wheels and bike/chain mechanics. Subjects were asked to rate...... the perception of exertion using the Borg RPE scale. Results of the experiment showed that most subjects perceived a difference in mechanical resistance from the bike between conditions, but did not consciously notice the variations of the auditory feedback, although these were significantly varied. This points...

  19. Feedback from dismantling operations (level 2) on EDF's first generation reactors

    International Nuclear Information System (INIS)

    West, J P.; Dionisio-Gomes, A.; Kus, J P.; Mervaux, P.; Bernet, P.; Dalmas, R.

    2003-01-01

    EDF's policy as regards the dismantling of the reactors that have ceased commercial operation, namely the eight power plants of the first generation and the Creys-Malville power plant, is explained. Generally speaking, prior to the year 2001, EDF had opted for the de-construction of these power plants to comply with a 'long wait' scenario, which consisted of waiting for a period of 5 to 10 years to achieve IAEA level 2 (partial release of the site), then postponing the total de-construction of the facilities for 25 to 50 years. Today, EDF has decided to undertake the total de-construction of these reactors, which have ceased commercial operation, over a period of 25 years. The purpose of this document is to present: - The reactors concerned, their background and their 'regulatory' situation, - The main operations performed and/or currently in progress, - The main elements of feedback from such operations, shedding light on the approach adopted in 2001. The installations concerned by the de-construction programme are as follows: - The 8 power plants of the first generation, which were built during the fifties and sixties and ceased commercial operation between 1973 and 1994, namely: Brennilis (industrial prototype using heavy water technology, jointly operated by EDF and CEA), the 6 power units of the NUGG type (natural uranium gas graphite) at Chinon, Saint-Laurent des Eaux and Bugey and the PWR reactor at Chooz A, - The storage silos at Saint-Laurent, where the sleeves for the fuel assemblies of reactors SLA1 and SLA2 are stored, corresponding to approximately 2000 tonnes of graphite, - The Creys-Malville reactor, FBR (fast breeder reactor) shut down in accordance with a government decision, which is currently undergoing decommissioning. At the current stage, our feedback from the dismantling operations carried out on nuclear facilities is based on (i) the work carried out or in progress that will make it possible to achieve the equivalent of IAEA level 2 in the

  20. Accelerator/Experiment Operations - FY 2015

    Energy Technology Data Exchange (ETDEWEB)

    Czarapata, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); et al.

    2015-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2015. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2015 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  1. Tap Arduino: An Arduino microcontroller for low-latency auditory feedback in sensorimotor synchronization experiments.

    Science.gov (United States)

    Schultz, Benjamin G; van Vugt, Floris T

    2016-12-01

    Timing abilities are often measured by having participants tap their finger along with a metronome and presenting tap-triggered auditory feedback. These experiments predominantly use electronic percussion pads combined with software (e.g., FTAP or Max/MSP) that records responses and delivers auditory feedback. However, these setups involve unknown latencies between tap onset and auditory feedback and can sometimes miss responses or record multiple, superfluous responses for a single tap. These issues may distort measurements of tapping performance or affect the performance of the individual. We present an alternative setup using an Arduino microcontroller that addresses these issues and delivers low-latency auditory feedback. We validated our setup by having participants (N = 6) tap on a force-sensitive resistor pad connected to the Arduino and on an electronic percussion pad with various levels of force and tempi. The Arduino delivered auditory feedback through a pulse-width modulation (PWM) pin connected to a headphone jack or a wave shield component. The Arduino's PWM (M = 0.6 ms, SD = 0.3) and wave shield (M = 2.6 ms, SD = 0.3) demonstrated significantly lower auditory feedback latencies than the percussion pad (M = 9.1 ms, SD = 2.0), FTAP (M = 14.6 ms, SD = 2.8), and Max/MSP (M = 15.8 ms, SD = 3.4). The PWM and wave shield latencies were also significantly less variable than those from FTAP and Max/MSP. The Arduino missed significantly fewer taps, and recorded fewer superfluous responses, than the percussion pad. The Arduino captured all responses, whereas at lower tapping forces, the percussion pad missed more taps. Regardless of tapping force, the Arduino outperformed the percussion pad. Overall, the Arduino is a high-precision, low-latency, portable, and affordable tool for auditory experiments.

  2. Operational feedback on internal structure vibration in 54 French PWRs during 300 fuel cycles

    International Nuclear Information System (INIS)

    Trenty, A.

    1995-01-01

    EDF has acquired extensive feedback on vibration of reactor vessel internals by analysing ex-core neutron noise on its 54 pressurized water reactors during the course of over 300 fuel cycles. This feedback has been built up by processing more than 3,000 vibratory signatures acquired since the startup of its reactors. These signatures are now centralized for the whole of France in the ''SINBAD'' data base. Signature processing has enabled: distinguishing between mechanical phenomena and signature variation linked to unit operation: in particular, the impact on signature level of unit operating parameters such as initial fuel enrichment and burn-up rate was assessed; among the purely mechanical phenomena, pointing up slight changes in position of vessel internals and the first signs of structural wear; relaxation (in the hold-down spring and fuel rod assemblies) and wear on surfaces of contact between internals and reactor vessel were detected; lastly and most importantly, automatic recognition of the various types of vibratory behavior of internals. It was consequently possible to draw up user requirement specifications for automated monitoring of internals, which should soon be integrated in PSAD, a system which groups several reactor monitoring functions. (author)

  3. Accelerator/Experiment Operations - FY 2016

    International Nuclear Information System (INIS)

    Blake, A.; Convery, M.; Geer, S.; Geesaman, D.; Harris, D.; Johnson, D.; Lang, K.; McFarland, K.; Messier, M.; Moore, C. D.; Newhart, D.; Reimer, P. E.; Plunkett, R.; Rominsky, M.; Sanchez, M.; Schmidt, J. J.; Shanahan, P.; Tate, C.; Thomas, J.; Donatella Torretta, Donatella Torretta; Matthew Wetstein, Matthew Wetstein

    2016-01-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2016. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2016 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment and the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment, LArIAT experiment and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120). Each section was prepared by the relevant authors, and was then edited for inclusion in this summary.

  4. Accelerator/Experiment Operations - FY 2016

    Energy Technology Data Exchange (ETDEWEB)

    Blake, A. [Argonne National Lab. (ANL), Argonne, IL (United States); Convery, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Geer, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Geesaman, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Harris, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Johnson, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lang, K. [Argonne National Lab. (ANL), Argonne, IL (United States); McFarland, K. [Argonne National Lab. (ANL), Argonne, IL (United States); Messier, M. [Argonne National Lab. (ANL), Argonne, IL (United States); Moore, C. D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Newhart, D. [Fermilab; Reimer, P. E. [Argonne; Plunkett, R. [Fermilab; Rominsky, M. [Fermilab; Sanchez, M. [Iowa State U.; Schmidt, J. J. [Fermilab; Shanahan, P. [Fermilab; Tate, C. [Fermilab; Thomas, J. [University Coll. London; Donatella Torretta, Donatella Torretta [Fermilab; Matthew Wetstein, Matthew Wetstein [Iowa State University

    2016-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2016. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2016 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MicroBooNE experiment and the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment, LArIAT experiment and Meson Test Beam activities in the 120 GeV external switchyard beam (SY120). Each section was prepared by the relevant authors, and was then edited for inclusion in this summary.

  5. Feedback control systems for non-linear simulation of operational transients in LMFBRs

    International Nuclear Information System (INIS)

    Khatib-Rahbar, M.; Agrawal, A.K.; Srinivasan, E.S.

    1979-01-01

    Feedback control systems for non-linear simulation of operational transients in LMFBRs are developed. The models include (1) the reactor power control and rod drive mechanism, (2) sodium flow control and pump drive system, (3) steam generator flow control and valve actuator dynamics, and (4) the supervisory control. These models have been incorporated into the SSC code using a flexible approach, in order to accommodate some design dependent variations. The impact of system nonlinearity on the control dynamics is shown to be significant for severe perturbations. Representative result for a 10 cent and 25 cent step insertion of reactivity and a 10% ramp change in load in 40 seconds demonstrate the suitability of this model for study of operational transients without scram in LMFBRs

  6. Operational experience with CMS Tier-2 sites

    International Nuclear Information System (INIS)

    Gonzalez Caballero, I

    2010-01-01

    In the CMS computing model, more than one third of the computing resources are located at Tier-2 sites, which are distributed across the countries in the collaboration. These sites are the primary platform for user analyses; they host datasets that are created at Tier-1 sites, and users from all CMS institutes submit analysis jobs that run on those data through grid interfaces. They are also the primary resource for the production of large simulation samples for general use in the experiment. As a result, Tier-2 sites have an interesting mix of organized experiment-controlled activities and chaotic user-controlled activities. CMS currently operates about 40 Tier-2 sites in 22 countries, making the sites a far-flung computational and social network. We describe our operational experience with the sites, touching on our achievements, the lessons learned, and the challenges for the future.

  7. Summary of operating experience at Swedish nuclear power plants in 1984

    International Nuclear Information System (INIS)

    1985-01-01

    The four owners on nuclear power plants in Sweden - The Swedish State Power Board, Forsmarks Kraftgrupp AB, Sydkraft AB and OKG AKTIEBOLAG - formed in 1980 the Nuclear Safety Board of the Swedish Utilities as a joint body for collaboration in safety matters. The Board participates in coordination of the safety work of the utilities and conducts its own safety projects, whereever this is more efficient than the utilities' working independently. The work of the Board shall contribute to optimizing safety in the operation of the Swedish nuclear power plants. The most important function of the Board is to collect, process and evaluate information on operational disturbances and incidents at Swedish and foreign nuclear power plants and then use the knowledge thus gained to improve the safety of the operation of the Swedish nuclear power plants (experience feedback). The work with Experience Feedback proceeds in three stages: Event follow-up, Fault analysis and Feedback of results. The Board runs a system for experience feedback (ERF). ERF is a computer-based information and communication system. ERF provides the Board with a daily update of operating experience in both Swedish and foreign nuclear power plants. Each Swedish nuclear power station supplies the ERF system with data on, among other things, operation and operational distrubances. Important experiences are thereby fed back to plant operation. Experience from foreign nuclear power stations can be of interest to the Swedish nuclear power plants. This information comes to RKS and is reviewed daily. The information that is considered relevant to Swedish plants is fed after analysis into the ERF system. Conversely, foreign nuclear power stations can obtain information from the operation of the Swedish plants. (author)

  8. Feedback control and stabilization experiments on the Texas Experimental Tokamak (TEXT)

    International Nuclear Information System (INIS)

    Uckan, T.; Carreras, B.A.; Richards, B.; Wootton, A.J.; Bengtson, R.D.; Bravenec, R.; Li, G.X.; Hurwitz, P.D.; Phillips, P.E.; Rowan, W.L.

    1994-06-01

    Plasma edge feedback experiments on the Texas Experimental Tokamak (TEXT) have been successful in controlling the edge plasma potential fluctuation level. The feedback wave-launcher, consisting of electrostatic probes located in the shadow of the limiter, is driven by the local edge potential fluctuations. In general, the edge potential fluctuations are modified in a broad frequency band. Moreover, it is observed that the potential fluctuations can be reduced (≤100 kHz) without enhancing other modes, or excited (10 to 12 kHz), depending on the phase difference between the driver and the launcher signal, and gain of the system. This turbulence modification is achieved not only locally but also halfway around the torus and has about 2 cm of poloidal extent. Experiments on the characterization of the global plasma parameters with the edge feedback are discussed. Effects of the edge feedback on the estimated fluctuation-induced radial particle flux as well as on the local plasma parameters are presented

  9. Comparison between gas puffing and supersonic molecular beam injection in plasma density feedback experiments in EAST

    International Nuclear Information System (INIS)

    Zheng, Xingwei; Li, Jiangang; Hu, Jiansheng; Li, Jiahong; Ding, Rui; Cao, Bin; Wu, Jinhua

    2013-01-01

    To achieve desirable plasma density control, a supersonic molecular beam injection (SMBI) feedback control system has been developed recently for the EAST tokamak. The performance of the SMBI and gas puffing (GP) feedback systems were used and compared. The performance of pulse width mode is better than that of pulse amplitude mode when GP was used for density feedback control. During one-day experiments, the variation of gas input and wall retention can be clarified into two stages. In the first stage the retention ratio is as high as 80–90%, and the gas input is about an order of 10 22 D 2 . However, in the second stage, the retention ratio is at a range of 50–70%. The gas input of a single discharge is small and the net wall retention grows slowly. The results of the SMBI feedback control experiment was analyzed. The shorter delay time of SMBI makes it faster at feeding back control the plasma density. The result showed that, compared with GP, the gas input of SMBI was decreased ∼30% and the wall retention was reduced ∼40%. This shows SMBI's advantage for the long pulse high density discharges in EAST. (paper)

  10. HANARO operation experience in the year 2004

    International Nuclear Information System (INIS)

    Oh, Soo-Youl; Kim, Heonil; Cho, Yeong-Garp; Jun, Byung-Jin

    2006-01-01

    The experiences of the HANARO operation and maintenance in the year 2004 are presented in this article. The operation of HANARO, a 30 MW research reactor operated by the Korea Atomic Energy Research Institute (KAERI), aims at a safe and effective operation to enhance its utilization in various fields of scientific research and industry. Regardless of its importance of the routine operation, this article is devoted to rather unusual matters such as irregular maintenance events and incidents. Since the first criticality in 1995, it has been a long-cherished task to reach the designed power level of 30 MW from the temporarily approved 24 MW. By resolving the concern on the fuel integrity, the designed level could be licensed and, eventually, it was achieved last November. On the other hand, after its 9 years of operation, the mechanical integrity of the heavy water reflector tank was checked. The measurement of the vertical straightness of the tank inner shell indicated its integrity. Meanwhile, the HANARO fuel production facility was completed at the KAERI site, and it will begin to supply centrifugally atomized fuels, instead of conventional comminuted fuels, to HANARO shortly. There were several incidents in 2004, which have all been cleared, including a leak of heavy water, melting of a sample in an irradiation hole for the neutron activation analysis, and a condensation problem in a horizontal beam tube. The progress of and lessons from each incident are presented. The utilization of HANARO is expanding every year and the trend will also continue in 2005. The operation mode has been changed from an 18-day continuous operation and 10-day shutdown (18-10 mode) to the 23-12 mode since the end of 2004, and a further extension is planned to the 30-12 mode. Thanks to this extended operation term, an increased power level and, most importantly, a reliable operation, the HANARO is gaining more and more credit from the end users. (author)

  11. Applying operating experience to design the CANDU 3 process

    International Nuclear Information System (INIS)

    Harris, D.S.; Hinchley, E.M.; Pauksens, J.; Snell, V.; Yu, S.K.W.

    1991-01-01

    The CANDU 3 is an advanced, smaller (450 MWe), standardized version of the CANDU now being designed for service later in the decade and beyond. The design of this evolutionary nuclear power plant has been carefully planned and organized to gain maximum benefits from new technologies and from world experience to date in designing, building, commissioning and operating nuclear power stations. The good performance record of existing CANDU reactors makes consideration of operating experience from these plants a particularly vital component of the design process. Since the completion of the first four CANDU 6 stations in the early 1980s, and with the continuing evolution of the multi-unit CANDU station designs since then, AECL CANDU has devised several processes to ensure that such feedback is made available to designers. An important step was made in 1986 when a task force was set up to review and process ideas arising from the commissioning and early operation of the CANDU 6 reactors which were, by that time, operating successfully in Argentina and Korea, as well as the Canadian provinces of Quebec and New Brunswick. The task force issued a comprehensive report which, although aimed at the design of an improved CANDU 6 station, was made available to the CANDU 3 team. By that time also, the Institute of Power Operations (INPO) in the U.S., of which AECL is a Supplier Participant member, was starting to publish Good Practices and Guidelines related to the review and the use of operating experiences. In addition, details of significant events were being made available via the INPO SEE-IN (Significant Event Evaluation and Information Network) Program, and subsequently the CANNET network of the CANDU Owners' Group (COG). Systematic review was thus possible by designers of operations reports, significant event reports, and related documents in a continuing program of design improvement. Another method of incorporating operations feedback is to involve experienced utility

  12. Applying operating experience to design the CANDU 3 process

    Energy Technology Data Exchange (ETDEWEB)

    Harris, D S; Hinchley, E M; Pauksens, J; Snell, V; Yu, S K.W. [AECL-CANDU, Ontario (Canada)

    1991-04-01

    The CANDU 3 is an advanced, smaller (450 MWe), standardized version of the CANDU now being designed for service later in the decade and beyond. The design of this evolutionary nuclear power plant has been carefully planned and organized to gain maximum benefits from new technologies and from world experience to date in designing, building, commissioning and operating nuclear power stations. The good performance record of existing CANDU reactors makes consideration of operating experience from these plants a particularly vital component of the design process. Since the completion of the first four CANDU 6 stations in the early 1980s, and with the continuing evolution of the multi-unit CANDU station designs since then, AECL CANDU has devised several processes to ensure that such feedback is made available to designers. An important step was made in 1986 when a task force was set up to review and process ideas arising from the commissioning and early operation of the CANDU 6 reactors which were, by that time, operating successfully in Argentina and Korea, as well as the Canadian provinces of Quebec and New Brunswick. The task force issued a comprehensive report which, although aimed at the design of an improved CANDU 6 station, was made available to the CANDU 3 team. By that time also, the Institute of Power Operations (INPO) in the U.S., of which AECL is a Supplier Participant member, was starting to publish Good Practices and Guidelines related to the review and the use of operating experiences. In addition, details of significant events were being made available via the INPO SEE-IN (Significant Event Evaluation and Information Network) Program, and subsequently the CANNET network of the CANDU Owners' Group (COG). Systematic review was thus possible by designers of operations reports, significant event reports, and related documents in a continuing program of design improvement. Another method of incorporating operations feedback is to involve experienced utility

  13. Lessons Learned from Missing Flooding Barriers Operating Experience

    International Nuclear Information System (INIS)

    Simic, Z.; Veira, M. P.

    2016-01-01

    Flooding hazard is highly significant for nuclear power plant safety because of its potential for common cause impact on safety related systems, and because operating experience reviews regularly identify flooding as a cause of concern. Source of the flooding could be external (location) or internal (plant design). The amount of flooding water could vary but even small amount might suffice to affect redundant trains of safety related systems for power supply and cooling. The protection from the flooding is related to the design-basis flood level (DBFL) and it consists of three elements: structural, organizational and accessibility. Determination of the DBFL is critical, as Fukushima Daiichi accident terribly proved. However, as the topic of flooding is very broad, the scope of this paper is focused only on the issues related to the missing flood barriers. Structural measures are physically preventing flooding water to reach or damage safety related system, and they could be permanent or temporary. For temporary measures it is important to have necessary material, equipment and organizational capacity for the timely implementation. Maintenance is important for permanent protection and periodical review is important for assuring readiness and feasibility of temporary flooding protection. Final flooding protection element is assured accessibility to safety related systems during the flooding. Appropriate flooding protection is based on the right implementation of design requirements, proper maintenance and periodic reviews. Operating experience is constantly proving how numerous water sources and systems interactions make flooding protection challenging. This paper is presenting recent related operating experience feedback involving equipment, procedures and analysis. Most frequent deficiencies are: inadequate, degraded or missing seals that would allow floodwaters into safety related spaces. Procedures are inadequate typically because they underestimate necessary

  14. Operational experience of the ATLAS accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, P K; Bogaty, J M; Bollinger, L M; Clifft, B E; Craig, S L; Harden, R E; Markovich, P; Munson, F H; Nixon, J M; Pardo, R C; Phillips, D R; Shepard, K W; Tilbrook, I R; Zinkmann, G P [Argonne National Lab., IL (USA). Physics Div.

    1990-02-01

    The ATLAS accelerator consists of a HVEC model FN tandem accelerator injecting into a linac of independently-phased niobium superconducting resonators. The accelerator provides beams with masses 6 {le} A {le} 127 and with energies ranging up to 20 MeV/A for the lightest ions and 4 MeV/A for the heaviest ions. Portions of the linac have been in operation since 1978 and, over the last decade, more than 35000 h of operating experience have been accumulated. The long-term stability of niobium resonators, and their feasibility for use in heavy-ion accelerators is now well established. (orig.).

  15. Operational experience of extreme wind penetrations

    Energy Technology Data Exchange (ETDEWEB)

    Estanqueiro, Ana [INETI/LNEG - National Laboratory for Energy and Geology, Lisbon (Portugal); Mateus, Carlos B. [Instituto de Meteorologia, Lisboa (Portugal); Pestana, Rui [Redes Energeticas Nacionais (REN), Lisboa (Portugal)

    2010-07-01

    This paper reports the operational experience from the Portuguese Power System during the 2009/2010 winter months when record wind penerations were observed: the instantaneous wind power penetration peaked at 70% of consumption during no-load periods and the wind energy accounted for more than 50% of the energy consumed for a large period. The regulation measures taken by the TSO are presented in the paper, together with the additional reserves operated for added system security. Information on the overall power system behavior under such extreme long-term wind power penetrations will also be addressed. (org.)

  16. Operating procedures: Fusion Experiments Analysis Facility

    Energy Technology Data Exchange (ETDEWEB)

    Lerche, R.A.; Carey, R.W.

    1984-03-20

    The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with the facility. This manual is designed as a reference to assist the FEAF staff in carrying out their responsibilities. It is meant to supplement equipment and software manuals supplied by the vendors. Also this manual provides the FEAF staff with a set of consistent, written guidelines for the daily operation of the facility.

  17. Operating procedures: Fusion Experiments Analysis Facility

    International Nuclear Information System (INIS)

    Lerche, R.A.; Carey, R.W.

    1984-01-01

    The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with the facility. This manual is designed as a reference to assist the FEAF staff in carrying out their responsibilities. It is meant to supplement equipment and software manuals supplied by the vendors. Also this manual provides the FEAF staff with a set of consistent, written guidelines for the daily operation of the facility

  18. Preheat operating experiences at the FFTF

    International Nuclear Information System (INIS)

    Tucker, W.R.

    1978-01-01

    The rather extensive test program performed on the FFTF preheat control system resulted in successful sodium fill of one secondary heat transport loop on July 2, 1978. The data obtained during testing and the attendant operating experience gained resulted in some design changes and provided the information necessary to fully characterize system performance. Temperature excursions and deviations from preset limits of only a minor nature were encountered during preheat for sodium fill. The addition of the rate alarm feature was beneficial to operation of the preheat system and allowed early detection and correction of impending excursions

  19. Reducing Operating Room Costs Through Real-Time Cost Information Feedback: A Pilot Study.

    Science.gov (United States)

    Tabib, Christian H; Bahler, Clinton D; Hardacker, Thomas J; Ball, Kevin M; Sundaram, Chandru P

    2015-08-01

    To create a protocol for providing real-time operating room (OR) cost feedback to surgeons. We hypothesize that this protocol will reduce costs in a responsible way without sacrificing quality of care. All OR costs were obtained and recorded for robot-assisted partial nephrectomy and laparoscopic donor nephrectomy. Before the beginning of this project, costs pertaining to the 20 most recent cases were analyzed. Items were identified from previous cases as modifiable for replacement or omission. Timely feedback of total OR costs and cost of each item used was provided to the surgeon after each case, and costs were analyzed. A cost analysis of the robot-assisted partial nephrectomy before the washout period indicates expenditures of $5243.04 per case. Ten recommended modifiable items were found to have an average per case cost of $1229.33 representing 23.4% of the total cost. A postwashout period cost analysis found the total OR cost decreased by $899.67 (17.2%) because of changes directly related to the modifiable items. Therefore, 73.2% of the possible identified savings was realized. The same stepwise approach was applied to laparoscopic donor nephrectomies. The average total cost per case before the washout period was $3530.05 with $457.54 attributed to modifiable items. After the washout period, modifiable items costs were reduced by $289.73 (8.0%). No complications occurred in the donor nephrectomy cases while one postoperative complication occurred in the partial nephrectomy group. Providing surgeons with feedback related to OR costs may lead to a change in surgeon behavior and decreased overall costs. Further studies are needed to show equivalence in patient outcomes.

  20. Small scale thermal-hydraulic experiment for stable operation of a pius-type reactor

    International Nuclear Information System (INIS)

    Tasaka, K.; Tamaki, M.; Imai, S.; Irianto, I.D.; Tsuji, Y.; Kukita, Y.

    1994-01-01

    Thermal-hydraulic experiments using a small-scale atmospheric pressure test loop have been performed for the Process Inherent Ultimate Safety (PIUS)-type reactor to develop the new pump speed feedback control system. Three feedback control systems based on the measurement of flow rate, differential pressure, and fluid temperature distribution in the lower density lock have been proposed and confirmed by a series of experiments. Each of the feedback control systems had been verified in the simulation experiment such as a start-up simulation test. The automatic pump speed control based on the fluid temperature at the lower density lock was quite effective to maintain the stratified interface between primary water and borated pool water for stable operation of the reactor. (author)

  1. Evolution of the feedback from experience on degradations of French nuclear power plants condensers and foreseen solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mayos, M.; Chanel, F.; Copin, E.; Carlier, L. [EDF/DIN/CEIDRE, Saint-Denis (France); Coquio, N.; Garbay, E. [EDF/DIN/CEIDRE, Avoine (France); Bastian, C. [EDF/DPN/UNIE, Saint-Denis (France)

    2011-07-01

    The materials constituting the condenser tubes of French nuclear power plants display a great diversity and are subject to different degradations, known from the operational feedback from experience. Copper alloys (mainly brass), which were bound to disappear in renovated condensers, are still significantly present, due to their unique bacteriostatic ability. Brass tubes lifetime is still governed in general by steady abrasion, as evaluated by eddy current nondestructive testing. However, an atypical NDE (non-destructive evaluation) behavior has led to spot a new damage: localized under-deposit pitting corrosion on the raw water side, caused by the particular quality of water chemistry and heavy scaling of the tube surface. This damage is likely to overcome steady abrasion for tube life prediction. Prevention includes a tighter look at NDE indications and improved descaling solutions (chemical or mechanical). Other specific damages have been reported from operation feedback: the main one was accidental stress corrosion cracking, which has occurred on some recently renovated brass condenser tube bundles. Thanks to a metallurgical and mechanical study, its cause was found in the manufacturing process. This experience has resulted in tightened specifications for brass tubes manufacturing. Stainless steel and titanium still appear more damage-resistant and represent a safe solution when no microorganism issue is present. The degradation feedback, confirmed by NDE inspections, is very low in French power plants. However, titanium hydriding still represents an issue when cathodic protection is present. Furthermore, some other damages have been reported on titanium, like isolated steam erosion. Vibration fatigue damage has been observed on stainless steel tubes, but it is more in relationship with the condenser design than with the material itself. (authors)

  2. Operational and reliability experience with reactor instrumentation

    International Nuclear Information System (INIS)

    Dixon, F.; Gow, R.S.

    1978-01-01

    In the last 15 years the CEGB has experienced progressive plant development, integration and changes in operating regime through nine nuclear (gas-cooled reactor) power stations with corresponding instrumentation advances leading towards more refined centralized control. Operation and reliability experience with reactor instrumentation is reported in this paper with reference to the progressive changes related to the early magnox, late magnox and AGR periods. Data on instrumentation reliability in terms of reactor forced outages are presented and show that the instrumentation contributions to loss of generating plant availability are small. Reactor safety circuits, neutron flux and temperature measurements, gas analysis and vibration monitoring are discussed. In reviewing the reactor instrumentation the emphasis is on reporting recent experience, particularly on AGR equipment, but overall performance and changes to magnox equipment are included so that some appreciation can be obtained of instrumentation requirements with respect to plant lifetimes. (author)

  3. Output Feedback Fractional-Order Nonsingular Terminal Sliding Mode Control of Underwater Remotely Operated Vehicles

    Directory of Open Access Journals (Sweden)

    Yaoyao Wang

    2014-01-01

    Full Text Available For the 4-DOF (degrees of freedom trajectory tracking control problem of underwater remotely operated vehicles (ROVs in the presence of model uncertainties and external disturbances, a novel output feedback fractional-order nonsingular terminal sliding mode control (FO-NTSMC technique is introduced in light of the equivalent output injection sliding mode observer (SMO and TSMC principle and fractional calculus technology. The equivalent output injection SMO is applied to reconstruct the full states in finite time. Meanwhile, the FO-NTSMC algorithm, based on a new proposed fractional-order switching manifold, is designed to stabilize the tracking error to equilibrium points in finite time. The corresponding stability analysis of the closed-loop system is presented using the fractional-order version of the Lyapunov stability theory. Comparative numerical simulation results are presented and analyzed to demonstrate the effectiveness of the proposed method. Finally, it is noteworthy that the proposed output feedback FO-NTSMC technique can be used to control a broad range of nonlinear second-order dynamical systems in finite time.

  4. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2017-01-01

    Run 2 of the LHC collider sets new challenges to track and vertex reconstruction because of its higher energy, pileup and luminosity. The ATLAS tracking performance relies critically on the Pixel Detector. Therefore, in view of Run 2, the ATLAS collaboration has constructed the first 4-layer pixel detector in Particle Physics by installing a new pixel layer, called Insertable B-Layer (IBL). Operational experience and performance of the 4-layer Pixel Detector during Run 2 are presented.

  5. Modernization of electrical systems in NPP Kozloduy unit 5 and 6. Feedback of experience

    International Nuclear Information System (INIS)

    Stinshoff, H.

    2005-01-01

    In the frame of the modernization program for the nuclear power plant Kozloduy unit 5 and 6 Framatome ANP has implemented measures to increase the safety and availability of the electrical systems. The hardware installation is scheduled in the refueling outages of the years 2003 to 2005. In this paper the following items are presented: 1) an overview of the modernization measures; 2) some important technical features of the new equipment and diagnostic measures; 3) feedback of experience

  6. Operational Experience from Solar Thermal Energy Projects

    Science.gov (United States)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  7. Continuous Air Monitor Operating Experience Review

    International Nuclear Information System (INIS)

    Cadwallader, L.C.; Bruyere, S.A.

    2008-01-01

    Continuous air monitors (CAMs) are used to sense radioactive particulates in room air of nuclear facilities. CAMs alert personnel of potential inhalation exposures to radionuclides and can also actuate room ventilation isolation for public and environmental protection. This paper presents the results of a CAM operating experience review of the DOE Occurrence Reporting and Processing System (ORPS) database from the past 18 years. Regulations regarding these monitors are briefly reviewed. CAM location selection and operation are briefly discussed. Operating experiences reported by the U.S. Department of Energy and in other literature sources were reviewed to determine the strengths and weaknesses of these monitors. Power losses, human errors, and mechanical issues cause the majority of failures. The average 'all modes' failure rate is 2.65E-05/hr. Repair time estimates vary from an average repair time of 9 hours (with spare parts on hand) to 252 hours (without spare parts on hand). These data should support the use of CAMs in any nuclear facility, including the National Ignition Facility and the international ITER experiment

  8. Operating experience with the DRAGON High Temperature Reactor experiment

    International Nuclear Information System (INIS)

    Simon, R.A.; Capp, P.D.

    2002-01-01

    The Dragon Reactor Experiment in Winfrith/UK was a materials test facility for a number of HTR projects pursued in the sixties and seventies of the last century. It was built and managed as an OECD/NEA international joint undertaking. The reactor operated successfully between 1964 and 1975 to satisfy the growing demand for irradiation testing of fuels and fuel elements as well as for technological tests of components and materials. The paper describes the reactor's main experimental features and presents results of 11 years of reactor operation relevant for future HTRs. (author)

  9. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Operating experience, operating cycles, and... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... position, the operating experience, operating cycles, and the line operating flight time for consolidation...

  10. A durability analysis of the Cascad facility based on feedback obtained after 10 years of operation

    International Nuclear Information System (INIS)

    Samoel, R.; Canas, D.; Henry, H.; Battesti, P.

    1999-01-01

    The CASCAD facility at the nuclear research centre in Cadarache is a dry storage facility for spent fuel that has been placed in a vault. Feedback on its design and performance after 10 years of operation was obtained in order to identify the factors limiting its life time. This assessment corresponds to a durability analysis based on a combination of dependability methods. This is a critical analysis identifying the risks involving failure of the components when they are subjected to internal and external disturbances (aging, technology obsolescence, etc.). The measures to be implemented to extend the life time of the facility are subsequently enumerated. A proposed synthesis or 'logic diagram' of the analysis is also presented. (authors)

  11. Collaborative Assembly Operation between Two Modular Robots Based on the Optical Position Feedback

    Directory of Open Access Journals (Sweden)

    Liying Su

    2009-01-01

    Full Text Available This paper studies the cooperation between two master-slave modular robots. A cooperative robot system is set up with two modular robots and a dynamic optical meter-Optotrak. With Optotrak, the positions of the end effectors are measured as the optical position feedback, which is used to adjust the robots' end positions. A tri-layered motion controller is designed for the two cooperative robots. The RMRC control method is adopted to adjust the master robot to the desired position. With the kinematics constraints of the two robots including position and pose, joint velocity, and acceleration constraints, the two robots can cooperate well. A bolt and nut assembly experiment is executed to verify the methods.

  12. Experience from operating germanium detectors in GERDA

    Science.gov (United States)

    Palioselitis, Dimitrios; GERDA Collaboration

    2015-05-01

    Phase I of the Germanium Detector Array (GERDA) experiment, searching for the neutrinoless double beta (0νββ) decay of 76Ge, was completed in September 2013. The most competitive half-life lower limit for the 0νββ decay of 76Ge was set (T-0ν1/2 > 2.1 · 1025 yr at 90% C.L.). GERDA operates bare Ge diodes immersed in liquid argon. During Phase I, mainly refurbished semi-coaxial high purity Ge detectors from previous experiments were used. The experience gained with handling and operating bare Ge diodes in liquid argon, as well as the stability and performance of the detectors during GERDA Phase I are presented. Thirty additional new enriched BEGe-type detectors were produced and will be used in Phase II. A subgroup of these detectors has already been used successfully in GERDA Phase I. The present paper gives an overview of the production chain of the new germanium detectors, the steps taken to minimise the exposure to cosmic radiation during manufacturing, and the first results of characterisation measurements in vacuum cryostats.

  13. Experience from operating germanium detectors in GERDA

    International Nuclear Information System (INIS)

    Palioselitis, Dimitrios

    2015-01-01

    Phase I of the Germanium Detector Array (GERDA) experiment, searching for the neutrinoless double beta (0νββ) decay of 76 Ge, was completed in September 2013. The most competitive half-life lower limit for the 0νββ decay of 76 Ge was set (T- 0ν 1/2 > 2.1 · 10 25 yr at 90% C.L.). GERDA operates bare Ge diodes immersed in liquid argon. During Phase I, mainly refurbished semi-coaxial high purity Ge detectors from previous experiments were used. The experience gained with handling and operating bare Ge diodes in liquid argon, as well as the stability and performance of the detectors during GERDA Phase I are presented. Thirty additional new enriched BEGe-type detectors were produced and will be used in Phase II. A subgroup of these detectors has already been used successfully in GERDA Phase I. The present paper gives an overview of the production chain of the new germanium detectors, the steps taken to minimise the exposure to cosmic radiation during manufacturing, and the first results of characterisation measurements in vacuum cryostats. (paper)

  14. Tritium Room Air Monitor Operating Experience Review

    Energy Technology Data Exchange (ETDEWEB)

    L. C. Cadwallader; B. J. Denny

    2008-09-01

    Monitoring the breathing air in tritium facility rooms for airborne tritium is a radiological safety requirement and a best practice for personnel safety. Besides audible alarms for room evacuation, these monitors often send signals for process shutdown, ventilation isolation, and cleanup system actuation to mitigate releases and prevent tritium spread to the environment. Therefore, these monitors are important not only to personnel safety but also to public safety and environmental protection. This paper presents an operating experience review of tritium monitor performance on demand during small (1 mCi to 1 Ci) operational releases, and intentional airborne inroom tritium release tests. The tritium tests provide monitor operation data to allow calculation of a statistical estimate for the reliability of monitors annunciating in actual tritium gas airborne release situations. The data show a failure to operate rate of 3.5E-06/monitor-hr with an upper bound of 4.7E-06, a failure to alarm on demand rate of 1.4E-02/demand with an upper bound of 4.4E-02, and a spurious alarm rate of 0.1 to 0.2/monitor-yr.

  15. Operational experience of the ATLAS accelerator

    International Nuclear Information System (INIS)

    Den Hartog, P.K.; Bogaty, J.M.; Bollinger, L.M.

    1989-01-01

    The ATLAS accelerator consists of a HVEC model FN tandem accelerator injecting into a linac of independently-phased niobium superconducting resonators. The accelerator provides beams with masses from 6≤A≤127 and with energies ranging up to 20 MeV/A for the lightest ions and 4 MeV/A for the heaviest ions. Portions of the linac have been in operation since 1978 and, over the last decade, more than 35,000 hours of operating experience have been accumulated. The long-term stability of niobium resonators, and their feasibility for use in heavy-ion accelerators is now well established. 11 refs., 3 figs., 1 tab

  16. Operating experiences with 1 MW steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Sano, A; Kanamori, A; Tsuchiya, T

    1975-07-01

    1 MW steam generator, which was planned as the first stage of steam generator development in Power Reactor and Nuclear Fuel Corp. (PNC) in Japan, is a single-unit, once-through, integrated shell and tube type with multi-helical coil tubes. It was completed in Oarai Engineering Center of PNC in March of 1971, and the various performance tests were carried out up to April, 1972. After the dismantle of the steam generator for structural inspection and material test, it was restored with some improvements. In this second 1 MW steam generator, small leak occurred twice during normal operation. After repairing the failure, the same kind of performance tests as the first steam generator were conducted in order to verify the thermal insulation effect of argon gas in downcomer zone from March to June, 1974. In this paper the above operating experiences were presented including the outline of some performance test results. (author)

  17. Selection of operations staff, qualifications and experience

    International Nuclear Information System (INIS)

    Gutmann, H.

    1977-01-01

    Requirements and suggestions have been made by authorities and various organisations in a number of countries which define necessary experience and training for the various groups of nuclear power plant personnel. For two countries, the USA and the FRG, a comparison has been made which shows that there is only a slight deviation, taking into account the different education systems. With the example of the Biblis nuclear power plant the training on the job is described. Especially the production or operation department is looked at in more detail. The training is split up into several parts: a general part, such as nuclear physics, reactor physics and engineering, reactor safety, radiation protection and so on and a plant related part, such as arrangement and mode of operation of the plant under normal and accident conditions, license conditions and so on. (orig.) [de

  18. Operational experience with the ATLAS Pixel Detector

    CERN Document Server

    Ince, T; The ATLAS collaboration

    2012-01-01

    The ATLAS Pixel Detector is the innermost element of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this paper, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: 96.2% of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, an...

  19. Operational experience of the ATLAS Pixel detector

    CERN Document Server

    Hirschbuehl, D; The ATLAS collaboration

    2011-01-01

    The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this talk, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: 97,5% of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, an...

  20. Operational experience of the ATLAS Pixel Detector

    CERN Document Server

    Marcisovsky, M; The ATLAS collaboration

    2011-01-01

    The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this talk, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: 97,5% of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, an...

  1. The LHC test string first operational experience

    CERN Document Server

    Bézaguet, Alain-Arthur; Casas-Cubillos, J; Coull, L; Cruikshank, P; Dahlerup-Petersen, K; Faugeras, Paul E; Flemsæter, B; Guinaudeau, H; Hagedorn, Dietrich; Hilbert, B; Krainz, G; Kos, N; Lavielle, D; Lebrun, P; Leo, G; Mathewson, A G; Missiaen, D; Momal, F; Parma, Vittorio; Quesnel, Jean Pierre; Richter, D; Riddone, G; Rijllart, A; Rodríguez-Mateos, F; Rohmig, P; Saban, R I; Schmidt, R; Serio, L; Skiadelli, M; Suraci, A; Tavian, L; Walckiers, L; Wallén, E; Van Weelderen, R; Williams, L; McInturff, A

    1996-01-01

    CERN operates the first version of the LHC Test String which consists of one quadrupole and three 10-m twin aperture dipole magnets. An experimental programme aiming at the validation of the LHC systems started in February 1995. During this programme the string has been powered 100 times 35 of which at 12.4 kA or above. The experiments have yielded a number of results some of which, like quench recovery for cryogenics, have modified the design of subsystems of LHC. Others, like controlled helium leaks in the cold bore and quench propagation bewteen magnets, have given a better understanding on the evolution of the phenomena inside a string of superconducting magnets cooled at superfluid helium temperatures. Following the experimental programme, the string will be powered up and powered down in one hour cycles as a fatigue test of the structure thus simulating 20 years of operation of LHC.

  2. Small sodium valve design and operating experience

    International Nuclear Information System (INIS)

    McGough, C.B.

    1974-01-01

    The United States Liquid Metal Fast Breeder Reactor program (LMFBR) includes an extensive program devoted to the development of small sodium valves. This program is now focused on the development and production of valves for the Fast Flux Test Facility (FFTF) now under construction near Richland, Washington. Other AEC support facilities, such as various test loops located at the Liquid Metal Engineering Center (LMEC), Los Angeles, California, and at the Hanford Engineering Development Laboratory (HEDL), Richland, Washington, also have significant requirements for small sodium valves, and valves similar in design to the FFTF valves are being supplied to these AEC laboratories for use in their critical test installations. A principal motivation for these valve programs, beyond the immediate need to provide high-reliability valves for FFTF and the support facilities, is the necessity to develop small valve technology for the Clinch River Breeder Reactor Plant (CRBRP). FFTF small sodium valve design and development experience will be directly applied to the CRBRP program. Various test programs have been, and are being, conducted to verify the performance and integrity of the FFTF valves, and to uncover any potential problems so that they can be corrected before the valves are placed in service in FFTF. The principal small sodium valve designs being utilized in current U.S. programs, the test and operational experience obtained to date on them, problems uncovered, and future development and testing efforts being planned are reviewed. The standards and requirements to which the valves are being designed and fabricated, the valve designs in current use, valve operators, test and operating experience, and future valve development plans are summarized. (U.S.)

  3. Operating experience with BWR nuclear power

    International Nuclear Information System (INIS)

    Bonsdorf, Magnus von.

    1986-01-01

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

  4. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Lantzsch, Kerstin; The ATLAS collaboration

    2016-01-01

    Run 2 of the LHC is providing new challenges to track and vertex reconstruction with higher energies, denser jets and higher rates. Therefore the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). In addition the Pixel detector was refurbished with new service quarter panels to recover about 3% of defective modules lost during run 1 and a new optical readout system to readout the data at higher speed while reducing the occupancy when running with increased luminosity. The commissioning, operation and performance of the 4-layer Pixel Detector will be presented.

  5. Operating experience with gamma ray irradiators

    International Nuclear Information System (INIS)

    Fraser, F.M.; Ouwerkerk, T.

    1980-01-01

    The experience of Atomic Energy of Canada, Limited (AECL) with radioisotopes dates back to the mid-1940s when radium was marketed for medical purposes. Cobalt-60 came on the scene in 1949 and within a few years a thriving business in cancer teletherapy machines and research irradiators was developed. AECL's first full-scale cobalt-60 gamma ray sterilizer for medical products was installed in 1964. AECL now has over 50 plants and 30 million curies in service around the world. Sixteen years of design experience in cobalt-60 sources, radiation shielding, safety interlock systems, and source pass mechanisms have made gamma irradiators safe, reliable, and easy to operate. This proven technology is being applied in promising new fields such as sludge treatment and food preservation. Cesium-137 is expected to be extensively utilized as the gamma radiation source for these applications

  6. Operational Experience with the ATLAS Pixel Detector

    CERN Document Server

    Djama, Fares; The ATLAS collaboration

    2017-01-01

    Run-2 of the LHC is providing new challenges to track and vertex reconstruction imposed by the higher collision energy, pileup and luminosity that are being delivered. The ATLAS tracking performance relies critically on the Pixel Detector, therefore, in view of Run-2 of LHC, the ATLAS experiment has constructed the first 4-layer Pixel detector in HEP, installing a new Pixel layer, also called Insertable B-Layer (IBL). Pixel detector was refurbished with a new service quarter panel to recover about 3% of defective modules lost during run-1 and an additional optical link per module was added to overcome in some layers the readout bandwidth limitation when LHC will exceed the nominal peak luminosity by almost a factor of 3. The key features and challenges met during the IBL project will be presented, as well as its operational experience and Pixel Detector performance in LHC.

  7. Using voice input and audio feedback to enhance the reality of a virtual experience

    Energy Technology Data Exchange (ETDEWEB)

    Miner, N.E.

    1994-04-01

    Virtual Reality (VR) is a rapidly emerging technology which allows participants to experience a virtual environment through stimulation of the participant`s senses. Intuitive and natural interactions with the virtual world help to create a realistic experience. Typically, a participant is immersed in a virtual environment through the use of a 3-D viewer. Realistic, computer-generated environment models and accurate tracking of a participant`s view are important factors for adding realism to a virtual experience. Stimulating a participant`s sense of sound and providing a natural form of communication for interacting with the virtual world are equally important. This paper discusses the advantages and importance of incorporating voice recognition and audio feedback capabilities into a virtual world experience. Various approaches and levels of complexity are discussed. Examples of the use of voice and sound are presented through the description of a research application developed in the VR laboratory at Sandia National Laboratories.

  8. Industry use of operating experience to achieve improved nuclear plant safety

    International Nuclear Information System (INIS)

    Zebroski, E.L.

    1981-01-01

    A principal lesson drawn from the accident at Three Mile Island was the need for a comprehensive and rigorous system for analysis and feedback of operating experience to reactor operators. Chief executives of US utilities directed in mid-1979 that an intensive and rigorous system of analysis and feedback of operating experience be established. This system is commonly referred to as the ''Significant Events Program''. Since April 1980, the Nuclear Safety Analysis Center (NSAC) has been joined by the Institute for Nuclear Power Operations (INPO) in the field investigation of significant operating events. NSAC has responsibility for analysis of the design and physical events aspects, while INPO has primary responsibility for the operators' aspects, including procedures and training. The process of screening, analysis and feedback of operating experience is now functioning as a seven-step process. A variety of data sources is used, including License Event Reports and outage and major maintenance reports. These are compiled and indexed in convenient form. However, such data bases are used only as incidental tools for the basic investigations and analytical efforts. Rapid dissemination of results is provided by a computer-aided conferencing system, which links 70 operating LWR reactors in the USA, and which has now been extended to four utilities outside the USA, representing several dozen more reactors. Major safety and economic incentives are evident for the rigorous use of such operating experience and for participation in a comprehensive system. Traditional habits of secrecy are recognized as obstacles to timely communication. A principal responsibility of top management of reactor-operating organizations is to overcome such habits where they are counter to the public interest, as well as to the health and survival interest of the utility itself

  9. Operating experience of steam generator test facility

    International Nuclear Information System (INIS)

    Sureshkumar, V.A.; Madhusoodhanan, G.; Noushad, I.B.; Ellappan, T.R.; Nashine, B.K.; Sylvia, J.I.; Rajan, K.K.; Kalyanasundaram, P.; Vaidyanathan, G.

    2006-01-01

    Steam Generator (SG) is the vital component of a Fast Reactor. It houses both water at high pressure and sodium at low pressure separated by a tube wall. Any damage to this barrier initiates sodium water reaction that could badly affect the plant availability. Steam Generator Test Facility (SGTF) has been set up in Indira Gandhi Centre for Atomic Research (IGCAR) to test sodium heated once through steam generator of 19 tubes similar to the PFBR SG dimension and operating conditions. The facility is also planned as a test bed to assess improved designs of the auxiliary equipments used in Fast Breeder Reactors (FBR). The maximum power of the facility is 5.7 MWt. This rating is arrived at based on techno economic consideration. This paper covers the performance of various equipments in the system such as Electro magnetic pumps, Centrifugal sodium pump, in-sodium hydrogen meters, immersion heaters, and instrumentation and control systems. Experience in the system operation, minor modifications, overall safety performance, and highlights of the experiments carried out etc. are also brought out. (author)

  10. The Drop Tower Bremen -Experiment Operation

    Science.gov (United States)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    The idea behind the drop tower facility of the Center of Applied Space Technology and Micro-gravity (ZARM) in Bremen is to provide an inimitable technical opportunity of a daily access to short-term weightlessness on earth. In this way ZARM`s european unique ground-based microgravity laboratory displays an excellent economic alternative for research in space-related conditions at low costs comparable to orbital platforms. Many national and international ex-perimentalists motivated by these prospects decide to benefit from the high-quality and easy accessible microgravity environment only provided by the Drop Tower Bremen. Corresponding experiments in reduced gravity could open new perspectives of investigation methods and give scientists an impressive potential for a future technology and multidisciplinary applications on different research fields like Fundamental Physics, Astrophysics, Fluid Dynamics, Combus-tion, Material Science, Chemistry and Biology. Generally, realizing microgravity experiments at ZARM`s drop tower facility meet new requirements of the experimental hardware and may lead to some technical constraints in the setups. In any case the ZARM Drop Tower Operation and Service Company (ZARM FAB mbH) maintaining the drop tower facility is prepared to as-sist experimentalists by offering own air-conditioned laboratories, clean rooms, workshops and consulting engineers, as well as scientific personal. Furthermore, ZARM`s on-site apartment can be used for accommodations during the experiment campaigns. In terms of approaching drop tower experimenting, consulting of experimentalists is mandatory to successfully accomplish the pursued drop or catapult capsule experiment. For this purpose there will be a lot of expertise and help given by ZARM FAB mbH in strong cooperation to-gether with the experimentalists. However, in comparison to standard laboratory setups the drop or catapult capsule setup seems to be completely different at first view. While defining a

  11. Can Social Comparison Feedback Affect Indicators of Eco-Friendly Travel Choices? Insights from Two Online Experiments

    Directory of Open Access Journals (Sweden)

    Rouven Doran

    2017-01-01

    Full Text Available Two online experiments explored the effects of social comparison feedback on indicators of eco-friendly travel choices. It was tested whether the chosen indicators are sensitive to the information conveyed, and if this varies as a function of in-group identification. Study 1 (N = 134 focused on unfavourable feedback (i.e., being told that one has a larger ecological footprint than the average member of a reference group. People who received unfavourable feedback reported stronger intentions to choose eco-friendly travel options than those who received nondiscrepant feedback, when in-group identification was high (not moderate or low. Perceived self- and collective efficacy were not associated with the feedback. Study 2 (N = 323 extended the focus on favourable feedback (i.e., being told that one has a smaller ecological footprint than the average member of a reference group. Neither unfavourable nor favourable feedback was associated with behavioural intentions, self- or collective efficacy. This means that Study 2 failed to replicate the finding of Study 1 that behavioural intentions were associated with unfavourable feedback, given that in-group identification is high. The findings are discussed in light of the existing literature. Suggestions are made for future studies investigating social comparison feedback as a means to motivate people to make eco-friendly travel choices.

  12. Midwifery students experience of teamwork projects involving mark-related peer feedback.

    Science.gov (United States)

    Hastie, Carolyn R; Fahy, Kathleen M; Parratt, Jenny A; Grace, Sandra

    2016-06-01

    Lack of teamwork skills among health care professionals endangers patients and enables workplace bullying. Individual teamwork skills are increasingly being assessed in the undergraduate health courses but rarely defined, made explicit or taught. To remedy these deficiencies we introduced a longitudinal educational strategy across all three years of the Bachelor of Midwifery program. To report on students' experiences of engaging in team based assignments which involved mark-related peer feedback. Stories of midwifery students' experiences were collected from 17 participants across the three years of the degree. These were transcribed and analysed thematically and interpreted using feminist collaborative conversations. Most participants reported being in well-functioning teams and enjoyed the experience; they spoke of 'we' and said 'Everyone was on Board'. Students in poorly functioning teams spoke of 'I' and 'they'. These students complained about the poor performance of others but they didn't speak up because they 'didn't want to make waves' and they didn't have the skills to be able to confidently manage conflict. All participants agreed 'Peer-related marks cause mayhem'. Teamwork skills should be specifically taught and assessed. These skills take time to develop. Students, therefore, should be engaged in a teamwork assignment in each semester of the entire program. Peer feedback should be moderated by the teacher and not directly related to marks. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  13. Small sodium valve design and operating experience

    International Nuclear Information System (INIS)

    Abramson, R.; Elie, X.; Vercasson, M.; Nedelec, J.

    1974-01-01

    Conventionally, valves for sodium pipes smaller than 125 mm in diameter are called ''small sodium valves''. However, this limit should rather be considered as the lower limit o ''large sodium valves''. In fact, both the largest sizes of small valves and the smallest of large valves can be found in the range of 125-300 mm in diameter. Thus what is said about small valves also applies, for a few valve types, above the 125 mm limit. Sodium valves are described here in a general manner, with no manufacturing details except when necessary for understanding valve behavior. Operating experience is pointed out wherever possible. Finally, some information is given about ongoing or proposed development plans. (U.S.)

  14. Lessons learned from operating experience, maintenance procedures and training measures

    International Nuclear Information System (INIS)

    Guttner, K.; Gronau, D.

    2003-01-01

    Training programmes for nuclear facility personnel as a result of the developing phase of SAT have to be approved in the subsequent implementation and evaluation phases with the consequence of several feedback activities in the whole training process. The effectiveness of this procedure has to be evaluated especially with respect to an improvement of safety culture, shorter outage times or better plant performance, resulting in a smaller number of incidents due to human failures. The first two arguments are directly connected with all types of maintenance work in a nuclear power plant and the related preparatory training measures. The reduction of incidents due to human failures is the result of different influences, i.e. training of the operational as well as of the maintenance personnel together with changes of the operating procedures or system design. Though an evaluation of the training process should always be based on a clear definition of criteria by which the fulfilment of the learning objectives can be measured directly, the real effectiveness of training is proven by the behaviour and attitude of the personnel which can only be taken from indirect indicators. This is discussed in more detail for some examples being partly related to the above mentioned arguments. An excellent plant performance, representing a general objective of all activities, can be analysed by the changed number and reasons of incidents in a plant during its operation time. Two further examples are taken from the reactor service field where there is a tendency to reduce the individual dose rates by changed devices and/or procedures as an output from training experience with mockups. Finally the rationalisation of refresher training for operational personnel by the use of interactive teaching programs (Computer Based Training - CBT) is presented which integrate learning objectives together with a test module. (author)

  15. Use of experience for the improvement of technical specifications for operation

    International Nuclear Information System (INIS)

    Schweitz, J.P.; Seveon, J.J.

    1987-11-01

    The lessons drawn from experience led EdF to define in 1980 a national specification standard, to be applied to the first standardized series of 900 MWe units and to be adapted to the later 1300 MWe units. This document is periodically revised, every two years or so, to take into account new trends in safety thinking and lessons learnt from operating experience. In this paper we present the main developments in the field of technical specifications, particularly: the definition of rules applicable in the event of unavailability of safety-related equipment, the integration of plant unit operating feedback for specifications optimization

  16. Operational Performance of the Two-Channel 10 Megawatt Feedback Amplifier System for MHD Control on the Columbia University HBT-EP Tokamak

    International Nuclear Information System (INIS)

    Reass, W.A.; Wurden, G.A.

    1997-01-01

    The operational characteristics and performance of the two channel 10 Megawatt MHD feedback control system as installed by Los Alamos National Laboratory on the Columbia University HBT-EP tokamak are described. In the present configuration, driving independent 300 microH saddle coil sets, each channel can deliver 1100 Amperes and 16 kV peak to peak. Full power bandwidth is about 12 kHz, with capabilities at reduced power to 30 kHz. The present system topology is designed to suppress magnetohydrodynamic activity with m=2, n=1 symmetry. Application of either static (single phase) or rotating (twin phased) magnetic perturbations shows the ability to spin up or slow down the plasma, and also prevent (or cause) so-called ''mode-locking''. Open loop and active feedback experiments using a digital signal processor (DSP) have been performed on the HBT-EP tokamak and initial results show the ability to manipulate the plasma MHD mode frequency

  17. Reciprocal Markov Modeling of Feedback Mechanisms Between Emotion and Dietary Choice Using Experience-Sampling Data.

    Science.gov (United States)

    Lu, Ji; Pan, Junhao; Zhang, Qiang; Dubé, Laurette; Ip, Edward H

    2015-01-01

    With intensively collected longitudinal data, recent advances in the experience-sampling method (ESM) benefit social science empirical research, but also pose important methodological challenges. As traditional statistical models are not generally well equipped to analyze a system of variables that contain feedback loops, this paper proposes the utility of an extended hidden Markov model to model reciprocal the relationship between momentary emotion and eating behavior. This paper revisited an ESM data set (Lu, Huet, & Dube, 2011) that observed 160 participants' food consumption and momentary emotions 6 times per day in 10 days. Focusing on the analyses on feedback loop between mood and meal-healthiness decision, the proposed reciprocal Markov model (RMM) can accommodate both hidden ("general" emotional states: positive vs. negative state) and observed states (meal: healthier, same or less healthy than usual) without presuming independence between observations and smooth trajectories of mood or behavior changes. The results of RMM analyses illustrated the reciprocal chains of meal consumption and mood as well as the effect of contextual factors that moderate the interrelationship between eating and emotion. A simulation experiment that generated data consistent with the empirical study further demonstrated that the procedure is promising in terms of recovering the parameters.

  18. Operational experience review and methods to enhance safety and reliability in the NPP-Leibstadt (KKL)

    Energy Technology Data Exchange (ETDEWEB)

    Haeusermann, R [Kernkraftwerk Leibstadt AG, Leibstadt (Switzerland)

    1997-10-01

    In the nuclear community it became clear that an integrated feedback system of operating experience must also include the unsuccessful results. The deviations, expected to achieved performance are analysed to the failure mode and its effect. KKL has lowered the number of safety significant events since commercial operation started. The thoroughness of the review/analysis of the events has increased with high priority set to human factor induced events in operation and maintenance. Since the participation of the author in the ASSET-Mission in Smolensk in 1993, KKL introduced the ASSET-Root-Cause method and has supplemented it by the HPES (Human Performance Enhancement System). 4 refs, 6 figs.

  19. Operational experience review and methods to enhance safety and reliability in the NPP-Leibstadt (KKL)

    International Nuclear Information System (INIS)

    Haeusermann, R.

    1997-01-01

    In the nuclear community it became clear that an integrated feedback system of operating experience must also include the unsuccessful results. The deviations, expected to achieved performance are analysed to the failure mode and its effect. KKL has lowered the number of safety significant events since commercial operation started. The thoroughness of the review/analysis of the events has increased with high priority set to human factor induced events in operation and maintenance. Since the participation of the author in the ASSET-Mission in Smolensk in 1993, KKL introduced the ASSET-Root-Cause method and has supplemented it by the HPES (Human Performance Enhancement System). 4 refs, 6 figs

  20. MOX and UOX PWR fuel performances EDF operating experience

    International Nuclear Information System (INIS)

    Provost, Jean-Luc; Debes, Michel

    2005-01-01

    Based on a large program of experimentations implemented during the 90s, the industrial achievement of new FAs designs with increased performances opens up new prospects. The currently UOX fuels used on the 58 EDF PWR units are now authorized up to a maximum FA burn-up of 52 GWd/t with a large experience from 45 to 50 GWd/t. Today, the new products, along with the progress made in the field of calculation methods, still enable to increase further the fuel performances with respect to the safety margins. Thus, the conditions are met to implement in the next years new fuel managements on each NPPs series of the EDF fleet with increased enrichment (up to 4.5%) and irradiation limits (up to 62 GWd/t). The recycling of plutonium is part of EDF's reprocessing/recycling strategy. Up to now, 20 PWR 900 MW reactors are managed in MOX hybrid management. The feedback experience of 18 years of PWR operation with MOX is satisfactory, without any specific problem regarding manoeuvrability or plant availability. EDF is now looking to introduce MOX fuels with a higher plutonium content (up to 8.6%) equivalent to natural uranium enriched to 3.7%. It is the goal of the MOX Parity core management which achieve balance of MOX and UOX fuel performance with a significant increase of the MOX average discharge burn-up (BU max: 52 GWd/t for MOX and UOX). The industrial maturity of new FAs designs, with increased performances, allows the implementation in the next years of new fuel managements on each NPPs series of the EDF fleet. The scheduling of the implementation of the new fuel managements on the PWRs fleet is a great challenge for EDF, with important stakes: the nuclear KWh cost decrease with the improvement of the plant operation performance. (author)

  1. Medical supply on contingency military operations: experience from Operation GRITROCK.

    Science.gov (United States)

    Robinson, J P; Reeves, P

    2015-01-01

    Medical supply during military operations has the ability to affect the efficacy of the operation being undertaken, either negatively or positively. An appropriately-managed maritime platform with a robust medical supply chain during transit and on arrival in theatre is the main aim. A secure supply chain will reduce any implications that logistics may have with regard to capability, and negate the effects of deficiencies of short shelf life items occurring over time and during use in high tempo operations.

  2. Synthetic vision systems: operational considerations simulation experiment

    Science.gov (United States)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-04-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  3. Synthetic Vision Systems - Operational Considerations Simulation Experiment

    Science.gov (United States)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-01-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  4. USA/FBR program status FFTF operations startup experience

    International Nuclear Information System (INIS)

    Moffitt, W.C.; Izatt, R.D.

    1981-06-01

    This paper gives highlights of the major Operations evaluations and operational results of the startup acceptance testing program and initiation of normal operating cycles for experiment irradiation in the FFTF. 33 figures

  5. Evaluation of German and international operating experience

    International Nuclear Information System (INIS)

    Stueck, Reinhard; Verstegen, Claus

    2014-01-01

    The systematic analysis of safety-relevant events in nuclear power plants and their causes is a key driver for the further development of nuclear safety. The findings obtained from the evaluation of operating experience in this respect form the basis for both technical and organisational improvements in the plants as well as for adaptations of technical rules and standards. In its role as Technical Safety Organisation advising the German federal government, Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) has been concerned with the detection and analysis of failure mechanisms that underlie events in nuclear power plants at home and abroad since its foundation in 1977. This article provides an overview of the different objectives which are pursued in this context by order of or funded by the Federal Environment Ministry. Here, the focus is on the evaluation of reportable events for the preparation of so-called Information Notices and generic reports as well as for the acquisition of data that can be used for in-depth probabilistic analyses.

  6. PReSaFe: A model of barriers and facilitators to patients providing feedback on experiences of safety.

    Science.gov (United States)

    De Brún, Aoife; Heavey, Emily; Waring, Justin; Dawson, Pamela; Scott, Jason

    2017-08-01

    The importance of involving patients in reporting on safety is increasingly recognized. Whilst studies have identified barriers to clinician incident reporting, few have explored barriers and facilitators to patient reporting of safety experiences. This paper explores patient perspectives on providing feedback on safety experiences. Patients (n=28) were invited to take part in semi-structured interviews when given a survey about their experiences of safety following hospital discharge. Transcripts were thematically analysed using NVivo10. Patients were recruited from four hospitals in the UK. Three themes were identified as barriers and facilitators to patient involvement in providing feedback on their safety experiences. The first, cognitive-cultural, found that whilst safety was a priority for most, some felt the term was not relevant to them because safety was the "default" position, and/or because safety could not be disentangled from the overall experience of care. The structural-procedural theme indicated that reporting was facilitated when patients saw the process as straightforward, but that disinclination or perceived inability to provide feedback was a barrier. Finally, learning and change illustrated that perception of the impact of feedback could facilitate or inhibit reporting. When collecting patient feedback on experiences of safety, it is important to consider what may help or hinder this process, beyond the process alone. We present a staged model of prerequisite barriers and facilitators and hypothesize that each stage needs to be achieved for patients to provide feedback on safety experiences. Implications for collecting meaningful data on patients' safety experiences are considered. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

  7. Mitigation of Cognitive Bias with a Serious Game: Two Experiments Testing Feedback Timing and Source

    Science.gov (United States)

    Dunbar, Norah E.; Jensen, Matthew L.; Miller, Claude H.; Bessarabova, Elena; Lee, Yu-Hao; Wilson, Scott N.; Elizondo, Javier; Adame, Bradley J.; Valacich, Joseph; Straub, Sara; Burgoon, Judee K.; Lane, Brianna; Piercy, Cameron W.; Wilson, David; King, Shawn; Vincent, Cindy; Schuetzler, Ryan M.

    2017-01-01

    One of the benefits of using digital games for education is that games can provide feedback for learners to assess their situation and correct their mistakes. We conducted two studies to examine the effectiveness of different feedback design (timing, duration, repeats, and feedback source) in a serious game designed to teach learners about…

  8. First feedback with the AMMON integral experiment for the JHR calculations

    Directory of Open Access Journals (Sweden)

    Lemaire M.

    2013-03-01

    Full Text Available The innovative design of the next international Material Testing Reactor, the Jules Horowitz Reactor (JHR, induced the development of a new neutron and photon calculation formular HORUS3D/P&N, based on deterministic and stochastic codes and the European nuclear data library JEFF3.1.1. A new integral experiment, named the AMMON experiment, was designed in order to make the experimental validation of HORUS3D. The objectives of this experimental program are to calibrate the biases and uncertainties associated with the HORUS3D/N&P calculations for JHR safety and design calculations, but also the validation of some specific nuclear data (concerning mainly hafnium and beryllium isotopes. The experiment began in 2010 and is currently performed in the EOLE zero-power critical mock-up at CEA Cadarache. This paper deals with the first feedback of the AMMON experiments with 3D Monte Carlo TRIPOLI4©/JEFF3.1.1 calculations.

  9. Operating experience with existing light sources

    International Nuclear Information System (INIS)

    Barton, M.Q.

    1985-01-01

    It is instructive to consider what an explosive growth there has been in the development of light sources using synchrotron radiation. This is well illustrated by the list of facilities given in Table I. In many cases, synchrotron light facilities have been obtained by tacking on parasitic beam lines to rings that were built for high energy physics. Of the twenty-three facilities in this table, however, eleven were built explicitely for this synchrotron radiation. Another seven have by now been converted for use as dedicated facilities leaving only five that share time with high energy physics. These five parasitically operated facilities are still among our best sources of hard x-rays, however, and their importance to the fields of science where these x-rays are needed must be emphasized. While the number of facilities in this table is impressive, it is even more impressive to add up the total number of user beam lines. Most of these rings are absolutely surrounded by beam lines and finding real estate on the experimental floor of one of these facilities for adding a new experiment looks about as practical as adding a farm in the middle of Manhattan. Nonetheless, the managers of these rings seem to have an attitude of ''always room for one more'' and new experimental beam lines do appear. This situation is necessary because the demand for beam time has exploded at an even faster rate than the development of the facilities. The field is not only growing, it can be expected to continue to grow for some time. Some of the explicit plans for future development will be discussed in the companion paper by Lee Teng

  10. Stability of Switched Feedback Time-Varying Dynamic Systems Based on the Properties of the Gap Metric for Operators

    Directory of Open Access Journals (Sweden)

    M. De la Sen

    2012-01-01

    Full Text Available The stabilization of dynamic switched control systems is focused on and based on an operator-based formulation. It is assumed that the controlled object and the controller are described by sequences of closed operator pairs (L,C on a Hilbert space H of the input and output spaces and it is related to the existence of the inverse of the resulting input-output operator being admissible and bounded. The technical mechanism addressed to get the results is the appropriate use of the fact that closed operators being sufficiently close to bounded operators, in terms of the gap metric, are also bounded. That philosophy is followed for the operators describing the input-output relations in switched feedback control systems so as to guarantee the closed-loop stabilization.

  11. Defense waste processing facility radioactive operations. Part 1 - operating experience

    International Nuclear Information System (INIS)

    Little, D.B.; Gee, J.T.; Barnes, W.M.

    1997-01-01

    The Savannah River Site's Defense Waste Processing Facility (DWPF) near Aiken, SC is the nation's first and the world's largest vitrification facility. Following a ten year construction program and a 3 year non-radioactive test program, DWPF began radioactive operations in March 1996. This paper presents the results of the first 9 months of radioactive operations. Topics include: operations of the remote processing equipment reliability, and decontamination facilities for the remote processing equipment. Key equipment discussed includes process pumps, telerobotic manipulators, infrared camera, Holledge trademark level gauges and in-cell (remote) cranes. Information is presented regarding equipment at the conclusion of the DWPF test program it also discussed, with special emphasis on agitator blades and cooling/heating coil wear. 3 refs., 4 figs

  12. Reversed field pinch operation with intelligent shell feedback control in EXTRAP T2R

    Science.gov (United States)

    Brunsell, P. R.; Kuldkepp, M.; Menmuir, S.; Cecconello, M.; Hedqvist, A.; Yadikin, D.; Drake, J. R.; Rachlew, E.

    2006-11-01

    Discharges in the thin shell reversed field pinch (RFP) device EXTRAP T2R without active feedback control are characterized by growth of non-resonant m = 1 unstable resistive wall modes (RWMs) in agreement with linear MHD theory. Resonant m = 1 tearing modes (TMs) exhibit initially fast rotation and the associated perturbed radial fields at the shell are small, but eventually TMs wall-lock and give rise to a growing radial field. The increase in the radial field at the wall due to growing RWMs and wall-locked TMs is correlated with an increase in the toroidal loop voltage, which leads to discharge termination after 3-4 wall times. An active magnetic feedback control system has been installed in EXTRAP T2R. A two-dimensional array of 128 active saddle coils (pair-connected into 64 independent m = 1 coils) is used with intelligent shell feedback control to suppress the m = 1 radial field at the shell. With feedback control, active stabilization of the full toroidal spectrum of 16 unstable m = 1 non-resonant RWMs is achieved, and TM wall locking is avoided. A three-fold extension of the pulse length, up to the power supply limit, is observed. Intelligent shell feedback control is able to maintain the plasma equilibrium for 10 wall times, with plasma confinement parameters sustained at values comparable to those obtained in thick shell devices of similar size.

  13. Reversed field pinch operation with intelligent shell feedback control in EXTRAP T2R

    International Nuclear Information System (INIS)

    Brunsell, P.R.; Kuldkepp, M.; Menmuir, S.; Cecconello, M.; Hedqvist, A.; Yadikin, D.; Drake, J.R.; Rachlew, E.

    2006-01-01

    Discharges in the thin shell reversed field pinch (RFP) device EXTRAP T2R without active feedback control are characterized by growth of non-resonant m = 1 unstable resistive wall modes (RWMs) in agreement with linear MHD theory. Resonant m = 1 tearing modes (TMs) exhibit initially fast rotation and the associated perturbed radial fields at the shell are small, but eventually TMs wall-lock and give rise to a growing radial field. The increase in the radial field at the wall due to growing RWMs and wall-locked TMs is correlated with an increase in the toroidal loop voltage, which leads to discharge termination after 3-4 wall times. An active magnetic feedback control system has been installed in EXTRAP T2R. A two-dimensional array of 128 active saddle coils (pair-connected into 64 independent m = 1 coils) is used with intelligent shell feedback control to suppress the m = 1 radial field at the shell. With feedback control, active stabilization of the full toroidal spectrum of 16 unstable m = 1 non-resonant RWMs is achieved, and TM wall locking is avoided. A three-fold extension of the pulse length, up to the power supply limit, is observed. Intelligent shell feedback control is able to maintain the plasma equilibrium for 10 wall times, with plasma confinement parameters sustained at values comparable to those obtained in thick shell devices of similar size

  14. Reliability in mechanics: the application of experience feedback; La fiabilite en mecanique: mise en pratique du retour d`experience

    Energy Technology Data Exchange (ETDEWEB)

    Coudray, R.

    1994-12-31

    After a short overview of the available methods for statistical multi-dimensional studies, an application of these methods is described using the experience feedback of French nuclear reactors. The material studied is the RCV (chemical and volumetric control system) pump of the 900 MW PWR type reactors for which data used in the study are explained. The aim of the study is to show the pertinency of the rate of failures as an indicator of the material aging. This aging is illustrated by the most significant characteristics with an indication of their significance level. The method used combines the results from a mixed classification and those from a multiple correspondences analysis in several steps or evolutions. (J.S.). 8 refs., 6 figs., 3 tabs.

  15. Operating experience review for the AP1000 plant

    International Nuclear Information System (INIS)

    Chaney, T. E.; Lipner, M. H.

    2006-01-01

    Westinghouse is performing an update to the Operating Experience Review (OER) Report for the AP1000 project to account for operating experience since December 1996. Significant Operating Experience Reports, Significant Event Reports, Significant Event Notifications, Operations and Maintenance Reminders, Topical Reports, Event Analysis Reports and Licensee Event Reports were researched for pertinent input to the update. As a part of the OER, Westinghouse has also conducted operator interviews and observations during simulated plant operations and after operating events. The main purpose of the OER is to identify Human Factors Engineering (HFE) related safety issues from existing operating plant experience and to ensure that these issues are addressed in the new design. The issues and lessons learned regarding operating experience provide a basis for improving the plant design. (authors)

  16. Treatment of operational experience of nuclear power plants in WANO

    International Nuclear Information System (INIS)

    Ibanez, M.

    2013-01-01

    The article describes the activities associated to the Operating Experience Programme of the World Association of Nuclear Operators. The programme manages the event reports submitted by the nuclear power plants to the WANO database for the preparation by the Operating Experience Central Team of some documents like the significant Operating Experience Reports and Significant Event Reports that help the stations to avoid similar events. (Author)

  17. Operational Art and the ADF Experience

    Science.gov (United States)

    2017-05-25

    Joint operations; 9. Distributed free maneuver; 10. The continuous front; 11. The empty battlefield; and 12. Commanders exercising operational vision...and purpose. The value of this analogy is that it demonstrates that operational art involves both sides of the issue, strategy and tactics...Objectives.” Speech , The International Conference on the Afghanistan Conflict and Australia’s Role, October 22-23, 2009, accessed December 06, 2016, http

  18. Effects of positive electrical feedback in the oscillating Belousov-Zhabotinsky reaction: Experiments and simulations

    International Nuclear Information System (INIS)

    Sriram, K.

    2006-01-01

    This paper describes both the experimental and numerical investigations on the effect of positive electrical feedback in the oscillating Belovsou-Zhabotinsky (BZ) reaction under batch conditions. Positive electrical feedback causes an increase in the amplitude and period of the oscillations with the corresponding increase of the feedback strength. Oregonator model with a positive feedback term suitably incorporated in one of the dynamical variables is used to account for these experimental observations. Further, the effect of positive feedback on the Hopf points are investigated numerically by constructing the bifurcation diagrams. In the absence of feedback, for a particular stoichiometric parameter, the model exhibits both supercritical and subcritical Hopf bifurcations with canard existing near the former Hopf point. In the presence of positive feedback it is observed that (i) both the Hopf points advances, (ii) the distance between the two Hopf points decreases linearly, while the period increases exponentially with the increase of feedback strength near the Hopf points, (iii) only supercritical Hopf point without canard survives for a very strong positive feedback strength and (iv) moderate feedback strength takes the system away from limit cycle to the canard regime. These observations are explained in terms of Field-Koeroes-Noyes mechanism of the Belousov-Zhabotinsky reaction. This may be the first instance where the advancement of Hopf points due to positive feedback is clearly shown

  19. The Linkage of Joint Operational Fires, Information Operations and the Army: Does the Army Have Effective Feedback Mechanisms that Integrate Operational Fires (Physical Destruction) and Information Operations?

    National Research Council Canada - National Science Library

    Mills, Charles

    2004-01-01

    The information revolution seems to hold a lot of promise to the U.S. economy and the U.S. military, but rigid bureaucratic hierarchies make it extremely difficult for effective integration of operational fires and information operations...

  20. The tritium operations experience on TFTR

    International Nuclear Information System (INIS)

    Halle, A. von; Anderson, J.L.; Gentile, C.; Grisham, L.; Hosea, J.; Kamperschroer, J.; LaMarche, P.; Oldaker, M.; Nagy, A.; Raftopoulos, S.; Stevenson, T.

    1995-01-01

    The Tokamak Fusion Test Reactor (TFTR) tritium gas system is administratively limited to 5 grams of tritium and provides the feedstock gas for the neutral beam and torus injection systems. Tritium operations on TFTR began with leak checking of gas handling systems, qualification of the gas injection systems, and high power plasma operations using trace amounts of tritium in deuterium feedstock gas. Full tritium operation commenced with four highly diagnosed neutral beam pulses into a beamline calorimeter to verify planned tritium beam operating routines and to demonstrate the deuterium to tritium beam isotope exchange. Since that time, TFTR has successfully operated each of the twelve neutral beam ion sources in tritium during hundreds of tritium beam pulses and torus gas injections. This paper describes the TFTR tritium gas handling systems and TFTR tritium operations of the gas injection systems and the neutral beam ion sources. Tritium accounting and accountability is discussed, including tritium retention issues of the torus limiters and beam impinged surfaces of the beamline components. Also included is tritium beam velocity analysis that compares the neutral beam extracted ion species composition for deuterium and tritium and that determines the extent of beam isotope exchange on subsequent deuterium and tritium beam pulses. The required modifications to TFTR operating routines to meet the U.S. Department of Energy regulations for a low hazard nuclear facility and the problems encountered during initial tritium operations are described. (orig.)

  1. The tritium operations experience on TFTR

    International Nuclear Information System (INIS)

    von Halle, A.; Gentile, C.

    1994-01-01

    The Tokamak Fusion Test Reactor (TFTR) tritium gas system is administratively limited to 5 grains of tritium and provides the feedstock gas for the neutral beam and torus injection systems. Tritium operations on TFTR began with leak checking of gas handling systems, qualification of the gas injection systems, and high power plasma operations using using trace amounts of tritium in deuterium feedstock gas. Full tritium operation commenced with four highly diagnosed neutral beam pulses into a beamline calorimeter to verify planned tritium beam operating routines and to demonstrate the deuterium to tritium beam isotope exchange. Since that time, TFTR has successfully operated each of the twelve neutral beam ion sources in tritium during hundreds of tritium beam pulses and torus gas injections. This paper describes- the TFTR tritium gas handling systems and TFTR tritium operations of the gas injection systems and the neutral beam ion sources. Tritium accounting and accountability is discussed, including tritium retention issues of the torus limiters and beam impinged surfaces of the beamline components. Also included is tritium beam velocity analysis that compares the neutral beam extracted ion species composition for deuterium and tritium and that determines the extent of beam isotope exchange on subsequent deuterium and tritium beam pulses. The required modifications to TFTR operating routines to meet the US Department of Energy regulations for a low hazard nuclear facility and the problems encountered during initial tritium operations are described

  2. Systematisation of the use of experience feedback from NPP's in the regulatory field

    International Nuclear Information System (INIS)

    Vandewalle, A.

    2004-01-01

    Operating experience activities are important to maintain and to improve nuclear safety for nuclear power plant installations. Although with somewhat other objectives, the same kind of activities has to be performed by the regulatory organisations to support their functions, responsibilities and missions, without duplications and wastage of resources. International cooperation to share experience gained from events is also essential in this improvement process and each regulatory organisation should participate to this fundamental support to nuclear safety. (orig.)

  3. Recent operational experiments at the LANSCE facility

    Energy Technology Data Exchange (ETDEWEB)

    Rybarcyk, Lawrence J [Los Alamos National Laboratory

    2010-09-15

    The Los Alamos Neutron Science Center (LANSCE) consists of a pulsed 800-MeV room-temperature linear accelerator and an 800-MeV accumulator ring. It simultaneously provides H{sup +} and H{sup -} beams to several user facilities that have their own distinctive requirements, e.g. intensity, chopping pattern, duty factor, etc.. This multibeam operation presents challenges both from the standpoint of meeting the individual requirements but also achieving good overall performance for the integrated operation. Various aspects of more recent operations including the some of these challenges will be discussed.

  4. Active feedback control of kink modes in tokamaks: 3D VALEN modeling and HBT-EP experiments

    International Nuclear Information System (INIS)

    Maurer, D.A.

    2002-01-01

    Significant progress in the development of active feedback control as a robust technique for the suppression of the wall stabilized external kink or resistive wall mode (RWM) in tokamaks has been achieved through a combination of modeling and experiments. Results from the 3D feedback modeling code VALEN, which serves as the primary analysis and feedback control design tool for RWM studies on the HBT-EP and DIII-D experiments, are in good agreement with observations. VALEN modeling of proposed advanced control system designs on HBT-EP, DIII-D, NSTX, and FIRE are predicted to approach the ideal wall beta limit in agreement with design principles based on simple single mode analytic theory of RWM feedback control. Benchmark experiments on HBT-EP have shown suppression of plasma disruption at rational edge q values using active feedback control in agreement with model predictions. In addition, the observation in HBT-EP of the plasma amplification of static resonant magnetic fields in plasmas marginally stable to the RWM is in agreement with theory. (author)

  5. Online feedback assessments in physiology: effects on students' learning experiences and outcomes.

    Science.gov (United States)

    Marden, Nicole Y; Ulman, Lesley G; Wilson, Fiona S; Velan, Gary M

    2013-06-01

    Online formative assessments have become increasingly popular; however, formal evidence supporting their educational benefits is limited. This study investigated the impact of online feedback quizzes on the learning experiences and outcomes of undergraduate students enrolled in an introductory physiology course. Four quiz models were tested, which differed in the amount of credit available, the number of attempts permitted, and whether the quizzes were invigilated or unsupervised, timed or untimed, or open or closed book. All quizzes were composed of multiple-choice questions and provided immediate individualized feedback. Summative end-of-course examination marks were analyzed with respect to performance in quizzes and were also compared with examination performance in the year before the quizzes were introduced. Online surveys were conducted to gather students' perceptions regarding the quizzes. The vast majority of students perceived online quizzes as a valuable learning tool. For all quiz models tested, there was a significant relationship between performance in quizzes and end-of-course examination scores. Importantly, students who performed poorly in quizzes were more likely to fail the examination, suggesting that formative online quizzes may be a useful tool to identify students in need of assistance. Of the four quiz models, only one quiz model was associated with a significant increase in mean examination performance. This model had the strongest formative focus, allowing multiple unsupervised and untimed attempts. This study suggests that the format of online formative assessments is critical in achieving the desired impact on student learning. Specifically, such assessments are most effective when they are low stakes.

  6. [Nursing Experience of Using Mirror Visual Feedback for a Schizophrenia Patient With Visual Hallucinations].

    Science.gov (United States)

    Lan, Shu-Ling; Chen, Yu-Chi; Chang, Hsiu-Ju

    2018-06-01

    The aim of this paper was to describe the nursing application of mirror visual feedback in a patient suffering from long-term visual hallucinations. The intervention period was from May 15th to October 19th, 2015. Using the five facets of psychiatric nursing assessment, several health problems were observed, including disturbed sensory perceptions (prominent visual hallucinations) and poor self-care (e.g. limited abilities to self-bathe and put on clothing). Furthermore, "caregiver role strain" due to the related intense care burden was noted. After building up a therapeutic interpersonal relationship, the technique of brain plasticity and mirror visual feedback were performed using multiple nursing care methods in order to help the patient suppress her visual hallucinations by enhancing a different visual stimulus. We also taught her how to cope with visual hallucinations in a proper manner. The frequency and content of visual hallucinations were recorded to evaluate the effects of management. The therapeutic plan was formulated together with the patient in order to boost her self-confidence, and a behavior contract was implemented in order to improve her personal hygiene. In addition, psychoeducation on disease-related topics was provided to the patient's family, and they were encouraged to attend relevant therapeutic activities. As a result, her family became less passive and negative and more engaged in and positive about her future. The crisis of "caregiver role strain" was successfully resolved. The current experience is hoped to serve as a model for enhancing communication and cooperation between family and staff in similar medical settings.

  7. Operating experience at Scottish Nuclear's power stations

    International Nuclear Information System (INIS)

    Blackburn, P.

    1991-01-01

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

  8. Phobos L1 Operational Tether Experiment (PHLOTE)

    Data.gov (United States)

    National Aeronautics and Space Administration — A sensor package that “floats” just above the surface of Phobos, suspended by a tether from a small spacecraft operating at the Mars/Phobos Lagrange 1 (L1) Point...

  9. Assessment of Habitat Suitability Is Affected by Plant-Soil Feedback: Comparison of Field and Garden Experiment.

    Directory of Open Access Journals (Sweden)

    Lucie Hemrová

    Full Text Available Field translocation experiments (i.e., the introduction of seeds or seedlings of different species into different localities are commonly used to study habitat associations of species, as well as factors limiting species distributions and local abundances. Species planted or sown in sites where they naturally occur are expected to perform better or equally well compared to sites at which they do not occur or are rare. This, however, contrasts with the predictions of the Janzen-Connell hypothesis and commonly reported intraspecific negative plant-soil feedback. The few previous studies indicating poorer performance of plants at sites where they naturally occur did not explore the mechanisms behind this pattern.In this study, we used field translocation experiments established using both seeds and seedlings to study the determinants of local abundance of four dominant species in grasslands. To explore the possible effects of intraspecific negative plant-soil feedback on our results, we tested the effect of local species abundance on the performance of the plants in the field experiment. In addition, we set up a garden experiment to explore the intensity of intraspecific as well as interspecific feedback between the dominants used in the experiment.In some cases, the distribution and local abundances of the species were partly driven by habitat conditions at the sites, and species performed better at their own sites. However, the prevailing pattern was that the local dominants performed worse at sites where they naturally occur than at any other sites. Moreover, the success of plants in the field experiment was lower in the case of higher intraspecific abundance prior to experimental setup. In the garden feedback experiment, two of the species performed significantly worse in soils conditioned by their species than in soils conditioned by the other species. In addition, the performance of the plants was significantly correlated between the two

  10. Operating experience of Fugen Nuclear Power Station

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  11. EBR-II: summary of operating experience

    International Nuclear Information System (INIS)

    Perry, W.H.; Leman, J.D.; Lentz, G.L.; Longua, K.J.; Olson, W.H.; Shields, J.A.; Wolz, G.C.

    1978-01-01

    Experimental Breeder Reactor II (EBR-II) is an unmoderated, sodium-cooled reactor with a design power of 62.5 MWt. The primary cooling system is a submerged-pool type. The early operation of the reactor successfully demonstrated the feasibility of a sodium-cooled fast breeder reactor operating as an integrated reactor, power plant, and fuel-processing facility. In 1967, the role of EBR-II was reoriented from a demonstration plant to an irradiation facility. Many changes have been made and are continuing to be made to increase the usefulness of EBR-II for irradiation and safety tests. A review of EBR-II's operating history reveals a plant that has demonstrated high availability, stable and safe operating characteristics, and excellent performance of sodium components. Levels of radiation exposure to the operating and maintenance workers have been low; and fission-gas releases to the atmosphere have been minimal. Driver-fuel performance has been excellent. The repairability of radioactive sodium components has been successfully demonstrated a number of times. Recent highlights include installation and successful operation of (1) the hydrogen-meter leak detectors for the steam generators, (2) the cover-gas-cleanup system and (3) the cesium trap in the primary sodium. Irradiations now being conducted in EBR-II include the run-beyond-cladding breach fuel tests for mixed-oxide and carbide elements. Studies are in progress to determine EBR-II's capability for conducting important ''operational safety'' tests. These tests would extend the need and usefulness of EBR-II into the 1980's

  12. Best practices in the utilization and dissemination of operating experience at nuclear power plants

    International Nuclear Information System (INIS)

    2008-03-01

    IAEA Safety Standards Series No. SF-1 entitled Fundamental Safety Principles: Safety Fundamentals states the need for operating organizations to establish a programme for the collection and analysis of operating experience in nuclear power plants. Such a programme ensures that operating experience is analysed, events important to safety are reviewed in depth, lessons learned are disseminated to the staff of the organization and to relevant national and international organizations, operating experience is utilized and corrective actions are effectively implemented. This publication has been developed to provide advice and assistance to nuclear installations and related institutions, including contractors and support organizations, to strengthen and enhance their own feedback process through the implementation of best practices in the utilization and dissemination of operating experience and to assess their effectiveness. Dissemination and utilization of internal and external operating experience is essential in supporting a proactive safety management approach of preventing events from occurring. Few new events reveal a completely new cause or failure mechanism. Although not recognized prior to the event, most subsequent investigations identify internal or external industry operating experience that, if applied effectively, would have prevented the event. Therefore, the establishment of an effective utilization and dissemination process is very beneficial in raising awareness of the organization and individuals of available operating experience, and focussing effort in the implementation of the lessons learnt. This leads to improved safety and reliability. The present publication is the outcome of a coordinated effort involving the participation of experts of nuclear organizations in several Member States. It was written to complement the publication IAEA Services Series No. 10 entitled PROSPER Guidelines - Guidelines for Peer Review and for Plant Self-assessment of

  13. Five years of operating experience with Phenix

    International Nuclear Information System (INIS)

    Conte, F.

    1980-01-01

    The construction of Phenix began at the end of 1968; the unit first went critical on August 31 st, 1973, and it was first connected to the grid of Electricite de France on 31st December 1973. It started operating industrially on July 14th, 1974. The balance sheet after five years of operations is as follows: Gross thermal capacity: 590 MW; Grosss electric capacity: 264 MW; Gross capacity factor of the power station: 45%; Gross electrical power produced by 30th september 1979: more than six billion kWh. In 1976 and 1977 the operation of the plant was affected by modifications made to the intermediate heat exchangers following leaks discovered in October 1976. Since 1976 the plants has been working at full capacity and the availability rate during the period July 1978 - July 1979 was more than 80% [fr

  14. Vapour trap development and operational experience

    International Nuclear Information System (INIS)

    Jansing, W.; Kirchner, G.; Menck, J.

    1977-01-01

    Sodium aerosols have the unpleasant characteristic that they deposit at places with low temperature level. This effect can be utilized when sodium aerosols are to be trapped at places which are determined beforehand. Thus vapour traps were developed which can filter sodium vapour from the cover gas. By this means the necessity was eliminated to heat all gas lines and gas systems with trace heaters just as all sodium lines are heated. It was of special interest for the INTERATOM to develop vapour traps which must not be changed or cleaned after a certain limited operating period. The vapour traps were supposed to enable maintenance free operation, i.e. they were to operate 'self cleaning'

  15. Commonwealth Edison operating experience: the people factor

    International Nuclear Information System (INIS)

    Soth, L.

    1983-01-01

    Since 1955, Commonwealth Edison's nuclear commitment has evolved into three operating stations, another in startup, and two more under construction. Paralleling this evolution has been the investment in the personnel resources to operate, maintain, and manage these facilities. The personnel resource, its training and development, is the foundation for safe operation at any nuclear plant - the people factor. The personnel requirement at Edison has expanded and evolved with each station to meet ever increasing regulatory requirements. An extensive training organization has been developed to emphasize the importance of the man side of the human factors man/machine interface. Personnel errors are investigated to identify and correct the root causes, and outstanding personnel performance is recognized by the Company

  16. Impact of LMFBR operating experience on PFBR design

    International Nuclear Information System (INIS)

    Bhoje, S.B.; Chetal, S.C.; Chellapandi, P.; Govindarajan, S.; Lee, S.M.; Kameswara Rao, A.S.L.; Prabhakar, R.; Raghupathy, S.; Sodhi, B.S.; Sundaramoorthy, T.R.; Vaidyanathan, G.

    2000-01-01

    PFBR is a 500 MWe, sodium cooled, pool type, fast breeder reactor currently under detailed design. It is essential to reduce the capital cost of PFBR in order to make it competitive with thermal reactors. Operating experience of LMFBRs provides a vital input towards simplification of the design, improving its reliability, enhancing safety and achieving overall cost reduction. This paper includes a summary of LMFBR operating experience and details the design features of PFBR as influenced by operating experience of LMFBRs. (author)

  17. Operating experience with KRAFTWERK UNION cementation line

    International Nuclear Information System (INIS)

    Podmaka, L.; Tomik, L.

    1988-01-01

    A facility is described designed for fixation in a cement matrix of the radioactive concentrate produced by thickening waste water from the Bohunice nuclear power plant. The cementation line output is 0.6 m 3 concentrate/h. The concentrate is put in 200 l drums. The individual operating units, cement management, air conditioning, dosimetric monitoring and the building part are described. The requirements for the operators and the assessment of the quality of raw materials and the product are discussed. (M.D.). 3 figs., 4 refs

  18. Operational Experience with the CMS Pixel Detector

    CERN Document Server

    INSPIRE-00205212

    2015-05-15

    In the first LHC running period the CMS-pixel detector had to face various operational challenges and had to adapt to the rapidly changing beam conditions. In order to maximize the physics potential and the quality of the data, online and offline calibrations were performed on a regular basis. The detector performed excellently with an average hit efficiency above 99\\% for all layers and disks. In this contribution the operational challenges of the silicon pixel detector in the first LHC run and the current long shutdown are summarized and the expectations for 2015 are discussed.

  19. Feedback Systems for Linear Colliders

    International Nuclear Information System (INIS)

    1999-01-01

    Feedback systems are essential for stable operation of a linear collider, providing a cost-effective method for relaxing tight tolerances. In the Stanford Linear Collider (SLC), feedback controls beam parameters such as trajectory, energy, and intensity throughout the accelerator. A novel dithering optimization system which adjusts final focus parameters to maximize luminosity contributed to achieving record performance in the 1997-98 run. Performance limitations of the steering feedback have been investigated, and improvements have been made. For the Next Linear Collider (NLC), extensive feedback systems are planned as an integral part of the design. Feedback requirements for JLC (the Japanese Linear Collider) are essentially identical to NLC; some of the TESLA requirements are similar but there are significant differences. For NLC, algorithms which incorporate improvements upon the SLC implementation are being prototyped. Specialized systems for the damping rings, rf and interaction point will operate at high bandwidth and fast response. To correct for the motion of individual bunches within a train, both feedforward and feedback systems are planned. SLC experience has shown that feedback systems are an invaluable operational tool for decoupling systems, allowing precision tuning, and providing pulse-to-pulse diagnostics. Feedback systems for the NLC will incorporate the key SLC features and the benefits of advancing technologies

  20. Force-feedback tele operation of industrial robots a cost effective solution for decontamination of nuclear plants

    International Nuclear Information System (INIS)

    Desbats, P.; Andriot, C.; Gicquel, P.; Viallesoubranne, J.P.; Souche, C.

    1998-01-01

    Decontamination and maintenance in hot cells are some new emerging applications of industrial robots in the nuclear fuel cycle plants. Industrial robots are low cost, accurate and reliable manipulator arms which are used in manufacturing industries usually. Thanks to the recent evolution of robotics technologies, some industrial robots may be adapted to nuclear environment. These robots are transportable, sealed and can be decontaminated, and they may be 'hardened' up to a level of irradiation dose sufficient for operation in low and medium irradiating/contaminating environments. Although industrial robots are usually programmed to perform specific and repetitive tasks, they may be remotely tele-operated by human operators as well. This allows industrial robots to perform usual tele-manipulation tasks encountered in the nuclear plants and more. The paper presents the computer based tele-operation control system TAO2000 TM , developed by the Tele-operation and Robotics Service of CEA, which has been applied to the RX90 TM industrial robot from ST-UBLI company. This robot has been selected in order to perform various maintenance and decontamination tasks in COGEMA plants. TAO2000 provides the overall tele-robotic and robotic functions necessary to perform any remote tele-operation application in hostile environment: force-feedback master-slave control; computer- assisted tele-operation of mechanical processes; trajectory programming as well as various robotics functions; graphical modelling of working environment and simulation; automatic path planning with obstacle avoidance; man-machine interface for tasks programming and mission execution. Experimental results reported in the paper demonstrate the feasibility of force-feedback master-slave control of standard industrial robots. Finally, the design of new, cost effective. tele-operation systems based on industrial robots may be intended for nuclear plants maintenance. (author)

  1. Operational Applications of Autogenic Feedback Training Exercise as a Treatment for Airsickness in the Military

    Science.gov (United States)

    Gebreyesus, Fiyore; Cowings, Patricia S.; Toscano, William B.

    2012-01-01

    Airsickness is experienced by about 50% of military aviators some time in their career. Aviators who suffer from recurrent episodes of airsickness are typically referred to the Naval Aerospace Medical Institute (NAMI) at Pensacola where they undergo extensive evaluation and 8 weeks of training in the Self-Paced Airsickness Desensitization (SPAD) program. Researchers at NASA Ames have developed an alternative mitigation training program, Autogenic Feedback Training Exercise (AFTE) that has demonstrated an 80% success rate for improving motion sickness tolerance.

  2. Annual meeting on nuclear technology 1980. Technical meeting: Operating experiences

    International Nuclear Information System (INIS)

    1980-01-01

    In addition to general experiences, experiences in reactor operation with relation to the Phenix reactor, KNK-2 reactor, the AVR reactor, the BWR-type KKI-reactor, the Philippsburg-1 reactor and the Obrigheim reactor are described. (DG) [de

  3. Gamification and Smart, Competence-Centered Feedback: Promising Experiences in the Classroom

    Directory of Open Access Journals (Sweden)

    Michael D. Kickmeier-Rust

    2014-02-01

    Full Text Available Gamification appears being a promising approach to utilize the strong motivational potential of “gaming” in classroom without suffering from shortcomings such as low efficiency, weak pedagogy, or maybe most importantly the high costs. In the context of a European project we developed a rather light weight tool for learning and practicing multiplications. The target age group of the tool is 6 to 8 years. To benefit from the motivational potential of games we used a “gamification” approach. Accordingly we designed and developed a game-like, attractive user interface and integrated aspects of competition. The system is capable of providing students formative, competence-oriented feedback in real-time. Tailored to the age group this feedback is presented in form of a ninja character. For an experimental comparison of the effects of different feedback modes, we realized the conditions (i no feedback, (ii written only right/wrong feedback, (iii audio right/wrong feedback, and (iv competence-based, smart formative feedback. We applied and evaluated the tool in Austrian classrooms and found some evidence for the motivational aspect of the gamification elements, in particular the scoring. We also found strong positive effects of an individualized and meaningful feedback about achievements and progress.

  4. Modernization of the french early warning network in IRSN, experience feedback and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Debayle, C.; Bardet, A.; Beguin-Leprieur, M.; Chevreuil, M.; Malfait, V.; Mechenet, V. [PRP-ENV/SESURE/LS2A (France)

    2014-07-01

    Developed few years after the Chernobyl accident in 1991, the French early warning network, Teleray, composed by 160 ambient dose equivalent rate probes, had operated for 15 years. It was decided in 2007 to modernize this facility in order to keep the infrastructure up-to-date. The sensors, the data transmission network and the supervising system were considered separately, but each development took care about the modularity of the final IT system. After a benchmarking period and technical choices, a five years project started with the aim to increase the number of probes to 420, especially around the French nuclear facilities, to change the technology and the IT system including a new data transmission network. The project kick-off was planned in june 2011, but due to the Fukushima accident, the French government asked IRSN to implement a probe on the roof of the French embassy in Tokyo on March 18, 2011. Results and feedback will be discussed, focusing on new approach about data analysis purpose. In 2014, the modernization of this network will be finished one year before it was expected and with significant cost savings. All the relevant phase of the project will be described, including time schedule and economical aspects, with the aim to describe how it is now considered fundamental to have complementary mobile systems in case of nuclear crisis. Document available in abstract form only. (authors)

  5. Operational experience in water chemistry of PHWRs

    International Nuclear Information System (INIS)

    Krishna Rao, K.S.

    2000-01-01

    The chemistry related problems encountered in the moderator, primary heat transport systems, chemical control in the steam generators and the experience gained in the decontamination campaigns carried out in the primary heat transport systems of Indian PHWRs are highlighted in this paper. (author)

  6. Operational experience with the CERN hadron linacs

    International Nuclear Information System (INIS)

    Charmot, H.; Dutriat, C.; Hill, C.E.; Langbein, K.; Lombardi, A.M.; O'Neil, M.; Tanke, E.; Vretenar, M.

    1996-01-01

    The present CERN proton linac (Linac2) was commissioned in 1978 and since that date has been the primary source of protons to the CERN accelerator complex. During the past 18 years, the machine has had a very good reliability record in spite of the demands made upon it. Modifications have been made with the view of maintaining this reliability with reduced resources and new requirements from the users. Further demands will be made in the future for LHC operation. In 1994, a new linac for heavy ion production was put into service replacing the original CERN proton linac. As this machine was built within an international collaboration, operation had to take into account the novelty of the techniques used and the variety of equipment supplied by outside collaborators. Even so, the new machine has also had very good reliability. (author)

  7. Overview - Defense Waste Processing Facility Operating Experience

    International Nuclear Information System (INIS)

    Norton, M.R.

    2002-01-01

    The Savannah River Site's Defense Waste Processing Facility (DWPF) near Aiken, SC is the world's largest radioactive waste vitrification facility. Radioactive operations began in March 1996 and over 1,000 canisters have been produced. This paper presents an overview of the DWPF process and a summary of recent facility operations and process improvements. These process improvements include efforts to extend the life of the DWPF melter, projects to increase facility throughput, initiatives to reduce the quantity of wastewater generated, improved remote decontamination capabilities, and improvements to remote canyon equipment to extend equipment life span. This paper also includes a review of a melt rate improvement program conducted by Savannah River Technology Center personnel. This program involved identifying the factors that impacted melt rate, conducting small scale testing of proposed process changes and developing a cost effective implementation plan

  8. Operating experience from Swedish nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-06-01

    During 1997 the PWRs in Ringhals performed extremely well (capability factors 85-90%), the unit Ringhals 2 reached the best capability factor since commercial operation started in 1976. The BWRs made an average 76% capability, which is somewhat less than in 1996. The slightly reduced capability derives from ongoing modernization projects at several units. At the youngest plants, Forsmark 3 and Oskarshamn 3, capability and utilization were very high. Events and data for 1997 are given for each reactor, together with operational statistics for the years 1990-1997. A number of safety-related events are reported, which occurred st the Swedish plants during 1997. These events are classified as level 1 or higher on the international nuclear event scale (INES).

  9. Three years operational experience with biodiesel

    International Nuclear Information System (INIS)

    Murphy, J.

    2008-01-01

    TSI Terminal Systems Inc. is the largest container terminal operator in Canada, and has an annual payroll exceeding $150 million. The company started a biodiesel test program with the Canadian Bioenergy Corporation in order to assess the emission reduction impacts of using biodiesel. The pilot was tested with 6 different pieces of equipment used at the terminal over an initial period of 3 weeks. Emissions testing was then conducted for different biodiesel blend levels and compared with baseline data in relation to particulate matter, total hydrocarbons, carbon monoxide (CO), carbon dioxide (CO 2 ), and nitrous oxides (NO x ). Results of the tests confirmed that the biodiesel blends significantly reduced emissions at the terminal and confirmed the operability of biodiesel. Overall emissions were reduced by 30 per cent. The fuel is now being used in all the company's equipment. The use of the biodiesel has not resulted in any engine failures or power losses. tabs., figs

  10. Operating experience from Swedish nuclear power plants

    International Nuclear Information System (INIS)

    1998-01-01

    During 1997 the PWRs in Ringhals performed extremely well (capability factors 85-90%), the unit Ringhals 2 reached the best capability factor since commercial operation started in 1976. The BWRs made an average 76% capability, which is somewhat less than in 1996. The slightly reduced capability derives from ongoing modernization projects at several units. At the youngest plants, Forsmark 3 and Oskarshamn 3, capability and utilization were very high. Events and data for 1997 are given for each reactor, together with operational statistics for the years 1990-1997. A number of safety-related events are reported, which occurred st the Swedish plants during 1997. These events are classified as level 1 or higher on the international nuclear event scale (INES)

  11. FFTF operating experience, 1982-1984

    International Nuclear Information System (INIS)

    Waldo, J.B.; Franz, G.R.; Loika, E.F.; Krupar, J.J.

    1984-01-01

    The Fast Flux Test Facility (FFTF) is a 400 Mwt sodium-cooled fast reactor operating at the Hanford Engineering Development Laboratory, Richland, Washington, to conduct fuels and materials testing in support of the US Liquid Metal Fast Breeder Reactor (LMFBR) program. Startup and initial power testing included a comprehensive series of nonnuclear and nuclear tests to verify the thermal, hydraulic, and neutronic characteristics of the plant. A specially designed series of natural circulation tests were then performed to demonstrate the inherent safety features of the plant. Early in 1982, the FFTF began its first 100-day irradiation cycle. Since that time the plant has operated very well, achieving a cycle capacity factor of 94% in the most recent irradiation cycle. Seventy-five specific test assemblies and 25,000 individual fuel pins have been irradiated, some in excess of 80 MWd/Kg

  12. Operational experience with the Fermilab Linac

    International Nuclear Information System (INIS)

    Allen, L.J.; Lennox, A.J.; Schmidt, C.W.

    1992-01-01

    The Fermilab 200-MeV Linac has been in operation for nearly 22 years as a proton injector to the Booster synchrotron. It presently accelerates H - ions to 200 MeV for charge-exchange injection into the Booster and to 66 MeV for the production of neutrons at the Neutron Therapy Facility (NTF). The beam intensity is typically 35 mA with pulse widths of 30 μsec for the Booster for high energy physics and 57 μsec for NTF at a maximum of 15 pulses per sec. During a typical physics run of nine to twelve months, beam is available for greater than 98% of the scheduled time. The Linac history, operation, tuning, stability and reliability will be discussed. (Author) 15 refs., 2 tabs

  13. Operational experience with propulsion nuclear plants

    International Nuclear Information System (INIS)

    Polunichev, V.

    2000-01-01

    Russia possesses a powerful icebreaker transport fleet which offers a solution for important socio-economic tasks of the country's northern regions by maintaining a year-round navigation along the Arctic Sea route. The total operating record of the propulsion nuclear reactors till now exceeds 150 reactor-years, their main equipment items operating life amounted to 120,000 h. Progressive design-constructional solutions being perfected continuously during 40 years of nuclear-powered ships creation in Russia and well proven technology of all components used in the marine nuclear reactors give grounds to recommend marine Nuclear Steam Supply Systems (NSSSs) of KLT-40 type as energy sources for heat and power cogeneration plants and sea water desalination complexes, particularly as floating installations. Co-generation stations are considered for deployment in the extreme north of Russia. Nuclear floating desalination complexes can be used for drinkable water production in coastal regions of Northern Africa, the Near East, India etc. (author)

  14. Operational experience in the United Kingdom

    International Nuclear Information System (INIS)

    Gronow, W.S.

    1977-01-01

    In the UK there are 26 Magnox reactors and 4 AGRs operating on 11 licensed sites; a further 6 AGRs are under construction on 2 additional and one of the existing sites. The arrangements by which the Nuclear Installations Inspectorate, on behalf of the Health and Safety Executive, carries out its regulatory functions at operating nuclear power plants are described. The range of activities undertaken is described with special reference being made to the biennial shutdowns for approved maintenance and inspections which are required by conditions attached to the site licence. The other means by which the continuing safety of these power reactors is assured are explained and include the relationship with the licensee's own Nuclear Safety Committee, approved arrangements for modifications to plant systems or components which have importance for safety and long term reviews of safety aspects. (author)

  15. Weapons Experiments Division Explosives Operations Overview

    Energy Technology Data Exchange (ETDEWEB)

    Laintz, Kenneth E. [Los Alamos National Laboratory

    2012-06-19

    Presentation covers WX Division programmatic operations with a focus on JOWOG-9 interests. A brief look at DARHT is followed by a high level overview of explosives research activities currently being conducted within in the experimental groups of WX-Division. Presentation covers more emphasis of activities and facilities at TA-9 as these efforts have been more traditionally aligned with ongoing collaborative explosive exchanges covered under JOWOG-9.

  16. Operational experience at Fort St. Vrain

    International Nuclear Information System (INIS)

    Bramblett, G.C.; Fisher, C.R.; Swart, F.E.

    1981-01-01

    The Fort St. Vrain (FSV) station, a 330-MW(e) single reheat steam cycle powered by a high-temperature gas-cooled reactor (HTGR), is the first HTGR to enter commercial operation. Designed and built by General Atomic Company (GA), the plant is owned and operated by Public Service Company of Colorado (PSC). Many unique design features have been incorporated into this reactor system, including high-pressure helium as the primary system coolant, a graphite-moderated prismatic block core design, fission-product-containing carbide coatings on both fissile and fertile fuel particles, steam-driven helium circulators turning on water bearings, and once-through steam generators. All of these systems are contained in a prestressed concrete reactor vessel (PCRV). Extensive testing has been conducted during the rise to power following first criticality early in 1974 to verify system design performance. During this period, the plant has operated at power levels up to 70% and produced over one billion kilowatt hours of electricity. In 1979, the first refueling was conducted in conjunction with an extensive in-core inspection, the addition of in-core instrumentation, and a planned removal of a circulator for inspection. Later in the year, a scheduled shutdown was undertaken for surveillance tests, insertion of core region constraint devices (RCDs), and other maintenance. Fort St. Vrain has encountered problems of the type that would be expected in a first-of-a-kind system. The plant is currently restricted to 70% of design power by the Nuclear Regulatory Commission (NRC) pending resolution of the core region gas outlet temperature fluctuation problem. Even so, the basic performance of the HTGR concept and all of the unique design features have been successfully demonstrated. The system has been characterized by low personnel radiation exposures, operational flexibility, and long time afforded for status evaluation and response. (author)

  17. Fort St. Vrain circulator operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Brey, H. L.

    1988-08-15

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs.

  18. Fort St. Vrain circulator operating experience

    International Nuclear Information System (INIS)

    Brey, H.L.

    1988-01-01

    Fort St. Vrain, on the system of Public Service Company of Colorado, is the only high-temperature gas-cooled power reactor in the United States. Four helium circulators are utilized in this plant to transfer heat from the reactor to the steam generators. These unique machines have a single stage axial flow helium compressor driven by a single stage steam turbine. A single stage water driven (pelton wheel) turbine is the back-up drive utilizing either feed water, condensate, or fire water as the driving fluid. Developmental testing of the circulators was accomplished prior to installation into Fort St. Vrain. A combined machine operating history of approximately 250,000 hours has shown these machines to be of conservative design and proven mechanical integrity. However, many problems have been encountered in operating the complex auxiliaries which are necessary for successful circulator and plant operation. It has been 15 years since initial installation of the circulators occurred at Fort St. Vrain. During this time, a number of significant issues had to be resolved dealing specifically with machine performance. These events include cavitation damage of the pelton wheels during the initial plant hot functional testing, cracks in the water turbine buckets and cervic coupling, static shutdown seal bellows failure, and, most recently, degradation of components within the steam drive assembly. Unreliable operation particularly with the circulator auxiliaries has been a focus of attention by Public Service Company of Colorado. Actions to replace or significantly modify the existing circulators and their auxiliaries are currently awaiting decisions concerning the long-term future of the Fort St. Vrain plant. (author). 10 refs, 7 figs, 2 tabs

  19. Operational experience with the CEBAF control system

    International Nuclear Information System (INIS)

    Hovater, C.; Chowdhary, M.; Karn, J.; Tiefenback, M.; Zeijts, J. van; Watson, W.

    1996-01-01

    The CEBAF accelerator at Thomas Jefferson National Accelerator Facility (Jefferson Lab) successfully began its experimental nuclear physics program in November of 1995 and has since surpassed predicted machine availability. Part of this success can be attributed to using the EPICS (Experimental Physics and Industrial Control System) control system toolkit. The CEBAF control system is one of the largest accelerator control system now operating. It controls approximately 338 SRF cavities, 2,300 magnets, 500 beam position monitors and other accelerator devices, such as gun hardware and other beam monitoring devices. All told, the system must be able to access over 125,000 database records. The system has been well received by both operators and the hardware designers. The EPICS utilities have made the task of troubleshooting systems easier. The graphical and test-based creation tools have allowed operators to custom build control screens. In addition, the ability to integrate EPICS with other software packages, such as Tcl/Tk, has allowed physicists to quickly prototype high-level application programs, and to provide GUI front ends for command line driven tools. Specific examples of the control system applications are presented in the areas of energy and orbit control, cavity tuning and accelerator tune up diagnostics

  20. Operational experience at Fort St. Vrain

    Energy Technology Data Exchange (ETDEWEB)

    Bramblett, G. C.; Fisher, C. R.; Swart, F. E. [General Atomic Co., San Diego, CA (USA)

    1981-01-15

    The Fort St. Vrain (FSV) station, a 330-MW(e) single reheat steam cycle powered by a high-temperature gas-cooled reactor (HTGR), is the first HTGR to enter commercial operation. Designed and built by General Atomic Company (GA), the plant is owned and operated by Public Service Company of Colorado (PSC). Many unique design features have been incorporated into this reactor system, including high-pressure helium as the primary system coolant, a graphite-moderated prismatic block core design, fission-product-containing carbide coatings on both fissile and fertile fuel particles, steam-driven helium circulators turning on water bearings, and once-through steam generators. All of these systems are contained in a prestressed concrete reactor vessel (PCRV). Extensive testing has been conducted during the rise to power following first criticality early in 1974 to verify system design performance. During this period, the plant has operated at power levels up to 70% and produced over one billion kilowatt hours of electricity. In 1979, the first refueling was conducted in conjunction with an extensive in-core inspection, the addition of in-core instrumentation, and a planned removal of a circulator for inspection.

  1. Best practices in identifying, reporting and screening operating experience at nuclear power plants

    International Nuclear Information System (INIS)

    2008-03-01

    IAEA Safety Standards Series No. SF-1 entitled Fundamental Safety Principles: Safety Fundamentals states the need for operating organizations to establish a programme for the collection and analysis of operating experience in nuclear power plants. Such a programme ensures that operating experience is analysed, events important to safety are reviewed in depth, lessons learned are disseminated to the staff of the organization and to relevant national and international organizations, and corrective actions are effectively implemented. This publication has been developed to provide advice and assistance to nuclear installations, and related institutions including contractors and support organizations to strengthen and enhance their own feedback process through the implementation of best practices in identifying, reporting and screening processes and to assess the effectiveness of the above areas. To support a proactive safety management approach the nuclear installations are enhancing the operating experience feedback (OEF) processes. For this purpose, the nuclear industry is striving to collect more information on occurrences that are useful to address the early signs of declining performance and improve operational safety performance. In this environment a strong reporting culture that motivates people to identify and report issues is an important attribute. As a consequence, the number and diversity of issues identified increases, and there is a need to set thresholds of screening for further treatment. Thus, the establishment of an effective identification, reporting and screening process is very beneficial to streamline the efforts, and ensure that major incidents and latent weaknesses are being addressed and that operating experience is treated according to its significance. This leads to improved safety and production. This publication was written to complement the publication IAEA Services Series No. 10 - PROSPER Guidelines - Guidelines for Peer Review and for

  2. Quality and safety in radiotherapy: precursor events and experience feedback;Qualite et securite en radiotherapie: evenements precurseurs et retour d'experience

    Energy Technology Data Exchange (ETDEWEB)

    Lartigau, E. [Centre de Lutte Contre le Cancer Oscar-Lambret, Dept. Universitaire de Radiotherapie, Lille-1 Univ., 59 - Lille (France)

    2009-12-15

    The safety in radiotherapy through a method using the experience feedback. It corresponds to a global process organised around a prospective and systematic statement of incidents occurring during the cure activity or around it. The events are registered, analyzed, treated by the committee of experience feedback in order to avoid their repetition and to eliminate the passage to accident. The analysis of the events enlightens the organisational dysfunction.Their correction and the communication following is an essential tool of management in the framework of the non-punishment, guarantee of confidence of personnel. (N.C.)

  3. Experience feedback committee in emergency medicine: a tool for security management.

    Science.gov (United States)

    Lecoanet, André; Sellier, Elodie; Carpentier, Françoise; Maignan, Maxime; Seigneurin, Arnaud; François, Patrice

    2014-11-01

    Emergency departments are high-risk structures. The objective was to analyse the functioning of an experience feedback committee (EFC), a security management tool for the analysis of incidents in a medical department. We conducted a descriptive study based on the analysis of the written documents produced by the EFC between November 2009 and May 2012. We performed a double analysis of all incident reports, meeting minutes and analysis reports. During the study period, there were 22 meetings attended by 15 professionals. 471 reported incidents were transmitted to the EFC. Most of them (95%) had no consequence for the patients. Only one reported incident led to the patient's death. 12 incidents were analysed thoroughly and the committee decided to set up 14 corrective actions, including eight guideline writing actions, two staff trainings, two resource materials provisions and two organisational changes. The staff took part actively in the EFC. Following the analysis of incidents, the EFC was able to set up actions at the departmental level. Thus, an EFC seems to be an appropriate security management tool for an emergency department. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. International Experience with Fast Reactor Operation & Testing

    International Nuclear Information System (INIS)

    Sackett, John I.; Grandy, C.

    2013-01-01

    Conclusion: • Worldwide experience with fast reactors has demonstrated the robustness of the technology and it stands ready for worldwide deployment. • The lessons learned are many and there is danger that what has been learned will be forgotten given that there is little activity in fast reactor development at the present time. • For this reason it is essential that knowledge of fast reactor technology be preserved, an activity supported in the U.S. as well as other countries

  5. Continuous-wave dual-wavelength operation of a distributed feedback laser diode with an external cavity using a volume Bragg grating

    Science.gov (United States)

    Zheng, Yujin; Sekine, Takashi; Kurita, Takashi; Kato, Yoshinori; Kawashima, Toshiyuki

    2018-03-01

    We demonstrate continuous-wave dual-wavelength operation of a broad-area distributed feedback (DFB) laser diode with a single external-cavity configuration. This high-power DFB laser has a narrow bandwidth (current and temperature ranges.

  6. Operational experiences of INES in Japan

    International Nuclear Information System (INIS)

    1997-01-01

    Japan has introduced IAEA's INES in August, 1992. As of September, 1997, the total number of domestic nuclear events which have evaluated by using the INES system has amounted 119. In Japan, when a nuclear event occurs at a nuclear power plant, a provisional evaluation is performed immediately by Nuclear Power Operation Administration Office, MITI. The final evaluation of events is implemented a few months after event occurrence by the Evaluation Committee on Incidents and Failures of Nuclear Power Plant which holds a neutral position. The results of the evaluation are transmitted to IAEA according to the INES reporting criteria

  7. Operating experiences at the Finnish TRIGA reactor

    International Nuclear Information System (INIS)

    Salmenhaara, Seppo

    1988-01-01

    The Finnish TRIGA reactor has been in operation since March 1962. There are still 57 original Al-clad fuel elements in the core. So far we have had only two fuel cladding failures in 1981 and 1988. The first one was an Al-clad element and the second one a SS-clad. The low rate of fuel cladding failures has made it possible to use continuously also the Al-clad fuel elements. Although some conventional irradiations of certain type have been repeated successfully tens of times, new and unexpected incidents can still take place. As an example an event of a leaking irradiation capsule is described

  8. Operating experience with the ALS linac

    International Nuclear Information System (INIS)

    Selph, F.; Massoletti, D.

    1991-05-01

    The linac injector for the Advanced Light Source (ALS) at LBL was recently put into operation. Energy is 50 MeV, frequency 3 GHz. The electron gun delivers up to 6nC in a 3.0-ns bunch at 120 kV. A train of bunches is injected into a 1-Hz booster and accelerated to 1.5 GHz for storage ring injection. A magnetic analysis system is used for optimizing the linac. Measured beam properties from the gun and after acceleration in the linac are described. 9 refs., 3 figs

  9. Operating experience with 600 MW steam turbosets

    International Nuclear Information System (INIS)

    Tinapp, J.

    1978-01-01

    The turbosets of the 600 MW line are machines with 4 casing, with a single-flow high-pressure turbine, a double-flow MD part, and two double-flow low-pressure turbines. The common design of all BBC turbosets of this size is explained, with a few remarks on the typical constructional features of BBC technology. The plant has a mean availability of 96% and a mean forced shutdown rate of 1.2%. A table gives a survey of the start-up procedure and the operating results so far. (GL) [de

  10. Evaluation of operating experience with safety values

    International Nuclear Information System (INIS)

    Bung, W.; Hoemke, P.; Oberender, W.; Paul, H.; Rueter, W.

    1985-01-01

    This report describes statistical investigations of 2076 functional tests carried out on power operated safety valves in conventional power plants in 1972 until 1983 with special regard to Common Mode-Failures. The results clearly show that Common Mode-Failures play an important part of non-availability for the controlled safety valves, especially in the control system. The 'Deutsche Risikostudie' does not consider any Common Mode-Failures of the primary safety valves. However there is no significant increase of the risk resulted by the primary safety valves in the 'Referenzanlage' if the calculated Common Mode-Failures probabilities are considered. (orig.) [de

  11. MOX use in PWRs. EDF operation experience

    International Nuclear Information System (INIS)

    Provost, Jean-Luc; Debes, Michel

    2011-01-01

    From the origin, EDF back-end fuel cycle strategy has focused on 'closing the fuel cycle', in other words integrating fuel reprocessing, with vitrification of high level waste concentrated within small volumes, and the recycling of valuable materials. The implementation of this policy was marked in 1987 by the first loading of sixteen MOX. By December 2010, 20 reactors have been loaded with 1750 tHM of MOX. EDF current strategy is to match the reprocessing program with MOX manufacturing capacity to limit the quantity of separated plutonium. This is routinely called the 'flow ad-equation' strategy. Currently, the MOX Parity core management achieves balance of MOX and UOX performance with a significant increase of the MOX discharge burn-up. Globally, the behavior under irradiation of MOX fuel assemblies has been satisfactory. So far, from the beginning of MOX use in EDF PWRs, only 6 MOX FAs with rod leakage have been identified, which gives a very satisfactory level of reliability. The industrial maturity of MOX fuel, with increased performances, allows the improvement of nuclear KWh competitiveness and of the plant operation performance, while maintaining in operation the same safety level, without significant impact on environment and radiological protection. (author)

  12. Operational experience acquired in radioactive waste compaction

    International Nuclear Information System (INIS)

    Bauer, S.; Mohr, P.; Hempelmann, W.

    1993-01-01

    The low-level radioactive waste scrapping facility in the KfK decontamination division was commissioned in 1983. Non-combustible residues and removed system components of low activity, but which are to be handled and disposed of as radioactive waste are in drums, casks or containers delivered to the facility. The waste usually undergoes pretreatment in a crusher, with the volume being definitively reduced at a pressure of 690 bar in the high-pressure compactor. In 1990, the overhead-crane was refurbished for remote control handling in the scrapping caisson. The parts to undergo scrapping are unpacked in the material lock, and then go into the scrapping caisson. It is possible to use here various mechanical and thermal methods to dismantle the respective parts. But most of the parts to undergo scrapping are such as that it is possible to directly pretreat them in the crusher. The obtained scrap is loaded into 180-liter drums. Most of the machinery in the caisson is manually operated. The operating crew enters the caisson in fully ventilated protective overalls. The drums filled with the scrap then go to the high-pressure compactor in the caisson. The compacts are temporarily stored, until recalled depending on their height and filled into drums such as that optimal drum filling is guaranteed

  13. Feedback from Westinghouse experience on segmentation of reactor vessel internals - 59013

    International Nuclear Information System (INIS)

    Kreitman, Paul J.; Boucau, Joseph; Segerud, Per; Fallstroem, Stefan

    2012-01-01

    successful reactor vessel internals segmentation and packaging project. The purpose of this paper is to provide an overview of the Westinghouse reactor internals segmentation experience by illustrating projects related to various types of reactors and providing feedback from project execution. (authors)

  14. Best Practices in the Management of an Operating Experience Programme at Nuclear Power Plants

    International Nuclear Information System (INIS)

    2010-08-01

    The IAEA Fundamental Safety Principles (IAEA Safety Standards Series No. SF-1) state the need for operating organizations to establish a programme for the feedback and analysis of operating experience in nuclear power plants. Such a programme ensures that operating experience is analysed, events important to safety are reviewed in depth, lessons learned are disseminated to the staff of the organization and to the relevant national and international organizations and corrective actions are effectively implemented. In IAEA Operational Safety Review Team (OSART) and Peer Review of the effectiveness of the Operational Safety Performance Experience Review (PROSPER) missions, weaknesses in the management of operating experience (OE) programmes have been identified as one of the root causes of the recurrence of events. This publication has been developed to provide advice and assistance to nuclear installation managers and related institutions, including contractors and support organizations, to strengthen and enhance the management of their OE processes. In this publication, a number of barriers to the successful management of an OE programme have been identified. Managers are encouraged to review and evaluate these barriers with a view to identifying and eliminating them within their own organizations

  15. BN-600 power unit 15-year operating experience

    International Nuclear Information System (INIS)

    Saraev, O.M.; Oshkanov, N.N.; Vylomov, V.V.

    1996-01-01

    Comprehensive experience has been gained with the operating fast reactor BN-600 with a power out of 600 MWe. This paper includes important performance results and gives also an overview of the experience gained from BN-600 NPP commercial operation during 15 years. (author). 2 figs, 1 tab

  16. Physics experiments with the operating reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cullington, G R; King, D C

    1973-09-27

    Experimental techniques have been developed and used on Dragon to give consistent information on excess reactivity and shut down margin. The reactivity measurements have been correlated with the theoretical calculations and have led to improvements in the calculations. The methods used and the results obtained are accepted by the Safety Committee as sufficient evidence for compliance with the fuel loading safety rules. Although the reactor was not designed as an experimental facility, flux and dose measurements experiments have been successfully carried out. Mass flow and negative reactivity transient measurements have been carried out. These are valuable for demonstration of the flexibility of the reactor system and for giving confidence in theoretical calculations.

  17. RAS III - concept and operating experience

    International Nuclear Information System (INIS)

    Kunze, U.; Wander, J.

    1990-01-01

    A new noise analysis system RAS III is being employed at the Greifswald NPP 'Bruno Leuschner' units 5 and 6 which differs from its forerunner types by an extended number of measuring points and a higher degree of automation. Substantial prerequisite of the system's full efficiency is implementation of efficient signal monitoring techniques that free the power plant engineer from routine work as well. The system has therefore been completed by algorithms established for automatic noise signal spectra control and for monitoring the pressure vessel vibrations. Moreover, a number of special techniques have been developed, such as for recording velocity-time plots during control element drop experiments. (author)

  18. Operating experience in nuclear power plants

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The nuclear power plants in the Federal Republic of Germany kept their portion of power supply into the public grid system constant in 1983, compared to 1982. The generation had an absolute increase of 3.6% and amounts now to 65.9 TWh. Particularly mentioned should be the generation of the Grafenrheinfeld Nuclear Power Plant which is holding the 'World Record' with 9.969 TWh. The availability of the plants was generally satisfactory, as far as long-term retrofit measures with long outage periods were not necessary, as it was the case in Brunsbuettel and Wuergassen. The planned retrofit phases have been completed in all power plants. As far as safety is concerned, there was no reason to recommended a change of the present fundamental planning- and operation aspects. (orig.) [de

  19. Operational experience of gamma radiation processing facility

    International Nuclear Information System (INIS)

    Patel, Nilesh

    2014-01-01

    Universal lSO-MED is now proud to announce an extension of its irradiation service for low-dose applications specifically in agriculture commodities, food and healthcare applications with the start of Gujarat Agro Radiation Processing Facility at Village: Bavla, Ahmedabad (A Government Enterprise) Operated, Maintained and Managed by Universal Medicap Ltd. Availability of hygienic, safe and nutritious food commodities is essential for any sustainable human development. Food stability is an important element of economic stability and self-reliance of a nation. Though the need to preserve food has been felt by the mankind since the time immemorial, it is even stronger in today's context. The rising population and increasing gap between demand and supply, agro-climatic conditions, in adequate post-harvest practices, seasonal nature of produce and long distances between production and consumption centers underscore the need to device improved conservation and preservation strategies

  20. Incorporating operational experience and design changes in availability forecasts

    International Nuclear Information System (INIS)

    Norman, D.

    1988-01-01

    Reliability or availability forecasts which are based solely on past operating experience will be precise if the sample is large enough, and unbiased if nothing in the future design, environment, operating region or anything else changes. Unfortunately, life is never like that. This paper considers the methodology and philosophy of modifying forecasts based on past experience to take account also of changes in design, construction methods, operating philosophy, environments, operator training and so on, between the plants which provided the operating experience and the plant for which the forecast is being made. This emphasises the importance of collecting, assessing, and learning from past data and of a thorough knowledge of future designs, and procurement, operation, and maintenance policies. The difference between targets and central estimates is also discussed. The paper concludes that improvements in future availability can be made by learning from past experience, but that certain conditions must be fulfilled in order to do so. (author)

  1. Operating experience from Swedish nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-06-01

    The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section `Special Reports` three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES) Figs, tabs.; Also available in Swedish

  2. Operating experience from Swedish nuclear power plants

    International Nuclear Information System (INIS)

    1999-01-01

    The total production of electricity from Swedish nuclear power plants was 70.5 TWh during 1998, which is the second highest yearly production ever. Production losses due to low demand totaled 5.1 TWh combined for all twelve units and production losses due to coastdown operation totaled an additional 0.5 TWh. The reason for this low power demand was a very good supply of water to the hydropower system. Hydroelectric power production was 73.6 TWh, an increase by roughly 5 TWh since 1997. Hence, the hydroelectric power production substantially exceeded the 64 TWh expected during a normal year, i.e. a year with average rainfall. Remaining production sources, mainly fossil fuel electricity production combined with district heating, contributed with 10 TWh. The total electricity production was 154.2 TWh, the highest yearly production ever. The total electricity consumption including transmission losses was 143.5 TWh. This is also the highest consumption ever and an increase by one percent compared to 1997. The preliminary net result of the electric power trade shows a net export by 10.7 TWh. The figures above are calculated from the preliminary production results. A comprehensive report on electric power supply and consumption in Sweden is given in the 1998 Annual Report from the Swedish Power Association. Besides Oskarshamn 1, all plants have periodically been operated in load-following mode, mostly because of the abundant supply of hydropower. The energy availability for the three boiling water reactors at Forsmark averaged 93.3 % and for the three pressure water reactors at Ringhals 91.0 %, both figures are the highest ever noted. In the section 'Special Reports' three events of importance to safety that occurred during 1998 are reported. The events were all rated as level 1 according to the International Nuclear Event Scale (INES)

  3. Experience in startup and operation of fast flux facility

    International Nuclear Information System (INIS)

    Moffitt, W.C.

    1980-01-01

    The testing program was structured to perform all testing under formal testing procedures with a test engineer as the test director and the plant operators operating the systems and equipment. This provided excellent training and experience for the operators in preparation for eventual reactor operation. Operations preparations for the testing and operation activities has consisted of academic training, formal on-the-job training including systems operation and examinations by persons with an expert knowledge on that portion of the plant, training at EBR-II and the High Temperature Sodium Facility for selected senior operators, operating procedure preparation, training on an FFTF Control Room operator training simulator, and formal written, oral and operating examinations

  4. Proceedings of 2nd PHWR operating safety experience meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-04-01

    Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage.

  5. Operating experience with high beta superconducting RF cavities

    International Nuclear Information System (INIS)

    Dylla, H.F.; Doolittle, L.R.; Benesch, J.F.

    1993-01-01

    The number of installed and operational β=1 superconducting rf cavities has grown significantly over the last two years in accelerator laboratories in Europe, Japan and the U.S. The total installed acceleration capability as of mid-1993 is approximately 1 GeV at nominal gradients. Major installations at CERN, DESY, KEK and CEBAF have provided large increments to the installed base and valuable operational experience. A selection of test data and operational experience gathered to date is reviewed

  6. Natural uranium metallic fuel elements: fabrication and operating experience

    International Nuclear Information System (INIS)

    Hammad, F.H.; Abou-Zahra, A.A.; Sharkawy, S.W.

    1980-01-01

    The main reactor types based on natural uranium metallic fuel element, particularly the early types, are reviewed in this report. The reactor types are: graphite moderated air cooled, graphite moderated gas cooled and heavy water moderated reactors. The design features, fabrication technology of these reactor fuel elements and the operating experience gained during reactor operation are described and discussed. The interrelation between operating experience, fuel design and fabrication was also discussed with emphasis on improving fuel performance. (author)

  7. Large remote manipulator operating and maintenance experience at IEM cell

    International Nuclear Information System (INIS)

    Hicks, D.F.; McGuinness, P.W.

    1985-01-01

    The Interim Examination and Maintenance (IEM) Cell at the Fast Flux Test Facility (FFTF) has two large Electro-Mechanical Manipulators (EMM's). These manipulators are used for cell operations (processing of reactor core components) as well as general cell maintenance. From our eleven years of operation and maintenance experience with these large EMM's, we have learned many lessons concerning manipulator design. This paper describes the IEM Cell EMM design features and discusses operating and maintenance experience at the IEM Cell

  8. Operating experience with high beta superconducting rf cavities

    International Nuclear Information System (INIS)

    Dylla, H.F.; Doolittle, L.R.; Benesch, J.F.

    1993-06-01

    The number of installed and operational β = 1 superconducting rf cavities has grown significantly over the last two years in accelerator laboratories in Europe, Japan and the US. The total installed acceleration capability as of mid-1993 is approximately 1 GeV at nominal gradients. Major installations at CERN, DESY, KEK and CEBAF have provided large increments to the installed base and valuable operational experience. A selection of test data and operational experience gathered to date is reviewed

  9. Proceedings of 2nd PHWR operating safety experience meeting

    International Nuclear Information System (INIS)

    1991-04-01

    Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage

  10. Operating experience and construction status of ATLAS

    International Nuclear Information System (INIS)

    Pardo, R.C.; DenHartog, P.; Shepard, K.W.; Zinkann, G.

    1984-01-01

    The present Argonne Tandem-Linac accelerator has operated in a reliable manner during the past year. The accelerator system provided 4402 hours of experimental beam time with a wide variety of heavy-ions. Figure 1 shows the beams which have been provided during the past year. New beams accelerated by the linac include 300 MeV 82 Se and 390 MeV 109 Ag. In tests, the tandem accelerated 102 MeV 127 I. This is the heaviest beam ever accelerated by the Argonne tandem. The long-term performance of the niobium resonators appears to be good. No significant degradation of performance has been observed for most resonators over many years of use with the exceptions of problems caused by catastrophic vacuum accidents. Resonators whose performance has deteriorated after vacuum accidents have recently been restored to their original performance state by a simple technique. The technique used is to rinse the interior of the resonator with a sequence of baths of solvents and water

  11. HDS unit revamp and operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Reinhardt, J. [Veba Oel Verarbeitungs-GmbH, Gelsenkirchen (Germany); Balfanz, U. [Aral Forschung, Gelsenkirchen (Germany); Dimmig, T. [TU Bergakademie Freiberg, Freiberg (Germany)

    2002-12-01

    Ruhr Oel GmbH, a joint venture between BP and PDVSA, operates a HDS unit at its Gelsenkirchen-Scholven site. The unit produces a major blend component for diesel fuel. Driven by ambitious German environmental policy and by an agreement between the German car and oil industries on the one hand and the government on the other, more stringent low sulphur fuel specifications will be enforced in Germany much earlier than in the rest of the European Union. In view of this situation a project was developed to fulfill the new product specifications with minimum investment. In a joint effort involving the refinery, the company research facilities and the catalyst supplier (AKZO NOBEL), pilot plant tests were performed to develop the best catalyst system and the new process conditions. Based on these results, an existing HDS unit was accordingly revamped. After the revamp, the unit produced diesel fuel with 50 ppm sulphur content and furthermore test runs at 10 ppm were carried out successfully. These results are displayed in this article. (orig.)

  12. Operational experience at the Sludge Treatment Facility

    International Nuclear Information System (INIS)

    Sy, D.J.

    1987-01-01

    The Sludge Treatment Facility (STF) at the Oak Ridge Gaseous Diffusion Plant has been in operation since April 1987. The facility was designed to encapsulate hazardous sludge wastes in a cement matrix. Fixation will allow the waste to meet or exceed applicable compressive strength and leachability requirements. Thus, the grout mixture complies with the Resource Conservation and Recovery Act (RCRA) guidelines as a nonhazardous waste. The grout mixture is based upon a recipe formulation developed after several years of waste stream characterization and formulation studies. The wastes to be treated at the STF are wastes impounded in two ponds. The ponds have a combined capacity of 4.5 million gallons of sludge. The sludge is transferred from the ponds to a 15,000-gallon capacity storage tank by the use of a dredge. The grout mixture recipe dictates the amount of sludge, cement, fly ash, and admixture required for weighing per batch. All ingredients are weighed and then transferred to a tilt or high energy mixer for mixing. The grout mixture is then transferred to 89- or 96-gallon steel drums. The drums are placed in a storage yard designed for a point source discharge from the yard

  13. Decommissioning of the nuclear licensed facilities at the Fontenay aux Roses CEA Center; cleanup of nuclear licensed facility 57 and monitoring of operations and operating feedback

    International Nuclear Information System (INIS)

    Estivie, D.; Bohar, M.P.; Jeanjacques, M.; Binet, C.; Bremond, M.P.; Poyau, C.; Mandard, L.; Boissonneau, J.F.; Fouquereau, A.; Pichereau, E.

    2008-01-01

    This is a summary of the program for the decommissioning of all the CEA Licensed Nuclear Facilities in Fontenay aux Roses. The particularity of this center is now it is located in a built-up area. It is presented like example the operations to clean up the equipment of the Nuclear Licensed Facility 57 (NLF 57). Due to the diversity of the research and development work carried out on the reprocessing of spent fuel in it, this installation is emblematic of many of the technical and organizational issues liable to be encountered in the final closure of nuclear facilities. It was developed a method applied to establish the multi-annual budget, monitor the progress of operations and integrate, as work continues, the operating feedback. (author)

  14. Control Theory Perspective of Effects-Based Thinking and Operations: Modelling "Operations" as a Feedback Control System

    National Research Council Canada - National Science Library

    Farrell, Philip S

    2007-01-01

    This paper explores operations that involve effects-based thinking (EBT) using Control Theory techniques in order to highlight the concept's fundamental characteristics in a simple and straightforward manner...

  15. First operation of a powerful FEL with two-dimensional distributed feedback

    CERN Document Server

    Agarin, N V; Bobylev, V B; Ginzburg, N S; Ivanenko, V G; Kalinin, P V; Kuznetsov, S A; Peskov, N Yu; Sergeev, A S; Sinitsky, S L; Stepanov, V D

    2000-01-01

    A W-band (75 GHz) FEL of planar geometry driven by a sheet electron beam was realised using the pulse accelerator ELMI (0.8 MeV/3 kA/5 mu s). To provide the spatial coherence of radiation from different parts of the electron beam with a cross-section of 0.4x12 cm two-dimensional distributed feedback systems have been employed using a 2-D Bragg resonator of planar geometry. The resonator consisted of two 2-D Bragg reflectors separated by a regular waveguide section. The total energy in the microwave pulse of microsecond duration was 100 J corresponding to a power of approx 100 MW. The main component of the FEL radiation spectrum was at 75 GHz that corresponded to the zone of effective Bragg reflection found from 'cold' microwave testing of the resonator. The experimental data compared well with the results of theoretical analysis.

  16. Stable Single-Mode Operation of Distributed Feedback Quantum Cascade Laser by Optimized Reflectivity Facet Coatings

    Science.gov (United States)

    Wang, Dong-Bo; Zhang, Jin-Chuan; Cheng, Feng-Min; Zhao, Yue; Zhuo, Ning; Zhai, Shen-Qiang; Wang, Li-Jun; Liu, Jun-Qi; Liu, Shu-Man; Liu, Feng-Qi; Wang, Zhan-Guo

    2018-02-01

    In this work, quantum cascade lasers (QCLs) based on strain compensation combined with two-phonon resonance design are presented. Distributed feedback (DFB) laser emitting at 4.76 μm was fabricated through a standard buried first-order grating and buried heterostructure (BH) processing. Stable single-mode emission is achieved under all injection currents and temperature conditions without any mode hop by the optimized antireflection (AR) coating on the front facet. The AR coating consists of a double layer dielectric of Al2O3 and Ge. For a 2-mm laser cavity, the maximum output power of the AR-coated DFB-QCL was more than 170 mW at 20 °C with a high wall-plug efficiency (WPE) of 4.7% in a continuous-wave (CW) mode.

  17. Operating experience with nuclear power plants 2015. Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2016-07-01

    The VGB Technical Committee ''Nuclear Plant Operation'' has been exchanging operating experience about nuclear power plants for more than 30 years. Plant operators from several European countries are participating in the exchange. A report is given on the operating results achieved in 2015, events important to plant safety, special and relevant repair, and retrofit measures from Germany. The second part of this report will focus on nuclear power plant in Belgium, Finland, the Netherlands, Switzerland, and Spain.

  18. Remote maintenance of an operational fusion experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kiptily, V.G.; Jarvis, O.N.; Popovichev, S. [Euratom/UKAEA Fusion Assoc., Culham Science Centre, Abingdon, Oxon. (United Kingdom)] [and others

    2001-07-01

    Optimisation of auxiliary plasma heating by means of Ion Cyclotron Radio-Frequency (ICRF) and Neutral Beam Injection (NBI) as envisaged for the future fusion reactors is one of the main priorities in present research at today's tokamaks. Therefore, investigation of the production of fast ions during heating and of the subsequent fast ion behaviour in magnetically confined plasmas, together with an evaluation of the resulting bulk ion heating efficiency, are of essential importance for fusion reactor development. Gamma-ray diagnostics, based on the measurement of the gamma-ray emission from nuclear reactions between fast ions and the main plasma impurities, is a valuable technique for studying the fast particle energy distributions. Gamma-ray spectrometry provides information on the energy distribution, and the measurement of emission profiles supplies information on the spatial distribution of the reaction sites. Since 1987, the {gamma}-ray emission from JET plasmas has been systematically monitored and used successfully in the analysis of heating effects during ICRF and NBI heating in the JET tokamak. The classical character of the fast ion slowing down behaviour has been demonstrated and estimates have been obtained of the fast particle confinement time. The study of sawtooth crashes has demonstrated dramatic spatial redistribution of fast particles and other effects. In recent JET experiments to study the ITER-relevant ICRH scenarios ({sup 3}He)D and ({sup 3}He){sup 4}He, {gamma}-ray measurements provided information on the fast ion population, with the effective temperature of the energetic tail ions being deduced with the help of a {gamma}-ray spectrum simulation code, GAMMOD. In this paper, the main y-ray results are presented and the capabilities of gamma diagnostics are discussed in the light of the ITER-project programme.

  19. [Computerized ranking test in three French universities: Staff experience and students' feedback].

    Science.gov (United States)

    Roux, D; Meyer, G; Cymbalista, F; Bouaziz, J-D; Falgarone, G; Tesniere, A; Gervais, J; Cariou, A; Peffault de Latour, R; Marat, M; Moenaert, E; Guebli, T; Rodriguez, O; Lefort, A; Dreyfuss, D; Hajage, D; Ricard, J-D

    2016-03-01

    The year 2016 will be pivotal for the evaluation of French medical students with the introduction of the first computerized National Ranking Test (ECNi). The SIDES, online electronic system for medical student evaluation, was created for this purpose. All the universities have already organized faculty exams but few a joint computerized ranking test at several universities simultaneously. We report our experience on the organization of a mock ECNi by universities Paris Descartes, Paris Diderot and Paris 13. Docimological, administrative and technical working groups were created to organize this ECNi. Students in their fifth year of medical studies, who will be the first students to sit for the official ECNi in 2016, were invited to attend this mock exam that represented more than 50% of what will be proposed in 2016. A final electronic questionnaire allowed a docimological and organizational evaluation by students. An analysis of ratings and rankings and their distribution on a 1000-point scale were performed. Sixty-four percent of enrolled students (i.e., 654) attended the three half-day exams. No difference in total score and ranking between the three universities was observed. Students' feedback was extremely positive. Normalized over 1000 points, 99% of students were scored on 300 points only. Progressive clinical cases were the most discriminating test. The organization of a mock ECNi involving multiple universities was a docimological and technical success but required an important administrative, technical and teaching investment. Copyright © 2016 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  20. Ageing degradation mechanisms in nuclear power plants: lessons learned from operating experience

    International Nuclear Information System (INIS)

    Bieth, M.; Zerger, B.; Duchac, A.

    2014-01-01

    This paper presents main results of a comprehensive study performed by the European Clearinghouse on Operating Experience Feedback of Nuclear Power Plants (NPP) with the support of IRSN (Institut de Surete Nucleaire et de Radioprotection) and GRS (Gesellschaft fuer Anlagen und Reaktorsicherheit mbH). Physical ageing mechanisms of Structures, Systems and Components (SSC) that eventually lead to ageing related systems and components failures at nuclear power plants were the main focus of this study. The analysis of ageing related events involved operating experience reported by NPP operators in France, Germany, USA and to the IAEA/NEA International Reporting System on operating experience for the past 20 years. A list of relevant ageing related events was populated. Each ageing related event contained in the list was analyzed and results of analysis were summarized for each ageing degradation mechanism which appeared to be the dominant contributor or direct cause. This paper provides insights into ageing related operating experience as well as recommendations to deal with the physical ageing of nuclear power plant SSC important to safety. (authors)

  1. [Operating Room Nurses' Experiences of Securing for Patient Safety].

    Science.gov (United States)

    Park, Kwang Ok; Kim, Jong Kyung; Kim, Myoung Sook

    2015-10-01

    This study was done to evaluate the experience of securing patient safety in hospital operating rooms. Experiential data were collected from 15 operating room nurses through in-depth interviews. The main question was "Could you describe your experience with patient safety in the operating room?". Qualitative data from the field and transcribed notes were analyzed using Strauss and Corbin's grounded theory methodology. The core category of experience with patient safety in the operating room was 'trying to maintain principles of patient safety during high-risk surgical procedures'. The participants used two interactional strategies: 'attempt continuous improvement', 'immersion in operation with sharing issues of patient safety'. The results indicate that the important factors for ensuring the safety of patients in the operating room are manpower, education, and a system for patient safety. Successful and safe surgery requires communication, teamwork and recognition of the importance of patient safety by the surgical team.

  2. TSTA Piping and Flame Arrestor Operating Experience Data

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, Lee C.; Willms, R. Scott

    2014-10-01

    The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium handling technology and experiment research at the Los Alamos National Laboratory. The facility operated from 1984 to 2001, running a prototype fusion fuel processing loop with ~100 grams of tritium as well as small experiments. There have been several operating experience reports written on this facility’s operation and maintenance experience. This paper describes analysis of two additional components from TSTA, small diameter gas piping that handled small amounts of tritium in a nitrogen carrier gas, and the flame arrestor used in this piping system. The operating experiences and the component failure rates for these components are discussed in this paper. Comparison data from other applications are also presented.

  3. Fire protection system operating experience review for fusion applications

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1995-12-01

    This report presents a review of fire protection system operating experiences from particle accelerator, fusion experiment, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of fire protection system component failure rates and fire accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with these systems are discussed, including spurious operation. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor

  4. Fire protection system operating experience review for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, L.C.

    1995-12-01

    This report presents a review of fire protection system operating experiences from particle accelerator, fusion experiment, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of fire protection system component failure rates and fire accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with these systems are discussed, including spurious operation. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor.

  5. AREVA 10x10 BWR fuel experience feedback and on going upgrading

    International Nuclear Information System (INIS)

    Lippert, Hans Joachim; Rentmeister, Thomas; Garner, Norman; Tandy, Jay; Mollard, Pierre

    2008-01-01

    Established with engineering and manufacturing operations in the US and Europe, AREVA NP has been and is supplying nuclear fuel assemblies and associated core components to boiling water reactors worldwide, representing today more than 63 000 fuel assemblies. The evolution of BWR fuel rod arrays from early 6x6 designs to the 10x10 designs first introduced in the mid 1990's yielded significant improvements in thermal mechanical operating limits, critical power level, cold shutdown margin, discharge burnup, as well as other key operational capabilities. Since first delivered in 1992, ATRIUM T M 1 0 fuel assemblies have now been supplied to a total of 32 BWR plants in the US, Europe, and Asia resulting in an operating experience over 20 000 fuel assemblies. This article presents in detail the operational experience consolidated by these more than 20 000 ATRIUM T M 1 0 BWR assemblies already supplied to utilities. Within the different 10x10 fuel assemblies available, the Fuel Assembly design is chosen and tailored to the operating strategies of each reactor. Among them, the latest versions of ATRIUM T M a re ATRIUM T M 1 0XP and ATRIUM T M 1 0XM fuel assemblies which have been delivered to several utilities worldwide. The article details key aspects of ATRIUM T M 1 0 fuel assemblies in terms of reliability and performance. Special attention is paid to key proven features, ULTRAFLOW T M s pacer grids, the use of part length fuel rods (PLFRs) and their geometrical optimization, water channel and load chain, upgraded features available for inclusion with most advanced designs. Regular upgrading of the product has been made possible thanks to a continuous improvement process with the aim of further upgrading BWR fuel assembly performance and reliability. Regarding thermal mechanical behavior of fuel rods, chromia (Cr2O3) doped fuel pellets, described in Reference 1, well illustrate this improvement strategy to reduce fission gas release, increase power thresholds for PCI

  6. Dry cooling tower operating experience in the LOFT reactor

    International Nuclear Information System (INIS)

    Hunter, J.A.

    1980-01-01

    A dry cooling tower has been uniquely utilized to dissipate heat generated in a small experimental pressurized water nuclear reactor. Operational experience revealed that dry cooling towers can be intermittently operated with minimal wind susceptibility and water hammer occurrences by cooling potential steam sources after a reactor scram, by isolating idle tubes from the external atmosphere, and by operating at relatively high pressures. Operating experience has also revealed that tube freezing can be minimized by incorporating the proper heating and heat loss prevention features

  7. Operating Experience Review of Tritium-in-Water Monitors

    Energy Technology Data Exchange (ETDEWEB)

    S. A. Bruyere; L. C. Cadwallader

    2011-09-01

    Monitoring tritium facility and fusion experiment effluent streams is an environmental safety requirement. This paper presents data on the operating experience of a solid scintillant monitor for tritium in effluent water. Operating experiences were used to calculate an average monitor failure rate of 4E-05/hour for failure to function. Maintenance experiences were examined to find the active repair time for this type of monitor, which varied from 22 minutes for filter replacement to 11 days of downtime while waiting for spare parts to arrive on site. These data support planning for monitor use; the number of monitors needed, allocating technician time for maintenance, inventories of spare parts, and other issues.

  8. Steam generator operating experience update, 1982-1983

    International Nuclear Information System (INIS)

    Frank, L.

    1984-06-01

    This report is a continuation of earlier reports by the staff addressing pressurized water reactor steam generator operating experience. NUREG-0886, Steam Generator Tube Experience, published in February 1982 summarized experience in domestic and foreign plants through December 1981. This report summarizes steam generator operating experience in domestic plants for the years 1982 and 1983. Included are new problems encountered with secondary-side loose parts, sulfur-induced stress-assisted corrosion cracking, and flow-induced vibrational wear in the new preheater design steam generators. The status of Unresolved Safety Issues A3, A4, and A5 is also discussed

  9. A Medical Logistics Officer Training Needs Assessment Utilizing Feedback from Operation Iraqi Freedom

    National Research Council Canada - National Science Library

    Waddick, James L

    2004-01-01

    ... their missions during the initial Operation Iraqi Freedom deployment (OIF 1). Additionally, the study sought to identify the potential benefit of additional training on key medical logistics tasks and training events...

  10. Peer Teaching in the Food Chemistry Laboratory: Student-produced Experiments, Peer and Audio Feedback and Integration of Employability

    OpenAIRE

    Dunne, Julie

    2014-01-01

    This paper describes the author’s experience over the last several years of implementing an alternative Food Chemistry laboratory practical for a group of third-year BSc Nutraceuticals students. The initial main objectives were to prepare students for the more independent final-year research project; to incorporate innovative approaches to feedback; and to integrate key employability skills into the curriculum. These were achieved through building the skills required to ultimately allow stude...

  11. Research on Utilizing a Multivariate Feedback Algorithm to Maintain Stable Operation of Variable Energy Electron Accelerators

    International Nuclear Information System (INIS)

    Van Ausdeln, L.A.; Cordes, G.A.; Haskell, K.J.; Jones, J.L.

    2002-01-01

    Measurements performed utilizing particle accelerators rely on the stability and reproducibility of the accelerator operation, most notably for beam flux (beam current) and beam energy. This can be vital when the measurements rely on previous calibrations performed to establish a standard on which to base the end result of the measurement. The authors have designed a monitoring and control virtual instrument (VI) based on National Instruments LabVIEW TM which calls external modeling code that is written in a standard programming language. The LabVIEWTM virtual instrument allows the user to monitor multiple accelerator parameters while permitting user control of the most important four of these parameters which determine machine operation. The external modeling code, the Advanced Data Validation and Verification System (ADVVS), incorporates as a kernel the Universal Process Model (UPM) software from Triant Technologies, Inc. The kernel executes the accelerator modeling function based on previously acquired history data of the relevant parameters for accelerator operation for conditions of interest. This history data is stored as a reference set prior to subsequent operation. During accelerator operation, 11 accelerator parameters are input to ADVVS from the LabVIEW TM virtual instrument. The ADVVS uses the reference files to predict the eleven parameter values that would normally be expected for optimal accelerator operation. The set of 11 model values is the nearest model state. This multivariate modeling approach presented two principal advantages: 1. The ADVVS allowed rapid detection of anomalous accelerator behavior variant from normal accelerator behavior recorded in the reference set of the kernel. 2. The ADVVS presented a methodology to incrementally tune the accelerator back to optimal operation, thus maintaining highly stable and reproducible operation. In the future, this methodology may also be utilized to tune the accelerator initially or move

  12. Analysis of operating incidents, conclusions to be drawn - modifications as a result of information feedback

    International Nuclear Information System (INIS)

    Leckner, J.-M.

    1987-01-01

    The statistics currently available (year 1986) show that 40% of the declared events have a human component. The desire to reduce the number and importance of such events which, in varying degrees, affect the safety and availability of the nuclear installations has lead the Nuclear and Fossil Generation Division (SPT) of EDF to set up a system for gathering data concerning human errors. How does SPT approach this problem? 1. - By gathering data. 2. - By having improvements made. 3. - By making allowance for human factors in new designs. All three stages are described separately, and the first two of them are then analysed in detail. The case studies mentioned in the second part are either completed, in the process of validation or being carried out and integrated, in which case the information available at the present time is not sufficiently complete to enable assessment of information feedback. Nevertheless, insofar as possible, each case is described in terms of methods, results and proposed action. In certain instances, a simplified synopsis is given. 25 refs. (author)

  13. The Gerbil Jar: A Basic Home Experience in Operant Conditioning.

    Science.gov (United States)

    Plant, L.

    1980-01-01

    Explains how a teaching method such as allowing students to raise gerbils at home can encourage students to gain experience with the fundamental techniques of operant conditioning which are otherwise generally unavailable to students in large introductory psychology courses. (DB)

  14. Commissioning and Operational Experience in Power Reactor Fuel Reprocessing Plant

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, S., E-mail: spradhan@barctara.gov.in [Tarapur Based Reprocessing Plant, Bhabha Atomic Research Centre, Tarapur (India)

    2014-10-15

    After completing design, construction, commissioning, operation and maintenance experience of the reprocessing plants at Tarapur, Mumbai and Kalpakkam a new reprocessing plant is commissioned and put into operation at BARC, Tarapur since 2011. Subsequent to construction clearance, commissioning of the plant is taken in many steps with simultaneous review by design and safety committees. In spite of vast experience, all the staff was retrained in various aspects of process and utility operations and in operation of innovative changes incorporated in the design. Operating personnel are licensed through an elaborate procedure consisting of various check lists followed by personnel interview. Commissioning systems were divided in sub-systems. Sub-systems were commissioned independently and later integrated testing was carried out. For commissioning, extreme operating conditions were identified in consultation with designers and detailed commissioning procedures were made accordingly. Commissioning was done in different conditions to ensure safety, smooth operation and maintainability. Few modifications were carried out based on commissioning experience. Technical specifications for operation of the plant are made in consultation with designers and reviewed by safety committees. Operation of the plant was carried out after successful commissioning trials with Deep Depleted Uranium (DDU). Emergency operating procedures for each design basis accident were made. Performance of various systems, subsystems are quite satisfactory and the plant has given very good capacity factor. (author)

  15. Long-term operating experience for the ATLAS superconducting resonators

    International Nuclear Information System (INIS)

    Pardo, R.; Zinkann, G.

    1999-01-01

    Portions of the ATLAS accelerator have been operating now for over 21 years. The facility has accumulated several million resonator-hours of operation at this point and has demonstrated the long-term reliability of RF superconductivity. The overall operating performance of the ATLAS facility has established a level of beam quality, flexibility, and reliability not previously achieved with heavy-ion accelerator facilities. The actual operating experience and maintenance history of ATLAS are presented for ATLAS resonators and associated electronics systems. Solutions to problems that appeared in early operation as well as current problems needing further development are discussed

  16. Duke staff tap into a fund of operating experience

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    The benefits of the Operating Experience Database (OEDB) allows employees of the nuclear industry to access a fund of operating experience data on-line in order to help them make appropriate management decisions concerning problem solving for various plant-based problems. Recent successful uses include fire protection system design, improving compliance with technical specifications, and reducing unnecessary trips in turbines. It is anticipated that OEDB may well be used in the Ukraine and Russia in the future. (UK)

  17. Study on application of operating experience to new nuclear power plant

    International Nuclear Information System (INIS)

    Hong, Nam Pyo

    1991-01-01

    From the standpoint of designing the nuclear power plant, nine operating units have been designed and constructed as turn-key base by foreign Nuclear Steam Supply System (NSSS) Suppliers or as component base by foreign Architect/Engineer companies. In case of the component base project, the owner of electric company generally has merits that owner's operational experiences can be effectively incorporated from the beginning stage of design by A/E. Even though six nuclear units, Kori Units 3 and 4, Yonggwang Units 1 and 2, and Ulchin Units 1 and 2, were designed as component base by foreign A/E's, operational experience feedback from Kori Unit 1, such as design improvement and system upgrade, could not be reflected, because the design process of the following units started well ahead before Kori Unit 1 operating experience is obtained enough to reflect on future nuclear power plant design. It can be stated that foreign A/E's used their experience in designing nuclear projects on very limited basis

  18. Spacelab operations planning. [ground handling, launch, flight and experiments

    Science.gov (United States)

    Lee, T. J.

    1976-01-01

    The paper reviews NASA planning in the fields of ground, launch and flight operations and experiment integration to effectively operate Spacelab. Payload mission planning is discussed taking consideration of orbital analysis and the mission of a multiuser payload which may be either single or multidiscipline. Payload analytical integration - as active process of analyses to ensure that the experiment payload is compatible to the mission objectives and profile ground and flight operations and that the resource demands upon Spacelab can be satisfied - is considered. Software integration is touched upon and the major integration levels in ground operational processing of Spacelab and its experimental payloads are examined. Flight operations, encompassing the operation of the Space Transportation System and the payload, are discussed as are the initial Spacelab missions. Charts and diagrams are presented illustrating the various planning areas.

  19. Exploring Early Angiosperm Fire Feedbacks using Coupled Experiments and Modelling Approaches to Estimate Cretaceous Palaeofire Behaviour

    Science.gov (United States)

    Belcher, Claire; Hudpsith, Victoria

    2016-04-01

    Using the fossil record we are typically limited to exploring linkages between palaeoecological changes and palaeofire activity by assessing the abundance of charcoals preserved in sediments. However, it is the behaviour of fires that primarily governs their ecological effects. Therefore, the ability to estimate variations in aspects of palaeofire behaviour such as palaeofire intensity and rate of spread would be of key benefit toward understanding the coupled evolutionary history of ecosystems and fire. The Cretaceous Period saw major diversification in land plants. Previously, conifers (gymnosperms) and ferns (pteridophytes) dominated Earth's ecosystems until flowering plants (angiosperms) appear in the fossil record of the Early Cretaceous (~135Ma). We have created surface fire behaviour estimates for a variety of angiosperm invasion scenarios and explored the influence of Cretaceous superambient atmospheric oxygen levels on the fire behaviour occurring in these new Cretaceous ecosystems. These estimates are then used to explore the hypothesis that the early spread of the angiosperms was promoted by the novel fire regimes that they created. In order to achieve this we tested the flammability of Mesozoic analogue fuel types in controlled laboratory experiments using an iCone calorimeter, which measured the ignitability as well as the effective heat of combustion of the fuels. We then used the BehavePlus fire behaviour modelling system to scale up our laboratory results to the ecosystem scale. Our results suggest that fire-angiosperm feedbacks may have occurred in two phases: The first phase being a result of weedy angiosperms providing an additional easily ignitable fuel that enhanced both the seasonality and frequency of surface fires. In the second phase, the addition of shrubby understory fuels likely expanded the number of ecosystems experiencing more intense surface fires, resulting in enhanced mortality and suppressed post-fire recruitment of gymnosperms

  20. The BR2 refurbishment programme: achievements and two years operation feedback

    International Nuclear Information System (INIS)

    Gubel, P.; Dekeyser, J.; Koonen, E.; Van der Auwera, J.

    1999-01-01

    The BR2 reactor was shutdown end of June 1995 for an extensive refurbishment after more than 30 years utilization. The beryllium matrix needed to be replaced and the aluminium vessel inspected for an envisaged 15 year life extension. Other aspects of the refurbishment programme aimed at the reliability and availability of the installations, safety of operation and compliance with modern safety standards. The reactor was started again in' April '97 and operated only for three cycles in 1997. These first irradiation cycles were intended as a demonstration of the safety and reliability of all components and systems after refurbishment. Also during the extended shutdowns non-critical refurbishment tasks were allowed to be continued and finalized. At the request of the Safety Authorities, some modifications and studies are still in progress without perturbation of the reactor operation. (author)

  1. Precision operation of the Nova laser for fusion experiments

    International Nuclear Information System (INIS)

    Caird, J.A.; Ehrlich, R.B.; Hermes, G.L.; Landen, O.L.; Laumann, C.W.; Lerche, R.A.; Miller, J.L.; Murray, J.E.; Nielsen, N.D.; Powell, H.T.; Rushford, M.C.; Saunders, R.L.; Thompson, C.E.; VanArsdall, P.J.; Vann, C.S.; Weiland, T.L.

    1994-01-01

    The operation of a Neodymium glass laser of a special design for fusion experiments is improved by a better pulse synchronization, the gain stabilization, and the laser diagnostics. We used sensor upgrading and antifriction coating of focusing lenses. The pointing accuracy of the Nova laser meets now our goal for precision operation. (AIP) copyright 1994 American Institute of Physics

  2. The VEPP-2000 Collider Control System: Operational Experience

    CERN Document Server

    Senchenko, A I; Lysenko, A P; Rogovsky, Yu A; Shatunov, P Yu

    2017-01-01

    The VEPP-2000 collider was commissioned and operated successfully in 2010-2013. During the operation the facility underwent continuous updates and experience in maintenance was acquired. Strong cooperation between the staff of the accelerator complex and the developers of the control system proved effective for implementing the necessary changes in a short time.

  3. Gamification and Smart Feedback: Experiences with a Primary School Level Math App

    Science.gov (United States)

    Kickmeier-Rust, Michael D.; Hillemann, Eva-C.; Albert, Dietrich

    2014-01-01

    Gamification is a recent trend in the field of game-based learning that accounts for development effort, costs, and effectiveness concerns of games. Another trend in educational technology is learning analytics and formative feedback. In the context of a European project the developed a light weight tool for learning and practicing divisions named…

  4. 14th Biennial conference on reactor operating experience plant operations: The human element

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Separate abstracts were prepared for the papers presented in the following areas of interest: enhancing operator performance; structured approaches to maintenance standards and reliability-centered maintenance; human issues in plant operations and management; test, research, and training reactor utilization; methods and applications of root-cause analysis; emergency operating procedure enhancement programs; test, research, and training reactor upgrades; valve maintenance and diagnostics; recent operating experiences; and current maintenance issues

  5. Operating wind turbines in strong wind conditions by using feedforward-feedback control

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2014-01-01

    Due to the increasing penetration of wind energy into power systems, it becomes critical to reduce the impact of wind energy on the stability and reliability of the overall power system. In precedent works, Shen and his co-workers developed a re-designed operation schema to run wind turbines in s...

  6. Developing a Mystery Shopping Measure to Operate a Sustainable Restaurant Business: The Power of Integrating with Corporate Executive Members’ Feedback

    Directory of Open Access Journals (Sweden)

    Rachel J. C. Chen

    2015-09-01

    Full Text Available Mystery shopping has been used to objectively measure whether employees follow the visions of a company’s quality service standards. It then creates a feedback loop that allows companies to train their employees to consistently deliver quality services. The main purposes of this project are aimed at examining (1 the overall benefits of mystery shopper projects in the hospitality business through literature reviews; and (2 the importance of how a company can work with an outside agency (consultant, academic institution, etc. to develop a mystery shopping program that can enhance and complement ongoing service quality programs. A casual steakhouse restaurant in the Eastern U.S. was selected as our pilot project. The basic concept of using secret shoppers is to have individuals experience real-time and onsite quality of services and record how the mystery shoppers felt about the quality of services and if the employees met or exceeded the company’s standards. For this reason, the authors believe that mystery shopping, especially in hospitality, is an important means of developing and maintaining a sustainable business. While the sustainability of a business is largely dependent upon “people, profits and planet” in the hospitality industry, it is also dependent upon meeting service standards and developing a feedback loop. Mystery shopping programs have demonstrated their ability to contribute to organizations in this regard.

  7. Both movement-end and task-end are critical for error feedback in visuomotor adaptation: a behavioral experiment.

    Directory of Open Access Journals (Sweden)

    Takumi Ishikawa

    Full Text Available An important issue in motor learning/adaptation research is how the brain accepts the error information necessary for maintaining and improving task performance in a changing environment. The present study focuses on the effect of timing of error feedback. Previous research has demonstrated that adaptation to displacement of the visual field by prisms in a manual reaching task is significantly slowed by delayed visual feedback of the endpoint, suggesting that error feedback is most effective when given at the end of a movement. To further elucidate the brain mechanism by which error information is accepted in visuomotor adaptation, we tested whether error acceptance is linked to the end of a given task or to the end of an executed movement. We conducted a behavioral experiment using a virtual shooting task in which subjects controlled their wrist movements to meet a target with a cursor as accurately as possible. We manipulated the timing of visual feedback of the impact position so that it occurred either ahead of or behind the true time of impact. In another condition, the impact timing was explicitly indicated by an additional cue. The magnitude of the aftereffect significantly varied depending on the timing of feedback (p < 0.05, Friedman's Test. Interestingly, two distinct peaks of aftereffect were observed around movement-end and around task-end, irrespective of the existence of the timing cue. However, the peak around task-end was sharper when the timing cue was given. Our results demonstrate that the brain efficiently accepts error information at both movement-end and task-end, suggesting that two different learning mechanisms may underlie visuomotor transformation.

  8. Operating Experience Report: Counterfeit, Suspect and Fraudulent Items. Working Group on Operating Experience. Proceedings and Analysis on an Item of Generic Interest

    International Nuclear Information System (INIS)

    2011-01-01

    The NEA Committee on Nuclear Regulatory Activities (CNRA) believes that sharing operating experience from the national operating experience feedback programmes are a major element in the industry's and regulatory body's efforts to ensure the continued safe operation of nuclear facilities. Considering the importance of these issues, the Committee on the Safety of Nuclear Installations (CSNI) established a working group, PWG no.1 (Principle Working Group Number 1) to assess operating experience in the late 1970's, which was later renamed the Working Group on Operating Experience (WGOE). In 1978, the CSNI approved the establishment of a system to collect international operating experience data. The accident at Three Mile Island shortly after added impetus to this and led to the start of the Incident Reporting System (IRS). In 1983, the IRS database was moved to the International Agency for Atomic Energy (IAEA) to be operated as a joint database by IAEA and NEA for the benefit of all of the member countries of both organisations. In 2006, the WGOE was moved to be under the umbrella of the Committee on Nuclear Regulatory Activities (CNRA) in NEA. In 2009, the scope of the Incident Reporting System was expanded and re-named the International Reporting System for Operating Experience (although, the acronym remains the same). The purpose of WGOE is to facilitate the exchange of information, experience, and lessons learnt related to operating experience between member countries. The working group continues its mission to identify trending and issues that should be addressed in specialty areas of CNRA and CSNI working groups. The CSFI (Counterfeit, Suspect, and Fraudulent Items) issue was determined to be the Issue of Generic Interest at the April 2010 WGOE meeting. The Issue of Generic Interest is determined by the working group members for an in-depth discussion. They are often emerging issues in operating experience that a country or several countries would to the share

  9. Safety evaluation by living probabilistic safety assessment. Procedures and applications for planning of operational activities and analysis of operating experience

    International Nuclear Information System (INIS)

    Johanson, Gunnar; Holmberg, J.

    1994-01-01

    Living Probabilistic Safety Assessment (PSA) is a daily safety management system and it is based on a plant-specific PSA and supporting information systems. In the living use of PSA, plant status knowledge is used to represent actual plant safety status in monitoring or follow-up perspective. The PSA model must be able to express the risk at a given time and plant configuration. The process, to update the PSA model to represent the current or planned configuration and to use the model to evaluate and direct the changes in the configuration, is called living PSA programme. The main purposes to develop and increase the usefulness of living PSA are: Long term safety planning: To continue the risk assessment process started with the basic PSA by extending and improving the basic models and data to provide a general risk evaluation tool for analyzing the safety effects of changes in plant design and procedures. Risk planning of operational activities: To support the operational management by providing means for searching optimal operational maintenance and testing strategies from the safety point of view. The results provide support for risk decision making in the short term or in a planning mode. The operational limits and conditions given by technical specifications can be analyzed by evaluating the risk effects of alternative requirements in order to balance the requirements with respect to operational flexibility and plant economy. Risk analysis of operating experience: To provide a general risk evaluation tool for analyzing the safety effects of incidents and plant status changes. The analyses are used to: identify possible high risk situations, rank the occurred events from safety point of view, and get feedback from operational events for the identification of risk contributors. This report describes the methods, models and applications required to continue the process towards a living use of PSA. 19 tabs, 20 figs

  10. The experience of five years operation of Phenix

    International Nuclear Information System (INIS)

    Conte, F.; Lacroix, A.

    1980-01-01

    Two long periods of exceptional operation have satisfied the hopes of the designers and all parameters, power, efficiency, load factor, fuel behaviour, were better than was expected. The experience resulting from the only major incident provided a series of complementary data. Modern technology has need of sanction by experiment. The Phenix type reactor is a tool which is convenient to operate and to maintain. The two aspects of the demonstration, correct operation and ease of maintenance, take a concrete form in the harmlessness of Phenix on men and on the environment. There is no irradiation and few releases. (orig./DG)

  11. Cryogenic system operating experience review for fusion applications

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1992-01-01

    This report presents a review of cryogenic system operating experiences, from particle accelerator, fusion experiment, space research, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of cryogenic component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with cryogenic systems are discussed, including ozone formation, effects of spills, and modeling spill behavior. This information should be useful to fusion system designers and safety analysts, such as the team working on the International Thermonuclear Experimental Reactor design

  12. Operational safety experience reporting in the United States

    International Nuclear Information System (INIS)

    Hartfield, R.A.

    1978-01-01

    Licensees of nuclear power plants in the United States have many reporting requirements included in their technical specifications and the code of federal regulations, title 10. The Nuclear Regulatory Commisson receives these reports and utilizes them in its regulatory program. Part of this usage includes collecting and publishing this operating experience data in various reports and storing information in various data systems. This paper will discuss the data systems and reports on operating experience published and used by the NRC. In addition, some observations on operating experience will be made. Subjects included will be the Licensee Event Report (LER) Data File, the Operating Unit Status Report (Gray Book), Radiation Exposure Reports, Effluents Reports, the Nuclear Plant Reliability Data System, Current Events, Bulletin Wrapups and Annual Summaries. Some of the uses of the reports and systems will be discussed. The Abnormal Occurence Report to the US Congress will also be described and discussed. (author)

  13. Flooding PSA with Plant Specific Operating Experiences of Korean PWRs

    International Nuclear Information System (INIS)

    Choi, Sun Yeong; Yang, Joon Yull

    2006-01-01

    The purpose of this paper is to update the flooding PSA with Korean plant specific operating experience data and the appropriate estimation method for the flooding frequency to improve the PSA quality. The existing flooding PSA used the NPE (Nuclear Power Experience) database up to 1985 for the flooding frequency. They are all USA plant operating experiences. So an upgraded flooding frequency with Korean specific plant operation experience is required. We also propose a method of only using the PWR (Pressurized Water Reactor) data for the flooding frequency estimation in the case of the flooding area in the primary building even though the existing flooding PSA used both PWR and BWR (Boiled Water Reactor) data for all kinds of plant areas. We evaluate the CDF (Core Damage Frequency) with the modified flooding frequency and compare the results with that of the existing flooding PSA method

  14. Advanced I and C systems for nuclear power plants feedback of experience

    International Nuclear Information System (INIS)

    Prehler Heinz Josef

    2001-01-01

    Advanced I and C systems for nuclear power plants have to meet increasing demands for safety and availability. Additionally specific requirements arising from nuclear qualification have to be fulfilled. To meet both subjects adequately in the future, Siemens has developed advanced I and C technology consisting of the two complementary I and C systems TELEPERM XP and TELEPERM XS. TELEPERM XP is primarily oriented to automation of the non safety related part of the power plant process. Such applications involve extensive open and closed loop control systems and encompass all tasks required for process control via the man-machine interface. Therefore the TELEPERM XP system consists of the AS 620 automation system, the OM 690 process control and management system, the ES 680 engineering system, the DS 670 diagnostic system and the SIMATIC NET bus system. Three versions of automation systems are available: for standard automation, for fail safe automation of safety related tasks and for turbine automation. TELEPERM XS is designed to meet all the requirements on I and C important to safety in nuclear power plants. Typical applications include reactor protection (RPS) and Engineered Safety Features Actuation System functions (ESFAS). TELEPERM XS has been rapidly accepted by the market and has accumulated an extensive operational experience. The expected advantages, namely, reduced space requirements, consistent documentation, improved ergonomics, reduced testing effort, less repair have been confirmed by the operation. The new possibilities to apply intelligent diagnostic methods have been only applied in few cases. Very good service records from a broad field of safety application prove that it is right to use digital I and C systems for safety tasks. The expected advantages such as reduced space requirements, less repairs and less effort for periodic tests, have been confirmed by practical experience. For the future, use of digital I and C systems for safety

  15. Operations experience with the NAC-1 legal weight truck cask

    International Nuclear Information System (INIS)

    Viebrock, J.M.; Hoffman, C.C.

    1978-01-01

    The first three years of operation of Nuclear Assurance Corporation's (NAC) four (4) NAC-1 Casks have demonstrated that shipments of spent fuel, fuel rods and other highly irradiated reactor components can be moved routinely by legal weight truck transport. Shipments of these materials have involved some 800,000 miles of highway travel and cask handling at some fifteen different nuclear facilities. This paper presents details on NAC's operations experience with these casks including cask description, cask handling (loading and unloading), pre-shipment testing, facility turnaround and transit times, operator exposure, transport vehicles and shipper/carrier/cask owner responsibilities, actual experience with regard to facility interfacing requirements and operational procedures. Cask and equipment utilization is discussed together with the methods used to control operation costs and to improve the economics of truck transport

  16. EBR-II: twenty years of operating experience

    International Nuclear Information System (INIS)

    Lentz, G.L.; Buschman, H.W.; Smith, R.N.

    1985-01-01

    Experimental Breeder Reactor No. 2 (EBR-II) is an unmoderated, sodium-cooled reactor with a design power of 62.5 MWt. For the last 20 years EBR-II has operated safely, has demonstrated stable operating characteristics, has shown excellent performance of its sodium components, and has had an excellent plant factor. These years of operating experience provide a valuable resource to the nuclear community for the development and design of future liquid metal fast reactors. This report provides a brief description of the EBR-II plant and its early operating experience, describes some recent problems of interest to the nuclear community, and also mentions some of the significant operating achievements of EBR-II. Finally, a few words and speculations on EBR-II's future are offered. 4 figs., 1 tab

  17. Recent operating experiences and programs at EBR-II

    International Nuclear Information System (INIS)

    Lentz, G.L.

    1984-01-01

    Experimental Breeder Reactor No. II (EBR-II) is a pool-type, unmoderated, sodium-cooled reactor with a design power of 62.5 MWt and an electrical generation capability of 20 MW. It has been operated by Argonne National Laboratory for the US government for almost 20 years. During that time, it has operated safely and has demonstrated stable operating characteristics, high availability, and excellent performance of its sodium components. The 20 years of operating experience of EBR-II is a valuable resource to the nuclear community for the development and design of future LMFBR's. Since past operating experience has been extensively reported, this report will focus on recent programs and events

  18. Radiological operating experience at FFTF [Fast Flux Test Facility

    International Nuclear Information System (INIS)

    Bunch, W.L.; Prevo, P.R.

    1986-11-01

    The Fast Flux Test Facility has been in operation for approximately five years, including about one thousand days of full power operation of the Fast Test Reactor. During that time the collective dose equivalents received by operating personnel have been about two orders of magnitude lower than those typically received at commercial light water reactors. No major contamination problems have been encountered in operating and maintaining the plant, and release of radioactive gas to the environment has been minimal and well below acceptable limits. All shields have performed satisfactorily. Experience to date indicates an apparent radiological superiority of liquid metal reactor systems over current light water plants

  19. Prospects for steady-state tokamak reactor operation through feedback control of the current density profile

    Energy Technology Data Exchange (ETDEWEB)

    Moreau, D

    1994-12-31

    A brief overview of the most relevant experiments on current profile modifications, strong improvements with respect to the usual L-mode scaling laws and Troyon beta limit is presented, as relevant issues for most tokamaks. Practical means and scenarios for producing and maintaining the optimum current profiles in the various phases of the thermonuclear discharge (profile formation, current ramp-up, burn phase) are proposed. (author). 34 refs., 3 figs.

  20. Risk management for operations of the LANL Critical Experiments Facility

    International Nuclear Information System (INIS)

    Paternoster, R.; Butterfield, K.

    1998-01-01

    The Los Alamos Critical Experiments Facility (LACEF) currently operates two burst reactors (Godiva-IV and Skua), one solution assembly [the Solution High-Energy Burst Assembly (SHEBA)], two fast-spectrum benchmark assemblies (Flattop and Big Ten), and five general-purpose remote assembly machines that may be configured with nuclear materials and assembled by remote control. Special nuclear materials storage vaults support these and other operations at the site. With this diverse set of operations, several approaches are possible in the analysis and management of risk. The most conservative approach would be to write a safety analysis report (SAR) for each assembly and experiment. A more cost-effective approach is to analyze the probability and consequences of several classes of operations representative of operations on each critical assembly machine and envelope the bounding case accidents. Although the neutron physics of these machines varies widely, the operations performed at LACEF fall into four operational modes: steady-state mode, approach-to-critical mode, prompt burst mode, and nuclear material operations, which can include critical assembly fuel loading. The operational sequences of each mode are very nearly identical, whether operated on one assembly machine or another. The use of an envelope approach to accident analysis is facilitated by the use of classes of operations and the use of bounding case consequence analysis. A simple fault tree analysis of operational modes helps resolve which operations are sensitive to human error and which are initiated by hardware of software failures. Where possible, these errors and failures are blocked by TSR LCOs. Future work will determine the probability of accidents with various initiators

  1. Safety review of experiments at Albuquerque Operations Office

    International Nuclear Information System (INIS)

    Elliott, K.

    1984-01-01

    The Department of Energy (DOE) Albuquerque Operations Office is responsible for the safety overview of nuclear reactor and critical assembly facilities at Sandia National Laboratories, Los Alamos National Laboratory, and the Rocky Flats Plant. The important safety concerns with these facilities involve the complex experiments that are performed, and that is the area emphasized. A determination is made by the Albuquerque Office (AL) with assistance from DOE/OMA whether or not a proposed experiment is an unreviewed safety question. Meetings are held with the contractor to resolve and clarify questions that are generated during the review of the proposed experiment. The AL safety evaluation report is completed and any recommendations are discussed. Prior to the experiment a preoperational appraisal is performed to assure that personnel, procedures, and equipment are in readiness for operations. During the experiment, any abnormal condition is reviewed in detail to determine any safety concerns

  2. Diagnostics comparing sea surface temperature feedbacks from operational hurricane forecasts to observations

    Directory of Open Access Journals (Sweden)

    Ian D. Lloyd

    2011-11-01

    Full Text Available This paper examines the ability of recent versions of the Geophysical Fluid Dynamics Laboratory Operational Hurricane Forecast Model (GHM to reproduce the observed relationship between hurricane intensity and hurricane-induced Sea Surface Temperature (SST cooling. The analysis was performed by taking a Lagrangian composite of all hurricanes in the North Atlantic from 1998–2009 in observations and 2005–2009 for the GHM. A marked improvement in the intensity-SST relationship for the GHM compared to observations was found between the years 2005 and 2006–2009 due to the introduction of warm-core eddies, a representation of the loop current, and changes to the drag coefficient parameterization for bulk turbulent flux computation. A Conceptual Hurricane Intensity Model illustrates the essential steady-state characteristics of the intensity-SST relationship and is explained by two coupled equations for the atmosphere and ocean. The conceptual model qualitatively matches observations and the 2006–2009 period in the GHM, and presents supporting evidence for the conclusion that weaker upper oceanic thermal stratification in the Gulf of Mexico, caused by the introduction of the loop current and warm core eddies, is crucial to explaining the observed SST-intensity pattern. The diagnostics proposed by the conceptual model offer an independent set of metrics for comparing operational hurricane forecast models to observations.

  3. Climate effects and feedback structure determining weed population dynamics in a long-term experiment.

    Science.gov (United States)

    Lima, Mauricio; Navarrete, Luis; González-Andujar, José Luis

    2012-01-01

    Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role of exogenous variables such as climate have been ignored in the study of weed populations and their management. Here, we use long-term data (22 years) on two annual weed species from a locality in Central Spain to determine the importance of endogenous and exogenous processes (local and large-scale climate factors). Our modeling study determined two different feedback structures and climate effects in the two weed species analyzed. While Descurainia sophia exhibited a second-order feedback and low climate influence, Veronica hederifolia was characterized by a first-order feedback structure and important effects from temperature and rainfall. Our results strongly suggest the importance of theoretical population dynamics in understanding plant population systems. Moreover, the use of this approach, discerning between the effect of exogenous and endogenous factors, can be fundamental to applying weed management practices in agricultural systems and to controlling invasive weedy species. This is a radical change from most approaches currently used to guide weed and invasive weedy species managements.

  4. Climate Effects and Feedback Structure Determining Weed Population Dynamics in a Long-Term Experiment

    Science.gov (United States)

    Lima, Mauricio; Navarrete, Luis; González-Andujar, José Luis

    2012-01-01

    Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role of exogenous variables such as climate have been ignored in the study of weed populations and their management. Here, we use long-term data (22 years) on two annual weed species from a locality in Central Spain to determine the importance of endogenous and exogenous processes (local and large-scale climate factors). Our modeling study determined two different feedback structures and climate effects in the two weed species analyzed. While Descurainia sophia exhibited a second-order feedback and low climate influence, Veronica hederifolia was characterized by a first-order feedback structure and important effects from temperature and rainfall. Our results strongly suggest the importance of theoretical population dynamics in understanding plant population systems. Moreover, the use of this approach, discerning between the effect of exogenous and endogenous factors, can be fundamental to applying weed management practices in agricultural systems and to controlling invasive weedy species. This is a radical change from most approaches currently used to guide weed and invasive weedy species managements. PMID:22272362

  5. Climate effects and feedback structure determining weed population dynamics in a long-term experiment.

    Directory of Open Access Journals (Sweden)

    Mauricio Lima

    Full Text Available Pest control is one of the areas in which population dynamic theory has been successfully applied to solve practical problems. However, the links between population dynamic theory and model construction have been less emphasized in the management and control of weed populations. Most management models of weed population dynamics have emphasized the role of the endogenous process, but the role of exogenous variables such as climate have been ignored in the study of weed populations and their management. Here, we use long-term data (22 years on two annual weed species from a locality in Central Spain to determine the importance of endogenous and exogenous processes (local and large-scale climate factors. Our modeling study determined two different feedback structures and climate effects in the two weed species analyzed. While Descurainia sophia exhibited a second-order feedback and low climate influence, Veronica hederifolia was characterized by a first-order feedback structure and important effects from temperature and rainfall. Our results strongly suggest the importance of theoretical population dynamics in understanding plant population systems. Moreover, the use of this approach, discerning between the effect of exogenous and endogenous factors, can be fundamental to applying weed management practices in agricultural systems and to controlling invasive weedy species. This is a radical change from most approaches currently used to guide weed and invasive weedy species managements.

  6. Operational-safety advantages of LMFBR's: the EBR-II experience and testing program

    International Nuclear Information System (INIS)

    Sackett, J.I.; Lindsay, R.W.; Golden, G.H.

    1982-01-01

    LMFBR's contain many inherent characteristics that simplify control and improve operating safety and reliability. The EBR-II design is such that good advantage was taken of these characteristics, resulting in a vary favorable operating history and allowing for a program of off-normal testing to further demonstrate the safe response of LMFBR's to upsets. The experience already gained, and that expected from the future testing program, will contribute to further development of design and safety criteria for LMFBR's. Inherently safe characteristics are emphasized and include natural convective flow for decay heat removal, minimal need for emergency power and a large negative reactivity feedback coefficient. These characteristics at EBR-II allow for ready application of computer diagnosis and control to demonstrate their effectiveness in response to simulated plant accidents. This latter testing objective is an important part in improvements in the man-machine interface

  7. Concluding from operating experience to instrumentation and control systems

    International Nuclear Information System (INIS)

    Pleger, H.; Heinsohn, H.

    1997-01-01

    Where conclusions are drawn from operating experience to instrumentation and control systems, two general statements should be made. First: There have been braekdowns, there have also been deficiencies, but in principle operating experience with the instrumentation and control systems of German nuclear power plants has been good. With respect to the debates about the use of modern digital instrumentation and control systems it is safe to say, secondly, that the instrumentation and control systems currently in use are working reliably. Hence, there is no need at present to replace existing systems for reasons of technical safety. However, that time will come. It is a good thing, therefore, that the use of modern digital instrumentation and control systems is to begin in the field of limiting devices. The operating experience which will thus be accumulated will benefit digital instrumentation and control systems in their qualification process for more demanding applications. This makes proper logging of operating experience an important function, even if it cannot be transferred in every respect. All parties involved therefore should see to it that this operating experience is collected in accordance with criteria agreed upon so as to prevent unwanted surprises later on. (orig.) [de

  8. Flexible Multi-Bit Feedback Design for HARQ Operation of Large-Size Data Packets in 5G

    DEFF Research Database (Denmark)

    Khosravirad, Saeed; Mudolo, Luke; Pedersen, Klaus I.

    2017-01-01

    large-size data packet thanks to which the transmitter node can reduce the retransmission size to only include the initially failed segments of the packet. We study the effect of feedback size on retransmission efficiency through extensive link-level simulations over realistic channel models. Numerical......A reliable feedback channel is vital to report decoding acknowledgments in retransmission mechanisms such as the hybrid automatic repeat request (HARQ). While the feedback bits are known to be costly for the wireless link, a feedback message more informative than the conventional single......-bit feedback can increase resource utilization efficiency. Considering the practical limitations for increasing feedback message size, this paper proposes a framework for the design of flexible-content multi-bit feedback. The proposed design is capable of efficiently indicating the faulty segments of a failed...

  9. US nuclear power plant operating cost and experience summaries

    International Nuclear Information System (INIS)

    Kohn, W.E.; Reid, R.L.; White, V.S.

    1998-02-01

    NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov)

  10. US nuclear power plant operating cost and experience summaries

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, W.E.; Reid, R.L.; White, V.S.

    1998-02-01

    NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov).

  11. Effects of galvanic skin response feedback on user experience in gaze-controlled gaming: A pilot study.

    Science.gov (United States)

    Larradet, Fanny; Barresi, Giacinto; Mattos, Leonardo S

    2017-07-01

    Eye-tracking (ET) is one of the most intuitive solutions for enabling people with severe motor impairments to control devices. Nevertheless, even such an effective assistive solution can detrimentally affect user experience during demanding tasks because of, for instance, the user's mental workload - using gaze-based controls for an extensive period of time can generate fatigue and cause frustration. Thus, it is necessary to design novel solutions for ET contexts able to improve the user experience, with particular attention to its aspects related to workload. In this paper, a pilot study evaluates the effects of a relaxation biofeedback system on the user experience in the context of a gaze-controlled task that is mentally and temporally demanding: ET-based gaming. Different aspects of the subjects' experience were investigated under two conditions of a gaze-controlled game. In the Biofeedback group (BF), the user triggered a command by means of voluntary relaxation, monitored through Galvanic Skin Response (GSR) and represented by visual feedback. In the No Biofeedback group (NBF), the same feedback was timed according to the average frequency of commands in BF. After the experiment, each subject filled out a user experience questionnaire. The results showed a general appreciation for BF, with a significant between-group difference in the perceived session time duration, with the latter being shorter for subjects in BF than for the ones in NBF. This result implies a lower mental workload for BF than for NBF subjects. Other results point toward a potential role of user's engagement in the improvement of user experience in BF. Such an effect highlights the value of relaxation biofeedback for improving the user experience in a demanding gaze-controlled task.

  12. Feedback control systems for non-linear simulation of operational transients in LMFBRs

    International Nuclear Information System (INIS)

    Khatib-Rahbar, M.; Agrawal, A.K.; Srinivasan, E.S.

    Adequate modeling of Plant Control Systems (PCS) for the study of Anticipated Transients Without Scram (ATWS) is of considerable significance in the design, operation and safety evaluation of Liquid-Metal-Cooled Fast Breeder Reactor (LMFBR) systems. To assess the system response to high frequency, low consequence events, the plant needs to be dynamically simulated. The description of analytical and numerical models for PCS that have been developed and incorporated into the loop version of the Super System Code (SSC-L) are described. The importance of detailed modeling of control systems is discussed. Sample transient results obtained for a 10% ramp change of load in 40 s in the Clinch River Breeder Reactor Plant (CRBRP) are also shown

  13. Ventilation Systems Operating Experience Review for Fusion Applications

    International Nuclear Information System (INIS)

    Cadwallader, L.C.

    1999-01-01

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection

  14. First insights from common GRS and IRSN evaluations of operational experiences for the European Clearinghouse

    International Nuclear Information System (INIS)

    Maqua, M.; Bertrand, R.

    2012-01-01

    The European Clearinghouse on Operating Experience Feedback (OEF) for NPPs was established in 2008 by several European Nuclear Safety Regulators. The technical work on common operational experience evaluation was launched at the Joint Research Center of the European Union. Main goals of the European Clearinghouse include promotion of collaboration on OEF, dissemination of the lessons learnt from NPP operational experience and promoting advanced event assessment approaches and methods. The extended knowledge of both IRSN and GRS in the evaluation of the national operating experiences in France and Germany, respectively, is used by the European Clearinghouse with the objective of receiving detailed insights on safety related topics. IRSN and GRS develop common reports on safety issues upon request of the Clearinghouse that involve a detailed review of their national event databases, and that are combined afterwards in a European Clearinghouse report including also the review carried out by the JRC on the basis of the Incident Report System (IRS) database and the US NRC Licensee Event Reports (LERs) database. The aim is to perform in-depth analyses (causes, root causes, contributing factors, actual and potential consequences, and lessons learnt) of specific OEF topics. 3 topics have been already analyzed: -) external events (Serious accidents caused by external hazards were not found in the German and French operating experience), -) ageing of components (it can be concluded that ageing management in French and German NPP is basically effective), and -) component supply (the main cause for events related to the supply of components was insufficiency during manufacturing or testing). This paper is followed by the slides of the presentation

  15. Design and operating experiences with 50MW steam generator

    International Nuclear Information System (INIS)

    Kawara, M.; Yamaki, H.; Kanamori, A.; Tanaka, K.; Takahashi, T.

    1975-01-01

    The main purpose of the 50 MW steam generator is to have experiences of manufacturing and operation with large scale steam generator including necessary research and development works which can be reflected on the design and fabrication of 'Monju' (Japan 300 MWe prototype LMFBR). The detailed design of the 50 MW steam, generator was begun on March, 1972 and succeeded in the demonstration of 72 hours continuous operation with full power on June, 1974. It has been successfully operated since then, the performances of which have been evaluated through various kinds of tests. In this paper, the following items are mainly discussed system design, thermal and hydraulic design, structure and fabrication and some experiences on testing operation including cleaning and sodium flushing of equipment, sodium level control system, the behavior of hydrogen detection system and general outlook of the performance. (author)

  16. Telescience testbed: Operational support functions for biomedical experiments

    Science.gov (United States)

    Yamashita, Masamichi; Watanabe, Satoru; Shoji, Takatoshi; Clarke, Andrew H.; Suzuki, Hiroyuki; Yanagihara, Dai

    A telescience testbed was conducted to study the methodology of space biomedicine with simulated constraints imposed on space experiments. An experimental subject selected for this testbedding was an elaborate surgery of animals and electrophysiological measurements conducted by an operator onboard. The standing potential in the ampulla of the pigeon's semicircular canal was measured during gravitational and caloric stimulation. A principal investigator, isolated from the operation site, participated in the experiment interactively by telecommunication links. Reliability analysis was applied to the whole layers of experimentation, including design of experimental objectives and operational procedures. Engineering and technological aspects of telescience are discussed in terms of reliability to assure quality of science. Feasibility of robotics was examined for supportive functions to reduce the workload of the onboard operator.

  17. Design and operating experiences with 50MW steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Kawara, M; Yamaki, H; Kanamori, A; Tanaka, K; Takahashi, T

    1975-07-01

    The main purpose of the 50 MW steam generator is to have experiences of manufacturing and operation with large scale steam generator including necessary research and development works which can be reflected on the design and fabrication of 'Monju' (Japan 300 MWe prototype LMFBR). The detailed design of the 50 MW steam, generator was begun on March, 1972 and succeeded in the demonstration of 72 hours continuous operation with full power on June, 1974. It has been successfully operated since then, the performances of which have been evaluated through various kinds of tests. In this paper, the following items are mainly discussed system design, thermal and hydraulic design, structure and fabrication and some experiences on testing operation including cleaning and sodium flushing of equipment, sodium level control system, the behavior of hydrogen detection system and general outlook of the performance. (author)

  18. From USA operation experience of industrial uranium-graphite reactors

    International Nuclear Information System (INIS)

    Burdakov, N.S.

    1996-01-01

    The review on materials, presented by a group of the USA specialists at the seminar in Moscow on October 9-11, 1995 is considered. The above specialists shared their experience in operation of the Hanford industrial reactors, aimed at plutonium production for atomic bombs. The purpose of the above visit consisted in providing assistance to the Russian specialists by evaluation and modernization of operational conditions safety improvement of the RBMK type reactors. Special attention is paid to the behaviour of the graphite lining and channel tubes with an account of possible channel power interaction with the reactor structural units. The information on the experience of the Hanford reactor operation may be useful for specialists, operating the RBMK type reactors

  19. New tools for C.A.D. of input devices for tele-operation with force feedback

    International Nuclear Information System (INIS)

    Gosselin, F.

    2000-01-01

    The performances of a tele-operation system are related to the master arm's ability to emulate the behavior of the remote environment. Ideally, it allows the operator to control the slave arm in a natural way as if that were an extension of its own body. The criteria to be checked for that are known but contradictory. It is thus necessary to make trade-offs on which there is not consensus. Existing input devices are therefore very varied thus more or less adapted to the tasks considered, which is in general checked a posteriori. In this document, we propose an original approach allowing to dimension the master arm a priori according to the use which one wishes to make. For that, we developed two tools: - the first one makes it possible to establish his specifications by taking account of the transmission of information between the operator and the slave arm. By exploiting their respective limitations, one is assured that the master arm will not limit the performances of the system, - the second one allows to design it (kinematics, size, motorization... ) according to the preceding specifications. For that, we use well-known theoretical tools which however are approached here as design tools. This leads to the definition of new concepts which do not appear in the literature. This approach is used to establish the specifications of a master arm for nuclear and offshore tele-operation then to design two input devices answering these specifications. The first has 3 degrees of freedom with force feedback. Its performances are higher than those of the best existing input devices. The second is a mock-up of a 6 degrees of freedom master arm. It uses a new parallel structure that is redundant in actuation and whose performances are remarkable. (author) [fr

  20. LMFBR operational safety: the EBR-II experience

    International Nuclear Information System (INIS)

    Sackett, J.I.; Allen, N.L.; Dean, E.M.; Fryer, R.M.; Larson, H.A.; Lehto, W.K.

    1978-01-01

    The mission of the Experimental Breeder Reactor II (EBR-II) has evolved from that of a small LMFBR demonstration plant to a major irradiation-test facility. Because of that evolution, many operational-safety issues have been encountered. The paper describes the EBR-II operational-safety experience in four areas: protection-system design, safety-document preparation, tests of off-normal reactor conditions, and tests of elements with breached cladding

  1. Current operations and experiments at the Tritium Systems Test Assembly

    International Nuclear Information System (INIS)

    Bartlit, J.R.; Anderson, J.L.

    1985-01-01

    The Tritium Systems Test Assembly (TSTA) has continued to move toward operation of a fully-integrated, full-sized, computer-controlled fusion fuel processing loop. Concurrent, nonloop experiments have answered important questions on new components and issues such as palladium diffusion membranes, ceramic electrolysis cells, regenerable tritium getters, laser Raman spectroscopy, unregenerable tritium inventory on molecular sieves, tritium contamination problems and decontamination methods, and operating data on reliability, emissions, doses, and wastes generated. 4 refs., 2 figs

  2. Simulator experiments on operator reliability and training effectiveness

    International Nuclear Information System (INIS)

    Singh, A. Spurgin, A.J.

    1990-01-01

    This paper discusses some aspects of the Operator Reliability Experiments project sponsored by Electric Power Research Institute. The paper deals with modifications to the HCR correlation which have resulted from the study of operators in responding to nuclear accident scenarios using emergency procedures. The interpretation of time response data and how insights in crew performance can lead to improvements in not only crew performance but also in training effectiveness are discussed

  3. Development of new HRA methods based upon operational experience

    International Nuclear Information System (INIS)

    Cooper, S.E.; Luckas, W.J.; Barriere, M.T.; Wreathall, J.

    2004-01-01

    Under the auspices of the US Nuclear Regulatory Commission (NRC), previously unaddressed human reliability issues are being investigated in order to support the development of human reliability analysis (HRA) methods for both low power and shutdown (LP and S) and full-power conditions. Actual operational experience, such as that reported in Licensee Event Reports (LERs), have been used to gain insights and provide a basis for the requirements of new HRA methods. In particular, operational experience has shown that new HRA methods for LP and S must address human-induced initiators, errors of commission, mistakes (vs. slips), dependencies, and the effects of multiple performance shaping factors (PSFs). (author)

  4. Operating experience on radiation reduction in the latest BWRs

    International Nuclear Information System (INIS)

    Ohsumi, K.; Uchida, S.; Aizawa, M.; Takagi, K.; Amano, O.; Yamashita, K.

    1988-01-01

    In Japan, BWR plants have been operated commercially since 1970, and the reduction of radiation exposure has been an important concern. The application of the procedure for reducing occupational exposure is incorporated in Japanese Improvement and Standardization Program for LWRs. No.2 and No.4 plants in Fukushima No.2 Nuclear Power Station were designed and constructed as the latest 1,100 MWe BWRs in conformity with the Improvement and Standardization Program. No.2 plant began the commercial operation in February, 1984, and experienced three times of the scheduled annual maintenance outage. No.4 plant began the commercial operation in September, 1987, and the first annual maintenance is scheduled from September, 1988. In this paper, discussion is focused on recent radiation reduction measures, that is the control of iron and nickel in primary coolant for reducing the radiation dose rate in primary systems, based on the experience with No.2 and No.4 plants. The design concept of a low radiation dose rate nuclear power plant, the experience on water chemistry in No.2 plant, the control of iron and nickel in No.4 plant operation and so on are reported. It is believed that these operation experiences contribute to the reduction of occupational exposure in BWR plants currently in operation and in future. (Kako, I.)

  5. Architectural study of the design and operation of advanced force feedback manual controllers

    Science.gov (United States)

    Tesar, Delbert; Kim, Whee-Kuk

    1990-01-01

    A teleoperator system consists of a manual controller, control hardware/software, and a remote manipulator. It was employed in either hazardous or unstructured, and/or remote environments. In teleoperation, the main-in-the-loop is the central concept that brings human intelligence to the teleoperator system. When teleoperation involves contact with an uncertain environment, providing the feeling of telepresence to the human operator is one of desired characteristics of the teleoperator system. Unfortunately, most available manual controllers in bilateral or force-reflecting teleoperator systems can be characterized by their bulky size, high costs, or lack of smoothness and transparency, and elementary architectures. To investigate other alternatives, a force-reflecting, 3 degree of freedom (dof) spherical manual controller is designed, analyzed, and implemented as a test bed demonstration in this research effort. To achieve an improved level of design to meet criteria such as compactness, portability, and a somewhat enhanced force-reflecting capability, the demonstration manual controller employs high gear-ratio reducers. To reduce the effects of the inertia and friction on the system, various force control strategies are applied and their performance investigated. The spherical manual controller uses a parallel geometry to minimize inertial and gravitational effects on its primary task of transparent information transfer. As an alternative to the spherical 3-dof manual controller, a new conceptual (or parallel) spherical 3-dof module is introduced with a full kinematic analysis. Also, the resulting kinematic properties are compared to those of other typical spherical 3-dof systems. The conceptual design of a parallel 6-dof manual controller and its kinematic analysis is presented. This 6-dof manual controller is similar to the Stewart Platform with the actuators located on the base to minimize the dynamic effects. Finally, a combination of the new 3-dof and 6-dof

  6. Building the feedback system of project experience,and expediting the scientific development of nuclear power construction

    International Nuclear Information System (INIS)

    Zhou Hai

    2009-01-01

    In accord with the status of the energy structure and electric power demand in China, the Chinese government has made the strategy of developing nuclear power actively. Confronting the good chance for nuclear power development, the writer takes the Fangjiashan nuclear power project as an example, puts forward a viewpoint that establishing the nuclear power project experience summarization and feedback system is an urgent need for expediting the scientific development of nuclear power. It also demonstrates the necessity, feasibility, and detailed measures, etc. (authors)

  7. Audio Feedback -- Better Feedback?

    Science.gov (United States)

    Voelkel, Susanne; Mello, Luciane V.

    2014-01-01

    National Student Survey (NSS) results show that many students are dissatisfied with the amount and quality of feedback they get for their work. This study reports on two case studies in which we tried to address these issues by introducing audio feedback to one undergraduate (UG) and one postgraduate (PG) class, respectively. In case study one…

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-10-15

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

  10. Evaluating health services with point of service feedback: perspectives and experiences of patients, staff and community volunteers in an inpatient rehabilitation facility.

    Science.gov (United States)

    Gill, Stephen D; Dolley, Pamela J; Dunning, Trisha L; Hughes, Andrew J

    2015-01-01

    To determine patient, staff and community volunteer opinions and experiences of point of service feedback (POSF) in an inpatient rehabilitation facility. Participants were recruited by purposeful sampling. Two researchers conducted in-depth semi-scripted interviews with patients, staff or volunteers until no new issues emerged. Manually transcribed interview data underwent thematic analysis that grouped information into categories of related information. Twenty patients, 26 staff from 10 different professional groups, and 2 community volunteers were interviewed. Patient and volunteer data were grouped into five main categories: patients wanted their voice heard and acted on; patients could be positively and negatively affected by POSF; patients could be reluctant to evaluate staff; patients preferred POSF to post-discharge mailed questionnaires; and patients' feedback was influenced by the data collector. Staff wanted: feedback to help them improve the patient experience; and feedback that was trustworthy, usable and used. Staff believed that the feedback-collector influenced patients' feedback and affected how feedback could be used. Patients, staff and community volunteers identified issues that determine the appropriateness and usefulness of POSF. Policy and practise should address the preferences, needs and experiences of health service users and providers so that POSF produces maximum benefits for both patients and health services. Implications for Rehabilitation POSF can enhance patients' experiences of inpatient rehabilitation by providing a mechanism to be heard and communicating that patients are valued; care must be exercised with patients who find giving feedback stressful. Collecting POSF is most beneficial when coupled with methods to efficiently and effectively respond to feedback. POSF requires interpretation in light of its limitations including patients' ability to accurately and unreservedly communicate their experiences. Who collects POSF

  11. Spanish Power Exchange Market Concepts and Operating Experience

    International Nuclear Information System (INIS)

    Gonzalez, J. J.; Gamito, C.

    2000-01-01

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

  12. Design improvements, construction and operating experience with BWRs in Japan

    International Nuclear Information System (INIS)

    Uchigasaki, G.; Yokomi, M.; Sasaki, M.; Aoki, R.; Hashimoto, H.

    1983-01-01

    (1) The first domestic-made 1100-MW(e) BWR in Japan commenced commercial operation in April 1982. The unit is the leading one of the subsequent three in Fukushima Daini nuclear power station owned by the Tokyo Electric Power Company Inc. (Tepco). Based on the accumulated construction and operation experience of 500-MW(e) and 800-MW(e) class BWRs, improvements in various aspects during both the design and construction stages were introduced in core and fuel design with advanced gadolinia distribution, reactor feedwater treatment technology for crud reduction, a radwaste island, control and instrumentation to cope with the lessons learned through Three Mile Island assessment etc. (2) Based on many operating experiences with BWRs, an improved BWR core, which has easier operability and higher load factor than the conventional core, has been developed. The characteristic of the improved core is ''axially two-zoned uranium enrichment distribution''; the enrichment of the upper part of the fuel is slightly higher than that of the lower part. Through the improved core it became possible to optimize the axial power flattening and core reactivity control separately by axial enrichment distribution and burnable poison content. The improved fuels were loaded into operating BWRs and successfully proved the performance by this experience. (3) To shorten annual outage time, to reduce radiation exposure, to save manpower, and to achieve high reliability and safety of inspection operation, the remote automatic service and inspection equipment were developed in Japan. This paper presents the concept, distinctive features, and actual operation experience of the automatic refuelling machine, control-rod drive (CRD) remote-handling machine, improved main steam line isolation plug, and the automated ultrasonic inspection system with a computerized data processing unit, which have been developed by Hitachi, Ltd. with excellent results. (author)

  13. Digital force-feedback for protein unfolding experiments using atomic force microscopy

    Science.gov (United States)

    Bippes, Christian A.; Janovjak, Harald; Kedrov, Alexej; Muller, Daniel J.

    2007-01-01

    Since its invention in the 1990s single-molecule force spectroscopy has been increasingly applied to study protein (un-)folding, cell adhesion, and ligand-receptor interactions. In most force spectroscopy studies, the cantilever of an atomic force microscope (AFM) is separated from a surface at a constant velocity, thus applying an increasing force to folded bio-molecules or bio-molecular bonds. Recently, Fernandez and co-workers introduced the so-called force-clamp technique. Single proteins were subjected to a defined constant force allowing their life times and life time distributions to be directly measured. Up to now, the force-clamping was performed by analogue PID controllers, which require complex additional hardware and might make it difficult to combine the force-feedback with other modes such as constant velocity. These points may be limiting the applicability and versatility of this technique. Here we present a simple, fast, and all-digital (software-based) PID controller that yields response times of a few milliseconds in combination with a commercial AFM. We demonstrate the performance of our feedback loop by force-clamp unfolding of single Ig27 domains of titin and the membrane proteins bacteriorhodopsin (BR) and the sodium/proton antiporter NhaA.

  14. Digital force-feedback for protein unfolding experiments using atomic force microscopy

    International Nuclear Information System (INIS)

    Bippes, Christian A; Janovjak, Harald; Kedrov, Alexej; Muller, Daniel J

    2007-01-01

    Since its invention in the 1990s single-molecule force spectroscopy has been increasingly applied to study protein (un-)folding, cell adhesion, and ligand-receptor interactions. In most force spectroscopy studies, the cantilever of an atomic force microscope (AFM) is separated from a surface at a constant velocity, thus applying an increasing force to folded bio-molecules or bio-molecular bonds. Recently, Fernandez and co-workers introduced the so-called force-clamp technique. Single proteins were subjected to a defined constant force allowing their life times and life time distributions to be directly measured. Up to now, the force-clamping was performed by analogue PID controllers, which require complex additional hardware and might make it difficult to combine the force-feedback with other modes such as constant velocity. These points may be limiting the applicability and versatility of this technique. Here we present a simple, fast, and all-digital (software-based) PID controller that yields response times of a few milliseconds in combination with a commercial AFM. We demonstrate the performance of our feedback loop by force-clamp unfolding of single Ig27 domains of titin and the membrane proteins bacteriorhodopsin (BR) and the sodium/proton antiporter NhaA

  15. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O. [Energovyzkum, Brno (Switzerland); Schmidt, S.; Mihalik, M. [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1997-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  16. EBO feed water distribution system, experience gained from operation

    Energy Technology Data Exchange (ETDEWEB)

    Matal, O [Energovyzkum, Brno (Switzerland); Schmidt, S; Mihalik, M [Atomove Elektrarne Bohunice, Jaslovske Bohunice (Switzerland)

    1998-12-31

    Advanced feed water distribution systems of the EBO design have been installed into steam generators at Units 3 and 4 of the NPP Jaslovske Bohunice (VVER 440). Experiences gained from the operation of steam generators with the advanced feed water distribution systems are discussed in the paper. (orig.). 4 refs.

  17. Operating experience and corrective action program at Ontario Hydro Nuclear

    International Nuclear Information System (INIS)

    Collingwood, Barry; Turner, David

    1998-01-01

    This is a slide-based talk given at the COG/IAEA: 5. Technical Committee Meeting on 'Exchange of operating experience of pressurized heavy water reactors'. In the introduction there are presented the operating experience (OPEX) program of OHN, and the OPEX Program Mission, ensuring that the right information gets to the right staff at the right time. The OPEX Processes are analysed. These are: - Internal Corrective Action; - Inter-site Lesson Transfer; - External Lesson Transfer; - External Posting of OHN Events; - Internalizing Operating Experience. Steps in solving the Corrective Action Program are described: - Identify the Problem; - Notify Immediate Supervision/Manager; - Evaluate the Problem; - Correct the Problem; Monitor/Report Status. The Internal Corrective Action is then presented as a flowchart. The internalizing operating experience is presented under three aspects: - Communication; - Interface; - Training. The following items are discussed, respectively: peer meetings, department/section meetings, safety meetings, e-mail folders, newsletters and bulletin boards; work planning, pre-job briefings, supervisors' briefing cards; classroom initial and refresher (case studies), simulator, management courses. A diagram is presented showing the flow and treatment of information within OHN, centered on the weekly screening meetings. Finally, the corrective action processes are depicted in a flowchart and analysed in details

  18. PFR experience of bellows operating in sodium systems

    International Nuclear Information System (INIS)

    Hodgson, D.

    1980-01-01

    Although there was little operating experience with bellows in sodium systems available during the design phase of the UK 250 MWe prototype fast reactor, bellows were extensively utilised to seal valves and to overcome the problems of differential thermal movements in several important applications. However, because of this lack of operational experience in sodium and the non-availability of design codes it was considered prudent not to install bellows in situations where failure could possibly initiate events of unpredictable proportions, or in positions where replacement following failure would be extremely difficult i.e. involving complete shutdown of the reactor over an extended period (in excess of six months) and/or necessitate removal of large quantities of primary sodium from the reactor vessel. This paper describes some of the bellows units installed in the PFR and the performance achieved during six years of reactor operation

  19. TSTA piping and flame arrestor operating experience data

    Energy Technology Data Exchange (ETDEWEB)

    Cadwallader, Lee C., E-mail: Lee.Cadwallader@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States); Willms, R. Scott [ITER International Organization, Cadarache (France)

    2015-10-15

    Highlights: • Experiences from the Tritium Systems Test Assembly were examined. • Failure rates of copper piping and a flame arrestor were calculated. • The calculated failure rates compared well to similar data from the literature. • Tritium component failure rate data support fusion safety assessment. - Abstract: The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium handling technology and experiment research at the Los Alamos National Laboratory. The facility was operated with tritium for its research and development program from 1984 to 2001, running a prototype fusion fuel processing loop with ∼100 g of tritium as well as small experiments. There have been several operating experience reports written on this facility's operation and maintenance experience. This paper describes reliability analysis of two additional components from TSTA, small diameter copper gas piping that handled tritium in a nitrogen carrier gas, and the flame arrestor used in this piping system. The component failure rates for these components are discussed in this paper. Comparison data from other applications are also presented.

  20. Recent operating experiences with steam generators in Japanese NPPs

    International Nuclear Information System (INIS)

    Yashima, Seiji

    1997-01-01

    In 1994, the Genkai-3 of Kyushu Electric Power Co., Inc. and the Ikata-3 of Shikoku Electric Power Co., Inc. started commercial operation, and now 22 PWR plants are being operated in Japan. Since the first PWR plant now 22 PWR plants are being operated in was started to operate, Japanese PWR plants have had an operating experience of approx. 280 reactor-years. During that period, many tube degradations have been experienced in steam generators (SGs). And, in 1991, the steam generator tube rupture (SGTR) occurred in the Mihama-2 of Kansai Electric Power Co., Inc. However, the occurrence of tube degradation of SGs has been decreased by the instructions of the MITI as regulatory authorities, efforts of Electric Utilities, and technical support from the SG manufacturers. Here the author describes the recent SGs in Japan about the following points. (1) Recent Operating Experiences (2) Lessons learned from Mihama-2 SGTR (3) SG replacement (4) Safety Regulations on SG (5) Research and development on SG