WorldWideScience

Sample records for building outage inspection

  1. Power Outages

    Science.gov (United States)

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

  2. Power Outages

    Science.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

  4. Hanford site post NPH building inspection plan

    Energy Technology Data Exchange (ETDEWEB)

    Wagenblast, G.R., Westinghouse Hanford

    1996-09-12

    This plan establishes consistent post-NPH building inspection procedures and defines a procedure for prioritization of buildings for inspection to ensure the safety of facilities prior to reentry. Qualification of systems for restart of operation is not included. This plan takes advantage, where possible, of existing national procedures for post-NPH inspection of buildings, of existing structural design and evaluation documentation of Hanford facilities, and current and proposed seismic instrumentation located throughout the Hanford site. A list of buildings, prioritized according to current building safety function and building vulnerability (without regard for or information about a damaging natural forces event) is provided.

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

    International Nuclear Information System (INIS)

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

  6. Hanford site post-NPH building inspection plan

    International Nuclear Information System (INIS)

    This plan establishes consistent post-NPH building inspection procedures and defines a procedure for prioritization of buildings for inspection to ensure the safety of facilities prior to reentry. Qualification of systems for restart of operation is not included. This plan takes advantage, where possible, of existing national procedures for post-NPH inspection of buildings, of existing structural design and evaluation documentation of Hanford facilities, and current and proposed seismic instrumentation located throughout the Hanford site. A list of buildings, prioritized according to current building safety function and building vulnerability (without regard for or information about a damaging natural forces event) is provided

  7. Experience from the Inspection of Licensees' Outage Activities, Including Fire Protection Programmes, Event Response Inspections, and the Impact of the Fukushima Daiichi NPP Accident on Inspection Programmes. Workshop Proceedings, Chattanooga, Tennessee, United States, 7-10 April 2014

    International Nuclear Information System (INIS)

    The main purpose of the workshop was to provide a forum of exchange of information on the regulatory inspection activities. Participants had the opportunity to meet with their counterparts from other countries and organisations to discuss current and future issues on the selected topics. They developed conclusions regarding these issues and hopefully, identified methods to help improve their own inspection programmes. The NEA Committee on Nuclear Regulatory Activities (CNRA) believes that an essential factor in ensuring the safety of nuclear installations is the continuing exchange and analysis of technical information and data. To facilitate this exchange the Committee has established working groups and groups of experts in specialised topics. The Working Group on Inspection Practices (WGIP) was formed in 1990 with the mandate '..to concentrate on the conduct of inspections and how the effectiveness of inspections could be evaluated..'. The WGIP facilitates the exchange of information and experience related to regulatory safety inspections between CNRA member countries. These proceedings cover the 12. International Workshop held by WGIP on regulatory inspection activities. This workshop, which is the twelfth in a series, along with many other activities performed by the Working Group, is directed towards this goal. The consensus from participants at previous workshops, noted that the value of meeting with people from other inspection organisations was one of the most important achievements. The focus of this workshop was on experience gained from regulatory inspection activities in three areas: - Inspection of Outage Activities Including Fire Protection Programmes. - Event Response Inspections. - The Impact of Inspection Programmes of the Fukushima Daiichi Nuclear Power Plant (NPP) Accident. The main objectives of the WGIP workshops are to enable inspectors to meet with inspectors from other organisations, to exchange information regarding regulatory inspection

  8. Darlington Station outage - a maintenance perspective

    International Nuclear Information System (INIS)

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

  9. Oblique Aerial Photography Tool for Building Inspection and Damage Assessment

    Science.gov (United States)

    Murtiyoso, A.; Remondino, F.; Rupnik, E.; Nex, F.; Grussenmeyer, P.

    2014-11-01

    Aerial photography has a long history of being employed for mapping purposes due to some of its main advantages, including large area imaging from above and minimization of field work. Since few years multi-camera aerial systems are becoming a practical sensor technology across a growing geospatial market, as complementary to the traditional vertical views. Multi-camera aerial systems capture not only the conventional nadir views, but also tilted images at the same time. In this paper, a particular use of such imagery in the field of building inspection as well as disaster assessment is addressed. The main idea is to inspect a building from four cardinal directions by using monoplotting functionalities. The developed application allows to measure building height and distances and to digitize man-made structures, creating 3D surfaces and building models. The realized GUI is capable of identifying a building from several oblique points of views, as well as calculates the approximate height of buildings, ground distances and basic vectorization. The geometric accuracy of the results remains a function of several parameters, namely image resolution, quality of available parameters (DEM, calibration and orientation values), user expertise and measuring capability.

  10. Experience from the Inspection of Licensees' Outage Activities, Including Fire Protection Programmes, Event Response Inspections, and the Impact of the Fukushima Daiichi NPP Accident on Inspection Programmes. Workshop Proceedings, Chattanooga, Tennessee, United States, 7-10 April 2014 - Appendix: Compilation of Survey Responses

    International Nuclear Information System (INIS)

    This appendix provides the complete compilation of responses received to the questionnaire issued in conjunction with the workshop announcements. The responses are provided as received, with changes made only to the formatting. The OECD Nuclear Energy Agency (NEA) Committee on Nuclear Regulatory Activities (CNRA) Working Group on Inspection Practices (WGIP) sponsored the 12. International Workshop on Nuclear Regulatory Inspection Activities. The workshop was hosted by the U.S. NRC, in Chattanooga, Tennessee, United States of America on 7 -10 April 2014. The three workshop topics that were addressed were as follows: - Inspection of Outage Activities Including Fire Protection Programmes. - Event Response Inspections. - The Impact of Inspection Programmes of the Fukushima Daiichi NPP Accident. Each of the respondents was given the following instructions in relation to their response: - Only one response per country is required. If more than one person from your country is participating, please co-ordinate the responses accordingly. - Please provide responses on separate sheet and clearly identify the questionnaire part and topic. For preparation of the workshop, participants are invited to supply their national inspection approaches used in inspection of events and incidents according to the surveys. Actual issues that were discussed during the workshop were generated by the topic leaders based on the responses submitted by participants with their registration forms. This formats helps to ensure that issues considered most important by the workshop participants are covered during the group discussions. (authors)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    International Nuclear Information System (INIS)

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

  14. Paper on outage philosophy

    International Nuclear Information System (INIS)

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

  15. Record outage at South Texas Project

    International Nuclear Information System (INIS)

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

  16. Maintenance and Outage Management Assessment (MOMA)

    International Nuclear Information System (INIS)

    a small team of experienced nuclear experts/specialists in the world. It can be requested for a single area or multiple ones, such as a) In-Service Inspection program review and optimization, including inspection qualification and risk informed inspection, b) maintenance program optimization by means of equipment reliability, performance based approach, risk informed on-line maintenance, condition based maintenance, c) outage improvement be means of streamlined integration of technologies and process, work planning and scheduling, plant modifications and configuration control, indicators and operating experience feedback system, safety culture, outsourcing and contract management, and spare parts

  17. Nuclear power plant outages

    International Nuclear Information System (INIS)

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

  18. 15 CFR 270.320 - Entry and inspection of site where a building failure has occurred.

    Science.gov (United States)

    2010-01-01

    ... building failure has occurred. 270.320 Section 270.320 Commerce and Foreign Trade Regulations Relating to... Entry and inspection of site where a building failure has occurred. When the Director establishes and... site where the building failure has occurred....

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

    International Nuclear Information System (INIS)

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

  20. Potential of Uav-Based Laser Scanner and Multispectral Camera Data in Building Inspection

    Science.gov (United States)

    Mader, D.; Blaskow, R.; Westfeld, P.; Weller, C.

    2016-06-01

    Conventional building inspection of bridges, dams or large constructions in general is rather time consuming and often cost expensive due to traffic closures and the need of special heavy vehicles such as under-bridge inspection units or other large lifting platforms. In consideration that, an unmanned aerial vehicle (UAV) will be more reliable and efficient as well as less expensive and simpler to operate. The utilisation of UAVs as an assisting tool in building inspections is obviously. Furthermore, light-weight special sensors such as infrared and thermal cameras as well as laser scanner are available and predestined for usage on unmanned aircraft systems. Such a flexible low-cost system is realized in the ADFEX project with the goal of time-efficient object exploration, monitoring and damage detection. For this purpose, a fleet of UAVs, equipped with several sensors for navigation, obstacle avoidance and 3D object-data acquisition, has been developed and constructed. This contribution deals with the potential of UAV-based data in building inspection. Therefore, an overview of the ADFEX project, sensor specifications and requirements of building inspections in general are given. On the basis of results achieved in practical studies, the applicability and potential of the UAV system in building inspection will be presented and discussed.

  1. Management of planned unit outages

    International Nuclear Information System (INIS)

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

  2. Reconstruction of Building Facades in 3D for Remote Inspection Using a Multicopter

    OpenAIRE

    Ottemo, Torjus Sveier

    2014-01-01

    This thesis' focus is on how computer vision can be used to reconstruct building facades in 3D based on images taken by an unmanned aerial vehicle for the purpose of inspection. It explores and presents different algorithms needed for 3D reconstruction of facades and how this can be used to improve facade inspection both in terms of user friendliness for the operator and increased efficiency. The thesis resulted in a reconstruction application with an interactive graphical user interface...

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

    International Nuclear Information System (INIS)

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

  4. Mast sipping and MULTIINSPECTION shorten refueling outages

    International Nuclear Information System (INIS)

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

  5. Capacity building improve Malaysia's inspection and monitoring system for aquaculture and fishery products

    NARCIS (Netherlands)

    Gevers, G.J.M.; Zoontjes, P.W.; Essers, M.L.; Klijnstra, M.; Gerssen, A.

    2012-01-01

    The project aimed to help build a credible inspection and monitoring system that can guarantee safe quality products of Ministry of Health (MoH) and Department of Fisheries (DoF) by upgrading the analytical capacity of the laboratory staff directly involved in the analysis and detection of forbidden

  6. Refuelling outage optimization

    International Nuclear Information System (INIS)

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

  7. Strategies for organizing outages

    International Nuclear Information System (INIS)

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

  8. Fessenheim makes the most of its ten year outage

    International Nuclear Information System (INIS)

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

  9. Outage management and health physics issue, 2009

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. Nuclear Plant Integrated Outage Management

    International Nuclear Information System (INIS)

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

  12. Implementation of the EU directive on the energy performance of buildings: Development of the Latvian Scheme for energy auditing of buildings and inspection of boilers. Project document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    'Development of the Latvian Scheme for energy auditing of buildings and inspection of boilers' includes major steps in implementing the EU EPB directive in Latvia. The EPB directive includes a number of efforts: 1. A methodology for calculation of the integrated energy performance of buildings 2. Application of minimum requirements on the energy performance for new buildings 3. Application of minimum requirements on the energy performance for larger existing buildings subject to major renovation 4. Energy performance certification (energy labelling) of buildings 5. Regular inspection of boilers and of air-conditioning systems in buildings, and assessment of heating installations in older systems. The present project includes activities connected to point 4 and point 5. The results will include 4 steps in implementing the EU EPB directive: 1) A Latvian training of certified independent energy auditors to be active conducting energy audits and issuing energy performance certificates. Including a handbook in energy auditing. 2) A Latvian training of certified independent experts for inspection of boilers, air-con systems and assessing older heating systems. Including a handbook in boiler inspection. 3) A proposal for the institutional set-up for a connected scheme for energy auditing and a scheme for boiler inspection 4) Initial information on the scheme of energy auditors and of the boiler inspection. (au)

  13. Outage rates and outage durations of opportunistic relaying systems

    CERN Document Server

    Hadzi-Velkov, Zoran; 10.1109/LCOMM.2010.02.091683

    2010-01-01

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

  14. Inspection procedure of buildings for the purpose of subsequent assessment of their residual life

    Directory of Open Access Journals (Sweden)

    Zolina Tat’yana Vladimirovna

    2014-12-01

    Full Text Available This paper considers and asserts the need to obtain the results of inspection of a building at the stage of its commissioning in order to apply comprehensive methodology for assessing its residual life. The author proposes to build regression relationship by correlating the levels of the time series dynamics of stress at certain points of the object calculation scheme considering the results of subsequent surveys. It allows estimating the wear rate of structural elements. The assessment of the reliability and durability of the building frame in a deterministic form is based on the limit states method. The application of this method allows taking into account the random nature of not only the combination of existing loads, but also the strength properties of construction materials by creating a system of safety factors.

  15. 35/30 outage improvement project

    International Nuclear Information System (INIS)

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

  16. Improvements in D2O leakage detection in restricted areas of Reactor Building during operation and tritium in air monitoring during outages

    International Nuclear Information System (INIS)

    This report describes the air sampling lines required for the improvement of simultaneous sampling for tritium in air monitoring in restricted areas of Reactor Building during operation. These sampling lines require penetrations equipped with containment sealing solenoid valves. It also describes the equipment used and the experience gained from some D2O leakages since Plant commissioning. By taking into account the current tendencies, improvements in gathering all data related to tritium concentrations in Reactor Building in Health Physicist's office, room S - 307 were made. Air samples were analyzed either by a liquid scintillation detector and/or by a proportional counter simultaneously, instead of the former single samples. These improvements also gave the possibility of a quicker detection of D2O leakage, thus contributing to keep low personnel dose, according to ALARA principles, as 'in situ' monitoring have proved to be not justifiable. (authors)

  17. Calculation of the thicknesses of the walls of the radiographic inspection building of the NKS enterprise

    International Nuclear Information System (INIS)

    During the month of February, 1983, the Structural Civil Department of the Latin American of Engineering, S.A. de C.V. company (LATISA), outline to the Engineering and Industry Applications Management of the ININ that the industrial group NKS had taken charge them the design of a building where it would lodge a linear electron accelerator of 4 MeV, one source of Co-60 of 30 Ci and an X-ray equipment, tube type, of range of 60 to 300 KV and that to make the design they required to know the necessary thickness of the walls, doors and roof to protect to the workers, outside of the building, of the X and gamma radiations generated by the sources mentioned during the radiographic inspections of metal-mechanical pieces. (Author)

  18. Implementation of the EU directive on the energy performance of buildings: Development of the Latvian Scheme for energy auditing of buildings and inspection of boilers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The project includes support to the Ministry of Economics responsible for implementing the EU directive on the energy performance of buildings. The directive includes a number of efforts with the main objective of establishing energy efficiency in buildings: 1. A methodology for calculation of the integrated energy performance of buildings. 2. Application of minimum requirements on the energy performance for new buildings. 3. Application of minimum requirements on the energy performance for larger existing buildings subject to major renovation. 4. Energy performance certification (energy labelling) of buildings. 5. Regular inspection of boilers and of air-conditioning systems in buildings, and assessment of heating installations in older systems. The present project included activities connected to point 4 and point 5. The results include support for major steps in implementing the EU Energy Performance of Buildings (EPB) directive: 1) A Latvian training for energy auditors to be active conducting energy audits and issuing energy performance certificates - energy labelling the buildings and installations. The training includes air-condition systems and assessing older heating systems.18 auditors have been trained by the Latvian teachers. 2) A Latvian training of experts for inspection of boilers. 13 inspectors have been trained. 3) A proposal for the institutional set-up for a connected scheme for energy auditing and a scheme for boiler inspection. 4) Initial information on the EPB directive, and the implementation in Latvia, including the suggested setup and the training of auditors and boiler inspectors. (au)

  19. Outage management: A case study

    International Nuclear Information System (INIS)

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

  20. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-01-01

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

  1. Outage management: A case study

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-09-01

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

  2. Power Outage - 16 October

    CERN Multimedia

    2014-01-01

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

  3. Improving refueling outages through partnership

    International Nuclear Information System (INIS)

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

  4. Exceptional outage for Fessenheim-1

    International Nuclear Information System (INIS)

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

  5. Minimizing forced outage risk in generator bidding

    Science.gov (United States)

    Das, Dibyendu

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  8. Outage capacity of multicarrier systems

    KAUST Repository

    Yilmaz, Ferkan

    2010-01-01

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

  9. Nuclear power plant outage optimisation strategy

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. Achieving outage excellence through partnership in performance

    International Nuclear Information System (INIS)

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

  12. Management strategies for nuclear power plant outages

    International Nuclear Information System (INIS)

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

  13. Nuclear operations branch outage management strategy

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  15. Areva: experiences in outage services

    International Nuclear Information System (INIS)

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

  16. Outage risk reduction at Diablo Canyon

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  18. Lay-up condition during ENPP refurbishment outage

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  1. Preparing and organizing inspection and maintenance

    International Nuclear Information System (INIS)

    The philosophy and goals of maintenance are discussed. The main principles in organizing the maintenance of the Loviisa power plant are: the people responsible for maintenance during operation are also responsible for maintenance during outages; outside contractors are used for the peak loads during outages but the planning and monitoring of outages is the responsibility of the plant personnel. Technically skilled and highly motivated personnel is the most important prerequisite of success. Loviisa has for several years very successfully utilized two different types of salary bonus system. The reloading outage bonus system gives more money per hour during the outage and an additional increase for all plant people participating in the outage work, if the duration of the outage is shorter than planned. The amount of the extra bonus depends on the final duration of the outage. The operation and maintenance of the Loviisa plant is based on quality assurance, operation and maintenance procedures. The annual and long-term plan of actions are controlled by regular planning meetings which utilize all reports produced by the maintenance groups. The technical outage report contains all technical information gathered during the outages according to the preventive maintenance and in-service inspection programs. The condition monitoring programs of the plant components were developed by the Research Laboratories of Imatran Voima and financed by the plant. (Z.S.) 9 figs., 5 refs

  2. Mast sipping technique optimises refueling outages

    International Nuclear Information System (INIS)

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

  3. San Onofre - the evolution of outage management

    International Nuclear Information System (INIS)

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

  4. A national survey on radon concentration in underground inspection rooms and in buildings of a telephone company: methods and first results

    International Nuclear Information System (INIS)

    A national survey has been carried out to measure radon concentration in a large sample of Telecom-Italia small underground inspection rooms, which form a particularly dense net in urban areas. Measuring radon in such underground places is interesting both for a possible contribution to radon mapping activities and to evaluate workers exposures. Radon concentration was also measured in Telecom buildings (i.e. buildings housing plant equipment, including telephone switches, often also offices, etc.) close and partially connected to the selected inspection rooms. The methodology and the first results of the survey related to the first year of measurements, for a total of 1438 inspection rooms and 1414 Telecom buildings, are reported. Radon concentration was measured with passive devices containing CR-39 detectors for about 12 consecutive months, in order to average seasonal variations. In underground inspection rooms, measured radon concentration reached values up to about 44,000 Bq/m3, with a regional median ranging from about 90 Bq/m3 up to about 1600 Bq/m3. In Telecom buildings, the regional median concentration ranged from 13 Bq/m3 to 174 Bq/m3. These results show that radon concentration in underground inspection rooms can reach very high values, whereas medians in monitored buildings are generally lower than those measured in dwellings in a representative national survey.

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

    International Nuclear Information System (INIS)

    drums and that of unit No. 3. Overhaul and inspection of new designs components, such as reactor internal pumps (RIPs), advanced type control rod drive mechanism (FMCRD) and large-capacity and high-efficiency turbine system, were conducted as planned, verifying their integrity after the commercial operation period. Operability during annual outage through ABWR-type main control room panels, which have a very new man-machine interface with touch-screen CRTs and flat displays, was also confirmed. In this paper, the commercial operation and annual outage experience of Kashiwazaki-Kariwa Nuclear Power Station units Nos. 6 and 7 are reported. (author)

  6. SAMPLE RESULTS FROM MCU SOLIDS OUTAGE

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-22

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

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

    Directory of Open Access Journals (Sweden)

    Ali Asgary

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  12. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

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

  13. Microbial secondary metabolites in school buildings inspected for moisture damage in Finland, The Netherlands and Spain

    NARCIS (Netherlands)

    Peitzsch, M.; Sulyok, M.; Täubel, M.; Vishwanath, V.; Krop, E.J.M.; Borràs-Santos, A.; Hyvärinen, A.; Nevalainen, A.; Krska, R.; Larsson, L.

    2012-01-01

    Secondary metabolites produced by fungi and bacteria are among the potential agents that contribute to adverse health effects observed in occupants of buildings affected by moisture damage, dampness and associated microbial growth. However, few attempts have been made to assess the occurrence of the

  14. Outage management and health physics issue, 2007

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  16. Residential outage cost estimation: Hong Kong

    International Nuclear Information System (INIS)

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

  17. Pricing power outages in the Netherlands

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-15

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

  18. Qinshan CANDU NPP outage performance improvement through benchmarking

    International Nuclear Information System (INIS)

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

  19. Devices for the contamination containment employees in the steam generator inspection

    International Nuclear Information System (INIS)

    The process of induced current inspection of the tubes of the steam generator is a typical programmed inspections at each refueling outages of pressurized water in nuclear power plants. components inspection being quite active, interested in the program of continuous improvement, further optimize the inspection system.

  20. Nuclear cost control focuses on refueling outages

    International Nuclear Information System (INIS)

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

  1. Outage management and health physics issue, 2006

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby

    2012-05-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  5. Pressurized water reactor inspection procedures

    International Nuclear Information System (INIS)

    Inspections of the reactor pressure vessels of pressurized water reactors (PWR) so far used to be carried out with different central mast manipulators. For technical reasons, parallel inspections of two manipulators alongside work on the refueling cavity, so as to reduce the time spent on the critical path in a revision outage, are not possible. Efforts made to minimize the inspection time required with one manipulator have been successful, but their effects are limited. Major reductions in inspection time can be achieved only if inspections are run with two manipulators in parallel. The decentralized manipulator built by GEC Alsthom Energie and so far emmployed in boiling water reactors in the USA, Spain, Switzerland and Japan allows two systems to be used in parallel, thus reducing the time required for standard inspection of a pressure vessel from some six days to three days. These savings of approximately three days are made possible without any compromises in terms of positioning by rail-bound systems. During inspection, the reactor refueling cavity is available for other revision work without any restrictions. The manipulator can be used equally well for inspecting standard PWR, PWR with a thermal shield, for inspecting the land between in-core instrumentation nozzles, BWR with and without jet pumps (complementary inspection), and for inspecting core support shrouds. (orig.)

  6. Bingham Pump Outage Pits: Environmental information document

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    Kim, Taedong; Wright, Stephen J

    2014-01-01

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

  10. Outage analysis of blind cooperative diversity

    KAUST Repository

    Tourki, Kamel

    2011-06-06

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-01

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

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

    International Nuclear Information System (INIS)

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

  15. Reducing outage times: a FROG perspective

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  17. Application of RCM analysis to the optimization of outages

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-04

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

  20. Technology Integration Initiative In Support of Outage Management

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Weatherby; David Gertman

    2012-07-01

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

  1. Role of shutdown PRA in outage planning

    International Nuclear Information System (INIS)

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

  2. Building

    OpenAIRE

    Seavy, Ryan

    2014-01-01

    Building for concrete is temporary. The building of wood and steel stands against the concrete to give form and then gives way, leaving a trace of its existence behind. Concrete is not a building material. One does not build with concrete. One builds for concrete.

  3. Devices for the contamination containment employees in the steam generator inspection; Dispositivo para confinamiento de la contaminacion empleados en la inspeccion de generadores de vapor

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Bueno, A.; Largo Izquierdo, P.; Calleja Rubio, J. A.

    2010-07-01

    The process of induced current inspection of the tubes of the steam generator is a typical programmed inspections at each refueling outages of pressurized water in nuclear power plants. components inspection being quite active, interested in the program of continuous improvement, further optimize the inspection system.

  4. Good practices for outage management in nuclear power plants

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  7. Follow up of the PWRs maintenance outages in France

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Amin, Osama

    2015-06-14

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

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

    CERN Document Server

    Liu, Chun-Hung

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Shawn St. Germain; Ronald Farris; Heather Medeman

    2013-09-01

    This research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which is a research and development (R&D) program sponsored by Department of Energy (DOE) and performed in close collaboration with industry R&D programs that provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. The LWRS program serves to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. The long term viability of existing nuclear power plants in the U.S. will depend upon maintaining high capacity factors, avoiding nuclear safety issues and reducing operating costs. The slow progress in the construction on new nuclear power plants has placed in increased importance on maintaining the output of the current fleet of nuclear power plants. Recently expanded natural gas production has placed increased economic pressure on nuclear power plants due to lower cost competition. Until recently, power uprate projects had steadily increased the total output of the U.S. nuclear fleet. Errors made during power plant upgrade projects have now removed three nuclear power plants from the U.S. fleet and economic considerations have caused the permanent shutdown of a fourth plant. Additionally, several utilities have cancelled power uprate projects citing economic concerns. For the past several years net electrical generation from U.S. nuclear power plants has been declining. One of few remaining areas where significant improvements in plant capacity factors can be made is in minimizing the duration of refueling outages. Managing nuclear power plant outages is a complex and difficult task. Due to the large number of complex tasks and the uncertainty that accompanies them, outage durations routinely exceed the planned duration. The ability to complete an outage on or near

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

    International Nuclear Information System (INIS)

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

  12. Design inspections for systems undergoing design modifications

    International Nuclear Information System (INIS)

    The US Nuclear Regulatory Commission's (NRC's) Office of Inspection and Enforcement (IE) has conducted direct inspections (integrated design inspections) of the technical aspects of the nuclear plant design process for several plants under construction. It has also evaluated independent design verification programs and engineering assurance programs at a number of other plants under construction. Many of the lessons learned from these construction phase efforts are directly applicable to operating plants undergoing major modifications. This has been confirmed by IE direct inspections of the design aspects of safety systems outage modifications, which have identified significant potential safety-related deficiencies. The paper discusses methodology for design inspections; failure to maintain up-to-date design basis documentation; and lessons learned common to plants under construction and undergoing major modifications

  13. Lightning Protection Research for Office Building of Inspection Bureau in Cangzhou%某市稽查局办公楼综合雷电防护研究

    Institute of Scientific and Technical Information of China (English)

    崔倩; 魏秀梅; 王淑云; 宿梅娟

    2012-01-01

      针对某市稽查局办公楼常遭雷击导致设备损坏的现状,根据现场勘测结果,结合所收集的当地地理环境及雷电活动规律的基础上,以网络信息系统、视频监控系统、大气采样系统及建筑物综合防雷系统为例,设计了一套较完整的雷电防护方案。通过对电源系统电涌保护器(SPD)能量配合的设计,能够有效减小雷电脉冲的影响,保证设备安全可靠的运行。%  In a city inspection bureau office building often lightning result in damage to the equipment status, the complete lightning pro-tection is given in this paper. This design is on the basis of net work information system, monitor system, atmospheric sampling system and building integrated lightning protection system, combining the local geographical condition and lightning activities. Through the energy coopera-tion design of SPD in power system, the plan can effectively reduce the influence of lightning pulse, and make equipment operate safely.

  14. TOPOLOGY AND CASCADING LINE OUTAGES IN POWER GRIDS

    Institute of Scientific and Technical Information of China (English)

    David L. PEPYNE

    2007-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Haenggi, Martin

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

  18. Multicast Capacity Scaling of Wireless Networks with Multicast Outage

    CERN Document Server

    Liu, Chun-Hung

    2010-01-01

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

  19. Remotely operated inspection equipment for the Candu fuel channels

    International Nuclear Information System (INIS)

    Equipment is described which has been successfully used for the nondestructive inspection of fuel channel components within Ontario Hydro's CANDU nuclear reactors. By the use of automated systems, significant savings in personnel radiation exposure and unit outage duration have been realized, with improved quality and quantity of nondestructive examination information. (author)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

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

    International Nuclear Information System (INIS)

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

  3. Inside story: inspecting RCP [reactor coolant pump] impellers in situ

    International Nuclear Information System (INIS)

    Using a specially developed robot, Pipe Walker, R Brooks Associates, Inc (Brooks) performed ground-breaking visual inspections of the four reactor coolant pump impellers at unit 1 of the Three Mile Island (TMI) plant. This is the first time that inspections of this type have been performed without any disassembly or removal of the pumps, resulting in considerable savings of outage time and cost. (Author)

  4. Impacts of organization and management on outage performance

    International Nuclear Information System (INIS)

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

  5. Steam Generator Inspection Planning Expert System

    International Nuclear Information System (INIS)

    Applying Artificial Intelligence technology to steam generator non-destructive examination (NDE) can help identify high risk locations in steam generators and can aid in preparing technical specification compliant eddy current test (ECT) programs. A steam Generator Inspection Planning Expert System has been developed which can assist NDE or utility personnel in planning ECT programs. This system represents and processes its information using an object oriented declarative knowledge base, heuristic rules, and symbolic information processing, three artificial intelligence based techniques incorporated in the design. The output of the system is an automated generation of ECT programs. Used in an outage inspection, this system significantly reduced planning time

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

    International Nuclear Information System (INIS)

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

  7. COMPLEX METHOD OF INSPECTION OF BUILDINGS AND CONSTRUCTIONS AT TEAMWORK BY COMMUNICATION TOWERS Комплексный метод обследования зданий и сооружений при совместной работе с вышками связи

    Directory of Open Access Journals (Sweden)

    Kozhenko N. V.

    2013-05-01

    Full Text Available In this article we developed and improved the algorithm for complex inspection of buildings and constructions at teamwork with communication towers. The inspection of a building which was made using the described algorithm is presented

  8. Development of the Latvian scheme for energy auditing of buildings and inspection of boilers and air-conditioning systems. Final report institutional set-up

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-12-01

    To implement EU directive 93/76/EEC on reduction of carbon dioxide emission by increasing energy efficiency and EU directive 2002/91/EC on building energy efficiency, Latvia must establish and institutional scheme and define all the organisations involved. From a general perspective the institutional scheme must as a minimum include the following four key players: the administrator, the operating unit, the auditors or independent experts, and finally the client. Furthermore, institutions dealing with financing of energy efficiency improvement activities, training and certification of experts, information about auditing and energy efficiency etc. need to be involved. At present there is no governmental or private Latvian organisation that could fully rearrange and assume the duties of an energy audit scheme secretariat. It is therefore recommended initially to place the secretariat as a separate, new unit within the Ministry of Economy, financed by the Ministry of Economy, with the intention of establishing at a later stage (after e.g. 5 years) a separate, new agency, an Energy Efficiency Agency partly financed by the incomes from the energy audit and boiler inspection schemes. The Secretariat should, both in its initial phase and later, assign the tasks of training, information campaigns, quality assurance and evaluation to external organisations. (BA)

  9. Inspection Database

    Data.gov (United States)

    U.S. Department of Health & Human Services — FDA is disclosing the final inspection classification for inspections related to currently marketed FDA-regulated products. The disclosure of this information is...

  10. Options for shortening nuclear power plant refueling outages

    International Nuclear Information System (INIS)

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

  11. Outage planning: basics are the key to success

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-11-01

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

  15. Inspection planning

    International Nuclear Information System (INIS)

    Slovenian Nuclear Safety Administration (SNSA) division of nuclear and radiological safety inspection has developed systematic approach to their inspections. To be efficient in their efforts regarding regular and other types of inspections, in past years, the inspection plan has been developed. It is yearly based and organized on a such systematic way, that all areas of nuclear safety important activities of the licensee are covered. The inspection plan assures appropriate preparation for conducting the inspections, allows the overview of the progress regarding the areas to be covered during the year. Depending on the licensee activities and nature of facility (nuclear power plant, research reactor, radioactive waste storage, others), the plan has different levels of intensity of inspections and also their frequency. One of the basic approaches of the plan is to cover all nuclear and radiological important activities on such way, that all regulatory requests are fulfilled. In addition, the inspection plan is a good tool to improve inspection effectiveness based on previous experience and allows to have the oversight of the current status of fulfillment of planned inspections. Future improvement of the plan is necessary in the light of newest achievements on this field in the nuclear world, that means, new types of inspections are planned and will be incorporated into plan in next year.(author)

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

    Directory of Open Access Journals (Sweden)

    I. Klein

    2012-09-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Tourki, Kamel

    2010-09-01

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

  20. Outage Constrained Secrecy Rate Maximization Using Cooperative Jamming

    CERN Document Server

    Luo, Shuangyu; Petropulu, Athina

    2012-01-01

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

  1. Safety review, assessment and inspection for nuclear power plants

    International Nuclear Information System (INIS)

    The NNSA always lays stress on the daily surveillance of operating NPPs. Considering that a short-term operation, lacking of experience and the problems for equipment reliability having not yet fully been revealed in NPPs, the NNSA improved effectively the safety level in NPPs by enhancing the routine inspection and the refueling outage inspection, conducting the operational events analysis and operational experience feedback actively. According to the Regulatory Inspection Program on Nuclear Safety during construction of NPP, the surveillance model on safety during construction of NPP has been further improved. The Surveillance Procedure during commissioning of NPP is enacted, the surveillance model during commissioning of NPP has been established

  2. Improving the reliability of on-site NDT inspection

    International Nuclear Information System (INIS)

    The authors review the conclusions of a number of projects conducted at AEA Technology to determine the effects of various possible factors which can affect the reliability of inspections during nuclear power plan maintenance outage. The factors investigated include: working practices and work scheduling (effect of long working hours and time pressures), the local environment (effects of temperature, humidity, noise), the inherent capability of the inspectors (influence of the inspector's training, qualifications, experience and attitude), inspection systems and procedures (relative performances of manual and automated inspections, role of validation and procedure assessment)

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Yang, Liang

    2012-03-01

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

  5. Upgrading BWR training simulators for annual outage operation training

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Ioannou, Ioanna; Loyka, Sergey

    2011-01-01

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

  8. Performance Shaping Factors Assessments and Application to PHWR Outages

    International Nuclear Information System (INIS)

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

  9. Hydro-Quebec inspection robot RIT-LRG

    International Nuclear Information System (INIS)

    Hydro Quebec's Research Centre (IREQ), has developed a variety of inspection tools over the years. The Metar bracelet for the feeder tubes, the REC robot for the heat exchanger and the RIT robot for the Delayed Neutron system just to name a few. This paper discusses with the successful deployment of the Camera Probe Positioning robot for Visual Inspection of the sample lines of the delayed neutron system of CANDU power plants. This RIT robot has three possible configurations (Face, Cabinet and LRG configurations) and has remained a prototype version although it has been used over the years in many outage inspection campaigns since 1997. The main advantages of using this robot are: the significant reduction in radiation exposure, the high quality of the data collected and the archiving of inspection data for further analysis and reports. In 2007, Gentilly-2 (G-2), decided to industrialize the LRG configuration of the RIT robot and to designate it the standard tool for the inspection of the Delayed Neutron System. An improved RIT-LRG robot, along with its control box and command station was developed. The software had to be rewritten requiring an ergonomics analysis of user tasks, work station and interface display. These issues included both physical and cognitive requirements aspects. The two principal topics of this paper will be on the Inspection Robot Technology developed and highlights of the 2008 outage inspection campaign. (author)

  10. CASTOR - Advanced System for VVER Steam Generator Inspection

    International Nuclear Information System (INIS)

    From the safety point of view, steam generator is a very important component of a nuclear power plant. Only a thin tube wall prevents leakage of radioactive material from the primary side into the environment. Therefore, it is very important to perform inspections in order to detect pipe damage and apply appropriate corrective actions during outage. Application of the nondestructive examination (NDE) technique, that can locate degradation and measure its size and orientation, is an integral part of nuclear power plant maintenance. The steam generator inspection system is consisted of remotely controlled manipulator, testing instrument and software for data acquisition and analysis. Recently, the inspection systems have evolved to a much higher level of automation, efficiency and reliability resulting in a lower cost and shorter outage time. Electronic components have become smaller and deal with more complex algorithms. These systems are very fast, precise, reliable and easy to handle. The whole inspection, from the planning, examination, data analysis and final report, is now a highly automated process, which makes inspection much easier and more reliable. This paper presents the new generation of INETEC's VVER steam generator inspection system as ultimate solution for steam generator inspection and repair. (author)

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

    Directory of Open Access Journals (Sweden)

    J.O. Adepitan

    2012-09-01

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

  12. Design Concepts for an Outage Control Center Information Dashboard

    International Nuclear Information System (INIS)

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

  13. Design Concepts for an Outage Control Center Information Dashboard

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-01

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

  14. Steam generator tube inspection and maintenance technology

    International Nuclear Information System (INIS)

    I am very happy to introduce a report which I'm sure will shows an important progress to the inspection and repair of steam generator in nuclear power industry. It will describe a tube inspection which has been applied to detect PWSCC at the top of tubesheet and a tube repair KPS supplied during last outage (Dec. 1998 to Feb. 1999). The presentation describe what KPS performed for the PWSCC degradation mechanism found in Ulchin unit 1 and 2 and explain the effort for new techique application to improve conventional techniques. Ulchin Nuclear Power Plants consist of 4 units which are 2 units (no. 1,2) with 980 Mwg and 2 units (no. 3,4) with 1000 Mwg. Ulchin unit 1 did initial startup on Jan. 1986. It has three Westinghouse Series 51 B Steam Generator with closed crevice tubesheet and kiss roll expansion. 51 B Steam Generators in Ulchin unit 1 and 2 have: - Recirculating SG with 3,330 U tubes each (0.875 OD x 0.05 Thick) , - Inconel 600 MA, - Full hydraulic expansions, - Thot of 620 deg F. Primary Water Stress Corrosion Cracks (PWSCC) on steam generator tube have been found in Ulchin unit 1 and 2 since the forth outage (1993). So these units have been much affected by PWSCC for normal operation. Therefore, the utility has continued to look for the advanced inspection and maintenance technology to extend the life of degraded steam generator tube. (author)

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

    International Nuclear Information System (INIS)

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

  16. Permanent start-up instrumentation for maintenance outages

    International Nuclear Information System (INIS)

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

  17. Hospital Inspections

    Data.gov (United States)

    U.S. Department of Health & Human Services — Welcome to hospitalinspections.org, a website run by the Association of Health Care Journalists (AHCJ) that aims to make federal hospital inspection reports easier...

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

    CERN Document Server

    Wu, Peng

    2007-01-01

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

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

    CERN Document Server

    Hines, Paul D H; Rezaei, Pooya

    2015-01-01

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

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

    CERN Document Server

    Giacomelli, Riccardo; Haenggi, Martin

    2010-01-01

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

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

    KAUST Repository

    Alabbasi, AbdulRahman

    2015-12-06

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

  2. Safety review, assessment and inspection for nuclear power plants

    International Nuclear Information System (INIS)

    Qinshan Nuclear Power Plant started first shut down for refuelling and overhaul in October, 1994. The two units of Guangdong Nuclear Power Station also started first shutdown for refuelling and overhaul in December 1994 and in April, 1995 respectively. Hence besides to conduct a routine operational inspection, the NNSA laid stress on the safety supervision of the first refuelling for two nuclear power plants, especially the treatment of event that the drop time of its control rods exceed criteria for the Unit 1 of GNPS. In the course of implementing supervision on the refuelling for nuclear power plants, the NNSA drew experience from foreign nuclear safety authorities to the practice of supervision during the commissioning stage for nuclear power plants, the inspection programs were prepared for outage respectively. The NNSA concerted closely with its regional offices to conduct a routine inspection and to combine with a special item inspection, to ensure the effective implementation of inspections

  3. Qualification of a motorized scanner for feeder bend inspection

    International Nuclear Information System (INIS)

    This paper will review the qualification of the Inspection System based on the motorized feeder bend-cracking crawler designed by IREQ and the inspection procedure COG-JP-4107- V43 developed by Hydro-Quebec and New-Brunswick Power. The mechanization of the inspection was necessary to address new concerns found after the discovery in 2003 of cracks on second bends and also the finding that several removed cracked bends had additional incipient OD cracks on the extrados. This document describes the apparatus, procedure and test-results that support the adequacy of the inspection system to meet the inspection specifications and the CSA N285.4 Standard. A review of the qualification process is included. A particular aspect of the work is the emphasis set on detecting OD flaws. Field results from PLGS and G-2 outages will be addressed. (author)

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

    OpenAIRE

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

    2013-01-01

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

  5. SICOM: On-site inspection systems

    International Nuclear Information System (INIS)

    As the irradiation conditions become more demanding for the fuel than in the past, there is a need for surveillance programs to gather in-reactor operating experience. The data obtained in these programs can be used to assess the performance of current fuel designs and the improvements incorporated to the fuel assembly design, the performance of the advanced cladding alloys, etc. In these regards, valuable data is obtained from on-site fuel inspections. These on-site data comprise fuel assembly dimensional data such as length and distortion (tilt, twist and bow) and fuel rod data such as length and oxide thickness. These data have to be reliable and accurate to be useful thus, demanding a high precision inspection equipment. However, the inspection equipment has to be also robust and flexible enough to operate in the plant spent fuel pool and, sometimes, without interfering in the works carried out during a plant outage. To meet these requirements, during the past years ENUSA and TECNATOM have developed two on-site inspection systems. While the first system can perform most of the typical measurements in a stand-alone manner thus, without interfering with the critical path of the reload, the second one reduces the inspection time but requires using the plant capabilities. The paper describes both equipment for fuel on-site inspection, their characteristics and main features. (author)

  6. Conceptual design for transmission line inspection robot

    International Nuclear Information System (INIS)

    Power transmission line is used for power distribution purposes due to their cost effective measure compared to underlying cable. However, prolonged exposure to natural weather may cause fatigue stress to the lines as well as induce material failure. Therefore, periodical line inspection is considered uttermost important as a preventive measure to avoid power outage. However, transmission line inspection has always been a high risk and expensive work. Hazardous works that may harm operator as well as routine that requires precise handling can be performed by robots. Various types of robots have been designed and developed for line inspection but only perform well on a straight and continuous line. As these robots encounter an obstacle during the inspection, then the real problem in terms of robot stability and smooth operation arises. In this paper, conceptual design and evaluation for transmission line inspection robot is presented. The inspection robot mobile robot must be able to bypass or avoid obstacles as it travels along the power transmission line.

  7. Strategies to reduce PWR inspection time

    International Nuclear Information System (INIS)

    During last few years, a constant reduction in inspection time was clearly demanded by most nuclear plant owners. This requirement has to be accomplished without any impact in inspection quality that, in general, has also to be improved. All this in a market with increasing competition that forces price reductions. Under these new demands from our customers, Tecnatom reoriented its development efforts to improve his products and services to meet this challenges. Two of our main inspection activities that have clear impact in outage duration are Steam Generator and Vessel inspections. This paper describes the improvements made in these two activities as an example of the reorientation of our development efforts with a focus on the technical improvements made on the software and robotic tools applied as in the data acquisition and analysis systems. In the Steam Generator inspections, new robots with dual guide tubes are commonly used. New eddy current instruments and software were developed to keep up with the data rates produced by the faster acquisition system. Use of automatic analysis software is also helping to improve speed while reducing cost and improving overall job quality. Production rates are close to double from the previous inspection system. (author)

  8. Operation and maintenance outage experience of reactor internal pump

    International Nuclear Information System (INIS)

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

  9. Availability and outage frequency of repairable parallel unit systems

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Tourki, Kamel

    2013-02-01

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

  12. Nuclear steam generator inspection and repair using robotics

    International Nuclear Information System (INIS)

    Although the steam generators in pressurized water reactors were not originally envisioned as high maintenance components, quite the opposite has been experienced. Steam generator work, including periodic inspection, tube plugging, sleeving, machining and welding not only represents a sizeable portion of an outage schedule, but can be a major contributor to personnel radiation exposure. This last area, radiation exposure, is one of the primary reasons for development of the remotely operated equipment discussed in the paper

  13. Calculation of the thicknesses of the walls of the radiographic inspection building of the NKS enterprise; Calculo de los espesores de los muros del edificio de inspeccion radiografica de la empresa NKS

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez A, G.; Gutierrez R, C

    1983-07-15

    During the month of February, 1983, the Structural Civil Department of the Latin American of Engineering, S.A. de C.V. company (LATISA), outline to the Engineering and Industry Applications Management of the ININ that the industrial group NKS had taken charge them the design of a building where it would lodge a linear electron accelerator of 4 MeV, one source of Co-60 of 30 Ci and an X-ray equipment, tube type, of range of 60 to 300 KV and that to make the design they required to know the necessary thickness of the walls, doors and roof to protect to the workers, outside of the building, of the X and gamma radiations generated by the sources mentioned during the radiographic inspections of metal-mechanical pieces. (Author)

  14. Inspection method as a tool for 'Bouwtransport'. Quality of building facade determines the functioning of installations; Ontwikkelde inspectiemethodiek Bouwtransport kan helpen. Kwaliteit gebouwschil bepaalt functioneren installaties

    Energy Technology Data Exchange (ETDEWEB)

    Ten Bolscher, G.H. [DWA installatie- en energieadvies, Bodegraven (Netherlands)

    2012-02-15

    Buildings that have energy efficient or sustainable energy systems with low temperature heating have high demands when it comes to the constructional quality. Defects in the building facade often cause comfort complaints resulting from draught or cold radiation. To support local authorities and construction parties, the Dutch province of North Holland developed an inspection method: BouwTransparant. This instrument supports local authorities, environmental agencies and construction parties in realizing the EPC requirements. [Dutch] Gebouwen met energie-efficiente of duurzame energiesystemen met lage-temperatuurverwarming stellen hoge eisen aan de bouwkundige kwaliteit. Gebreken in de gebouwschil veroorzaken vaak comfortklachten door tocht of koudestraling. Om gemeenten en bouwende partijen te ondersteunen heeft de provincie Noord-Holland een inspectiemethodiek ontwikkeld: BouwTransparant. Dit is een instrument om gemeenten, milieudiensten en bouwende partijen te ondersteunen bij de realisatie van de EPC-eisen.

  15. Inspection scheme

    International Nuclear Information System (INIS)

    As part of the Danish RERTR Program, three fuel elements with LEU U3O8-Al fuel and three fuel elements with LEU U3Si2-Al fuel were manufactured by NUKEM for irradiation testing in the DR-3 reactor at the Risoe National Laboratory in Denmark. The inspection scheme for the elements with U3O8-Al fuel is presented here as an illustration only. The inspection scheme for the elements with U3Si2-Al fuel was very similar. In this example, all document numbers, drawing numbers, and form numbers have been deleted or replaced with a generic identification. (author)

  16. Safety review, assessment and inspection for nuclear power plants

    International Nuclear Information System (INIS)

    The National Nuclear Safety Administration (NNSA) always laid stress on the surveillance of operating NPP. Considering that compared with international level there are some disparities in Chinese NPPs about the number of scram, the number of operation event and the ratio of human factor to operation event, and the problems about reliability of components have not revealed themselves entirely because of the short operating duration, by means of improving the routine inspection and the refueling outage inspection, carrying out the operational events analysis and operational experience feedback, the NNSA promoted effectively the safety level of NPP operation in China

  17. Occurrence of moisture problems in schools in three countries from different climatic regions of Europe based on questionnaires and building inspections - the HITEA study

    NARCIS (Netherlands)

    Haverinen-Shaughnessy, U.; Borras-Santos, A.; Turunen, M.; Zock, J.P.; Jacobs, J.H.; Krop, E.J.M.; Casas, L.; Shaughnessy, R.; Täubel, M.; Heederik, D.; Hyvärinen, A.; Pekkanen, J.; Nevalainen, A.

    2012-01-01

    Abstract  The aim of this study was to assess occurrence of dampness and mold in school buildings in three European countries (the Netherlands, Spain, and Finland), representing different climatic regions. An assessment was performed utilizing both questionnaires and on-site building investigations,

  18. Outage analysis for underlay relay-assisted cognitive networks

    KAUST Repository

    Tourki, Kamel

    2012-12-01

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

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

    Science.gov (United States)

    Witthaut, Dirk; Timme, Marc

    2012-08-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Sugimoto, Hitoshi; Shimasaki, Katsuhiko

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Germain, Shawn

    2015-02-01

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

  4. 77 FR 63757 - Extension of the Commission's Rules Regarding Outage Reporting to Interconnected Voice Over...

    Science.gov (United States)

    2012-10-17

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

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

    OpenAIRE

    Anjana Shukla Dr. Vineeta Saxena Nigam

    2011-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

  8. Optimizing pre-service inspection data

    International Nuclear Information System (INIS)

    The phenomenon of intergranular stress corrosion cracking (IGSCC) in nuclear power plant piping systems has been the single biggest factor in an evolution that has changed and continues to change in-service inspection practices and philosophy throughout the industry. In-service inspection has been found to deal with several distinct phases of the problem. At the onset, existing technology was demonstrated to be unable to detect IGSCC adequately. This inability to detect IGSCC was soon overcome. However, it immediately pointed out the difficulties associated with the discrimination between IGSCC and other harmless metallurgical conditions. On the heels of detection and discrimination came problems associated with determining crack size and the monitoring of overlayed flaws. A wealth of information has been written on all phases of IGSCC; however, one particular aspect has as of yet seen little attention. With an increasing number of plants choosing to replace flawed pipe, the pre-service inspection of the replaced piping demands increased attention. The lessons learned through inspection for IGSCC need again to be applied to the replacement piping. Through increased attention at installation, many of the difficulties associated with proper inservice inspection may be reduced or eliminated, thereby realizing an economy in outage scheduling, personnel exposure, and, overall, a more reliable in-service examination

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

    KAUST Repository

    Amin, Osama

    2016-03-29

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  12. Application of Eddy current examination in in-service inspection

    International Nuclear Information System (INIS)

    In-service inspection (ISI) of generating plant components also called as periodic inspection is generally carried out to provide assurance against plant outages, increase safety of plant, personnel and environment and avoid economic loss from component failure and production loss. However in-service inspection ensures that no unacceptable degradation in component quality is occurring and probability of failures remains acceptably low for the life of the plant. ET- Eddy Current Testing and its use for in-service inspection are discussed. Eddy current examination is one of the Non-Destructive Testing methods used basically for conducting materials. It is considered a relatively recent addition to NDT family but it is actually one of the oldest methods used for NDT

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    Klinger, Chaamala; Landeg, Owen; Murray, Virginia

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  19. 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.

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

    DEFF Research Database (Denmark)

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

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

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

    CERN Document Server

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Alabbasi, Abdulrahman

    2016-07-13

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2012-12-01

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

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

    Directory of Open Access Journals (Sweden)

    Liang Zhao

    2014-07-01

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

  8. In-service inspection a tool for ageing management

    International Nuclear Information System (INIS)

    The in-service inspection (ISI) programme for nuclear power plants is specified and cover generally all safety-related components. The assessment of residual life of components is important for avoiding unplanned outages and improving the availability factor of the station. The specified ISI programmes with slight modification can be purposefully utilised to meet this objective. This paper gives a brief outlook of the efforts made in this direction at Narora Atomic Power Station (NAPS), with particular reference to pipe lines, heat exchangers and their supports etc. (author)

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

    Directory of Open Access Journals (Sweden)

    Hachimenum N. Amadi

    2015-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-01

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

  11. Inspection of dissimilar metal welds in reactor pressure vessels in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Gadea, J.R.; Regidor, J.J.; Pelaez, J.A.; Serrano, P. [Tecnatom, S.A., San Sebastian de los Reyes, Madrid (Spain)

    2011-07-01

    MRP-139 recommendations for inspection of dissimilar metal (DM) welds in PWR vessels were launched in the last years in the USA. Basically, it increases the frequency of the examinations in these type of welds, with major emphasis in the hot loops, adding one intermediate inspection at the ten years interval in outlet nozzles. The spanish nuclear power plants (NPP's) have begun the implementation of this type of inspections on the vessel nozzles DM welds. As this type of inspections could have an impact in the critical path duration of the outage, it is necessary the use of a mechanical equipment able to examine the nozzles DM welds in a short vessel occupation time (VOT) with high quality, qualified techniques and minimum requirements of the refuelling platform. Tecnatom undertook the design and development of a new more advanced equipment, named TENIS-DM, for implementing the reactor pressure vessel (RPV) nozzles examination. This equipment was designed in order to accomplish the stringent requirements and the updated examination techniques; it was used for the inspection of the DM welds of Asco 1 NPP inlet and outlet nozzles in March 2011. Examination techniques and procedures were qualified through the GRUVAL validation program, based on ENIC methodology. Mechanical scanner was equipped with a large number of examination probes, and TV cameras -for visual inspection and also for monitoring the ultrasonic inspections. A remote operated submarine was also used to give support to the operational personnel during the manipulation of the equipment and its movements from one nozzle to the others. During two months before the inspection, tests of the complete inspection system were made on a nozzle mock-up installed in a 4 meters deep well at Tecnatom's facilities; this scenario was also used during the training sessions of the inspection crew. The defined technical and practical objectives were achieved: use of qualified techniques and minimal impact on the

  12. Inspection of dissimilar metal welds in reactor pressure vessels in Spain

    International Nuclear Information System (INIS)

    MRP-139 recommendations for inspection of dissimilar metal (DM) welds in PWR vessels were launched in the last years in the USA. Basically, it increases the frequency of the examinations in these type of welds, with major emphasis in the hot loops, adding one intermediate inspection at the ten years interval in outlet nozzles. The spanish nuclear power plants (NPP's) have begun the implementation of this type of inspections on the vessel nozzles DM welds. As this type of inspections could have an impact in the critical path duration of the outage, it is necessary the use of a mechanical equipment able to examine the nozzles DM welds in a short vessel occupation time (VOT) with high quality, qualified techniques and minimum requirements of the refuelling platform. Tecnatom undertook the design and development of a new more advanced equipment, named TENIS-DM, for implementing the reactor pressure vessel (RPV) nozzles examination. This equipment was designed in order to accomplish the stringent requirements and the updated examination techniques; it was used for the inspection of the DM welds of Asco 1 NPP inlet and outlet nozzles in March 2011. Examination techniques and procedures were qualified through the GRUVAL validation program, based on ENIC methodology. Mechanical scanner was equipped with a large number of examination probes, and TV cameras -for visual inspection and also for monitoring the ultrasonic inspections. A remote operated submarine was also used to give support to the operational personnel during the manipulation of the equipment and its movements from one nozzle to the others. During two months before the inspection, tests of the complete inspection system were made on a nozzle mock-up installed in a 4 meters deep well at Tecnatom's facilities; this scenario was also used during the training sessions of the inspection crew. The defined technical and practical objectives were achieved: use of qualified techniques and minimal impact on the critical

  13. Aspects of Inspection Planning

    DEFF Research Database (Denmark)

    Faber, M. H.; Sørensen, John Dalsgaard

    Inspection planning for systems is considered with special emphasis to the effect of the quality of inspections on the system reliability and the probability of repair. Inspection quality is described and discussed in terms of inspection reliability and inspection coverage where the latter is set...... theoretical framework for updating of the reliability of components and systems on the basis of inspection results is outlined. Systems representative for inspection planning of different engineering systems subjected to typical deterioration processes are presented. Numerical simulation studies are performed...... on the presented systems and the effect of inspection reliability and coverage is investigated for systems of different sizes. The results of the studies illustrate the effect of inspections in practical inspection problems and can be used as an initial guideline for selecting the quality of...

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

    Directory of Open Access Journals (Sweden)

    Romain Couillet

    2009-01-01

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

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

    KAUST Repository

    Benjillali, Mustapha

    2010-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Hussein M.A. Basi

    2004-01-01

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

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

    KAUST Repository

    Benjillali, Mustapha

    2010-01-01

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

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

    KAUST Repository

    Hyadi, Amal

    2015-01-07

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Al-Murad, Tamim M.

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Xiaoyu Hu

    2007-11-01

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

  12. Characteristics of outage radiation fields around various reactor components

    International Nuclear Information System (INIS)

    Full text: Activity monitoring surveys, consisting of gamma spectroscopy and dose rate measurements, of various CANDU station components such as the reactor face, feeder cabinet, steam generators and moderator heat exchangers are often performed during shutdown in order to trend the transport of activity around the primary heat transport and moderator systems. Recently, the increased dose expenditure for work such as feeder inspection and replacement in the reactor vault has also spurred interest in improved characterization of the reactor face fields to facilitate better ALARA decision making and hence a reduction in future dose expenditures. At present, planning for reactor face work is hampered by insufficient understanding of the relative contribution of the various components to the overall dose. In addition to the increased dose expenditure for work at the reactor face, maintenance work associated with horizontal flux detectors and liquid injection systems has also resulted in elevated dose expenditures. For instance at Darlington, radiation fields in the vicinity of horizontal flux detectors (HFD) and Liquid Injection Shutdown System (LISS) nozzle bellows are trending upwards with present contact fields being in the range 16-70 rem/h and working distance fields being in the range 100-500 mrem/h. This paper presents findings based on work currently being funded by the CANDU Owners Group. Measurements were performed at Ontario Power Generation's Pickering and Darlington nuclear stations. Specifically, the following are addressed: Characteristics of Reactor Vault Fields; Characteristics of Steam Generator Fields; Characteristics of Moderator Heat Exchanger Fields. Measurements in the reactor vault were performed at the reactor face, along the length of end fittings, along the length of feeders, at the bleed condenser and at the HFD and LISS nozzle bellows. Steam generator fields were characterized at various elevations above the tube sheet, with and without the

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

    International Nuclear Information System (INIS)

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

  14. Fuel channel in-service inspection programs program design for maximum cost effectiveness

    International Nuclear Information System (INIS)

    Inspection is an integral part of fuel channel life management strategy. Inspection data is used to assess the state of reactor core integrity and provide the information necessary to optimize long term maintenance programs. This paper will provide an overview of the structured approach to developing fuel channel inspection programs within OHN. The inspection programs are designed to balance the resources utilized (cost, outage time, and dose expenditure) with the benefits provided by the inspection data obtained (improved knowledge of component status, degradation mechanisms and rates, etc..). The CANDU community has yet to have a fuel channel operate for a full 30 year design life. Since research programs can not fully simulate reactor operating conditions, inspections become an essential feature of the life management strategy as the components age. Inspection programs often include activities designed to develop predictive capability for long term fuel channel behaviour and provide early warning of changes in behaviour. It should be noted that although this paper addresses the design of fuel channel inspection programs, the basic principles presented can be applied to the design of inspection programs for any major power plant component or system. (author)

  15. CRDM nozzle inspection/repair

    International Nuclear Information System (INIS)

    The susceptibility of Alloy 600 to Primary Water Stress Corrosion Cracking (PWSCC) continues to plague nuclear power plants. Recently, the problem PWSCC has manifested itself in Control Rod Drive Mechanism (CRDM) head penetrations in nuclear plants in Europe and the U.S. B and W Nuclear Technologies (BWNT) has been involved in responding to this potentially industry-wide concern through the B and W Owners Group (B and WOG). The program also includes work performed in cooperation with the Nuclear Energy Institute (NEI) Task Force and other Owners Groups. BWNT, building on our parent company's (Framatome) technology, has also developed a fully integrated service package and robotic manipulator to inspect and repair CRDM head penetrations for U.S. utilities. This paper describes the work performed by the B and WOG to address this issue globally, and the overall range of inspection and repair tooling and processes developed by Framatome and BWNT to address this issue. (author). 6 figs

  16. Software Formal Inspections Guidebook

    Science.gov (United States)

    1993-01-01

    The Software Formal Inspections Guidebook is designed to support the inspection process of software developed by and for NASA. This document provides information on how to implement a recommended and proven method for conducting formal inspections of NASA software. This Guidebook is a companion document to NASA Standard 2202-93, Software Formal Inspections Standard, approved April 1993, which provides the rules, procedures, and specific requirements for conducting software formal inspections. Application of the Formal Inspections Standard is optional to NASA program or project management. In cases where program or project management decide to use the formal inspections method, this Guidebook provides additional information on how to establish and implement the process. The goal of the formal inspections process as documented in the above-mentioned Standard and this Guidebook is to provide a framework and model for an inspection process that will enable the detection and elimination of defects as early as possible in the software life cycle. An ancillary aspect of the formal inspection process incorporates the collection and analysis of inspection data to effect continual improvement in the inspection process and the quality of the software subjected to the process.

  17. Technical objectives of inspection

    International Nuclear Information System (INIS)

    The various technical objectives of inspection are discussed in a very general manner. The discussion includes how the inspection function is related to the assumed threat, the various degrees of assurance and reliance on criteria, and the hierarchy of assurance which is obtained from the various types or levels of inspection

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

    Directory of Open Access Journals (Sweden)

    HUANG, T.

    2014-08-01

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

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

    International Nuclear Information System (INIS)

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

  20. 36 CFR 702.9 - Inspection of property.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Inspection of property. 702.9 Section 702.9 Parks, Forests, and Public Property LIBRARY OF CONGRESS CONDUCT ON LIBRARY PREMISES § 702.9 Inspection of property. (a) Individuals entering Library buildings do so with the understanding that all property in their possession...

  1. Approximations in Inspection Planning

    DEFF Research Database (Denmark)

    Engelund, S.; Sørensen, John Dalsgaard; Faber, M. H.; Bloch, Allan

    2000-01-01

    . One of the more important of these approximations is the assumption that all inspections will reveal no defects. Using this approximation the optimal inspection plan may be determined on the basis of conditional probabilities, i.e. the probability of failure given no defects have been found by the......Planning of inspections of civil engineering structures may be performed within the framework of Bayesian decision analysis. The effort involved in a full Bayesian decision analysis is relatively large. Therefore, the actual inspection planning is usually performed using a number of approximations...... inspection. In this paper the quality of this approximation is investigated. The inspection planning is formulated both as a full Bayesian decision problem and on the basis of the assumption that the inspection will reveal no defects....

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

    Science.gov (United States)

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

    2014-12-01

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

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

    International Nuclear Information System (INIS)

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

  4. Regulatory inspection practices on fuel elements and core lay-out at NPPs

    International Nuclear Information System (INIS)

    The basic description of the reactor core of a nuclear power plant (NPP) is an important part of the Safety Analysis Report in all countries. Due to increased interest by regulatory authorities in the Member countries, in 1996 WGIP proposed looking at inspection aspects on fuel elements and core lay-out at nuclear power plants. The CNRA subsequently approved proceeding with this report. The report deals primarily with inspection practices and inspection requirements during nuclear power plant (NPP) operation with special emphasis on refuelling procedures. All license related topics, such as fuel and core design (mechanical, neutronic, thermal-hydraulic), as well as inspection philosophy and practices on fuel fabrication are included as appropriate serving as background information and may not be completely described. WGIP members describe their country's inspection programme according to the structure of a questionnaire (appendix 1). The individual contributions are contained in the appendix 2 and are compiled within the main chapters (1 through 3). Report Structure: 1. Licensing and Quality Assurance (QA) requirements for nuclear fuel; 2. Regulatory inspection programme during NPP operation and refuelling outages; 3. Procedures for inspection practices and inspection programme. Appendix: Questionnaire and Country specific contributions. Contributions are presented by Belgium, Finland, France, Germany, Hungary, Italy, Japan, Mexico, The Netherlands, Spain, Sweden, Switzerland, United Kingdom, USA

  5. Use of a remotely operated vehicle (submarine) for nuclear plant inspections

    International Nuclear Information System (INIS)

    This paper describes the use of a specialized remotely operated vehicle (ROV) to perform visual inspections underwater in nuclear power plant. An underwater ROV, or minisubmarine, for visual inspections has several advantages over the more traditional camera-on-a-pole techniques and can perform some inspections easily that in the past were considered too difficult to conduct remotely. Other advantages include radiation dose savings, outage critical path savings, and reduced manpower and expenses. Some of the principal advantages of the ROV is its maneuverability, accessibility, and stability. This ROV is remarkably stable and has some stationary positioning capabilities. A necessary inspection inside a boiling water reactor (BWR) steam drier would not have been practical using other techniques. Containment suppression pool inspection was once considered nearly impossible using conventional remote inspection equipment; however, the ROV has reduced this mammoth task to one of a few person-days without the risk of having a diver in the water. Inside the BWR vessel this unit can inspect everything above the top guide. Because of the radiation-resistant color camera, the ROV proved extremely helpful during fuel movement for fuel assembly identification, orientation, and core verification. Fuel pools, reactor cavities, and storage pools all have liner seam welds that the ROV can readily inspect while they are flooded without interfering with other work occurring simultaneously

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-09-01

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

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

    Science.gov (United States)

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

    2016-02-01

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

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

    KAUST Repository

    Rezki, Zouheir

    2014-06-01

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

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

    Directory of Open Access Journals (Sweden)

    Wenjie Peng

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Omitaomu, Olufemi A.; Fernandez, Steven J.

    2016-01-05

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

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

    KAUST Repository

    Khafagy, Mohammad Galal

    2013-02-25

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

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

    OpenAIRE

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

    2010-01-01

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

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

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

    Jedlovec, Gary; Molthan, Andrew

    2008-01-01

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

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

    CERN Document Server

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Bao, Vo Nguyen Quoc; Duong, Trung Quang

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

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

    2015-01-01

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

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

    OpenAIRE

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-15

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

  3. Inspection device for buried equipment

    International Nuclear Information System (INIS)

    In an inspection device for a buried equipment, a rail is suspended at the upper portion of a vessel of a pit-vessel type pump buried in a plant building floor, and a truck movable vertical in the vessel along the rail, and an ultrasonic wave probe contained in the truck and urged to the vessel by an electromagnet are disposed. In addition, an elevator moving vertically along a shaft is disposed, and an arm having the ultrasonic probe disposed at the end portion and driven by a piston are disposed to the elevator. The ultrasonic wave probe moves vertically together with the truck along the rail in the vessel while being urged to the vessel by the electromagnet to inspect and measure the state at the inner and outer surfaces of the vessel. Further, the length of the arm is controlled so as to set a predetermined distance between the ultrasonic wave probe and the vessel. Subsequently, the elevator is moved vertically along a shaft passing through a shaft hole of a mount, and the shaft is rotated thereby enabling to inspect and measure the state of the inner and outer surfaces of the vessel. (N.H.)

  4. An Extensible Sensing and Control Platform for Building Energy Management

    Energy Technology Data Exchange (ETDEWEB)

    Rowe, Anthony [Carnegie Mellon Univ., Pittsburgh, PA (United States); Berges, Mario [Carnegie Mellon Univ., Pittsburgh, PA (United States); Martin, Christopher [Robert Bosch LLC, Anderson, SC (United States)

    2016-04-03

    The goal of this project is to develop Mortar.io, an open-source BAS platform designed to simplify data collection, archiving, event scheduling and coordination of cross-system interactions. Mortar.io is optimized for (1) robustness to network outages, (2) ease of installation using plug-and-play and (3) scalable support for small to large buildings and campuses.

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

    Science.gov (United States)

    Anderson, G. Brooke; Bell, Michelle L.

    2012-01-01

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

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

    CERN Document Server

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

    2010-01-01

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

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

    KAUST Repository

    Benjillali, Mustapha

    2013-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; TIAN Hui

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

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

    Directory of Open Access Journals (Sweden)

    Zhi Chen

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-15

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

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

    Directory of Open Access Journals (Sweden)

    Guanyao Du

    2015-01-01

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

  15. Remote robotic inspection of irregular surfaces on the inner diameter of the AECL NRU reactor

    Energy Technology Data Exchange (ETDEWEB)

    Zeller, B., E-mail: bzeller@eclipsescientific.com [Eclipse Scientific Ltd., Waterloo, Ontario (Canada); Lombardi, L., E-mail: llombardi@utex.com [Utex Scientific Instruments, Mississauga, Ontario (Canada); Cyr, P., E-mail: pcyr@eclipsescientific.com [Eclipse Scientific Ltd., Waterloo, Ontario (Canada); Mair, H.D., E-mail: dmair@utex.com [Utex Scientific Instruments, Mississauga, Ontario (Canada); Ginzel, R., E-mail: rginzel@eclipsescientific.com [Eclipse Scientific Ltd., Waterloo, Ontario (Canada)

    2013-01-15

    In May of 2009, the NRU (National Research Universal) reactor was forced to shut down after a small heavy water leak. In 2009-2010 repairs were performed in order to restart medical isotope production mid-August 2010. Since the NRU vessel's return to service, a series of periodic inspections is required to ensure the safe operation of the reactor. Eclipse Scientific in collaboration with Utex Scientific Instruments and Liburdi Automation developed the NDE inspection system for the In-Service Inspection program of the NRU vessel. In addition to the difficult environmental, delivery and inspection circumstances the inspection team was faced with the problem of doing an immersion inspection of the inside surface of the reactor vessel through a small 120 mm access port at a distance of more than 10 m to the inspection area at the bottom of the reactor. The vessel was built over 50 years ago and as the inner surface was modified by the repair program during the forced outage, there were no accurate drawings of the inner surface of the vessel that an automated system could rely upon. Eclipse Scientific in collaboration with Liburdi Automation developed a robotic arm designed to enter from the remote access port to deploy the Phased Array and Eddy Current Array inspection heads into the reactor vessel. The motion control and data acquisition system was developed in collaboration with Utex Scientific Instruments using their Inspection Ware software. This paper will highlight the challenges faced in the development of an inspection system capable of using ultrasonic signals to learn a surface and, using this acquired surface topography, effectively and safely deploy and articulate the different inspection heads required to perform the In-Service Inspection of the NRU vessel. (author)

  16. Remote robotic inspection of irregular surfaces on the inner diameter of the AECL NRU reactor

    International Nuclear Information System (INIS)

    In May of 2009, the NRU (National Research Universal) reactor was forced to shut down after a small heavy water leak. In 2009-2010 repairs were performed in order to restart medical isotope production mid-August 2010. Since the NRU vessel's return to service, a series of periodic inspections is required to ensure the safe operation of the reactor. Eclipse Scientific in collaboration with Utex Scientific Instruments and Liburdi Automation developed the NDE inspection system for the In-Service Inspection program of the NRU vessel. In addition to the difficult environmental, delivery and inspection circumstances the inspection team was faced with the problem of doing an immersion inspection of the inside surface of the reactor vessel through a small 120 mm access port at a distance of more than 10 m to the inspection area at the bottom of the reactor. The vessel was built over 50 years ago and as the inner surface was modified by the repair program during the forced outage, there were no accurate drawings of the inner surface of the vessel that an automated system could rely upon. Eclipse Scientific in collaboration with Liburdi Automation developed a robotic arm designed to enter from the remote access port to deploy the Phased Array and Eddy Current Array inspection heads into the reactor vessel. The motion control and data acquisition system was developed in collaboration with Utex Scientific Instruments using their Inspection Ware software. This paper will highlight the challenges faced in the development of an inspection system capable of using ultrasonic signals to learn a surface and, using this acquired surface topography, effectively and safely deploy and articulate the different inspection heads required to perform the In-Service Inspection of the NRU vessel. (author)

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

    International Nuclear Information System (INIS)

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

  18. Contineous inspection during fabrication

    International Nuclear Information System (INIS)

    The continuous inspection process is a method used in a Manufacturing plant in order to obtain a fast feed-back between inspection results and manufacturing process. It often requires a specific approach in design and a wide cooperation between Engineering and Manufacturing people. This method leads to additional advantages such as high motivation, and better quality knowledge. (orig.)

  19. Eddy currents inspection of CANDU steam generator' tubes using Zetec's ZR-1 Robot: experience in Romania

    International Nuclear Information System (INIS)

    'Full text:' The paper introduces the new ZR-1 Robot System for Inspection and Maintenance/Repair from Zetec that combines the newest state-of-the-art robotics technology with Zetec experience-based innovation to address the needs for inspection and repair of steam generators. The multipurpose ZR-1 can be easily installed to perform the necessary eddy current inspection and remain installed ready for follow-up maintenance and repair. It has superior technical performances and a modular three axis motion of arm that enables 100% coverage of tube sheet. Automated, repeatable, and precise positioning of toolheads, ensures accurate delivery and reducing costly rework and reduces inspection time by 30%. The modular, lightweight, and portable design permits easy assembly and disassembly through small openings and it reduces setup/tear down time by 30%. The first deployment of the new ZR-1 Robot was made in September 2004 at the Cernavoda NPP inspection outage. The Cernavoda plant has four Advanced 600 MW CANDU-design generators that have been in service since 1996. The paper presents also the Zetec's filed experience and customer experience with this system. It describes the equipment setup in Cernavoda's generator mock-up, functional testes and calibration. Finally, provides details on the execution of the inspection, options for standardizing the inspection techniques and conclusions. (author)

  20. Eddy current arrays for wheel inspection

    Science.gov (United States)

    Leclerc, Rémi

    2001-04-01

    Wheel inspections are routine and very time-consuming, especially for large aircraft wheels where a single-coil probe is moved manually taking precious long minutes. Eddy current arrays can decrease the inspection time by reducing to one the number of rotations needed to completely cover the wheel surface. Since the EC array probe fits the profile of the wheel, manipulation is easy and the lift-off is kept constant improving signal quality. C-scan displays assist the analysis and help locate the defect by dividing the inspected wheel surface into a small grid. Furthermore, the impedance plane and the strip chart, for all the channels used to build the C-scan, are accessible to provide better sizing accuracy of the defect.

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

    KAUST Repository

    Hyadi, Amal

    2012-04-01

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

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

    CERN Document Server

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

    2013-01-01

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

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

    KAUST Repository

    Tourki, Kamel

    2010-11-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

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

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

    International Nuclear Information System (INIS)

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

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

    OpenAIRE

    2014-01-01

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

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

    KAUST Repository

    Khan, Fahd Ahmed

    2012-10-01

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

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

    DEFF Research Database (Denmark)

    Maham, Behrouz; Popovski, Petar

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    DEFF Research Database (Denmark)

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

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

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

    KAUST Repository

    Mehbodniya, Abolfazl

    2011-09-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  15. Magnetic rubber inspection (MRI)

    International Nuclear Information System (INIS)

    Magnetic Rubber Inspection (MRI) was developed to inspect for small cracks and flaws encountered in high performance aircraft. A formula of very fine magnetic particles immersed in a room temperature curing rubber is catalysed and poured into dams (retainers) on the surface of the part to be inspected. Inducing a magnetic field then causes the particles to be drawn to discontinuities in the component under test. These indicating particles are held to the discontinuity by magnetic attraction, as the rubber cures. The solid rubber cast (Replica) is then removed and examined under a microscope for indicating lines of particle concentrations. 3 refs., 6 figs

  16. The Status and Inspection of Bottom Mounted Instrumentation Nozzle in Korea

    International Nuclear Information System (INIS)

    The PWSCC Cracking of Alloy 600 material has been issued since CRDM Penetration cracking of Bugey in France in 1990's. And J-groove weld cracking of CRDM at Oconee and PCR Nozzle cracking at Wolf Creek in USA were raising concern of the integrity for Dissimilar Metal Weld of Alloy 600. BMI(Bottom Mounted Instrumentation) Nozzle cracks were found at Takahama unit 1 in Japan and South Texas Project unit 1 in USA in 2003. And recent cracks of Reactor Head Vent line at Yonggwang unit 3 in Korea are enough to cause worry about the integrity for BMI Nozzles in Korea. BMI inspections of Westinghouse type plant were performed by KPS for Kori unit 1 in 2006, Ulchin unit 2 in 2007, and Kori unit 3 in 2008. The first inspection of OCR-1000 plant was carried out on May 2011 at Yonggwang unit 3. KPS developed the inspection technique of OCR-1000 plant for End Effector Module and controller, a quarterly actual sized Bottom head Mock up, Inspection probes meeting the regulatory guide lines and typical configuration of OCR-1000 plant. Two specimens with actual PWSCC cracks were used to demonstrate the Inspection technique of Detection and Sizing. and the quarterly actual sized Bottom head Mock up was very meaningful to check the Interference during the inspection by narrow gap between newly developments led to a successful inspection of the BMI Inspection. And the inspection was concurrently performed with 10 year Reactor Vessel ICI without hurting any critical path of the outage. This BMI inspection is contributing to keep Operational Safety of plants by prevention of Leakage at BMI nozzle and weld. And performing 10 Year ISI for BMI nozzle is very effective to prevent BMI nozzle Break by detecting PWSCC Initiation per PFM Sensitivity study

  17. Inception report and gap analysis. Boiler inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-06-01

    This inception and gap analysis report on boilers in Latvia, has been prepared in the framework of the 'Implementation of the EU directive on energy performance of buildings: development of the Latvian Scheme for energy auditing of building and inspection of boilers'. The report is the basis for the establishment of training of boiler inspectors; it develops a gap analysis for better understanding and estimating the number of installations in Latvia and develops suggestions for the institutional set up. In particular includes information on existing standard and regulation on boiler, suggestion for the content of the training material of experts for boiler inspections and a syllabus of the training course. A specific section is dedicated to the suggestion for certification system of trained boiler inspectors. (au)

  18. Waste Calcining Facility remote inspection report

    International Nuclear Information System (INIS)

    The purpose of the Waste Calcining Facility (WCF) remote inspections was to evaluate areas in the facility which are difficult to access due to high radiation fields. The areas inspected were the ventilation exhaust duct, waste hold cell, adsorber manifold cell, off-gas cell, calciner cell and calciner vessel. The WCF solidified acidic, high-level mixed waste generated during nuclear fuel reprocessing. Solidification was accomplished through high temperature oxidation and evaporation. Since its shutdown in 1981, the WCFs vessels, piping systems, pumps, off-gas blowers and process cells have remained contaminated. Access to the below-grade areas is limited due to contamination and high radiation fields. Each inspection technique was tested with a mock-up in a radiologically clean area before the equipment was taken to the WCF for the actual inspection. During the inspections, essential information was obtained regarding the cleanliness, structural integrity, in-leakage of ground water, indications of process leaks, indications of corrosion, radiation levels and the general condition of the cells and equipment. In general, the cells contain a great deal of dust and debris, as well as hand tools, piping and miscellaneous equipment. Although the building appears to be structurally sound, the paint is peeling to some degree in all of the cells. Cracking and spalling of the concrete walls is evident in every cell, although the east wall of the off-gas cell is the worst. The results of the completed inspections and lessons learned will be used to plan future activities for stabilization and deactivation of the facility. Remote clean-up of loose piping, hand tools, and miscellaneous debris can start immediately while information from the inspections is factored into the conceptual design for deactivating the facility

  19. Pressurizer manway and inspection port re-engineering

    International Nuclear Information System (INIS)

    The Pressurizer Vessels at Darlington Generation Station have had problems with leaks form the gasketed joints. The Pressurizer vessel is part of the Pressure and Inventory Control System, which produces and controls the coolant in the Heat Transport System, which facilitates the transfer of heat from the fission process to the steam generators. Figure 1 illustrates the location of the 18-inch ID manway and the 12-inch ID inspection Port. Figure 2 shows the typical double-gasketed bolted joint, which provides a double barrier against D2O leakage into containment. Leakage past the first gasket to the HT D2O Collection System via the inner gasket leak-off line is used to detect and monitor inner gasket seal failures. Over the last number of years, the gasketed joints have required significant maintenance. Occasionally, leakage to the D2O Collection System from failure of the inner gasket seals has resulted in additional cost to upgrade the D2O and return it to the PHT system. Larger leaks have resulted in minor erosion damage to the gasket sealing surfaces and in one instance, a leak through the outer gasket contributed to a forced outage. This paper describes the seal-welded diaphragm modification to the Inspection Port and Manway closures to replace the original gasketed connections and eliminate leakage. The modification was designed, analytically qualified and field installed by Babcock and Wilcox Canada (BWC) at the Darlington Nuclear Power Station on all four units spanning five outages. The pressurizer vessels are ASME Section III Class 1 components and were designed and manufactured by Dominion Bridge Ltd. (author)

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

    International Nuclear Information System (INIS)

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

  1. Guidelines for software inspections

    Science.gov (United States)

    1983-01-01

    Quality control inspections are software problem finding procedures which provide defect removal as well as improvements in software functionality, maintenance, quality, and development and testing methodology is discussed. The many side benefits include education, documentation, training, and scheduling.

  2. Information-Driven Inspections

    International Nuclear Information System (INIS)

    New uranium enrichment capacity is being built worldwide in response to perceived shortfalls in future supply. To meet increasing safeguards responsibilities with limited resources, the nonproliferation community is exploring next-generation concepts to increase the effectiveness and efficiency of safeguards, such as advanced technologies to enable unattended monitoring of nuclear material. These include attribute measurement technologies, data authentication tools, and transmission and security methods. However, there are several conceptual issues with how such data would be used to improve the ability of a safeguards inspectorate such as the International Atomic Energy Agency (IAEA) to reach better safeguards conclusions regarding the activities of a State. The IAEA is pursuing the implementation of information-driven safeguards, whereby all available sources of information are used to make the application of safeguards more effective and efficient. Data from continuous, unattended monitoring systems can be used to optimize on-site inspection scheduling and activities at declared facilities, resulting in fewer, better inspections. Such information-driven inspections are the logical evolution of inspection planning - making use of all available information to enhance scheduled and randomized inspections. Data collection and analysis approaches for unattended monitoring systems can be designed to protect sensitive information while enabling information-driven inspections. A number of such inspections within a predetermined range could reduce inspection frequency while providing an equal or greater level of deterrence against illicit activity, all while meeting operator and technology holder requirements and reducing inspector and operator burden. Three options for using unattended monitoring data to determine an information-driven inspection schedule are to (1) send all unattended monitoring data off-site, which will require advances in data analysis techniques to

  3. Information-Driven Inspections

    Energy Technology Data Exchange (ETDEWEB)

    Laughter, Mark D [ORNL; Whitaker, J Michael [ORNL; Lockwood, Dunbar [U.S. Department of Energy, NNSA

    2010-01-01

    New uranium enrichment capacity is being built worldwide in response to perceived shortfalls in future supply. To meet increasing safeguards responsibilities with limited resources, the nonproliferation community is exploring next-generation concepts to increase the effectiveness and efficiency of safeguards, such as advanced technologies to enable unattended monitoring of nuclear material. These include attribute measurement technologies, data authentication tools, and transmission and security methods. However, there are several conceptual issues with how such data would be used to improve the ability of a safeguards inspectorate such as the International Atomic Energy Agency (IAEA) to reach better safeguards conclusions regarding the activities of a State. The IAEA is pursuing the implementation of information-driven safeguards, whereby all available sources of information are used to make the application of safeguards more effective and efficient. Data from continuous, unattended monitoring systems can be used to optimize on-site inspection scheduling and activities at declared facilities, resulting in fewer, better inspections. Such information-driven inspections are the logical evolution of inspection planning - making use of all available information to enhance scheduled and randomized inspections. Data collection and analysis approaches for unattended monitoring systems can be designed to protect sensitive information while enabling information-driven inspections. A number of such inspections within a predetermined range could reduce inspection frequency while providing an equal or greater level of deterrence against illicit activity, all while meeting operator and technology holder requirements and reducing inspector and operator burden. Three options for using unattended monitoring data to determine an information-driven inspection schedule are to (1) send all unattended monitoring data off-site, which will require advances in data analysis techniques to

  4. Wedges for ultrasonic inspection

    Energy Technology Data Exchange (ETDEWEB)

    Gavin, Donald A. (Rexford, NY)

    1982-01-01

    An ultrasonic transducer device is provided which is used in ultrasonic inspection of the material surrounding a threaded hole and which comprises a wedge of plastic or the like including a curved threaded surface adapted to be screwed into the threaded hole and a generally planar surface on which a conventional ultrasonic transducer is mounted. The plastic wedge can be rotated within the threaded hole to inspect for flaws in the material surrounding the threaded hole.

  5. Source Inspection Scheduling Calendar

    Science.gov (United States)

    Hollis, Brayden

    2011-01-01

    Quality is an essential component for creating flight hardware travelling through space since the hardware is extremely expensive and cannot be reworked or repaired once launched. An important step in this process is ensuring the quality of hardware procured from Jet Propulsion Laboratory's (JPL) suppliers. An important element of determining supplier quality is source inspection. Source inspections are performed at suppliers' facilities by JPL employeesto ensure that hardware characteristics are acceptable before being covered up and/or delivered to JPL.

  6. In-Space Inspection Technologies Vision

    Science.gov (United States)

    Studor, George

    2012-01-01

    Purpose: Assess In-Space NDE technologies and needs - current & future spacecraft. Discover & build on needs, R&D & NDE products in other industries and agencies. Stimulate partnerships in & outside NASA to move technologies forward cooperatively. Facilitate group discussion on challenges and opportunities of mutual benefit. Focus Areas: Miniaturized 3D Penetrating Imagers Controllable Snake-arm Inspection systems Miniature Free-flying Micro-satellite Inspectors

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-02-15

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

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

    Science.gov (United States)

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

    2016-02-01

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

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

    CERN Document Server

    Loyka, Sergey

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Ansari, Imran Shafique

    2014-09-01

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

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Rakia, Tamer

    2015-08-01

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

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Law, John

    1994-11-14

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

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

    International Nuclear Information System (INIS)

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

  19. Inspection of tendons

    International Nuclear Information System (INIS)

    There is no reliable inspection method of tendons in use in Finland. In this research an inspection method was developed which can be applied when the sheath is of metallic material. The sheath is first revealed using a core cutter. A hole is then picked on the sheath and the condition of the injection grout and the tendons are inspected using an endoscope. A camera may be attached to the endoscope. To prevent the sheath from damaging during drilling a protective voltage is connected to the drill and the sheath is earthed. When the cutting edge hits the sheath the electric current is disconnected automatically. Experiments were made with the inspection method on three bridges one of which was still under construction and had no superstructure, one had just been constructed and one was 29 years old. The drillings for inspection were carried out on the top of the decks. The method worked as planned in all cases. In section 6 an example of corrosion classification is given which may be used when estimating whether the corrosion weakens the bearing capacity of the inspected tendons or not. (au) (1 ref., 25 figs.)

  20. Building Regulation Knowledge Modeling and Application in Construction Quality Inspection Based on the Decision-table%基于决策表的建筑工程质量监控规范建模与质量监控系统

    Institute of Scientific and Technical Information of China (English)

    钟波涛; 胡云忠; 胡海盟

    2012-01-01

    Building regulations plays important roles in assuring the construction quality. However, due to not familiarity with or even lack of the regulation knowledge, the construction quality inspectors often do not know how to inspect. In order to give more computerized support to the construction quality inspection, against regulations, in this paper, a representation of building regulations based on decision tables is selected to model the rule knowledge in the regulations, and a frame-based representation is selected to organize the construction quality information. The Drools inference engine is selected to execute the construction quality checking against the regulation rules. Finally, a regulation-based quality inspection system is developed. Our approach facilitates the regulations management and application. The system will improve the proficiency, reduce the error and save human resource in construction quality inspection.%针对目前建筑工程质量监控规范存在的应用不便,质量监控效率低等问题,利用决策表对规范知识进行建模,并采用框架表示法组织质量监控信息,在此基础上,实现基于Drools规则引擎的建筑工程质量监控.一方面,基于决策表的质量监控规范知识表达,便于实现面向监控对象的规范知识的组织和应用;另一方面,基于规则引擎将质量监控规范知识与质量监控数据分开管理,增强了规范知识的可维护性和系统的适应性.研究对于面向应用的建筑规范知识组织以及实现建筑工程质量监控自动化具有参考价值.

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

    KAUST Repository

    Al-Qahtani, Fawaz S.

    2011-09-01

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

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

    KAUST Repository

    Hwang, Kyusung

    2013-09-01

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

  3. Automatic optical inspection method for soft contact lenses

    Science.gov (United States)

    Chang, Chun-Li; Wu, Wen-Hong; Hwang, Chi-Chun

    2015-07-01

    In general, the manufacture of contact lenses is conventionally labor intensive, requiring manual handling and inspection of the cast lens during production. This paper is to build an AOI (automatic optical inspection) system, which include suitable light source, camera and image processing algorithms, for contact lenses defect inspection. The mainly defect type are missing lens and surface defect on the contact lenses. An illumination system with fixed focal lens and charge coupled device (CCD) is used to capture the images of contact lenses. After images are captured, an algorithm is employed to check if there are flaws showed on the images. Five kinds of defect can be detected by the designed algorithm. A prototype of the AOI system for contact lenses inspection is implemented. The experimental result shows that the proposed system is robust for in-line inspection.

  4. Incore inspection device

    International Nuclear Information System (INIS)

    The device of the present invention can inspect surfaces of equipments in reactor water in a nuclear reactor in a state of atmospheric air. Namely, an inspection device is movable forwardly and backwardly in a water-proof vessel. An annular sucker with pleats is disposed to the outer side of a lid of the water-proof vessel. A television camera for an under water monitoring is disposed to the inner side of the lid of the water-proof vessel by way of a partitioning wall with lid. Transferring screws are disposed at the back and on the side of the water-proof vessel. In the device having such a constitution, (1) the inside of the water-proof vessel is at first made water-tight by closing the partitioning wall with lid, (2) the back and the side screws are operated by the guide of the underwater monitoring television camera, to transfer the water-proof vessel to the surface of the reactor core to be inspected, (3) the annular sucker with pleats is urged on the surface to be inspected by the back screw, to fix the water-proof vessel, (4) reactor water in a space of the annular sucker with pleats is discharged and replaced with air, and (5) the lid of the partition wall with lid is opened and the inspection device is disposed at a position of the underwater monitoring television camera, to inspect the surface to be inspected in a state of atmospheric air. (I.S.)

  5. Inspection Strategies for Concrete Bridges

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    In this paper an optimal inspection strategy for concrete bridges based on periodic routine and detailed inspections is presented. The failure mode considered is corrosion of the reinforcement due to chlorides. A simple modelling of the corrosion and of the inspection strategy is presented. The...... optimal inspection strategy is determined from an optimization problem, where the design variables are time intervals between detailed inspections and the concrete cover. The strategy is illustrated on a simple structure, namely a reinforced concrete beam....

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

    Science.gov (United States)

    Egawa, Masanao

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

  7. Piping inspection round robin

    International Nuclear Information System (INIS)

    The piping inspection round robin was conducted in 1981 at the Pacific Northwest National Laboratory (PNNL) to quantify the capability of ultrasonics for inservice inspection and to address some aspects of reliability for this type of nondestructive evaluation (NDE). The round robin measured the crack detection capabilities of seven field inspection teams who employed procedures that met or exceeded the 1977 edition through the 1978 addenda of the American Society of Mechanical Engineers (ASME) Section 11 Code requirements. Three different types of materials were employed in the study (cast stainless steel, clad ferritic, and wrought stainless steel), and two different types of flaws were implanted into the specimens (intergranular stress corrosion cracks (IGSCCs) and thermal fatigue cracks (TFCs)). When considering near-side inspection, far-side inspection, and false call rate, the overall performance was found to be best in clad ferritic, less effective in wrought stainless steel and the worst in cast stainless steel. Depth sizing performance showed little correlation with the true crack depths

  8. Safety System functional inspections

    International Nuclear Information System (INIS)

    The basic purpose of Safety System Functional Inspections (SSFI) is to carry out an impartial and independent assessment of previously selected safety systems, in order to determine whether they have been installed, tested, operated and managed in accordance with the original Design Bases and with the applicable regulatory requirements, codes and standards, that is, their Licensing Bases. These functional inspections are performed within the framework established by the Quality Assurance Programmes of electric utility owners, and in accordance with specifically prepared procedures previously approved for each power plant. These SSFIs verify, for safety systems and their support systems (eg HVAC systems, etc), the operational availability of inspected systems of components by researching and determining whether there have been generic or programmed deficiencies in the course of Operation, that will prevent the systems from adequately performing the functions for which they were originally designed. PSA and IPE results are used as the basis for selecting the systems that should undergo functional inspections. As a consequence of these SSFIs, final reports will be prepared, summarizing actions taken at the plants and contemplating discrepancies or deviations detected during inspection. The necessary corrective actions for these discrepancies will be indicated in either the design documentation or the Operation and Maintenance Procedures. (Author)

  9. Inspection device in liquid

    International Nuclear Information System (INIS)

    The present invention provides an inspection device in PWR reactor core in which inspection operations are made efficient by stabilizing a posture of the device in front-to-back, vertical and left-to-right directions by a simple structure. When the device conducts inspection while running in liquid, the front and the back directions of the device main body are inspected using a visual device while changing the posture by operating a front-to-back direction propulsion device and a right-to-left direction propulsion device, and a vertical direction propulsion device against to rolling, pitching and yawing of the device main body. In this case, a spherical magnet moves freely in the gravitational direction in a vibration-damping fluid in a non-magnetic spherical shell following the change of the posture of the device main body, in which the vibrations due to the movement of the spherical magnet is settled by the vibration-damping fluid thereby stabilizing the posture of the device main body. At a typical inspection posture, the settling effect is enhanced by the attraction force between the spherical magnets in the spherical shell and each of magnetic force-attracted magnetic members disposed to the outer circumference of the shell, and the posture of the device main body can be confirmed in front-to-back, right-to-left and vertical directions by each of the posture confirming magnetic sensors. (N.H.)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  12. Ball screw inspection setup

    Science.gov (United States)

    Janusz, Rzepka; Sambor, Slawomir; Pienkowski, Janusz; Bielenin, Marcin

    2003-05-01

    In the following paper we describe arrangements of laser interferometer for investigation of screws and for inspection of ball screws. We have constructed two of them, namely: the technological setup for investigations of screw in process of production and the ball screw inspection setup. The former one is used to measure the pitch of screws. The data gathered during measurement is used to calculate the parameters for grinding machine. The later setup is used for testing parameters of complete ball screws. The software supporting this setup makes calculation of parameters of tested ball screw and creation of reports possible. Additionally, the inspection setup is the one that the torque measuring arrangements have been integrated on. Both the arrangements and the software allow for measurements of all parameters during movement of nut in full travel length of the ball screw and make charts and reports.

  13. Advances in inspection automation

    Science.gov (United States)

    Weber, Walter H.; Mair, H. Douglas; Jansen, Dion; Lombardi, Luciano

    2013-01-01

    This new session at QNDE reflects the growing interest in inspection automation. Our paper describes a newly developed platform that makes the complex NDE automation possible without the need for software programmers. Inspection tasks that are tedious, error-prone or impossible for humans to perform can now be automated using a form of drag and drop visual scripting. Our work attempts to rectify the problem that NDE is not keeping pace with the rest of factory automation. Outside of NDE, robots routinely and autonomously machine parts, assemble components, weld structures and report progress to corporate databases. By contrast, components arriving in the NDT department typically require manual part handling, calibrations and analysis. The automation examples in this paper cover the development of robotic thickness gauging and the use of adaptive contour following on the NRU reactor inspection at Chalk River.

  14. NRU light water reflector inspections

    International Nuclear Information System (INIS)

    In 2009 May, the National Research Universal (NRU) calandria leaked. In the next year the calandria was inspected with six new techniques, repaired, and the repair inspected with four additional new techniques. The calandria is surrounded by a light water reflector vessel. Concerns that the same corrosion mechanism may have damaged the reflector vessel led to plans to inspect the full circumference of the reflector wall for corrosion damage, through a 64 mm diameter port, from 10 m away, while inspecting from the corroded surface. The ultrasonic technique is intended to produce a very fine inspection grid, through the corroded surface, using a very small probe body over the approximately 5 m2 to be inspected. The calandria vessel inspections were successfully performed, in a short time period, under difficult conditions. This paper will discuss Operating Experience (OPEX) from the 2009/2010 calandria wall inspections and industry dialogue that were applied to the Reflector Wall Inspection (RWI) project. Interaction with the CANDU Inspection Qualification Bureau (CIQB) on procedures, training plans, and mock-up training, led to improvements in how these activities were performed for the RWI project. Experience with shift turnover meetings led to improvements in how the inspection team captures lessons learned, trends issues, and eliminates reoccurring design and procedure problems. Experience with collected and analyzed data, inspection shift logs, and video captured from inspections and repairs, were used to improve inspection performance. Finally, OPEX from radiation/activation and the calibration process reduced dose through tool design and procedure changes. (author)

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

    KAUST Repository

    Tourki, Kamel

    2011-04-01

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

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

    CERN Document Server

    Torbatian, Mehdi

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Litvintsev, A.V.

    1987-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Skraparlis D

    2009-01-01

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

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

    KAUST Repository

    Ben Rached, Nadhir

    2015-06-14

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  3. Federal environmental inspections handbook

    International Nuclear Information System (INIS)

    This Federal Environmental Inspection Handbook has been prepared by the Department of Energy (DOE), Office of Environmental Guidance, RCRA/CERCLA Division (EH-231). It is designed to provide DOE personnel with an easily accessible compilation of the environmental inspection requirements under Federal environmental statutes which may impact DOE operations and activities. DOE personnel are reminded that this Handbook is intended to be used in concert with, and not as a substitute for, the Code of Federal Regulations (CFR). Federal Register (FR), and other applicable regulatory documents

  4. Inspection and test planning

    International Nuclear Information System (INIS)

    Purpose of Quality Plan - arrangement of all necessary tests or inspections as far as possible filted to certain components or systems. Subject of Quality Plan - precise determination of tests or inspections and - according to the actual safety significance - the certificates to be done. Disposition of Quality Plan - accommodation of tests to the actual state of fabrication. Application of Quality Plan - to any component or system that is regarded. Supervision of Employment - by authorized personnel of manufacturer, customer or authority providing exact employment of quality plan. Overservance of Instructions - certificates given by authorized personnel. (orig./RW)

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

    International Nuclear Information System (INIS)

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

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

    KAUST Repository

    Ben Rached, Nadhir

    2015-11-13

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  9. Inspection of Emergency Arrangements

    International Nuclear Information System (INIS)

    The Working Group on Inspection Practices (WGIP) was tasked by the NEA CNRA to examine and evaluate the extent to which emergency arrangements are inspected and to identify areas of importance for the development of good inspection practices. WGIP members shared their approaches to the inspection of emergency arrangements by the use of questionnaires, which were developed from the requirements set out in IAEA Safety Standards. Detailed responses to the questionnaires from WGIP member countries have been compiled and are presented in the appendix to this report. The following commendable practices have been drawn from the completed questionnaires and views provided by WGIP members: - RBs and their Inspectors have sufficient knowledge and information regarding operator's arrangements for the preparedness and response to nuclear emergencies, to enable authoritative advice to be given to the national coordinating authority, where necessary. - Inspectors check that the operator's response to a nuclear emergency is adequately integrated with relevant response organisations. - Inspectors pay attention to consider the integration of the operator's response to safety and security threats. - The efficiency of international relations is checked in depth during some exercises (e.g. early warning, assistance and technical information), especially for near-border facilities that could lead to an emergency response abroad. - RB inspection programmes consider the adequacy of arrangements for emergency preparedness and response to multi-unit accidents. - RBs assess the adequacy of arrangements to respond to accidents in other countries. - The RB's role is adequately documented and communicated to all agencies taking part in the response to a nuclear or radiological emergency. - Inspectors check that threat assessments for NPPs have been undertaken in accordance with national requirements and that up-to-date assessments have been used as the basis for developing emergency plans for

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

    Science.gov (United States)

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

    2012-01-01

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

  11. Development of the visual inspection system for the top of the tube sheet in steam generators

    International Nuclear Information System (INIS)

    Steam Generators at Nuclear Power plants have a important function to isolate Radioactivity between the primary side radioactive fluid running through tubes and the secondary side with non-radioactive fluid through out of a tube bundle, in addition to a function of steam generation. Therefore, To obtain integrity of Steam Generator is really important for safety in the nuclear power plant. At the same time, sludge and foreign objects in steam generators are known as major sources causing the damage of SG tubes. But there is no way to prevent those coming to steam generators until now. Therefore, a periodic inspection and removal of those in steam generators is the only way for those Generally, Most of the Nuclear Power Plants have been inspecting visually every outage for the top of the tube sheet in which sludge and foreign objects lead to the buildup to know how these are

  12. Inspection Technology, Detection and Compliance: Evidence from Florida Restaurant Inspections

    OpenAIRE

    Jin, Ginger Zhe; Lee, Jungmin

    2013-01-01

    In this article, we show that a small innovation in inspection technology can make substantial differences in inspection outcomes. For restaurant hygiene inspections, the state of Florida has introduced a handheld electronic device, the portable digital assistant (PDA), which reminds inspectors of 1,000 potential violations that may be checked for. Using inspection records from July 2003 to June 2009, we find that the adoption of PDA led to 11% more detected violations and subsequently restau...

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

    International Nuclear Information System (INIS)

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

  14. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  15. 14 CFR 91.409 - Inspections.

    Science.gov (United States)

    2010-01-01

    ... detail— (i) An explanation of the progressive inspection, including the continuity of inspection... the name and address of the person responsible for scheduling the inspections required by the...

  16. Long range guided wave inspection of a small-bone tube with the magnetostrictive transducer technique

    International Nuclear Information System (INIS)

    There are several incidents from the leakage of the pipes which are in the category of a safety class as well as a non-safety class in nuclear power plants. However, in many cases, because of their geometrical complexity and inaccessibility, it is difficult to inspect them by the conventional ultrasonic method. A long-range guided ultrasonic inspection, thus, is an option to inspect them during an outage period. The magnetostrictive transducer technique has several advantages for practical applications, for such as a 100-percent volumetric coverage of a long segment of a structure, the inspection time and its cost effective, with a relatively simple and easy transducer structure. This study investigated the applicability of a long-rang guided ultrasonic method for the detection of artificial notches even in the presence of various foreign objects. Both the torsional (T(0,1) mode) and the longitudinal (L(0,1) mode) guided ultrasonic waves were effective for the long-range inspection of the tubes. It showed that it had a good detectability for the notch in the tubes, even though several obstacles are attached in front of the notch.

  17. Risk informed inservice inspection evaluation of the ComEd nuclear plants

    International Nuclear Information System (INIS)

    In November, 1999 Commonwealth Edison Company began the largest scope project yet performed to implement risk informed in-service inspection programs for piping systems. A contractor team led by ERIN Engineering and Research was selected to perform full scope risk informed evaluations on ten reactor units at five sites including 3 BWR and 2 PWR stations. This risk informed evaluation has applied a number of advancements to RISI technology in key areas including risk quantification of inspection program changes, element selection, treatment of multiple damage mechanisms at a given location, and in streamlining an approach to RISI initially developed by EPRI. The scope of the evaluation covered more than 18,000 ASME Class 1 and 2 welds not counting those that will continue to be inspected as part of augmented programs for flow accelerated corrosion, stress corrosion cracking, and service water systems. When the current ASME Section XI based exams are replaced by the risk informed program, while some new inspection locations will be added, substantial cost savings and person-rem exposures are projected from the elimination of most of the current exams. ComEd expects to recover its investment in the RISI evaluation for each of the 10 reactor units in 1 to 2 refueling outages, from the cost savings of reduced inspections. At the same time, the risk of a severe accident due to pipe ruptures is not expected to exhibit significant changes. (author)

  18. Ultrasonic inspection methodology

    International Nuclear Information System (INIS)

    Steam generator tubes are known to be susceptible to stress corrosion cracking (SCC). Primary water SCC (PWSCC) and more recently secondary water SCC (SWSCC) have been observed in some Belgian plants. To help dealing with these problems, Laborelec developed an ultrasonic (UT) inspection system. It has been used for the last two years on a sampling basis in several plants. The field and laboratory measurements confirmed the advantage of using UT for the early detection of small circumferential cracks while an excellent correlation was demonstrated between eddy current RPC and UT for axial PWSCC. In conclusion: The latest in-service inspections demonstrated an average measurement cycle of 50 to 60 seconds per tube including the manipulator displacement from tube to tube. A sample of about 250 tubes with axial cracks was measured on-site with the eddy current RPC technique and the new UT system. All the UT measured lengths were within ± 1.5 mm of the RPC results. The same results were obtained from the inspection of the tubes repaired with the nickel process (Doel 3). Some indications of circumferential secondary side stress corrosion cracking were recently observed. A comparison with the eddy current rotating pancake coil confirmed the improved detectability of the UT system. The field and laboratory results obtained with this UT inspection system demonstrated the advantage of applying the ultrasonic technique for the detection and sizing of small volume cracks like SCC. Also, the small focal spot of the UT beam provided a clear advantage for the detection of circumferential PWSCC in the presence of multiple axial cracks. With an average rate dose to 60 tubes per hour for the top of the tubesheet area, this UT system can be considered as an industrial tool for the inspection of steam generator tubes

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

    International Nuclear Information System (INIS)

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

  20. Big Lake Dam Inspection Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes an inspection of the Big Lake Dam that was done in September of 1983. The inspection did not reveal any conditions that constitute and...

  1. Visual inspection of vessel internals

    International Nuclear Information System (INIS)

    Visual inspection has matured to a qualified testing method and has become a standard method for inspection of reactor pressure vessels. Until today, all known defects in RPV internals have been detected by visual inspection. The codes KTA 3204 and DIN 25435-4 describe the framework conditions and requirements for visual inspections, which should be adhered to to the most possible extent. Visual inspections are carried by now at all RPV internals, also at those where access is difficult and limited. The inspection robot SUSI is applied in most cases. The camera and manipulator technology meanwhile has been upgraded to a standard performance quality allowing reliable, fast and easy visual inspection. The personnel is trained accordingly, so as to keep abreast with enhancements. Qualification of the inspection system has been simplified and standardised to a large extent. (orig/CB)

  2. Optical inspection of NGL masks

    Science.gov (United States)

    Pettibone, Donald W.; Stokowski, Stanley E.

    2004-12-01

    For the last five years KLA-Tencor and our joint venture partners have pursued a research program studying the ability of optical inspection tools to meet the inspection needs of possible NGL lithographies. The NGL technologies that we have studied include SCALPEL, PREVAIL, EUV lithography, and Step and Flash Imprint Lithography. We will discuss the sensitivity of the inspection tools and mask design factors that affect tool sensitivity. Most of the work has been directed towards EUV mask inspection and how to optimize the mask to facilitate inspection. Our partners have succeeded in making high contrast EUV masks ranging in contrast from 70% to 98%. Die to die and die to database inspection of EUV masks have been achieved with a sensitivity that is comparable to what can be achieved with conventional photomasks, approximately 80nm defect sensitivity. We have inspected SCALPEL masks successfully. We have found a limitation of optical inspection when applied to PREVAIL stencil masks. We have run inspections on SFIL masks in die to die, reflected light, in an effort to provide feedback to improve the masks. We have used a UV inspection system to inspect both unpatterned EUV substrates (no coatings) and blanks (with EUV multilayer coatings). These inspection results have proven useful in driving down the substrate and blank defect levels.

  3. From Inspection to School Improvement? Evaluating the Accelerated Inspection Programme in Waltham Forest.

    Science.gov (United States)

    Hopkins, David; Harris, Alma; Watling, Rob; Beresford, John

    1999-01-01

    Outlines the main findings from the evaluation of the Accelerated Inspection Programme (AIP) in Waltham Forest under three main phases (pre-inspection, inspection, and post inspection). Focuses on the relationship between inspection and school improvement. Discusses the recommendations. (CMK)

  4. Building a professional portfolio.

    OpenAIRE

    Arhippainen, Mikko

    2016-01-01

    Building a professional portfolio is a thesis report with buiding a professional portfolio for the author with a background in graphic design and event management with main interest on aesthetics side. This report describes the main process of selecting materials, planning and actually producing the portfolio. In addition to the portfolio there is a chapter with inspection on LinkedIn and other social medias when planning for jobsearch. Altogether it is many channels and a combination of ...

  5. Overview of the software inspection process

    Energy Technology Data Exchange (ETDEWEB)

    Lane, G.L.; Dabbs, R. [Sandia National Labs., Albuquerque, NM (United States)

    1997-11-01

    This tutorial introduces attendees to the Inspection Process and teaches them how to organize and participate in a software inspection. The tutorial advocates the benefits of inspections and encourages attendees to socialize the inspection process in their organizations.

  6. Inspection and teachers’ emotions: An emotional evaluation of inspection

    Directory of Open Access Journals (Sweden)

    Binali Tunç

    2015-02-01

    Full Text Available In the study, inspection is discussed in relation to the teachers’ feelings and emotions it creates before inspection, during inspection and after inspection process. Teacher’s emotions have been investigated intentionally as emotional side of education has been neglected. Education is closely related to the emotions of teachers, who are the most important producers of educational activities.Educational activities are reduced to standard activities and defined with simple explanations or single labels such as ‘good-bad’, ‘successful-unsuccessful’, ‘adequate-inadequate’. Inspection causes emotions to be neglected. Moreover, recently, it has been discussed that there are approaches and systems that suggest constant and multi-dimensional inspection instead of traditional inspection.Qualitative research model was used to understand of teacher emotions. A semi structured form was used for the 38 primary school teachers’ interviews. After teacher interviews were completed, we analyzed and compared the interviews. Participants’ expressions were checked in terms of correctness, potential validity and reliability problems such as misinterpretation.   The results of the study can be summarized as follows: There were no positive expressions related to the emotional impact of inspection on teachers. In addition, teachers felt that the inspectors were stressed, anxious, uneasy, accusatory, coercive, looking for defect and areas of unsuccessful teaching performance. Most of teachers reported that being observed and evaluated caused them to have negative emotions.Teachers’ perceptions about inspection are found to be negative. There are no statements that indicate there is a positive impression of inspection on teachers. The emotions that are experienced before inspection: pressure, hurry, stress, concern, tension, anxiety, worry, uncertainty; during inspection: stress, tension, anger, loss of strength, humiliation and lack of self

  7. Eddy current inspection methodology

    International Nuclear Information System (INIS)

    World-wide operating experience with nuclear pressurized water reactors shows that most steam generators show evidence of major degradation phenomena. Laborelec has designed several automated inspection systems using eddy current (bobbin coil, pancake coils and rotating coil) and ultrasound techniques. The bobbin coil is mostly used as a fast and global detection method while dedicated sensors, like the rotating pancake coil, are applied for an improved defect characterization. Experience has demonstrated that significant advantages in accuracy, reliability and cost are intimately related to the automation process. In conclusion: The concept of a multipurpose inspection system satisfies the safety goal and the utility requirements for reliability, accuracy and lower costs. An optimum was reached by equipment modularity, computer control and integrated design of sensors and instrumentation. What previously required several man-weeks of work is now achieved within a few hours time. With a presently unparalleled field performance, Laborelec has set the basis of new industrial standards

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-15

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

  9. B Plant treatment, storage, and disposal (TSD) units inspection plan

    International Nuclear Information System (INIS)

    This inspection plan is written to meet the requirements of WAC 173-303 for operations of a TSD facility. Owners/operators of TSD facilities are required to inspection their facility and active waste management units to prevent and/or detect malfunctions, discharges and other conditions potentially hazardous to human health and the environment. A written plan detailing these inspection efforts must be maintained at the facility in accordance with Washington Administrative Code (WAC), Chapter 173-303, ''Dangerous Waste Regulations'' (WAC 173-303), a written inspection plan is required for the operation of a treatment, storage and disposal (TSD) facility and individual TSD units. B Plant is a permitted TSD facility currently operating under interim status with an approved Part A Permit. Various operational systems and locations within or under the control of B Plant have been permitted for waste management activities. Included are the following TSD units: Cell 4 Container Storage Area; B Plant Containment Building; Low Level Waste Tank System; Organic Waste Tank System; Neutralized Current Acid Waste (NCAW) Tank System; Low Level Waste Concentrator Tank System. This inspection plan complies with the requirements of WAC 173-303. It addresses both general TSD facility and TSD unit-specific inspection requirements. Sections on each of the TSD units provide a brief description of the system configuration and the permitted waste management activity, a summary of the inspection requirements, and details on the activities B Plant uses to maintain compliance with those requirements

  10. Charles M. Russell NWR administrative inspection, July 25-29, 1994

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is an administrative inspection report for Charles M. Russell National Wildlife Refuge, completed July 2529, 1994. The following areas were reviewed: buildings...

  11. NRU light water reflector inspections

    Energy Technology Data Exchange (ETDEWEB)

    Lumsden, R.H.; Hebert, H.; Zahn, N.; Simpson, N.W. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2011-07-01

    In 2009 May, the National Research Universal (NRU) calandria leaked. In the next year the calandria was inspected with six new techniques, repaired, and the repair inspected with four additional new techniques. The calandria is surrounded by a light water reflector vessel. Concerns that the same corrosion mechanism may have damaged the reflector vessel led to plans to inspect the full circumference of the reflector wall for corrosion damage, through a 64 mm diameter port, from 10 m away, while inspecting from the corroded surface. The ultrasonic technique is intended to produce a very fine inspection grid, through the corroded surface, using a very small probe body over the approximately 5 m{sup 2} to be inspected. The calandria vessel inspections were successfully performed, in a short time period, under difficult conditions. This paper will discuss Operating Experience (OPEX) from the 2009/2010 calandria wall inspections and industry dialogue that were applied to the Reflector Wall Inspection (RWI) project. Interaction with the CANDU Inspection Qualification Bureau (CIQB) on procedures, training plans, and mock-up training, led to improvements in how these activities were performed for the RWI project. Experience with shift turnover meetings led to improvements in how the inspection team captures lessons learned, trends issues, and eliminates reoccurring design and procedure problems. Experience with collected and analyzed data, inspection shift logs, and video captured from inspections and repairs, were used to improve inspection performance. Finally, OPEX from radiation/activation and the calibration process reduced dose through tool design and procedure changes. (author)

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

    Giovanidis, Anastasios

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-15

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

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Sonia M. Orlando Gibelli

    2012-01-01

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

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

    KAUST Repository

    Khan, Fahd Ahmed

    2013-06-01

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

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    A. Y. Abdelaziz

    2013-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-02-15

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

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

    Directory of Open Access Journals (Sweden)

    Fariborz Haghighatdar fesharaki

    2011-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-15

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

  7. Eddy Currents Inspection of CANDU Steam Generator Tubes using Zetec's ZR-1 Robot. Experience in Romania

    International Nuclear Information System (INIS)

    Full text of publication follows: The commercial operation of Unit 1 of Cernavoda NPP started on 2 December, 1996. The unit's reactor type is PHWR-CANDU 6 (electrical capacity 706 MWe), using natural uranium. The nuclear fuel is manufactured in Romania. The Cernavoda nuclear power plant has four CANDU - design steam generators that have been in service since 1996. The paper introduces the new ZR-1 Robot System for Inspection and Maintenance/Repair from Zetec that combines the newest state-of-the-art robotics technology with Zetec experience - based innovation to address the needs for inspection and repair of steam generators. The multipurpose ZR-1 can be easily installed to perform the necessary eddy current inspection and remain installed ready for follow-up maintenance and repair. It has superior technical performances and a modular three axis motion of arm that enables 100% coverage of tube sheet. Automated, repeatable, and precise positioning of tool heads ensures accurate delivery and reducing costly rework and reduces inspection time by 30%. The modular, light weight, and portable design permits easy assembly and disassembly through small openings and it reduces setup/tear down time by 30%. The first deployment of the new ZR-1 Robot was made in September 2004 at the Cernavoda NPP inspection outage. The unit's reactor type is PHWR-CANDU 6 (electrical capacity 706 MWe), using natural uranium; the nuclear fuel is manufactured in Romania. The Cernavoda nuclear power plant Unit 1 has four CANDU - design steam generators that have been in service since 1996. The paper presents also the Zetec's field experience and customer experience with this system. It describes the equipment setup in Cernavoda's steam generators mock-up, functional tests and calibration. Finally, provides details on the execution of the inspection, options for standardizing the inspection techniques and conclusions. (authors)

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

    International Nuclear Information System (INIS)

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

  9. CTBT on-site inspections

    Energy Technology Data Exchange (ETDEWEB)

    Zucca, J. J. [Principal Deputy, Global Security Directorate, Lawrence Livermore National Laboratory, Livermore, California (United States)

    2014-05-09

    On-site inspection (OSI) is a critical part of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The OSI verification regime provides for international inspectors to make a suite of measurements and observations on site at the location of an event of interest. The other critical component of the verification regime is the International Monitoring System (IMS), which is a globally distributed network of monitoring stations. The IMS along with technical monitoring data from CTBT member countries, as appropriate, will be used to trigger an OSI. After the decision is made to carry out an OSI, it is important for the inspectors to deploy to the field site rapidly to be able to detect short-lived phenomena such as the aftershocks that may be observable after an underground nuclear explosion. The inspectors will be on site from weeks to months and will be working with many tens of tons of equipment. Parts of the OSI regime will be tested in a field exercise in the country of Jordan late in 2014. The build-up of the OSI regime has been proceeding steadily since the CTBT was signed in 1996 and is on track to becoming a deterrent to someone considering conducting a nuclear explosion in violation of the Treaty.

  10. Development of Wall Thinning Distinction Method using the Multi-inspecting UT Data of Carbon Steel Piping

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyeong Mo; Yun, Hun; Lee, Chan Kyoo [KEPCO E and C, Yongin (Korea, Republic of)

    2012-05-15

    To manage the wall thinning of carbon steel piping in nuclear power plants, the utility of Korea has performed thickness inspection for some quantity of pipe components during refueling outages and determined whether repair or replacement after evaluating UT (Ultrasonic Test) data. When the existing UT data evaluation methods, such as Band, Blanket, PTP (Point to Point) Methods, are applied to a certain pipe component, unnecessary re-inspecting situations may be generated even though the component does not thinned. In those cases, economical loss caused by repeated inspection and problems of maintaining the pipe integrity followed by decreasing of newly inspected components may be generated. EPRI (Electric Power Research Institute) in USA has suggested several statistical methods, TPM (Total Point Method), LSS (Least Square Slope) Method, etc. to distinguish whether multiple inspecting components have thinned or not. This paper presents the analysis results for multiple inspecting components over three times based on both NAM (Near Area of Minimum) Method developed by KEPCO-E and C and the other methods suggested by EPRI.

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

    KAUST Repository

    Xia, Minghua

    2012-10-01

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

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

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Hanyu Li

    2009-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Pengyu Liu

    2013-01-01

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

  16. Safeguards management inspection procedures

    Energy Technology Data Exchange (ETDEWEB)

    Barth, M.J.; Dunn, D.R.

    1984-08-01

    The objective of this inspection module is to independently assess the contributions of licensee management to overall safeguards systems performance. The inspector accomplishes this objective by comparing the licensee's safeguards management to both the 10 CFR, parts 70 and 73, requirements and to generally accepted management practices. The vehicle by which this comparison is to be made consists of assessment questions and key issues which point the inspector to areas of primary concern to the NRC and which raise additional issues for the purpose of exposing management ineffectiveness. Further insight into management effectiveness is obtained through those assessment questions specifically directed toward the licensee's safeguards system performance. If the quality of the safeguards is poor, then the inspector should strongly suspect that management's role is ineffective and should attempt to determine management's influence (or lack thereof) on the underlying safeguards deficiencies. (The converse is not necessarily true, however.) The assessment questions in essence provide an opportunity for the inspector to identify, to single out, and to probe further, questionable management practices. Specific issues, circumstances, and concerns which point to questionable or inappropriate practices should be explicitly identified and referenced against the CFR and the assessment questions. The inspection report should also explain why the inspector feels certain management practices are poor, counter to the CFR, and/or point to ineffecive management. Concurrent with documenting the inspection results, the inspector should provide recommendations for alleviating observed management practices that are detrimental to effective safeguards. The recommendations could include: specific changes in the practices of the licensee, followup procedures on the part of NRC, and proposed license changes.

  17. Laser Safety Inspection Criteria

    International Nuclear Information System (INIS)

    A responsibility of the Laser Safety Officer (LSO) is to perform laser audits. The American National Standard Z136.1 Safe Use of Lasers references this requirement through several sections. One such reference is Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''. The composition, frequency and rigor of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms It is common for audit findings from one inspector or inspection to the next to vary even when reviewing the same material. How often has one heard a comment, ''well this area has been inspected several times over the years and no one ever said this or that was a problem before''. A great number of audit items, and therefore findings, are subjective because they are based on the experience and interest of the auditor to particular items on the checklist. Beam block usage, to one set of eyes might be completely adequate, while to another, inadequate. In order to provide consistency, the Laser Safety Office of the National Ignition Facility Directorate has established criteria for a number of items found on the typical laser safety audit form. The criteria are distributed to laser users. It serves two broad purposes; first, it gives the user an expectation of what will be reviewed by an auditor. Second, it is an opportunity to explain audit items to the laser user and thus the reasons for some of these items, such as labelling of beam blocks

  18. Safeguards management inspection procedures

    International Nuclear Information System (INIS)

    The objective of this inspection module is to independently assess the contributions of licensee management to overall safeguards systems performance. The inspector accomplishes this objective by comparing the licensee's safeguards management to both the 10 CFR, parts 70 and 73, requirements and to generally accepted management practices. The vehicle by which this comparison is to be made consists of assessment questions and key issues which point the inspector to areas of primary concern to the NRC and which raise additional issues for the purpose of exposing management ineffectiveness. Further insight into management effectiveness is obtained through those assessment questions specifically directed toward the licensee's safeguards system performance. If the quality of the safeguards is poor, then the inspector should strongly suspect that management's role is ineffective and should attempt to determine management's influence (or lack thereof) on the underlying safeguards deficiencies. (The converse is not necessarily true, however.) The assessment questions in essence provide an opportunity for the inspector to identify, to single out, and to probe further, questionable management practices. Specific issues, circumstances, and concerns which point to questionable or inappropriate practices should be explicitly identified and referenced against the CFR and the assessment questions. The inspection report should also explain why the inspector feels certain management practices are poor, counter to the CFR, and/or point to ineffecive management. Concurrent with documenting the inspection results, the inspector should provide recommendations for alleviating observed management practices that are detrimental to effective safeguards. The recommendations could include: specific changes in the practices of the licensee, followup procedures on the part of NRC, and proposed license changes

  19. Comparative study of Palito inspection and MFL Inspection

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Anne A. de; Miranda, Ivan Vicente Janvrot; Silva, Jose Augusto Pereira da [Pipeway Engenharia, Rio de Janeiro, RJ (Brazil); Guimaraes, Frederico S.; Magalhaes, Joao Alfredo P. [Minds at Work, Rio de Janeiro, RJ (Brazil); Sabino, Joao Marcos [Petroleo Brasileiro S.A. (PETROBRAS/UN-RN/CE), Natal, RN (Brazil). Unidade de Negocios Rio Grande do Norte e Ceara

    2009-07-01

    A 16 inches oil pipeline was surveyed with MFL and Palito pig in 2007. The MFL inspection was performed by Pipeway Engenharia while Palito inspection was performed by PETROBRAS. A comparison between the results of these two ILI inspections has been made to validate Palito Pig and to assess main characteristics and differences between the two techniques. The purpose of this paper is to detail the methodology applied to perform the comparison and to present a comparative study of results registered in the MFL and Palito inspections by Pipeway Engenharia, PETROBRAS/CENPES and CPTI/PUC-Rio. (author)

  20. Development and field validation of advanced array probes for steam generator inspection

    Energy Technology Data Exchange (ETDEWEB)

    Dodd, C.V.; Pate, J.R. [Oak Ridge National Lab., TN (United States)

    1995-04-01

    The aging of the steam generators at the nation`s nuclear power plants has led to the appearance of new forms of degradation in steam generator tubes and an increase in the frequency of forced outages due to major tube leak events. The eddy-current techniques currently being used for the inspection of steam generator tubing are no longer adequate to ensure that flaws will be detected before they lead to a shutdown of the plant. To meet the need for a fast and reliable method of inspection, ORNL has designed a 16-coil eddy-current array probe which combines an inspection speed similar to that of the bobbin coil with a sensitivity to cracks of any orientation similar to the rotating pancake coil. In addition, neural network and least square methods have been developed for the automatic analysis of the data acquired with the new probes. The probes and analysis software have been tested at two working steam generators where we have found an increase in the signal-to-noise ratio of a factor of five an increase in the inspection speed of a factor of 75 over the rotating pancake coil which maintaining similar detection and characterization capabilities.

  1. KeproVt : underwater robotic system for visual inspection of nuclear reactor internals

    International Nuclear Information System (INIS)

    An underwater robotic system for visual inspection of reactor vessel internals has been developed. The Korea Electric Power Robot for Visual Test (KeproVt) consists of an underwater robot, a vision processor based measuring unit, a master control station and a servo control station. The vision processor based measuring unit employs a first-of-a-kind engineering technology in nuclear robotics. The vision processor makes use of a camera located at the top of the water level referenced to the reactor center line to get an image of the robot, and computes the location and orientation of the robot. The robot guided by the control station with the measuring unit can be controlled to have any motion at any position in the reactor vessel with ±1 cm positioning and ±2 deg. heading accuracies with enough precision to inspect reactor internals. A simple and fast installation process is emphasized in the developed system. The installation process consists of hooking a vision camera on the guide rail of the refueling machine and putting a small robot (14.5 kg in weight) in the reactor cavity pool. The easy installation and automatic operation meet the demand of shortening the reactor outage and reducing the number of inspection personnel. The developed robotic system was successfully deployed at the Yonggwang Nuclear Unit 1 for the visual inspection of reactor internals

  2. Realization by inspection

    OpenAIRE

    Rosenthal, J.; Schumacher, Hans

    1997-01-01

    We investigate which first-order representations can be obtained from high-order representations of linear systems “by inspection”, that is, just by rearrangement of the data. Under quite weak conditions it is possible to obtain minimal realizations in the so-called pencil form; under stronger conditions one can obtain minimal realizations in standard state-space form by inspection. The development is based on a reformulation of the realization problem as a problem of finding a complete set o...

  3. Vibrational Based Inspection of Civil Engineering Structures

    DEFF Research Database (Denmark)

    Rytter, Anders

    University of Aalborg from 1988 to 1991. Secondly, a research project, In-Field Vibration Based Inspection of Civil Engineering Structures, which has been performed as a pilot project by the Consulting Engineers Rambøll, Hannemann and Højlund in cooperation with the department of Building Technology and......The thesis has been written in relation to two different research projects. Firstly, an offshore test programme, Integrated Experimental/Numerical Analysis of the Dynamic behavior of offshore structures, which was performed at the department of Building Technology and Structural Engineering at the...... Structural Engineering at the University of Aalborg since the beginning of 1992. Both projects have been supported by the Danish Technical Research Council. Further, the first mentioned project was supported by the Danish Energy Agency. Their financial support is gratefully acknowledged....

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

    International Nuclear Information System (INIS)

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

  5. INSPECTION OF CNC MADE PARTS

    OpenAIRE

    Prof. Yogesh R. Falak*; Rahul Patil; Kalpesh Bhagat,

    2015-01-01

    Inspection is an important process of manufacturing system. It is means of rejecting error parts and assuring good quality parts. The advantages of technological innovation in inspection equipment helped to overcome the problems associated with traditional approaches. Such means that used of labour intensive method increase in total manufacturing time and production cost. Advanced sensor and inspection technologies, interfaced with computer based systems to automate the operations...

  6. Inspections - a cost effective approach

    International Nuclear Information System (INIS)

    This paper describes a cost effective approach for inspections of Computerized Nuclear Materials Control and Accounting Systems (CNMCAS). Highlighted is the capability to conduct an inspection program via portable telephone terminals from off-site locations. The program can be applied to various materials management functions including materials control, quality assurance, and materials accounting. The system is designed to facilitate inspections by both external and internal groups

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

    International Nuclear Information System (INIS)

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

  8. Waste inspection tomography (WIT)

    Energy Technology Data Exchange (ETDEWEB)

    Bernardi, R.T. [Bio-Imaging Research, Inc., Lincolnshire, IL (United States)

    1995-10-01

    Waste Inspection Tomography (WIT) provides mobile semi-trailer mounted nondestructive examination (NDE) and assay (NDA) for nuclear waste drum characterization. WIT uses various computed tomography (CT) methods for both NDE and NDA of nuclear waste drums. Low level waste (LLW), transuranic (TRU), and mixed radioactive waste can be inspected and characterized without opening the drums. With externally transmitted x-ray NDE techniques, WIT has the ability to identify high density waste materials like heavy metals, define drum contents in two- and three-dimensional space, quantify free liquid volumes through density and x-ray attenuation coefficient discrimination, and measure drum wall thickness. With waste emitting gamma-ray NDA techniques, WIT can locate gamma emitting radioactive sources in two- and three-dimensional space, identify gamma emitting, isotopic species, identify the external activity levels of emitting gamma-ray sources, correct for waste matrix attenuation, provide internal activity approximations, and provide the data needed for waste classification as LLW or TRU.

  9. Waste inspection tomography (WIT)

    International Nuclear Information System (INIS)

    The WIT program will provide an inspection system that offers the nuclear waste evaluator a unique combination of tools for regulatory-driven characterization of low-level waste (LLW), transuranic waste (TRU), and mixed waste drums. WIT provides nondestructive, noninvasive, and environmentally safe inspections using X-ray and gamma ray technologies, with reasonable cost and throughput. Two emission imaging techniques will be employed for characterizing materials in waste containers. The first of these is gamma emission tomography, commonly called single-photon emission computed tomography (SPECT). Rather than using an external radiation source, SPECT uses the emission of radioactive materials within the object of interest for imaging. In this case, emission from actual nuclear waste within a container will provide a three-dimensional image of the radioactive substances in the container. The second emission technique will use high-purity germanium detectors for gamma ray spectroscopy. This technique, called nondestructive assay (NDA), can identify the emitting isotopic species and strength. Work in emission tomography and assay of nuclear waste has been undertaken at Lawrence Livermore National Laboratory using a technique called Passive Tomography. Results from a process development unit are presented

  10. Ultrasonic wave inspection device

    International Nuclear Information System (INIS)

    The device of the present invention inspects incore structural components by visualizing them by scanning an ultrasonic transducer in an opaque liquid metal sodium in a pressure vessel of an FBR type reactor. Namely, a piezoelectric vibrator for transmitting/receiving ultrasonic waves is formed into a protruded shape. A portion at the center of the protruded piezoelectric vibrator is coaxially separated. Upon transmitting ultrasonic waves, a large opening of the entire piezoelectric vibrator is used. A small opening at the center of the piezoelectric vibrator is used upon receiving ultrasonic waves. With such a constitution, an object to be inspected is visualized based on the waveform of the received ultrasonic wave signals defining the center of a curvature of the protruded piezoelectric vibrator as a position of transmitting ultrasonic waves and defining the center of the opening at the center of the piezoelectric vibrator as a position of receiving ultrasonic waves. As a result, the energy of the ultrasonic waves can be enhanced to improve sensitivity upon transmitting ultrasonic waves. Since the distance between an optional position of the receiving surface and the reflecting surface of the object is minimized upon receiving ultrasonic waves, there is no distortion in the waveforms of the received signals thereby enabling to obtain images at high accuracy. (I.S.)

  11. Inspection system performance test procedure

    International Nuclear Information System (INIS)

    This procedure establishes requirements to administer a performance demonstration test. The test is to demonstrate that the double-shell tank inspection system (DSTIS) supplied by the contractor performs in accordance with the WHC-S-4108, Double-Shell Tank Ultrasonic Inspection Performance Specification, Rev. 2-A, January, 1995. The inspection system is intended to provide ultrasonic (UT) and visual data to determine integrity of the Westinghouse Hanford Company (WHC) site underground waste tanks. The robotic inspection system consists of the following major sub-systems (modules) and components: Mobile control center; Deployment module; Cable management assembly; Robot mechanism; Ultrasonic testing system; Visual testing system; Pneumatic system; Electrical system; and Control system

  12. Optimal allocation of inspection resources

    International Nuclear Information System (INIS)

    Allocation of inspection resources for international safeguards is considered as the problem of designing a complex system that is composed of individual inspection activities and that has the objective of detecting material loss. Optimization theory is applied in selecting those inspection activities that maximize a system performance measure within resource constraints. The method is applicable to a global allocation problem in which inspection resources are distributed throughout a hierarchy consisting of multiple countries, multiple facilities within each country, and multiple activities within each facility. 9 references

  13. On-site inspections: The ultimate verification measure

    International Nuclear Information System (INIS)

    Having existed for a mere six weeks in 2008, the State of Arcania was short-lived. The fictitious state helped to test on-site inspections, a key element of a global alarm system that monitors the Earth for signs of nuclear explosions. The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is mandated to build this system to verify States' compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). On-site inspections (OSI ) complement the verification regime's other elements: the International Monitoring System with its network of 337 facilities, the International Data Centre with its extensive data analysis capacities, and the Global Communications Infrastructure. On-site inspections can be invoked only after the Treaty's entry into force. A Member State may request an inspection should the analysis of monitoring data indicate that a nuclear explosion was carried out in violation of the CT BT. Facts gathered directly on the ground during an inspection will help States to establish whether or not a nuclear explosion did indeed take place. Thus, on-site inspections constitute the final verification measure under the Treaty.

  14. Thermographic Inspections And The Residential Conservation Service Program (RCS)

    Science.gov (United States)

    Ward, Ronald J.

    1983-03-01

    Rhode Islanders Saving Energy (RISE) is a non-profit corporation founded in 1977 to provide Rhode Island residents with a variety of energy conservation services. Since January of 1981, it has been performing energy audits in compliance with the Department of Energy's (DOE) Residential Conservation Service Program (RCS). One aspect of the RCS program is the performance of inspections on energy conservation activities completed according to RCS installation guidelines. This paper will describe both the use and results of thermographic inspections within the RISE program. The primary objective of these inspections has been to assure the quality of the building envelope after completion of retrofit measures. Thermal anamolies have been detected that vary in size, location and probable cause. Approximately 37% of all jobs performed through RISE in conjunction with the RCS program have required remedial work as a result of problems that were identi-fied during the thermographic inspection. This percentage was much higher when infra-red inspections were conducted on "Non-RCS" retrofits. Statistics will be presented that provide an interesting insight on the quality of retrofit work when performed in associa-tion with a constant inspection process.

  15. Methodology for predicting flow-accelerated corrosion wear using unreferenced multiple inspection data

    International Nuclear Information System (INIS)

    Highlights: ► We develop a new method for flow accelerated corrosion (FAC) wear prediction. ► The method is based on a small circular patch near the point of minimum thickness. ► Inspection uncertainties and errors are minimized by surface interpolation. ► The method is applied to the assessment of feeder piping in CANDU reactors. ► The results provide valuable risk information for long-term planning and LCM. - Abstract: The lack of fixed spatial referencing in inspection data is a confounding factor in the assessment of wall thinning due to flow-accelerated corrosion (FAC). Because of the loss of wall thickness over time, it is impossible to match any two unreferenced points precisely between inspection outages, making the use of point-to-point comparison methods highly uncertain. In this study, we develop a new methodology for estimating the FAC rate and component lifetime from spatially unreferenced inspection data. The method is based on a small circular patch that represents the minimum wall thickness as a random variable. This allows the predictions to be performed in a probabilistic setting, hence providing valuable risk information for long-term replacement planning and life-cycle management. The uncertainty and errors introduced by inspection and grid coverage are minimized in the analysis by fitting a continuous surface through the inspection data using the method of kriging. The developed methodology is applied to the assessment of carbon steel feeder piping in CANDU reactors, where the economic and safety consequences of FAC can be highly significant. Based on the analysis of a large industry dataset, FAC in feeder piping appears to be a relatively uniform and stationary process. The results of the study demonstrate the key advantages of the developed methodology and how it can be used to support risk-informed decision making with respect to FAC at power plants.

  16. Laser Safety Inspection Criteria

    International Nuclear Information System (INIS)

    A responsibility of the Laser Safety Officer (LSO) is to perform laser safety audits. The American National Standard Z136.1 Safe use of Lasers references this requirement in several sections: (1) Section 1.3.2 LSO Specific Responsibilities states under Hazard Evaluation, ''The LSO shall be responsible for hazards evaluation of laser work areas''; (2) Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''; and (3) Appendix D, under Survey and Inspections, it states, ''the LSO will survey by inspection, as considered necessary, all areas where laser equipment is used''. Therefore, for facilities using Class 3B and or Class 4 lasers, audits for laser safety compliance are expected to be conducted. The composition, frequency and rigueur of that inspection/audit rests in the hands of the LSO. A common practice for institutions is to develop laser audit checklists or survey forms. In many institutions, a sole Laser Safety Officer (LSO) or a number of Deputy LSO's perform these audits. For that matter, there are institutions that request users to perform a self-assessment audit. Many items on the common audit list and the associated findings are subjective because they are based on the experience and interest of the LSO or auditor in particular items on the checklist. Beam block usage is an example; to one set of eyes a particular arrangement might be completely adequate, while to another the installation may be inadequate. In order to provide more consistency, the National Ignition Facility Directorate at Lawrence Livermore National Laboratory (NIF-LLNL) has established criteria for a number of items found on the typical laser safety audit form. These criteria are distributed to laser users, and they serve two broad purposes: first, it gives the user an expectation of what will be reviewed by an auditor, and second, it is an

  17. A cargo inspection system based on pulsed fast neutron analysis (PFNATM)

    International Nuclear Information System (INIS)

    A cargo inspection system based on pulsed fast neutron analysis (PFNATM) is to be used at a border crossing to detect explosives and contraband hidden in trucks and cargo containers. Neutrons are produced by the interaction of deuterons in a deuterium target mounted on a moveable scan arm. The collimated pulsed fast neutron beam is used to determine the location and composition of objects in a cargo container. The neutrons produce secondary gamma rays that are characteristic of the object's elemental composition. The cargo inspection system building consists of an accelerator room and an inspection tunnel. The accelerator room is shielded and houses the injector, accelerator and the neutron production gas target. The inspection tunnel is partially shielded. The truck or container to be inspected will be moved through the inspection tunnel by a conveyor system. The facility and radiation source terms considered in the shielding design are described. (authors)

  18. Labor inspection in Brazil

    Directory of Open Access Journals (Sweden)

    Adalberto Cardoso

    2006-01-01

    Full Text Available One aspect the literature overlooks on the effects of labor regulation of labor market efficiency is the degree of the legislation's effectiveness, i.e., its actual enforcement in daily work relations. Even the more sophisticated econometric studies (which take into account the effects of interaction between labor market regulatory institutions in explaining its dynamics leave this central issue aside, namely enforcement versus non-enforcement of the law. Keeping this issue in mind, we seek to answer the following question in this article: given that the effectiveness of labor legislation depends on the interaction between the overall sanctions and the probability of the employer getting caught breaking the law, and given that the law's effectiveness is a decisive aspect for the real measurement of a country's labor costs, to what extent is the Brazilian labor inspection system designed to meet its objective, namely, to enforce the law?

  19. Reduced Mandated Inspection by Remote Field Eddy Current Inspection of Unpiggable Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Albert Teitsma; Julie Maupin

    2006-09-29

    The Remote Field Eddy Current (RFEC) technique is ideal for inspecting unpiggable pipelines because all of its components can be made much smaller than the diameter of the pipe to be inspected. For this reason, RFEC was chosen as a technology for unpiggable pipeline inspections by DOE-NETL with the support of OTD and PRCI, to be integrated with platforms selected by DOENETL. As part of the project, the RFEC laboratory facilities were upgraded and data collection was made nearly autonomous. The resulting improved data collection speeds allowed GTI to test more variables to improve the performance of the combined RFEC and platform technologies. Tests were conducted on 6-, 8-, and 12-inch seamless and seam-welded pipes. Testing on the 6-inch pipes included using seven exciter coils, each of different geometry with an initial focus on preparing the technology for use on an autonomous robotic platform with limited battery capacity. Reductions in power consumption proved successful. Tests with metal components similar to the Explorer II modules were performed to check for interference with the electromagnetic fields. The results of these tests indicated RFEC would be able to produce quality inspections while on the robot. Mechanical constraints imposed by the platform, power requirements, control and communication protocols, and potential busses and connectors were addressed. Much work went into sensor module design including the mechanics and electronic diagrams and schematics. GTI participated in two Technology Demonstrations for inspection technologies held at Battelle Laboratories. GTI showed excellent detection and sizing abilities for natural corrosion. Following the demonstration, module building commenced but was stopped when funding reductions did not permit continued development for the selected robotic platform. Conference calls were held between GTI and its sponsors to resolve the issue of how to proceed with reduced funding. The project was rescoped for 10

  20. Automated visual inspection of textile

    DEFF Research Database (Denmark)

    Jensen, Rune Fisker; Carstensen, Jens Michael

    A method for automated inspection of two types of textile is presented. The goal of the inspection is to determine defects in the textile. A prototype is constructed for simulating the textile production line. At the prototype the images of the textile are acquired by a high speed line scan camera...

  1. Inspection of disposal canisters components

    International Nuclear Information System (INIS)

    This report presents the inspection techniques of disposal canister components. Manufacturing methods and a description of the defects related to different manufacturing methods are described briefly. The defect types form a basis for the design of non-destructive testing because the defect types, which occur in the inspected components, affect to choice of inspection methods. The canister components are to nodular cast iron insert, steel lid, lid screw, metal gasket, copper tube with integrated or separate bottom, and copper lid. The inspection of copper material is challenging due to the anisotropic properties of the material and local changes in the grain size of the copper material. The cast iron insert has some acoustical material property variation (attenuation, velocity changes, scattering properties), which make the ultrasonic inspection demanding from calibration point of view. Mainly three different methods are used for inspection. Ultrasonic testing technique is used for inspection of volume, eddy current technique, for copper components only, and visual testing technique are used for inspection of the surface and near surface area

  2. Chapter No.3. Assessment and inspection of nuclear installations

    International Nuclear Information System (INIS)

    2001. The total number of operational events shows decreasing tendency. According to the INES scale, 19 events have been assessed by level '0' and 1 event by level 'out of scale'. Based on the result of the inspection a permit for further operation of the unit was issued. On the basis of complex assessment, UJD consider the operation of Bohunice V-1 NPP in 2001 safe and reliable. Bohunice V-2 Nuclear Power Plant consists of two units with WWER 440 type reactors of improved V-213 type, which were put into operation in 1984 and 1985. Both units operated in 2001 according to the needs of the energy dispatch centre in based load, or also in the regime of 'tertiary regulation' and 'primary regulation' respectively. From both unit of Bohunice V-2 NPP also the non-electric production heat was used by steam bleeding from the turbine which served as a heat source for heating Trnava, Hlohovec and Leopoldov towns. In 2001 the planned refuelling outage was performed at both units. The ongoing review and assessment of the document 'Concept of modernisation and safety improvement of Bohunice V-2 NPP', submitted by the operator based on UJD decision was a significant activity of UJD in connection with safety assessment of Bohunice V-2 NPP in 2001. Consequently the top management of the Slovak Republic power utility SE, a.s. definitely approved the modernisation programme for Bohunice V-2 NPP. In 2001 a refuelling outages on units 3 and 4 of Bohunice V-2 NPP were performed. UJD reviewed the programmes of in-service inspection for refuelling outages on units 3 and 4 and conducted the current inspections aimed at the fulfilment of these programmes and assessment of the results obtained. During the in-service inspections no significant indication were found which would require an extraordinary measures. State of the plant equipment was assessed as a good one and not limiting further operation of the both units of Bohunice V-2 NPP. In 2001 the programme of systematic improvement of

  3. Planning and performance of inspections

    International Nuclear Information System (INIS)

    Inspections in power plants are decisive factors for profitable and safe power production. Inspection schedulling needs to consider output demand, fuel application, manufacturers' recommendations and, above all, operational records of the state of the plant. Inspection schedulling is aimed at finding an optimum time-to-cost ratio for a defined scope of inspection. A large utility with a power plant pool featuring nuclear, black coal, brown coal, gas and hydro electric plants makes great and varied demands on inspection schedulling and implementation which the author exemplifies by PreussenElektra with its installed capacity of ca. 12,000 MW distributed among 7 nuclear power plants, 20 coal and gas units, 10 pump storage units and 40 run-of-river turbines. (orig./GL)

  4. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from July 1989 through September 1989

  5. Licensee contractor and Vendor Inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from October 1992 through December 1992

  6. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from January 1991 through March 1991

  7. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from October 1989 through December 1989

  8. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from April through June 1993

  9. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from January 1993 through March 1993

  10. Licensee contractor and Vendor Inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from January through March 1992

  11. Licensee Contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from October through December 1991

  12. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from January 1990 through March 1990

  13. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from April 1990 through June 1990

  14. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from July 1992 through September 1992

  15. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organizations during the period from October 1990 through December 1990

  16. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from April 1991 through June 1991

  17. Licensee contractor and vendor inspection status report

    International Nuclear Information System (INIS)

    This periodical covers the results of inspections performed by the NRC's Vendor Inspection Branch that have been distributed to the inspected organization during the period from July 1991 through September 1991

  18. A UAV system for inspection of industrial facilities

    Science.gov (United States)

    Nikolic, J.; Burri, M.; Rehder, J.; Leutenegger, S.; Huerzeler, C.; Siegwart, R.

    This work presents a small-scale Unmanned Aerial System (UAS) capable of performing inspection tasks in enclosed industrial environments. Vehicles with such capabilities have the potential to reduce human involvement in hazardous tasks and can minimize facility outage periods. The results presented generalize to UAS exploration tasks in almost any GPS-denied indoor environment. The contribution of this work is twofold. First, results from autonomous flights inside an industrial boiler of a power plant are presented. A lightweight, vision-aided inertial navigation system provides reliable state estimates under difficult environmental conditions typical for such sites. It relies solely on measurements from an on-board MEMS inertial measurement unit and a pair of cameras arranged in a classical stereo configuration. A model-predictive controller allows for efficient trajectory following and enables flight in close proximity to the boiler surface. As a second contribution, we highlight ongoing developments by displaying state estimation and structure recovery results acquired with an integrated visual/inertial sensor that will be employed on future aerial service robotic platforms. A tight integration in hardware facilitates spatial and temporal calibration of the different sensors and thus enables more accurate and robust ego-motion estimates. Comparison with ground truth obtained from a laser tracker shows that such a sensor can provide motion estimates with drift rates of only few centimeters over the period of a typical flight.

  19. Reactor process water (PW) piping inspections, 1984--1990

    International Nuclear Information System (INIS)

    In July 1983, the NRC ordered the shutdown of five boiling water reactors (BWR's) because of concerns about reliability of ultrasonic examination for detecting intergranular stress corrosion cracking (IGSCC). These concerns arose because of leaking piping at Niagara Mohawk's Nine Mile Point which was attributed to IGSCC. The leaks were detected shortly after completion of ultrasonic examinations of the piping. At that time, the Dupont plant manager at Savannah River (SR) directed that investigations be performed to determine if similar problems could exist in SR reactors. Investigation determined that all conditions believed necessary for the initiation and propagation of IGSCC in austenitic stainless steel exist in SR reactor process water (PW) systems. Sensitized, high carbon, austenitic stainless steel, a high purity water system with high levels of dissolved oxygen, and the residual stresses associated with welding during construction combine to provide the necessary conditions. A periodic UT inspection program is now in place to monitor the condition of the reactor PW piping systems. The program is patterned after NRC NUREG 0313, i.e., welds are placed in categories based on their history. Welds in upgraded or replacement piping are examined on a standard schedule (at least every five years) while welds with evidence of IGSCC, evaluated as acceptable for service, are inspected at every extended outage (15 to 18 months). This includes all welds in PW systems three inches in diameter and above. Welds are replaced when MSCC exceeds the replacement criteria of more than twenty percent of pipe circumference of fifty percent of through-wall depth. In the future, we intend to perform flow sizing with automated UT techniques in addition to manual sizing to provide more information for comparison with future examinations

  20. 190-C Facility <90 Day Storage Pad inspection plan

    International Nuclear Information System (INIS)

    This document provides the inspection plan for the 190-C Facility <90 Day Storage Pad. The 190-C Facility <90 Day Storage Pad stores waste oils contaminated with lead generated while draining oil from equipment within 290-C. The 190-C pumphouse originally pumped water to the C Reactor after the water was treated/filtered in an adjacent building. Characteristic waste oil is removed from the facility equipment, packaged and stored in fifty-five-gallon drums. Included in this plan are the details concerning necessary security equipment, inspection for proper sign posting and other factors that may affect the integrity of the facility. The 190-C Facility <90 Day Storage Pad shall be inspected at lease once each calendar week

  1. Visual inspection for CTBT verification

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, W.; Wohletz, K.

    1997-03-01

    On-site visual inspection will play an essential role in future Comprehensive Test Ban Treaty (CTBT) verification. Although seismic and remote sensing techniques are the best understood and most developed methods for detection of evasive testing of nuclear weapons, visual inspection can greatly augment the certainty and detail of understanding provided by these more traditional methods. Not only can visual inspection offer ``ground truth`` in cases of suspected nuclear testing, but it also can provide accurate source location and testing media properties necessary for detailed analysis of seismic records. For testing in violation of the CTBT, an offending party may attempt to conceal the test, which most likely will be achieved by underground burial. While such concealment may not prevent seismic detection, evidence of test deployment, location, and yield can be disguised. In this light, if a suspicious event is detected by seismic or other remote methods, visual inspection of the event area is necessary to document any evidence that might support a claim of nuclear testing and provide data needed to further interpret seismic records and guide further investigations. However, the methods for visual inspection are not widely known nor appreciated, and experience is presently limited. Visual inspection can be achieved by simple, non-intrusive means, primarily geological in nature, and it is the purpose of this report to describe the considerations, procedures, and equipment required to field such an inspection.

  2. From PISC to risk informed inspection

    International Nuclear Information System (INIS)

    In this paper the correlation between inspection effectiveness, inspection qualification and risk informed inspection will be treated in view of harmonisation of inspection of nuclear plant components. Through the different phases of the PISC programme the necessity has been demonstrated to show the effectiveness of the inspection through a formal process of qualification in order to ensure that a certain level of effectiveness has been reached. Inspection qualification is indeed the way to quantify the capability level of inspection techniques used. The targets to be met by the inspection is information which should be obtained from risk based analyses. (author)

  3. Tools for nuclear inspection

    International Nuclear Information System (INIS)

    IAEA nuclear inspectors have a range of high-tech tools at their disposal. Over the last decade, there have been significant improvements in the technology they use, mostly software advances make equipment more powerful and provide faster results. As they gather evidence, inspectors use a broad array of technologies, such as hand held radiation detectors and measurement instruments. Some instruments are used to search for nuclear and radioactive materials known to be associated with weapons making. Others can identify specific radioactive elements in samples that inspectors collect for fuller analysis in laboratories. Methods and equipment used include swipe sampling, multi-channel analyzers (MCAs), alloy detectors (ALEX), environmental monitoring instruments, digital video surveillance systems, satellite imagery and inspection databases. The IAEA has its own experts and facilities, through its Safeguards Analytical Laboratory in Austria, experienced in sample measurements and analysis. A 'Clean Laboratory' equipped with highly sensitive instruments including electron microscopes and mass-spectrometers is operational there. Network labs involved are in Australia, France, Germany, Japan, Russia, united Kingdom and the United States

  4. Final inspection of photomask blanks

    Science.gov (United States)

    Schubert, Fredi; Sauerbrei, Hartmut; Aschke, Lutz; Knapp, Konrad

    2001-04-01

    In order to increase the quality in manufacturing of future photon mask generations Schott Lithotec is brought in a brand new, much increased automatic laser inspection system into a new manufacturing line of photo mask blanks. It is in a position to detect additionally to the standard defect types further defect types like dim- and bright-chrome defects. The resolution of the system is less than 100 nm. With a quickly inspecting time per blank of less than three minutes and for the first time in the world used automatic SMIF-pod-handling this is a tool for the 100 percent final inspection in the manufacturing of photo mask blanks.

  5. Non-destructive inservice inspections

    International Nuclear Information System (INIS)

    In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

  6. Pipe inspection using the pipe crawler. Innovative technology summary report

    International Nuclear Information System (INIS)

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned

  7. Pipe inspection using the pipe crawler. Innovative technology summary report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-05-01

    The US Department of Energy (DOE) continually seeks safer and more cost-effective remediation technologies for use in the decontamination and decommissioning (D and D) of nuclear facilities. In several of the buildings at the Fernald Site, there is piping that was used to transport process materials. As the demolition of these buildings occur, disposal of this piping has become a costly issue. Currently, all process piping is cut into ten-foot or less sections, the ends of the piping are wrapped and taped to prevent the release of any potential contaminants into the air, and the piping is placed in roll off boxes for eventual repackaging and shipment to the Nevada Test Site (NTS) for disposal. Alternatives that allow for the onsite disposal of process piping are greatly desired due to the potential for dramatic savings in current offsite disposal costs. No means is currently employed to allow for the adequate inspection of the interior of piping, and consequently, process piping has been assumed to be internally contaminated and thus routinely disposed of at NTS. The BTX-II system incorporates a high-resolution micro color camera with lightheads, cabling, a monitor, and a video recorder. The complete probe is capable of inspecting pipes with an internal diameter (ID) as small as 1.4 inches. By using readily interchangeable lightheads, the same system is capable of inspecting piping up to 24 inches in ID. The original development of the BTX system was for inspection of boiler tubes and small diameter pipes for build-up, pitting, and corrosion. However, the system is well suited for inspecting the interior of most types of piping and other small, confined areas. The report describes the technology, its performance, uses, cost, regulatory and policy issues, and lessons learned.

  8. Visual Inspection of the Flow Distribution Plates of Ulchin NPP 3 SG

    International Nuclear Information System (INIS)

    An equipment for visually inspecting the joining bolts of the flow distribution plates (FDP) of the OPR1000 steam generators(SG) of Ulchin NPP 3 had been developed and tested during plant outage from 25th to 26th of February, 2010. By using the equipment, we could visually identify that most of the FDP joining bolts were in good condition. During the hot test of the equipment, we further found that the surface of the internal structure of Ulchin 3 SG was covered with light absorbing powder mostly composed of metal oxides. Therefore, we could not take good images for certain bolts which were relatively far away. Even though the development and hot application was successful, we concluded that further experiments are necessary using SG mockup which is prepared to be similar to the actual SG internal covered with metal oxide powder

  9. Condition Assessment Survey (CAS) Program. Deficiency standards and inspections methods manual: Volume 3, 0.03 Superstructure

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    General information is presented on asset determinant factor/CAS profile codes/CAS cost process; guide sheet tool & material listing; testing methods; inspection frequency; standard system design life tables; system work breakdown structure; and general system/material data. Deficiency standards and inspection methods are presented for beams; pre-engineered building systems; floors; roof structure; stairs; and fireproofing.

  10. New developments for optimization of automatic inspections in nuclear power plants

    International Nuclear Information System (INIS)

    One of the most important factors to be taken into acount with respect to remote control mechanized inspection tasks carried out during refueling outages in nuclear power plants, which include components and systems as varied as the reactor vessel, nozzles, piping, vessel head closure bolts, turbine discs, etc., is the unification of systems used to control the inspection systems themselves. Likewise, the implementation in these systems of specific functions simplifying operational sequences and confirming correct execution of work implies a set of criteria that must be taken into account if the reliability of the tasks carried out is to be increased. The system presented in this paper, SIROCCO (Sistema Robotizado de Control) has been designed taking into consideration the above mentioned criteria, with two clear obectives in mind: a reduction in inspection times and in the dose received by the participating technical personnel, and an increase in the reliability of the electronic equipment used. In February and March of this year, during shutdown of a BMR-type nuclear power plant, several SIROCCO control units were usids in mechanized inspection systems of various kinds, applicable to components such as those mentioned above, with forecasts regarding the reduction of inspection times being met. The main reasons for this reduction were the familiarity of the operators with this single control system, the unification of replacement parts for equipment maintenance and the availability of interchangeable units. This philosophy of unification of electronic systems also includes data acquisition and the transmission of information between different areas, which require the unification of control systems already commented and accomplished. This course of action is currently under development at Tecnatom. (author). 4 figs

  11. Simulation examples of ultrasonic inspection

    International Nuclear Information System (INIS)

    The paper gives examples of application of two very different computer programs that are used to simulate and model ultrasonic inspection. The real propagation path of the sound beam can be difficult to trace when the geometry is complex. Ray tracing simulation on a three dimensional model of the inspection geometry can be very useful and sometimes nearly a necessity to analyse the probe angles and scanning paths. The modelling of the sound pulse behaviour in the material and its interaction with geometric details and defects produces information about the signals that can occur during the inspection. Simulation examples show how information can be generated to support inspection design, data analyses and qualification. (orig.)

  12. Incore inspection and repairing device

    International Nuclear Information System (INIS)

    The present invention provides a device for inspecting and repairing the inside of a reactor container even if it is narrow, with no trouble by using a swimming-type operation robot. Namely, the device of the present invention conducts inspection and repairing operations for the inside of the reactor by introducing a swimming type operation robot into the reactor container. The swimming-type operation robot comprises a robot main body having a propeller, a balancer operably disposed to the robot main body and an inspection and repairing unit attached detachable to the balancer. In the device of the present invention, since the inspection and preparing unit is attached detachably to the swimming robot, a robot which transports tools is formed as a standard product. As a result, the production cost can be reduced, and the reliability of products can be improved. Appropriate operations can be conducted by using best tools. (I.S.)

  13. Multifamily Housing Physical Inspection Scores

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Real Estate Assessment Center conducts physical property inspections of properties that are owned, insured or subsidized by HUD, including public housing and...

  14. National Automated Conformity Inspection Process

    Data.gov (United States)

    Department of Transportation — The National Automated Conformity Inspection Process (NACIP) Application is intended to expedite the workflow process as it pertains to the FAA Form 81 0-10 Request...

  15. CIGAR - a remote inspection system

    International Nuclear Information System (INIS)

    CIGAR (Channel Inspection and Gauging Apparatus for Reactors) is an automated system that has been developed by Ontario Hydro, Canadian General Electric and AECL for the inspection of pressure tubes in CANDU reactors. It performs volumetric flaw detection, diameter and wall thickness measurement, sag profile measurement and spacer location determination. The inspection systems employed may have application in other situations and they well demonstrate the capabilities that exist in Canada for the development of sophisticated technology to solve complex problems. Part 1 of this paper discusses the requirements for the system and describes the CIGAR inspection, data acquisition and processing components that were developed by Ontario Hydro's Research Division. Part 2 describes the CIGAR delivery system that was developed by Canadian General Electric

  16. Sea bed mapping and inspection

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The conference has 24 presentations on the topics: Sea bed mapping, inspection, positioning, hydrography, marine archaeology, remote operation vehicles and computerized simulation technologies, oil field activities and plans, technological experiences and problems. (tk)

  17. Ultrasonic Inspection Of Thick Sections

    Science.gov (United States)

    Friant, C. L.; Djordjevic, B. B.; O'Keefe, C. V.; Ferrell, W.; Klutz, T.

    1993-01-01

    Ultrasonics used to inspect large, relatively thick vessels for hidden defects. Report based on experiments in through-the-thickness transmission of ultrasonic waves in both steel and filament-wound composite cases of solid-fuel rocket motors.

  18. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

  19. Public Housing Physical Inspection Scores

    Data.gov (United States)

    Department of Housing and Urban Development — HUD's Real Estate Assessment Center conducts physical property inspections of properties that are owned, insured or subsidized by HUD, including public housing and...

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

    KAUST Repository

    Nam, Sungsik

    2010-11-01

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

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

    KAUST Repository

    Xia, Minghua

    2012-11-01

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

  2. Virtual World Security Inspection

    Directory of Open Access Journals (Sweden)

    Nicholas Charles Patterson

    2012-06-01

    Full Text Available Virtual property theft is a serious problem that exists in virtual worlds. Legitimate users of these worlds invest considerable amounts of time, effort and real-world money into obtaining virtual property, but unfortunately, are becoming victims of theft in high numbers. It is reported that there are over 1 billion registered users of virtual worlds containing virtual property items worth an estimated US$50 billion dollars. The problem of virtual property theft is complex, involving many legal, social and technological issues. The software used to access virtual worlds is of great importance as they form the primary interface to these worlds and as such the primary interface to conduct virtual property theft. The security vulnerabilities of virtual world applications have not, to date, been examined. This study aims to use the process of software inspection to discover security vulnerabilities that may exist within virtual world software – vulnerabilities that enable virtual property theft to occur. Analyzing three well know virtual world applications World of Warcraft, Guild Wars and Entropia Universe, this research utilized security analysis tools and scenario testing with focus on authentication, trading, intruder detection and virtual property recovery. It was discovered that all three examples were susceptible to keylogging, mail and direct trade methods were the most likely method for transferring stolen items, intrusion detection is of critical concern to all VWEs tested, stolen items were unable to be recovered in all cases and lastly occurrences of theft were undetectable in all cases. The results gained in this study present the key problem areas which need to be addressed to improve security and reduce the occurrence of virtual property theft.

  3. Automation of painted slate inspection

    OpenAIRE

    Carew, Tim

    2002-01-01

    This thesis is concerned with the problem of how to detect visual defects on painted slates using an automated visual inspection system. The vision system that has been developed consists of two major components. The first component addresses issues such as the mechanical implementation and interfacing the inspection system with the optical and sensing equipment whereas the second component involves the development of an image processing algorithm able to identify the visual defects present o...

  4. Ultrasonic nondestructive tubing inspection system

    International Nuclear Information System (INIS)

    A system for measuring the extent of tube wall erosion in an inspection region of a heat exchanger tube of a nuclear steam generator, uses an ultrasonic means driven helically inside the eroded tube which may be filled with a fluid (e.g., water) to minimize ultrasonic wave attenuation. A control means cooperates with the ultrasonic means to produce a map of the tube wall thickness in an inspection region

  5. An intelligent inspection and survey robot

    International Nuclear Information System (INIS)

    ARIES (Autonomous Robotic Inspection Experimental System) is a semi-autonomous robotic system intended for use in the automatic inspection of stored containers of low level nuclear waste. The project is being performed by a team under the SCUREF (South Carolina University Research and Education Foundation) comprised of the University of South Carolina, and Clemson University, and their industrial partner Cybermotion Inc., with funding from METC, Morgantown, WV. The ARIES program is unusual in the level of cooperation between the universities and Cybermotion. By maintaining daily communications via telephone and E-Mall, participating in frequent meetings with each other and the end users, and by developing an open flow of (sometimes sensitive) technical information, the team has been able to build on a very broad base of intellectual strengths and existing technology without wasteful duplication. This base includes all of the navigation and control software and hardware developed by Cybermotion over nearly a decade and the deep technology resources of the university partners. It is anticipated that the result will be a technically advanced system that is much closer to a deployable configuration than is typical for this stage of research. In this decade of shrinking budgets, such relationships can provide a crucial advantage for all participants

  6. PROMSYS, Plant Equipment Maintenance and Inspection Scheduling

    International Nuclear Information System (INIS)

    1 - Description of problem or function: PROMSYS is a computer system designed to automate the scheduling of routine maintenance and inspection of plant equipment. This 'programmed maintenance' provides the detailed planning and accomplishment of lubrication, inspection, and similar repetitive maintenance activities which can be scheduled at specified predetermined intervals throughout the year. The equipment items included are the typical pumps, blowers, motors, compressors, automotive equipment, refrigeration units, filtering systems, machine shop equipment, cranes, elevators, motor-generator sets, and electrical switchgear found throughout industry, as well as cell ventilation, shielding, containment, and material handling equipment unique to nuclear research and development facilities. Four related programs are used to produce sorted schedule lists, delinquent work lists, and optional master lists. Five additional programs are used to create and maintain records of all scheduled and unscheduled maintenance history. 2 - Method of solution: Service specifications and frequency are established and stored. The computer program reviews schedules weekly and prints, on schedule cards, instructions for service that is due the following week. The basic output from the computer program comes in two forms: programmed-maintenance schedule cards and programmed-maintenance data sheets. The data sheets can be issued in numerical building, route, and location number sequence as equipment lists, grouped for work assigned to a particular foreman as the foreman's equipment list, or grouped by work charged to a particular work order as the work-order list. Data sheets grouped by equipment classification are called the equipment classification list

  7. An intelligent inspection and survey robot

    Energy Technology Data Exchange (ETDEWEB)

    Byrd, J.; Holland, J.M.

    1995-02-01

    ARIES (Autonomous Robotic Inspection Experimental System) is a semi-autonomous robotic system intended for use in the automatic inspection of stored containers of low level nuclear waste. The project is being performed by a team under the SCUREF (South Carolina University Research and Education Foundation) comprised of the University of South Carolina, and Clemson University, and their industrial partner Cybermotion Inc., with funding from METC, Morgantown, WV. The ARIES program is unusual in the level of cooperation between the universities and Cybermotion. By maintaining daily communications via telephone and E-Mall, participating in frequent meetings with each other and the end users, and by developing an open flow of (sometimes sensitive) technical information, the team has been able to build on a very broad base of intellectual strengths and existing technology without wasteful duplication. This base includes all of the navigation and control software and hardware developed by Cybermotion over nearly a decade and the deep technology resources of the university partners. It is anticipated that the result will be a technically advanced system that is much closer to a deployable configuration than is typical for this stage of research. In this decade of shrinking budgets, such relationships can provide a crucial advantage for all participants.

  8. Ultrasonic inspection of inpile tubes

    International Nuclear Information System (INIS)

    The in-service inspection (ISI) of inpile tubes can be performed accurately and safely with a semiautomatic ultrasonic inspection system. The ultrasonic technique uses a set of multiple transducers to detect and size cracks, voids, and laminations radially and circumferentially. Welds are also inspected for defects. The system is designed to inspect stainless steel and Inconel tubes ranging from 53.8 mm (2.12 in.) to 101.6 mm (4 in.) inner diameter with wall thickness on the order of 5 mm. The inspection head contains seven transducers mounted in a surface-following device. Six angle-beam transducers generate shear waves in the tubes. Two of the six are oriented to detect circumferential cracks, and two detect axial cracks. Although each of these four transducers is used in the pulse-echo mode, they are oriented in aligned sets so pitch-catch operation is possible if desired. The remaining angle-beam transducers are angulated to detect flaws that are off axial or circumferential orientation. The seventh transducer is used for longitudinal inspection and detects and sizes laminar-type defects

  9. Structural assessment of roof decking using visual inspection methods

    International Nuclear Information System (INIS)

    The Hanford Site has approximately 1,100 buildings, some of which date back to the early 1940s. The roof on these buildings provides a weather resisting cover as well as the load resisting structure. Past experience has been that these roof structures may have structural modifications, the weather resisting membrane may have been replaced several times, and the members may experience some type of material degradation. This material degradation has progressed to cause the collapse of some roof deck members. The intent of the Hanford Site Central Engineering roof assessment effort is to provide an expedient structural assessment of the large number of buildings at the Hanford Site. This assessment is made by qualified structural inspectors following the open-quotes Preliminary Assessmentclose quotes procedures given in the American Society of Civil Engineers (ASCE) Standard ASCE 11-90. This roof assessment effort does not provide a total qualification of the roof for the design or in-place loads. This inspection does provide a reasonable estimate of the roof loading capacity to determine if personnel access restrictions are needed. A document search and a visual walkdown inspection provide the initial screening to identify modifications and components having questionable structural integrity. The structural assessment consists of baseline dead and live load stress calculations of all roofing components based on original design material strengths. The results of these assessments are documented in a final report which is retrievable in a form that future inspections will have comparative information

  10. Structural assessment of roof decking using visual inspection methods

    Energy Technology Data Exchange (ETDEWEB)

    Giller, R.A.; McCoy, R.M.; Wagenblast, G.R.

    1993-10-01

    The Hanford Site has approximately 1,100 buildings, some of which date back to the early 1940s. The roof on these buildings provides a weather resisting cover as well as the load resisting structure. Past experience has been that these roof structures may have structural modifications, the weather resisting membrane may have been replaced several times, and the members may experience some type of material degradation. This material degradation has progressed to cause the collapse of some roof deck members. The intent of the Hanford Site Central Engineering roof assessment effort is to provide an expedient structural assessment of the large number of buildings at the Hanford Site. This assessment is made by qualified structural inspectors following the {open_quotes}Preliminary Assessment{close_quote} procedures given in the American Society of Civil Engineers (ASCE) Standard ASCE 11-90. This roof assessment effort does not provide a total qualification of the roof for the design or in-place loads. This inspection does provide a reasonable estimate of the roof loading capacity to determine if personnel access restrictions are needed. A document search and a visual walkdown inspection provide the initial screening to identify modifications and components having questionable structural integrity. The structural assessment consists of baseline dead and live load stress calculations of all roofing components based on original design material strengths. The results of these assessments are documented in a final report which is retrievable form that future inspections will have comparative information.

  11. Structural assessment of roof decking using visual inspection methods

    International Nuclear Information System (INIS)

    The Hanford Site has approximately 1,100 buildings, some of which date back to the early 1940s. The roof on these buildings provides a weather resisting cover as well as the load resisting structure. Past experience has been that these roof structures may have structural modifications, the weather resisting membrane may have been replaced several times, and the members may experience some type of material degradation. This material degradation has progressed to cause the collapse of some roof deck members. The intent of the Hanford Site Central Engineering roof assessment effort is to provide an expedient structural assessment of the large number of buildings at the Hanford Site. This assessment is made by qualified structural inspectors following the open-quotes Preliminary Assessment close-quote procedures given in the American Society of Civil Engineers (ASCE) Standard ASCE 11-90. This roof assessment effort does not provide a total qualification of the roof for the design or in-place loads. This inspection does provide a reasonable estimate of the roof loading capacity to determine if personnel access restrictions are needed. A document search and a visual walkdown inspection provide the initial screening to identify modifications and components having questionable structural integrity. The structural assessment consists of baseline dead and live load stress calculations of all roofing components based on original design material strengths. The results of these assessments are documented in a final report which is retrievable form that future inspections will have comparative information

  12. Risk based inspection programmes; Risikobaserte inspeksjonsprogrammer

    Energy Technology Data Exchange (ETDEWEB)

    Haugland, Haakon

    1998-07-01

    Risk based inspection is a method of selecting which parts or components of an offshore installation should be inspected and when if the resources available for inspection is to be fully exploited. By inspecting the components involving the highest risk, an optimum risk reduction is achieved. The risk level is a function of fault probability and fault consequence.

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

    International Nuclear Information System (INIS)

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

  14. Inspection procedures for effective GPR surveying of buildings

    OpenAIRE

    Pérez Gracia, María de la Vega; Solla Carracelas, Mercedes

    2015-01-01

    This book, based on Transport and Urban Development COST Action TU1208, presents the most advanced applications of ground penetrating radar (GPR) in a civil engineering context, with documentation of instrumentation, methods and results. It explains clearly how GPR can be employed for the surveying of critical transport infrastructure, such as roads, pavements, bridges and tunnels and for the sensing and mapping of underground utilities and voids. Detailed attention is also devoted to use of ...

  15. 49 CFR Appendix A to Part 230 - Inspection Requirements

    Science.gov (United States)

    2010-10-01

    .... Inspection of brake cylinders for piston travel. 11. Inspection of foundation brake gear. 12. Inspection of... crossheads and guides. 16. Inspection of piston rods and fasteners. 17. Inspection of main, side, and...

  16. Road navigation using multiple dissimilar environmental features to bridge GNSS outages

    OpenAIRE

    Walter, D; Groves, P. D.; Mason, B.; Harrison, J.(School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom); Woodward, J.; Wright, P

    2015-01-01

    Many navigation techniques have now become so reliant on GNSS that there is no back-up when there is limited or no signal reception. If there is interference, deliberate jamming or spoofing, and/or blockage and reflection of the signals by buildings, navigation could be lost or become misleading. Other navigation techniques harness different technologies such as Wi-Fi, eLoran and inertial navigation. However, each of these techniques has its own limitations, such as coverage, degradation in u...

  17. ROBOTIC TANK INSPECTION END EFFECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Rachel Landry

    1999-10-01

    The objective of this contract between Oceaneering Space Systems (OSS) and the Department of Energy (DOE) was to provide a tool for the DOE to inspect the inside tank walls of underground radioactive waste storage tanks in their tank farms. Some of these tanks are suspected to have leaks, but the harsh nature of the environment within the tanks precludes human inspection of tank walls. As a result of these conditions only a few inspection methods can fulfill this task. Of the methods available, OSS chose to pursue Alternating Current Field Measurement (ACFM), because it does not require clean surfaces for inspection, nor any contact with the Surface being inspected, and introduces no extra by-products in the inspection process (no coupling fluids or residues are left behind). The tool produced by OSS is the Robotic Tank Inspection End Effector (RTIEE), which is initially deployed on the tip of the Light Duty Utility Arm (LDUA). The RTEE combines ACFM with a color video camera for both electromagnetic and visual inspection The complete package consists of an end effector, its corresponding electronics and software, and a user's manual to guide the operator through an inspection. The system has both coarse and fine inspection modes and allows the user to catalog defects and suspected areas of leakage in a database for further examination, which may lead to emptying the tank for repair, decommissioning, etc.. The following is an updated report to OSS document OSS-21100-7002, which was submitted in 1995. During the course of the contract, two related subtasks arose, the Wall and Coating Thickness Sensor and the Vacuum Scarifying and Sampling Tool Assembly. The first of these subtasks was intended to evaluate the corrosion and wall thinning of 55-gallon steel drums. The second was retrieved and characterized the waste material trapped inside the annulus region of the underground tanks on the DOE's tank farms. While these subtasks were derived from the original

  18. ROBOTIC TANK INSPECTION END EFFECTOR

    International Nuclear Information System (INIS)

    The objective of this contract between Oceaneering Space Systems (OSS) and the Department of Energy (DOE) was to provide a tool for the DOE to inspect the inside tank walls of underground radioactive waste storage tanks in their tank farms. Some of these tanks are suspected to have leaks, but the harsh nature of the environment within the tanks precludes human inspection of tank walls. As a result of these conditions only a few inspection methods can fulfill this task. Of the methods available, OSS chose to pursue Alternating Current Field Measurement (ACFM), because it does not require clean surfaces for inspection, nor any contact with the Surface being inspected, and introduces no extra by-products in the inspection process (no coupling fluids or residues are left behind). The tool produced by OSS is the Robotic Tank Inspection End Effector (RTIEE), which is initially deployed on the tip of the Light Duty Utility Arm (LDUA). The RTEE combines ACFM with a color video camera for both electromagnetic and visual inspection The complete package consists of an end effector, its corresponding electronics and software, and a user's manual to guide the operator through an inspection. The system has both coarse and fine inspection modes and allows the user to catalog defects and suspected areas of leakage in a database for further examination, which may lead to emptying the tank for repair, decommissioning, etc.. The following is an updated report to OSS document OSS-21100-7002, which was submitted in 1995. During the course of the contract, two related sub-tasks arose, the Wall and Coating Thickness Sensor and the Vacuum Scarifying and Sampling Tool Assembly. The first of these sub-tasks was intended to evaluate the corrosion and wall thinning of 55-gallon steel drums. The second was retrieved and characterized the waste material trapped inside the annulus region of the underground tanks on the DOE's tank farms. While these sub-tasks were derived from the original intent

  19. Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

    Energy Technology Data Exchange (ETDEWEB)

    J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

    2006-09-30

    be sufficiently small with respect to the bore of the pipe to pass obstructions that limit the application of many inspection technologies. Also, since the largest dimension of the Hall Effect sensor is two tenths of an inch, the sensor packages can be small, flexible and light. The power consumption, on the order of ten watts, is low compared to some inspection systems; this would enable autonomous systems to inspect longer distances between charges. This project showed there are no technical barriers to building a field ready unit that can pass through narrow obstructions, such as plug valves. The next step in project implementation is to build a field ready unit that can begin to establish optimal performance capabilities including detection thresholds, sizing capability, and wall thickness limitations.

  20. OSE inspection of protection program operations field perspective of inspections

    International Nuclear Information System (INIS)

    Protection Program Operations includes three functional areas: Physical Protection Systems, Protective Forces, and System Performance Testing. The Office of Security Evaluations (OSE) inspects field offices in these areas by evaluating programs relative to Standards and Criteria and by performing a variety of exercises and other types of tests to assure protective systems are effective and maintained at a proper level to meet the defined threat. Their perception of the OSE inspections has been positive. The approach taken by ID, with key areas/activities emphasized, during each phase of the field inspection process is described in this report. The most important areas for field offices to concentrate are: inspection preparations through self-evaluation, improving communications, assigning knowledgeable trusted agents, increasing awareness of facility procedures and operations, and assuring daily validations of inspected areas. Emphasis is placed on striving for a balance in reporting both positive and negative findings, and for consistency between ratings and the importance of report findings. OSE efforts to develop improved rating methodologies are encouraged

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

    International Nuclear Information System (INIS)

    This report contains the findings from the first phase of a study on safety during outage and restart of nuclear power plants. Operational Readiness Verification (ORV) - in Swedish called Driftklarhetsverifiering (DKV) - refers to the test and verification activities that are necessary to ensure that plant systems are able to provide their required functions when needed - more concretely that all plant systems are in their correct functional state when the plant is restarted after an outage period. The concrete background for this work is that nine ORV related incidents were reported in Sweden between July 1995 and October 1998. The work reported here comprised a literature survey of research relevant for ORV issues, and an assessment of the present situation at Swedish NPPs with respect to ORV. The literature survey was primarily aimed at research related to NPPs, but also looked at domains where similar problems have occurred, such as maintenance in commercial aviation. The survey looked specifically for organisational and MTO aspects relevant to the present situation in Swedish NPPs. One finding was that ORV should be seen as an integral part of maintenance, rather than as a separate activity. Another, that there is a characteristic distribution of error modes for maintenance and ORV, with many sequence errors and omissions, rather than a set of unique error modes. An international study further showed that there are important differences in how procedures are used, and in the balance between decentralisation and centralisation. Several studies also suggested that ORV could usefully be described as a barrier system in relation to the flow of work, for instance using the following five stages: (1) preventive actions during maintenance/outage, (2) post-test after completion of work, (3) pre-test before start-up, (4) the start-up sequence itself, and (5) preventive actions during power operation - possibly including automatic safety systems. In the field survey

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-06-01

    This report contains the findings from the first phase of a study on safety during outage and restart of nuclear power plants. Operational Readiness Verification (ORV) - in Swedish called Driftklarhetsverifiering (DKV) - refers to the test and verification activities that are necessary to ensure that plant systems are able to provide their required functions when needed - more concretely that all plant systems are in their correct functional state when the plant is restarted after an outage period. The concrete background for this work is that nine ORV related incidents were reported in Sweden between July 1995 and October 1998. The work reported here comprised a literature survey of research relevant for ORV issues, and an assessment of the present situation at Swedish NPPs with respect to ORV. The literature survey was primarily aimed at research related to NPPs, but also looked at domains where similar problems have occurred, such as maintenance in commercial aviation. The survey looked specifically for organisational and MTO aspects relevant to the present situation in Swedish NPPs. One finding was that ORV should be seen as an integral part of maintenance, rather than as a separate activity. Another, that there is a characteristic distribution of error modes for maintenance and ORV, with many sequence errors and omissions, rather than a set of unique error modes. An international study further showed that there are important differences in how procedures are used, and in the balance between decentralisation and centralisation. Several studies also suggested that ORV could usefully be described as a barrier system in relation to the flow of work, for instance using the following five stages: (1) preventive actions during maintenance/outage, (2) post-test after completion of work, (3) pre-test before start-up, (4) the start-up sequence itself, and (5) preventive actions during power operation - possibly including automatic safety systems. In the field survey

  3. Restaurant Inspection Scores and Foodborne Disease

    OpenAIRE

    Jones, Timothy F.; Pavlin, Boris I; LaFleur, Bonnie J.; Ingram, L. Amanda; Schaffner, William

    2004-01-01

    Restaurants in the United States are regularly inspected by health departments, but few data exist regarding the effect of restaurant inspections on food safety. We examined statewide inspection records from January 1993 through April 2000. Data were available from 167,574 restaurant inspections. From 1993 to 2000, mean scores rose steadily from 80.2 to 83.8. Mean inspection scores of individual inspectors were 69–92. None of the 12 most commonly cited violations were critical food safety haz...

  4. Examination of the association between announced inspections and inspection scores.

    Science.gov (United States)

    Waters, A Blake; VanDerslice, James; Porucznik, Christina A; Kim, Jaewhan; DeLegge, Royal; Durrant, Lynne

    2013-09-01

    In 2010 the Salt Lake Valley Health Department conducted a pilot of an announced inspection program utilizing a randomized assignment of restaurants to an intervention group with announced inspections and a control group that remained on the usual schedule of unannounced inspections. After adjusting for food type, visible kitchen, outside quality assurance, season, and standardized inspector, significant reductions were found in the odds ratios of personal hygiene (adjusted odds ratios [aOR] = 0.11, p = .00) and equipment cleanliness (aOR = 0.19, p = .00) violations. In the models for the control group, none of the odds ratios were statistically different from one, indicating no change in the postintervention time period as compared to the preintervention period. PMID:24073484

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

    International Nuclear Information System (INIS)

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

  6. Reactor building

    International Nuclear Information System (INIS)

    The whole reactor building is accommodated in a shaft and is sealed level with the earth's surface by a building ceiling, which provides protection against penetration due to external effects. The building ceiling is supported on walls of the reactor building, which line the shaft and transfer the vertical components of forces to the foundations. The thickness of the walls is designed to withstand horizontal pressure waves in the floor. The building ceiling has an opening above the reactor, which must be closed by cover plates. Operating equipment for the reactor can be situated above the building ceiling. (orig./HP)

  7. Independent validation of ultrasonic inspection

    International Nuclear Information System (INIS)

    As a part of its inspection strategy for the Sizewell-B PWR station, the Central Electricity Generating Board (in part now Nuclear Electric) decided that the ultrasonic inspection procedures for the incredibility of failure components would be subjected to independent confirmation of their adequacy. The incorporation of validation into a large-scale inspection strategy was unique at the time (1982), indeed remains so today. The CEGB's general philosophy is one of diversity, redundancy and validation. In order to carry out independent validation of the specific procedures and ultrasonic operators to be used during the manufacture and in-service inspection of the reactor pressure vessel and steam plant components, the Inspection Validation Centre (IVC) has operated as a contractor to Nuclear Electric with special arrangements in place to guarantee independence. The setting-up and early methods of operation of IVC are briefly reviewed, the most recent operational experience summarized and the technical significance of the validations to date discussed. (author). 1 fig

  8. Building America

    Energy Technology Data Exchange (ETDEWEB)

    Brad Oberg

    2010-12-31

    IBACOS researched the constructability and viability issues of using high performance windows as one component of a larger approach to building houses that achieve the Building America 70% energy savings target.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  11. Improvement of foundation for inspection

    International Nuclear Information System (INIS)

    Japan Nuclear Energy Safety Organization has been carrying out improvement of inspection system for nuclear plants in Japan since 2003FY. The new inspection system was introduced into nuclear power plants in-2008FY. In this project, improvement of comprehensive plant performance assessment and management tool for the new inspection system are developed. In 2012FY, a trend analysis method of the plant performance was developed with reference to the IAEA literature. And the trend analysis was tried based on the results of the comprehensive plant performance assessment of all domestic plants except Fukushima-Daiichi Nuclear Power Station. In addition, the teaching materials for QMS training guideline were made. And improvement of a quality management system evaluation support tool was performed. (author)

  12. Autonomous underwater riser inspection tool

    Energy Technology Data Exchange (ETDEWEB)

    Camerini, Claudio; Marnet, Robson [Petrobras SA, (Brazil); Freitas, Miguel; Von der Weid, Jean Pierre [CPTI/PUC-Rio, Rio de Janeiro, (Brazil); Artigas Lander, Ricardo [EngeMOVI, Curitiba, (Brazil)

    2010-07-01

    The detection of damage on the riser is a serious concern for pipeline companies. Visual examinations by remotely operated vehicle (ROV) are presently carried out to detect the defects but this process has limitations and is expensive. This paper presents the development of a new tool to ensure autonomous underwater riser inspection (AURI) that uses the riser itself for guidance. The AURI, which is autonomous in terms of control and power supply, is equipped with several cameras that perform a complete visual inspection of the riser with 100 % coverage of the external surface of the riser. The paper presents the detailed characteristics of the first AURI prototype, describes its launching procedure and provides the preliminary test results from pool testing. The results showed that the AURI is a viable system for autonomous riser inspection. Offshore tests on riser pipelines are scheduled to be performed shortly.

  13. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

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

    KAUST Repository

    Yang, Yuli

    2012-09-01

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

  15. Building 2000

    International Nuclear Information System (INIS)

    This is the first volume of Building 2000, a pilot project of the Commission's R and D-programme 'Solar Energy Applications to Buildings' with the purpose of encouraging the adoption of solar architecture in large buildings. In this first rich illustrated volume the results of the design studies illustrating passive solar architecture in buildings in the European Community are presented in particular for the building categories as mentioned in the subtitle. In a second volume, a similar series of studies is presented for the building categories: office buildings, public buildings and hotels and holiday complexes. Several Design Support Workshops were organized during the Building 2000 programme during which Building 2000 design teams could directly exchange ideas with the various design advice experts represented at these workshops. In the second part of the Building 2000 final report a summary of a selection of many reports is presented (15 papers), as produced by Design Support experts. Most of the design support activities resulted in changes of the various designs, as have been reported by the design teams in the brochures presented in the first part of this book. It is to be expected that design aids and simulation tools for passive solar options, daylighting concepts, comfort criteria etc., will be utilized more frequently in the future. This will result in a better exchange of information between the actual design practitioners and the European R and D community. This technology transfer will result in buildings with a higher quality with respect to energy and environmental issues

  16. Evaluation of inservice inspection examinatiions

    International Nuclear Information System (INIS)

    In order to evaluate the effectiveness of Section 11, Division 1, ''Rules for Inservice Inspection of Nuclear Power Plant Components,'' of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code examinations, 26 inservice inspection (ISI) summary reports from 24 facilities were reviewed. It was found that these ASME Code examinations and tests are instrumental in revealing indications and defects in welds and plant components. In addition, this study uncovered that fact that some of the Section 11 requirements are apparently not clear and are misunderstood by some of the facilities. Also, the need for more stringent requirements was evaluated and some Code changes are recommended

  17. Evaluation of inservice inspection examinatiions

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, D.A.; Cook, J.F.

    1990-05-01

    In order to evaluate the effectiveness of Section 11, Division 1, ``Rules for Inservice Inspection of Nuclear Power Plant Components,`` of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code examinations, 26 inservice inspection (ISI) summary reports from 24 facilities were reviewed. It was found that these ASME Code examinations and tests are instrumental in revealing indications and defects in welds and plant components. In addition, this study uncovered that fact that some of the Section 11 requirements are apparently not clear and are misunderstood by some of the facilities. Also, the need for more stringent requirements was evaluated and some Code changes are recommended.

  18. Evaluation of inservice inspection examinatiions

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, D.A.; Cook, J.F.

    1990-05-01

    In order to evaluate the effectiveness of Section 11, Division 1, Rules for Inservice Inspection of Nuclear Power Plant Components,'' of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code examinations, 26 inservice inspection (ISI) summary reports from 24 facilities were reviewed. It was found that these ASME Code examinations and tests are instrumental in revealing indications and defects in welds and plant components. In addition, this study uncovered that fact that some of the Section 11 requirements are apparently not clear and are misunderstood by some of the facilities. Also, the need for more stringent requirements was evaluated and some Code changes are recommended.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2016-10-01

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