WorldWideScience

Sample records for plant generic aging

  1. Nuclear power plant Generic Aging Lessons Learned (GALL). Appendix B

    International Nuclear Information System (INIS)

    Kasza, K.E.; Diercks, D.R.; Holland, J.W.; Choi, S.U.

    1996-12-01

    The purpose of this generic aging lessons learned (GALL) review is to provide a systematic review of plant aging information in order to assess materials and component aging issues related to continued operation and license renewal of operating reactors. Literature on mechanical, structural, and thermal-hydraulic components and systems reviewed consisted of 97 Nuclear Plant Aging Research (NPAR) reports, 23 NRC Generic Letters, 154 Information Notices, 29 Licensee Event Reports (LERs), 4 Bulletins, and 9 Nuclear Management and Resources Council Industry Reports (NUMARC IRs) and literature on electrical components and systems reviewed consisted of 66 NPAR reports, 8 NRC Generic Letters, 111 Information Notices, 53 LERs, 1 Bulletin, and 1 NUMARC IR. More than 550 documents were reviewed. The results of these reviews were systematized using a standardized GALL tabular format and standardized definitions of aging-related degradation mechanisms and effects. The tables are included in volumes 1 and 2 of this report. A computerized data base has also been developed for all review tables and can be used to expedite the search for desired information on structures, components, and relevant aging effects. A survey of the GALL tables reveals that all ongoing significant component aging issues are currently being addressed by the regulatory process. However, the aging of what are termed passive components has been highlighted for continued scrutiny. This report consists of Volume 2, which consists of the GALL literature review tables for the NUMARC Industry Reports reviewed for the report

  2. Nuclear power plant Generic Aging Lessons Learned (GALL). Main report and appendix A

    Energy Technology Data Exchange (ETDEWEB)

    Kaza, K.E.; Diercks, D.R.; Holland, J.W.; Choi, S.U. [and others

    1996-12-01

    The purpose of this generic aging lessons learned (GALL) review is to provide a systematic review of plant aging information in order to assess materials and component aging issues related to continued operation and license renewal of operating reactors. Literature on mechanical, structural, and thermal-hydraulic components and systems reviewed consisted of 97 Nuclear Plant Aging Research (NPAR) reports, 23 NRC Generic Letters, 154 Information Notices, 29 Licensee Event Reports (LERs), 4 Bulletins, and 9 Nuclear Management and Resources Council Industry Reports (NUMARC IRs) and literature on electrical components and systems reviewed consisted of 66 NPAR reports, 8 NRC Generic Letters, 111 Information Notices, 53 LERs, 1 Bulletin, and 1 NUMARC IR. More than 550 documents were reviewed. The results of these reviews were systematized using a standardized GALL tabular format and standardized definitions of aging-related degradation mechanisms and effects. The tables are included in volume s 1 and 2 of this report. A computerized data base has also been developed for all review tables and can be used to expedite the search for desired information on structures, components, and relevant aging effects. A survey of the GALL tables reveals that all ongoing significant component aging issues are currently being addressed by the regulatory process. However, the aging of what are termed passive components has been highlighted for continued scrutiny. This document is Volume 1, consisting of the executive summary, summary and observations, and an appendix listing the GALL literature review tables.

  3. Nuclear power plant Generic Aging Lessons Learned (GALL). Main report and appendix A

    International Nuclear Information System (INIS)

    Kasza, K.E.; Diercks, D.R.; Holland, J.W.; Choi, S.U.

    1996-12-01

    The purpose of this generic aging lessons learned (GALL) review is to provide a systematic review of plant aging information in order to assess materials and component aging issues related to continued operation and license renewal of operating reactors. Literature on mechanical, structural, and thermal-hydraulic components and systems reviewed consisted of 97 Nuclear Plant Aging Research (NPAR) reports, 23 NRC Generic Letters, 154 Information Notices, 29 Licensee Event Reports (LERs), 4 Bulletins, and 9 Nuclear Management and Resources Council Industry Reports (NUMARC IRs) and literature on electrical components and systems reviewed consisted of 66 NPAR reports, 8 NRC Generic Letters, 111 Information Notices, 53 LERs, 1 Bulletin, and 1 NUMARC IR. More than 550 documents were reviewed. The results of these reviews were systematized using a standardized GALL tabular format and standardized definitions of aging-related degradation mechanisms and effects. The tables are included in volumes 1 and 2 of this report. A computerized data base has also been developed for all review tables and can be used to expedite the search for desired information on structures, components, and relevant aging effects. A survey of the GALL tables reveals that all ongoing significant component aging issues are currently being addressed by the regulatory process. However, the aging of what are termed passive components has been highlighted for continued scrutiny. This document is Volume 1, consisting of the executive summary, summary and observations, and an appendix listing the GALL literature review tables

  4. The Northeast Utilities generic plant computer system

    International Nuclear Information System (INIS)

    Spitzner, K.J.

    1980-01-01

    A variety of computer manufacturers' equipment monitors plant systems in Northeast Utilities' (NU) nuclear and fossil power plants. The hardware configuration and the application software in each of these systems are essentially one of a kind. Over the next few years these computer systems will be replaced by the NU Generic System, whose prototype is under development now for Millstone III, an 1150 Mwe Pressurized Water Reactor plant being constructed in Waterford, Connecticut. This paper discusses the Millstone III computer system design, concentrating on the special problems inherent in a distributed system configuration such as this. (auth)

  5. Using Service Oriented Architecture in a Generic Virtual Power Plant

    DEFF Research Database (Denmark)

    Andersen, Peter Bach; Poulsen, Bjarne; Træholt, Chresten

    2009-01-01

    The purpose of this paper is to find and describe a suitable software framework that can be used to help implement the concept of a Generic Virtual Power Plant in the future power system. The Generic Virtual Power Plant concept, along with the utilization of distributed energy resources, has many...... the Generic Virtual Power Plant, an array of different software design principles, patterns and architectures must be applied. Especially Service Oriented Architecture (SOA) can aid in implementing the Generic Virtual Power Plant.......The purpose of this paper is to find and describe a suitable software framework that can be used to help implement the concept of a Generic Virtual Power Plant in the future power system. The Generic Virtual Power Plant concept, along with the utilization of distributed energy resources, has many...... interesting properties that can influence the future shape of power markets. The concept holds many promises including cheaper power to the consumer, a more flexible and responsive power production and the support of a more environment-friendly development. In order to realize a software solution supporting...

  6. Generic nuclear power plant component failure data bank

    International Nuclear Information System (INIS)

    Araujo Goes, A.G. de; Gibelli, S.M.O.

    1988-11-01

    This report consist in the development of a generic nuclear power plant component failure data bank. This data bank was implemented in a PC-XT microcomputer, IBM compatible, using the Open Access II program. Generic failure data tables for Westinghouse nuclear power plants and for general PWR power plants are presented. They are the final product of a research which included a preselection and a selection of data collected from the available sources in the library of CNEN (National Nuclear Energy Commission) and from the CIN/CNEN (Neclear Information Center). Futhermore, a proposal of evaluating models of average failure rates of pumps and valves are also presented. Through the electronic data bank one can easily have a generic view of failure rate ranges as well as failure models foe a certain component. It is very importante to develop procedures to collect and store generic failure data that can be quickly accessed, in order to update the Probabilistic Safety Study of Angra-1 and to used in studies which may have component failures of nuclear power plant safety systems. In the future, data specialization can be achieved by means of statistical calculations involving specific data collected from the operational experience of Angra-1 nuclear power plant and the generic data bank. (author) [pt

  7. Method for assigning sites to projected generic nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Holter, G.M.; Purcell, W.L.; Shutz, M.E.; Young, J.R.

    1986-07-01

    Pacific Northwest Laboratory developed a method for forecasting potential locations and startup sequences of nuclear power plants that will be required in the future but have not yet been specifically identified by electric utilities. Use of the method results in numerical ratings for potential nuclear power plant sites located in each of the 10 federal energy regions. The rating for each potential site is obtained from numerical factors assigned to each of 5 primary siting characteristics: (1) cooling water availability, (2) site land area, (3) power transmission land area, (4) proximity to metropolitan areas, and (5) utility plans for the site. The sequence of plant startups in each federal energy region is obtained by use of the numerical ratings and the forecasts of generic nuclear power plant startups obtained from the EIA Middle Case electricity forecast. Sites are assigned to generic plants in chronological order according to startup date.

  8. Method for assigning sites to projected generic nuclear power plants

    International Nuclear Information System (INIS)

    Holter, G.M.; Purcell, W.L.; Shutz, M.E.; Young, J.R.

    1986-07-01

    Pacific Northwest Laboratory developed a method for forecasting potential locations and startup sequences of nuclear power plants that will be required in the future but have not yet been specifically identified by electric utilities. Use of the method results in numerical ratings for potential nuclear power plant sites located in each of the 10 federal energy regions. The rating for each potential site is obtained from numerical factors assigned to each of 5 primary siting characteristics: (1) cooling water availability, (2) site land area, (3) power transmission land area, (4) proximity to metropolitan areas, and (5) utility plans for the site. The sequence of plant startups in each federal energy region is obtained by use of the numerical ratings and the forecasts of generic nuclear power plant startups obtained from the EIA Middle Case electricity forecast. Sites are assigned to generic plants in chronological order according to startup date

  9. Generic environmental impact statement for license renewal of nuclear plants

    International Nuclear Information System (INIS)

    1996-05-01

    Volume 2 of the Generic Environmental Impact Statement for License Renewal of Nuclear Plants contains the appendices. These include: (A) General characterisitics and environmental settings of domestic nuclear plants, (B) Definition of impact initiators, (C) Socioeconomics and case studies, (D) Aquatic organisms and human health, (E) Radiation protection considerations, (F) Methodology for assessing impacts to aquatic ecology and water resources, (G) Postulated accidents, and (H) Environmental statutes and regulations affecting license renewal

  10. Generic implications of ATWS events at the Salem Nuclear Power Plant: generic implications. Vol. 1

    International Nuclear Information System (INIS)

    1983-04-01

    This report is the first of two volumes. It documents the work of an interoffice, interdisciplinary NRC Task Force established to determine the generic implications of two anticipated transients without scram (ATWS) at the Salem Nuclear Power Plant, Unit 1 on February 22 and 25, 1983. A second report will document the NRC actions to be taken based on the work of the Task Force. The Task Force was established to address three questions: (1) Is there a need for prompt action for similar equipment in other facilities. (2) Are NRC and its licensees learning the sefety-management lessons, and, (3) How should the priority and content of the ATWS rule be adjusted. A number of short-term actions were taken through Bulletins and an Information Notice. Intermediate-term actions to address the generic issues will be addressed in the separate report and implemented through appropriate regulatory mechanisms

  11. Generic aging management programs for license renewal of BWR reactor coolant systems components

    International Nuclear Information System (INIS)

    Shah, V.N.; Liu, Y.Y.

    2002-01-01

    The paper reviews the existing generic aging management programs (AMPs) for the reactor coolant system (RCS) components in boiling water reactors (BWRs), including the reactor pressure vessel and internals, the reactor recirculation system, and the connected piping. These programs have been evaluated in the U.S. Nuclear Regulatory Commission (NRC) report, Generic Aging Lessons Learned (GALL), NUREG-1801, for their use in the license renewal process to manage several aging effects, including loss of material, crack initiation and growth, loss of fracture toughness, loss of preload, wall thinning, and cumulative fatigue damage. The program evaluation includes a review of ten attributes (scope of program, preventive actions, parameters monitored/inspected, detection of aging effects, monitoring and trending, acceptance criteria, corrective actions, confirmative process, administrative control, and operating experience) for their effectiveness in managing a specific aging effect in a given component(s). The generic programs are based on the ASME Section XI inservice inspection requirements; industry guidelines for inspection and evaluation of aging effects in BWR reactor vessel, internals, and recirculation piping; monitoring and control of BWR water chemistry; and operating experience as reported in the USNRC generic communications and industry reports. The review concludes that all generic AMPs are acceptable for managing aging effects in BWR RCS components during an extended period of operation and do not need further evaluation. However, the plant-specific programs for managing aging in certain RCS components during an extended period of operation do require further evaluation. For some plant-specific AMPs, the GALL report recommends an aging management activity to verify their effectiveness. An example of such an activity is a one-time inspection of Class 1 small-bore piping to ensure that service-induced weld cracking is not occurring in the piping. Several of

  12. Generic Aging Management Programs for License Renewal of BWR Reactor Coolant System Components

    International Nuclear Information System (INIS)

    Shah, V.N.; Liu, Y.Y.

    2002-01-01

    The paper reviews the existing generic aging management programs (AMPs) for the reactor coolant system (RCS) components in boiling water reactors (BWRs), including the reactor pressure vessel and internals, the reactor recirculation system, and the connected piping. These programs have been evaluated in the U.S. Nuclear Regulatory Commission (NRC) report, Generic Aging Lessons Learned (GALL), NUREG-1801, for their use in the license renewal process to manage several aging effects, including loss of material, crack initiation and growth, loss of fracture toughness, loss of preload, wall thinning, and cumulative fatigue damage. The program evaluation includes a review of ten attributes (scope of program, preventive actions, parameters monitored/inspected, detection of aging effects, monitoring and trending, acceptance criteria, corrective actions, confirmative process, administrative control, and operating experience) for their effectiveness in managing a specific aging effect in a given component(s). The generic programs are based on the ASME Section XI inservice inspection requirements; industry guidelines for inspection and evaluation of aging effects in BWR reactor vessel, internals, and recirculation piping; monitoring and control of BWR water chemistry; and operating experience as reported in the USNRC generic communications and industry reports. The review concludes that all generic AMPs are acceptable for managing aging effects in BWR RCS components during an extended period of operation and do not need further evaluation. However, the plant-specific programs for managing aging in certain RCS components during an extended period of operation do require further evaluation. For some plant-specific AMPs, the GALL report recommends an aging management activity to verify their effectiveness. An example of such an activity is a one-time inspection of Class 1 small-bore piping to ensure that service-induced weld cracking is not occurring in the piping. Several of

  13. Ageing management in German nuclear power plants

    International Nuclear Information System (INIS)

    Becker, D.E.; Reiner, M.

    1998-01-01

    In Germany, the term 'ageing management' comprises several aspects. A demand for a special ageing monitoring programme is not explicitly contained in the regulations. However, from the Atomic Energy Act and its regulations results the operator's obligation to perform extensive measures to maintain the quality of the plant and the operating personnel working in the plant. From this point of view, comprehensive ageing management in German nuclear power plants has taken place right from the start under the generic term of quality assurance. (author)

  14. LISSAT Analysis of a Generic Centrifuge Enrichment Plant

    International Nuclear Information System (INIS)

    Lambert, H; Elayat, H A; O'Connell, W J; Szytel, L; Dreicer, M

    2007-01-01

    The U.S. Department of Energy (DOE) is interested in developing tools and methods for use in designing and evaluating safeguards systems for current and future plants in the nuclear power fuel cycle. The DOE is engaging several DOE National Laboratories in efforts applied to safeguards for chemical conversion plants and gaseous centrifuge enrichment plants. As part of the development, Lawrence Livermore National Laboratory has developed an integrated safeguards system analysis tool (LISSAT). This tool provides modeling and analysis of facility and safeguards operations, generation of diversion paths, and evaluation of safeguards system effectiveness. The constituent elements of diversion scenarios, including material extraction and concealment measures, are structured using directed graphs (digraphs) and fault trees. Statistical analysis evaluates the effectiveness of measurement verification plans and randomly timed inspections. Time domain simulations analyze significant scenarios, especially those involving alternate time ordering of events or issues of timeliness. Such simulations can provide additional information to the fault tree analysis and can help identify the range of normal operations and, by extension, identify additional plant operational signatures of diversions. LISSAT analyses can be used to compare the diversion-detection probabilities for individual safeguards technologies and to inform overall strategy implementations for present and future plants. Additionally, LISSAT can be the basis for a rigorous cost-effectiveness analysis of safeguards and design options. This paper will describe the results of a LISSAT analysis of a generic centrifuge enrichment plant. The paper will describe the diversion scenarios analyzed and the effectiveness of various safeguards systems alternatives

  15. Review of the generic aging lessons learned (GALL) report for U.S. NPPs

    International Nuclear Information System (INIS)

    Gong Yi; Dou Yikang

    2014-01-01

    Generic aging lessons learned (GALL) report is a technical basis document issued by U.S. nuclear regulatory commission (NRC) for guiding the review of license renewal application (LRA) of its domestic nuclear power plants (NPPs). By form of tabulations, GALL report addresses the correlation among materials, environments, aging effects/mechanisms, and aging management programs (AMPs) from the level of specific structures and/or components. Based on literature investigation and analysis, the essential information of GALL report in the aspects of background, development history, content framework, and application was reviewed in this paper, which should be the first time in China and would have reference value for establishment of both the AMPs and the nuclear safety regulations of extending the lifetime of its NPPs. (authors)

  16. Nuclear Plant Aging Research (NPAR) program plan

    International Nuclear Information System (INIS)

    1991-06-01

    A comprehensive Nuclear Plant Aging Research (NPAR) Program was implemented by the US NRC office of Nuclear Regulatory Research in 1985 to identify and resolve technical safety issues related to the aging of systems, structures, and components in operating nuclear power plants. This is Revision 2 to the Nuclear Plant Aging Research Program Plant. This planes defines the goals of the program the current status of research, and summarizes utilization of the research results in the regulatory process. The plan also describes major milestones and schedules for coordinating research within the agency and with organizations and institutions outside the agency, both domestic and foreign. Currently the NPAR Program comprises seven major areas: (1) hardware-oriented engineering research involving components and structures; (2) system-oriented aging interaction studies; (3) development of technical bases for license renewal rulemaking; (4) determining risk significance of aging phenomena; (5) development of technical bases for resolving generic safety issues; (6) recommendations for field inspection and maintenance addressing aging concerns; (7) and residual lifetime evaluations of major LWR components and structures. The NPAR technical database comprises approximately 100 NUREG/CR reports by June 1991, plus numerous published papers and proceedings that offer regulators and industry important insights to aging characteristics and aging management of safety-related equipment. Regulatory applications include revisions to and development of regulatory guides and technical specifications; support to resolve generic safety issues; development of codes and standards; evaluation of diagnostic techniques; (e.g., for cables and valves); and technical support for development of the license renewal rule. 80 refs., 25 figs., 10 tabs

  17. 78 FR 37325 - License Renewal of Nuclear Power Plants; Generic Environmental Impact Statement and Standard...

    Science.gov (United States)

    2013-06-20

    ... Nuclear Power Plants; Generic Environmental Impact Statement and Standard Review Plans for Environmental... for Nuclear Power Plants, Supplement 1: Operating License Renewal'' (ESRP). The ESRP serves as a guide... published a final rule, ``Revisions to Environmental Review for Renewal of Nuclear Power Plant Operating...

  18. Draft report on compilation of generic safety issues for light water reactor nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    A generally accepted approach to characterizing the safety concerns in nuclear power plants is to express them as safety issues which need to be resolved. When such safety issues are applicable to a generation of plants of a particular design or to a family of plants of similar design, they are termed generic safety issues. Examples of generic safety issues are those related to reactor vessel embrittlement, control rod insertion reliability or strainer clogging. The safety issues compiled in this document are based on broad international experience. This compilation is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. Refs.

  19. Draft report on compilation of generic safety issues for light water reactor nuclear power plants

    International Nuclear Information System (INIS)

    1997-07-01

    A generally accepted approach to characterizing the safety concerns in nuclear power plants is to express them as safety issues which need to be resolved. When such safety issues are applicable to a generation of plants of a particular design or to a family of plants of similar design, they are termed generic safety issues. Examples of generic safety issues are those related to reactor vessel embrittlement, control rod insertion reliability or strainer clogging. The safety issues compiled in this document are based on broad international experience. This compilation is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. Refs

  20. Aging management guideline for commercial nuclear power plants - heat exchangers

    International Nuclear Information System (INIS)

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  1. Aging management guideline for commercial nuclear power plants - heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  2. Evaluation of a Generic Virtual Power Plant Framework Using Service Oriented Architecture

    DEFF Research Database (Denmark)

    Andersen, Peter Bach; Poulsen, Bjarne; Decker, Morten

    2008-01-01

    interesting properties that can influence the future shape of power markets. The concept holds many promises including cheaper power to the consumer, a more flexible and responsive power production and the support of a more environment- friendly development. In order to realize a software solution supporting...... the generic virtual power plant, an array of different software design principles, patterns and architectures must be applied. Especially Service Oriented Architecture (SOA) can aid in implementing the generic virtual power plant. An analysis of the Nordic power market has been carried out in order...... to identify potential issues and barriers, henceforth mentioned as challenges, connected with the introduction of the generic virtual power plant concept. In this paper, three use case scenarios will show how each of these challenges can be overcome by the proposed solution framework. The use case scenarios...

  3. Evaluation of the Latest Generic Data for PSA Applications of Domestic Nuclear Plants

    International Nuclear Information System (INIS)

    Hwang, Seok Won; Oh, Ji Yong; Lee, Byung Sik

    2009-01-01

    Generic data of domestic PSAs have mostly referred to 'Advanced Light Water Reactor (ALWR) Utility Requirements Document (URD) 'issued by EPRI. Generally, current data of domestic PSA have been customized with the generic and plant specific data through Bayesian analysis. The generic reference has established by collecting US nuclear plant practices from mid 1980s to early 1990s. Over the decade, US plants had showed low performances and capabilities in operation. On the other hand, the current domestic nuclear plants shows world class performance in operation and maintenance compared with the corresponding US nuclear plants in URD. Therefore, it is necessary to apply proper generic sources which can represent the current domestic plant performances and status. In 2007, the latest generic source (NUREG/CR-6928) is published by US NRC, which deals with new types of failure modes and analysis methods. A fundamental improvement in NUREG/CR-6928 compared with previous data source is the distinction between standby and alternating/running component basic events, which shows different failure mechanisms. Significant differences were also noted running failure events occurred within and beyond the first hour for emergency diesel generators, cooling units, and pumps. This was done because the historical perspective on running failure rates indicated approximately a factor of 15 differences between the two failure rates for several component types. ALWR URD uses lognormal distribution in the estimation of failure rates. On the contrary, NUREG/CR-6928 uses beta and gamma distributions for demand and running failures, respectively. This work has proposed an approach to the application of NUREG/CR-6928 to current PSA practice by comparing it with URD data. Moreover, this attempt results in eliciting substantial insights of the establishment of the domestic generic database

  4. Generic environmental impact statement for license renewal of nuclear plants. Final report

    International Nuclear Information System (INIS)

    1996-05-01

    This GEIS examines the possible environmental impacts that could occur as a result of renewing the licenses of individual nuclear power plants under 10 CFR 54. To the extent possible, it establishes the bounds and significance of these potential impacts. The analysis encompasses all operating light-water reactors. For each type of environmental impact, the GEIS attempts to establish generic findings covering as many plants as possible. While plant and site-specific information is used in developing the generic findings, the NRC does not intend for the GEIS to be a compilation of individual plant environmental impacts statements. This document has three principal objectives: (1) to provide an understanding of the types and severity of environmental impacts that may occur as a result of license renewal, (2) to identify and assess those impacts that are expected to be generic to license renewal, and (3) to support rulemaking (10 CFR 51) to define the number and scope of issues that need to be addressed by the applicants in plant-by-plant license renewal proceedings

  5. Validation of generic cost estimates for construction-related activities at nuclear power plants: Final report

    International Nuclear Information System (INIS)

    Simion, G.; Sciacca, F.; Claiborne, E.; Watlington, B.; Riordan, B.; McLaughlin, M.

    1988-05-01

    This report represents a validation study of the cost methodologies and quantitative factors derived in Labor Productivity Adjustment Factors and Generic Methodology for Estimating the Labor Cost Associated with the Removal of Hardware, Materials, and Structures From Nuclear Power Plants. This cost methodology was developed to support NRC analysts in determining generic estimates of removal, installation, and total labor costs for construction-related activities at nuclear generating stations. In addition to the validation discussion, this report reviews the generic cost analysis methodology employed. It also discusses each of the individual cost factors used in estimating the costs of physical modifications at nuclear power plants. The generic estimating approach presented uses the /open quotes/greenfield/close quotes/ or new plant construction installation costs compiled in the Energy Economic Data Base (EEDB) as a baseline. These baseline costs are then adjusted to account for labor productivity, radiation fields, learning curve effects, and impacts on ancillary systems or components. For comparisons of estimated vs actual labor costs, approximately four dozen actual cost data points (as reported by 14 nuclear utilities) were obtained. Detailed background information was collected on each individual data point to give the best understanding possible so that the labor productivity factors, removal factors, etc., could judiciously be chosen. This study concludes that cost estimates that are typically within 40% of the actual values can be generated by prudently using the methodologies and cost factors investigated herein

  6. MAAP4 CANDU analysis of a generic CANDU-6 plant: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Petoukhov, S.M.; Mathew, P.M

    2001-10-01

    To support the generic probabilistic safety analysis (PSA) program at AECL, in particular to conduct Level 2 PSA analysis of a CANDU 6 plant undergoing a postulated severe accident, the capability to conduct severe accident consequence analysis for a CANDU plant is required. For this purpose, AECL selected MAAP4 CANDU from a number of other severe accident codes. The necessary models for a generic CANDU 6 station have been implemented in the code, and the code version 0.2 beta was tested using station data, which were assembled for a generic CANDU 6 station. This paper describes the preliminary results of the consequence analysis using MAAP4 CANDU for a generic CANDU 6 station, when it undergoes a station blackout and a large loss-of-coolant accident scenario. The analysis results show that the plant response is consistent with the physical phenomena modeled and the failure criteria used. The results also confirm that the CANDU design is robust with respect to severe accidents, which is reflected in the calculated long times that are available for administering accident management measures to arrest the accident progression before the calandria vessel or containment become at risk. (author)

  7. Generic demonstration plant study (A/E package)

    International Nuclear Information System (INIS)

    Molzen, D.F.

    1979-01-01

    Molzen--Corbin and Associates, Albuquerque, New Mexico, under contract to Sandia Laboratories, has prepared preliminary drawings, descriptive material and a scale model of the demonstration plant. This information will be made available to A/E firms to assist them in the preparation of proposals for complete construction plans and specifications. The four categories for which preliminary work has been prepared consist of structural work, mechanical work, electrical work, and cost estimates. In addition, preliminary specifications, including a written description of the facility consisting of mechanical electrical systems and operations, a description of the safety features, the basic design criteria, three-dimensional sketches, and a scale model of the design have been prepared. The preliminary drawings indicate the required minimum wall thicknesses, overall dimensions and the necessary layout of the removable concrete blocks and slabs required for radiation protection and control

  8. Nuclear plant aging research program

    International Nuclear Information System (INIS)

    Eissenberg, D.M.

    1987-01-01

    The U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, has established the Nuclear Plant Aging Research (NPAR) program in its Division of Engineering Technology. Principal contractors for this program include Oak Ridge National Laboratory, Brookhaven National Laboratory, Idaho National Engineering Laboratory, and Pacific Northwest Laboratory. The program goals are: to identify and characterize time-dependent degradation (aging) of nuclear plant safety-related electrical and mechanical components which could lead to loss of safety function; to identify and recommend methods for detecting and trending aging effects prior to loss of safety function so that timely maintenance can be implemented; and to recommend maintenance practices for mitigating the effects of aging. Research activities include prioritization of system and component aging in nuclear plants, characterization of aging degradation of specific components including identification of functional indicators useful for trending degradation, and testing of practical methods and devices for measuring the functional indicators. Aging assessments have been completed on electric motors, snubbers, motor-operated valves, and check valves. Testing of trending methods and devices for motor-operated valves and check valves is in progress

  9. Aging management guideline for commercial nuclear power plants-pumps

    International Nuclear Information System (INIS)

    Booker, S.; Katz, D.; Daavettila, N.; Lehnert, D.

    1994-03-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant pumps important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  10. Aging management guideline for commercial nuclear power plants-pumps

    Energy Technology Data Exchange (ETDEWEB)

    Booker, S.; Katz, D.; Daavettila, N.; Lehnert, D. [MDC-Ogden Environmental and Energy Services, Southfield, MI (United States)

    1994-03-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant pumps important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  11. Aging Management Guideline for commercial nuclear power plants: Electrical switchgear

    International Nuclear Information System (INIS)

    Toman, G.; Gazdzinski, R.; Schuler, K.

    1993-07-01

    This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant electrical switchgear important to license renewal. The latent of this AMG to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner which allows personnel responsible for performance analysis and maintenance, to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  12. A generic task approach to a real time nuclear power plant fault diagnosis and advisory system

    International Nuclear Information System (INIS)

    Hajek, B.K.; Miller, D.W.; Bhatnagar, R.; Stasenko, J.E.; Punch, W.F. III; Yamada, N.

    1988-01-01

    A generic task toolkit developed at The Ohio State University Laboratory for Artificial Intelligence Research (LAIR) has been used in the development of an aid for operators of nuclear power plants. The toolkit consists of high level programming tools that enable knowledge to be used in accordance with its need. That is, if diagnosis is the need, a framework for performing diagnosis is provided. The operator aid provides for monitoring the conditions in the plant, detecting abnormal events, and providing the operator with guidance and advice through procedures on what path should be followed to mitigate the consequences. 8 refs., 5 figs

  13. Nuclear plant-aging research on reactor protection systems

    International Nuclear Information System (INIS)

    Meyer, L.C.

    1988-01-01

    This report presents the rsults of a review of the Reactor Trip System (RTS) and the Engineered Safety Feature Actuating System (ESFAS) operating experiences reported in Licensee Event Reports (LER)s, the Nuclear Power Experience data base, Nuclear Plant Reliability Data System, and plant maintenance records. Our purpose is to evaluate the potential significance of aging, including cycling, trips, and testing as contributors to degradation of the RTS and ESFAS. Tables are presented that show the percentage of events for RTS and ESFAS classified by cause, components, and subcomponents for each of the Nuclear Steam Supply System vendors. A representative Babcock and Wilcox plant was selected for detailed study. The US Nuclear Regulatory Commission's Nuclear Plant Aging Research guidelines were followed in performing the detailed study that identified materials susceptible to aging, stressors, environmental factors, and failure modes for the RTS and ESFAS as generic instrumentation and control systems. Functional indicators of degradation are listed, testing requirements evaluated, and regulatory issues discussed

  14. Resolution of Generic Safety Issue 29: Bolting degradation or failure in nuclear power plants

    International Nuclear Information System (INIS)

    Johnson, R.E.

    1990-06-01

    This report describes the US Nuclear Regulatory Commission's (NRC's) Generic Safety Issue 29, ''Bolting Degradation or Failure in Nuclear Power Plants,'' including the bases for establishing the issue and its historical highlights. The report also describes the activities of the Atomic Industrial Forum (AIF) relevant to this issue, including its cooperation with the Materials Properties Council (MPC) to organize a task group to help resolve the issue. The Electric Power Research Institute, supported by the AIF/MPC task group, prepared and issued a two-volume document that provides, in part, the technical basis for resolving Generic Safety Issue 29. This report presents the NRC's review and evaluation of the two-volume document and NRC's conclusion that this document, in conjunction with other information from both industry and NRC, provides the bases for resolving this issue

  15. Simulation study of near-real-time accounting in a generic reprocessing plant

    International Nuclear Information System (INIS)

    Coulter, C.A.; Whiteson, R.; Zardecki, A.

    1992-01-01

    Our simulation program FacSim has been used to estimate balance closure variances for a number of real proposed nuclear material processing facilities that rely primarily on item measurements. We are enhancing the program so that it can be applied to facilities such as reprocessing plants that handle bulk materials ad primarily perform bulk and flow measurements. The extended simulation program can apply any of several types of sequential statistical tests to near-real-time accounting information to evaluate the capability of the facility accounting system to detect material and operational anomalies in a timely fashion. The program allows facility designers and operators to evaluate measurement and anomaly detection strategies before system implementation and to demonstrate facility's capability for maintaining accurate inventory information during plant operation. These features are illustrated by application to a generic reprocessing plant

  16. AGE RELATED DEGRADATION OF STEAM GENERATOR INTERNALS BASED ON INDUSTRY RESPONSES TO GENERIC LETTER 97-06

    International Nuclear Information System (INIS)

    SUBUDHI, M.; SULLIVAN, JR. E.J.

    2002-01-01

    THIS PAPER PRESENTS THE RESULTS OF AN AGING ASSESSMENT OF THE NUCLEAR POWER INDUSTRY RESPONSES TO NRC GENERIC LETTER 97-06 ON THE DEGRADATION OF STEAM GENERATOR INTERNALS EXPERIENCED AT ELECTRICITE DE FRANCE (EDF) PLANTS IN FRANCE AND AT A UNITED STATES PRESSURIZED WATER REACTOR (PWR). WESTINGHOUSE (W), COMBUSTION ENGINEERING (CE), AND BABCOCK AND WILCOX (BW) STEAM GENERATOR MODELS, CURRENTLY IN SERVICE AT U.S. NUCLEAR POWER PLANTS, POTENTIALLY COULD EXPERIENCE DEGRADATION SIMILAR TO THATFOUND AT EDF PLANTS AND THE U.S. PLANT. THE STEAM GENERATORS IN MANY OF THE U.S. PWRS HAVE BEEN REPLACED WITH STEAM GENERATORS WITH STEAM GENERATORS WITH IMPROVED DESIGNS AND MATERIALS. THESE REPLACEMENT STEAM GENERATORS HAVE BEEN MANUFACTURED IN THE U.S. AND ABROAD. DURING THIS ASSESSMENT, EACH OF THE THREE OWNERS GROUPS (W,CE, AND BW) IDENTIFIED FOR ITS STEAM GENERATOR, MODELS ALL THE POTENTIAL INTERNAL COMPONENTS THAT ARE VULNERABLE TO DEGRADATION WHILE IN SERVICE. EACH OWNERS GROUPDEVELOPED INSPEC TION AND MONITORING GUIDANCE AND RECOMMENDATIONS FOR ITS PARTICULAR STEAM GENERATOR MODELS. THE NUCLEAR ENERGY INSTITUTE INCORPORATED IN NEI 97-06 STEAM GENERATOR PROGRAM GUIDELINES, A REQUIREMENT TO MONITOR SECONDARY SIDE STEAM GENERATOR COMPONENTS IF THEIR FAILURE COULD PREVENT THE STEAM GENERATOR FROM FULFILLING ITS INTENDED SAFETY-RELATED FUNCTION. LICENSEES INDICATED THAT THEY IMPLEMENTED OR PLANNED TO IMPLEMENT, AS APPROPRIATE FOR THEIR STEAM GENERATORS, THEIR OWNERS GROUPRECOMMENDATIONS TO ADDRESS THE LONG-TERM EFFECTS OF THE POTENTIAL DEGRADATION MECHANISMS ASSOCIATED WITH THE STEAM GENERATOR INTERNALS

  17. Bayesian methodology for generic seismic fragility evaluation of components in nuclear power plants

    International Nuclear Information System (INIS)

    Yamaguchi, Akira; Campbell, R.D.; Ravindra, M.K.

    1991-01-01

    Bayesian methodology for updating the seismic fragility of components in nuclear power plants is presented. The generic fragility data which have been evaluated based on the past SPSAs are combined with the seismic experience data. Although the seismic experience is limited to the acceleration range below the median capacity of the components, it has been found that the evidence is effective to update the fragility tail. In other words, the uncertainty of the fragility is reduced although the median capacity itself is not modified to a great extent. The annual frequency of failure is also reduced as a result of the updating of the fragility tail. The PDF of the seismic capacity is handled in discrete form, which enables the use of arbitrary type of prior distribution. Accordingly, the Log-N prior can be used which is consistent with the widely used fragility model. For evaluating posterior fragility parameters (A m and B U ), two methods have been proposed. Furthermore, it has been found that the importance of evidence used in the Bayesian methodology can be quantified by the entropy of the evidence. Only the events with high entropy need to be considered in the Bayesian updating of the fragility. The currently available seismic experience database for typical components can be utilized to develop the fragility tail which is contributive to the seismically-induced failure frequency. The combined use of generic fragility and seismic experience data, with the aid of Bayesian methodology, provides refined generic fragility curves which are useful for SPSA studies. (author)

  18. Diagnosing component faults in a generic nuclear power plant using counterfactual and temporal reasoning

    International Nuclear Information System (INIS)

    Oehrstroem, P.; Nielsen, F.R.; Pedersen, S.A.

    1992-01-01

    The subject of main interest is the logical and epistemological aspects of diagnostic reasoning. The aim was to understand the role of conditionals and causality in this respect. A model of causal and temporal reasoning was developed and evaluated in a controlled but complex setting. The generic nuclear power plant was used as a test ground. The coherence and scope of a logical theory of diagnostic reasoning was studied in order to discover whether the theory constitutes an adequate tool for making correct diagnoses of component faults in a generic nuclear power plant. A diagnosing system based on the CIMP system was run on a computer model of a nuclear power plant, various errors were then introduced. The aim of the diagnosis is mainly explanation and only partly repair. The causal field defines a conceptual framework within which the diagnostic purpose is given and within which various diagnostic possibilities and causal relationships are given, here with regard to error detection in a control room. The causal field is tacitly given and related to the operator's training and experience. The logical aspects of the problem of the diagnosis is described. The computer model is described and the symptom language is introduced. The process of reasoning about the possible diagnosis is presented. The utilization of ideas similiar to the heuristic classification is discussed. A data base command language for manipulating lists of symptoms is described and the design of a CIMP user interface for symptom language visualization is outlined. (AB)

  19. Knowledge-based operation guidance system for nuclear power plants based on generic task methodology

    International Nuclear Information System (INIS)

    Yamada, Naoyuki; Chandrasekaran, B.; Bhatnager, R.

    1989-01-01

    A knowledge-based system for operation guidance of nuclear power plants is proposed. The Dynamic Procedure Management System (DPMS) is designed and developed to assist human operators interactively by selecting and modifying predefined operation procedures in a dynamic situation. Unlike most operation guidance systems, DPMS has been built based on Generic Task Methodology, which makes the overall framework of the system perspicuous and also lets domain knowledge be represented in a natural way. This paper describes the organization of the system, the definition of each task, and the form and organization of knowledge, followed by an application example. (author)

  20. Generic Virtual Power Plants: Management of Distributed Energy Resources under Liberalized Electricity Market

    DEFF Research Database (Denmark)

    You, Shi; Træholt, Chresten; Poulsen, Bjarne

    2009-01-01

    The emergence of Virtual Power Plant (VPP) can be attributed to the major boost of distributed energy resources (DER), which satisfies the changing needs of modern society on energy industry. Based on this concept, DER units disregarding the differences in each individualtechnology are loosely...... aggregated with a unique interface to the external grid and energy market. This paper gives a broad overview of state-of-the-art VPP concepts and proposes a detailed generic VPP (GVPP) model running in liberalized electricity market environment. An attempt is made to provide an outline of the main functions...

  1. Seismic sensitivity study of a generic CANDU nuclear power plant: Soil-structure interaction

    International Nuclear Information System (INIS)

    Lee, L.S.S.; Duff, C.G.

    1983-01-01

    The seismic sensitivity and capability study for a generic CANDU Plant is part of an overall development program of design standardization. The purpose of this paper is to investigate the sensitivities of structural responses and floor response spectra (FRS) to variations of structural and soil parameters. In the seismic design standardization, a wide range of soil conditions is considered and the envelopes of the resulting site spectra (soil-structure interaction effect) are then used for the design of the generic plant. The nuclear island structures considered herein have different relative stiffness and one of them has two layout/structure schemes: one is relatively flexible and the other is moderately stiff. In the preliminary phase of the seismic sensitivity study presented hereby, the soil-structure interaction seismic analysis is based on the half-space modelling (soil-spring lumped-mass) method and the response spectrum method for the seismic responses. Distinct patterns and sensitivity of the site spectrum analysis for structure schemes of different relative stiffness and for different structural elevations are observed and discussed. (orig.)

  2. Generic Containment: Detailed comparison of containment simulations performed on plant scale

    International Nuclear Information System (INIS)

    Kelm, St.; Klauck, M.; Beck, S.; Allelein, H.-J.; Preusser, G.; Sangiorgi, M.; Klein-Hessling, W.; Bakalov, I.; Bleyer, A.; Bentaib, A.; Kljenak, I.; Stempniewicz, M.; Kostka, P.; Morandi, S.; Ada del Corno, B.; Bratfisch, C.; Risken, T.; Denk, L.; Parduba, Z.; Paci, S.

    2014-01-01

    Highlights: • Consequent implementation of the recommendations derived from the OECD/NEA ISP-47. • Phenomenological code-to-code comparison performed on plant scale. • Systematic identification and elimination of the user effect. • Identification of fundamental differences in the model basis. • Application to PAR system analysis. - Abstract: One outcome of the OECD/NEA ISP-47 activity was the recommendation to elaborate a ‘Generic Containment’ in order to allow comparing and rating the results obtained by different lumped-parameter models on plant scale. Within the European SARNET2 project ( (http://www.sar-net.eu)), such a Generic Containment nodalisation, based on a German PWR (1300 MW el ), was defined. This agreement on the nodalisation allows investigating the remaining differences among the results, especially the ‘user-effect’, related to the modelling choices, as well as fundamental differences in the underlying model basis in detail. The methodology applied in order to compare the different code predictions consisted of a series of three benchmark steps with increasing complexity as well as a systematic comparison of characteristic variables and observations. This paper summarises the benchmark series, the lessons learned during specifying the steps, comparing and discussing the results and finally gives an outlook on future steps

  3. Select Generic Dry-Storage Pilot Plant Design for Safeguards and Security by Design (SSBD) per Used Fuel Campaign

    Energy Technology Data Exchange (ETDEWEB)

    Demuth, Scott Francis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sprinkle, James K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-26

    As preparation to the year-end deliverable (Provide SSBD Best Practices for Generic Dry-Storage Pilot Scale Plant) for the Work Package (FT-15LA040501–Safeguards and Security by Design for Extended Dry Storage), the initial step was to select a generic dry-storage pilot plant design for SSBD. To be consistent with other DOE-NE Fuel Cycle Research and Development (FCR&D) activities, the Used Fuel Campaign was engaged for the selection of a design for this deliverable. For the work Package FT-15LA040501–“Safeguards and Security by Design for Extended Dry Storage”, SSBD will be initiated for the Generic Dry-Storage Pilot Scale Plant described by the layout of Reference 2. SSBD will consider aspects of the design that are impacted by domestic material control and accounting (MC&A), domestic security, and international safeguards.

  4. Aging assessment of large electric motors in nuclear power plants

    International Nuclear Information System (INIS)

    Villaran, M.; Subudhi, M.

    1996-03-01

    Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failure in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry's large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs

  5. FPFPspace2: A code for following airborne fission products in generic nuclear plant flow paths

    International Nuclear Information System (INIS)

    Owcarski, P.C.; Burk, K.W.; Ramsdell, J.V.; Yasuda, D.D.

    1991-03-01

    In order to assure that a nuclear power plant control room remains habitable during certain types of postulated accidents, Pacific Northwest Laboratory (PNL) has undertaken a special study for the US Nuclear Regulatory Commission. This purpose of this study is to develop software that can aid in the analyses of control room habitability during accidents in which airborne fission products could challenge internal air pathways to the control room. PNL has completed an initial version (FPFP) and final version (FPFP 2) of a software package that can estimate the unsteady-state invasion of quantities of fission products into the control room or any other destination within the nuclear plant via generic internal flow paths. This report consists of three parts: Section 2.0, Technical Bases, describes the flow path components and mechanisms of natural fission product deposition; Section 3.0, FPFP 2 Code Description, describes code organization and the functions of the subroutines; and Section 4.0, Code Operation, discusses details of input requirements, code output, and a sample case demonstration. The appendices consist of an FPFP 2 Fortran code listing, a listing of a code for building input files, forms for building input files, and the sample case input and output files. 7 refs., 3 figs

  6. Model of a Generic Natural Uranium Conversion Plant ? Suggested Measures to Strengthen International Safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Raffo-Caiado, Ana Claudia [ORNL; Begovich, John M [ORNL; Ferrada, Juan J [ORNL

    2009-11-01

    This is the final report that closed a joint collaboration effort between DOE and the National Nuclear Energy Commission of Brazil (CNEN). In 2005, DOE and CNEN started a collaborative effort to evaluate measures that can strengthen the effectiveness of international safeguards at a natural uranium conversion plant (NUCP). The work was performed by DOE s Oak Ridge National Laboratory and CNEN. A generic model of a NUCP was developed and typical processing steps were defined. Advanced instrumentation and techniques for verification purposes were identified and investigated. The scope of the work was triggered by the International Atomic Energy Agency s 2003 revised policy concerning the starting point of safeguards at uranium conversion facilities. Prior to this policy only the final products of the uranium conversion plant were considered to be of composition and purity suitable for use in the nuclear fuel cycle and therefore, subject to the IAEA safeguards control. DOE and CNEN have explored options for implementing the IAEA policy, although Brazil understands that the new policy established by the IAEA is beyond the framework of the Quadripartite Agreement of which it is one of the parties, together with Argentina, the Brazilian-Argentine Agency for Accounting and Control of Nuclear Materials (ABACC) and the IAEA. Two technical papers on this subject were published at the 2005 and 2008 INMM Annual Meetings.

  7. Generic safety issues for nuclear power plants with light water reactors and measures taken for their resolution

    International Nuclear Information System (INIS)

    1998-09-01

    The IAEA Conference on 'The Safety of Nuclear Power: Strategy for the Future' in 1991 was a milestone in nuclear safety. Two of the important items addressed by this conference were ensuring and enhancing safety of operating plants and treatment of nuclear power plants built to earlier safety standards. A number of publications related to these two items issued subsequent to this conference were: A Common Basis for Judging the Safety of Nuclear Power Plants Built to Earlier Standards, INSAG-9 (1995), the IAEA Safety Guide 50-SG-O12, periodic Safety Review of Operational Nuclear Power Plants (1994) and an IAEA publication on the Safety Evaluation of Operating Nuclear Power Plants Built to Earlier Standards - A Common Basis for Judgement (1997). Some of the findings of the 1991 Conference have not yet been fully addressed. An IAEA Symposium on reviewing the Safety of Existing Nuclear Power Plants in 1996 showed that there is an urgent need for operating organizations and national authorities to review operating nuclear power plants which do not meet the high safety levels of the vast majority of plants and to undertake improvements with assistance from the international community if required. Safety reviews of operating nuclear power plants take on added importance in the context of the Convention on Nuclear safety and its implementation. The purpose of this TECDOC compilation based on broad international experience, is to assist the Member States in the reassessment of operating plants by providing a list of generic safety issues identified in nuclear power plants together with measures taken to resolve these issues. These safety issues are generic in nature with regard to light water reactors and the measures for their resolution are for use as a reference for the safety reassessment of operating plants. The TECDOC covers issues thought to be significant to Member States based on consensus process. It provides an introduction to the use of generic safety issues for

  8. Safe ageing management of nuclear power plants: An European synthesis

    International Nuclear Information System (INIS)

    Grandemange, J.M.

    2002-01-01

    for the most important (nonreplaceable) components; generic evaluations of specific important issues on the main ageing phenomena. Comparisons of ageing management approaches cover the following aspects, according to IAEA AMAT guidelines: strategy, utility organisation, activities including methodologies, procedures, and surveillance programs, and monitoring and assessment. The various ageing phenomena have been identified, with possible evaluation and mitigation methods. Management strategies include: identification and prioritisation of components of importance to safety and plant life; selection and identification of significant ageing mechanisms; ageing prediction criteria; surveillance and periodic testing methods; mitigation of ageing effects; maintenance programs and updating of operating parameters. Other aspects including industrial obsolescence and human, organisation and knowledge ageing are also identified and recommendations expressed. Material ageing management programs are given to illustrate the above strategies. Taking into account the physical understanding of these phenomena, zones of components concerned and potential effects are identified, prediction laws established, surveillance programs prepared, criteria applied and mitigation methods proposed

  9. A PLC generic requirements and specification for safety-related applications in nuclear power plants

    International Nuclear Information System (INIS)

    Han, Jea Bok; Lee, C. K.; Lee, D. Y.

    2001-12-01

    This report presents the requirements and specification to be applied to the generic qualification of programmable Logic Controller(PLC), which is being developed as part of the KNICS project, 'Development of the Digital Reactor Safety Systems' of which purpose is the application to safety-related instrumentation and control systems in nuclear power plants. This report defines the essential and critical characteristics that shall be included as part of a PLC design for safety-related application. The characteristics include performance, reliability, accuracy, the overall response time from an input to the PLC exceeding it trip condition to the resulting outputs, and the specification of processors and memories in digital controller. It also specifies the quality assurance process for software development, dealing with executive software, firmware, application software tools for developing the application software, and human machine interface(HMI). In addition, this report reviews the published standards and guidelines that are required for the PLC development and the quality assurance processes such as environment requirements, seismic withstand requirements, EMI/RFI withstand requirements, and isolation test

  10. Generic conditional clearance for very low level active charcoal generated in nuclear power plant operation

    International Nuclear Information System (INIS)

    Gomez Perales, J. J.; Burgos Gallego, J.; Alvarez Mir, F.; Luis de Diego, J.; Adrada Garcia, J.

    1998-01-01

    This report proposes a generic conditional exemption to the very low level active charcoal generated in the operation of a NPP. The project has been developed in two parts: a common one (applied to the stream to be exempted) and a specific one (specific to the NPP that fulfills already the common part requirements). The common project specifies the methodology and the disposal options. It provides derived exemption levels and maximum amount of activity the exemption of which be feasible, demonstrating the viability of their conventional management. The specific project of each NPP will develop the amount of waste to be managed and other details that supplement the previous project, adjusting to the methodology and disposal options in the common project. The proposed management suggestion consists in burning the waste in a coal-burning plant and disposing of the scum in a controlled landfill. The resultant radiological dose is considered negligible according to the document Safety Series N 89 of the IAEA. The calculation of the radiological dose associated to several stages has been carried out using the IMPACTS-BRC code, contained in NUREG/CR-3585 and NUREG/5517. The methodology used in the radiological dose evaluation is as recommended in the Safety Guide n. 7.8 of the Spanish Nuclear Safety Council. (Author)

  11. Generic evaluation of feedwater transients and small break loss-of-coolant accidents in combustion engineering designed operating plants

    International Nuclear Information System (INIS)

    1980-01-01

    The purpose of this report is to summarize the results of a generic evaluation of feedwater transients, small break loss-of-coolant accidents (LOCAs), and other TMI-2-related events in the Combustion Engineering (CE)-designed operating plants and to establish or confirm the bases for their continued operation. The results of this evaluation are presented in this report in the form of a set of findings and recommendations in each of the principal review areas

  12. Generic Screening Models for Assessing Exposures to the Public and ICRP Reference Animals and Plants

    Energy Technology Data Exchange (ETDEWEB)

    Yankovich, Tamara L.; Proehl, Gerhard; Telleria, Diego [International Atomic Energy Agency, P.O. Box 100, 1400 Vienna (Austria); Berkovskyy, Volodymyr [Ukrainian Radiation Protection Institute (RPI), 53, Melnikova Street, 04050, Kiev (Ukraine)

    2014-07-01

    With the update of the IAEA Fundamental Safety Principles (SF-1) stating the objective to protect people and the environment from harmful effects of ionizing radiation, it has been necessary to update International Basic Safety Standards (BSS) on Radiation Protection and Safety of Radiation Sources and the underlying safety guides and technical documents to provide guidance on how this could be achieved in practice. The current paper provides an update on the status and plans to revise the IAEA Safety Report 'Generic Models for Use in Assessing the Impact of Discharges of Radioactive Substances to the Environment' (SRS 19) that was published in 2001. The models of SRS 19 (2001), which was focused on assessment of exposures to the public, is being expanded into three volumes that provide methodologies for screening assessments for the public, as well as for flora and fauna. The revised SRS 19 guide will ultimately facilitate the application of screening models for different levels of assessment using updated parameter values from database that have been developed as part of the IAEA's EMRAS (Environmental Modelling for Radiation Safety) and EMRAS II international model validation programmes. The scope of the revised SRS 19 covers prospective screening assessment of doses to the representative person and Reference Animals and Plants (RAPs), and will provide simple and robust assessment methods for radiological assessment related to planning and design, applying a graded approach. Tabulated screening coefficients and environmental dilution factors will be included for 825 radionuclides. The screening coefficients are developed assuming equilibrium conditions; they can be used to assess radiological impacts arising from routine discharges of radionuclides to terrestrial and aquatic receptors for planned exposure situations. Volumes 1 and 2 of the revised SRS 19 are at an advanced stage of completion and are focused on 'Screening Assessment of Public

  13. Nuclear plant service water system aging degradation assessment

    International Nuclear Information System (INIS)

    Jarrell, D.B.; Larson, L.L.; Stratton, R.C.; Bohn, S.J.; Gore, M.L.

    1992-10-01

    This report discusses the second phase of the aging assessment of nuclear plant service water systems (SWSs) which was performed by the Pacific Northwest Laboratory (PNL) to support the US Nuclear Regulatory Commission's (NRC's) Nuclear Plant Aging Research (NPAR) program. The SWS was selected for study because of its essential role in the mitigation of and recovery from accident scenarios involving the potential for core-melt, and because it is subject to a variety of aging mechanisms. The objectives of the SWS task under the NPAR program are to identify and characterize the principal age-related degradation mechanisms relevant to this system, to assess the impact of aging degradation on operational readiness, and to provide a methodology for the management of aging on the service water aspect of nuclear plant safety. The primary degradation mechanism in the SWSs as stated in the Phase I assessment and confirmed by the analysis in Phase II, is corrosion compounded by biologic and inorganic accumulation. It then follows that the most effective means for mitigating degradation in these systems is to pursue appropriate programs to effectively control the water chemistry properties when possible and to use biocidal agents where necessary. A methodology for producing a complete root-cause analysis was developed as a result of needs identified in the Phase I assessment for a more formal procedure that would lend itself to a generic, standardized approach. It is recommended that this, or a similar methodology, be required as a part of the documentation for corrective maintenance performed on the safety-related portions of SWSs to provide an accurate focus for effective management of aging

  14. Aging effects in PWR power plants components

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Diogo da S.; Guimaraes, Antonio C.F.; Moreira, Maria de Lourdes, E-mail: diogosb@outlook.com, E-mail: tony@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This paper presents a contribution to the study of aging process of components in commercial plants of Pressurized Water Reactors (PWRs). The analysis is made through application of the Fault Trees Method, Monte Carlo Method and Fussell-Vesely Importance Measure. The approach of the study of aging in nuclear power plants, besides giving attention to the economic factors involved directly with the extent of their operational life, also provide significant data on security issues. The latest case involving process of life extension of a PWR could be seen in Angra 1 Nuclear Power Plant through investing of $27 million for the installation of a new reactor lid. The corrective action has generated an estimated operating life extension of Angra I in twenty years, offering great economy compared with building cost of a new plant and anterior decommissioning, if it had reached the time operating limit of forty years. The Extension of the operating life of a nuclear power plant must be accompanied by a special attention to the components of the systems and their aging process. After the application of the methodology (aging analysis of the injection system of the containment spray) proposed in this work, it can be seen that 'the increase in the rate of component failure, due the aging process, generates the increase in the general unavailability of the system that containing these basic components'. The final results obtained were as expected and may contribute to the maintenance policy, preventing premature aging process in Nuclear Plant Systems. (author)

  15. IPRDS: component histories and nuclear plant aging

    International Nuclear Information System (INIS)

    Borkowski, R.J.; Kahl, W.K.

    1984-01-01

    A comprehensive assessment of nuclear power plant component operating histories, maintenance histories, and design and fabrication details is essential to understanding aging phenomena. As part of the In-Plant Reliability Data System (IPRDS), an attempt is being made to collect and analyze such information from a sampling of US nuclear power plants. Utilizing the IPRDS, one can reconstruct the failure history of the components and gain new insight into the causes and modes of failures resulting from normal or premature aging. This information assembled from the IPRDS can be combined with operating histories and postservice component inspection results for cradle-to-grave assessments of component aging under operating conditions. A comprehensive aging assessment can then be used to provide guidelines for improving the detection, monitoring, and mitigation of aging-related failures

  16. IAEA effort on the evaluation and management of safety aspects of nuclear power plant ageing

    International Nuclear Information System (INIS)

    Pachner, J.; Yaremy, E.M.

    1991-01-01

    The questions attached to nuclear power plant (NPP) ageing and the need for monitoring and assessment of plant condition will grow in importance as more NPPs approach and pass the end of their nominal design lives. Ageing in nuclear plants must be effectively managed to ensure plant safety during their entire service life. This paper provides an overview of the IAEA programme and its results on the evaluation and management of safety aspects of NPP ageing. Under this programme, three generic guidance documents have been prepared on: data collection and record keeping; ageing management methodology; and the use of probabilistic safety assessment in plant life extension considerations. A two pronged strategy involving both technical and regulatory aspects has been adopted for the current and future work. (author)

  17. Safety aspects of nuclear power plant ageing

    International Nuclear Information System (INIS)

    1990-01-01

    The nuclear community is facing new challenges as commercial nuclear power plants (NPPs) of the first generation get older. At present, some of the plants are approaching or have even exceeded the end of their nominal design life. Experience with fossil fired power plants and in other industries shows that reliability of NPP components, and consequently general plant safety and reliability, may decline in the middle and later years of plant life. Thus, the task of maintaining operational safety and reliability during the entire plant life and especially, in its later years, is of growing importance. Recognizing the potential impact of ageing on plant safety, the IAEA convened a Working Group in 1985 to draft a report to stimulate relevant activities in the Member States. This report provided the basis for the preparation of the present document, which included a review in 1986 by a Technical Committee and the incorporation of relevant results presented at the 1987 IAEA Symposium on the Safety Aspects of the Ageing and Maintenance of NPPs and in available literature. The purpose of the present document is to increase awareness and understanding of the potential impact of ageing on plant safety; of ageing processes; and of the approach and actions needed to manage the ageing of NPP components effectively. Despite the continuing growth in knowledge on the subject during the preparation of this report it nevertheless contains much that will be of interest to a wide technical and managerial audience. Furthermore, more specific technical publications on the evaluation and management of NPP ageing and service life are being developed under the Agency's programme, which is based on the recommendations of its 1988 Advisory Group on NPP ageing. Refs, figs and tabs

  18. Glossary of nuclear power plant ageing

    International Nuclear Information System (INIS)

    1999-01-01

    A glossary is presented of the terminology for understanding and managing the ageing of nuclear power plant systems, structures and components. This glossary has been published by NEA, in cooperation with CEC and IAEA, as a handy reference to facilitate and encourage use of common ageing terminology. The main benefits are improved reporting and interpretation of plant data on SSC degradation and failure, and improved interpretation and compliance with codes, regulations and standards related to nuclear plant ageing. The goal is to provide plant personnel with a common set of terms that have uniform, industry-wide meanings, and to facilitate discussion between experts from different countries. The glossary is in five languages: English, French, German, Spanish and Russian. In each language section terms are listed alphabetically, with sequential members which are repeated in the English section thus allowing cross-reference between al languages. (R.P.)

  19. RBMK nuclear power plants: Generic safety issues. A publication of the extrabudgetary programme on the safety of WWER and RBMK nuclear power plants

    International Nuclear Information System (INIS)

    1996-05-01

    This report has been prepared on the basis of above mentioned report and it is intended to provide information on RBMK NPPs generic safety issues. As all other insights, recommendations and conclusions resulting from the IAEA Programme, this report is intended to assist national decision makers, who have sole responsibility for the regulation and safe operation of their nuclear power plants. It also serves to focus national and international projects on priority of the RBMK safety improvements. 23 refs, 10 figs, 3 tabs

  20. IPRDS - Component histories and nuclear plant aging

    International Nuclear Information System (INIS)

    Borkowski, R.J.; Kahl, W.K.

    1984-01-01

    A comprehensive assessment of nuclear power plant component operating histories, maintenance histories, and design and fabrication details is essential to understanding aging phenomena. As part of the In-Plant Reliability Data System (IPRDS), an attempt is being made to collect and analyze such information from a sampling of U.S. nuclear power plants. Utilizing the IPRDS, one can reconstruct the failure history of the components and gain new insight into the causes and modes of failures resulting from normal or premature aging. This information assembled from the IPRDS can be combined with operating histories and postservice component inspection results for ''cradle-to-grave'' assessments of component aging under operating conditions. A comprehensive aging assessment can then be used to provide guidelines for improving the detection, monitoring, and mitigation of aging-related failures. The examples chosen for this paper illustrate two aging-related areas: the effects of an improved preventive maintenance policy in mitigating aging of a feedwater pump and the identification of reoccuring failures in parts of diesel generators

  1. Aging Management Guideline for commercial nuclear power plants: Power and distribution transformers

    International Nuclear Information System (INIS)

    Toman, G.; Gazdzinski, R.

    1994-05-01

    This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in power and distribution transformers important to license renewal in commercial nuclear power plants. The intent of this AMG to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner which allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  2. Aging Management Guideline for commercial nuclear power plants: Battery chargers, inverters and uninterruptible power supplies

    International Nuclear Information System (INIS)

    Berg, R.; Stroinski, M.; Giachetti, R.

    1994-02-01

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant battery chargers, inverters and uninterruptible power supplies important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already, experienced) and aging management program activities to the more generic results and recommendations presented herein

  3. Age-Related Degradation of Nuclear Power Plant Structures and Components

    International Nuclear Information System (INIS)

    Braverman, J.; Chang, T.-Y.; Chokshi, N.; Hofmayer, C.; Morante, R.; Shteyngart, S.

    1999-01-01

    This paper summarizes and highlights the results of the initial phase of a research project on the assessment of aged and degraded structures and components important to the safe operation of nuclear power plants (NPPs). A review of age-related degradation of structures and passive components at NPPs was performed. Instances of age-related degradation have been collected and reviewed. Data were collected from plant generated documents such as Licensing Event Reports, NRC generic communications, NUREGs and industry reports. Applicable cases of degradation occurrences were reviewed and then entered into a computerized database. The results obtained from the review of degradation occurrences are summarized and discussed. Various trending analyses were performed to identify which structures and components are most affected, whether degradation occurrences are worsening, and what was the most common aging mechanisms. The paper also discusses potential aging issues and degradation-susceptible structures and passive components which would have the greatest impact on plant risk

  4. Aging management guideline for commercial nuclear power plants-stationary batteries

    International Nuclear Information System (INIS)

    Berg, R.; Shao, J.; Krencicki, G.; Giachetti, R.

    1994-03-01

    The Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in BWR and PWR commercial nuclear power plant stationary batteries important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  5. Aging Management Guideline for commercial nuclear power plants: Motor control centers

    International Nuclear Information System (INIS)

    Toman, G.; Gazdzinski, R.; O'Hearn, E.

    1994-02-01

    This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR) commercial nuclear power plant motor control centers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

  6. Generic implications of ATWS events at the Salem Nuclear Power Plant. Licensee and staff actions

    International Nuclear Information System (INIS)

    1983-08-01

    This report, Volume 2 of two volumes of NUREG-1000, describes the intermediate term actions to be taken by licensees and applicants of the US Nuclear Regulatory Commission (NRC), on the one hand, and by NRC staff, on the other, to address the generic issues raised by two anticipated transients without scram (ATWS) at the Salem Nuclear Generating Station, Unit 1, on February 22 and 25, 1983. These actions came about as a result of the findings of NUREG-1000, Volume 1, and of reviews by the NRC Committee to Review Generic Requirements, the NRC Program Offices, and the Commission. The actions to be taken by licensees and applicants have been detailed in a letter pursuant to 10 CFR 50.54(f)

  7. Ice age plant refugia in East Greenland

    DEFF Research Database (Denmark)

    Funder, Svend Visby

    1979-01-01

    From the distribution of plants it has been inferred by some botanists that ice-free areas existed in East Greenland accommodating a flora which survived one or several ice ages in the area. Comparing this evidence with recent information on the chronology of glaciations and post-glacial vegetation...

  8. Plant aging and design bases documentation

    International Nuclear Information System (INIS)

    Kelly, J.

    1985-01-01

    As interest in plant aging and lifetime extension continues to grow, the need to identify and capture the original design bases for the plant becomes more urgent. Decisions on lifetime extension and availability must be based on a rational understanding of design input, assumptions, and objectives. As operating plant time accumulates, the history of the early design begins to fade. The longer the utility waits, the harder it will be to re-establish the original design bases. Therefore, the time to develop this foundation is now. This paper demonstrates the impact that collecting and maintaining the original design bases of the plant can have on a utility's lifetime extension program. This impact becomes apparent when considering the technical, regulatory and financial aspects of lifetime extension. It is not good enough to know that the design information is buried somewhere in the corporate archives, and that given enough time, it could be retrieved. To be useful to the lifetime extension program, plant design information must be concise, readily available (i.e., retrievable), and easy to use. These objectives can only be met through a systematic program for collecting and presenting plant design documentation. To get the maximum benefit from a lifetime extension program, usable design bases documentation should be available as early in the plant life as possible. It will help identify areas that require monitoring today so that data is available to make rational decisions in the future

  9. Nuclear Plant Aging Research (NPAR) program plan

    International Nuclear Information System (INIS)

    1985-07-01

    The nuclear plant aging research described in this plan is intended to resolve issues related to the aging and service wear of equipment and systems at commercial reactor facilities and their possible impact on plant safety. Emphasis has been placed on identification and characterization of the mechansims of material and component degradation during service and evaluation of methods of inspection, surveillance, condition monitoring and maintenance as means of mitigating such effects. Specifically the goals of the program are as follows: (1) to identify and characterize aging and service wear effects which, if unchecked, could cause degradation of structures, components, and systems and thereby impair plant safety; (2) to identify methods of inspection, surveillance and monitoring, or of evaluating residual life of structures, components, and systems, which will assure timely detection of significant aging effects prior to loss of safety function; and (3) to evaluate the effectiveness of storage, maintenance, repair and replacement practices in mitigating the rate and extent of degradation caused by aging and service wear

  10. Ageing and plant life management software Comsy

    Energy Technology Data Exchange (ETDEWEB)

    Nopper, H.; Daeuwel, W.; Kastner, W. [Siemens Nuclear Power GmbH (SNP), Erlangen (Germany)

    2001-07-01

    Cost-effective power generation is becoming more important as the prices charged by power producers in the energy market continue to fall. To ease the cost situation there is a growing demand for innovative maintenance management methods which allow power plants to be economically operated over their entire lifetime. The purpose of a systematic ageing and plant life management program is to allow the lifetime of plant components to be planned, and to indicate when a component has reached the end of its effective lifetime before it fails. Another important function of such programs is to increase the availability of power plants as they age, and to enable implementation of a targeted maintenance strategy in terms of its economic and technical effect. Implementation of such programs requires the existence of detailed information concerning the status of the components as well as their operating conditions. Based on this information, an understanding of how the relevant ageing and degradation mechanisms work enables a prediction to be made concerning component lifetime. Advanced software programs provide such predictions at reasonable cost across all systems. (author)

  11. Ageing and plant life management software Comsy

    International Nuclear Information System (INIS)

    Nopper, H.; Daeuwel, W.; Kastner, W.

    2001-01-01

    Cost-effective power generation is becoming more important as the prices charged by power producers in the energy market continue to fall. To ease the cost situation there is a growing demand for innovative maintenance management methods which allow power plants to be economically operated over their entire lifetime. The purpose of a systematic ageing and plant life management program is to allow the lifetime of plant components to be planned, and to indicate when a component has reached the end of its effective lifetime before it fails. Another important function of such programs is to increase the availability of power plants as they age, and to enable implementation of a targeted maintenance strategy in terms of its economic and technical effect. Implementation of such programs requires the existence of detailed information concerning the status of the components as well as their operating conditions. Based on this information, an understanding of how the relevant ageing and degradation mechanisms work enables a prediction to be made concerning component lifetime. Advanced software programs provide such predictions at reasonable cost across all systems. (author)

  12. Basis for snubber aging research: Nuclear Plant Aging Research Program

    International Nuclear Information System (INIS)

    Brown, D.P.; Palmer, G.R.; Werry, E.V.; Blahnik, D.E.

    1990-01-01

    This report describes a research plan to address the safety concerns of aging in snubbers used on piping and equipment in commercial nuclear power plants. The work is to be performed under Phase 2 of the Snubber Aging Study of the Nuclear Plant Aging Research Program of the US Nuclear Regulatory Commission with the Pacific Northwest Laboratory (PNL) as the prime contractor. Research conducted by PNL under Phase 1 provided an initial assessment of snubber operating experience and was primarily based on a review of licensee event reports. The work proposed is an extension of Phase 1 and includes research at nuclear power plants and in test laboratories. Included is technical background on the design and use of snubbers in commercial nuclear power applications; the primary failure modes of both hydraulic and mechanical snubbers are discussed. The anticipated safety, technical, and regulatory benefits of the work, along with concerns of the NRC and the utilities, are also described. 21 refs., 7 figs., 1 tab

  13. Generic safety issues for nuclear power plants with pressurized heavy water reactors and measures for their resolution

    International Nuclear Information System (INIS)

    2007-06-01

    be used in reassessing the safety of individual operating plants. In 1998, the IAEA completed IAEA-TECDOC-1044 entitled Generic Safety Issues for Nuclear Power Plants with Light Water Reactors and Measures Taken for their Resolution and established the associated LWRGSIDB database (Computer Manual Series No. 13). The present compilation, which is based on broad international experience, is an extension of this work to cover pressurized heavy water reactors (PHWRs). As in the case of LWRs, it is one element in the framework of IAEA activities to assist Member States in reassessing the safety of operating nuclear power plants. It addresses generic safety issues identified in nuclear power plants using PHWRs. In most cases, the measures taken or planned to resolve these issues are also identified. The work on this report was initiated by the Senior Regulators of Countries Operating CANDU-Type Nuclear Power Plants at one of their annual meetings. It was carried out within the framework of the IAEA's programme on National Regulatory Infrastructure for Nuclear Installation Safety and serves to enhance regulatory effectiveness through the exchange of safety related information

  14. A method to generate generic floor response spectra for operating nuclear power plants

    International Nuclear Information System (INIS)

    Curreri, J.; Costantino, C.; Subudhi, M.; Reich, M.

    1985-01-01

    A free-field earthquake response spectra was used to generate horizontal earthquake time histories. The excitation was applied through the soil and into the various structures to produce responses in equipment. An entire range of soil conditions was used with each structure, from soft soil to solid rock. Actual PWR and BWR - Mark I structural models were used as representative of a class of structures. For each model, the stiffness properties were varied, with the same mass, so as to extend the fundamental base structure natural frequency from 2 cps to 36 cps. This resulted in fundamental mode coupled natural frequencies as low as 0.86 cps and as high as 30 cps. From all of these models of soils and structures, floor response spectra were generated at each floor level. The natural frequencies of the structures were varied to obtain maximum response conditions. The actual properties were first used to locate the natural frequencies. The stiffness properties were than varied, with the same mass, to extend the range of the fundamental base structure natural frequency. The intention was to have the coupled structural material frequencies in the vicinity of the peak amplitude frequency content of the excitation spectrum. Particular attention was therefore given to the frequency band between 2 Hz and 4 Hz. A horizontal generic floor response spectra is proposed for the top level of a generic structure. Reduction factors are applied to the peak acceleration for equipment at lower levels. (orig./HP)

  15. Prototype of generic server for wind power plants using IEC 61400-25 standard

    DEFF Research Database (Denmark)

    Olsen, Andreas K.; Ösdil, B.; Poulsen, Bjarne

    2006-01-01

    from interfaces for control and monitoring to a standardized and secure way of handling communication. An analysis focusing on isolating the necessary requirements has been carried out based on the IEC61400-25 in order to create a generic prototype which can be used by WPP vendors. The main...... communications interface of the prototype utilizes web services and the prototype developed is comprised of several independent modules to allow for the possibility of choosing a fully customizable setup by the end user. Configuration of the system needs to be done in a simple way, ensuring a flexible...... and reusable system, where different choices for the system can be added or left out depending on user specifications. From the requirements a prototype with the purpose of examining the key aspects of these definitions has been elaborated....

  16. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae.

    Science.gov (United States)

    Chen, Ling-Yun; Chen, Jin-Ming; Gituru, Robert Wahiti; Wang, Qing-Feng

    2012-03-10

    Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite) and divergence time estimates (BEAST) resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma). Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges) probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Our study has shed light on the previously controversial

  17. Method to generate generic floor response spectra for operating nuclear power plant

    International Nuclear Information System (INIS)

    Curreri, J.; Costantino, C.; Subudhi, M.; Reich, M.

    1985-01-01

    The general approach in the development of the response spectra was to study the effects on the dynamic characteristics of each of the elements in the chain of events that goes between the loads and the responses. This includes the loads, the soils and the structures. A free-field earthquake response spectra was used to generate horizontal earthquake time histories. The excitation was applied through the soil and into the various structures to produce responses in equipment. An entire range of soil conditions was used with each structure, from soft soil to solid rock. Actual PWR and BWR - Mark I structural models were used as representative of a class of structures. For each model, the stiffness properties were varied, with the same mass, so as to extend the fundamental base structure natural frequency from 2 cps to 36 cps. This resulted in fundamental mode coupled natural frequencies as low as 0.86 cps and as high as 30 cps. From all of these models of soils and structures, floor response spectra were generated at each floor level. The natural frequencies of the structures were varied to obtain maximum response conditions. The actual properties were first used to locate the natural frequencies. The stiffness properties were then varied, with the same mass, to extend the range of the fundamental base structure natural frequency. The intention was to have the coupled structural material frequencies in the vicinity of the peak amplitude frequency content of the excitation spectrum. Particular attention was therefore given to the frequency band between 2 Hz and 4 Hz. A horizontal generic floor response spectra is proposed for the top level of a generic structure. Reduction factors are applied to the peak acceleration for equipment at lower levels

  18. NPAR [Nuclear Plant Aging Research] approach to managing aging in nuclear power plants

    International Nuclear Information System (INIS)

    Christensen, J.A.

    1989-01-01

    Over the past 5 years, the Nuclear Plant Aging Research program (NPAR) has been devoted to developing technical understanding of the time dependent processes that, through deterioration of components, systems, or structures (C/S/S), can reduce safety margins in nuclear power plants. A major and necessary element of the program involves the application of this basic knowledge in defining functional approaches to managing aging by anticipating and mitigating important deterioration processes. Fundamental understanding and characterization of aging processes are being accomplished through NPAR-sponsored research projects, review and analysis of aging related information, integration of NPAR results with those from industry and other aging studies, and interfacing of all of these with the existing body of codes, standards and regulatory instruments that convey aging-related guidance to NPP licensees. Products of these efforts are applied to structuring and providing aging-related technical recommendations in forms that are useful in: (1) developing and implementing good aging management practices, (2) developing regulatory guidance and requirements for understanding and managing aging during normal plant operations and in support of license renewal, and (3) planning and implementing other regulatory actions and initiatives in which aging-related concerns have a bearing on scope or priority

  19. Handbook for cost estimating. A method for developing estimates of costs for generic actions for nuclear power plants

    International Nuclear Information System (INIS)

    Ball, J.R.; Cohen, S.; Ziegler, E.Z.

    1984-10-01

    This document provides overall guidance to assist the NRC in preparing the types of cost estimates required by the Regulatory Analysis Guidelines and to assist in the assignment of priorities in resolving generic safety issues. The Handbook presents an overall cost model that allows the cost analyst to develop a chronological series of activities needed to implement a specific regulatory requirement throughout all applicable commercial LWR power plants and to identify the significant cost elements for each activity. References to available cost data are provided along with rules of thumb and cost factors to assist in evaluating each cost element. A suitable code-of-accounts data base is presented to assist in organizing and aggregating costs. Rudimentary cost analysis methods are described to allow the analyst to produce a constant-dollar, lifetime cost for the requirement. A step-by-step example cost estimate is included to demonstrate the overall use of the Handbook

  20. 77 FR 21813 - Changes to the Generic Aging Lessons Learned (GALL) Report Revision 2 AMP XI.M41, “Buried and...

    Science.gov (United States)

    2012-04-11

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0055] Changes to the Generic Aging Lessons Learned (GALL) Report Revision 2 AMP XI.M41, ``Buried and Underground Piping and Tanks'' AGENCY: Nuclear Regulatory... Guidance (LR-ISG), LR-ISG-2011-03, ``Changes to GALL Report Revision 2 Aging Management Program (AMP) XI...

  1. Generic phylogeny, historical biogeography and character evolution of the cosmopolitan aquatic plant family Hydrocharitaceae

    Directory of Open Access Journals (Sweden)

    Chen Ling-Yun

    2012-03-01

    Full Text Available Abstract Background Hydrocharitaceae is a fully aquatic monocot family, consists of 18 genera with approximately 120 species. The family includes both fresh and marine aquatics and exhibits great diversity in form and habit including annual and perennial life histories; submersed, partially submersed and floating leaf habits and linear to orbicular leaf shapes. The family has a cosmopolitan distribution and is well represented in the Tertiary fossil record in Europe. At present, the historical biogeography of the family is not well understood and the generic relationships remain controversial. In this study we investigated the phylogeny and biogeography of Hydrocharitaceae by integrating fossils and DNA sequences from eight genes. We also conducted ancestral state reconstruction for three morphological characters. Results Phylogenetic analyses produced a phylogeny with most branches strongly supported by bootstrap values greater than 95 and Bayesian posterior probability values of 1.0. Stratiotes is the first diverging lineage with the remaining genera in two clades, one clade consists of Lagarosiphon, Ottelia, Blyxa, Apalanthe, Elodea and Egeria; and the other consists of Hydrocharis-Limnobium, Thalassia, Enhalus, Halophila, Najas, Hydrilla, Vallisneria, Nechamandra and Maidenia. Biogeographic analyses (DIVA, Mesquite and divergence time estimates (BEAST resolved the most recent common ancestor of Hydrocharitaceae as being in Asia during the Late Cretaceous and Palaeocene (54.7-72.6 Ma. Dispersals (including long-distance dispersal and migrations through Tethys seaway and land bridges probably played major roles in the intercontinental distribution of this family. Ancestral state reconstruction suggested that in Hydrocharitaceae evolution of dioecy is bidirectional, viz., from dioecy to hermaphroditism, and from hermaphroditism to dioecy, and that the aerial-submerged leaf habit and short-linear leaf shape are the ancestral states. Conclusions

  2. Plant specification of a generic human-error data through a two-stage Bayesian approach

    International Nuclear Information System (INIS)

    Heising, C.D.; Patterson, E.I.

    1984-01-01

    Expert judgement concerning human performance in nuclear power plants is quantitatively coupled with actuarial data on such performance in order to derive plant-specific human-error rate probability distributions. The coupling procedure consists of a two-stage application of Bayes' theorem to information which is grouped by type. The first information type contains expert judgement concerning human performance at nuclear power plants in general. Data collected on human performance at a group of similar plants forms the second information type. The third information type consists of data on human performance in a specific plant which has the same characteristics as the group members. The first and second information types are coupled in the first application of Bayes' theorem to derive a probability distribution for population performance. This distribution is then combined with the third information type in a second application of Bayes' theorem to determine a plant-specific human-error rate probability distribution. The two stage Bayesian procedure thus provides a means to quantitatively couple sparse data with expert judgement in order to obtain a human performance probability distribution based upon available information. Example calculations for a group of like reactors are also given. (author)

  3. Generic report on health effects for the US Gaseous Diffusion Plants. Sect. 8, Pt. 1

    International Nuclear Information System (INIS)

    Just, R.A.; Emler, V.S.

    1984-06-01

    Toxic substances present in uranium enrichment plants include uranium hexafluoride (UF 6 ), hydrogen fluoride (HF), uranyl fluoride (UO 2 F 2 ), chlorine (Cl 2 ), chlorine trifluoride (ClF 3 ), fluorine (F 2 ), uranium tetrafluoride (UF 4 ), and technetium (Tc). The current knowledge of the expected health effects of acute exposures to these substances is described. 10 references, 2 figures, 6 tables

  4. Status of safety issues at licensed power plants: TMI action plan requirements, unresolved safety issues, generic safety issues

    International Nuclear Information System (INIS)

    1991-12-01

    As part of ongoing US Nuclear Regulatory Commission (NRC) efforts to ensure the quality and accountability of safety issue information, a program was established whereby an annual NUREG report would be published on the status of licensee implementation and NRC verification of safety issues in major NRC requirements areas. This information was compiled and reported in three NUREG volumes. Volume 1, published in March 1991, addressed the status of of Three Mile Island (TMI) Action Plan Requirements. Volume 2, published in May 1991, addressed the status of unresolved safety issues (USIs). Volume 3, published in June 1991, addressed the implementation and verification status of generic safety issues (GSIs). This annual NUREG report combines these volumes into a single report and provides updated information as of September 30, 1991. The data contained in these NUREG reports are a product of the NRC's Safety Issues Management System (SIMS) database, which is maintained by the Project Management Staff in the Office of Nuclear Reactor Regulation and by NRC regional personnel. This report is to provide a comprehensive description of the implementation and verification status of TMI Action Plan Requirements, safety issues designated as USIs, and GSIs that have been resolved and involve implementation of an action or actions by licensees. This report makes the information available to other interested parties, including the public. An additional purpose of this NUREG report is to serve as a follow-on to NUREG-0933, ''A Prioritization of Generic Safety Issues,'' which tracks safety issues up until requirements are approved for imposition at licensed plants or until the NRC issues a request for action by licensees

  5. Preventive maintenance-A countermeasure to plant aging

    International Nuclear Information System (INIS)

    Hlubek, W.

    1985-01-01

    The aging of power plants is caused by manifold and different influences. For instance, mechanical and thermal stress, radiation exposure, denting or wastage can considerably affect the aging of plant components and thus cause premature failures of components. In this presentation, the term 'Plant Aging' in nuclear power plants is to be understood more comprehensively than wear on components and material fatigue. In addition, nuclear power plants are to be adjusted to the advancing state of the science and technology (state-of-the-art) in order to guarantee safe operation at all times. The preventive maintenance - as a countermeasure to plant aging - comprises the systematic checks and servicing of the plant systems in operation and follows aging by inspection and tests. Experience with Rheinisch-Westfaelisches Elektrizitaetswerk AG (RWE) preventive maintenance program at the Biblis NNP (1300 MW, PWR) is discussed. The concept of an 'Integrated Maintenance System' as a means to avoid 'Plant Aging' is presented

  6. Control of heavy loads at nuclear power plants: Resolution of Generic Technical Activity A-36. Technical report

    International Nuclear Information System (INIS)

    George, H.J.

    1980-07-01

    This report summarizes work performed by the NRC staff in the resolution of Generic Technical Activity A-36, Control of Heavy Loads Near Spent Fuel. Generic Technical Activity A-36 is one of the generic technical subjects designated as unresolved safety issues pursuant to Section 210 of the Energy Reorganization Act of 1974. The report describes the technical studies and evaluations performed by the NRC staff, the staff's guidelines based on these studies, and the staff's plans for implementaton of its technical guidelines

  7. Modified enforcement policy relating to 10 CFR 50.49, ''Environmental qualification of electrical equipment important to safety for nuclear power plants'' (Generic Letter 88-07)

    International Nuclear Information System (INIS)

    Miraglia, F.J.

    1992-01-01

    Generic Letters, Bulletins, and Information Notices have been issued to provide guidance regarding the application and enforcement of 10 CFR 50.49, ''Environmental Qualification of Electric Equipment Important to Safety for Nuclear Power Plants.'' Generic Letter 85-15, issued August 6, 1985, and Generic Letter 86-15, issued September 22, 1986, provided information related to the deadlines for compliance with 10 CFR 50.49 and possible civil penalties applicable to licensees who were not in compliance with the rule as of the November 30, 1985 deadline. Upon review, the Commission found that the EQ Enforcement Policy promulgated in Generic Letter 86-15, could result in imposition of civil penalties that did not properly reflect the safety significance of EQ violations with respect to civil penalties imposed in the past. In the interest of continuing a tough but fair enforcement policy, the Commission determined that the EQ Enforcement Policy should be revised. The purpose of this letter is to provide a modification to the NRC's enforcement policy, as approved by the Commission, for environmental qualification (EQ) violations. This letter replaces the guidance provided in Generic Letters 85-15 and 86-15

  8. Clinical and economic consequences of treating patients with peripheral neuropathic pain with brand name or generic drugs in routine clinical practice: The effects of age and sex.

    Science.gov (United States)

    Navarro-Artieda, R; Rejas-Gutiérrez, J; Pérez-Paramo, M; Sicras-Mainar, A

    2018-04-01

    We aimed to analyse the effects of age and sex on pain and cost for patients with chronic peripheral neuropathic pain (PNP) who have started treatment with brand name gabapentin versus generic gabapentin (EFG). We conducted a retrospective multicentre study using electronic medical records (EMR) for patients of both sexes, older than 18, who began treatment with brand name or generic gabapentin. Adherence (medication possession ratio [MPR]), persistence, use of healthcare resources, cost, and pain reduction were measured for one year. We analysed 1369 EMRs [61.1% women; mean age 64.6 (15.9), 52.4%≥65 years]; 400 used brand name drugs while 969 used generic gabapentin. Persistence and adherence were higher in patients using brand name gabapentin (7.3 vs 6.3 months, Pbrand-name gabapentin in both age groups (brand treatment showed greater pain relief: 13.5% (10.9-16.2) and 10.8% (8.2-13.5) in brand name medication showed greater persistence and adherence to treatment than those taking generic drugs. Brand name treatment also involved lower healthcare costs, and greater pain relief. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Generic Advantages

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Generic Advantages. Scalability an incremental coverage. Standardization. Business Plan Flexibility. Lifecycle Flexibility. Reliability. Service Interoperability. Changed Industry dynamics.

  10. Aging and service wear of air compressors and dryers in nuclear power plants

    International Nuclear Information System (INIS)

    Moyers, J.C.

    1989-01-01

    Compressed air systems and their associated compressors and dryers as incorporated in LWR power plants usually are not classified as safety related systems and components because their continued operation is not required to bring the plant to a safe shutdown condition. However, control air is a vital requirement for maintaining stable plant operation and its loss often results in a reactor trip and, on occasion, the actuation of engineered safety feature systems. Concerns caused by repeated instances of failures in air systems resulted in the high-priority ranking of Generic Issue No. 43, ''Reliability of Air Systems'' by the NRC. In support of the Nuclear Plant Aging Research (NPAR) Program, the Oak Ridge National Laboratory is carrying out a Phase I aging assessment of air compressors and dryers used in LWR power plants. The objectives of this study include: (1) determination of the types and ratings of equipment utilized in typical plants; (2) identification of aging and service wear stressors imposed on the machines; (3) evaluation of operating experience with the machines; (4) comparison of user and manufacturer-recommended inspection, surveillance, and monitoring (ISM) methods; and (5) the identification of any improved ISM methods that might lead to longer, more reliable, service. 2 refs

  11. Generic evaluation of small break loss-of-coolant accident behavior in Babcock and Wilcox designed 177-FA operating plants

    International Nuclear Information System (INIS)

    1980-01-01

    Slow system depressurization resulting from small break loss-of-coolant accidents (LOCAs) in the reactor coolant system have not, until recently, received detailed analytical study comparable to that devoted to large breaks. Following the TMI-2 accident, the staff had a series of meetings with Babcock and Wilcox (B and W) and the B and W licensees. The staff requested that B and W and the licensees: (1) systematically evaluate plant response for small break loss-of-coolant accidents; (2) address each of the concerns documented in the Michelson report; (3) validate the computer codes used against the TMI-2 accident; (4) extend the break spectrum analysis to very small breaks, giving special consideration to failure of pressurizer valves to close; (5) analyze degraded conditions where AFW is not available; (6) prepare design changes aimed at reducing the probability of loss-of-coolant accidents produced by the failure of a PORV to close; and (7) develop revised emergency procedures for small breaks. This report describes the review of the generic analyses performed by B and W based on the requests stated above

  12. Human factors: A major issue in plant aging

    International Nuclear Information System (INIS)

    Widrig, R.D.

    1985-01-01

    Humans play a significant role in the effects of aging on safe and reliable operation of nuclear power plants. These human issues may be more important than the issues of materials and component degradation with age. Human actions can accelerate or decelerate physical aging of a plant. And an aging plant can have a significant negative impact on staff quality and performance. The purpose of this paper is to provide some insights into the nature of these human factors issues and their relationship to plant aging. An early awareness of these issues facilitates timely action to at least mitigate these problems before they become insurmountable

  13. Aging management of reactor internals and license renewal of US PWR plants

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H. T. [Electric Power Research Institute, EPRI, 3420 Hillview Avenue, Palo Alto, California 94304 (United States)

    2006-09-15

    Age-related degradation mechanisms of key components are subject to aging management review by utilities considering plant license renewal. The management of aging effects in PWR internals must be demonstrated as specified in the US NRC Standard Review. The US NRC staff has also issued a Generic Aging Lessons Learned (GALL) report that documents the staff's basis for determining when existing generic programs are adequate to manage aging without change and when existing generic programs should be augmented for license renewal. The EPRI Materials Reliability Program (MRP) has been conducting studies to develop technical bases and guidelines to support aging management of PWR internals, with a particular attention to utility License Renewal commitments. The strategic approach taken by the MRP includes: developing an overall aging management framework, defining degradation mechanism screening values, categorizing and ranking internals components based on screening, performing functionality analyses and safety evaluation, and developing inspection and evaluation guidelines associated with each category of components. Screening criteria are developed for the following potential internals degradation mechanisms: - Stress Corrosion Cracking [Excluding Irradiation Effects]; - Irradiation-Assisted Stress Corrosion Cracking; - Thermal Aging Embrittlement; - Irradiation Embrittlement; - Void Swelling; - Stress Relaxation and Creep [Irradiation-enhanced]; - Wear; - Fatigue. The ranking and categorization calls to bin internals components into four categories: - Category A: component items for which aging degradation significance is minimal and aging effects are below the screening criteria; - Category C: 'lead' component items for which aging degradation significance is high or moderate and aging effects are above screening levels; - Category B: component items above screening levels but are not 'lead' component items and aging degradation significance

  14. Utilisation of real-scale renewable energy test facility for validation of generic wind turbine and wind power plant controller models

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Gevorgian, Vahan; Wallen, Robb

    2016-01-01

    This article presents an example of application of a modern test facility conceived for experiments regarding the integration of renewable energy in the power system. The capabilities of the test facility are used to validate dynamic simulation models of wind power plants and their controllers....... The models are based on standard and generic blocks. The successful validation of events related to the control of active power (control phenomena in...

  15. Reliability methods in nuclear power plant ageing management

    International Nuclear Information System (INIS)

    Simola, K.

    1999-01-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  16. Reliability methods in nuclear power plant ageing management

    Energy Technology Data Exchange (ETDEWEB)

    Simola, K. [VTT Automation, Espoo (Finland). Industrial Automation

    1999-07-01

    The aim of nuclear power plant ageing management is to maintain an adequate safety level throughout the lifetime of the plant. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time-dependent degradation. The phases of ageing analyses are generally the identification of critical components, identification and evaluation of ageing effects, and development of mitigation methods. This thesis focuses on the use of reliability methods and analyses of plant- specific operating experience in nuclear power plant ageing studies. The presented applications and method development have been related to nuclear power plants, but many of the approaches can also be applied outside the nuclear industry. The thesis consists of a summary and seven publications. The summary provides an overview of ageing management and discusses the role of reliability methods in ageing analyses. In the publications, practical applications and method development are described in more detail. The application areas at component and system level are motor-operated valves and protection automation systems, for which experience-based ageing analyses have been demonstrated. Furthermore, Bayesian ageing models for repairable components have been developed, and the management of ageing by improving maintenance practices is discussed. Recommendations for improvement of plant information management in order to facilitate ageing analyses are also given. The evaluation and mitigation of ageing effects on structural components is addressed by promoting the use of probabilistic modelling of crack growth, and developing models for evaluation of the reliability of inspection results. (orig.)

  17. Generic evaluation of feedwater transients and small break loss-of-coolant accidents in GE-designed operating plants and near-term operating license applications

    International Nuclear Information System (INIS)

    1980-01-01

    The results are presented of a generic evaluation of feedwater transients, small-break loss-of-coolant accidents (LOCAs), and other TMI-2-related events for General Electric Company (GE)-designed operating plants and near-term operating license applications to confirm or establish the bases for the continued safe operation of the operating plants. The results of this evaluation are presented in this report in the form of a set of findings and recommendations in each of the principal review areas. Additional review of the accident is continuing and further information is being obtained and evaluated. Any new information will be reviewed and modifications will be made as appropriate

  18. Consumption of polyphenol plants may slow aging and associated diseases.

    Science.gov (United States)

    Uysal, Utku; Seremet, Sila; Lamping, Jeffrey W; Adams, Jerome M; Liu, Deede Y; Swerdlow, Russell H; Aires, Daniel J

    2013-01-01

    Slowing aging is a widely shared goal. Plant-derived polyphenols, which are found in commonly consumed food plants such as tea, cocoa, blueberry and grape, have been proposed to have many health benefits, including slowing aging. In-vivo studies have demonstrated the lifespan-extending ability of six polyphenol-containing plants. These include five widely consumed foods (tea, blueberry, cocoa, apple, pomegranate) and a flower commonly used as a folk medicine (betony). These and multiple other plant polyphenols have been shown to have beneficial effects on aging-associated changes across a variety of organisms from worm and fly to rodent and human.

  19. Management of ageing in nuclear power plants

    International Nuclear Information System (INIS)

    Bora, J.S.; Ramteke, P.K.; Babar, A.K.; Kushwaha, H.S.; Venkat Raj, V.

    2001-01-01

    Ageing is time dependent degradation of hardware and measured by percentage deviation of performance parameters with reference to their respective reference values. Ageing is influenced by environmental and operating stresses; lower the magnitude of stresses, lower the rate of degradation and vice versa. This paper describes test results of thermal ageing, radiation ageing and performance during loss of coolant accident (LOCA) environment (steam bound condition at 120 degC) on various types of electrical cables, elastomers and electronic process instruments. (author)

  20. Aging of electric motors in nuclear power plants

    International Nuclear Information System (INIS)

    Subudhi, M.; Taylor, J.H.

    1987-06-01

    Motor degradation due to aging and service wear decreases reliability and increases the potential for failure during nuclear plant accident and post accident conditions. The impact of motor failures on plant safety is an important concern among the nuclear utilities and the government agency regulating this industry. Economic impacts, relating to plant availability and safety, as well as corrective maintenance, have prompted utilities to improve their maintenance programs to mitigate such aging effects. 2 refs., 3 figs

  1. Comparison of generic-to-brand switchback patterns for generic and authorized generic drugs

    Science.gov (United States)

    Hansen, Richard A.; Qian, Jingjing; Berg, Richard; Linneman, James; Seoane-Vazquez, Enrique; Dutcher, Sarah K.; Raofi, Saeid; Page, C. David; Peissig, Peggy

    2018-01-01

    Background While generic drugs are therapeutically equivalent to brand drugs, some patients and healthcare providers remain uncertain about whether they produce identical outcomes. Authorized generics, which are identical in formulation to corresponding brand drugs but marketed as a generic, provide a unique post-marketing opportunity to study whether utilization patterns are influenced by perceptions of generic drugs. Objectives To compare generic-to-brand switchback rates between generics and authorized generics. Methods A retrospective cohort study was conducted using claims and electronic health records data from a regional U.S. healthcare system. Ten drugs with authorized generics and generics marketed between 1999 and 2014 were evaluated. Eligible adult patients received a brand drug during the 6 months preceding generic entry, and then switched to a generic or authorized generic. Patients in this cohort were followed for up to 30 months from the index switch date to evaluate occurrence of generic-to-brand switchbacks. Switchback rates were compared between patients on authorized generics versus generics using Kaplan-Meier curves and Cox proportional hazards models, controlling for individual drug effects, age, sex, Charlson comorbidity score, pre-index drug use characteristics, and pre-index healthcare utilization. Results Among 5,542 unique patients that switched from brand-to-generic or brand-to-authorized generic, 264 (4.8%) switched back to the brand drug. Overall switchback rates were similar for authorized generics compared with generics (HR=0.86; 95% CI 0.65-1.15). The likelihood of switchback was higher for alendronate (HR=1.64; 95% CI 1.20-2.23) and simvastatin (HR=1.81; 95% CI 1.30-2.54) and lower for amlodipine (HR=0.27; 95% CI 0.17-0.42) compared with other drugs in the cohort. Conclusions Overall switchback rates were similar between authorized generic and generic drug users, indirectly supporting similar efficacy and tolerability profiles for

  2. Monitoring ageing of components in nuclear plants

    International Nuclear Information System (INIS)

    Fritz, M.R.

    1992-01-01

    There are several mechanisms of ageing or damage in nuclear components, of which the best known can be classified into three categories: generalized damage mechanisms (wear, corrosion, erosion,...), local damage phenomena (fatigue, corrosion,...) and material property degradations. For ageing evaluation, the first requirement is a good understanding of the damage mechanisms and the determination of the kinetic laws and major influencing factors. When these factors are measurable physical parameters, ageing monitoring and periodic evaluation of damage level become possible. From the set of tools available for ageing evaluation, four are presented here in more detail: the transient logging procedure, the defect injuriousness analysis, the fatigue meter, the probabilistic approach to structural integrity. (author)

  3. Monitoring ageing of components in nuclear plants

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, M R [FRAMATOME, Paris (France)

    1992-07-01

    There are several mechanisms of ageing or damage in nuclear components, of which the best known can be classified into three categories: generalized damage mechanisms (wear, corrosion, erosion,...), local damage phenomena (fatigue, corrosion,...) and material property degradations. For ageing evaluation, the first requirement is a good understanding of the damage mechanisms and the determination of the kinetic laws and major influencing factors. When these factors are measurable physical parameters, ageing monitoring and periodic evaluation of damage level become possible. From the set of tools available for ageing evaluation, four are presented here in more detail: the transient logging procedure, the defect injuriousness analysis, the fatigue meter, the probabilistic approach to structural integrity. (author)

  4. Status of safety issues at licensed power plants: TMI Action Plan requirements, unresolved safety issues, generic safety issues, other multiplant action issues

    International Nuclear Information System (INIS)

    1992-12-01

    This report is to provide a comprehensive description of the implementation and verification status of Three Mile Island (TMI) Action Plan requirements, safety issues designated as Unresolved Safety Issues (USIs), Generic Safety Issues(GSIs), and other Multiplant Actions (MPAs) that have been resolved and involve implementation of an action or actions by licensees. This report makes the information available to other interested parties, including the public. An additional purpose of this NUREG report is to serve as a follow-on to NUREG-0933, ''A Prioritization of Generic Safety Issues,'' which tracks safety issues up until requirements are approved for imposition at licensed plants or until the NRC issues a request for action by licensees

  5. Framatome ANP worldwide experience in ageing and plant life management

    International Nuclear Information System (INIS)

    Daeuwel, W.; Kastner, B.; Nopper, H.

    2004-01-01

    The deregulation of the power generation industry has resulted in increased competitive pressure and is forcing operators to improve plant operating economy while maintaining high levels of plant safety. A key factor to meet this challenge is to apply a comprehensive plant life management (PLIM) approach which addresses all relevant ageing and degradation mechanisms regarding the safety concept, plant components and documentation, plant personnel, consumables, operations management system and administrative controls. For this reason, Framatome ANP has developed an integrated PLIM concept focussing on the safety concept, plant components and documentation. Representative examples for plant wide analyses are described in the following. The results of the analyses support the plant owner for taking the strategic decisions, involved in plant life extension (PLEX). (orig.)

  6. Seismic and dynamic qualification of safety-related electrical and mechanical equipment in operating nuclear power plants: development of a method to generate generic floor-response spectra

    International Nuclear Information System (INIS)

    Curreri, J.; Costantino, C.; Subudhi, M.; Reich, M.

    1983-09-01

    Generic floor response spectra were developed for use in the qualification of electrical and mechanical equipment in operating nuclear power plants. The characteristics of 1000 floor response spectra were studied to determine the generic spectra. The procedure developed uses as much or as little information that currently exists at the plant relating to the question of equipment qualification. The general approach was to study the effects on the dynamic characteristics of each of the elements in the chain of events that goes between the loads and the responses. This includes the loads, the soils and the structures. A free-field earthquake response spectra was used to generate horizontal earthquake time histories. The excitation was applied through the soil and into the various structures to produce responses in equipment. An entire range of soil conditions was used with each structure. Actual PWR and BWR - Mark I structural models were used. For each model, the stiffness properties were varied, with the same mass, so as to extend the fundamental base structure natural frequency from 2 cps to 36 cps. The natural frequencies of the structures were varied to obtain maximum response conditions. The actual properties were first used to locate the natural frequencies. The stiffness properties were than varied, with the same mass, to extend the range of the fundamental base structure natural frequency. The intention was to have the coupled structural material frequencies in the vicinity of the peak amplitude frequency content of the excitation spectrum. Particular attention was therefore given to the frequency band between 2 Hz and 4 Hz. A horizontal generic floor response spectra is proposed for the top level of a generic structure. Reduction factors are applied to the peak acceleration for equipment at lower levels

  7. Nuclear power plant ageing management programmes in foreign countries

    International Nuclear Information System (INIS)

    Simola, K.; Laakso, K.; Pekkonen, A.

    1992-09-01

    The report describes ageing studies of nuclear power plants and research programmes on plant life extension in foreign countries. Ageing studies are aimed to ascertain that the availability and safety of components and structures can be maintained throughout the plant lifetime. In life extension programmes the purpose is to evaluate the technical and economical possibilities to extend the plant lifetime beyond the originally planned operation period, without reducing the plant safety. The main emphasis of the report is put on the ageing and life extension programmes in the United States. Besides the U.S. studies, research on plant life extension possibilities conducted in France and Japan are also described. Examples of studies performed in other nuclear energy producing countries are given. These examples are mainly related to the development of maintenance programmes and techniques

  8. COMSY - A Software Tool for Aging and Plant Life Management

    International Nuclear Information System (INIS)

    Zander, Andre; Nopper, Helmut

    2012-01-01

    A Plant-wide and systematic Aging and Plant Life Management is essential for the safe operation and/or availability of nuclear power plants. The Aging Management (AM) has the objective to monitor and control degradation effects for safety relevant Systems, Structures and Components (SSCs) which may compromise safety functions of the plant. The Plant Life Management (PLM) methodology also includes aging surveillance for availability relevant SSCs. AM and PLM cover mechanical components, electrical and I and C systems and civil structures All Aging and Plant Life Management rules call for a comprehensive approach, requiring the systematic collection of various aging and safety relevant data on a plant-wide basis. This data needs to be serviced and periodically evaluated. Due to the complexity of the process, this activity needs to be supported by a qualified software tool for the management of aging relevant data and associated documents (approx. 30 000 SSCs). In order to support the power plant operators AREVA NP has developed the software tool COMSY. The COMSY software with its integrated AM modules enables the design and setup of a knowledge-based power plant model compatible to the requirements of international and national rules (e.g. IAEA Safety Guide NS-G-2.12, KTA 1403). In this process, a key task is to identify and monitor degradation mechanisms. For this purpose the COMSY tool provides prognosis and trending functions, which are based on more than 30 years of experience in the evaluation of degradation effects and numerous experimental studies. Since 1998 COMSY has been applied successfully in more than fifty reactor units in this field. The current version 3.0 was revised completely and offers additional AM functions. All aging-relevant component data are compiled and allocated via an integrated power plant model. Owing to existing interfaces to other software solutions and flexible import functions, COMSY is highly compatible with already existing data

  9. Recommendations for managing equipment aging in nuclear power plants

    International Nuclear Information System (INIS)

    Gunther, W.E.; Subudhi, M.; Aggarwal, S.K.

    1992-01-01

    Research conducted under the auspices of the US NRC's Nuclear Plant Aging Research (NPAR) Program has resulted in a large database of component and system operating, maintenance, and testing information. This database has been used to determine the susceptibility to aging of selected components, and the potential for equipment aging to impact plant safety and availability. it has also identified methods for detecting and mitigating component and system aging. This paper describes the research recommendations on electrical components which could be applied to maintenance, testing, and inspection activities to detect and mitigate the effects of aging prior to equipment failures

  10. Failure analysis and success analysis: roles in plant aging assessments

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.

    1985-06-01

    Component aging investigations are an important element in NRC's Nuclear Plant Aging Research (NPAR) strategy. Potential sources of components include plants in decommissioning and commercial plant, both for in situ tests and for examination of equipment removed from service. Nuclear utilities currently have voluntary programs addressing aspects of equipment reliability, such as root cause analysis for safety-related equipment that malfunctions, and trending analysis to follow the course of both successful and abnormal equipment performance. Properly coordinated, the NPAR and utility programs offer an important approach to establish the data base necessary for life extension of nuclear electrical generating plants

  11. Ageing effects modelling in probabilistic safety assessment of nuclear power plants

    International Nuclear Information System (INIS)

    Nitoi, M.; Turcu, I.; Florescu, G.; Apostol, M.; Farcasiu, M.; Pavelescu, M.

    2005-01-01

    Ageing management has become a major concern for many responsible organizations during the last years, because as the operating power plants have got older, they may have the tendency to become less safe. The effects of age-related degradation of plant components, systems and structures are necessary to be assessed in order to assure a continuous safe operation of nuclear power plants. The Probabilistic Safety Analysis (PSA) is an efficient system analysis method which is used to assess the risk of operation of nuclear power plants. In the assessment of risk level for a plant, most of the PSA studies generally didn't take into account the ageing effects, and uses a time averaged unavailability. By incorporation of ageing effects, the results enable an identification of the components that have the greatest effect on risk if their failure rates increase due to ageing effects modelling. In this paper, it was assessed the impact on Class IV Electrical Power System unavailability of the assumed increase in components failure probability caused by components ageing. The electrical system was chosen for the study because there are a lot of cables and for these types of equipment there is no planned preventive or corrective maintenance, and they are originally designed to reach the end of plant life with an adequate safety margin. To quantify the effects of age-related degradation on components, the linear ageing model was used. In this model, the failure rate of a component λ (t) is expressed as a sum of two independent failure rates, one associated with random failure, λ 0 , and the other associated with failures due to aging α, so: λ(t) = λ 0 + αt. The basic events were coded using a computer code similar to CAFTA, developed in INR Pitesti. For the reliability data allocation for basic events a intern data base was used. This data base contains data from the following generic data bases: IAEA Component Reliability Data for use in PSA, Point Lepreau Component

  12. Human factors: a major issue in plant aging

    International Nuclear Information System (INIS)

    Widrig, R.D.

    1985-07-01

    Human factors issues will be of great significance in the safe and reliable operation of aging nuclear power plants, and they may be more important than materials/component-type issues. Human actions can accelerate or decelerate te physical aging process. And an aging plant can have significant negative implications on staff performance and actions. Some examples include difficulties in attracting and retaining good managers, financial decisions based on a short and uncertain remaining plant life, difficulties in replacing retiring staff, increased maintenance complexity, and increased burden on training. These problems can be dealt with more effectively by early recognition and a well conceived mitigation effort

  13. Catalogue of generic plant states leading to core melt in PWRs: includes appendix 1: detailed description of sequences leading to core melt

    International Nuclear Information System (INIS)

    1996-11-01

    The Task Group on thermal-hydraulic system behaviour was given a mandate from PWG 2 on Coolant System-Behaviour with the approval of CSNI to deal with the topic of Accident Management. A writing group was set up to identify generic plant states leading to core melt for pressurized water reactors (PWR) and find 'possible approaches to accident management measures' (AM-Measures) for dealing with them. From a matrix of 15 initiating events and 12 system failures (i.e. from 180 possibilities), 32 event sequences have been identified as leading to core melt. Each sequence has been divided into characteristic plant state intervals according to safety function challenges. For each of the 141 defined characteristic plant state intervals, the members of the Writing Group made proposals for AM-Measures

  14. Family Genericity

    DEFF Research Database (Denmark)

    Ernst, Erik

    2006-01-01

    Type abstraction in object-oriented languages embody two techniques, each with its own strenghts and weaknesses. The first technique is extension, yielding abstraction mechanisms with good support for gradual specification. The prime example is inheritance. The second technique is functional abst...... the result as family genericity. The presented language design has been implemented....

  15. The use of NPAR [Nuclear Plant Aging Research] results in plant inspection activities

    International Nuclear Information System (INIS)

    Gunther, W.; Taylor, J.

    1989-01-01

    The US NRC's Nuclear Plant Aging Research (NPAR) Program is a hardware oriented research program which has produced a large data base of equipment and system operating, maintenance, and testing information. Equipment and systems which have a propensity for age related degradation are identified, and methods for detecting and mitigating aging effects have been evaluated. As plants age, it becomes increasingly important that NRC inspectors be cognizant of plant aging phenomena. This paper describes the NPAR information which can enhance inspection activities, and provides a mechanism for making pertinent research available to the inspectors. 7 refs., 2 figs

  16. Nuclear plant aging research - an overview (electrical and mechanical components)

    International Nuclear Information System (INIS)

    Vora, J.P.

    1985-01-01

    As the operating nuclear power plants advance in age there must be a conscious national and international effort to understand the influence and safety implications of aging and service wear of components and structures in nuclear power plants and develop measures which are practical and cost effective for timely mitigation of aging degradation that could significantly affect plant safety. The Office of Nuclear Regulatory Research has, therefore, initiated a multi-year, multi-disciplinary program on Nuclear Plant Aging Research (NPAR). The overall goals identified for the program are as follows: 1) to identify and characterize aging and service wear effects associated with electrical and mechanical components, interfaces, and systems whose failure could impair plant safety; 2) to identify and recommend methods of inspection, surveillance and condition monitoring of electrical and mechanical components and systems which will be effective in detecting significant aging effects prior to loss of safety function so that timely maintenance and repair or replacement can be implemented; and, 3) to identify and recommend acceptable maintenance practices which can be undertaken to mitigate the effects of aging and to diminish the rate and extent of degradation caused by aging and service wear. The specific research activities to be implemented to achieve these goals are described

  17. FDS simulation of the fuel fireball from a hypothetical commercial airliner crash on a generic nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Luther, Wolfgang [GRS, Forschungsinstitute, Garching (Germany); Mueller, W. Christoph [GRS, Forschungsinstitute, Garching (Germany)], E-mail: mur@grs.de

    2009-10-15

    In the aftermath of 9/11 events it became clear that the impact of a fast flying commercial airliner hitting the NPP could no longer be excluded as a potential external hazard threatening the nuclear power plant (NPP) safety. One of the potential consequences of the impact is the occurrence of a fireball, large enough to engulf the entire NPP. The knowledge about fireballs from air crashes is rather poor since it is only based on footage shot by chance. From careful physical and chemical examinations using first principles, it can be concluded that the physics and chemistry of the kerosene fireball are similar to BLEVE fireballs in gas tank accidents which have been studied during the last decades. The knowledge from these analyses can be applied to air crash fireball analysis. In order to obtain an adequate understanding of the potential hazards to a NPP engulfed by a fireball a detailed analysis of the fireball is necessary. It is only by a detailed analysis that the effect of the NPP structures on the evolution of the fireball can be derived. Though the safety-relevant parts of the NPP are strong concrete structures, according to IAEA regulations the hypothesized entry of combustion products into ventilation or air supply systems and the entry of fuel into buildings through normal openings have to be analyzed in detail. This requires local transient values of the safety-relevant fireball parameters. With the NPP being a very large structure an adequately detailed simulation requires large computing grids and substantial computing power. With the release of Version 5 of the Fire Dynamic Simulator (FDS) from NIST in 2007 a simulation tool is now available which is capable to perform simulations of large fireballs on sufficiently large computing grids. These fireball simulations can be performed also by any other CFD code in which the relevant models have been implemented. The FDS fireball simulation capabilities were validated with the help of a well

  18. Plant responses to variable timing of aboveground clipping and belowground herbivory depend on plant age

    NARCIS (Netherlands)

    Wang, Minggang; Bezemer, T. Martijn; van der Putten, W.H.; Brinkman, Pella; Biere, Arjen

    2017-01-01

    Aims Plants use different types of responses such as tolerance and induced defense to mitigate the effects of herbivores. The direction and magnitude of both these plant responses can vary with plant age. However, most studies have focused on aboveground herbivory, whereas important feeding occurs

  19. DORIAN, Bayes Method Plant Age Risk Analysis

    International Nuclear Information System (INIS)

    Atwood, C.L.

    2002-01-01

    1 - Description of program or function: DORIAN is an integrated package for performing Bayesian aging analysis of reliability data; e.g. for identifying trends in component failure rates and/or outage durations as a function of time. The user must specify several alternative hypothesized 'aging models' (i.e., possible trends) along prior probabilities indicating the subject probability that each trend is actually the correct one. DORIAN then uses component failure and/or repair data over time to update these prior probabilities and develop a posterior probability for each aging model, representing the probability that each model is the correct one in light of the observed data rather than a priori. Mean, median, and 5. and 95. percentile trends are also compiled from the posterior probabilities. 2 - Method of solution: DORIAN carries out a Bayesian analysis of failure data and a prior distribution on a time-dependent failure rate to obtain a posterior distribution on the failure rate. The form of the time-dependent failure rate is arbitrary, because DORIAN approximates the form by a step-function, constant within specified time intervals. Similarly, the parameters may have any prior distribution, because DORIAN uses a discrete distribution to approximate this. Likewise, the database file produced by DORIAN approximates the entire range of possible failure rates or outage durations developed by means of a discrete probability distribution containing no more than 20 distinct values with their probabilities. 3 - Restrictions on the complexity of the problem: Prior distribution is discrete with up to 25 values. Up to 60 times are accommodated in the discrete time history

  20. Evaluation of cable aging degradation based on plant operating condition

    International Nuclear Information System (INIS)

    Kim, Jong-Seog

    2005-01-01

    Extending the lifetime of nuclear power plant [(hereafter referred simply as ''NPP'')] is one of the most important concerns in the world nuclear industry. Cables are one of the long live items which have not been considered to be replaced during the design life of NPP. To extend the cable life beyond the design life, we need to prove that the design life is too conservative compared with the actual aging. Condition monitoring is one of the useful ways for evaluating the aging condition of cable. In order to simulate the natural aging in nuclear power plant, a study on accelerated aging needs to be conducted first. In this paper, evaluations of mechanical aging degradation for cable jacket were performed after accelerated aging under the continuous heating and intermittent heating. Contrary to general expectation, the intermittent heating to cable jacket showed low aging degradation, 50% break-elongation and 60% indenter modulus, compared with continuous heating. With the plant maintenance period of 1 month after every 12 or 18 months operation, we can easily deduce that the life time of cable jacket can be extended much longer than estimated through the general EQ (Environmental Qualification) test, which adopts continuous accelerated aging for determining cable life. Therefore, a systematic approach which considers the actual environment condition of nuclear power plant is required for determining the life of cables. (author)

  1. Managing ageing of Karachi nuclear power plant (KANUPP)

    International Nuclear Information System (INIS)

    Hoda, M. Qamrul; Jamal-ur-Rahman

    2002-01-01

    Full text: Karachi Nuclear power Plant (KANUPP), a 137 MWe CANDU plant, was built on a turn-key basis by the Canadian General Electric (CGE) in the late sixties. The plant with a design life of thirty years went into commercial operation in October, 1972. After nearly three decades of operation, KANUPP like all other plants has faced the problem of equipment ageing and obsolescence. KANUPP has been striving hard to combat these problems with the assistance from IAEA, COG and WANO. During early eighties IAEA expert missions were called at KANUPP on various safety issues and on their recommendations various projects such as Safe Operation of KANUPP, Technical Upgradation Project, Balancing, Modernization and Rehabilitation project were initiated to combat equipment ageing and obsolescence. KANUPP has made substantial progress in the implementation of the tasks under these projects and the operating life of the plant is expected to be extended by 15 years. Three IAEA expert missions were invited at KANUPP during 1999-2000 to carry out assessment of the ongoing activities related to plant ageing management. On the basis of their recommendations an ageing Management Programme has been formally established at KANUPP to manage age-related degradation of plant systems, structures and components important to safety and to ensure that the required safety functions are available for the extended life of the plant. Being close to completion of its nominal design life in October 2002, KANUPP has already applied to Pakistan Nuclear Regulatory Authority for renewal of operating license. This paper briefly describes the activities related to ageing management of KANUPP to fulfil the requirement for its continued operation beyond its design life. (author)

  2. Probabilistic methods in nuclear power plant component ageing analysis

    International Nuclear Information System (INIS)

    Simola, K.

    1992-03-01

    The nuclear power plant ageing research is aimed to ensure that the plant safety and reliability are maintained at a desired level through the designed, and possibly extended lifetime. In ageing studies, the reliability of components, systems and structures is evaluated taking into account the possible time- dependent decrease in reliability. The results of analyses can be used in the evaluation of the remaining lifetime of components and in the development of preventive maintenance, testing and replacement programmes. The report discusses the use of probabilistic models in the evaluations of the ageing of nuclear power plant components. The principles of nuclear power plant ageing studies are described and examples of ageing management programmes in foreign countries are given. The use of time-dependent probabilistic models to evaluate the ageing of various components and structures is described and the application of models is demonstrated with two case studies. In the case study of motor- operated closing valves the analysis are based on failure data obtained from a power plant. In the second example, the environmentally assisted crack growth is modelled with a computer code developed in United States, and the applicability of the model is evaluated on the basis of operating experience

  3. Nuclear power plant ageing and life extension: Safety aspects

    International Nuclear Information System (INIS)

    Novak, S.; Podest, M.

    1987-01-01

    Experience with large fossil-fired electrical generating units, as well as in all process industries, shows that plants begin to deteriorate with age after approximately 10 years of operation. Similar phenomena will prevail for nuclear plants, and it is reasonable to postulate that their availability will be affected, as will their safety, if appropriate measures are not taken. It is evident that the average age of power reactors in the IAEA's Member States is increasing. By 2000, more than 50 nuclear plants will have been providing electricity for 25 years or longer. Most nuclear power plants have operating lifetimes of between 20 and 40 years. Ageing is defined as a continuing time-dependent degradation of material due to service conditions, including normal operation and transient conditions. It is common experience that over long periods of time, there is a gradual change in the properties of materials. These changes can affect the capability of engineered components, systems, or structures to perform their required function. Not all changes are deleterious, but it is commonly observed that ageing processes normally involve a gradual reduction in performance capability. All materials in a nuclear power plant can suffer from ageing and can partially or totally lose their designed function. Ageing is not only of concern for active components (for which the probability of malfunction increases with time) but also for passive ones, since the safety margin is being reduced towards the lowest allowable level

  4. Performance measures for aging of nuclear power plants

    International Nuclear Information System (INIS)

    Ross, D.F. Jr.

    1993-01-01

    The Nuclear Power Plant licenses are granted by the US Nuclear Regulatory Commission (NRC) for a 40-year term. There is at present consideration being given to extending the authorized service lifetime beyond that, perhaps for a total of 60 or 70 years total. A logical concern for such a length of operation is whether the plant ages in such a way as to be significantly less safe as it gets older. As a corollary to this, there would be the question as to how to measure a diminution in plant safety. Each operating utility has, of course, ways to observe the plant performance. It has maintenance and surveillance programs which are used for this purpose. The NRC maintains a presence at each operating plant in the form of resident inspectors. The NRC also receives utility reports which may then be used to synthesize operating performance. It also reviews plant performance directly through what is known as the Systematic Assessment of Licensee Performance (SALP). In the paper the various data management programs used by the NRC will be described. The results of each program is presented, and observations are made as to the potential effect of age on safety performance. It is also necessary to define the size of the population being examined. There are at present 109 operating reactors. The age distribution is used to normalize the data. Some of the indicators discussed in this paper are concerned more with the indirect effect of aging, such as inadvertent shutdown. The regulated industry maintains a program known as the Nuclear Power Reliability Data System (NPRDS) to which the electric utilities participate in a voluntary manner. Data from NPRDS can be accessed to observe the direct aging effect; this is not covered in this paper. To the degree that plant operating staff learns how to cope with aging equipment and operate in a safe manner nonetheless, the performance indicators would not fully reflect the aging effect

  5. Utilization of aging program results in plant inspections

    International Nuclear Information System (INIS)

    Gunther, W.; Fullwood, R.

    1989-01-01

    Research conducted under the auspices of the US Nuclear Regulatory Commission Nuclear Plant Aging Research (NPAR) Program has resulted in a large data base of component and system operating experience. This data base has been used to determine equipment aging susceptibility and the potential for equipment aging to impact plant safety and reliability. Methods of detecting and mitigating component and system aging have also been identified. This paper discusses how the NPAR results could be used to focus inspection activities on age-sensitive components and systems and on the specific modes and mechanisms of age degradation. These activities range from the regular inspections conducted by resident inspectors to extensive special inspections such as the Safety System Functional Inspection typically conducted by a team of inspectors. 5 refs., 3 figs., 1 tab

  6. Utilization of aging program results in plant inspections

    International Nuclear Information System (INIS)

    Gunther, W.; Fullwood, R.

    1988-01-01

    Research conducted under the auspices of the US Nuclear Regulatory Commission Nuclear Plant Aging Research (NPAR) Program has resulted in a large data base of component and system operating experience. This data base has been used to determine equipment aging susceptibility and the potential for equipment aging to impact plant safety and reliability. Methods of detecting and mitigating component and system aging have also been identified. This paper discusses how the NPAR results could be used to focus inspection activities on age-sensitive components and systems and on the specific modes and mechanisms of age degradation. These activities range from the regular inspections conducted by resident inspectors to extensive special inspections such as the Safety System Functional Inspection typically conducted by a team of inspectors. 5 refs., 3 figs., 1 tab

  7. Overview of the age-related degradation of nuclear power plant structures

    International Nuclear Information System (INIS)

    Deng, Daniel

    2004-01-01

    License renewal of nuclear power plants is an issue of increasing interest to the U.S. nuclear industry and the U.S. NRC. This paper presents and evaluates the plausible age-related degradation mechanisms that may affect the concrete and steel containment structures and other Class I structures to continue to perform their safety functions. Preventive and/or mitigative options are outlined for managing degradation mechanisms that could significantly affect plant performance during the license renewal period. The provided technical information and the degradation management options may be used as references for comparison with plant specific conditions to ensure that age-related degradation is controlled during the license renewal term. Plausible degradation mechanisms described and analyzed as they may affect the concrete, reinforcing steel, containment steel shell, prestressed-tendon, steel liner and other structural components typically used in Class I structures. The significance of these age-related degradation mechanisms to the structural components are evaluated, giving consideration to the design basis and quality of construction; typical service conditions; operating and maintenance history; and current test, inspection and refurbishment practices for containment and Class I structures. Degradation mechanisms which cannot be generically dispositioned on the basis of the two-step approach: (1) they will not cause significant degradation, or (2) any potential degradation will be bounded by current test, inspection, analytical evaluation, and/or refurbishment programs are identified. Aging degradation management measures are recommended to address the remaining age-related degradation mechanisms. A three-phase approach for the management of the containment and Class I structures is introduced. Various techniques, testing tools and the acceptable criteria for each step of the evaluation of the structures status are provided. The preventive and mitigative

  8. Handbook for quick cost estimates. A method for developing quick approximate estimates of costs for generic actions for nuclear power plants

    International Nuclear Information System (INIS)

    Ball, J.R.

    1986-04-01

    This document is a supplement to a ''Handbook for Cost Estimating'' (NUREG/CR-3971) and provides specific guidance for developing ''quick'' approximate estimates of the cost of implementing generic regulatory requirements for nuclear power plants. A method is presented for relating the known construction costs for new nuclear power plants (as contained in the Energy Economic Data Base) to the cost of performing similar work, on a back-fit basis, at existing plants. Cost factors are presented to account for variations in such important cost areas as construction labor productivity, engineering and quality assurance, replacement energy, reworking of existing features, and regional variations in the cost of materials and labor. Other cost categories addressed in this handbook include those for changes in plant operating personnel and plant documents, licensee costs, NRC costs, and costs for other government agencies. Data sheets, worksheets, and appropriate cost algorithms are included to guide the user through preparation of rough estimates. A sample estimate is prepared using the method and the estimating tools provided

  9. Handbook for quick cost estimates. A method for developing quick approximate estimates of costs for generic actions for nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Ball, J.R.

    1986-04-01

    This document is a supplement to a ''Handbook for Cost Estimating'' (NUREG/CR-3971) and provides specific guidance for developing ''quick'' approximate estimates of the cost of implementing generic regulatory requirements for nuclear power plants. A method is presented for relating the known construction costs for new nuclear power plants (as contained in the Energy Economic Data Base) to the cost of performing similar work, on a back-fit basis, at existing plants. Cost factors are presented to account for variations in such important cost areas as construction labor productivity, engineering and quality assurance, replacement energy, reworking of existing features, and regional variations in the cost of materials and labor. Other cost categories addressed in this handbook include those for changes in plant operating personnel and plant documents, licensee costs, NRC costs, and costs for other government agencies. Data sheets, worksheets, and appropriate cost algorithms are included to guide the user through preparation of rough estimates. A sample estimate is prepared using the method and the estimating tools provided.

  10. Guideline for ageing management in nuclear power plants

    International Nuclear Information System (INIS)

    Herter, K.H.; Schuler, X.; Hienstorfer, W.; Pompe, W.

    2007-01-01

    During operation of nuclear power plants, the quality of systems, structures and components may change as a result of ageing (conceptional ageing, technological ageing or physical ageing), which will affect the system quality. Ageing management is necessary to ensure safety and availability throughout the life of the systems. This necessitates a systematic, integrative and knowledge-based approach. Systems, structures and components are grouped according to their relevance for meeting the set goals. Ageing mangement should be process-oriented and should be integrated in the organisational procedure in cooperation with the safety manager. The procedure should follow the PDCA principle (plan - do - check - act). The data, documents, knowledge and evaluations required for ageing management are part of the knowledge base of the nuclear power station and are updated regularly. The efficiency of ageing management must be reassessed at regular intervals. (orig.)

  11. Plant maintenance and aging management: Are they the same?

    International Nuclear Information System (INIS)

    Lofaro, R.J.

    1995-01-01

    As part of the NRC's Nuclear Plant Aging Research Program, a number of aging studies were performed on safety-related systems and components which found that, even with current maintenance and monitoring practices in place, a large number of the reported failures are related to aging. This suggests that current practices are not sufficient to completely manage aging degradation, and other factors need to be considered. This paper examines the aging management process and the degree to which maintenance plays a part in it. Component failures and degradation mechanisms identified in aging studies of several different safety systems are summarized and evaluated, then con-elated with the components most frequently failed. This information, along with an analysis of failure causes, is then used to determine the extent to which aging is managed by current maintenance practices. Conclusions and recommendations for proper aging management arc also presented

  12. EPRI research on component aging and nuclear plant life extension

    International Nuclear Information System (INIS)

    Sliter, G.E.; Carey, J.J.

    1985-01-01

    This paper first describes several research efforts sponsored by the Electric Power Research Institute (EPRI) that examine the aging degradation of organic materials and the nuclear plant equipment in which they appear. This research includes a compendium of material properties characterizing the effects of thermal and radiation aging, shake table testing to evaluate the effects of aging on the seismic performance of electrical components, and a review of condition monitoring techniques applicable to electrical equipment. Also described is a long-term investigation of natural versus artificial aging using reactor buildings as test beds. The paper then describes how the equipment aging research fits into a broad-scoped EPRI program on nuclear plant life extension. The objective of this program is to provide required information, technology, and guidelines to enable utilities to significantly extend operating life beyond the current 40-year licensed term

  13. Differentiation of plant age in grasses using remote sensing

    Science.gov (United States)

    Knox, Nichola M.; Skidmore, Andrew K.; van der Werff, Harald M. A.; Groen, Thomas A.; de Boer, Willem F.; Prins, Herbert H. T.; Kohi, Edward; Peel, Mike

    2013-10-01

    Phenological or plant age classification across a landscape allows for examination of micro-topographical effects on plant growth, improvement in the accuracy of species discrimination, and will improve our understanding of the spatial variation in plant growth. In this paper six vegetation indices used in phenological studies (including the newly proposed PhIX index) were analysed for their ability to statistically differentiate grasses of different ages in the sequence of their development. Spectra of grasses of different ages were collected from a greenhouse study. These were used to determine if NDVI, NDWI, CAI, EVI, EVI2 and the newly proposed PhIX index could sequentially discriminate grasses of different ages, and subsequently classify grasses into their respective age category. The PhIX index was defined as: (AVNIRn+log(ASWIR2n))/(AVNIRn-log(ASWIR2n)), where AVNIRn and ASWIR2n are the respective normalised areas under the continuum removed reflectance curve within the VNIR (500-800 nm) and SWIR2 (2000-2210 nm) regions. The PhIX index was found to produce the highest phenological classification accuracy (Overall Accuracy: 79%, and Kappa Accuracy: 75%) and similar to the NDVI, EVI and EVI2 indices it statistically sequentially separates out the developmental age classes. Discrimination between seedling and dormant age classes and the adult and flowering classes was problematic for most of the tested indices. Combining information from the visible near infrared (VNIR) and shortwave infrared region (SWIR) region into a single phenological index captures the phenological changes associated with plant pigments and the ligno-cellulose absorption feature, providing a robust method to discriminate the age classes of grasses. This work provides a valuable contribution into mapping spatial variation and monitoring plant growth across savanna and grassland ecosystems.

  14. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.; Graves, H.L. III; Norris, W.E.

    1994-01-01

    Research is being conducted by ORNL under US Nuclear Regulatory Commission (USNRC) sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of nondestructive evaluation techniques. assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants

  15. Comparison of Generic-to-Brand Switchback Rates Between Generic and Authorized Generic Drugs.

    Science.gov (United States)

    Hansen, Richard A; Qian, Jingjing; Berg, Richard; Linneman, James; Seoane-Vazquez, Enrique; Dutcher, Sarah K; Raofi, Saeid; Page, C David; Peissig, Peggy

    2017-04-01

    Generic drugs contain identical active ingredients as their corresponding brand drugs and are pharmaceutically equivalent and bioequivalent, whereas authorized generic drugs (AGs) contain both identical active and inactive ingredients as their corresponding brand drugs but are marketed as generics. This study compares generic-to-brand switchback rates between generic and AGs. Retrospective cohort study. Claims and electronic health record data from a regional U.S. health care system. The full cohort consisted of 5542 unique patients who received select branded drugs during the 6 months prior to their generic drug market availability (between 1999 and 2014) and then were switched to an AG or generic drug within 30 months of generic drug entry. For these patients, 5929 unique patient-drug combinations (867 with AGs and 5062 with generic drugs) were evaluated. Ten drugs with AGs and generics marketed between 1999 and 2014 were evaluated. The date of the first generic prescription was considered the index date for each drug, and it marked the beginning of follow-up to evaluate the occurrence of generic-to-brand switchback patterns over the subsequent 30 months. Switchback rates were compared between patients receiving AGs versus those receiving generics using multivariable Cox proportional hazards models, controlling for individual drug effects, age, sex, Charlson Comorbidity Score, pre-index drug use characteristics, and pre-index health care utilization. Among the 5542 unique patients who switched from brand to generic or brand to AG, 264 (4.8%) switched back to the brand drug. Overall switchback rates were similar for AGs compared with generics (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.65-1.15). The likelihood of switchback was higher for alendronate (HR 1.64, 95% CI 1.20-2.23) and simvastatin (HR 1.81, 95% CI 1.30-2.54) and lower for amlodipine (HR 0.27, 95% CI 0.17-0.42) compared with the other drugs evaluated. Overall switchback rates were similar

  16. Aging of concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Pland, C.B.; Arndt, E.G.

    1991-01-01

    The Structural Aging (SAG) Program, sponsored by the US Nuclear Regulatory Commission (USNRC) and conducted by the Oak Ridge National Laboratory (ORNL), had the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant structures for continued service. The program consists of three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued service determinations. Major accomplishments under the SAG Program during the first two years of its planned five-year duration have included: development of a Structural Materials Information Center and formulation of a Structural Aging Assessment Methodology for Concrete Structures in Nuclear Power Plants. 9 refs

  17. Integration of renewable energy plants based on generic data models in the energy management of a virtual power plant; Integration von erneuerbaren Energieanlagen auf Basis generischer Datenmodelle in das Energiemanagement eines virtuellen Kraftwerks

    Energy Technology Data Exchange (ETDEWEB)

    Wickert, Manuel; Slaby, Wolfgang; Hochloff, Patrick [Fraunhofer Institut fuer Windenergie und Energiesystemtechnik (IWES), Kassel (Germany); Winter, Martin [Siemens AG, Muenchen (Germany). Corporate Technology

    2012-07-01

    The integration of different types of energy resources manufactured by different vendors is one of the main challenges for virtual power plants. One of the important problems is a highly heterogeneous standardization environment for decentralized renewable energy resources. On the one hand proprietary solutions are implemented for some types of energy resources. In a future smart grid it is getting more and more important to handle decentralized energy generation. The project RegModHarz researched the dynamic integration of energy resources in virtual power plants based on generic data models. This paper introduces a concept for the integration of heterogeneous energy resources into the energy management of a virtual power plant using a uniform data model. On the assumption of a market-oriented virtual power plant the main attributes of this data model are generally identified and afterwards explained by examples. The capability of this data model is shown in a comprehensive field test with different renewable energy resources. (orig.)

  18. Assessment of electrical equipment aging for nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The electrical and instrumentation equipments, especially whose parts are made of polymer material, are gradually degraded by thermal and radiation environment in the normal operation, and the degradation is thought to progress rapidly when they are exposed to the environment of the design basis event (DBE). The integrity of the equipments is evaluated by the environmental qualification (EQ) test simulating the environment of the normal operation and the DBE. The project of 'Assessment of Cable Aging for Nuclear Power Plants' (ACA, 2002-2008) indicated the importance of applying simultaneous thermal and radiation aging for simulating the aging in normal operation. The project of 'Assessment of Electrical Equipment Aging for Nuclear Power Plants' (AEA) was initiated in FY2008 to apply the outcome of ACA to the other electrical and instrumentation equipment and to establish an advanced EQ test method that can appropriately simulate the environment in actual plants. In FY2012, aging characteristics of thermal aging and simultaneous aging were obtained for the epoxy resin of electrical penetrations and the O-ring of connectors. Physical property measurement was carried out for epoxy resin of electrical penetration subject to the type testing in FY2010. (author)

  19. Assessment of electrical equipment aging for nuclear power plant

    International Nuclear Information System (INIS)

    2013-01-01

    The electrical and instrumentation equipments, especially whose parts are made of polymer material, are gradually degraded by thermal and radiation environment in the normal operation, and the degradation is thought to progress rapidly when they are exposed to the environment of the design basis event (DBE). The integrity of the equipments is evaluated by the environmental qualification (EQ) test simulating the environment of the normal operation and the DBE. The project of 'Assessment of Cable Aging for Nuclear Power Plants' (ACA, 2002-2008) indicated the importance of applying simultaneous thermal and radiation aging for simulating the aging in normal operation. The project of 'Assessment of Electrical Equipment Aging for Nuclear Power Plants' (AEA) was initiated in FY2008 to apply the outcome of ACA to the other electrical and instrumentation equipment and to establish an advanced EQ test method that can appropriately simulate the environment in actual plants. In FY2012, aging characteristics of thermal aging and simultaneous aging were obtained for the epoxy resin of electrical penetrations and the O-ring of connectors. Physical property measurement was carried out for epoxy resin of electrical penetration subject to the type testing in FY2010. (author)

  20. Allowance for aging in Spanish nuclear power plants

    International Nuclear Information System (INIS)

    Rodriguez, C.

    2009-01-01

    In Spain, as in most European Union countries, the nuclear power plants (NPP) operation license is open regarding its duration, there being no legal restrictions for extending the operational life of the NPP by renewing their licenses. Plant operation permits are renewed every ten years, following the performance of periodic safety reviews, which constitute a reasonable guarantee that safety conditions will be maintained throughout the next ten years period. Plant ageing management programmes in Spain started in mid 80's with a joint programme shared by all Spanish utilities through their common organisation, U.N.E.S.A., and the Spanish nuclear regulatory Authority (C.S.N.). The development of the methodology was based mainly in technical documents from IAEA and from U.S.N.R.C. rulemaking and documents, as well as in the international experience available. C.S.N. is interested in realising an effective management of components ageing processes. Therefore C.S.N. has introduced within its inspection and control functions specific requirements related to ageing management. The regulatory requirements related to NPP lifetime management are basically the following: NPP operation license requires preparing and submitting to the C.S.N. an annually updated report on the ageing control activities or the Lifetime Management Programme; - continuous NPP safety evaluation process by C.S.N., complemented with periodic safety reviews, to be performed every 10 years, including: a) review of components behaviour (identify degradation mechanism and current corrective measures adopted by the plant for ageing mechanisms control and mitigation) and b) updating of the safety evaluation and improvement programmes (Lifetime management programme is included among them). In the case the period of validity of a new operation permit exceeds the lifetime considered in the initial design of the plant, the periodic safety review process remains valid, but it must be supplemented with additional

  1. Integrated management for aging of Atucha Nuclear Power Plant

    International Nuclear Information System (INIS)

    Ranalli, J.M.; Marchena, M.H.; Sabransky, M.; Fonseca, M.; Santich, J.; Pedernera, P.

    2012-01-01

    Atucha NPP is a two PHWR unit site located in Lima, Province of Buenos Aires, 120 km north of Buenos Aires, Argentina.. With the start-up of Atucha II and aiming to integrate the Ageing Management of the plants, the Utility (Nucleolectrica Argentina Sociedad Anonima - NASA) created an Ageing Management Department to cope with all ageing issues of both Atucha I and II. In this project both organization has formed a joint working group. The role of CNEA is providing technical support to the plant in the development of procedures a methodological framework for the Ageing Management Program of Atucha NPP. The main documents that have being issued so far are: . An Ageing Management Manual, including standard definition of Materials, Ageing Related Degradation Mechanisms, Operation Environments customized for Atucha NPP. . Walk down procedures and checklists aimed to systematize data collection during outages. . Procedures for performing Ageing Management Reviews and Maintenance Reviews for passive and active components. . Condition Assessments of several safety related systems. . Condition assessment of electrical components. In the present work a summary of the activities, documental structure and first outputs of the Integrated Ageing Management Program of Atucha NPP is presented (author)

  2. Brain surgery breathes new life into aging plants

    Energy Technology Data Exchange (ETDEWEB)

    Makansi, J. [Pearl Street Inc. (United States)

    2006-04-15

    Unlike managing the human aging process, extending the life of a power plant often includes brain surgery, modernizing its control and automation system. Lately, such retrofits range from wholesale replacing of existing controls to the addition of specific control elements that help optimize performance. Pending revisions to safety codes and cybersecurity issues also need to be considered. 4 figs.

  3. Component aging and reliability trends in Loviisa Nuclear Power Plant

    International Nuclear Information System (INIS)

    Jankala, K.E.; Vaurio, J.K.

    1989-01-01

    A plant-specific reliability data collection and analysis system has been developed at the Loviisa Nuclear Power Plant to perform tests for component aging and analysis of reliability trends. The system yields both mean values an uncertainty distribution information for reliability parameters to be used in the PSA project underway and in living-PSA applications. Several different trend models are included in the reliability analysis system. Simple analytical expressions have been derived from the parameters of these models, and their variances have been obtained using the information matrix. This paper is focused on the details of the learning/aging models and the estimation of their parameters and statistical accuracies. Applications to the historical data of the Loviisa plant are presented. The results indicate both up- and down-trends in failure rates as well as individuality between nominally identical components

  4. Aging and Plant Life Management with the Software Tool COMSY

    International Nuclear Information System (INIS)

    Nopper, Helmut; Rossner, Roland; Zander, Andre

    2006-01-01

    Within the scope of PLEX, a systematic and efficient ageing and plant life management system is becoming more and more important to ensure a safe and economical power plant operation in spite of continuous plant ageing. For the methodical implementation of PLIM and PLEX strategies, AREVA NP has developed the software tool COMSY. This knowledge-based program integrates degradation analysis tools with an inspection data management system. COMSY provides the capability to establish a program guided technical documentation by utilizing a virtual plant model which includes information regarding thermal hydraulic operation, water chemical conditions and materials applied for mechanical components. It provides the option to perform a plant-wide screening for identifying system areas, which are sensitive for degradation mechanisms typically experienced in nuclear power plants (FAC, corrosion fatigue, IGSCC, Pitting, etc.). If a system area is identified as being susceptible to degradation, a detailed analysis function enables the condition-oriented service life evaluation of vessels and piping systems in order to localize and conservatively quantify the effect of degradation. Based on these forecasts with COMSY, specific strategies can be developed to mitigate the effect of degradation and inspection activities can be focused on degradation sensitive areas. In addition, a risk-informed assessment tool serves to optimize inspection activities in respect to degradation potential and the associated damage consequence. After an in-service inspection is performed for a distinct location, the inspection data is to be evaluated according to generally accepted procedures. For this purpose an integrated inspection data management system module provides standardized, interactively operated evaluation functions. The key inspection results are transmitted as feedback in respect to the as-is condition of the component. Subsequently, all further life evaluations of the associated

  5. Technical strategy map to employing nuclear power plant aging management

    International Nuclear Information System (INIS)

    Sekimura, Naoto; Kanno, Masanori

    2008-01-01

    Stated in this report are back ground of technical strategy map for nuclear power plant aging management, result of the first road map, significance of technical strategy map, introduction scenario, technology map, road map, upgrade in every year, three groups of academia, industry and government, plan of technical strategy map, upgrade system, comprehensive introduction scenario, measures of nuclear power plant aging management in Japan and the world, new inspection system, outline of 'technical strategy map 2008', preparation of technical information bases in industry, academia and government, collaboration of them, safety researches of neutron radiation damage, stress corrosion crack, fatigue, piping thinning, insulation degradation, concrete degradation, thermal aging, evaluation technologies of earthquake resistance, preparation of rules and standards, ideal maintenance, and training talent. (S.Y.)

  6. Plant age, communication, and resistance to herbivores: young sagebrush plants are better emitters and receivers.

    Science.gov (United States)

    Shiojiri, Kaori; Karban, Richard

    2006-08-01

    Plants progress through a series of distinct stages during development, although the role of plant ontogeny in their defenses against herbivores is poorly understood. Recent work indicates that many plants activate systemic induced resistance after herbivore attack, although the relationship between resistance and ontogeny has not been a focus of this work. In addition, for sagebrush and a few other species, individuals near neighbors that experience simulated herbivory become more resistant to subsequent attack. Volatile, airborne cues are required for both systemic induced resistance among branches and for communication among individuals. We conducted experiments in stands of sagebrush of mixed ages to determine effects of plant age on volatile signaling between branches and individuals. Young and old control plants did not differ in levels of chewing damage that they experienced. Systemic induced resistance among branches was only observed for young plants. Young plants showed strong evidence of systemic resistance only if airflow was permitted among branches; plants with only vascular connections showed no systemic resistance. We also found evidence for volatile communication between individuals. For airborne communication, young plants were more effective emitters of cues as well as more responsive receivers of volatile cues.

  7. Aging management review for license renewal and plant life management

    International Nuclear Information System (INIS)

    Rinckel, M.A.; Young, G.G.

    2002-01-01

    Full text: United States nuclear power plants are initially licensed for a period of 40-years. The 40-year term, which was established by the Atomic Energy Commission in the 1950s, is believed to be based on engineering judgement and is consistent with the typical amortization schedule for purchasing fossil power plants. Under 10 CFR Part 54, the license renewal rule, additional terms of 20-years may be obtained through the preparation of a license renewal application that must be reviewed and approved by the Nuclear Regulatory Commission (NRC). The license renewal rule requires that applicants perform ageing management reviews on passive long-lived structures and components to demonstrate that ageing will be managed during the period of extended operation (i.e., additional 20 years of operation). ageing of active components, which are excluded from 10 CFR Part 54, is accomplished through the Maintenance Rule, 10 CFR Part 65, using performance-based monitoring. The license renewal rule, 10 CFR Part 54, was initially published in 1991. After significant interaction with the nuclear industry from 1991 through 1994, the NRC revised the rule in 1995 to focus on passive long-lived structures and components. In 1998, the first two applications for license renewal were submitted to the NRC by Baltimore Gas and Electric for the two-unit Calvert Cliffs nuclear power plant and by Duke Energy for the three-unit Oconee nuclear power plant. In March 2000, the NRC approved the application for the two-unit Calvert Cliffs nuclear power plant for an additional 20 years. Two months later, the NRC approved the renewal of the operating licenses for the three-unit Oconee nuclear station. The NRC completed these reviews in a timely, predictable, and stable manner. As of February 2002, the NRC has approved renewal of operating licenses for eight nuclear units and has applications under review for 15 more units. Twelve additional companies have notified the NRC of their intention to seek

  8. Aging management and preventive maintenance for nuclear power plants

    International Nuclear Information System (INIS)

    Bessho, Toichi; Sagawa, Wataru; Oyamada, Osamu; Uchida, Shunsuke

    1995-01-01

    It is expected that nuclear power generation will bear main electric power supply for long term. For this purpose, by applying proper preventive maintenance to the nuclear power plants in operation, the maintenance of high reliability and the rate of plant operation is extremely important. Especially it has been strongly demanded to execute efficiently the periodic inspection which is carried out every year to shorten its period and increase the rate of operation, and to maintain the reliability by the proper maintenance for the aged plants with long operation years. As to efficient and short periodic inspection, the preparation is advanced by the guidance of electric power companies aiming at realizing it in nearest fiscal year, and further, effort is exerted for the development of technology in long term to optimize periodic inspection. For securing the reliability of aged plants, it is important to do proper inspection and diagnosis and to take the countermeasures by repair and replacement, based on the grasp of secular change mechanism and the evaluation of life of machinery, equipment and materials. In particular, effort is exerted for the development of maintenance technology for reactor pressure vessels and in-core equipment which are hard to access. The confirmation of the function of remote operation equipment and the establishment of execution condition are carried out by uisng the full scale mock-up of BWR plant. The problems in maintenance service and the activities and results of reliability improvement are reported. (K.I.)

  9. Report on aging of nuclear power plant reinforced concrete structures

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1996-03-01

    The Structural Aging Program provides the US Nuclear Regulatory Commission with potential structural safety issues and acceptance criteria for use in continued service assessments of nuclear power plant safety-related concrete structures. The program was organized under four task areas: Program Management, Materials Property Data Base, Structural Component Assessment/Repair Technology, and Quantitative Methodology for Continued Service Determinations. Under these tasks, over 90 papers and reports were prepared addressing pertinent aspects associated with aging management of nuclear power plant reinforced concrete structures. Contained in this report is a summary of program results in the form of information related to longevity of nuclear power plant reinforced concrete structures, a Structural Materials Information Center presenting data and information on the time variation of concrete materials under the influence of environmental stressors and aging factors, in-service inspection and condition assessments techniques, repair materials and methods, evaluation of nuclear power plant reinforced concrete structures, and a reliability-based methodology for current and future condition assessments. Recommendations for future activities are also provided. 308 refs., 61 figs., 50 tabs

  10. Report on aging of nuclear power plant reinforced concrete structures

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.; Oland, C.B. [Oak Ridge National Lab., TN (United States); Ellingwood, B.R. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering

    1996-03-01

    The Structural Aging Program provides the US Nuclear Regulatory Commission with potential structural safety issues and acceptance criteria for use in continued service assessments of nuclear power plant safety-related concrete structures. The program was organized under four task areas: Program Management, Materials Property Data Base, Structural Component Assessment/Repair Technology, and Quantitative Methodology for Continued Service Determinations. Under these tasks, over 90 papers and reports were prepared addressing pertinent aspects associated with aging management of nuclear power plant reinforced concrete structures. Contained in this report is a summary of program results in the form of information related to longevity of nuclear power plant reinforced concrete structures, a Structural Materials Information Center presenting data and information on the time variation of concrete materials under the influence of environmental stressors and aging factors, in-service inspection and condition assessments techniques, repair materials and methods, evaluation of nuclear power plant reinforced concrete structures, and a reliability-based methodology for current and future condition assessments. Recommendations for future activities are also provided. 308 refs., 61 figs., 50 tabs.

  11. Ageing management of nuclear power plant - the Tarapur experience

    International Nuclear Information System (INIS)

    Anilkumar, K.R.; Das, P.K.; Bhattacharjee, S.; Ramamurty, U.

    2006-01-01

    Tarapur Atomic Power Station, the longest serving Nuclear Power Plant in the Asian continent has completed 36 years of successful operation and generated more than 70,000 million units of electric power. Built in late sixties, with the state-of-the-art safety features prevailing then, TAPS through the process of evolution has become safer plant due to efforts of upgradation, renovation and refurbishment prompted by the station's operating experience, feed back from overseas reactors, lessons learnt from nuclear incidents, accidents and fresh review of design basis and safety analysis of the plant. All components of a Nuclear power plant experience some degradation with time. The Reactor Pressure Vessels (RPV) designed for 40 effective full power years (EFPY) of operation have operated for less than 20 EFPY and the material condition is assessed to be fit for some more years of service. The condition of the containment and main plant buildings was assessed to be satisfactory. The Ageing Management Programme (AMP) involved identification of key systems, structures and components (SSCs) that may experience degradation due to ageing, and take corrective measures through maintenance, repair and/or replacement. The identified components were classified as major critical components, important systems and other critical components. For each component mode of degradation was identified, ageing assessment was done and action plan was finalized. Replacement of some important equipment like 3 x 50 % capacity Emergency Diesel Generators (EDG) with 3 x 100 % capacity EDG, Salt Service Water (SSW) pumps, Control rod drive (CRD) pumps, Emergency Condenser tube bundles, Station battery has been done on the basis of condition monitoring and to obviate common cause failure and enhance the system reliability. Samples of Safety related cables were subjected to residual life assessment (RLA) and replacement action firmed up on the basis of the RLA findings. Condition survey of Main

  12. NPAR approach to controlling aging in nuclear power plants

    International Nuclear Information System (INIS)

    Christensen, J.A.

    1990-01-01

    Aging degradation in nuclear power plants must be controlled to prevent safety margins from declining below limits provided in plant design bases. The NPAR Program and other aging-related programs conducted under the auspices of the Nuclear Regulatory Commission (NRC) Office of Research are developing needed technical guidance for control of aging. Results from these programs, together with relevant information developed by industry and elsewhere, are implemented through various ongoing NRC and industry programs and initiatives as well as by means of conventional regulatory instruments. The aging control process central to these efforts consists of three key elements: (1) selection of components, systems, and structures (CSS) in which aging must be controlled, (2) understanding of the mechanisms and rates of degradation in these CSS, and (3) managing degradation through effective surveillance and maintenance. These elements are addressed in Good Practices Guidance that integrates information developed under NPAR and other studies of aging into a systems-oriented format that tracks directly with the safety analysis reports

  13. Management of age-related degradation for nuclear power plants

    International Nuclear Information System (INIS)

    Gregor, Frank E.

    2004-01-01

    Life extension for nuclear power plants has been studied in the USA for the last six years, largely supported by EPRI, DOE and the USNRC. Though there are diverse opinions for the strategies and priorities of life extension and aging management, one common conclusion has been formulated regarding the need of current maintenance programs having to focus on aging and degradation management. Such program, called 'Maintenance Effectiveness Evaluation and Enhancement' or M3E for short, has been developed to assist plant operators to upgrade and enhance existing programs by integrating aging/degradation management activities for important or critical equipment and components. The key elements of the M3E program consist of the definition and selection of the critical components or commodities to be included in the scope, the survey/inventory of the current programs and their respective action steps, frequencies, corrective measures and extent of coverage, the component/commodity degradation mechanism, sites and severity, safety functions and service environments and lastly, the correlation of degradation/aging with the individual maintenance activities. The degree of correlation provides a measure of effectiveness and the opportunity to identify/specify needed enhancements, abandonment or generation of new maintenance activities. Implementation of the activities can then be prioritized at the option of the plant staff. (author)

  14. Nuclear plant service water system aging degradation assessment: Phase 1

    International Nuclear Information System (INIS)

    Jarrell, D.B.; Johnson, A.B. Jr.; Zimmerman, P.W.; Gore, M.L.

    1989-06-01

    The initial phase of an aging assessment of nuclear power plant service water systems (SWSs) was performed by the Pacific Northwest Laboratory to support the Nuclear Regulatory Commission Nuclear Plant Aging Research (NPAR) program. The SWS was selected for study because of its essential role in the mitigation of and recovery from accident scenarios involving the potential for core-melt. The objectives of the SWS task under the NPAR program are to identify and characterize the principal aging degradation mechanisms relevant to this system and assess their impact on operational readiness, and to provide a methodology for the mitigation of aging on the service water aspect of nuclear plant safety. The first two of these objectives have been met and are covered in this Phase 1 report. A review of available literature and data-base information indicated that motor operated valve torque switches (an electro-mechanical device) were the prime suspect in component service water systems failures. More extensive and detailed data obtained from cooperating utility maintenance records and personnel accounts contradicted this conclusion indicating that biologic and inorganic accumulation and corrosive attack of service water on component surfaces were, in fact, the primary degradation mechanisms. A review of the development of time dependent risk assessment (aging) models shows that, as yet, this methodology has not been developed to a degree where implementation is reliable. Improvements in the accuracy of failure data documentation and time dependent risk analysis methodology should yield significant gains in relating aging phenomena to probabilistic risk assessment. 23 refs., 8 figs., 10 tabs

  15. Status of safety issues at licensed power plants: TMI Action Plan requirements; unresolved safety issues; generic safety issues; other multiplant action issues

    International Nuclear Information System (INIS)

    1993-12-01

    As part of ongoing US Nuclear Regulatory Commission (NRC) efforts to ensure the quality and accountability of safety issue information, the NRC established a program for publishing an annual report on the status of licensee implementation and NRC verification of safety issues in major NRC requirements areas. This information was initially compiled and reported in three NUREG-series volumes. Volume 1, published in March 1991, addressed the status of Three Mile Island (TMI) Action Plan Requirements. Volume 2, published in May 1991, addressed the status of unresolved safety issues (USIs). Volume 3, published in June 1991, addressed the implementation and verification status of generic safety issues (GSIs). The first annual supplement, which combined these volumes into a single report and presented updated information as of September 30, 1991, was published in December 1991. The second annual supplement, which provided updated information as of September 30, 1992, was published in December 1992. Supplement 2 also provided the status of licensee implementation and NRC verification of other multiplant action (MPA) issues not related to TMI Action Plan requirements, USIs, or GSIs. This third annual NUREG report, Supplement 3, presents updated information as of September 30, 1993. This report gives a comprehensive description of the implementation and verification status of TMI Action Plan requirements, safety issues designated as USIs, GSIs, and other MPAs that have been resolved and involve implementation of an action or actions by licensees. This report makes the information available to other interested parties, including the public. Additionally, this report serves as a follow-on to NUREG-0933, ''A Prioritization of Generic Safety Issues,'' which tracks safety issues until requirements are approved for imposition at licensed plants or until the NRC issues a request for action by licensees

  16. Status of safety issues at licensed power plants: TMI Action Plan requirements, unresolved safety issues, generic safety issues, other multiplant action issues. Supplement 4

    International Nuclear Information System (INIS)

    1994-12-01

    As part of ongoing US Nuclear Regulatory Commission (NRC) efforts to ensure the quality and accountability of safety issue information, the NRC established a program for publishing an annual report on the status of licensee implementation and NRC verification of safety issues in major NRC requirements areas. This information was initially compiled and reported in three NUREG-series volumes. Volume 1, published in March 1991, addressed the status of Three Mile Island (TMI) Action Plan Requirements. Volume 2, published in May 1991, addressed the status of unresolved safety issues (USIs). Volume 3, published in June 1991, addressed the implementation and verification status of generic safety issues (GSIs). The first annual supplement, which combined these volumes into a single report and presented updated information as of September 30, 1991, was published in December 1991. The second annual supplement, which provided updated information as of September 30, 1992, was published in December 1992. Supplement 2 also provided the status of licensee implementation and NRC verification of other multiplant action (MPA) issues not related to TMI Action Plan requirements, USIs, or GSIs. Supplement 3 gives status as of September 30, 1993. This annual report, Supplement 4, presents updated information as of September 30, 1994. This report gives a comprehensive description of the implementation and verification status of TMI Action Plan requirements, safety issues designated as USIs, GSIs, and other MPAs that have been resolved and involve implementation of an action or actions by licensees. This report makes the information available to other interested parties, including the public. Additionally, this report serves as a follow-on to NUREG-0933, ''A Prioritization of Generic Safety Issues,'' which tracks safety issues until requirements are approved for imposition at licensed plants or until the NRC issues a request for action by licensees

  17. In-plant natural versus artificial aging study

    International Nuclear Information System (INIS)

    Shaw, M.

    1989-01-01

    A few years ago, cable specimens and small electrical components were placed in the reactor buildings of several operating nuclear plants in the United States. Temperature and radiation at the specimen locations are being monitored during the life of the plants. Measured physical properties of materials removed periodically during planned outages over the next 10 to 30 years will be compared with properties of artificially aged materials in identical specimens to assess artificial aging practice. This will also lead to improved lifetime predictions for cables and equipment. The study is being performed by the University of Connecticut's Institute for Materials Science in collaboration with U. S. utilities under the sponsorship of the Electric Power Research Institute (EPRI). Cofunding is being provided by Northeast Utilities and Detroit Edison. This paper gives the status of the study, along with some preliminary results

  18. Aging management guidelines for commercial nuclear power plant equipment

    International Nuclear Information System (INIS)

    Nakos, J.T.; Gazdzinski, R.F.; Toman, G.J.

    1994-01-01

    The US Department of Energy, in cooperation with the Electric Power Research Institute and nuclear power plant utilities, has prepared ''Aging Management Guidelines'' (AMGs) for commodity types of equipment (e.g., pumps, electrical switchgear) important to license renewal. For the most part, this is also consistent with the Maintenance Rule, 10 CFR 50.65 (1991). AMGs concentrate on technical, (not licensing) issues and are directed toward systems engineers and plant maintenance staff. AMGs include a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance practices that can be combined to create effective programs that manage aging. All aging mechanisms were addressed; no attempt was made to limit the evaluation to aging mechanisms ''unique to license renewal,'' as defined in the License Renewal Rule, 10 CFR 54 (1991). The first AMG on Electrical Switchgear was published in July 1993. Six (6) additional AMGs will be published by the first quarter of calendar year 1994. It is anticipated that two more AMGs will be started in 1994. The seven ongoing AMG topics are as follows: (1) battery chargers, inverters and uninterruptible power supplies; (2) batteries, stationary; (3) heat exchangers; (4) motor control centers; (5) pumps; (6) switchgear, electric; (7) transformers, power and distribution. In Section 7, industry feedback regarding AMGs is discussed. Overall, the response has been very positive

  19. Overview of plant reliability and aging in Sweden

    International Nuclear Information System (INIS)

    Eckered, T.

    1985-01-01

    In a wide sense aging includes all the phenomena that cause properties of a system to deviate from those existing at the time of start of operation of the system. Such phenomena are of course those well known ones as corrosion, erosion, fatigue and wear. But other phenomena can be included like technological development making original designs obsolete or the learning or forgetting of operators. In this presentation the Swedish nuclear power programme will be briefly described, especially as concerns different generations of nuclear reactors and their operation history. Operating experience, including scram statistics and trends, will be covered as well as availability and reliability as functions of plant age and plant generation. Specific aging phenomena which have been experienced in Sweden, will be described as well as the actions taken or planned for coping with them. The means and tools used in Sweden for tracking aging phenomena will also be covered. The question is posed whether we need an international data bank for aging, maintenance and repair information similar to the already existing, successful incident data banks

  20. Generic Safety Issue (GSI) 171 -- Engineered Safety Feature (ESF) failure from a loop subsequent to LOCA: Assessment of plant vulnerability and CDF contributions

    International Nuclear Information System (INIS)

    Martinez-Guridi, G.; Samanta, P.; Chu, L.; Yang, J.

    1998-01-01

    Generic Safety Issue 171 (GSI-171), Engineered Safety Feature (ESF) from a Loss Of Offsite Power (LOOP) subsequent to a Loss Of Coolant Accident (LOCA), deals with an accident sequence in which a LOCA is followed by a LOOP. This issue was later broadened to include a LOOP followed by a LOCA. Plants are designed to handle a simultaneous LOCA and LOOP. In this paper, the authors address the unique issues that are involved i LOCA with delayed LOOP (LOCA/LOOP) and LOOP with delayed LOCA (LOOP/LOCA) accident sequences. LOCA/LOOP accidents are analyzed further by developing event-tree/fault-tree models to quantify their contributions to core-damage frequency (CDF) in a pressurized water reactor and a boiling water reactor (PWR and a BWR). Engineering evaluation and judgments are used during quantification to estimate the unique conditions that arise in a LOCA/LOOP accident. The results show that the CDF contribution of such an accident can be a dominant contributor to plant risk, although BWRs are less vulnerable than PWRs

  1. Proceedings of the international nuclear power plant aging symposium

    International Nuclear Information System (INIS)

    Beranek, A.

    1989-03-01

    This report presents the proceedings of the International Nuclear Power Plant Aging Symposium that was held at the Hyatt Regency Hotel in Bethesda, Maryland, on August 30-31 and September 1, 1988. The Symposium was presented in cooperation with the American Nuclear Society, the American Society of Civil Engineers, the American Society of Mechanical Engineers, and the Institute of Electrical and Electronics Engineers. There were approximately 550 participants from 16 countries at the Symposium

  2. Properties of different aged jicama (Pachyrhizus Erozus) plants

    Science.gov (United States)

    Nursandi, F.; Machmudi, M.; Santoso, U.; Indratmi, D.

    2017-07-01

    Jicama crop potential is very large, the tuber is used as a fresh fruit, ice mix fruit, salad, and can be made into flour, starch and inulin. The nutritional content of yam tubers depends on the age of the harvest, while farmers harvest jicama tubers at the age varying between 4-6 months. The research objective is to analyze the content of proximate fresh tubers and three kinds of flour (flour, starch and starch dregs) by harvesting different age plants. The study was conducted in Malang at a height of 560 m above sea level. Planting was done using plastic mulch with a spacing of 80 cm × 20 cm. Research using complete Randomized block Design with one factor harvesting consisting of 16, 18, 20 and 22 weeks after planting. Jicama tubers were harvested and analyzed the proximate for moisture, ash, fat, protein and carbohydrates in the fresh tubers, flour, starch and jicama flour dregs. The results showed that the late harvest resulted in moisture content, ash content, fiber and fat increase while the protein and carbohydrate decreased. The content of carbohydrates in the flour, starch and starch dregs was almost the same at different harvest time. The protein content of the flour is from 4.22 to 5.87%; while protein content of starch and protein content flour dregs is from 1.05 to 1.90% and 3.95 to 4.84%. Flour fiber content increased with increasing age of plants, while the fiber content of starch decreased but the dregs flour fiber content is almost the same

  3. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.; Graves, H.L. III; Norris, W.E.

    1996-01-01

    Research is being conducted by Oak Ridge National Laboratory under US nuclear regulatory commission (USNRC) sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the USNRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a structural materials information center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of non-destructive evaluation techniques, assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants. (orig.)

  4. Aging management of containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1994-01-01

    Research is being conducted by Oak Ridge National Laboratory under U.S. Nuclear Regulatory Commission sponsorship to address aging management of nuclear power plant containment and other safety-related structures. Documentation is being prepared to provide the US-NRC with potential structural safety issues and acceptance criteria for use in continued service evaluations of nuclear power plants. Accomplishments include development of a Structural Materials Information Center containing data and information on the time variation of 144 material properties under the influence of pertinent environmental stressors or aging factors, evaluation of models for potential concrete containment degradation factors, development of a procedure to identify critical structures and degradation factors important to aging management, evaluations of nondestructive evaluation techniques, assessments of European and North American repair practices for concrete, review of parameters affecting corrosion of metals embedded in concrete, and development of methodologies for making current condition assessments and service life predictions of new or existing reinforced concrete structures in nuclear power plants. (author). 29 refs., 2 figs

  5. NRC program for the resolution of generic issues related to nuclear power plants. (Includes plans for the resolution of ''unresolved safety issues'' pursuant to Section 210 of the Energy Reorganization Act of 1974, as amended)

    International Nuclear Information System (INIS)

    1977-12-01

    This report provides a description of the Nuclear Regulatory Commission's Program for the Resolution of Generic Issues Related to Nuclear Power Plants. The NRC program is of considerably broader scope than the ''Unresolved Safety Issues Plan'' required by Section 210. The NRC program does include plans for the resolution of ''Unresolved Safety Issues''; however, in addition, it includes generic tasks for the resolution of environmental issues, for the development of improvements in the reactor licensing process and for consideration of less conservative design criteria or operating limitations in areas where over conservatisms may be unnecessarily restrictive or costly

  6. Aging characteristics of nuclear plant RTDs and pressure transmitters

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2004-01-01

    Resistance Temperature Detectors (RTDs) and pressure, level, and flow transmitters provide almost all the vital signals that are used for the control and safety of nuclear power plants. Therefore, it is crucial to ensure that the performance of these sensors remain acceptable as they age in the process under normal operating conditions. Four comprehensive research projects were conducted for the U.S. Nuclear Regulatory Commission (NRC) to evaluate the effects of normal aging on calibration stability and response time of RTDs and pressure transmitters of the types used for safety-related measurements in nuclear power plants. Each project was conducted over a three year period. The projects involved laboratory testing of representative RTDs and pressure transmitters aged in simulated reactor conditions. The main purpose of these projects was to establish the degradation rate of the sensors and use the information to determine if the current testing intervals practiced by the nuclear power industry are adequate for management of aging of the sensors. The results have indicated that the current nuclear industry practice of testing the response time and calibration of the sensors once every fuel cycle is adequate. (author)

  7. 76 FR 54507 - Proposed Generic Communication; Draft NRC Generic Letter 2011-XX: Seismic Risk Evaluations for...

    Science.gov (United States)

    2011-09-01

    ... NUCLEAR REGULATORY COMMISSION [NRC-2011-0204] Proposed Generic Communication; Draft NRC Generic... functions. SSCs in operating nuclear power plants are designed either in accordance with, or have been... nuclear reactors. The background information relevant to this GL includes the individual plant...

  8. Aging of steel containments and liners in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.; Norris, W.E.

    1998-02-01

    Aging of the containment pressure boundary in light water reactor plants is being addressed to understand the significant factors relating occurrence of corrosion efficacy of inspection and structural capacity reduction of steel containments and liners of concrete containments. and to make recommendations on use of risk models in regulatory decisions. Current regulatory in-service inspection requirements are reviewed and a summary of containment related degradation experience is presented. Current and emerging nondestructive examination techniques and a degradation assessment methodology for characterizing and quantifying the amount of damage present are described. Quantitative tools for condition assessment of aging structures using time dependent structural reliability analysis methods are summarized. Such methods provide a framework for addressing the uncertainties attendant to aging in the decision process. Results of this research provide a means for establishing current and estimating future structural capacity margins of containments, and to address the significance of incidences of reported containment degradation

  9. Effect of antioxidants on aging of nuclear plant cable insulation

    International Nuclear Information System (INIS)

    Reynolds, A.B.; Ray, J.W.; Wlodkowski, P.A.

    1991-01-01

    The effects of various antioxidants and antioxidant concentrations on the radiation and thermal stability of EPDM and XLPE polymers used for insulation of electric cable in nuclear power plants were measured. The objective was to determine if particular antioxidants could be identified as being especially effective for stabilization against radiation aging and combined thermal and radiation aging. Elongation to rupture was used as the measure of stability. Materials were irradiated to doses up to 2 MGy (200 Mrad) at a dose rate of 200 to 300 Gy/h in the Cobalt-60 Gamma Irradiation Facility at the University of Virginia. All of the antioxidants tested, which were known to provide excellent thermal stability, also provided good stability for radiation aging and combined thermal/radiation aging, although small differences between antioxidants were noted. No antioxidant or antioxidant combination was identified as being especially outstanding. Stabilization against radiation increased with increasing antioxidant concentration, but this trend was not observed for thermal aging. Damage from thermal and radiation aging was superposable. 9 refs., 16 figs., 12 tabs

  10. Aging of concrete containment structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.; Mori, Yasuhiro; Arndt, E.G.

    1992-01-01

    Concrete structures play a vital role in the safe operation of all light-water reactor plants in the US Pertinent concrete structures are described in terms of their importance design, considerations, and materials of construction. Degradation factors which can potentially impact the ability of these structures to meet their functional and performance requirements are identified. Current inservice inspection requirements for concrete containments are summarized. A review of the performance history of the concrete components in nuclear power plants is provided. A summary is presented. A summary is presented of the Structural Aging (SAG) Program being conducted at the Oak Ridge National Laboratory for the US Nuclear Regulatory Commission. The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved bases for their continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technologies, and quantitiative methodology for continued service conditions. Objectives and a summary of accomplishments under each of these tasks are presented

  11. Generic component failure data base

    International Nuclear Information System (INIS)

    Eide, S.A.; Calley, M.B.

    1992-01-01

    This report discusses comprehensive component generic failure data base which has been developed for light water reactor probabilistic risk assessments. The Nuclear Computerized Library for Assessing Reactor Reliability (NUCLARR) was used to generate component failure rates. Using this approach, most of the failure rates are based on actual plant data rather then existing estimates

  12. Generic requirements specification for qualifying a commercially available PLC for safety-related applications in nuclear power plants. Final report

    International Nuclear Information System (INIS)

    Ostenso, A.; May, R.

    1996-12-01

    This is a specification for qualifying a commercially available PLC for application to safety systems in nuclear power plants. The specifications are suitable for evaluating a particular PLC product line as a platform for safety-related applications, establishing a suitable qualification test program, and confirming that the manufacturer has a quality assurance program that is adequate for safety-related applications or is sufficiently complete that, with a reasonable set of compensatory actions, it can be brought into conformance. The specification includes requirements for: (1) quality assurance measures applied to the qualification activities, (2) documentation to support the qualification, and (3) documentation to provide the information needed for applying the qualified PLC platform to a specific application. The specifications are designed to encompass a broad range of safety applications; however, qualifying a particular platform for a different range of applications can be accomplished by appropriate adjustments to the requirements

  13. FDS simulation of the fuel fireball from a hypothetical commercial airliner crash on a generic nuclear power plant

    International Nuclear Information System (INIS)

    Luther, W.; Mueller, C.; Zocher, O.

    2008-01-01

    Before September 11, 2001 nuclear installations were designed to withstand the impact of a typical aircraft fighter of that time. In the aftermath of 9/11 it became clear that any new NPP (Nuclear Power Plant) must be designed sufficiently robust against terrorist attack and that the impact of a fast flying commercial airliner hitting the NPP can no longer be excluded as a potential external hazard threatening the NPP safety. The lesson learnt from the WTC and Pentagon attack is that the impact of the aircraft and the onboard jet fuel can cause structural damage, a fireball and a consecutive fire. This paper deals with the simulation of the fireball and its consequence for the NPP safety. (orig.)

  14. HTGR generic technology program plan (FY 80)

    International Nuclear Information System (INIS)

    1980-01-01

    Purpose of the program is to develop base technology and to perform design and development common to the HTGR Steam Cycle, Gas Turbine, and Process Heat Plants. The generic technology program breaks into the base technology, generic component, pebble-bed study, technology transfer, and fresh fuel programs

  15. Aging management of nuclear power plants in Japan

    International Nuclear Information System (INIS)

    Maeda, Noriyoshi

    2003-01-01

    The Resource and Energy Agency of the Ministry of Trade and Industry (at present, the Nuclear and Industrial Safety Agency of the Ministry of Economy and Industry) carried out technical and present state conservation evaluations on soundness on a case of supposing operation of main apparatuses important for safety for sixty years, on three nuclear power plants constructed at initial period, on April, 1996, to open her basic concept on their aging management. The electricity companies also carried out their technical evaluation to investigate aging management measures for apparatuses important for safety and succession of operation, to summarize some essential measures for its long-term conservation plan. And, long-term and steady efforts such as technical development, preparation on national technical codes and private standards, data accumulation on materials and apparatuses are also required, to successively act them under adequate role-sharing and cooperation among government, universities and industries. Here were described periodical safety review, containing aging management technical evaluation, preparations of standards on apparatus maintenance standard, and so on, promotion of technical development, and Nuclear Power Plant Life Engineering Center (PLEC). (G.K.)

  16. Natural versus artificial aging of nuclear power plant components

    International Nuclear Information System (INIS)

    Shaw, M.T.

    1992-01-01

    This program seeks to understand the aging of polymeric materials, in cables and other components in nuclear reactor containment, by comparing aging processes for a variety of materials under natural conditions with those under the accelerated laboratory conditions used in qualification. The first five-year phase has been completed in what is planned as a long-term study of up to 40 years. Data from the program can be used as a basis of forecasting more realistic lifetimes in reactor service. The program is of critical importance for utilities both for the safe operation of plants and for minimizing the cost of periodic replacements upon expiration of originally predicted qualified life. The first five-year period has involved the selection and acquisition of test specimens, their preparation for placement in the containment, the selection of plants and locations for the specimens, the establishment of methods for monitoring radiation and temperature levels at each site, development of plans for scheduled removals, test method development, and testing of the specimens by physical and mechanical methods. Specimens have been subjected to short-term accelerated aging, as well as to reactor containment aging for up to five years. They consist of many types of polymers in products of several different manufacturers. Environmental conditions cover a wide range of temperature and radiation levels at 17 locations in 9 reactors of participating utilities. Initial results, which include tests of special cases subject to 8 years of reactor aging at Northeast Utilities, indicate several instances of changes having statistical significance in density or tensile properties due to containment service, but none of these changes are large enough to be of any concern. 12 refs., 19 figs., 21 tabs

  17. Impact of aging and material structure on CANDU plant performance

    International Nuclear Information System (INIS)

    Nadeau, E.; Ballyk, J.; Ghalavand, N.

    2011-01-01

    In-service behaviour of pressure tubes is a key factor in the assessment of safety margins during plant operation. Pressure tube deformation (diametral expansion) affects fuel bundle dry out characteristics resulting in reduced margin to trip for some events. Pressure tube aging mechanisms also erode design margins on fuel channels or interfacing reactor components. The degradation mechanisms of interest are primarily deformation, loss of fracture resistance and hydrogen ingress. CANDU (CANada Deuterium Uranium, a registered trademark of the Atomic Energy of Canada Limited used under exclusive licence by Candu Energy Inc.) owners and operators need to maximize plant capacity factor and meet or exceed the reactor design life targets while maintaining safety margins. The degradation of pressure tube material and geometry are characterized through a program of inspection, material surveillance and assessment and need to be managed to optimize plant performance. Candu is improving pressure tubes installed in new build and life extension projects. Improvements include changes designed to reduce or mitigate the impact of pressure tube elongation and diametral expansion rates, improvement of pressure tube fracture properties, and reduction of the implications of hydrogen ingress. In addition, Candu provides an extensive array of engineering services designed to assess the condition of pressure tubes and address the impact of pressure tube degradation on safety margins and plant performance. These services include periodic and in-service inspection and material surveillance of pressure tubes and deterministic and probabilistic assessment of pressure tube fitness for service to applicable standards. Activities designed to mitigate the impact of pressure tube deformation on safety margins include steam generator cleaning, which improves trip margins, and trip design assessment to optimize reactor trip set points restoring safety and operating margins. This paper provides an

  18. Impact of aging and material structure on CANDU plant performance

    Energy Technology Data Exchange (ETDEWEB)

    Nadeau, E.; Ballyk, J.; Ghalavand, N. [Candu Energy Inc., Mississauga, Ontario (Canada)

    2011-07-01

    In-service behaviour of pressure tubes is a key factor in the assessment of safety margins during plant operation. Pressure tube deformation (diametral expansion) affects fuel bundle dry out characteristics resulting in reduced margin to trip for some events. Pressure tube aging mechanisms also erode design margins on fuel channels or interfacing reactor components. The degradation mechanisms of interest are primarily deformation, loss of fracture resistance and hydrogen ingress. CANDU (CANada Deuterium Uranium, a registered trademark of the Atomic Energy of Canada Limited used under exclusive licence by Candu Energy Inc.) owners and operators need to maximize plant capacity factor and meet or exceed the reactor design life targets while maintaining safety margins. The degradation of pressure tube material and geometry are characterized through a program of inspection, material surveillance and assessment and need to be managed to optimize plant performance. Candu is improving pressure tubes installed in new build and life extension projects. Improvements include changes designed to reduce or mitigate the impact of pressure tube elongation and diametral expansion rates, improvement of pressure tube fracture properties, and reduction of the implications of hydrogen ingress. In addition, Candu provides an extensive array of engineering services designed to assess the condition of pressure tubes and address the impact of pressure tube degradation on safety margins and plant performance. These services include periodic and in-service inspection and material surveillance of pressure tubes and deterministic and probabilistic assessment of pressure tube fitness for service to applicable standards. Activities designed to mitigate the impact of pressure tube deformation on safety margins include steam generator cleaning, which improves trip margins, and trip design assessment to optimize reactor trip set points restoring safety and operating margins. This paper provides an

  19. A without-prejudice list of generic names of fungi for protection under the International Code of Nomenclature for algae, fungi, and plants

    NARCIS (Netherlands)

    Kirk, P.M.; Stalpers, J.A.; Braun, U.; Crous, P.W.; Hansen, K.; Hawksworth, D.L.; Hyde, K.D.; Lücking, R.; Lumbsch, T.H.; Rossman, A.Y.; Seifert, K.A.; Stadler, M.

    2013-01-01

    As a first step towards the production of a List of Protected Generic Names for Fungi, a without-prejudice list is presented here as a basis for future discussion and the production of a List for formal adoption. We include 6995 generic names out of the 17072 validly published names proposed for

  20. Current status of countermeasures for ageing of nuclear power plants in Japan

    International Nuclear Information System (INIS)

    Koyama, M.; Ishikawa, M.; Tajima, K.

    2002-01-01

    This paper summarizes ageing coutermeasure program of the nuclear power plants performed by the Japanese Government and industries and related activities, and describes current research program and utilization of the research results for the aged nuclear power plants. Regulatory bodies (NISA of METI: Nuclear and Industrial Safety Agency of the Ministry of Economy, Trade and Industry) reviewed the ageing issues of nuclear power plants to enhance countermeasures for the aged plants. Nuclear Power Plant Life Engineering Center (PLEC) entrusted by NISA is carrying out the task relating to the aged plants. (orig.)

  1. Study of aging effects in PWR power plants components - 15043

    International Nuclear Information System (INIS)

    Silva Borges, D. da; Lava, D.D.; Guimaraes, A.C.F.; Moreira, M. de L.

    2015-01-01

    In this paper we present a simulation about the aging process of the containment spray injection system (CSIS) of a pressurized water reactor (PWR) using the fault tree method (FT). The FT has the capacity to present the logic of events that leads to system unavailability, to capture frequency estimation of events, to model and calculate hazardous events frequency (before they happen) and help developing protective layers. The Monte Carlo method and Fussell-Vesely importance measure are used in this paper to determine the system unavailability probability and the most sensitive events to the aging process. The injection system fault tree consists of a main tree and 10 sub-trees. The main tree is composed of 35 basic events, 5 gates and 1 top event. The paper details the methodology. It can be seen that the increase of the failure rate of components due to the aging process, generates the increase in the general unavailability of the system that contains these components. The extension of the operating life of nuclear power plant must be accompanied by a special attention to the aging process of its components

  2. HYSSOP COMPOSITION DEPENDING ON AGE AND PLANTS DEVELOPMENT PHASES

    Directory of Open Access Journals (Sweden)

    L. A. Kotyuk

    2015-10-01

    Full Text Available The aim of the paper is to research biochemical composition of Hyssopus officinalis L. (Lamiaceae in relation to plant age and phenological growth stage under conditions of Ukrainian Polissya, bin order to determine the optimal harvest dates of the herbal material and its application spheres. The raw material samples under analysis were cut at various growth stages: the vegetative, budding, blooming, ripening stages. To study the hyssop oil composition, areal parts of H. officinalis were used. The composition analysis was aimed at determining absolute dry matter (by drying samples at 105 °C up to the constant mass, “crude” cellulose, amounts of protein, fats, calcium, potassium, phosphorus, ascorbic acid, carotene, discernible sugars and tannins and essential oil. The present study has proved that in the plant ontogenesis the amount of essential oil, obtained from H. officinalis areal parts, does not markedly decrease: volatile oil yield in plants of the first, second and third years of life amounted to 1.007%, 0.75% and 0.71% respectively. The composition of volatile oil in the plants of the first year of life reveals 46 components, of which pinocampone (53.73%, isopinocampone (4.66% myrtenol (9.35% and camphor (3.86% prevailed. In H. officinalis volatile oil of the third year 30 components were identified, the prevailing of which were isopinocampone (44.43%, pinocampone (35.49%, myrtenol (5.26%, germacrene D (3.15%, pulegone (2.93% and bicyclogermacrene (1.35%. We could observe the change in the quantitative and qualitative composition of H. officinalis volatile oil throughout the entire vegetation period. Thus, in the phase of vegetative growth one can identify 25 compounds, the most predominant being elemol (33.25%, germacren D (21.59% and bicyclogermacrene (15.78%. In the phase of blossoming 30 components can be identified, a high amount of isopinocampone and pinocampone (44.43% and 35.49% and somewhat lover amount of myrtenol (5

  3. Space/age forestry: Implications of planting density and rotation age in SRIC management decisions

    Energy Technology Data Exchange (ETDEWEB)

    Merriam, R.A.; Phillips, V.D.; Liu, W.

    1993-12-31

    Short-rotation intensive-culture (SRIC) of promising tree crops is being evaluated worldwide for the production of methanol, ethanol, and electricity from renewable biomass resources. Planting density and rotation age are fundamental management decisions associated with SRIC energy plantations. Most studies of these variables have been conducted without the benefit of a unifying theory of the effects of growing space and rotation age on individual tree growth and stand level productivity. A modeling procedure based on field trials of Eucalyptus spp. is presented that evaluates the growth potential of a tree in the absence and presence of competition of neighboring trees in a stand. The results of this analysis are useful in clarifying economic implications of different growing space and rotation age decisions that tree plantation managers must make. The procedure is readily applicable to other species under consideration for SRIC plantations at any location.

  4. Safety aspects of nuclear power plant component aging

    International Nuclear Information System (INIS)

    Conte, M.; Deletre, G.; Henry, J.Y.

    1988-01-01

    The safety of nuclear plants depends on the capacity of the systems they are composed to perform the functions they were designed for. The identification and understanding of phenomena liable to degrade this operational capacity thus constitute one of the safety problems for which allowance must be made at the earliest stage of a project. Aging, a natural and hence unavoidable process affecting all the components of an installation, was identified at a very early stage as being one of these phenomena. The investigation and implementation of solutions to the safety problems associated to aging make it necessary to: defining the domain in which the consequences of aging are to be evaluated, identifying the parameters involved, identifying the components sensitive to these parameters, understanding the mechanisms which govern its evolution. The results of qualification tests, and of tests and checks carried out at different stages of construction and operation, as well as allowance for operating experience, constitute the necessary basis for establishing or improving the regulatory requirements. The procedures for validating components and systems of the installation are also drawn up on the basis of these tests. Finally, the actions initiated within the scope of research and development programmes supply the additional data necessary for such validation, and provide the indispensable support for knowledge improvement

  5. Impact of persistent and nonpersistent generic Escherichia coli and Salmonella sp. recovered from a beef packing plant on biofilm formation by E. coli O157.

    Science.gov (United States)

    Visvalingam, J; Ells, T C; Yang, X

    2017-12-01

    To examine the influence of meat plant Escherichia coli and Salmonella sp. isolates on E. coli O157 biofilm formation. Biofilm formation was quantified by crystal violet staining (A 570 nm ) and viable cell numbers for up to 6 days at 15°C. All five persistent E. coli genotypes formed strong biofilms when cultured alone or co-cultured with E. coli O157, with A 570 nm values reaching ≥4·8 at day 4, while only two of five nonpersistent genotypes formed such biofilms. For E. coli O157:H7 co-culture biofilms with E. coli genotypes 136 and 533, its numbers were ≥1·5 and ≥1 log CFU per peg lower than those observed for its mono-culture biofilm at days 2 and 4, respectively. The number of E. coli O157:NM in similar co-culture biofilms was 1 log CFU per peg lower than in its mono-culture biofilm at day 4 and 6, respectively. Salmonella sp. lowered the number of E. coli O157:NM by 0·5 log unit, once, at day 6. Generic E. coli may outcompete E. coli O157 strains while establishing biofilms. Findings advance knowledge regarding inter-strain competition for a similar ecological niche and may aid development of biocontrol strategies for E. coli O157 in food processing environments. © 2017 Her Majesty the Queen in Right of Canada. Journal of Applied Microbiology © 2017 The Society for Applied Microbiology Reproduced with the permission of the Minister of the Department of Agriculture and Agri-Food Canada.

  6. Aging Evaluation of Nuclear Power Plant Concrete Structures

    International Nuclear Information System (INIS)

    Kitsutaka, Y.; Takesue, N.; Tsukagoshi, M.

    2012-01-01

    In this paper, method on the aging evaluation in nuclear power plant concrete structures was investigated. Problems on the durability evaluation of reinforced concrete structures were pointed out and an evaluation framework was considered. In view of the importance of evaluating the degree of deterioration of reinforced concrete structures, relationships should be formulated among the number of years elapsed, t, the amount of action of a deteriorative factor, F, the degree of material deterioration, D, and the performance of the structure, P. Evaluation by PDFt diagrams combining these relationships may be effective. A detailed procedure of durability evaluation for a reinforced concrete structure using PDFt concept is presented for the deterioration factors of thermal effect, irradiation, neutralization and penetration of salinity by referring to the recent papers. And the evaluation framework of the deteriorated material constitutive model which can be used for the numerical analysis of the integrity evaluation for the concrete structure was proposed. (author)

  7. Management of aging of water heaters in nuclear power plants

    International Nuclear Information System (INIS)

    Martin-Serrano Ledesma, C.; Toro del toro, J.; Real Rubio, I.; Garcia Montejano, A.

    2014-01-01

    The scope of this work includes the study of all feedwater heaters (from 1 to 6) in their two trains (A and B). In this study the main degradation phenomena that affect them, the operating parameters that can warn of a possible malfunction of the heater and possible strategies inspection, repair and replacement are analyzed. As a result of this study, a higher priority is obtained at a lower state of degradation of the heaters, possibly with a strategy inspection, repair or replacement, for each recharge, until the end of life of the plant. This will be a live program, which must be fed back to the studies of the parameters of operation of the heater during operation and results of the inspection of each recharge. May verify the effectiveness of aging management program using different indicators. (Author)

  8. The generic article

    NARCIS (Netherlands)

    Farkas, D.F.; Swart, Henriëtte de

    2005-01-01

    We take a fresh look at the connection between genericity and (in)definiteness by reconsidering a long-standing puzzle concerning the relation between definiteness and genericity. We contrast English on the one hand and Romance languages and Hungarian on the other, focusing on generic sentences

  9. Assessment and Management of Aging in Phenix Nuclear Power Plant

    International Nuclear Information System (INIS)

    Dumarcher, V.; Bourrier, J.L.; Chaucheprat, P.; Boulegue, D.

    2006-01-01

    The combination of one or several processes of ruins can involve the materials failure of a nuclear power plant. These processes arise from the external agents action such as the pressure, the mechanical efforts, the heat flows and the radiations constitute the whole of the 'actions' of the surrounding medium. The prolongation and the repetition of these effects can involve a deterioration of the machine. In accordance with the decree of February 26, 1974, the PWR operator must be firstly, sure that the system is controlled according to the situations considered in the file of dimensioning and secondly, be able to know anytime the life of the equipment. The physical phenomena which cause the structures ruin are less complex in the PWR than in the SFR. In the SFR, the high temperatures imposed on components for long periods can involve a significant creep. In the course of time, this deformations accelerate the release of fatigue cracks. To consider the creep, the reactor lifespan is correlated at the numbers of thermals transients envisaged initially. To realize the management of aging in Phenix power plant, it is necessary to carry out an individualized monitoring of the structures and not only on the vessel. We must ensure the good state and/or the correct operation of the significant stations for safety which are the control of the reactivity, the movement of control rods, the primary sodium containment and the decay heat removal. For that, we monitor the main vessel, the conical skirt, the IHX and the Core Cover Plug. A profound knowledge of the thermal transients of the past is necessary to carry out an effective assessment. In order to guarantee that any harmful situation is well taken into the management of aging, we monitor permanently certain measurements (primary and secondary pump speed, hot and cold pool temperatures, IHX-main vessel and reactor roof temperatures). We present in the article the scientific method used in the Physics Section. A logical

  10. [Generic drugs: good or bad? Physician's knowledge of generic drugs and prescribing habits].

    Science.gov (United States)

    García, A J; Martos, F; Leiva, F; Sánchez de la Cuesta, F

    2003-01-01

    In this article we analyze the responses of 1220 Spanish physicians who participated in a survery about generic drugs. A previously validated questionnaire was sent to physicians through the Spanish Medical Councils of the different provinces. Four items were analyzed: what doctors know about generic drugs (knowledge); physicians' prescribing habits concerning these drugs (attitude and professional competence); how prescription of generic drugs effects pharmaceutical costs amd, finally, what doctors believe a generic drug should be. The influence of physician-related variables (age, type of contract, specialty, workload, etc.) on prescribing of generic drugs was also analyzed. In view of the results, we believe that to rationalize expenditure through and appropriate policy on generic drugs Spanish health authorities should offer more and better training and information (clear and independent) about what generic drugs are.

  11. Aging assessment of surge protective devices in nuclear power plants

    International Nuclear Information System (INIS)

    Davis, J.F.; Subudhi, M.; Carroll, D.P.

    1996-01-01

    An assessment was performed to determine the effects of aging on the performance and availability of surge protective devices (SPDs), used in electrical power and control systems in nuclear power plants. Although SPDs have not been classified as safety-related, they are risk-important because they can minimize the initiating event frequencies associated with loss of offsite power and reactor trips. Conversely, their failure due to age might cause some of those initiating events, e.g., through short circuit failure modes, or by allowing deterioration of the safety-related component(s) they are protecting from overvoltages, perhaps preventing a reactor trip, from an open circuit failure mode. From the data evaluated during 1980--1994, it was found that failures of surge arresters and suppressers by short circuits were neither a significant risk nor safety concern, and there were no failures of surge suppressers preventing a reactor trip. Simulations, using the ElectroMagnetic Transients Program (EMTP) were performed to determine the adequacy of high voltage surge arresters

  12. Determinants of generic drug substitution in Switzerland

    Directory of Open Access Journals (Sweden)

    Lufkin Thomas M

    2011-01-01

    Full Text Available Abstract Background Since generic drugs have the same therapeutic effect as the original formulation but at generally lower costs, their use should be more heavily promoted. However, a considerable number of barriers to their wider use have been observed in many countries. The present study examines the influence of patients, physicians and certain characteristics of the generics' market on generic substitution in Switzerland. Methods We used reimbursement claims' data submitted to a large health insurer by insured individuals living in one of Switzerland's three linguistic regions during 2003. All dispensed drugs studied here were substitutable. The outcome (use of a generic or not was modelled by logistic regression, adjusted for patients' characteristics (gender, age, treatment complexity, substitution groups and with several variables describing reimbursement incentives (deductible, co-payments and the generics' market (prices, packaging, co-branded original, number of available generics, etc.. Results The overall generics' substitution rate for 173,212 dispensed prescriptions was 31%, though this varied considerably across cantons. Poor health status (older patients, complex treatments was associated with lower generic use. Higher rates were associated with higher out-of-pocket costs, greater price differences between the original and the generic, and with the number of generics on the market, while reformulation and repackaging were associated with lower rates. The substitution rate was 13% lower among hospital physicians. The adoption of the prescribing practices of the canton with the highest substitution rate would increase substitution in other cantons to as much as 26%. Conclusions Patient health status explained a part of the reluctance to substitute an original formulation by a generic. Economic incentives were efficient, but with a moderate global effect. The huge interregional differences indicated that prescribing behaviours and

  13. The effects of aging on electrical and I ampersand C components: Results of US Nuclear Plant Aging Research

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Gunther, W.E.

    1993-01-01

    The US NRC's hardware oriented engineering research program for plant aging and degradation monitoring has achieved results in the area of electrical, control, and instrumentation (ECI) components used in nuclear power plants (NPPs). The principal goals of the program, known as the Nuclear Power Plant Aging Research (NPAR) Program, are to understand the effects of age-related degradation in NPPs and how to manage and mitigate them effectively. This paper describes how these goals have been achieved for key ECI components used in the safety systems of NPPs. The status of relevant on-going and planned research projects is also provided

  14. The effects of aging on electrical and I ampersand C components: Results of US nuclear plant aging research

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Gunther, W.E.

    1991-01-01

    The US NRC's hardware oriented engineering research program for plant aging and degradation monitoring has achieved results in the area of electrical, control, and instrumentation (ECI) components used in nuclear power plants (NPPs). The principal goals of the program, known as the Nuclear Power Plant Aging Research (NPAR) Program, are to understand the effects of age-related degradation in NPPs and how to manage and mitigate them effectively. This paper describes how these goals have been achieved for key ECI components used in the safety systems of NPPs. The status of relevant on-going and planned research projects is also provided

  15. Aging of safety class 1E transformers in safety systems of nuclear power plants

    International Nuclear Information System (INIS)

    Roberts, E.W.; Edson, J.L.; Udy, A.C.

    1996-02-01

    This report discusses aging effects on safety-related power transformers in nuclear power plants. It also evaluates maintenance, testing, and monitoring practices with respect to their effectiveness in detecting and mitigating the effects of aging. The study follows the US Nuclear Regulatory Commission's (NRC's) Nuclear Plant-Aging Research approach. It investigates the materials used in transformer construction, identifies stressors and aging mechanisms, presents operating and testing experience with aging effects, analyzes transformer failure events reported in various databases, and evaluates maintenance practices. Databases maintained by the nuclear industry were analyzed to evaluate the effects of aging on the operation of nuclear power plants

  16. Aging of safety class 1E transformers in safety systems of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, E.W.; Edson, J.L.; Udy, A.C. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States)

    1996-02-01

    This report discusses aging effects on safety-related power transformers in nuclear power plants. It also evaluates maintenance, testing, and monitoring practices with respect to their effectiveness in detecting and mitigating the effects of aging. The study follows the US Nuclear Regulatory Commission`s (NRC`s) Nuclear Plant-Aging Research approach. It investigates the materials used in transformer construction, identifies stressors and aging mechanisms, presents operating and testing experience with aging effects, analyzes transformer failure events reported in various databases, and evaluates maintenance practices. Databases maintained by the nuclear industry were analyzed to evaluate the effects of aging on the operation of nuclear power plants.

  17. In vitro determination of the anti-aging potential of four southern African medicinal plants

    CSIR Research Space (South Africa)

    Ndlovu, G

    2013-11-01

    Full Text Available southern African medicinal plants; Clerodendrum glabrum, Schotia brachypetala, Psychotria capensis and Peltophorum africanum, were investigated to assess their anti-aging properties....

  18. Ageing of power plants socio-economical, sanitary and environmental impact

    International Nuclear Information System (INIS)

    Bataille, Ch.; Denner, M.; Vouilloux, F.; Foucher, L.; Serviere, M.; Vila d'Abadal Serra, M.

    2005-01-01

    The National Association of the local Commissions of Information (A.N.C.L.I.) presents a colloquium about the ageing of nuclear power plants. The different following points are presented. The life cycle of nuclear power plants and the new types of reactors. The ageing of power plants: stakes and perspectives for the French and world nuclear park. A power plant of 30 years is it sure? The role of the studies of ageing and the follow-up according to the age. Stop or continue to exploit a nuclear power plant: who decides, when and how. The socio-economic consequences of a stop of power plant: the Spanish experience. Ten-year visits of a power plant: the associative experience. 58 reactors today: how to assume their end of life and welcome equipments to come. (N.C.)

  19. A developmental analysis of generic nouns in Southern Peruvian Quechua.

    Science.gov (United States)

    Mannheim, Bruce; Gelman, Susan A; Escalante, Carmen; Huayhua, Margarita; Puma, Rosalía

    2010-01-01

    Generic noun phrases (e.g., "Cats like to drink milk") are a primary means by which adults express generalizations to children, yet they pose a challenging induction puzzle for learners. Although prior research has established that English speakers understand and produce generic noun phrases by preschool age, little is known regarding the cross-cultural generality of generic acquisition. Southern Peruvian Quechua provides a valuable comparison because, unlike English, it is a highly inflected language in which generics are marked by the absence rather than the presence of any linguistic markers. Moreover, Quechua is spoken in a cultural context that differs markedly from the highly educated, middle-class contexts within which earlier research on generics was conducted. We presented participants from 5 age groups (3-6, 7-9, 10-12, 14-35, and 36-90 years of age) with two tasks that examined the ability to distinguish generic from non-generic utterances. In Study 1, even the youngest children understood generics as applying broadly to a category (like "all") and distinct from indefinite reference ("some"). However, there was a developmental lag before children understood that generics, unlike "all", can include exceptions. Study 2 revealed that generic interpretations are more frequent for utterances that (a) lack specifying markers and (b) are animate. Altogether, generic interpretations are found among the youngest participants, and may be a default mode of quantification. These data demonstrate the cross-cultural importance of generic information in linguistic expression.

  20. Nettle as a distinct Bronze Age textile plant

    DEFF Research Database (Denmark)

    Bergfjord, C.; Mannering, Ulla; Frei, Karin Margarita

    2012-01-01

    It is generally assumed that the production of plant fibre textiles in ancient Europe, especially woven textiles for clothing, was closely linked to the development of agriculture through the use of cultivated textile plants (flax, hemp). Here we present a new investigation of the 2800 year old...

  1. An approach to safety problems relating to ageing of nuclear power plant components

    International Nuclear Information System (INIS)

    Conte, M.; Deletre, G.; Henry, J.Y.; Le Meur, M.

    1989-10-01

    The safety of nuclear power plants, in France, is discussed. The attention is focused on the ageing phenomena, as a potential cause of the degradation of the systems functional capabilities. The allowance for ageing in design and its importance on safety, are analyzed. The understanding of phenomena relating to ageing and the components surveillance, are considered. As the effective ageing on the components of nuclear power plants is not fully understood, technical improvements and more accurate analysis are required

  2. Efficient Generic Functional Programming

    NARCIS (Netherlands)

    Alimarine, A.; Smetsers, J.E.W.

    2005-01-01

    Generic functions are defined by induction on the structural representation of types. As a consequence, by defining just a single generic operation, one acquires this operation over any particular data type. An instance on a specific type is generated by interpretation of the type's structure. A

  3. Optimizing Generic Functions

    NARCIS (Netherlands)

    Alimarine, A.; Smetsers, J.E.W.

    2004-01-01

    Generic functions are defined by induction on the structural representation of types. As a consequence, by defining just a single generic operation, one acquires this operation over any particular type. An instance on a specific type is generated by interpretation of the type's structure. A direct

  4. The use of NPAR [Nuclear Plant Aging Research] results in plant inspection activities

    International Nuclear Information System (INIS)

    Gunther, W.; Taylor, J.

    1989-01-01

    The Nuclear Plant Aging Research (NPAR) Program is a hardware oriented research program which has produced a large data base of equipment and system operating, maintenance, and testing information. A review of the NRC Inspection Program and discussions with NRC inspection personnel have revealed several areas where NPAR research results would be valuable to the inspector. This paper describes the NPAR information which can enhance inspection activities, and provides alternatives for making these pertinent research results available to the inspectors. The NRC Inspection Program emphasis is on evaluating the performance of licensees by focusing on requirements and standards associated with administrative, managerial, engineering, and operational aspects of licensee activities. The Program recognizes that licensees may satisfy NRC requirements differently, and therefore expresses inspection guidance in the form of performance objectives and evaluation criteria. for the resident and regional inspectors, procedures have been written covering various subject areas, such as operations, maintenance, and surveillance. Some of these procedures contain guidance related to aging degradation. The types of information generated by NPAR which were found to be relevant to inspection needs include the following: functional indicators; failure modes, causes, effects; stresses which cause degradation; maintenance recommendations; inspection prioritization. 3 refs

  5. A without-prejudice list of generic names of fungi for protection under the International Code of Nomenclature for algae, fungi, and plants.

    Science.gov (United States)

    Kirk, Paul M; Stalpers, Joost A; Braun, Uwe; Crous, Pedro W; Hansen, Karen; Hawksworth, David L; Hyde, Kevin D; Lücking, Robert; Lumbsch, Thorsten H; Rossman, Amy Y; Seifert, Keith A; Stadler, Mark

    2013-12-01

    As a first step towards the production of a List of Protected Generic Names for Fungi, a without-prejudice list is presented here as a basis for future discussion and the production of a List for formal adoption. We include 6995 generic names out of the 17072 validly published names proposed for fungi and invite comments from all interested mycologists by 31 March 2014. The selection of names for inclusion takes note of recent major publications on different groups of fungi, and further the decisions reached so far by international working groups concerned with particular families or genera. Changes will be sought in the Code to provide for this and lists at other ranks to be protected against any competing unlisted names, and to permit the inclusion of names of lichen-forming fungi. A revised draft will be made available for further discussion at the 10(th) International Mycological Congress in Bangkok in August 2014. A schedule is suggested for the steps needed to produce a list for adoption by the International Botanical Congress in August 2017. This initiative provides mycologists with an opportunity to place nomenclature at the generic level on a more secure and stable base.

  6. Childhood leukaemia incidence below the age of 5 years near French nuclear power plants

    International Nuclear Information System (INIS)

    Laurier, D; Hemon, D; Clavel, J

    2008-01-01

    A recent study indicated an excess risk of leukaemia among children under the age of 5 years living in the vicinity of nuclear power plants in Germany. We present results relating to the incidence of childhood leukaemia in the vicinity of nuclear power plants in France for the same age range. These results do not indicate an excess risk of leukaemia in young children living near French nuclear power plants. (note)

  7. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Nie,J.; Braverman, J.; Hofmayer, C.; Kim, M. K.; Choi, I-K.

    2009-04-27

    When performing seismic safety assessments of nuclear power plants (NPPs), the potential effects of age-related degradation on structures, systems, and components (SSCs) should be considered. To address the issue of aging degradation, the Korea Atomic Energy Research Institute (KAERI) has embarked on a five-year research project to develop a realistic seismic risk evaluation system which will include the consideration of aging of structures and components in NPPs. Three specific areas that are included in the KAERI research project, related to seismic probabilistic risk assessment (PRA), are probabilistic seismic hazard analysis, seismic fragility analysis including the effects of aging, and a plant seismic risk analysis. To support the development of seismic capability evaluation technology for degraded structures and components, KAERI entered into a collaboration agreement with Brookhaven National Laboratory (BNL) in 2007. The collaborative research effort is intended to continue over a five year period with the goal of developing seismic fragility analysis methods that consider the potential effects of age-related degradation of SSCs, and using these results as input to seismic PRAs. In the Year 1 scope of work BNL collected and reviewed degradation occurrences in US NPPs and identified important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. This information is presented in the Annual Report for the Year 1 Task, identified as BNL Report-81741-2008 and also designated as KAERI/RR-2931/2008. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, the report provides a description of U.S. current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. This report

  8. The art and trend of nuclear power plants aging management and licenses renewal activity In USA

    International Nuclear Information System (INIS)

    Zhong Zhimin; Li Jinsong; Zhang Mengyi

    2014-01-01

    This paper briefly introduced the history and the art of nuclear power plants licenses renewal in United State. The aims, working scope, methodology, the art and trend of aging management and its role in license renewal process in United State nuclear power plants license renewal process were discussed in details. Furthermore, the aging management current research focus in United State was described. Then, take into account the AP serials Pressurized Water Reactor and nuclear safety requirements in the regulatory and safety guide in China, some suggestions and recommendation on nuclear power plants aging management were introduced, which will be helpful when we developed related aging management works in China. (authors)

  9. AVISE, ageing anticipation methodology using expert judgement and stimulation. Application to a nuclear power plant component: the pressurizer

    International Nuclear Information System (INIS)

    Bouzaiene-Marle, L.

    2005-04-01

    This thesis deals with components ageing anticipation in the context of life cycle management. The proposed approach, called AVISE, allows the identification of potentials problems related to ageing, to measure the risks in terms of degradation probability and degradation consequences and gives the adequate solutions to stop or to postpone ageing. This research was undertaken in a particular industrial context, the nuclear industry. Equipments used in this context are specific and particularly reliable. These characteristics result in limited feedback (low number of failures). To compensate for this limited information, two solutions are proposed in this approach. The first solution that we can consider as a classical one consists in using expert judgement. The second one, more original, consists in using the operation feedback of 'similar' components. In order to apply these solutions and to obtain the anticipation results, a set of methodological tools was developed and tested in a real industrial application on a nuclear power plant component: the pressurizer. The first tool is a generic process for expert judgement, identified thanks to a comparison between eleven existing methods using expert judgement. Two methods based on expert stimulation and called STIMEX-IMDP and STIMEX-IPP were elaborated. A reference list of degradation mechanisms and a reference list of ageing effects were constructed and used in the method STIMEX-IMDP in order to help expert stimulation. Then, the developed approach proposes the use of belief networks to model and quantify the risks related to the potential degradations. Finally, the construction of a conceptual data model and specifications are given for the creation of an ageing database. The data to capitalize was identified on the basis of the research undertaken in this thesis. (author)

  10. An introduction to a new IAEA safety guide: 'ageing management for nuclear power plants'

    International Nuclear Information System (INIS)

    Pachner, J.; Inagaki, T.; Kang, K.S.

    2008-01-01

    This paper reports on a new IAEA Safety Guide entitled 'Ageing Management for Nuclear Power Plants' which is currently in an advanced draft form, awaiting approval of publication. The new Safety Guide will be an umbrella document for a comprehensive set of guidance documents on ageing management which have been issued by the IAEA. The Safety Guide first presents basic concepts of ageing management as a common basis for the recommendations on: proactive management of ageing throughout the life cycle of a nuclear power plant (NPP); systematic approach to managing ageing in the operation of NPPs; managing obsolescence; and review of ageing management for long term operation (life extension). The Safety Guide is intended to assist operators in establishing, implementing and improving systematic ageing management programs in NPPs and may be used by regulators in preparing regulatory standards and guides, and in verifying that ageing in nuclear power plants is being effectively managed. (author)

  11. Generic antibiotics in Japan.

    Science.gov (United States)

    Fujimura, Shigeru; Watanabe, Akira

    2012-08-01

    Generic drugs have been used extensively in many developed countries, although their use in Japan has been limited. Generic drugs reduce drug expenses and thereby national medical expenditure. Because generic drugs provide advantages for both public administration and consumers, it is expected that they will be more widely used in the future. However, the diffusion rate of generic drugs in Japan is quite low compared with that of other developed countries. An investigation on generic drugs conducted by the Ministry of Health, Labour and Welfare in Japan revealed that 17.2 % of doctors and 37.2 % of patients had not used generic drugs. The major reasons for this low use rate included distrust of off-patent products and lower drug price margin compared with the brand name drug. The generic drugs available in the market include external drugs such as wet packs, antihypertensive agents, analgesics, anticancer drugs, and antibiotics. Among them, antibiotics are frequently used in cases of acute infectious diseases. When the treatment of these infections is delayed, the infection might be aggravated rapidly. The pharmacokinetics-pharmacodynamics (PK-PD) theory has been adopted in recent chemotherapy, and in many cases, the most appropriate dosage and administration of antibiotics are determined for individual patients considering renal function; high-dosage antibiotics are used preferably for a short duration. Therefore, a highly detailed antimicrobial agent is necessary. However, some of the generic antibiotics have less antibacterial potency or solubility than the brand name products. We showed that the potency of the generic products of vancomycin and teicoplanin is lower than that of the branded drugs by 14.6 % and 17.3 %, respectively. Furthermore, we confirmed that a generic meropenem drug for injection required about 82 s to solubilize in saline, whereas the brand product required only about 21 s. It was thought that the cause may be the difference in size of bulk

  12. Canadian programs on understanding and managing aging degradation of nuclear power plant components

    International Nuclear Information System (INIS)

    Chadha, J.A.; Pachner, J.

    1989-06-01

    Maintaining adequate safety and reliability of nuclear power plants and nuclear power plant life assurance and life extension are growing in importance as nuclear plants get older. Age-related degradation of plant components is complex and not fully understood. This paper provides an overview of the Canadian approach and the main activities and their results towards understanding and managing age-related degradation of nuclear power plant components, structures and systems. A number of pro-active programs have been initiated to anticipate, detect and mitigate potential aging degradation at an early stage before any serious impact on plant safety and reliability. These programs include Operational Safety Management Program, Nuclear Plant Life Assurance Program, systematic plant condition assessment, refurbishment and upgrading, post-service examination and testing, equipment qualification, research and development, and participation in the IAEA programs on safety aspects of nuclear power plant aging and life extension. A regulatory policy on nuclear power plants is under development and will be based on the domestic as well as foreign and international studies and experience

  13. Guide for generic application of Reliability Centered Maintenance (RCM) recommendations

    International Nuclear Information System (INIS)

    Schwan, C.A.; Toomey, G.E.; Morgan, T.A.; Darling, S.S.

    1991-02-01

    Previously completed reliability centered maintenance (RCM) studies form the basis for developing or refining a preventive maintenance program. This report describes a generic methodology that will help utilities optimize nuclear plant maintenance programs using RCM techniques. This guide addresses the following areas: history of the generic methodology development process, and use of the generic methodology for conducting system-to-system and component-to-component evaluations. 2 refs., 2 figs., 5 tabs

  14. Results from the Nuclear Plant Aging Research Program: Their use in inspection activities

    International Nuclear Information System (INIS)

    Gunther, W.; Taylor, J.

    1990-09-01

    The US NCR's Nuclear Plant Aging Research (NPAR) Program has determined the susceptibility to aging of components and systems, and the potential for aging to impact plant safety and availability. The NPAR Program also identified methods for detecting and mitigating aging in components. This report describes the NPAR results which can enhance NRC inspection activities. Recommendations are provided for communicating pertinent information to NRC inspectors. These recommendations are based on a detailed assessment of the NRC's Inspection Program, and feedback from resident and regional inspectors as described within. Examples of NPAR report summaries and aging inspection guides for components and systems are included. 13 refs., 3 figs., 4 tabs

  15. Aging management guideline for commercial nuclear power plants - tanks and pools

    Energy Technology Data Exchange (ETDEWEB)

    Blocker, E.; Smith, S.; Philpot, L.; Conley, J.

    1996-02-01

    Continued operation of nuclear power plants for periods that extend beyond their original 40-year license period is a desirable option for many U.S. utilities. U.S. Nuclear Regulatory Commission (NRC) approval of operating license renewals is necessary before continued operation becomes a reality. Effective aging management for plant components is important to reliability and safety, regardless of current plant age or extended life expectations. However, the NRC requires that aging evaluations be performed and the effectiveness of aging management programs be demonstrated for components considered within the scope of license renewal before granting approval for operation beyond 40 years. Both the NRC and the utility want assurance that plant components will be highly reliable during both the current license term and throughout the extended operating period. In addition, effective aging management must be demonstrated to support Maintenance Rule (10 CFR 50.65) activities.

  16. Aging management guideline for commercial nuclear power plants - tanks and pools

    International Nuclear Information System (INIS)

    Blocker, E.; Smith, S.; Philpot, L.; Conley, J.

    1996-02-01

    Continued operation of nuclear power plants for periods that extend beyond their original 40-year license period is a desirable option for many U.S. utilities. U.S. Nuclear Regulatory Commission (NRC) approval of operating license renewals is necessary before continued operation becomes a reality. Effective aging management for plant components is important to reliability and safety, regardless of current plant age or extended life expectations. However, the NRC requires that aging evaluations be performed and the effectiveness of aging management programs be demonstrated for components considered within the scope of license renewal before granting approval for operation beyond 40 years. Both the NRC and the utility want assurance that plant components will be highly reliable during both the current license term and throughout the extended operating period. In addition, effective aging management must be demonstrated to support Maintenance Rule (10 CFR 50.65) activities

  17. Practicing the Generic (City)

    DEFF Research Database (Denmark)

    Hansen, Lone Koefoed

    2010-01-01

    Flanagan proposes that most locative media artworks neglect the particularities of spaces, their historical and political layers. Koolhaas, on the other hand, states that all urban areas are alike, that we are facing a global Generic City. The paper analyses digital media artist Esther Polak......’s NomadicMILK project in light of the generic and particular properties of space as laid out by Flanagan and Koolhaas in order to discuss the possible reconfiguring practices of locative media....

  18. Ageing of significant to safety structure elements of nuclear power plants

    International Nuclear Information System (INIS)

    Maksimovas, G.; Ramanauskiene, A.; Ziliukas, A.

    1999-01-01

    The paper analyzes the ageing problems of structure elements in nuclear power plants. The standard documents and principal parts of the ageing evaluation program are presented. The ageing evaluation model is being worked out and degradation mechanisms of different atomic reactor materials are being compared. (author)

  19. IAEA's experience in compiling a generic component reliability data base

    International Nuclear Information System (INIS)

    Tomic, B.; Lederman, L.

    1988-01-01

    Reliability data are an essential part of probabilistic safety assessment. The quality of data can determine the quality of the study as a whole. It is obvious that component failure data originated from the plant being analyzed would be most appropriate. However, in few cases complete reliance on plant experience is possible, mainly because of the rather limited operating experience. Nuclear plants, although of different design, often use fairly similar components, so some of the experience could be combined and transferred from one plant to another. In addition information about component failures is available also from experts with knowledge on component design, manufacturing and operation. That bring us to the importance of assessing generic data. (Generic is meant to be everything that is not plant specific regarding the plant being analyzed). The generic data available in the open literature, can be divided in three broad categories. The first one includes data base used in previous analysis. These can be plant specific or updated from generic with plant specific information (latter case deserve special attention). The second one is based on compilation of plants' operating experience usually based on some kind of event reporting system. The third category includes data sources based on expert opinions (single or aggregate) or combination of expert opinions and other nuclear and non-nuclear experience. This paper reflects insights gained in compiling data from generic data sources and highlights advantages and pitfalls of using generic component reliability data in PSAs

  20. Aging considerations for pressurizers in nuclear power plants

    International Nuclear Information System (INIS)

    Ware, A.G.

    1988-01-01

    This paper discusses the degradation mechanisms affecting the residual life of the nuclear pressurized water reactor (PWR) pressurizer and its subcomponents. The major sources of degradation for pressurizers are thermal transients such as plant heatups and cooldowns, internal pressure within the vessel, high intermittent flow through the spray nozzle, differential thermal movement causing rubbing of the immersion heater sheathes, and prolonged exposure to chemical and thermal conditions that can potentially lead to degradation. The latter includes thermal embrittlement of cast stainless steel spray heads and chemically assisted intergranular stress corrosion cracking of stainless steel. Steam leakage that interacts with lubricants used to assemble manway bolted joints can cause corrosion of bolts

  1. Generic hyper-diversity in Stachybotriaceae

    Czech Academy of Sciences Publication Activity Database

    Lombard, L.; Houbraken, J.; Decock, C.; Samson, R.A.; Meijer, M.; Réblová, Martina; Groenewald, J.Z.; Crous, P. W.

    2016-01-01

    Roč. 36, SI Jun (2016), s. 156-246 ISSN 0031-5850 R&D Projects: GA ČR GAP506/12/0038 Institutional support: RVO:67985939 Keywords : biodegraders * generic concept * human and plant pathogens Subject RIV: EF - Botanics Impact factor: 7.511, year: 2016

  2. Scripting XML with Generic Haskell

    NARCIS (Netherlands)

    Atanassow, F.; Clarke, D.; Jeuring, J.T.

    2003-01-01

    A generic program is written once and works on values of many data types. Generic Haskell is a recent extension of the functional programming language Haskell that supports generic programming. This paper discusses how Generic Haskell can be used to implement XML tools whose behaviour depends on

  3. Scripting XML with Generic Haskell

    NARCIS (Netherlands)

    Atanassow, F.; Clarke, D.; Jeuring, J.T.

    2007-01-01

    A generic program is written once and works on values of many data types. Generic Haskell is a recent extension of the functional programming language Haskell that supports generic programming. This paper discusses how Generic Haskell can be used to implement XML tools whose behaviour depends on

  4. Industry's efforts toward technology development related to aging management of PWR plants

    International Nuclear Information System (INIS)

    Tanaka, Hideo

    2010-01-01

    The term, 'aging plants', which refers to nuclear power plants operating more than 30 years, has become popular among local residents around nuclear power plants as well as among the media. The term 'aging' was first used in the title of the document issued by Agency of Natural Resources and Energy in 1996, 'The Basic Concept of Aging Management'. In addressing aging degradation, it was a matter of question which measure of time (date, month or year) should be used as a unit to consider an events. Although the aging plant was defined as a plant operating more than 30 years, the mode and timing of aging degradation depend on the environment and service conditions under which a component has been operating. Previous efforts made by related parties have contributed to the prevention of potential aging events which may challenge the reactor safety. Owing to such efforts, causes of some events attributable to defective design have been clarified and preventive maintenance measures, including the replacement and mitigation, have been taken accordingly. As a result, the number of events resulting from such aging phenomena has been reduced. On other other hand, the events caused by aging phenomena attributable to manufacturing processes (welding, surface treatment, etc.), which hardly emerge, are slightly increasing. There have been many cases that a shorter weld line due to lack of penetration in the narrow gap has been led to fatigue cracking. More recently, incidents of stress corrosion cracking due to work hardening and local tensile stresses on the surface have been observed. It should be noted that an effort to analyze not only the phenomena but also the mechanisms of the above events to clarify the root causes can improve the quality of preventive maintenance by means of rolling-out the analytical results to relevant plants. This paper introduces valuable experiences with the application of the results of technology development regarding to aging degradation of

  5. Lithuanian requirements for ageing management of systems and components important to safety of nuclear power plant

    International Nuclear Information System (INIS)

    Ramanauskiene, A.

    2000-01-01

    In this paper the Lithuanian requirements for ageing management of systems and components important to safety of Ignalina nuclear power plant (two RBMK-1500 water-cooled graphite moderated channel-type power reactors) are presented

  6. Aging plant life management - the requirements defined to date by the KTA nuclear engineering codes

    International Nuclear Information System (INIS)

    Kalinowski, I.

    1996-01-01

    German nuclear engineering codes so far do not enclose a specific aging plant life management programme. However, the existing codes and standards do contain a number of applicable requirements and principles of relevance to objectives and principles of such programmes, as they also cover aging-induced effects on power plants. The major principles relating to preventive safety engineering and quality assurance are laid down in the publications KTA 1401, 1404, 1201, 1202, and KTA 3211. (DG) [de

  7. Pump power plants for wind age; Pumpekraftverk for vindalderen

    Energy Technology Data Exchange (ETDEWEB)

    Bakken, Marte

    2010-07-01

    Power giant Sira-Kvina, Norway, prepares to expand Tonstad power station with pump options to save energy and benefit from price fluctuations in the electricity market. How pump power plant works; Consists mainly of two reservoirs at different heights. Bottom placed a turbine that can run both ways, or a pump and turbine mounted on the generator. The generator acts as an engine of pumping. When saving energy, water is pumped up to the highest magazine. The energy is extracted by letting the water run back through the turbine. Amount of energy that can be saved depends on the height difference between the magazines and magazine size, while the effect is determined by the size of the pump turbine.(AG)

  8. Generic phytosanitary irradiation treatments

    International Nuclear Information System (INIS)

    Hallman, Guy J.

    2012-01-01

    The history of the development of generic phytosanitary irradiation (PI) treatments is discussed beginning with its initial proposal in 1986. Generic PI treatments in use today are 150 Gy for all hosts of Tephritidae, 250 Gy for all arthropods on mango and papaya shipped from Australia to New Zealand, 300 Gy for all arthropods on mango shipped from Australia to Malaysia, 350 Gy for all arthropods on lychee shipped from Australia to New Zealand and 400 Gy for all hosts of insects other than pupae and adult Lepidoptera shipped to the United States. Efforts to develop additional generic PI treatments and reduce the dose for the 400 Gy treatment are ongoing with a broad based 5-year, 12-nation cooperative research project coordinated by the joint Food and Agricultural Organization/International Atomic Energy Agency Program on Nuclear Techniques in Food and Agriculture. Key groups identified for further development of generic PI treatments are Lepidoptera (eggs and larvae), mealybugs and scale insects. A dose of 250 Gy may suffice for these three groups plus others, such as thrips, weevils and whiteflies. - Highlights: ► The history of phytosanitary irradiation (PI) treatments is given. ► Generic PI treatments in use today are discussed. ► Suggestions for future research are presented. ► A dose of 250 Gy for most insects may suffice.

  9. Managing aging in nuclear power plants: Insights from NRC maintenance team inspection reports

    Energy Technology Data Exchange (ETDEWEB)

    Fresco, A.; Subudhi, M.; Gunther, W.; Grove, E.; Taylor, J. [Brookhaven National Lab., Upton, NY (United States)

    1993-12-01

    A plant`s maintenance program is the principal vehicle through which age-related degradation is managed. From 1988 to 1991, the NRC evaluated the maintenance program of every nuclear power plant in the United States. Forty-four out of a total of 67 of the reports issued on these in-depth team inspections were reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant systems, structures, and components. Relevant information was extracted from these inspection reports and sorted into several categories, including Specific Aging Insights, Preventive Maintenance, Predictive Maintenance and Condition Monitoring, Post Maintenance Testing, Failure Trending, Root Cause Analysis and Usage of Probabilistic Risk Assessment in the Maintenance Process. Specific examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging have been identified. The information also was sorted according to systems and components, including: Auxiliary Feedwater, Main Feedwater, High Pressure Injection for both BWRs and PWRs, Service Water, Instrument Air, and Emergency Diesel Generator Air Start Systems, and Emergency Diesel Generators Air Start Systems, emergency diesel generators, electrical components such as switchgear, breakers, relays, and motor control centers, motor operated valves and check valves. This information was compared to insights gained from the Nuclear Plant Aging Research (NPAR) Program. Attributes of plant maintenance programs where the NRC inspectors felt that improvement was needed to properly address the aging issue also are discussed.

  10. Study on aging management of fire protection system in nuclear power plant

    International Nuclear Information System (INIS)

    Fang Huasong; Du Yu; Li Jianwen; Shi Haining; Tu Fengsheng

    2010-01-01

    Fire prevention, fire fighting and fire automatic alarms are three aspects which be included in fire protection system in nuclear power plants. The fire protection system can protect personnel, equipment etc in the fire, so their performance will have a direct influence on the safe operation in nuclear power plants. The disabled accidents caused by aging have happened continuously with the extension of time in the fire protection system, which is the major security risk during the running time in nuclear power plants. In view of the importance of fire protection system and the severity of aging problems, the aging are highly valued by the plant operators and related organizations. Though the feedback of operating experience in nuclear power plant, the impact of the fire-fighting equipment aging on system performance and reliability be assessed, the aging sensitive equipment be selected to carry out the aging analysis and to guide the management and maintenance to guarantee the healthy operation in life time of fire protection system in nuclear power plant. (authors)

  11. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    International Nuclear Information System (INIS)

    Gunther, W.E.; Higgins, J.C.; Aggarwal, S.K.

    1991-01-01

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance

  12. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.E.; Higgins, J.C. [Brookhaven National Lab., Upton, NY (United States); Aggarwal, S.K. [Nuclear Regulatory Commission, Washington, DC (United States)

    1991-12-31

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  13. The effect of plant aging on equipment qualification and human performance issues related to license renewal

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.E.; Higgins, J.C. (Brookhaven National Lab., Upton, NY (United States)); Aggarwal, S.K. (Nuclear Regulatory Commission, Washington, DC (United States))

    1991-01-01

    The aging of nuclear power plants is one of the most important issues facing the nuclear industry worldwide. Aging encompasses as forms of degradation to nuclear power plant components, systems, and structures that result from exposure to environmental conditions or from operational stresses. Both the degradation from aging and actions taken to address the aging, such as increased maintenance and testing, can significantly impact human performance in the plant. Research into the causes and effects of aging as obtained through the assessment of operating experience and testing have raised questions regarding the adequacy of existing industry standards for addressing the concerns raised by this research. This paper discusses these issues, with particular emphasis in the area of equipment qualification and human performance.

  14. The effects of age on nuclear power plant containment cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A. [Brookhaven National Lab., Upton, NY (United States); Davis, J. [Science Applications International Corp., New York, NY (United States)

    1994-04-01

    A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The effects of age were characterized for the containment cooling system by reviewing and analyzing failure data from national databases, as well as plant-specific data. The predominant failure causes and aging mechanisms were identified, along with the components that failed most frequently. Current inspection, surveillance, and monitoring practices were also examined. A containment cooling system unavailability analysis was performed to examine the potential effects of aging by increasing failure rates for selected components. A commonly found containment spray system design and a commonly found fan cooler system design were modeled. Parametric failure rates for those components in each system that could be subject to aging were accounted for in the model to simulate the time-dependent effects of aging degradation, assuming no provisions are made to properly manage it. System unavailability as a function of increasing component failure rates was then calculated.

  15. The effects of age on nuclear power plant containment cooling systems

    International Nuclear Information System (INIS)

    Lofaro, R.; Subudhi, M.; Travis, R.; DiBiasio, A.; Azarm, A.; Davis, J.

    1994-04-01

    A study was performed to assess the effects of aging on the performance and availability of containment cooling systems in US commercial nuclear power plants. This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The effects of age were characterized for the containment cooling system by reviewing and analyzing failure data from national databases, as well as plant-specific data. The predominant failure causes and aging mechanisms were identified, along with the components that failed most frequently. Current inspection, surveillance, and monitoring practices were also examined. A containment cooling system unavailability analysis was performed to examine the potential effects of aging by increasing failure rates for selected components. A commonly found containment spray system design and a commonly found fan cooler system design were modeled. Parametric failure rates for those components in each system that could be subject to aging were accounted for in the model to simulate the time-dependent effects of aging degradation, assuming no provisions are made to properly manage it. System unavailability as a function of increasing component failure rates was then calculated

  16. Ageing Management for Nuclear Power Plants. Safety Guide (Russian Edition); Upravlenie stareniem atomnykh ehlektrostantsij. Rukovodstvo po bezopasnosti

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-01-15

    The median age of nuclear power plants connected to the grid worldwide is increasing. Ageing management has become an important issue in ensuring the availability of required safety functions throughout the service life of a plant. This Safety Guide provides recommendations on meeting the requirements for safe long term operation and identifies key elements of effective ageing management for nuclear power plants.

  17. Virtual age model for equipment aging plant based on operation environment and service state

    International Nuclear Information System (INIS)

    Zhang Liming; Cai Qi; Zhao Xinwen; Chen Ling

    2010-01-01

    The accelerated life model based on the operation environment and service state was established by taking the virtual age as the equipment aging indices. The effect of different operation environments and service states on the reliability and virtual age under the continuum operation conditions and cycle operation conditions were analyzed, and the sensitivities of virtual age on operational environments and service states were studied. The results of the example application show that the effect of NPP equipment lifetime and the key parameters related to the reliability can be quantified by this model, and the result is in accordance with the reality.(authors)

  18. Generic robot architecture

    Science.gov (United States)

    Bruemmer, David J [Idaho Falls, ID; Few, Douglas A [Idaho Falls, ID

    2010-09-21

    The present invention provides methods, computer readable media, and apparatuses for a generic robot architecture providing a framework that is easily portable to a variety of robot platforms and is configured to provide hardware abstractions, abstractions for generic robot attributes, environment abstractions, and robot behaviors. The generic robot architecture includes a hardware abstraction level and a robot abstraction level. The hardware abstraction level is configured for developing hardware abstractions that define, monitor, and control hardware modules available on a robot platform. The robot abstraction level is configured for defining robot attributes and provides a software framework for building robot behaviors from the robot attributes. Each of the robot attributes includes hardware information from at least one hardware abstraction. In addition, each robot attribute is configured to substantially isolate the robot behaviors from the at least one hardware abstraction.

  19. Managing aging in nuclear power plants: Insights from NRC's maintenance team inspection reports

    International Nuclear Information System (INIS)

    Fresco, A.; Subudhi, M.

    1994-01-01

    Age-related degradation is managed through the maintenance program of a nuclear plant. From 1988 to 1991, the Nuclear Regulatory Commission (NRC) evaluated the maintenance program of every nuclear power plant in the United States. The authors reviewed 44 out of a total of 67 of the reports issued by the NRC on these in-depth team inspections. The reports were reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant structures, systems, and components. The authors' conclusions are presented. 6 refs

  20. Aging research program at the LaCrosse nuclear power plant

    International Nuclear Information System (INIS)

    DiBenedetto, P.A.; Goller, K.R.; Sideris, T.

    1988-01-01

    A research program on the time-dependent, environmentally and operationally induced degradation of components, systems and structures---that is aging---is being conducted at the LaCrosse Boiling Water Reactor (LACBWR) nuclear power plant. In the spring of 1987, Dairyland Power Cooperative, the owner/licensee of the LACBWR plant announced that it was permanently shutting down this plant and intended to decommission it. Shortly thereafter, Dairyland entered into an agreement with DiBenedetto Associates (DBA) to be the exclusive agent and manager of the Aging Research Program (ARP). Wyle Laboratories is the primary supporting contractor to DBA in this effort

  1. Lithium Ion Batteries Ageing Analysis when used in a PV Power Plants

    DEFF Research Database (Denmark)

    Beltran, H.; Swierczynski, Maciej Jozef; Aparicio, N.

    2012-01-01

    This paper analyzes the integration of lithium ion (Li-ion) batteries into large scale grid-connected PV plants. It performs a systematic analysis on both the operation improvement obtained by a PV+ES power plant and the ageing experienced by the Li-ion batteries used as Energy Storage (ES) system...... when operating under different energy management strategies (EMS). In this paper, the PV+ES power plant structure is presented and the selection of Li-on batteries as ES system (ESS) is justified. Moreover, the simulation model used for studying the Li-ion battery ageing is explained and tested...

  2. Interim report on assessment of cable aging for nuclear power plants

    International Nuclear Information System (INIS)

    2006-12-01

    Research on assessment of cable aging for nuclear power plants (NPPs) started in 2002 in order to obtain data of safety-related cables affected by thermal aging, simultaneous thermal and radiation aging, and Loss-of-Coolant Accident (LOCA) equivalent test, which could contribute to draft guideline on comprehensive assessment of cable aging for NPPs while taking into consideration the latest knowledge. For the cable aging test, cross-linked polyethylene, flame-retardant cross-linked polyethylene, ethylene propylene rubber, flame-retardant ethylene propylene rubber, silicone rubber and special heat-resistant polyvinyl chloride insulators were selected from the safety-related cables used in the nuclear power plants. Furthermore, 2 to 3 kinds of cables with insulators of different manufacturers were added making a total of 14 kinds of cable specimens for the test. Aging period was selected as a basic parameter while three temperature conditions for thermal aging specimen and combined nine conditions of three temperatures with three dose rates for simultaneous aging specimens. Degradation of cable aging was characterized by elongation at break of tensile test. LOCA test for 9 kinds of cables was also conducted using the simultaneous aging specimens. Furthermore, the investigation of applicability of non-destructive degradation diagnostic technologies for aged cables was conducted to confirm the validity of cable aging evaluation at actual operating plants. Interim report was issued in 2006 and based on cable aging test until 21,000 hrs maximum; 1) a significant difference might be observed at times in the aging progress depending on the insulator manufacturer even if the insulator type was identical, 2) activation energy values calculated from the thermal aging test data were smaller than those currently used and principles of calculation and application of the activation energy were developed for evaluation and 3) superposition of time dependent data was applicable to

  3. Integration of generic issues

    International Nuclear Information System (INIS)

    Thatcher, D.

    1989-01-01

    The NRC has recognized the need to integrate generic issues (GIs). The GI process includes a number of phases, all of which should recognize the potential for overlap and conflict among related issues. In addition to the issues themselves, other related NRC and industry programs and activities need to be factored into the GI process. Integration has taken place, or is taking place, for a number of GIs. Each case of integration involves a specific set of circumstances and, as a result, the way in which integration proceeds can vary. This paper discusses the integration of issues in the generic issue process and provides a number of examples

  4. Rethinking generic skills

    Directory of Open Access Journals (Sweden)

    Roy Canning

    2013-10-01

    Full Text Available The paper provides a critical analysis of the notion of generic or transversal skillscontained with European Union policy discourses. The author presents a conceptualframework that challenges the idea that generic skills are universal, transferable andautonomous. An alternative analysis is put forward that argues the case forcontextualising skills and knowledge within particular understandings and cultures thatare more collective than individualistic in nature. The arguments are framed withinwider cross-disciplinary debates in linguistics, geosemiotics and social-cultural theoryand build upon an earlier paper exploring core skills in the UK (Canning, 2007.

  5. Life Cycle Management Managing the Aging of Critical Nuclear Plant Components

    International Nuclear Information System (INIS)

    Meyer, Theodore A.; Elder, G. Gary; Llovet, Ricardo

    2002-01-01

    Life Cycle Management is a structured process to manage equipment aging and long-term equipment reliability for nuclear plant Systems, Structures and Components (SSCs). The process enables the identification of effective repair, replace, inspect, test and maintenance activities and the optimal timing of the activities to maximize the economic value to the nuclear plant. This paper will provide an overview of the process and some of the tools that can be used to implement the process for the SSCs deemed critical to plant safety and performance objectives. As nuclear plants strive to reduce costs, extend life and maximize revenue, the LCM process and the supporting tools summarized in this paper can enable development of a long term, cost efficient plan to manage the aging of the plant SSCs. (authors)

  6. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 2. Generic material: Codes, standards, criteria. Working material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The Co-ordinated research programme on the benchmark study for the seismic analysis and testing of WWER-type nuclear power plants was initiated subsequent to the request from representatives of Member States. The conclusions adopted at the Technical Committee Meeting on Seismic Issues related to existing nuclear power plants held in Tokyo in 1991 called for the harmonization of methods and criteria used in Member States in issues related to seismic safety. The Consulltants' Meeting which followed resulted in producing a working document for CRP. It was decided that a benchmark study is the most effective way to achieve the principal objective. Two types of WWER reactors (WWER-440/213 and WWER-1000) were selected as prototypes for the benchmark exercise to be tested on a full scale using explosions and/or vibration generators. The two prototypes are Kozloduy Units 5/6 for WWER-1000 and Paks for WWER-440/213 nuclear power plants. This volume of Working material contains reports related to generic material, namely codes, standards and criteria for benchmark analysis.

  7. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 2. Generic material: Codes, standards, criteria. Working material

    International Nuclear Information System (INIS)

    1995-01-01

    The Co-ordinated research programme on the benchmark study for the seismic analysis and testing of WWER-type nuclear power plants was initiated subsequent to the request from representatives of Member States. The conclusions adopted at the Technical Committee Meeting on Seismic Issues related to existing nuclear power plants held in Tokyo in 1991 called for the harmonization of methods and criteria used in Member States in issues related to seismic safety. The Consulltants' Meeting which followed resulted in producing a working document for CRP. It was decided that a benchmark study is the most effective way to achieve the principal objective. Two types of WWER reactors (WWER-440/213 and WWER-1000) were selected as prototypes for the benchmark exercise to be tested on a full scale using explosions and/or vibration generators. The two prototypes are Kozloduy Units 5/6 for WWER-1000 and Paks for WWER-440/213 nuclear power plants. This volume of Working material contains reports related to generic material, namely codes, standards and criteria for benchmark analysis

  8. Ageing management of electrical and C/I-systems in power plants of RWE Power

    International Nuclear Information System (INIS)

    Hentschel, Reinhard; Kochs, Wolfgang; Zander, Ralf-Michael

    2010-01-01

    Maintenance and enhancement of the availability and safety of fossil-fired and nuclear power plants currently in operation are increasing in importance with plants' age. The paper deals with issues related to e.g. the operation of C and I-systems at the end of production and with the challenges involved in their replacement during plant operation and describes the various measures taken for monitoring electrical equipment. Taking the improvement of the existing protection systems against internal arcs in electrical bus bars as an example, practical approaches for ageing management are described. In addition, the strategic approaches will be explained that were developed within a VGB working group due to the introduction of a new regulation on ageing management in nuclear power plants. (orig.)

  9. Using systematic aging assessments to improve effectiveness of plant maintenance programs

    International Nuclear Information System (INIS)

    Watson, P.; Yang, J.X.; Dam, R.F.; Nickerson, J.H.

    2003-01-01

    Nuclear plant equipment aging assessment studies provided by AECL include life assessments, condition assessments or systematic assessments of maintenance. AECL has developed several tools to apply the results of aging assessment studies to improve the effectiveness of actual plant maintenance programs. The Systematic Assessment of Maintenance and the SYSTMS tool generate maintenance tasks for a system. The System Maintenance Datastore tool assesses the maintenance resources on a system basis, and can thus quantify the savings realized by optimizing the maintenance program. Long term trends in condition-based maintenance due to component aging can be predicted, and resource savings due to optimum timing of component replacement or general plant refurbishment can be quantified. The System based Adaptive Maintenance Process ensures the maintenance program is continually updated to reflect the latest plant equipment condition and maintenance strategy information. (author)

  10. Lifetime extension of ageing nuclear power plants. Entering a new era of risk. Report comissionned by Greenpeace

    International Nuclear Information System (INIS)

    2014-03-01

    The abbreviated version of the Greenpeace report on the lifetime extension of aging nuclear power plants - entering a new era of risk - covers the following topics: age of the nuclear power plants in Europe, covered amounts of insurance in Europe in case of a nuclear accident, progress of the ageing of nuclear power plants, and the power up-rating of nuclear reactors. The economy of aged reactors is discussed in connection with the lifetime extension and the liabilities for the aging reactors.

  11. Detection and mitigation of aging effects of nuclear power plant components

    International Nuclear Information System (INIS)

    Pachner, J.

    1988-09-01

    This paper describes the general principles of the methods for timely detection and mitigation of aging effects. These methods include condition monitoring, failure trending, system reliability monitoring, predictive maintenance and scheduled maintenance. In addition, developments of existing detection and mitigation methods needed to improve the capability for effective managing of nuclear power plant aging are discussed

  12. Proceedings of the international conference on nuclear power plant aging, availability factor and reliability analysis

    International Nuclear Information System (INIS)

    Goel, V.S.

    1985-01-01

    This book presents the papers given at a conference on nuclear power plant life extension. Topics considered at the conference included availability, accelerated aging techniques, the qualification of electrical equipment, probabilistic risk assessment, reactor maintenance, outages, reliability, computer-aided design, seismic effects, mechanical vibrations, fatigue monitoring, steam generators, and materials degradation by aging and embrittlement

  13. A Proactive Aging/Asset Management Model to Optimize Equipment Maintenance Resources Over Plant Lifetime

    International Nuclear Information System (INIS)

    Meyer, Theodore A.; Perdue, Robert K.; Woodcock, Joel; Elder, G. Gary

    2002-01-01

    Experience has shown that proactive aging/asset management can best be defined as an ongoing process. Station goals directly supported by such a process include reducing Unplanned Capability Loss Factor and gaining the optimum value from maintenance and aging management budgets. An effective aging/asset management process must meet evolving and sometimes conflicting requirements for efficient and reliable nuclear power plant operation. The process should identify most likely contributors before they fail, and develop cost-effective contingencies. Current trends indicate the need for focused tools that give quantitative input to decision-making. Opposing goals, such as increasing availability while optimizing aging management budgets, must be balanced. Recognizing the importance of experience in reducing the uncertainty inherent in predicting equipment degradation rates, nuclear industry demographics suggest the need to capture existing expert knowledge in a usable form. The Proactive Aging/Asset Management Process has been developed to address these needs. The proactive approach is a process supported by tools. The process identifies goals and develops criteria - including safety, costs, and power production - that are used to prioritize systems and equipment across the plant. The process then draws upon tools to most effectively meet the plant's goals. The Proactive Aging/Asset Management Model TM is one software-enabled tool designed for mathematical optimization. Results assist a plant in developing a plant-wide plan of aging management activities. This paper describes the proactive aging/asset management process and provides an overview of the methodology that has been incorporated in a model to perform a plant-wide optimization of aging management activities. (authors)

  14. Ageing study of protection automation components of Olkiluoto nuclear power plant

    International Nuclear Information System (INIS)

    Simola, K.; Haenninen, S.

    1993-07-01

    A study on ageing of reactor protection system of the Olkiluoto nuclear power plant is described. The objective of the study was to present an ageing analysis approach and apply in to the automation chains of reactor protection system of the Olkiluoto nuclear power plant. The study includes the measuring instrumentation, the protection logics, and the control electronics of some pumps and valves. The analysis is based on the information collected on the structure of the system, environmental conditions and maintenance practices of components, and operating experience. Based on this information, the possible ageing effects of equipment and their safety significance are evaluated. (orig.). (15 refs., 16 figs., 12 tabs.)

  15. Effect of plant age on fresh rhizome yield and volatile oil composition of Acorus calamus linn

    International Nuclear Information System (INIS)

    Osman, M.A.; Bahl, J.R.; Darokar, M. P.; Garg, S.N.; Lal, R.K.; Khanuja, S.P.S.

    2008-01-01

    The effect of plant age on growth, yield and oil content and composition of sweet flag (Acorus calamus) was studied in four populations at four different ages, raised at CIMAP experimental research Farm, India. The plant age had significant effect on total fresh yield and leaves and rhizomes fresh weights. These parameters showed increasing trend with advancement of harvesting age up to 6 years, and age increase to more than 15 years resulted in their decrease . Significantly highest number of shoots per square meter was recorded in more than 15 year old crop, and the lowest number was recorded in the 6 year old crop. The highest oil yield of rhizomes was obtained from the six year old plants. Shoot length, rhizome leaf ratio (R/L) and oil yield of leaves did not show significant differences with the age of the plant. However, 6 year old plants recorded the highest average shoot length, and the three year old plants gave the highest oil yield of leaves. The total fresh yield showed a highly significant positive correlation with rhizomes fresh weight (r = 0.999), leaves fresh weight (r=0.994) and with rhizome: leaf ratio (r = 0.998). Highly significant positive correlations (r = 0.999) were also obtained between rhizomes oil content and rhizomes oil yield and between leaves oil content and leaves oil yield. β-asarone was the most dominant constituent in the oils of both leaves and rhizomes , constituting an average of 84.2% in the leaves and 88.9% in the rhizomes oil. The study indicated that the oil content of fresh rhizomes and leaves is the main contributor to their oil yields, and selection for high oil content will be effective. The constituents of the volatile oil remained the same irrespective of the plant age.(Author)

  16. Managing aging in nuclear power plants: Insights from NRC's Maintenance Team Inspection reports

    International Nuclear Information System (INIS)

    Fresco, A.; Subudhi, M.

    1992-01-01

    A plant's maintenance program is the principal vehicle through which age-related degradation is managed. From 1988 to 1991, the NRC evaluated the maintenance program of every nuclear power plant in the United States. Forty-four out of a total of sixty-seven of the reports issued on these in-depth team inspections have been reviewed for insights into the strengths and weaknesses of the programs as related to the need to understand and manage the effects of aging on nuclear plant structures, systems, and components (SSCs). Relevant information has been extracted from these inspection reports sorted into several categories; including Specific Aging Insights, Preventive Maintenance, Predictive Maintenance and Condition Monitoring, Post Maintenance Testing, Failure Trending, Root Cause Analysis and Usage of Probabilistic Risk Assessment in the Maintenance Process. Specific examples of inspection and monitoring techniques successfully used by utilities to detect degradation due to aging have been identified

  17. Generic clearance values

    International Nuclear Information System (INIS)

    Bossio, M.C.; Muniz, C.C.

    2009-01-01

    This paper analyzes the Generic Clearance Values established for natural and artificial radionuclides with the objective of evaluating their degree of conservatism in views of adopting them into the regulatory body. Generic clearance values for natural radionuclides have been chosen by experts judgments as the optimum boundary between, on one hand, the ubiquitous unmodified soil concentrations and, on the other hand, activity concentrations in ores, mineral sands, industrial residues and wastes. For artificial radionuclides the clearance levels have been derived from the scenarios postulated in the document 'Safety Reports Series Nr 44' of the IAEA considering quantitative exemption criteria. A set of 8 scenarios were postulated covering external, ingestion and inhalation exposure pathways. For each radionuclide, the generic clearance level was derived as the more restrictive value obtained from the scenarios, that is the lowest ratio between the applicable individual dose and the dose per unit activity concentration (Bq/g). The individual dose was calculated by a formula depending on each scenario and pathway, with different parameters, such as exposure time, dosimetric factors, dilution factor, density of the material, geometric factors, etc. It was concluded that the basis and parameters used for the derivation of the generic clearance levels are quite conservative and therefore its the adoption in Argentina has been recommended. It is expected that their implementation will contribute to optimize the regulatory management system. (author)

  18. Generic Clearance Values

    International Nuclear Information System (INIS)

    Bossio, M.C.; Muniz, C.C.

    2010-01-01

    This paper analyzes the Generic Clearance Values established for natural and artificial radionuclides with the objective of evaluating their degree of conservatism in views of adopting them into the regulatory body. Generic clearance values for natural radionuclides have been chosen by experts judgments as the optimum boundary between, on the one hand, the ubiquitous unmodified soil concentrations and, on the other hand, activity concentrations in ores, mineral sands, industrial residues and wastes. For artificial radionuclides the clearance levels have been derived from the scenarios postulated in the document Safety Reports Series 44 of the IAEA considering quantitative exemption criteria. A set of 8 scenarios were postulated covering external, ingestion and inhalation exposure pathways. For each radionuclide, the generic clearance level was derived as the more restrictive value obtained from the scenarios, that is the lowest ratio between the applicable individual dose and the dose per unit activity concentration (Bq/g). The individual dose was calculated by a formula depending on each scenario and pathway, with different parameters, such as exposure time, dosimetric factors, dilution factor, density of the material, geometric factors, etc. It was concluded that the basis and parameters used for the derivation of the generic clearance levels are quite conservative and therefore its the adoption in Argentina has been recommended. It is expected that their implementation will contribute to optimize the regulatory management system. (authors) [es

  19. Generic phytosanitary irradiation treatments

    Science.gov (United States)

    Hallman, Guy J.

    2012-07-01

    The history of the development of generic phytosanitary irradiation (PI) treatments is discussed beginning with its initial proposal in 1986. Generic PI treatments in use today are 150 Gy for all hosts of Tephritidae, 250 Gy for all arthropods on mango and papaya shipped from Australia to New Zealand, 300 Gy for all arthropods on mango shipped from Australia to Malaysia, 350 Gy for all arthropods on lychee shipped from Australia to New Zealand and 400 Gy for all hosts of insects other than pupae and adult Lepidoptera shipped to the United States. Efforts to develop additional generic PI treatments and reduce the dose for the 400 Gy treatment are ongoing with a broad based 5-year, 12-nation cooperative research project coordinated by the joint Food and Agricultural Organization/International Atomic Energy Agency Program on Nuclear Techniques in Food and Agriculture. Key groups identified for further development of generic PI treatments are Lepidoptera (eggs and larvae), mealybugs and scale insects. A dose of 250 Gy may suffice for these three groups plus others, such as thrips, weevils and whiteflies.

  20. Generic phytosanitary irradiation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Hallman, Guy J [United States Department of Agriculture, Agricultural Research Service, Weslaco, TX (United States)

    2013-01-15

    The history of the development of generic phytosanitary irradiation (PI) treatments is discussed beginning with its initial proposal in 1986. Generic PI treatments in use today are 150 Gy for all hosts of Tephritidae, 250 Gy for all arthropods on mango and papaya shipped from Australia to New Zealand, 300 Gy for all arthropods on mango shipped from Australia to Malaysia, 350 Gy for all arthropods on lychee shipped from Australia to New Zealand and 400 Gy for all hosts of insects other than pupae and adult Lepidoptera shipped to the United States. Efforts to develop additional generic PI treatments and reduce the dose for the 400 Gy treatment are ongoing with a broad based 5-year, 12-nation cooperative research project coordinated by the joint Food and Agricultural Organization/International Atomic Energy Agency Program on Nuclear Techniques in Food and Agriculture. Key groups identified for further development of generic PI treatments are Lepidoptera (eggs and larvae), mealybugs and scale insects. A dose of 250 Gy may suffice for these three groups plus others, such as thrips, weevils and whiteflies. (author)

  1. The generic strategy trap.

    Science.gov (United States)

    Miller, D

    1992-01-01

    Management experts claim that for a company to thrive, it must concentrate on a single generic strategy--on one thing it does better than its rivals. But specialization also has its disadvantages. The author suggests that a broader, mixed approach may be preferable.

  2. Prioritization of generic safety issues

    International Nuclear Information System (INIS)

    Emrit, R.; Minners, W.; VanderMolen, H.

    1983-12-01

    This report presents the priority rankings for generic safety issues related to nuclear power plants. The purpose of these rankings is to assist in the timely and efficient allocation of NRC resources for the resolution of those safety issues that have a significant potential for reducing risk. The report focuses on the prioritization of generic safety issues. Issues primarily concerned with the licensing process or environmental protection and not directly related to safety have been excluded from prioritization. The prioritized issues include: TMI Action Plan items under development; previously proposed issues covered by Task Action Plans, except issues designated at Unresolved Safety Issues (USIs) which had already been assigned high priority; and newly-proposed issues. Future supplements to this report will include the prioritization of additional issues. The safety priority rankings are HIGH, MEDIUM, LOW, and DROP and have been assigned on the basis of risk significance estimates, the ratio of risk to costs and other impacts estimated to result if resolutions of the safety issues were implemented, and the consideration of uncertainties and other quantitative or qualitative factors. To the extent practical, estimates are quantitative

  3. U.S.-NPAR approach to managing aging in operating nuclear power plants

    International Nuclear Information System (INIS)

    Bosnak, R.; Vagins, M.; Vora, J.

    1991-01-01

    Aging degradation in operating nuclear power plants must be managed to prevent safety margins from eroding below the levels provided in plant design bases. The NPAR program and other aging-related programs conducted under the auspices of the US NRC Office of Nuclear Regulatory Research are developing needed technical bases and guidance for understanding and managing aging in operating nuclear power plants (NPP) of all ages. Results from these programs, together with relevant information developed by industry are implemented through various ongoing NRC and industry programs. The aging management process central to these efforts consists of three key element: 1) selection and prioritization of components, systems, and structures (CSS) in which aging must be managed, 2) understanding of the relevant aging mechanisms and rates of degradation processes in these CSS, and 3) managing degradation through effective inspection, surveillance, condition monitoring, trending, preventive and corrective maintenance, and mitigation. This paper provides a historical perspective on the aging related research programs sponsored by the Office of U.S. Nuclear Regulatory Research. Also, briefly described are the major element of the NPAR program and its status and results or accomplishments. In the process the authors emphasize the need for total industry commitment and participation in implementing programs for understanding and managing aging in operating nuclear power plants. 'Aging' is universal in nature. No industrial complex including NPP should be considered immune from its effects. For NPP aging is manageable its ti symptoms are recognized and predicted, if it is monitored and appropriate steps are taken for timely mitigation of age-related degradation. (author)

  4. Benefits of Digital Equipment Generic Qualification Activities

    International Nuclear Information System (INIS)

    Thomas, James E.; Steiman, Samuel C.

    2002-01-01

    As a result of nuclear power plant instrumentation and control obsolescence issues, there have been numerous activities during recent years relating to the qualification of digital equipment. Some of these activities have been 'generic' in nature in that the qualification was not limited to plant specific applications, but was intended to cover a broad base of potential applications of the digital equipment. These generic qualifications have been funded by equipment manufacturers and by utility groups and organizations. The generic activities sponsored by the Electric Power Research Institute (EPRI) have been pilot projects for an overall generic qualification approach. The primary benefit resulting from the generic qualification work to date is that a number of digital platforms and digital devices are now available for use in various nuclear safety-related applications. Many of the tests and evaluations necessary to support plant specific applications have been completed. The amount of data and documentation that each utility must develop on a case by case basis has been significantly reduced. There are also a number of additional benefits resulting from these industry efforts. The challenges and difficulties in qualifying digital equipment for safety-related applications are now more clearly understood. EPRI has published a lessons learned document (EPRI Report 1001452, Generic Qualification of Commercial Grade Digital Devices: Lessons Learned from Initial Pilots, which covers several different qualification areas, including device selection, project planning, vendor surveys and design reviews, and electromagnetic compatibility (EMC) qualification. Application of the experience and lessons learned from the EPRI pilot activities should help reduce the effort and cost required for future qualification work. Most generic qualification activities for commercial equipment have been conducted using the approach of EPRI TR-106439, Guideline on Evaluation and Acceptance

  5. Research on technological assessment for ageing management of commercial reprocessing plant

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-08-15

    The research program has been carried out to provide technical database and review manuals for evaluating the adequacy of Tokai plant's Ageing Management report from F.Y.2006 to F.Y.2011. In the near future, the regulator will be to carry out the evaluation of Rokkasho plant, which is commercial-size plant mainly designed by the technologies in Britain and France. This plant is different from Tokai plant in a technique of the prevention of corrosion. The purpose of the research program is to provide supplementary database and improve the review manual in order to evaluate the adequacy of Rokkasho plant's Ageing Management report. We selected three experimental subjects on ageing phenomena listed bellow in this program on the basis of the result of the operational experience of the foreign plants and the related previous studies. Effect of solid deposit adhering on the metal, Np(VI) and nitrous ions in solution on the corrosion of stainless steel made reduced pressure evaporator in boiling nitric acid solutions, Conditions of initiation of Stress Corrosion Cracking of the zirconium made components in boiling nitric acid solutions including highly-concentrated plutonium, Conditions of initiation of Hydrogen Embrittlement Stress Corrosion Cracking of Pipe Fittings Composed of Zirconium, Tantalum and Stainless Steel in high radioactive nitric acid solutions. (author)

  6. Data collection and record keeping for the management of nuclear power plant ageing: A safety practice

    International Nuclear Information System (INIS)

    1991-01-01

    This Safety Practice is the first in a series of reports under the programme on the management of nuclear power plant ageing. The purpose of the programme is to facilitate the exchange of information and to promote co-operation among Member States towards understanding and managing the ageing degradation of components, with the aim of maintaining safe and reliable plant operation. The availability and evaluation of appropriate data on nuclear power plant components are essential to safety and constitute a key factor in plant life extension considerations. The present publication provides guidance on data requirements and an effective and practical system for data collection and record keeping in relation to the evaluation and management of ageing and service life. This guidance is based on current practices. It is envisaged that the application of the guidance will contribute to the safe and reliable operation of nuclear power plants and will facilitate international information exchange on ageing related component failures, malfunctions and degradation, since data collected using the same ground rules would be easier to exchange and compare. The guidance is intended primarily for the management, maintenance and technical staff of nuclear power plants, on whom the ultimate success of the recommended system and its associated benefits depend. Intended secondary audiences include utility management and central technical support organizations, regulatory bodies, standards organizations, design companies, and research and development institutes. 8 refs, 1 fig., 1 tab

  7. 77 FR 14446 - Changes to the Generic Aging Lessons Learned (GALL) Report Revision 2 AMP XI.M41, “Buried and...

    Science.gov (United States)

    2012-03-09

    ...) Report Revision 2 AMP XI.M41, ``Buried and Underground Piping and Tanks'' AGENCY: Nuclear Regulatory...), LR- ISG-2011-03, ``Changes to GALL Report Revision 2 Aging Management Program (AMP) XI.M41, `Buried... Report Revision 2 AMP XI.M41 based on the staff's review of several license renewal applications' buried...

  8. Aging and lifetime management - A plant-wide concept and examples for realization

    International Nuclear Information System (INIS)

    Erve, M.

    1998-01-01

    It is of central importance to understand, analyze and manage aging-related phenomena and to apply this information in the systematic utilization and as-necessary extension of the service life of components and systems. 'Aging' in this context is understood to mean the change over time of the service-related characteristics and properties of the following nuclear power plant items: the equipment (mechanical components, structures, electrical and I and C systems); the computer systems (hardware and software) required for plant operation; the plant specifications and documentation. From this it is obvious that a competent strategy for aging and plant life management must cover all key-components relevant for safety and availability of the plant. Besides mechanical components, instrumentation and control devices, and civil engineering structures are to be considered, regarding both aspects, function and integrity. 'Aging and plant life management' encompasses all organizational and technical measures with which aging phenomena are recognized and managed by the plant operator, and which thereby guarantee full utilization of a component or system over its entire service life, or which must be taken at the proper time to extend service life and guarantee long-term plant integrity. An adequate strategy follows for taking measures to avoid detrimental effects on lifetime. Preventive measures can be the change of operation modes to suppress rigid degradation, the change of operating parameters or system engineering methods to optimize the operation of systems and components, and the replacement of aged component parts, components, or systems by new ones, made with an improved design or representing an advanced technique. The strategy is challenging: the improvement of availability by optimizing the outage times and the operation; the increase of safety and reliability; the reduction of man-rem exposure and costs for waste management and amount of waste; the optimized early

  9. Guideline for ageing management in nuclear power plants; Leitlinie zum Alterungsmanagement in Kernkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Herter, K.H.; Schuler, X. [Materialpruefungsanstalt (MPA), Univ. Stuttgart, Stuttgart (Germany); Hienstorfer, W.; Pompe, W. [TUeV SUeD Energietechnik GmbH, Filderstadt (Germany)

    2007-07-01

    During operation of nuclear power plants, the quality of systems, structures and components may change as a result of ageing (conceptional ageing, technological ageing or physical ageing), which will affect the system quality. Ageing management is necessary to ensure safety and availability throughout the life of the systems. This necessitates a systematic, integrative and knowledge-based approach. Systems, structures and components are grouped according to their relevance for meeting the set goals. Ageing mangement should be process-oriented and should be integrated in the organisational procedure in cooperation with the safety manager. The procedure should follow the PDCA principle (plan - do - check - act). The data, documents, knowledge and evaluations required for ageing management are part of the knowledge base of the nuclear power station and are updated regularly. The efficiency of ageing management must be reassessed at regular intervals. (orig.)

  10. Results from the Nuclear Plant Aging Research Program: Their use in inspection activities

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.; Taylor, J. (Brookhaven National Lab., Upton, NY (USA))

    1990-09-01

    The US NCR's Nuclear Plant Aging Research (NPAR) Program has determined the susceptibility to aging of components and systems, and the potential for aging to impact plant safety and availability. The NPAR Program also identified methods for detecting and mitigating aging in components. This report describes the NPAR results which can enhance NRC inspection activities. Recommendations are provided for communicating pertinent information to NRC inspectors. These recommendations are based on a detailed assessment of the NRC's Inspection Program, and feedback from resident and regional inspectors as described within. Examples of NPAR report summaries and aging inspection guides for components and systems are included. 13 refs., 3 figs., 4 tabs.

  11. Ageing degradation mechanisms in nuclear power plants: lessons learned from operating experience

    International Nuclear Information System (INIS)

    Bieth, M.; Zerger, B.; Duchac, A.

    2014-01-01

    This paper presents main results of a comprehensive study performed by the European Clearinghouse on Operating Experience Feedback of Nuclear Power Plants (NPP) with the support of IRSN (Institut de Surete Nucleaire et de Radioprotection) and GRS (Gesellschaft fuer Anlagen und Reaktorsicherheit mbH). Physical ageing mechanisms of Structures, Systems and Components (SSC) that eventually lead to ageing related systems and components failures at nuclear power plants were the main focus of this study. The analysis of ageing related events involved operating experience reported by NPP operators in France, Germany, USA and to the IAEA/NEA International Reporting System on operating experience for the past 20 years. A list of relevant ageing related events was populated. Each ageing related event contained in the list was analyzed and results of analysis were summarized for each ageing degradation mechanism which appeared to be the dominant contributor or direct cause. This paper provides insights into ageing related operating experience as well as recommendations to deal with the physical ageing of nuclear power plant SSC important to safety. (authors)

  12. Modelling the power conversion unit of a generic nuclear fusion plant, with a dual coolant blanket and a supercritical CO2 power cycle, by means of RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    Batet, L.

    2015-07-01

    In the framework of the Spanish fusion program TECNO-FUS, a dual coolant blanket design was proposed for DEMO. A generic power conversion system (supercritical recompression CO2 cycle) based on this proposal has been simulated using RELAP5-3D, a multipurpose system thermal-hydraulic code developed by the Idaho National Laboratory (USA). The code allows the dynamic simulation of thermal-hydraulic systems, including the control features. A model has been set up by assembling the available RELAP5-3D components: pipe, branch, pump, compressor, turbine, etc. Thermal fluxes between fluids in heat exchangers are simulated by means of heat structures, which are used as well to simulate the heating from plasma. A number of control features have been designed for the simulated plant, and their parameters have been adjusted. The code is then able to simulate robustly the dynamics of the system with a few boundary conditions. This paper exemplifies the usefulness of the code and model to understand the behavior of the plant and to perform sensitivity analyses of the control parameters or other design features. (Author)

  13. Public opinion on age-related degradation in nuclear power plants

    International Nuclear Information System (INIS)

    Matsuda, Toshihiro

    2005-01-01

    The first objective of this study is to shed light on the public opinion on age-related degradation at nuclear power plants, namely, on how the general public recognizes or views age-related degradation, which is a safety-related issue and one of the factors contributing to accidents and failures which occur at nuclear power plants. The second objective is to look into the impacts of the accident at Mihama Unit 3, which was caused by a failure to check on the piping wall thickness, on the public opinion on age-related degradation. The first survey was conducted in August 2003, followed by the second survey in October 2004, two months after the accident. The surveys found that the age-related degradation is being perceived by people as one of the risk factors that affect the safety of nuclear power plants. The characteristics of the citizens' perceptions toward age-related degradation in the form of piping cracks are that: (a) many respondents feel uneasy but a relatively few people consider that nuclear operators are technologically capable of coping with this problem; (b) many people believe that radioactivity may be released; and (c) numerous respondents consider that signs of cracks must be thoroughly detected through inspections, while on the other hand, a large percentage of the respondents attribute the accident to improper inspections/maintenance. Based on these results, the government and nuclear operators are expected to give most illuminating explanation on the current situation of and remedial measures against age-related degradation at nuclear power plants. As for the effects of the Mihama-3 accident on the public opinion on age-related degradation, it was revealed that the accident has not so significantly affected the general view for the safety of nuclear power plants, but has newly or strongly aroused people's consciousness of two of the risk factors - improper inspections/maintenance and the age-related degradation of piping. (author)

  14. Mechanisms of Heavy Metal Sequestration in Soils: Plant-Microbe Interactions and Organic Matter Aging

    Energy Technology Data Exchange (ETDEWEB)

    Teresa W.-M. Fan; Richard M. Higashi; David Crowley; Andrew N. Lane: Teresa A. Cassel; Peter G. Green

    2004-12-31

    For stabilization of heavy metals at contaminated sites, the three way interaction among soil organic matter (OM)-microbes-plants, and their effect on heavy metal binding is critically important for long-term sustainability, a factor that is poorly understood at the molecular level. Using a soil aging system, the humification of plant matter such as wheat straw was probed along with the effect on microbial community on soil from the former McClellan Air Force Base.

  15. Generic and biosimilar medicines: quid?

    Directory of Open Access Journals (Sweden)

    Steven Simoens

    2012-12-01

    Full Text Available Once intellectual property protection, data and marketing exclusivity of reference medicines have expired, generic medicines and biosimilar medicines can enter the off-patent market. This market entry is conditional on the approval of marketing authorization, pricing and reimbursement. Given that there tends to be confusion surrounding generic and biosimilar medicines, this Editorial introduces basic concepts related to generic and biosimilar medicines and presents the different studies and articles included in this supplement dedicated to generic and biosimilar medicines.

  16. Training for the seismic qualification utility group (SQUG) generic implementation procedure (GIP) for verification of seismic effects on nuclear power plant equipment

    International Nuclear Information System (INIS)

    Schaffstall, R.E.; Smith, N.P.; Baker, K.M.

    1993-01-01

    Resolution of USI A-46 was accomplished May, 1992 with the issuance of the SER for the GIP, Revision 2. The implementation of the resolution for the SQUG plants will be completed by 1996. Both the USNRC and the SQUG utilities have expended considerable resources to effect a common understanding that the effort has been worth the price. The Training Program developed to ensure that the efforts expended by the SQUG was indeed worth the price will be a major contributor in the success of the implementation. All of the older nuclear power plants in the United States now have an alternative standard to determine seismic resistance using experience data- a standard against which they can be evaluated and found seismically adequate to achieve and maintain a safe and reliable shutdown when subjected to strong motion earthquakes

  17. An evaluation of information sources and requirements for nuclear plant-aging research with life-extension implications

    International Nuclear Information System (INIS)

    Jacobs, P.T.

    1986-01-01

    Information requirements for plant-aging and life-extension research are discussed. Various information sources that have been used in plant-aging studies and reliability assessments are described. Data-base searches and analyses were performed for a specific system using several data bases and plant sources. Comments are provided on the results using the various information sources

  18. Gender, aging, and work: aging workers' strategies to confront the demands of production in maquiladora plants in nogales, Mexico.

    Science.gov (United States)

    Adarga, Mireya Scarone; Becerril, Leonor Cedillo; Champion, Catalina Denman

    2010-01-01

    This work is part of a qualitative socio-cultural investigation with a group of men and women 40 years and older in the maquila export industry in Nogales, Sonora, Mexico. In 1994, as a result of the North American Free Trade Agreement, maquila plants combined traditional intensive work methods with new "just in time" production norms that impacted work and health conditions, particularly in older, or aging, workers. The workers that were interviewed for this study show a reduction in their functional ability to work starting at 40 years of age. Work organization demands, general health conditions, and a decrease in physical abilities brings these 40-year-old workers to prematurely construct an image of themselves as aging workers and to develop coping strategies that vary by gender.

  19. Aging countermeasures for nuclear power plants in Japan and PLEC's activities

    International Nuclear Information System (INIS)

    Tajima, K.; Ishikawa, M.; Koyama, M.

    2002-01-01

    Full text: This summarizes aging countermeasure program of the nuclear power plants performed by the Japanese Government and industries, and describes current R and D program and utilization of the research results for the aged plants. The regulatory bodies (NISA of METI: the Nuclear Industry Safety Agency of the Ministry of Economy, Trade and Industry, MITI was reorganized to the Ministry of Economy, Trade and Industry (METI) in 2001) reviewed the results of technical assessments of aging phenomena of structures and components of nuclear power plants, conducted by the electric utilities. Major technical research projects related to aging of nuclear power plants in Japan have been conducted by Japan Power Engineering and Inspection Corporation (JAPEIC) under the asepses of the regulatory bodies. The results of the research projects were applied to the review and technical assessments. Environmental Fatigue Tests of Nuclear Power Plants Materials for Reliability Verification Project (EFT Project), has been conducting the fatigue tests for carbon steels, low alloy steels and austenitic steels under the simulated light water reactor (LWR) water environmental conditions. Based on the results, EFT project developed the models for evaluating fatigue initiation life reduction in LWR environment. The models were applied to the fatigue evaluation in the technical assessments mentioned above. On the other hand, the Nuclear Power Plant Life Engineering Center (PLEC) entrusted by NISA is conducting to coordinate planning of technology research on aging, to integrate technologies and knowledge of aging for management and assessment, to promote practical applications of results of technical research, and to promote sharing of information on aging technology. As to codes and standards the PLEC plans to develop them, based on the research results of the national projects performed by JAPEIC, with completion of the projects in order. Current planning technical standard is based to

  20. Generics Pricing: The Greek Paradox.

    Science.gov (United States)

    Karafyllis, Ioannis; Variti, Lamprini

    2017-01-01

    This paper explains and develops a methodological framework to help evaluate the performance of generic pharmaceutical policies and the correct evaluation of generics sales. Until today erroneous recording of generics does not help proper pricing and their penetration in the Greek market. This classifies Greece on the outliners in every study or comparison that is referred on papers or studies.

  1. Generic Reed Solomon Encorder

    Directory of Open Access Journals (Sweden)

    Petrus Mursanto

    2006-11-01

    Full Text Available Reed Solomon (RS codes is a mechanism to detect and correct burst of errors in data transmission and storage systems. It provides a solid introduction to foundation mathematical concept of Galois Field algebra and its application. With the development of digital hardware technology, the RS concepts were brought into reality, i.e. the implementation of RS codec chips. This paper presents the development steps of a generic RS encoder using VHDL. The encoder is able to handle generic width of data, variable length of information, number of error as well as variable form of primitive polynomial and generator polynomial used in the system. The design has been implemented for FPGA chip Xilinx XC3S200-5FT256 and has a better performance than commercially available equivalent encoder.

  2. Aging management and life assessment of buried commodities in nuclear power plants

    International Nuclear Information System (INIS)

    Park, J. H.; Jung, I. S.; Jo, H. S.; Kim, M. G.; Kim, S. T.; Lee, S. S.

    2000-01-01

    General field survey, inspection and life assessment were performed to establish effective aging management program of buried commodities in nuclear power plant. Basic informations on material characteristics, aging degradation experiences and maintenance history were gathered. Considering their degradation effects on power operation or safety, buried commodities were screened for the aging management priority. Various inspection techniques were applied in field survey and inspection, and their results were incorporated in the life assessment of buried commodities. In the aspect of aging degradation, general status of buried commodities were considered still sound while some revealed local degradation

  3. Aging management of safety-related concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Arndt, E.G.

    1990-01-01

    The Structural Aging Program has the overall objective of providing the US Nuclear Regulatory Commission with an improved basis for evaluating nuclear power plants for continued service. In meeting this objective, a materials property data base is being developed as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, studies are well under way to review and assess inservice inspection techniques for concrete structures and to develop a methodology which can be used for performing current as well as reliability-based future conditions assessments of these structures. 16 refs., 2 tabs

  4. Effects of normal aging on calibration and response time of nuclear plant RTDs and pressure sensors

    International Nuclear Information System (INIS)

    Hashemian, H.L.; Riner, J.L.

    1993-01-01

    Resistance temperature detectors (RTDs) and pressure, level, and flow transmitters provide a majority of the vital signals for the control and safety of nuclear power plants. Therefore, it is crucial to ensure that the performance of these sensors are maintained at an acceptable level while the plant is operating. Since aging has the potential to cause performance degradation in RTDs and pressure transmitters, several research projects have been sponsored by the US Nuclear Regulatory Commission (NRC) to study the aging characteristics of these sensors and ensure that adequate test methods and test frequencies are followed by the nuclear industry to ensure safety. The details of these projects are summarized in this paper

  5. Generic safety documentation model

    International Nuclear Information System (INIS)

    Mahn, J.A.

    1994-04-01

    This document is intended to be a resource for preparers of safety documentation for Sandia National Laboratories, New Mexico facilities. It provides standardized discussions of some topics that are generic to most, if not all, Sandia/NM facilities safety documents. The material provides a ''core'' upon which to develop facility-specific safety documentation. The use of the information in this document will reduce the cost of safety document preparation and improve consistency of information

  6. Study on risk indicator for appropriate plant maintenance considering aging effect

    International Nuclear Information System (INIS)

    Mano, Akihiro; Yamaguchi, Akira; Takata, Takashi

    2014-01-01

    Since, nuclear power plants run for a long term and plant component may deteriorate due to aging, plant safety must be maintained through maintenance activities of components. The maintenance will become more important as the number of aged plant increases. In the planning of maintenance, one must select appropriate components and interval. In general, Fussell-Vesely importance (FV) and Risk Achievement Worth (RAW) are used as a risk indicator for the maintenance. A priority order of each component can be evaluated using those risk indicators at a certain condition. However, the influence of aging (time history) on the order cannot be estimated directly. In the paper, a change of conditional core damage probability (ΔCCDP) and a change of conditional containment failure probability (ΔCCFP) are proposed as additional indicators in which the aging effect is evaluated directly so as to determine the priority order. A simplified level one probabilistic risk assessment (PRA) has been carried out in order to investigate the change of the risk indicators by considering the change of a component failure probability due to aging. In the analyses, three conditions are assumed; base (original) state, aging state and further aging state without maintenance activities. It is demonstrated that the proposed indicator (ΔCCDP and ΔCCFP) reveals the aging effect of each component, while the change of the FV and RAW represent unrealistic behavior through the states. As a result, it is found that the ΔCCDP and ΔCCFP are superior to the others in terms of the ability to evaluate components appropriately in deteriorated (aging) states and take account of differences of deterioration behavior. It is also found that the priority order of the multiple-components maintenance at the same time can also be evaluated using the ΔCCDP and ΔCCFP. Additionally, a risk informed decision making based on the risk acceptance criteria can be discussed for the maintenance procedure using the

  7. Ageing management program of wires for Atucha II Nuclear Power Plant

    International Nuclear Information System (INIS)

    Zorrilla, J.; Antonaccio, E.; Luraschi, C.; Simionato, E.; Nieto, H.

    2012-01-01

    Electrical cables constitute one of the most important components of NPP in terms o maintenance, safety and availability of the plant. Due to their large extension (thousands of kilometers) it is impossible to fully replace them and aging management becomes essential for long term operation of NPP. Since Atucha II is under construction there was a good opportunity to establish and implement a holistic cable aging management program from the beginning according to the state of the art in this field. The scope of this program involves safety related cables, including EQ cables and non EQ cables as well. Due to the diversity of the installed cables is impossible to address an aging management program of every single specimen. However it is possible to establish 'cables families' of similar aging behavior based on insulation and jacket material, manufacture, etc Several aging management strategies were set for the different 'cables families'. These strategies include cables deposit in plant, elaboration of procedures of visual and tactile inspection, NDE techniques, etc Currently the aging management program is being implemented covering topic such as: Cable screening and grouping. Review of EQ documentation and conventional qualification information referring to the installed cables. Establishment of base line of condition monitoring techniques. Calibration and set up of test parameters for NDE techniques. Aging mechanism characterization and determination of. Design construction and installation of cable deposit in plant (author)

  8. A review of electric cable aging effects and monitoring programs for plant license renewal

    International Nuclear Information System (INIS)

    Lofaro, R.J.

    1999-01-01

    As commercial nuclear power plants approach the end of their original license period, some utilities are considering the possibility of license renewal. The requirements for applying for license renewal are specified in the License Renewal Rule, which is in Title 10 of the Code of Federal Regulations, Part 54 (10 CFR54). Among the requirements specified in the rule is the performance of an Integrated Plant Assessment (IPA) which identifies and lists structures and components subject to an aging management review. The intent of this requirement is to ensure that aging degradation will not adversely affect plant safety during the license renewal period. The aging management review includes an identification of the aging effects and monitoring programs for components within the scope of the rule. Among the components within the scope are electric cables since they are passive, long-lived components that are not replaced on a periodic basis. This paper examines the aging causes and effects of electric cables, along with the programs that are typically used to ensure that proper aging management practices are in place to monitor and mitigate the effects of aging on electric cables

  9. Developing a computerized aging management system for concrete structures in finnish nuclear power plants

    International Nuclear Information System (INIS)

    Al-Neshawy, F.; Piironen, J.; Sistonen, E.; Vesikari, E.; Tuomisto, M.; Hradil, P.; Ferreira, M.

    2013-01-01

    Finland has four nuclear reactors units in two power plants. The first unit started operation in 1977 and in the early 1980's all four units were in use. During the last few years the aging management of the Nuclear Power Plant's (NPP) concrete structures has grown an important issue because the existing structures are reaching the end of their licensed operating lifetime (about 40 years). Therefore the nuclear power companies are developing aging management systems to avoid premature degradation of NPP facilities and to be able to extend their operating lifetime. This paper is about the development of a computerized ageing management system for the nuclear power plants concrete structures. The computerized ageing management system is built upon central database and implementation applications. It will assist the personnel of power companies to implement the aging management activities at different phases of the lifetime of a power plant. It will provide systematic methods for planning, surveillance, inspection, monitoring, condition assessment, maintenance and repair of structures. (authors)

  10. Candu Energy's Aging and Obsolescence Program and its Application to Operating Facilities and New Plant Design

    International Nuclear Information System (INIS)

    Dam, R.; Gold, R.; McCrea, L.

    2012-01-01

    While plant aging is inevitable, predictable and 'graceful 'aging' behavior can be achieved through the implementation of a comprehensive and integrated Plant Life Management (PLiM) program. Despite organizations like the IAEA and INPO placing more emphasis on equipment reliability, there is still a lack of completely integrated programs in the industry as evidenced by: - Piece-meal, often crisis-driven, implementation comprising many different, partial solutions; - Duplication of effort often seen when different groups work in 'silos'. A strategy which fits with existing plant processes and programs, and which coordinates a broad range of equipment reliability activities is key to achieving the desired results. An example of such a program is the Aging and Obsolescence Program (AOP). AOP follows application of INPO AP-913 guidance for equipment reliability. The program is augmented to include single point vulnerability identification, unified approach to short and long lived components, risk management, spare parts management, and the identification and resolution of obsolescence issues. The systematic nature of the program provides the needed foundation to old and new stations alike. For existing operating stations some of the key uses include outage interval extension, reduced forced outages, and/or outage time reduction, any of which can translate into improving plant performance, competitiveness, and significant dollars saved. Program elements applied to new plant design are commensurate with the industry direction to 'design for reliability', and has allowed Candu Energy to learn and to improve upon what it can offer to operating stations. This paper intends to describe the basic elements of Candu Energy's Aging and Obsolescence Program and will share some of the experience having applied it to existing operating stations, consider applications to support expanding regulatory requirements, and describe the integration into the design of new plants, promoting

  11. NRC research program on plant aging: Listing and summaries of reports issued through July 1992

    International Nuclear Information System (INIS)

    Kondic, N.N.

    1992-09-01

    The US Nuclear Regulatory Commission is conducting the Nuclear Plant Aging Research (NPAR) Program. This is a comprehensive hardware-oriented engineering research program focused on understanding the aging mechanisms of components and systems in nuclear power plants. The NPAR program also focuses on methods for simulating and monitoring the aging-related degradation of these components and systems. In addition, it provides recommendations for effective maintenance to manage aging and for implementation of the research results in the regulatory process. This document contains a listing and index of reports generated in the NPAR Program that were issued through July 1992 and summaries of those reports. Each summary describes the elements of the research covered in the report and outlines the significant results. For the convenience of the user, the reports are indexed by personal author, corporate author, and subject

  12. NRC Research Program on Plant Aging: Listing and summaries of reports issued through June 1991

    International Nuclear Information System (INIS)

    Kondic, N.N.; Hill, E.L.

    1991-07-01

    The US Nuclear Regulatory Commission is conducting the Nuclear Plant Aging Research (NPAR) Program. This is a comprehensive hardware-oriented engineering research program focused on understanding the aging mechanisms of components and systems in nuclear power plants. The NPAR program also focuses on methods for simulating and monitoring the aging-related degradation of these components and systems. In addition, it provides recommendations for effective maintenance to manage aging and for the implementation of the research results in the regulatory process. This document contains a listing and index of reports generated in the NPAR Program that were issued through June 1991 and summaries of those reports. Each summary describes the elements of the research covered in the report and outlines the significant results. For the convenience of the user, the reports are indexed by personal author, corporate author, and subject. 102 refs

  13. NRC research program on plant aging: Listing and summaries of reports issued through May 1990

    International Nuclear Information System (INIS)

    Kondic, N.N.; Hill, E.L.

    1990-07-01

    The US Nuclear Regulatory Commission is conducting the Nuclear Plant Aging Research (NPAR) Program. This is a comprehensive hardware-oriented engineering research program focused on understanding the aging mechanisms of components and systems in nuclear plants. The NPAR program also focuses on methods for simulating and monitoring the aging-related degradation of these components and systems. In addition, it provides recommendations for effective maintenance to manage aging and for the implementation of the research results in the regulatory process. This document contains a listing and index of reports generated in the NPAR Program that were issued through May 1990 and summaries of those reports. Each summary describes the elements of the research covered in the report and outlines the significant results. For the convenience of the user, the reports are indexed by personal author, corporate author, and subject

  14. Aging assessment of essential HVAC chillers used in nuclear power plants

    International Nuclear Information System (INIS)

    Blahnik, D.E.; Camp, T.W.

    1996-09-01

    The Pacific Northwest Laboratory conducted a comprehensive aging assessment of chillers used in the essential safety air-conditioning systems in nuclear power plants (NPPs). The chillers used, and air-conditioning systems served, vary in design from plant to plant. The review of operating experience indicated that chillers experience aging degradation and failures. The primary aging factors of concern for chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. The evaluation of Licensee Event Reports (LERs) indicated that about 38% of the failures were primarily related to aging, 55% were partially aging related, and 7% of the failures were unassignable. About 25% of the failures were primarily caused by human, design, procedure, and other errors. The large number of errors is probably directly related to the complexity of chillers and their interfacing systems. Nearly all of the LERs were the result of entering plant Technical Specification Limiting Condition for Operation (LCO) that initiated remedial actions like plant shutdown procedures. The trend for chiller-related LERs has stabilized at about 0.13 LERs per plant year since 1988. Carefully following the vendor procedures and monitoring the equipment can help to minimize and/or eliminate most of the premature failures. Recording equipment performance can be useful for trending analysis. Periodic operation for a few hours on a weekly or monthly basis is useful to remove moisture and non-condensable gases that gradually build up inside the chiller. Chiller pressurization kits are available that will help minimize the amount of moisture and air ingress to low-pressure chillers during standby periods. The assessment of service life condition monitoring of chillers indicated there are many simple to sophisticated methods available that can help in chiller surveillance and monitoring

  15. Aging assessment of essential HVAC chillers used in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Blahnik, D.E.; Camp, T.W.

    1996-09-01

    The Pacific Northwest Laboratory conducted a comprehensive aging assessment of chillers used in the essential safety air-conditioning systems in nuclear power plants (NPPs). The chillers used, and air-conditioning systems served, vary in design from plant to plant. The review of operating experience indicated that chillers experience aging degradation and failures. The primary aging factors of concern for chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. The evaluation of Licensee Event Reports (LERs) indicated that about 38% of the failures were primarily related to aging, 55% were partially aging related, and 7% of the failures were unassignable. About 25% of the failures were primarily caused by human, design, procedure, and other errors. The large number of errors is probably directly related to the complexity of chillers and their interfacing systems. Nearly all of the LERs were the result of entering plant Technical Specification Limiting Condition for Operation (LCO) that initiated remedial actions like plant shutdown procedures. The trend for chiller-related LERs has stabilized at about 0.13 LERs per plant year since 1988. Carefully following the vendor procedures and monitoring the equipment can help to minimize and/or eliminate most of the premature failures. Recording equipment performance can be useful for trending analysis. Periodic operation for a few hours on a weekly or monthly basis is useful to remove moisture and non-condensable gases that gradually build up inside the chiller. Chiller pressurization kits are available that will help minimize the amount of moisture and air ingress to low-pressure chillers during standby periods. The assessment of service life condition monitoring of chillers indicated there are many simple to sophisticated methods available that can help in chiller surveillance and monitoring.

  16. Japan's policy on the nuclear power plant life management, life management for nuclear power plants and measures to cope with aging

    International Nuclear Information System (INIS)

    Takuma, Masao

    2002-01-01

    Full text: Nuclear Plant is born after a lengthy, multi-year construction period, and ends its life decades later, having generated a vast amount of electricity. Its period of operation is, far longer than its period of construction. 'Construction' is the process of 'creating something of value', a new nuclear plant, using technology. 'Operation' is the process of 'raising the child with care' so that its potential can be realized to the fullest over the course of its life. From the view point of plant life management, it is appropriate to divide the life of a power plant into three stages, 'fostering, mature and aging', from the start of operation to the end of its operation. It is important to manage a plant accordingly. It is recently become important to the Utility companies under the competitive power market to manage aging plants effectively, in order to extend its life with sustained high level of performances, with plant safety in the first place. Whether this is, in fact, possible or not, depends upon how the plant was operated in the prior stages, that means, depends upon how it was 'brought up'. This report briefly shows what are important points of management in these 3 stages, and also describes general significances of plant maintenance and inspection, with the practices applied to the plants in Japan. Currently 52 plants Light Water Reactor Nuclear Plants are in operation in Japan, and 13 plants within next 5 years and 23 plants within 10 years are regarded as aged plants. So the contents of periodic inspections by the government and maintenance requirements on the Utilities will be modified to keep and enhance safe and stable operations of the aged plants. In the year 1994, Japanese Government released the report 'Basic Concepts on the Nuclear Power Plant Aging', the objectives of which was the evaluation of the soundness of major equipment and to establish the concepts of aging measures, assuming the plant to be operated 60 years. Utilities, in

  17. Liquid pathway generic study. Impacts of accidental radioactive releases to the hydrosphere from floating and land-based nuclear power plants

    International Nuclear Information System (INIS)

    1978-02-01

    The staff concludes that for representative sites, there are differences in the impacts of accidental radioactive releases to the hydrosphere between floating nuclear plants (FNPs) and land-based plants (LBPs) of the ice-condenser type. The consequences of releases from design basis accidents are found to be lower for an FNP than for an LBP. For core-melt events which we consider to be of very low probability, the staff results indicate that the expected liquid pathway consequences are higher at an FNP than at an LBP, and that interdiction at the site is not likely for an FNP. The staff considers this combination of differences in release magnitude and interdiction potential to be significant. An assessment of the overall significance of the total risk associated with potential releases to liquid and airborne pathways will be considered in a forthcoming environmental impact statement for the FNP. This environmental impact statement will include a consideration of the environmental, social, and economic impacts of the operation of the FNP, as well as a value-impact analysis of alternatives which may avoid or mitigate radiological impacts to the environment

  18. Levels of rhizome endophytic fungi fluctuate in Paris polyphylla var. yunnanensis as plants age

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-02-01

    Full Text Available Paris polyphylla var. yunnanensis is an important medicinal plant with abundant saponins that are widely used in the pharmaceuticals industry. It is unclear why the levels of active ingredients increase as these plants age. We speculated that the concentrations of those components in the rhizomes are mediated by fungal endophytes. To test this hypothesis, we took both culture-dependent and -independent (metagenomics approaches to analyze the communities of endophytic fungi that inhabit those rhizomes in plants of different age classes (four, six, and eight years old. In all, 147 isolates representing 18 fungal taxa were obtained from 270 segments (90 per age class. Based on morphological and genetic characteristics, Fusarium oxysporum (46.55% frequency of occurrence was the predominant endophyte, followed by Leptodontidium sp. (8.66% and Trichoderma viride (6.81%. Colonization of endophytic fungi was maximized in the eight-year-old rhizomes (33.33% when compared with four-year-old (21.21% and six-year-old (15.15% rhizomes. Certain fungal species were present only at particular ages. For example, Alternaria sp., Cylindrocarpon sp., Chaetomium sp., Paraphaeosphaeria sporulosa, Pyrenochaeta sp., Penicillium swiecickii, T. viride, and Truncatella angustata were found only in the oldest plants. Analysis of (metagenomics community DNA extracted from different-aged samples revealed that, at the class level, the majority of fungi had the highest sequence similarity to members of Sordariomycetes, followed by Eurotiomycetes and Saccharomycetes. These results were mostly in accord with those we obtained using culture methods. Fungal diversity and richness also changed over time. Our investigation is the first to show that the diversity of fungi in rhizomes of P. polyphylla var. yunnanensis is altered as plants age, and our findings provide a foundation for future examinations of useful compounds.

  19. Aging management of instrumentation and control sensors in nuclear power plants

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2010-01-01

    Pressure to improve plant efficiency and maximize safety and the increasing age of existing NPPs are forcing the global nuclear power industry to confront the challenges of aging - caused by stressors such as temperature, humidity, radiation, electricity, and vibration - in key instrument and control (I and C) components like pressure transmitters, temperature sensors, neutron detectors, and cables. Traditional aging management methods, such as equipment replacement, required the process to be shut down. Recent aging management technologies, collectively known as online monitoring (OLM), enable plants to monitor the condition and aging of their installed I and C while the plant is operating. Developed through R and D initiatives worldwide, such OLM techniques include low- and high-frequency methods that use existing sensors, such as noise analysis; methods based on test or diagnostic sensors, such as for vibration-measuring accelerometers; and methods, such as the power interrupt (PI) test, based on active measurements made by injecting a test signal into the component under test. A review of these aging management methods, their effectiveness, and their interrelation provides a foundation for understanding the next stage in the evolution of OLM: truly integrated hybrid OLM systems capable of robust condition monitoring in both novel and familiar operating conditions.

  20. The Interleukin-6 inflammation pathway from cholesterol to aging – Role of statins, bisphosphonates and plant polyphenols in aging and age-related diseases

    Directory of Open Access Journals (Sweden)

    Omoigui Sota

    2007-03-01

    Full Text Available Abstract We describe the inflammation pathway from Cholesterol to Aging. Interleukin 6 mediated inflammation is implicated in age-related disorders including Atherosclerosis, Peripheral Vascular Disease, Coronary Artery Disease, Osteoporosis, Type 2 Diabetes, Dementia and Alzheimer's disease and some forms of Arthritis and Cancer. Statins and Bisphosphonates inhibit Interleukin 6 mediated inflammation indirectly through regulation of endogenous cholesterol synthesis and isoprenoid depletion. Polyphenolic compounds found in plants, fruits and vegetables inhibit Interleukin 6 mediated inflammation by direct inhibition of the signal transduction pathway. Therapeutic targets for the control of all the above diseases should include inhibition of Interleukin-6 mediated inflammation.

  1. An Economic Evaluation on Replacement Plan for Aged Thermal Power Plants through a Real Option Approach

    Science.gov (United States)

    Kato, Moritoshi; Zhou, Yicheng

    This paper presents a novel method to evaluate replacement plan for aged thermal power plants under uncertain circumstances through a real option approach. The most economical plan is selected among the three options: an option to operate an existing oil-fired thermal plant, an option to mothball it, and an option to abandon it and to construct an advanced gas combined cycle power plant (ACC) at the same time. Basic ideas of our model are: we use quadranomial approach in order to evaluate an option value consisted by two different uncertain assets; we consider cash flow with a dividend in order to reflect conditions of an aged oil-fired thermal plant and use the sequential compound option approach; we evaluate replacement time using quadranomial decision tree taking into account the options. We also analyze value and time of replacement using numerical examples. Our proposed method will be practically used for generation planning. For example it is possible to make priority quantitatively in replacements of aged thermal power plants by real option values. The target year of replacement may be set as a year when cumulative probability of replacement becomes over certain level.

  2. Impact of structural aging on seismic risk assessment of reinforced concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Ellingwood, B.; Song, J.

    1996-03-01

    The Structural Aging Program is addressing the potential for degradation of concrete structural components and systems in nuclear power plants over time due to aging and aggressive environmental stressors. Structures are passive under normal operating conditions but play a key role in mitigating design-basis events, particularly those arising from external challenges such as earthquakes, extreme winds, fires and floods. Structures are plant-specific and unique, often are difficult to inspect, and are virtually impossible to replace. The importance of structural failures in accident mitigation is amplified because such failures may lead to common-cause failures of other components. Structural condition assessment and service life prediction must focus on a few critical components and systems within the plant. Components and systems that are dominant contributors to risk and that require particular attention can be identified through the mathematical formalism of a probabilistic risk assessment, or PRA. To illustrate, the role of structural degradation due to aging on plant risk is examined through the framework of a Level 1 seismic PRA of a nuclear power plant. Plausible mechanisms of structural degradation are found to increase the core damage probability by approximately a factor of two

  3. Aging of concrete components and its significance relative to life extension of nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.

    1987-01-01

    Nuclear power currently supplies about 16% of the US electricity requirements, with the percentage expected to rise to 20% by 1990. Despite the increasing role of nuclear power in energy production, cessation of orders for new nuclear plants in combination with expiration of operating licenses for several plants in the next 15 to 20 years results in a potential loss of electrical generating capacity of 50 to 60 gigawatts during the time period 2005 to 2020. A potential timely and cost-effective solution to the problem of meeting future energy demand is available through extension of the service life of existing nuclear plants. Any consideration of plant life extension, however, must consider the concrete components in these plants, since they play a vital safety role. Under the USNRC Nuclear Plant Aging Research (NPAR) Program, a study was conducted to review operating experience and to provide background that will lead to subsequent development of a methodology for assessing and predicting the effects of aging on the performance of concrete-based structures. The approach followed was in conformance with the NPAR strategy

  4. Report on assessment of electrical equipment aging for nuclear power plant (AEA), FY2011

    International Nuclear Information System (INIS)

    Minakawa, T.

    2012-11-01

    Electrical components with safety function used in nuclear power plants, such as cables, medium voltage motors, low voltage motors, electrical penetration of reactor containment vessel, motor operated valve, pressure transmitter, temperature detector, etc, are required to be operational under the environment of design basis event (DBE) to shut down a reactor safely and to prevent radioactive materials from being leaked to outside. Polymer materials used as parts of these equipments are gradually degraded by thermal and radiation environment in the normal operation. In addition, the degradation is thought to progress rapidly when they are exposed to the DBE environment and a decrease in performance of the equipment may be caused. From these reason, electrical components with safety function are tested for long-term integrity in accordance with IEEE standard. However, conventional method of accelerated aging which assumes thermal and radiation aging during normal operation is said to have uncertainty in simulating the degradation given in actual operating environment. To address this issue, the project of 'Assessment of Cable Aging for Nuclear Power Plants' (ACA, 2002-2008) was carried out and 'Guide for Cable Environmental Qualification Test for Nuclear Power Plant' was developed. The need for developing an aging evaluation method for other electrical and I and C components was pointed out in the 'Strategy maps 2007', prepared by the cooperation among government, industry and academia. Under the circumstance, the project of 'Assessment of Electrical Equipment Aging for Nuclear Power Plants' (AEA) was initiated in FY2008. In this study, parts of electrical and I and C component with safety function used in nuclear power plant whose aging needs to be considered are employed as specimens, and their aging characteristics under the thermal environment and the combined radiation and thermal environment are obtained (herein after referred to as 'critical part test

  5. SALTO guidelines. Guidelines for peer review of long term operation and ageing management of nuclear power plants

    International Nuclear Information System (INIS)

    2008-01-01

    The average age of nuclear power plants (NPPs) connected to the grid worldwide is increasing. About 20% of all the power reactors operating worldwide have been in operation for more than 30 years, and almost 50% have been in operation for 20 to 30 years, while a rather limited number of new NPPs are being put into operation. In view of this trend, many countries are giving a high priority to continuing the operation of NPPs beyond the time frame originally anticipated (e.g. 30 or 40 years). Long term operation (LTO) for NPPs is operation beyond the established time frame originally set forth by the license term, design limits, standards or regulations. LTO needs to be justified by a safety assessment considering life limiting processes and features for structures, systems and components. Proper and safe LTO is based on the experience and practices of various countries in areas such as plant license renewal, life extension, continued operation and life management. Other activities, including periodic safety review, ageing management and plant modification, are also relevant to LTO. Ageing management of an NPP is an important activity that must be considered before and in conjunction with the decision to enter LTO. Ageing management of NPPs deals with the physical ageing of structures, systems and components (SSCs) that can result in the degradation of their performance characteristics. Thus ageing management helps ensure that SSCs important to safety remain capable of performing their required safety functions. An effective ageing management programme (AMP) is a key element of the safe and reliable operation of NPPs during the originally planned time frame originally planned for their operation, as well as for the period of LTO. In order to assist Member States in managing ageing effectively, the IAEA is developing related safety standards and guidance publications. International peer review is a useful tool for Member States to exchange experience, learn from each

  6. A new generic plant growth model framework (PMF): Simulating distributed dynamic interaction of biomass production and its interaction with water and nutrients fluxes

    Science.gov (United States)

    Multsch, Sebastian; Kraft, Philipp; Frede, Hans-Georg; Breuer, Lutz

    2010-05-01

    Today, crop models have a widespread application in natural sciences, because plant growth interacts and modifies the environment. Transport processes involve water and nutrient uptake from the saturated and unsaturated zone in the pedosphere. Turnover processes include the conversion of dead root biomass into organic matter. Transpiration and the interception of radiation influence the energy exchange between atmosphere and biosphere. But many more feedback mechanisms might be of interest, including erosion, soil compaction or trace gas exchanges. Most of the existing crop models have a closed structure and do not provide interfaces or code design elements for easy data transfer or process exchange with other models during runtime. Changes in the model structure, the inclusion of alternative process descriptions or the implementation of additional functionalities requires a lot of coding. The same is true if models are being upscaled from field to landscape or catchment scale. We therefore conclude that future integrated model developments would benefit from a model structure that has the following requirements: replaceability, expandability and independency. In addition to these requirements we also propose the interactivity of models, which means that models that are being coupled are highly interacting and depending on each other, i.e. the model should be open for influences from other independent models and react on influences directly. Hence, a model which consists of building blocks seems to be reasonable. The aim of the study is the presentation of the new crop model type, the plant growth model framework, PMF. The software concept refers to an object-oriented approach, which is developed with the Unified Modeling Language (UML). The model is implemented with Python, a high level object-oriented programming language. The integration of the models with a setup code enables the data transfer on the computer memory level and direct exchange of information

  7. Detection and mitigation of aging and service wear effects of nuclear power plant components in Canada

    International Nuclear Information System (INIS)

    Pachner, J.

    1987-07-01

    In Canada, the operational safety management of nuclear power plants employs methods which are intended to prevent, detect, correct and mitigate system and component failures from any cause, including the effects of aging and service wear degradation. The paper gives an overview of the application of these methods in the detection and mitigation of aging effects before they impact on plant safety and production reliability. Regulatory audits of these methods, to ensure that an acceptable level of plant safety is maintained by the nuclear power plant licensees, are also described. The methods are: a preventive maintenance program, Significant Event Reporting system, and a reliability based assessment of performance of safety related systems. The above methods are discussed and illustrated by examples. The soundness of the approach has been proven by the results achieved in 163 reactor-years of operation. Present and future developments include reviews of current monitoring, testing and inspection methods to ensure that appropriate time variant parameters (capable of revealing aging degradation before loss of functional capability) are monitored, and reviews of the effectiveness of existing maintenance programs and methods in mitigating aging and service wear effects

  8. Evaluation of effectiveness of inservice inspection in aging PWR plants based on PSA

    Energy Technology Data Exchange (ETDEWEB)

    Hanafusa, Hidemitsu; Irie, Takashi; Suyama, Takeshi [Institute of Nuclear Safety Systems Inc., Mihama, Fukui (Japan); Morota, Hidetsugu [Computer Software Development Co., Ltd., Tokyo (Japan)

    2001-09-01

    By making use of a probabilistic fracture mechanics (PFM) code which had been improved to be able to evaluate the influence of thermal aging embrittlement of cast stainless steel, we evaluated the fracture probability of welding parts of the piping of the pressurized water reactor plants in Japan and the core damage frequency by the fracture. In addition, we ranked the welding parts by the safety significance and evaluated the effectiveness of inservice inspection (ISI). As a result, it is seen that the risk increases about 25% for extending the plant life from 40 to 60 years without ISI. However, the influence of the risk on the plant life becomes negligible, when the ISI is performed adequately. This assessment is useful to plan efficient inspection and test programs of a plant under limited resources, because it is available to rank piping segments by the safety significance and to evaluate the effectiveness of inspection and test quantitatively. (author)

  9. A conceptual framework to analyze and mitigate aging effects of a system in nuclear power plants

    International Nuclear Information System (INIS)

    Ahmed, S.

    1985-01-01

    A conceptual framework is developed to analyze, characterize, and mitigate the degradation of a system in a nuclear power plant due to aging. The system is evaluated, based on an aging-specific system decision model, to understand and implement decisions pertaining to surveillance, maintenance, and replacement. Decisions on other corrective measures to mitigate the effects of aging of a number of equipment items, interconnections (relationships with other systems), and interfaces (relationships within the system) can also be made based on the proposed approach

  10. Measurement of N uptake efficiency at various age of tea plant using isotope technique

    International Nuclear Information System (INIS)

    Wibowo, Z.S.; Rachmiati, Y.

    1988-01-01

    Three months experiment to determine the efficiency of N uptake by tea plant of various age was conducted. The experiment was carried out on Andosols soil and the chosen plants were groupen in 1-5, 6-15, 16-30, 31-60 and 60 years old. The experiment used urea fertilizer enriched by 2% 15-N atom, excess. Urea of the rate of 23 kg N/ha was given in one application in the form of solution. The 15-N assay was done weekly for young shoots, old leaves, stalks, and branches. Results of the experiment showed that N uptake of tea plant increased significantly after two weeks upto five weeks of N application. The efficiency of N uptake accumulated in the plucked leaves was the highest in the plant of 6-15 years old. The N uptake efficiency of the other groups of plant was nearly equal. The uptake of N-fertilizer accumulated in pruning materials of the older plant was higher than in the younger one. It proved that the absorbed N in the older plant was mostly used for old leaves and wood development. (author). 4 refs.; 1 fig.; 3 tabs

  11. Generic patch inference

    DEFF Research Database (Denmark)

    Andersen, Jesper; Lawall, Julia

    2010-01-01

    A key issue in maintaining Linux device drivers is the need to keep them up to date with respect to evolutions in Linux internal libraries. Currently, there is little tool support for performing and documenting such changes. In this paper we present a tool, spdiff, that identifies common changes...... developers can use it to extract an abstract representation of the set of changes that others have made. Our experiments on recent changes in Linux show that the inferred generic patches are more concise than the corresponding patches found in commits to the Linux source tree while being safe with respect...

  12. Nuclear Plant Aging Research (NPAR) program plan: Components, systems, and structures

    International Nuclear Information System (INIS)

    1987-09-01

    The nuclear plant aging research described in this plan is intended to resolve issues related to the aging and service wear of equipment and systems and major components at commercial reactor facilities and their possible impact on plant safety. Emphasis has been placed on identification and characterization of the mechanisms of material and component degradation during service and evaluation of methods of inspection, surveillance, condition monitoring, and maintenance as means of mitigating such effects. Specifically, the goals of the program are as follows: (1) to identify and characterize aging and service wear effects which, if unchecked, could cause degradation of equipment, a systems, and major components and thereby impair plant safety; (2) to identify methods of inspection, surveillance, and monitoring, or of evaluating residual life of equipment, systems, and major components, which will ensure timely detection of significant aging effects prior to loss of safety function; and (3) to evaluate the effectiveness of storage, maintenance, repair, and replacement practices in mitigating the rate and extent of degradation caused by aging and service wear

  13. NRC research program on plant aging: Listing and abstracts of reports issued through February 1, 1989

    International Nuclear Information System (INIS)

    Kondic, N.N.

    1989-08-01

    The US Nuclear Regulatory Commission is conducting the Nuclear Plant Aging Research (NPAR) Program. This is a comprehensive hardware-oriented program focused on understanding the aging mechanisms of components and systems in nuclear plants. The NPAR Program also focuses on methods for simulating and monitoring the aging-related degradation of these components and systems. This document contains a listing and index of reports generated in the NPAR Program that were issued through February 1, 1989, and abstracts of those reports. Each abstract describes the elements of the research covered in the report and outlines the significant results. For the convenience of the user, the reports are indexed by personal author, corporate author, and subject

  14. Pilot studies on management of ageing of nuclear power plant components: Results of Phase 1

    International Nuclear Information System (INIS)

    1992-10-01

    To facilitate cooperation between the IAEA Member States and thus to enhance the safety and reliability of operating nuclear plants the IAEA has initiated pilot studies on the management of ageing of four representative plant components: the primary nozzle of the reactor pressure vessel, a motor operated valve, the concrete containment building and instrumentation and control cables. Phase 1 of the studies has been completed and its results are presented in this report. The report documents current understanding of ageing and methods for monitoring and mitigation of this ageing for the above components, identifies existing knowledge and technology gaps and defines follow-up work to deal with these gaps. Refs, figs and tabs

  15. Research on U.S. nuclear power plant major equipment aging

    International Nuclear Information System (INIS)

    Nakos, J.T.; Rosinski, S.T.

    1994-01-01

    The U.S. Department of Energy (DOE) and the Electric Power Research Institute (EPRI), in cooperation with nuclear power plant utilities and the Nuclear Energy Institute, have prepared equipment aging evaluations of nuclear power plant equipment for life extension considerations. Specifically, these evaluations focused on equipment considered important for plant license renewal (U.S. Code of Federal Regulations 10CFR54). open-quotes Industry Reportsclose quotes (IRs), jointly funded by DOE and EPRI, evaluated the aging of major systems, structures, and components (e.g., reactor pressure vessels, Class I structures, PWR and BWR containments, etc.) and contain a mixture of technical and licensing information. open-quotes Aging Management Guidelinesclose quotes (AMGs), funded by DOE, evaluate aging for commodity types of equipment (e.g., pumps, electrical switchgear, heat exchangers, etc.) and concentrate on technical issues only. AMGs are intended for systems engineers and plant maintenance staff. A significant number of technical issues were resolved during IR interactions with the U.S. Nuclear Regulatory Commission (NRC). However, certain technical issues have not been resolved and are considered open-quotes openclose quotes. Examples include certain issues related to fatigue, neutron irradiation embrittlement, intergranular stress corrosion cracking (IGSCC) and electrical cable equipment qualification. Direct NRC interaction did not take place during preparation of individual AMGs due to their purely technical nature. The eventual use of AMGs in a future license renewal application will likely require NRC interaction at that time. With a few noted exceptions, the AMG process indicated that current aging management practices of U.S. utilities were effective in preventing age-related degradation. This paper briefly describes the IR and AMG processes and summarizes the unresolved technical issues identified through preparation of the documents

  16. Advances on generic exemption levels and generic clearance levels in the argentinean regulatory field

    International Nuclear Information System (INIS)

    Muñiz, C.C.; Bossio, M.C.

    2011-01-01

    With the aim of optimizing the regulatory effort in Argentina, the Nuclear Regulatory Authority (ARN) evaluated two worldwide concepts used in the radioactive waste management field: “Generic Exemption Levels” and “Generic Clearance Levels”. The objective of this paper is to present the progress made in the past two years in relation to these topics and to present the results of the specific requests received from users of radioactive material. Since the approval of both Generic Levels, the ARN received two exemption requests. The first one, regarding the practice of dismantling lighting rods with 241 Am. The other case regards the international trade, distribution, usage and final disposal of lighting products with radioactive material ( 85 Kr and 232 Th). Concerning clearance, there has not been any request yet. However, in the future the ARN expects to receive this kind of requests from nuclear power plants and other facilities related to the nuclear fuel cycle. (authors) [es

  17. Pilot studies of management of ageing of nuclear power plant instrumentation and control components

    International Nuclear Information System (INIS)

    Burnay, S.G.; Simola, K.; Kossilov, A.; Pachner, J.

    1993-01-01

    This paper describes pilot studies which have been implemented to study the aging behavior of safety related component parts of nuclear power plants. In 1989 the IAEA initiated work on pilot studies related to the aging of such components. Four components were identified for study. They are the primary nozzle of a reactor vessel; a motor operated isolating valve; the concrete containment building; and instrumentation and control cables within the containment facility. The study was begun with phase 1 efforts directed toward understanding the aging process, and methods for monitoring and minimizing the effects of aging. Phase 2 efforts are directed toward aging studies, documentation of the ideas put forward, and research to answer questions identified in phase 1. This paper describes progress made on two of these components, namely the motor operated isolation valves, and in-containment I ampersand C cables

  18. Results of Cable Aging Management Tests for Laguna Verde Nuclear Power Plant

    International Nuclear Information System (INIS)

    Garcia Hernandez, E.E.; Vazquez Cervantes, R.M.; Bonifacio M, J.; Garcia Garcia, J.

    2012-01-01

    Laguna Verde Nuclear Power Plant (LVNPP) located in Veracruz, Mexico is a BWR plant, two Units with 810 MWe each one, Unit 1 (1989) and Unit 2 (1990). The Equipment Qualification (EQ) Group at the Nuclear Research National Institute (ININ) has been working with the plant on tasks to develop the LVNPP cables Aging Management Program (AMP), as part of the technical basis to extend the operational life of the plant through license renewal up to 60 years. LVNPP cables are qualified for 40 years plus a LOCA DBA in accordance with 10.CFR 50.49 and the IEEE Std-323 and IEEE St. 383. The first studies for cables AMP have been performed with samples of safety related I and C cables taken from the LVNPP warehouse, similar brands and models as installed at the plant. ININ applied the condition monitoring techniques to these samples to identify predictive degradation and to establish the methodology for cables AMP, focused to the LVNPP license renewal. Cable tests program has been running at the EQ Lab in ININ, performing accelerated aging by steps up to 60 years and to 40 years plus a LOCA test. Determination for Activation Energy (Ea) and Oxidation Induction Time (OIT) methods were developed applying a DSC/TGA calorimeter. (author)

  19. Aging of control and service air compressors and dryers used in nuclear power plants

    International Nuclear Information System (INIS)

    Moyers, J.C.

    1990-07-01

    This report was produced under the Detection of Defects and Degradation Monitoring of Nuclear Plant Safety Equipment element of the Nuclear Plant Aging Research Program. This element includes the identification of practical and cost-effective methods for detecting, monitoring, and assessing the severity of time-dependent degradation (aging) of control and service air compressors and dryers in nuclear power plants. These methods are to provide capabilities for establishing degradation trends prior to failure and developing guidance for effective maintenance. The topics of this Phase 1 assessment report are failure modes and causes resulting from aging, manufacturer--recommended maintenance and surveillance practices, and measurable parameters (including functional indicators) for use in assessing operational readiness, establishing degradation trends, and detecting incipient failure. the results presented are based on information derived from operating experience records, manufacturer-supplied information, and input from plant operators. For each failure mode, failure causes are listed by subcomponent, and parameters potentially useful for detecting degradation that could lead to failure are identified. 13 refs., 9 figs., 16 tabs

  20. IAEA's experience in compiling a generic component reliability data base

    International Nuclear Information System (INIS)

    Tomic, B.; Lederman, L.

    1991-01-01

    Reliability data are essential in probabilistic safety assessment, with component reliability parameters being particularly important. Component failure data which is plant specific would be most appropriate but this is rather limited. However, similar components are used in different designs. Generic data, that is all data that is not plant specific to the plant being analyzed but which relates to components more generally, is important. The International Atomic Energy Agency has compiled the Generic Component Reliability Data Base from data available in the open literature. It is part of the IAEA computer code package for fault/event tree analysis. The Data Base contains 1010 different records including most of the components used in probabilistic safety analyses of nuclear power plants. The data base input was quality controlled and data sources noted. The data compilation procedure and problems associated with using generic data are explained. (UK)

  1. All that is gold does not glitter? Age, taxonomy, and ancient plant DNA quality

    Directory of Open Access Journals (Sweden)

    JinHee Choi

    2015-07-01

    Full Text Available More than 600 herbarium samples from four distantly related groups of flowering plants were used for DNA extraction and subsequent measurements of DNA purity and concentration. We did not find any significant relation between DNA purity and the age of the sample. However, DNA yields were different between plant groups studied. We believe that there there should be no reservations about “old” samples if the goal is to extract more DNA of better purity. We argue that the older herbarium samples are the mine for the future DNA studies, and have the value not less than the “fresh” specimens.

  2. Aging assessment of essential HVAC chillers used in nuclear power plants

    International Nuclear Information System (INIS)

    Blahnik, D.E.; Klein, R.F.

    1993-09-01

    The Pacific Northwest Laboratory conducted a Phase I aging assessment of chillers used in the essential safety air-conditioning systems of nuclear power plants. Centrifugal chillers in the 75- to 750-ton refrigeration capacity range are the predominant type used. The chillers used, and air-conditioning systems served, vary in design from plant-to-plant. It is crucial to keep chiller internals very clean and to prevent the leakage of water, air, and other contaminants into the refrigerant containment system. Periodic operation on a weekly or monthly basis is necessary to remove moisture and noncondensable gases that gradually build up inside the chiller. This is especially desirable if a chiller is required to operate only as an emergency standby unit. The primary stressors and aging mechanisms that affect chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. Aging is accelerated by moisture, non-condensable gases (e.g., air), dirt, and other contamination within the refrigerant containment system, excessive start/stop cycling, and operating below the rated capacity. Aging is also accelerated by corrosion and fouling of the condenser and evaporator tubes. The principal cause of chiller failures is lack of adequate monitoring. Lack of performing scheduled maintenance and human errors also contribute to failures

  3. Aging assessment of essential HVAC chillers used in nuclear power plants. Phase 1, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Blahnik, D.E.; Klein, R.F. [Pacific Northwest Lab., Richland, WA (United States)

    1993-09-01

    The Pacific Northwest Laboratory conducted a Phase I aging assessment of chillers used in the essential safety air-conditioning systems of nuclear power plants. Centrifugal chillers in the 75- to 750-ton refrigeration capacity range are the predominant type used. The chillers used, and air-conditioning systems served, vary in design from plant-to-plant. It is crucial to keep chiller internals very clean and to prevent the leakage of water, air, and other contaminants into the refrigerant containment system. Periodic operation on a weekly or monthly basis is necessary to remove moisture and noncondensable gases that gradually build up inside the chiller. This is especially desirable if a chiller is required to operate only as an emergency standby unit. The primary stressors and aging mechanisms that affect chillers include vibration, excessive temperatures and pressures, thermal cycling, chemical attack, and poor quality cooling water. Aging is accelerated by moisture, non-condensable gases (e.g., air), dirt, and other contamination within the refrigerant containment system, excessive start/stop cycling, and operating below the rated capacity. Aging is also accelerated by corrosion and fouling of the condenser and evaporator tubes. The principal cause of chiller failures is lack of adequate monitoring. Lack of performing scheduled maintenance and human errors also contribute to failures.

  4. Plants traditionally used in age-related brain disorders (dementia): an ethanopharmacological survey.

    Science.gov (United States)

    Natarajan, Suganthy; Shunmugiah, Karutha Pandian; Kasi, Pandima Devi

    2013-04-01

    Epidemiological studies have shown that despite mortality due to communicable diseases, poverty and human conflicts, the incidence of dementia increases in the developing world in tandem with the ageing population. Although some FDA approved drugs are available for the treatment of dementia, the outcomes are often unsatisfactory. In traditional practices of medicine, numerous plants have been used to treat cognitive disorders, including neurodegenerative diseases such as Alzheimer's disease (AD) and other memory-related disorders. In western medicine most of the drugs used for the treatment of neurodegenerative disorders are derived from plant sources. This article reviews plants and their active constituents that have been used for their reputed cognitive-enhancing and antidementia effects. A literature survey in Science Direct, Pubmed, and Google Scholar was performed to gather information regarding drug discovery from plants sources for the treatment of congnitive disorders and dementia. More than forty herbal remedies were identified with cholinesterase inhibitory, anti-inflammatory, or antioxidant activities. Bioactive compounds include alkaloids, flavonoids, steroids, saponins, terpenoids, and essential oils. About eleven herbal plants with multipotent activity against AD are discussed. Literature surveys show that most of the research has been conducted on herbal remedies effect on cholinesterase inhibitory and antioxidant activities. Studies regarding the effect of herbal drugs on β-secretase inhibitory activity and antiaggregation property are lacking. This review provides leads for identifying potential new drugs from plant sources for the treatment of neurodegenerative disorders.

  5. A Methodology for Modeling Nuclear Power Plant Passive Component Aging in Probabilistic Risk Assessment under the Impact of Operating Conditions, Surveillance and Maintenance Activities

    Science.gov (United States)

    Guler Yigitoglu, Askin

    In the context of long operation of nuclear power plants (NPPs) (i.e., 60-80 years, and beyond), investigation of the aging of passive systems, structures and components (SSCs) is important to assess safety margins and to decide on reactor life extension as indicated within the U.S. Department of Energy (DOE) Light Water Reactor Sustainability (LWRS) Program. In the traditional probabilistic risk assessment (PRA) methodology, evaluating the potential significance of aging of passive SSCs on plant risk is challenging. Although passive SSC failure rates can be added as initiating event frequencies or basic event failure rates in the traditional event-tree/fault-tree methodology, these failure rates are generally based on generic plant failure data which means that the true state of a specific plant is not reflected in a realistic manner on aging effects. Dynamic PRA methodologies have gained attention recently due to their capability to account for the plant state and thus address the difficulties in the traditional PRA modeling of aging effects of passive components using physics-based models (and also in the modeling of digital instrumentation and control systems). Physics-based models can capture the impact of complex aging processes (e.g., fatigue, stress corrosion cracking, flow-accelerated corrosion, etc.) on SSCs and can be utilized to estimate passive SSC failure rates using realistic NPP data from reactor simulation, as well as considering effects of surveillance and maintenance activities. The objectives of this dissertation are twofold: The development of a methodology for the incorporation of aging modeling of passive SSC into a reactor simulation environment to provide a framework for evaluation of their risk contribution in both the dynamic and traditional PRA; and the demonstration of the methodology through its application to pressurizer surge line pipe weld and steam generator tubes in commercial nuclear power plants. In the proposed methodology, a

  6. Advertising and generic market entry.

    Science.gov (United States)

    Königbauer, Ingrid

    2007-03-01

    The effect of purely persuasive advertising on generic market entry and social welfare is analysed. An incumbent has the possibility to invest in advertising which affects the prescribing physician's perceived relative qualities of the brand-name and the generic version of the drug. Advertising creates product differentiation and can induce generic market entry which is deterred without differentiation due to strong Bertrand competition. However, over-investment in advertising can deter generic market entry under certain conditions and reduces welfare as compared to accommodated market entry.

  7. NET 40 Generics Beginner's Guide

    CERN Document Server

    Mukherjee, Sudipta

    2012-01-01

    This is a concise, practical guide that will help you learn Generics in .NET, with lots of real world and fun-to-build examples and clear explanations. It is packed with screenshots to aid your understanding of the process. This book is aimed at beginners in Generics. It assumes some working knowledge of C# , but it isn't mandatory. The following would get the most use out of the book: Newbie C# developers struggling with Generics. Experienced C++ and Java Programmers who are migrating to C# and looking for an alternative to other generic frameworks like STL and JCF would find this book handy.

  8. Method for developing cost estimates for generic regulatory requirements

    International Nuclear Information System (INIS)

    1985-01-01

    The NRC has established a practice of performing regulatory analyses, reflecting costs as well as benefits, of proposed new or revised generic requirements. A method had been developed to assist the NRC in preparing the types of cost estimates required for this purpose and for assigning priorities in the resolution of generic safety issues. The cost of a generic requirement is defined as the net present value of total lifetime cost incurred by the public, industry, and government in implementing the requirement for all affected plants. The method described here is for commercial light-water-reactor power plants. Estimating the cost for a generic requirement involves several steps: (1) identifying the activities that must be carried out to fully implement the requirement, (2) defining the work packages associated with the major activities, (3) identifying the individual elements of cost for each work package, (4) estimating the magnitude of each cost element, (5) aggregating individual plant costs over the plant lifetime, and (6) aggregating all plant costs and generic costs to produce a total, national, present value of lifetime cost for the requirement. The method developed addresses all six steps. In this paper, we discuss on the first three

  9. 77 FR 12089 - Proposed Generic Communication; Regulatory Issue Summary 2012-XX: Developing Inservice Testing...

    Science.gov (United States)

    2012-02-28

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0048] Proposed Generic Communication; Regulatory Issue... CFR) Part 52, ``Licenses, Certifications, and Approvals for Nuclear Power Plants,'' to satisfy the... inservice testing programs during the initial 120-month program interval following nuclear power plant...

  10. Statistical models for thermal ageing of steel materials in nuclear power plants

    International Nuclear Information System (INIS)

    Persoz, M.

    1996-01-01

    Some category of steel materials in nuclear power plants may be subjected to thermal ageing, whose extent depends on the steel chemical composition and the ageing parameters, i.e. temperature and duration. This ageing affects the 'impact strength' of the materials, which is a mechanical property. In order to assess the residual lifetime of these components, a probabilistic study has been launched, which takes into account the scatter over the input parameters of the mechanical model. Predictive formulae for estimating the impact strength of aged materials are important input data of the model. A data base has been created with impact strength results obtained from an ageing program in laboratory and statistical treatments have been undertaken. Two kinds of model have been developed, with non linear regression methods (PROC NLIN, available in SAS/STAT). The first one, using a hyperbolic tangent function, is partly based on physical considerations, and the second one, of an exponential type, is purely statistically built. The difficulties consist in selecting the significant parameters and attributing initial values to the coefficients, which is a requirement of the NLIN procedure. This global statistical analysis has led to general models that are unction of the chemical variables and the ageing parameters. These models are as precise (if not more) as local models that had been developed earlier for some specific values of ageing temperature and ageing duration. This paper describes the data and the methodology used to build the models and analyses the results given by the SAS system. (author)

  11. Knowledge of ageing phenomenons of materials used in the PWR power plants

    International Nuclear Information System (INIS)

    Vancon, D.; Meyzaud, Y.; Soulat, P.

    1996-01-01

    The nuclear power plants with PWR type reactors are planned to work during forty years and are the subject of studies aiming to check their integrity during all their life. The materials used to the fabrication of the components can be submitted different stress. The temperature, the mechanical constraints, the irradiation are examples of stress which can make the materials getting old. This text presents three themes: the ageing by irradiation, the thermal ageing and the corrosion, and their principle industrial consequences. (N.C.)

  12. Aging and service wear of auxiliary feedwater pumps for PWR nuclear power plants

    International Nuclear Information System (INIS)

    Greenstreet, W.L.

    1989-01-01

    This paper describes investigations on auxiliary feedwater pumps being done under the Nuclear Plant Aging Research (NPAR) Program. Objectives of these studies are: to identify and evaluate practical, cost-effective methods for detecting, monitoring, and assessing the severity of time-dependent degradation (aging and service wear); recommend inspection and maintenance practices; establish acceptance criteria; and help facilitate use of the results. Emphasis is given to identifying and assessing methods for detecting failure in the incipient stage and to developing degradation trends to allow timely maintenance, repair or replacement actions. 3 refs

  13. Concrete component aging and its significance relative to life extension of nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.

    1986-09-01

    The objectives of this study are to (1) expand upon the work that was initiated in the first two Electric Power Research Institute studies relative to longevity and life extension considerations of safety-related concrete components in light-water reactor (LWR) facilities and (2) provide background that will logically lead to subsequent development of a methodology for assessing and predicting the effects of aging on the performance of concrete-based materials and components. These objectives are consistent with Nuclear Plant Aging Research (NPAR) Program goals: (1) to identify and characterize aging and service wear effects that, if unchecked, could cause degradation of structures, components, and systems and, thereby, impair plant safety; (2) to identify methods of inspection, surveillance, and monitoring or of evaluating residual life of structures, components, and systems that will ensure timely detection of significant aging effects before loss of safety function; and (3) to evaluate the effectiveness of storage, maintenance, repair, and replacement practices in mitigating the rate and extent of degradation caused by aging and service wear

  14. Testing of a naturally aged nuclear power plant inverter and battery charger

    International Nuclear Information System (INIS)

    Gunther, W.E.

    1988-09-01

    A naturally aged inverter and battery charger were obtained from the Shippingport facility. This equipment was manufactured in 1974, and was installed at Shippingport in 1975 as part of a major plant modification. Testing was performed on this equipment under the auspices of the NRC's Nuclear Plant Aging Research (NPAR) Program to evaluate the type and extent of degradation due to aging, and to determine the effectiveness of condition monitoring techniques which could be used to detect aging effects. Steady state testing was conducted over the equipment's entire operating range. Step load changes were also initiated in order to monitor the electrical response. During this testing, component temperatures were monitored and circuit waveforms analyzed. Results indicated that aging had not substantially affected equipment operation. On the other hand, when compared with original acceptance test data, the monitoring techniques employed were sensitive to changes in measurable component and equipment parameters indicating the viability of detecting degradation prior to catastrophic failure. 7 refs., 34 figs., 12 tabs

  15. Ageing management of nuclear power plant concrete structures - Overview and suggested research topics

    International Nuclear Information System (INIS)

    Naus, J.

    2009-01-01

    Nuclear power plant concrete structures are described and their operating experience noted. Primary considerations related to management of their ageing are noted and an indication of their status provided: degradation mechanisms, damage models, and material performance; assessment and remediation (i.e., component selection, in-service inspection, non-destructive examinations, and remedial actions); and estimation of performance at present or some future point in time (i.e., application of structural reliability theory to the design and optimisation of in-service inspection/maintenance strategies, and determination of the effects of degradation on plant risk). Several activities are identified that provide background information and data on areas of concern with respect to non-destructive examination of nuclear power plant concrete structures: inspection of thick-walled, heavily-reinforced sections; basemat; and inaccessible areas of the containment metallic pressure boundary. Topics are noted where additional research would be of benefit to ageing management of nuclear power plant concrete structures. (author)

  16. Ageing of polymers in electrical equipment used in nuclear power plants

    International Nuclear Information System (INIS)

    Clavreul, R.

    1999-01-01

    Ageing of polymers in electrical equipment used in nuclear power plants has been studied in (Electricite de France) EDF for several years. The objective of such studies is to predict the polymers lifetime in normal and accidental conditions. The prediction of polymers behaviour in normal conditions requires accelerated tests in order to get rapidly experimental results. Experimental conditions must carefully be chosen and representative of real ageing. Accelerated ageing is usually done by applying higher temperature, (dose) or dose rate. When such experiments are done, the effects of temperature, (dose) or dose rate are first determined. In a second step, experimental results are extrapolated to real conditions. To predict lifetime of polymers, the following recommendations have to be checked: in order to assume that accelerated tests are representative of normal ageing, the observed mechanisms in experiments must be the same as those in real conditions. For accidental conditions, the same tests as those described in standards can be applied to polymers. The simulation of any accident occurring just after the installation of electrical equipment in nuclear power plants is easy to manage: only the accidental test can be carried out on the electrical equipment. To determine whether polymers in electrical equipment would have a good behaviour or not when an accident would occur after a period of several years or decades in normal conditions in a nuclear power plant, the accidental test must be done on aged materials; their physical, mechanical and electrical characteristics must be relevant to aged polymers in normal conditions. In order to detect any evolution of properties during ageing, the electrical, mechanical or chemical tests have to be proceeded on polymers samples. The characterisation tests which are applied on non-aged and aged samples depend on the nature of the polymers, their application in electrical equipment and their environment. The IEC 544

  17. U.S. NRC's generic issues program

    International Nuclear Information System (INIS)

    Kauffman, J.V.; Foster, J.W.

    2008-01-01

    The United States Nuclear Regulatory Commission (NRC) has a Generic Issues Program (GIP) to address Generic Issues (GI). A GI is defined as 'a regulatory matter involving the design, construction, operation, or decommissioning of several, or a class of, NRC licensees or certificate holders that is not sufficiently addressed by existing rules, guidance, or programs'. This rather legalistic definition has several practical corollaries: First, a GI must involve safety. Second, the issue must involve at least two plants, or it would be a plant-specific issue rather than a GI. Third, the potential safety question must not be covered by existing regulations and guidance (compliance). Thus, the effect of a GI is to potentially change the body of regulations and associated guidance (e.g., regulatory guides). The GIP was started in 1976, thus it is a relatively mature program. Approximately 850 issues have been processed by the program to date. More importantly, even after 30 years, new GIs continue to be proposed. The entire set of Generic Issues (GIs) is updated annually in NUREG-0933, 'A Prioritization of Generic Safety Issues'. GIs normally involve complex questions of safety and regulation. Efficient and effective means of addressing these issues are very important for regulatory effectiveness. If an issue proves to pose a genuine, significant safety question, then swift, effective, enforceable, and cost-effective action needs to be taken. Conversely, if an issue is of little safety significance, the issue should be dismissed in an expeditious manner, avoiding unnecessary expenditure of resources and regulatory burden or uncertainty. This paper provides a summary of the 5-stage program, from identification through the regulatory assessment stage. The paper also includes a discussion of the program's seven criteria, sources of proposed GIs, recent improvements, publicly available information, historical performance, and status of current GIs. (authors)

  18. Savannah River Site generic data base development

    International Nuclear Information System (INIS)

    Blanchard, A.

    2000-01-01

    This report describes the results of a project to improve the generic component failure database for the Savannah River Site (SRS). Additionally, guidelines were developed further for more advanced applications of database values. A representative list of components and failure modes for SRS risk models was generated by reviewing existing safety analyses and component failure data bases and from suggestions from SRS safety analysts. Then sources of data or failure rate estimates were identified and reviewed for applicability. A major source of information was the Nuclear Computerized Library for Assessing Reactor Reliability, or NUCLARR. This source includes an extensive collection of failure data and failure rate estimates for commercial nuclear power plants. A recent Idaho National Engineering Laboratory report on failure data from the Idaho Chemical Processing Plant was also reviewed. From these and other recent sources, failure data and failure rate estimates were collected for the components and failure modes of interest. For each component failure mode, this information was aggregated to obtain a recommended generic failure rate distribution (mean and error factor based on a lognormal distribution). Results are presented in a table in this report. A major difference between generic database and previous efforts is that this effort estimates failure rates based on actual data (failure events) rather than on existing failure rate estimates. This effort was successful in that over 75% of the results are now based on actual data. Also included is a section on guidelines for more advanced applications of failure rate data. This report describes the results of a project to improve the generic component failure database for the Savannah River site (SRS). Additionally, guidelines were developed further for more advanced applications of database values

  19. Identification and Assessment of Recent Aging-Related Degradation Occurrences in U.S. Nuclear Power Plants

    International Nuclear Information System (INIS)

    Choi, In Kil; Kim, Min Kyu; Choun, Young Sun; Hofmayer, Charles; Braverman, Joseph; Nie, Jinsou

    2008-11-01

    This report describes the research effort performed by BNL for the Year 1 scope of work. This research focused on collecting and reviewing degradation occurrences in US NPPs and identifying important aging characteristics needed for the seismic capability evaluations that will be performed in the subsequent evaluations in the years that follow. The report presents results of the statistical and trending analysis of this data and compares the results to prior aging studies. In addition, this report provides a description of current regulatory requirements, regulatory guidance documents, generic communications, industry standards and guidance, and past research related to aging degradation of SSCs. Finally, this report provides the conclusions reached from this research effort, which includes a summary of the findings from the identification and evaluation effort of degradation occurrences, an assessment of the degradation trending results, and insights into the important aging characteristics that should be considered in the tasks to be performed in the Year 2 through 5 research effort

  20. Article choice in plural generics

    NARCIS (Netherlands)

    Farkas, D.F.; Swart, Henriëtte de

    2007-01-01

    We discuss two groups of languages where article use contrasts in generic plural sentences but is otherwise essentially similar. The languages in the first group (English and Dutch) use bare plurals in the expression of kind reference (‘Dinosaurs are extinct’) and in generic

  1. TRAC-PF1/MOD2 best-estimate analysis of a large-break LOCA in a 15 x 15 generic four-loop Westinghouse nuclear power plant

    International Nuclear Information System (INIS)

    Spore, J.W.; Lin, J.C.; Schnurr, N.M.; White, J.R.; Cappiello, M.C.

    1992-01-01

    Calculations of a large-break loss-of-coolant accident (LOCA) in a 15 x 15 generic four-loop Westinghouse nuclear power plant with both the TRAC-PF1/MOD1 and TRAC-PF1/MOD2 computer codes will be presented. The Transient Reactor Analysis Code (TRAC) has been developed by Los Alamos National Laboratory to provide advanced best-estimate simulations of real postulated transients in pressurized light-water reactors (LWRs) and for many related thermal-hydraulic facilities. The latest released version of TRAC is TRAC-PF1/MOD2. Significant improvements and enhancements over the MOD1 version were implemented in the MOD2 heat-transfer and constitutive models. One of the most significant improvements in the MOD2 code has been the implementation of the two-step numerics method in the three-dimensional components, which can significantly reduce run times for long, slow transients. A very important area of improvement has been in the reflood heat-transfer models. Developmental assessment results (i.e., code comparisons with experimental data) will be discussed for several separate-effects and integral test, including analysis of the Upper Plenum Test Facility (UPTF), the Cylindrical Core Test Facility (CCTF), and the Loss-of-Fluid Test Facility (LOFT). The assessment results provide information on the anticipated accuracy for the best-estimate models in the MOD2 computer code. The MOD1 to MOD2 comparison will provide an estimate for the effect of improved heat-transfer models on predicted peak cladding temperatures

  2. Effects of aging on calibration and response time of nuclear plant pressure transmitters

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    1991-01-01

    This paper presents the key results of an experimental research project conducted for the Nuclear Regulatory Commission to quantify the effects of normal aging on static and dynamic performance of nuclear grade pressure, level, and flow transmitters (hereafter referred to as pressure transmitters). The project involved laboratory testing of representative pressure transmitters manufactured by Barton, Foxboro, Rosemount, and Tobar (or Veritrak) companies. These manufacturers provide the four most commonly used pressure transmitters in the safety systems of US nuclear power plants. The transmitters were tested under normal aging conditions as opposed to accelerated aging, even though accelerated aging will be used in the last few months of the project to determine the weak links and failure modes of the transmitters. The project has been performed in two phases. The Phase 1 project which was a six month feasibility study has been completed and the results published in NUREG/CR-5383. The Phase 2 project is still underway with the final report due in the fall of 1991. The project has focused on the following areas: (1) effects of aging on calibration stability; (2) effects of aging on response time; (3) study of individual components of pressure transmitters that are sensitive to aging degradation; (4) sensing line blockages due to solidification of boron, formation of sludge, freezing, and other effects; (5) search of licensee event reports and component reliability databases for failures of safety-related pressure transmitters; and (6) oil loss syndrome in Rosemount pressure transmitters

  3. Modeling and analysis of aging behavior of concrete structures in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, J.Y.R.; James, R.J.; Dunham, R.S. [ANATECH (United States)

    2011-07-01

    As nuclear power plants approach the end of their original design life and begin to transition to the life extension phase, consideration has to be given to the effects of structural aging when evaluating the extended operation of reinforced or pre-stressed concrete structures. The behavior of concrete is highly nonlinear, having low tensile strength, shear stiffness and strength that depend on crack widths, and a confinement-dependent compressive elasto-plasticity. A concrete material model is described having the appropriate capabilities required for evaluating structural aging. The model treats reinforced concrete as a three-phase composite: plain concrete material as a three-dimensional continuum phase, steel reinforcement (rebar) as a uni-directional phase, and a rebar-concrete interaction phase. Structural aging is defined as the combined effects of time dependent material properties degradation and service induced changes in loading and operational conditions. Three broad categories of structural aging, and the interaction between them, are considered: 1) Aging effects due to expected time dependent changes in material properties, 2) Aging effects due to unexpected time dependent material degradation, and 3) Aging effects due to operational environment and loading. Example analyses are presented which illustrate the value of using advanced modeling and simulation in evaluating expected and unusual structural behavior. This is particularly important for safety structures that are approaching the end of their design life and are facing the prospect of re-licensing for extended operation

  4. Development of a generic data base for failure rate

    International Nuclear Information System (INIS)

    Mosleh, A.; Apostolakis, G.

    1985-01-01

    The data analysis task in a probabilistic risk assessment (PRA) involves the assessment of data needs, the collection of information, and, finally, the analysis of the data to generate estimates for various parameters. This paper describes a framework for developing a data base for component failure rates and presents mathematical methods for the analysis of various types of information. The discussion is focused on the development of generic data bases used in PRAs. For plants without an operating history, the generic distributions are used directly to calculate component unavailability. In the case of plants that have operated for some time, the generic distributions can be used as priors in Bayesian analysis and, thus, specialized by plant-specific experience

  5. Declining plant nitrogen supply and carbon accumulation in ageing primary boreal forest ecosystems

    Science.gov (United States)

    Högberg, Mona N.; Yarwood, Stephanie A.; Trumbore, Susan; Högberg, Peter

    2016-04-01

    Boreal forest soils are commonly characterized by a low plant nitrogen (N) supply. A high tree below-ground allocation of carbon (C) to roots and soil microorganisms in response to the shortage of N may lead to high microbial immobilisation of N, thus aggravating the N limitation. We studied the N supply at a Swedish boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound. The youngest soils develop with meadows by the coast, followed by a zone of dinitrogen fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. With increasing ecosystem age, the proportion of microbial C out of the total soil C pool from the youngest to the oldest coniferous ecosystem was constant (c. 1-1.5%), whereas immobilised N (microbial N out of total soil N) increased and approached the levels commonly observed in similar boreal coniferous forests (c. 6-7 %), whereas gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of N-15 in the soil increased. More specifically, the difference in N-15 between plant foliage and soil increased, which is related to greater retention of N-15 relative to N-14 by ectomycorrhizal fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ectomycorrhizal fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing N supply to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to C limited ectomycorrhizal fungi (and other soil microorganisms), a strong sink for available soil N. Data on organic matter C-14 suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest

  6. Research activities for nuclear power plant aging promoted by PLEC, JAPEIC, Japan

    International Nuclear Information System (INIS)

    Maeda, Noriyoshi; Tajima, Kenichi

    2004-01-01

    In order to perform research activity for aging countermeasure of nuclear power plant effectively, Plant Life Engineering Center (PLEC) was established in Japan Power Engineering and Inspection Corporation (JAPEIC) in April 2000 sponsored by Ministry of International Trade and Industry (MITI, presently METI). Outlined activities of PLEC are as follows. Results of technical survey for research and development for aging phenomena have been summarized in a table (Research Map) categorizing them into ''inspection and monitoring'', ''evaluation method for aging'' and ''preventive maintenances and refurbishment''. Necessary research themes have been extracted from the Research Map consulting to experts of the specified research area and they are summarized into Medium and Long-term Research Perspective (Research Perspective), which contains prioritized research themes and outlined specification of each theme. Several new research themes proposed by various organizations and selected by PLEC as effective for the regulation activities are identified and proposed to be funded by METI every year. This paper also provides outlines and obtained results of aging related research projects currently conducted by JAPEIC sponsored by METI. (author)

  7. Reliability of some ageing nuclear power plant systems: a simple stochastic model

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2007-01-01

    The random number of failure-related events in certain repairable ageing systems, like certain nuclear power plant components, during a given time interval, may be often modelled by a compound Poisson distribution. One of these is the Polya-Aeppli distribution. The derivation of a stationary Polya-Aeppli distribution as a limiting distribution of rare events for stationary Bernouilli trials with first order Markov dependence is considered. But if the parameters of the Polya-Aeppli distribution are suitable time functions, we could expect that the resulting distribution would allow us to take into account the distribution of failure-related events in an ageing system. Assuming that a critical number of damages produce an emergent failure, the abovementioned results can be applied in a reliability analysis. It is natural to ask under what conditions a Polya-Aeppli distribution could be a limiting distribution for non-homogeneous Bernouilli trials with first order Markov dependence. In this paper this problem is analyzed and possible applications of the obtained results to ageing or deteriorating nuclear power plant components are considered. The two traditional ways of modelling repairable systems in reliability theory: the - as bad as old - concept, that assumes that the replaced component is exactly under the same conditions as was the aged component before failure, and the - as good as new - concept, that assumes that the new component is under the same conditions of the replaced component when it was new, are briefly discussed in relation with the findings of the present work

  8. Research activities for nuclear power plant aging promoted by PLEC, JAPEIC, Japan

    International Nuclear Information System (INIS)

    Maeda, N.; Tajima, K.

    2003-01-01

    In order to perform research activity for aging; countermeasure of nuclear power plant effectively, Plant Life Engineering Center (PLEC) was established in Japan Power Engineering and Inspection Corporation (JAPEIC) in April 2000 sponsored by Ministry of Economy, Trade and Industry (METI, called as MITI, at that time). Results of technical survey for research and development for aging phenomena have been summarized in a table (Research Map) categorizing them into 'inspection and monitoring', 'evaluation method for aging' and 'preventive maintenances and refurbishment'. Necessary research themes have been extracted from the Research Map consulting to experts of the specified research area. Medium and long-term research perspective (Research Perspective) has been established which contains prioritized research themes and outlined specification of each theme. Several new research themes proposed by various organizations and selected by PLEC as effective for the regulation activities of METI every year. There are about ten on-going research programs funded by METI. Their progress and performance are evaluated annually to improve their efficiency including their alteration, abolition and integration. This cycle of research is going to be attained successfully. Technology Advisory Committee composed of members from various field of nuclear power including prefectural and municipal governments supervises the PLEC activity to concentrate national wide potentials and to secure transparency, openness and neutrality. This paper also provides an outline of the aging related research projects currently conducted by JAPEIC under the auspices of METI. (author)

  9. Ageing studies on materials, components and process instruments used in nuclear power plants

    International Nuclear Information System (INIS)

    Bora, J.S.

    1997-04-01

    This report is a compilation of test results of thermal and radiation ageing tests carried out in the laboratory over a period of 25 years on diverse engineering materials, components and instruments used in nuclear power plants. Test items covered are different types of electrical cables, elastomers, surface coatings, electrical and electronics components and process instruments. Effects of thermal and radiation ageing on performance parameters are shown in tabular forms. Apart from finding the characteristics, capabilities and limitations of test items, ageing research has helped in pin-pointing sub-standard and critical parts and necessary corrective action has been taken. This report is expected to be quite useful to the manufacturers users and researchers for reference and guidance. (author)

  10. IAEA-IFRAM joint development of nuclear plant aging management handbooks

    International Nuclear Information System (INIS)

    Yeji Kim, II Soon Hwang

    2015-01-01

    As attentions to the beyond design basis accident have increased following Fukushima accident, the importance of aging management for key system, structure and components of nuclear power plant (NPP) also has been emerged as the key factor for safety and reliability of NPPs. The diverse experiences can serve as the foundation for aging management processes that has major trust in the understanding of materials degradation mechanisms. IAEA and IFRAM have collaborated to produce the nuclear plant aging management handbook in order to help entry-level engineers and graduate students understand big pictures. As the number of old NPPs and new-comer countries have increased, sharing experiences and accumulated knowledge from existing nuclear industries has become increasingly important. From this point of view, the handbook has been completed for publication by IAEA which assembled a panel of international experts to integrate the vast body of background knowledge regarding aging mechanism and the extensive know-hows of expertsinto a primer handbook. The next step is to actively utilize the IAEA handbook to produce its web version. In order to reach the ultimate purpose of nuclear safety culture of IAEA, information the handbook should be made easily accessible ana understandable. In this regards, the conversion of IFRAM handbook to web version is being planned. Careful considerations about how to restructure the content and how to reflect opinions from experts and readers are needed. In addition, this handbook can be extended to a training program for maintenance managers, vendors, research organizations and regulators to assist them in their work on aging management in operating NPPs. Through these two aspects, this IFRAM handbook on aging management of NPPs will support of NPP staff both new-comer and established countries. This paper introduces the purpose, approach, structure, content of already completed IAEA handbook and the status and plan for IFRAM Web

  11. Issues related to structural aging in probabilistic risk assessment of nuclear power plants

    International Nuclear Information System (INIS)

    Ellingwood, Bruce R.

    1998-01-01

    Structural components and systems have an important safety function in nuclear power plants. Although they are essentially passive under normal operating conditions, they play a key role in mitigating the impact of extreme environmental events such as earthquakes, winds, fire and floods on plant safety. Moreover, the importance of structural components and systems in accident mitigation is amplified by common-cause effects. Reinforced concrete structural components and systems in NPPs are subject to a phenomenon known as aging, leading to time-dependent changes in strength and stiffness that may impact their ability to withstand various challenges during their service lives from operation, the environment and accidents. Time-dependent changes in structural properties as well as challenges to the system are random in nature. Accordingly, condition assessment of existing structures should be performed within a probabilistic framework. The mathematical formalism of a probabilistic risk assessment (PRA) provides a means for identifying aging structural components that may play a significant role in mitigating plant risk. Structural condition assessments supporting a decision regarding continued service can be rendered more efficient if guided by the logic of a PRA

  12. Quality of generic medicines in South Africa

    DEFF Research Database (Denmark)

    Patel, Aarti; Gauld, Robin; Norris, Pauline

    2012-01-01

    Generic Medicines are an important policy option allowing for access to affordable, essential medicines. Quality of generic medicines must be guaranteed through the activities of national medicines regulatory authorities. Existing negative perceptions surrounding the quality of generic medicines ...

  13. Paradigms of structural safety of AGED plants. Lessons learned from Russian activities

    International Nuclear Information System (INIS)

    Saji, Genn; Timofeev, Boris

    2007-01-01

    The study of the effects behind the degradation of components and material is becoming increasingly important for the safe operation of aged plants especially when it comes to life-extension. Since the Russian nuclear community began to examine life extension issues nearly fifteen years ago, there is much to learn from these Russian pioneering studies, a portion of which were performed under the TACIS (Technical Assistance for Commonwealth of Independent States) international collaboration program with EU countries. At the Ninth International Conference, recent data were introduced regarding the ageing effects of mechanical properties of various kinds of steel and the welding joints of Russian NPP components. The full title of the conference was Material Issues in Design, Manufacturing and Operation of Nuclear Power Plants Equipment. The meeting was organized by the Central Research Institute of Structural Materials (CRISM) 'Prometey' in cooperation with the IAEA and JRC-EU. In reviewing the recent data presented at the Ninth Conference, the authors think that the paradigms of structural integrity issues in aged plants are now reasonably well established in (1) fracture mechanics and irradiation hardening of reactor vessels and core internals and (2) thermal ageing and annealing effects. Yet even when considering these well established paradigms, the current direction of study is not adequately addressing the effects of a corrosive environment. The first author believes that the current approach of low cycle fatigue is far from able to prevent and predict environmentally assisted cracks. This fundamental flaw stems from design codes, which do not incorporate the basic knowledge of corrosion mechanisms. Our focus in researching aged plants should be re-directed toward environmentally assisted cracking, typically the film rupture-slip dissolution mechanism of crack propagation under the effect of long cell action on local cells, as discussed by the first author in

  14. IAEA guidance on ageing management for nuclear power plants. Guidance on effective management of the physical ageing of systems, structures and components important to safety for nuclear power plants. Overview. Programmatic guidelines. Component specific guidelines. Review guidelines. Version 1, 2002

    International Nuclear Information System (INIS)

    2002-01-01

    Operational experience shows that excellent plant safety and excellent performance go hand in hand, and that they are achieved by effective leadership and management that includes a unified approach to safety and production. This is also applicable to ageing management. Effective ageing management leads to both enhanced plant safety and enhanced performance and is a prerequisite for long service life. The IAEA project on Safety Aspects of NPP Ageing has produced since 1990 a comprehensive set of programmatic and component specific guidelines on managing ageing, while providing an interactive environment for information exchange and co-operation among practitioners, and has assisted Member States in the application of the guidelines through the provision of training and advice. The objective of the CD-ROM is to preserve the IAEA's guidance on ageing management and to facilitate its retrieval, updating, extension and dissemination in order to help increase the effectiveness of ageing management at nuclear power plants

  15. Encouraging generic use can yield significant savings.

    Science.gov (United States)

    Zimmerman, Christina

    2012-11-01

    Key findings. (1) Zero copayment for generic drugs is the greatest influencer of generic statin utilization. (2) Both higher copayments for generic drugs and lower copayments for competing brands are associated with a decreased probability of using generic statins. (3) Prior authorization and step therapy requirements for brand-name statins are associated with an increased use of generic drugs. (4) Greater use of generic statins should reduce costs for patients, plans, and Medicare.

  16. Purposes and related aspects of the nuclear power plant aging Project

    International Nuclear Information System (INIS)

    Garaud, J.; Reynes, L.; Montardy, A. de

    1989-01-01

    The purposes and some aspects of the nuclear power plant Lifetime project is presented. The work is focused on the study of the aging of the PWR type power plant components. The project consists in two phases. The first one involves: the status reports and the analysis of the lifetime data of the most sensitive units, as well as the applied actions and proposals, the influence of the exploitation modes, the safety and the cost prospectives. The second phase includes: the definition, the contracts, the complementary actions and their achievement, the reasons and the surveyance improvements, the development of the decision supporting means, the summary and the conclusions. The selected units for the project first step and the project of actions, are listed. The first conclusions of the project show that most of the 900 MW PWR reactor components will have about 40 years of service life [fr

  17. Summary and conclusions of a program addressing aging of nuclear power plant concrete structures

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Hookham, C.J.; Graves, H.L. III

    1999-01-01

    Research has been conducted by the Oak Ridge National Laboratory to address aging management of nuclear power plant concrete structures. The purpose was to identify potential structural safety issues and acceptance criteria for use in continued service assessments. The focus of this program was on structural integrity rather than on leaktightness or pressure retention of concrete structures. Primary program accomplishments include formulation of a Structural Materials Information Center that contains data and information on the time variation of material properties under the influence of pertinent environmental stressors and aging factors for 144 materials, an aging assessment methodology to identify critical structures and degradation factors that can potentially impact their performance, guidelines and evaluation criteria for use in condition assessments of reinforced concrete structures, and a reliability-based methodology for current condition assessments and estimations of future performance of reinforced concrete nuclear power plant structures. In addition, in-depth evaluations were conducted of several nondestructive evaluation and repair-related technologies to develop guidance on their applicability. (orig.)

  18. Proceeding of 27th domestic symposium on trends in aging management and current status of aging degradation studies in nuclear power plants

    International Nuclear Information System (INIS)

    2000-11-01

    As the 27th domestic symposium of Atomic Energy Research Committee, the Japan Welding Engineering Society, the symposium was held titled as 'Trends of aging managements and current status of aging effect studies in nuclear power plants'. Six speakers gave lectures titled as 'Present status of research on mechanism and prediction method of neutron irradiation embrittlement of pressure vessel steels', 'Present status of research on mechanism and prediction method of environmentally assisted cracking in the LWR environments', 'Domestic and overseas trends of aging management of the LWR plants', 'Trends of prediction/evaluation, inspection/monitoring and repair/replacement technologies for aging of the LWR plants', 'Present status of research on mechanism and prediction method of high cycle thermal fatigue due to the thermal fluid-structure interaction in the LWR environments' and Present status of research on very high cycle fatigue of structural materials'. (T. Tanaka)

  19. Final environmental statement related to the proposed manufacture of floating nuclear power plants: (Docket No. STN 50-437): Part 2, A generic environmental statement considering the siting and operation of floating nuclear power plants

    International Nuclear Information System (INIS)

    1976-09-01

    The proposed action is the issuance of a manufacturing license to Offshore Power Systems for the startup and operation of a proposed manufacturing facility located at Blount Island, Jacksonville, Florida (Docket No. STN 50-437). No nuclear fuel will be handled or stored at the manufacturing site. The plants will be fueled after they have been towed to and moored within protected basins at specific locations designated by the purchaser and after an operating license has been issued by the Nuclear Regulatory Commission. Each nuclear generating plant, mounted on a floating platform, has a net capacity of 1150 MWe. This energy is provided by a pressurized water reactor steam supply system consisting of a Westinghouse four-loop 3425-MWt unit with an ice-condenser containment system. When one or more of these units is located within a single breakwater, the installation is designated an offshore power station. 226 figs., 95 tabs

  20. Aging and condition monitoring of electric cables in nuclear power plants

    International Nuclear Information System (INIS)

    Lofaro, R.J.; Grove, E.; Soo, P.

    1998-05-01

    There are a variety of environmental stressors in nuclear power plants that can influence the aging rate of components; these include elevated temperatures, high radiation fields, and humid conditions. Exposure to these stressors over long periods of time can cause degradation of components that may go undetected unless the aging mechanisms are identified and monitored. In some cases the degradation may be mitigated by maintenance or replacement. However, some components receive neither and are thus more susceptible to aging degradation, which might lead to failure. One class of components that falls in this category is electric cables. Cables are very often overlooked in aging analyses since they are passive components that require no maintenance. However, they are very important components since they provide power to safety related equipment and transmit signals to and from instruments and controls. This paper will look at the various aging mechanisms and failure modes associated with electric cables. Condition monitoring techniques that may be useful for monitoring degradation of cables will also be discussed

  1. Evaluation of aged concrete structures for continued service in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

    1988-01-01

    Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability

  2. Evaluation of aged concrete structures for continued service in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Marchbanks, M.F.; Arndt, E.G.

    1988-01-01

    Results are summarized of a study on concrete component aging and its significance relative to continued service of nuclear power plants (NPPs) beyond the initial period for which they were granted operating licenses. Progress is presented of a second study being conducted to identify and provide acceptance criteria for structural safety issues which the USNRC staff will need to address when applications are submitted for continued service of NPPs. Major activities under this program include: development of a materials property data base, establishment of structural component assessment and repair procedures, and development of a methodology for determination of structural reliability. 19 refs., 5 figs., 3 tabs

  3. Generic Drugs: Questions and Answers

    Science.gov (United States)

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Drugs Home Drugs Resources for You Information for Consumers (Drugs) Questions & Answers Generic Drugs: Questions & Answers Share Tweet Linkedin Pin it More ...

  4. The Generic Data Capture Facility

    Science.gov (United States)

    Connell, Edward B.; Barnes, William P.; Stallings, William H.

    1987-01-01

    The Generic Data Capture Facility, which can provide data capture support for a variety of different types of spacecraft while enabling operations costs to be carefully controlled, is discussed. The data capture functions, data protection, isolation of users from data acquisition problems, data reconstruction, and quality and accounting are addressed. The TDM and packet data formats utilized by the system are described, and the development of generic facilities is considered.

  5. Hanford Generic Interim Safety Basis

    Energy Technology Data Exchange (ETDEWEB)

    Lavender, J.C.

    1994-09-09

    The purpose of this document is to identify WHC programs and requirements that are an integral part of the authorization basis for nuclear facilities that are generic to all WHC-managed facilities. The purpose of these programs is to implement the DOE Orders, as WHC becomes contractually obligated to implement them. The Hanford Generic ISB focuses on the institutional controls and safety requirements identified in DOE Order 5480.23, Nuclear Safety Analysis Reports.

  6. Hanford Generic Interim Safety Basis

    International Nuclear Information System (INIS)

    Lavender, J.C.

    1994-01-01

    The purpose of this document is to identify WHC programs and requirements that are an integral part of the authorization basis for nuclear facilities that are generic to all WHC-managed facilities. The purpose of these programs is to implement the DOE Orders, as WHC becomes contractually obligated to implement them. The Hanford Generic ISB focuses on the institutional controls and safety requirements identified in DOE Order 5480.23, Nuclear Safety Analysis Reports

  7. Reliability of some ageing nuclear power plant system: a simple stochastic model

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Antola, Roberto [Catholic University of Uruguay, Montevideo (Uruguay). School of Engineering and Technologies; Ministerio de Industria, Energia y Mineria, Montevideo (Uruguay). Direccion Nacional de Energia y Tecnologia Nuclear; E-mail: rsuarez@ucu.edu.uy

    2007-07-01

    The random number of failure-related events in certain repairable ageing systems, like certain nuclear power plant components, during a given time interval, may be often modelled by a compound Poisson distribution. One of these is the Polya-Aeppli distribution. The derivation of a stationary Polya-Aeppli distribution as a limiting distribution of rare events for stationary Bernouilli trials with first order Markov dependence is considered. But if the parameters of the Polya-Aeppli distribution are suitable time functions, we could expect that the resulting distribution would allow us to take into account the distribution of failure-related events in an ageing system. Assuming that a critical number of damages produce an emergent failure, the above mentioned results can be applied in a reliability analysis. It is natural to ask under what conditions a Polya-Aeppli distribution could be a limiting distribution for non-homogeneous Bernouilli trials with first order Markov dependence. In this paper this problem is analyzed and possible applications of the obtained results to ageing or deteriorating nuclear power plant components are considered. The two traditional ways of modelling repairable systems in reliability theory: the 'as bad as old' concept, that assumes that the replaced component is exactly under the same conditions as was the aged component before failure, and the 'as good as new' concept, that assumes that the new component is under the same conditions of the replaced component when it was new, are briefly discussed in relation with the findings of the present work. (author)

  8. Frequency Domain Reflectometry NDE for Aging Cables in Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Samuel W.; Jones, Anthony M.; Fifield, Leonard S.; Hartman, Trenton S.

    2017-02-16

    Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to

  9. Regulation of Aging Power Plants: Ensuring Safety in a Changing Environment

    International Nuclear Information System (INIS)

    Jackson, S.A.

    1999-01-01

    In her keynote address to the Plim and Plex 1997 Conference, Dr. Jackson, President of the US Nuclear Regulatory Commission, dealt with four problem areas: (i) the development and application of safety margins; (ii) aging mechanisms and the use of inspection and testing methods; (iii) the U. S. licence renewal process; and (iv) risk-informed, performance-based regulation. Aging effects can further complicate existing interactions between 'explicit' and 'implicit' safety margins. Attempting to satisfy these combined margins can have a significant technical and financial impact on the plant operator. Aging degradation affects a broad range of plant systems, structures and components. Inspection and testing methods are improved continually, but development of methods for direct measuring of material properties on a more microscopic level together with elaboration of more precise predictive models of aging is still needed. In the U. S., the decision on whether to seek licence renewal rests with the licensee. The NRC task is to establish a reasonable process and clear safety standards. License renewal (extension of a NPP 40-years operating licence for additional 20 years) is explicitly allowed in NRS regulations in 10 CFR Part 54. In the U. S. nuclear power industry, there is considerable interest in licence renewal. A 'risk informed' approach to regulation means that, in the decision-making, the risk information is considered along with other factors. Performance-based regulation is, by definition, results focused; its essential component is the feedback of operating experience into subsequent evaluation. When the results focus is linked to risk analysis and ranking, the result is risk-informed, performance-based regulation. The NRS applies this combined approach in all its activities and, also, in its collaborative programs with the nuclear power industry. At the threshold of the 21st century, the nuclear power industry faces an array of challenges and opportunities

  10. Consumer choice between common generic and brand medicines in a country with a small generic market.

    Science.gov (United States)

    Fraeyman, Jessica; Peeters, Lies; Van Hal, Guido; Beutels, Philippe; De Meyer, Guido R Y; De Loof, Hans

    2015-04-01

    Generic medicines offer an opportunity for governments to contain pharmaceutical expenditures, since generics are generally 10%-80% lower in price than brand medicines. Belgium has a small generic market that takes up 15% of the total pharmaceutical market in packages sold. To determine the knowledge of consumers about the different available packages of a common over-the-counter medicine (acetaminophen) with regard to price advantage, quality, and effectiveness in a country with a small generic market. We conducted an online survey in the general Flemish population using a questionnaire with 25 statements. The questionnaire also contained 2 informative interventions. First, we showed the price per package and per tablet that the patient would pay in the pharmacy. Second, we provided the respondent with general information about generic medication (equivalence, effectiveness, price, and recognition). Before and after the interventions, we probed for preferences and knowledge about the different packages. Multivariate logistic models were used to examine the independent effects of consumer characteristics on responses to the survey statements. We obtained a sample of 1,636 respondents. The general attitude towards generic medication was positive-only 5% would rather not use a generic. Nevertheless, only 17% of the respondents were able to recognize a generic medicine. Older consumers (aged 60 years and above) were more often confused about the different packages (OR = 2.59, 95% CI = 1.76-3.80, P ≤ 0.001). Consumers without a higher education degree tended to be more doubtful about the difference in effectiveness and quality between the different brands (OR = 0.59, 95% CI = 0.44-0.79, P ≤ 0.001). Consumer recognition of the name of the active substance of acetaminophen was poor. When different brands were displayed, possible price advantage seemed to be an important motive to switch to a cheaper brand. Consumers generally found medicines

  11. Final environmental statement related to the proposed manufacture of floating nuclear power plants by Offshore Power Systems: (Docket No. STN 50-437): Part 2, A generic environmental statement considering the siting and operation of floating nuclear power plants

    International Nuclear Information System (INIS)

    1976-09-01

    The proposed action is the issuance of a manufacturing license to Offshore Power Systems for the startup and operation of a proposed manufacturing facility located at Blount Island, Jacksonville, Florida (Docket No. STN 50-437). No nuclear fuel will be handled or stored at the manufacturing site. The plants will be fueled after they have been towed to and moored within protected basins at specific locations designated by the purchaser and after an operating license has been issued by the Nuclear Regulatory Commission. Each nuclear generating plant, mounted on a floating platform, has a net capacity of 1150 MWe. This energy is provided by a pressurized water reactor steam supply system consisting of a Westinghouse four-loop 3425-MWt unit with an ice-condenser containment system. When one or more of these units is located within a single breakwater, the installation is designated an offshore power station. Volume 2 contains the siting criteria, regulations, effects of construction, effects of operation, and a safety analysis. 2 figs., 2 tabs

  12. Thermal ageing of steels; from expertise and understanding of the ageing mechanisms to a maintenance strategy for operating nuclear power plants

    International Nuclear Information System (INIS)

    Bezdikian, G.; Ould, P.

    2004-01-01

    Some parts of reactor coolant circuit on Nuclear PWR power plants, elbows on primary circuit, are made in cast duplex stainless steel material. It is now identify that the mechanical characteristic of this material should be decrease under thermal ageing mainly after a long time in operation in at reactor coolant circuit temperature conditions. The sensitiveness to the thermal ageing of these components is in relation with chemical composition and the ferrite content, especially the grade of Chromium equivalent (Ceq %Cr + %Si + %Mo). In the context of justification to maintain in operation on the plants these cat duplex components, an important programme of expertises was carried out on cast elbows after removing on the plants during the Steam Generators replacements (SGR). Several expertises, performed in the objective to understand the thermal ageing phenomenon and mechanism on cast components in service on plants, were permit to validate the prediction formulas established from a large database and programme in laboratories. The expertises were based on a lot of metallurgical, mechanical and chemical characteristics of components in operation Small Angle Neutrons Scattering (SANS), Thermal Electric Power (TEP), micro hardness and toughness measurement on small specimens from boat sample (CT10-5) The expertise carried out on one SG inlet elbows from DAMPIERRE, removed a during SGR after 100000 h in operation is shown, the toughness values are very high compared to the prediction formulas. The TEP measurements performed on the specimen cut off on two elbows and the ingots of the same material aged in laboratory in furnace, are very coherent; it is confirmed that this methodology is a good indicator to follow the ageing characteristic of material. The results of expertises on aged material are a mean of validation of the methodology applied on the file of demonstration of maintaining in operation of cast duplex stainless steel sensitive to thermal ageing. So the

  13. Differences in rates of switchbacks after switching from branded to authorized generic and branded to generic drug products: cohort study

    Science.gov (United States)

    Sarpatwari, Ameet; Dejene, Sara; Khan, Nazleen F; Lii, Joyce; Rogers, James R; Dutcher, Sarah K; Raofi, Saeid; Bohn, Justin; Connolly, John; Fischer, Michael A; Kesselheim, Aaron S; Gagne, Joshua J

    2018-01-01

    Abstract Objectives To compare rates of switchbacks to branded drug products for patients switched from branded to authorized generic drug products, which have the same active ingredients, appearance, and excipients as the branded product, with patients switched from branded to generic drug products, which have the same active ingredients as the branded product but may differ in appearance and excipients. Design Observational cohort study. Setting Private (a large commercial health plan) and public (Medicaid) insurance programs in the US. Participants Beneficiaries of a large US commercial health insurer between 2004 and 2013 (primary cohort) and Medicaid beneficiaries between 2000 and 2010 (replication cohort). Main outcome measures Patients taking branded products for one of the study drugs (alendronate tablets, amlodipine tablets, amlodipine-benazepril capsules, calcitonin salmon nasal spray, escitalopram tablets, glipizide extended release tablets, quinapril tablets, and sertraline tablets) were identified when they switched to an authorized generic or a generic drug product after the date of market entry of generic drug products. These patients were followed for switchbacks to the branded drug product in the year after their switch to an authorized generic or a generic drug product. Cox proportional hazard models were used to estimate hazard ratios and 95% confidence intervals after adjusting for demographics, including age, sex, and calendar year. Inverse variance meta-analysis was used to pool adjusted hazard ratios across all drug products. Results A total of 94 909 patients switched from branded to authorized generic drug products and 116 017 patients switched from branded to generic drug products and contributed to the switchback analysis. Unadjusted incidence rates of switchback varied across drug products, ranging from a low of 3.8 per 100 person years (for alendronate tablets) to a high of 17.8 per 100 person years (for amlodipine

  14. Size, age and composition: characteristics of plant taxa as diversity predictors of gall-midges (Diptera: Cecidomyiidae

    Directory of Open Access Journals (Sweden)

    Walter S Araújo

    2011-12-01

    Full Text Available Many hypotheses have been proposed to explain the diversity of gall-midge insects (Diptera: Cecidomyiidae, some of them taking into account plant diversity. This study aims to test the importance of size, age and composition of host plant taxa in the diversity of Cecidomyiidae. For this we used inventories data on the diversity of galling and host plants in Brazil. We found that Asterales, Myrtales and Malpighiales, were the most important orders, with 34, 33 and 25, gall morphotypes, respectively. The most representative host families were Asteraceae (34 morphotypes, Myrtaceae (23 and Fabaceae (22. In general, the order size and the plant family were good predictors of the galling diversity, but not the taxon age. The most diverse host genera for gall-midges were Mikania, Eugenia and Styrax, with 15, 13 and nine galler species, respectively. The size of plant genera showed no significant relationship with the richness of Cecidomyiidae, contrary to the prediction of the plant taxon size hypothesis. The plant genera with the greatest diversity of galling insects are not necessarily those with the greatest number of species. These results indicate that some plant taxa have a high intrinsic richness of galling insects, suggesting that the plant species composition may be equally or more important for the diversity of gall-midges than the size or age of the host taxon. Rev. Biol. Trop. 59 (4: 1599- 1607. Epub 2011 December 01.

  15. Assessment and management of aging of nuclear power plant safety-related structures

    International Nuclear Information System (INIS)

    Naus, D.J.; Graves, H.L. III; Ellingwood, B.R.

    2003-01-01

    Background information and data have been developed for improving existing and developing new methods to assist in quantifying the effects of age-related degradation on the performance of nuclear power plant (NPP) safety-related structures. Factors that can lead to age-related degradation of safety-related structures are identified and their manifestations described. Current regulatory testing and inspection requirements are reviewed and a summary of degradation experience presented. Techniques commonly used to inspect NPP concrete structures to assess and quantify age-related degradation are summarized. An approach for conduct of condition assessments of structures in NPPs is presented. Criteria, based primarily on visual indications, are provided for use in classification and assessment of concrete degradation. Materials and techniques for repair of degraded structures are noted and guidance provided on repair options available for various forms of degradation. A probabilistic methodology for condition assessment and reliability-based life prediction has been developed and applied to structures subject to combinations of structural load processes and to structural systems. The methodology has also been used to investigate optimization of in-service inspection and maintenance strategies to maintain failure probability below a specified target value as well as to minimize costs. Fragility assessments involving analytical solutions and finite-element methods have been utilized to predict the effect of aging degradation on structural component performance. (author)

  16. Development of an investment decision tool for aged nuclear power plants under uncertainty

    International Nuclear Information System (INIS)

    Takashima, Ryuta; Nagano, Koji

    2010-01-01

    The nuclear power generating stock in Japan, which provides 30% or more of the nationwide electricity supply in recent years, is heading into the era of plant aging as those units over 40 years of operation emerge in 2010 and onward. Under accumulating uncertainties surrounding investment decisions, one of the key questions is how best to manage the existing capacity by choosing a wisest option among dismantling, refurbishment, and replacement. This report attempts to develop a methodology to analyze investment decision on aged nuclear units based on real-option analysis, and then presents illustrative simulation runs to demonstrate functions of the numerical models. Major findings are summarized as follows: a) When compared with the conventional net present value (NPV) method, the proposed model is capable to deal with uncertainty explicitly by taking volatility in the formula. Also, for the replacement option, one can choose optimal timings of the dismantling the new plant independently. b) As the profitability increases, the model suggests different investment option as optimal, starting from dismantling to replacement, further to refurbishment, and again to replacement as the most basic pattern. Additionally, where two of the strategies have similar values, postponement of both decisions can be optimal. Through these exercises, the proposed methodology proved itself capable for raising valuable implications to investment decisions in managing the production fleet. (author)

  17. Proactive pressure relief system management of life cycle and ageing in nuclear power plants

    International Nuclear Information System (INIS)

    Kolenc, J.; Ferrar, S.

    2011-01-01

    The last major power nuclear station built in North America was built when the Altair Company introduced the first microcomputer sparking the PC frenzy. It is safe to assume that there have been a great many changes since 1977 on both accounts. As the world's aging nuclear plants continue to be challenged with maintenance and replacement issues (obsolescence), as well making improvements within their facilities, proper pressure relief system management looms as a growing concern. This problem grows more acute as new engineering best practices are promulgated across industries and regulatory standards become more rigorous with much stricter enforcements. Unlike most pieces of operating equipment in a nuclear facility, pressure relief devices demand an extra level of consideration; as they form the 'last line of defense'. Combine the on-going obsolescence issue, with today's ever increasing demands for overall plant and public safety; pressure relief safety management will require increasing 'proactive' efforts to ensure safe facilities. This paper has been written to address some global pressure relief system management issues with respect the worlds aging nuclear facilities. This paper reflects findings we have discovered while conducting engineering pressure relief system audits on various nuclear power stations. It should be noted that these finding are not atypical of similar findings in pressure relief systems in the hydrocarbon processing world. (author)

  18. Liming and plant aging influence on micronutrient uptake by Brachiaria decumbens forage

    International Nuclear Information System (INIS)

    Armelin, Maria Jose A.; Saiki, Mitiko; Primavesi, Odo; Primavesi, Ana C.

    2007-01-01

    Brachiaria decumbens is the main forage in pastures of several Brazilian regions. The effects of liming and plant age on micronutrient uptake by the forage of a degraded Brachiaria decumbens pasture under restoration process, were studied in Sao Carlos - SP, southeastern Brazil, under altitude tropical climate. Experimental design was a random block (100 m 2 ), with 6 replications and 3 treatments. Each block received the following treatment: 0 t/ha of limestone with NK; 2 t/ha of limestone applied on soil surface with NK and maintenance of 1 t/ha per annum; 8 t/ha of limestone applied once on soil surface with NK. Forage samples were collected 14 cm above soil surface, each 36 days in the rain season. Instrumental neutron activation analysis (INAA) followed by gamma-ray spectrometry was the analytical method used to determine the micronutrient content. In some cases, Co Fe, Mn and Zn were negatively affected by increasing limestone doses. The opposite effect was observed for Cl. Decreases of Cl, Co and Mo uptake in forage were enhanced with plant aging. (author)

  19. COMSY- A Software Tool For Aging And Plant Life Management With An Integrated Documentation Tool

    International Nuclear Information System (INIS)

    Baier, Roman; Zander, Andre

    2008-01-01

    For the aging and plant life management the integrity of the mechanical components and structures is one of the key objectives. In order to ensure this integrity it is essential to implement a comprehensive aging management. This should be applied to all safety relevant mechanical systems or components, civil structures, electrical systems as well as instrumentation and control (I and C). The following aspects should be covered: - Identification and assessment of relevant degradation mechanisms; - Verification and evaluation of the quality status of all safety relevant systems, structures and components (SSC's); - Verification and modernization of I and C and electrical systems; - Reliable and up-to-date documentation. For the support of this issue AREVA NP GmbH has developed the computer program COMSY, which utilizes more than 30 years of experience resulting from research activities and operational experience. The program provides the option to perform a plant-wide screening for identifying system areas, which are sensitive to specific degradation mechanisms. Another object is the administration and evaluation of NDE measurements from different techniques. An integrated documentation tool makes the document management and maintenance fast, reliable and independent from staff service. (authors)

  20. Patients' concern about their medicine after a generic switch

    DEFF Research Database (Denmark)

    Østergaard Rathe, Jette; Søndergaard, Jens; Jarbøl, Dorte E

    2014-01-01

    PURPOSE: This study aims to investigate the possible association between patients' concerns about their medicine and generic switch. METHODS: Cross-sectional survey was carried out comprising responses from 2217 randomly selected persons aged 20 years or older and living in the Region of Southern...... Denmark, who had redeemed generically substitutable drugs in September 2008. For each patient, we focused on the purchase of one generically substitutable drug (index drug). We applied the specific concerns subscale from the Beliefs about Medicine Questionnaire (BMQ) to analyse lack of confidence....... RESULTS: No statistically significant associations were found between concerns about the index medicine and the generic switch (-0.02 95% CI: -0.10; 0.05). Viewing medicines as harmful in general was associated with increased concerns (BMQ general harm: 0.39 95% CI: 0.30; 0.47 and BMQ general overuse: 0...

  1. A generic Approach for Reliability Predictions considering non-uniformly Deterioration Behaviour

    International Nuclear Information System (INIS)

    Krause, Jakob; Kabitzsch, Klaus

    2012-01-01

    Predictive maintenance offers the possibility to prognosticate the remaining time until a maintenance action of a machine has to be scheduled. Unfortunately, current predictive maintenance solutions are only suitable for very specific use cases like reliability predictions based on vibration monitoring. Furthermore, they do not consider the fact that machines may deteriorate non-uniformly, depending on external influences (e.g., the work piece material in a milling machine or the changing fruit acid concentration in a bottling plant). In this paper two concepts for a generic predictive maintenance solution which also considers non-uniformly aging behaviour are introduced. The first concept is based on system models representing the health state of a technical system. As these models are usually statically (viz. without a timely dimension) their coefficients are determined periodically and the resulting time series is used as aging indicator. The second concept focuses on external influences (contexts) which change the behaviour of the previous mentioned aging indicators in order to increase the accuracy of reliability predictions. Therefore, context-depended time series models are determined and used to predict machine reliability. Both concepts were evaluated on data of an air ventilation system. Thereby, it could be shown that they are suitable to determine aging indicators in a generic way and to incorporate external influences in the reliability prediction. Through this, the quality of reliability predictions can be significantly increased. In reality this leads to a more accurate scheduling of maintenance actions. Furthermore, the generic character of the solutions makes the concepts suitable for a wide range of aging processes.

  2. Bulk Electrical Cable Non-Destructive Examination Methods for Nuclear Power Plant Cable Aging Management Programs

    Energy Technology Data Exchange (ETDEWEB)

    Glass, Samuel W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jones, Anthony M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fifield, Leonard S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hartman, Trenton S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-09-01

    This Pacific Northwest National Laboratory milestone report describes progress to date on the investigation of nondestructive test methods focusing particularly on bulk electrical test methods that provide key indicators of cable aging and damage. The work includes a review of relevant literature as well as hands-on experimental verification of inspection capabilities. As nuclear power plants consider applying for second, or subsequent, license renewal to extend their operating period from 60 years to 80 years, it is important to understand how the materials installed in plant systems and components will age during that time and develop aging management programs to assure continued safe operation under normal and design basis events (DBE). Normal component and system tests typically confirm the cables can perform their normal operational function. The focus of the cable test program, however, is directed toward the more demanding challenge of assuring the cable function under accident or DBE. The industry has adopted 50% elongation at break (EAB) relative to the un-aged cable condition as the acceptability standard. All tests are benchmarked against the cable EAB test. EAB, however, is a destructive test so the test programs must apply an array of other nondestructive examination (NDE) tests to assure or infer the overall set of cable’s system integrity. Assessment of cable integrity is further complicated in many cases by vendor’s use of dissimilar material for jacket and insulation. Frequently the jacket will degrade more rapidly than the underlying insulation. Although this can serve as an early alert to cable damage, direct test of the cable insulation without violating the protective jacket becomes problematic. This report addresses the range of bulk electrical NDE cable tests that are or could be practically implemented in a field-test situation with a particular focus on frequency domain reflectometry (FDR). The FDR test method offers numerous advantages

  3. Assessment and management of ageing of major nuclear power plant components important to safety: PWR vessel internals

    International Nuclear Information System (INIS)

    1999-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness-for-service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. The guidance reports are directed at technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific plant

  4. Generic Example Proving Criteria for All

    Science.gov (United States)

    Yopp, David; Ely, Rob; Johnson­-Leung, Jennifer

    2015-01-01

    We review literature that discusses generic example proving and highlight ambiguities that pervade our research community's discourse about generic example arguments. We distinguish between pedagogical advice for choosing good examples that can serve as generic examples when teaching and advice for developing generic example arguments. We provide…

  5. Generic penetration in the retail antidepressant market.

    Science.gov (United States)

    Ventimiglia, Jeffrey; Kalali, Amir H

    2010-06-01

    In this article, we explore the accelerated penetration of generic antidepressants in the United States market following the availability of generic citalopram and sertraline. Analysis suggests that overall, generic penetration into the antidepressant market has grown from approximately 41 percent in January 2004 to over 73 percent in January 2010. Similar trends are uncovered when branded and generic prescriptions are analyzed by specialty.

  6. Towards a generic user support system (GUS)

    International Nuclear Information System (INIS)

    Garland, W.J.; Wilson, R.J.

    1993-01-01

    One relevant issue confronting the operator of a nuclear power plant is information and task overload. The goal, then, of the various developers is to improve the current situations by creating an environment where the operator can perform at optimum capacity. This is to be accomplished by providing tools and techniques which reduce operator involvement in low level tasks (freeing up time for higher level cognitive tasks) and assist in information and knowledge manipulation so that high level tasks can be performed more efficiently. This paper reviews the operational environment of nuclear plants from the viewpoint of engineering design and from the viewpoint of the operators and technical support staff. Principles are advanced for a generic operator companion. These design principles are being applied to a test case: the Point Lepreau NGS secondary side central sampling system. 6 refs., 6 figs

  7. NuPEER Dijon 2005 Symposium. Ageing issues in nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Emond, David (ed.) [BCCN, Autorite de Surete Nucleaire, ASN, 6, place du Colonel Bourgoin, 75572 Paris Cedex 12 (France)

    2005-07-01

    The French Nuclear Safety Authority (ASN) organized an international symposium on regulatory aspects of ageing issues for nuclear pressure equipment. The ageing of nuclear pressure equipment is an issue of growing importance for nuclear regulators and material experts worldwide as age-related degradation of major pressure-retaining components challenges the remaining operating life of nuclear power plants. This symposium aimed at providing a forum for technical exchange among the staffs responsible for nuclear pressure equipment within the safety authorities and the associated expertise organisations. The contents of the symposium is as follows: 1. Control and supervision of safety of nuclear pressure equipment in France and abroad; 1.1. Position of the French Nuclear Safety Authority (1 paper); 1.2. Regulatory practices worldwide (4 papers); 1.3. Licence renewal: Field experience (2 papers); 1.4. Role of international organisations (1 paper); 2. Management of equipment and materials: From design to degradation mechanisms; 2.1. Operation and equipment (4 papers); 2. Evolution of materials (4 papers); 2.3. Fatigue degradation mechanisms (3 papers); 2.4. Contribution of research and development (4 papers); 3. In-service inspection: Evolutions, methods and strategies; 3.1. Methods and evolution (1 paper); 3.2. Qualification of methods (2 papers); 3.3. Surveillance strategies (2 papers); 4. Testimonies and points of view of utilities (3 papers); 5. Ageing issues taken into account in non nuclear fields (2 papers). The symposium began with workshops devoted to: Operation and equipment; Behaviour of materials; Fatigue degradations; Contributions of research and development. The symposium continued with plenary session that addressed the following issues: Control and supervision of safety of nuclear pressure equipment; Role of international organisations; In-service inspection: Objectives, methods and strategies; Point of view of utilities; Technical summary and

  8. Generic safety insights for inspection of boiling water reactors

    International Nuclear Information System (INIS)

    Higgins, J.C.; Taylor, J.H.; Fresco, A.N.; Hillman, B.M.

    1987-01-01

    As the number of operating nuclear power plants (NPP) increases, safety inspection has increased in importance. However, precisely what is important, and what is not important? What should one focus inspection efforts on. Over the last two years Probabilistic Risk Assessment (PR) techniques have been developed to aid in the inspection process. Broad interest in generic PRA-based methods has arisen in the past year, since only about 25% of the US nuclear power plants have completed PRAs, and also, inspectors want PRA-based tools for these plants. This paper describes the BNL program to develop generic BWR PRA-based inspection insights or inspection guidance designed to be applied to plants without PRAs

  9. PWSCC issues and material aging management for nuclear power plants in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seong Sik; Lim, Yun Soo; Kim, Dong Jin; Kim, Sung Woo; Kim, Hong Pyo [Nuclear Materials Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The primary water stress corrosion cracking (PWSCC) of alloy 600 in a PWR has been reported in the control rod drive mechanism (CRDM). Beginning in the mid-seventies, the pressurized water reactor (PWR) plants suffered from a sequence of SCC events mostly confined to S/G tubes, initially ODSCC, and then PWSCC. PWSCC was first reported in Bugey 3 vessel head penetration made of forged alloy 600 materials in September 1991. Other PWRs experienced cracking attributed to the PWSCC of the major primary side weld area made from alloy 182 at the end of the year 2000. Examples of dissimilar metal butt welds between the main austenitic stainless steel primary circuit piping and the outlet pressure vessel nozzles are the cracking of Ringhals 4, V. C. Summer and some J-groove welds of the CRDM of the RVH at Oconee 1. In addition to the Reactor Vessel Head (RVH), the PWSCC of alloy 182/82 has been reported at bottom mounted instrumentation (BMI) nozzle J-welds, steam generator(SG) J-weld drain nozzle, and SG tube sheet cladding. Two cases of boric acid precipitation were reported at the bottom head surface of a SG in Korea. Cracking was found in the cold leg drain nozzles made of alloy 600 in two units, hot side nozzles were fabricated with alloy 690 from the beginning. The cracking of steam generator tubings made of alloy 600 is another concern in Korea, because some plants still have alloy 600 HTMA tubings. The flow accelerated corrosion of secondary pipings is another type of corrosion problems, though it has not been treated as a severe problem in Korea. To properly manage the corrosion issues and seek out research items for maintaining the integrity of nuclear plants, the PRIMA-Net (Proactive Research and Innovative Material Aging Network) was organized in 2007. The research and development expert group consists of a National research laboratory (KAERI), regulatory body (KINS), utility (KHNP), engineering and design company (KEPCO EC), manufacturer (Doosan Heavy

  10. Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

    International Nuclear Information System (INIS)

    Gillen, K.T.; Clough, R.L.

    1991-06-01

    In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs

  11. Plant life extension and ageing mechanisms: an ANSALDO proposal for the application to Kozloduy NPPs

    International Nuclear Information System (INIS)

    Orlandi, S.; Macco, A.; Zanaboni, P.

    1999-01-01

    In the frame of extension of NPP's installations lifetime, ageing management has become a topical subject to obtain the items: - Evaluation of residual life of the plant through the investigation of the residual life of well identified Safety Related Equipment in the as built configuration; - Organization of identified representative equipment per typological Classes (as Piping Systems, Tanks, Valves, Pumps, Electrical Equipment, Pressurized Components) in order to define for each High Level Class a set of elementary families capable to have, within each family, a common ageing mechanism and methodological investigation and potential common on-line monitoring; Application of a consistent methodology for residual life evaluation at each High Level Class (and subsequent elementary family and group if any) in order to assess an integral approach to backfitting and ageing management, taking also into account the economical investment effort required to the utility. In this report, a technical proposal for the application of the ANSALDO standard methodology approach, applied to the re-evaluation of the Kozloduy NPP's (Unit 1 - to 4) is presented. (authors)

  12. The Relationship between Insect Resistance and Tree Age of Transgenic Triploid Populus tomentosa Plants.

    Science.gov (United States)

    Ren, Yachao; Zhang, Jun; Wang, Guiying; Liu, Xiaojie; Li, Li; Wang, Jinmao; Yang, Minsheng

    2018-01-01

    To explore the stability of insect resistance during the development of transgenic insect-resistant trees, this study investigated how insect resistance changes as transgenic trees age. We selected 19 transgenic insect-resistant triploid Populus tomentosa lines as plant material. The presence of exogenous genes and Cry1Ac protein expression were verified using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) analyses. The toxicity for Clostera anachoreta and Lymantria dispar was evaluated by feeding fresh leaves to first instar larvae after the trees were planted in the field for 2 years and after the sixth year. Results of PCR showed that the exogenous genes had a long-term presence in the poplar genome. ELISA analyses showed significant differences existed on the 6-year-old transgenic lines. The insect-feeding experiment demonstrated significant differences in the mortality rates of C. anachoreta and L. dispar among different transgenic lines. The average corrected mortality rates of C. anachoreta and L. dispar ranged from 5.6-98.7% to 35.4-7.2% respectively. The larval mortality rates differed significantly between the lines at different ages. Up to 52.6% of 1-year-old transgenic lines and 42.1% of 2-year-old transgenic lines caused C. anachoreta larval mortality rates to exceed 80%, whereas only 26.3% of the 6-year-old transgenic lines. The mortality rates of L. dispar exhibited the same trend: 89.5% of 1-year-old transgenic lines and 84.2% of 2-year-old transgenic lines caused L. dispar larval mortality rates to exceed 80%; this number decreased to 63.2% for the 6-year-old plants. The proportion of 6-year-old trees with over 80% larval mortality rates was clearly lower than that of the younger trees. The death distribution of C. anachoreta in different developmental stages also showed the larvae that fed on the leaves of 1-year-old trees were killed mostly during L 1 and L 2 stages, whereas the proportion of larvae that died in L 3

  13. Radiocarbon ages of insects and plants frozen in the No. 31 Glacier, Suntar-Khayata Range, eastern Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Nakazawa, F., E-mail: nakazawa@nipr.ac.jp [National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518 (Japan); Transdisciplinary Research Integration Center, Hulic Kamiyacho Bldg. 2F, 4-3-13 Toranomon, Minato-ku, Tokyo 105-0001 (Japan); Uchida, M.; Kondo, M. [Center for Environmental Measurement and Analysis, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-0053 (Japan); Kadota, T. [Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka 237-0061 (Japan); Shirakawa, T. [Kitami Institute of Technology, Kitami, Hokkaido 090-8507 (Japan); Enomoto, H. [National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518 (Japan); Department of Polar Science, The Graduate University for Advanced Studies (SOKENDAI), 10-3 Midori-cho, Tachikawa, Tokyo 190-8518 (Japan); Fedorov, A.N. [Melnikov Permafrost Institute, SB RAN, Yakutsk 6770110 (Russian Federation); North-Eastern Federal University, Yakutsk 677010 (Russian Federation); Fujisawa, Y. [Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Konstantinov, P.Y. [Melnikov Permafrost Institute, SB RAN, Yakutsk 6770110 (Russian Federation); Kusaka, R. [Kitami Institute of Technology, Kitami, Hokkaido 090-8507 (Japan); Miyairi, M. [Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Ohata, T.; Yabuki, H. [Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka 237-0061 (Japan)

    2015-10-15

    The aim of this study was to estimate the age of glacier ice in the No. 31 Glacier in the Suntar-Khayata Range of eastern Siberia by performing dating of insects thought to be long-legged fly species (Dolichopodidae) as well as plants (species unknown) fragments preserved in the ice. Ice samples containing organisms were collected at depths of 0.4–1.1 m at five points from the middle to lowest parts of the glacier in 2013. The age of an insect collected at the lowest point on the glacier was estimated as 2038 ± 32 yr B.P. Insects collected at higher points had a modern or near-modern radiocarbon age. The age of plant fragments collected at the uppermost and middle points was 1531 ± 44 and 1288 ± 26 yr B.P., respectively, and that of a mixture of plant and insect fragments collected at the lowest point was 9772 ± 42 yr B.P. When comparing specimens collected at the same point, the plant fragments were found to be older than the insects. In 2012–2014 observations, some living insects were found on the glacier, and thus the age of the insects appears to correspond to the age of the ice. On the other hand, the plant fragments might have already aged since detachment from the source plants. This study found an approximately 2000-year gap in the age of the ice between the lowest and higher points. Annual mass balance observations from 2012 to 2014 showed that in recent years, the glacier sometimes had no accumulation area. Therefore, the wide gap in the age of ice may be due to a difference in past melting processes between the lowest and higher points on the glacier.

  14. Age-dependent risk-based methodology and its application to prioritization of nuclear power plant components and to maintenance for managing aging using PRAs

    International Nuclear Information System (INIS)

    Levy, I.S.; Vesely, W.E.

    1990-01-01

    This paper is based on a study to demonstrate several important ways that the age-dependent risk-based methodology developed by the Nuclear Plant Aging Research (NPAR) Program may be applied to resolving important issues related to the aging of nuclear power plant systems, structures, and components (SSCs). The study was sponsored by the NPAR Program of the Division of Engineering, Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission (NRC). Initiated on the basis of a Users Need Request, the age-dependent risk-based methodology has been under development by the NPAR Program for several years. In this methodology, the time-dependent change in a component's risk contribution is the product of two factors: (1) the risk importance of the component (e.g., the change in its risk contribution when it is assumed to be totally unavailable to perform its intended safety function) and (2) the change in its unavailability with time. This change in the component's unavailability with time is a function of the component's aging rate and plant inspection and maintenance practices. The methodology permits evaluations of the age-dependent risk contributions from both single- and multiple-components. Principal results and conclusions generated by the methodology demonstrations are discussed

  15. Assessment and management of ageing of major nuclear power plant components important to safety: Concrete containment buildings

    International Nuclear Information System (INIS)

    1998-06-01

    The report presents the results of the Co-ordinated Research Programme (CRP) on the Management of Ageing of Concrete Containment Buildings (CCBs) addressing current practices and techniques for assessing fitness-for-service and the inspection, monitoring and mitigation of ageing degradation of selected components of CANDU reactor, BWR reactor, PWR reactor and WWER plants. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age-related licensing issues

  16. Aging assessment of reactor instrumentation and protection system components, Phase 1

    International Nuclear Information System (INIS)

    Gehl, A.C.; Hagen, E.W.; Farmer, W.S.

    1992-01-01

    A study of the aging-related operating experiences throughout a five year period (1984--1988) of six generic instrumentation modules (indicators, sensors, controllers, transmitters, annunciators, and recorders) was performed as a part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The effects of aging from operational and environmental stressors were characterized from results depicted in Licensee Event Reports (LERs). The data are graphically displayed as frequency of events per plant year for operating plant ages from 1 to 28 years to determine aging-related failure trend patterns. This document describes the results and conclusions from this study

  17. Development of inspection technology for inner wall pipe of aging nuclear power plant

    International Nuclear Information System (INIS)

    Ito, Fuyumi; Nishimura, Akihiko

    2013-01-01

    Careful inspection should be paid on aging nuclear power plants. Due to the Fukushima BWR accident, more advanced inspection techniques are now requested in Japan. To find SCC along welded sections by Ultrasonic Testing or Eddy Current Testing is difficult due to the low S/N. Here we propose to apply Magnetic particle Testing (MT) on the inspection. MT uses magnetic particles uniting fluorescent pigment. It is a weak point of MT that uniting particles and pigment is breakable. To extend the lifetime, we developed unique capsule for the magnetic particle to coexist with fluorescent pigment. In addition, Laser-Induced Breakdown Spectroscopy (LIBS) used for the laser cleaning of materials, is reported in this paper as a preliminary experiment. The intensity of 621nm peak gradually decreases over time. This result will become a measure of the degree of oxide layer removal. (author)

  18. Accumulation of strontium and cesium by kale as a function of age of plant

    International Nuclear Information System (INIS)

    Weaver, C.M.; Harris, N.D.; Fox, L.R.

    1981-01-01

    The accumulation of Sr and Cs throughout the growth cycle of a hydroponically grown vegetable crop (Brassica oleracea var. acephala D.C. Blue Curl) was studied. The cumulative effect of supplying the radionuclides through the nutrient solution to kale throughout the growth cycle, simulating a continuous discharge, was compared to exposure at each stage of the growth cycle to a single dose of radioactivity, simulating an accidental release. The time course of accumulation of 137 Cs supplied continuously through the nutrient solution resembled the sigmoidal dry weight growth curve of the vegetable. Accumulation of this nuclide after exposure of kale to radioactivity for 48 hours at each stage of growth decreased with age of the plant. The time course of 90 Sr supplied continuously resembled the pattern of the periodic 48-hour accumulation for this radionuclide, although there was a 1- to 2-week lag period between the two uptake patterns

  19. Ageing of reinforced concrete pipes subjected to seawater in nuclear plants: optimization of maintenance operations

    International Nuclear Information System (INIS)

    Auge, L.; Capra, B.; Lasne, M.; Benefice, P.; Comby, R.

    2007-01-01

    Seaside nuclear power plants have to face the ageing of nuclear reactor cooling piping systems. In order to minimize the duration of the production unit shutdown, maintenance operations have to be planned well in advance. In a context where owners of infrastructures tend to extend the life span of their goods while having to keep the safety level maximum, it is more and more important to develop high level expertise and know-how in management of infrastructures life cycle. A patented monitoring technique based on optic fiber sensors, has been designed. This preventive maintenance enables the owner to determine criteria for network replacement based on degradation impacts. A methodology to evaluate and optimize operation budgets, depending on predictions of future functional deterioration and available maintenance solutions, has been developed and applied. (authors)

  20. Ageing nuclear plants inspection, maintenance and performance monitoring eased by Data Validation and Reconciliation (DVR) approach

    International Nuclear Information System (INIS)

    Quang, A. Tran; Chares, R.

    2012-01-01

    With the long term operation of nuclear power plants, decisions to replace or repair should be optimized from an economical, human resource and safety point of view. In that frame, the operation requires a continuous inspection and testing of systems in order to detect degradations and failures at an early stage. Nevertheless, in spite of the fact that such assiduous vigilance ensures safety, it is not optimized in terms of man power and maintenance costs. Preventive strategies show the same types of drawbacks. On top of that, these maintenance procedures rely on process measurements which accuracy, availability and reliability cannot always be ensured. The present paper introduces a new approach to the maintenance management of ageing installations and suggests a method that overcomes the actual drawbacks. The Reconciliation and Validation of data (DVR) is an advanced and innovative technology that relies on process data statistics, thermodynamic and on-site process knowledge. Benefits of real-time applications are also presented. (author)

  1. Retailing policies for generic medicines.

    Science.gov (United States)

    Narciso, Susana

    2005-06-01

    As there is general disagreement about the way generic medicines should be commercialized, two retailing policies are analyzed, taking into account their effects on the welfare of patients, government, pharmacies and physicians. In the first policy scenario, pharmacies are allowed to substitute generic medicines for branded ones, while in the second, substitution is forbidden. In both cases a pharmacies association is allowed to have a share in the production of generic medicines. The model predicts that under some conditions patients may prefer substitution by pharmacies but when doctors' decisions are binding, they are never "excessively bad". However, the policy choice belongs to the government, which prefers to allow for substitution more often than patients would like.

  2. Assessment of NDE for key indicators of aging cables in nuclear power plants - Interim status

    Science.gov (United States)

    Glass, S. W.; Ramuhalli, P.; Fifield, L. S.; Prowant, M. S.; Dib, G.; Tedeschi, J. R.; Suter, J. D.; Jones, A. M.; Good, M. S.; Pardini, A. F.; Hartman, T. S.

    2016-02-01

    Degradation of the cable jacket, electrical insulation, and other cable components of installed cables within nuclear power plants (NPPs) is known to occur as a function of age, temperature, radiation, and other environmental factors. System tests verify cable function under normal loads; however, the concern is over cable performance under exceptional loads associated with design-basis events (DBEs). The cable's ability to perform safely over the initial 40-year planned and licensed life has generally been demonstrated and there have been very few age-related cable failures. With greater than 1000 km of power, control, instrumentation, and other cables typically found in an NPP, replacing all the cables would be a severe cost burden. Justification for life extension to 60 and 80 years requires a cable aging management program to justify cable performance under normal operation as well as accident conditions. Currently the gold standard for determining cable insulation degradation is the elongation-at-break (EAB). This, however, is an ex-situ measurement and requires removal of a sample for laboratory investigation. A reliable nondestructive examination (NDE) in-situ approach is desirable to objectively determine the suitability of the cable for service. A variety of tests are available to assess various aspects of electrical and mechanical cable performance, but none of these tests are suitable for all cable configurations nor does any single test confirm all features of interest. Nevertheless, the complete collection of test possibilities offers a powerful range of tools to assure the integrity of critical cables. Licensees and regulators have settled on a practical program to justify continued operation based on condition monitoring of a lead sample set of cables where test data is tracked in a database and the required test data are continually adjusted based on plant and fleet-wide experience. As part of the Light Water Reactor Sustainability program sponsored

  3. Continuing the service of aging concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Arndt, E.G.

    1993-01-01

    Concrete structures play a vital role in the safe operation of all light-water reactor plants because they provide foundation, support, shielding and containment functions. History tells us that concrete is a durable material. However, a number of factors can compromise its performance, singly or in combination: (1) faulty design, (2) use of unsuitable materials, (3) improper workmanship, (4) exposure to aggressive environments, and (5) excessive structural loads. Furthermore, aging of nuclear power plant (NPP) concrete structures occurs with the passage of time and has the potential, if its effects are not controlled, to increase the risk to public health and safety. Although limited, incidences of degradation of concrete structures in NPPs indicate that there is a need for improved surveillance, inspection/testing, and maintenance to enhance the technical bases for assurance of continued safe operation of NPPs. Guidelines and criteria for use in evaluating the remaining structural margins (residual life) are required. Potential regulatory applications of this research include: improved predictions of long-term material and structural performance and available safety margins at future times; establishment of limits on exposure to environmental stressors; reduction in total reliance by licensing on inspection and surveillance through development of a methodology which will enable the integrity of structures to be assessed (either pre- or post-accident); and improvements in damage inspection methodology through potential incorporation of results into national standards which could be referenced by standard review plans

  4. HTGR generic technology program. Semiannual report ending March 31, 1980

    International Nuclear Information System (INIS)

    1980-05-01

    This document reports the technical accomplishments on the HTGR Generic Technology Program at General Atomic during the first half of FY-80. It covers a period when the design direction of the National HTGR Program is in the process of an overall review. The HTGR Generic Technology Program activities have continued so as to provide the basic technology required for all HTGR applications. The activities include the need to develop an MEU fuel and the need to qualify materials and components for the higher temperatures of the gas turbine and process heat plants

  5. Leveraging consumer's behaviour to promote generic drugs in Italy.

    Science.gov (United States)

    Zerbini, Cristina; Luceri, Beatrice; Vergura, Donata Tania

    2017-04-01

    The aim of this study was to fill the lack of knowledge regarding a more grounded exploration of the consumer's decision-making process in the context of generic drugs. In this perspective, a model, within the theoretical framework of the Theory of Planned Behaviour (TPB), for studying the consumers' purchase intention of generic drugs was developed. An online survey on 2,222 Italian people who bought drugs in the past was conducted. The proposed model was tested through structural equation modelling (SEM). Almost all the constructs considered in the model, except the perceived behavioural control, contribute to explain the consumer's purchase intention of generic drugs, after controlling for demographic variables (age, income, education). Specifically, attitude, subjective norm, past behaviour, self-identity and trust in the pharmacist have a positive influence on the intention to buy generic drugs. On the contrary, perceived risk towards products and brand sensitivity act negatively. The results of the present study could be useful to public policy makers in developing effective policies and educational campaigns aimed at promoting generic drugs. Specifically, marketing efforts should be directed to inform consumers about the generic drugs' characteristics to mitigate the perceived risk towards these products and to raise awareness during their decision-making process. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Assessment and management of ageing of major nuclear power plant components important to safety: CANDU reactor assemblies

    International Nuclear Information System (INIS)

    2001-02-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance, design or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wearout of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring, and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs) including the Soviet designed water moderated and water cooled energy reactors (WWERs), are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age-related licensing issues. Since the reports are written from a safety perspective, they do not address life or life-cycle management of the plant components, which

  7. Assessment and management of ageing of major nuclear power plant components important to safety: BWR pressure vessels

    International Nuclear Information System (INIS)

    2005-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (caused for instance by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and wear out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. Since the reports are written from a safety perspective, they do not address life or life cycle management of plant components, which involves economic considerations. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues

  8. Assessment and management of ageing of major nuclear power plant components important to safety. Primary piping in PWRs

    International Nuclear Information System (INIS)

    2003-07-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (caused for instance by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and wear out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. Since the reports are written from a safety perspective, they do not address life or life cycle management of plant components, which involves economic considerations. The current practices for the assessment of safety margins (fitness-for-service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and to provide a common technical basis for dialogue between plant operators and regulators when dealing with age-related licensing issues. The

  9. Generic Graph Grammar: A Simple Grammar for Generic Procedural Modelling

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Bærentzen, Jakob Andreas

    2012-01-01

    in a directed cyclic graph. Furthermore, the basic productions are chosen such that Generic Graph Grammar seamlessly combines the capabilities of L-systems to imitate biological growth (to model trees, animals, etc.) and those of split grammars to design structured objects (chairs, houses, etc.). This results...

  10. Experience in monitoring ageing phenomena for improving nuclear power plant availability. Proceedings of a specialists' meeting. Working material

    International Nuclear Information System (INIS)

    1992-01-01

    For more than thirty years nuclear power plants have been supplying electricity to national grids. Today, the nuclear power community is facing great challenges. The safe, reliable operation of existing nuclear power plants (NPPs) must continue to be ensured. From an economic viewpoint, because of the long lead times associated with bringing new plants into service, securing the continued operation of existing plants for their planned lifetimes and possible life extension will be very important in the near term for meeting electrical power demands. The IAEA programmes in nuclear power plant ageing and life extension and in control and instrumentation promote technical information exchange between Member States with new programmes, offers assistance to Member States with an interest in reliability of NPP components, in-service inspection methods and programmes using on-line techniques, component monitoring and special technological topics of nuclear reactors. Significant experience already exists in the nuclear industry in developing and applying the monitoring techniques for different nuclear power plant applications, especially in monitoring of ageing phenomena for improving NPP availability. The purpose of this Specialists' Meeting was to bring together experts from operations, design, research and development and licensing to share their experience in: ageing mechanics of key structural components, methods of monitoring such ageing, tools for cost-effective implementation of the methods and methodologies, life management approaches and examples from current reactors, future direction for monitoring of key structural components in nuclear power plants. The meeting was organized by the IAEA International Working Groups on Life Management of Nuclear Power Plants (IWG-LMNPP) and Nuclear Power Plant Control and Instrumentation (TWG-NPPCI) in co-operation with the Czechoslovak Atomic Energy Commission and Skoda concern. Around 40 participants from 10 countries

  11. Experience in monitoring ageing phenomena for improving nuclear power plant availability. Proceedings of a specialists' meeting. Working material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-07-01

    For more than thirty years nuclear power plants have been supplying electricity to national grids. Today, the nuclear power community is facing great challenges. The safe, reliable operation of existing nuclear power plants (NPPs) must continue to be ensured. From an economic viewpoint, because of the long lead times associated with bringing new plants into service, securing the continued operation of existing plants for their planned lifetimes and possible life extension will be very important in the near term for meeting electrical power demands. The IAEA programmes in nuclear power plant ageing and life extension and in control and instrumentation promote technical information exchange between Member States with new programmes, offers assistance to Member States with an interest in reliability of NPP components, in-service inspection methods and programmes using on-line techniques, component monitoring and special technological topics of nuclear reactors. Significant experience already exists in the nuclear industry in developing and applying the monitoring techniques for different nuclear power plant applications, especially in monitoring of ageing phenomena for improving NPP availability. The purpose of this Specialists' Meeting was to bring together experts from operations, design, research and development and licensing to share their experience in: ageing mechanics of key structural components, methods of monitoring such ageing, tools for cost-effective implementation of the methods and methodologies, life management approaches and examples from current reactors, future direction for monitoring of key structural components in nuclear power plants. The meeting was organized by the IAEA International Working Groups on Life Management of Nuclear Power Plants (IWG-LMNPP) and Nuclear Power Plant Control and Instrumentation (TWG-NPPCI) in co-operation with the Czechoslovak Atomic Energy Commission and Skoda concern. Around 40 participants from 10 countries.

  12. FHR Generic Design Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, George F [ORNL; Holcomb, David Eugene [ORNL; Cetiner, Sacit M [ORNL

    2012-06-01

    The purpose of this document is to provide an initial, focused reference to the safety characteristics of and a licensing approach for Fluoride-Salt-Cooled High-Temperature Reactors (FHRs). The document does not contain details of particular reactor designs nor does it attempt to identify or classify either design basis or beyond design basis accidents. Further, this document is an initial attempt by a small set of subject matter experts to document the safety and licensing characteristics of FHRs for a larger audience. The document is intended to help in setting the safety and licensing research, development, and demonstration path forward. Input from a wider audience, further technical developments, and additional study will be required to develop a consensus position on the safety and licensing characteristics of FHRs. This document begins with a brief overview of the attributes of FHRs and then a general description of their anticipated safety performance. Following this, an overview of the US nuclear power plant approval process is provided that includes both test and power reactors, as well as the role of safety standards in the approval process. The document next describes a General Design Criteria (GDC) - based approach to licensing an FHR and provides an initial draft set of FHR GDCs. The document concludes with a description of a path forward toward developing an FHR safety standard that can support both a test and power reactor licensing process.

  13. Standardization of a rearing procedure of Tetranychus urticae Koch (Acari: Tetranychidae) on bean (Phaseolus vulgaris): plant age and harvest time

    International Nuclear Information System (INIS)

    Bustos, Alexander; Cantor, Fernando; Cure, Jose R; Rodriguez, Daniel

    2009-01-01

    A rearing technique was standardized to produce Tetranychus urticae Koch on Phaseolus vulgaris (ICA Cerinza variety) as a prey of the predatory mite Phytoseiulus persimilis Athias-Henriot. Two assays were conducted to assess the following variables: the most suitable plant age for mite infestation, and the best time to harvest the mites and re infest the plants. In the first experiment, four, five, six, and seven-week-old plants of P. vulgaris were infested with six T. urticae per foliole. The lower plant stratum exhibited the largest number of mites regardless of plant age. However, four-week old plants had the larger average number of individuals. In the second experiment four-week-old plants were infested with 0.5 female mite/cm 2 of leaf. The number of individuals per instar of T. urticae was recorded weekly. The highest mite production occurred between four and five weeks after infestation, indicating this to be the most suitable for mite harvesting and for plant reinfestation. (author)

  14. Uptake of radionuclides by plants growing on Brazilian soil: the effect of soil ageing

    International Nuclear Information System (INIS)

    Wasserman, Maria A.; Rochedo, Elaine R.R.; Ferreira, Ana C.M.; Vidal Perez, Daniel

    2008-01-01

    The behaviour of radionuclides in soil is governed by several mechanisms that can vary significantly according to the specific reactivity of each element and soil properties. The 137 Cs is one of radionuclides that generally reduces with time its mobility and phytoavailability due to irreversible fixation in high activity clay mineral such as illite, vermiculite and montmorilonite. A long-term experimental essay using Brazilian soils was done in order to determine the effect of ageing of contamination on 137 Cs mobility in soils and transfer to plants. To perform this study, 4 different soils with different properties were contaminated with 137 Cs at different period: The older contamination refers to an urban soil contaminated at the Goiania accident (1987). A similar type of Goiania's soil (Ferralsol rich in Gibbsite) was artificially contaminated with 137 Cs in 1993. A subtropical class of soil (Nitisol) was contaminated in 1996 and two other tropical soils were contaminated in 2000 (Acrisol and Ferralsol rich in Goethite). The time's effect was studied by characterizing the evolution of soil properties and the changes in the distribution of radionuclides between phases till 2006. In addition, the phytoavailability was evaluated by carrying out experiments in lysimeters where radish was sowed at different periods:1996, 2000 and 2004. These results showed that the phytoavailability changed with time only in 2 situations: after changes in some soil properties such as pH or due to Cs fixation in high activity clay mineral when it was present in the soils even as trace mineral. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element in all type of soil and 14 years after contamination, the 137 Cs was still available for plants in the Ferralsol Gbbiste rich. In the Nitisol, 5 years after contamination, the 137 Cs was not detected as in the slightly acidic phase of sequential extraction neither detectable in radish roots or leaves

  15. Leaf-age and soil-plant relationships: key factors for reporting trace-elements hyperaccumulation by plants and design applications.

    Science.gov (United States)

    Losfeld, Guillaume; L'Huillier, Laurent; Fogliani, Bruno; Mc Coy, Stéphane; Grison, Claude; Jaffré, Tanguy

    2015-04-01

    Relationships between the trace-elements (TE) content of plants and associated soil have been widely investigated especially to understand the ecology of TE hyperaccumulating species to develop applications using TE phytoextraction. Many studies have focused on the possibility of quantifying the soil TE fraction available to plants, and used bioconcentration (BC) as a measure of the plants ability to absorb TE. However, BC only offers a static view of the dynamic phenomenon of TE accumulation. Accumulation kinetics are required to fully account for TE distributions in plants. They are also crucial to design applications where maximum TE concentrations in plant leaves are needed. This paper provides a review of studies of BC (i.e. soil-plant relationships) and leaf-age in relation to TE hyperaccumulation. The paper focuses of Ni and Mn accumulators and hyperaccumulators from New Caledonia who were previously overlooked until recent Ecocatalysis applications emerged for such species. Updated data on Mn hyperaccumulators and accumulators from New Caledonia are also presented and advocate further investigation of the hyperaccumulation of this element. Results show that leaf-age should be considered in the design of sample collection and allowed the reclassification of Grevillea meisneri known previously as a Mn accumulator to a Mn hyperaccumulator.

  16. Maintenance Management Support Systems for component aging estimation at nuclear power plants

    International Nuclear Information System (INIS)

    Shimizu, Shunichi; Ando, Yasumasa; Morioka, Toshihiko; Okuzumi, Naoaki

    1991-01-01

    Maintenance Management Support Systems (MMSSs) for nuclear power plants have been developed using component aging estimation methods and decision tree analysis for maintenance planning. The former evaluates actual component reliability through statistical analysis on field maintenance data. The latter provides preventive maintenance (PM) planning guidance using heuristic expert knowledge and estimated reliability parameters. The following aspects have been investigated: (1) A systematic and effective method of managing components/parts design information and field maintenance data (2) A method for estimating component aging based on a statistical analysis of field maintenance data (3) A method for providing PM planning guidance using estimated component reliability/performance parameters and decision tree analysis. Based on these investigations, two MMSSs were developed. One deals with 'general maintenance data', which are common to all component types and are amenable to common data handling. The other system deals with 'specific maintenance data', which are specific to an individual component type. Both systems provide PM planning guidance for PM cycles propriety and the PM work priority. The function of these systems were verified using simulated maintenance data. (author)

  17. Summary of nuclear plant aging research at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Eissenberg, D.M.

    1991-01-01

    Oak Ridge National Laboratory (ORNL) has been a major contributor to the Nuclear Regulatory Commission (NRC) Nuclear Plant Aging Research Program since its inception. The research at ORNL has consisted primarily of the preparation of comprehensive aging assessments and other studies of safety related and other components and systems. The components and systems have been identified and prioritized based on risk considerations, as well as by operating experience. In each case, ORNL has been preparing a Phase 1 assessment which summarizes design features, operating conditions, and stressors which lead to degradation and failure; identified parameters which could be used to detect, trend and differentiate the degradations; and proposed potential inspection, surveillance, and monitoring methods which could be applied to the parameters. Where appropriate, Phase 2 assessments have been prepared, which verify and recommend inspection, surveillance and monitoring methods based on vendor information, laboratory and field tests, and in-situ inspections and tests. Finally, Phase 3 assessments are prepared which provide recommendations regarding implementing the inspection, surveillance and monitoring methods, and provide recommendations regarding criteria to be applied. Other activities include providing assistance to NRC/Nuclear Regulatory Research and regional offices as requested, and participation in ASME and IEEE codes and standards

  18. Offsets in radiocarbon ages between plants and shells from same horizons of coastal sediments in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Toshimichi [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Hong, Wan, E-mail: whong@kigam.re.kr [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Sung, Ki Suk [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); Carbon Analysis Laboratory (CAL), 25, 114 Gil, Taejeon-ro, Dong-gu, Daejeon (Korea, Republic of); Sung, Kil Ho [Geologic Environment Division, Korea Institute of Geoscience & Mineral Resources, Gajeong-dong 30, Yuseong-gu, Daejeon (Korea, Republic of); University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon (Korea, Republic of); Nakashima, Rei [Institute of Geology & Geoinformation, Advanced Industrial Science & Technology, Higashi 1-1-1, Tsukuba, Ibaraki (Japan)

    2015-10-15

    To measure the spatial and chronological changes of the reservoir effect around the Korean Peninsula, the radiocarbon ages of 38 marine shell and terrestrial plant pairs from the same horizons of six cores of Holocene sediments collected from the southern coast and western coast sites of the peninsula were measured. These reservoir ages (R) were distributed in the range of 430 ± 190 yrs within 60 ± 60 to 1000 ± 60 yrs starting in 9000 cal BP. The average R values of the cores obtained from large rivers, such as the S13 and YAR-4 cores (340 and 190 yrs), were clearly smaller than the R values of the sites far from a large river, such as the S15 and W09 cores (470 and 650 yrs). This is thought to be associated with the mixing process of old brine and young freshwater. On the other hand, the R values of the S13, W17, and YAR-4 cores gradually increased during the time span from 6700 to 8200 cal BP. The R values for the S15 core also increased in the period from 2800 to 3800 cal BP. Such tendencies result from the mixing ratio increase of brine due to the rising sea level.

  19. Assessment and Management of Ageing of Major Nuclear Power Plant Components Important to Safety: Steam Generators. 2011 Update

    International Nuclear Information System (INIS)

    2011-11-01

    At present there are over four hundred forty operational nuclear power plants (NPPs) in IAEA Member States. Ageing degradation of the systems, structures of components during their operational life must be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This IAEA-TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuteriumuranium (CANDU) reactor, boiling water reactor (BWR), pressurized water reactor (PWR), and water moderated, water cooled energy reactor (WWER) plants are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. Since the reports are written from a safety perspective, they do not address life or life cycle management of the plant components, which involves the integration of ageing management and economic planning. The target audience of the reports consists of technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific plant components addressed in the reports. The component addressed in the present publication is the steam

  20. Plant life (PLIM) and ageing management (AM) in German NPPs. Prerequisite for long term operation (LTO)

    International Nuclear Information System (INIS)

    Schuler, X.

    2010-01-01

    The German nuclear power plants have implemented a comprehensive ageing management (AM) in recent years. Within AM the quality of safety relevant systems, structures and components (SSC) has to be assessed, regularly. Thus the safety margin can be verified (and demonstrated) at every stage of operation and if necessary it can be reacted in time. The effort of this assessment depends on the requirements regarding the SSC. Therefore, it was appropriate to introduce groups of SSCs related to these requirements. Three groups have been defined: - group 1: integrity of SSC in this group has to be guaranteed, pro-actively; - group 2: systematic failures have to be prevented (reactive approach); - group 3: failures are without consequences (reactive approach). The ''Integrity Concept'' is applied to those mechanical systems and components that must not fail (grp. 1). This pro-active procedure bases on the German basis safety concept that was developed in the 1980s and addresses SSC in operation, specially. This procedure was included in the German nuclear code KTA in 1999. Following this procedure a required quality of the SSC is established during design and manufacture (production); in operation possible damage mechanisms have to be under control. This is done by extensive monitoring of the causes (i.e. loads, water chemistry), regular evaluation and assessment of the monitoring results and redundant monitoring of the consequences of possible damage mechanisms. The assessment has to be performed for each component, specifically, taking into account all available information and changes of knowledge, too. The quality of the second group of SSC has to be maintained, this means the consequences of possible damage mechanisms have to be kept under control; thus the possibility of a failure is minimized. To maintain quality (integrity and function) there are adequate surveillance methods like inspections, function tests and maintenance actions that are applied regularly (time

  1. Assessment and management of ageing of major nuclear power plant components important to safety: BWR pressure vessel internals

    International Nuclear Information System (INIS)

    2005-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (caused for instance by unanticipated phenomena and by operating maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and ware out of components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of guidance reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. Since the reports are written from a safety perspective, they do not address life or life cycle management of plant components, which involves economic considerations. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of heavy water moderated reactors (HWRs), boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues

  2. Assessment and Management of ageing of major nuclear power plant components important to safety: PWR pressure vessels

    International Nuclear Information System (INIS)

    1999-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g., caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness-for-service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), including water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs; and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. Since the reports are written from a safety perspective, they do not address life or life-cycle management of the plant components, which involves the integration of

  3. Review of nuclear power plant safety cable aging studies with recommendations for improved approaches and for future work

    International Nuclear Information System (INIS)

    Gillen, Kenneth Todd; Bernstein, Robert

    2010-01-01

    Many U. S. nuclear power plants are approaching 40 years of age and there is a desire to extend their life for up to 100 total years. Safety-related cables were originally qualified for nuclear power plant applications based on IEEE Standards that were published in 1974. The qualifications involved procedures to simulate 40 years of life under ambient power plant aging conditions followed by simulated loss of coolant accident (LOCA). Over the past 35 years or so, substantial efforts were devoted to determining whether the aging assumptions allowed by the original IEEE Standards could be improved upon. These studies led to better accelerated aging methods so that more confident 40-year lifetime predictions became available. Since there is now a desire to potentially extend the life of nuclear power plants way beyond the original 40 year life, there is an interest in reviewing and critiquing the current state-of-the-art in simulating cable aging. These are two of the goals of this report where the discussion is concentrated on the progress made over the past 15 years or so and highlights the most thorough and careful published studies. An additional goal of the report is to suggest work that might prove helpful in answering some of the questions and dealing with some of the issues that still remain with respect to simulating the aging and predicting the lifetimes of safety-related cable materials.

  4. Greenhouse gas emissions from landfill leachate treatment plants: A comparison of young and aged landfill

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaojun, E-mail: xjwang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Jia, Mingsheng, E-mail: msjia@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Chen, Xiaohai, E-mail: cxiaoh_xm@126.com [Xiamen City Environmental Sanitation Management Department, Xiamen 361000 (China); Xu, Ying, E-mail: yxu@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Lin, Xiangyu, E-mail: xylin@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Kao, Chih Ming, E-mail: jkao@mail.nsysu.edu.tw [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Chen, Shaohua, E-mail: shchen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2014-07-15

    Highlights: • Young and aged leachate works accounted for 89.1% and 10.9% of 33.35 Gg CO{sub 2} yr{sup −1}. • Fresh leachate owned extremely low ORP and high organic matter content. • Strong CH{sub 4} emissions occurred in the fresh leachate ponds, but small in the aged. • N{sub 2}O emissions became dominant in the treatment units of both systems. • 8.45–11.9% of nitrogen was removed as the form of N{sub 2}O under steady-state. - Abstract: With limited assessment, leachate treatment of a specified landfill is considered to be a significant source of greenhouse gas (GHG) emissions. In our study, the cumulative GHG emitted from the storage ponds and process configurations that manage fresh or aged landfill leachate were investigated. Our results showed that strong CH{sub 4} emissions were observed from the fresh leachate storage pond, with the fluxes values (2219–26,489 mg C m{sup −2} h{sup −1}) extremely higher than those of N{sub 2}O (0.028–0.41 mg N m{sup −2} h{sup −1}). In contrast, the emission values for both CH{sub 4} and N{sub 2}O were low for the aged leachate tank. N{sub 2}O emissions became dominant once the leachate entered the treatment plants of both systems, accounting for 8–12% of the removal of N-species gases. Per capita, the N{sub 2}O emission based on both leachate treatment systems was estimated to be 7.99 g N{sub 2}O–N capita{sup −1} yr{sup −1}. An increase of 80% in N{sub 2}O emissions was observed when the bioreactor pH decreased by approximately 1 pH unit. The vast majority of carbon was removed in the form of CO{sub 2}, with a small portion as CH{sub 4} (<0.3%) during both treatment processes. The cumulative GHG emissions for fresh leachate storage ponds, fresh leachate treatment system and aged leachate treatment system were 19.10, 10.62 and 3.63 Gg CO{sub 2} eq yr{sup −1}, respectively, for a total that could be transformed to 9.09 kg CO{sub 2} eq capita{sup −1} yr{sup −1}.

  5. Generic Software Architecture for Launchers

    Science.gov (United States)

    Carre, Emilien; Gast, Philippe; Hiron, Emmanuel; Leblanc, Alain; Lesens, David; Mescam, Emmanuelle; Moro, Pierre

    2015-09-01

    The definition and reuse of generic software architecture for launchers is not so usual for several reasons: the number of European launcher families is very small (Ariane 5 and Vega for these last decades); the real time constraints (reactivity and determinism needs) are very hard; low levels of versatility are required (implying often an ad hoc development of the launcher mission). In comparison, satellites are often built on a generic platform made up of reusable hardware building blocks (processors, star-trackers, gyroscopes, etc.) and reusable software building blocks (middleware, TM/TC, On Board Control Procedure, etc.). If some of these reasons are still valid (e.g. the limited number of development), the increase of the available CPU power makes today an approach based on a generic time triggered middleware (ensuring the full determinism of the system) and a centralised mission and vehicle management (offering more flexibility in the design and facilitating the long term maintenance) achievable. This paper presents an example of generic software architecture which could be envisaged for future launchers, based on the previously described principles and supported by model driven engineering and automatic code generation.

  6. Testing properties of generic functions

    NARCIS (Netherlands)

    Jansson, P.; Jeuring, J.T.; Cabenda, L.; Engels, G.; Kleerekoper, J.; Mak, S.; Overeem, M.; Visser, Kees

    2007-01-01

    A datatype-generic function is a family of functions indexed by (the structure of) a type. Examples include equality tests, maps and pretty printers. Property based testing tools like QuickCheck and Gast support the de¯nition of properties and test-data generators, and they check if a

  7. 'Genericism' in Danish welfare professions

    DEFF Research Database (Denmark)

    Larsen, Verner

    and skills in the basic disciplines of the professions also termed as disciplinary and procedural knowledge '. Thus the main research question for this paper is: What consequences do recent reform actions in Danish welfare education concerning generic competence have on developing professional knowledge...

  8. A prioritization of generic safety issues

    International Nuclear Information System (INIS)

    Emrit, R.; Riggs, R.; Milstead, W.; Pittman, J.

    1991-07-01

    This report presents the priority rankings for generic safety issues and related to nuclear power plants. The purpose of these rankings is to assist in the timely and efficient allocation of NRC resources for the resolution of those safety issues that have a significant potential for reducing risk. The report focuses on the prioritization of generic safety issues. Issues primarily concerned with the licensing process or environmental protection and not directly related to safety have been excluded from prioritization. The prioritized issues include: TMI Action Plan items under development; previously proposed issues covered by Task Action Plans, except issues designated as Un-resolved Safety Issues (USIs) which had already been assigned high priority; and newly-proposed issues. Future supplements to this report will include the prioritization of additional issues. The safety priority rankings are High, Medium, Low, and Drop and have been assigned on the basis of risk significance estimates, the ratio of risk to costs and other impacts estimated to result if resolutions of the safety issues were implemented, and the consideration of uncertainties and other quantitative or qualitative factors. To the extent practical, estimates are quantitative. 1310 refs

  9. Effects evaluation of artificial aging by temperature and gamma radiation on cables for Laguna Verde nuclear power plant (LVNPP)

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez C, R. M.; Bonifacio M, J.; Garcia H, E. E.; Loperena Z, J. A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia M, C., E-mail: raulmario.vazquez@inin.gob.m [CFE, Central Nuclear Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)

    2010-10-15

    A set of tests has been carried out at the Equipment Qualification Laboratory at National Institute of Nuclear Research to perform accelerated aging up to 60 years under temperature and gamma radiation environment for electrical cables. The results obtained from such tests are the base line data for comparison to with the current cable conditions at the plant. This work is intended for establishing the cable aging management program for the Laguna Verde nuclear power plant (LVNPP). For such purpose, the Institute has prepared methodologies and procedures to apply condition monitoring techniques in accelerated aging tests on samples of new cables drawn from the LVNPP warehouse. The condition indicators of the material selected for condition monitoring and the aging management process of cables were: Elongation at Break (EAB) and Oxidation Induction Time (OIT). A cable aging management program includes activities for cable selection, determination of condition indicators of the cable materials (EAB, OIT, Ind enter), accelerated aging of cable samples at the laboratory, analysis of maintenance history, operational experience of the plant and analysis of the environmental and service conditions (temperature and gamma radiation), as well as the establishment of a condition monitoring plan for cables in the plant. Two cable model samples were thermally aged and gamma irradiated with doses corresponding to differential operational periods. EAB and OIT values of cable insulating material (ethylene propylene and cross linked polyethylene) were obtained. It was found that the EAB and OIT data correlation is very closed, and it could be applied to infer values that are not possible to measure directly at the plant and be used for cable aging evaluation and remaining life time determination. (Author)

  10. New technology for optimized I and C maintenance and management of ageing of critical equipment in nuclear power plants

    International Nuclear Information System (INIS)

    Hashemian, H.M.

    2000-01-01

    Advanced sensors and new testing and maintenance technologies have become available over the last ten years for nuclear power plants (NPPs) to replace outdated, obsolete, and troublesome instruments, provide for management of ageing of critical plant equipment, optimize maintenance activities, reduce maintenance costs and personnel radiation exposure, and at the same time, improve plant safety and availability. These new developments are reviewed in this TECDOC. The material covered here has been summarized from NUREG/CR-5501, a 1998 report written by H.M. Hashemian and his co-authors for the US Nuclear Regulatory Commission. (author)

  11. Assessment and management of ageing of major nuclear power plant components important to safety: Metal components of BWR containment systems

    International Nuclear Information System (INIS)

    2000-10-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety, which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs), and water moderated, water cooled energy reactors (WWERs) are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. The guidance reports are directed toward technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific

  12. Development and application of the methodology to establish life extension and modernization plan of aged hydropower plants

    International Nuclear Information System (INIS)

    Kim, Jong Sung; Kwon, Hyuck Cheon; Song, Byung Hun; Kwon, Chang Seop

    2009-01-01

    This paper provides how to establish an integrated plan for LE (Life Extension) and MD (MoDernization) of aged hydropower plants. The methodology is developed through review of overseas/domestic LE/MD histories, investigation of the previous overseas methodologies and consideration of domestic practices. The methodology includes reviews of the various factors such as condition, operation and maintenance history, up-to-date technology, and economic benefit. In order to establish the life extension/modernization plan, the methodology is applied to the domestic aged hydropower plants. Finally, priority rankings and draft practice plans for LE/MD are derived.

  13. The (safety-related) heat exchangers aging management guideline for commercial nuclear power plants, and developments since 1994

    International Nuclear Information System (INIS)

    Clauss, J.M.

    1998-01-01

    The US Department of Energy (DOE), in cooperation with the Electric Power Research Institute (EPRI) and US nuclear power plant utilities, is preparing a series of aging management guidelines (AMGs) for commodity types of components (e.g., heat exchangers, electrical cable and terminations, pumps). Commodities are included in this series based on their importance to continued nuclear plant operation and license renewal. The AMGs contain a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance and surveillance practices that can be combined to create an effective aging management program. Each AMG is intended for use by the systems engineers and plant maintenance staff (i.e., an AMG is intended to be a hands-on technical document rather than a licensing document). The heat exchangers AMG, published in June 1994, includes the following information of interest to nondestructive examination (NDE) personnel: aging mechanisms determined to be non-significant for all applications; aging mechanisms determined to be significant for some applications; effective conventional programs for managing aging; and effective unconventional programs for managing aging. Since the AMG on heat exchangers was published four years ago, a brief review has been conducted to identify emerging regulatory issues, if any. The results of this review and lessons learned from the collective set of AMGs are presented

  14. Tuning a 96-Well Microtiter Plate Fluorescence-Based Assay to Identify AGE Inhibitors in Crude Plant Extracts

    Directory of Open Access Journals (Sweden)

    Luc Séro

    2013-11-01

    Full Text Available Advanced glycation end-products (AGEs are involved in the pathogenesis of numerous diseases. Among them, cellular accumulation of AGEs contributes to vascular complications in diabetes. Besides using drugs to lower blood sugar, a balanced diet and the intake of herbal products potentially limiting AGE formation could be considered beneficial for patients’ health. The current paper presents a simple and cheap high-throughput screening (HTS assay based on AGE fluorescence and suitable for plant extract screening. We have already implemented an HTS assay based on vesperlysines-like fluorescing AGEs quickly (24 h formed from BSA and ribose under physiological conditions. However, interference was noted when fluorescent compounds and/or complex mixtures were tested. To overcome these problems and apply this HTS assay to plant extracts, we developed a technique for systematic quantification of both vesperlysines (λexc 370 nm; λem 440 nm and pentosidine-like (λexc 335 nm; λem 385 nm AGEs. In a batch of medicinal and food plant extracts, hits were selected as soon as fluorescence decreased under a fixed threshold for at least one wavelength. Hits revealed during this study appeared to contain well-known and powerful anti-AGE substances, thus demonstrating the suitability of this assay for screening crude extracts (0.1 mg/mL. Finally, quercetin was found to be a more powerful reference compound than aminoguanidine in such assay.

  15. Factors affecting the opinions of family physicians regarding generic drugs – a questionnaire based study

    Directory of Open Access Journals (Sweden)

    Pawel Lewek

    2014-12-01

    Full Text Available A range of factors are believed to exert a negative influence on opinions of physicians about generic drugs.The aim of this study was to survey the opinions of primary care doctors on generics, and determine the factors which may affect them. A questionnaire comprising thirty eight questions was distributed among primary care doctors working in seventy out-patient clinics of the Lodzkie province, Poland, during the period of January 1, 2010 – December 31, 2010. A total of170 of 183 participants completed the survey (average age 48.5; 70.0% women: a 92.9%response rate. While 38.8% of physicians claimed that generics were worse than brand name drugs, 54.1% considered them to be better. However, 36.5% of the doctors did not choose generics for their own use. Two key opinions were identified among the responses concerning the effectiveness of generic drugs: use of generic drugs by the physician (p<0.001, and their opinion that pharmacists do inform patients about generic drugs (p<0.05. Although existing evidence confirms that generic and brand name drugs are equally effective, many physicians doubt this, which prevents them from being used as cost effective drug therapy. In order to increase healthcare savings through the use of generics, these factors should be addressed: for example, convincing a physician to adopt generics for personal use may be an efficient way to support more cost effective treatment of his patients.

  16. Influence of conventional biochar and ageing biochar application to arable soil on soil fertility and plant yield

    Science.gov (United States)

    Dvořáčková, Helena; Záhora, Jaroslav; Elbl, Jakub; Kynický, Jindřich; Hladký, Jan; Brtnický, Martin

    2017-04-01

    Biochar represents very controversial material which is product of pyrolysis. According to many studies biochar has positive effect on physical and chemical properties such as pH, conductivity, aggregates stability etc. Unfortunately biochar is product of combustion, so it can content toxic substance as are aromatic compound. These substances may have a negative effect on yield and microbial activities in soil. Our aim was eliminated concentration of toxic compound but preserved positive effect of biochar on soil properties. We was ageing/ activating of biochar in water environment and for soil inoculum we used native soil from landscape. Moreover two types of biochar was tested by pot experiment with seven variants, where conventional biochar from residual biomass and ageing biochar were applied in different doses: 10 t/ha, 20t/ha and 50 t/ha. Pots were placed in green house for 90 days and after the end of experiment the following parameters of soil fertility, health and quality were evaluated: content of soil organic matter, arbuscular mycorrhizal colonisation of Lactuca sativa L. roots, leaching of mineral nitrogen, changes in plant available nutrient content, EC and pH. Above all the total yield of indicator plant was observed. The significant (P plant yield and soil properties were found. The application of conventional biochar didn't have positive effect on plant yield in comparison with ageing biochar. The positive effect of ageing biochar addition on soil fertility was directly proportional to the dose which were applied - increasing in dose of ageing biochar resulted in increase of plant yield. Moreover the special experimental containers were used, where we was able to monitor the development of root in soil with and without addition of biochar (conventional or ageing). The positive influence of ageing biochar addition into soil on development of Lactuca sativa L. roots was observed.

  17. Effect of generic issues program on improving safety

    International Nuclear Information System (INIS)

    Fard, M. R.; Kauffman, J. V.

    2010-01-01

    The U.S. Nuclear Regulatory Commission (NRC) identifies (by its assessment of plant operation) certain issues involving public health and safety, the common defense and security, or the environment that could affect multiple entities under NRC jurisdiction. The Generic Issues Program (GIP) addresses the resolution of these Generic Issues (GIs). The resolution of these issues may involve new or revised rules, new or revised guidance, or revised interpretation of rules or guidance that affect nuclear power plant licensees, nuclear material certificate holders, or holders of other regulatory approvals. U.S. NRC provides information related to the past and ongoing GIP activities to the general public by the use of three main resources, namely NUREG-0933, 'Resolution of Generic Safety Issues, ' Generic Issues Management Control System (GIMCS), and GIP public web page. GIP information resources provide information such as historical information on resolved GIs, current status of the open GIs, policy documents, program procedures, GIP annual and quarterly reports and the process to contact GIP and propose a GI This paper provides an overview of the GIP and several examples of safety improvements resulting from the resolution of GIs. In addition, the paper provides a brief discussion of a few recent GIs to illustrate how the program functions to improve safety. (authors)

  18. Generic study on the relation between contamination if primary coolants and occupational radiation exposure in nuclear power plants with PWR. Final report; Generische Studie zum Zusammenhang zwischen Kontamination von Primaerkreislaufmedien und beruflicher Strahlenexposition bei Kernkraftwerken mit Druckwasserreaktor. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Artmann, Andreas; Bruhn, Gerd; Schneider, Sebastian [Gesellschaft fuer Anlagen- und Reaktorsicherheit, Koeln (Germany); Strub, Erik [Koeln Univ. (Germany)

    2016-01-15

    A generic model for the primary cooling system contamination in pressurized water reactors and the resulting radiological consequences has been developed. The functional capability was demonstrated by means of three examples concerning manipulation procedures during revision outages. Activities at the main reactor coolant pumps were studied and the influence of the coolant contamination on the resulting dose rates and collective doses were calculated. The effect of a Co-90 hot spot in a more remote area on the radiation exposure during the specific action at the reactor pumps was considered.

  19. Neuroprotective and Anti-Aging Potentials of Essential Oils from Aromatic and Medicinal Plants

    Directory of Open Access Journals (Sweden)

    Muhammad Ayaz

    2017-05-01

    Full Text Available The use of essential oils (EOs and their components is known since long in traditional medicine and aromatherapy for the management of various diseases, and is further increased in the recent times. The neuroprotective and anti-aging potentials of EOs and their possible mechanism of actions were evaluated by numerous researchers around the globe. Several clinically important EOs and their components from Nigella sativa, Acorus gramineus, Lavandula angustifolia, Eucalyptus globulus, Mentha piperita, Rosmarinus officinalis, Jasminum sambac, Piper nigrum and so many other plants are reported for neuroprotective effects. This review article was aimed to summarize the current finding on EOs tested against neurodegenerative disorders like Alzheimer disease (AD and dementia. The effects of EOs on pathological targets of AD and dementia including amyloid deposition (Aβ, neurofibrillary tangles (NFTs, cholinergic hypofunction, oxidative stress and glutamatergic abnormalities were focused. Furthermore, effects of EOs on other neurological disorders including anxiety, depression, cognitive hypofunction epilepsy and convulsions were also evaluated in detail. In conclusion, EOs were effective on several pathological targets and have improved cognitive performance in animal models and human subjects. Thus, EOs can be developed as multi-potent agents against neurological disorders with better efficacy, safety and cost effectiveness.

  20. Studying radiolytic ageing of nuclear power plant electric cables with FTIR spectroscopy.

    Science.gov (United States)

    Levet, A; Colombani, J; Duponchel, L

    2017-09-01

    Due to the willingness to extend the nuclear power plants length of life, it is of prime importance to understand long term ageing effect on all constitutive materials. For this purpose gamma-irradiation effects on insulation of instrumentation and control cables are studied. Mid-infrared spectroscopy and principal components analysis (PCA) were used to highlight molecular modifications induced by gamma-irradiation under oxidizing conditions. In order to be closer to real world conditions, a low dose rate of 11Gyh -1 was used to irradiate insulations in full cable or alone with a dose up to 58 kGy. Spectral differences according to irradiation dose were extracted using PCA. It was then possible to observe different behaviors of the insulation constitutive compounds i.e. ethylene vinyl acetate (EVA), ethylene propylene diene monomer (EPDM) and aluminium trihydrate (ATH). Irradiation of insulations led to the oxidation of their constitutive polymers and a modification of filler-polymer ratio. Moreover all these modifications were observed for insulations alone or in full cable indicating that oxygen easily diffuses into the material. Spectral contributions were discussed considering different degradation mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Neuroprotective and Anti-Aging Potentials of Essential Oils from Aromatic and Medicinal Plants.

    Science.gov (United States)

    Ayaz, Muhammad; Sadiq, Abdul; Junaid, Muhammad; Ullah, Farhat; Subhan, Fazal; Ahmed, Jawad

    2017-01-01

    The use of essential oils (EOs) and their components is known since long in traditional medicine and aromatherapy for the management of various diseases, and is further increased in the recent times. The neuroprotective and anti-aging potentials of EOs and their possible mechanism of actions were evaluated by numerous researchers around the globe. Several clinically important EOs and their components from Nigella sativa , Acorus gramineus, Lavandula angustifolia, Eucalyptus globulus, Mentha piperita, Rosmarinus officinalis, Jasminum sambac, Piper nigrum and so many other plants are reported for neuroprotective effects. This review article was aimed to summarize the current finding on EOs tested against neurodegenerative disorders like Alzheimer disease (AD) and dementia. The effects of EOs on pathological targets of AD and dementia including amyloid deposition (Aβ), neurofibrillary tangles (NFTs), cholinergic hypofunction, oxidative stress and glutamatergic abnormalities were focused. Furthermore, effects of EOs on other neurological disorders including anxiety, depression, cognitive hypofunction epilepsy and convulsions were also evaluated in detail. In conclusion, EOs were effective on several pathological targets and have improved cognitive performance in animal models and human subjects. Thus, EOs can be developed as multi-potent agents against neurological disorders with better efficacy, safety and cost effectiveness.

  2. Assessment and management of ageing of major nuclear power plant components important to safety: PWR pressure vessels. 2007 update

    International Nuclear Information System (INIS)

    2007-06-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that effective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) is one of the most important issues for plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. IAEA-TECDOC-1120 documented ageing assessment and management practices for pressurized water reactor (PWR) reactor pressure vessels (RPVs) that were current at the time of its finalization in 1997-1998. Safety significant operating events have occurred since the finalization of the TECDOC, e.g. primary water stress corrosion cracking (PWSCC) of Alloy 600 control rod drive mechanism (CRDM) penetrations and boric acid corrosion/wastage of RPV heads, which threatened the integrity of the RPV heads. These events led to new ageing management actions by both NPP operators and regulators. Therefore it was recognized that IAEA-TECDOC-1120 should be updated by incorporating those new events and their countermeasures. The objective of this report is to update IAEA-TECDOC-1120 in order to provide current ageing management guidance for PWR RPVs to all involved in the operation and regulation of PWRs and thus to help ensure PWR RPV integrity in IAEA Member States throughout their entire service life

  3. Assessment and management of ageing of major nuclear power plant components important to safety: PWR vessel internals: 2007 update

    International Nuclear Information System (INIS)

    2007-06-01

    At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that effective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance or manufacturing errors) is one of the most important issues for plant safety and also plant life. Ageing in these NPPs must be therefore effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wearout of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. IAEA-TECDOC-1119 documents ageing assessment and management practices for PWR Reactor Vessel Internals (RVIs) that were current at the time of its finalization in 1997-1998. Safety significant operating events have occurred since the finalization of the TECDOC, e.g. irradiation assisted stress corrosion cracking (IASCC) of baffle-former bolts, which threatened the integrity of the vessel internals. In addition, concern of fretting wear of control rod guide tubes has been raised in Japan. These events led to new ageing management actions by both NPP operators and regulators. Therefore it was recognized that IAEA-TECDOC-1119 should be updated by incorporating those new events and their countermeasures. The objective of this report is to update relevant sections of the existing IAEA-TECDOC- 1119 in order to provide current ageing management guidance for PWR RVIs to all involved in the operation and regulation of PWRs and thus to help ensure PWR safety in IAEA Member States throughout their entire service life

  4. Exploring knowledge, perceptions and attitudes about generic ...

    African Journals Online (AJOL)

    Exploring knowledge, perceptions and attitudes about generic medicines among final-year health science students. ... had knowledge deficits about the safety, quality and efficacy of generic medicines. The dissemination of information about generic medicines may strengthen future knowledge, attitudes and perceptions.

  5. Comparing approaches to generic programming in Haskell

    NARCIS (Netherlands)

    Hinze, R.; Jeuring, J.T.; Löh, A.

    2006-01-01

    The last decade has seen a number of approaches to generic programming: PolyP, Functorial ML, `Scrap Your Boilerplate', Generic Haskell, `Generics for the Masses', etc. The approaches vary in sophistication and target audience: some propose full-blown pro- gramming languages, some suggest

  6. Comparing approaches to generic programming in Haskell

    NARCIS (Netherlands)

    Hinze, R.; Jeuring, J.T.; Löh, A.

    2006-01-01

    The last decade has seen a number of approaches to data- type-generic programming: PolyP, Functorial ML, `Scrap Your Boiler- plate', Generic Haskell, `Generics for the Masses', etc. The approaches vary in sophistication and target audience: some propose full-blown pro- gramming languages, some

  7. Proceedings Workshop on Generic Programming (WGP2000)

    NARCIS (Netherlands)

    Jeuring, J.T.

    2000-01-01

    This report contains the papers selected for presentation at the 2nd Workshop on Generic Programming (WGP2000), which was held on July 6, 2000 in Ponte de Lima, Portugal. Generic programming is about making programs more adaptable by making them more general. Generic programs often embody

  8. Slow growth of Empetrum nigrum in industrial barrens: Combined effect of pollution and age of extant plants

    Energy Technology Data Exchange (ETDEWEB)

    Zverev, Vitali E. [Section of Ecology, University of Turku, FI-20014 Turku (Finland)], E-mail: vitzve@utu.fi; Zvereva, Elena L.; Kozlov, Mikhail V. [Section of Ecology, University of Turku, FI-20014 Turku (Finland)

    2008-11-15

    We studied the impact of industrial pollution on population demography (age structure), growth and reproduction of crowberry, Empetrum nigrum L. Crowberry growing in severely polluted sites near non-ferrous smelters (at Harjavalta, Monchegorsk and Nikel) was on average twice as old as in unpolluted habitats, as indicated by the number of annual rings at root collar. Shoot length decreased both with plant ageing and due to pollution impact, while neither the proportion of generative plants nor berry production was affected by pollution or plant age. Our results suggest that death of the extant individuals of E. nigrum near the non-ferrous smelters is to a large extent explained by age-related damage of the main stem accelerated by pollution. Since vegetative propagation, seed germination and seedling establishment are hampered by soil toxicity, E. nigrum populations near the smelters continue to decline with ageing in spite of the gradual decline of emissions. - Both older age of crowberry in heavily polluted sites and pollution-induced environmental disturbance contributed to slower growth, but had no effect on fructification.

  9. Proof of integrity and ageing management of mechanical components in nuclear power plants

    International Nuclear Information System (INIS)

    Roos, E.; Herter, K.-H.; Kockelmann, H.; Schuler, X.

    2005-01-01

    Demands and requirements for a safe operation of mechanical components during the whole operation life time (plant life management) to assure aging phenomena (aging management) and to prove the integrity (prove of integrity, e.g. in order to exclude large breaks) can be found in guidelines, codes and standards. In the present paper a general concept to proof the integrity as part of the ageing management of pressurized components and systems is presented. The concept is based on the actual material characteristics, the actual as-built configurations and the design of the components and systems including the knowledge of possible failure mechanism during operation. An important part of the assessment is the leak before break behavior and the break preclusion concept. Based on essential research results the developed procedures and methodologies for the assessment of the critical crack sizes as well as the critical loading conditions are reported and discussed. In detail the following aspects have to be treated: (a) evaluation of the as-built status of quality (design, construction, material, fabrication; results of recurrent non destructive examinations up to now, operational experience); (b) determination of the relevant loading conditions by means of in-service monitoring (monitoring of the mode of operation, the water chemistry, the mechanical and thermal stresses, the dynamic loading), emergency and faulted condition loads as specified; (c) evaluation of the actual status of quality with respect to the relevant loading conditions (stress analysis-limitation of the stresses; fatigue analysis-determination of the usage factor; fracture mechanics analysis-determination of crack growth, critical crack sizes and loading conditions); (d) evaluation and extent of the in-service monitoring and recurrent inspections to guarantee the succeeding operation (recurrent non destructive examination - minimum detectable flaw sizes, examination area, examination intervals; leak

  10. Generic medications for you, but brand-name medications for me.

    Science.gov (United States)

    Keenum, Amy J; Devoe, Jennifer E; Chisolm, Deena J; Wallace, Lorraine S

    2012-01-01

    Because generic medications are less expensive than brand-name medications, government and private insurers have encouraged and/or mandated the use of generics. This study aimed at evaluating perceptions about generic medications among English-speaking women of childbearing age currently enrolled in U.S. TennCare (Medicaid). We recruited a convenience sample of patients from the waiting room of a primary care/gynecology health clinic, with 80% recruitment rate among those approached. We orally administered a 25-item questionnaire to gather sociodemographic information and to assess beliefs regarding the efficacy, safety, cost, and preferences for personal use of generic medications. The average age of the women (n=172) was 28.8 ± 6.4 years, and most were white (82.0%) and currently married (58.1%). Nearly one-fifth (19.2%) had not completed high school. Most women believed that generic medications were less expensive (97.6%) and better value (60.5%) than brand-name medications, but only 45.3% preferred to take generics themselves. About a quarter (23.3%) believed that brand-name medications were more effective than generics, whereas 13.4% believed that generics caused more side effects. Few women reported that their doctor (29.7%) and/or pharmacist (35.5%) had ever talked to them about taking generics. Awareness of the benefits of generics did not equal preferences for personal use of generics among this sample of women enrolled in U.S. TennCare. Furthermore, women reported that providers-both physicians and pharmacists-infrequently discussed generic substitution with them. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Enhancing Safety through Generic Competencies

    Directory of Open Access Journals (Sweden)

    S. Mockel

    2014-03-01

    Full Text Available This article provides insights into proactive safety management and mitigation. An analysis of accident reports reveals categories of supervening causes of accidents which can be directly linked to the concept of generic competencies (information management, communication and coordination, problem solving, and effect control. These findings strongly suggest adding the human element as another safety-constituting pillar to the concept of ship safety next to technology and regulation. We argue that the human element has unique abilities in dealing with critical and highly dynamic situations which can contribute to the system's recovery from non-routine or critical situations. By educating seafarers in generic competencies we claim to enable the people onboard to successfully deal with critical situations.

  12. Young Children's Drawings of Plant Life: A Study Concerning the Use of Colours and Its Relationship with Age

    Science.gov (United States)

    Villarroel, José Domingo

    2016-01-01

    This study examines the drawings that elementary grade school children make on the subject of plant life. More specifically, the pictorial elements drawn by children are analysed together with their colour choices and the size of coloured surfaces. Furthermore, the results are put into perspective with the age of the children in the sample. The…

  13. Verde plant bug (Hemiptera: Miridae) feeding injury to cotton bolls charcterized by boll age, size and damage ratings

    Science.gov (United States)

    Our studies over 2 years (2009 and 2010) and 2 locations (Weslaco and Corpus Christi, TX) investigated the relationship of feeding-injury of the verde plant bug, Creontiades signatus Distant, to a range of cotton boll age classes further defined by boll diameter and accumulated degree-days (anthesis...

  14. Thermal Aging Effect Analysis of 17-4PH Martensitic Stainless Steel Valves for Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    BAI; Bing; ZHANG; Chang-yi; TONG; Zhen-feng; YANG; Wen

    2015-01-01

    The valve stem used in the main steam system of nuclear power plant is usually martensitic stainless steel(such as 17.4ph16.4Mo etc.).When served in high temperature for a long time,the thermal aging embrittlement of valve stem will be significant,and even lead to the fracture.

  15. Aging management and PLEX in Swiss nuclear power plants and prioritization of safety class 2 and 3 components

    International Nuclear Information System (INIS)

    Fuchs, R.; Stejskal, J.

    2000-01-01

    In this presentation ageing management of systems and components important to safety of the Swiss nuclear power plants are presented. Status of electrical components, status of mechanical components as well as status of civil structures are reviewed. The scheme of the high pressure core spray system is included

  16. Net ecosystem production in a Little Ice Age moraine: the role of plant functional traits

    Science.gov (United States)

    Varolo, E.; Zanotelli, D.; Tagliavini, M.; Zerbe, S.; Montagnani, L.

    2015-07-01

    Current glacier retreat allows vast mountain ranges available for vegetation establishment and growth. Little is known about the effective carbon (C) budget of these new ecosystems and how the presence of different vegetation communities, characterized by their specific physiology and life forms influences C fluxes. In this study, using a comparative analysis of the C fluxes of two contrasting vegetation types, we intend to evaluate if the different physiologies of the main species have an effect on Ecosystem Respiration (Reco), Gross Primary Production (GPP), annual cumulated Net Ecosystem Exchange (NEE), and long-term carbon accumulation in soil. The NEE of two plant communities present on a Little Ice Age moraine in the Matsch glacier forefield (Alps, Italy) was measured over two growing seasons. They are a typical C3 grassland, dominated by Festuca halleri All. and a community dominated by CAM rosettes Sempervivum montanum L. on rocky soils. Using transparent and opaque chambers, we extrapolated the ecophysiological responses to the main environmental drivers and performed the partition of NEE into Reco and GPP. Soil samples were collected from the same site to measure long-term C accumulation in the ecosystem. The two communities showed contrasting GPP but similar Reco patterns and as a result significantly different in NEE. The grassland acted mainly as a carbon sink with a total cumulated value of -46.4 ± 35.5 g C m-2 NEE while the plots dominated by the CAM rosettes acted as a source with 31.9 ± 22.4 g C m-2. In spite of the NEE being different in the two plant communities, soil analysis did not reveal significant differences in carbon accumulation. Grasslands showed 1.76 ± 0.12 kg C m-2, while CAM rosettes showed 2.06 ± 0.23 kg C m-2. This study demonstrates that carbon dynamics of two vegetation communities can be distinct even though the growing environment is similar. The physiological traits of the dominant species determine large differences in

  17. [Users sceptical about generic drugs: an anthropological approach].

    Science.gov (United States)

    Sarradon-Eck, A; Blanc, M-A; Faure, M

    2007-06-01

    Since the enactment of the 2002 legislative measures favoring the prescription of generic drugs, various quantitative studies have shown that approval by prescribers and users has risen in France. Nevertheless, scepticism remains as well as distrust towards these drugs focusing on their effectiveness compared with brand-name drugs, on potential dangers, and on the interruption they cause in prescription and consumption habits. Using a comprehensive approach, this article analyzes the social and cultural logic behind the negative image of generic drugs. The materials issued from an ethnographic study on the prescription of drugs for high blood pressure. Sixty-eight interviews were undertaken between April 2002 and October 2004 with people (39 women and 29 men, between the age of 40 and 95, 52 over the age of 60) treated for over a year for high blood pressure in rural areas in the Southeast of France. Thirteen people provided unsolicited opinions about generic drugs. Analysis of the information collected shows that users have various representations of generic drugs, including the idea of counterfeited and foreign drugs. These representations interfere with the adjustment process and the development of consumer loyalty. They are part of a set of social representations about drugs which form and express the user's reality. In these representations, the drug is an ambivalent object, carrier of both biological effectiveness and toxicity; it is also the metonymical extension of the prescriber, bestowing upon the prescription a symbolic value. By placing the generic drug in its network of symbolic and social meaning, this study highlights the coherence of the scepticism towards generic drugs by consumers (and prescribers) with a system of common opinion in which drugs are everyday things, personalized and compatible with users, symbolic exchange carriers in the physician-patient relationship, and in which confidence in the drug is also that given to the health care

  18. Automated analysis in generic groups

    Science.gov (United States)

    Fagerholm, Edvard

    This thesis studies automated methods for analyzing hardness assumptions in generic group models, following ideas of symbolic cryptography. We define a broad class of generic and symbolic group models for different settings---symmetric or asymmetric (leveled) k-linear groups --- and prove ''computational soundness'' theorems for the symbolic models. Based on this result, we formulate a master theorem that relates the hardness of an assumption to solving problems in polynomial algebra. We systematically analyze these problems identifying different classes of assumptions and obtain decidability and undecidability results. Then, we develop automated procedures for verifying the conditions of our master theorems, and thus the validity of hardness assumptions in generic group models. The concrete outcome is an automated tool, the Generic Group Analyzer, which takes as input the statement of an assumption, and outputs either a proof of its generic hardness or shows an algebraic attack against the assumption. Structure-preserving signatures are signature schemes defined over bilinear groups in which messages, public keys and signatures are group elements, and the verification algorithm consists of evaluating ''pairing-product equations''. Recent work on structure-preserving signatures studies optimality of these schemes in terms of the number of group elements needed in the verification key and the signature, and the number of pairing-product equations in the verification algorithm. While the size of keys and signatures is crucial for many applications, another aspect of performance is the time it takes to verify a signature. The most expensive operation during verification is the computation of pairings. However, the concrete number of pairings is not captured by the number of pairing-product equations considered in earlier work. We consider the question of what is the minimal number of pairing computations needed to verify structure-preserving signatures. We build an

  19. A generic individual-based model to simulate morphogenesis, C-N acquisition and population dynamics in contrasting forage legumes.

    Science.gov (United States)

    Louarn, Gaëtan; Faverjon, Lucas

    2018-04-18

    Individual-based models (IBMs) are promising tools to disentangle plant interactions in multi-species grasslands and foster innovative species mixtures. This study describes an IBM dealing with the morphogenesis, growth and C-N acquisition of forage legumes that integrates plastic responses from functional-structural plant models. A generic model was developed to account for herbaceous legume species with contrasting above- and below-ground morphogenetic syndromes and to integrate the responses of plants to light, water and N. Through coupling with a radiative transfer model and a three-dimensional virtual soil, the model allows dynamic resolution of competition for multiple resources at individual plant level within a plant community. The behaviour of the model was assessed on a range of monospecific stands grown along gradients of light, water and N availability. The model proved able to capture the diversity of morphologies encountered among the forage legumes. The main density-dependent features known about even-age plant populations were correctly anticipated. The model predicted (1) the 'reciprocal yield' law relating average plant mass to density, (2) a self-thinning pattern close to that measured for herbaceous species and (3) consistent changes in the size structure of plant populations with time and pedo-climatic conditions. In addition, plastic changes in the partitioning of dry matter, the N acquisition mode and in the architecture of shoots and roots emerged from the integration of plant responses to their local environment. This resulted in taller plants and thinner roots when competition was dominated by light, and shorter plants with relatively more developed root systems when competition was dominated by soil resources. A population dynamic model considering growth and morphogenesis responses to multiple resources heterogeneously distributed in the environment was presented. It should allow scaling plant-plant interactions from individual to

  20. Study on Developing Degradation Model for Nuclear Power Plants With Ageing Elements Affected on Operation Parameter

    International Nuclear Information System (INIS)

    Choi, Yong Won; Lim, Sung Won; Lee, Un Chul; Kim, Man Woong; Kim, Kab; Ryu, Yong Ho

    2009-01-01

    As a part of development the evaluation system of safety margin effects for degradation of CANDU reactors, it is required that the degradation model represents the distribution of each ageing factor's value during operating year. Unfortunately, it is not easy to make an explicit relation between the RELAP-CANDU parameters and ageing mechanism because of insufficient data and lack of applicable models. So, operating parameter related with ageing is used for range determination of ageing factor. Then, relation between operating parameter and ageing elements is analyzed and ageing constant values for degradation model are determined. Also the other ageing factor is derived for more accurate ageing analysis

  1. Renewable products, towards a new golden age of plants?; Produits renouvelables, vers un nouvel age d'or du vegetal?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    Our industrial civilization was built on the use of fossil materials. It has only 3 centuries of existence, but the use of these non-renewable resources will necessary come to an end in a near future. However alternate ways already exist through the use of biomass-derived products. These proceedings summarize the main discussions that took place during the different round tables of this colloquium. The first round table makes a status of the shortage of fossil energy reserves and of the new challenges and solutions offered by plants and bio-energies. The second round table presents the reality of the market, products and consumption of todays renewable vegetal resources (environmental advantages, economic aspect and competitiveness of markets). The last round table deals with the role of governments in the political sustain of renewable vegetal products development (genetic research, financial aspects, incentives, competition with food agriculture). (J.S.)

  2. Aging of the containment pressure boundary in light-water reactor plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1997-01-01

    Research is being conducted by the Oak Ridge National Laboratory to address aging of the containment pressure boundary in light-water reactor plants. The objectives of this work are to (1) identify the significant factors related to occurrence of corrosion, efficacy of inspection, and structural capacity reduction of steel containments and liners of concrete containments, and to make recommendations on use of risk models in regulatory decisions; (2) provide NRC reviewers a means of establishing current structural capacity margins for steel containments, and concrete containments as limited by liner integrity; and (3) provide recommendations, as appropriate, on information to be requested of licensees for guidance that could be utilized by NRC reviewers in assessing the seriousness of reported incidences of containment degradation. In meeting these objectives research is being conducted in two primary task areas - pressure boundary condition assessment and root-cause resolution practices, and reliability-based condition assessments. Under the first task area a degradation assessment methodology was developed for use in characterizing the in-service condition of metal and concrete containment pressure boundary components and quantifying the amount of damage that is present. An assessment of available destructive and nondestructive techniques for examining steel containments and liners is ongoing. Under the second task area quantitative structural reliability analysis methods are being developed for application to degraded metallic pressure boundaries to provide assurances that they will be able to withstand future extreme loads during the desired service period with a level of reliability that is sufficient for public safety. To date, mathematical models that describe time-dependent changes in steel due to aggressive environmental factors have been identified, and statistical data supporting their use in time-dependent reliability analysis have been summarized

  3. Ageing of power plants socio-economical, sanitary and environmental impact; Veillissement des centrales Impacts socio-economiques, sanitaires et environnementaux

    Energy Technology Data Exchange (ETDEWEB)

    Bataille, Ch. [Depute du nord (France); Denner, M. [EDF pour la Region Bourgogne (France); Vouilloux, F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay-aux-Roses (France); Foucher, L. [Direction Generale de la Surete Nucleaire et de la Radioprotection, 75 - Paris (France); Serviere, M. [Electricite de France (EDF), 75 - Paris (France); Vila d' Abadal Serra, M

    2005-07-01

    The National Association of the local Commissions of Information (A.N.C.L.I.) presents a colloquium about the ageing of nuclear power plants. The different following points are presented. The life cycle of nuclear power plants and the new types of reactors. The ageing of power plants: stakes and perspectives for the French and world nuclear park. A power plant of 30 years is it sure? The role of the studies of ageing and the follow-up according to the age. Stop or continue to exploit a nuclear power plant: who decides, when and how. The socio-economic consequences of a stop of power plant: the Spanish experience. Ten-year visits of a power plant: the associative experience. 58 reactors today: how to assume their end of life and welcome equipments to come. (N.C.)

  4. Survey of the state-of-the-art in aging of electronics with application to nuclear-power-plant instrumentation

    International Nuclear Information System (INIS)

    Johnson, R.T. Jr.; Thome, F.V.; Craft, C.M.

    1983-04-01

    The purpose of this report is to present results of a study to evaluate the state-of-the-art and outline needed research on aging of electronics in nuclear power plants. The emphasis is on aging of electronics (e.g., semiconductors, capacitors, resistors) used in safety-related Class 1E instrumentation, particularly those used in harsh environments. Some attention is also given to encapsulants, printed circuit boards and bonds (e.g., solder joints) since they are integral parts of circuits. Four major tasks were addressed in this study and are the subject of this report. These include (1) selecting candidate electronic components for study and review; (2) defining the aging environment and initiating an effort to determine the state-of-the-art in aging degradation; (3) recommending follow-on investigations and research; and (4) outlining the first steps in defining a program on accelerated aging

  5. Factors influencing the preference for purchasing generic drugs in a Southern Brazilian city

    Directory of Open Access Journals (Sweden)

    Marília Cruz Guttier

    Full Text Available ABSTRACT OBJECTIVE The objective of this study is to identify factors associated with the preference for purchasing generic drugs in a medium-sized municipality in Southern Brazil. METHODS We have analyzed data from a population-based cross-sectional study conducted in 2012 with a sample of 2,856 adults (≥ 20 years old. The preference for purchasing generic drugs was the main outcome. The explanatory variables were the demographic and socioeconomic variables. Statistical analyses included Poisson regressions. RESULTS The preference for purchasing generic drugs was 63.2% (95%CI 61.4–64.9. The variables correlated with this preference in the fully adjusted models were: male (prevalence ratio [PR] = 1.08; 95%CI 1.03–1.14, age of 20–39 years (PR = 1.10; 95%CI 1.02–1.20, low socioeconomic status (PR = 1.15; 95%CI 1.03–1.28, and good knowledge about generic drugs (PR= 4.66; 95%CI 2.89–7.52. Among those who preferred to purchase generic drugs, 55.1% have reported accepting to replace the prescribed drug (if not a generic with the equivalent generic drug. Another correlate of the preference for purchasing generic drugs was because individuals consider their quality equivalent to reference medicines (PR = 2.15; 95%CI 1.93–2.41. CONCLUSIONS Knowledge about generic drugs was the main correlate of the preference for purchasing generic drugs. The greater the knowledge or positive perception about generic drugs, the greater is the preference to purchase them. Therefore, educational campaigns for healthcare professionals and consumers appear to be the best strategy for expanding the use of generic drugs in Brazil.

  6. Factors influencing the preference for purchasing generic drugs in a Southern Brazilian city.

    Science.gov (United States)

    Guttier, Marília Cruz; Silveira, Marysabel Pinto Telis; Luiza, Vera Lucia; Bertoldi, Andréa Dâmaso

    2017-06-26

    The objective of this study is to identify factors associated with the preference for purchasing generic drugs in a medium-sized municipality in Southern Brazil. We have analyzed data from a population-based cross-sectional study conducted in 2012 with a sample of 2,856 adults (≥ 20 years old). The preference for purchasing generic drugs was the main outcome. The explanatory variables were the demographic and socioeconomic variables. Statistical analyses included Poisson regressions. The preference for purchasing generic drugs was 63.2% (95%CI 61.4-64.9). The variables correlated with this preference in the fully adjusted models were: male (prevalence ratio [PR] = 1.08; 95%CI 1.03-1.14), age of 20-39 years (PR = 1.10; 95%CI 1.02-1.20), low socioeconomic status (PR = 1.15; 95%CI 1.03-1.28), and good knowledge about generic drugs (PR= 4.66; 95%CI 2.89-7.52). Among those who preferred to purchase generic drugs, 55.1% have reported accepting to replace the prescribed drug (if not a generic) with the equivalent generic drug. Another correlate of the preference for purchasing generic drugs was because individuals consider their quality equivalent to reference medicines (PR = 2.15; 95%CI 1.93-2.41). Knowledge about generic drugs was the main correlate of the preference for purchasing generic drugs. The greater the knowledge or positive perception about generic drugs, the greater is the preference to purchase them. Therefore, educational campaigns for healthcare professionals and consumers appear to be the best strategy for expanding the use of generic drugs in Brazil.

  7. Age

    Science.gov (United States)

    ... adults? How can you reduce anesthesia risks in older patients? Age Age may bring wisdom but it also brings ... Ask your physician to conduct a pre-surgery cognitive test — an assessment of your mental function. The physician can use the results as a ...

  8. The effects of planting density and cultural intensity on loblolly pine crown characteristics at age twelve

    Science.gov (United States)

    Madison Akers; Michael Kane; Robert Teskey; Richard Daniels; Dehai Zhao; Santosh Subedi

    2012-01-01

    Twelve-year old loblolly pine (Pinus taeda L.) stands were analyzed for the effects of planting density and cultural intensity on tree and crown attributes. Four study installations were located in the Piedmont and Upper Coastal Plain regions of the U.S. South. The treatments included six planting densities (740, 1480, 2220, 2960, 3700, 4440 trees...

  9. Generic Crystalline Disposal Reference Case

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott Leroy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chu, Shaoping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harp, Dylan Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, Frank Vinton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-20

    A generic reference case for disposal of spent nuclear fuel and high-level radioactive waste in crystalline rock is outlined. The generic cases are intended to support development of disposal system modeling capability by establishing relevant baseline conditions and parameters. Establishment of a generic reference case requires that the emplacement concept, waste inventory, waste form, waste package, backfill/buffer properties, EBS failure scenarios, host rock properties, and biosphere be specified. The focus in this report is on those elements that are unique to crystalline disposal, especially the geosphere representation. Three emplacement concepts are suggested for further analyses: a waste packages containing 4 PWR assemblies emplaced in boreholes in the floors of tunnels (KBS-3 concept), a 12-assembly waste package emplaced in tunnels, and a 32-assembly dual purpose canister emplaced in tunnels. In addition, three failure scenarios were suggested for future use: a nominal scenario involving corrosion of the waste package in the tunnel emplacement concepts, a manufacturing defect scenario applicable to the KBS-3 concept, and a disruptive glaciation scenario applicable to both emplacement concepts. The computational approaches required to analyze EBS failure and transport processes in a crystalline rock repository are similar to those of argillite/shale, with the most significant difference being that the EBS in a crystalline rock repository will likely experience highly heterogeneous flow rates, which should be represented in the model. The computational approaches required to analyze radionuclide transport in the natural system are very different because of the highly channelized nature of fracture flow. Computational workflows tailored to crystalline rock based on discrete transport pathways extracted from discrete fracture network models are recommended.

  10. GLAD: a generic lattice debugger

    International Nuclear Information System (INIS)

    Lee, M.J.

    1992-01-01

    Today, numerous simulation and analysis codes exist for the design, commission, and operation of accelerator beam lines. There is a need to develop a common user interface and database link to run these codes interactively. This paper will describe a proposed system, GLAD (Generic LAttice Debugger), to fulfill this need. Specifically, GLAD can be used to find errors in beam lines during commissioning, control beam parameters during operation, and design beam line optics and error correction systems for the next generation of linear accelerators and storage rings. (author)

  11. Generic maximum likely scale selection

    DEFF Research Database (Denmark)

    Pedersen, Kim Steenstrup; Loog, Marco; Markussen, Bo

    2007-01-01

    in this work is on applying this selection principle under a Brownian image model. This image model provides a simple scale invariant prior for natural images and we provide illustrative examples of the behavior of our scale estimation on such images. In these illustrative examples, estimation is based......The fundamental problem of local scale selection is addressed by means of a novel principle, which is based on maximum likelihood estimation. The principle is generally applicable to a broad variety of image models and descriptors, and provides a generic scale estimation methodology. The focus...

  12. The global biopharma industry and the rise of Indian drug multinationals: implications for Australian generics policy.

    Science.gov (United States)

    Löfgren, Hans

    2007-06-01

    This article provides a synopsis of the new dynamics of the global biopharma industry. The emergence of global generics companies with capabilities approximating those of 'big pharma' has accelerated the blurring of boundaries between the innovator and generics sectors. Biotechnology-based products form a large and growing segment of prescription drug markets and regulatory pathways for biogenerics are imminent. Indian biopharma multinationals with large-scale efficient manufacturing plants and growing R&D capabilities are now major suppliers of Active Pharmaceutical Ingredients (APIs) and generic drugs across both developed and developing countries. In response to generic competition, innovator companies employ a range of life cycle management techniques, including the launch of 'authorised generics'. The generics segment in Australia will see high growth rates in coming years but the prospect for local manufacturing is bleak. The availability of cheap generics in international markets has put pressure on Pharmaceutical Benefits Scheme (PBS) pricing arrangements, and a new policy direction was announced in November 2006. Lower generics prices will have a negative impact on some incumbent suppliers but industrial renewal policies for the medicines industry in Australia are better focused on higher value R&D activities and niche manufacturing of sophisticated products.

  13. Development of a new cause classification method considering plant ageing and human errors for adverse events which occurred in nuclear power plants and some results of its application

    International Nuclear Information System (INIS)

    Miyazaki, Takamasa

    2007-01-01

    The adverse events which occurred in nuclear power plants are analyzed to prevent similar events, and in the analysis of each event, the cause of the event is classified by a cause classification method. This paper shows a new cause classification method which is improved in several points as follows: (1) the whole causes are systematically classified into three major categories such as machine system, operation system and plant outside causes, (2) the causes of the operation system are classified into several management errors normally performed in a nuclear power plant, (3) the content of ageing is defined in detail for their further analysis, (4) human errors are divided and defined by the error stage, (5) human errors can be related to background factors, and so on. This new method is applied to the adverse events which occurred in domestic and overseas nuclear power plants in 2005. From these results, it is clarified that operation system errors account for about 60% of the whole causes, of which approximately 60% are maintenance errors, about 40% are worker's human errors, and that the prevention of maintenance errors, especially worker's human errors is crucial. (author)

  14. Aging

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Kodama, Kazunori; Yamada, Michiko

    1991-01-01

    The hypothesis that exposure to ionizing radiation accelerates the aging process has been actively investigated at ABCC-RERF since 1958, when longitudinal cohort studies of the Adult Health Study (AHS) and the Life Span Study (LSS) were initiated. In their 1975 overall review of aging studies related to the atomic bomb (A-bomb) survivors, Finch and Beebe concluded that while most studies had shown no correlation between aging and radiation exposure, they had not involved the large numbers of subjects required to provide strong evidence for or against the hypothesis. Extending LSS mortality data up to 1978 did not alter the earlier conclusion that any observed life-shortening was associated primarily with cancer induction rather than with any nonspecific cause. The results of aging studies conducted during the intervening 15 years using data from the same populations are reviewed in the present paper. Using clinical, epidemiological, and laboratory techniques, a broad spectrum of aging parameters have been studied, such as postmortem morphological changes, tests of functional capacity, physical tests and measurements, laboratory tests, tissue changes, and morbidity. With respect to the aging process, the overall results have not been consistent and are generally thought to show no relation to radiation exposure. Although some preliminary results suggest a possible radiation-induced increase in atherosclerotic diseases and acceleration of aging in the T-cell-related immune system, further study is necessary to confirm these findings. In the future, applying the latest gerontological study techniques to data collected from subjects exposed 45 years ago to A-bomb radiation at relatively young ages will present a new body of data relevant to the study of late radiation effects. (author) 103 refs

  15. Aging

    International Nuclear Information System (INIS)

    Finch, S.C.; Beebe, G.W.

    1975-01-01

    The hypothesis that ionizing radiation accelerates natural aging has been under investigation at the Atomic Bomb Casualty Commission since 1959. Postmortem observations of morphologic and chemical changes, tests of functional capacity, physical tests and measurements, clinical laboratory tests, tissue changes, morbidity, and mortality have all been examined by ABCC investigators interested in this hypothesis. These studies have been beset with conceptual difficulties centered on the definition and measurement of aging. An empirical approach early led to the calculation of an index of physiologic age as a linear combination of age-related tests of various organ systems. Most studies have been negative but have not involved the large numbers that might be required to provide strong evidence for or against the hypothesis. Mortality, however, has been examined on the basis of a large sample and over the period 1950-1972 had provided no support for the hypothesis of radiation-accelerated aging. Ionizing radiation dose, of course shorten human life, but its life-shortening effect appears to be the result of specific radiation-induced disease, especially neoplasms. The hypothesis is now much less attractive than it was 10-20 years ago but still has some value in stimulating research on aging. The experience of the A-bomb survivors provides an unusual opportunity for a definitive test of the hypothesis. (auth.)

  16. Generic Performance Measures. Chapter 8

    Energy Technology Data Exchange (ETDEWEB)

    Daube-Witherspoon, M. E. [Department of Radiology, University of Pennsylvania, Philadelphia, PA (United States)

    2014-12-15

    The generic nuclear medicine imager, whether a gamma camera, single photon emission computed tomography (SPECT) system or positron emission tomography (PET) scanner, comprises several main components: a detection system, a form of collimation to select γ rays at specific angles, electronics and a computing system to create the map of the radiotracer distribution. This section discusses these components in more detail. The first stage of a generic nuclear medicine imager is the detection of the γ rays emitted by the radionuclide. In the case of PET, the radiation of interest are the 511 keV annihilation photons that result from the interaction of the positron emitted by the radionuclide with an electron in the tissue. For general nuclear medicine and SPECT, there is one or sometimes more than one γ ray of interest, with energies in the range of <100 to >400 keV. The γ rays are detected when they interact and deposit energy in the crystal(s) of the imaging system. There are two main types of detector: crystals that give off light that can be converted to an electrical signal when the γ ray interacts (‘scintillators’) and semiconductors, crystals that generate an electrical signal directly when the γ ray deposits energy in the crystal. Scintillation detectors include NaI(Tl), bismuth germanate (BGO) and lutetium oxyorthosilicate (LSO); semiconductor detectors used in nuclear medicine imagers include cadmium zinc telluride (CZT). Radiation detectors are described in more detail in Chapter 6.

  17. Generic communications index: User's manual

    International Nuclear Information System (INIS)

    Dean, R.S.; Steinbrecher, D.H.; Hennick, A.

    1987-12-01

    This report is a manual for providing information required to use a special computer program developed by the NRC for indexing generic communications. The program is written in a user-friendly menu driven form using dBASE III programming language. It facilitates use of the required dBASE III search and sort capabilities to access records in a database called Generic Communications Index. This index is made up of one record each for all bulletins, circulars, and information notices, including revisions and supplements, from 1971, when such documentation started, through 1986 (or to the latest update). The program is designed for use by anyone modestly acquainted with the general use of IBM-compatible personal computers. The manual contains both a brief overview and a detailed description of the program, as well as detailed instructions for getting started using the program on a personal computer with either a two-floppy disk or a hard disk system. Included at the end are a brief description of how to handle problems which might occur, and notes on the makeup of the program and database files for help in adding records of communications for future years

  18. Management of the aging of critical safety-related concrete structures in light-water reactor plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Arndt, E.G.

    1990-01-01

    The Structural Aging Program has the overall objective of providing the USNRC with an improved basis for evaluating nuclear power plant safety-related structures for continued service. The program consists of a management task and three technical tasks: materials property data base, structural component assessment/repair technology, and quantitative methodology for continued-service determinations. Objectives, accomplishments, and planned activities under each of these tasks are presented. Major program accomplishments include development of a materials property data base for structural materials as well as an aging assessment methodology for concrete structures in nuclear power plants. Furthermore, a review and assessment of inservice inspection techniques for concrete materials and structures has been complete, and work on development of a methodology which can be used for performing current as well as reliability-based future condition assessment of concrete structures is well under way. 43 refs., 3 tabs

  19. Plant G-Proteins Come of Age: Breaking the Bond with Animal Models.

    Science.gov (United States)

    Trusov, Yuri; Botella, José R

    2016-01-01

    G-proteins are universal signal transducers mediating many cellular responses. Plant G-protein signaling has been modeled on the well-established animal paradigm but accumulated experimental evidence indicates that G-protein-dependent signaling in plants has taken a very different evolutionary path. Here we review the differences between plant and animal G-proteins reported over past two decades. Most importantly, while in animal systems the G-protein signaling cycle is activated by seven transmembrane-spanning G-protein coupled receptors, the existence of these type of receptors in plants is highly controversial. Instead plant G-proteins have been proven to be functionally associated with atypical receptors such as the Arabidopsis RGS1 and a number of receptor-like kinases. We propose that, instead of the GTP/GDP cycle used in animals, plant G-proteins are activated/de-activated by phosphorylation/de-phosphorylation. We discuss the need of a fresh new look at these signaling molecules and provide a hypothetical model that departs from the accepted animal paradigm.

  20. Structural Aging Program to evaluate continued performance of safety-related concrete structures in nuclear power plants

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.; Ellingwood, B.R.

    1994-01-01

    This report discusses the Structural Aging (SAG) Program which is being conducted at the Oak Ridge National Laboratory (ORNL) for the United States Nuclear Regulatory commission (USNRC). The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. The program is organized into three technical tasks: Materials Property Data Base, Structural Component Assessment/Repair Technologies, and Quantitative Methodology for continued Service Determinations. Objectives and a summary of recent accomplishments under each of these tasks are presented

  1. Skin rash during treatment with generic itraconazole.

    Science.gov (United States)

    De Vuono, Antonio; Palleria, Caterina; Scicchitano, Francesca; Squillace, Aida; De Sarro, Giovambattista; Gallelli, Luca

    2014-04-01

    Generic drugs have the same active substance, the same pharmaceutical form, the same therapeutic indications and a similar bioequivalence with the reference medicinal product (branded). Although a similar efficacy is postulated, some cases of clinical inefficacy during treatment with generic formulations have been reported. In this case, we describe a woman with onychomycosis that developed a skin rash during treatment with a generic formulation of itraconazole. Drug administration and its re-challenge confirmed the association between itraconazole and skin rash. Both Naranjo probability scale and World Health Organization causality assessment scale documented a probable association between generic-itraconazole and skin rash. The switch from generic formulation to brand one induced an improvement of symptoms. Since we are unable to evaluate the role of each excipient in the development of skin rash, we cannot rule out their involvement. However, more data are necessary to better define the similarities or differences between branded and generic formulations.

  2. Generic medicines and generic substitution: contrasting perspectives of stakeholders in Ireland.

    Science.gov (United States)

    O'Leary, A; Usher, C; Lynch, M; Hall, M; Hemeryk, L; Spillane, S; Gallagher, P; Barry, M

    2015-12-15

    The Health (Pricing and Supply of Medical Goods) Act 2013 passed into law in July 2013 and legislated for generic substitution in Ireland. The aim of the study was to ascertain the knowledge and perceptions of stakeholders i.e. patients, pharmacists and prescribers, of generic medicines and to generic substitution with the passing of legislation. Three stakeholder specific questionnaires were developed to assess knowledge of and perceptions to generic medicines and generic substitution. Purposive samples of patients, prescribers and pharmacists were analysed. Descriptive quantitative and qualitative analyses were undertaken. A total of 762 healthcare professionals and 353 patients were recruited. The study highlighted that over 84% of patients were familiar with generic medicines and are supportive of the concept of generic substitution. Approximately 74% of prescribers and 84% of pharmacists were supportive of generic substitution in most cases. The main areas of concern highlighted by the healthcare professionals that might impact on the successful implementation of the policy, were the issue of bioequivalence with generic medicines, the computer software systems used at present in general practitioner (GP) surgeries and the availability of branded generics. The findings from this study identify a high baseline rate of acceptance to generic medicines and generic substitution among patients, prescribers and pharmacists in the Irish setting. The concerns of the main stakeholders provide a valuable insight into the potential difficulties that may arise in its implementation, and the need for on-going reassurance and proactive dissemination of the impact of the generic substitution policy. The existing positive attitude to generic medicines and generic substitution among key stakeholders in Ireland to generic substitution, combined with appropriate support and collaboration should result in the desired increase in rates of prescribing, dispensing and use of generic

  3. Generic domain models in software engineering

    Science.gov (United States)

    Maiden, Neil

    1992-01-01

    This paper outlines three research directions related to domain-specific software development: (1) reuse of generic models for domain-specific software development; (2) empirical evidence to determine these generic models, namely elicitation of mental knowledge schema possessed by expert software developers; and (3) exploitation of generic domain models to assist modelling of specific applications. It focuses on knowledge acquisition for domain-specific software development, with emphasis on tool support for the most important phases of software development.

  4. PROBLEM OF GENERIC REPLACEMENT: ADVANTAGES AND DISADVANTAGES

    Directory of Open Access Journals (Sweden)

    S. N. Tolpygina

    2009-01-01

    Full Text Available The main differences between original and generic drugs as well as registration criteria for generics are described. Possible reasons of discrepancy in bioequivalence and therapeutic equivalence of original and generic drugs are reviewed. The examples of such a discrepancy as a result of comparative clinical trails (enalapril maleate are discussed. Approaches to planning of comparative trails on drug therapeutic equivalence are presented. 

  5. Skin rash during treatment with generic itraconazole

    OpenAIRE

    De Vuono, Antonio; Palleria, Caterina; Scicchitano, Francesca; Squillace, Aida; De Sarro, Giovambattista; Gallelli, Luca

    2014-01-01

    Generic drugs have the same active substance, the same pharmaceutical form, the same therapeutic indications and a similar bioequivalence with the reference medicinal product (branded). Although a similar efficacy is postulated, some cases of clinical inefficacy during treatment with generic formulations have been reported. In this case, we describe a woman with onychomycosis that developed a skin rash during treatment with a generic formulation of itraconazole. Drug administration and its re...

  6. Development of generic soil profiles and soil data development for SSI analyses

    Energy Technology