WorldWideScience

Sample records for plant life extension

  1. Nuclear plant life extension

    International Nuclear Information System (INIS)

    Negin, C.A.

    1989-01-01

    The nuclear power industry's addressing of life extension is a natural trend in the maturation of this technology after 20 years of commercial operation. With increasing emphasis on how plants are operated, and less on how to build them, attention is turning on to maximizing the use of these substantial investments. The first studies of life extension were conducted in the period from 1978 and 1982. These were motivated by the initiation, by the Nuclear Regulatory Commission (NRC), of studies to support decommissioning rulemaking. The basic conclusions of those early studies that life extension is feasible and worth pursuing have not been changed by the much more extensive investigations that have since been conducted. From an engineering perspective, life extension for nuclear plants is fundamentally the same as for fossil plants

  2. Managing BWR plant life extension

    International Nuclear Information System (INIS)

    Ianni, P.W.; Kiss, E.

    1985-01-01

    Recent studies have confirmed that extending the useful life of a large nuclear plant can be justified with very high cost benefit ratio. In turn, experience with large power plant systems and equipment has shown that a well-integrated and -managed plan is essential in order to achieve potential economic benefits. Consequently, General Electric's efforts have been directed at establishing a life extension plan that considers alternative options and cost-effective steps that can be taken in early life, those appropriate during middle life, and those required in late life. This paper briefly describes an approach designed to provide the plant owner a maximum of flexibility in developing a life extension plan

  3. NDE and plant life extension

    International Nuclear Information System (INIS)

    Liu, S.N.; Ammirato, F.V.; Nottingham, L.D.

    1991-01-01

    Component life extension is the process of making run-repair-replace decisions for plant components and includes a thorough analysis of the capability of the component to perform throughout the projected lifetime. For many critical plant components, nondestructive evaluation (NDE) is essential in determining whether the component can be operated safely and economically in the extended life period and to help utilities determine safe and economic inspection intervals. NDE technology is required for not only detecting defects that could grow to a size of concern during extended lifetimes, but also will be called upon to measure and monitor accumulating material degradation that strongly affects component reliability. This paper discusses the role of NDE in life extension by reviewing three examples--a reactor pressure vessel, steam turbine-generator rotors, and generator retaining rings. In each example, the contribution of NDE to life extension decisions is described. (author)

  4. Japanese plant life extension program

    International Nuclear Information System (INIS)

    Yoshitsugu, M.

    1988-01-01

    As one of the main items of up-grading light water reactor program in Japan, plant life extension has been recommended by Advisory Committee of Ministry of International trade and Industry and the practical work has begun to be carried out. It is overviewed here. After preliminary works, including investigation on the state of the arts through a entrusted survey work, participation in international meetings and exchange of informations with related organizations, actual work has just started. So-called critical components based on our experience during the past 17 years have been listed up and some experimental works inaugurated as from 1987

  5. Remaining life assessment and plant life extension in high temperature components of power and petrochemical plant

    International Nuclear Information System (INIS)

    Fleming, A.

    2003-01-01

    This paper explains the reasons why plant life can so easily be extended beyond the original design life. It details the means by which plant life extension is normally achieved, a structured plan for achieving such plant life extension at reasonable cost and some of the key techniques used in assessing the remaining life and discusses the simple repair options available. (author)

  6. Life extension for German nuclear power plants

    International Nuclear Information System (INIS)

    Heller, W.

    2005-01-01

    The Federation of German Industries (BDI) commissioned a study of the ''Economic Effects of Alternative Lifetimes of Nuclear Power Plants in Germany.'' The expert organizations invited as authors were the Power Economy Institute of the University of Cologne (EWI) and Energy Environment Forecast Analysis GmbH (EEFA), Berlin. The reasons for commissioning the Study include the changed framework conditions (deregulation, CO 2 emission certificate trading, worldwide competition for resources), which have altered the energy supply situation in Europe. The findings of the Study were presented to the public by the BDI on October 26, 2005. The study deals with two scenarios of extended lifetimes for German nuclear power plants of 40 and 60 years as against the existing regulations with plant lifetimes limited to approx. 32 years. The longer service lives of plants are reflected in reduced electricity generation costs and thus may have a positive influence on electricity prices. Moreover, there would be additional growth of production together with additional jobs, all of which would add up to nearly 42,000 persons for all sectors of the economy as compared to the basic scenario. Also, CO 2 emissions could be curbed by up to 50 million tons of carbon dioxide. The Study offers ample and valid reasons in favor of extending the lifetimes of nuclear power plants. In the interest of general welfare, politics would be well advised to relax the restrictions on plant life in the course of this legislative term. (orig.)

  7. Plant maintenance and plant life extension issue, 2008

    International Nuclear Information System (INIS)

    Agnihotri, Newal

    2008-01-01

    The focus of the March-April issue is on plant maintenance and plant life extension. Major articles include the following: Exciting time to be at the U.S. NRC, by Dale Klein, Nuclear Regulatory Commission; Extraordinary steps to ensure a minimal environmental impact, by George Vanderheyden, UniStar Nuclear Energy, LLC.; Focused on consistent reduction of outages, by Kevin Walsh, GE Hitachi Nuclear Energy; On the path towards operational excellence, by Ricardo Perez, Westinghouse Electric Company; Ability to be refuelled on-line, by Ian Trotman, CANDU Services, Atomic Energy of Canada, Ltd.; ASCA Application for maintenance of SG secondary side, by Patrick Wagner, Wolf Creek Nuclear Operating Corporation, Phillip Battaglia and David Selfridge, Westinghouse Electric Company; and, An integral part of the landscape and lives, by Tyler Lamberts, Entergy Nuclear Operations, Inc. The Industry Innovation article is titled Steam generator bowl drain repairs, by John Makar and Richard Gimple, Wolf Creek Nuclear Operating Corporation

  8. Operational data collection and analysis for nuclear plant life extension

    International Nuclear Information System (INIS)

    DuCharme, A.R.; Berg, R.M.; Bailey, T.L.

    1989-01-01

    This paper describes initial work undertaken by the US Department of Energy, through Sandia National Laboratories in Albuquerque, New Mexico, to define the operational data necessary for support of nuclear plant life extension (PLEX) programs. This work is being performed in coordination with the Working Group on Plant Life Extension of the US Nuclear Management and Resources Council. The intent of the effort is to use results gained initially from pilot PLEX programs a US BWR and a US PWR to build towards the use of ''PLEX indicators'' by which a plant's readiness for successful life extension can be measured. Another objective of the study was to examine chemistry data in detail to determine how well US plants are collecting, preserving, and trending the chemistry data that is important to PLEX. The methods used to disseminate this data to outside agencies and other utilities were studied. Finally, an analysis was made to determine additional chemistry data needed to support PLEX

  9. Analysis of integrated plant upgrading/life extension programs

    International Nuclear Information System (INIS)

    McCutchan, D.A.; Massie, H.W. Jr.; McFetridge, R.H.

    1988-01-01

    A present-worth generating cost model has been developed and used to evaluate the economic value of integrated plant upgrading life extension project in nuclear power plants. This paper shows that integrated plant upgrading programs can be developed in which a mix of near-term availability, power rating, and heat rate improvements can be obtained in combination with life extension. All significant benefits and costs are evaluated from the viewpoint of the utility, as measured in discounted revenue requirement differentials between alternative plans which are equivalent in system generating capacity. The near-term upgrading benefits are shown to enhance the benefit picture substantially. In some cases the net benefit is positive, even if the actual life extension proves to be less than expected

  10. Nuclear power plants life extension and decommissioning its economic aspects

    International Nuclear Information System (INIS)

    Watanabe, Yoshiaki

    1994-06-01

    In USA where the development of nuclear power was started early, the life of nuclear power plants expires successively around the turn of century, and the serious hindrance to electric power supply is feared. Therefore, the research for extending 40 year approved period of operation is in progress. By the extension of life of nuclear power plants, huge cost reduction is estimated as compared with the construction of new plants. However, due to the rise of the cost for the life extension, there were the cases of forced decommissioning. In this book, the present state of the life extension of nuclear power stations, the economical assessment and analysis of the life extension by DOE, the economical assessment by MIDAS method of Electric Power Research Institute, the economical assessment by cost-benefit method of Northern States Power Co., the assessment of the long term operation possibility of nuclear power stations, the economical assessment system for the life extension in Japan, the present state of the decommissioning of nuclear power stations and that in USA, Canada and Europe, the assessment of the decommissioning cost by OECD/NEA, and the decommissioning cost for thermal power stations are described. (K.I.)

  11. Technology and testing for the extension of plant life

    International Nuclear Information System (INIS)

    Blumer, U.R.; Edelmann, X.

    1988-01-01

    This paper describes selected portions of a recommended program for the application of equipment-manufacturing-related technology and testing for the extension of life for operating nuclear power plants. It is appropriate to mention that the Swiss nuclear plants, their staffs, and the supporting Swiss nuclear industry are rightfully proud of their record of performance. Plant staffs have been intimately involved in system and equipment design and engineering from the very beginnings of their plants. Maintenance of the plant systems and equipment is referred to as engineering rather than maintenance, because it is viewed as a technical effort and an extension of the original plant and equipment design and construction effort. Care, competence, cleanliness, and attention to detail have been bywords for the Swiss plants. Success has been demonstrated through enviable availability performance. With operation and availability capability already demonstrated, the Swiss are now turning their attention to the extension of plant life. This summary describes some aspects of this work, which is fundamentally based on the application of technology and testing skills developed for equipment manufacture and the original installation of this equipment in the plants, but has been enhanced by research and development (R and D) and an ongoing effort to serve utilities in their maintenance activities

  12. Nuclear power plant life extension in the United Kingdom

    International Nuclear Information System (INIS)

    Goodison, D.; Seddon, J.W.; Pape, E.M.

    1991-01-01

    The safety cases for the United Kingdom's older nuclear power plant have been reviewed by their utilities in order to justify continued operation of the reactors up to an age of at least 30 year. These 'long term safety reviews' have identified worthwhile plant modifications and aspects where further studies or plant inspections are required. As the plants approach the age of 30 years, 'life extension reviews' are now being undertaken, concentrating on management of ageing, to support operation to at least 40 years. (author)

  13. Reliability Centered Maintenance as a tool for plant life extension

    International Nuclear Information System (INIS)

    Elliott, J.O.; Mulay, J.N.; Nakahara, Y.

    1991-01-01

    Currently in the nuclear industry there is a growing interest in lowering the cost and complexity of maintenance activities while at the same time improving plant reliability and safety in an effort to prepare for the technical and regulatory challenges of life extension. This seemingly difficult task is being aided by the introduction of a maintenance philosophy developed originally by the airline industry and subsequently applied with great success both in that industry and the U.S. military services. Reliability Centered Maintenance (RCM), in its basic form, may be described as a consideration of reliability and maintenance problems from a systems level approach, allowing a focus on preservation of system function as the aim of a maintenance program optimized for both safety and economics. It is this systematic view of plant maintenance, with the emphasis on overall functions rather than individual parts and components which sets RCM apart from past nuclear plant maintenance philosophies. It is also the factor which makes application of RCM an ideal first step in development of strategies for life extension, both for aging plants, and for plants just beginning their first license term. (J.P.N.)

  14. EPRI/DOE nuclear plant life extension overview

    International Nuclear Information System (INIS)

    Carey, J.J.; Lapides, M.E.; Harrison, D.; Ducharme, A.

    1987-01-01

    Recognizing the major investment in current U.S. nuclear capacity and the excellent prospects that these units have a useful life substantially in excess of their 40 year license term, EPRI and DOE have jointly undertaken a comprehensive, multiyear, nuclear plant life extension program. The program, which has its antecedents in EPRI studies of 1978-9, aims to support U.S. utilities, first in verifying the requirements of extended operation and then in implementing a plan for achieving extended service and license renewal. The effort, begun in 1985, has already yielded numerous benefits and is expected to further aid in improving near-term performance of nuclear units. A utility LWR Plant Life Extension Committee has been established to provide overview and guidance to the DOE/EPRI research and development activities and also to develop and integrate utility responses to licensing and codes and standards issues. Pilot study projects, performed by Virginia Power and Northern States Power, were the initial EPRI/DOE focus. This base has gradually expanded to incorporate other utilities and generating units, as well as a broad base of technology support. The latter includes: a) economic and financial analysis methods applicable at the unit, region and national level, b) long-term materials deterioration analysis and sampling, c) component life prediction methods and d) refurbishment and repair evaluations. This paper presents the history and status of the overall EPRI/DOE program

  15. 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

  16. Near-term benefits of the plant life extension program

    International Nuclear Information System (INIS)

    Kaushansky, M.M.

    1987-01-01

    The aging process can be expected to reduce the availability and increase the production costs of nuclear power plants over time. To mitigate this process and recover or enhance plant availability, capacity, thermal efficiency, and maintenance expenditures, the utility must dedicate increased attention and commitment to a comprehensive plant life extension (PLEX) program. Improvements must be justified by balancing the cost of the recommended modifications with the economic value of benefits obtained from its implementation. It is often extremely difficult for utility management to make an optimal selection from among hundreds of proposed projects, most of which are cost-effective. A properly structured PLEX program with an emphasis on near-term benefits should provide the utility with a means of evaluating proposed projects, thus determining the optimum combination for authorization and implementation

  17. Low-level radioactive waste associated with plant life extension

    International Nuclear Information System (INIS)

    Sciacca, F.; Zigler, G.; Walsh, R.

    1992-01-01

    Many utilities operating nuclear power plants are expected to seek to extend the useful life of their plants through license renewal. These US Nuclear Regulatory Commission (NRC) licensees are expected to implement enhanced inspection, surveillance, testing, and monitoring (ISTM) as needed to detect and mitigate age-related degradation of important structures, systems, and components (SSCs). In addition, utilities may undertake various refurbishment and upgrade activities at these plants to better assure economic and reliable power generation. These activities performed for safety and/or economic reasons can result in radioactive waste generation, which is incremental to that generated in the original licensing term. Work was performed for the NRC to help define and characterize potential environmental impacts associated with nuclear plant license renewal and plant life extension. As part of this work, projections were made of the types and quantities of low-level radioactive waste (LLRW) likely to be generated by licensee programs. These projections were needed to estimate environmental impacts related to the disposal of such wastes

  18. International requirements for life extension of nuclear power plants

    International Nuclear Information System (INIS)

    Wernicke, Robert

    2009-01-01

    Lifetime extension or long-term operation of nuclear facilities are topics of great international significance against the backdrop of a fleet of nuclear power plants of which many have reached 2/3 of their planned life. The article deals with the conditions for, and the specific requirements of, seeking long-term operation of nuclear power plants as established internationally and on the basis of IAEA collections. Technically, long-term operation is possible for many of the nuclear power plants in the world because, normally, they were built on the basis of conservative rules and regulations and, as a consequence, incorporate significant additional safety. Application of requirements to specific plants implies assessments of technical safety which show that conservative design philosophies created reserves and, as a consequence, there is an adequate level of safety also in long-term plant operation. For this purpose, the technical specifications must be revised, necessary additions made, and (international) operating experience taken into account and management of aging established. Two examples are presented to show how the approach to long-term plant operation is put into practice on a national level. (orig.)

  19. Overview of plant life extension technology development in Japan

    International Nuclear Information System (INIS)

    Takahashi, T.; Arai, H.; Akiyama, M.; Mishima, Y.; Okubo, T.

    1993-01-01

    In Japan, it is expected that the nuclear power will continue to play an important role in electric power supply. Since it is expected that the fast breeder reactor (FBR) will be introduced sometime during the first half of the 21st century, light water reactors (LWRs) will continue to play a key role some 30 to 40 years to come. For this reason, technology development projects are being implemented to further enhance light water reactor technology and thereby improve the reliability of LWRs. From this point, the Plant Life Extension (PLEX) technology development program [1-4] is entrusted by the Ministry of International Trade and Industry to the Japan Power Engineering and Inspection Corporation (JAPEIC). This program is an 11-year plan which started in 1985. The objectives are to extend the service lives of existing LWRs to increase the energy generated by these plants during their lifetime, and to reduce the lifetime generating costs. In this report, we will present our project overview and recent activities with respect to extensive verification tests on component material behavior. The JAPEIC PLEX project is divided into 3 phases. Phase I is the feasibility study. Phase 2 involves the verification tests and the evaluation of life extension technologies. The overall evaluation of the project will be conducted in Phase 3. The feasibility study of Phase I has been completed in fiscal year 1985 and 1986. In Phase I, the important components (the components and structures that are likely to govern the lives of nuclear power plants) have been selected. (author)

  20. US national and regional impacts of nuclear plant life extension

    International Nuclear Information System (INIS)

    Makovich, L.; Forest, L.; Fletcher, T.

    1988-01-01

    The US will need new sources of electricity in the early 21st century due to retirement of much of the nation's generating capacity. Almost all of the US nuclear capacity would be included in those retirements if, as originally expected, the nuclear units were shut down and decommissioned as the operating licenses expired between 2005 and 2025. However, given the large demands for new capacity during that period, nuclear plant life extension (NUPLEX) -- the extension of operating life beyond the original license period -- needs to be considered as an electricity source. This study assesses the benefits and costs of NUPLEX relative to the anticipated competing sources of electricity supply in the early 21st century. We find that NUPLEX yields large net benefits under a wide range of plausible economic conditions. This study associates net benefits with electricity cost savings, thereby abstracting from speculative reliability considerations. To illustrate the effects of uncertainty, the study assesses NUPLEX net benefits under varying assumptions on NUPLEX investment costs and other future economic conditions

  1. Proceedings of the topical meeting on nuclear power plant life extension

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    This book contains the proceedings of the topical meeting on nuclear power plant life extension. The sessions are organized under the following headings: Perspectives on nuclear power plant life extension, the potential for additional years of power production, NRC and industry life extension initiatives, concrete and structures degradation and evaluation of useful remaining life, plant life extension programs, Reactor pressure vessel and intervals degradation and evaluation of useful remaining life, life extension decision making issues and institutions, systems degradation and evaluation of remaining life, monitoring and repair, design records and maintenance activities for life extension, Mechanical and electrical component degradation and evaluation of remaining life, expert systems and other techniques for enhanced and continued operation, life extension aspect of codes, standards, and related technologies, piping and valve degradation and evaluation of useful remaining life

  2. Plant control system upgrades in the context of industry trends towards plant life-extension

    International Nuclear Information System (INIS)

    De Grosbois, J.; Basso, R.; Hepburn, A.; Kumar, V.

    2002-01-01

    Domestic CANDU nuclear plants were brought online between 1972 and 1986. Over the next decade, most of these stations will be nearing the end of their designed operating life. Effort has traditionally been placed on ensuring that the existing installed plant control system equipment could operate reliably until the end of this design life. Until recently, little attention has been given to plant control system upgrades or replacements to meet the expected requirement for 30+ years of additional plant operation following potential plant refurbishments. Industry developments are changing this thinking. The combination of expected increases in electricity demand (and prices), and the many recent successful turnaround stories of U.S. nuclear power plants has resulted in new interest in plant life improvement and plant life extension programs. Plant control system upgrade decisions are now being driven by the need to replace or upgrade these systems to support plant life extension. This article is the first of several that investigate aspects of plant control system upgrades or replacement, specifically in the context of the CANDU station digital control computers (DCCs). It sets the context for the discussion in the subsequent articles by providing a brief review of industry trends favouring plant refurbishment, by outlining the basic issues of aging and obsolescence of control system equipment, by establishing the need for upgrades and replacements, and by introducing some of the basic challenges to be addressed by the industry as it moves forward. (author)

  3. Plant life extensions for German nuclear power plants? Controversial discussion on potential electricity price effects

    International Nuclear Information System (INIS)

    Matthes, Felix C.; Hermann, Hauke

    2009-06-01

    The discussions on electricity price effects in case of the plant life extension of German nuclear power plants covers the following topics: (1) Introduction and methodology. (2) Electricity generation in nuclear power plants and electricity price based on an empirical view: electricity generation in nuclear power plants and final consumption price for households and industry in the European Union; electricity generation in nuclear power plants and electricity wholesale price in case of low availability of nuclear power plants in Germany; comparison of electricity wholesale prices in Germany and France. (3) Model considerations in relation to electricity prices and nuclear phase-out. (4) Concluding considerations.

  4. U.S. National and regional impacts nuclear plant life extension

    International Nuclear Information System (INIS)

    Makovick, L.; Fletcher, T.; Harrison, D.L.

    1987-01-01

    The purpose of this study was to evaluate the economic impacts of nuclear plant life extension on a national and regional level. Nuclear generating capacity is expected to reach 104 Gigawatts (119 units) in the 1994-1995 period. Nuclear units of the 1970 to 1980 vintage are expected to account for 96% of nuclear capacity. As operating licenses expire, a precipitous decline in nuclear capacity results, with an average of 5 gigawatts of capacity lost each year from 2010 to 2030. Without life extension, 95% of all nuclear capacity is retired between the years 2010 and 2030. Even with historically slow growth in electric demand and extensive fossil plant life extension, the need for new generating capacity in the 2010-2030 time period is eight times greater than installed nuclear capacity. Nuclear plant life extension costs and benefits were quantified under numerous scenarios using the DRI Electricity Market Model. Under a wide range of economic assumptions and investment requirements, nuclear plant life extension resulted in a net benefit to electricity consumers. The major source of net benefits from nuclear plant life extension results from the displacement of fossil-fired generating sources. In the most likely case, nuclear plant life extension provides a dollar 200 billion net savings through the year 2030. Regions with a large nuclear capacity share, newer nuclear units and relatively higher costs of alternative fuels benefit the most from life extension. This paper also discusses the importance of regulatory policies on nuclear plant life extension

  5. Repair and replacement of reactor internals for plant life extension

    International Nuclear Information System (INIS)

    Graae, T.

    1998-01-01

    Recent experience from early Swedish BWRs corroborate that all components in a nuclear power plant can be repaired or replaced with new ones. Oskarshamn 1 has gone through a thorough refurbishment project. A number of internals were repaired or replaced including the core shroud support which was welded to the bottom of the reactor pressure vessel. The project verifies that it is fully possible to carry out complicated inspection and repair work inside a nuclear pressure vessel which has been in operation for more than 20 years. Along with increased capacity factor, operating nuclear power plants get the financial conditions needed for extensive repair and modernization projects. Large power output leads to short pay-back times for the investments. The FENIX project at Oskarshamn 1 is such a project. There are utilities whose policy is to keep their plants in as-new condition for an unlimited length of time. (orig.)

  6. Plant life extensions for German nuclear power plants? Controversial discussion profit taking of nuclear power plant operators

    International Nuclear Information System (INIS)

    Matthes, Felix C.

    2009-10-01

    The discussion on the plant life extensions for German nuclear power plants beyond the residual quantity of electricity particularly focus on three aspects: Effects for the emission of carbon dioxide as a greenhouse gas; Development of the electricity price for which a reduction or attenuation is postulated due to a plant life extension; Skimming of additional profits at operating companies and their use in the safeguarding of the future (development of renewable energies, support of energy efficiency, promotion of the research, consolidation of the public budget, and so on). Under this aspect, the author of the contribution under consideration reports on the profit taking of nuclear power plant operators. The presented analysis considers three aspects: (a) Specification of the quantity structures for the investigated model of plant life extension; (b) The decisive parameter is the revenue situation and thus the price development for electricity at wholesale markets; (c) Determination and evaluation of the course in time of the profit taking.

  7. Life prediction study of reactor pressure vessel as essential technical foundation for plant life extension

    International Nuclear Information System (INIS)

    Nakajima, H.; Nakajima, N.; Kondo, T.

    1987-01-01

    The life of a LWR plant is determined essentially by the limit of reliable performance of the components which are difficult to replace without high economic and/or safety risks. Typical of such a component is the reactor pressure vessel (RPV). The engineering life of a RPV of a given quality of steel is considered to be a complex function of factors such as the resistance to fracture, which has deteriorated due to neutron irradiation and thermal aging, and generation of surface flaws by environmental effects such as corrosion and their growth under operational load that varies during steady state operation and transients. In an attempt to evaluate the engineering life of a RPV of a LWR, a preliminary survey was made by applying a set of knowledge accumulated primarily in the field of subcritical crack growth behavior of RPV steels in reactor water environments. The major conclusions drawn are: (1) the life of a RPV is dependent on the quality of steel used, particularly with respect to any minor impurities it contains. (2) The issue of plant life extension in RPV aspect is found to be optimistic for cases where the steels used satisfy a reasonable level of quality control. (3) The importance of providing sound scientific foundation is stressed for the implementation of a practicable life extension scheme: this can be established through intensified studies of flaw growth and fracture behaviours in well defined testings under reasonably simulated service conditions

  8. Oconee: Is life extension in the cards for plants of this vintage

    International Nuclear Information System (INIS)

    Killian, D.E.; Moore, K.E.; Tally, C.W.

    1986-01-01

    Recent nuclear-industry interest in plant life extension is prompted by the realization that the economics of plant life extension are clearly favorable. Studies sponsored by the Electric Power Research Institute (EPRI) show that replacing even the most costly nuclear components can easily be justified, if the life of the plant can be extended just a few years. This may not be apparent for the early, small plants, but its applicability to the larger plants that started to appear in the early 70s-such as the three 860-MW Oconee units-is hard to dispute. The large capital investment in the typical nuclear station and extensive decommissioning costs add impetus to life-extension efforts. The same is true for fossil plants, and they are being successfully refurbished to extend their operating lives. Refurbishment of a fossil plant is comparatively simple, however, especially with regard to licensing and environmental qualifications where recognized standards are already in place. In the case of nuclear plants, much work must be done before all the pertinent issues and alternatives are identified. Potentially conflicting objectives may require resolution before a utility makes long-term decisions about life extension. For example, a utility may decide to designate a plant to accommodate grid load swings. In the near term, this may be a logical choice. However, the long-term negative aspects of component thermal cycling should be considered, especially if plant life extension is deemed important

  9. The ASME Section 11 Special Working Group On Plant Life Extension

    International Nuclear Information System (INIS)

    Katz, L.R.

    1990-01-01

    The codes and standards applicable to plant life extension have not been identified in the U.S. at this time. However, several initiatives have been taken to establish specific codes and standards pertaining to nuclear plant life extension (PLEX). One of these initiatives, sponsored by ASME, is the Section XI Special Working Group on Plant Life Extension (SWG-PLEX). The SWG-PLEX reports to the ASME Section XI Subcommittee and is responsible for recommending or drafting rules and requirements for modifying Section XI to accommodate age-related degradation to support nuclear plant life extension. This paper summarizes the results and reports the activities of the SWG-PLEX during the 1989/1990 period

  10. Nuclear plant owners move closer to life extension

    International Nuclear Information System (INIS)

    Smith, D.J.

    1991-01-01

    A major debate is now underway about the safety of 40-year-old nuclear power plants. Under the Atomic Energy Act of 1954 a nuclear power plant's license is limited to a maximum of 40 years. Although the act permits the renewal of an operating license, it does not outline any standards or procedures for determining when or under what conditions a plant's operating license should be renewed. This paper reports that the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE) are co-sponsors of a program to demonstrate the license renewal process for two nuclear power plants - Yankee Atomic Electric's 175-MW Yankee PWR plant and Northern States Power's 536-MW Monticello BWR plant. The demonstration is known as the lead plant project. Yankee Atomic has already analyzed the plant's condition and evaluated aging using computer-based expert systems and the plant's operating experience. During these tests Yankee Atomic found embrittlement of the reactor vessel

  11. 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

  12. Plant-life extension planning for an operating LMFBR

    International Nuclear Information System (INIS)

    King, R.W.

    1985-01-01

    The study concluded that continued EBR-II operation is certainly feasible for well beyond 10 more years, and that continued demonstration of the unique inherent safety and operability features of a pool-type liquid-metal-cooled reactor and the demonstration of a reasonable operating lifetime are very important and will provide invaluable information for the design and development of the next generation nuclear power plants

  13. Development of procedural requirements for life extension of nuclear power plants

    International Nuclear Information System (INIS)

    Lee, Sang Hoon; Son, Moon Kyu; Jeong, Ji Hwan; Chang, Keun Sun; Ham, Chul Hoon; Chang, Soon Hong

    2002-03-01

    Technical issues relevant to life extension of NPP were investigated. The GALL report, domestic PSR and periodic inspection rules were reviewed. Technical issues appearing in the safety evaluation reports related to license renewal of Calvert Ciffs 1 and 2 and Qconee 1,2 and 3 NPPs were reviewed. Preliminary study on PSA usage in NPP life extension assessment was performed and further works were suggested. The environment of rules and regulations was analyzed from the viewpoint of plant life extension. Two alternatives are suggested to revise the current domestic nuclear acts

  14. Development of procedural requirements for life extension of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Son, Moon Kyu [Korea Association for Nuclear Technology, Taejon (Korea, Republic of); Jeong, Ji Hwan [Baekseok College, Cheonan (Korea, Republic of); Chang, Keun Sun [Sunmoon Univ., Asan (Korea, Republic of); Ham, Chul Hoon [The Catholic University of Korea, Seoul (Korea, Republic of); Chang, Soon Hong [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    2002-03-15

    Technical issues relevant to life extension of NPP were investigated. The GALL report, domestic PSR and periodic inspection rules were reviewed. Technical issues appearing in the safety evaluation reports related to license renewal of Calvert Ciffs 1 and 2 and Qconee 1,2 and 3 NPPs were reviewed. Preliminary study on PSA usage in NPP life extension assessment was performed and further works were suggested. The environment of rules and regulations was analyzed from the viewpoint of plant life extension. Two alternatives are suggested to revise the current domestic nuclear acts.

  15. Characterization of in-containment cables for nuclear plant life extension

    International Nuclear Information System (INIS)

    DuCharme, A.R.; Bustard, L.D.

    1988-01-01

    Electrical cable is made by a large number of manufacturers and used for a variety of applications in nuclear plants. cables have been identified in the Monticello and Surry Pilot Plant life extension studies and the NRC Nuclear Plant Aging Research Program as components important to the economic and safety aspects of life extension. Currently, fitness for service is largely determined by preoperational testing. The US Department of Energy is supporting work at Sandia National Laboratories to assess the technical basis for the life extension of cables found inside containment at US nuclear plants. The work is being performed in coordination with the Nuclear Management and Resource Council's (NUMARC) NUPLEX Working Group. The initial task of this effort is to characterize the design attributes of in-containment cables. This has been completed via development of a data base depicting the manufacturer, type, material composition, use, qualification, and relative popularity of cables installed in containment. Other ongoing work is focused on a review of cable operational experience and assessment of the issues affecting cable life extension. In the long term, the work aims to identify the technical criteria and life extension strategies needed to support continued cable qualification by nuclear plant owner/operators. 7 refs., 4 tabs

  16. Life extension for fossil power plants: The EPRI [Electric Power Research Institute] strategy

    International Nuclear Information System (INIS)

    Byron, J.; Dooley, B.

    1988-01-01

    Fossil fuel-fired generating plants have traditionally been built under the assumption of an economic life of 20-30 years. Due to low load growth, escalating interest rates and costs of construction, and increasing regulation, great interest is expressed in retaining these units in service for 50-60 years or longer. Life extension activities are part of an ongoing process that continues throughout the extended lives of a utility's units. The process begins with an initial evaluation of life extension as a generation alternative, resulting in a ranking of units for life extension and a prioritization of components for evaluation. As the process continues, more detailed inspection data are created by a three-level approach, as well as a means for collecting, organizing and scheduling the information. This is implemented through the Integrated Life Extension Management (ILEM) model. This model provides information needed for management decision making such as component performance on unit power rating, availability of components on unit availability, component performance on unit availability and overall costs of the life extension tasks. Risks involved in life extension include the initial unavailability of capacity credits, uncertainty as to the level of availability that can be achieved by the life-extended plant, and uncertainties in environmental compliance. 8 refs., 1 fig., 2 tabs

  17. I and C systems refurbishment projects for plant life extension

    International Nuclear Information System (INIS)

    Andrashov, A.A.; Sklyar, V.V.; Siora, A.A.

    2012-01-01

    This paper describes the approach to implementation of Nuclear Power Plants (NPPs) Instrumentation and Control (I and C) systems refurbishment projects using Field Programmable Gate Array (FPGA)-based platform. The analysis identifying advantages of refurbishment projects for NPPs is performed. The main goals of the utilities with respect to refurbishment of NPPs I and C systems are outlined. The advantages of FPGA technology application for NPP I and C systems are described. Regulatory framework of FPGA technology for NPPs I and C systems is presented. General principles which may be used for implementation of NPPs I and C system refurbishment projects are presented. The experience of Research and Production Corporation (RPC) Radiy in implementation of NPPs I and C system refurbishment projects is considered. (author)

  18. Acoustic monitoring to support plant life extension at Sellafield

    International Nuclear Information System (INIS)

    Wit, M. de; Hovhanessian, G.

    2015-01-01

    Tensioned steel wires are widely used in civil engineering structures. They can, however, be vulnerable to corrosion. To reduce the probability of corrosion, sophisticated protection systems are used. Extensive inspection and maintenance regimes are also able to be implemented to confirm that the design strength is available over the lifetime of the wires. These regimes include tests to confirm the condition of post-tensioning cables or stay cables, which can verify the overall performance of the structure. This paper presents a technology to detect and locate wire failures in tensioned cables for use on a wide variety of pre-stressed or post tensioned structures, where they have increased confidence in the structures and reduced maintenance costs. This methodology is the continuous acoustic monitoring technology which uses distinctive acoustic characteristics of wire breaks to separate them from other acoustic activity on the structure. With a combination of instrumentation, data acquisition and data management, it is possible to identify a wire break event, as well as to locate the position and time of the failure. Over 10 years' experience of acoustic monitoring for this application with several independent and blind tests, shows that even in noisy environments the acoustic monitoring method is able to identify and locate wire breaks in fully grouted and partially grouted tendons, stay cables and suspension cables. The design (number of sensors and location) is very important to be sure to cover all wires in the structure. This paper explains the principles of the systems and shows them in practice on a case study of a project in a pre-stressed roof structure of an active tank farm at Sellafield site

  19. Plant life extension program for Indian PHWR power plants - Actual experience and future plans

    International Nuclear Information System (INIS)

    Sharma, M.B.; Ghoshal, B.; Shirolkar, K.M.; Ahmad, S.N.

    2002-01-01

    Full text: The Nuclear Power Corporation of India Limited (NPCIL) is responsible for design, construction and operation for all nuclear power plants in India. Currently, it has fourteen (14) reactor units under operation and another eight units are under various stages of planning and construction. India has adopted Pressurised Heavy Water Reactors (PHWRs) for the initial phase of its nuclear power program. In the earlier PHWRs zircaloy-2 has been used as coolant tube material. Subsequent studies and experience have shown their life to be considerably lower (about 10 full power years) than originally estimated. This meant that reactors at Rajasthan - 1 and 2 Madras - 1 and 2 Narora - 1 and 2 and Kakrapara-1 would require en-masse coolant channel replacement at least once in their lifetime. Subsequent reactors from Kakrapara-2 onwards would not need this en-masse coolant channel replacement as the coolant tube material has been upgraded to Zr 2.5% Nb. En-masse coolant channel replacement and other life extension work have been carried out successfully in Rajasthan Unit-2 (RAPS-2). Madras unit-2 (MAPS-2) has been shutdown since January 2002 and preparatory work for en-masse coolant channel replacement and plant life extension is in progress. This paper discusses in brief the experience of RAPS-2 in carrying out the above jobs as well as the strategies being adopted for MAPS-2. Since the coolant channel replacement work requires a plant outage of about 18 months, this opportunity is used to extend life of existing systems as well as upgradation work. This life extension and upgradation program is based on the results of detailed in service inspection, evaluation of performance of critical equipment, obsolescence and other strategic reasons. This paper discusses in detail some of the major areas of work done, for example introduction of supplementary control room, process control, computer based plant information and event analysis systems, provision of enhanced

  20. Life extension of nuclear power plants. World situation and the USA case

    International Nuclear Information System (INIS)

    Leon, Pablo T.; Cuesta, Loreto; Serra, Eduardo; Yaguee, Luis

    2010-01-01

    Life extension of Nuclear Power Plants above 40 years of operation is an important issue in many countries. The Kyoto limits for CO 2 emissions, the security of supply, the costs and predictability of renewable energy, etc., are putting nuclear energy in the agenda of many countries all around the world. The delay, due to the economic crisis, of the new nuclear projects in many countries, push governments to continue operation of nuclear plants above the 40 years design life. This is the case in the USA, where 59 units have obtained the extension of operation license from 40 to 60 years, and currently have 19 units are in the reviewing process. The life extension of these plants permits savings in CO 2 emissions and in the consumption of additional amounts of fossil fuels. In this paper, the position of the different nuclear countries about the Extension of Life will be reviewed, with a special emphasis on the situation in the USA. In this last case, the NRC approach for operation licenses above 40 years will be explained, and actions taken by nuclear companies in the country will be reviewed. In this country, the debate about life extension over 40 years has been surpassed, and the new technical discussion focuses on the operation of nuclear power plants above 60 years. (authors)

  1. Life extension of nuclear power plants. World situation and the USA case

    Energy Technology Data Exchange (ETDEWEB)

    Leon, Pablo T.; Cuesta, Loreto; Serra, Eduardo; Yaguee, Luis [Endesa. C/ Ribera del Loira, No.60, 28042 Madrid (Spain)

    2010-07-01

    Life extension of Nuclear Power Plants above 40 years of operation is an important issue in many countries. The Kyoto limits for CO{sub 2} emissions, the security of supply, the costs and predictability of renewable energy, etc., are putting nuclear energy in the agenda of many countries all around the world. The delay, due to the economic crisis, of the new nuclear projects in many countries, push governments to continue operation of nuclear plants above the 40 years design life. This is the case in the USA, where 59 units have obtained the extension of operation license from 40 to 60 years, and currently have 19 units are in the reviewing process. The life extension of these plants permits savings in CO{sub 2} emissions and in the consumption of additional amounts of fossil fuels. In this paper, the position of the different nuclear countries about the Extension of Life will be reviewed, with a special emphasis on the situation in the USA. In this last case, the NRC approach for operation licenses above 40 years will be explained, and actions taken by nuclear companies in the country will be reviewed. In this country, the debate about life extension over 40 years has been surpassed, and the new technical discussion focuses on the operation of nuclear power plants above 60 years. (authors)

  2. Discussion on life extension of nuclear power plant around the world

    International Nuclear Information System (INIS)

    Chen Ming; Zhang Yuansi

    2010-01-01

    The very Paper introduces the concept, basic working flow and fundamental elements of the life extension of nuclear power plant (NPP) around the world; and it generally collects and summarizes the status datum of life extension of NPPs. Afterwards, the Paper analyses the present status of life extension of NPP in various countries with strong nuclear power industry, i.e. the United States, France, Germany, Russia Federation, Japan, South Korea and Canada. At the end, the Paper make a conclusion that whether an operating NPP will adopt life extension at the end of its design life, this issue depends on the factor of economy, safety and technical feasibility of life extension on the NPP. According to latest datum collected in 2009, the nuclear power units around the world, which have exceeded the design lives or are close to design life ends, most of them (about 64%) have selected to extend their service lives; based on this statistical data, we concludes that when an operating nuclear unit is facing with the issue of to extend life or to retire itself, it will be apt to make life extension. (authors)

  3. A study on the optimization of plant life extension and decommissioning for the improvement of economy in nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae In; Jung, K. J.; Chung, U. S.; Baik, S. T.; Park, S. K.; Lee, D. G.; Kim, H. R.; Park, B. Y

    2000-01-01

    Fundamentals on the plan, the national policy, the safety securities for the life extension of the nuclear power plant was established from the domestic/abroad documents and case studies in relation with the life extension and decommissioning of the nuclear power plant. Concerning the decommissioning of the nuclear power plant, the management according to decommissioning stages was analyzed by the investigation of the domestic/abroad standard of the decommissioning (decontamination. dismantling) technology and regulation. Moreover, the study on the cost estimation method has been carried out for the decommissioning of the nuclear power plant. (author)

  4. Pattern-recognition system application to EBR-II plant-life extension

    International Nuclear Information System (INIS)

    King, R.W.; Radtke, W.H.; Mott, J.E.

    1988-01-01

    A computer-based pattern-recognition system, the System State Analyzer (SSA), is being used as part of the EBR-II plant-life extension program for detection of degradation and other abnormalities in plant systems. The SSA is used for surveillance of the EBR-II primary system instrumentation, primary sodium pumps, and plant heat balances. Early results of this surveillance indicate that the SSA can detect instrumentation degradation and system performance degradation over varying time intervals, and can provide derived signal values to replace signals from failed critical sensors. These results are being used in planning for extended-life operation of EBR-II

  5. Near-term benefits of life extension planning for nuclear power plants

    International Nuclear Information System (INIS)

    Pickens, T.; Gregor, F.E.

    1988-01-01

    Life Extension of Nuclear Power Plants is now viewed as a realistic alternative to construction of new generating facilities. The subject has been under intensive study since 1984 and two comprehensive pilot plant programs have been completed under EPRI, U.S. Department of Energy and utility sponsorship. A major lesson learned from these studies is that planning for life extension must start early and that many activities must be implemented as early in life as possible to enhance the option for life extension through mitigate and preventive actions. It was also determined that achievement of a 40-year licensed life is by no means guaranteed without substantial effort during the remaining plant life. In examining these recommended actions, it becomes obvious that conscientious implementation also leads to realization of significant short-term benefits in the form of availability improvement, outage reduction, maintenance optimization and longer term planning decisions. In addition to the economic benefits, plant safety is also enhanced by reducing challenges to the safety systems and slowly switching from a corrective maintenance to a preventive maintenance program

  6. UNIRAM modeling for increased nuclear-plant availability and life extension

    International Nuclear Information System (INIS)

    O'Mara, R.L.

    1988-01-01

    At the start of a nuclear-power plant's design life of 40 years, most parts of the plant are effectively brand new, but some subcomponents have already experienced significant wear and aging effects. In short, the spectrum of where each component is in its life cycle at any time is quite broad, and this makes the prediction of the future availability of the plant a complex issue. Predictive models that account for the differential effects of aging, wear, and functional failure on the plant are desirable as a means to represent this complex behavior. This paper addresses the task of using a computer model to account for the relationships between components, systems, and plant availability, in the context of current and future needs, including eventual life extension. The computer model is based on the Electric Power Research Institute's (EPRI) code, UNIRAM, which has a large and growing user base among utilities

  7. Economic evaluation of Kori and Wolsong Unit 1 plant life extension

    International Nuclear Information System (INIS)

    Song, T. H.; Jeong, I. S.

    2002-01-01

    24 years have been passed since Kori Unit 1 began its commercial operation, and 19 years have been passed since Wolsong Unit 1 began its commercial operation. As the end point of design life become closer, plant life extension and periodic safety assessment is paid more and more attention to by the utility company. In this paper, the methodologies and results of plant lifetime management economic evaluations of both units have been presented in comparison with Korean standard nuclear power plant 10, 20 and 30 year life extension cases respectively. In addition to that, sensitivity analysis and break even point analysis results are presented with the variables of capacity factor, operation and maintenance cost, and discount rate

  8. Evaluation and measures of the life extension of TVO I and TVO II power plant

    International Nuclear Information System (INIS)

    Hakala, J.

    1994-01-01

    A continuous and wide preventive maintenance and renovation is chosen to the life extension strategy at TVO I and II units. This requires extensive concentration on all ageing phenomena on theoretical level as well as on following their development at the power plant. The work related to ageing is partly performed by persons who are responsible for systems and components in the power plant organization, partly by the working groups, which are organized for those purposes. The evaluation of the ageing phenomenon of the power plant systems, of large components and of different technical fields has revealed several needs for measures. Partly those are already performed. However the evaluation has not revealed any such ageing phenomena, which would limit the power plant life time to originally planned 40 years. (orig.)

  9. It is never too early to start planning for plant life extension

    International Nuclear Information System (INIS)

    Neils, G.H.

    1987-01-01

    This paper outlines some of the reasons why the subject of plant life extension (PLEX) deserves the attention it is receiving and describes some of the work that is currently being conducted in order to make PLEX a reality for U.S. nuclear power plants. One such major effort is a pilot program at the Monticello Nuclear Generating plant. This program, as well as other programs, have already produced some valuable lessons from which other plant owners can benefit. The Monticelle pilot program and the lessons learned thereof are described in some detail in this paper. (Liu)

  10. Life extension economic analysis

    International Nuclear Information System (INIS)

    Smithling, A.P.

    1992-01-01

    Life extension economic analyses of fossil fueled power plants need the development of consistent methods which consider the capital costs associated with component replacement or repair and estimates of normal station capital expenditures over the units remaining life. In order to link capital and production costs, Niagra Mohawk Power Corp. develops most and worst cases. A most case includes capital components that would definitely need replacement or modification for life extension. The worst case scenario contains must case capital costs plus various components which may need replacement or modification. In addition, two forecasted conditions are used, base case capacity and low capacity

  11. A study on the optimization of plant life extension and decommissioning for the improvement of economy in nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae In; Jung, K. J.; Chung, U. S.; Baik, S. T.; Park, S. K.; Lee, D. G.; Kim, H. R.; Park, B. Y

    2001-01-01

    Fundamental concepts on the life extension of the nuclear power plant and decommissioning optimization were established from the domestic abroad information and case analyses. Concerning the decommissioning of the nuclear power plant, the management according to decommissioning stages was analyzed by the investigation of the standard of the decommissioning(decontamination dismantling) regulation. Moreover, basics were set for the decommissioning of domestic nuclear power plants and research reactors from the analyses on the decommissioning technology and precedence.

  12. On economic efficiency of nuclear power unit life extension using steam-gas topping plant

    International Nuclear Information System (INIS)

    Kuznetsov, Y.N.; Lisitsa, F.D.; Smirnov, V.G.

    2001-01-01

    The different options for life extension of the operating nuclear power units have been analyzed in the report with regard for their economic efficiency. A particular attention is given to the option envisaging the reduction of reactor power output and its subsequent compensation with a steam-gas topping plant. Steam generated at its heat-recovery boilers is proposed to be used for the additional loading of the nuclear plant turbine so as to reach its nominal output. It would be demonstrated that the implementation of this option allows to reduce total costs in the period of power plant life extension by 24-29% as compared with the alternative use of the replacing steam-gas unit and the saved resources could be directed, for instance, for decommissioning of a reactor facility. (authors)

  13. Life extension of nuclear power plants: world situation and the Usa case

    International Nuclear Information System (INIS)

    Leon, P.T.; Cuesta, L.; Serra, E.; Yague, L.

    2010-01-01

    Life extension of nuclear power plants above 40 years of operation is an important issue in many countries. The Kyoto limits for CO 2 emissions, the security of supply, the costs of renewable energies and the economic crisis have pushed governments to continue operation of nuclear plants over the 40 years design life. In the Usa 59 units have obtained the extension of operation license from 40 to 60 years, and currently 19 units are in the reviewing process. The situation in the rest of the world is different. A list of countries, where nuclear units with a service life over 30 years, are still operating has been drawn up. A few countries like Belgium, Germany, Spain and Sweden are opposed to life extension. Some countries like Finland, the Netherlands, Switzerland, India, Japan and Usa, have adopted a life extension policy for their nuclear fleet. Other countries like France, Russia, United-Kingdom, Pakistan, South-Korea and Argentina have not yet taken any final decision. United-Kingdom and France have a case by case policy. In some countries like Japan, Indian or Pakistan, the legislation makes no reference to a maximum operating time but the reactors are allowed to continue operating as long as they comply with established safety conditions. (A.C.)

  14. PLEXFIN a computer model for the economic assessment of nuclear power plant life extension. User's manual

    International Nuclear Information System (INIS)

    2007-01-01

    The IAEA developed PLEXFIN, a computer model analysis tool aimed to assist decision makers in the assessment of the economic viability of a nuclear power plant life/licence extension. This user's manual was produced to facilitate the application of the PLEXFIN computer model. It is widely accepted in the industry that the operational life of a nuclear power plant is not limited to a pre-determined number of years, sometimes established on non-technical grounds, but by the capability of the plant to comply with the nuclear safety and technical requirements in a cost effective manner. The decision to extend the license/life of a nuclear power plant involves a number of political, technical and economic issues. The economic viability is a cornerstone of the decision-making process. In a liberalized electricity market, the economics to justify a nuclear power plant life/license extension decision requires a more complex evaluation. This user's manual was elaborated in the framework of the IAEA's programmes on Continuous process improvement of NPP operating performance, and on Models for analysis and capacity building for sustainable energy development, with the support of four consultants meetings

  15. Concept design of overall evaluation system for nuclear plant life extension, (1)

    International Nuclear Information System (INIS)

    Takao, Takeshi

    1989-01-01

    In this report the frameworks of the plans for the Overall Evaluation System and the 8 systems concerning the plant Life extension are discussed. Main results are as follows. 1) The extension period decision subsystem supported by the AI techniques and Fuzzy theory will be added to the Overall Evaluation System. By using this subsystem the plant lives will be overall evaluated. 2) The range of the data collection for constructing the plant operation and maintenance data base is covered by, i) Operation data in the typical plant start/stop cycling, ii) Operation data at the representative point of the period, iii) All data of the repair and replacement. 3) The degradation monitoring and diagnosing system will be constructed for the expert system based on the knowledge base using the elastic wave theorem. (author) 74 refs

  16. 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

  17. A review of assessment and retrofitting of structures for plant life extension (PLEX) programme

    International Nuclear Information System (INIS)

    Samota, A.; Verma, U.S.P.; Tilak, M.M.

    1994-01-01

    Assessment of the life of existing civil engineering structures for the plant life extension programme has to be made considering various factors such as strength, deterioration, environmental impact particularly with regard to radiation field, etc. which need to be evaluated very carefully. Generally, it is considered that initial design usually caters for a period of around 40 years, though structural failures have been reported even at a much younger stage due to deficiency in design and construction. In the context of nuclear power plant when the initial license is given for a period 30-40 years, it becomes necessary to evaluate the health of the various structures particularly while applying for a license for the extension of plant life. The present paper discuss the various issues connected with the evaluation of the future life of an existing structure in terms of strength and change in its property particularly when the structure is exposed to radiation. The various effects with regard to ageing and radiation exposure and the destructive and non-destructive tests which need to be carried out are discussed in detail. (author). 8 refs., 4 figs

  18. Update on the status of life extension in U.S. Nuclear Power Plants

    International Nuclear Information System (INIS)

    Hevia Ruperez, F.; Lehnert, D.F.; Gregor, F.E.

    1997-01-01

    The purpose of this paper is to provide an update on the status of key activities that may affect the plant life extension option for U.S. nuclear power plants and to explain how the progress on the regulatory and technical developments may affect the world-wide nuclear industry. Establishing a predictable and stable regulatory process is the final piece that is needed by U.S. utilities to confidently consider the plant life extension option in their strategic planning. Certain technical issues were also identified in the previous studies where additional investigation would benedict the U.S. nuclear power industry's understanding of an aging effect and/or capability to demonstrate that the aging effect can be effectively managed. It is concluded that the lessons learned from the U.S. industry activities and the associated interactions with the NRC are leading to a positive indication that U.S. utilities believe the differences between the NRC and industry on the implementation of the amended license renewal rule can be successfully resolved and the that many utilities generally are interested in pursuing the life extension option as part of their strategic planning. The methodology and guidance developed in the U.S. for performing integrated plant assessments and evaluating time-limited aging analyses will be of significant interest to utilities and regulators in other countries. They will undoubtedly lay the foundation for an acceptable approach for demonstrating that aging processes are being processes are being effectively managed by plant programs and that safety margins or bases will be maintained during an extended operating period. (Author)

  19. Inspection and mitigating measures for life extension of nuclear power plant containment structures

    International Nuclear Information System (INIS)

    Meyers, B.L.; Daye, M.A.

    1989-01-01

    The subject of life extension of nuclear power plants has drawn considerable attention during the last few years. Interest in life extension initiated because of both safety and economic reasons. A number of evaluations have been performed. The main thrust of earlier work was directed toward evaluating the factors causing aging, and defining degradation sites, degradation mechanism and failure modes. At present, attention is directed toward establishing the appropriate inspection programs suitable for each of the defined aging sites. Some components and aging sites are already subjected to routine inspection programs such as the surveillance of post-tensioning system and the integrated leak rate test (ILRT) of prestressed concrete and reinforced concrete containments. The aging process affects mechanical, electrical and structural components in all types of containments. This paper addresses the structural components of PWR containments only and presents examples of inspection approaches and describes methods to prevent further degradation of select sites

  20. Development of a support system to make economic and technical assessments for the issues relating to plant life extension

    International Nuclear Information System (INIS)

    Takao, T.; Soneda, N.; Sakai, T.

    1994-01-01

    To realize the life extension of nuclear power plants, overall evaluation for the plant is required, which covers technology, economy such as cost of repair or/and replacement of components, and regal regulations for licensing. A prototype of integrated assessment support system for life extension ''INPLEX'' have developed in order to evaluate the technical and economic issues relating to the plant life extension and to make a life extension scenario. Analysis procedure of INPLEX is as follows. A comparison of the cost between the life extension and the reconstruction is made to see whether the life extension is cost effective or not. Next, components required detailed assessments are selected, and the residual life assessment of these components are made. After those procedures life extension measures are selected and the implementation time schedule is set on the basis of the formulas for predicting the degradation of the components and the component reliability data. Finally the implementation time schedule is optimized from the viewpoint of economy, and the life extension scenario is proposed. INPLEX also has the data base ''PRINS'', in which information and data related to life extension are registered, such as component degradation experiences, degradation management methodologies, degradation mitigation measures, and so on. PRINS can be referred at any time during the operation of INPLEX

  1. Cost drivers for the assessment of nuclear power plant life extension

    International Nuclear Information System (INIS)

    2002-09-01

    In the period of the nineteen-sixties to eighties, nuclear power had rapidly expanded in many countries of the world. The nuclear power plants built in this period, will reach the end of their planned life in the near future. Statistics drawn from IAEA's Power Reactor Information System (PRIS) indicate that, by the end of 2001, there were 175 nuclear power units (NPPs) with about 122 GWe of net electrical capacity, having 21 to 45 years of operation. This represents about 34% of the total installed nuclear capacity in the world. Since these plants were initially designed for 30-40 years of operation, utilities operating such NPPs will now have to consider whether they will shutdown, decommission, and replace the plants reaching the end of their planned life, or refurbish the plants and extend their original design life. This decision is quite complex, involving a number of political, technical and economic issues. Finally, the utilities involved should manage their assets in a manner that is as close as practicable to the best possible economic optimum scenario. Well before the end of the plant life, NPP operators must evaluate the technical and economic feasibility for PLEX options, seek and obtain regulatory approvals, and implement PLEX schemes that are justified. Often they also have to substantiate the planned life extension, including the economic viability to the relevant governmental bodies, as well as to assure the general public acceptance. Economic feasibility analysis requires cost data that are not readily available. A recent IAEA review of published information on costs of PLEX revealed the scarcity of published information, while the estimated costs of NPP decommissioning are widely available. This is due in part to the reluctance by NPP operators to divulge the cost data that are considered commercial/confidential, as more plant operators are being privatised, and in part to the absence of a common framework and methodology to account for the

  2. Replacement of major nuclear power plant components for service life extension

    International Nuclear Information System (INIS)

    Novak, S.

    1987-01-01

    Problems are discussed associated with replacement of nuclear power plant components with the aim to extend their original scheduled life. The existing foreign experience shows that it is technically feasible to replace practically all basic components for which the necessity of replacement is established. Data is summed up on the replacement of steam generators in US and West German nuclear power plants showing the duration of the job, the total consumption of manhours, the collective dose equivalent and the cost. Attention is also focused on implemented and projected replacements of circulation pipes in nuclear power plants abroad. Based on these figures, the cost is estimated of the replacement of the reactor vessel and the steam generators for WWER-440 nuclear power plants. The conclusion is arrived at that even based on a conservative estimate, the extension by 20 years of the service life of a nuclear power plant is economically more effective than the construction of a new plant. (Z.M.) 2 tabs., 15 refs., 3 figs

  3. Trend in foreign countries of life extension for nuclear power plants

    International Nuclear Information System (INIS)

    Kusanagi, Hideo

    1992-01-01

    When the nuclear power generation in the world is converted to oil burning thermal power generation, the required quantity of oil is twice as much as the oil production in Saudi Arabia. This represents the size of the role that nuclear power generation plays. More than 30 years have already elapsed since the start of nuclear power generation, and the number of nuclear power plants in operation in the world was 426 as of the end of 1990, and their capacity of about 344 million kW is about 17% of the total generated electric power in the world. Though circumstances are different in respective countries, the construction of new nuclear power plants is not always advancing smoothly, and the possibility of operating existing nuclear power plants as long as possible has been investigated. In USA, the approved term of operation of nuclear power plants is 40 years, and the trend of the research and development of the plant life extension is described. In France, the life of nuclear power plants is not stipulated by the law. In U.K., also it is not stipulated by the law. The trend in these countries is reported. IAEA also has carried out the activities on this problem. (K.I.)

  4. Safeguard assessment for life extension in nuclear power plants (NPPs) using a production function

    International Nuclear Information System (INIS)

    Woo, Tae-Ho; Lee, Un-Chul

    2011-01-01

    Research highlights: → The numerical value is constructed for the secure operation. → As the power increases, the NSEF increases. → Specific month could be indicated by the relative value of NSEF. → It is suggested for the better power in NPPs. → There is another possibility for the secure operation factors. - Abstract: Life extension is investigated as a safeguard assessment for the stability on the operation of the nuclear power plants (NPPs). The Cobb-Douglas function, one of the production functions, is modified for the nuclear safeguard in NPPs, which was developed for the life quality of the social and natural objects. Nuclear Safeguard Estimator Function (NSEF) is developed for the application in NPPs. The cases of NPPs are compared with each other in the aspect of the secure performance. The results are obtained by the standard productivity comparisons with the designed power operations. The range of secure life extension is between 1.008 and 5.353 in 2000 MW e and the range is between 0.302 and 0.994 in 600 MW e . So, the successfulness of the power operation increases about 5 times higher than that of the interested power in this study, which means that the safeguard assessment has been performed in the life extension of the NPPs. The technology assessment (TA) is suggested for the safe operation which is an advanced method comparing conventional probabilistic safety assessment (PSA).

  5. Coal handling system structural analysis for modifications or plant life extension

    International Nuclear Information System (INIS)

    Dufault, A.; Weider, F.; Doyle, P.

    1989-01-01

    One neglected aspect of plant modification or life extension is the extent to which previous projects may have affected the integrity of existing structures. During the course of a project to backfit fire protection facilities to existing coal handling systems, it was found that past modifications had added loads to existing coal handling structures which exceeded the available design margin. This paper describes the studies that discovered the original problem areas, as well as the detailed analysis and design considerations used to repair these structures

  6. International requirements for life extension of nuclear power plants; Internationale Anforderungen zur Lebensdauerverlaengerung von Kernkraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Wernicke, Robert [TUeV NORD SysTec GmbH und Co. KG, Abt. Festigkeit und Konstruktion, Hamburg (Germany)

    2009-11-15

    Lifetime extension or long-term operation of nuclear facilities are topics of great international significance against the backdrop of a fleet of nuclear power plants of which many have reached 2/3 of their planned life. The article deals with the conditions for, and the specific requirements of, seeking long-term operation of nuclear power plants as established internationally and on the basis of IAEA collections. Technically, long-term operation is possible for many of the nuclear power plants in the world because, normally, they were built on the basis of conservative rules and regulations and, as a consequence, incorporate significant additional safety. Application of requirements to specific plants implies assessments of technical safety which show that conservative design philosophies created reserves and, as a consequence, there is an adequate level of safety also in long-term plant operation. For this purpose, the technical specifications must be revised, necessary additions made, and (international) operating experience taken into account and management of aging established. Two examples are presented to show how the approach to long-term plant operation is put into practice on a national level. (orig.)

  7. Rehabilitation of heat exchange equipment a key to power plant life extension and performance improvement

    Energy Technology Data Exchange (ETDEWEB)

    Taveau, F.; Huiban, A.M. [Alstom Power Heat Exchange, 78 - Velizy Villacoublay (France)

    2001-07-01

    With the current evolutions of the energy market and the life extension of the power plants, all the equipment initially supplied need one day or another partial or total rehabilitation. For heat exchange equipment, this includes the condensers, feed water heaters and various heat exchangers. Modernization is in particular necessary when in-service monitoring and periodic inspections show significant deteriorations of the tubes and cooling water leakages leading to forced outages or when tube and tube plate materials are no longer suited to cooling water characteristics or to updated specifications of the secondary system. Feedwater heaters and heat exchangers damaged by erosion/corrosion, vibrations, etc. can be re-designed, manufactured and replaced easily. The operation is more complex on condensers and requires technical surveys, study of alternative solutions and has a more direct impact on the global output of the power plant. That is why our conference will focus on the condenser refurbishment. (author)

  8. Rehabilitation of heat exchange equipment a key to power plant life extension and performance improvement

    International Nuclear Information System (INIS)

    Taveau, F.; Huiban, A.M.

    2001-01-01

    With the current evolutions of the energy market and the life extension of the power plants, all the equipment initially supplied need one day or another partial or total rehabilitation. For heat exchange equipment, this includes the condensers, feed water heaters and various heat exchangers. Modernization is in particular necessary when in-service monitoring and periodic inspections show significant deteriorations of the tubes and cooling water leakages leading to forced outages or when tube and tube plate materials are no longer suited to cooling water characteristics or to updated specifications of the secondary system. Feedwater heaters and heat exchangers damaged by erosion/corrosion, vibrations, etc. can be re-designed, manufactured and replaced easily. The operation is more complex on condensers and requires technical surveys, study of alternative solutions and has a more direct impact on the global output of the power plant. That is why our conference will focus on the condenser refurbishment. (author)

  9. 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

  10. Development of procedural requirements for life extension of nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hun; Son, Moon Kyu [Korea Association for Nuclear Technology, Taejon (Korea, Republic of); Ham, Cheol Hun [The Catholic University of Korea, Seoul (Korea, Republic of); Chang, Keun Sun [Sunmoon Univ., Asan (Korea, Republic of); Paek, Won Phil [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of); Cheong, Ji Hwan [Baekseok College Cultural Studies, Cheonan (Korea, Republic of)

    2001-03-15

    Current status of regulatory aspects of life extension and upgrading of NPPs is reviewed for major foreign countries. Most countries require similar technical requirements; however, procedural aspects differ country by country. Regulatory systems suitable for NPP life extension is investigated. The procedure and requirements for reassessment of design life should be established first; then it can be incorporated into the PSR system. The concept of 'Current Licensing Basis (CLB)' can be adopted in Korea, but further elaboration for terms and definitions is needed for common understanding between interested groups. The procedure for maintenance and backfitting should also be improved. The Systems, Structures, and Components (SSCs) that require development of regulatory requirements for life extension are identified based on extensive analysis of foreign experiences. By analyzing the rules and regulations related to life extension. Basic directions are suggested to harmonize or establish regulatory systems for life extension, two-step licensing, PSR, and backfitting.

  11. Advanced condition monitoring techniques and plant life extension studies at EBR-2

    International Nuclear Information System (INIS)

    Singer, R.M.; Gross, K.C.; Perry, W.H.; King, R.W.

    1991-01-01

    Numerous advanced techniques have been evaluated and tested at EBR-2 as part of a plant-life extension program for detection of degradation and other abnormalities in plant systems. Two techniques have been determined to be of considerable assistance in planning for the extended-life operation of EBR-2. The first, a computer-based pattern-recognition system (System State Analyzer or SSA) is used for surveillance of the primary system instrumentation, primary sodium pumps and plant heat balances. This surveillance has indicated that the SSA can detect instrumentation degradation and system performance degradation over varying time intervals and can be used to provide derived signal values to replace signals from failed sensors. The second technique, also a computer-based pattern-recognition system (Sequential Probability Ratio Test or SPRT) is used to validate signals and to detect incipient failures in sensors and components or systems. It is being used on the failed fuel detection system and is experimentally used on the primary coolant pumps. Both techniques are described and experience with their operation presented

  12. Dynamic assessment for life extension of nuclear power plants (NPPs) using system dynamics (SD) method

    International Nuclear Information System (INIS)

    Woo, Tae Ho

    2012-01-01

    It has been proposed to extend the life of nuclear power plants (NPPs) for the economic purpose. Especially, the primary systems in reactor are considered in the thermohydraulic and neutronic aspect, which is related to the safety system. The electric power and the lifespan of components are expressed as economic situation. In addition, political considerations are given by the presidential change and the nuclear non-proliferation characteristics. The dynamical investigation using system dynamics (SD) shows the effective time for the life extension of the NPPs by Monte-Carlo simulations. This non-linear algorithm is incorporated with the feedback loop of the event sequences. The expected event is related to the past event, which affects to the dynamical simulations of lifetime in the NPPs. In the conclusions, the safety guarantee as well as the economic profit in the re-use of long term operated power plants is presented, which is mentioned as the transient time between 2019 and 2021 in this paper. (orig.)

  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. Dynamic assessment for life extension of nuclear power plants (NPPs) using system dynamics (SD) method

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2012-12-15

    It has been proposed to extend the life of nuclear power plants (NPPs) for the economic purpose. Especially, the primary systems in reactor are considered in the thermohydraulic and neutronic aspect, which is related to the safety system. The electric power and the lifespan of components are expressed as economic situation. In addition, political considerations are given by the presidential change and the nuclear non-proliferation characteristics. The dynamical investigation using system dynamics (SD) shows the effective time for the life extension of the NPPs by Monte-Carlo simulations. This non-linear algorithm is incorporated with the feedback loop of the event sequences. The expected event is related to the past event, which affects to the dynamical simulations of lifetime in the NPPs. In the conclusions, the safety guarantee as well as the economic profit in the re-use of long term operated power plants is presented, which is mentioned as the transient time between 2019 and 2021 in this paper. (orig.)

  15. 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)

  16. State of technology assessment for life extension of electrical and I and C equipment in nuclear power plants

    International Nuclear Information System (INIS)

    DuCharme, A.R.; Boger, R.M.; Meyer, L.C.; Beament, P.R.

    1988-01-01

    As part of the IEEE Working Group 3.4 on Nuclear Plant Life Extension, an assessment is made of the current state of technology for the life extension of certain classes of electrical and IandC equipment. The classes investigated include motors, cables, emergency diesel generators, penetrations, inverters/chargers, switchgear, and reactor protection systems. The work is focussed on assessment of current or recently completed RandD efforts to resolve issues affecting life extension of the equipment. Aspects discussed include the degree of resolution of these issues, potentially affected standards, and technical aspects requiring further research. 15 refs., 2 tabs

  17. State of technology assessment for life extension of electrical and I and C equipment in nuclear power plants

    International Nuclear Information System (INIS)

    Du Charme, A.R.; Boger, R.M.; Meyer, L.C.; Beament, P.R.

    1988-01-01

    As part of the IEEE Working Group 3.4 on Nuclear Plant Life Extension, an assessment is made of the current state of technology for the life extension of certain classes of electrical and I and C equipment. The classes investigated include motors, cables, emergency diesel generators, penetrations, inverters/charges, switchgear, and reactor protection systems. The work is focussed on assessment of current or recently completed R and D efforts to resolve issues affecting life extension of the equipment. Aspects discussed include the degree of resolution of these issues, potentially affected standards, and technical aspects requiring further research

  18. Electricity-cost savings obtained by means of nuclear plant life extension

    International Nuclear Information System (INIS)

    Forest, L.; Fletcher, T.; DuCharme, A.; Harrison, D.L.

    1987-01-01

    This study examines savings caused by nuclear-plant life extension (NUPLEX) and describes the effects of changes in assumptions on costs and technology using an approach simpler than the large economic-model simulations used in other reports. Under the simplified approach, we estimate savings at the broad national level by comparing projected costs/kWh for the typical NUPLEX plant with those for new coal-fired plants, which seem the most likely alternative in most regions. While ignoring some complications handled by the large, regionally disaggregated econometric models, the approach used in this study has advantages in sensitivity analyses. It reveals relationships between savings and basic assumptions on costs and technology in a more transparent way than in large-model simulations. We find that, absent major technological breakthroughs for present generating options, NUPLEX saves consumers money on their electric bills under most plausible economic scenarios. Using mid-range assumptions, we find that NUPLEX saves consumers a total of about dollar 180 billion spread over the period 2010-50. Under optimistic assumptions, the savings swell to over dollar 900 billion. Under extremely pessimistic assumptions, the savings actually turn negative. This wide range of estimates largely reflects the uncertainty in cost projections. Within plausible limits, higher- or lower-than-expected load growth does not affect the savings estimates. The NUPLEX construction costs stand out as the most critical unknown. If they turn out to be 50% (dollar 500 billion) above the baseline estimate savings would fall by almost 60% (dollar 105 billion). A 50% rise in nuclear fuel costs would drop baseline savings by almost 22%. A 50% increase in nuclear-plant operations-and-maintenance costs, would cut baseline savings by about 36%. These sensitivities highlight the need for continued monitoring of economic developments

  19. 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.

  20. Life extension, power upgrade, and return to service work for Pickering NGS and other PWR and CANDU plants

    International Nuclear Information System (INIS)

    Millman, J.; Idvorian, N.; Schneider, W.

    2002-01-01

    Work on life extension, power upgrade and return to service has been performed and is in progress for a number of PWR and CANDU plants. For PWR plants, power upgrade work has been done for the new replacement steam generators in several cases. This work consists of redoing the formal equipment qualification analysis and reports for the uprated operating conditions to support the application for license adjustment. Life extension assessments have been performed for several CANDU plants. These are highly detailed assessments in which the particular steam generator is reassessed part by part as to the ability of each to sustain full life operation and also extended life operation. Return to service work for Pickering NGSA specifically has included this type of assessment and also specific repair, cleaning and retrofit activities including secondary side inspection, waterlancing, divider plate repair, eddy current inspection, etc. Steam generator modifications and retrofit work have been performed in a number of cases. The paper discusses various life extension, power upgrade, equipment modification and return to service activities all of which are part of the renewed drive in the industry to realise the full potential of nuclear plants by getting more and better performance from the extended service of existing plants. (author)

  1. Corrosion issues in the BWR and their mitigation for plant life extension

    International Nuclear Information System (INIS)

    Gordon, B.M.

    1988-01-01

    Corrosion is a major service life limiting mechanism for both pressurized water reactors (PWRs) and boiling water reactors (BWRs). For the BWR, stress corrosion cracking of piping has been the major source of concern where extensive research has led to a number of qualified remedies and currently > 90% of susceptible welds have been mitigated or replaced. Stress corrosion cracking of reactor internals due to the interaction of irradiation, as discussed elsewhere in this conference, is also a possible life limiting phenomenon. This paper focusses on two corrosion phenomena in the BWR which have only recently been identified as impacting the universal goal of BWR life extension: the general corrosion of containment structures and the erosion-corrosion of carbon steel piping

  2. Overview of United States Department of Energy activities to support life extension of nuclear power plants

    International Nuclear Information System (INIS)

    Harrison, D.L.

    1993-01-01

    Today, 109 nuclear power plants provide over 20 percent of the electrical energy generated in the US The operating license of the first of these plants will expire in the year 2000; one-third of the operating licenses will expire by 2010 and the remaining plant licenses are scheduled to expire by 2033. The National Energy Strategy assumes that 70 percent of these plants will continue to operate beyond their current license expiration to assist in ensuring an adequate, diverse, and environmentally acceptable energy supply for economic growth. In order to preserve this energy resource in the US three major tasks must be successfully completed: establishment of regulations, technical standards, and procedures for the preparation and review of a license renewal application; development, verification, and validation of technical criteria and bases for monitoring, refurbishing, and/or replacing plant equipment; and demonstration of the regulatory process. Since 1985, the US Department of Energy (DOE) has been working with the nuclear industry and the US Nuclear Regulatory Commission (NRC) to establish and demonstrate the option to extend the life of nuclear power plants through the renewal of operating licenses. This paper focuses primarily on DOE's Plant Lifetime Improvement (PLIM) Program efforts to develop the technical criteria and bases for effective aging management and lifetime improvement for continued operation of nuclear power plants. This paper describes current projects to resolve generic technical issues in the principal areas of reactor pressure vessel (RPV) integrity, fatigue, and environmental qualification (EQ)

  3. Analysis of Piping Systems for Life Extension of Heavy Water Plants in India

    International Nuclear Information System (INIS)

    Mishra, Rajesh K.; Soni, R.S.; Kushwaha, H.S.; Raj, V. Venkat

    2002-01-01

    Heavy water production in India has achieved many milestones in the past. Two of the successfully running heavy water plants are on the verge of completion of their design life in the near future. One of these two plants, situated at Kota, is a hydrogen sulfide based plant and the other one at Tuticorin is an ammonia-based plant. Various exercises have been planned with an aim to assess the fatigue usage for the various components of these plants in order to extend their life. Considering the process parameters and the past history of the plant performance, critical piping systems and equipment are identified. Analyses have been carried out for these critical piping systems for mainly two kinds of loading, viz. sustained loads and the expansion loads. Static analysis has been carried out to find the induced stress levels due to sustained as well as thermal expansion loading as per the design code ANSI B31.3. Due consideration has been given to the design corrosion allowance while evaluating the stresses due to sustained loads. At the locations where the induced stresses (S L ) due to the sustained loads are exceeding the allowable limits (S h ), exercises have been carried out considering the reduced corrosion allowance value. This strategy is adopted in view of the fact that the thickness measurements carried out at site at various critical locations show a very low rate of corrosion. It has been possible to qualify the system with reduced corrosion allowance values however, it is recommended to keep that location under periodic monitoring. The strategy adopted for carrying out analysis for thermal expansion loading is to qualify the system as per the code allowable value (S a ). If the stresses are more than the allowable value, credit of liberal allowable value as suggested in the code i.e., with the addition of the term (S h -S L ) to the term 0.25 S h , has been taken. However, if at any location, it is found that thermal stress is high, fatigue analysis has

  4. Development of overall evaluation system for nuclear plant life extension, (3)

    International Nuclear Information System (INIS)

    Soneda, Naoki; Takao, Takeshi

    1990-01-01

    Life and integrity assessment of structural components is essential for the nuclear plant life evaluation. Many works have been done on the life and integrity assessment methods up to date. However, there are few methods for the reliability evaluation of analysis results obtained by those methods. This report presents a reliability evaluation method of analysis results based on knowledge base and its application to the integrity assessment of PWR reactor pressure vessel against PTS event. Probabilistic fracture mechanics method is used to obtain the sensitivity of failure probability to analysis inputs. Knowledge base of fuzzy rules is constructed using the sensitivity analysis results. This method makes it possible to set reasonable safety margins to the analysis results. (author)

  5. In-situ metallography for damage assessment and life extension in power plants- a few case studies

    International Nuclear Information System (INIS)

    Raghu, N.; Muralidharan, N.G.; Jayakumar, T.; Kasiviswanathan, K.V.

    1996-01-01

    In-service inspection of components in power plants is necessary for damage assessment, life prediction and extension. The useful life of some of the components like pipelines are most crucial in case they are exposed to the conditions of high temperature and pressure. Periodic inservice inspection by means of non-destructive testing to obtain information on damage assessment is carried out as a routine and mandatory procedure. During these inspections, only reduction in localised and uniform wall thickness are measured. However, the microstructural degradation due to both normal and abnormal temperatures occurring conditions are not revealed by conventional non-destructive test methods during this routine inspection. For life prediction and extension programme, the information on microstructural degradation is essential and the same can be studies in an effective manner through in-situ metallography technique. (author)

  6. Inservice inspection of heavy water plants - a tool in assessing damage to components and life extension

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Thavasimuthu, M.; Bhattacharys, D.K.; Baldev Raj

    1994-01-01

    Any system and its components are expected to give trouble free service over a certain period of time known as life time. The life time is estimated during the design stage. To achieve the design life, certain level of quality are to be defined and this quality has to be worked into the components by proper fabrication processes and their compliance with quality are to be checked. In addition, one has to guard against initiation or propagation of defects which may occur due to normal and abnormal service conditions. Non-destructive test (NDT) techniques are widely used for finding the health of the component. The role of NDT extends from the production stage to the entire life period of the system. This paper highlights the periodic in-service inspection (ISI) carried out on various components of the Heavy Water Plants (HWP) in India in assessing the integrity of the components and predicting the life of the components. (author). 3 refs., 4 figs

  7. Piping analysis for the life extension of Heavy Water Plant, Kota

    International Nuclear Information System (INIS)

    Mishra, Rajesh; Soni, R.S.; Kushwaha, H.S.; Venkat Raj, V.

    2001-02-01

    Heavy water production in India has achieved many milestones in the past. One of the most successfully running heavy water plant situated at Kota (Rajasthan) is on the verge of completion of its design life in near future. Heavy Water Plant, Kota is hydrogen sulfide based plant. Various exercises have been planned with an aim to assess the fatigue usage for the various components of these plants in order to extend their life. Considering the process parameters and past history of the plant performance, 25 process critical nozzle locations and connected piping systems are identified. Analyses have been carried out for these critical piping systems for mainly two kinds of loading, viz. sustained loads and the expansion loads. The static analysis has been carried out to find the induced stress levels due to sustained as well as thermal expansion loading as per the design code ANSI B31.3. Due consideration is given to the design corrosion allowance while evaluating the stresses due to sustained loads. At the locations where induced stresses (S 1 ) due to the sustained loads are exceeding the allowable limits (S h ), exercises have been carried out considering the reduced corrosion allowance value. This strategy is adopted due to the fact that the corrosion measurements carried out at site at various critical locations show a very low rate of corrosion. Where it is found that system is getting qualified with reduced corrosion allowance values, it is recommended to keep that location under periodic monitoring. The strategy adopted for carrying out the analysis for thermal expansion loading is to qualify the system as per the code allowable value (S a ). Where it is found that the stresses are more than the allowable value, credit of liberal allowable value as suggested in the code i.e., with the addition of the term (S h -S 1 ) to the allowable stress (S a ) value, has been taken. If at any location, it is found that the problem of high thermal stress still persists, the

  8. Plant condition assessments as a requirement before major investment in life extension for a CANDU nuclear power plant

    International Nuclear Information System (INIS)

    Aubray, Marc

    2002-01-01

    Full text: Since, to extend the life of a CANDU-6 reactor beyond its original design life requires the replacement of reactor components (380 pressure and calandria tubes), a major investment will have to be done. After a preliminary technical and economical feasibility study, Hydro- Quebec, owner of the Gentilly-2 NPP, has decided to perform a more detailed assessment to: 1. Get assurance that it is technically and economically viable to extend Gentilly-2 for another 20 years beyond the original design life; 2. Identify the detailed work to be done during the refurbishment period planned in 2008-2009; 3. Define the overall cost and the general schedule of the refurbishment phase; 4. Ensure an adequate licensing strategy to restart after refurbishment; 5. Complete all the Environmental Impact Studies required to obtain the government authorizations. The business case to support the refurbishment of Gentilly-2 has to take in consideration the reactor core components, which will be the major work to be completed during refurbishment. In summary the following main component will have to be changed or refreshed: The pressure and calandria tubes and the feeders (partial replacement only) (ageing mechanisms); The control computers (obsolescence); The condenser tubes (tubes plugging); The turbine control and electric-governor (obsolescence). An extensive campaign is under way to assess the 'health' of the station systems, structures and components (SSC). Two processes have been used for this assessment: Plant Life Management Studies (PLIM) for approximately 10 critical SSC or families of SSC (PLIM Studies); Condition Assessment Studies for other SSC with a lower impact on the Plant production or safety). The PLIM Studies are done on SSC's, which were judged critical because they are not replaceable (Reactor Building, Calandria), or that their failure could have a significant impact on safety or production (electrical motors, majors pumps, heat exchangers and pressure

  9. Plant life extensions for German nuclear power plants? Controversial discussion profit taking of nuclear power plant operators; Laufzeitverlaengerungen fuer die deutschen Kernkaftwerke? Kurzanalyse zu den Gewinnmitnahmen der KKW-Betreiber

    Energy Technology Data Exchange (ETDEWEB)

    Matthes, Felix C.

    2009-10-15

    The discussion on the plant life extensions for German nuclear power plants beyond the residual quantity of electricity particularly focus on three aspects: Effects for the emission of carbon dioxide as a greenhouse gas; Development of the electricity price for which a reduction or attenuation is postulated due to a plant life extension; Skimming of additional profits at operating companies and their use in the safeguarding of the future (development of renewable energies, support of energy efficiency, promotion of the research, consolidation of the public budget, and so on). Under this aspect, the author of the contribution under consideration reports on the profit taking of nuclear power plant operators. The presented analysis considers three aspects: (a) Specification of the quantity structures for the investigated model of plant life extension; (b) The decisive parameter is the revenue situation and thus the price development for electricity at wholesale markets; (c) Determination and evaluation of the course in time of the profit taking.

  10. Identification and management of plant aging and life extension issues for a liquid-metal-cooled reactor

    International Nuclear Information System (INIS)

    King, R.W.; Perry, W.H.

    1991-06-01

    Experimental Breeder Reactor 2 (EBR-2) is a pool-type sodium-cooled fast reactor that supports extensive experimental, test and demonstration programs while providing electrical power to the local grid. EBR-2 is a US Department of Energy Facility located at the Idaho National Engineering Laboratory and operated by Argonne National Laboratory (ANL). The current mission of EBR-2 is to serve as the operational prototype for the Integral Fast Reactor demonstration program. This mission and other programs require EBR-2 to operate reliability to a 40-year lifetime, a significant extension beyond the five to ten year life originally planned for the facility. The benefits of operating EBR-2 in the extended-life mode are important for providing long-term operational performance data for a sodium-cooled fast reactor that is not available elsewhere. Identification and preliminary assessment of potential life-limiting factors indicate that, with appropriate consideration given in the design phase, the sodium-cooled plant has potential for a very long operational lifetime. Achievement of a 40-year lifetime with high reliability is important not only for achieving the near-term goals of the EBR-2/IFR programs, but for the advancement of the liquid-metal-cooled reactor concept to the demonstration/commercialization phase. Key features make extended-life operation feasible based on the use of sodium as the primary coolant: low-pressure, high thermal capacity primary system and a low-pressure secondary system requiring no active valves; and limited corrosion of components. 2 refs

  11. Challenges in the Licensing of New Nuclear Power Plant, Service Life Extension of Operating Ones (Safeguards-Safety-Security Aspects)

    International Nuclear Information System (INIS)

    Horvath, K.

    2016-01-01

    The Hungarian Atomic Energy Authority (HAEA), as the Hungarian nuclear regulator is faced with dual challenges meant by the licensing of the planned construction of two AES-2006 type nuclear power plant units and the licensing of the service life extension of the existing units that have been operating for more than 30 years. The HAEA has full regulatory competence; its mission is to oversee the safety and security of all the peaceful applications of atomic energy. Accordingly, the licensing scope covers safeguards, safety as well as security. The paper shows the current status of the Hungarian nuclear programme and the future plans, as well as summarizes the regulatory approach followed by HAEA. (author)

  12. Safety margin evaluation concepts for plant Up rates and life extension. Results of the OECD/NEA/CSNI working group on Safety Margin Action Plan (SMAP)

    International Nuclear Information System (INIS)

    Belac, J

    2006-01-01

    This presentation summarizes results of the OECD/NEA/CSNI working group on Safety Margin Action Plan (SMAP) aimed to develop generalized safety margin concept and means of its quantification for the process of evaluating plant safety in the frame of plant life extension and power up rating activities to be used by OECD member countries. (author)

  13. Boiler-turbine life extension

    Energy Technology Data Exchange (ETDEWEB)

    Natzkov, S. [TOTEMA, Ltd., Sofia (Bulgaria); Nikolov, M. [CERB, Sofia (Bulgaria)

    1995-12-01

    The design life of the main power equipment-boilers and turbines is about 105 working hours. The possibilities for life extension are after normatively regulated control tests. The diagnostics and methodology for Boilers and Turbines Elements Remaining Life Assessment using up to date computer programs, destructive and nondestructive control of metal of key elements of units equipment, metal creep and low cycle fatigue calculations. As well as data for most common damages and some technical decisions for elements life extension are presented.

  14. Plant life management

    International Nuclear Information System (INIS)

    Charbonneau, S.; Framatome, J.B.

    1992-01-01

    Plant life assessment and extension studies have been performed by numerous companies all over the world. Critical equipment has been identified as well as various degradation mechanisms involved in the plant aging process. Nowadays one has to think what to implement to improve the existing situation in the Nuclear Power Plant (NPP). FRAMATOME has undertaken this thought process in order to find the right answers and bring them to utilities facing either critical concern for plant life extension or the problem of management of power plant potential longevity. This is why we prepared a Plant Life Improvement Action Plan, comprising 10 (ten) major items described hereafter using examples of work performed by FRAMATOME for its utility customers desiring to manage the lives of their plants, both in France with EDF and abroad

  15. Life extension and life cycle management

    International Nuclear Information System (INIS)

    Hoang, H.

    2010-10-01

    To continue the effort of nuclear energy as the clean energy offsetting the increase in greenhouse gas emission that contributes to the increased global warming effect, the nuclear industry is focused on the optimization of their current nuclear generation assets. Plant life extension (Plex) and Plant life management (Plim), together with power up rate, are the key strategies for the optimization effort. Plex begins with the process to obtain the regulatory approval for an additional 20 years of operation, beyond the current 40-year limit. This highly standardized process consists of the following steps: 1) Scoping: identify the systems, structures and components for inclusion in the license renewal scope of work. 2) Screening: narrow down the selection of the in-scope systems, structures and components based on passive and long-lived characteristics. 3) Aging management review: demonstrate that aging effects will continue to be managed during the additional 20 years of operation. 4) Time limiting aging analyses: confirm the acceptability of design bases analyses that assume the 40-year plant life as a key input assumptions. To provide a consistent approach for the preparation of the license renewal application, the following are the key guidance documents: NUREG-1800: Standard review plan; NUREG-1801: Generic aging lessons learned; Nuclear Energy Institute NEI 95-10. The objectives of Plim are to focus on improving plant reliability/availability, and to plan for equipment upgrades for efficiency improvement as well as technological obsolescence. Plim is a technical evaluation combined with a risk assessment to produce a long-range business plant with a time horizon of 10 years or longer. Due to its long view nature, this plan will be reviewed on a yearly basis for any required adjustments. The technical evaluation consists of the following major steps: 1) Select systems, structures and components with performance deficiencies experience. 2) Collect operating data

  16. An application of modulated poisson processes to aging evaluation for the extension of qualified life of nuclear power plant equipment

    International Nuclear Information System (INIS)

    Saldanha, Pedro Luiz da Cruz

    2003-03-01

    The modulated power law process (MPLP) is a three-parameter stochastic point process model that can be used to describe the failures time of reparable systems. While the power law process implies that a system is exactly on the same condition just after a repair as just before a failure, the MPLP allows for the system to be affected both by failure and repair. For this reason this model is adequate for evaluating the recurrent events that incorporate both time trends and effects of past events such as the renewal type behavior. The purpose of this study is to evaluate the MPLP as a model for the rate of occurrence of failures of a repairable system to decide for an extension of qualified life in the context of licence renewal of a nuclear power plant. Standard statistical techniques, such as the maximum likelihood and linear regression models, are applied to estimate parameters of the MPLP. As a conclusion of the study, the MPLP is adequate for modelling rate of occurrence of failures that are time dependent, and can be used where the aging mechanisms are present in the operation of repairable systems. (author)

  17. Structural considerations in nuclear life extension

    International Nuclear Information System (INIS)

    Dodson, W.B.; McHale, P.F.

    1986-01-01

    The ability to extend the licensed life of a nuclear power plant requires that technical, economic, and regulatory criteria be satisfied. Two ongoing Electric Power Research Institute/US Department of Energy funded pilot studies are looking at the technical and economic aspects from a plant wide viewpoint to life extension. In each, structures have been identified to have a potentially strong effect on the viability for extended life because of the possible major cost, schedule, and person-rem factors should major refurbishment, modifications, or replacement be required. This paper reviews the degradation mechanisms and counterbalancing design features for one of these pilot plants in the studies. It further reviews the recommended ongoing practices to be followed to better ensure that life extension for the structures remains a future option

  18. Economic modeling for life extension decision making

    International Nuclear Information System (INIS)

    Farber, M.A.; Harrison, D.L.; Carlson, D.D.

    1986-01-01

    This paper presents a methodology for the economic and financial analysis of nuclear plant life extension under uncertainty and demonstrates its use in a case analysis. While the economic and financial evaluation of life extension does not require new analytical tools, such studies should be based on the following three premises. First, the methodology should examine effects at the level of the company or utility system, because the most important economic implications of life extension relate to the altered generation system expansion plan. Second, it should focus on the implications of uncertainty in order to understand the factors that most affect life extension benefits and identify risk management efforts. Third, the methodology should address multiple objectives, at a minimum, both economic and financial objectives

  19. Economic modelling for life extension decision making

    International Nuclear Information System (INIS)

    Farber, M.A.; Harrison, D.L.; Carlson, D.D.

    1987-01-01

    This paper presents a methodology for the economic and financial analysis of nuclear plant life extension under uncertainty and demonstrates its use in a case analysis. While the economic and financial evaluation of life extension does not require new analytical tools, such studies should be based on the following three premises. First, the methodology should examine effects at the level of the company or utility system, because the most important economic implications of life extension relate to the altered generation system expansion plan. Second, it should focus on the implications of uncertainty in order to understand the factors that most affect life extension benefits and identify risk management efforts. Third, the methodology should address multiple objectives, at a minimum, both economic and financial objectives. An analysis of the role of life extension for Virginia Power's generating system was performed using the MIDAS model, developed by the Electric Power Research Institute. MIDAS is particularly well suited to this type of study because of its decision analysis framework. The model incorporates modules for load analysis, capacity expansion, production costing, financial analysis, and rates. The decision tree structure facilitates the multiple-scenario analysis of uncertainty. The model's output includes many economic and financial measures, including capital expenditures, fuel and purchases power costs, revenue requirements, average rates, external financing requirements, and coverage ratio. Based on findings for Virginia Power's Surry 1 plant, nuclear plant life extension has economic benefits for a utility's customers and financial benefits for the utility's investors. These benefits depend on a number of economic, technical and regulatory factors. The economic analysis presented in this paper identifies many of the key factors and issues relevant to life extension planning

  20. Extension of life of nuclear power stations

    International Nuclear Information System (INIS)

    Takahashi, Hideaki

    1991-01-01

    At the time of designing nuclear power stations, as their service life, generally 40 years are taken, and the basic design specifications of machinery and equipment are determined. In USA where atomic energy has been developed, the new construction of nuclear power stations is cased for a while, however, if this situation continues as it is, since old power stations reach the service life of 40 years and are retired in near future, it is feared that the circumstance of the total amount of power generation becoming short will occur. As one of the countermeasures to this, the research on the extension of life of nuclear power stations has been carried out in many fields in USA, and it is expected that the application for extending the life for the power stations constructed in the initial period of development is submitted in 1991. The researches that have been carried out for solving the technical problems in this extension of life and the situation in Japan are reported. The NEC of USA decided that the operation period of nuclear power stations in USA, which is considered to be 40 years so far, can be extended up to the limit of 20 years. The background and circumstances of this problem in USA, Nuclear Plant Aging Research Program, Plant Life Extension Program and so on are reported. (K.I.)

  1. Boiling water reactor life extension monitoring

    International Nuclear Information System (INIS)

    Stancavage, P.

    1991-01-01

    In 1991 the average age of GE-supplied Boiling Water Reactors (BWRs) reached 15 years. The distribution of BWR ages range from three years to 31 years. Several of these plants have active life extension programmes, the most notable of which is the Monticello plant in Minnesota which is the leading BWR plant for license renewal in the United States. The reactor pressure vessel and its internals form the heart of the boiling water reactor (BWR) power plant. Monitoring the condition of the vessel as it operates provides a continuous report on the structural integrity of the vessel and internals. Monitors for fatigue, stress corrosion and neutron effects can confirm safety margins and predict residual life. Every BWR already incorporates facilities to track the key aging mechanisms of fatigue, stress corrosion and neutron embrittlement. Fatigue is measured by counting the cycles experienced by the pressure vessel. Stress corrosion is gauged by periodic measurements of primary water conductivity and neutron embrittlement is tracked by testing surveillance samples. The drawbacks of these historical procedures are that they are time consuming, they lag the current operation, and they give no overall picture of structural integrity. GE has developed an integrated vessel fitness monitoring system to fill the gaps in the historical, piecemetal monitoring of the BWR vessel and internals and to support plant life extension. (author)

  2. Experiences with the technical cooperation project TC MEX 04/53. Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant. Management program of the plant life (PLIM)

    International Nuclear Information System (INIS)

    Arganis J, C.R.; Aguilar T, J.A.; Guevara M, A.; Garcia M, C.; Martinez G, R.R.; Griz C, M.M.; Sanchez M, M.A.; Diaz O, R.C.

    2006-01-01

    In the biennium 2005-2006 the project of technical cooperation with the International Atomic Energy Agency OIEA TC MEX 04/53 'Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant Plant life handling program (PLIM)' was approved, which has as objective the one to begin the actions to apply the methodology of Handling of life of Plant (PLIM) in the Unit I (Ul) of the Laguna Verde Nucleo electric Central (CNLV), in order to obtain the Renovation of License (LR), in a long term (2020). To apply this methodology 5 systems they were selected, structures or components (SEC) to carry out the handling programs of the one aging (AMP), and PLIM which are: The encircling of the reactor core (Core Shroud), the pressure vessel of the reactor (Reactor Pressure Vessel), the one primary container (Primary Containment), the system of feeding water (Reactor Feed Water) and cables, which were not in this work to be of another nature. The report presents the more important aspects considered in these systems for their programs of AMP and PLIM, as like a revision of those selection processes and evaluation (screening and scoping) for the application of PLIM in the systems of the Ul of the CNLV. (Author)

  3. Technical Evaluation on Ageing Management in Nuclear Power in Japan -Life Extension over 40 Years at Japanese Nuclear Power Plants-

    International Nuclear Information System (INIS)

    Tanaka, H.; Iwasaki, M.; Miyama, S.

    2012-01-01

    The Japanese commercial reactors have accumulated more than 40 years operating experience since Tsuruga-1 started commercial operation in March 1970. However, the severe accident occurred at Fukushima nuclear power plants triggered by East Japan Great Earthquake on March 11 last year. The facts that all the reactors having experienced core meltdown had operated for more than 30 years and Fukushima Daiichi unit 1 had just received the approval for its 40th year Ageing Management Technical Evaluation results from the Japanese government caused increasing distrust among the public in nuclear power plants operating for a long period of time. However, investigations of the accident conducted so far have not revealed any evidence that ageing degradation accelerated the accident. In addition, the analysis of seismic accelerations of the earthquake did not show that any component function was lost due to the accident. Considering these facts, I would like to discuss the issues to be continuously pursued and to be additionally implemented as part of the plat life management activities. In addition, I will introduce the efforts made by the Japanese utilities following the accident. (author)

  4. Plant life extension of nuclear power plants. No thank you? A scientific study on the influence of media and communication on the public opinion concerning nuclear power

    International Nuclear Information System (INIS)

    Arlt, Dorothee

    2013-01-01

    The present study examined the influence of the individual use of media on attitudes towards nuclear power with focus in the run-time extension of German nuclear power plants, planned by the German government in the year 2010. The theoretical framework for explaining media effects on attitudes based on opinion research as well as on the second-level agenda setting. This approach assumes that highlighting attributes about attitude objects in the media makes them cognitively more accessible for recipients, so that these attributes are used to evaluate attitude object. In this study, arguments for and against the run-time extension were defined as attributes. For the investigation of individual media effects, this study was carried out in a two-method design to combine survey data and content analysis data on an individual level. From 16.08.2010 to 05.09.2010 the data on attitudes towards the planned run-time extension, nuclear power, energy, policy as well as individual media usage was collected in a representative telephone survey of n=551 people in Thuringia. In a quantitative content analysis the pro and contra arguments about the planned run-time extension in n=480 articles and news items, published during six months before the political decision, were analyzed. The findings of the content analysis showed that the media reported from 08.03.2010 to 05.09.2010 overall positively about the planned run-time extension and that the coverage intensity increased significantly shortly before the political decision. The main focus was on arguments regarding the efficiency and security of supply. By combining the content analysis data with the media usage data, new variables (sum and average value indices) for the specific individual media input of arguments about the run-time extension were formed. With these variables medium- and long-term media effects on attitudes towards nuclear power were tested. The results of the regression analyses showed that the individual media

  5. Residual life of technical systems; diagnosis, prediction and life extension

    International Nuclear Information System (INIS)

    Reinertsen, Rune

    1996-01-01

    The paper presents and discusses research related to residual life of non-repairable and repairable technical systems. Diagnosis of systems and extension of residual life of technical systems are also presented and discussed. This paper concludes that research published describing determination and extension of residual life as well as methods for diagnosis of non-repairable and repairable technical systems, is somewhat limited. Many papers have a rather pragmatic approach. The authors only describe special cases from their own plant and do not provide any explanation of a more academical nature. The other papers are mainly describing very specific applications of statistical models, leaving the more general case out of consideration. One of the main results of this paper is to point out these facts, and thereby identify the need for future research in this area

  6. Use of on-line fatigue monitoring of nuclear reactor components as a tool for plant life extension

    International Nuclear Information System (INIS)

    Stevens, G.L.; Ranganath, S.

    1991-01-01

    In this paper the application of an on-line fatigue monitoring system for tracking fatigue usage in operating power plants is described. The system, like several others which have been developed, uses the influence function approach, operates on a microcomputer, and determines component stresses using temperature, pressure, and flow rate data that are typically available from plant computers. Using plant-unique influence functions developed specifically for each component location, the system calculates stresses as a function of time and computes the fatigue usage. Stress values are calculated at time internals defined by the user and the fatigue values are saved on files for use at a later time. The application of the GE Fatigue Monitoring System (GEFMS) to calculate fatigue usage in the feedwater nozzle of a GE boiling Water Reactor is described in this paper

  7. The BWR owners' group planning guide for life extension

    International Nuclear Information System (INIS)

    Smith, S.K.; Lehnert, D.F.; Locke, R.K.

    1991-01-01

    Extending the operating life of a commercial nuclear power plant has been shown to be economically beneficial to both the utility and the electric customer. As such, many utilities are planning and implementing plant life extension (PLEX) programs. A document has been developed which provides guidance to utilities in formulating a PLEX program plant for one or more boiling water reactor (BWR) plants. The guide has been developed by the BWR Owners' Group Plant Life Extension Committee. The principal bases for this guide were the BWR Pilot and Lead Plant Programs. These programs were used as models to develop the 'base plan' described in this guide. By formulating their program plant utilizing the base plan, utilities will be able to maximize the use of existing evaluations and results. The utility planner will build upon the base plan by adding any tasks or features that are unique to their programs. (author)

  8. Plant life management in Hungary

    International Nuclear Information System (INIS)

    Gillemot, F.

    1998-01-01

    The life management in Hungary is in an early stage. The preparation of a suitable database, development of maintenance systems and education of the plant and consultant staff is essential. The Act of Nuclear Safety, the introduction of the 10 years periodic safety review system (periodic licence extension) is a good basis for life management. At the same time the economic changes in the country make the life management difficult. Presently most important task is to prepare the technical environment and the methodology for NPP Life management, and within a few years, when the economy would be consolidated, a real life management will be performed

  9. Aging management and life extension

    International Nuclear Information System (INIS)

    Carey, John; Deng, Daniel; Tai, Tom M.

    2004-01-01

    Approximately 20% of the present electric generating capacity in the United States is supplied by nuclear power plants and may be retired due to initial license expiration between the years 2002 and 2030. One of the recommended actions for implementing the National Energy Strategy (Bill H.R. 776) is license renewal of currently operating nuclear power plants which DOE has estimated would save between $800 million and $1 billion in avoided new construction costs - and represent a nationwide benefit of as much as $350 billion - assuming the licenses are renewed for 20 years. The U.S. Atomic Energy Act of 1954 limits the duration of operating licenses of nuclear power plants to a maximum of 40 years but permits their renewal. And, although Title 10, Part 50.51 of Code of Federal Regulations (10CFR50.51) permitted license renewal, it provided no standards or procedures for renewal applications. License renewal requirements were established on January 13, 1992 when NRC's Final Rule (10 CFR Part 54) went into effect. The Final rule established the requirements that an applicant for license renewal must meet, the information that must be submitted to the NRC for review. This involves the performance of an Integrated Plant Assessment (IPA) which is designed to ensure that the effects of aging on important equipment will be adequately managed during the renewal term. The issuance of 10 CFR Part 54 established the regulatory and legal requirements for license renewal. The technical basis for, or viability of, license renewal has been explored by the Electric Power Research Institute (EPRI) since the late 1970s/early 1980s. The NRC as well as industry organizations such as EPRI have studied aging effects for close to two decades. The NRC's research program on plant aging degradation, which began formally in the early 1980s, is a comprehensive effort for the understanding and management of age-related degradation in safety-related systems, structures, and components (SSCs) and

  10. Safety reassessment and life extension

    International Nuclear Information System (INIS)

    Gouffon, A.

    1992-12-01

    The safety reassessment policy implemented in France is a means of ensuring that no important point has been overlooked in the continuous safety reassessment process constituted by the integration of operating feedback. It also provides an opportunity for reappraisal of the basic design of a plant and examination of discrepancies between the safety options prevailing when it was built and those currently adopted. After a ten-year operating period, safety reassessment should enable identification of aging effects on structures and equipment, leading to improvement of component servicing and surveillance programs and provision for replacements which could be necessary

  11. NPP Evaluation, backfitting and life extension. An engineering viewpoint

    International Nuclear Information System (INIS)

    Gonzalez Lopez, A.

    1993-01-01

    During the decade of the 80s, the Owners of the two oldest operating plants in Spain designed and built during the 60s - namely, Jose Cabrera NPP, a Westinghouse PWR, and Santa Maria de Garona NPP, a GE BWR- undertook the following important programs: 1. A far-reaching Systematic Evaluation Program (SEP) for the Jose Cabrera NPP consisting in the systematic safety review of the plant design, followed by the necessary hardware modifications, to upgrade it and make it comply with current safety criteria, and a Plant Upgrading Program for the Garona Nuclear Station focusing on specific topics affecting GE BWR Mark-I type plants of the same vintage. 2. A Remaining Life Management Program to ensure that the units, after extensive backfittings and high capital investment, would complete their design life, leaving open the option for plant life extension. These two units are today considered by the Spanish nuclear industry as the pilot plants for Plant Life Extension (PLEX) programs for PWRs and BWRs in our country The purpose of this paper is to summarize the principal lessons learned from EMPRESARIOS AGRUPADOS' participation as an architect-engineering organization in the engineering, design and implementation of these Programs. They are practical examples of positive experience which could be considered as a reference when carrying out similar programs for other plants. (author)

  12. NPP Evaluation, backfitting and life extension. An engineering viewpoint

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Lopez, A [Empresarios Agrupados, A.I.E., Madrid (Spain)

    1993-12-15

    During the decade of the 80s, the Owners of the two oldest operating plants in Spain designed and built during the 60s - namely, Jose Cabrera NPP, a Westinghouse PWR, and Santa Maria de Garona NPP, a GE BWR- undertook the following important programs: 1. A far-reaching Systematic Evaluation Program (SEP) for the Jose Cabrera NPP consisting in the systematic safety review of the plant design, followed by the necessary hardware modifications, to upgrade it and make it comply with current safety criteria, and a Plant Upgrading Program for the Garona Nuclear Station focusing on specific topics affecting GE BWR Mark-I type plants of the same vintage. 2. A Remaining Life Management Program to ensure that the units, after extensive backfittings and high capital investment, would complete their design life, leaving open the option for plant life extension. These two units are today considered by the Spanish nuclear industry as the pilot plants for Plant Life Extension (PLEX) programs for PWRs and BWRs in our country The purpose of this paper is to summarize the principal lessons learned from EMPRESARIOS AGRUPADOS' participation as an architect-engineering organization in the engineering, design and implementation of these Programs. They are practical examples of positive experience which could be considered as a reference when carrying out similar programs for other plants. (author)

  13. Radurisation of broilers for shelf life extension

    International Nuclear Information System (INIS)

    Bok, H.E.; Holzapfel, W.H.; Van der Linde, H.J.

    1982-01-01

    Radurization is discussed as a method for the shelf life extension of refrigerated chicken carcasses. One of the advantages is that radurization eliminates potential food pathogenic bacteria like Salmonella in the chicken carcasses. Materials and methods for the radurization of chicken are discussed. The objective of the investigation was to determine the influence of different irradiation doses and storage conditions on the microbiological shelf life and organoleptic quality of fresh broilers

  14. Economic case for CANDU life extension projects

    International Nuclear Information System (INIS)

    Qureshi, S.; Tenev, T.; Lewi, M.

    2014-01-01

    As CANDU reactors approach their original end of design life utilities are faced with two options: to extend the operating life of the reactor by undergoing a life extension project (LEP), or to commence decommissioning activities. Recent project experience has shown that there is economic merit in extending the life of the operating reactor. There are many benefits to such a decision, the most obvious being the revenue that will be generated from the additional years of electricity production by the utility. Delays in decommissioning are also advantageous since the large costs associated with such a long-term activity are pushed into the future, thereby decreasing the net present value (NPV) of the investment. In addition, relatively few power reactors have been fully decommissioned to date and deferring this activity transfers the associated risks to others that are currently obligated to undertake decommissioning activities sooner. Candu Energy has been involved with the life extension projects of the following CANDU reactors: Point Lepreau (New Brunswick, Canada), Bruce Unit 1 and Unit 2 (Ontario, Canada), and Wolsong Unit 1 (South Korea). These reactors underwent fuel channel replacement programs in addition to replacement of major reactor components. Most recently, both Ontario Power Generation (OPG) and Nucleoelectrica Argentina Sociedad Anonima (NA-SA) have commenced work on life extension projects at the Darlington (Canada) and Embalse (Argentina) sites respectively. The experience gained from previous LEP projects allows Candu Energy to deliver future projects in a timely, efficient, and cost effective manner. (author)

  15. PSAD-a monitoring and aid to diagnosis system participating in saving on maintenance and operation costs and for plant life extension

    International Nuclear Information System (INIS)

    Brasseur, S.; Morel, J.; Joussellin, A.

    1997-01-01

    Monitoring nuclear plants components enable to save on operation and maintenance costs by reducing incidents gravity and casual plant stoppages thank to early detection and fast diagnosis. Improving the knowledge of the behaviour of the plant will also allow to optimize maintenance and to increase plant life. In order to improve monitoring and diagnosis capabilities in nuclear power plants. Electricite de France (EDF) is extending the existing data processing chains towards automatic aided interpretation and diagnosis. Therefore, EDF has designed an integrated monitoring and diagnosis assistance system: PSAD-Poste de Surveillance et d'Aide au Diagnostic, including several monitoring functions of the main components. It integrates on-line monitoring, off-line diagnosis and knowledge based systems. PSAD stations provide homogeneous aids to diagnosis which enable plant personnel to pinpoint the mechanical behaviour of plant equipment. The objective of PSAD is to provide them with high-efficiency and user-friendly tools which can considerabily free them from routine tasks. The first version of the prototype is working on a French Plant. This version includes the software host structure and two monitoring functions: the Reactor Coolant Pumps and the Turbo-generator Monitoring functions. Internal Structures Monitoring function and Loose Parts Detection are still under development and should be integrated into PSAD prototype in 1998

  16. Power generation options. Rehabilitation for life extension and cogeneration

    International Nuclear Information System (INIS)

    1993-01-01

    The first step in evaluating a life extension or upgrading project is to determine the project's economic benefit to the utility. A screening study should be performed for as many candidate plants as are available; two of the most useful screening tools for rapid economic analysis of life extension possibilities are: Present Worth Revenue Requirements (PWRR) Analysis, and Life Cycle Cost (LCC) Analysis. (Examples of both methods are discussed). PWRR analysis considers only the expenses associated with operation of a plant or electrical system, and the revenue required to meet those expenses. The total revenue that may be received from the system is not considered in the analysis. The estimated costs for a base case (usually no rehabilitation or life extension) is compared to the operating costs of various alternatives, calculated over an operating life span of several years, and reduced to a Present Worth value, usually for the year in which the study started. If the PWRR of any alternative is estimated to be less than the base case, then an investment in the alternative plant equal to or less than this differential is a preferred economic choice. PWRR analysis is useful if future systems development and future gross revenue to the utility is difficult to estimate; it is also useful when comparing like technologies when differences in fuel supply and fuel cost are minimal

  17. Life extension of the St. Lucie unit 1 reactor vessel

    International Nuclear Information System (INIS)

    Rowan, G.A.; Sun, J.B.; Mott, S.L.

    1991-01-01

    In late 1989, Florida Power and Light Company (FP and L) established the policy that St. Lucie unit 1 should not be prevented from achieving a 60-yr operating life by reactor vessel embrittlement. A 60-yr operating life means that the plant would be allowed to operate until the year 2036, which is 20 years beyond the current license expiration date of 2016. Since modifications to the reactor vessel and its components are projected to be expensive, the desire of FP and L management was to achieve this lifetime extension through the use of fuel management and proven technology. The following limitations were placed on any acceptable method for achieving this lifetime extension capability: low fuel cycle cost; low impact on safety parameters; very little or no operations impact; and use of normal reactor materials. A task team was formed along with the Advanced Nuclear Fuels Company (ANF) to develop a vessel-life extension program

  18. Service life optimization and extension of structures

    International Nuclear Information System (INIS)

    Hornet, P.; Venturini, V.; Persoz, M.; Debost-Eymard, I.; Meister, E.

    1998-01-01

    In order to justify its power plants safety which conditions their service life, EDF uses a deterministic approach until now. A probabilistic approach also exists which has a decisive advantage because it quantifies risk and makes it possible to optimize maintenance volume. The application of this approach is illustrated on the case of a reactor vessel; a coupling between the Code Aster tool and a probabilistic analysis software is necessary. (authors)

  19. Life extension of CANDU reactor cores

    International Nuclear Information System (INIS)

    Millard, J.; Kerker, J.; Albert, M.

    2011-01-01

    Candu Energy (formerly AECL), in partnership with station operators, has developed a robust methodology for demonstrating the fitness of reactor core structures, and associated reactivity control devices, as an essential element in conducting a station life extension project. The ageing of reactors is affected by ageing mechanisms impacted by operational history and design related factors such as materials, chemistries and stress distributions. The methodology of this life extension work is based on the IAEA TECDOC 1197; which documents practices for ageing management in CANDU reactors. This paper uses the work in Bruce Units 1 and 2, conducted from 2007 through to 2011, to explain the methodology. The work started with analysis of historical operational conditions and identification of the forms of degradation that could have occurred. The assessment and related inspections considered the safety and pressure boundary significance of each item, as well as its failure modes and margins. It then moved through both general and local inspection, focused mainly inside the calandria vessel once the calandria tubes were removed. The inspection found the bulk of the hardware to be in good condition, with a small number of remediation opportunities. In the course of that remediation some foreign material was sampled and removed. The minor remediation was successful and the work was completed through formal documentation of the fitness for extended life. It has been demonstrated through these analyses and visual inspections that the reactor structures and components inspected are free of indications and active degradation mechanisms that would prevent the safe and reliable operation of Bruce A Units 1 and 2 through its next 25 years of life. (author)

  20. Life extension of low and medium voltage equipment

    International Nuclear Information System (INIS)

    Bharteey, B.M.; Hart, T.J.

    1990-01-01

    Nuclear plant life extension is becoming a very important issue with the passing of each day. Within 3 to 10 years after the turn of the century, licenses of a number of nuclear power plants in the United States will expire. For the near future, new construction of nuclear power plants in the United States is expected to be inhibited, if the current economic and regulatory environment continues to persist. This situation, coupled with aging of utility equipment and the high cost of financing new construction is resulting in a growing emphasis on preserving and extending the capability of existing power plants. Until now, the utilities have placed more emphasis on high cost items, but experience shows that extending life of low cost of device/components in items like Motor Control Center Centers and switchgear pays big dividends. According to the current practice, devices of these items are replaced at the end of their assigned qualified life or attended to when there is a problem resulting in an unplanned outage. In this paper based on extensive experience in the field of motor control centers and medium switchgear, the authors proposed a cookbook methodology to determine the extent or absence of degradation and establish trends of the pertinent operational properties of devices of this type of equipment. The test results also provide satisfactory evidence of class 1E nuclear safety-related function

  1. Evaluation of the integrity and duration of the Laguna Verde nuclear power plant life- Plant Life Management program (PLIM). TC MEX 04/53 Technical Cooperation Project; Evaluacion de la integridad y extension de vida de la planta de potencia nuclear Laguna Verde- Programa de manejo de vida de planta (PLIM). Proyecto de cooperacion tecnica TC MEX 04/53

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C.R.; Diaz S, A.; Aguilar T, J.A. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2006-07-01

    As part of the IAEA TC MEX 04/53 Project 'Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant Handling Program of plant' whose objective is the one of beginning the actions to apply the methodology of Handling of plant life in the Unit 1 of the Laguna Verde Nucleo electric Central for to obtain the Renovation of License in 2020 the ININ, through the Department of Synthesis and Characterization of materials has carried out more of 20 analysis of susceptibility to the intergranular cracking for corrosion under effort in interns so much of the reactor of the unit 1 like of the unit 2 documenting the current state of components based on the type or types of materials that conform them, to it thermomechanical history, operational and of production, as well as of the particularities associated to its use and operation. For the application of the methodology of life handling of plant 5 structure systems or pilot components were selected, to carry out the programs of handling of the aging and handling of plant life: The encircling of the reactor core (Core Shroud), the reactor pressure vessel (Reactor Pressure Vessel), the primary container (Primary Containment), the recirculation system of feeding water (Reactor Feed Water) and cables. (Author)

  2. Program to justify life extension of older nuclear piping systems

    International Nuclear Information System (INIS)

    Burr, T.K.; Dwight, J.E. Jr.; Morton, D.K.

    1991-01-01

    The Idaho National Engineering Laboratory (INEL) has a history of more than 40 years devoted to the operation of nuclear reactors designed for research and experiments. The Advanced Test Reactor (ATR) is one such operating reactor whose mission requires continued operation for an additional 25 years or more. Since the ATR is approaching its design life of twenty years, life extension evaluations have been initiated. Of particular importance are the associated high temperature, high pressure loop piping system supporting in--reactor experiments. Failure of this piping could challenge core safety margins. Since regulatory rules for nuclear power plant life extension are only in the formulation stage, the current technical guidance on this subject provided by the Department of Energy (DOE) or the commercial nuclear industry is incomplete. In the interim, order to assure continued safe operation of this piping beyond its initial design life, a program has been developed to provide the necessary technical justification for life extension. This paper describes a program that establishes Section 11 of the ASME Boiler and Pressure Vessel Code as the governing criteria document, retains B31.1 as the Code of record for Section 11 activities, specifies additional inservice inspection requirements more strict than Section 11, and relies heavily on flaw detection and fracture mechanics evaluations. 18 refs., 2 figs

  3. Studies and development of essential systems in the surveillance program, life extension potential of the vessel and master curve in nuclear power plants

    International Nuclear Information System (INIS)

    Romero C, J.; Hernandez C, R.; Rocamontes A, M.; Perez R, N.

    2010-01-01

    The nuclear power plants owners should demonstrate that the effects of the embrittlement by neutronic radiation do not commit the structural integrity of the pressure vessel of the nuclear reactors, so much under conditions of routine operation as below an accident postulate. In consequence, in Mexico surveillance programs of the vessels of the nuclear power plant of Laguna Verde exist, in which three surveillance capsules are have by reactor. A surveillance capsule is composed by a support and between six and eight containers for test tubes and dosemeters. The containers for test tubes are of two types: rectangular container for Charpy V test tubes and cylindrical container for tension test tubes. These test tubes are subject to a same or bigger neutronic flow that of the vessel, being representative witness of the mechanical conditions of the vessel. The objective of to assay the test tubes to impact is to evaluate the embrittlement grade of the vessel beforehand during its useful life of operation, as well as to determinate the running of the ductile-fragile transition temperature in function of the time. (Author)

  4. Computers make rig life extension an option

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    The worldwide semisubmersible drilling rig fleet is approaching retirement. But replacement is not an attractive option even though dayrates are reaching record highs. In 1991, Schlumberger Sedco Forex managers decided that an alternative might exist if regulators and insurers could be convinced to extend rig life expectancy through restoration. Sedco Forex chose their No. 704 semisubmersible, an 18-year North Sea veteran, to test their process. The first step was to determine what required restoration, meaning fatigue life analysis of each weld on the huge vessel. If inspected, the task would be unacceptably time-consuming and of questionable accuracy. Instead a suite of computer programs modeled the stress seen by each weld, statistically estimated the sea states seen by the rig throughout its North Sea service and calibrated a beam-element model on which to run their computer simulations. The elastic stiffness of the structure and detailed stress analysis of each weld was performed with ANSYS, a commercially available finite-element analysis program. The use of computer codes to evaluate service life extension is described.

  5. Nuclear unit life extension: technico-economic considerations

    International Nuclear Information System (INIS)

    Bertron, L.

    1987-01-01

    The outstanding place of PWR power plants among the overall power generating facilities indicates the need for particular attention to be paid to assessing their expected useful life. The more so as they are not, in the medium term, exposed to the risk of becoming financially absolute which might result from more efficient generating tools entering the market. Yet, in no case should plant life extension affect safety in operation. This makes it necessary to ascertain and produce evidence that the various items of equipment remain equal to their function in terms of safety. Components ageing problems should be steadily monitored and ageing indicators adopted, allowing decisions of refurbishing or replacement to be made to avert plant shutdown. The alternative between repair works or shutdown will possibly arise in the case of heavy equipment likely to require protracted repairs and intricate works in radioactive environment. A technico-economic study, making allowance for anticipated savings in life extension through replacement operations, should help make the most appropriate decision [fr

  6. Nuclear power plant life extension and management aspects; neutron irradiation embrittlement and stress corrosion cracking - two possible degradation mechanisms and methods for their mitigation

    International Nuclear Information System (INIS)

    Tipping, P.; Ineichen, U.; Cripps, R.C.

    1994-01-01

    The response of a mock-up low alloy ferritic reactor pressure vessel (RPV) steel and associated weldments to neutron irradiation has been studied using a combination of hardness, tensile, fracture mechanical and toughness tests in combination with annealing treatments. Thermal analysis using isochronal and isothermal techniques has indicated that annealing at a minimum of 440 o C for 168h is needed to mitigate neutron embrittlement received at 290 o C. Rates of re-embrittlement after annealing and reirradiating are no faster than initial rates, even up to neutron fluences as high as 5x10 19 cm -2 (energy E>1 MeV). All mechanical properties measured benefited from annealing. Thus, annealing is indicated as one measure for maintaining mechanical properties in irradiated low alloy steels and welds and should be considered in plant life management strategies. The influence of simulated reactor coolant water chemistry on the stress corrosion cracking propensity of ferritic low alloy steel specimens in autoclave loop experiments has also been studied. The double cantilever bend specimens were fatigue pre-cracked and wedge-loaded to different degrees to induce nominal stress intensity factors between 15-95 MPa.m 1/2 . Other specimens were subjected to stress using a tensile loading device integral with the test autoclave. The importance of close control of the dissolved oxygen content and the conductivity of the water has become evident under these experimental conditions. The RPV material and degree and mode of loading are also important parameters in SCC studies; stress intensity factors above 30 MPa.m 1/2 have been associated with SCC in these studies. (author) 2 figs., 13 refs

  7. Life extension of containment structures of Indian PHWRs

    International Nuclear Information System (INIS)

    Roy, Raghupati; Garg, R.P.; Verma, U.S.P.

    2006-01-01

    Containment structures prevent radioactivity release in the event of any postulated Design Basis Accident (DBA) so that the level of radiation in the external environment is within acceptable limits. Containment structures of Indian PHWRs are typically unlined prestressed concrete structures, which are required to maintain its leak tightness characteristics and strength under DBA during the life of the structure. As nuclear power plant structures age, a number of degradation mechanisms begin to affect critical containment structure. Depending on the type and severity of these degradation mechanisms, its adverse effect on the leak tightness and pressure carrying capacity can be significant. Since the containment structures of Indian PHWRs are unlined, the leak tightness characteristics are solely dependent on the concrete properties and the prestressing material. Prestressing, which is introduced to control the deformation and strength requirement, is affected due to aging. Hence, adequacy of prestressing during the life of the structure to withstand internal pressure and the related leak tightness must be ensured for life extension of prestressed concrete containment structure in view of their significant long term losses. Prevention of corrosion in prestressing steel and assessment of the same at the end of extended design life of the structure, require utmost attention in view of their catastrophic nature of failure. This paper describes the various degradation mechanisms pertaining to concrete and their effect on the leak tightness characteristics and the strength requirement. The issues related to prestressing are also discussed in detail in this paper. The requirement of periodic monitoring of the containment structure for assessing its deformation and leak tightness characteristics and development of database for life extension of containment structure is also addressed in this paper. This paper also discusses the various provisions and measures, which are

  8. Experiences with the technical cooperation project TC MEX 04/53. Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant. Management program of the plant life (PLIM); Experiencias con el proyecto de cooperacion tecnica TC MEX 04/53. Evaluacion de la integridad y extension de vida de la planta de potencia nuclear Laguna Verde. Programa de Manejo de vida de planta (PLIM)

    Energy Technology Data Exchange (ETDEWEB)

    Arganis J, C.R.; Aguilar T, J.A. [ININ, 52750 Ocoyoacac, Estado de Mexico (Mexico); Guevara M, A.; Garcia M, C.; Martinez G, R.R.; Griz C, M.M.; Sanchez M, M.A.; Diaz O, R.C. [CFE, Subgerencia de Ingenieria, Carretera Veracruz-Medellin, Km. 7.5 Veracruz (Mexico)]. e-mail: craj@nuclear.inin.mx

    2006-07-01

    In the biennium 2005-2006 the project of technical cooperation with the International Atomic Energy Agency OIEA TC MEX 04/53 'Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant Plant life handling program (PLIM)' was approved, which has as objective the one to begin the actions to apply the methodology of Handling of life of Plant (PLIM) in the Unit I (Ul) of the Laguna Verde Nucleo electric Central (CNLV), in order to obtain the Renovation of License (LR), in a long term (2020). To apply this methodology 5 systems they were selected, structures or components (SEC) to carry out the handling programs of the one aging (AMP), and PLIM which are: The encircling of the reactor core (Core Shroud), the pressure vessel of the reactor (Reactor Pressure Vessel), the one primary container (Primary Containment), the system of feeding water (Reactor Feed Water) and cables, which were not in this work to be of another nature. The report presents the more important aspects considered in these systems for their programs of AMP and PLIM, as like a revision of those selection processes and evaluation (screening and scoping) for the application of PLIM in the systems of the Ul of the CNLV. (Author)

  9. Plant life management at Loviisa

    International Nuclear Information System (INIS)

    Hytoenen, Y.; Savikoski, A.

    1998-01-01

    IVO, Power Engineering Ltd. has developed a company-wide approach to plant life management. The first stage of plant life management comprises operational and maintenance histories, design and plant inspection data using advanced computer systems. The life of the plant can be controlled by maintenance, refurbishment and inspection programs, and by varying the method of plant operation. On-line monitoring is needed, and cost control and training must be taken into account if the life of the plant is to be managed efficiently. Identifying the life-limiting factors is essential at Loviisa. It has been concentrated on the aging in the form of materials degradation due to fatigue, erosion, corrosion, radiation and thermal effects. Certain other life-limiting factors are also mentioned

  10. Plant life management optimized utilization of existing nuclear power plants

    International Nuclear Information System (INIS)

    Watzinger, H.; Erve, M.

    1999-01-01

    For safe, reliable and economical nuclear power generation 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. An operator's overall approach to aging and plant life management which also improves performance characteristics can help to optimize plant operating economy. In view of the deregulation of the power generation industry with its increased competition, nuclear power plants must today also increasingly provide for or maintain a high level of plant availability and low power generating costs. This is a difficult challenge even for the newest, most modern plants, and as plants age they can only remain competitive if a plant operator adopts a strategic approach which takes into account the various aging-related effects on a plant-wide basis. The significance of aging and plant life management for nuclear power plants becomes apparent when looking at their age: By the year 2000 roughly fifty of the world's 434 commercial nuclear power plants will have been in operation for thirty years or more. According to the International Atomic Energy Agency, as many as 110 plants will have reached the thirty-year service mark by the year 2005. In many countries human society does not push the construction of new nuclear power plants and presumably will not change mind within the next ten years. New construction licenses cannot be expected so that for economical and ecological reasons existing plants have to be operated unchallengeably. On the other hand the deregulation of the power production market is asking just now for analysis of plant life time to operate the plants at a high technical and economical level until new nuclear power plants can be licensed and constructed. (author)

  11. Nuclear power plant life management

    International Nuclear Information System (INIS)

    Rorive, P.; Berthe, J.; Lafaille, J.P.; Eussen, G.

    1998-01-01

    Several definitions can be given to the design life of a nuclear power plant just as they can be attributed to the design life of an industrial installation: the book-keeping life which is the duration of the provision for depreciation of the plant, the licensed life which corresponds to the duration for which the plant license has been granted and beyond which a new license should be granted by the safety authorities, the design life which corresponds to the duration specified for ageing and fatigue calculations in the design of some selected components during the plant design phase, the technical life which is the duration of effective technical operation and finally the economic life corresponding to the duration of profitable operation of the plant compared with other means of electricity production. Plant life management refers to the measures taken to cope with the combination of licensed, design, technical and economical life. They can include repairs and replacements of components which have arrived to the end of their life due to known degradation processes such as fatigue, embrittlement, corrosion, wear, erosion, thermal ageing. In all cases however, it is of great importance to plan the intervention so as to minimise the economic impact. Predictive maintenance is used together with in-service inspection programs to fulfil this goal. The paper will go over the methodologies adopted in Belgium in all aspects of electrical, mechanical and civil equipment for managing plant life. (author)

  12. Life extension of German nuclear power plants only with the consent of the Federal Council? The importance and extent of the need for consent to an amendment to the German Atomic Energy Act

    International Nuclear Information System (INIS)

    Schneider, Horst

    2010-01-01

    In its coalition agreement of October 26, 2009, the new German federal government plans ''to extend the service life of German nuclear power plants while, at the same time, complying with the strict German and international safety standards.'' This has triggered a debate not only about (nuclear) energy, as in the past election campaign in the summer of 2009, but also about the constitutional law issue whether an amendment to the Atomic Energy Act resulting in longer operating life of nuclear power plants required the consent of the Federal Council (the ''Bundesrat,'' the second chamber of parliament). After the election to the state parliament in North Rhine-Westphalia on May 9, 2010, majority in the Federal Council changed. As a consequence, no consent to an amendment to the Atomic Energy Act must be expected. In view of the large number of recent statements about constitutional law in opinions for various federal and ministerial accounts as well as firms and associations, the outline by R. Scholz in the May issue of atw 2010 will be followed in this issue by the key points of examination of the need for consent, under aspects of constitutional law, and an attempt will be made to explain the evaluations underlying the generation of a legal concept about these items. The decision by the German Federal Constitutional Court of May 4, 2010, published on June 11, 2010, plays a major role in this respect because it established clarity in some important aspects of a legal subject matter in the field of state admini-stration on behalf of the federation, albeit in the field of air traffic law, not nuclear law. However, the structures of the norms in the German Basic Law (Art. 87c and Art. 87d, para.2) to be applied are almost identical. The energy policy and energy economy aspects of a plant life extension are considered along with the option of an appeal to the Federal Constitutional Court against any plant life extension. Finally, the key findings are summarized briefly

  13. Development of an aging evaluation and life extension program for the Advanced Test Reactor

    International Nuclear Information System (INIS)

    Dwight, J.E. Jr.

    1988-01-01

    A life extension program has been developed for the US Department of Energy's Advanced Test Reactor. The program is an adaptation of life extension pilot programs at the Surry Unit 1 and Monticello generating stations and is being completed in three phases. In Phase 1, the critical plant components were identified. In Phase 2, existing lifetime analyses and support data for the critical components were reviewed. The results from the review give a preliminary indication that an overall plant lifetime in excess of forty years is feasible. In Phase 3, now in progress, detailed evaluations for component life extensions are being performed. 2 refs., 2 figs., 1 tab

  14. Molecular regulation of plant cell wall extensibility

    Science.gov (United States)

    Cosgrove, D. J.

    1998-01-01

    Gravity responses in plants often involve spatial and temporal changes in cell growth, which is regulated primarily by controlling the ability of the cell wall to extend. The wall is thought to be a cellulose-hemicellulose network embedded in a hydrated matrix of complex polysaccharides and a small amount of structural protein. The wall extends by a form of polymer creep, which is mediated by expansins, a novel group of wall-loosening proteins. Expansins were discovered during a molecular dissection of the "acid growth" behavior of cell walls. Expansin alters the rheology of plant walls in profound ways, yet its molecular mechanism of action is still uncertain. It lacks detectable hydrolytic activity against the major components of the wall, but it is able to disrupt noncovalent adhesion between wall polysaccharides. The discovery of a second family of expansins (beta-expansins) sheds light on the biological role of a major group of pollen allergens and implies that expansins have evolved for diverse developmental functions. Finally, the contribution of other processes to wall extensibility is briefly summarized.

  15. Safety aspects in life extension of NPPs. Working material

    International Nuclear Information System (INIS)

    2002-01-01

    Due to current social and economical framework, in last years many Member States (MS) started a process of Plant Life Extension (PLEX) for their older nuclear facilities. The process followed many different approaches, being intrinsically dependent on the national regulatory framework and technical tradition. This process has many nuclear safety implications, other than strategic and political ones, and therefore a need for tailoring the available safety assessment tools to such applications has become urgent in recent years. Typical safety assessment processes such as the Periodic Safety Review has been used already and can be used in the future as a framework for a PLEX. Also the review of regular maintenance and ageing management programs and the continuous upgrading of the Safety Analysis Report are tools widely used in a life extension context in many MS. However, recently some MS highlighted the need to identify in a clear way the technical aspects more directly affecting the decision for a long-term operation of a nuclear facility. Many Technical Cooperation projects have been requested for the year 2003-2004 on this subject and a generic task in Nuclear Safety proved necessary as a background activity. Therefore, on May 6-10, 2002, a Consultant Meeting dealing with Safety Aspects of life extension for NPPs was convened at the Nuclear Safety Dept. of the IAEA. It was attended by representatives of Regulatory Bodies and Utilities, both from countries with experience of life extension of NPPs and countries where the process is at the beginning. The main application problems were identified and discussed and a first attempt was carried out to define the key elements of the life extension process, isolating peculiar technical items, LTO related, from generic safety related tasks. The result was a preliminary technical document with a collection of basic experience and information for the implementation of a PLEX program. Therefore the draft document was thought

  16. Proactive life extension of pressure vessels

    Science.gov (United States)

    Mager, Lloyd

    1998-03-01

    place while our vessels are in service. As the inspection takes place we are able to view a real time image of detected discontinuities on a video monitor. The B-scan ultrasonic technique is allowing us to perform fast accurate examinations covering up to 95% of the surface area of each pressure vessel. Receiving data on 95% of a pressure vessel provides us with a lot of useful information. We use this data to determine the condition of each pressure vessel. Once the condition is known the vessels are classed by risk. The risk level is then managed by making decisions related to repair, operating parameters, accepting and monitoring or replacement of the equipment. Inspection schedules are set at maximum intervals and reinspection is minimized for the vessels that are not at risk. The remaining life of each pressure vessel is determined, mechanical integrity is proven and regulatory requirements are met. Abbott Laboratories is taking this proactive approach because we understand that our process equipment is a critical element for successful operation. A run to failure practice would never allow Abbott Laboratories to achieve the corporation's objective of being the world's leading health care company. Nondestructive state of the art technology and the understanding of its capabilities and limitations are key components of a proactive program for life extension of pressure vessels. 26

  17. Actions concerning nuclear power plant life evaluation

    International Nuclear Information System (INIS)

    Chocron, M.; Fabbri, S.; Mizrahi, R.; Savino, E.J.; Versaci, R.A.

    1998-01-01

    One of the main activities to be undertaken by CNEA will be to provide technological assistance to NASA in problems concerning NPP operation. Works on life extensions of NPP are included in these activities. To fulfill these requirements the Atomic Energy National Commission (CNEA) has constituted a technical committee for Nuclear Power Plants Support (CAPCEN). CAPCEN should be the knowledge reservoir of those issues concerning the performance, safety and life extension of Nuclear Power Plants. One of CAPCEN's most important activities is to promote research work connected with such issues. The main technical areas are: Pressure Vessel and Piping, Heat Exchanges and Fuel Channels and Reactor Inner Components. Efforts are focused on the identification of the main components susceptible of ageing, the study of their ageing mechanisms, the follow-up of their behaviour during operation, and the measures taken to extend their life. (author)

  18. Symposium on extension of life time of atomic energy facilities

    International Nuclear Information System (INIS)

    1987-01-01

    This symposium was held on November 18, 1987 in University of Tokyo under the sponsorship of Japan Welding Engineering Society. The papers were presented on the various problems on the examination of the extension of life time and the deterioration with the lapse of years of nuclear power plants, the data of corrosion fatigue strength in high temperature water and the controlling factors, the trend of the research on corrosion fatigue crack development in high temperature, high pressure water and future problems, long life corrosion fatigue characteristics and the method of estimating remaining life, the trend of the research on the neutron irradiation embrittlement of pressure vessels, the results of the property confirmation test on the strain aging of reactor pressure vessel materials, the evaluation of life time by probabilistic fracture mechanics, the radiation deterioration of electric wire coating and insulation materials, the deterioration of concrete structures with the lapse of years, and the detection of the deterioration with the lapse of years. (K.I.)

  19. CANDU plant life management - An integrated approach

    International Nuclear Information System (INIS)

    Charlebois, P.; Hart, R.S.; Hopkins, J.R.

    1998-01-01

    objective of these programs is to assure safe, economic operation of the CANDU 6 unit stations for the remaining portion of their design life, and to preserve the option for plant life extension to about double their original life. Work on comprehensive PLIM programs building on this generic work has started with 2 CANDU utilities. Results of the program are being fed back into the new CANDU 6 and 9 products, to provide customers with the improved assurance of safe and economic operation, with the opportunity for plant life extension. This paper describes the status of the programs undertaken by both the utilities and AECL to safeguard the investment they have made in CANDU stations and technology. (author)

  20. A business model framework for product life extension

    NARCIS (Netherlands)

    Den Hollander, M.C.; Bakker, C.A.

    2012-01-01

    Product life extension is an increase in the utilization period of products. Design research on product life extension strategies has so far mainly focused on technical aspects of products, like ‘prevention engineering’ or ‘design for repair, maintenance and upgradability’, and on individual

  1. Reactor vessel assessment and the development of a reactor vessel life extension program for Calvert Cliffs Units One and Two

    International Nuclear Information System (INIS)

    Montgomery, B.; Hijeck, P.J.

    1988-01-01

    A study has been undertaken to provide a general assessment of the life extension capabilities for the Calvert Cliffs Units One and Two reactor pressure vessels. The purpose of the study is to assess the general life extension capabilities for the Calvert Cliffs reactor pressure vessels based upon an extension and variation of the Surry pilot plant life extension study. This assessment provided a detailed reactor vessel surveillance program for plant life extension along with a hierarchy of specific tasks necessary for attaining maximum useful life. The assessment identified a number of critical issues which may impact life attainment and extension along with potential solutions to address these issues to ensure the life extension option is not precluded

  2. [Quality of life after extensive pelvic surgery].

    Science.gov (United States)

    Levý, M; Lipská, L; Visokai, V; Šimša, J

    Multiorgan resections in the small pelvis are standard procedures in oncosurgery and some indications have no alternative. In advanced pelvic cancer, pelvic exenteration with en bloc resection of the involved organs and structures, including portions of the bony pelvis, is indicated. The 5-year survival rate is fairly good, around 50%, but little is known about the long-term quality of life. The aim was to describe the quality of life of long-term total pelvic exenteration survivors. In total, 63 pelvic exenterations were performed between 2000 to 2015 at the Department of Surgery, Thomayer Hospital, First Faculty of Medicine, Charles University in Prague, mostly for primary or relapsed rectal cancer. In this retrospective cohort study, the quality of life was assessed using the EORTC QLQ-C30 (version 3.0) and the EORTC QLQ-CR29 questionnaires. The completed questionnaires were scored according to EORTC instructions. At the time of this survey, 24 patients after TPE were surviving longer than one year after the surgery. The five-year survival of all patients was 49%, median survival 4.6 years, and median follow-up 15 months. Most of our patients reported a good level of their physical, emotional, cognitive and social functions. Some patients reported a worse body image, and of course a worsening in their sexual life. Regarding symptom-oriented questions, some patients evaluated the necessity of more frequent care of the stomia as slightly problematic; most patients reported impotence (men) or painful sexual intercourse (women). Long-term quality of life in survivors of pelvic exenteration for rectal cancer is comparable with reported results following primary rectal cancer resection with the exception of the sexual function. The quality of life gradually improves in the course of weeks to months from the surgery. pelvic exenteration quality of life.

  3. Life management of SG for WWER plants

    International Nuclear Information System (INIS)

    Trunov, N. B.; Dragunov, Yu. G.; Banyuk, G. F.

    2004-01-01

    Nowadays, 252 steam generators (SG) of horizontal type are in operation at WWER plants constructed by the Russian designs. In connection with end of the specified service life of the reactor plant equal to 30 years the activities are performed on service life extension of the main equipment including the SG. At some Units, throughout the design service life of SG there were problems resulting in necessity of SG replacement. At the same time the SGs at some Units are in successful operation above the design service life. This report deals with the peculiarities of operation of the horizontal SGs and the problems to be highlighted as the most important for service life extension. The main component to determine possibility for SG service life extension is the SG tubing. As the operating experience shows it is water chemistry of the secondary circuit that is the main factor influencing operability of the SG tubing. Therefore, differences in water chemistry organization leads to significant differences in operability of the SG tubing at various Units and in some cases within one Unit. Owing to the fact that the cases of water chemistry disturbance and the process of tubes fouling with the corrosion products of the main condensate system are not excluded, the damages continue to occur. Tube integrity shall be inspected by eddy current method using the various instrument complexes. This method has certain disadvantages but allows to estimate the degree and direction of degradation processes. The results of eddy current test (ECT) can be used to determine the plugging criterion for defective tubes. The significant number of defective tubes at some Units makes a choice of the plugging criterion to be an important problem, on which solution the SG safety, reliability and service life depends. The report deals with directions of activities in service life management for the SG at WWER plants. Main activities are improvement of water chemistry and non-destructive tests.(author)

  4. BIF butterfly valve life extension at WNP-2

    International Nuclear Information System (INIS)

    Armstrong, D.

    1991-01-01

    Primary containment purging, venting, inerting, and reactor building ventilation at the WNP-2 plant are accomplished with a series of large butterfly valves. A total of 31 valves which are similar in design, but of different sizes, employ an elastomer to achieve sealing integrity when closed. These valves, which were originally manufactured by BIF, a unit of General Signal, range in size from 18 to 84 inches in diameter. Service life in the plant was much less than desired for safety-related equipment, and several seal failures had been experienced shortly after valve overhaul. This program covers a design change made to enhance performance of the elastomer seal to achieve a very meaningful life extension. While numerous configurations of BIF valves exist, this work relates only to the model 657 unit assembled with an elastomer seal mounted onto the valve disc by a stainless steel clamping ring held with studs and nuts. The problems encountered, and the steps taken to resolve the deficiencies may, however, be applicable to other butterfly valve configurations

  5. Establishment of safety verification method for life extension based on periodic safety review

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soong Pyung; Yeom, Yu Son; Yoon, In Sik; Lee, Jeo Young [Chosun Univ., Gwangju (Korea, Republic of)

    2004-02-15

    Safe management of operating lifetimes of Nuclear Power Plants is a subject of prime interests. As the design life of the Nuclear Power Plant will be ended in 2008, an appropriate procedure for the design life re-assessment or lifetime extension is necessary in Korea. Therefore, the objective of this work is to develop procedural requirements which can be applied to the regulation of lifetime management or life extension of Nuclear Power Plants in Korea. Review on the linkage of the PSR with the extension of the operating lifetime of Nuclear Power Plants was performed to enhance the utilization of PSR results and analysis of the insufficiencies in the license rule in Korea.

  6. Life extension program of KORI Unit 1 NPP in Korea

    International Nuclear Information System (INIS)

    Hong, Sun-Yull

    1998-01-01

    The two phases of Life extension program for KORI Unit 1 NPP are presented. Phase I is completed. It was concluded that life extension is a feasible option in technical and economic aspects. Detailed analysis of RPV is underway, plan for Phase II is finished. It deals with screening and sorting of all relevant SSCs, detailed life evaluation of SSCs, ageing management program and documentation for license renewal application

  7. Plant life management (PLIM) in Swiss nuclear power plants

    International Nuclear Information System (INIS)

    Stejskal, Jan; Steudler, Daniel; Thoma, Kurt; Fuchs, Reinhard

    2002-01-01

    Full text: The Swiss Utility Working group for ageing Management (AM) presented their programme for the first time at the PLIM/PLEX 93. In the meantime the key guideline documents have been prepared and the most so called S teckbrief - files for Safety Class 1 (SC1) are issued. The 'Steckbrief' file is a summary of the component history and includes the results of the Reviews performed and measures taken or planned to counteract ageing mechanisms. The scope of these activities does not only serve the important aspect of reliable plant service but also facilitates component and plant life extension feasibility. The older plants have been operated now for up to 30 years, so PLEX will become a more important topic for Swiss NPP. It is very encouraging, that there is an official memorandum of the Swiss authority with the clear statement, that they could not identify any technical reason, why the older plants should not extend their design life of 40 years for at least 10 and the younger for 20 years. The result of this is that a well established Ageing Management Programme (AMP) provide a good basis for Plant Life Extension (PLEX), e.g. the Swiss AMP has to be seen as a PLIM. (author)

  8. The PREEV project of the Latin American Forum.Regulatory practices on aging and life extension

    International Nuclear Information System (INIS)

    Figueras, J. M.

    2011-01-01

    The American Forum Plenary approved in 2008 the PREEV project, Regulatory Practices in Aging and Life Extension, whose main objective is to improve the regulatory action with regard to the management programs of life and long-term operation of nuclear power plants in the countries of the region Latin American.

  9. Cost savings from extended life nuclear plants

    International Nuclear Information System (INIS)

    Forest, L.R. Jr.; Deutsch, T.R.; Schenler, W.W.

    1988-09-01

    This study assesses the costs and benefits of nuclear power plant life extension (NUPLEX) for the overall US under widely varying economic assumptions and compares these with alternative new coal- fired plants (NEWCOAL). It is found that NUPLEX saves future electricity consumers more than 3 cents/-kwh compared with NEWCOAL. The NUPLEX costs and benefits for existing individual US nuclear power plants under base-line, or most likely, assumptions are assessed to determine the effects of the basic plant design and plant age. While benefits vary widely, virtually all units would have a positive benefit from NUPLEX. The study also presents a cost-benefit analysis of the nuclear industry's planned advanced light water reactor (ALWR). It is concluded that ALWR offers electrical power at a substantially lower cost than NEWCOAL. 9 refs., 6 figs

  10. Solid Propulsion Systems, Subsystems, and Components Service Life Extension

    Science.gov (United States)

    Hundley, Nedra H.; Jones, Connor

    2011-01-01

    The service life extension of solid propulsion systems, subsystems, and components will be discussed based on the service life extension of the Space Transportation System Reusable Solid Rocket Motor (RSRM) and Booster Separation Motors (BSM). The RSRM is certified for an age life of five years. In the aftermath of the Columbia accident there were a number of motors that were approaching the end of their five year service life certification. The RSRM Project initiated an assessment to determine if the service life of these motors could be extended. With the advent of the Constellation Program, a flight test was proposed that would utilize one of the RSRMs which had been returned from the launch site due to the expiration of its five year service life certification and twelve surplus Chemical Systems Division BSMs which had exceeded their eight year service life. The RSRM age life tracking philosophy which establishes when the clock starts for age life tracking will be described. The role of the following activities in service life extension will be discussed: subscale testing, accelerated aging, dissecting full scale aged hardware, static testing full scale aged motors, data mining industry data, and using the fleet leader approach. The service life certification and extension of the BSMs will also be presented.

  11. Least cost options for life extension

    Energy Technology Data Exchange (ETDEWEB)

    Davis, F.; Bradaric, M. [Bechtel Corp., San Francisco, CA (United States)

    1995-12-01

    Rehabilitation of existing electric generating capacity offers one of the most cost-effective ways of meeting near-term power needs in many Eastern and Central European countries. In particular, the uncertainty associated with other supply sources and severe capital constraints tends to favor investments which maximize the utilization of existing fossil-fired equipment. However, it is critical that least-cost planning principles, including the consideration of environmental impacts, be applied to the economic analysis of rehabilitation options. This paper draws on Bechtel`s experience in applying least-cost planning to plant rehabilitation studies in Bulgaria, Romania and Slovakia. The examples provided illustrate the importance of least-cost planning and the effect of the value placed on environmental emissions.

  12. Central Air-Conditioning Plant (CAP) extension

    International Nuclear Information System (INIS)

    Shetty, P.S.; Kaul, S.K.; Mishra, H.

    2017-01-01

    Central Air-Conditioning Plant (CAP) and its associated chilled water network of BARC is one among the largest central plants in India for such application. The plant was planned in 1960s to cater to the air-conditioning and process water requirements of laboratories, workshops and buildings spread over a distance of 1.5 Km in three directions from CAP through underground network of chilled water pipelines. The plant was designed for a total capacity of 6600 TR. The present installed capacity of the plant is 7250 TR. The connected load at present is 9800 TR. After the XII plan capacity will be augmented to 7650 TR. The connected load is expected to cross 11,000 TR after the commissioning of new Engg. Halls 9, 10 and 11

  13. Extension of the nuclear power plant lifetime

    International Nuclear Information System (INIS)

    Keramsi, Alain

    2011-01-01

    After a presentation of the French nuclear context (history of the reactor fleet, choice of reactor type, PWR operation principle, competitiveness, environmental performance), this Power Point presentation addresses the context and challenges of the operation lifetime (average fleet age in different countries, examples of extensions, case of the United States, what is at stake with lifetime extension, decennial visits, EDF strategy), discusses the EDF's safety objectives (definition of the three main safety functions, impact of the operation duration and of the coexistence of two generations for the safety functions), discusses how to manage the ageing phenomenon for replaceable and non-replaceable components

  14. Conservation of boundary extension mechanisms between plants and animals

    OpenAIRE

    Mathur, Jaideep

    2005-01-01

    Locomotion clearly sets plants and animals apart. However, recent studies in higher plants reveal cell-biological and molecular features similar to those observed at the leading edge of animal cells and suggest conservation of boundary extension mechanisms between motile animal cells and nonmotile plant cells.

  15. Shelf-life extension of fresh chicken through radurisation

    International Nuclear Information System (INIS)

    Niemand, J.G.; Van der Linde, H.J.

    1982-01-01

    The article discusses the shelf-life extension of fresh chicken through radurization. In order to assess the potential of this process on the South African market, a detailed investigation was carried out to determine the shelf-life extension under local conditions. The following aspects were investigated; 1) reduction of bacterial numbers at different radurisation doses; 2) influence of storage temperature on shelf-life and 3) the elimination of Salmonella. Organoleptic testing was carried out on poultry radurised to doses of 3, 5, 7,5 and 10 kGy as well as on non-radurised controls

  16. Allocating nuclear power plant costs: an extension

    International Nuclear Information System (INIS)

    Bierman, H. Jr.

    1984-01-01

    The author modifies and extends the argument presented in the September 22, 1983 issue by Richard E. Nellis for using economic depreciation to allocate nuclear power plant costs. The two goals of his model are to charge constant real costs to consumers and to provide a fair return of .125 to investors in each period. The addition of other objectives requires further modification of the model since the schedule of revenues that are deemed to be optimum defines the depreciation schedule. 1 table

  17. Life extension of boilers using weld overlay protection

    Energy Technology Data Exchange (ETDEWEB)

    Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

    1998-12-31

    The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

  18. Life extension of boilers using weld overlay protection

    Energy Technology Data Exchange (ETDEWEB)

    Lai, G; Hulsizer, P [Welding Services Inc., Norcross, GA (United States); Brooks, R [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

    1999-12-31

    The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

  19. EXTENSION EDUCATION SYMPOSIUM: Getting the most out of your extension appointment and still having a life.

    Science.gov (United States)

    Powers, W; Cockett, N; Lardy, G

    2017-04-01

    Managing the demands of an academic appointment in extension can be a challenging task. Demands from constituent groups, expectations of supervisors, and rigors of promotion and tenure processes can create pressures that young faculty did not expect. Throw in spousal and family duties and you have created a situation that many will find hard to navigate. However, there are ways to cope and, even better news, there are ways to excel in meeting the demands of an academic appointment and enjoying life. Because many new extension faculty members do not have prior experience in extension, best practices in documenting programs and extension scholarship over the pretenure period are provided in this paper. Appointments that include both research and extension are quite common at many land grant universities. The advantages of joint appointments are numerous and include the fact that more and more grant agencies are seeking integrated research, teaching, and/or extension projects. However, the time demands of joint appointments can be challenging. Joint appointments can be designed to help faculty members conduct important translational research and have it be applied in a production setting. By seeking commonalities in research and extension efforts, joint appointments can be very synergistic. Development of highly successful programs requires planning on the front end with an emphasis on an in-depth needs assessment to determine stakeholder needs for both research and extension. Impact assessment should be part of this planning effort. Performing as a successful extension faculty member while maintaining relationships outside of work is challenging and requires deliberate effort on the part of employees and supervisors to realize there is more to life than work. Some authors have referred to this as work-life balance, but it may be more helpful to think of it as work-life effectiveness. To do this, one needs to 1) define what success looks like, 2) set boundaries and

  20. Application of annealing for WWER vessels life extension

    International Nuclear Information System (INIS)

    Badanin, V.I.; Gorynin, I.V.; Nickolaev, V.A.; Dragunov, Y.G.; Fedorov, V.G.

    1989-01-01

    Safe operation of NPP is greatly dependent on the guarantee of reactor vessel brittle failure strength with account for the effect of radiation embrittlement of vessel material. Recovery of irradiated material properties is principally important way to extend radiation life of reactor vessel. The aim of this report is to demonstrate the efficiency of annealing for recovery of vessel material properties and extension of its service-life

  1. Shelf life extension of ground beef by radurization

    International Nuclear Information System (INIS)

    Holzapfel, W.H.; Niemand, J.G.

    1982-01-01

    Radurization was investigated as a technique in the shelf life extension of ground beef. Although radurization does not necessarily kill off all meat spoilage bacteria, this process may be used for extending the bacteriological keeping quality of fresh meat. The materials and methods used in the investigation are also discussed

  2. International database on ageing management and life extension

    International Nuclear Information System (INIS)

    Ianko, L.; Lyssakov, V.; McLachlan, D.; Russell, J.; Mukhametshin, V.

    1995-01-01

    International database on ageing management and life extension for reactor pressure vessel materials (RPVM) is described with the emphasis on the following issues: requirements of the system; design concepts for RPVM database system; data collection, processing and storage; information retrieval and dissemination; RPVM information assessment and evaluation. 1 fig

  3. Non-arrhenius behavior in product life extension

    International Nuclear Information System (INIS)

    Dulka, C.P.; Scamman, J.F.

    1988-01-01

    The purpose of the work reported in this paper was to investigate contact sticking, which was determined to be caused by a materials shrinkage phenomenon. The phenomenon was noted after a brief accelerated thermal aging format, which was followed during the course of a General Electric materials analysis technique (GEMAT) product life extension program. The original qualification work did not address this phenomenon. This shrinkage phenomenon occurs in some materials and, depending upon the design of the product, could be a significant factor in a product life extension program. Further tests are planned in which this phenomenon will be investigated as a function of temperature and time duration in a GEMAT program. The extent of this phenomenon's effect on product life depends on type of material, product design, and product tolerances. Furthermore, this phenomenon may or may not exhibit an Arrhenius-type behavior, and more investigation is required in this area. In any product life extension program, the existence of this phenomenon and the degree to which it affects the product's life should be investigated. This phenomenon can be a significant factor

  4. 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.)

  5. Life extension of semi-submersible drilling unit

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, I.; Sinclair, C.I.K. [TWI, Cambridge (United Kingdom). Structural Integrity Dept.; Magne, E. [Schlumberger Sedco Forex, Montrouge (France)

    1995-12-31

    This paper describes the life extension of a semi-submersible drilling rig built in the early 1970`s. A nominal design life of 20 years was estimated at the time of building; however, in the interim period, numerous improvements have been made in fatigue life estimation ad life improvement techniques, raising the possibility that a further 20 years of operation could be considered. The life extension strategy made use of a number of aspects of offshore technology which were not available at the time of construction of the rig. Finite element studies and results from offshore research programs were used to gauge the effect of fatigue life improvement techniques. The program demonstrated the feasibility of extending the operation of the rig for a further 20 years, with the interval between in-service inspection increased to every five years. It also provided a valuable database of fracture toughness data for the rig materials, which may be used in future work to address reliability issues.

  6. CANDU steam generator life management: laboratory data and plant experience

    International Nuclear Information System (INIS)

    Tapping, R.L.; Nickerson, J.H.; Subash, N.; Wright, M.D.

    2001-10-01

    As CANDU reactors enter middle age, and the potential value of the plants in a deregulated market is realized, life management and life extension issues become increasingly important. An accurate assessment of critical components, such as the CANDU 6 steam generators (SGs), is crucial for successful life extension, and in this context, material issues are a key factor. For example, service experience with Alloy 900 tubing indicates very low levels of degradation within CANDU SGs; the same is also noted worldwide. With little field data for extrapolation, life management and life extension decisions for the tube bundles rely heavily on laboratory data. Similarly, other components of the SGs, in particular the secondary side internals, have only limited inspection data upon which to base a condition assessment. However, in this case there are also relatively little laboratory data. Decisions on life management and life extension are further complicated--not only is inspection access often restricted, but repair or replacement options for internal components are, by definition, also limited. The application of CANDU SG life management and life extension requires a judicious blend of in-service data, laboratory research and development (R and D) and materials and engineering judgment. For instance, the available laboratory corrosion and fretting wear data for Alloy 800 SG tubing have been compared with plant experience (with all types of tubing), and with crevice chemistry simulations, in order to provide an appropriate inspection guide for a 50-year SG life. A similar approach has been taken with other SG components, where the emphasis has been on known degradation mechanisms worldwide. This paper provides an outline of the CANDU SG life management program, including the results to date, a summary of the supporting R and D program showing the integration with condition assessment and life management activities, and the approach taken to life extension for a typical

  7. Shelf life extension for the lot AAE nozzle severance LSCs

    Science.gov (United States)

    Cook, M.

    1990-01-01

    Shelf life extension tests for the remaining lot AAE linear shaped charges for redesigned solid rocket motor nozzle aft exit cone severance were completed in the small motor conditioning and firing bay, T-11. Five linear shaped charge test articles were thermally conditioned and detonated, demonstrating proper end-to-end charge propagation. Penetration depth requirements were exceeded. Results indicate that there was no degradation in performance due to aging or the linear shaped charge curving process. It is recommended that the shelf life of the lot AAE nozzle severance linear shaped charges be extended through January 1992.

  8. Life extension of the BR2 aluminium vessel

    International Nuclear Information System (INIS)

    Koonen, E.; Fabry, A.; Chaouadi, R.; Verwerft, M.; Raedt, C. de; Winckel, S. van; Wacquier, W.; Dadoumont, J.; Verwimp, A.

    2000-01-01

    The BR2 reactor has recently undergone a major refurbishment comprising the replacement of all vessel internals. The vessel itself however was not replaced. An important requalification programme has been executed to prove that the vessel would remain fit during the contemplated life extension period of BR2. Representative material samples could be obtained from the shroud surrounding the vessel. A comprehensive in-service inspection was carried out and a vessel surveillance programme has been established. (author)

  9. Crack arrest concepts for failure prevention and life extension. Proceedings

    International Nuclear Information System (INIS)

    Wiesner, C.S.

    1996-01-01

    These proceedings contain the thirteen papers presented at a seminar on crack arrest concepts for failure prevention and life extension. They provide a picture of the current position of crack arrest testing, models and applications, discussion of the relevance of recent research to industrial problems, and an assessment of whether the application of crack arrest models provides additional safety. Separate abstracts have been prepared for seven papers of relevance to the nuclear industry and, in particular, reactor pressure vessels. (UK)

  10. Ageing of materials and methods for the assessment and extension of lifetimes of engineering plant

    International Nuclear Information System (INIS)

    Stumpf, W.E.

    1994-01-01

    Life-extension (LIFEX) strategies for engineering plant are discussed against the background of the decline in the level of sustainability of the global environment. By directing LIFEX strategies towards better energy efficiency, better pollution control and higher quality throughputs, a significant contribution can be made to establishing more acceptable limits of sustainability. The decision-making process and implementation management of life extension are briefly examined. The question as to whether LIFEX programmes can contribute to the creation of wealth within acceptable limits of sustainability is addressed by considering past trends and future developments in both the fossil-fuelled and nuclear power industries. (UK)

  11. Contribution of Enterprise Asset Management (EAM) systems and CAP programs to support NPP life extension program

    International Nuclear Information System (INIS)

    Luanco, E.

    2007-01-01

    There is no specific IS (Information System) which supports the entire scope of a plant life extension, but there are a number of existing solutions that contributes to support it. Globally there are 2 categories of IS solution in the market: those supporting the Plant Life Improvement (PLIM) side of the life extension program and the others supporting the Plant Life Extension (PLEX) process side of it. The first category involves a large number of applications that span from ageing evaluation criteria programs, to monitoring solution for the critical components and to analysis and decision tools. The second category comprises solutions which support partially or globally the overall business process under a regulatory controlled manner. Both categories require 3 conditions to be satisfied: -) a comprehensive set of data (these data are often produced by various applications and the ability to correlate all the data together with a high degree of integrity is an important success factor); -) a feedback mechanism whose dual aspect is the monitoring of the ageing phenomena and the management of all the actions to be coordinated to ensure that preset objectives will be achieved in due time; and -) good people management to ensure particularly that staff will be well acquainted with new equipment or with new operating processes

  12. Life span extension and neuronal cell protection by Drosophila nicotinamidase.

    Science.gov (United States)

    Balan, Vitaly; Miller, Gregory S; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F A; Arking, Robert; Freeman, D Carl; Maiese, Kenneth; Tzivion, Guri

    2008-10-10

    The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone deacetylases. In Caenorhabditis elegans, knockdown of a pnc1 homolog was shown recently to shorten the worm life span, whereas its overexpression increased survival under conditions of oxidative stress. The function and regulation of nicotinamidases in higher organisms has not been determined. Here, we report the identification and biochemical characterization of the Drosophila nicotinamidase, D-NAAM, and demonstrate that its overexpression significantly increases median and maximal fly life span. The life span extension was reversed in Sir2 mutant flies, suggesting Sir2 dependence. Testing for physiological effectors of D-NAAM in Drosophila S2 cells, we identified oxidative stress as a primary regulator, both at the transcription level and protein activity. In contrast to the yeast model, stress factors such as high osmolarity and heat shock, calorie restriction, or inhibitors of TOR and phosphatidylinositol 3-kinase pathways do not appear to regulate D-NAAM in S2 cells. Interestingly, the expression of D-NAAM in human neuronal cells conferred protection from oxidative stress-induced cell death in a sirtuin-dependent manner. Together, our findings establish a life span extending the ability of nicotinamidase in flies and offer a role for nicotinamide-modulating genes in oxidative stress regulated pathways influencing longevity and neuronal cell survival.

  13. Considering plant life management influences on new plant design

    International Nuclear Information System (INIS)

    Dam, R.F.; Choy, E.; Soulard, M.; Nickerson, J.H.; Hopwood, J.

    2003-01-01

    After operating successfully for more than half their design life, owners of CANDU reactors are now engaging in Plant Life Management (PLiM) activities to ensure not only life attainment, but also life extension. For several years, Atomic Energy of Canada Ltd. (AECL) has been working with domestic and offshore CANDU utilities on a comprehensive and integrated CANDU PLiM program that will see existing CANDU plants successfully and reliably operate through their design life and beyond. To support the PLiM program development, a significant level of infrastructure has been, and continues to be, developed at AECL. This includes the development of databases that document relevant knowledge and background to allow for a more accessible and complete understanding of degradation issues and the strategies needed to deal with these issues. As the level of integration with various project, services and R and D activities in AECL increases, this infrastructure is growing to encompass a wider range of design, operations and maintenance details to support comprehensive and quantitative assessment of CANDU stations. With the maturation of the PLiM program, these processes were adapted for application to newer plants. In particular, a fully integrated program was developed that interrelates the design basis, operations, safety, and reliability and maintenance strategies, as applied to meet plant design goals. This has led to the development of the maintenance-based design concept. The various PLiM technologies, developed and applied in the above programs with operating stations, are being modified and tailored to assist with the new plant design processes to assure that ACR- Advanced CANDU Reactor meets its targets for operation, maintenance, and lifetime performance. Currently, the ACR, developed by Atomic Energy of Canada Ltd. (AECL), is being designed with features to increase capacity factors, to reduce the risk of major equipment failures, to improve access to key components

  14. Aging management and life extension - Containment aging study

    International Nuclear Information System (INIS)

    Tai, Tom M.; Deng, Daniel

    2004-01-01

    Bechtel is currently completing an aging study on a concrete containment structure. The target plant is a two-unit PWR plant with a generating capacity of about 850 MWe from each unit. Both units are less than 20 years old. The total electrical energy output from this plant site accounts for more than 50% of the utility's baseload operation. Although no utility in the United States has made a decision to submit a license renewal application, some have begun to investigate the feasibility of developing an life cycle management (LCM) program for a strategy to operate their plants efficiently, to investigate the financial benefit and safety implications of license renewal to operate their nuclear power plants beyond their current licensed periods, and to prepare a program plan for plant decommissioning. The LCM program includes economic, environmental, regulatory and technical aspects of continuing plant operations beyond the current license period. The Electric Power Research Institute (EPRI) has been supportive to assist utilities and owners groups in their research and development efforts to develop the technical requirements and the issues associated with important to license renewal structures. The focus of this paper is on the technical issues related to the evaluation of the material condition of the containment structure with respect to aging and the effective management of that aging. (author)

  15. Orion: a glimpse of hope in life span extension?

    Science.gov (United States)

    Muradian, K; Bondar, V; Bezrukov, V; Zhukovsky, O; Polyakov, V; Utko, N

    2010-01-01

    Orion is a multicomponent drug based on derivatives of taurocholic acid and several other compounds. Application of Orion into the feeding medium of Drosophila melanogaster resulted in increased life span and survival at stressful conditions. Two paradoxical features of the drug should be stressed: The "age-threshold" (life span extension was observed only when the drug was applied starting from the second half of life) and induction of "centenarian" flies (older 100 days). Orion enhanced survival at heat shock (38 degrees C) and acidic (pH = 1.6) or alkaline (pH = 11.8) feeding mediums, but not at oxidative stresses modeled by 100% oxygen or application of hydrogen peroxide (H(2)O(2)).

  16. An integrated approach to plant life management

    International Nuclear Information System (INIS)

    Fredlund, L.

    1998-01-01

    Plant life is no longer determined by components, almost everything can be replaced. A plant life management program should aim at actions and replacements being performed at the right time. In order to manage this there is need for experience feedback systems, a plant specific risk study and safety upgrades. (author)

  17. Two endogenous proteins that induce cell wall extension in plants

    Science.gov (United States)

    McQueen-Mason, S.; Durachko, D. M.; Cosgrove, D. J.

    1992-01-01

    Plant cell enlargement is regulated by wall relaxation and yielding, which is thought to be catalyzed by elusive "wall-loosening" enzymes. By employing a reconstitution approach, we found that a crude protein extract from the cell walls of growing cucumber seedlings possessed the ability to induce the extension of isolated cell walls. This activity was restricted to the growing region of the stem and could induce the extension of isolated cell walls from various dicot stems and the leaves of amaryllidaceous monocots, but was less effective on grass coleoptile walls. Endogenous and reconstituted wall extension activities showed similar sensitivities to pH, metal ions, thiol reducing agents, proteases, and boiling in methanol or water. Sequential HPLC fractionation of the active wall extract revealed two proteins with molecular masses of 29 and 30 kD associated with the activity. Each protein, by itself, could induce wall extension without detectable hydrolytic breakdown of the wall. These proteins appear to mediate "acid growth" responses of isolated walls and may catalyze plant cell wall extension by a novel biochemical mechanism.

  18. Nuclear plant life cycle costs

    International Nuclear Information System (INIS)

    Durante, R.W.

    1994-01-01

    Life cycle costs of nuclear power plants in the United States are discussed. The author argues that these costs have been mishandled or neglected. Decommissioning costs have escalated, e.g. from $328 per unit in 1991 to $370 in 1993 for the Sacramento Municipal Utility District, though they still only amount to less than 0.1 cent per kWh. Waste management has been complicated in the U.S. by the decision to abandon civilian reprocessing; by the year 2000, roughly 30 U.S. nuclear power units will have filled their storage pools; dry storage has been delayed, and will be an expense not originally envisaged. Some examples of costs of major component replacement are provided. No single component has caused as much operational disruption and financial penalties as the steam generator. Operation and maintenance costs have increased steadily, and now amount to more than 70% of production costs. A strategic plan by the Nuclear Power Oversight Committee (of U.S. utilities) will ensure that the ability to correctly operate and maintain a nuclear power plant is built into the original design. 6 figs

  19. Disinfestation and vase-life extension of orchids by irradiation

    International Nuclear Information System (INIS)

    Piriyathamrong, S.; Chouvalitvongporn, P.; Sudathit, B.

    1985-01-01

    Studies on disinfestation and vase-life extension of orchids by irradiation were conducted to determine whether gamma-radiation can be effectively used to eliminate thrips and prolong the vase life of cut flowers. Cut flowers of Dendrobium Pompadour were subjected to Co-60 irradiation at 0, 50, l00, l50, and 200 krd doses 5 to 6 hours after picking. The flowers were separated into two groups. The first group was used to count the number of thrips. The other group was held at controlled room temperature (20 0 C and 80 percent RH) for 36 hours before being unpacked and placed in water. The results of two experiments illustrated that at 2 days after irradiation at l50 and 200 krad no thrips were found on the flowers, whereas on flowers untreated and those treated at 50 and l00 krad, a higher number of thrips were detected. As far as the vase life is concerned, treated flowers have a shorter life. Irradiation at 0, 50, l00, l05, and 200 krad doses resulted in average vase life of l8.75, l2.l5, l0.85, 8.85, and 6.20 days, respectively, in the first test and l4.60, l0.05, 8.75, 7.35, and 6.85, respectively, in the second test. Increased doses of radiation caused flowers to wilt and drop off within a few days. Further study is being conducted

  20. Aging and life extension of major light water reactor components

    International Nuclear Information System (INIS)

    Shah, V.N.; MacDonald, P.E.

    1993-01-01

    An understanding of the aging degradation of the major pressurized and boiling water reactor structures and components is given. The design and fabrication of each structure or component is briefly described followed by information on the associated stressors. Interactions between the design, materials and various stressors that cause aging degradation are reviewed. In many cases, aging degradation problems have occurred, and the plant experience to date is analyzed. The discussion summarize the available aging-related information and are supported with extensive references, including references to US Nuclear Regulatory Commission (USNRC) documents, Electric Power Research Institute reports, US and international conference proceedings and other publications

  1. Motor life management at Gentilly 2 nuclear power plant

    International Nuclear Information System (INIS)

    Lazic, L.; Renaud, P.; Marcotte, P.

    2002-01-01

    Hydro Quebec's Gentilly 2 CANDU Nuclear Power Plant (NPP) located on the St. Lawrence River about 150 kms NE of Montreal Quebec Canada, is completing its second full decade of commercial operation. Since the original design life of 30 years is fast approaching, Hydro Quebec (HQ) is positioning itself proactively, to ensure plant operation for the original design life as well implementing a plant life management program to achieve a plant life extension to 50 years. All components in a nuclear plant are affected by ageing during the plant service life. This affects the availability, reliability, and safety of the plant operation and could affect the plant service life. However, if a life management program (LMP) is implemented; the ageing mechanisms can be understood and monitored, and their effects can be controlled and even mitigated. Among other vital equipment in the plant, the station motors are being examined to determine what has to be done to ensure that the motors do not contribute negatively to the plant operating plan. Gentilly 2 NPP has almost 900 motors of various configurations. Their size ranges from 0.1 HP to 9000 HP. A distribution of quantity at different horsepower levels is given. This paper will describe the plant's motor history, method of operation, and proposed future changes required to ensure effective life management of the motors. Up to the present time, Gentilly 2 NPP staff has had very good experience with plant motor operation and reliability. Nevertheless, indications from other industry motor experiences indicate that this favourable trend is unlikely to continue. A plant motor life management strategy as outlined in this paper, based on condition based maintenance in combination with traditional types of maintenance, can help to ensure protection against unexpected plant motor problems and help to ensure achievement of motor design life and beyond. Although nothing will ever replace a thorough visual inspection for discovering

  2. The significance of plant life management

    International Nuclear Information System (INIS)

    Myrddin Davies, L.

    2000-01-01

    The paper carries a definition and describes Plant life and plant life management. It also describes the procedures and defines the categorisation of components giving examples and referring to key components. Examples of 'good practice and guidance' are given for the establishment and implementation of plant life management programmes. A description is given of recent and current IAEA activities under the aegis of the International Working Group on Nuclear Power Plant Life Management (IWG-LMNPP). Some of the future activities in this field are described. (author)

  3. Remanent life management of nuclear power plants

    International Nuclear Information System (INIS)

    Pinedo, J.; Gomez Santamaria, J.

    1995-01-01

    The concept of life in the nuclear power plants is very special. The main aceptions are: design life, economic life and useful life. The good management of NPP will do the prolongation of the life in the NPP. The remanent of management life summarizes certain activities in order to prolong the lifetime of the NPP. This article presents the activities of the RML program, the technological program and its benefits

  4. Life extension, overpopulation and the right to life: against lethal ethics.

    Science.gov (United States)

    Cutas, D E

    2008-09-01

    Some of the objections to life-extension stem from a concern with overpopulation. I will show that whether or not the overpopulation threat is realistic, arguments from overpopulation cannot ethically demand halting the quest for, nor access to, life-extension. The reason for this is that we have a right to life, which entitles us not to have meaningful life denied to us against our will and which does not allow discrimination solely on the grounds of age. If the threat of overpopulation creates a rights conflict between the right to come into existence, the right to reproduce, the right to more opportunities and space (if, indeed, these rights can be successfully defended), and the right to life, the latter ought to be given precedence.

  5. Comparison of economic evaluation methodology for the nuclear plant lifetime extension

    International Nuclear Information System (INIS)

    Song, T. H.; Jung, I. S.

    2003-01-01

    In connection with economic evaluation of NPP lifetime management, there are lots of methodologies such as present worth calculation, Levelized Unit Energy Cost (LUEC) calculation, and market benefit comparison methodology. In this paper, economic evaluation of NPP lifetime management was carried out by using these three methodologies, and the results of each was compared with the other methodologies. With these three methodologies, break even points of investment cost related to life extension of nuclear power plant were calculated. It was turned out to be as a analysis result that LUEC is more conservative than present worth calculation and that benefit comparison is more conservative than LUEC, which means that Market Benefit Comparison is the most conservative methodology, and which means base load demand of the future would be far more important than any other factors such as capacity factor, investment cost of life extension, and performance of replacing power plant

  6. Development of life evaluation technology for nuclear power plant components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin [Sungkyunkwan Univ., Seoul (Korea, Republic of); Kwon, J. D. [Yeungnam Univ., Gyeongsan (Korea, Republic of); Kang, K. J. [Chonnam National Univ., Gwangju (Korea, Republic of)] (and others)

    2001-03-15

    This research focuses on development of reliable life evaluation technology for nuclear power plant (NPP) components, and is divided into two parts, development of life evaluation systems for pressurized components and evaluation of applicability of emerging technology to operating plants. For the development of life evaluation system for nuclear pressure vessels, the following seven topics are covered: development of expert systems for integrity assessment of pressurized components, development of integrity evaluation systems of steam generator tubes, prediction of failure probability for NPP components based on probabilistic fracture mechanics, development of fatigue damage evaluation technique for plant life extension, domestic round robin analysis for pressurized thermal shock of reactor vessels, domestic round robin analysis of constructing P--T limit curves for reactor vessels, and development of data base for integrity assessment. For evaluation of applicability of emerging technology to operating plants, on the other hand, the following eight topics are covered: applicability of the Leak-Before-Break analysis to Cast S/S piping, collection of aged material tensile and toughness data for aged Cast S/S piping, finite element analyses for load carrying capacity of corroded pipes, development of Risk-based ISI methodology for nuclear piping, collection of toughness data for integrity assessment of bi-metallic joints, applicability of the Master curve concept to reactor vessel integrity assessment, measurement of dynamic fracture toughness, and provision of information related to regulation and plant life extension issues.

  7. Life management plants at nuclear power plants PWR

    International Nuclear Information System (INIS)

    Esteban, G.

    2014-01-01

    Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

  8. Determination of ABOS 1-3+ system components belonging to the scope of license application of Paks Nuclear Power Plant Unit 1 for extension of service life, designated for the review, and verification of completeness of the scope

    International Nuclear Information System (INIS)

    Biro, Agnes Janosine; Tanits, Katalin Baumann-ne; Gosi, Peter; Kovacs, Andras; Ratkai, Sandor

    2012-01-01

    It is one major requirement of licensing the extension of design service life to determine the systems, structures and components that belong to the scope of licensing. According to the domestic regulatory requirements the ABOS 1-3 safety class components, the non safety system components of seismic safety class 3 and those non safety class components whose failure would occur due to its unmanaged ageing process and which may jeopardize safety class components with the released medium shall be involved into the scope of licensing of service life extension (SLE). In the task the components for the scope of SLE licensing of Unit 1 was determined using and, if necessary, further developing the tools provided by and exploiting, verifying and, as appropriate, supplementing the data included in the central technical database (IMR/MDM) of the NPP. As basis for determination of the scope the systems, structures and individual components categorized into safety class in the Final Safety Report were taken. Digitalized mechanical technological schemes were also used in determining the components of the systems fulfilling safety functions and in verifying the completeness. In order to assign the components belonging to the fulfillment of the function of the systems and to review the scope, the digitalization of the ABOS 2-3 electric and the ABOS 2 I and C circuit diagrams and distributor single-line diagrams and the processing and analysis of the digitalized data was performed. The ABOS + scope components were verified by walkdown. The completed component lists were compared to the components of the SLE licensing scope of the IMR/MDM database and the necessary supplementation, correction of the IMR/MDM data was also performed. In order to identify the components requiring review during licensing, also the active/passive safety function fulfillment modes were determined for every component of the licensing scope for Unit 1, which is now regarded as complete. As the results of

  9. Life extension and replacement management for RAPS type steam generators

    International Nuclear Information System (INIS)

    Arya, R.C.; Rastogi, A.K.

    1996-01-01

    The steam generating equipment in first four units of Indian PHWRs Rajasthan Atomic Power Station (RAPS) 1-2 and Madras Atomic Power Station (MAPS) 1-2 are hairpin type and comprise of eight boiler assemblies. Each assembly consists of identical, single pass, inverted and vertical hairpin heat exchangers (10 for RAPS and 11 for MAPS) containing 195 monel-400 U tubes of 12.7 mm dia x 1.242 mm thick. The hot heavy water flows through these tubes and imparts heat to feed, light demineralized water entering the shell at the bottom of preheat leg. The heat is generated on the outer surface of the tubes. Details of studies carried out for life extension and replacement management for RAPS type steam generators are given. 1 fig., 5 tabs

  10. Overview of German R and D activities relevant to life management of nuclear power plants

    International Nuclear Information System (INIS)

    Gillot, R.

    1998-01-01

    Life management issues of German NPPs include measures for qualifying continuous operation of NPPs and research activities related to materials behaviour under operating conditions. Plant management for life extension demand use of on-line monitoring systems for load (mechanical and thermal); vibration; leakage; water chemistry; neutron irradiation as well as replacement of systems, structures and components. The main goals to be achieved under international cooperation are increased safety, increased plant availability, extension of operating lifetime and improvement of plant economics

  11. BALTICA III. Plant condition and life management

    International Nuclear Information System (INIS)

    Hietanen, S.; Auerkari, P.

    1995-01-01

    The BALTICA III, International Conference on Plant Condition and Life Management was held on June 6 - 8, 1995 on board Silja Serenade on its cruise between Helsinki - Stockholm and at the Forest Lake Hotel Korpilampi in Espoo. BALTICA III provides forum for the transfer of technology from applied research to practise. This is the second volume of the publications, which contain the presentations given at the BALTICA III, Plant Condition and Life Management. A total of 45 articles report recent experience in plant condition and life management. The conference focuses on recent applications that have been demonstrated for the benefit of safe and economical operation of power plants. Practical approach is emphasised, including the presentations that aim to provide insight into new techniques, improvements in assessment methodologies as well as maintenance strategies. Compared to earlier occasions in the BALTICA series, a new aspect is in the applications of knowledge-based systems in the service of power plant life management. (orig.)

  12. Application of structural reliability and risk assessment to life prediction and life extension decision making

    International Nuclear Information System (INIS)

    Meyer, T.A.; Balkey, K.R.; Bishop, B.A.

    1987-01-01

    There can be numerous uncertainties involved in performing component life assessments. In addition, sufficient data may be unavailable to make a useful life prediction. Structural Reliability and Risk Assessment (SRRA) is primarily an analytical methodology or tool that quantifies the impact of uncertainties on the structural life of plant components and can address the lack of data in component life prediction. As a prelude to discussing the technical aspects of SRRA, a brief review of general component life prediction methods is first made so as to better develop an understanding of the role of SRRA in such evaluations. SRRA is then presented as it is applied in component life evaluations with example applications being discussed for both nuclear and non-nuclear components

  13. Life extension of components with high cumulative fatigue usage

    International Nuclear Information System (INIS)

    Server, W.L.

    1985-01-01

    The current ASME Boiler and Pressure Vessel Code fatigue design approach has significant margins of safety as evidenced by fatigue data on full-scale vessels. In order to extend qualification (life) of components which have reached the Code design usage limit of unity, improved criteria are needed which address crack initiation and propagation separately such that safe operation of these components is ensured. The fatigue initiation phase is composed of two processes: initial microcracking of internal particles or accumulation of local strain (cyclic slip) creating discontinuities which form microcracks, and the growth of the microcracks in a noncontinuum manner. The microcracks which initiate will eventually grow to a size in which continuum mechanics apply, and fracture mechanics concepts have been employed. The later propagation to failure of a component is also composed of two parts, continuum crack growth in a stable manner and eventual unstable fracture of the remaining ligament of material. This paper reviews the current status of technology in assessing initiation and propagation relative to the current design Code and suggests areas of improvement to cover extended life of high usage factor components. To illustrate some of these considerations, a case study for a small manufacturing defect was reviewed. A realistic component was analyzed to investigate the interrelationship between the ASME Code Section III design life and crack propagation behavior of a small manufacturing defect. A pressurized water reactor (PWR) primary coolant system was used in the analysis, and the terminal end of the hot-leg pipe at the safe end weld was selected since usage factors as high as 0.95 had been reported. The particular plant chosen was Zion-1 because the necessary information on loading, including thermal transients, was available in the open literature. 11 refs., 1 fig., 1 tab

  14. Plant life management and maintenance technologies for nuclear power plants

    International Nuclear Information System (INIS)

    Ikegami, Tsukasa; Aoki, Masataka; Shimura, Takao; Kaimori, Kimihiro; Koike, Masahiro

    2001-01-01

    Nuclear power generation occupying an important position for energy source in Japan and supplying about one third of total electric power usage is now required for further upgrading of its economics under regulation relaxation of electric power business. And, under execution retardation of its new planning plant, it becomes important to operate the already established plants for longer term and to secure their stability. Therefore, technical development in response to the plant life elongation is promoted under cooperation of the Ministry of Economics and Industries, electric power companies, literate, and plant manufacturers. Under such conditions, the Hitachi, Ltd. has progressed some technical developments on check inspection, repairs and maintenance for succession of the already established nuclear power plants for longer term under securing of their safety and reliability. And in future, by proposing the check inspection and maintenance program combined with these technologies, it is planned to exert promotion of maintenance program with minimum total cost from a viewpoint of its plant life. Here were described on technologies exerted in the Hitachi, Ltd. such as construction of plant maintenance program in response to plant life elongation agreeing with actual condition of each plant, yearly change mechanism grasping, life evaluation on instruments and materials necessary for maintenance, adequate check inspection, repairs and exchange, and so forth. (G.K.)

  15. International symposium on nuclear power plant life management. Book of extended synopses

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    A number of nuclear power plants in operation are meeting the problems of aging. Besides maintaining safety and reliability many NPP owners are concerned with service life extension, life management policy, and reactor maintenance procedures. The topics covered in this report are devoted to: NPP life management, economics and technical aspects of service life extension, reactor licensing procedures; aging of reactor components; physical radiation effects on reactor materials; corrosion; mechanical properties of reactor materials; reactor control systems; reactor safety systems.

  16. International symposium on nuclear power plant life management. Book of extended synopses

    International Nuclear Information System (INIS)

    2002-01-01

    A number of nuclear power plants in operation are meeting the problems of aging. Besides maintaining safety and reliability many NPP owners are concerned with service life extension, life management policy, and reactor maintenance procedures. The topics covered in this report are devoted to: NPP life management, economics and technical aspects of service life extension, reactor licensing procedures; aging of reactor components; physical radiation effects on reactor materials; corrosion; mechanical properties of reactor materials; reactor control systems; reactor safety systems

  17. Regulatory considerations for extending the life of nuclear plants

    International Nuclear Information System (INIS)

    Feinroth, H.; Rowden, M.

    1987-01-01

    This study provides the nuclear industry with its first systematic evaluation of the regulatory implications of nuclear plant life extension. The report recommends courses of action that might be followed by the industry and its regulators to ensure the development of a process that is both reasonable and predictable. The study holds that ''license renewal should be a reaffirmation of the ongoing and continuous process of hardware renewal that is already an integral part of every nuclear power plant's operating program.'' The report's findings can be used by the new AIF Subcommittee on License Renewal, by other industry groups, and by individual licensees in making constructive recommendations to NRC for the development of a workable license renewal policy. No such policy now exists, and the establishment of one is preferable to allowing the consideration of life extension matters on a case-by-case basis

  18. Trempel hydropower station - renewal and extension of the existing plant

    International Nuclear Information System (INIS)

    Binder, F.M.; Burri, J.

    2003-01-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a study made on the refurbishment and/or extension of a 450 kW hydropower plant near Krummenau, Switzerland. Three possible variants are presented, one involving the renewal of the installation and two variants for enhancing production to provide 1 MW and 2.25 MW of power respectively. Details on the hydrology of the location are given and the equipment of the existing two-turbine power station is described. Residual water questions are discussed and the civil works envisaged are described. The report also presents data on the economics of the project and assesses the effects on the environment, landscape and ground water it would bring with it

  19. Life Extension of Critical Components Betterments and Modifications

    International Nuclear Information System (INIS)

    Baero, G.; D'Annucci, F.; Russ, J.

    1992-01-01

    Ageing plants reveal that some of the components within the primary circuit do not show the expected life time. Betterments have been enabled by repairing or replacing defective parts. ABB. has developed specific repair processes to meet these requirements. The goal is to be as flexible as possible in order to adjust methods, procedures, and equipment to the specific needs of each plant within the shortest time possible. Inspection methods and repair procedures are discussed to present betterments and modifications for some components within the primary circuit by explaining the ABB. approach for e. g. the Inspection of pressure vessel closure head penetrations: The manipulator is designed, constructed, controlled and monitored just like a manipulator developed for steam generator inspections and repair. The E CT-probes are qualified to resolve cracks ensuring a high sensitivity if there is no thermal sleeve or if the probe is inserted into the gap. Looking through the thermal sleeve by an E CT-probe reduces the sensitivity slightly. The inspection and repair of internals, e. g. fuel alignment pins and baffle former bolts: the UST-methods, the manipulator equipment, the tools and the procedures are provided to find defective pins resp. Bolts, and to replace them. Approximately 1000 fuel alignment pins have been replaced. Three inspection systems have been provided to inspect baffle former bolts. They were upgraded for an exchange of baffle former bolts. The bolt resp. pin betterment is achieved by an improved material and a ventilation preventing stagnant water. Advances in maintenance of steam generators: Focus is given to identify potentially defective steam generator tube areas within tube support plates or ABB reviation bars. The good experience gained with the Micro lock of ABB. removable plugs is transferred to the sleeves which have a Micro lock joint at the bottom. Chemically cleaning the secondary side of a steam generator utilizing the SIG process at

  20. Enhanced design, operation and maintenance practices for a longer plant service life

    International Nuclear Information System (INIS)

    Raimondo, E.; Courcoux, A.

    2004-01-01

    Plant service life problems have been under detailed investigation in France and the experience acquired by our company over the past 25 years in the design, construction and maintenance of Pressurized Water Reactors has contributed to develop skills, equipment and capabilities available for efficient plant aging management and component service life extension. The service life of a nuclear power plant is deeply dependant of the provisions made during the design stage, directly linked to good operating conditions and adequate maintenance practices. This paper presents the importance of these three steps (design, operation and maintenance) for plant service life concern. (author)

  1. Comparison of Plant Life Management Approaches for Long Term Operations

    International Nuclear Information System (INIS)

    Kang, Kisig

    2012-01-01

    Plant life management can be defined as the integration of ageing and economic planning to maintain a high level of safety and optimize operations. Many Member States have given high priority to long term operation of nuclear power plants beyond the time frame originally anticipated (e. g. 30 or 40 years). Out of a total of 445 (369 GWe) operating nuclear power plants, 349 units (297 GWe) have been in operation for more than 20 years (as of November 2011). The need for engineering support to operation, maintenance, safety review and life management for long term operation as well as education and training in the field is increasingly evident. In addition the Fukushima accident has rendered all stake holders even more attentive to safety concerns and to the provision of beyond safety measures in the preparation and scrutiny of applications for operational design life extensions. In many countries, the safety performance of NPPs is periodically followed and characterized via the periodic safety review (PSR) approach. The regulatory The regulatory review and acceptance of the PSR gives the licensee the permission to operate the plant for up to the end of the next PSR cycle (usually 10 years). In the USA and other countries operating US designed plants, the license renewal application is based on the five pre-requisite requirements and ageing management programme for passive long life system structure and components(SSCs) and active systems is adequately addressed by the maintenance rule (MR) requirements and other established regulatory processes. Other Member States have adopted a combined approach that incorporates elements of both PSR and additional LRA specific requirements primarily focused on time limited ageing analysis. Taking into account this variety of approaches, the international atomic energy agency (IAEA) initiated work for collecting and sharing information among Member States about good practices on plant life management for long term operation in

  2. Nuclear plant life - A business decision

    International Nuclear Information System (INIS)

    Joosten, J.K.

    1995-01-01

    Regarding the future of the nuclear power option, many scenarios have been put forth over the years. The most commonly accepted projections for installed nuclear capacity show it growing at a rate of about 2% per year throughout the next few decades. These projections appear modes on the surface. However, underlying the projections are critical assumptions and sometimes misconceptions about the lifetimes of existing reactors and how they are determined. The notion of a 40 year plant life is very common. Consequently, many projections start either with the assumption that no plants will be retired in the near terms or with the assumption that each retired plant will be replaced by another nuclear plant after 40 years. Effectively, these assumptions yield future projections for installed capacity that might be characterized as low growth, medium growth and high growth scenarios - or grow, grow, grow. The question remains as to whether or not these assumptions accurately model the driving forces and constraints to nuclear development. After all, there is no scientific basis for believing that all plants, PWRs BWRs, RBMKs, etc., should have the same 40 year life. Most power plant owners purchase the plant for the main reason of supplying electrical power to their consumer. For these owners, electricity production is a day to day commercial activity with various alternatives on how to achieve the prime objective. The decision of which electricity generation alternative to select (gas, coal, nuclear or renewable energy) and how long to operate the plant before replacing it with a new one is essentially a business decision. The paper discusses ageing, the nuclear plant life decision process, the factors which influence the decision and their ramifications regarding the near term growth of nuclear power capacity. The modelling of nuclear plant lifetimes is also discussed. (author). 5 refs, 10 figs, 1 tab

  3. Plant Betterment as Anticipated Measure For Plant Life Management

    International Nuclear Information System (INIS)

    Louvat, J. P.

    1991-01-01

    A lot of modifications have been made since critically on each of the 28 standardized 900 MW class PWR units in France. Most of this technical upgrading was accomplished to facilitate operation, improve availability, or bring the unit design in line with evolving regulatory requirements, but a substantial part of the modifications was dedicated to Plant Life Management. As part of the program launched by EDF for plant life management, this paper introduces the Frustum's contribution for plant betterment and enhancement of reactor operation concurrently to ensure or extend plant service life. The solutions contemplated in this field are provided to reduce the frequency of unexpected reactor trip occurrences, to mitigate their negative effects or to smooth off the reactor operation and thus the magnitude of associated transients. The lifetime evaluation of NPP is basically an economical exercise, which tries to determine how long the operation of the plant will remain competitive, taking into account the long term perspective maintenance costs. There cannot be any conflict between lifetime and safety considerations, based upon the pituitary requisite that the safety requirement must be met at any time of the operation. Plant life management needs a consistent approach that can not be improvised on a case by case basis. Instead, it must be kept in mind from the very beginning of unit operation. This is the sense of the backfitting and technical upgrading carried out in France for the PWRs of the 900 MW class. It is thanks to this necessary anticipation that plant life will be actually managed, giving benefit both from the standpoint of availability and from that of the service lives of sensitive components. Substantial savings will thus be obtained

  4. The PREEV project of the Latin American Forum.Regulatory practices on aging and life extension; El proyecto {sup P}reev del Foro Iberoamericano. Practicas reguladoras en envejecimiento y extension de vida.

    Energy Technology Data Exchange (ETDEWEB)

    Figueras, J. M.

    2011-07-01

    The American Forum Plenary approved in 2008 the PREEV project, Regulatory Practices in Aging and Life Extension, whose main objective is to improve the regulatory action with regard to the management programs of life and long-term operation of nuclear power plants in the countries of the region Latin American.

  5. Life Extension Program for the Modular Caustic Side Solvent Extraction Unit at Savannah River Site - 13179

    International Nuclear Information System (INIS)

    Samadi, Azadeh

    2013-01-01

    Caustic Side Solvent Extraction (CSSX) is currently used at the U.S. Department of Energy (DOE) Savannah River Site (SRS) for removal of cesium from the high-level salt-wastes stored in underground tanks. Currently, the Actinide Removal Process (ARP) and the CSSX process are deployed in the (ARP)/Modular CSSX Unit (MCU), to process salt waste for permanent disposition. The CSSX technology utilizes a multi-component organic solvent and annular centrifugal contactors to extract cesium from alkaline salt waste. The original plant was permitted for a three year design life; however, given the successful operation of the plant, a life extension program was completed to continue operations. The program included detailed engineering analyses of the life-expectancy of passive and active components, resulting in component replacement and/or maintenance and monitoring program improvements. The program also included a review of the operations and resulted in a series of operational improvements. Since the improvements have been made, an accelerated processing rate has been demonstrated. In addition, plans for instituting a next-generation solvent are in place and will enhance the decontamination factors. (author)

  6. Considerations related to plant life management for Cernavoda-1

    International Nuclear Information System (INIS)

    Cojan, Mihail

    2002-01-01

    Cernavoda-1 NPP, the first CANDU 6 Unit in Eastern Europe, is one of the original five CANDU 6 plants and the first CANDU 6 producing over 700 MWe. CANDU Pressurized Heavy Water Reactors (PHWR) continues to play a significant role in electricity supply both in Canada and some offshore countries (Korea, Argentina, Romania). The commercial versions of CANDU reactors were put into service more than 30 years ago. While the first series of CANDU 6 plants (which entered service in the early 1980's) have now reached the middle portion of their 30 years design life, the Cernavoda-1 was put into service on 2 December 1996. However, the Cernavoda-1 Plant Life Management should be an increasingly important program to Utility ('CNE-Prod') in order to protect the investment and the continued success of plant operation. Over the past three years, INR (Institute for Nuclear Research - Romania) has been working with AECL-Canada on R and D Programs to support a comprehensive and integrated Cernavoda-1 Plant Life Management (PLiM) program that will see the Cernavoda-1 NPP successfully and reliably through to design life and beyond. The PLiM program has a focus on critical systems, structures, and components (CSSCs) and will be applied in three phases: Phase 1 - Planning (assessment and recommendations); Phase 2 - Life attainment implementation, and; Phase 3 - Plant Life Extension (PLEx), also known as plant extended operation. The key activities during each phase are shown. The schedule of each Phase are shown using the in service date of 1983 as the basis. This schedule applies to three original CANDU 6 plants with an in-service date of 1983: Point Lepreau, Gentilly-2, Wolsong-1 and shortly thereafter (1984) the 4th original CANDU 6 Embalse NPP was declared in service. Cernavoda-1 is the 5th original CANDU 6 plant and was put into service on 2 December 1996 (on site activities were started in 1980). The paper will describe the elements of an integrated program, the multiphase

  7. Life extension decision making of safety critical systems: An overview

    OpenAIRE

    Shafiee, Mahmood; Animah, I.

    2017-01-01

    In recent years, the concept of “asset life extension” has become increasingly important to safety critical industries including nuclear power, offshore oil and gas, petrochemical, renewable energy, rail transport, aviation, shipping, electricity distribution and transmission, etc. Extending the service life of industrial assets can offer a broad range of economic, technical, social and environmental benefits as compared to other end-of-life management strategies such as decommissioning and r...

  8. Model 9975 Life Extension Package 1 - Final Report

    International Nuclear Information System (INIS)

    Daugherty, W.

    2011-01-01

    Life extension package LE1 (9975-03382) was instrumented and subjected to a temperature/humidity environment that bounds KAMS package storage conditions for 92 weeks. During this time, the maximum fiberboard temperature was ∼180 F, and was established by a combination of internal heat (12 watts) and external heat (∼142 F). The relative humidity external to the package was maintained at 80 %RH. This package was removed from test in November 2010 after several degraded conditions were observed during a periodic examination. These conditions included degraded fiberboard (easily broken, bottom layer stuck to the drum), corrosion of the drum, and separation of the air shield from the upper fiberboard assembly. Several tests and parameters were used to characterize the package components. Results from these tests generally indicate agreement between this full-scale shipping package and small-scale laboratory tests on fiberboard and O-ring samples. These areas of agreement include the rate of fiberboard weight loss, change in fiberboard thermal conductivity, fiberboard compression strength, and O-ring compression set. In addition, this package provides an example of the extent to which moisture within the fiberboard can redistribute in the presence of a temperature gradient such as might be created by a 12 watt internal heat load. Much of the moisture near the fiberboard ID surface migrated towards the OD surface, but there was not a significant axial moisture gradient during most of the test duration. Only during the last inspection period (i.e. after 92 weeks exposure during the second phase) did enough moisture migrate to the bottom fiberboard layers to cause saturation. A side effect of moisture migration is the leaching of soluble compounds from the fiberboard. In particular, the corrosion observed on the drum appears related primarily to the leaching and concentration of chlorides. In most locations, this attack appears to be general corrosion, with shallow

  9. Nuclear power plant life management in a changing business world

    International Nuclear Information System (INIS)

    2000-01-01

    At the end of 1999, there were 348 nuclear power plants connected to the grid in OECD Member countries, representing a total capacity of 296 GWe and generating some 24% of their electricity. One third of these nuclear power plants had been in operation for over 20 years. The demand for electricity throughout OECD countries is increasing steadily but the construction of new nuclear power plants has become increasingly difficult. Many utilities would like to keep existing nuclear power plants operating for as long as they can continue to function safely and economically because. extending the lifetime of nuclear power plants is a substitute to constructing new plants. Therefore, nuclear plant life management (PLIM) has been carried out in many OECD Member countries and has played a very important role in the nuclear generation field. Nuclear power plant owners seek to economically optimise the output from their plants, taking into consideration internal and external influences, as well as equipment reliability and maintenance workload. Nuclear power plant life management and extension is generally an attractive option for utilities supplying electricity because of its low marginal cost and low investment risk. PLIM has become an important issue in the context of changing business circumstances caused by regulatory reform of the electricity market. Specifically, the economic aspect of PLIM has become an important focus in the competitive electricity market. The international workshop on 'Plant Life Management in a Changing Business World' was hosted by the United States Department of Energy (USDOE) in co-operation with the Electric Power Research Institute (EPRI) and the Nuclear Energy Institute (NEI) in Washington, DC, on 26-27 June 2000. Some 50 senior utility executives and policy makers from 12 Member countries, the International Energy Agency (IEA) and the European Commission (EC) attended the meeting. The objective of the workshop was to examine the status of

  10. Nuclear power plant life management. Proceedings of a symposium

    International Nuclear Information System (INIS)

    2003-01-01

    Presently, an area of major interest of the IAEA is the management of the nuclear power plant (NPP) life cycle from concept development to decommissioning and disposal, with the primary objective of maximising the return on investment in nuclear facilities through efficient operation of NPPs. 441 NPPs, with a capacity of about 350GW(e) supplied 16% of global electricity in 2002. Of these, about 300 NPPs have been in operation for 15 years or more and these older units with partially or fully amortized capital costs have proven to be the most profitable. Moreover, there are no significant safety or economic reasons not to continue the operation of well managed NPPs over a longer period and consequently the issues of plant life management and license extension are receiving increasing emphasis in many countries. Forecasts of nuclear power growth over the next two decades range from 350GW(e) in the worst case to 500GW(e) in the best case. This will need additional personnel and expansion of the infrastructure in the developing countries, particularly as much of the new demand growth is forecast to take place outside the countries where most of the existing infrastructure resides. All aspects of NPP life cycle management are addressed by the IAEA and are briefly described in these proceedings. The IAEA Technical Working Group on Life Management of Nuclear Power Plants (TWG-LMNPP) recommended, during its regular meeting in February 1999, that the IAEA should consider holding a symposium on this subject area in 2002. This TWG-LMNPP Proposal was approved and, this symposium was held, attended by 138 participants from 32 Member States and 2 international organizations. The objectives of the symposium were as follows: Emphasise the role of NPP life management programmes in assuring a safe and reliable NPP operating cycle; Identify progress in methodological and technological developments for managing ageing processes and understanding ageing mechanisms; Provide a forum for

  11. Analysis of the extension and reduction method of qualified life used in equipment with ambiental qualification

    International Nuclear Information System (INIS)

    Serrano R, M.L. .e -mail: mlserrano@cnsns.gob.mx

    2005-01-01

    With the purpose of reducing costs of acquisition, maintenance, design, hour-man, dose, production, etc. or by changes in the temperature of service, diverse Nuclear Plants (NP) in the world have been carried out extensions and reductions of life of equipment and/or components related with the safety. The used methods are mainly tests type on equipment or component aged quickly, tests type on equipment or component aged naturally and use of the Arrhenius model with monitoring of temperatures in place. The present article carries out an analysis of the Arrhenius model with monitoring of temperatures in place, which is presented in two variants, equation (1) and (2), since it is the but used by the NP with extension purposes and reduction of qualified life. As back information, it was made one search of investigations, applied to diverse fields of the science that try about the reliability of the results provided by Arrhenius for the aging case. The results of the analysis indicate: I) that this method make uncertainties in some intervals of temperature and 2) which of the two variants it provides data more reliable. (Author)

  12. Extension Education Symposium: Getting the Most Out of Your Extension Appointment and Still Having a Life

    OpenAIRE

    Powers, W.; Cockett, Noelle E.; Lardy, Gregory P.

    2017-01-01

    Managing the demands of an academic appointment in extension can be a challenging task. Demands from constituent groups, expectations of supervisors, and rigors of promotion and tenure processes can create pressures that young faculty did not expect. Throw in spousal and family duties and you have created a situation that many will find hard to navigate. However, there are ways to cope and, even better news, there are ways to excel in meeting the demands of an academic appointment and enjoyin...

  13. Plant life extension of nuclear power plants. No thank you? A scientific study on the influence of media and communication on the public opinion concerning nuclear power; Laufzeitverlaengerung von Atomkraftwerken. Nein, Danke.? Eine kommunikationswissenschaftliche Studie zum Einfluss medialer Kommunikation auf Einstellung gegenueber Atomkraft

    Energy Technology Data Exchange (ETDEWEB)

    Arlt, Dorothee

    2013-07-01

    The present study examined the influence of the individual use of media on attitudes towards nuclear power with focus in the run-time extension of German nuclear power plants, planned by the German government in the year 2010. The theoretical framework for explaining media effects on attitudes based on opinion research as well as on the second-level agenda setting. This approach assumes that highlighting attributes about attitude objects in the media makes them cognitively more accessible for recipients, so that these attributes are used to evaluate attitude object. In this study, arguments for and against the run-time extension were defined as attributes. For the investigation of individual media effects, this study was carried out in a two-method design to combine survey data and content analysis data on an individual level. From 16.08.2010 to 05.09.2010 the data on attitudes towards the planned run-time extension, nuclear power, energy, policy as well as individual media usage was collected in a representative telephone survey of n=551 people in Thuringia. In a quantitative content analysis the pro and contra arguments about the planned run-time extension in n=480 articles and news items, published during six months before the political decision, were analyzed. The findings of the content analysis showed that the media reported from 08.03.2010 to 05.09.2010 overall positively about the planned run-time extension and that the coverage intensity increased significantly shortly before the political decision. The main focus was on arguments regarding the efficiency and security of supply. By combining the content analysis data with the media usage data, new variables (sum and average value indices) for the specific individual media input of arguments about the run-time extension were formed. With these variables medium- and long-term media effects on attitudes towards nuclear power were tested. The results of the regression analyses showed that the individual media

  14. Practice and perspectives of nuclear power plants life management activities in Russia

    International Nuclear Information System (INIS)

    Kurakov, Y.; Yanko, L.

    1998-01-01

    Extension of safe operation of NPPs is of special importance for Russia for economical reasons. The principles of NPP life extension are the same as for issuing licences for operation by the Regulatory body. It is requested to prove that undertaken measures compensate effects of ageing of structural components. Special attention is foreseen for methods of modernization of power plants for their safe operation

  15. Life extension studies and refurbishing of C and I systems of Cirus

    International Nuclear Information System (INIS)

    Awale, P.K.; Sumanth, P.; Roy, Kallol; Bharadwaj, G.

    2005-01-01

    Effects of ageing and component obsolescence of C and I systems of Cirus has been studied, by classifying the C and I systems as (a) those which may affect the operating life of the plant and cannot be repaired/replaced without core-unloading and dismantling the reactor structure. (Group-A), (b) those components which can be repaired/replaced but with considerable difficulty (Group-B) and (c) those which do not affect plant operations and can be easily repaired or replaced (Group-C). Life extension studies included performance assessment, reliability centred evaluation, parametric deviations from base-line characteristics and identification of specific ageing phenomenon and examination of internals. Based on these studies a comprehensive ageing mitigation programme was evolved, necessitating suitable modifications, instrumentation upgradation and component repair/replacement. A major modification job has been to provide an alternate failed fuel detection (FFD) system, since the success rate of the present system, had been decreasing over the years. Further, taking advantage of the available refurbishing outage, a number of instruments and accessories, pertaining to Group-C, were also replaced with state-of-the-art, components. Consideration is also given to requirements of special reactor start-up instrumentation for sensing the initial low neutron count in presence of a high gamma background, during the ensuing reactor start-up with fresh fuel. (author)

  16. NULIFE - the European NoE 'Nuclear Plant Life Prediction'

    International Nuclear Information System (INIS)

    Cojan, Mihail

    2008-01-01

    INR Pitesti become on the 29th September 2006 a partner in the European Network of Excellence Nuclear Plant Life Prediction (NULIFE) coordinated by Technical Research Centre of Finland (VTT). The EU's Network of Excellence NULIFE has been launched under the EURATOM FP6 Program with a clear focus on integrating safety-oriented research on materials, structures and systems and exploiting the results of this integration through the production of harmonized lifetime assessment methods. NULIFE will help provide a better common understanding of, and information on, the factors affecting the lifetime of nuclear power plants which, together with associated management methods, will help facilitate extensions to the safe and economic lifetime of existing nuclear power plants. (author)

  17. Germany: the government has approved of the extension of the service life of nuclear reactors

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    The German coalition government has decided on 28 september 2009 to expend the service life of the 17 operating nuclear reactors through the approval of the plan 'Energy 2050'. The average extension will be of 12 years. This decision will postpone the shutdown of the last reactor till 2040. The reciprocal arrangement implies that the nuclear plant operators (EON, RWE, Wattenfall and EnBW) will have to pay an annual tax of 2.3*10 9 euros till 2016. The operators will also have to finance a capital for the development of renewable energies: 200*10 6 euros in 2011 and in 2012 then 300*10 6 euros per year between 2013 and 2016 and eventually to pay a tax of 9 euros per MW of nuclear power produced. (A.C.)

  18. Food losses, shelf life extension and environmental impact of a packaged cheesecake: A life cycle assessment.

    Science.gov (United States)

    Gutierrez, Michele Mario; Meleddu, Marta; Piga, Antonio

    2017-01-01

    Packaging is associated with a high environmental impact. This is also the case in the food industry despite packaging being necessary for maintaining food quality, safety assurance and preventing food waste. The aim of the present study was to identify improvements in food packaging solutions able to minimize environmental externalities while maximizing the economic sustainability. To this end, the life cycle assessment (LCA) methodology was applied to evaluate the environmental performance of new packaging solutions. The environmental impact of packaging and food losses and the balance between the two were examined in relation to a cheesecake that is normally packaged in low density polyethylene film and has a limited shelf life due to microbial growth. A shelf life extension was sought via application of the well-established modified atmosphere packaging (MAP) technique. Samples for MAP (N 2 /CO 2 : 70/30) were placed inside multilayer gas barrier trays, which were then wrapped with a multilayer gas and water barrier film (i.e. AerPack packaging); control batches were packaged in gas barrier recycled polyethylene terephthalate (XrPet) trays and wrapped with a XrPet film. Samples were then stored at 20°C and inspected at regular intervals for chemical-physical, microbiological and sensory parameters. Results show that the new packaging solution could considerably extend the shelf life of cheesecakes, thereby reducing food waste and decreasing the overall environmental impact. Moreover, the new packaging allows one to minimize transport costs and to generate economies of scale in manufacturing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Shelf Life Extension of Toasted Groundnuts through the Application ...

    African Journals Online (AJOL)

    The use of cassava starch and soy protein concentrate edible coatings containing 20% glycerol in extending the shelf life of toasted groundnut during ambient (27 ± 1oC) storage for 14 days was studied. Chemical indices of oxidative rancidity and sensory parameters were evaluated using standard procedures. Moisture ...

  20. Extension plant pathology: strengthening resources to continue serving the public interest.

    Science.gov (United States)

    Everts, K L; Osborne, L; Gevens, A J; Vasquez, S J; Gugino, B K; Ivors, K; Harmon, C

    2012-07-01

    Extension plant pathologists deliver science-based information that protects the economic value of agricultural and horticultural crops in the United States by educating growers and the general public about plant diseases. Extension plant pathologists diagnose plant diseases and disorders, provide advice, and conduct applied research on local and regional plant disease problems. During the last century, extension plant pathology programs have adjusted to demographic shifts in the U.S. population and to changes in program funding. Extension programs are now more collaborative and more specialized in response to a highly educated clientele. Changes in federal and state budgets and policies have also reduced funding and shifted the source of funding of extension plant pathologists from formula funds towards specialized competitive grants. These competitive grants often favor national over local and regional plant disease issues and typically require a long lead time to secure funding. These changes coupled with a reduction in personnel pose a threat to extension plant pathology programs. Increasing demand for high-quality, unbiased information and the continued reduction in local, state, and federal funds is unsustainable and, if not abated, will lead to a delay in response to emerging diseases, reduce crop yields, increase economic losses, and place U.S. agriculture at a global competitive disadvantage. In this letter, we outline four recommendations to strengthen the role and resources of extension plant pathologists as they guide our nation's food, feed, fuel, fiber, and ornamental producers into an era of increasing technological complexity and global competitiveness.

  1. Investigation of the effects of a seismic event on accelerated aged components and benefits in equipment life extension

    International Nuclear Information System (INIS)

    Rygg, D.E.; Epstein, J.L.

    1985-01-01

    Westinghouse has performed extensive testing to determine the effects of aging on a wide range of components. Additionally, Westinghouse has an extensive data base of nuclear plant equipment and components. This paper presents how the data base of information on plant parts can be analyzed, modified, and managed or tracked to reflect in-plant parts life extension based on actual tests on aging. Such an approach can benefit utility programs for parts inventory, plant operations and plant availability, and can also reduce the costs of parts reordering. Rather than weigh the merits of the positions in this debate, this paper presents the results of a component aging program which simulates from five to twenty years of operation followed by a seismic event and identifies the possible incorporation of this data into a plant data base which offers quick reference and provides other relevant information on the component and equipment. The use of this data as part of a well structured maintenance and surveillance program offers an avenue to resolve this debate in a cost effective manner

  2. Planning study and economic feasibility for extended life operation of light water reactor plants

    International Nuclear Information System (INIS)

    Negin, C.A.; Goudarzi, L.A.; Kenworthy, L.U.; Lapides, M.E.

    1980-01-01

    The purpose of this planning study was to perform an assessment of the engineering and economic feasibility of extended life operation of present nuclear power plant units and to recommend future programs that may be warranted by the feasibility assessments. This effort concludes, essentially, that there is sufficient economic motivation for refurbishment to warrant more extensive examination for present plants and to identify possible design modifications that would facilitate extended service life in future plants. The costs of replacing the deterioration-prone equipment in a nuclear power plant appear to represent a small portion of the total plant costs, provided downtime is not excessive. A refurbishment and economic analysis is presented

  3. Lifetime-management and lifetime-extension at PAKS nuclear power plant

    International Nuclear Information System (INIS)

    Katona, Tamas; Ratkai, Sandor; Janosi, Agnes Biro

    2002-01-01

    core might be necessary with 50% probability. Annealing is not a cost critical method and it has been successfully applied in the practice of VVER plants (i.e. Finland and Slovakia). The study indicates that the steam generators are very important and critical equipment at VVER/440/213 type units. Stress corrosion cracking of heat-transfer tubes shall be considered also in case of steam generators. Considering the effects of already implemented measures, e.g. main turbine-condenser replacement, copper removing, protecting the secondary side of steam generators, replacement of steam generators can be excluded also in case of 50 years of operation. However, local corrosion effects appearing on the secondary side shall be monitored even in case of high PH water regime, transport of erosion products into the steam generator shall be minimised, for example by means of correct selection of the structural materials during replacement of high pressure preheaters. Business model of the lifetime extension covered incomes, expenses and financing. The costs of plant life management and lifetime extension have been estimated conservatively. The market conditions, including liberalisation of the electrical power market have been taken into account. The business analysis shows that the plant lifetime extension is a reasonable business decision. Based on the results of the feasibility study and the public acceptance of extended operation NPP Paks launched a project to elaborate on the plant lifetime management programme and preparation of the necessary licence renewal. The current ageing-management programme of the Paks NPP shall be reviewed and extended to the required scope of SSC (passive long living items). Programme for maintaining the environmental qualification of equipment has to be elaborated on and implemented. Simultaneous to the preparation of the license renewal new requirements shall be implemented in the field of maintenance, also. The plant lifetime extension might

  4. Applicability of qualification testing of electric cable to life extension

    International Nuclear Information System (INIS)

    Reynolds, A.B.

    1988-01-01

    The methods for qualification testing of electric cable for nuclear power plants followed by U.S. cable manufacturers and endorsed by the U.S. Nuclear Regulatory Commission (NRC) involve irradiation aging at high dose rates at room temperature and accident aging in steam without the pressure of air. Testing is done sequentially. The research data which led to some concerns have been reviewed, and some conclusions regarding these concerns are suggested

  5. Ethical objections against including life-extension costs in cost-effectiveness analysis: a consistent approach.

    Science.gov (United States)

    Gandjour, Afschin; Müller, Dirk

    2014-10-01

    One of the major ethical concerns regarding cost-effectiveness analysis in health care has been the inclusion of life-extension costs ("it is cheaper to let people die"). For this reason, many analysts have opted to rule out life-extension costs from the analysis. However, surprisingly little has been written in the health economics literature regarding this ethical concern and the resulting practice. The purpose of this work was to present a framework and potential solution for ethical objections against life-extension costs. This work found three levels of ethical concern: (i) with respect to all life-extension costs (disease-related and -unrelated); (ii) with respect to disease-unrelated costs only; and (iii) regarding disease-unrelated costs plus disease-related costs not influenced by the intervention. Excluding all life-extension costs for ethical reasons would require-for reasons of consistency-a simultaneous exclusion of savings from reducing morbidity. At the other extreme, excluding only disease-unrelated life-extension costs for ethical reasons would require-again for reasons of consistency-the exclusion of health gains due to treatment of unrelated diseases. Therefore, addressing ethical concerns regarding the inclusion of life-extension costs necessitates fundamental changes in the calculation of cost effectiveness.

  6. Risk informed life cycle plant design

    International Nuclear Information System (INIS)

    Hill, Ralph S. III; Nutt, Mark M.

    2003-01-01

    Many facility life cycle activities including design, construction, fabrication, inspection and maintenance are evolving from a deterministic to a risk-informed basis. The risk informed approach uses probabilistic methods to evaluate the contribution of individual system components to total system performance. Total system performance considers both safety and cost considerations including system failure, reliability, and availability. By necessity, a risk-informed approach considers both the component's life cycle and the life cycle of the system. In the nuclear industry, risk-informed approaches, namely probabilistic risk assessment (PRA) or probabilistic safety assessment (PSA), have become a standard tool used to evaluate the safety of nuclear power plants. Recent studies pertaining to advanced reactor development have indicated that these new power plants must provide enhanced safety over existing nuclear facilities and be cost-competitive with other energy sources. Risk-informed approaches, beyond traditional PRA, offer the opportunity to optimize design while considering the total life cycle of the plant in order to realize these goals. The use of risk-informed design approaches in the nuclear industry is only beginning, with recent promulgation of risk-informed regulations and proposals for risk-informed codes. This paper briefly summarizes the current state of affairs regarding the use of risk-informed approaches in design. Key points to fully realize the benefit of applying a risk-informed approach to nuclear power plant design are then presented. These points are equally applicable to non-nuclear facilities where optimization for cost competitiveness and/or safety is desired. (author)

  7. CANDU plant life management - An integrated approach

    International Nuclear Information System (INIS)

    Hopkins, J.R.

    1998-01-01

    An integrated approach to plant life management has been developed for CANDU reactors. Strategies, methods, and procedures have been developed for assessment of critical systems structures and components and for implementing a reliability centred maintenance program. A Technology Watch program is being implemented to eliminate 'surprises'. Specific work has been identified for 1998. AECL is working on the integrated program with CANDU owners and seeks participation from other CANDU owners

  8. Extension of operation of nuclear plants. Synthesis of the qualitative study and of the citizen committee

    International Nuclear Information System (INIS)

    Suteau, Regis

    2014-01-01

    The author comments the results of a survey which was based on 20 interviews with French citizens of different ages, political opinions, geographical locations and also different opinions on nuclear energy. The objective was to obtain their perception and feeling about the issue of nuclear plant service life extension, in order to assess whether they were aware of this issue, could understand it, and what was their opinion about it. Then, these citizens have been gathered three weeks later and met three experts (a representative of a NGO, a member of the ASN and a representative of EDF) who answered their questions and discussed their arguments. These citizens then made statements and recommendations. It appeared that the issue of lifetime extension is hardly known by the public, and is therefore not a topic of public debate but a modality within the important debate about nuclear energy. However, the citizen committee accepts this lifetime extension for different reasons (no known alternatives; economic aspects; safety, nuclear energy is non polluting energy; jobs will be saved) but under some conditions which depend on the opinion on nuclear energy (rather for or rather against). The opinion may change negatively in relationship with some issues: the future of radioactive wastes and dismantled installations, quality and traceability of subcontracted components. This survey is an opportunity to question the general relationship of French people with nuclear energy. In this respect, five profiles are identified: confident, resigned, realistic and reasonable, realistic and anxious, and opponent

  9. Extension of mushroom (Agaricus bisporus) shelf life by gamma radiation

    International Nuclear Information System (INIS)

    Lescano, G.

    1994-01-01

    Fresh mushroom sporophores (Agaricus bisporus) were placed in trays and covered with PVC film. Forty-eight of the number of packs were irradiated by a γ-source with a dose of 3 kGy, and the remaining 24 treated as control packs. Both treated and control samples were subsequently stored at 10 ± 2°C and relative humidity of 94 ± 6%. After storage, mushrooms were subjected to quality assessments and taste panel-testing, both raw and when cooked. Irradiated sporophores had an extended shelf-life compared with control samples, with less browning and a delay in cap opening. Desiccation was slowed and stipe elongation reduced so that irradiated mushrooms were still acceptable for consumption 16 days after treatment. Deleterious effects of irradiation at this relatively low level were not observed

  10. Irradiation of refrigerated corned beef for shelf-life extension

    International Nuclear Information System (INIS)

    Sallam, Y.I.; El-Magoli, S.B.M.; Mohamed, H.H.; El-Mongy, T.M.

    2000-01-01

    The development of the microflora of unirradiated and irradiated cowed beef was followed during storage at 5 degree. The total aerobic counts in unirradiated corned beef samples reached x 10 7 cfu/g after 10 days and after 15, 20 , 25 and 30 days of cold storage in irradiated samples at 2, 4, 6, 8 kGy, respectively, accompanied with obvious organoleptic evidence of microbial. Radiation doses up to 8 kGy and cold storage (5 degree) of cowed beef had no effect on the major constituents (moisture, protein and lipids) of these products. During storage, total volatile bases nitrogen (TVBN) and thiobarbituric acid (TBA) values tended to increase; the Ph of corned beef fall down to ca. 5. 7. Increasing the radiation dose level to 6 and 8 kGy, to increase the product shelf-life, affects generally the physical properties of the corned beef samples, and therefore, it could be concluded that the radiation dose level should be chosen to inhibit public health concern bacteria and reduce spoilage organisms, and at the same time preserve the natural properties of the food. At the present study a dose level of 4 kGy was found to be quite enough to reach such requirements for corned beef samples

  11. Technological feasibility of irradiating pineapples for shelf-life extension

    International Nuclear Information System (INIS)

    Sharma, Jiten

    2001-01-01

    The spoilage of food caused by infestation, contamination and deterioration of the world's food supply is enormous in the developing countries where warm and humid climate favour the growth of spoilage organisms and hasten deterioration of stored food. Particularly, in a country like India where the population growth has already attained one billion, any preventable loss of food is intolerable. Since food security of a nation also largely determines the economic stability as well as self-reliance, this problem draws utmost attention not only of the food scientists but also of the food policy makers. From these above facts, it may be concluded that radiation technology can be safely used for extending shelf-life of pineapple fruits thereby maximizing the transportation and marketing potentials. Consumption of such irradiated pineapples simultaneously does not pose any immediate or long-term human health risks. Keeping these techno-economic considerations in view establishment of large scale industrial operations for irradiating fruits, vegetables, cereals etc. are of immense importance

  12. Current status of technology for plant life management

    International Nuclear Information System (INIS)

    Roche, B.

    2000-01-01

    In most developed countries of the world, deregulation of electricity markets has been established: competition is fierce, and utilities have to improve the competitiveness of their plants. It is an important challenge for nuclear power plants: a smart way to deal with this problem is life extension of existing units. The financial stakes associated with maintaining or extending the lifetime of nuclear power stations are very high; thus, if their lifetime is shortened by about ten years, dismantling and renewal would be brought forward which would increase their costs by several tens of billions of French francs. Furthermore, every extra year of operation of a 900 MWe unit should save about 500 million French francs per year on financial charges that would be necessary for a new investment, provided that maintenance costs do not become excessive. In order to succeed, utilities must improve their knowledge of ageing mechanisms, demonstrate to safety authorities the feasibility of life extension (especially taking into account critical components), operate existing units in an exemplary way, manage and master the long-term evolution of the safety reference state. (author)

  13. Application of subsize specimens in nuclear plant life extension

    International Nuclear Information System (INIS)

    Rosinski, S.T.; Kumar, A.S.; Cannon, N.S.; Hamilton, M.L.

    1993-01-01

    The US Department of Energy is sponsoring a research effort through Sandia National Laboratories and the University of Missouri-Rolla to test a correlation for the upper shelf energy (USE) values obtained from the impact testing of subsize Charpy V-notch specimens to those obtained from the testing of full-size samples. The program involves the impact testing of unirradiated and irradiated full-, half-, and third-size Charpy V-notch specimens. To verify the applicability of the correlation on LWR materials, unirradiated and irradiated full-, half-, and third-size Charpy V-notch specimens of a commercial pressure vessel steel (ASTM A533 Grade B) will be tested. The correlation methodology is based on the partitioning of the USE into crack initiation and crack propagation energies. To accomplish this partition, both precracked and notched-only specimens will be used. Whereas the USE of notched-only specimens is the sum of both crack initiation and crack propagation energies, the USE of precracked specimens reflects only the crack propagation component. The difference in the USE of the two types of specimens represents a measure of the crack initiation energy. Normalizing the values of the crack initiation energy to the fracture volume of the sample produces similar values for the full-, half-, and third-size specimens. In addition, the ratios of the USE and the crack propagation energy are also in agreement for full-, half-, and third-size specimens. These two observations will be used to predict the USE of full-size specimens based on subsize USE data. This paper provides details of the program and presents results obtained from the application of the developed correlation methodology to the impact testing of the unirradiated full-, half-, and third-size A533 Grade B Charpy V-notch specimens

  14. Extension of Space Food Shelf Life Through Hurdle Approach

    Science.gov (United States)

    Cooper, M. R.; Sirmons, T. A.; Froio-Blumsack, D.; Mohr, L.; Young, M.; Douglas, G. L.

    2018-01-01

    The processed and prepackaged space food system is the main source of crew nutrition, and hence central to astronaut health and performance. Unfortunately, space food quality and nutrition degrade to unacceptable levels in two to three years with current food stabilization technologies. Future exploration missions will require a food system that remains safe, acceptable and nutritious through five years of storage within vehicle resource constraints. The potential of stabilization technologies (alternative storage temperatures, processing, formulation, ingredient source, packaging, and preparation procedures), when combined in hurdle approach, to mitigate quality and nutritional degradation is being assessed. Sixteen representative foods from the International Space Station food system were chosen for production and analysis and will be evaluated initially and at one, three, and five years with potential for analysis at seven years if necessary. Analysis includes changes in color, texture, nutrition, sensory quality, and rehydration ratio when applicable. The food samples will be stored at -20 C, 4 C, and 21 C. Select food samples will also be evaluated at -80 C to determine the impacts of ultra-cold storage after one and five years. Packaging film barrier properties and mechanical integrity will be assessed before and after processing and storage. At the study conclusion, if tested hurdles are adequate, formulation, processing, and storage combinations will be uniquely identified for processed food matrices to achieve a five-year shelf life. This study will provide one of the most comprehensive investigations of long duration food stability ever completed, and the achievement of extended food system stability will have profound impacts to health and performance for spaceflight crews and for relief efforts and military applications on Earth.

  15. Decision support for life extension of technical systems through virtual age modelling

    International Nuclear Information System (INIS)

    Pérez Ramírez, Pedro A.; Utne, Ingrid Bouwer

    2013-01-01

    This article presents a virtual age model for decision support regarding life extension of ageing repairable systems. The aim of the model is to evaluate different life extension decision alternatives and their impact on the future performance of the system. The model can be applied to systems operated continuously (e.g., process systems) and systems operated on demand (e.g., safety systems). Deterioration and efficiency of imperfect maintenance is assessed when there is limited or no degradation data, and only failure and maintenance data is available. Systems that are in operation can be studied, meaning that the systems may be degraded. The current degradation is represented by a “current virtual age”, which is calculated from recorded maintenance data. The model parameters are estimated with the maximum likelihood method. A case study illustrates the application of the model for life extension of two fire water pumps in an oil and gas facility. The performance of the pump system is assessed with respect to number of failures, safety unavailability and costs during the life extension period. -- Highlights: ► Life extension assessment of technical systems using virtual age model is proposed. ► A virtual age model is generalised for systems in stand-by and continuous operation. ► The concept of current virtual age describes technical condition of the system. ► Different decision alternatives for life extension can be easily analysed. ► The decision process is improved even when only scarce failure data is available

  16. FANP concept for plant life management and recent experience

    International Nuclear Information System (INIS)

    Nopper, H.; Daeuwel, W.; Waas, U.

    2002-01-01

    conduce a condition-oriented lifetime analysis for various damage mechanisms which may occur in power plants (e.g. strain-induced cracking, material fatigue, flow-accelerated corrosion, cavitation erosion, droplet impingement erosion). The resulting service life prediction is validated and optimized through the performance of a small number of examinations at priority locations. This provides the capability to systematically trace the current condition of LM components and ensures the generation of a quantifiable database which is continually kept up to date with information related to the technical as-is status of the plant. On the basis of reliable and damage-relevant predictions, maintenance management and plant availability can be optimized. The efficiency of this software based strategy was already confirmed by field experience in various power plants. The integral PLIM concept provides the plant owner also with the technical support necessary for taking the strategic decisions involved in plant life extension (PLEX). From the technical point of view, a systematic PLIM strategy makes a major contribution to the PLEX process because it provides all safety related data, including forecasts for the residual lifetime of components

  17. Methods for preservation and extension of shelf life.

    Science.gov (United States)

    Gould, G W

    1996-11-01

    There is potential for spoilage of all foods at some rate or other following harvest, slaughter or manufacture and spoilage may occur at any of the stages between the acquisition of raw materials and the eventual consumption of a food product. These stages include processing, packaging, distribution, retail display, transport, storage and use by the consumer. They are under varying degrees of control that aim to deliver a satisfactory shelf life, to ensure that the finally-consumed product is of high quality and to ensure that it is safe. Spoilage may be caused by a wide range of reactions including some that are essentially physical, some that are chemical, some enzymic and some microbiological. The various forms of microbiological spoilage are preventable to a large degree by a wide range of preservation techniques, most of which act by preventing or inhibiting microbial growth (e.g., chilling, freezing, drying, curing, conserving, vacuum packing, modified atmosphere packing, acidifying, fermenting and adding preservatives). A smaller number of techniques act by inactivating microorganisms (e.g., pasteurization, sterilization and irradiation). Additional techniques restrict the access of microorganisms to products (e.g., aseptic processing and packaging. A major trend is that new and emerging preservation techniques which are coming into use or are under development include more that act by inactivation (e.g., ultrahigh pressure, electroporation, manothermosonication and addition of bacteriolytic enzymes). A further trend is towards the use of procedures that deliver products that are less heavily preserved, have higher quality, are more natural, freer from additives and nutritionally healthier. Less severe preservation procedures are therefore being developed that make use of preservative factors in combinations to deliver (a) less damage to product quality (hurdle technologies); (b) new methods of heating that are better controlled and therefore deliver milder

  18. 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)

  19. 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)

  20. Strategies and policies for nuclear power plant life management. Proceedings of the IAEA specialists meeting. Working document

    International Nuclear Information System (INIS)

    1998-01-01

    The purpose of the Specialists Meeting organized by the IAEA was to provide an international forum for discussing of recent results in national and utility experience in development of nuclear power plant life management programmes and their technical, regulatory and economic assessments. Plant life management requires detailed knowledge of ageing degradation of the components and the results of mitigation technologies. The basic conclusion includes the need of Guide on NPP Life management which should encompass: plant safety; plant availability; plant operating life extension; human resources policy; research and development needs

  1. Plant life management study of Japanese nuclear power plants

    International Nuclear Information System (INIS)

    Fukuda, Toshihiko

    1999-01-01

    Already more than twenty-five years have passed since the first commercial LWR plant went into operation in Japan. In this situation, MITI and 3 electric utilities (Tokyo Electric Power Company, Kansai Electric Power Co., Inc, Japan Atomic Power Company) have started a plant life management (PLM) study from 1994 to evaluate the long-term integrity of major systems, structures and components of aged LWR plants and ensure the safe, steady and highly reliable long-term operation. It consists of two phases: part 1 study and part 2 study. The part 1 study started in 1994 and focused on seven typical safety-related components. The part 1 study reports were made public in 1996. The part 2 study started in 1997. In this study we reviewed not only safety-related components but also plant reliability related components. The part 2 study reports were opened to the public in February 1999. This paper shows a summary of the part 2 study and our future PLM program. (author)

  2. 77 FR 37839 - Veterans' Group Life Insurance (VGLI) No-Health Period Extension

    Science.gov (United States)

    2012-06-25

    ... DEPARTMENT OF VETERANS AFFAIRS 38 CFR Part 9 RIN 2900-AO24 Veterans' Group Life Insurance (VGLI) No-Health Period Extension AGENCY: Department of Veterans Affairs. ACTION: Proposed rule. SUMMARY... Veterans' Group Life Insurance (VGLI) to extend to 240 days the current 120-day ``no-health'' period during...

  3. Application of plant life management program and experience at NRU

    International Nuclear Information System (INIS)

    Nickerson, J.; Dam, R.; Arnold, J.; See Hoye, D.

    2004-01-01

    The National Research Universal (NRU) reactor has seen extensive and excellent service since going into operation in 1957. During that time, significant investments in upgrading and improving the facility have been implemented. Recently, as part of the NRU Licenseability Extension (LE) program, AECL has developed a Plant Life Management (PLiM) program to support planned operation to at least 2012. The objective of the PLiM program is to systematically assess the various aging related degradation mechanisms in order to evaluate both current condition and the potential for further extending service life. Another objective is to identify the associated maintenance, surveillance and inspection strategy for service life extension of important Structures, Systems, and Components (SSCs). The strategy uses approaches that build on AECL's PLiM/PLEx experience at CANDU plants, but also utilizes previous Age Management and refurbishment work performed at NRU. The program is multi-faceted, systematic and integrated, and involves the facility operations organization in the assessment process. The PLiM program has used a number of pilot studies in the initial stages to test out PLiM procedures, gain experience with the various aging assessment techniques and enhance effectiveness of interfaces between the aging assessment team and the facility staff. The aging assessment process begins with the screening and prioritization of the facility SSCs. Selection of the appropriate assessment technique is based on priority and component type. Life and condition assessment techniques used at other plants have been adapted to NRU and performed on important components and structures. For important systems, a combination of condition assessment and systematic maintenance assessment techniques are being used. Detailed PLiM procedures have been developed and are in trial use in pilot studies. These procedures are currently being updated with the experience gained during the pilot studies. In

  4. Life Span Extension and Neuronal Cell Protection by Drosophila Nicotinamidase*S⃞

    OpenAIRE

    Balan, Vitaly; Miller, Gregory S.; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F. A.; Arking, Robert; Freeman, D. Carl; Maiese, Kenneth; Tzivion, Guri

    2008-01-01

    The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone ...

  5. Shelf life extension as solution for environmental impact mitigation: A case study for bakery products.

    Science.gov (United States)

    Bacenetti, Jacopo; Cavaliere, Alessia; Falcone, Giacomo; Giovenzana, Valentina; Banterle, Alessandro; Guidetti, Riccardo

    2018-06-15

    Over the last years, increasing attention has been paid to environmental concerns related to food production and potential solutions to this issue. Among the different strategies being considered to reduce the impact food production has on the environment, only moderate has been paid to the extension of shelf life; a longer shelf life can reduce food losses as well as the economic and environmental impacts of the distribution logistics. The aim of this study is to assess the environmental performance of whole-wheat breadsticks with extended shelf lives and to evaluate whether the shelf-life extension is an effective mitigation solution from an environmental point of view. To this purpose, the life cycle assessment (LCA) approach was applied from a "cradle-to-grave" perspective. Rosmarinic acid was used as an antioxidant to extend the shelf life. To test the robustness of the results and to investigate the influence of the choices made in the modelling phase, a sensitivity and uncertainty analysis were carried out. The achieved results highlighted how, for 10 of the 12 evaluated impact categories, the shelf-life extension is a proper mitigation solution, and its effectiveness depends on the magnitude of product loss reduction that is achieved. The shelf-life extension doesn't allow for the reduction of environmental impact in the categories of human toxicity, cancer effects and freshwater eutrophication. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Use of environmental qualification data and techniques for life extension purposes

    International Nuclear Information System (INIS)

    Sinnappan, J.

    1991-01-01

    As several nuclear power plants in the United States now reach or exceed the midpoint of their original 40-year design life, efforts are underway to identify techniques and methods to demonstrate that the actual useful life of these plants exceeds the original design life. Some surveillance and monitoring programs for safety-related components are being developed to determine the actual consumed life and predict the remaining life. These data are useful for showing that plant components actually have a longer qualified life, which is the basis for the license renewal of nuclear power plants. This paper summarizes a proposed methodology using existing environmental qualification (EQ) data for safety-related Class 1E equipment and the results of surveillance and monitoring techniques to assess the actual consumed life and, consequently, predict the remaining life. It also discusses several techniques that can be used to address various aging degradation mechanisms to demonstrate longer qualified life of safety-related components. Examples of how these techniques can be used on components are shown

  7. The thematic plant life assessment network (PLAN)

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, R.C.; McGarry, D. [EC/JRC Institute for Advanced Materials, Petten (Netherlands); Pedersen, H.H. [Brite Euram DG XII, Brussels (Belgium)

    1998-12-31

    The Plant Life Assessment Network (PLAN) is a Brite Euram Type II Thematic Network, initiated by the European Commission to facilitate structured co-operation between all cost shared action projects already funded by the Commission which fall under this common technical theme. The projects involved address a multiplicity of problems associated with plant life assessment and are drawn from Brite-Euram, Standards, Measurement and Testing, Nuclear Fission Safety and Esprit EC programmes. The main aim of the Network is to initiate, maintain and monitor a fruitful co-operation process between completed, ongoing and future EC R and D projects, thereby promoting improved cross fertilization and enhanced industrial exploitation of R and D results. As the project is in its infancy, this presentation covers the background to the initiative in some detail. In particular two key aspects are highlighted, namely, the requirement of the EC to launch such a network in the area of plant life assessment including its evolution from two small Thematic Research Actions and, secondly, the mechanism for structuring the Network in an ordered and proven way along the lines of the EC/JRC European Networks, PISC, NESC, AMES, ENIQ, ENAIS and EPERC. The operating and financial structure of the Network is detailed with reference made to the role of the executive Steering Committee, The Network Project Leader and the Network Financial Co-ordinator. Each of the 58 projects involved in the Network, representing a wide range of industrial sectors and disciplines, is distributed in terms of their efforts between 4 disciplinary Clusters covering Inspection, Instrumentation and Monitoring, Structural Mechanics and Maintenance. For each of these Clusters, an expert has been appointed as a Project Technical Auditor to support the elected Cluster Co-ordinator to define Cluster Tasks, which contribute to the overall objectives of the project. From the Project Representatives, Cluster Task Leaders and

  8. The thematic plant life assessment network (PLAN)

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, R C; McGarry, D [EC/JRC Institute for Advanced Materials, Petten (Netherlands); Pedersen, H H [Brite Euram DG XII, Brussels (Belgium)

    1999-12-31

    The Plant Life Assessment Network (PLAN) is a Brite Euram Type II Thematic Network, initiated by the European Commission to facilitate structured co-operation between all cost shared action projects already funded by the Commission which fall under this common technical theme. The projects involved address a multiplicity of problems associated with plant life assessment and are drawn from Brite-Euram, Standards, Measurement and Testing, Nuclear Fission Safety and Esprit EC programmes. The main aim of the Network is to initiate, maintain and monitor a fruitful co-operation process between completed, ongoing and future EC R and D projects, thereby promoting improved cross fertilization and enhanced industrial exploitation of R and D results. As the project is in its infancy, this presentation covers the background to the initiative in some detail. In particular two key aspects are highlighted, namely, the requirement of the EC to launch such a network in the area of plant life assessment including its evolution from two small Thematic Research Actions and, secondly, the mechanism for structuring the Network in an ordered and proven way along the lines of the EC/JRC European Networks, PISC, NESC, AMES, ENIQ, ENAIS and EPERC. The operating and financial structure of the Network is detailed with reference made to the role of the executive Steering Committee, The Network Project Leader and the Network Financial Co-ordinator. Each of the 58 projects involved in the Network, representing a wide range of industrial sectors and disciplines, is distributed in terms of their efforts between 4 disciplinary Clusters covering Inspection, Instrumentation and Monitoring, Structural Mechanics and Maintenance. For each of these Clusters, an expert has been appointed as a Project Technical Auditor to support the elected Cluster Co-ordinator to define Cluster Tasks, which contribute to the overall objectives of the project. From the Project Representatives, Cluster Task Leaders and

  9. Using Plants to Explore the Nature & Structural Complexity of Life

    Science.gov (United States)

    Howard, Ava R.

    2014-01-01

    Use of real specimens brings the study of biology to life. This activity brings easily acquired plant specimens into the classroom to tackle common alternative conceptions regarding life, size, complexity, the nature of science, and plants as multicellular organisms. The activity occurs after a discussion of the characteristics of life and engages…

  10. 9. Nuclear power plant service life prolongation

    International Nuclear Information System (INIS)

    Evropin, S.V.

    1998-01-01

    The problem of prolongation of nuclear power plant service life duration is discussed. A schematic diagram of the program developed in the course of activities dealing with NPP service time prolongation is shown and analyzed in details. It is shown that the basic moment when determining the strategy for NPP service time prolongation is the positive confirmation of the agreement between the NPP safety provisions and modern safety requirements. The other very important aspect of the problem is engineering substantiation of the measures assuring the reactor operation prolongation. The conclusion is made that available methods of recovering reactor materials properties, main components repair and replacement, the modern techniques for nondestructive testing of metals and NPP pipelines, as well as the developed approaches to reactor facility safety improvements make the prolongation of the Russian NPP service lifetimes possible from engineering viewpoint and economically desirable

  11. An albumin-oligonucleotide assembly for potential combinatorial drug delivery and half-life extension applications

    DEFF Research Database (Denmark)

    Kuhlmann, Matthias; Hamming, Jonas Bohn Refslund; Voldum, Anders

    2017-01-01

    The long blood circulatory property of human serum albumin, due to engagement with the cellular recycling neonatal Fc receptor (FcRn), is an attractive drug half-life extension enabling technology. This work describes a novel site-specific albumin double-stranded (ds) DNA assembly approach, in wh...... technology platform that offers potential combinatorial drug delivery and half-life extension applications.......The long blood circulatory property of human serum albumin, due to engagement with the cellular recycling neonatal Fc receptor (FcRn), is an attractive drug half-life extension enabling technology. This work describes a novel site-specific albumin double-stranded (ds) DNA assembly approach......, in which the 3' or 5' end maleimide-derivatized oligodeoxynucleotides are conjugated to albumin cysteine at position 34 (cys34) and annealed with complementary strands to allow single site-specific protein modification with functionalized ds oligodeoxynucleotides. Electrophoretic gel shift assays...

  12. Use of dynamic Bayesian networks for life extension assessment of ageing systems

    International Nuclear Information System (INIS)

    Ramírez, Pedro A. Pérez; Utne, Ingrid Bouwer

    2015-01-01

    Extending the operating lifetime of ageing technical systems is of great interest for industrial applications. Life extension requires identifying and selecting decision alternatives which allow for a safe and economic operation of the system beyond its design lifetime. This article proposes a dynamic Bayesian network for assessing the life extension of ageing repairable systems. The main objective of the model is to provide decision support based on the system performance during a finite time horizon, which is defined by the life extension period. The model has three main applications: (i) assessing and selecting optimal decision alternatives for the life extension at present time, based on historical data; (ii) identifying and minimizing the factors that have a negative impact on the system performance; and (iii) reassessing and optimizing the decision alternatives during operation throughout the life extension period, based on updating the model with new operational data gathered. A case study illustrates the application of the model for life extension of a real firewater pump system in an oil and gas facility. The case study analyzes three decision alternatives, where preventive maintenance and functional test policies are optimized, and the uncertainty involved in each alternative is computed. - Highlights: • A dynamic Bayesian network is used for predicting the system performance. • The performance is measured with relevant variables: cost; unavailability; safety. • The model can be used when scarce data is available, no degradation data is needed. • The uncertainty associated to each alternative is computed in the model. • A detailed case study of a real safety system shows the applicability of the model

  13. Regulatory issues for nuclear power plant life management

    International Nuclear Information System (INIS)

    Roe, J.

    2000-01-01

    The workshop of 26-27 june 2000, on nuclear power Plant LIfe Management (PLIM), also included working groups in which major issues facing PLIM activities for nuclear power plants were identified and discussed. The second group was on Regulation. The Regulatory Working Group will attempt to identify some of the more pertinent issues affecting nuclear plant regulation in a changing PLIM environment, to identify some possible actions to be taken to address these issues, and to identify some of the parties responsible for taking these actions. Some preliminary regulatory issues are noted below. This is not intended to be a comprehensive list of such issues but rather is intended to stimulate discussion among the experts attending this Workshop. One of the concerns in the regulatory arena is how the structural integrity of the plants can be assured for an extended lifetime. Technological advances directed toward the following are likely to be important factors in the regulatory process of life extension. - Preventive and corrective maintenance (e.g., water chemistry control, pressure vessel annealing, and replacement of core internals). - Ageing and degradation mechanisms and evaluation (e.g., embrittlement, wear, corrosion/erosion, fatigue, and stress corrosion). - Monitoring, surveillance, and inspection (e.g., fatigue monitoring and non-destructive testing). - Optimisation of maintenance (e.g., using risk-based analysis). On the business side, there is concern about technical support by manufacturers, fuel companies, and construction companies. Maintaining a strong technical base and skilled workers in a potentially declining environment is another concern in the regulatory community. Waste management and decommissioning remain significant issue regarding PLIM. These issues affect all three areas of concern - technology, business, and regulation. It is against this background, that the issues put forth in this paper are presented. The objective of presenting these

  14. Considerations for Applying Design Extension Conditions to Domestic Nuclear Power Plants

    International Nuclear Information System (INIS)

    Ryu, Yongho

    2013-01-01

    The concept is designed to include more serious accidents than the existing design basis accidents considering additional failures. Design extension conditions can be derived based on engineering judgments, deterministic analysis or probabilistic analysis of the nuclear power plants. They are used to secure practical response capabilities to prevent or mitigate accidents. They may also require the deployment of additional safety equipment for existing nuclear power plants currently in operation. Though the general requirements of design extension conditions are described under the IAEA standards, no specific guidelines have been presented as required for their actual application to the nuclear power plant design. Furthermore, there is great variation between countries in implementing the requirements of design extension conditions. Therefore, for the actual application, considerable effort should be made among relevant organizations to establish detailed requirements of the design extension conditions. Such activities could constitute a part of the efforts of the nuclear community to meet the general public's expectations concerning the safety of nuclear power plants. The introduction of design extension conditions is expected to be a means of systematically enhancing the safety of nuclear power plants. Yet, there exists great differences in terms of the scope of analysis and the acceptance criteria, as no uniform practices have yet been established in applying the specific requirements for design extension conditions. A careful review is required in terms of the technical basis for setting the requirements, including those pertaining to the scope of analysis and the acceptance criteria. The introduction of these new requirements to Korean nuclear power plants may cause unexpected problems. Therefore, it is desirable for the regulatory agency to systematically assess the impact of design extension conditions and to discuss the arising issues with the stake holder

  15. Waste-to-energy: A review of life cycle assessment and its extension methods.

    Science.gov (United States)

    Zhou, Zhaozhi; Tang, Yuanjun; Chi, Yong; Ni, Mingjiang; Buekens, Alfons

    2018-01-01

    This article proposes a comprehensive review of evaluation tools based on life cycle thinking, as applied to waste-to-energy. Habitually, life cycle assessment is adopted to assess environmental burdens associated with waste-to-energy initiatives. Based on this framework, several extension methods have been developed to focus on specific aspects: Exergetic life cycle assessment for reducing resource depletion, life cycle costing for evaluating its economic burden, and social life cycle assessment for recording its social impacts. Additionally, the environment-energy-economy model integrates both life cycle assessment and life cycle costing methods and judges simultaneously these three features for sustainable waste-to-energy conversion. Life cycle assessment is sufficiently developed on waste-to-energy with concrete data inventory and sensitivity analysis, although the data and model uncertainty are unavoidable. Compared with life cycle assessment, only a few evaluations are conducted to waste-to-energy techniques by using extension methods and its methodology and application need to be further developed. Finally, this article succinctly summarises some recommendations for further research.

  16. Technological evaluation for the extension of the operation license to the nuclear power plant of Laguna Verde

    International Nuclear Information System (INIS)

    Arganis J, C. R.; Medina A, A. L.

    2010-01-01

    At the present time one of the tendencies in the nuclear industry is the renovation of operation licenses of the nuclear power plants, with the purpose of prolonging their operation 20 years more than the time settled down in their original license, which is of 30 years for the case of the nuclear power plant of Laguna Verde. This allows the electric power generation for a major period of time and to a relatively low price, giving this way a bigger competitiveness to the power stations of nuclear power. However, to request the license extension of the nuclear power plant requires to get ready the documentation and necessary studies for: to maintain a high level of security, to optimize the operation, maintenance and service life of the structures, systems and components, to maintain an acceptable level of performance, to maximize the recovery of the investment about the service of the nuclear power plant and to preserve the sure conditions for a major operation period at the license time. This paper describes the studies conducted by the Materials Technology Department of the Instituto Nacional de Investigaciones Nucleares (ININ) to substantiate the required documentation for obtaining the extension of operating license of the nuclear power plant. These studies are focused mainly in the reactor pressure vessels of both units, as well as in the deposit of noble metals and the influence of the sludges (crud s) in this deposit. (Author)

  17. An overview of actions concerning life management of nuclear power plants in Argentina

    International Nuclear Information System (INIS)

    Pochettino, A.A.

    1995-01-01

    An overview of actions concerning life management of nuclear power plants in Argentina is presented including the following issues: reorganization of nuclear activities in Argentina; life extension actions; main specific research and development actions (reactor pressure vessel integrity assessment project; reactor internal components project; heat exchanges project); other research and development actions (non-destructive testing developments; eddy current techniques; acoustic emission applications; materials; vibrations and fretting wear; reactor chemistry; control and instrumentation; probabilistic safety assessment)

  18. Wall extensibility: its nature, measurement and relationship to plant cell growth

    Science.gov (United States)

    Cosgrove, D. J.

    1993-01-01

    Expansive growth of plant cells is controlled principally by processes that loosen the wall and enable it to expand irreversibly. The central role of wall relaxation for cell expansion is reviewed. The most common methods for assessing the extension properties of plant cell walls ( wall extensibility') are described, categorized and assessed critically. What emerges are three fundamentally different approaches which test growing cells for their ability (a) to enlarge at different values of turgor, (b) to induce wall relaxation, and (c) to deform elastically or plastically in response to an applied tensile force. Analogous methods with isolated walls are similarly reviewed. The results of these different assays are related to the nature of plant cell growth and pertinent biophysical theory. I argue that the extensibilities' measured by these assays are fundamentally different from one another and that some are more pertinent to growth than others.

  19. The Ethics of Human Life Extension: The Second Argument from Evolution.

    Science.gov (United States)

    Gyngell, Chris

    2015-12-01

    One argument that is sometimes made against pursuing radical forms of human life extension is that such interventions will make the species less evolvable, which would be morally undesirable. In this article, I discuss the empirical and evaluative claims of this argument. I argue that radical increases in life expectancy could, in principle, reduce the evolutionary potential of human populations through both biological and cultural mechanisms. I further argue that if life extension did reduce the evolvability of the species, this will be undesirable for three reasons: (1) it may increase the species' susceptibility to extinction risks, (2) it may adversely affect institutions and practices that promote well-being, and (3) it may impede moral progress. © The Author 2015. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Integration of plant life management in operation and maintenance

    International Nuclear Information System (INIS)

    Hutin, Jean-Pierre

    2002-01-01

    people is an important feature of EDF strategy. Because operating experience often brings evidences of phenomenon which may impact component lifetime, EDF developed a powerful experience feedback organisation. Other key points of lifetime management process are described: Long term repair/replacement strategies Because of the high level of standardization of the EDF fleet, it is absolutely necessary to eliminate the risk of a generic problem which would affect all units at once. For that, EDF must have a very prospective view of all major degradations which could impair component reliability or integrity with appropriate repair/replacement strategies; Collecting relevant data When assessing plant lifetime expectancy, past data about operation and maintenance are needed. Typical examples are the bookkeeping of operating transients which may affect fatigue life of primary system components or the recording of component reliability data; Surveying industrial capacities In the next years, there is a risk for some 'nuclear' companies to go out of business so that EDF could have difficulties in finding appropriate support. To cope with this issue, EDF set up a 'world industrial capacity observatory' which permanently surveys international situation and try to identify 'product/company' pairs which are 'critical' and 'sensitive'. 4 - THE TEN YEAR REVIEW PROCESS. Before the first ten-year outage of a series, a new set of safety references is defined with Safety Authorities. All component/system/structure situations and operating conditions are reviewed, taking in account experience feedback. The results of these reviews are compared with references and a modification and upgrading program is defined. During ten-year outages, modifications are implemented. Extensive inspections and maintenance works are performed, including a set of anticipatory measures. A specific investigation program is also implemented to look for unexpected ageing phenomenon. 5 - THE PLANT LIFE MANAGEMENT

  1. Nuclear power plant life management and longer-term operation

    International Nuclear Information System (INIS)

    2006-01-01

    This book, prepared by NEA member country experts, contains data and analyses relevant to nuclear power plant life management and the plants' extended, longer-term operation (LTO). It addresses technical, economic and environmental aspects and provides insights into the benefits and challenges of plant life management and LTO. It will be of interest to policy makers and senior managers in the nuclear power sector and governmental bodies involved in nuclear power programme design and management. The data and information on current trends in nuclear power plant life management will be useful to researchers and analysts working in the field of nuclear energy system assessment. (authors)

  2. Canadians' support for radical life extension resulting from advances in regenerative medicine.

    Science.gov (United States)

    Dragojlovic, Nick

    2013-04-01

    This paper explores Canadian public perceptions of a hypothetical scenario in which a radical increase in life expectancy results from advances in regenerative medicine. A national sample of 1231 adults completed an online questionnaire on stem cell research and regenerative medicine, including three items relating to the possibility of Canadians' average life expectancy increasing to 120 years by 2050. Overall, Canadians are strongly supportive of the prospect of extended lifespans, with 59% of the sample indicating a desire to live to 120 if scientific advances made it possible, and 47% of respondents agreeing that such increases in life expectancy are possible by 2050. The strongest predictors of support for radical life extension are individuals' general orientation towards science and technology and their evaluation of its plausibility. These results contrast with previous research, which has suggested public ambivalence for biomedical life extension, and point to the need for more research in this area. They suggest, moreover, that efforts to increase public awareness about anti-aging research are likely to increase support for the life-extending consequences of that research program. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. The method of life extension for the High Flux Isotope Reactor vessel

    International Nuclear Information System (INIS)

    Chang, Shib-Jung.

    1995-01-01

    The state of the vessel steel embrittlement as a result of neutron irradiation can be measured by its increase in the nil ductility temperature (NDT). This temperature is sometimes referred to as the brittle-ductile transition temperature (DBT) for fracture. The life extension of the High Flux Isotope Reactor (HFIR) vessel is calculated by using the method of fracture mechanics. A hydrostatic pressure test (hydrotest) is performed in order to determine a safe vessel static pressure. It is then followed by using fracture mechanics to project the reactor life from the safe hydrostatic pressure. The life extension calculation provides the following information on the remaining life of the reactor as a function of the nil ductility temperature increase: the probability of vessel fracture due to hydrotest vs vessel life at several hydrotest pressures; the hydrotest time interval vs the uncertainty of the nil ductility temperature increase rate; and the hydrotest pressure vs the uncertainty of the nil ductility temperature increase rate. It is understood that the use of a complete range of uncertainties of the nil ductility temperature increase is equivalent to the entire range of radiation damage that can be experienced by the vessel steel. From the numerical values for the probabilities of the vessel fracture as a result of hydrotest, it is estimated that the reactor vessel life can be extended up to 50 EFPY (100 MW) with the minimum vessel operating temperature equal to 85 degree F

  4. Life styles of Colletotrichum species and implications for plant biosecurity

    NARCIS (Netherlands)

    Silva, Dilani D. De; Crous, Pedro W.; Ades, Peter Kevin; Hyde, Kevin D.; Taylor, Paul W. J.

    Colletotrichum is a genus of major plant pathogens causing anthracnose diseases in many plant crops worldwide. The genus comprises a highly diverse group of pathogens that infect a wide range of plant hosts. The life styles of Colletotrichum species can be broadly categorised as necrotrophic,

  5. Decoupling factors affecting plant diversity and cover on extensive green roofs.

    Science.gov (United States)

    MacIvor, J Scott; Margolis, Liat; Puncher, Curtis L; Carver Matthews, Benjamin J

    2013-11-30

    Supplemental irrigation systems are often specified on green roofs to ensure plant cover and growth, both important components of green roof performance and aesthetics. Properties of the growing media environment too can alter the assemblage of plant species able to thrive. In this study we determine how plant cover, above ground biomass and species diversity are influenced by irrigation and growing media. Grass and forb vegetative cover and biomass were significantly greater in organic based growing media but there was no effect of supplemental irrigation, with two warm season grasses dominating in those treatments receiving no supplemental irrigation. On the other hand, plant diversity declined without irrigation in organic media, and having no irrigation in inorganic growing media resulted in almost a complete loss of cover. Sedum biomass was less in inorganic growing media treatments and species dominance shifted when growing media organic content increased. Our results demonstrate that supplemental irrigation is required to maintain plant diversity on an extensive green roof, but not necessarily plant cover or biomass. These results provide evidence that planting extensive green roofs with a mix of plant species can ensure the survival of some species; maintaining cover and biomass when supplemental irrigation is turned off to conserve water, or during extreme drought. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  6. Shelf life extension of whole-wheat breadsticks: Formulation and packaging strategies.

    Science.gov (United States)

    Alamprese, Cristina; Cappa, Carola; Ratti, Simona; Limbo, Sara; Signorelli, Marco; Fessas, Dimitrios; Lucisano, Mara

    2017-09-01

    The aim of this study was the shelf life extension of whole-wheat breadsticks through the addition of a rosemary extract and packaging under nitrogen. Shelf life was studied at four temperatures (20, 27, 35, 48°C) for up to 200 storage days. The minimal changes observed in moisture, water activity and texture of the samples, coupled with the high peroxide values (13-539meqO 2 /kg fat ) measured at the end of storage, and the exponential increase of hexanal concentrations (up to 13-34mg/kg) confirmed that quality decay of whole-wheat breadsticks is mainly associated to lipid oxidation. The kinetic study of oxidation development and the consumer sensory acceptance determined by the survival analysis demonstrated that the rosemary extract addition yields a 42% shelf life extension, higher than that observed using nitrogen in the package (24-29%). The combination of the formulation and packaging strategies gave the best result (83% shelf life extension at 25°C). Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Long Term Operation R and D to Investigate the Technical Basis for Life Extension and License Renewal Decisions

    International Nuclear Information System (INIS)

    Gaertner, John

    2012-01-01

    Establishing an improved technical basis for long term operation of existing plants is a nuclear industry priority. The Electric Power Research Institute (EPRI) has responded with a comprehensive Long Term Operation (LTO) Program addressing this need for existing nuclear power plants world-wide. The program supports both the business decisions necessary to achieve high performance operation and the licensing requirements for operation beyond 60 years. The program selects its R and D priorities in a structured and objective way with much industry input to provide useful results for decisions in the 2014 to 2019 time frame. The program is highly collaborative with U.S. Department of Energy (DOE) and with EPRI-member utilities. The R and D portfolio includes materials aging (metals, concrete, and cables), modernization of information and control technology, enhanced safety analysis, advanced fuel design, demonstration plant activities, life cycle management, and identification of aging management program need for subsequent license renewal. The program has focussed stakeholders world-wide on the technical issues of long term operation, and it is on-track to provide practical results for life extension and license renewal decisions. (author)

  8. Relationship between mitochondrial electron transport chain dysfunction, development, and life extension in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Shane L Rea

    2007-10-01

    Full Text Available Prior studies have shown that disruption of mitochondrial electron transport chain (ETC function in the nematode Caenorhabditis elegans can result in life extension. Counter to these findings, many mutations that disrupt ETC function in humans are known to be pathologically life-shortening. In this study, we have undertaken the first formal investigation of the role of partial mitochondrial ETC inhibition and its contribution to the life-extension phenotype of C. elegans. We have developed a novel RNA interference (RNAi dilution strategy to incrementally reduce the expression level of five genes encoding mitochondrial proteins in C. elegans: atp-3, nuo-2, isp-1, cco-1, and frataxin (frh-1. We observed that each RNAi treatment led to marked alterations in multiple ETC components. Using this dilution technique, we observed a consistent, three-phase lifespan response to increasingly greater inhibition by RNAi: at low levels of inhibition, there was no response, then as inhibition increased, lifespan responded by monotonically lengthening. Finally, at the highest levels of RNAi inhibition, lifespan began to shorten. Indirect measurements of whole-animal oxidative stress showed no correlation with life extension. Instead, larval development, fertility, and adult size all became coordinately affected at the same point at which lifespan began to increase. We show that a specific signal, initiated during the L3/L4 larval stage of development, is sufficient for initiating mitochondrial dysfunction-dependent life extension in C. elegans. This stage of development is characterized by the last somatic cell divisions normally undertaken by C. elegans and also by massive mitochondrial DNA expansion. The coordinate effects of mitochondrial dysfunction on several cell cycle-dependent phenotypes, coupled with recent findings directly linking cell cycle progression with mitochondrial activity in C. elegans, lead us to propose that cell cycle checkpoint control

  9. Modeling Operating Modes during Plant Life Cycle

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lind, Morten

    2012-01-01

    Modelling process plants during normal operation requires a set a basic assumptions to define the desired functionalities which lead to fullfillment of the operational goal(-s) for the plant. However during during start-up and shut down as well as during batch operation an ensemble of interrelated...... modes are required to cover the whole operational window of a processs plant including intermediary operating modes. Development of such an model ensemble for a plant would constitute a systematic way of defining the possible plant operating modes and thus provide a platform for also defining a set...... of candidate control structures. The present contribution focuses on development of a model ensemble for a plant with an illustartive example for a bioreactor. Starting from a functional model a process plant may be conceptually designed and qualitative operating models may be developed to cover the different...

  10. Performance of dryland and wetland plant species on extensive green roofs.

    Science.gov (United States)

    MacIvor, J Scott; Ranalli, Melissa A; Lundholm, Jeremy T

    2011-04-01

    Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further evidence that plant composition and diversity can

  11. Evaluation of the integrity and duration of the Laguna Verde nuclear power plant life- Plant Life Management program (PLIM). TC MEX 04/53 Technical Cooperation Project

    International Nuclear Information System (INIS)

    Arganis J, C.R.; Diaz S, A.; Aguilar T, J.A.

    2006-01-01

    As part of the IAEA TC MEX 04/53 Project 'Evaluation of the integrity and extension of life of the Laguna Verde nuclear power plant Handling Program of plant' whose objective is the one of beginning the actions to apply the methodology of Handling of plant life in the Unit 1 of the Laguna Verde Nucleo electric Central for to obtain the Renovation of License in 2020 the ININ, through the Department of Synthesis and Characterization of materials has carried out more of 20 analysis of susceptibility to the intergranular cracking for corrosion under effort in interns so much of the reactor of the unit 1 like of the unit 2 documenting the current state of components based on the type or types of materials that conform them, to it thermomechanical history, operational and of production, as well as of the particularities associated to its use and operation. For the application of the methodology of life handling of plant 5 structure systems or pilot components were selected, to carry out the programs of handling of the aging and handling of plant life: The encircling of the reactor core (Core Shroud), the reactor pressure vessel (Reactor Pressure Vessel), the primary container (Primary Containment), the recirculation system of feeding water (Reactor Feed Water) and cables. (Author)

  12. Plant life management for long term operation of nuclear power plants

    International Nuclear Information System (INIS)

    2005-01-01

    The world's fleet of Nuclear Power Plants (NPPs) is approximately 20 years old on average, and most plants are believed to be able to operate for 60 years or more. The design life of a NPP is typically 30 to 40 years. This may be extended by 10 to 20 years, or more, provided that the plant can demonstrate by analysis, trending, equipment and system upgrades, increased vigilance, testing, ageing management, and other means that license renewal presents no threat to public health and safety. The basic goal of Plant Life Management (PLiM) is to satisfy requirements for safe long-term supplies of electricity in an economically competitive way. The basic goal of the operating company and the owners to operate as long as economically reasonable and possible from safety point of view. PLiM is a management tool for doing that. PLiM is a system of programmes and procedures to satisfy safety requirements for safe operation and for power production in a competitive way and for time which is rational from technical and economical point of view. PLiM is not only a technical system, it is also an attitude of the operational company to keep the plant in operation as long as possible from safety and business point of view. The common objectives of PLiM assessment is to help and review the pre-conditions for PLiM and long-term operation approaches. PLiM should not be associated with extension of operational life-time of the NPP only. It is an owner's attitude and rational approach of the operating company to run the business economically and safely. The effectiveness of PLiM Programme can be assessed by three complementary kinds of assessment: self-assessment, peer review and comprehensive programme review by the plant owner/ operator. IAEA will provide the assessment service for peer review of PLiM. Preparation for a PLiM Assessment service will be initiated only after the IAEA has been formally approached by a MS and funding (e.g. an existing Technical cooperation project) has

  13. Lifetime extension and repairing insurance of WWER type nuclear power plants

    International Nuclear Information System (INIS)

    1989-12-01

    The proceedings contain full texts of 9 contributions, all of which fall within the INIS Subject Scope. The topics treated include general aspects of nuclear power plant lifetime extension, repair and maintenance, as well as lifetime problems of the main components with respect to the structural materials and operating modes. (Z.M.)

  14. Dysthanasia: Between the Life Extension And the Right to Die With Dignity

    Directory of Open Access Journals (Sweden)

    Alice Pompeu Viana

    2016-12-01

    Full Text Available During the XX century, arise new techniques and drugs that can prolong life. However, an unreasonable extension of the vital process of human being that does not have dignified conditions of living it could result in a slow and painful death. Dysthanasia is characterized as medical treatment whose beneficial potentials for the terminal patient are non-existent or unlikely, they are not able to overcome their maleficent potentials. In the context, the present study aims to demonstrate that to deny the right to die to such patient is violate the right to life, as well as to harm the human dignity.

  15. Effect of decontamination on aging processes and considerations for life extension

    International Nuclear Information System (INIS)

    Diercks, D.R.

    1987-10-01

    The basis for a recently initiated program on the chemical decontamination of nuclear reactor components and the possible impact of decontamination on extended-life service is described. The incentives for extending plant life beyond the present 40-year limit are discussed, and the possible aging degradation processes that may be accentuated in extended-life service are described. Chemical decontamination processes for nuclear plant primary systems are summarized with respect to their corrosive effects on structural alloys, particularly those in the aged condition. Available experience with chemical cleaning processes for the secondary side of PWR steam generators is also briefly considered. Overall, no severe materials corrosion problems have been found that would preclude the use of these chemical processes, but concerns have been raised in several areas, particularly with respect to corrosion-related problems that may develop during extended service

  16. Study of Potential Extension For Improving Knowledge Society in Ngadas Village about Medicinal plants

    Directory of Open Access Journals (Sweden)

    hajmia guswika

    2017-09-01

    Full Text Available Society knowledge in Ngadas village about medicinal plants began to fade, as people do not know the plants that can be consume as a drug around them. However, the treatment by plant utilizing is a traditional medicine that has become a cultural heritage that should be conserved and has been recommended by the WHO as the effort back to nature for the maintenance of public health, prevention and treatment of disease. Wild plant that has potential as a drug in the village Ngadas big enough examples adas, ajeran, akasia duri, anting-anting, alang-alang, patikan kebo, pegagan, semanggi gunung, kersen, krisan, kecubung gunung, tempuyung, etc. The purpose of writing this article is to examine the potential of extension as a efforts on improving knowledge of society. The method used is to review literature of some journal that examines the educational efforts to improve public knowledge. Based on data obtained from reviewing the literature, extension activities proved potentially in increasing knowledge of society. Thus it is needed to do extension in an effort to provide information on the potential of medicinal plants in the Ngadas villages.

  17. Impurities in air and their effect on plant life

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanyam, P

    1957-01-01

    Air is said to be polluted when it contains an unusual amount of contaminants. The fact that several of these impurities influence plant life has been fairly well established. Damage caused to agriculture and forestry has been a subject of economic interest in the highly industrialized countries of Europe and America for more than a century now. Germany was the pioneer in this aspect of study and as early as in 1842. Researchers described the poisoning of elm trees. England's history records that the smoke and fume has been one of concern to its citizens ever since the days of the Industrial Revolution. As early as in 1848, the Government initiated a study of the harmful gases to vegetation. The subject attracted the attention of United States of America by about 1900. The writings of one researcher from 1906 to 1916 give evidence of the frequent instances of injuries to trees in New England, attributed to the escape of illuminating gas. Extensive research has followed the periodic concern regarding localized or general pollution. Similar attention has also been paid in Italy and Austria to the effect of impurities of air on vegetation. However, in India the problem attracted the attention of administrators, plant pathologists and chemists only very recently. The vicinity of industrial plants in many places has been responsible for litigation, setting up of commissions and regulation of acts in several countries. The purpose of the present contribution is to bring out the salient features of research work done so far on this subject. 30 references.

  18. Science fiction and human enhancement: radical life-extension in the movie 'In Time' (2011).

    Science.gov (United States)

    Roduit, Johann A R; Eichinger, Tobias; Glannon, Walter

    2018-03-20

    The ethics of human enhancement has been a hotly debated topic in the last 15 years. In this debate, some advocate examining science fiction stories to elucidate the ethical issues regarding the current phenomenon of human enhancement. Stories from science fiction seem well suited to analyze biomedical advances, providing some possible case studies. Of particular interest is the work of screenwriter Andrew Niccol (Gattaca, S1m0ne, In Time, and Good Kill), which often focuses on ethical questions raised by the use of new technologies. Examining the movie In Time (2011), the aim of this paper is to show how science fiction can contribute to the ethical debate of human enhancement. In Time provides an interesting case study to explore what could be some of the consequences of radical life-extension technologies. In this paper, we will show how arguments regarding radical life-extension portrayed in this particular movie differ from what is found in the scientific literature. We will see how In Time gives flesh to arguments defending or rejecting radical life-extension. It articulates feelings of unease, alienation and boredom associated with this possibility. Finally, this article will conclude that science fiction movies in general, and In Time in particular, are a valuable resource for a broad and comprehensive debate about our coming future.

  19. BALTICA IV. Plant maintenance for managing life and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hietanen, S.; Auerkari, P. [eds.] [VTT Manufacturing Technology, Espoo (Finland). Operational Reliability

    1998-12-31

    BALTICA IV International Conference on Plant Maintenance Managing Life and performance held on September 7-9, 1998 on board M/S Silja Symphony on its cruise between Helsinki-Stockholm and at Aavaranta in Kirkkonummi. The BALTICA IV conference provides a forum for the transfer of technology from applied research to practice. This is one of the two volumes of the proceedings of the BALTICA IV International Conference on Plant Maintenance Managing Life and Performance. The BALTICA IV conference focuses on new technology, recent experience and applications of condition and life management, and on improvements in maintenance strategies for safe and economical operation of power plants. (orig.)

  20. BALTICA IV. Plant maintenance for managing life and performance

    Energy Technology Data Exchange (ETDEWEB)

    Hietanen, S; Auerkari, P [eds.; VTT Manufacturing Technology, Espoo (Finland). Operational Reliability

    1999-12-31

    BALTICA IV International Conference on Plant Maintenance Managing Life and performance held on September 7-9, 1998 on board M/S Silja Symphony on its cruise between Helsinki-Stockholm and at Aavaranta in Kirkkonummi. The BALTICA IV conference provides a forum for the transfer of technology from applied research to practice. This is one of the two volumes of the proceedings of the BALTICA IV International Conference on Plant Maintenance Managing Life and Performance. The BALTICA IV conference focuses on new technology, recent experience and applications of condition and life management, and on improvements in maintenance strategies for safe and economical operation of power plants. (orig.)

  1. Life Span Extension and Neuronal Cell Protection by Drosophila Nicotinamidase*S⃞

    Science.gov (United States)

    Balan, Vitaly; Miller, Gregory S.; Kaplun, Ludmila; Balan, Karina; Chong, Zhao-Zhong; Li, Faqi; Kaplun, Alexander; VanBerkum, Mark F. A.; Arking, Robert; Freeman, D. Carl; Maiese, Kenneth; Tzivion, Guri

    2008-01-01

    The life span of model organisms can be modulated by environmental conditions that influence cellular metabolism, oxidation, or DNA integrity. The yeast nicotinamidase gene pnc1 was identified as a key transcriptional target and mediator of calorie restriction and stress-induced life span extension. PNC1 is thought to exert its effect on yeast life span by modulating cellular nicotinamide and NAD levels, resulting in increased activity of Sir2 family class III histone deacetylases. In Caenorhabditis elegans, knockdown of a pnc1 homolog was shown recently to shorten the worm life span, whereas its overexpression increased survival under conditions of oxidative stress. The function and regulation of nicotinamidases in higher organisms has not been determined. Here, we report the identification and biochemical characterization of the Drosophila nicotinamidase, D-NAAM, and demonstrate that its overexpression significantly increases median and maximal fly life span. The life span extension was reversed in Sir2 mutant flies, suggesting Sir2 dependence. Testing for physiological effectors of D-NAAM in Drosophila S2 cells, we identified oxidative stress as a primary regulator, both at the transcription level and protein activity. In contrast to the yeast model, stress factors such as high osmolarity and heat shock, calorie restriction, or inhibitors of TOR and phosphatidylinositol 3-kinase pathways do not appear to regulate D-NAAM in S2 cells. Interestingly, the expression of D-NAAM in human neuronal cells conferred protection from oxidative stress-induced cell death in a sirtuin-dependent manner. Together, our findings establish a life span extending the ability of nicotinamidase in flies and offer a role for nicotinamide-modulating genes in oxidative stress regulated pathways influencing longevity and neuronal cell survival. PMID:18678867

  2. Shelf-life extension of gilthead seabream fillets by osmotic treatment and antimicrobial agents.

    Science.gov (United States)

    Tsironi, T N; Taoukis, P S

    2012-02-01

    The objectives of the study were to evaluate the effect of selected antimicrobial agents on the shelf life of osmotically pretreated gilthead seabream and to establish reliable kinetic equations for shelf-life determination validated in dynamic conditions. Fresh gilthead seabream (Sparus aurata) fillets were osmotically treated with 50% high dextrose equivalent maltodextrin (HDM, DE 47) plus 5% NaCl and 0·5% carvacrol, 0·5% glucono-δ-lactone or 1% Citrox (commercial antimicrobial mix). Untreated and treated slices were aerobically packed and stored isothermally (0-15°C). Microbial growth and quality-related chemical indices were modelled as functions of temperature. Models were validated at dynamic storage conditions. Osmotic pretreatment with the use of antimicrobials led to significant shelf-life extension of fillets, in terms of microbial growth and organoleptic deterioration. The shelf life was 7 days for control samples at 5°C. The osmotic pretreatment with carvacrol, glucono-δ-lactone and Citrox allowed for shelf-life extension by 8, 10 and 5 days at 5°C, respectively. The results of the study show the potential of adding carvacrol, glucono-δ-lactone or Citrox in the osmotic solution to extend the shelf life and improve commercial value of chilled osmotically pretreated fish products. The developed models can be a reliable tool for predicting the shelf life of fresh or minimally processed gilthead seabream fillets in the real chill chain. © 2012 The Authors. Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

  3. Controlling RPV embrittlement through wet annealing in support of life attainment and life extension decisions

    International Nuclear Information System (INIS)

    Krasikov, E. A.

    2012-01-01

    As a main barrier against radioactivity outlet reactor pressure vessel (RPV) is a key component in terms of Nuclear Power Plant (NPP) safety. Therefore present-day demands in RPV reliability enhance have to be met by all possible actions for RPV in-service embrittlement mitigation. Annealing treatment is known to be the effective measure to restore the RPV metal properties deteriorated by neutron irradiation. Low temperature 'wet' annealing at a maximum coolant temperature which can be obtained using the reactor core or primary circuit pumps, although it cannot be expected to produce complete recovery, is more attractive from the practical point of view especially in cases when the removal of the internals is impossible. As a rule there is no recovery effect up to annealing and irradiation temperature difference of 70 deg. C. It is known, however, that along with radiation embrittlement neutron irradiation may mitigate the radiation damage in metals. Therefore we have tried to test the possibility to use the effect of radiation-induced ductilization in 'wet' annealing technology by means of nuclear heat utilization as heat and neutron irradiation sources at once. In support of the above-mentioned conception the 3-year duration reactor experiment on 15Cr3NiMoV type steel with preliminary irradiation at operating Pressurized Water Reactor (PWR) at 270 deg. C and following extra irradiation (87 h at 330 deg. C) at IR-8 test reactor was fulfilled. In fact, embrittlement was partly suppressed up to value equivalent to 1,5 fold neutron fluence decrease. The degree of recovery in case of radiation enhanced annealing is equal to 27% whereas furnace annealing results in zero effect under existing conditions. Mechanism of the radiation-induced damage mitigation is proposed. It is hoped that 'wet' annealing technology will help provide a better management of the RPV degradation as a factor affecting the lifetime of nuclear power plants which, together with associated

  4. Controlling RPV embrittlement through wet annealing in support of life attainment and life extension decisions

    International Nuclear Information System (INIS)

    Krasikov, E.A.

    2012-01-01

    As a main barrier against radioactivity outlet reactor pressure vessel (RPV) is a key component in terms of Nuclear Power Plant (NPP) safety. Therefore present-day demands in RPV reliability enhance have to be met by all possible actions for RPV in-service embrittlement mitigation. Annealing treatment is known to be the effective measure to restore the RPV metal properties deteriorated by neutron irradiation. Low temperature annealing at a maximum coolant temperature which can be obtained using the reactor core or primary circuit pumps, although it cannot be expected to produce complete recovery, is more attractive from the practical point of view especially in cases when the removal of the internals is impossible. As a rule there is no recovery effect up to annealing and irradiation temperature difference of 70 o C. It is known, however, that along with radiation embrittlement neutron irradiation may mitigate the radiation damage in metals. Therefore we have tried to test the possibility to use the effect of radiation-induced ductilization in annealing technology by means of nuclear heat utilization as heat and neutron irradiation sources at once. In support of the above-mentioned conception the 3-year duration reactor experiment on 15Cr3NiMoV type steel with preliminary irradiation at operating Pressurized Water Reactor (PWR) at 270 o C and following extra irradiation (87 h at 330 o C) at IR-8 test reactor was fulfilled. In fact, embrittlement was partly suppressed up to value equivalent to 1,5 fold neutron fluence decrease. The degree of recovery in case of radiation enhanced annealing is equal to 27% whereas furnace annealing results in zero effect under existing conditions. Mechanism of the radiation-induced damage mitigation is proposed. It is hoped that annealing technology will help provide a better management of the RPV degradation as a factor affecting the lifetime of nuclear power plants which, together with associated management methods, will help

  5. Controlling RPV embrittlement through wet annealing in support of life attainment and life extension decisions

    Energy Technology Data Exchange (ETDEWEB)

    Krasikov, E. A. [National Research Centre Kurchatov Inst., 1, Kurchatov Sq., Moscow, 123182 (Russian Federation)

    2012-07-01

    As a main barrier against radioactivity outlet reactor pressure vessel (RPV) is a key component in terms of Nuclear Power Plant (NPP) safety. Therefore present-day demands in RPV reliability enhance have to be met by all possible actions for RPV in-service embrittlement mitigation. Annealing treatment is known to be the effective measure to restore the RPV metal properties deteriorated by neutron irradiation. Low temperature 'wet' annealing at a maximum coolant temperature which can be obtained using the reactor core or primary circuit pumps, although it cannot be expected to produce complete recovery, is more attractive from the practical point of view especially in cases when the removal of the internals is impossible. As a rule there is no recovery effect up to annealing and irradiation temperature difference of 70 deg. C. It is known, however, that along with radiation embrittlement neutron irradiation may mitigate the radiation damage in metals. Therefore we have tried to test the possibility to use the effect of radiation-induced ductilization in 'wet' annealing technology by means of nuclear heat utilization as heat and neutron irradiation sources at once. In support of the above-mentioned conception the 3-year duration reactor experiment on 15Cr3NiMoV type steel with preliminary irradiation at operating Pressurized Water Reactor (PWR) at 270 deg. C and following extra irradiation (87 h at 330 deg. C) at IR-8 test reactor was fulfilled. In fact, embrittlement was partly suppressed up to value equivalent to 1,5 fold neutron fluence decrease. The degree of recovery in case of radiation enhanced annealing is equal to 27% whereas furnace annealing results in zero effect under existing conditions. Mechanism of the radiation-induced damage mitigation is proposed. It is hoped that 'wet' annealing technology will help provide a better management of the RPV degradation as a factor affecting the lifetime of nuclear power plants which

  6. Predicting the residual life of plant equipment - Why worry

    International Nuclear Information System (INIS)

    Jaske, C.E.

    1985-01-01

    Predicting the residual life of plant equipment that has been in service for 20 to 30 years or more is a major concern of many industries. This paper reviews the reasons for increased concern for residual-life assessment and the general procedures used in performing such assessments. Some examples and case histories illustrating procedures for assessing remaining service life are discussed. Areas where developments are needed to improve the technology for remaining-life estimation are pointed out. Then, some of the critical issues involved in residual-life assessment are identified. Finally, the future role of residual-life prediction is addressed

  7. Extensive Management Promotes Plant and Microbial Nitrogen Retention in Temperate Grassland

    Science.gov (United States)

    de Vries, Franciska T.; Bloem, Jaap; Quirk, Helen; Stevens, Carly J.; Bol, Roland; Bardgett, Richard D.

    2012-01-01

    Leaching losses of nitrogen (N) from soil and atmospheric N deposition have led to widespread changes in plant community and microbial community composition, but our knowledge of the factors that determine ecosystem N retention is limited. A common feature of extensively managed, species-rich grasslands is that they have fungal-dominated microbial communities, which might reduce soil N losses and increase ecosystem N retention, which is pivotal for pollution mitigation and sustainable food production. However, the mechanisms that underpin improved N retention in extensively managed, species-rich grasslands are unclear. We combined a landscape-scale field study and glasshouse experiment to test how grassland management affects plant and soil N retention. Specifically, we hypothesised that extensively managed, species-rich grasslands of high conservation value would have lower N loss and greater N retention than intensively managed, species-poor grasslands, and that this would be due to a greater immobilisation of N by a more fungal-dominated microbial community. In the field study, we found that extensively managed, species-rich grasslands had lower N leaching losses. Soil inorganic N availability decreased with increasing abundance of fungi relative to bacteria, although the best predictor of soil N leaching was the C/N ratio of aboveground plant biomass. In the associated glasshouse experiment we found that retention of added 15N was greater in extensively than in intensively managed grasslands, which was attributed to a combination of greater root uptake and microbial immobilisation of 15N in the former, and that microbial immobilisation increased with increasing biomass and abundance of fungi. These findings show that grassland management affects mechanisms of N retention in soil through changes in root and microbial uptake of N. Moreover, they support the notion that microbial communities might be the key to improved N retention through tightening linkages

  8. Negative plant-phyllosphere feedbacks in native Asteraceae hosts - a novel extension of the plant-soil feedback framework.

    Science.gov (United States)

    Whitaker, Briana K; Bauer, Jonathan T; Bever, James D; Clay, Keith

    2017-08-01

    Over the past 25 years, the plant-soil feedback (PSF) framework has catalyzed our understanding of how belowground microbiota impact plant fitness and species coexistence. Here, we apply a novel extension of this framework to microbiota associated with aboveground tissues, termed 'plant-phyllosphere feedback (PPFs)'. In parallel greenhouse experiments, rhizosphere and phyllosphere microbiota of con- and heterospecific hosts from four species were independently manipulated. In a third experiment, we tested the combined effects of soil and phyllosphere feedback under field conditions. We found that three of four species experienced weak negative PSF whereas, in contrast, all four species experienced strong negative PPFs. Field-based feedback estimates were highly negative for all four species, though variable in magnitude. Our results suggest that phyllosphere microbiota, like rhizosphere microbiota, can potentially mediate plant species coexistence via negative feedbacks. Extension of the PSF framework to the phyllosphere is needed to more fully elucidate plant-microbiota interactions. © 2017 John Wiley & Sons Ltd/CNRS.

  9. Deterioration and shelf-life extension of fish and fishery products by modified atmosphere packaging

    Directory of Open Access Journals (Sweden)

    Payap Masniyom

    2011-04-01

    Full Text Available Fish and fishery products have been recognized as a nutrition source due to their high protein content. Moreover, theycontain considerable amount of unsaturated fatty acids, especially omega-3 fatty acids, which are regarded as preventivecompounds. However, shelf-life of seafood is limited by biochemical and microbiological changes. Modified atmospherepackaging (MAP is widely used for minimally processed fishery products including fresh meat for retarding microbial growthand enzymatic spoilage. CO2, O2, and N2 are most often used in MAP. CO2 enriched atmosphere inhibits the autolyticdegradation of fish muscle during storage. However, high levels of CO2 negatively affect product quality, especially by increasingdrip loss and altering texture. Development of satisfactory methods for shelf-life extension that ensure qualitymaintenance of products with minimum loss has drawn the attention of food technologists. The application of MAP andcombination process in seafood is a promising preservation method to extend the shelf-life of fish and fishery products.

  10. Probabilistic fracture mechanics analysis for the life extension estimate of the high flux isotope reactor vessel

    International Nuclear Information System (INIS)

    Chang, S.J.

    1997-01-01

    The state of the vessel steel embrittlement as a result of neutron irradiation can be measured by its increase in the nil ductility temperature (NDT). This temperature is sometimes referred to as the brittle-ductile transition temperature (DBT) for fracture. The life extension of the High Flux Isotope Reactor (HFIR) vessel is calculated by using the method of fracture mechanics. A new method of fracture probability calculation is presented in this paper. The fracture probability as a result of the hydrostatic pressure test (hydrotest) is used to determine the life of the vessel. The hydrotest is performed in order to determine a safe vessel static pressure. It is then followed by using fracture mechanics to project the safe reactor operation time from the time of the satisfactory hydrostatic test. The life extension calculation provides the following information on the remaining life of the reactor as a function of the NDT increase: (1) the life of the vessel is determined by the probability of vessel fracture as a result of hydrotest at several hydrotest pressures and vessel embrittlement conditions, (2) the hydrotest time interval vs the NDT increase rate, and (3) the hydrotest pressure vs the NDT increase rate. It is understood that the use of a complete range of uncertainties of the NDT increase is equivalent to the entire range of radiation damage that can be experienced by the vessel steel. From the numerical values for the probabilities of the vessel fracture as a result of hydrotest, it is estimated that the reactor vessel life can be extended up to 50 EFPY (100 MW) with the minimum vessel operating temperature equal to 85 degrees F

  11. Energy policy, economic and engineering issues of the extension of Paks Nuclear Power Plant

    International Nuclear Information System (INIS)

    Aszodi, Attila; Boros, Ildiko; Kovacs, Arnold

    2014-01-01

    The four operating blocks of the Paks Nuclear Power Plant are of Russian design. They entered into operation three decades ago, between 1982 and 1987. In 2013 they produced 15 TWh out of the 42 TWh energy consumption of Hungary, that is they produced 36% of the energy demand. In the beginning of 2014 the Hungarian and the Russian governments signed the agreement on the extension of Paks site with building two new blocks, producing 1200 MW each. The paper summarizes the energy policy, engineering, safety and economic aspects of the extension. (TRA)

  12. Determination of the remaining operational life of power plant components

    International Nuclear Information System (INIS)

    Eiden, H.; Vorwerk, K.; Graeff, D.; Hoff, E.

    1983-01-01

    The proceedings volume presents, in full wording, eight papers read at a TUEV Rheinland meeting in Johannesburg, South Africa, in August 1982. Subjects: Layout, quality assurance, service life analysis etc. of power plant components. (RW) [de

  13. Regulatory Approach To and Lessons Learned with Licensing of Service Life Extension at PAKS NPP

    International Nuclear Information System (INIS)

    Petofi, G.

    2012-01-01

    Paks Nuclear Power Plant of Hungary decided to extend the original design lifetime of the plant by 20 years, which expires on December 31, 2012 concerning unit 1. The Hungarian Atomic Energy Authority established the legal environments in order to license the extension using an approach similar to that followed in the United States. The regulation specifies the pre-conditions for the extension, defines the scoping and screening process for the passive and long lived systems, structures and components to be involved in the licensing and the respective methods of treatment and also determines how the active components shall be dealt with during the extended lifetime. The regulatory procedure is a two-step process including the oversight of the preparatory programme of the operator for the extension that started 4 years before the expiry of the lifetime and the licensing process itself, which is currently under way for unit 1 after the submittal of the licensee's application at the end of 2011. The first experiences with the regulatory assessment of the application are available yet and presented in this paper. (author)

  14. Plant life management for long term operation of light water reactors. Principles and guidelines

    International Nuclear Information System (INIS)

    2006-01-01

    The subject of this report was originally suggested by the IAEA Technical Working Group on Life Management of Nuclear Power Plants. It was then approved by the IAEA for work to begin in 2004. The participants in the group felt that it was time to address plant life management and ageing issues from the point of view of long term operation and licence renewal. It is believed that the nuclear power industry will only be able to survive if plant economics are favourable and safety is maintained. Therefore, the issue of ageing and obsolescence has to be addressed from an operational and safety standpoint, but also in the context of plant economics in terms of the cost of electricity production, including initial and recurring capital costs. Use of new technologies, such as advanced in-service inspection and condition based maintenance, should be considered, not only to predict the consequences of ageing and guard against them, but also to monitor equipment performance throughout the lifetime of the plant and to help establish replacement schedules for critical systems, structures and components, and to better estimate the optimum end of the operating licence, which means the end of the nuclear power plant's lifetime. The importance of nuclear power plant life management in facilitating the technical and economic goals of long term operation is presented in this report in terms of the requirement to ensure safe long term supplies of electricity in the most economically competitive way. Safe and reliable operation is discussed in terms of the overall economic benefits when plant life management is implemented. Preconditions for plant life management for long term operation are identified and approaches are reviewed. Plant life management should not be associated only with the extension of the operational lifetime of the nuclear power plant, but with an owner's attitude and a rational approach of the operating company towards running the business economically and safely

  15. Implications of Extension of Station Blackout Cooping Capability on Nuclear Power Plant Safety

    International Nuclear Information System (INIS)

    Volkanovski, Andrija

    2015-01-01

    The safety of the nuclear power plant depends on the availability of the continuous and reliable sources of electrical energy during all modes of operation of the plant. The station blackout corresponds to a total loss of all alternate current (AC) power as a result of complete failure of both offsite and on-site AC power sources. The electricity for the essential systems during station blackout is provided from the batteries installed in the nuclear power plant. The results of the probabilistic safety assessment show that station blackout is one of the main and frequently the dominant contributor to the core damage frequency. Results of the analysis of the implications of the strengthening of the SBO mitigation capability on safety of the NPP will be presented. The assessment is done with state-of-art deterministic and probabilistic methods and tolls with application on reference models of nuclear power plants. The safety analysis is done on reference model of the nuclear power plant. Obtained results show large decrease of the core damage frequency with strengthening of the station blackout mitigation capability. The time extension of blackout coping capability results in the delay of the core heat up for at least the extension time interval. Availability and operation of the steam driven auxiliary feedwater system maintains core integrity up to 72 h after the successful shutdown, even in the presence of the reactor coolant pumps seal leakage. The largest weighted decrease of the core damage frequency considering the costs for the modification is obtained for the modification resulting in extension of the station blackout coping capability. The importance of the common cause failures of the emergency diesel generators for the obtained decrease of the core damage frequency and overall safety of the plant is identified in the obtained results. (authors)

  16. Contribution of research and development and engineering to a large reprocessing plant project. Extension of the La Hague plant

    International Nuclear Information System (INIS)

    Boutaud de la Combe, P.; Courouble, J.M.; Sauteron, J.; Redon, A.

    1983-01-01

    Two reprocessing plants are operated by Cogema: Marcoule (since 1958) and La Hague (since 1967). Since 1976 the latter has been reprocessing LWR assemblies in its 'HAO' workshop, operation of which has provided industrial experience in the reprocessing of this type of fuel. This experience will be drawn upon in the construction of extensions to the La Hague plant, namely the UP3 plant, which will have a capacity of 800 t/a, and UP2-800, which will expand the present plant likewise to a capacity of 800 t/a. These extensions will contain a number of improvements, particularly in the areas of safety and waste treatment, and of procedure and equipment. A considerable R and D contribution is provided by the French Atomic Energy Commission (CEA), which is the licence holder, with its laboratories at Fontenay and the pilot workshop and industrial prototypes service at Marcoule. This activity supports all phases of the project, from the establishment of basic principles to the definition of essential characteristics of equipment, covering also the testing of full-scale prototypes (mock-ups) for the principal components: rotating continuous dissolver, swinging decanter, subcritical pulsed columns, used-solvent distilling apparatus, fission-product vitrification furnace, etc. Engineering work for the new facilities is performed by the Societe generale pour les techniques nouvelles in four phases: (1) establishment of basic data; (2) preparation of preliminary plans (including an estimate and a preliminary schedule) and of the preliminary safety reports; (3) drafting of the 'project' file, giving definitive costs and deadlines; (4) implementation, up to and including the operational testing stage. All phases of design and implementation are subject to a quality assurance programme. Extension of the La Hague plant represents an investment of 23,500 million French francs (in July 1981). Construction is expected to be completed in 1989. (author)

  17. Plant life history and above–belowground interactions

    NARCIS (Netherlands)

    Deyn, de Gerlinde

    2017-01-01

    The importance of above–belowground interactions for plant growth and community dynamics became clear in the last decades, whereas the numerous studies on plant life history improved our knowledge on eco-evolutionary dynamics. However, surprisingly few studies have linked both research fields

  18. A methodology for on-line fatigue life monitoring of Indian nuclear power plant components

    International Nuclear Information System (INIS)

    Mukhopadhyay, N.K.; Dutta, B.K.; Kushawaha, H.S.

    1992-01-01

    Fatigue is one of the most important aging effects of nuclear power plant components. Information about accumulation of fatigue helps in assessing structural degradation of the components. This assists in-service inspection and maintenance and may also support future life extension program of a plant. In the present report a methodology is being proposed for monitoring on line fatigue life of nuclear power plant components using available plant instrumentations. Major factors affecting fatigue life of a nuclear power plant components are the fluctuations of temperature, pressure and flow rate. Green's function technique is used in on line fatigue monitoring as computation time is much less than finite element method. A code has been developed which computes temperature and stress Green's functions in 2-D and axisymmetric structure by finite element method due to unit change in various fluid parameters. A post processor has also been developed which computes the temperature and stress responses using corresponding Green's functions and actual fluctuation in fluid parameters. In this post processor, the multiple site problem is solved by superimposing single site Green's function technique. It is also shown that Green's function technique is best suited for on line fatigue life monitoring of nuclear power plant components. (author). 6 refs., 43 figs

  19. Novel Repair Technique for Life-Extension of Hydraulic Turbine Components in Hydroelectric Power Stations

    Science.gov (United States)

    Hiramatsu, Yoichi; Ishii, Jun; Funato, Kazuhiro

    A significant number of hydraulic turbines operated in Japan were installed in the first half of the 20th century. Today, aging degradation and flaws are observed in these turbine equipments. So far, Japanese engineers have applied NDI technology of Ultrasonic Testing (UT) to detect the flaws, and after empirical evaluation of the remaining life they decided an adequate moment to replace the equipments. Since the replacement requires a large-scale field site works and high-cost, one of the solutions for life-extension of the equipments is introduction of repair services. We have been working in order to enhance the accuracy of results during the detection of flaws and flaws dimensioning, in particular focusing on the techniques of Tip-echo, TOFD and Phased-Array UT, accompanied by the conventional UT. These NDI methods made possible to recognize the entire image of surface and embedded flaws with complicated geometry. Then, we have developed an evaluation system of these flaws based on the theory of crack propagation, of the logic of crack growth driven by the stress-intensity factor of the crack tip front. The sophisticated evaluation system is constituted by a hand-made software and database of stress-intensity factor. Based on these elemental technologies, we propose a technique of repair welding to provide a life-extension of hydraulic turbine components.

  20. Design and fabrication of stainless steel components for long life of spent fuel reprocessing plants

    International Nuclear Information System (INIS)

    Natarajan, R.; Ramkumar, P.; Sundararaman, V.; Kamachi Mudali, U.; Baldev Raj; Shanmugam, K.

    2010-01-01

    Reprocessing of spent nuclear fuels based on the PUREX process is the proven process with many commercial plants operating satisfactorily worldwide. The process medium being nitric acid, austenitic stainless steel is the material of construction as it is the best commercially available material for meeting the conditions in the reprocessing plants. Because of the high radiation fields, contact maintenance of equipment and systems of these plants are very time consuming and costly unlike other chemical process plants. Though the plants constructed in the early years required extensive shut downs for replacement of equipment and systems within the first fifteen years of operation itself, development in the field of stainless steel metallurgy and fabrication techniques have made it possible to design the present day plants for an operating life period of forty years. A review of the operational experience of the PUREX process based aqueous reprocessing plants has been made in this paper and reveals that life limiting failures of equipment and systems are mainly due to corrosion while a few are due to stresses. Presently there are no standards for design specification of materials and fabrication of reprocessing plants like the nuclear power plants, where well laid down ASTM and ASME codes and standards are available which are based on the large scale operational feedbacks on pressure vessels for conventional and nuclear industries. (author)

  1. Prediction and attendance of Angra 2 nuclear power plant cycle extension

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  2. Life extension program initiation at Davis-Besse nuclear power station

    International Nuclear Information System (INIS)

    Staudinger, Deborah K.

    1991-01-01

    Davis-Besse is a 900 MW Babcock and Wilcox designed plant located in Northwest Ohio. Effective December 31, 1990, the construction period was recovered making the current license expiration 2007. The economic effects of this extension reduced the depreciation expense for 1990 by $9,790,000 and increased earnings per share by $.04. This positive impact has resulted in an evaluation of pursuing license renewal for Davis-Besse in accordance with the proposed rule on license renewal (10CFR54 'Requirements for renewal of operating licenses for nuclear power plants'). This paper reviews preliminary efforts to evaluate these actions and summarizes strategies planned to ensure continued operation of Davis-Besse remains a viable option for base load generation for Toledo Edison. (author)

  3. Concept of a Maneuvering Load Control System and Effect on the Fatigue Life Extension

    Directory of Open Access Journals (Sweden)

    N. Paletta

    Full Text Available Abstract This paper presents a methodology for the conceptual design of a Maneuver Load Control system taking into account the airframe flexibility. The system, when switched on, is able to minimize the bending moment augmentation at a wing station near the wing root during an unsteady longitudinal maneuver. The reduction of the incremental wing bending moment due to maneuvers can lead to benefits such as improved pay-loads/gross weight capabilities and/or extended structural fatigue life. The maneuver is performed by following a desired vertical load factor law with elevators deflections, starting from the trim equilibrium in level flight. The system observes load factor and structural bending through accelerometers and calibrated strain sensors and then sends signals to a computer that symmetrically actuates ailerons for reducing the structural bending and elevators for compensating the perturbation to the longitudinal equilibrium. The major limit of this kind of systems appears when it has to be installed on commercial transport aircraft for reduced OEW or augmented wing aspect-ratio. In this case extensive RAMS analyses and high redundancy of the MLC related sub-systems are required by the Certification Authority. Otherwise the structural design must be performed at system off. Thus the unique actual benefit to be gained from the adoption of a MLC system on a commercial transport is the fatigue life extension. An application to a business aircraft responding to the EASA Certification Specifications, Part 25, has been performed. The aircraft used for the numerical application is considered only as a test case-study. Most of design and analysis considerations are applicable also to other aircraft, such as unmanned or military ones, although some design requirements can be clearly different. The estimation of the fatigue life extension of a structural joint (wing lower skin-stringer, located close to the wing root, has been estimated by showing

  4. Role of organizational leadership in plant life management

    International Nuclear Information System (INIS)

    Mohindra, R.K.; Chou, Q.B.

    2007-01-01

    The nuclear power plant (NPP) operational trend shows that the plants of the same design and brought to service about the same time demonstrate a wide range of life time operational performance. Based on years of performance assessment experience from various types of industry audits, it can be seen that there is a strong relationship between organizational leadership and the good performing plants. A review based on this relationship is provided to suggest important characteristics needed in management and leadership team for an organization to have a successful life management program in a NPP. The required characteristics and attributes are discussed in the following three important organizational elements: Environment, People and Process

  5. Procedure for validating the life extension for the WWER-440 internals at NV NPP unit 3

    International Nuclear Information System (INIS)

    Filatov, V.M.; Evropin, S.V.

    2001-01-01

    The design lifetime (30 years) of the 1st generation WWER-440 reactor facilities is nearing completion in Russia. One of the major problems is to validate the life extension (LE) of the reactor internals ensuring the core arrangement and free passage of the control and protection system components during different operating modes, emergency modes included. The internals at the 1st generation units are designed so that to enable their replacement. But it requires a lot of funds and time. The work has been done to demonstrate that the internals may be further safely operated without their components being replaced provided their strength, longevity and serviceability are sufficiently validated. (author)

  6. The influence of gamma irradiation on shelf-life extension of banana

    International Nuclear Information System (INIS)

    Tiravat, K.

    1971-01-01

    Effect of various doses of gamma radiation on shelf-life extension of Hom Tong banana stored at 17 0 C, 20 0 C, and 23 0 C was described. Irradiated banana stored at 20 0 C and 23 0 C did not show any retardation in ripening. Doses from 20-40 Krad appeared to delay ripening of the banana stored at 17 0 C for 3-5 days. No significant difference in weight losses between irradiated and non-irradiated banana was detected during storage

  7. Determining the residual lifetime for the main RBMK components in frame of life extension of power units

    International Nuclear Information System (INIS)

    Baldin, V.D.; Petrov, A.A.; Potapov, A.A.

    2005-01-01

    At present time 11 power units of NPPs with RBMK reactors produce annually 140 billion kWh of electricity, which is about half of all electricity generated at Russian NPPs. Commissioned during the period of 1973 to 1990, they have the specified service life of 30 years. The power units have been regularly upgraded during operation to raise their safety and reliability. As the result now they meet modem requirements in terms of safety and their lifetime can considerably exceed their specified service life. The task of the plant life extension becomes more urgent. The main nonreplaceable RBMK reactor components that determine the reactor life, are graphite stack and metal support structures. The aging of these structures is monitored and the structures residual lifetime is predicted in accordance with procedures approved by regulatory authorities. The lead unit among all RBMK power units is Leningrad NPP Unit 1 commissioned in 1973. A complex of activities was performed for this power unit in 2002-2003 to prove the feasibility of its life extension. In terms of defining the residual lifetime of the reactor components, the activities were performed in three major areas: - examination of the state of the reactor structures; - materials studies of irradiated metal and graphite specimens in hot chambers; - performing the calculation and prediction evaluations. The results of examining the metal structures and studying specimens have shown that: 1)The metal and the welds do not have visible defects. The state of protective coatings is largely satisfactory. 2)The ultimate strength and hardness of steel have grown. 3)The brittle fracture transition temperature shift is at the allowable level. 4)The leak-tightness of the metal structures has not been violated. The results of the graphite stack examination have shown that the graphite is at the hardening stage. No tendency for deterioration of mechanical properties has been recorded. According to the results of measuring the

  8. Countermeasure to plant life management of the nuclear power plants out of Japan

    International Nuclear Information System (INIS)

    1999-01-01

    Some investigations on countermeasure to plant life management of the nuclear power plants were begun since beginning of 1990s under cooperation with Ministry of International Trade and Industry and all electric power companies under consideration of recent state on abroad and at concept of preventive conservation implementation against the plant life management. As a result, the Tokyo Electric Power Company, the Kansai Electric Power Company and the Japan Atomic Power Company settled each program on countermeasure to plant life management of the Fukushima-1 Power Plant, the Mihama-1 Power Plant and the Tsuruga-1 Power Plant, respectively, which were reported to the Atomic Energy Safety Commission to issue on February, 1999, after deliberation in the Adviser Group of Ministry of International Trade and Industry. Such investigations on countermeasure to the plant life management are also conducted out of Japan in parallel to those in Japan, which contain programs reflecting states of operation and maintenance of nuclear power plants and atmosphere around atomic energy in each country. Here were described on some present states of the countermeasures to plant life management in U.S.A., France, Germany, Sweden, England and so forth. (G.K.)

  9. A service life extension (SLEP) approach to operating aging aircraft beyond their original design lives

    Science.gov (United States)

    Pentz, Alan Carter

    With today's uncertain funding climate (including sequestration and continuing budget resolutions), decision makers face severe budgetary challenges to maintain dominance through all aspects of the Department of Defense (DoD). To meet war-fighting capabilities, the DoD continues to extend aircraft programs beyond their design service lives by up to ten years, and occasionally much more. The budget requires a new approach to traditional extension strategies (i.e., reuse, reset, and reclamation) for structural hardware. While extending service life without careful controls can present a safety concern, future operations planning does not consider how much risk is present when operating within sound structural principles. Traditional structural hardware extension methods drive increased costs. Decision makers often overlook the inherent damage tolerance and fatigue capability of structural components and rely on simple time- and flight-based cycle accumulation when determining aircraft retirement lives. This study demonstrates that decision makers should consider risk in addition to the current extension strategies. Through an evaluation of eight military aircraft programs and the application and simulation of F-18 turbine engine usage data, this dissertation shows that insight into actual aircraft mission data, consideration of fatigue capability, and service extension length are key factors to consider. Aircraft structural components, as well as many critical safety components and system designs, have a predefined level of conservatism and inherent damage tolerance. The methods applied in this study would apply to extensions of other critical structures such as bridges. Understanding how much damage tolerance is built into the design compared to the original design usage requirements presents the opportunity to manage systems based on risk. The study presents the sensitivity of these factors and recommends avenues for further research.

  10. Regenerative heat treatments for the extension of the creep life of the superalloy IN-738

    International Nuclear Information System (INIS)

    Stevens, R.A.; Flewitt, P.E.J.

    1979-01-01

    Uniaxial creep tests have been performed on the cast nickel-base superalloy IN-738 at 1023K and 1123K. Microstructural damage occurring during creep has been characterised using transmission electron microscopy of surface and extraction replicas. Considerable coarsening of the γ' precipitates occurs during creep causing a progressive loss of creep strength. Intermediate heat treatment of interrupted specimens regenerates a microstructure similar to the original, and on re-testing significant creep life extensions are observed. These heat treatments do not completely recover the creep life due to the development of grain boundary cavitation. Additional heat treatments were performed under a superimposed hydrostatic pressure of 138 MPa to remove these cavities. (orig.) [de

  11. Modified Atmosphere Systems and Shelf Life Extension of Fish and Fishery Products

    Science.gov (United States)

    DeWitt, Christina A. Mireles; Oliveira, Alexandra C.M.

    2016-01-01

    This review aims at summarizing the findings of studies published over the past 15 years on the application of modified atmosphere (MA) systems for shelf life extension of fish and fishery products. This review highlights the importance of CO2 in the preservation of seafood products, and underscores the benefits of combining MA technology with product storage in the superchilled temperature range. It is generally accepted that MA technology cannot improve product quality and should not be utilized as a substitute for good sanitation and strict temperature control. Benefits derived from application of MA, however, can significantly impact preservation of product quality and it subsequent shelf-life. For this reason, this review is the first of its kind to propose detailed handling and quality guidelines for fresh fish to realize the maximum benefit of MA technology. PMID:28231143

  12. Fatigue life extension techniques for weldments via mechanical surface post treatment

    International Nuclear Information System (INIS)

    Han, Seung Ho; Han, Jeong Woo; Cho, In Ho

    2008-01-01

    In many welded structures, fatigue failures are often occurred at welded joints in which stress concentrations due to the joint geometry are relatively high. Although employing good detail design practices by upgrading the welded detail class enables to improve the fatigue performance, in many cases, the modification of the detail may not be practicable. As an alternative, fatigue life extension techniques, that reduce the severity of the stress concentration at the weld toe region, remove imperfections, and introduce local compressive welding residual stress, can be applied. These techniques are also used as remedial measures to extend the fatigue life of critical welds that have failed prematurely and have been repaired. This paper introduces peening techniques via a pneumatic hammer peening and ultrasonic impact which make it possible to give the weld not only a favorable shape reducing the local stress concentration, but also a beneficial compressive residual stress into material surface

  13. Interrelationships of food safety and plant pathology: the life cycle of human pathogens on plants.

    Science.gov (United States)

    Barak, Jeri D; Schroeder, Brenda K

    2012-01-01

    Bacterial food-borne pathogens use plants as vectors between animal hosts, all the while following the life cycle script of plant-associated bacteria. Similar to phytobacteria, Salmonella, pathogenic Escherichia coli, and cross-domain pathogens have a foothold in agricultural production areas. The commonality of environmental contamination translates to contact with plants. Because of the chronic absence of kill steps against human pathogens for fresh produce, arrival on plants leads to persistence and the risk of human illness. Significant research progress is revealing mechanisms used by human pathogens to colonize plants and important biological interactions between and among bacteria in planta. These findings articulate the difficulty of eliminating or reducing the pathogen from plants. The plant itself may be an untapped key to clean produce. This review highlights the life of human pathogens outside an animal host, focusing on the role of plants, and illustrates areas that are ripe for future investigation.

  14. Computational models for residual creep life prediction of power plant components

    International Nuclear Information System (INIS)

    Grewal, G.S.; Singh, A.K.; Ramamoortry, M.

    2006-01-01

    All high temperature - high pressure power plant components are prone to irreversible visco-plastic deformation by the phenomenon of creep. The steady state creep response as well as the total creep life of a material is related to the operational component temperature through, respectively, the exponential and inverse exponential relationships. Minor increases in the component temperature can thus have serious consequences as far as the creep life and dimensional stability of a plant component are concerned. In high temperature steam tubing in power plants, one mechanism by which a significant temperature rise can occur is by the growth of a thermally insulating oxide film on its steam side surface. In the present paper, an elegantly simple and computationally efficient technique is presented for predicting the residual creep life of steel components subjected to continual steam side oxide film growth. Similarly, fabrication of high temperature power plant components involves extensive use of welding as the fabrication process of choice. Naturally, issues related to the creep life of weldments have to be seriously addressed for safe and continual operation of the welded plant component. Unfortunately, a typical weldment in an engineering structure is a zone of complex microstructural gradation comprising of a number of distinct sub-zones with distinct meso-scale and micro-scale morphology of the phases and (even) chemistry and its creep life prediction presents considerable challenges. The present paper presents a stochastic algorithm, which can be' used for developing experimental creep-cavitation intensity versus residual life correlations for welded structures. Apart from estimates of the residual life in a mean field sense, the model can be used for predicting the reliability of the plant component in a rigorous probabilistic setting. (author)

  15. 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.

  16. Plant life management of the ACR-1000 Concrete containment structure

    International Nuclear Information System (INIS)

    Abrishami, H.H.; Ricciuti, R.; Elgohary, M.

    2009-01-01

    The Ageing of reinforced concrete structures due to service conditions, aggressive environments, or accidents may cause their strength, serviceability and durability to decrease over time. For a new plant, a Plant Life Management (PLiM) program should start in the design process and then continues through the plant operation and decommissioning. Hence, PLiM must provide not only Ageing Management program (AMP) but also provide requirements on material characteristic and design criteria as well. The purpose of this paper is to present the Plant Life Management (PLiM) strategy for the concrete containment structure of the ACR-10001 (Advanced CANDU Reactor) designed by AECL. The ACR-1000 is designed for a 100-year plant life including 60-year operating life and an additional 40-year decommissioning period. The approach adopted for the PLiM strategy of the concrete containment structure is a preventive one, key areas being: 1) design methodology, 2) material performance and 3) ageing management program. During the design phase, in addition to strength and serviceability, durability, throughout the service life and decommissioning phase of the ACR-1000 structure, is a major consideration. Factors affecting durability design include: a) concrete performance, b) structural application, and c) consideration of environmental conditions. In addition to addressing the design methodology and material performance requirements, a systematic approach for the ageing management program for the concrete containment structure is presented. (authors)

  17. Economics and policies of nuclear plant life management

    International Nuclear Information System (INIS)

    Yamagata, H.

    1998-01-01

    NEA provides an opportunity for international exchange of information on the economics and policies of nuclear plant life management for governments and plant owners. The NEA Secretariat is finalising the 'state-of-the-art report' on the economics and policies of nuclear plant life management, including the model approach and national summaries. In order to meet power supply obligations in the early 2000, taking into account energy security, environmental impact, and the economics of nuclear power plants whose lives have been extended, initiatives at national level must be taken to monitor, co-ordinate, and support the various industry programmes of nuclear plant life management by integrated and consistent policies, public acceptance, R and D, and international co-operation. Nuclear power owners should establish an organisation and objectives to carry nuclear plant life management in the most economic and smoothest way taking into consideration internal and external influences. The organisation must identify the critical item and the ageing processes, and optimise equipment reliability and maintenance workload. (author)

  18. 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

  19. 78 FR 36506 - Notice of Request for Extension of Approval of an Information Collection; Importation of Plants...

    Science.gov (United States)

    2013-06-18

    ... 2013. Kevin Shea, Acting Administrator, Animal and Plant Health Inspection Service. [FR Doc. 2013-14466... DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service [Docket No. APHIS-2013-0035] Notice of Request for Extension of Approval of an Information Collection; Importation of Plants for...

  20. Development of stress corrosion techniques for structural integrity evaluation and life extension of PWR facilities

    International Nuclear Information System (INIS)

    Moreira, Pedro A.L.D.L. Pinheiro; Vilela, Jeferson J.; Lorenzo, Roberto F. Di; Lopes, Jadir A.M.

    2000-01-01

    The stress corrosion is a mechanism of degradation present in the nuclear plants. To extend the life of the plants components, this corrosion type it should be known. An evaluation for the implantation of methodologies of stress corrosion study in CDTN/CNEN, shows that the technique of slow deformation can be used in the evaluation of integrity structural nuclear power stations. This technique consists of straining a sample slowly, usually, in strain rate between 10 -4 and 10- 8 s -1 and in conditions that simulate the reactivity of the metal in environment (pressure, temperature, chemical composition of the water and etc) similar to the found at the nuclear power power stations. This simulation allows evaluating susceptibility the stress corrosion of components mechanical and structure that operate in central nuclear. (author)

  1. Fenobody: A Ferritin-Displayed Nanobody with High Apparent Affinity and Half-Life Extension.

    Science.gov (United States)

    Fan, Kelong; Jiang, Bing; Guan, Zhe; He, Jiuyang; Yang, Dongling; Xie, Ni; Nie, Guohui; Xie, Can; Yan, Xiyun

    2018-04-10

    Nanobodies consist of a single domain variable fragment of a camelid heavy-chain antibody. Nanobodies have potential applications in biomedical fields because of their simple production procedures and low cost. Occasionally, nanobody clones of interest exhibit low affinities for their target antigens, which, together with their short half-life limit bioanalytical or therapeutic applications. Here, we developed a novel platform we named fenobody, in which a nanobody developed against H5N1 virus is displayed on the surface of ferritin in the form of a 24mer. We constructed a fenobody by substituting the fifth helix of ferritin with the nanobody. TEM analysis showed that nanobodies were displayed on the surface of ferritin in the form of 6 × 4 bundles, and that these clustered nanobodies are flexible for antigen binding in spatial structure. Comparing fenobodies with conventional nanobodies currently used revealed that the antigen binding apparent affinity of anti-H5N1 fenobody was dramatically increased (∼360-fold). Crucially, their half-life extension in a murine model was 10-fold longer than anti-H5N1 nanobody. In addition, we found that our fenobodies are highly expressed in Escherichia coli, and are both soluble and thermo-stable nanocages that self-assemble as 24-polymers. In conclusion, our results demonstrate that fenobodies have unique advantages over currently available systems for apparent affinity enhancement and half-life extension of nanobodies. Our fenobody system presents a suitable platform for various large-scale biotechnological processes and should greatly facilitate the application of nanobody technology in these areas.

  2. Thermal performance of different planting substrates and irrigation frequencies in extensive tropical rooftop greeneries

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Jiung [Department of Environmental Engineering and Science, Foo-Yin University, Kaohsiung (China); No. 16, Lane 29, Chen-Sing 7th Street, Niao-Song, Kaohsiung 833 (China); Lin, Hsien-Te [Department of Architecture, National Cheng Kung University, Tainan (China); No. 1, Ta-Hsueh Road, Tainan 701 (China)

    2011-02-15

    The need for the better use of scarce planetary resources has never been more evident than it is today. However, this need is poorly reflected in human housing. In recent years, there has been a growing realization of the importance of constructing human shelters that better conserve energy and water through appropriate insulation and architectural designs. Among the important advancements in these areas is the use of rooftop greeneries for both energy and water conservation. This paper performs an investigation into this topic within the specific climatic context of tropical regions. Long-term experimental results are provided from a four-floor building in Kaohsiung in the southern part of Taiwan. The study involves a fully monitored extensive rooftop greenery and examines four different plant substrates, three different irrigation regimes, and different types of drought-enduring plants to find the most efficient combination of all three in providing maximum heat insulation and water usage efficiency. The attenuation of solar radiation through the vegetation layer is evaluated, as well as the thermal insulation performance of the rooftop greenery structure. Among the substrates, burned sludge has the best thermal reduction percentage of heat amplitude under the roof slab surface (up to 84.4%). Irrigation twice a week has the best thermal reduction percentage of heat amplitude (91.6%). Among the plant types, Sansevieria trifasciata cv. Laurentii Compacta and Rhoeo spathaceo cv. Compacta are found to be suitable for extensive rooftop greeneries because they have the best coverage ratio and are most drought enduring. (author)

  3. Integrated plant life management (PLiM)-the IAEA contribution

    International Nuclear Information System (INIS)

    Kang, K.-S.; Clark, C.R.; Omoto, A.; )

    2005-01-01

    For the past couple of decades there has been a change of emphasis in the world nuclear power from that of building new Nuclear Power Plants (NPP) to that of taking measures to optimize the life cycle of operational plants. National approaches in many countries showed an increase of interest in Plant Life Management (PLiM), both in terms of plant service life assurance and in optimizing the service or operational life of NPP. A strong convergence of views is emerging from different National approaches, particularly in the area of the economic aspects of NPP operation and in the evolution in the scope of NPP PLIM. The latter can directly affect the cost of electricity from NPP in an increasingly competitive environment. The safety considerations of a NPP are paramount and those requirements have to be met to obtain and to extend/renew the operating license. To achieve the goal of the long term safe, economic and reliable operation of the plant an integrated Plant Life Management Programme (PLiM) is necessary. Some countries already have advanced PLiM Programmes while others still have none. The PLiM objective is to identify all that factors and requirements for the overall plant life cycle. The optimization of these requirements would allow for the minimum period of the investment return and maximum of the revenue from the sell of the produced electricity. Recognizing the importance of this issue and in response to the requests of the Member States the IAEA Division of Nuclear Power implements the Sub-programme on 'Engineering and Management Support for Competitive Nuclear Power'. Four projects within this sub-programme deal with different aspects of the NPP life cycle management with the aim to increase the capabilities of interested Member States in implementing and maintenance of the competitive and sustainable nuclear power. Although all four projects contain certain issues of PLiM there is one specific project on guidance on engineering and management practices

  4. Mold spoilage of bread and its biopreservation: A review of current strategies for bread shelf life extension.

    Science.gov (United States)

    Axel, Claudia; Zannini, Emanuele; Arendt, Elke K

    2017-11-02

    Microbial spoilage of bread and the consequent waste problem causes large economic losses for both the bakery industry and the consumer. Furthermore the presence of mycotoxins due to fungal contamination in cereals and cereal products remains a significant issue. The use of conventional chemical preservatives has several drawbacks, necessitating the development of clean-label alternatives. In this review, we describe current research aiming to extend the shelf life of bread through the use of more consumer friendly and ecologically sustainable preservation techniques as alternatives to chemical additives. Studies on the in situ-production/-expression of antifungal compounds are presented, with special attention given to recent developments over the past decade. Sourdough fermented with antifungal strains of lactic acid bacteria (LAB) is an area of increasing focus and serves as a high-potential biological ingredient to produce gluten-containing and gluten-free breads with improved nutritional value, quality and safety due to shelf-life extension, and is in-line with consumer's demands for more products containing less additives. Other alternative biopreservation techniques include the utilization of antifungal peptides, ethanol and plant extracts. These can be added to bread formulations or incorporated in antimicrobial films for active packaging (AP) of bread. This review outlines recent progress that has been made in the area of bread biopreservation and future perspectives in this important area.

  5. Bio-fortification and shelf-life extension of idli batter using curry leaves (Murraya koenigii).

    Science.gov (United States)

    Chelliah, R; Ramakrishnan, S R; Premkumar, D; Antony, U

    2016-06-01

    Among several traditional foods of India, idli is one of the most popular and commonly consumed steamed products. A new method of adding Murraya koenigii (curry leaves) to idli batter as a vehicle for fortification and extension of shelf-life has been developed. Dried curry leaves powder was incorporated with other ingredients like rice and dehusked black gram in different proportions to optimize the most palatable formulation. Rate of fermentation and microbial changes in the batter; nutritional qualities, texture and sensory properties of the prepared product were assessed. Incorporation of curry leaves powder (5 %) in idli batter increased the shelf-life and also increased the flavour, texture and appearance of the idli. The calcium content of the prepared idli was 10 times more than that of the control idli, while dietary fiber content increased by 18.6 %. Anti-microbial activity of the curry leaves in idli batter extended the shelf-life from 2 to 5 days when stored at 30 °C.

  6. "Pull and push back" concepts of longevity and life span extension.

    Science.gov (United States)

    Muradian, Khachik

    2013-12-01

    The negative relation between metabolism and life span is a fundamental gerontological discovery well documented in a variety of ontogenetic and phylogenetic models. But how the long-lived species and populations sustain lower metabolic rate and, in more general terms, what is the efficient way to decline the metabolism? The suggested 'pull and push back' hypothesis assumes that decreased Po2 (hypoxia) and/or increased [Formula: see text] (hypercapnia) may create preconditions for the declined metabolic and aging rates. However, wider implementation of such ideas is compromised because of little advances in modification of the metabolic rate. Artificial atmosphere with controlled [Formula: see text] and [Formula: see text] could be a promising approach because of the minimal external invasions and involvement of the backward and forward loops ensuring physiological self-regulation of the metabolic perturbations. General considerations and existing data indicate that manipulations of [Formula: see text] may be more efficient in life span extension than [Formula: see text]. Thus, maximum life span of mammals positively correlates with the blood [Formula: see text] and HCO3 (-) but not with [Formula: see text]. Yet, proportional decease of the body [Formula: see text] and increase of [Formula: see text] seems the most optimal regime ensuring lower losses of the energy equivalents. Furthermore, especially rewarding results could be expected when such changes are modeled without major external invasions using the animals' inner capacity to consume O2 and generate CO2, as it is typical for the extreme longevity.

  7. Influence of the non-singular stress on the crack extension and fatigue life

    International Nuclear Information System (INIS)

    Cheng, C.Z.; Recho, N.; Niu, Z.R.

    2012-01-01

    Highlights: ► BEM is combined by characteristic analysis to calculate the singular stress field. ► A new method is proposed to evaluate the full stress field at crack tip region. ► Effect of non-singular stress on the propagation direction of the fatigue crack is analyzed. ► The influence of non-singular stress on the fatigue crack life is evaluated. - Abstract: The complete elasticity stress field at a crack tip region can be presented by the sum of the singular stress and several non-singular stress terms according to the Williams asymptotic expansion theory. The non-singular stress has a non-negligible influence on the prediction of the crack extension direction and crack growth rate under the fatigue loading. A novel method combining the boundary element method and the singularity characteristic analysis is proposed here to evaluate the complete stress field at a crack tip region. In this new method, any non-singular stress term in the Williams series expansion can be evaluated according to the computational accuracy requirement. Then, a modified Paris law is introduced to predict the crack propagation under the mixed-mode loading for exploring the influence of the non-singular stress on the fatigue life duration. By comparing with the existed experimental results, the predicted crack fatigue life when the non-singular stress is taken into consideration is more accurate than the predicted ones only considering the singular stress.

  8. Nuclear plant life cycle management implementation guide. Final report

    International Nuclear Information System (INIS)

    Sliter, G.E.; Negin, C.A.

    1998-11-01

    Nuclear power plants, as baseload suppliers of electricity, are major corporate assets. As the nuclear industry enters its fourth decade as a major producer of clean electricity, the structure of the utility industry is undergoing a historical landmark transition from economic deregulation to a competitive, market-driven industry. An integral part of competition is to manage the operation of the key asset, the plant, in the long term, thereby enhancing its long-term profitability. Life cycle management (LCM) is a well-known technical-economic decision-making process for any large industrial facility. LCM optimizes the service life of a facility and maximizes its life-cycle asset value. LCM integrates aging management (maintaining the availability of costly-to-replace components and structures) with asset management (plant valuation and investment strategies that account for economic, performance, regulatory, and environmental uncertainties). LCM involves predicting maintenance, repair, and other capital costs for a nuclear unit far into the future, as well as planning and managing strategic issues such as waste disposal, fuel storage, decommissioning, and public acceptance. This Life Cycle Management Implementation Guide introduces the reader to the LCM concept and its benefits, describes the elements and activities associated with an LCM program (most of which already exist in all plants), gives an overview of asset and aging management, and provides key references related to life cycle management for nuclear power plants. It also summarizes the major elements of life cycle management required for license renewal or, for newer plants, keeping open the option of license renewal

  9. South African Regulatory Framework for Nuclear Power Plant Life Management

    International Nuclear Information System (INIS)

    Mbebe, B.Z.

    2012-01-01

    The paper presents the regulatory approach to plant life management (PLiM) adopted by the National Nuclear Regulator (NNR) in South Africa, the licensing basis and regulatory requirements for Koeberg Nuclear Power Station (KNPS),operational programmes ensuring continued safe operation, issues related to the ageing of the plant, and the requirements for spent fuel as well as radioactive waste management. The paper will further present insights from the Periodic Safety Review (PSR) and Long Term Asset Management. (author)

  10. [The evolution of plant life span: facts and hypotheses].

    Science.gov (United States)

    2006-01-01

    There are two different views on the evolution of life forms in Cormophyta: from woody plants to herbaceous ones or in opposite direction - from herbs to trees. In accordance with these views it is supposed that life span in plants changed in the course of evolution from many years (perennials) to few years (annuals, biennials), or went in reverse - from few years to many years. The author discusses the problems of senescence and longevity in Cormophyta in the context of various hypotheses of ageing (programmed death theory, mutation accumulation, antagonistic pleiotropy, disposable soma, genes of ageing, genes of longevity). Special attention is given to bio-morphological aspects of longevity and cases of non-ageing plants ("negative senescence", "potential immortality"). It is proposed to distinguish seven models of simple ontogenesis in Cormophyta that can exemplify the diversity of mechanisms of ageing and longevity. The evolution of life span in plants is considered as an indirect result of natural selection of other characteristics of organisms or as a consequence of fixation of modifications (episelectional evolution). It seems that short life span could emerge several times during evolution of one group of plants, thus favoring its adaptive radiation.

  11. Service Life Extension of the Propulsion System of Long-Term Manned Orbital Stations

    Science.gov (United States)

    Kamath, Ulhas; Kuznetsov, Sergei; Spencer, Victor

    2014-01-01

    . There are no representative ground test articles for some of the components. A 'test everything' approach would require manufacturing new test articles. The paper outlines some of the techniques used for selective testing, by way of cherry picking candidate components based on failure mode effects analysis, system level impacts, hazard analysis, etc. The type of testing required for extending the service life depends on the design and criticality of the component, failure modes and failure mechanisms, life cycle margin provided by the original certification, operational and environmental stresses encountered, etc. When specific failure mechanism being considered and the underlying relationship of that mode to the stresses provided in the test can be correlated by supporting analysis, time and effort required for conducting life extension testing can be significantly reduced. Exposure to corrosive propellants over long periods of time, for instance, lead to specific failure mechanisms in several components used in the propulsion system. Using Arrhenius model, which is tied to chemically dependent failure mechanisms such as corrosion or chemical reactions, it is possible to subject carefully selected test articles to accelerated life test. Arrhenius model reflects the proportional relationship between time to failure of a component and the exponential of the inverse of absolute temperature acting on the component. The acceleration factor is used to perform tests at higher stresses that allow direct correlation between the times to failure at a high test temperature to the temperatures to be expected in actual use. As long as the temperatures are such that new failure mechanisms are not introduced, this becomes a very useful method for testing to failure a relatively small sample of items for a much shorter amount of time. In this article, based on the example of the propulsion system of the first ISS module Zarya, theoretical approaches and practical activities of

  12. A novel life cycle arising from leaf segments in plants regenerated from horseradish hairy roots.

    Science.gov (United States)

    Mano, Y; Matsuhashi, M

    1995-03-01

    Horseradish (Armoracia rusticana) hairy root clones were established from hairy roots which were transformed with the Ri plasmid in Agrobacterium rhizogenes 15834. The transformed plants, which were regenerated from hairy root clones, had thicker roots with extensive lateral branches and thicker stems, and grew faster compared with non-transformed horseradish plants. Small sections of leaves of the transformed plants generated adventitious roots in phytohormone-free G (modified Gamborg's) medium. Root proliferation was followed by adventitious shoot formation and plant regeneration. Approximately twenty plants were regenerated per square centimeter of leaf. The transformed plants were easily transferable from sterile conditions to soil. When leaf segments of the transformed plants were cultured in a liquid fertilizer under non-sterile conditions, adventitious roots were generated at the cut ends of the leaves. Adventitious shoots were generated at the boundary between the leaf and the adventitious roots and developed into complete plants. This novel life cycle arising from leaf segments is a unique property of the transformed plants derived from hairy root clones.

  13. Probability of fracture and life extension estimate of the high-flux isotope reactor vessel

    International Nuclear Information System (INIS)

    Chang, S.J.

    1998-01-01

    The state of the vessel steel embrittlement as a result of neutron irradiation can be measured by its increase in ductile-brittle transition temperature (DBTT) for fracture, often denoted by RT NDT for carbon steel. This transition temperature can be calibrated by the drop-weight test and, sometimes, by the Charpy impact test. The life extension for the high-flux isotope reactor (HFIR) vessel is calculated by using the method of fracture mechanics that is incorporated with the effect of the DBTT change. The failure probability of the HFIR vessel is limited as the life of the vessel by the reactor core melt probability of 10 -4 . The operating safety of the reactor is ensured by periodic hydrostatic pressure test (hydrotest). The hydrotest is performed in order to determine a safe vessel static pressure. The fracture probability as a result of the hydrostatic pressure test is calculated and is used to determine the life of the vessel. Failure to perform hydrotest imposes the limit on the life of the vessel. The conventional method of fracture probability calculations such as that used by the NRC-sponsored PRAISE CODE and the FAVOR CODE developed in this Laboratory are based on the Monte Carlo simulation. Heavy computations are required. An alternative method of fracture probability calculation by direct probability integration is developed in this paper. The present approach offers simple and expedient ways to obtain numerical results without losing any generality. In this paper, numerical results on (1) the probability of vessel fracture, (2) the hydrotest time interval, and (3) the hydrotest pressure as a result of the DBTT increase are obtained

  14. Teaching Couple Relationship Education: The Influence on Regional Extension Agents and Family Life Educators

    Directory of Open Access Journals (Sweden)

    Julianne McGill

    2017-10-01

    Full Text Available Couple Relationship Education (CRE programs are a prevention resource used to assist adult individuals, couples, and families reduce relationship distress and improve prosocial behaviors. Regional Extension agents (REAs and other community family life educators (FLEs who teach CRE are involved in a facilitation process that develops relationships and rapport with their participants similar to other helping relationships. To date, no published research has focused on how CRE may affect the REAs/FLEs who provide the programs through community adult education programs. Informed by relational-cultural theory and the ecological systems perspective, the current study focused on assessing change in ten outcomes measuring REAs/FLEs’ (N = 54 individual, couple, and co-parenting functioning and whether that change differed by gender. Results from repeated measure ANCOVAs indicate REAs/FLEs experience gains across several domains of functioning. There were no differences by gender. Implications for REAs/FLEs and suggestions for future research are described.

  15. Data package addendum for COBRA-1A2 life extension to 400 EFPD

    International Nuclear Information System (INIS)

    Hecht, S.L.; Ermi, A.M.

    1994-01-01

    The COBRA-1A experiment was originally designed for irradiations up to 350 effective full power days (EFPD) in EBR-II. Three of the seven B7A test capsules were discharged after 88.6 EFPD (COBRA-1A1; EBR-II designation X516), while the remaining four capsules continued to be irradiated to a goal exposure of 300 EFPD (COBRA-1A2; EBR-II designation X516A). However, it was recently decided that COBRA-1A2 was to remain in the reactor during Run 170, giving and nominal end-of-life (EOL) exposure of 375 EFPD. Since the revised test exposure exceeds the design basis given in supporting analyses, amended analyses are provided herein, giving the technical bases for the extended irradiation. This report describes the safety analysis for the extension of the COBRA-1A2 test (X516A) to 400 effective full power days in FBR-II

  16. 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

  17. Reactor Dosimetry Aspects of the Service Life Extension of the Hungarian Paks NPP

    Directory of Open Access Journals (Sweden)

    Zsolnay Eva M.

    2016-01-01

    Full Text Available The service life of the Hungarian Paks Nuclear Power Plant (NPP will be extended from the originally planned 30 years to 50 years. To improve the reliability of the results obtained in frame of the old reactor pressure vessel (RPV surveillance programme, new methods have been developed, and based on them, the old exposition data have been re-evaluated for all the four reactor units. At the same time, a new RPV surveillance programme has been developed and introduced, and long term irradiations have been performed to determine the radiation damage of the surveillance specimens due to the high fast neutron exposition. Neutron transport calculations have been performed with a validated neutron transport code system to determine the fast neutron exposition of the RPVs during the extended service life. The cavity dosimetry is in the introductory phase. This paper presents the new developments in the field of the RPV surveillance dosimetry and summarises the results obtained. According to the results the service life of the NPP can safely be extended for the planned 50 years.

  18. Environmentally Clean Mitigation of Undesirable Plant Life Using Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Rubenchik, A M; McGrann, T J; Yamamoto, R M; Parker, J M

    2009-07-01

    This concept comprises a method for environmentally clean destruction of undesirable plant life using visible or infrared radiation. We believe that during the blossom stage, plant life is very sensitive to electromagnetic radiation, with an enhanced sensitivity to specific spectral ranges. Small doses of irradiation can arrest further plant growth, cause flower destruction or promote plant death. Surrounding plants, which are not in the blossoming stage, should not be affected. Our proposed mechanism to initiate this effect is radiation produced by a laser. Tender parts of the blossom possess enhanced absorptivity in some spectral ranges. This absorption can increase the local tissue temperature by several degrees, which is sufficient to induce bio-tissue damage. In some instances, the radiation may actually stimulate plant growth, as an alternative for use in increased crop production. This would be dependent on factors such as plant type, the wavelength of the laser radiation being used and the amount of the radiation dose. Practical, economically viable realization of this concept is possible today with the advent of high efficiency, compact and powerful laser diodes. The laser diodes provide an efficient, environmentally clean source of radiation at a variety of power levels and radiation wavelengths. Figure 1 shows the overall concept, with the laser diodes mounted on a movable platform, traversing and directing the laser radiation over a field of opium poppies.

  19. Nuclear power plant life management: flow accelerated corrosion and chemical control. Application to Embalse Nuclear power plant

    International Nuclear Information System (INIS)

    Chocron, Mauricio; Saucedo, Ramona E.; Sainz, Ricardo A.; Ovando, Luis E.

    2006-01-01

    The chemistry of a water-steam cycle is one of the main aspects of the Plant Life Management of a Nuclear Power Plant and it is important for the preservation, efficiency and availability of the whole system. In that sense this aspect has to be prioritized in any study whose aim is the life extension of the plant. In particular, the flow-assisted -corrosion or FAC is a problem that worldwide has been considered important due to the piping wall thinning that in some occasions has led to severe accidents. The FAC phenomena is not easy to be interpreted and addressed although nowadays there are some accepted models to understand and predict sensitive areas of the cycle. The objectives of the present paper have been: a) The construction of an integrated code that involves all the aspects that have influence on FAC, i.e., materials, composition, geometry, temperature and flow rate, quality, chemistry, etc.; b) Establish or adapting current models to the circuit of Embalse PHWR NPP; c) Identify new locations for inspection and wall thickness measurement in order to predict residual life; d) Compare different chemistries and e) handle large sets of inspection data. Among the results, new lines have been incorporated to the inspection schedule of the 2005' programmed outage. Also, the evaluation is part of the PLIM-PLEX programme at Embalse-N.A.S.A. in collaboration with C.N.E.A. is being carried out. (author)

  20. METHODS AND RESEARCH CONCERNING SERVICE LIFE EXTENSION OF SUPORTING STRUCTURES OF TRACTION ROLLING STOCK FOR INDUSTRIAL TRANSPORT

    Directory of Open Access Journals (Sweden)

    O. M. Bondarev

    2014-04-01

    Full Text Available Purpose. The purpose of work is scientifically grounded introduction of the acquired techniques into works for service life extension of the traction and motor rolling stock for industrial transport. Methodology. To achieve the purpose it was analyzed the acquired techniques for service life extension of the traction and motor rolling stock for mainline transport. The acquired techniques during solution of problems concerning the service life extension of rolling stock units were adapted to the locomotives TGM6A and traction aggregates OPE1. Findings. On the basis of experimental and theoretical complex of studies some results were obtained. They gave the ground to determine the possibility of acquired techniques use when solving the problems on service life extension of rolling stock units concerning locomotives TGM6A and traction aggregates OPE1. Originality. On the basis of conducted experimental and theoretical studies scientific maintenance of the works providing extension of service life of traction and motor units of industrial rolling stock was executed. Practical value. Technical solutions and measures, which have to be carried out during operation within the prolonged appointed service life of traction and motor units of industrial rolling stock enterprises using locomotives and traction aggregates to provide the basic technological cycles were developed.

  1. The Effects of Different Aspects of Tourism Services on Travelers' Quality of Life: Model Validation, Refinement, and Extension

    OpenAIRE

    Neal, Janet Davis

    2000-01-01

    The Effects of Different Aspects of Tourism Services on Travelers' Quality of Life: Model Validation, Refinement, and Extension by Janet Davis Neal ABSTRACT Numerous satisfaction studies have been conducted in both tourism and marketing which have examined various aspects of travelers and/or consumers. Quality of life satisfaction studies look beyond the types of satisfaction experiences that endure for only a short time to those that "spill over" into individuals' life domains ...

  2. Plant life management and modernisation: Research challenges in the EU

    International Nuclear Information System (INIS)

    Rintamaa, R.; Aho-Mantila, I.

    2010-01-01

    The NULIFE (Nuclear plant life prediction) European network of excellence is described in detail. The following topics are highlighted: Vision; Consortium; Organization and working methods; Research and development planning; Research project portfolio (pilot projects, umbrella projects); Strategic research planning; and Conclusions. (P.A.)

  3. 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.

  4. Declaration of the rights of animal and plant life

    NARCIS (Netherlands)

    Jacobs, M.

    1977-01-01

    i Each living creature on earth has the right to exist, independent of its usefulness to humans. ii Every effort should be made to preserve all species of animal and plant life from premature extinction. Special protection should be afforded to those species whose survival is already threatened.

  5. Shelf life extension of minimally processed ready-to-cook (RTC) cabbage by gamma irradiation

    International Nuclear Information System (INIS)

    Banerjee, Aparajita; Chatterjee, Suchandra; Variyar, Prasad S.; Sharma, Arun

    2016-01-01

    Gamma irradiation (0.5-2.5 kGy) in combination with low temperature (4-15 °C) storage was attempted to increase shelf life of ready-to-cook shredded cabbage wrapped in cling films. A maximum extension in shelf life of 8 days, while retaining the microbial and sensory quality, was obtained with an irradiation dose of 2 kGy and storage at 10 °C. Gamma irradiation also inhibited browning of shredded cabbage at their cut edges resulting in enhanced visual appeal. An increase in total antioxidant activity was observed with respect to DPPH and hydroxyl radical scavenging ability while the nitric oxide radical scavenging activity and ferric reducing property remained unaffected with irradiation. Total phenolic, flavonoid and vitamin C content remained unchanged due to irradiation. No significant migration of additives from cling films into stimulant water was observed up to a radiation dose of 2 kGy thus demonstrating the feasibility of such films for above applications. (author)

  6. Shelf life extension of minimally processed ready-to-cook (RTC) cabbage by gamma irradiation.

    Science.gov (United States)

    Banerjee, Aparajita; Chatterjee, Suchandra; Variyar, Prasad S; Sharma, Arun

    2016-01-01

    Gamma irradiation (0.5-2.5 kGy) in combination with low temperature (4-15 °C) storage was attempted to increase shelf life of ready-to-cook shredded cabbage wrapped in cling films. A maximum extension in shelf life of 8 days, while retaining the microbial and sensory quality, was obtained with an irradiation dose of 2 kGy and storage at 10 °C. Gamma irradiation also inhibited browning of shredded cabbage at their cut edges resulting in enhanced visual appeal. An increase in total antioxidant activity was observed with respect to DPPH and hydroxyl radical scavenging ability while the nitric oxide radical scavenging activity and ferric reducing property remained unaffected with irradiation. Total phenolic, flavonoid and vitamin C content remained unchanged due to irradiation. No significant migration of additives from cling films into stimulant water was observed up to a radiation dose of 2 kGy thus demonstrating the feasibility of such films for above applications.

  7. Study on shelf life extension of papayas irradiated by /sup 60/Co gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Chang, M.S.; Chen, M.D.; Lin, C.T.; Fu, Y.K.

    1984-11-01

    Papayas are one of the main fresh fruits in Taiwan area. Papaya fruits were treated with hot water to pasteurize peels followed by /sup 60/Co gamma-ray irradiation to extend the ripening time. The purpose of synergetic methods is to extend the shelf life of papaya fruits. This experiment was carried out by seven treatments, which were: (1) control group, (2) hot water treatment only, (3) hot water treatment with a 25 krad ..gamma..-irradiation, (4) hot water treatment with a 50 krad ..gamma..-irradiation, (5) hot water treatment with a 75 krad ..gamma..-irradiation, (6) 75 krad ..gamma..-irradiation only, and (7) hot water treatment with a 100 krad ..gamma..-irradiation. The items of observation were: surface yellowing, surface decaying, quality of texture, and length of period lasted after irradiation for 50% marketable papayas. The results of this study showed that a shelf-life extension of six days could be obtained for papayas subjected to hot water (50 to 55/sup 0/C) treatment and a 100 krad irradiation. 3 refs., 2 figs., 2 tabs.

  8. Shelf life extension of whole Norway lobster Nephrops norvegicus using modified atmosphere packaging.

    Science.gov (United States)

    Gornik, Sebastian G; Albalat, Amaya; Theethakaew, Chonchanok; Neil, Douglas M

    2013-11-01

    Once a nuisance by-catch, today the Norway lobster (Nephrops norvegicus) is a valuable UK fisheries commodity. Unfortunately, the species is very susceptible to quality deterioration post harvest as it quickly develops black spots and also spoils rapidly due to bacterial growth. Treatment with chemicals can stop the blackening and carefully monitored cold storage can result in a sensory shelf life of up to 6.5 days. The high susceptibility to spoilage greatly restricts the extent to which N. norvegicus can be distributed to retailers and displayed for sale. The application of modified atmosphere (MA) could be extremely beneficial, allowing the chilled product to stay fresh for a long period of time, thus ensuring higher sales. In the present study, we identified a gas mix for the MA packaging (MAP) of whole N. norvegicus lobster into 200 g retail packs. Our results show that a shelf life extension to 13 days can be achieved when retail packs are stored in MAP at 1 °C. Effectiveness of the MAP was evaluated by using a newly developed QIM for MA-packaged whole N. norvegicus and also by analyzing bacterial plate counts. Changes in the microflora and effects of different storage temperatures on the quality of the MA packs are also presented. The main specific spoilage organism (SSO) of modified atmosphere packaged Norway lobster is Photobacterium phosphoreum. © 2013.

  9. An extensive alien plant inventory from the inhabited areas of galapagos.

    Directory of Open Access Journals (Sweden)

    Anne Guézou

    Full Text Available BACKGROUND: Plant invasions are causing habitat degradation in Galapagos. Problems are concentrated on the four inhabited islands. Plants introduced to rural areas in the humid highlands and urban areas on the arid coast act as foci for invasion of the surrounding Galapagos National Park. METHODOLOGY/PRINCIPAL FINDINGS: Here we present results of the most comprehensive inventory to date of alien vascular plants in the inhabited areas of Galapagos. The survey was conducted between 2002 and 2007, in 6031 properties (97% of the total on Floreana, Isabela, San Cristobal and Santa Cruz Islands. In total 754 alien vascular plant taxa were recorded, representing 468 genera in 123 families. Dicotyledons represented 554 taxa, monocotyledons 183, there were 7 gymnosperms and 10 pteridophytes. Almost half (363 of the taxa were herbaceous. The most represented families were Fabaceae (sensu lato, Asteraceae and Poaceae. The three most recorded species in the humid rural areas were Psidium guajava, Passiflora edulis and Bryophyllum pinnatum, and in the dry urban areas, Aloe vera, Portulaca oleracea and Carica papaya. In total, 264 (35% taxa were recorded as naturalized. The most common use for taxa was ornamental (52%. CONCLUSIONS/SIGNIFICANCE: This extensive survey has increased the known alien vascular flora of Galapagos by 257 species, giving a ratio of alien to native taxa of 1.57:1. It provides a crucial baseline for plant invasion management in the archipelago and contributes data for meta analyses of invasion processes worldwide. A repeat of the survey in the future would act as an effective early detection tool to help avoid further invasion of the Galapagos National Park.

  10. Development of life evaluation technology for nuclear power plant components

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Jin; Kim, Yun Jae; Choi, Jae Boong [Sungkyunkwan Univ., Seoul (Korea, Republic of)] (and others)

    2002-03-15

    This project focuses on developing reliable life evaluation technology for nuclear power plant components, and is divided into two parts, development of a life evaluation system for nuclear pressure vessels and evaluation of applicability of emerging technology to operating plants. For the development of life evaluation system for nuclear pressure vessels, the following seven topics are covered in this project: defect assessment method for steam generator tubes, development of fatigue monitoring system, assessment of corroded pipes, domestic round robin analysis for constructing P-T limit curve for RPV, development of probabilistic integrity assessment technique, effect of aging on strength of dissimilar welds, applicability of LBB to cast stainless steel, and development of probabilistic piping fracture mechanics.

  11. Extensive clonal spread and extreme longevity in saw palmetto, a foundation clonal plant.

    Science.gov (United States)

    Takahashi, Mizuki K; Horner, Liana M; Kubota, Toshiro; Keller, Nathan A; Abrahamson, Warren G

    2011-09-01

    The lack of effective tools has hampered out ability to assess the size, growth and ages of clonal plants. With Serenoa repens (saw palmetto) as a model, we introduce a novel analytical framework that integrates DNA fingerprinting and mathematical modelling to simulate growth and estimate ages of clonal plants. We also demonstrate the application of such life-history information of clonal plants to provide insight into management plans. Serenoa is an ecologically important foundation species in many Southeastern United States ecosystems; yet, many land managers consider Serenoa a troublesome invasive plant. Accordingly, management plans have been developed to reduce or eliminate Serenoa with little understanding of its life history. Using Amplified Fragment Length Polymorphisms, we genotyped 263 Serenoa and 134 Sabal etonia (a sympatric non-clonal palmetto) samples collected from a 20 × 20 m study plot in Florida scrub. Sabal samples were used to assign small field-unidentifiable palmettos to Serenoa or Sabal and also as a negative control for clone detection. We then mathematically modelled clonal networks to estimate genet ages. Our results suggest that Serenoa predominantly propagate via vegetative sprouts and 10,000-year-old genets may be common, while showing no evidence of clone formation by Sabal. The results of this and our previous studies suggest that: (i) Serenoa has been part of scrub associations for thousands of years, (ii) Serenoa invasion are unlikely and (ii) once Serenoa is eliminated from local communities, its restoration will be difficult. Reevaluation of the current management tools and plans is an urgent task. © 2011 Blackwell Publishing Ltd.

  12. Plant Life Management of the EC6 Concrete Containment Structure

    Energy Technology Data Exchange (ETDEWEB)

    Abrishami, Homayoun; Ricciuti, Rick; Khan, Azhar [CANDU Energy Inc., Mississauga (Canada)

    2012-03-15

    Aging of reinforced concrete structures due to service conditions, aggressive environments, or accidents may cause their strength, serviceability and durability to decrease over time. Due to the complex nature of safety-related structures in nuclear power plants in comparison to other structures, they possess a number of characteristics that make them comparison to other structures, they possess a number of characteristics that make them unique. These characteristics are: thick concrete cross-sections, heavy reinforcement, often one-side access only, subjected to such ageing stresses as irradiation and elevated temperature, in addition to other typical ageing mechanisms (i. e., exposure to freeze/thaw cycles, aggressive chemicals, etc.) that typically affects other types of non-nuclear structures. For a new plant, the Plant Life Management Program (PLiM) should start in the design process and then continues through construction, plant operation and decommissioning. Hence PLiM must provide not only Ageing Management program (AMP) but also provide requirements on material characteristic and the design criteria as well. The purpose of this paper is to present the Plant Life Management (PLiM) strategy for the concrete containment structure of EC6 (Enhanced CANDU 6) Nuclear Power Plant designed by CANDU Energy Inc. The EC6 is designed for 100-year plant life including a 60-year operating life and an additional 40-year decommissioning period of time. The approach adopted for the PLiM strategy of the concrete containment structure is a preventive one, key areas being: 1) design methodology, 2) material performance and 3) life cycle management and ageing management program. In addition to strength and serviceability, durability is a major consideration during the design phase, service life and up to the completion of decommissioning. Factors affecting durability design include: a) concrete performance, b) structural application, and c) consideration of environmental

  13. Plant Life Management of the EC6 Concrete Containment Structure

    International Nuclear Information System (INIS)

    Abrishami, Homayoun; Ricciuti, Rick; Khan, Azhar

    2012-01-01

    Aging of reinforced concrete structures due to service conditions, aggressive environments, or accidents may cause their strength, serviceability and durability to decrease over time. Due to the complex nature of safety-related structures in nuclear power plants in comparison to other structures, they possess a number of characteristics that make them comparison to other structures, they possess a number of characteristics that make them unique. These characteristics are: thick concrete cross-sections, heavy reinforcement, often one-side access only, subjected to such ageing stresses as irradiation and elevated temperature, in addition to other typical ageing mechanisms (i. e., exposure to freeze/thaw cycles, aggressive chemicals, etc.) that typically affects other types of non-nuclear structures. For a new plant, the Plant Life Management Program (PLiM) should start in the design process and then continues through construction, plant operation and decommissioning. Hence PLiM must provide not only Ageing Management program (AMP) but also provide requirements on material characteristic and the design criteria as well. The purpose of this paper is to present the Plant Life Management (PLiM) strategy for the concrete containment structure of EC6 (Enhanced CANDU 6) Nuclear Power Plant designed by CANDU Energy Inc. The EC6 is designed for 100-year plant life including a 60-year operating life and an additional 40-year decommissioning period of time. The approach adopted for the PLiM strategy of the concrete containment structure is a preventive one, key areas being: 1) design methodology, 2) material performance and 3) life cycle management and ageing management program. In addition to strength and serviceability, durability is a major consideration during the design phase, service life and up to the completion of decommissioning. Factors affecting durability design include: a) concrete performance, b) structural application, and c) consideration of environmental

  14. Engineering support for plant life management: the IAEA contribution

    International Nuclear Information System (INIS)

    Kang, K.; Hezoucky, F.; Clark, R. C.; )

    2007-01-01

    For the past couple of decades there has been a change of emphasis in the world nuclear power from that of building new Nuclear Power Plants (NPP) to that of taking measures to optimize the life cycle of operational plants. National approaches in many countries showed an increase of interest in Plant Life Management (PLiM), both in terms of plant service life assurance and in optimizing the service or operational life of NPP. The safety considerations of a NPP are paramount and those requirements have to be met to obtain and to extend/renew the operating license. To achieve the goal of the long term safe, economic and reliable operation of the plant, PLiM programme is essential. Some countries already have advanced PLiM programmes while others still have none. The PLiM objective is to identify all that factors and requirements for the overall plant life cycle. The optimization of these requirements would allow for the minimum period of the investment return and maximum of the revenue from the sell of the produced electricity. Recognizing the importance of this issue and in response to the requests of the Member States the IAEA Division of Nuclear Power implements the Sub-programme on 'Engineering and Management Support for Competitive Nuclear Power'. Three projects within this sub-programme deal with different aspects of the NPP life cycle management with the aim to increase the capabilities of interested Member States in implementing and maintenance of the competitive and sustainable nuclear power. Although all three projects contain certain issues of PLiM, there is one specific project on guidance on engineering and management practices for optimization of NPP service life. This particular project deals with different specific issues of PLiM including aspects of ageing phenomena and their monitoring, issues of control and instrumentation, maintenance and operation issues, economic evaluation of PLiM including guidance on its earlier shut down and decommissioning

  15. Life extension of MAPS-2 by replacement of boiler hairpin type heat exchangers

    International Nuclear Information System (INIS)

    Tripathi, J.C.; Rastogi, S.K.; Rastogi, A.K.

    2006-01-01

    The steam generating equipment in MAPS-1 and 2 are Hairpin type comprises of eight boiler assemblies arranged in two banks of four boilers each. Each hairpin type heat exchangers consist of 195 Monel-400 tubes of 12.7 mm OD x 1.24 mm WT. One boiler assembly consists of eleven inverted U type heat exchangers (called hairpin type heat exchangers) mounted in parallel on inlet and outlet heavy water manifolds and connected to steam drum through individual short riser. Heavy water flows through these tubes where as feed water enters the shell at the bottom of one leg called pre-heat leg. After commissioning of MAPS-2 in 1985, five hairpins of MAPS-2 developed leak during the course of operation by the year 1999. Absence of physical access for health assessment of steam generator tube and lack of provision for tube sheet cleaning to remove the deposits on feed water side had caused pile and resulted in tube failures by under deposit pitting corrosion. All the 88 hairpins of MAPS-2 were replaced to extend the plant life when MAPS-2 was taken out of grid for En-masse Coolant Channel Replacement job (EMCCR) in the year 2001 - 03. The long shutdown of MAPS units for EMCCR was considered to be cost effective since unscheduled plant shut downs on account of tube leaks could be avoided. (author)

  16. 27 CFR 19.206 - Curtailment and extension of plant premises for the manufacture of eligible flavors.

    Science.gov (United States)

    2010-04-01

    ... of plant premises for the manufacture of eligible flavors. 19.206 Section 19.206 Alcohol, Tobacco... and extension of plant premises for the manufacture of eligible flavors. (a) General. The premises of... permit the use of the facilities for the manufacture of eligible flavors. (b) Qualifying documents. When...

  17. Life cycle analysis of photovoltaic cell and wind power plants

    International Nuclear Information System (INIS)

    Uchiyama, Yohji

    1997-01-01

    The paper presents life cycle analyses of net energy and CO 2 emissions on photovoltaic cell and wind power generation plants. Energy requirements associated with a plant are estimated for producing materials, manufacturing equipment, constructing facilities, acid operating plants. Energy ratio and net supplied energy are calculated by the process energy analysis that examines the entire energy inventory of input and output during life time of a plant. Life cycle CO 2 emission can also be calculated from the energy requirements obtained by the net energy analysis. The emission also includes greenhouse effect equivalent to CO 2 emission of methane gas leakage at a mining as well as CO 2 emissions from fossil fuel combustion during generating electricity, natural gas treatment at an extracting well and cement production in industry. The commercially available and future-commercial technologies are dealt with in the study. Regarding PV technologies, two different kinds of installation are investigated; roof-top typed installation of residential houses and ground installation of electric utilities. (author)

  18. Evapotranspiration over spatially extensive plant communities in the Big Cypress National Preserve, southern Florida, 2007-2010

    Science.gov (United States)

    Shoemaker, W. Barclay; Lopez, Christian D.; Duever, Michael J.

    2011-01-01

    Evapotranspiration (ET) was quantified over plant communities within the Big Cypress National Preserve (BCNP) using the eddy covariance method for a period of 3 years from October 2007 to September 2010. Plant communities selected for study included Pine Upland, Wet Prairie, Marsh, Cypress Swamp, and Dwarf Cypress. These plant communities are spatially extensive in southern Florida, and thus, the ET measurements described herein can be applied to other humid subtropical locations such as the Everglades.

  19. Shelf life extension and sensory evaluation of birch tree sap using chemical preservatives

    Directory of Open Access Journals (Sweden)

    Maciej Bilek

    2016-10-01

    Full Text Available The aim of this study was to assess the stability of the birch tree sap, depending on the addition and concentration of two chemical factors, ie. potassium sorbate and acids: malic, citric or lactic. As in our previous studies we found that the optimal physical parameter to assess the stability of birch sap is turbidity measurement, we used turbidimeter for estimate the effectiveness of shelf life extending. Sensory evaluation was carried out by university sensory panel with 8 skilled people (students and teachers with pre-selection and basic training of sensory methodology. On the other hand artificial perception measurements were realized by electronic nose. Birch tree sap stability without addition of preservatives, both room temperature and refrigerated, is less than three days. The effectiveness of preservation of birch tree sap depends on the concentration of acids. Independently of storage temperature, samples that received stability during the whole one-month storage period, were those with potassium sorbate and three acids in the highest concentrations, ie. malic acid at 0.3%, citric acid at 0.5% and lactic acid at 0.5%. Unfortunately, concentrations of acids, which allow extension of shelf life at least for one month in a room temperature, are characterized by the worst sensory evaluation rating. Thus, they should be corrected by the use of additives for improving the flavor, such as fruit syrups or herbal extracts. On the other hand, additionally storage in a refrigerated conditions allows one-month-stability for the sample with the highest sensory evaluation rating, ie. with the addition of lactic acid at 0.1% and potassium sorbate, which taste not need to be corrected.

  20. LEVERAGING AGING MATERIALS DATA TO SUPPORT EXTENSION OF TRANSPORTATION SHIPPING PACKAGES SERVICE LIFE

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, K. [Savannah River National Laboratory; Bellamy, S. [Savannah River National Laboratory; Daugherty, W. [Savannah River National Laboratory; Sindelar, R. [Savannah River National Laboratory; Skidmore, E. [Savannah River National Laboratory

    2013-08-18

    Nuclear material inventories are increasingly being transferred to interim storage locations where they may reside for extended periods of time. Use of a shipping package to store nuclear materials after the transfer has become more common for a variety of reasons. Shipping packages are robust and have a qualified pedigree for performance in normal operation and accident conditions but are only certified over an approved transportation window. The continued use of shipping packages to contain nuclear material during interim storage will result in reduced overall costs and reduced exposure to workers. However, the shipping package materials of construction must maintain integrity as specified by the safety basis of the storage facility throughout the storage period, which is typically well beyond the certified transportation window. In many ways, the certification processes required for interim storage of nuclear materials in shipping packages is similar to life extension programs required for dry cask storage systems for commercial nuclear fuels. The storage of spent nuclear fuel in dry cask storage systems is federally-regulated, and over 1500 individual dry casks have been in successful service up to 20 years in the US. The uncertainty in final disposition will likely require extended storage of this fuel well beyond initial license periods and perhaps multiple re-licenses may be needed. Thus, both the shipping packages and the dry cask storage systems require materials integrity assessments and assurance of continued satisfactory materials performance over times not considered in the original evaluation processes. Test programs for the shipping packages have been established to obtain aging data on materials of construction to demonstrate continued system integrity. The collective data may be coupled with similar data for the dry cask storage systems and used to support extending the service life of shipping packages in both transportation and storage.

  1. Fracture mechanics based life assessment in petrochemical plants

    International Nuclear Information System (INIS)

    Norasiah Ab Kasim; Abd Nassir Ibrahim; Ab Razak Hamzah; Shukri Mohd

    2004-01-01

    The increasing use of thick walled pressure vessels in petrochemical plants operating at high pressure under severe service conditions could lead to catastrophic failure. In the Malaysian Institute for Nuclear Technology Research (MINT), initial efforts are underway to apply fracture mechanics approach for assessment of significance of defects detected during periodic in service inspection (ISI) of industrial plants. This paper outlines the integrity management strategy based on fracture mechanics and proposes a new procedure for life assessment of petrochemical plants based on ASME Boiler and Pressure Vessel Code, Section XI, BSI PD 6493:1991, BSI 6539:1994, BSI Standard 7910:1999 and API 579:2000. Essential relevant data required for the assessment is listed. Several methods available for determination of fracture toughness are reviewed with limitations in their application to petrochemical plants. A new non destructive method for determination of fracture toughness based on hardness testing and normalized key roughness curve is given. Results of fracture mechanics based life assessment conducted for 100 mm thick ammonia converter of Ni r o steel and 70 mm thick plat forming reactor vessel of ASTM A 38 7 grade B steel in operational fertilizer and petroleum refining plants are presented. (Author)

  2. Practical standard for nuclear power plant life management programs: 2007

    International Nuclear Information System (INIS)

    2006-03-01

    The standard specifies the method of implementing nuclear power plant life management programs. The plant life management programs evaluate the integrity of the plant structures, systems and components, assessing if appropriate measures are taken against existing aging phenomena, if there are possibilities of occurrence and development of aging phenomena and if a sufficient level of margin is maintained to assure the integrity throughout the future operating period. The programs also assess the validity of the current maintenance activities, such as trend monitoring, walkdowns, periodic tests and inspections, repair and replacement work for the purpose of preventive maintenance, and utilization of lessons learned from past trouble experience, in order to newly identify maintenance measures. The technical evaluation on aging phenomena is conducted to establish the 10 year maintenance program for nuclear power plants until the plant reaches 30 years of service. The standard was established and issued by the Atomic Energy Society of Japan (AESJ) through the discussion of experts in the associated fields. (T. Tanaka)

  3. Technical and economic proposal for the extension of the Laguna Verde Nuclear Power plant with an additional nuclear reactor

    International Nuclear Information System (INIS)

    Leal C, C.D.; Francois L, J.L.

    2006-01-01

    The increment of the human activities in the industrial environments and of generation of electric power, through it burns it of fossil fuels, has brought as consequence an increase in the atmospheric concentrations of the calls greenhouse effect gases and, these in turn, serious repercussions about the environment and the quality of the alive beings life. The recent concern for the environment has provoked that industrialized countries and not industrialized carry out international agreements to mitigate the emission from these gases to the atmosphere. Our country, like part of the international community, not is exempt of this problem for what is necessary that programs begin guided toward the preservation of the environment. As for the electric power generation, it is indispensable to diversify the sources of primary energy; first, to knock down the dependence of the hydrocarbons and, second, to reduce the emission of polluting gases to the atmosphere. In this item, the nucleo electric energy not only has proven to be safe and competitive technical and economically, able to generate big quantities of electric power with a high plant factor and a considerable cost, but rather also, it is one of the energy sources that less pollutants it emits to the atmosphere. The main object of this work is to carry out a technical and economic proposal of the extension of the Laguna Verde Nuclear power plant (CNLV) with a new nuclear reactor of type A BWR (Advanced Boiling Water Reactor), evolutionary design of the BWR technology to which belong the two reactors installed at the moment in the plant, with the purpose of increasing the installed capacity of generation of the CNLV and of the Federal Commission of Electricity (CFE) with foundation in the sustainable development and guaranteeing the protection of the environment by means of the exploitation of a clean and sure technology that counts at the moment with around 12,000 year-reactor of operational experience in more of

  4. Beyond the conventional life cycle inventory in wastewater treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo-Toja, Yago, E-mail: yago.lorenzo@usc.es [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia (Spain); Alfonsín, Carolina [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia (Spain); Amores, María José; Aldea, Xavier; Marin, Desirée [Cetaqua, Water Technology Centre, 08940 Cornellà de Llobregat, Barcelona (Spain); Moreira, María Teresa; Feijoo, Gumersindo [Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, 15782 Santiago de Compostela, Galicia (Spain)

    2016-05-15

    The conventional approach for the environmental assessment of wastewater treatment plants (WWTPs) is typically based on the removal efficiency of organic load and nutrients as well as the quantification of energy and chemicals consumption. Current wastewater treatment research entails the monitoring of direct emissions of greenhouse gases (GHG) and emerging pollutants such as pharmaceutical and personal care products (PPCPs), which have been rarely considered in the environmental assessment of a wastewater treatment facility by life cycle assessment (LCA) methodology. As a result of that, the real environmental impacts of a WWTP may be underestimated. In this study, two WWTPs located in different climatic regions (Atlantic and Mediterranean) of Spain were evaluated in extensive sampling campaigns that included not only conventional water quality parameters but also direct GHG emissions and PPCPs in water and sludge lines. Regarding the GHG monitoring campaign, on-site measurements of methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) were performed and emission factors were calculated for both WWTPs. GHG direct emissions accounted for 62% of the total global warming potential (GWP), much more relevant than indirect CO{sub 2} emissions associated with electricity use. Regarding PPCPs, 19 compounds were measured in the main streams: influent, effluent and sludge, to perform the evaluation of the toxicity impact categories. Although the presence of heavy metals in the effluent and the sludge as well as the toxicity linked to the electricity production may shade the toxicity impacts linked to PPCPs in some impact categories, the latter showed a notable influence on freshwater ecotoxicity potential (FETP). For this impact category, the removal of PPCPs within the wastewater treatment was remarkably important and arose as an environmental benefit in comparison with the non-treatment scenario. - Highlights: • The influence of LCI quality on the environmental assessment

  5. Nuclear Power Plant Life Management - Challenges and Proposal for a Unified Model Integrating Safety and Economics

    International Nuclear Information System (INIS)

    Contri, Paolo; Elsing, Bernhard

    2011-01-01

    In recent years many electric utilities and nuclear power plants adopted policies for improved coordination of both safety and non-safety programs, called plant life management (PLIM), also in view on plant life extension programs, but mainly for an optimisation of operating costs. The implementation of PLIM programs has followed many different approaches, being intrinsically dependent on the national regulatory framework and technical traditions. In Countries with some experience, the PLIM program proved very convenient, especially when coupled with Maintenance, Surveillance an Inspection (MS and I) optimization: average savings are reported in the range of 20-30% of total (maintenance) costs. A unified European model for PLIM was developed at the JRC-Institute for Energy with the support of a network of stakeholders (SENUF), and validated at some EU nuclear plants. This paper provides a summary of the model features, the result of its validation at some plants and summarises the perceived scientific/technological challenges on which JRC proposes to focus, based upon its competencies and skills, having in mind both the European and world-wide context and its potential evolution. (author)

  6. Field dodder life cycle and interaction with host plants

    Directory of Open Access Journals (Sweden)

    Sarić-Krsmanović Marija

    2017-01-01

    Full Text Available Field dodder is a parasitic plant that attaches to stems and leaves of broadleaf plants, including weeds, field crops, vegetables and ornamentals, across most agricultural regions of the world. Effective field dodder control is extremely difficult to achieve due to the nature of attachment and close association between the host and the parasite, which require a highly effective and selective herbicide to destroy the parasite without damaging its host. To establish a strategy for controlling parasite growth and restricting the spread of field dodder in crop fields, it is important to learn more about this weed, its life cycle and development.

  7. Life form succession in plant communities on colliery waste tips

    Energy Technology Data Exchange (ETDEWEB)

    Down, C G

    1973-01-01

    Five disused colliery waste tips in the Somerset Coalfield, 12, 15, 21, 55 and 98 years old, respectively, were examined to determine the life forms of the naturally-occurring vascular plant species. Hemicryptophytes comprised between 68 and 79% of the number of species on each tip. Rosette hemicryptophytes comprised 31.8% of the species on the 12-year tip, declining to 11.8% on the 98-year tip. It is suggested that artificial planting of rosette hemicryptophytes may be beneficial in reclamation schemes. 3 tables.

  8. Habitat Fragmentation Drives Plant Community Assembly Processes across Life Stages

    Science.gov (United States)

    Hu, Guang; Feeley, Kenneth J.; Yu, Mingjian

    2016-01-01

    Habitat fragmentation is one of the principal causes of biodiversity loss and hence understanding its impacts on community assembly and disassembly is an important topic in ecology. We studied the relationships between fragmentation and community assembly processes in the land-bridge island system of Thousand Island Lake in East China. We focused on the changes in species diversity and phylogenetic diversity that occurred between life stages of woody plants growing on these islands. The observed diversities were compared with the expected diversities from random null models to characterize assembly processes. Regression tree analysis was used to illustrate the relationships between island attributes and community assembly processes. We found that different assembly processes predominate in the seedlings-to-saplings life-stage transition (SS) vs. the saplings-to-trees transition (ST). Island area was the main attribute driving the assembly process in SS. In ST, island isolation was more important. Within a fragmented landscape, the factors driving community assembly processes were found to differ between life stage transitions. Environmental filtering had a strong effect on the seedlings-to-saplings life-stage transition. Habitat isolation and dispersal limitation influenced all plant life stages, but had a weaker effect on communities than area. These findings add to our understanding of the processes driving community assembly and species coexistence in the context of pervasive and widespread habitat loss and fragmentation. PMID:27427960

  9. Specification of life cycle assessment in nuclear power plants

    International Nuclear Information System (INIS)

    Abbaspour, M.; Kargari, N.; Mastouri, R.

    2008-01-01

    Life Cycle Assessment is an environmental management tool for assessing the environmental impacts of a product of a process. life cycle assessment involves the evaluation of environmental impacts through all stages of life cycle of a product or process. In other words life cycle assessment has a c radle to grave a pproach. Some results of life cycle assessment consist of pollution prevention, energy efficient system, material conservation, economic system and sustainable development. All power generation technologies affect the environment in one way or another. The main environmental impact does not always occur during operation of power plant. The life cycle assessment of nuclear power has entailed studying the entire fuel cycle from mine to deep repository, as well as the construction, operation and demolition of the power station. Nuclear power plays an important role in electricity production for several countries. even though the use of nuclear power remains controversial. But due to the shortage of fossil fuel energy resources many countries have started to try more alternation to their sources of energy production. A life cycle assessment could detect all environmental impacts of nuclear power from extracting resources, building facilities and transporting material through the final conversion to useful energy services

  10. Preliminary investigation on the extension of shelf-life of boiled Chub mackerel by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P; Prombubesara, C; Songprasertchai, S

    1971-12-31

    The influence of irradiation on the extension of shelf-life of boiled Chub mackerel stored at room temperature (25-30{sup 0}C) was investigated. It was found that boiled Chub mackerel irradiated at 0.1, 0.2, or 0.3 Mrad could be kept with good organoleptic properties at room temperature for 5, 8, and 11 days respectively; while the unirradiated sample could be kept for only 2 days. Boiled Chub mackerel used in this study was found to be heavily contaminated with microorganisms. Irradiation at doses mentioned caused reduction of more than 99% of bacteria. Bacillus and Acinetobacter were found to predominate in the irradiated boiled mackerel. The predominant flora in unirradiated boiled mackerel included Micrococcus, Staphylococcus, Bacillus, Acinetobacter, and Proteus. E. coli was always detected in unirradiated samples and was occasionally detected only in samples irradiated at 0.1 Mrad. Trimethylamine nitrogen (TMA-N) content, total volatile basic nitrogen (TVB-N) content, and total bacterial count (TBC) were used as indices of decomposition of both irradiated and unirradiated samples. TMA-N and TBC were found to be good indices of quality of only unirradiated boiled Chub mackerel, whereas TVB-N was found to be a good index of quality of both irradiated and unirradiated samples.

  11. Shelf-life extension of pear (Pyrus communis L.) by gamma-irradiation

    International Nuclear Information System (INIS)

    Wani, A.M.; Hussain, P.R.; Dar, M.A.; Mir, M.A.

    2007-01-01

    Hard and unripe pear fruit was precooled and subjected to γ-irradiation in the range of 0.1-2.5 kGy. After irradiation fruit was stored under ambient conditions (25±2 degC, RH 70%) and evaluated periodically for firmness, total soluble solids, titratable acidity, chlorophyll, physiological loss in weight, visual colour score, overall acceptability and microbial load. γ-irradiation at 0.1-0.9 kGy did not show any significant effect with respect to shelf-life extension and microbial load. However, irradiation doses of 1.0-1.5 kGy significantly (p≤0.05) delayed ripening and did not spoil for 14 days of storage under ambient conditions. The microbial load was reduced without affecting the physico-chemical and sensory attributes. The irradiation doses of 2.0-2.5 kGy resulted in reduced microbial load and delayed ripening but adversely affected the fruit colour. (author)

  12. Optimal design of accelerated life tests for an extension of the exponential distribution

    International Nuclear Information System (INIS)

    Haghighi, Firoozeh

    2014-01-01

    Accelerated life tests provide information quickly on the lifetime distribution of the products by testing them at higher than usual levels of stress. In this paper, the lifetime of a product at any level of stress is assumed to have an extension of the exponential distribution. This new family has been recently introduced by Nadarajah and Haghighi (2011 [1]); it can be used as an alternative to the gamma, Weibull and exponentiated exponential distributions. The scale parameter of lifetime distribution at constant stress levels is assumed to be a log-linear function of the stress levels and a cumulative exposure model holds. For this model, the maximum likelihood estimates (MLEs) of the parameters, as well as the Fisher information matrix, are derived. The asymptotic variance of the scale parameter at a design stress is adopted as an optimization objective and its expression formula is provided using the maximum likelihood method. A Monte Carlo simulation study is carried out to examine the performance of these methods. The asymptotic confidence intervals for the parameters and hypothesis test for the parameter of interest are constructed

  13. Study The Effect Extension Of Fuel Element Life Time In The Core Small Power Reactor

    International Nuclear Information System (INIS)

    Dewita, E.; Rusli, A.; Tuka, V.

    1998-01-01

    Mini power reactor is a low power nuclear reactor which mostly are designed especially to supply energy demand in the remote areas, such as for electricity generation, industries, desalination and district heating.The goal of the operation cycle extension to 3 - 5 years is to maximize the use of the fuel in order to achieve much cheaper energy generated. From the stand point of fuel element, in order to maximize the fuel life time there is a need to see all possible effects of extended life time to the fuel behavior in the core. This study has been carried out in order to obtain the understanding on all influencing factors to the fuel element behaviors at extended operation cycle whose results are expected to be useful as the input to fuel design and fabrication. The study has show that the material selection for fuel and cladding materials are the essential factor in maximizing the fuel life time. Development of cladding and fuel materials has been done, and shown that the new zirconium alloy, zircaloy, having composition of Zr-1,0 Sn-0,27 Fe-0,16 Cr-0,1 Nb-0,01 Ni has higher corrosion resistance and mechanical characteristics better than that of the standard zircaloy-4. Adding the Nb content (0,005-0,2 wt %), decreasing the Sn content until 0,5 wt %, and decreasing the ratio of Fe/Cr from 0,6 to 0,5 can increase resistance to corrosion, while decreasing the ratio of Fe and Cr from 0,3 to 0,7 wt % can increase the mechanical characteristics. To enhance the resistance to nodular corrosion in the BWR system, adding the Nb-Mo, Nb-W and Nb-V at low Sn zircaloy-2 can be done. In improving the fuel element it has been shown that adding niobium (Nb 2 O 5 -0,3 wt %) can enlarge the particle size of fuel hence improving the fuel performance

  14. Advanced maintenance strategies for power plant operators--introducing inter-plant life cycle management

    International Nuclear Information System (INIS)

    Graeber, Ulrich

    2004-01-01

    One of the most important goals of competing power plant operators is to ensure safe operation of their plants, characterized by maximum availability throughout the entire life cycle and minimized specific generating costs. One parameter crucial to the total price of electricity--and one that can be actively influenced by the power plant operators--is maintenance. Up to 30% of all electricity generating costs accrue from maintenance. In the past years maintenance measures have been optimized particularly by the application and continuing development of testing and diagnostic techniques, by the increased level of system and component automation as well as more efficient organization structures. Despite the considerable success of these efforts, the potential for further cost reductions is still far from exhausted. But the risks connected to reliability, availability and safety need to be analyzed in greater detail in order to ensure the sustainability of the savings already achieved as well as those yet to be realized. The systematic application of condition-based maintenance and the implementation of structured life cycle management are essential requirements. An inter-plant approach is recommended to make a quick implementation of maintenance optimization potentials possible. Plant-specific improvement potentials can be established with the help of a best-practice comparison, and measures and priorities can be defined for realizing them. Creating an inter-plant database will allow experience and findings to be analyzed quickly and efficiently by experts and made available to all participants on a neutral platform. Despite--or maybe owing to--the increasingly competitive marketplace, a sustained reduction in the maintenance costs of power plant operators can only be achieved through a structured, inter-plant exchange of experience. The ZES offers the industry a suitable platform for cooperation with its 'Condition-Based Maintenance' research focus. The introduction

  15. What reassurances do the community need regarding life extension? Evidence from studies of community attitudes and an analysis of film portrayals.

    Science.gov (United States)

    Underwood, Mair

    2014-04-01

    It is increasingly recognized that community attitudes impact on the research trajectory, entry, and reception of new biotechnologies. Yet biogerontologists have generally been dismissive of public concerns about life extension. There is some evidence that biogerontological research agendas have not been communicated effectively, with studies finding that most community members have little or no knowledge of life extension research. In the absence of knowledge, community members' attitudes may well be shaped by issues raised in popular portrayals of life extension (e.g., in movies). To investigate how popular portrayals of life extension may influence community attitudes, I conducted an analysis of 19 films depicting human life extension across different genres. I focussed on how the pursuit of life extension was depicted, how life extension was achieved, the levels of interest in life extension shown by characters in the films, and the experiences of extended life depicted both at an individual and societal level. This paper compares the results of this analysis with the literature on community attitudes to life extension and makes recommendations about the issues in which the public may require reassurance if they are to support and accept life extension technologies.

  16. R and D in support of CANDU plant life management

    International Nuclear Information System (INIS)

    Tapping, R.L.; Holt, R.A.

    1999-01-01

    One of the keys to the long-term success of CANDUs is a high capacity factor over the station design life. Considerable R and D in underway at AECL to develop technologies for assessing, monitoring and mitigating the effect of plant ageing and for improving plant performance and extending plant life. To achieve longer service life and to realize high capacity factor from CANDU stations, AECL is developing new technologies to enhance fuel channel and steam generator inspection capabilities, to monitor system health, and to allow preventive maintenance and cleaning (e.g., on-line chemical cleaning processes that produce small volumes of wastes). The life management strategy for fuel channels and steam generators requires a program to inspect components on a routine basis to identify mechanisms that could potentially affect fitness-for-service. In the case of fuel channels, the strategy includes inspections for dimensional changes, flaw detection, and deuterium concentration. New techniques are been developed to enhance these inspection capabilities; examples include accurate measurement of the gap between a pressure tube and its calandria tube and rapid full-length inspections of steam generator tubes for all known flaw types. Central to life management of components are Fitness-for-Service Guidelines (FFSG) that have been developed with the CANDU Owners Group (COG) that provide a standardized method to assess the potential for propagation of flaws detected during in-service inspections, and assessment of any change in fracture characteristics of the material. FFSG continue to be improved with the development of new technologies such as the capability to credit relaxation of stresses due to creep and non-rejectable flaws in pressure tubes. Effective management of plant systems throughout their lifetime requires much more than data acquisition and display - it requires that system health is continually monitored and managed. AECL has developed a system Health Monitor

  17. Life management of power plant based on structural damage testing

    Energy Technology Data Exchange (ETDEWEB)

    Tallermo, H.; Klevtsov, I. [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia); Arras, V. [Eesti Energia, Tallinn (Estonia)

    1998-12-31

    Life management system is based on the valid nowadays in Estonian power plants regulation documentation. The system allows to estimate stress distribution in components, find computational assessment of cumulated creep damage, determine when and where it is necessary to cut off the particular number of microsamples or take replicas. Finally, the real metal condition may be assessed on the basis of metallographic specimen research and reasonable 3-R decision - run, repair, replacement - made on further component use. (orig.) 6 refs.

  18. Life Cycle Assessment of Daugavgriva Waste Water Treatment Plant

    OpenAIRE

    Romagnoli, F; Fraga Sampaio, F; Blumberga, D

    2009-01-01

    This paper presents the assessment of the environmental impacts caused by the treatment of Riga’s waste water in the Daugavgriva plant with biogas energy cogeneration through the life cycle assessment (LCA). The LCA seems to be a good tool to assess and evaluate the most serious environmental impacts of a facility The results showed clearly that the impact category contributing the most to the total impact –eutrophicationcomes from the wastewater treatment stage. Cl...

  19. Life management of power plant based on structural damage testing

    Energy Technology Data Exchange (ETDEWEB)

    Tallermo, H; Klevtsov, I [Thermal Engineering Department of Tallinn Technical University, Tallinn (Estonia); Arras, V [Eesti Energia, Tallinn (Estonia)

    1999-12-31

    Life management system is based on the valid nowadays in Estonian power plants regulation documentation. The system allows to estimate stress distribution in components, find computational assessment of cumulated creep damage, determine when and where it is necessary to cut off the particular number of microsamples or take replicas. Finally, the real metal condition may be assessed on the basis of metallographic specimen research and reasonable 3-R decision - run, repair, replacement - made on further component use. (orig.) 6 refs.

  20. 24. MPA-seminar: safety and reliability of plant technology with special emphasis on integrity and life management. Vol. 2. Papers 28-63

    International Nuclear Information System (INIS)

    1999-01-01

    The second volume is dedicated to the safety and reliability of plant technology with special emphasis on the integrity and life management. The following topics are discussed: 1. Integrity of vessels, pipes and components. 2. Fracture mechanics. 3. Measures for the extension of service life, and 4. Online Monitoring. All 30 contributions are separately analyzed for this database. (orig.)

  1. Plant life management processes and practices for heavy water reactors

    International Nuclear Information System (INIS)

    Kang, K.-S.; Cleveland, J.; Clark, C.R.

    2006-01-01

    In general, heavy water reactor (HWR) nuclear power plant (NPP) owners would like to keep their NPPs in service as long as they can be operated safely and economically. Their decisions are depending on essentially business model. They involve the consideration of a number of factors, such as the material condition of the plant, comparison with current safety standards, the socio-political climate and asset management/ business planning considerations. Continued plant operation, including operation beyond design life, called 'long term operation, depends, among other things, on the material condition of the plant. This is influenced significantly by the effectiveness of ageing management. Key attributes of an effective plant life management program include a focus on important systems, structure and components (SSCs) which are susceptible to ageing degradation, a balance of proactive and reactive ageing management programmes, and a team approach that ensures the co-ordination of and communication between all relevant nuclear power plant and external programmes. Most HWR NPP owners/operators use a mix of maintenance, surveillance and inspection (MSI) programs as the primary means of managing ageing. Often these programs are experienced-based and/or time-based and may not be optimised for detecting and/or managing ageing effects. From time-to-time, operational history has shown that this practice can be too reactive, as it leads to dealing with ageing effects (degradation of SSCs) after they have been detected. In many cases premature and/or undetected ageing cannot be traced back to one specific reason or an explicit error. The root cause is often a lack of communication, documentation and/or co-ordination between design, commissioning, operation or maintenance organizations. This lack of effective communication and interfacing frequently arises because, with the exception of major SSCs, such as the fuel channels or steam generators, there is a lack of explicit

  2. Life Cycle Cost Analysis of Ready Mix Concrete Plant

    Science.gov (United States)

    Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

    2013-11-01

    India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

  3. Non-destructive testing for plant life assessment

    International Nuclear Information System (INIS)

    2005-01-01

    The International Atomic Energy Agency (IAEA) is promoting industrial applications of nondestructive testing (NDT) technology, which includes radiography testing (RT) and related methods, to assure safety and reliability of operation of industrial facilities and processes. NDT technology is essentially needed for improvement of the quality of industrial products, safe performance of equipment and plants, including safety of metallic and concrete structures and constructions. The IAEA is playing an important role in promoting the NDT use and technology support to Member States, in harmonisation for training and certification of NDT personnel, and in establishing national accreditation and certifying bodies. All these efforts have led to a stage of maturity and self sufficiency in numerous countries especially in the field of training and certification of personnel, and in provision of services to industries. This has had a positive impact on the improvement of the quality of industrial goods and services. NDT methods are primarily used for detection, location and sizing of surface and internal defects (in welds, castings, forging, composite materials, concrete and many more). Various NDT methods are applied for preventive maintenance (aircraft, bridge), for the inspection of raw materials, half-finished and finished products, for in-service-inspection and for plant life assessment studies. NDT is essential for quality control of the facilities and products, and for fitness - for purpose assessment (so-called plant life assessment). NDT evaluates remaining operation life of plant components (processing lines, pipes, vessels) providing an accurate diagnosis that allows predicting extended life operation beyond design life. Status and trends on the NDT for plant life assessment have been discussed in many IAEA meetings related with NDT development, training and education. Experts have largely demonstrated that, using NDT methods, a comprehensive assessment of the life

  4. ANTIMICROBIAL SUBSTANCES: AN ALTERNATIVE APPROACH TO THE EXTENSION OF SHELF LIFE

    Directory of Open Access Journals (Sweden)

    Ekaterina A. Lukinova

    2017-01-01

    Full Text Available The problem of high losses of raw materials and products in the food industry is reviewed in the article. Brief lists of spoilage types as well as the available approaches to meat preservation are discussed including technological, physical and chemical. Natural antimicrobial substances are considered as alternative approaches, the existence of which has been known for more than 60 years. Antimicrobial peptides are the evolutionary ancient factor of innate immunity and are found in the cells and tissues of vertebrate and invertebrate animals, plants, fungi and bacteria. Present approaches to their classification, structure and mechanisms of action are discussed. The information from the Antimicrobial Peptide Database and the UniProt Protein Database is systematized in relation to the presence of antimicrobial substances in the tissues of pigs and cattle. Such parameters as the molecular weight, isoelectric point, charge, amino acid sequence and share a hydrophobic part, as well as a range of activities: antibacterial, antifungal, antiviral, antiparasitic, etc. are presented in the article. On the basis of the review, alternative sources of antimicrobial proteins and peptides are proposed as well as technology for shelf life prolonging.

  5. Status and Perspectives of Nuclear Reactor Pressure Vessel Life Extension up to 60 Years Operation in Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Chaouadi, R.; Scibetta, M.; Van Walle, E.

    2009-09-15

    The scope of this report involves a safety evaluation of the reactor pressure vessel (RPV) against neutron embrittlement, in the most severely irradiation region (belt line) and in the event of a pressurized thermal shock. The irreplaceable RPV is considered to be the most critical component for lifetime considerations of the nuclear power plant. However, an application for operation extension will also depend upon a number of additional considerations, including the technical assessment of other plant components, as well as non-technical arguments (e.g. political, environmental, economical, strategical that are outside the scope this report. In the hypothesis of a request for operation extension, it is the responsibility of the utilities to provide the safety authorities with an exhaustive dossier demonstrating that safe extended operation is guaranteed. The role of the safety authorities is to critically evaluate the safety dossier for eventually granting the operation extension.

  6. Status and Perspectives of Nuclear Reactor Pressure Vessel Life Extension up to 60 Years Operation in Belgium

    International Nuclear Information System (INIS)

    Lucon, E.; Chaouadi, R.; Scibetta, M.; Van Walle, E.

    2009-01-01

    The scope of this report involves a safety evaluation of the reactor pressure vessel (RPV) against neutron embrittlement, in the most severely irradiation region (belt line) and in the event of a pressurized thermal shock. The irreplaceable RPV is considered to be the most critical component for lifetime considerations of the nuclear power plant. However, an application for operation extension will also depend upon a number of additional considerations, including the technical assessment of other plant components, as well as non-technical arguments (e.g. political, environmental, economical, strategical that are outside the scope this report. In the hypothesis of a request for operation extension, it is the responsibility of the utilities to provide the safety authorities with an exhaustive dossier demonstrating that safe extended operation is guaranteed. The role of the safety authorities is to critically evaluate the safety dossier for eventually granting the operation extension.

  7. An approach to nuclear-power-plant life management

    International Nuclear Information System (INIS)

    Vojvodic Tuma, J.; Celin, R.; Udovc, M.; Bundara, B.; Zabric, I.

    2007-01-01

    The plant life of a nuclear power plant (NPP) depends on degradation processes and ageing. Degradation is a deterioration phenomenon that can lead to component failure or limit the life of a component or the NPP itself. Ageing describes a continuous time or operational degradation of materials due to operational conditions, which include both normal and operating conditions. As a result of ageing degradation the state of the NPP or component can vary throughout the operating life. The degradation mechanisms for metallic components are general and local corrosion, erosion/corrosion, fatigue, corrosion fatigue, material changes due to irradiation and temperature, creep and wear. All the components of an NPP are subject to ageing, which may lead to the degradation of the physical barriers and redundant components, resulting in an increased probability of common-cause failures. The aims of NPP ageing management are to ensure that the necessary safety margins, adequate reliability and unforeseen and uncontrolled ageing of critical components do not shorten the NPP's lifetime. For the reasons stated above, plans are necessary to maintain the NPP in a state of high reliability. These are plans for an assessment of the life of the components that cannot be readily replaced, plans for operating life assessment or the planned replacement of major components where economic considerations will largely condition whether replacement or decommissioning should be pursued and plans for maintenance and replacements so that outages and delays can be minimised. In this paper some aspects of the process of NPP life management will be presented. (author)

  8. Microbial inactivation and shelf life extension of Korean traditional prepared meals by irradiation

    International Nuclear Information System (INIS)

    Jo, C.

    2009-01-01

    The effects of gamma irradiation on microbial inactivation and shelf life extension of Korean traditional prepared meals, including bulgogi and its sauce, marinated beef rib and Kimbab, were investigated. Raw vegetables, fruits and soy sauce used for making bulgogi sauce were highly contaminated and most of them with Bacillus spp. and coliform bacteria at the initial stage. Irradiation at 10 kGy eliminated coliforms in the bulgogi sauce and no growth was found during the 4 weeks of storage at 20 deg. C. The sensory evaluation of bulgogi and its sauce showed that the colour of irradiated samples was better than that of non-irradiated controls or heat treated samples. The total bacteria count and coliform of marinated beef ribs were 5.68 and 3.68 in CFU/g, respectively. The effect of irradiation on the growth of the four test microorganisms inoculated (about 106-107 CFU/g) into the marinated beef ribs were dose dependent (a higher dose produced a greater reduction). All the four pathogens inoculated on marinated beef ribs were eliminated at 4 kGy. The D 10 values of Bacillus cereus, Staphylococcus aureus, Salmonella typhimurium and Escherichia coli on inoculated marinated beef ribs were 0.66 ± 0.01, 0.59 ± 0.05, 0.64 ± 0.02 and 0.54 ± 0.01 kGy, respectively. Of these, E. coli was the most radiation sensitive in the raw marinated beef ribs. The number of the four pathogens inoculated into Kimbab decreased by 2-3 ln CFU/g for every 1 kGy increment and were not detected after 3 kGy. The D 10 values of pathogens inoculated into the Kimbab were in the range 0.31-0.44 kGy. This study indicated that irradiation is effective in ensuring the safety of Korean traditional prepared meals, including bulgogi sauce, bulgogi, marinated beef ribs and Kimbab with acceptable sensory quality. For Kimchijumeokbab, viable cells of the four pathogens inoculated increased slightly after abusive storage condition (20 deg. C), although under commercial condition (4 deg. C), and after 2

  9. Cybernetic principles of aging and rejuvenation: the buffering- challenging strategy for life extension.

    Science.gov (United States)

    Heylighen, Francis

    2014-01-01

    Aging is analyzed as the spontaneous loss of adaptivity and increase in fragility that characterizes dynamic systems. Cybernetics defines the general regulatory mechanisms that a system can use to prevent or repair the damage produced by disturbances. According to the law of requisite variety, disturbances can be held in check by maximizing buffering capacity, range of compensatory actions, and knowledge about which action to apply to which disturbance. This suggests a general strategy for rejuvenating the organism by increasing its capabilities of adaptation. Buffering can be optimized by providing sufficient rest together with plenty of nutrients: amino acids, antioxidants, methyl donors, vitamins, minerals, etc. Knowledge and the range of action can be extended by subjecting the organism to an as large as possible variety of challenges. These challenges are ideally brief so as not to deplete resources and produce irreversible damage. However, they should be sufficiently intense and unpredictable to induce an overshoot in the mobilization of resources for damage repair, and to stimulate the organism to build stronger capabilities for tackling future challenges. This allows them to override the trade-offs and limitations that evolution has built into the organism's repair processes in order to conserve potentially scarce resources. Such acute, "hormetic" stressors strengthen the organism in part via the "order from noise" mechanism that destroys dysfunctional structures by subjecting them to strong, random variations. They include heat and cold, physical exertion, exposure, stretching, vibration, fasting, food toxins, micro-organisms, environmental enrichment and psychological challenges. The proposed buffering-challenging strategy may be able to extend life indefinitely, by forcing a periodic rebuilding and extension of capabilities, while using the Internet as an endless source of new knowledge about how to deal with disturbances.

  10. Tor1/Sch9-regulated carbon source substitution is as effective as calorie restriction in life span extension.

    Directory of Open Access Journals (Sweden)

    Min Wei

    2009-05-01

    Full Text Available The effect of calorie restriction (CR on life span extension, demonstrated in organisms ranging from yeast to mice, may involve the down-regulation of pathways, including Tor, Akt, and Ras. Here, we present data suggesting that yeast Tor1 and Sch9 (a homolog of the mammalian kinases Akt and S6K is a central component of a network that controls a common set of genes implicated in a metabolic switch from the TCA cycle and respiration to glycolysis and glycerol biosynthesis. During chronological survival, mutants lacking SCH9 depleted extracellular ethanol and reduced stored lipids, but synthesized and released glycerol. Deletion of the glycerol biosynthesis genes GPD1, GPD2, or RHR2, among the most up-regulated in long-lived sch9Delta, tor1Delta, and ras2Delta mutants, was sufficient to reverse chronological life span extension in sch9Delta mutants, suggesting that glycerol production, in addition to the regulation of stress resistance systems, optimizes life span extension. Glycerol, unlike glucose or ethanol, did not adversely affect the life span extension induced by calorie restriction or starvation, suggesting that carbon source substitution may represent an alternative to calorie restriction as a strategy to delay aging.

  11. Analysis of the extension and reduction method of qualified life used in equipment with ambiental qualification; Analisis del metodo de extension y reduccion de vida calificada utilizado en equipo con calificacion ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Serrano R, M.L. [CNSNS, 03020 Mexico D.F. (Mexico)].e -mail: mlserrano@cnsns.gob.mx

    2005-07-01

    With the purpose of reducing costs of acquisition, maintenance, design, hour-man, dose, production, etc. or by changes in the temperature of service, diverse Nuclear Plants (NP) in the world have been carried out extensions and reductions of life of equipment and/or components related with the safety. The used methods are mainly tests type on equipment or component aged quickly, tests type on equipment or component aged naturally and use of the Arrhenius model with monitoring of temperatures in place. The present article carries out an analysis of the Arrhenius model with monitoring of temperatures in place, which is presented in two variants, equation (1) and (2), since it is the but used by the NP with extension purposes and reduction of qualified life. As back information, it was made one search of investigations, applied to diverse fields of the science that try about the reliability of the results provided by Arrhenius for the aging case. The results of the analysis indicate: I) that this method make uncertainties in some intervals of temperature and 2) which of the two variants it provides data more reliable. (Author)

  12. Is it possible to assure structural integrity and demonstrate life extension of older nuclear piping systems built to ASA B31.1?

    International Nuclear Information System (INIS)

    Burr, T.K.; Hawkes, G.L.; Morton, D.K.; Pace, N.E.

    1990-01-01

    Among the issues associated with older non-commercial reactors and irradiation facilities are (a) whether plant system designs are adequate relative to current industry standards and (b) whether degradation due to system aging adversely challenges the required margins of safety. These issues are being addressed at the Advanced Test Reactor (ATR) as part of a continuous effort to assure that ATR plant systems and safety analyses are consistent with state-of-the-art technology, evolving industry standards, and lessons learned from industry experience (e.g., Three Mile Island and Chernobyl). This paper presents a methodology for reevaluating loop experiment facility piping systems relative to concepts contained in the current ASME Boiler and Pressure Vessel Code, Section 3 and Section 11. Insights gained on the challenges associated with reevaluating older piping systems for structural adequacy and life extension considerations are discussed. 14 refs., 3 figs

  13. Lifetime extension of nuclear power plants. Exclusive competence of the Bundestag?

    International Nuclear Information System (INIS)

    Scholz, Rupert

    2010-01-01

    With the Act on the structured phase-out of the utilisation of nuclear energy for the commercial generation of electricity (Gesetz zur geordneten Beendigung der Kernenergienutzung zur gewerblichen Erzeugung von Elektrizitaet) of 22 April 2002 (Federal Gazette I p. 1351), the ''nuclear power phase-out'' was implemented into law. Ever since then, section 7 (1a) of the Atomic Energy Act (Atomgesetz - AtG) has provided that the authorisation to operate a nuclear power plant expires once the electricity volume for the respective installation as listed in Appendix 3, column 2 or the electricity volume derived from transfers has been produced. The coalition treaty of the current government factions provides for extending the operating periods of nuclear power plants. To this end, paragraphs 1a to 1d of section 7 AtG could be repealed, thus restoring the legal status prevailing prior to the ''phase-out''. As an alternative it would be conceivable to increase the values set forth in Appendix 3 for the energy volume quantity of a given installation accordingly. Both alternatives require an amendment of the Atomic Energy Act, over which the Deutsche Bundestag has exclusive competence. This is stated in the Grundgesetz (Constitution). Such a amendment would not require the consent of the Bundesrat, since the administrative tasks assigned to the Federal States (Laender) on behalf of the Federal Government pursuant to sec. 7, 24 (2) AtG would not be changing in a qualitative sense. Consequently, it would not constitute interference with the administrative powers of the Federal States from an organizational or procedural point of view. The quantitative change in the tasks to be performed by the Federal States on behalf of the Federal Government that would accompany an extension of the operating periods would not lead to a right of consent on the part of the Bundesrat pursuant to Art. 87c of the Grundgesetz. (orig.)

  14. Plant life management in Belgium: an integrated project

    International Nuclear Information System (INIS)

    Wacquier, W.; Smet, M. de; Hennart, J.C.; Greer, J.L.; Breesch, Ch.; Havard, P.

    2001-01-01

    In Belgium, a specific plant life management project, named ''Continuous Operation of Belgian NPPs'' is currently developing. Its final objective is to centralize all safety and economic aspects of plant life management in order to determine, for each NPP unit, the optimal actions required to maintain their safe and reliable operation. As the lifetime of safety-related active components is permanently controlled by the current maintenance programs, the project focuses only on passive safety-related components and on non-safety components important for the availability of the plants. These structures and components were evaluated and compared on the basis of a set of weighted criteria in order to measure their criticality and to identify those which must be considered in the project. The selection and the ranking of those components is based on the KBM TM methodology (Knowledge Based Maintenance). This methodology facilitates the collection, formalization and exchange of know-how and gives immediate results thanks to a sequential and systematic step by step analysis. (author)

  15. Life Cycle Assessment to Municipal Wastewater Treatment Plant

    International Nuclear Information System (INIS)

    Garcia, J. s.; Herrera, I.; Rodriguez, A.

    2011-01-01

    The evaluation was done at a Municipal Wastewater Treatment Plant (MWTP), through the application of the methodology of Life Cycle Assessment (LCA) performed by using a commercial tool called SIMAPRO. The objective of this study was to apply Life Cycle Assessment (LCA) in two systems: municipal wastewater effluent without treatment and Wastewater Treatment Plant (WTP) that is operating in poor condition and has a direct discharge to a natural body, which is a threat to the environment. A LCA was done using SIMAPRO 7, in order to determine the environmental impact in each scenery was assessed, a comparison of the impacts and propose improvements to decrease, following the steps this methodology and according to the respective standardized normative (ISO 14040/ ISO 14044). In this study, most of used data have been reported by the plant from early 2010 and some data from literature. We identified the environmental impacts generated by the treatment, making emphasis on those related to the subsequent use of the water body receiving the discharge, such as eutrophication (near to 15% reduction). Likewise, a comparative analysis between the impacts in the two systems, with and without treatment by analyzing the variation in the impact categories studied. Finally within this work, alternatives of improvements, in order to reduce the identified and quantified impacts are proposed. (Author) 33 refs.

  16. Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)

    Science.gov (United States)

    Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...

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

    International Nuclear Information System (INIS)

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

    2002-01-01

    license renewal for 25 nuclear units by 2005. It is anticipated that over 90% of the 103 operating nuclear plants in the United States will pursue license renewal and seek an additional 20 years of operation. Some plants may pursue operation to 80 years or longer since the license renewal rule does not limit the operating life of a nuclear power plant. The estimated cost to prepare and process a license renewal application is approximately $10M to $15M, which includes NRC review fees. The NRC review for license renewal is strictly a safety review and plant economics is not a consideration. However, economics will drive the decision to pursue license renewal for U.S. nuclear power plants. For nuclear units with strong performance records, license renewal is a good business decision when compared to the cost of building new generating capacity. The license renewal rule focuses on ageing of passive long-lived components and ageing management programs that manage those structures and components. Ninety to ninety-five percent of the ageing management programs credited in a plant license renewal application are existing programs (e.g., ASME Section XI, Chemistry Control Program, and Steam Generator Integrity). Typical examples of new programs required to manage ageing include reactor vessel internals, small bore Class 1 piping, Alloy 600, buried piping, and buried high voltage cable exposed to wetted environments. At present, there have been no commitments by any utility to replace components as a result of license renewal. After the NRC has approved a license renewal application, the credited ageing management programs (i.e., existing and new) become commitments for the remaining plant life. These commitments typically form the bases for a comprehensive plant life management program (PLIM). PLIM differs from license renewal in that it considers active and passive components as well as economics of plant operation and maintenance. Plants that have recently received renewed

  18. The impact of the MCU life extension solvent on sludge batch 8 projected operating windows

    International Nuclear Information System (INIS)

    Peeler, D.K.; Edwards, T.B.

    2013-01-01

    As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01 M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B203 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B203 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

  19. Model 9975 Life Extension Test Package 3 - Interim Report - January 2017

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-01-31

    Life extension package LE3 (9975-03203) has been instrumented and subjected to an elevated temperature environment for approximately 8 years. During this time, the cane fiberboard has been maintained at a maximum temperature of ~160 - 165 °F, which was established by a combination of internal (19 watts) and external heat sources. Several tests and parameters were used to characterize the package components. Results from these tests generally indicate agreement between this full-scale shipping package and small-scale laboratory tests on fiberboard samples, including the degradation models based on the laboratory tests. These areas of agreement include the rate of change of fiberboard weight, dimensions and density, and change in fiberboard thermal conductivity. Corrosion of the lead shield occurred at a high rate during the first several weeks of aging, but dropped significantly after most of the moisture in the fiberboard migrated away from the lead shield. Dimensional measurements of the lead shield indicate that no significant creep deformation has occurred. This is consistent with literature data that predict a very small creep deformation for the time at temperature experienced by this package. The SCV O-rings were verified to remain leak-tight after ~5 years aging at an average temperature of ~170 °F. This package provides an example of the extent to which moisture within a typical fiberboard assembly can redistribute in the presence of a temperature gradient such as might be created by a 19 watt internal heat load. The majority of water within the fiberboard migrated to the bottom layers of fiberboard, with approximately 2 kg of water (2 liters) eventually escaping from the package. Two conditions have developed that are not consistent with package certification requirements. The axial gap at the top of the package increased to a maximum value of 1.549 inches, exceeding the 1 inch criterion. In addition, staining and/or corrosion have formed in a few spots

  20. Only in dying, life: programmed cell death during plant development.

    Science.gov (United States)

    Van Hautegem, Tom; Waters, Andrew J; Goodrich, Justin; Nowack, Moritz K

    2015-02-01

    Programmed cell death (PCD) is a fundamental process of life. During the evolution of multicellular organisms, the actively controlled demise of cells has been recruited to fulfil a multitude of functions in development, differentiation, tissue homeostasis, and immune systems. In this review we discuss some of the multiple cases of PCD that occur as integral parts of plant development in a remarkable variety of cell types, tissues, and organs. Although research in the last decade has discovered a number of PCD regulators, mediators, and executers, we are still only beginning to understand the mechanistic complexity that tightly controls preparation, initiation, and execution of PCD as a process that is indispensable for successful vegetative and reproductive development of plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Age- and calorie-independent life span extension from dietary restriction by bacterial deprivation in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Sager Jennifer

    2008-05-01

    Full Text Available Abstract Background Dietary restriction (DR increases life span and delays age-associated disease in many organisms. The mechanism by which DR enhances longevity is not well understood. Results Using bacterial food deprivation as a means of DR in C. elegans, we show that transient DR confers long-term benefits including stress resistance and increased longevity. Consistent with studies in the fruit fly and in mice, we demonstrate that DR also enhances survival when initiated late in life. DR by bacterial food deprivation significantly increases life span in worms when initiated as late as 24 days of adulthood, an age at which greater than 50% of the cohort have died. These survival benefits are, at least partially, independent of food consumption, as control fed animals are no longer consuming bacterial food at this advanced age. Animals separated from the bacterial lawn by a barrier of solid agar have a life span intermediate between control fed and food restricted animals. Thus, we find that life span extension from bacterial deprivation can be partially suppressed by a diffusible component of the bacterial food source, suggesting a calorie-independent mechanism for life span extension by dietary restriction. Conclusion Based on these findings, we propose that dietary restriction by bacterial deprivation increases longevity in C. elegans by a combination of reduced food consumption and decreased food sensing.

  2. Prognostics and Life Beyond 60 for Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Leonard J. Bond; Pradeep Ramuhalli; Magdy S. Tawfik; Nancy J. Lybeck

    2011-06-01

    Safe, secure, reliable and sustainable energy supply is vital for advanced and industrialized life styles. To meet growing energy demand there is interest in longer term operation (LTO) for the existing nuclear power plant fleet and enhancing capabilities in new build. There is increasing use of condition based maintenance (CBM) for active components and periodic in service inspection (ISI) for passive systems: there is growing interest in deploying on-line monitoring. Opportunities exist to move beyond monitoring and diagnosis based on pattern recognition and anomaly detection to and prognostics with the ability to provide an estimate of remaining useful life (RUL). The adoption of digital I&C systems provides a framework within which added functionality including on-line monitoring can be deployed, and used to maintain and even potentially enhance safety, while at the same time improving planning and reducing both operations and maintenance costs.

  3. The life prediction study of Rokkasho reprocessing plant materials

    International Nuclear Information System (INIS)

    Kiuchi, K.; Yano, M.; Takizawa, M.; Shibata, S.

    1998-01-01

    The life prediction study of major equipment materials used in heavily corrosive nitric acid solutions of the RRP was carried out. The nitric acid recovery made of type 304ULC austenitic steel and the dissolver made of type 705 metallic zirconium are selected on the present study. This study is composed of major three programs, namely, the mock-up tests by small-sized equipments simulated to the practical design, laboratory tests for examining corrosion controlling factors by small specimens and to establish the data base system for the life prediction. Important parameters on this study was extracted with analyzing the past data of the life prediction on the Tokai reprocessing equipments. The mock-ups design was made by considering the quantitative evaluation of the most important parts on objective equipments, namely, heat conducting tubes in an acid recovery evaporator and a thermal jacket in a dissolver. From pre-examinations, the effects of radioactive species, nitric acid solution chemistry, the corrosion mechanisms were elucidated. Mock-up testing conditions corrosion monitoring methods and a data base concept for the the life prediction were selected from pre-examination data by referencing the plant operation planning. (author)

  4. TAF-4 is required for the life extension of isp-1, clk-1 and tpk-1 Mit mutants.

    Science.gov (United States)

    Khan, Maruf H; Ligon, Melissa; Hussey, Lauren R; Hufnal, Bryce; Farber, Robert; Munkácsy, Erin; Rodriguez, Amanda; Dillow, Andy; Kahlig, Erynn; Rea, Shane L

    2013-10-01

    While numerous life-extending manipulations have been discovered in the nematode Caenorhabditis elegans, one that remains most enigmatic is disruption of oxidative phosphorylation. In order to unravel how such an ostensibly deleterious manipulation can extend lifespan, we sought to identify the ensemble of nuclear transcription factors that are activated in response to defective mitochondrial electron transport chain (ETC) function. Using a feeding RNAi approach, we targeted over 400 transcription factors and identified 15 that, when reduced in function, reproducibly and differentially altered the development, stress response, and/or fecundity of isp-1(qm150) Mit mutants relative to wild-type animals. Seven of these transcription factors--AHA-1, CEH-18, HIF-1, JUN-1, NHR-27, NHR-49 and the CREB homolog-1 (CRH-1)-interacting protein TAF-4--were also essential for isp-1 life extension. When we tested the involvement of these seven transcription factors in the life extension of two other Mit mutants, namely clk-1(qm30) and tpk-1(qm162), TAF-4 and HIF-1 were consistently required. Our findings suggest that the Mit phenotype is under the control of multiple transcriptional responses, and that TAF-4 and HIF-1 may be part of a general signaling axis that specifies Mit mutant life extension.

  5. Physics based modeling of a series parallel battery pack for asymmetry analysis, predictive control and life extension

    Science.gov (United States)

    Ganesan, Nandhini; Basu, Suman; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Yeo, Taejung; Sohn, Dong Kee; Doo, Seokgwang

    2016-08-01

    Lithium-Ion batteries used for electric vehicle applications are subject to large currents and various operation conditions, making battery pack design and life extension a challenging problem. With increase in complexity, modeling and simulation can lead to insights that ensure optimal performance and life extension. In this manuscript, an electrochemical-thermal (ECT) coupled model for a 6 series × 5 parallel pack is developed for Li ion cells with NCA/C electrodes and validated against experimental data. Contribution of the cathode to overall degradation at various operating conditions is assessed. Pack asymmetry is analyzed from a design and an operational perspective. Design based asymmetry leads to a new approach of obtaining the individual cell responses of the pack from an average ECT output. Operational asymmetry is demonstrated in terms of effects of thermal gradients on cycle life, and an efficient model predictive control technique is developed. Concept of reconfigurable battery pack is studied using detailed simulations that can be used for effective monitoring and extension of battery pack life.

  6. International Working Group on Life Management of Nuclear Power Plants. (IWG-LMNPP). Regular meeting. Working material. V. 2

    International Nuclear Information System (INIS)

    1998-01-01

    National programs of Hungary, Japan, Korea, Russian Federation, Bulgaria, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom and USA, related to nuclear power plants life management presented at the Technical Committee Meeting are published in this volume. The main features of the reports are oriented towards extension of NPP lifetime and conditions indispensable to achieve in order to fulfil the safety requirements including testing the mechanical properties of relevant reactor components

  7. International Working Group on Life Management of Nuclear Power Plants. (IWG-LMNPP). Regular meeting. Working material. V. 1

    International Nuclear Information System (INIS)

    1998-01-01

    National programs of Argentina, Brazil, Belgium, Czech Republic, Canada, France and Germany related to nuclear power plants life management presented at the Technical Committee Meeting are published in this volume. Finnish report VTT-TIED-1843 included in this volume was already included separately in the INIS Database. The main features of the reports are oriented towards extension of NPP lifetime and conditions indispensable to achieve in order to fulfil the safety requirements including testing the mechanical properties of relevant reactor components

  8. Plant life management and modernisation: Research challenges in the EU

    International Nuclear Information System (INIS)

    Rintamaa, R.; Aho-Mantila, I.

    2011-01-01

    The European network of excellence NULIFE (nuclear plant life prediction) has been launched with a clear focus on integrating safety-oriented research on materials, structures and systems and exploiting the results of this integration through the production of harmonised lifetime assessment methods. NULIFE will help provide a better common understanding of the factors affecting the lifetime of nuclear power plants which, together with associated management methods, will help facilitate safe and economic long-term operation of existing nuclear power plants. In addition, NULIFE will help in the development of design criteria for future generations of nuclear power plant. NULIFE was kicked-off in October 2006 and will work over a 5-year period to create a single organization structure, capable of providing harmonised research and development (R and D) at European level to the nuclear power industry and the related safety authorities. Led by VTT (Technical Research Centre of Finland), the project has a total budget in excess of 8 million euros, with over 40 partners drawn from leading research institutions, technical support organizations, electric power utilities and manufacturers throughout Europe. NULIFE also involves many industrial organizations and, in addition to their R and D contributions, these take part in a dedicated End User Group. Over the last 15 years the European Commission has sponsored a significant number of R and D projects under the Euratom Framework Programme and its Joint Research Centre has developed co-operative European Networks for mutual benefits on specific topics related to plant life management. However, their overall impact has been reduced due to fragmentation. These networks are considered forerunners to NULIFE. The importance of the long-term operation of the plants has been recognized at European level, in the strategic research agenda of SNETP (Sustainable Nuclear Energy Technology Platform). In NULIFE, the joint EU

  9. Environmental life cycle assessment of high temperature nuclear fission and fusion biomass gasification plants

    International Nuclear Information System (INIS)

    Takeda, Shutaro; Sakurai, Shigeki; Kasada, Ryuta; Konishi, Satoshi

    2017-01-01

    The authors propose nuclear biomass gasification plant as an advancement of conventional gasification plants. Environmental impacts of both fission and fusion plants were assessed through life cycle assessment. The result suggested the reduction of green-house gas emissions would be as large as 85.9% from conventional plants, showing a potential for the sustainable future for both fission and fusion plants. (author)

  10. Shelf life extension of litchi (Litchi chinensis) and overcoming quarantine barriers to international trade using radiation technology

    International Nuclear Information System (INIS)

    Gautam, Satyendra; Saxena, Sudhanshu; Kumar, Sanjeev; Hajare, Sachin N.; Wadhawan, Surbhi; Mishra, B.B.; More, Varsha S.; Sharma, Arun

    2010-01-01

    Litchi (Litchi chinensis) has a very short shelf life of 2-3 days at ambient temperature limiting its marketability. Gamma radiation processing in combination with low temperature storage was explored as a method to achieve shelf life extension and fulfill quarantine requirement for export during storage physics, biochemical, microbiological, organoleptic, antioxidant and radioprotective properties of two major commercially grown Indian cultivars of litchi, 'Shahi' and 'China', were analysed. Radiation treatment reduced microbial load in a dose dependent manner. Radiation (0.5kGy) treated and low temperature stored fruits retained the 'good' organoleptic rating till 28 days of storage while maintaining other quality attributes. (author)

  11. The Impact Of The MCU Life Extension Solvent On Sludge Batch 8 Projected Operating Windows

    International Nuclear Information System (INIS)

    Peeler, D. K.; Edwards, T. B.; Stone, M. E.

    2013-01-01

    As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS) and a new strip acid will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing or evaluations with the next generation solvent are required to determine the impact of these changes (if any) to Chemical Process Cell (CPC) activities, glass formulation strategies, and melter operations at the Defense Waste Processing Facility (DWPF). The introduction of the dilute (0.01M) boric acid stream into the DWPF flowsheet has a potential impact on glass formulation and frit development efforts since B2O3 is a major oxide in frits developed for DWPF. Prior knowledge of this stream can be accounted for during frit development efforts but that was not the case for Sludge Batch 8 (SB8). Frit 803 has already been recommended and procured for SB8 processing; altering the frit to account for the incoming boron from the strip effluent (SE) is not an option for SB8. Therefore, the operational robustness of Frit 803 to the introduction of SE including its compositional tolerances (i.e., up to 0.0125M boric acid) is of interest and was the focus of this study. The primary question to be addressed in the current study was: What is the impact (if any) on the projected operating windows for the Frit 803 - SB8 flowsheet to additions of B2O3 from the SE in the Sludge Receipt and Adjustment Tank (SRAT)? More specifically, will Frit 803 be robust to the potential compositional changes occurring in the SRAT due to sludge variation, varying additions of ARP and/or the introduction of SE by providing access to waste loadings (WLs) of interest to DWPF? The Measurement Acceptability Region (MAR) results indicate there is very little, if any, impact on the projected operating windows for the Frit 803 - SB8 system regardless of the presence or absence of

  12. The Impact Of The Mcu Life Extension Solvent On Dwpf Glass Formulation Efforts

    International Nuclear Information System (INIS)

    Peeler, D.; Edwards, T.

    2011-01-01

    As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NG-CSSX), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes in 512-S operations as well as Chemical Process Cell (CPC), Defense Waste Processing Facility (DWPF) glass formulation activities, and melter operations at DWPF. To support programmatic objectives, the downstream impacts of the boric acid strip effluent (SE) to the glass formulation activities and melter operations are considered in this study. More specifically, the impacts of boric acid additions to the projected SB7b operating windows, potential impacts to frit production temperatures, and the potential impact of boron volatility are evaluated. Although various boric acid molarities have been reported and discussed, the baseline flowsheet used to support this assessment was 0.01M boric acid. The results of the paper study assessment indicate that Frit 418 and Frit 418-7D are robust to the implementation of the 0.01M boric acid SE into the SB7b flowsheet (sludge-only or ARP-added). More specifically, the projected operating windows for the nominal SB7b projections remain essentially constant (i.e., 25-43 or 25-44% waste loading (WL)) regardless of the flowsheet options (sludge-only, ARP added, and/or the presence of the new SE). These results indicate that even if SE is not transferred to the Sludge Receipt and Adjustment Tank (SRAT), there would be no need to add boric acid (from a trim tank) to compositionally compensate for the absence of the boric acid SE in either a sludge-only or ARP-added SB7b flowsheet. With respect to boron volatility, the Measurement Acceptability Region (MAR) assessments also

  13. Nitrogen vs argon: what is the most effective atmosphere for shelf-life extension of buckler sorrel leaves?

    OpenAIRE

    Pinela, José; Barros, Lillian; Antonio, Amilcar L.; Barreira, João C.M.; Carvalho, Ana Maria; Oliveira, M.B.P.P.; Ferreira, Isabel C.F.R.

    2016-01-01

    Buckler sorrel (Rumex induratus Boiss. & Reut.) is an underutilized leafy vegetable with peculiar sensory properties and potential as a gourmet food. In the food industry, different packaging methods have been used for shelf-life extension, but it is important to know how the quality of minimally processed vegetable is affected by these treatments. Recently, nitrogen and argon have been used for food packaging. Nitrogen is low soluble in water and other food constituents and does ...

  14. Overview of plant life management for long term operation in nuclear power plants

    International Nuclear Information System (INIS)

    Kang, K.S.; Vincze, P.; Bychkov, A.

    2014-01-01

    Many IAEA member states have given high priority to licensing their nuclear power plants to operate for terms longer than the time frame originally anticipated (generally 40 years). The task of managing plant ageing is assigned in most member states to an engineering specialty called 'plant life management' (PLiM) applying a systematic analysis methodology to System Structure Components (SSCs) ageing. In many countries, the safety performance of nuclear power plants is periodically assessed and characterized via the periodic safety review (PSR) process. Regulatory review and acceptance of PSRs constitutes for these countries the licensing requirement for continued operation of the plant to the following PSR cycle (usually 10 years). In the USA and in other countries operating US designed plants, instead of PSR process, a license renewal application (LRA) process is followed, which requires certain prerequisites such as ageing management programs, particularly for passive irreplaceable SSCs. Active components are normally addressed via the maintenance rule (MR) requirements and other established regulatory processes. A third group of member states have adopted a combined approach that incorporates elements of both the PSR process and selected LRA specific requirements, such as time limited ageing analysis. The article ends with some IAEA recommendations for the implementation of national PLiM programs

  15. Life management plants at nuclear power plants PWR; Planes de gestion de vida en centrales nucleares PWR

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, G.

    2014-10-01

    Since in 2009 the CSN published the Safety Instruction IS-22 (1) which established the regulatory framework the Spanish nuclear power plants must meet in regard to Life Management, most of Spanish nuclear plants began a process of convergence of their Life Management Plants to practice 10 CFR 54 (2), which is the current standard of Spanish nuclear industry for Ageing Management, either during the design lifetime of the plant, as well as for Long-Term Operation. This article describe how Life Management Plans are being implemented in Spanish PWR NPP. (Author)

  16. Lack of robustness of life extension associated with several single-gene P element mutations in Drosophila melanogaster.

    Science.gov (United States)

    Mockett, Robin J; Nobles, Amber C

    2013-10-01

    The hypothesis tested in this study was that single-gene mutations found previously to extend the life span of Drosophila melanogaster could do so consistently in both long-lived y w and standard w (1118) genetic backgrounds. GAL4 drivers were used to express upstream activation sequence (UAS)-responder transgenes globally or in the nervous system. Transgenes associated with oxidative damage prevention (UAS-hSOD1 and UAS-GCLc) or removal (EP-UAS-Atg8a and UAS-dTOR (FRB) ) failed to increase mean life spans in any expression pattern in either genetic background. Flies containing a UAS-EGFP-bMSRA (C) transgene associated with protein repair were found not to exhibit life extension or detectable enhanced green fluorescent protein (EGFP) activity. The presence of UAS-responder transgenes was confirmed by PCR amplification and sequencing at the 5' and 3' end of each insertion. These results cast doubt on the robustness of life extension in flies carrying single-gene mutations and suggest that the effects of all such mutations should be tested independently in multiple genetic backgrounds and laboratory environments.

  17. Factors affecting the longevity of interim ILW stores, monitoring methods and techniques supporting store life extension - 59151

    International Nuclear Information System (INIS)

    Morris, Jenny; Wickham, Stephen; Hicks, Tim; Richardson, Phil; McKinney, James; Morris, Darrell; Brownridge, Melanie; Tearle, Mark

    2012-01-01

    Life-limiting features of stores (i.e. components of a typical Intermediate Level Waste (ILW) store that are vulnerable to failure) can be separated into those related to store design, the continuing operation of the store and equipment and store management. Environmental factors, including temperature, humidity, atmospheric pollutants and radiation fields also affect the longevity of ILW storage buildings and the integrity of the waste packages within the store. The current condition of the store and the causes and rates of any observed deterioration need to be determined to estimate the current operating life of the store and to analyse the costs and benefits associated with life extension. Suitable monitoring techniques and methods for extending the operating life of stores, either by remediation or replacement of identified life-limiting features, have also been assessed. Techniques including visual inspection (directly or by use of CCTV or inspection cells), corrosion coupons, crane monitoring and a wide range of indirect measurement methods can be used to monitor the condition of life-limiting features and the store environment. Methods for extending store life include the application of paint or coatings to retard degradation, use of electro-chemical treatments and repair of the concrete structure or replacement of components. Life-limiting features and environmental factors that affect the longevity of facilities for the interim storage of ILW have been identified through a literature review and Expert Workshop. Monitoring techniques are available for the key life-limiting feature of structural integrity of reinforced concrete, and for the atmospheric or surface concentration of corrosion-accelerating substances. Methods for remediating the reinforced concrete structure or crane rails to increase the expected lifetime of the store are also reviewed. Many of these techniques have previously been used at radioactive waste stores or other nuclear facilities in

  18. Application of the Combined Cycle LWR-Gas Turbine to PWR for NPP Life Extension Safety Upgrade and Improving Economy

    International Nuclear Information System (INIS)

    Kuznetsov, Yu. N.

    2006-01-01

    Currently, some of the most important problem for the nuclear industry are life extension, advance competitiveness and safety of aging LWR NPPs. Based on results of studies performed in the USA (Battelle Memorial Institute) and in Russia (NIKIET), a new power technology, using a combined cycle gas-turbine facility CCGT - LWR, so called TD-Cycle, can significantly help in resolution of some problems of nuclear power industry. The nuclear steam and gas topping cycle is used for re-powering a light water pressurized reactor of PWR or VVER type. An existing NPP is topped with a gas turbine facility with a heat recovery steam generator (HRSG) generating steam from waste heat. The superheated steam of high pressure (P=90-165 bar, T=500-550 C) generated in the HRSG, is expanded in a high pressure (HP) turbine for producing electricity. The HP turbine can work on one shaft with the the gas turbine or at one shaft with intermediate (IP) or low (LP) pressure parts of the main nuclear steam turbine, or with a separate electric generator. The exhausted steam from the HP turbine is injected into the steam mixer where it is mixed with the saturated steam from the NPP steam generator (SG). The mixer is intended to superheat the main nuclear steam and should be characterized by minimum losses during mixing superheated and saturated steam. Steam from the mixer superheated by 20-60 C directs to the existing IP turbine, and then, through a separator-reheater flows into the LP turbine. Feed water re-heaters of LP and HP are actually unchanged in this case. Feed water extraction to the HRSG is supplied after one of LP water heaters. This proposal is intended to re-power existing LWR NPPs. To minimize cost, the IP and LP turbines and electric generator would remain the same. The reactor thermal power and fast neutron flux to the reactor vessel would decrease by 30-50 percent of nominal values. The external peripheral row of fuel elements can be replaced with metal absorber rods to

  19. Report on countermeasure to plant life management of the nuclear power plants at three electric power companies

    International Nuclear Information System (INIS)

    1999-01-01

    Three nuclear power reactors of the Fukushima-1 nuclear power plant, the Mihama-1 power plant and the Tsuruga-1 power plant were investigated according to the estimation plan shown in the Fundamental Concept on Plant Life Management of Agency of Natural Resources and Energy, Ministry of International Trade and Industry on April, 1996. Their reports contained the technical evaluation against, the responsive items to and the future examinations of the plant life management. In special, in the responsive items, some items to be added to the present maintenance process and some technical developmental problems are described in details and concretely. (G.K.)

  20. Plant life time management for safe long term operation

    International Nuclear Information System (INIS)

    Burket, Danes

    2010-01-01

    The topics discussed include LTO (long-term operation) and licensing procedure in general and specifically for the Dukovany NPP, components of an LTO programme, the PLIM (plant life management) concept for Dukovany and Temelin, the LTO implementation project for Dukovany, LTO strategy, LTO risk study, international verification. The Conclusions include the following items: (i) Technical-economic study of Dukovany NPP LTO demonstrates technical feasibility and economic profitability of Dukovany NPP LTO with perspective for up to 60 years of operation. (ii) Safety part of Program for assurance of Dukovany NPP LTO complies with IAEA SALTO recommendations. (iii) Dukovany NPP LTO programme incorporated IAEA SALTO Peer Review Mission recommendations. (iv) LTO Implementation Project for 2009-2015 was approved with major targets to renew operational permission and prepare NPP for operation up to 60 years. (v) Preparation of Temelin NPP LTO programme has been started. (P.A.)

  1. 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

  2. French nuclear plants PWR vessel integrity assessment and life management

    Energy Technology Data Exchange (ETDEWEB)

    Bezdikian, G. [Electricite de France (EDF), Div. Production Nucleaire, 93 - Saint-Denis (France); Quinot, P. [FRAMATOME, Dept. Bloc Reacteur et Boucles Primaires, 92 - Paris-La-Defence (France); Faidy, C.; Churier-Bossennec, H. [Electricite de France (EDF), Div. Ingenierie et Service, 69 - Villeurbanne (France)

    2001-07-01

    The Reactor Pressure Vessel life management of 56 PWR 3 loop and 4 loop reactors units was engaged by the French Utility EDF (Electricite de France) a few years ago and is yet on going on. This paper will present the work carried out within the framework of justifying why the 34 three loop reactor vessels will remain acceptable for operation for a lifetime of at least 40-years. A summary of the measures will be given. An overall review of actions will be presented describing the French approach, using important existing databases, including studies related to irradiation surveillance monitoring program and end of life fluence assessment. The last results obtained are based on generic integrity analyses for all categories of situations (normal upset emergency and faulted conditions) until the end of lifetime, postulating circumferential an radial kinds of flaw located in the stainless steel cladding or shallow sub-cladding area. The results of structural integrity analyses beginning with elastic computations and completed with three-dimensional finite element elastic plastic computations for envelope cases, are compared with code criteria for operating plants. The objective is to evaluate the margins on different parameters as RTNDT (Reference Nil Ductility Transition Temperature), toughness or crack size, to justify the global fitness for service of all these Reactor Pressure Vessels. The paper introduces EDF's maintenance strategy, related to integrity assessment, for those nuclear power plants under operation, based on NDE in-service inspection of the first thirty millimeters in the thickness of the wall and major surveillance programs of the vessels. (author)

  3. French nuclear plants PWR vessel integrity assessment and life management

    International Nuclear Information System (INIS)

    Bezdikian, G.; Quinot, P.; Faidy, C.; Churier-Bossennec, H.

    2001-01-01

    The Reactor Pressure Vessel life management of 56 PWR 3 loop and 4 loop reactors units was engaged by the French Utility EDF (Electricite de France) a few years ago and is yet on going on. This paper will present the work carried out within the framework of justifying why the 34 three loop reactor vessels will remain acceptable for operation for a lifetime of at least 40-years. A summary of the measures will be given. An overall review of actions will be presented describing the French approach, using important existing databases, including studies related to irradiation surveillance monitoring program and end of life fluence assessment. The last results obtained are based on generic integrity analyses for all categories of situations (normal upset emergency and faulted conditions) until the end of lifetime, postulating circumferential an radial kinds of flaw located in the stainless steel cladding or shallow sub-cladding area. The results of structural integrity analyses beginning with elastic computations and completed with three-dimensional finite element elastic plastic computations for envelope cases, are compared with code criteria for operating plants. The objective is to evaluate the margins on different parameters as RTNDT (Reference Nil Ductility Transition Temperature), toughness or crack size, to justify the global fitness for service of all these Reactor Pressure Vessels. The paper introduces EDF's maintenance strategy, related to integrity assessment, for those nuclear power plants under operation, based on NDE in-service inspection of the first thirty millimeters in the thickness of the wall and major surveillance programs of the vessels. (author)

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

    International Nuclear Information System (INIS)

    Gibelli, Sonia Maria Orlando

    2008-03-01

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

  5. A study on development of a rule based expert system for steam generator life extension

    International Nuclear Information System (INIS)

    Park, Jin Kyun

    1994-02-01

    The need of predicting the integrity of the steam generator(SG) tubes and environmental conditions that affect their integrity is growing to secure nuclear power plant(NPP) safety and enhance plant availability. To achieve their objectives it is important to diagnose the integrity of the SG tubes. An expert system called FEMODES(failure mode diagnosis expert system) has been developed for diagnosis of such tube degradation phenomena as denting, intergranular attack(IGA) and stress corrosion cracking(SCC) in the secondary side of the SG. It is possible with use of FEMODES to estimate possibilities of SG tube degradation and diagnosis environmental conditions that influence such tube degradation. The method of certainty factor theory(CFT) and the rule based backward reasoning inference strategy are used to develop FEMODES. The information required for diagnosis is acquired from SG tube degradation experiences of two local reference plants, some limited oversea plants and technical reports/research papers about such tube degradation. Overall results estimated with use of FEMODES are in reasonable agreement with actual SG tube degradation. Some discrepancy observed in several estimated values of SG tube degradation appears to be due to insufficient heuristic knowledge for knowledge data base of FEMODES

  6. Does extensive agriculture influence the concentration of trace elements in the aquatic plant Veronica anagallis-aquatica?

    Science.gov (United States)

    Kroflič, Ana; Germ, Mateja; Golob, Aleksandra; Stibilj, Vekoslava

    2018-04-15

    The present study describes the influence of extensive agriculture on the concentrations of As, Cr, Cu, Cd, Se, Pb and Zn in sediments and in the aquatic plant Veronica anagallis-aquatica. The investigation, spanning 4 years, was conducted on three watercourses in Slovenia (Pšata, Lipsenjščica and Žerovniščica) flowing through agricultural areas. The different sampling sites were chosen on the basis of the presence of different activities in these regions: dairy farming, stock raising and extensive agriculture. The concentrations of the selected elements in sediments and V. anagallis-aquatica were below the literature background values. The distribution of the selected elements among different plant parts (roots, stems and leaves) were also investigated. The majority of the studied elements, with the exception of Zn and Cu, were accumulated mainly in root tissues. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Plant X-tender: An extension of the AssemblX system for the assembly and expression of multigene constructs in plants

    Science.gov (United States)

    Machens, Fabian; Coll, Anna; Baebler, Špela; Messerschmidt, Katrin; Gruden, Kristina

    2018-01-01

    Cloning multiple DNA fragments for delivery of several genes of interest into the plant genome is one of the main technological challenges in plant synthetic biology. Despite several modular assembly methods developed in recent years, the plant biotechnology community has not widely adopted them yet, probably due to the lack of appropriate vectors and software tools. Here we present Plant X-tender, an extension of the highly efficient, scar-free and sequence-independent multigene assembly strategy AssemblX, based on overlap-depended cloning methods and rare-cutting restriction enzymes. Plant X-tender consists of a set of plant expression vectors and the protocols for most efficient cloning into the novel vector set needed for plant expression and thus introduces advantages of AssemblX into plant synthetic biology. The novel vector set covers different backbones and selection markers to allow full design flexibility. We have included ccdB counterselection, thereby allowing the transfer of multigene constructs into the novel vector set in a straightforward and highly efficient way. Vectors are available as empty backbones and are fully flexible regarding the orientation of expression cassettes and addition of linkers between them, if required. We optimised the assembly and subcloning protocol by testing different scar-less assembly approaches: the noncommercial SLiCE and TAR methods and the commercial Gibson assembly and NEBuilder HiFi DNA assembly kits. Plant X-tender was applicable even in combination with low efficient homemade chemically competent or electrocompetent Escherichia coli. We have further validated the developed procedure for plant protein expression by cloning two cassettes into the newly developed vectors and subsequently transferred them to Nicotiana benthamiana in a transient expression setup. Thereby we show that multigene constructs can be delivered into plant cells in a streamlined and highly efficient way. Our results will support faster

  8. Plant X-tender: An extension of the AssemblX system for the assembly and expression of multigene constructs in plants.

    Science.gov (United States)

    Lukan, Tjaša; Machens, Fabian; Coll, Anna; Baebler, Špela; Messerschmidt, Katrin; Gruden, Kristina

    2018-01-01

    Cloning multiple DNA fragments for delivery of several genes of interest into the plant genome is one of the main technological challenges in plant synthetic biology. Despite several modular assembly methods developed in recent years, the plant biotechnology community has not widely adopted them yet, probably due to the lack of appropriate vectors and software tools. Here we present Plant X-tender, an extension of the highly efficient, scar-free and sequence-independent multigene assembly strategy AssemblX, based on overlap-depended cloning methods and rare-cutting restriction enzymes. Plant X-tender consists of a set of plant expression vectors and the protocols for most efficient cloning into the novel vector set needed for plant expression and thus introduces advantages of AssemblX into plant synthetic biology. The novel vector set covers different backbones and selection markers to allow full design flexibility. We have included ccdB counterselection, thereby allowing the transfer of multigene constructs into the novel vector set in a straightforward and highly efficient way. Vectors are available as empty backbones and are fully flexible regarding the orientation of expression cassettes and addition of linkers between them, if required. We optimised the assembly and subcloning protocol by testing different scar-less assembly approaches: the noncommercial SLiCE and TAR methods and the commercial Gibson assembly and NEBuilder HiFi DNA assembly kits. Plant X-tender was applicable even in combination with low efficient homemade chemically competent or electrocompetent Escherichia coli. We have further validated the developed procedure for plant protein expression by cloning two cassettes into the newly developed vectors and subsequently transferred them to Nicotiana benthamiana in a transient expression setup. Thereby we show that multigene constructs can be delivered into plant cells in a streamlined and highly efficient way. Our results will support faster

  9. Spoilage and shelf-life extension of fresh fish and shellfish.

    Science.gov (United States)

    Ashie, I N; Smith, J P; Simpson, B K

    1996-01-01

    Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish-processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low-dose irradiation, ultra-high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.

  10. Transitions in waste treatment as a driver for product life extension

    DEFF Research Database (Denmark)

    Lauridsen, Erik Hagelskjær; Jørgensen, Michael Søgaard

    2015-01-01

    that emphasise prolonged product life and stresses the importance of avoiding down cycling of products and material streams. The destabilisation of the old incineration regime thus opens up for new opportunities with both new policies and potentially new social practices. This paper describes a number...

  11. Use of plant specific information in life management

    International Nuclear Information System (INIS)

    Simola, K.; Talja, H.

    2002-01-01

    In plant life management decisions are made on prevention and mitigation measures of ageing phenomena. In these processes, information from several sources has to be combined, and the decisions are based on data and analyses including lots of uncertainties. In order to make good decisions, the uncertainties and limitations related to both analyses and the raw data should be recognised. A schematic presentation of the information used in the decision making with an emphasis on data needs and analyses for the technical life assessment of a component is given. On the way from the raw data to the final decision on ageing management there are several steps where engineering judgement is used or more sophisticated analyses are made. In this paper we present a view upon the decision making process in managing the ageing of components, systems and structures. Further, we propose practices to improve the transparency of ageing analyses and means to improve the availability and usability of plant specific information for ageing management purposes. The availability of plant specific information and easy access to these records are vital for the efficient ageing management. Often, the data collection and record keeping has not been organised in an efficient way and the use of experience data is very laborious. As illustrated, a lot of plant specific information is needed in ageing assessment. It is also very important to ensure that the information is up-to-date, e.g. possible modifications are taken into account in lifetime predictions. As an example of improvement in the data collection practices we shortly summarise the pipeline analysis and monitoring system that VTT is developing together with TVO. The system is meant to contain all up-to-date information necessary to analyse and monitor piping systems of an operating plant. The core of the system contains five databases. Piping database contains information like geometry, material, loading, detected cracks etc. All

  12. How does react power price on a possible lifetime extension for power plants? Nuclear power, power prices and power market models; Wie reagiert der Strompreis auf eine moegliche Verlaengerung der Laufzeiten fuer Kernkraftwerke? Kernkraft, Strompreis und Strommarktmodelle

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, Uwe [Buendnis 90/Die Gruenen, Berlin (Germany). Bundesarbeitsgemeinschaft Energie

    2010-08-23

    Extending the life of the nuclear power plants currently operated in Germany is being discussed in the light of a more likely change in government for a Christian Democrat/Liberal coalition. The reason cited most frequently is the impossibility to meet the objectives of climate protection without raising further the price of electricity if the life of nuclear power plants cannot be extended. The question to be looked into is that of the legal pre-requisites to be established in Germany in order for the existing nuclear power plants to be operated for longer periods of time. So in this contribution some discussion is done wether a possible lifetime extension of nuclear power plants will react on power prices.(GL)

  13. An extension of the plant ontology project supporting wood anatomy and development research

    Science.gov (United States)

    Federic Lens; Laurel Cooper; Maria Alejandra Gandolfo; Andrew Groover; Pankaj Jaiswal; Barbara Lachenbruch; Rachel Spicer; Margaret E. Staton; Dennis W. Stevenson; Ramona L. Walls; Jill. Wegrzyn

    2012-01-01

    A wealth of information on plant anatomy and morphology is available in the current and historical literature, and molecular biologists are producing massive amounts of transcriptome and genome data that can be used to gain better insights into the development, evolution, ecology, and physiological function of plant anatomical attributes. Integrating anatomical and...

  14. Decentralized power plants. Steam engines in an agriculture cooperative in Paraguay, plant extension in cooperation with the GTZ

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    About 1 cent are the running costs to generate 1 kWh - less than three years is the time for return of investment: tThat are the facts of steam engines using tungfruit shells as a fuel. The more oil prices are rising the more efficiently will such plants work. The way an agricultural cooperative in Paraquay changed their power supply is a good example for varying decentralized power plants - and how to save oil.

  15. The opening of the debates on the extension of German nuclear plant lifetime

    International Nuclear Information System (INIS)

    Guidez, J.

    2010-01-01

    After having recalled that the German nuclear plants were to be progressively stopped by 2021, the author reports that the political coalition has thrown this Agenda back into question, because the development of alternative energies is insufficient to compensate the programmed closing down, and the German government wants to avoid the use of thermal plants which are generating CO 2 emissions. Negotiations are underway between the German government and the four electric companies in charge of different plants. It appears that even plants which were to be stopped in 2010, could keep on operating. The report contains tables indicating, for each nuclear plant, its type, its operator, its power, its dates of beginning and programmed end of commercial activity, its production variation in time. Some comments are given about already stopped reactors (Brunsbuttel and Krummel) which faced some problems in the past, and about waste storing sites (Asse, Gorleben, Morsleben, Konrad)

  16. A ubiquitin carboxyl extension protein secreted from a plant-parasitic nematode Globodera rostochiensis is cleaved in planta to promote plant parasitism.

    Science.gov (United States)

    Chronis, Demosthenis; Chen, Shiyan; Lu, Shunwen; Hewezi, Tarek; Carpenter, Sara C D; Loria, Rosemary; Baum, Thomas J; Wang, Xiaohong

    2013-04-01

    Nematode effector proteins originating from esophageal gland cells play central roles in suppressing plant defenses and in formation of the plant feeding cells that are required for growth and development of cyst nematodes. A gene (GrUBCEP12) encoding a unique ubiquitin carboxyl extension protein (UBCEP) that consists of a signal peptide for secretion, a mono-ubiquitin domain, and a 12 amino acid carboxyl extension protein (CEP12) domain was cloned from the potato cyst nematode Globodera rostochiensis. This GrUBCEP12 gene was expressed exclusively within the nematode's dorsal esophageal gland cell, and was up-regulated in the parasitic second-stage juvenile, correlating with the time when feeding cell formation is initiated. We showed that specific GrUBCEP12 knockdown via RNA interference reduced nematode parasitic success, and that over-expression of the secreted Gr(Δ) (SP) UBCEP12 protein in potato resulted in increased nematode susceptibility, providing direct evidence that this secreted effector is involved in plant parasitism. Using transient expression assays in Nicotiana benthamiana, we found that Gr(Δ) (SP) UBCEP12 is processed into free ubiquitin and a CEP12 peptide (GrCEP12) in planta, and that GrCEP12 suppresses resistance gene-mediated cell death. A target search showed that expression of RPN2a, a gene encoding a subunit of the 26S proteasome, was dramatically suppressed in Gr(Δ) (SP) UBCEP12 but not GrCEP12 over-expression plants when compared with control plants. Together, these results suggest that, when delivered into host plant cells, Gr(Δ) (SP) UBCEP12 becomes two functional units, one acting to suppress plant immunity and the other potentially affecting the host 26S proteasome, to promote feeding cell formation. © 2013 The Authors The Plant Journal © 2013 Blackwell Publishing Ltd.

  17. Rights and quality of life of individuals with intellectual disability and extensive support needs

    Directory of Open Access Journals (Sweden)

    Patricia NAVAS MACHO

    2018-04-01

    Full Text Available People with intellectual (ID and developmental disabilities who have generalized or extensive support needs constitute a particularly vulnerable group that has traditionally experienced situations of exclusion. Despite this, their situation has not been a priority subject of study nor have there been specific developments in social policy to respond to their needs, which can be translated into an absence of interest in knowing the reality of these group, difficulties to guarantee the fulfillment of their rights, and lack of initiative aimed to achieve their full inclusion in society. Is therefore necessary to undertake different actions, translated into objectives of the present work: to explore and synthesize existing data on this group in our country; to detect their needs and their fulfillment; and to propose evidence-based guidelines to ensure their well-being and rights. For this purpose, the methodology used consisted of: (a a review of the most relevant scientific literature of the last ten years on ID and extensive support needs; and (b the analysis of the results yield by two national surveys carried out in Spain: the Disability, Independence, and Dependency Situations survey, EDAD (INE, 2008, and the System for Autonomy and Care for Dependency, SAAD (IMSERSO, 2016, among others. Considering the disparities observed within this group, urgent lines of action are highlighted, which are aimed to improve the knowledge about the living conditions of people with more significant ID and drive better practices in the provision of supports to this group.

  18. Effect of irradiation on the extension of shelf life of tropical food products

    International Nuclear Information System (INIS)

    Avadhani, P.N.; Lian, O.B.; Nio, L.E.

    1985-01-01

    The effect of gamma-radiation with cobalt-60 at doses ranging from 02.5 to 2.00 kGy on selected local fruits and vegetables was studied. It was found that ripening was delayed in unripe chikus at 0.5 and 1.0 kGy. At similar doses fungal infection in ripe papayas was retarded. Ripening was accelerated and shelf life was prolonged in mature, unripe papayas. Other effects noted were: mangosteens were better preserved (0.25-0.40 kGy), pineapples showed core damage (0.5-2.0 kGy), limes were damaged (0.5-1.0 kGy), and brinjals kept fresh for several days (0.5-1.0 kGy). At similar doses, acceleration of ripening was noted for green chillies, and the shelf life was prolonged for red chillies

  19. Deterioration and shelf-life extension of fish and fishery products by modified atmosphere packaging

    OpenAIRE

    Payap Masniyom

    2011-01-01

    Fish and fishery products have been recognized as a nutrition source due to their high protein content. Moreover, theycontain considerable amount of unsaturated fatty acids, especially omega-3 fatty acids, which are regarded as preventivecompounds. However, shelf-life of seafood is limited by biochemical and microbiological changes. Modified atmospherepackaging (MAP) is widely used for minimally processed fishery products including fresh meat for retarding microbial growthand enzymatic spoila...

  20. Shelf-life extension of pre-packed whole wheat flour using low dose gamma irradiation

    International Nuclear Information System (INIS)

    Rao, V.S.; Marathe, S.A.; Pednekar, M.D.; Machaiah, J.P.; Rao, B.Y.K.; Adhikari, H.R.; Thomas, Paul

    1997-01-01

    Storage studies on irradiated (0.25, 0.5 and 1.0 kGy) and non-irradiated prepacked whole wheat flour have shown that wheat flour irradiated at 0.25 kGy and stored at room temperature for 6 months did not show significant changes in the functional qualities and acceptability of the product, thereby extending the shelf-life and marketability of the product. (author). 3 refs., 4 figs

  1. Shelf life extension of fresh turmeric ( Curcuma longa L.) using gamma radiation

    Science.gov (United States)

    Dhanya, R.; Mishra, B. B.; Khaleel, K. M.; Cheruth, Abdul Jaleel

    2009-09-01

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 °C storage temperature was found to keep peeled turmeric samples microbe free and acceptable until 60 days of storage. The control sample without radiation treatment spoiled within a week of storage. The changes in color, texture and moisture content of fresh turmeric due to radiation treatment were found to be statistically insignificant.

  2. Shelf life extension of fresh turmeric (Curcuma longa L.) using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dhanya, R. [P.G. Department and Research Centre in Botany, Sir Syed College, Taliparamba 670142, Kerala (India); Mishra, B.B. [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Khaleel, K.M. [P.G. Department and Research Centre in Botany, Sir Syed College, Taliparamba 670142, Kerala (India)], E-mail: khaleelchovva@yahoo.co.in; Cheruth, Abdul Jaleel [DMJM International (Cansult Maunsell/AECOM Ltd.), Consultant of Gardens Sector Projects, Alain Municipality and Eastern Emirates, P.O. Box 1419, Al-Ain, Abu Dhabi (United Arab Emirates)], E-mail: abdul79jaleel@yahoo.co.in

    2009-09-15

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 {sup o}C storage temperature was found to keep peeled turmeric samples microbe free and acceptable until 60 days of storage. The control sample without radiation treatment spoiled within a week of storage. The changes in color, texture and moisture content of fresh turmeric due to radiation treatment were found to be statistically insignificant.

  3. Shelf life extension of fresh turmeric (Curcuma longa L.) using gamma radiation

    International Nuclear Information System (INIS)

    Dhanya, R.; Mishra, B.B.; Khaleel, K.M.; Cheruth, Abdul Jaleel

    2009-01-01

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 o C storage temperature was found to keep peeled turmeric samples microbe free and acceptable until 60 days of storage. The control sample without radiation treatment spoiled within a week of storage. The changes in color, texture and moisture content of fresh turmeric due to radiation treatment were found to be statistically insignificant.

  4. Use of E-Beam for Shelf-Life Extension and Sanitizing of Marinated Pork Loin

    Science.gov (United States)

    García-Márquez, I.; Ordóñez, J. A.; Cambero, M. I.; Cabeza, M. C.

    2012-01-01

    The effectiveness of E-beam radiation to extend the shelf-life of marinated pork loin slices stored at 4 and 8°C (temperature abuse) has been studied. The shelf-life was extended from 7 to 16 and >20 days after the application of 1 and 2 kGy, respectively. In the event of a temperature abuse occuring during the product distribution (e.g., increase to 8°C), the shelf-life would be extended from 5 to 10 and 16 days, respectively, when applying the doses mentioned previously. From a public health point of view, the irradiation of marinated pork loin may be marketable for a longer period of time of up to two weeks, and guarantees a practically Salmonella and Listeria-free product. Minor changes are produced by the E-beam treatment in the main sensory and rheological characteristics. The odor was the most affected feature, but the off-odors diminished with increased storage. In any case, testers judged the samples to be adequate for marketing. PMID:23227053

  5. Shelf-life Extension and Improvement of the Microbiological Quality of Fresh Sausage by Irradiation

    International Nuclear Information System (INIS)

    Hammad, A.A.I.; El-Mongy, T.M.; Mabrouk, A.K.

    2000-01-01

    Fifty samples of fresh sausage were randomly collected from different meat products markets in Great Cairo. They were analysed for microbiological quality. The results showed that 26 (52%) samples had total aerobic bacterial counts more than 10 7 cfu/g. Staphylococcus aureus was present in all samples and 19 (38%) samples had counts more than maximum permissible level (10 3 cfu/g). Enterococcus faecalis numbers more than 10 5 cfu/g were found in 14 (28%) samples. Coliform bacteria were present in all sausage samples and 19(38%) samples had counts more than 10 3 cfu/g, while salmonella was detected in only 5 (10%) samples. Therefore, fresh sausages in local market were highly contaminated with different microorganisms including spoilage and pathogenic bacteria. Irradiation dose of 4 kGy greatly reduced the numbers of aerobic and anaerobic bacteria, lactobacilli and yeasts without affecting the organoleptic properties of the samples. It extended the shelf-life of fresh sausage up to about 15 days at refrigeration temperature (5+-1) while the shelf-life was only 5 days for unirradiated samples. Irradiation dose of 6 kGy had greater effect on the microbiological counts and extended the shelf-life of fresh sausage more than 25 days, however, it slightly affected its organoleptic properties. Sausage samples exposed to this irradiation dose was microbiologically safe, being free from Enterobacteriaceae, Staph, aureus, Ent, faecalis, coliform bacteria, Salmonella and moulds

  6. Use of E-Beam for Shelf-Life Extension and Sanitizing of Marinated Pork Loin

    Directory of Open Access Journals (Sweden)

    I. García-Márquez

    2012-01-01

    Full Text Available The effectiveness of E-beam radiation to extend the shelf-life of marinated pork loin slices stored at 4 and 8°C (temperature abuse has been studied. The shelf-life was extended from 7 to 16 and >20 days after the application of 1 and 2 kGy, respectively. In the event of a temperature abuse occuring during the product distribution (e.g., increase to 8°C, the shelf-life would be extended from 5 to 10 and 16 days, respectively, when applying the doses mentioned previously. From a public health point of view, the irradiation of marinated pork loin may be marketable for a longer period of time of up to two weeks, and guarantees a practically Salmonella and Listeria-free product. Minor changes are produced by the E-beam treatment in the main sensory and rheological characteristics. The odor was the most affected feature, but the off-odors diminished with increased storage. In any case, testers judged the samples to be adequate for marketing.

  7. The shelf life extension of refrigerated grass carp (Ctenopharyngodon idellus) fillets by chitosan coating combined with glycerol monolaurate.

    Science.gov (United States)

    Yu, Dawei; Jiang, Qixing; Xu, Yanshun; Xia, Wenshui

    2017-08-01

    A novel chitosan-based coating solution was prepared by combining glycerol monolaurate (GML) for shelf life extension of refrigerated grass carp fillets. The control and coated fillets were analyzed periodically for physicochemical (pH, thiobarbituric acid (TBA) value, total volatile basic nitrogen (TVB-N) value, K value, and shear force), microbiological (total viable counts (TVC), psychrophilic bacteria counts (PTC), Pseudomonads and H 2 S-producing bacteria) and sensorial characteristics. The results showed that chitosan-GML coated samples presented better quality preservation effects than chitosan coating alone. In addition, 2% chitosan enriched with 0.3% GML showed the significant (Pchitosan coating enriched with GML was a promising method to extend the shelf life of refrigerated fillets. Copyright © 2017. Published by Elsevier B.V.

  8. Plant cell wall extensibility: connecting plant cell growth with cell wall structure, mechanics, and the action of wall-modifying enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, Daniel J.

    2015-11-25

    The advent of user-friendly instruments for measuring force/deflection curves of plant surfaces at high spatial resolution has resulted in a recent outpouring of reports of the ‘Young's modulus’ of plant cell walls. The stimulus for these mechanical measurements comes from biomechanical models of morphogenesis of meristems and other tissues, as well as single cells, in which cell wall stress feeds back to regulate microtubule organization, auxin transport, cellulose deposition, and future growth directionality. In this article I review the differences between elastic modulus and wall extensibility in the context of cell growth. Some of the inherent complexities, assumptions, and potential pitfalls in the interpretation of indentation force/deflection curves are discussed. Reported values of elastic moduli from surface indentation measurements appear to be 10- to >1000-fold smaller than realistic tensile elastic moduli in the plane of plant cell walls. Potential reasons for this disparity are discussed, but further work is needed to make sense of the huge range in reported values. The significance of wall stress relaxation for growth is reviewed and connected to recent advances and remaining enigmas in our concepts of how cellulose, hemicellulose, and pectins are assembled to make an extensible cell wall. A comparison of the loosening action of α-expansin and Cel12A endoglucanase is used to illustrate two different ways in which cell walls may be made more extensible and the divergent effects on wall mechanics.

  9. Expert Panel Recommendations for Hanford Double-Shell Tank Life Extension

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Charles W; Bush, Spencer H; Berman, Herbert Stanton; Czajkowski, Carl J; Divine, James R; Posakony, Gerald J; Johnson, A B; Elmore, Monte R; Reynolds, D A; Anantatmula, Ramamohan P; Sindelar, Robert L; Zapp, Philip E

    2001-06-29

    Expert workshops were held in Richland in May 2001 to review the Hanford Double-Shell Tank Integrity Project and make recommendations to extend the life of Hanford's double-shell waste tanks. The workshop scope was limited to corrosion of the primary tank liner, and the main areas for review were waste chemistry control, tank inspection, and corrosion monitoring. Participants were corrosion experts from Hanford, Savannah River Site, Brookhaven National Lab., Pacific Northwest National Lab., and several consultants. This report describes the current state of the three areas of the program, the final recommendations of the workshop, and the rationale for their selection.

  10. Effect of gamma-irradiation for shelf life extension of chicken meat

    International Nuclear Information System (INIS)

    Prachasitthisak, Y.; Ito, Hitoshi.

    1996-01-01

    On the study of microbiological quality of 12 samples of chicken meat produced in several different area in Japan, total aerobic bacteria were determined as 8x10 4 to 5x10 7 per g. Coliforms were 8x10 1 to 3x10 4 per g with Escherichia, Proteus and Klebsiella. Dominant putrefactive bacteria were determined as lactic acid bacteria, Pseudomonas and Flavobacterium. The shelf life of irradiated chicken meat at 1 kGy extended more than 6 days at 10degC storage. Irradiation of chicken meat at 3 kGy extended 12 days. Coliforms were disappeared at 1 kGy irradiation. (author)

  11. Leveraging Available Data to Support Extension of Transportation Packages Service Life

    International Nuclear Information System (INIS)

    Dunn, K.; Abramczyk, G.; Bellamy, S.; Daugherty, W.; Hackney, B.; Hoffman, E.; Skidmore, E.; Stefek, T.

    2012-01-01

    Data obtained from testing shipping package materials have been leveraged to support extending the service life of select shipping packages while in nuclear materials transportation. Increasingly, nuclear material inventories are being transferred to an interim storage location where they will reside for extended periods of time. Use of a shipping package to store nuclear materials in an interim storage location has become more attractive for a variety of reasons. Shipping packages are robust and have a qualified pedigree for their performance in normal operation and accident conditions within the approved shipment period and storing nuclear material within a shipping package results in reduced operations for the storage facility. However, the shipping package materials of construction must maintain a level of integrity as specified by the safety basis of the storage facility through the duration of the storage period, which is typically well beyond the one year transportation window. Test programs have been established to obtain aging data on materials of construction that are the most sensitive/susceptible to aging in certain shipping package designs. The collective data are being used to support extending the service life of shipping packages in both transportation and storage.

  12. Extension of raw watermelon juice shelf-life up to 58days by hyperbaric storage.

    Science.gov (United States)

    Lemos, Álvaro T; Ribeiro, Ana C; Fidalgo, Liliana G; Delgadillo, Ivonne; Saraiva, Jorge A

    2017-09-15

    Hyperbaric storage (HS) of raw watermelon juice, at 50, 62.5 and 75MPa, at temperatures of 10, 15 and ≈25°C (room temperature, RT), was studied to evaluate shelf-life comparatively to refrigeration (RF, 4°C). Generally, RF caused an increase of microbial loads to values ≥6.0logCFU/mL after 7days of storage. Contrarily, HS at 62.5/75MPa (15°C) showed a reduction of initial loads, by at least 2.5logCFU/mL, up to 58days, while pH and colour values did not changed under these HS conditions. Additionally, the combination of a lower temperature with HS has beneficial effects to control microbial development, particularly for the lower pressure studied (50MPa/10°C). In conclusion, HS increased watermelon juice shelf-life for at least 58days, indicating a great potential for future RF replacement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Leveraging Available Data to Support Extension of Transportation Packages Service Life

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, K.; Abramczyk, G.; Bellamy, S.; Daugherty, W.; Hackney, B.; Hoffman, E.; Skidmore, E.; Stefek, T.

    2012-06-12

    Data obtained from testing shipping package materials have been leveraged to support extending the service life of select shipping packages while in nuclear materials transportation. Increasingly, nuclear material inventories are being transferred to an interim storage location where they will reside for extended periods of time. Use of a shipping package to store nuclear materials in an interim storage location has become more attractive for a variety of reasons. Shipping packages are robust and have a qualified pedigree for their performance in normal operation and accident conditions within the approved shipment period and storing nuclear material within a shipping package results in reduced operations for the storage facility. However, the shipping package materials of construction must maintain a level of integrity as specified by the safety basis of the storage facility through the duration of the storage period, which is typically well beyond the one year transportation window. Test programs have been established to obtain aging data on materials of construction that are the most sensitive/susceptible to aging in certain shipping package designs. The collective data are being used to support extending the service life of shipping packages in both transportation and storage.

  14. Uses of irradiation or sodium tripolyphosphate for shelf-life extension of quail carcasses

    International Nuclear Information System (INIS)

    Rady, A.H.; Khalaf, H.H.; Afifi, E.A.; Nasr, E.H.

    2002-01-01

    this investigation aims to study the possibility of using gamma iraadiation or sodium tripolyphoshate (STPP) for increasing shelf-life of quail carcasses during cold storage. The quail carcasses were gamma irradiated at 4, 6 and 8 kGy or soaked in 3% STPP. The effect of these treatments on the organoleptic, microbiological aspects and chemical properties of samples under investigation were evaluated during cold storage (4± 1C degree). The results indicated that, the chemical compositions of samples did not alter by gamma irradiation or soaking in STPP. Futhermore, treatment had no deterious effects on the organoleptic properties of quail samples. Meanwhile, irradiation of samples at doses of 4, 6 and 8 kGy or soaking in STPP greatly reduced its microbial count and prolonged the shelf-life for 15,21,24 and 9 days at 4 ± 1 Cdegree in comparison with 6 days for control samples. Moreover, the acid value (A.V), peroxide value (P.V) and thiobarbituric acid (TBA) value were increased after irradiation, while total volatile basic nitrogen (TVBN) content had no real change by this treatment. On the other hand, soakking in STPP treatment decreased these values and gradual increases were observed during cold storage

  15. Shelf-life extension of Pacific white shrimp using algae extracts during refrigerated storage.

    Science.gov (United States)

    Li, Yingchang; Yang, Zhongyan; Li, Jianrong

    2017-01-01

    Shrimp is a low-fat, high-protein aquatic product, and is susceptible to spoilage during storage. To establish an effective method for the quality control of Pacific white shrimp, the effects of polyphenols (PP) and polysaccharides (PS) from Porphyra yezoensis on the quality of Pacific white shrimp were assessed during refrigerated storage. Pacific white shrimp samples were treated with 5 g L -1 polyphenols, and 8 g L -1 polysaccharides, then stored at 4 ± 1 °C for 8 days. All samples were subjected to measurement of total viable count (TVC), pH, total volatile basic nitrogen (TVB-N), K-value, thiobarbituric acid (TBA), polyphenol oxidase (PPO) activity, and were also assessed by sensory evaluation. The results showed that PP, PS, and the mixture of polyphenols and polysaccharides (PP+PS) could inhibit the increase of total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and K-value, and reduce total viable count (TVC) compared with the control group. PP could also inhibit polyphenol oxidase (PPO) activity. Sensory evaluation proved the efficacy of PP and PS by maintaining the overall quality of Pacific white shrimp during refrigerated storage. Moreover, PP+PS could extend the shelf-life of shrimp by 3-4 days compared with the control group. PP+PS could more effectively maintain quality and extend shelf-life during refrigerated storage. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Shelf-life extension of the merluccius merluccius hubbsi's commercialization by gamma radiation

    International Nuclear Information System (INIS)

    Narvaiz, Patricia; Kairiyama, Eulogia; Lescano, Hilda; Kaupert, Norma

    1989-01-01

    The hake (merluccius merluccius hubbsi), caught in the South Atlantic Ocean, was filleted and then irradiated in the semi-industrial irradiation plant of the Ezeiza Atomic Center, with a dose of 3.3 kGy, at the temperature of melting ice. Control and irradiated samples were stored at 0 deg C ± 1 deg C. Irradiated hake kept a good microbiological condition until day 28 after catch, which triplicates the commercialization period of the product. The determination of volatile basic nitrogen showed acceptable values, according to the Argentine Alimentary Codex specifications, for a longer period (47 days after catch) probably due to the selection exerted by ionizing radiations of the flora. Also, exudation was below 5% (v/w) during 52 days. The sonsory quality of the irradiated fillets was generally good along the 39 days of analysis. (Author) [es

  17. Telomerase-mediated life-span extension of human primary fibroblasts by human artificial chromosome (HAC) vector

    International Nuclear Information System (INIS)

    Shitara, Shingo; Kakeda, Minoru; Nagata, Keiko; Hiratsuka, Masaharu; Sano, Akiko; Osawa, Kanako; Okazaki, Akiyo; Katoh, Motonobu; Kazuki, Yasuhiro; Oshimura, Mitsuo; Tomizuka, Kazuma

    2008-01-01

    Telomerase-mediated life-span extension enables the expansion of normal cells without malignant transformation, and thus has been thought to be useful in cell therapies. Currently, integrating vectors including the retrovirus are used for human telomerase reverse transcriptase (hTERT)-mediated expansion of normal cells; however, the use of these vectors potentially causes unexpected insertional mutagenesis and/or activation of oncogenes. Here, we established normal human fibroblast (hPF) clones retaining non-integrating human artificial chromosome (HAC) vectors harboring the hTERT expression cassette. In hTERT-HAC/hPF clones, we observed the telomerase activity and the suppression of senescent-associated SA-β-galactosidase activity. Furthermore, the hTERT-HAC/hPF clones continued growing beyond 120 days after cloning, whereas the hPF clones retaining the silent hTERT-HAC senesced within 70 days. Thus, hTERT-HAC-mediated episomal expression of hTERT allows the extension of the life-span of human primary cells, implying that gene delivery by non-integrating HAC vectors can be used to control cellular proliferative capacity of primary cultured cells

  18. Assimilation of endogenous nicotinamide riboside is essential for calorie restriction-mediated life span extension in Saccharomyces cerevisiae.

    Science.gov (United States)

    Lu, Shu-Ping; Kato, Michiko; Lin, Su-Ju

    2009-06-19

    NAD(+) (nicotinamide adenine dinucleotide) is an essential cofactor involved in various biological processes including calorie restriction-mediated life span extension. Administration of nicotinamide riboside (NmR) has been shown to ameliorate deficiencies related to aberrant NAD(+) metabolism in both yeast and mammalian cells. However, the biological role of endogenous NmR remains unclear. Here we demonstrate that salvaging endogenous NmR is an integral part of NAD(+) metabolism. A balanced NmR salvage cycle is essential for calorie restriction-induced life span extension and stress resistance in yeast. Our results also suggest that partitioning of the pyridine nucleotide flux between the classical salvage cycle and the NmR salvage branch might be modulated by the NAD(+)-dependent Sir2 deacetylase. Furthermore, two novel deamidation steps leading to nicotinic acid mononucleotide and nicotinic acid riboside production are also uncovered that further underscore the complexity and flexibility of NAD(+) metabolism. In addition, utilization of extracellular nicotinamide mononucleotide requires prior conversion to NmR mediated by a periplasmic phosphatase Pho5. Conversion to NmR may thus represent a strategy for the transport and assimilation of large nonpermeable NAD(+) precursors. Together, our studies provide a molecular basis for how NAD(+) homeostasis factors confer metabolic flexibility.

  19. Development of life evaluation technology for nuclear power plant components

    Energy Technology Data Exchange (ETDEWEB)

    Song, Sung Jin; Kim, Young Hwan; Shin, Hyun Jae [Sungkwunkwan Univ., Seoul (Korea, Republic of); Lee, Hyang Beom [Soongsil Univ., Seoul (Korea, Republic of); Shin, Young Kil [Kunsan National Univ., Gunsan (Korea, Republic of); Chung, Hyun Jo [Wonkwang Univ., Iksan (Korea, Republic of); Park, Ik Keun; Park, Eun Soo [Seoul National University of Technology, Seoul (Korea, Republic of)

    2001-03-15

    Retaining reliabilities of nondestructive testing is essential for the life-time maintenance of nuclear power plant. In order to Improve reliabilities of ultrasonic testing and eddy current testing, the following five subjects were carried out in this study: development of BEM analysis technique for ECT of SG tube, development of neural network technique for the intelligent analysis of ECT flaw signals of SG tubes, development of RFECT technology for the inspection of SG tube, FEM analysis of ultrasonic scattering field and evaluation of statistical reliability of PD-RR test of ultrasonic testing. As results, BEM analysis of eddy current signal, intelligent analysis of eddy current signal using neural network, and FEM analysis of remote field eddy current testing have been developed for the inspection of SG tubes. FEM analysis of ultrasonic waves in 2-dimensional media and evaluation of statistical reliability of ultrasonic testing with PD-RR test also have been carried out for the inspection of weldments. Those results can be used to Improve reliability of nondestructive testing.

  20. Life cycle management of french operating nuclear power plants

    International Nuclear Information System (INIS)

    Valibus, L.; Loriette, Ph.

    1998-01-01

    The PWR units of the EDF generation capacity in operation are young. They represent a technical and financial asset with a strategic significance both for the company and for France. According to regulations, even if the safety reports take into account a 40-year lifetime for the NSSS, the French regulations do not specify a time limit for the operation of the facilities according to the plant authorization decree. The Safety Authorities may, at any time require another safety re-examination. In fact, it was decided to carry out unit safety periodic reviews according to types of series. A program was set up in order to achieve regular assessments on the aging of the facilities. This program, combining all the skills within EDF and the manufacturers, is a guarantee for the coherence and the exhaustivity of the consideration as it relies on a great number of evaluation areas. It seems to day that under operational conditions, an appropriate surveillance and maintenance of components the 900 and 1300 MWe units should be able to fulfill the expected duty for a 40-year design life and very likely even longer. (author)

  1. Probabilistic approaches to life prediction of nuclear plant structural components

    International Nuclear Information System (INIS)

    Villain, B.; Pitner, P.; Procaccia, H.

    1996-01-01

    In the last decade there has been an increasing interest at EDF in developing and applying probabilistic methods for a variety of purposes. In the field of structural integrity and reliability they are used to evaluate the effect of deterioration due to aging mechanisms, mainly on major passive structural components such as steam generators, pressure vessels and piping in nuclear plants. Because there can be numerous uncertainties involved in a assessment of the performance of these structural components, probabilistic methods. The benefits of a probabilistic approach are the clear treatment of uncertainly and the possibility to perform sensitivity studies from which it is possible to identify and quantify the effect of key factors and mitigative actions. They thus provide information to support effective decisions to optimize In-Service Inspection planning and maintenance strategies and for realistic lifetime prediction or reassessment. The purpose of the paper is to discuss and illustrate the methods available at EDF for probabilistic component life prediction. This includes a presentation of software tools in classical, Bayesian and structural reliability, and an application on two case studies (steam generator tube bundle, reactor pressure vessel). (authors)

  2. Probabilistic approaches to life prediction of nuclear plant structural components

    International Nuclear Information System (INIS)

    Villain, B.; Pitner, P.; Procaccia, H.

    1996-01-01

    In the last decade there has been an increasing interest at EDF in developing and applying probabilistic methods for a variety of purposes. In the field of structural integrity and reliability they are used to evaluate the effect of deterioration due to aging mechanisms, mainly on major passive structural components such as steam generators, pressure vessels and piping in nuclear plants. Because there can be numerous uncertainties involved in an assessment of the performance of these structural components, probabilistic methods provide an attractive alternative or supplement to more conventional deterministic methods. The benefits of a probabilistic approach are the clear treatment of uncertainty and the possibility to perform sensitivity studies from which it is possible to identify and quantify the effect of key factors and mitigative actions. They thus provide information to support effective decisions to optimize In-Service Inspection planning and maintenance strategies and for realistic lifetime prediction or reassessment. The purpose of the paper is to discuss and illustrate the methods available at EDF for probabilistic component life prediction. This includes a presentation of software tools in classical, Bayesian and structural reliability, and an application on two case studies (steam generator tube bundle, reactor pressure vessel)

  3. Development of life evaluation technology for nuclear power plant components

    International Nuclear Information System (INIS)

    Song, Sung Jin; Kim, Young Hwan; Shin, Hyun Jae; Lee, Hyang Beom; Shin, Young Kil; Chung, Hyun Jo; Park, Ik Keun; Park, Eun Soo

    2001-03-01

    Retaining reliabilities of nondestructive testing is essential for the life-time maintenance of nuclear power plant. In order to Improve reliabilities of ultrasonic testing and eddy current testing, the following five subjects were carried out in this study: development of BEM analysis technique for ECT of SG tube, development of neural network technique for the intelligent analysis of ECT flaw signals of SG tubes, development of RFECT technology for the inspection of SG tube, FEM analysis of ultrasonic scattering field and evaluation of statistical reliability of PD-RR test of ultrasonic testing. As results, BEM analysis of eddy current signal, intelligent analysis of eddy current signal using neural network, and FEM analysis of remote field eddy current testing have been developed for the inspection of SG tubes. FEM analysis of ultrasonic waves in 2-dimensional media and evaluation of statistical reliability of ultrasonic testing with PD-RR test also have been carried out for the inspection of weldments. Those results can be used to Improve reliability of nondestructive testing

  4. Nutritional and cultural aspects of plant species selection for a controlled ecological life support system

    Science.gov (United States)

    Hoff, J. E.; Howe, J. M.; Mitchell, C. A.

    1982-01-01

    The feasibility of using higher plants in a controlled ecological life support system is discussed. Aspects of this system considered important in the use of higher plants include: limited energy, space, and mass, and problems relating to cultivation and management of plants, food processing, the psychological impact of vegetarian diets, and plant propagation. A total of 115 higher plant species are compared based on 21 selection criteria.

  5. Shelf-life extension of convenience meat products sold in Indian supermarkets by radiation processing

    Science.gov (United States)

    Kanatt, Sweetie R.; Shobita Rao, M.; Chawla, S. P.; Sharma, Arun

    2010-12-01

    A variety of ready-to-cook meat products available in Indian supermarkets (mutton mince, chicken mince, chicken chunks, and chicken legs) were studied. The samples were irradiated (2.5 kGy), or left untreated as control, and stored at 0-3 °C for up to 21 days. The effect of irradiation on the microbiological, chemical, and sensory properties was evaluated at intervals during the storage period. Irradiated samples had a longer shelf-life at 0-3 °C compared with the corresponding non-irradiated samples. Fecal coliforms were eliminated by irradiation treatment. Radiation processed samples had lower counts of Staphylococcus spp. There were no significant organoleptic changes in irradiated samples stored at chilled temperatures.

  6. Shelf-life extension of convenience meat products sold in Indian supermarkets by radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Kanatt, Sweetie R.; Shobita Rao, M. [Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Chawla, S.P., E-mail: spchawla@barc.gov.i [Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Sharma, Arun [Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2010-12-15

    A variety of ready-to-cook meat products available in Indian supermarkets (mutton mince, chicken mince, chicken chunks, and chicken legs) were studied. The samples were irradiated (2.5 kGy), or left untreated as control, and stored at 0-3 {sup o}C for up to 21 days. The effect of irradiation on the microbiological, chemical, and sensory properties was evaluated at intervals during the storage period. Irradiated samples had a longer shelf-life at 0-3 {sup o}C compared with the corresponding non-irradiated samples. Fecal coliforms were eliminated by irradiation treatment. Radiation processed samples had lower counts of Staphylococcus spp. There were no significant organoleptic changes in irradiated samples stored at chilled temperatures.

  7. Shelf-life extension of convenience meat products sold in Indian supermarkets by radiation processing

    International Nuclear Information System (INIS)

    Kanatt, Sweetie R.; Shobita Rao, M.; Chawla, S.P.; Sharma, Arun

    2010-01-01

    A variety of ready-to-cook meat products available in Indian supermarkets (mutton mince, chicken mince, chicken chunks, and chicken legs) were studied. The samples were irradiated (2.5 kGy), or left untreated as control, and stored at 0-3 o C for up to 21 days. The effect of irradiation on the microbiological, chemical, and sensory properties was evaluated at intervals during the storage period. Irradiated samples had a longer shelf-life at 0-3 o C compared with the corresponding non-irradiated samples. Fecal coliforms were eliminated by irradiation treatment. Radiation processed samples had lower counts of Staphylococcus spp. There were no significant organoleptic changes in irradiated samples stored at chilled temperatures.

  8. Extension of shelf life of paneer by sorbic acid and irradiation

    International Nuclear Information System (INIS)

    Singh, L.; Murali, H.S.; Sankaran, R.

    1991-01-01

    Paneer, an acid and heat coagulated milk product, is highly perishable because of high moisture (58-60%) and low acidity (pH 5.6-5.8). The product had 430 total plate count, 120 proteolytic bacteria, 170 lipolytic bacteria and 40 fungi/g of sample with a shelf life of few hr. Treatment with sorbic acid and/or gamma irradiation reduced the microbial load. Combination treatment of 0.10% sorbic acid in milk and irradiation of the product at 2.5 kGy preserved the paneer for 30 days at ambient temperature (25-35degC) with good acceptance. (author). 14 refs., 3 tabs., 2 figs

  9. Safe extension of red blood cell storage life at 4{degree}C

    Energy Technology Data Exchange (ETDEWEB)

    Bitensky, M.; Yoshida, Tatsuro

    1996-04-01

    The project sought to develop methods to extend the storage life of red blood cells. Extended storage would allow donor to self or autologous transfusion, expand and stabilize the blood supply, reduce the cost of medical care and eliminate the risk of transfusion related infections, including a spectrum of hepatitides (A, B and C) and HIV. The putative cause of red blood cell spoilage at 4 C has been identified as oxidative membrane damage resulting from deoxyhemoglobin and its denaturation products including hemichrome, hemin and Fe{sup 3+}. Trials with carbon monoxide, which is a stabilizer of hemoglobin, have produced striking improvement of red blood cell diagnostics for cells stored at 4 C. Carbonmonoxy hemoglobin is readily converted to oxyhemoglobin by light in the presence of oxygen. These findings have generated a working model and an approach to identify the best protocols for optimal red cell storage and hemoglobin regeneration.

  10. Balance-of-plant outage availability study. Phase I. Extension report. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Thomasson, F.R.

    1978-09-01

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

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

    International Nuclear Information System (INIS)

    Thomasson, F.R.

    1978-09-01

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

  12. Irradiation of prepared meals for microbiological safety and shelf life extension

    International Nuclear Information System (INIS)

    Nketsia-Tabiri, K.; Adu-Gyamfi, A.; Apea Bah, F.

    2009-01-01

    Fourteen international ready meals prepared under the approved hazard analysis critical control point (HACCP) plan and two Ghanaian ready meals, waakye (co-boiled rice and cowpeas served with gravy, minimally processed vegetable salad, hydrated gari, fried fish and macaroni) and jollof rice (rice cooked in tomato sauce and served with gravy and beef tripe), were investigated with the view to enhancing microbiological safety and extending shelf life under chilled conditions. The microbiological count of the complete waakye meal exceeded the microbiological standard. The microbiological counts on meals prepared under the HACCP plan and the jollof rice meals were within the microbiological standards. The D 10 values for potential pathogens on waakye were 0.271 kGy for Escherichia coli, 0.325 kGy for Salmonella aureus and 0.440 kGy for Salmonella spp. while the D 10 values on jollof rice meal were 0.173 kGy, 0.260 kGy and 0.285 kGy, respectively. Challenge tests with the pathogens on one of the HACCP meals (poached chicken) or jollof rice suggested that the 3 kGy dose was sufficient for the elimination of the pathogens to ensure the microbiological safety of the meals and extended their shelf life under chilled storage for 28 days without significant effects on their sensory quality. Doses of 1 and 2 kGy did not affect the sensory quality of the rice and chicken/gravy but boiled carrots were unable to withstand a dose of more than 1 kGy. (author)

  13. Recent Advances in Physical Post-Harvest Treatments for Shelf-Life Extension of Cereal Crops

    Science.gov (United States)

    Schmidt, Marcus; Zannini, Emanuele; Arendt, Elke K.

    2018-01-01

    As a result of the rapidly growing global population and limited agricultural area, sufficient supply of cereals for food and animal feed has become increasingly challenging. Consequently, it is essential to reduce pre- and post-harvest crop losses. Extensive research, featuring several physical treatments, has been conducted to improve cereal post-harvest preservation, leading to increased food safety and sustainability. Various pests can lead to post-harvest losses and grain quality deterioration. Microbial spoilage due to filamentous fungi and bacteria is one of the main reasons for post-harvest crop losses and mycotoxins can induce additional consumer health hazards. In particular, physical treatments have gained popularity making chemical additives unnecessary. Therefore, this review focuses on recent advances in physical treatments with potential applications for microbial post-harvest decontamination of cereals. The treatments discussed in this article were evaluated for their ability to inhibit spoilage microorganisms and degrade mycotoxins without compromising the grain quality. All treatments evaluated in this review have the potential to inhibit grain spoilage microorganisms. However, each method has some drawbacks, making industrial application difficult. Even under optimal processing conditions, it is unlikely that cereals can be decontaminated of all naturally occurring spoilage organisms with a single treatment. Therefore, future research should aim for the development of a combination of treatments to harness their synergistic properties and avoid grain quality deterioration. For the degradation of mycotoxins the same conclusion can be drawn. In addition, future research must investigate the fate of degraded toxins, to assess the toxicity of their respective degradation products. PMID:29565832

  14. Application of the combined cycle LWR-gas turbine to PWR for NPP life extension, safety upgrade and improving economy

    International Nuclear Information System (INIS)

    Kuznetsov, Yu.N.; Gabaraev, B.A.

    2002-01-01

    Full text: The unconventional technology to extend the lifetime for the NPPs now in operation and make a construction of new NPPs cheaper - erection of steam-gas toppings to the nuclear power units - is considered in the paper. Application of the steam-gas toppings permits through reducing power of ageing reactors to extend lifetime of nuclear power unit, enhance its safety and at the same time to keep full load operation of NPP turbine and other balance-of-plant equipment. Proposed technology is examined for Russian VVER-440 reactor as an example and, also, as a pilot project, for Russian boiling VK-50 reactor now in operation Application of the steam-gas topping permits: extend the service life of ageing VVER-440 reactor by 10...15 years; use the turbine and other NPP balance-of-plant equipment at full power; increase the efficiency of combined cycle up to 48% and more; enhance the safety of NPP operation; utilize NPP balance-of-plant equipment after reactor decommissioning; perform the cost-effective operation in maneuvering modes; increase capacity factor of the plant. The construction of pilot project on the basis of the VK-50 reactor will allow not only to demonstrate new technology but also to attain appreciable economic effect including that obtained due to using the available reserves of the NPP turbine. (author)

  15. Life Limiting Issues for Long Term Operation of Nuclear Power Plants

    International Nuclear Information System (INIS)

    Esselman, Thomas; Gaertner, John

    2012-01-01

    This paper reports on a study which identified and characterized life limiting issues for consideration by nuclear plant owners in their decision to extend plant life or seek subsequent license renewal. As nuclear plants operate for longer periods, the risk that a condition in the plant or an event that occurs, at the plant or elsewhere, will cause a plant owner not to extend plant life increases. The Fukushima accident has made this concept concrete. This paper defines 'Life Limiting' concepts for nuclear plants. It identifies the highest risk conditions and events that may limit duration of continued operation in nuclear plants and employs a survey to prioritize these concerns. Methods for evaluating these risks and changing the capability of systems, structures, and components (SSC) to reduce and manage this risk in long term operation are presented. Integrated obsolescence -the existence of an accumulation of events or condition that can threaten long term operation- is discussed. Many of the life limiting conditions or events may be controllable by early identification, recognition, and mitigation of the potential threat. The recognition of conditions may allow measures to be taken to mitigate the condition. Recognition of the potential for events that may be life limiting may allow actions to be taken that will minimize the likelihood or consequences of the event. These actions may include enhanced research on the expected behavior of the SSC, risk assessment and management, and enhanced monitoring and aging management at the plant. (author)

  16. Irradiation of prepared meals for microbiological safety and shelf-life extension

    Energy Technology Data Exchange (ETDEWEB)

    Nketsia-Tabiri, J; Adu-Gyamfi, A; Owusu-Biney, Alex; Apea Bah, F; Akomeah-Adjei, F [Biotechnology and Nuclear Agriculture Research Institute, Ghana Atomic Energy Commission, Legon (Ghana)

    2004-07-01

    Current trends suggest increasing world-wide demand for convenience foods such as prepared meals and those that require minimum preparation before consumption. In Ghana, the trend is the same with ready-to-eat or prepared meals mostly sold in the informal sector, playing a major role in meeting the nutritional needs of the people these meals are prepared on daily basis as in most developing countries. With increasing urbanization and rapid adoption of refrigeration for food preservation in developing countries, the demand for such foods in supermarkets should be expected. Over 90% of ready-to-eat meals prepared in Ghana are marketed under ambient conditions and have shelf-life of less than 12 hours. However, there are a few caterers who prepare cook-chill meals using hygienic and preventative approach (e.g. HACCP) in order to enhance the safety of their meals. Preliminary investigations have demonstrated that these cook-chill meals are potential sources of pathogenic bacteria and have been implicated in food-borne disease outbreaks. There is therefore the need to ensure the safety of ready-to-eat meals through effective processing such as irradiation.

  17. Studies on extension of shelf-life of rawa by gamma irradiation

    International Nuclear Information System (INIS)

    Sudha Rao, V.; Srirangarajan, A.N.; Kamat, A.S.; Adhikari, H.R.; Nair, P.M.

    1994-01-01

    Semolina, a wheat product, popularly termed as rawa, was packed in 500g pouches prepared individually from high density polyethylene (HDP), biaxially oriented polypropylene : low density polyethylene laminate (BOPP/LDP), polyester : low density polyethylene laminate (PET/LDP) and irradiated using a Cobalt-60 source at dose of 0.15 to 0.50 kGy. At the end of six months' storage at room temperature, the unirradiated rawa developed infestation, whereas the irradiated samples were completely free of any infestation, thereby indicating a complete destruction of all stages of the insects due to irradiation. There was no significant difference in the moisture content and the total bacterial as well as mould counts of the irradiated and unirradiated rawa. Gamma irradiation significantly decreased the gelatinization viscosity of rawa. In sensory evaluation tests, irradiated rawa scored the same on a 9-point Hedonic scale, thereby showing that overall acceptability of the rawa was not altered due to irradiation upto 0.25 kGy. Amongst the packaging materials used, BOPP/LDP was found to be better, because of its comparatively higher resistance to penetration by insects. Gamma irradiation at 0.25 kGy could thus be recommended for effectively extending the shelf-life of rawa, prepacked in pouches made from BOPP/LDP laminate, for six months. (author). 26 refs., 1 fig., 2 tabs

  18. Extension shelf life of batte by using hydrocolloids and gamma irradiation

    Directory of Open Access Journals (Sweden)

    Mervat M. Anwar

    2015-10-01

    Full Text Available Batte (is baked french one of the most baked coated most prevalent in the markets after the cake wrapping. Batte exposed generally two types of corruption which is occurring phenomenon of (anti-staling and corruption microbial (molds. In this study produced batte with an attempt to prolong the period of its validity by addition 1.5% hydrocolloids, (which is 0.5% sodium alginate, 0.5% k-carrageenan and 0.5% hydroxyl propyl methylcellulose (HPMC to hard wheat flour 72% (HWF to improve materials for mellowness and anti-staling, whereas batte exposed to gamma irradiation at doses 0.5, 1, 1.5, 2, 3 and 5 kGy to decrease microbial load. Hydrocolloids at 1.5% improved the rheological properties of dough farinogragh and aextensograph parameters. The hydrocolloids increase flexibility, rubber and freshness of batte to 24 days compared to 8 days in control sample. Thiobarbituric acid (T.B.A values at the end of storage at room temperature (ranged to 0.253–0.352 mg malonaldehyde/kg that were less than these mentioned by the Egyptian Standard. Also, gamma irradiation reduced the total bacterial count of batte product. Sensory evaluation of produced batte was done. The addition of 1.5% hydrocolloids and exposed to gamma irradiation had higher freshness and increase shelf-life for 20, 25, 30, 35 and 40 days against only 15 days for control sample.

  19. Shelf-life extension of bread by heat and irradiation treatment [Bangladesh

    International Nuclear Information System (INIS)

    Begum, F.; Siddique, A.K.; Choudhury, N.; Mollah, R.A.

    1994-01-01

    Bread slices were given irradiation treatment 0.5, 1.0, 1.5, and 2.0 KGy and heat treatment at 60 deg. C for 20 min to control mould growth. Mould growth was reladed at ambient temperature by 3, 4, 6 and 8 days after 0.5, 1.0, 1.5 and 2.0 KGy treatments, respectively, compared to 2 days in case of control sample and 3 days for heat treatment alone. Combination of heat with irradiation at 0.5, 1.0, 1.5 and 2.0 KGy retarded mould growth up to 4, 6, 7 an 9 days, respectively. Organoleptically, the irradiated bread slices were acceptable up to 3 to 6 days depending on the treatment. The combination method treated slices were acceptable up to 8 days. The application of radiation dose exceeding 2.0 KGy caused off flavour. Mild heat treatment and radiation in combination resulted in a synergistic antifungal effect and enhanced shelf-life of bread

  20. Maintenance Cycle Extension in the IRIS Advanced Light Water Reactor Plant Design

    International Nuclear Information System (INIS)

    Galvin, Mark R.; Todreas, Neil E.; Conway, Larry E.

    2003-01-01

    New nuclear power generation in the United States will be realized only if the economic performance can be made competitive with other methods of electrical power generation. The economic performance of a nuclear power plant can be significantly improved by increasing the time spent on-line generating electricity relative to the time spent off-line conducting maintenance and refueling. Maintenance includes planned actions (surveillances) and unplanned actions (corrective maintenance) to respond to component degradation or failure. A methodology is described that can be used to resolve, in the design phase, maintenance-related operating cycle length barriers. A primary goal was to demonstrate the applicability and utility of the methodology in the context of the International Reactor, Innovative and Secure (IRIS) design. IRIS is an advanced light water nuclear power plant that is being designed to maximize this on-line generating time by increasing the operating cycle length. This is consequently a maintenance strategy paper using the IRIS plant as the example.Potential IRIS operating cycle length maintenance-related barriers, determined by modification of an earlier operating pressurized water reactor (PWR) plant cycle length analysis to account for differences between the design of IRIS and this operating PWR, are presented. The proposed methodology to resolve these maintenance-related barriers by the design process is described. The results of applying the methodology to two potential IRIS cycle length barriers, relief valve testing and emergency heat removal system testing, are presented