Heading for the fourth nuclear age

Energy Technology Data Exchange (ETDEWEB)

Levite, A.E.

2009-07-01

The author examines the evolution of the global nuclear order since the advent of nuclear weapons in 1945 to present by breaking down the sixty-plus years of nuclear history into three analytically distinct 'ages', each lasting roughly twenty years. By doing so, the author traces back the roots of the current nuclear predicament to some early seeds of trouble which have gradually grown more profound. He attributes much of the unraveling of the nuclear order to: - Certain inherent weaknesses in the original NPT formula; - Changes in the global distribution of power since the codification of the nuclear order in the 1960's; - The dissemination of nuclear weapon technology; and - Complacency and subsequent disillusionment with the nuclear order since the early 1990's. The paper further analyzes what could precipitate a new nuclear age around 2010. The author argues that such a 'fourth nuclear age' would likely be characterized by either a nuclear anarchy, which he believes has become the default option, or a more benign nuclear order manifested by lower numbers of weapons and stringent controls and restrictions on remaining nuclear arsenals and activities. He concludes by considering the more pressing requirements for regaining nuclear stability

IPRDS - Component histories and nuclear plant aging

International Nuclear Information System (INIS)

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

1984-01-01

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

Aging characteristics of nuclear plant RTDs and pressure transmitters

International Nuclear Information System (INIS)

Hashemian, H.M.

2004-01-01

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

Anthropology for the nuclear age

International Nuclear Information System (INIS)

Mandelbaum, D.G.

1984-01-01

An anthropological approach to preparing for a turning point in the nuclear age as a result of a large-scale accident or act of terrorism suggests three areas for preliminary study: institutional changes that would reinforce international structures to be more effective in preserving the peace and would redirect military institutions toward that end; cultural changes that would deal with the fears and perceptions of citizens within each nation to find new ways of communication and conflict resolution, but keeping in mind the major class, religious, regional, and ethnic groupings; and global forces that would deal with population pressures. These preliminary studies would need revision after the nuclear event to incorporate the new circumstances. 15 references

Numerology in the second nuclear age

Energy Technology Data Exchange (ETDEWEB)

Krepon, M.

2009-07-01

The nuclear numbers game has changed. During the Cold War - the first nuclear age - deterrence strategists such as Henry Kissinger, Paul Nitze and Albert Wohlstetter claimed that the nuclear balance mattered, even at extraordinarily high numbers. ' As a result, one great irony of the first nuclear age was that the 'absolute' weapon still lent itself to the twin impulses of seeking advantage and seeking to avoid being placed at a disadvantage. This factor, among others, led to the production of approximately 125,000 U.S. and Soviet nuclear weapons during the Cold War. Nuclear 'numerology' during the Cold War centered around deployed capabilities in various categories, especially 'prompt hard-target kill' capabilities, missile 'throw-weight' and nuclear exchange ratios. By this musty logic, the United States now has more deterrence leverage against Russia than at any time since the Soviet nuclear build-up in the 1960's. This may help explain why the Kremlin feels so protective of its large stocks of tactical nuclear weapons, despite Washington's preferences. US leverage on Moscow also appears to be limited on other matters pertaining to the nuclear order, including ways to persuade North Korea and Iran to adhere to UN Security Council resolutions. Critics of the Obama administration ascribe this lack of suasion to 'soft' leadership that does not command respect or compel preferred behavior. But the 'hard' policies they preferred during the presidency of George W. Bush produced, to put it charitably, mixed results. Whatever value the nuclear numbers game had during the first nuclear age related primarily to contests played out with computers and hand calculators, not to real battlefields where nuclear-armed states fought with weaker foes, including contests between states with and without nuclear weapons. Numerical imbalances have been far more profound between the United States and China. For

Numerology in the second nuclear age

International Nuclear Information System (INIS)

Krepon, M.

2009-01-01

The nuclear numbers game has changed. During the Cold War - the first nuclear age - deterrence strategists such as Henry Kissinger, Paul Nitze and Albert Wohlstetter claimed that the nuclear balance mattered, even at extraordinarily high numbers. ' As a result, one great irony of the first nuclear age was that the 'absolute' weapon still lent itself to the twin impulses of seeking advantage and seeking to avoid being placed at a disadvantage. This factor, among others, led to the production of approximately 125,000 U.S. and Soviet nuclear weapons during the Cold War. Nuclear 'numerology' during the Cold War centered around deployed capabilities in various categories, especially 'prompt hard-target kill' capabilities, missile 'throw-weight' and nuclear exchange ratios. By this musty logic, the United States now has more deterrence leverage against Russia than at any time since the Soviet nuclear build-up in the 1960's. This may help explain why the Kremlin feels so protective of its large stocks of tactical nuclear weapons, despite Washington's preferences. US leverage on Moscow also appears to be limited on other matters pertaining to the nuclear order, including ways to persuade North Korea and Iran to adhere to UN Security Council resolutions. Critics of the Obama administration ascribe this lack of suasion to 'soft' leadership that does not command respect or compel preferred behavior. But the 'hard' policies they preferred during the presidency of George W. Bush produced, to put it charitably, mixed results. Whatever value the nuclear numbers game had during the first nuclear age related primarily to contests played out with computers and hand calculators, not to real battlefields where nuclear-armed states fought with weaker foes, including contests between states with and without nuclear weapons. Numerical imbalances have been far more profound between the United States and China. For financial and other reasons, Beijing did not play the nuclear numbers game

Basis for snubber aging research: Nuclear Plant Aging Research Program

International Nuclear Information System (INIS)

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

1990-01-01

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

Performance measures for aging of nuclear power plants

International Nuclear Information System (INIS)

Ross, D.F. Jr.

1993-01-01

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

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

International Nuclear Information System (INIS)

Christensen, J.A.

1989-01-01

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

Tools and techniques for ageing predictions in nuclear reactors through condition monitoring

International Nuclear Information System (INIS)

Verma, R.M.P.

1994-01-01

To operate the nuclear reactors beyond their design predicted life is gaining importance because of huge replacement and decommissioning costs. But experience shows that nuclear plant safety and reliability may decline in the later years of plant life due to ageing degradation. Ageing of nuclear plant components, structures and systems, if unmitigated reduces their safety margins provided in the design and thus increases risks to public health and safety. These safety margins must be monitored throughout plant service life including any extended life. Condition monitoring of nuclear reactor components/equipment and systems can be done to study the effect of ageing, status of safety margins and effect of corrective and mitigating actions taken. The tools and techniques of condition monitoring are also important in failure trending, predictive maintenance, evaluation of scheduled maintenance, in mitigation of ageing, life extension and reliability studies. (author). 1 fig., 1 annexure

Nuclear Plant Aging Research (NPAR) program plan

International Nuclear Information System (INIS)

1985-07-01

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

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

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

International Nuclear Information System (INIS)

Ahmed, S.

1985-01-01

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

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

International Nuclear Information System (INIS)

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

1996-02-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-02-01

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

Public opinion on age-related degradation in nuclear power plants

International Nuclear Information System (INIS)

Matsuda, Toshihiro

2005-01-01

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

Aging assessment of large electric motors in nuclear power plants

International Nuclear Information System (INIS)

Villaran, M.; Subudhi, M.

1996-03-01

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

NPAR approach to controlling aging in nuclear power plants

International Nuclear Information System (INIS)

Christensen, J.A.

1990-01-01

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

Nuclear AMPK regulated CARM1 stabilization impacts autophagy in aged heart

International Nuclear Information System (INIS)

Li, Chen; Yu, Lu; Xue, Han; Yang, Zheng; Yin, Yue; Zhang, Bo; Chen, Mai; Ma, Heng

2017-01-01

Senescence-associated autophagy downregulation leads to cardiomyocyte dysfunction. Coactivator-associated arginine methyltransferase 1 (CARM1) participates in many cellular processes, including autophagy in mammals. However, the effect of CARM1 in aging-related cardiac autophagy decline remains undefined. Moreover, AMP-activated protein kinase (AMPK) is a key regulator in metabolism and autophagy, however, the role of nuclear AMPK in autophagy outcome in aged hearts still unclear. Hers we identify the correlation between nuclear AMPK and CARM1 in aging heart. We found that fasting could promote autophagy in young hearts but not in aged hearts. The CARM1 stabilization is markedly decrease in aged hearts, which impaired nucleus TFEB-CARM1 complex and autophagy flux. Further, S-phase kinase-associated protein 2(SKP2), responsible for CARM1 degradation, was increased in aged hearts. We further validated that AMPK dependent FoxO3 phosphorylation was markedly reduced in nucleus, the decreased nuclear AMPK-FoxO3 activity fails to suppress SKP2-E3 ubiquitin ligase. This loss of repression leads to The CARM1 level and autophagy in aged hearts could be restored through AMPK activation. Taken together, AMPK deficiency results in nuclear CARM1 decrease mediated in part by SKP2, contributing to autophagy dysfunction in aged hearts. Our results identified nuclear AMPK controlled CARM1 stabilization as a new actor that regulates cardiac autophagy. - Highlights: • AMPK-dependent CARM1 stabilization is an important nuclear mechanism in cardiac autophagy. • AMPK deficiency lead to SKP2-mediated decrease in CARM1. • AMPK–SKP2–CARM1 in the regulation of autophagy dysfunction in aged heart.

The use of research results for effective aging management

International Nuclear Information System (INIS)

Gunther, W.E.; Taylor, J.H.

1989-01-01

The study of the degradation of structures, components, and systems due to aging is an important ongoing area of research in the nuclear industry. Efforts by the U.S. Nuclear Regulatory Commission (NRC) and the utility industry, through organizations such as the Electric Power Research Institute (EPRI), have produced substantial research results that can be used by inspectors and operators to effectively understand and manage the aging of nuclear power plants. One of the primary objectives of the NRC's Nuclear Plant Aging Research (NPAR) Program is to determine how aging affects the safety of nuclear power plants. This program uses operating experience, testing, and engineering analysis to identify failures caused by age-related degradation. Useful information on aging has also resulted from research being performed by the industry to support plant-life extension (PLEX). The EPRI program, for instance, is directed toward the resolution of issues related to materials and components. Degradation of equipment and systems due to aging can occur which, if unmitigated, could result in reduction of the nuclear power plant safety margin as the plant ages. This paper describes how aging research results may be used by plant operating management to effectively address the aging issue and by inspectors responsible for monitoring plant activities and programs

Aging management guideline for commercial nuclear power plants-pumps

International Nuclear Information System (INIS)

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

1994-03-01

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

Aging management guideline for commercial nuclear power plants-pumps

Energy Technology Data Exchange (ETDEWEB)

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

1994-03-01

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

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

International Nuclear Information System (INIS)

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

1989-10-01

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

Nuclear Plant Aging Research (NPAR) program plan

International Nuclear Information System (INIS)

1991-06-01

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

Aging management guideline for commercial nuclear power plants - heat exchangers

International Nuclear Information System (INIS)

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

1994-06-01

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

Aging management guideline for commercial nuclear power plants - heat exchangers

Energy Technology Data Exchange (ETDEWEB)

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

1994-06-01

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

Recommendations for managing equipment aging in nuclear power plants

International Nuclear Information System (INIS)

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

1992-01-01

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

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

International Nuclear Information System (INIS)

Fresco, A.; Subudhi, M.

1994-01-01

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

The effects of aging on friction of MOVs

International Nuclear Information System (INIS)

Hunt, T.H.; Sinha, U.P.

1991-01-01

This report studied the effect of three aging mechanisms: corrosion, erosion, and deposition on the friction coefficients of the sliding surfaces of motor-operated valves (MOVs) used in nuclear plant systems. The US Nuclear Regulatory Commission (NRC) sponsored the study, and it was performed following the guidelines of their Nuclear Plant Aging Research (NPAR) program. The authors reached three general conclusions: corrosion and deposition should not prevent valve operation by obstructing the mechanical tolerances of the MOVs; the aging mechanisms may increase the friction coefficients due to roughening the surfaces with age; and the codes and standards defining MOV surveillance requirements need review to include methods for detecting aging degradation

Ageing study of protection automation components of Olkiluoto nuclear power plant

International Nuclear Information System (INIS)

Simola, K.; Haenninen, S.

1993-07-01

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

Aging management guideline for commercial nuclear power plants-stationary batteries

International Nuclear Information System (INIS)

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

1994-03-01

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

Aging Management Guideline for commercial nuclear power plants: Electrical switchgear

International Nuclear Information System (INIS)

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

1993-07-01

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

Nuclear plant-aging research on reactor protection systems

International Nuclear Information System (INIS)

Meyer, L.C.

1988-01-01

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

Aging of nuclear safety related concrete structures

International Nuclear Information System (INIS)

Cerny, R.; Vydra, V.; Toman, J.; Vodak, F.

1994-01-01

An analysis of aging processes in nuclear-safety-related concrete structures (NSRCS) is presented. The major environmental stressor and aging factors affecting the performance of NSRCS are summarized, as are drying and plastic shrinkage, expansion of water during the freeze-thaw cycle, water passing through cracks dissolving or leaching the soluble calcium hydroxide, attack of acid rain and ground water, chemical reactions between particular aggregates and the alkaline solution within cement paste, reaction of calcium hydroxide in cement paste hydration products with atmospheric carbon dioxide, and physical radiation effects of neutrons and gamma radiation. The current methods for aging management in NSRCS are analyzed and evaluated. A new treatment is presented for the monitoring, evaluation and prediction of aging processes, consisting in a combination of theoretical methods, laboratory experiments, in-situ measurements and numerical simulations. 24 refs

IPRDS: component histories and nuclear plant aging

International Nuclear Information System (INIS)

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

1984-01-01

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

Strain ageing in welds of nuclear pressure vessels

International Nuclear Information System (INIS)

Otterberg, R.; Karlsson, C.

1979-01-01

Static and dynamic strain ageing have been investigated on submerged-arc welds and repair welds from plates of the pressure vessel steel A 533B. The results permit the determination of the worst strain ageing conditions existing in a nuclear pressure vessel. Static strain ageing was investigated by means of data from tension tests, hardness measurements and Charpy-V impact properties for prestrained and aged material for ageing temperatures from room temperature to 350 deg C and ageing times up to 1000h. Dynamic strain ageing was investigated by tensile tests up to 350 deg C at different strain rates. At the most static strain ageing was found to increase the impact transition temperature from -75 deg C in the as-received condition to -55 deg C after prestraining and ageing for the plate material, from -35 to -10 deg C for the submerged arc weld and from -90 to -40 deg C for the repair weld. Approximately 10 deg C of the deleterious effect is due to the effect of ageing for the two former materials whereas the corresponding figure for the repair weld amounts to 35 deg C. The dynamic strain ageing is strongest at very low strain rates at temperatures just below 300 deg C. The effect of strain ageing can be reduced by stress relief heat treatment or by other means decreasing the content of nitrogen in solution. (author)

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

International Nuclear Information System (INIS)

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

1996-12-01

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

Effective maintenance practices to manage system aging

International Nuclear Information System (INIS)

Chockie, A.; Bjorkelo, K.

1992-01-01

For a variety of economic and technical reasons, there has been a growing concern with the aging of complex systems and components and the role that maintenance can play in reducing this degradation. A study for the Nuclear Regulatory Commission was recently undertaken to identify effective maintenance practices that could be adapted by the nuclear industry in the United States to assist in managing the aging degradation of plant systems and components. Four organizations were examined to assess the influence that their maintenance programs have on their ability to address the systems and component aging degradation issues. An effective maintenance program was found to be essential to the management of system and component aging. The four key elements of an effective maintenance program that are important to an aging management program were identified. These are: the selection of critical systems and components; the development of an understanding of aging through the collection and analysis of equipment performance information; the development of appropriate preventive and predictive maintenance tasks to manage equipment and system aging degradation; the use of feedback mechanisms to continuously improve the management of aging systems and components. These elements were found to be common to all four organizations. In examining how the four organizations have structured their maintenance programs to include these key elements provides valuable lessons not only for the nuclear power industry, but also for any industrial organization that is concerned with the management of system and component aging degradation. This document provides detail, of these studies

Aging assessment of nuclear air-treatment system HEPA filters and adsorbers

International Nuclear Information System (INIS)

Winegardner, W.K.

1993-08-01

A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission's (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants

Safety aspects of nuclear power plant ageing

International Nuclear Information System (INIS)

1990-01-01

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

Life Cycle Management Managing the Aging of Critical Nuclear Plant Components

International Nuclear Information System (INIS)

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

2002-01-01

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

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

International Nuclear Information System (INIS)

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

1994-01-01

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

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

International Nuclear Information System (INIS)

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

2002-01-01

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

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

International Nuclear Information System (INIS)

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

2000-01-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Guideline for ageing management in nuclear power plants

International Nuclear Information System (INIS)

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

2007-01-01

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

Glossary of nuclear power plant ageing

International Nuclear Information System (INIS)

1999-01-01

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

Aging of concrete structures in nuclear power plants

International Nuclear Information System (INIS)

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

1991-01-01

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

Ageing evaluation model of nuclear reactors structural elements

International Nuclear Information System (INIS)

Ziliukas, A.; Jutas, A.; Leisis, V.

2002-01-01

In this article the estimation of non-failure probability by random faults on the structural elements of nuclear reactors is presented. Ageing is certainly a significant factor in determining the limits of nuclear plant lifetime or life extensions. Usually the non failure probability rates failure intensity, which is characteristic for structural elements ageing in nuclear reactors. In practice the reliability is increased incorrectly because not all failures are fixed and cumulated. Therefore, the methodology with using the fine parameter of the failures flow is described. The comparison of non failure probability and failures flow is carried out. The calculation of these parameters in the practical example is shown too. (author)

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

International Nuclear Information System (INIS)

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

1994-02-01

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

The Greenpeace book of the nuclear age

International Nuclear Information System (INIS)

May, John

1989-01-01

This is a comprehensive popular account of both civil and military nuclear accidents. It documents major reactor accidents in certain categories such as where significant injury of death occurred, where there was considerable radioactivity release offsite or where there was actual or suspected core damage. Military accidents on nuclear submarines or involving nuclear weapons and civil incidents such as those involving radioactive waste are also included. the book is organised chronologically from the 1940s through succeeding decades to the 1980s. A concluding chapter gives Greenpeace's own perspective on the state of the nuclear age. (author)

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-01-15

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

The effects of aging on Boiling Water Reactor core isolation cooling system

International Nuclear Information System (INIS)

Lee, Bom Soon.

1994-01-01

A study was performed to assess the effects of aging on the Reactor Core Isolation Cooling system in commercial Boiling Water Reactors. This study is part of the Nuclear Plant Aging Research program sponsored by the US Nuclear Regulatory Commission. The failure data, from national databases, as well as plant specific data were reviewed and analyzed to understand the effects of aging on the RCIC system. This analysis identified important components that should receive the highest priority in terms of aging management. The aging characterization provided information on the effects of aging on component failure frequency, failure modes, and failure causes

The coming age of nuclear energy

International Nuclear Information System (INIS)

1967-01-01

Exciting prospects of food factories in the desert and the use of nuclear energy for industrial processes rivalling in importance the achievement of the first chain reaction were among the forecasts of Alvin M. Weinberg, Director of the Oak Ridge National Laboratory, at the eleventh session of the General Conference. His lecture on 'The Coming Age of Nuclear Energy', with its emphasis on the task of producing really cheap energy, was one of the three in a scientific series

The coming age of nuclear energy

Energy Technology Data Exchange (ETDEWEB)

NONE

1967-12-15

Exciting prospects of food factories in the desert and the use of nuclear energy for industrial processes rivalling in importance the achievement of the first chain reaction were among the forecasts of Alvin M. Weinberg, Director of the Oak Ridge National Laboratory, at the eleventh session of the General Conference. His lecture on 'The Coming Age of Nuclear Energy', with its emphasis on the task of producing really cheap energy, was one of the three in a scientific series

Ship nuclear power device of cable aging management

International Nuclear Information System (INIS)

Wei Hua; Chen Miao; Chen Tao

2012-01-01

Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

Evidence of aging effects on certain safety-related components: summary and analysis

International Nuclear Information System (INIS)

1995-09-01

In response to interest shown by the Nuclear Energy Agency (NEA), Principal Working Group I (PWG- 1) of the Committee on the Safety of Nuclear Installations (CSNI) conducted a generic study on the effects of aging of active components in nuclear power plants. Representatives from France, Sweden, Finland, Japan, the United States, and the United Kingdom participated in the study by submitting reports documenting aging studies performed in their countries. This report consists of summaries of those reports, along with a comparison of the various statistical analysis methods used in the studies. The studies indicate that with some exceptions, active components generally do not present a significant aging problem in nuclear power plants. Design criteria and effective preventative maintenance programs, including timely replacement of components, are effective in mitigating potential aging problems. However, aging studies (such as qualitative and statistical analyses of failure modes and maintenance data) are an important part of efforts to identify and solve potential aging problems. Solving these problems typically includes such strategies as replacing suspect components with improved components, and implementing improved maintenance programs

New maintenance strategy of Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant for effective ageing management and safe long-term operation

International Nuclear Information System (INIS)

Inagaki, Takeyuki; Yamashita, Norimichi

2009-01-01

Fukushima Dai-ichi Nuclear Power Plant is the oldest among three nuclear power plants owned and operated by Tokyo Electric Power Company, which consists of six boiling water reactor units. The commercial operation of Unit 1 was commenced in 1971 (37 years old) and Unit 6 in 1978 (29 years old). Currently ageing degradations of systems, structures and components are managed through maintenance programs, component replacement/refurbishment programs and long-term maintenance plans. The long-term maintenance plans are established through ageing management component replacement/refurbishment programs reviews performed before the 30th year of operation and they are for safe and reliable operation after 30 years (long-term operation). However the past maintenance actions and past component replacement/refurbishment programs were not always proactive and past operational experience and maintenance practices suggest that effective/proactive ageing management programs be introduced in earlier stage of the plant operation. In this circumstance, Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant are setting up a new maintenance strategy that includes 1) improving the normal maintenance programs by using ageing degradation data, 2) effective use of information on internal/external operational experience and maintenance practices related to ageing, and 3) proactive component/equipment refurbishment programs during a refreshment outage for safe and reliable long-term operation. To accomplish the goal of this strategy, strengthening engineering capability of plant staff members is a crucial required for the plant. The objective of this paper is to briefly explain main results ageing management reviews, past and current significant ageing issues and management programs against them, and the new maintenance strategy established by Tokyo Electric Power Company and Fukushima Dai-ichi Nuclear Power Plant. (author)

Good practices for effective maintenance to manage aging at NPPs

International Nuclear Information System (INIS)

Scott, W.B.; Enderlin, W.I.; Levy, I.S.

1989-01-01

The Nuclear Regulatory Commission's Office of Nuclear Regulatory Research is sponsoring this effort to study maintenance as it relates to aging, under the Nuclear Plant Aging Research (NPAR). Maintenance is the primary means of combating and correcting the effects of aging degradation at nuclear power plants. Maintenance effectiveness directly affects the safety of nuclear power plants. Several recent plant events have shown that improper maintenance or a lack of maintenance can be a significant contributory cause of plant incidents (e.g., transients at Rancho Seco and Davis Besse, and the Salem anticipated transient without scram event). In these, and other events, safety related plant equipment functions have been impaired by poor maintenance practices or a lack of maintenance on the specific equipment or in ancillary equipment that affects the ability of the safety related equipment to function. In some cases, the ancillary equipment has been nonsafety-related equipment, or balance-of-plant equipment that has not received adequate maintenance attention. In addition to the potential for causing safety significant plant transients, poor or lacking maintenance may allow the licensing basis of the plant to be eroded without detection. In some cases, time-related aging degradation of equipment that has not been detected, corrected or managed by the maintenance program has been a significant contributory factor. The NPAR program has developed significant information on aging degradation, detection, mitigation, and correction practices for safety-significant structures, systems and components that can be factored into maintenance programs and their effectiveness

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

International Nuclear Information System (INIS)

Toman, G.; Gazdzinski, R.

1994-05-01

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

Aging management of containment structures in nuclear power plants

International Nuclear Information System (INIS)

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

1996-01-01

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

Aging management of containment structures in nuclear power plants

International Nuclear Information System (INIS)

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

1994-01-01

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

Aging management of containment structures in nuclear power plants

International Nuclear Information System (INIS)

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

1994-01-01

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

Fundamentals of asset management in an ageing nuclear power station

International Nuclear Information System (INIS)

Crook, B.

2014-01-01

In an ageing nuclear power station there are many challenges associated with implementing and refining an asset management program. Ageing nuclear power stations are faced with the formidable task of replacing and refurbishing major Structures, Systems, and Components (SSCs) in a managed and cost-effective way. This paper provides a brief background on equipment reliability and asset management, covers Bruce Power's methodology for implementing this complex and all-encompassing program, and describes one of the key challenges faced by Bruce Power and the industry. The effective scoping and identification of critical components is an on-going challenge which can affect the integrity of many processes built upon it. This is a fundamental building block to nearly all processes at Bruce Power and one that is at the centre of many improvement initiatives and projects. The consequences from lacking this baseline data, or worse relying upon incorrect data, can permeate the asset management process and hinder the organization's ability to assess risk properly and take the necessary steps to mitigate this risk in the short and long term. (author)

Ageing of polymers in electrical equipment used in nuclear power plants

International Nuclear Information System (INIS)

Clavreul, R.

1999-01-01

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

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

International Nuclear Information System (INIS)

Moyers, J.C.

1990-07-01

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

NuPEER Dijon 2005 Symposium. Ageing issues in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Emond, David (ed.) [BCCN, Autorite de Surete Nucleaire, ASN, 6, place du Colonel Bourgoin, 75572 Paris Cedex 12 (France)

2005-07-01

The French Nuclear Safety Authority (ASN) organized an international symposium on regulatory aspects of ageing issues for nuclear pressure equipment. The ageing of nuclear pressure equipment is an issue of growing importance for nuclear regulators and material experts worldwide as age-related degradation of major pressure-retaining components challenges the remaining operating life of nuclear power plants. This symposium aimed at providing a forum for technical exchange among the staffs responsible for nuclear pressure equipment within the safety authorities and the associated expertise organisations. The contents of the symposium is as follows: 1. Control and supervision of safety of nuclear pressure equipment in France and abroad; 1.1. Position of the French Nuclear Safety Authority (1 paper); 1.2. Regulatory practices worldwide (4 papers); 1.3. Licence renewal: Field experience (2 papers); 1.4. Role of international organisations (1 paper); 2. Management of equipment and materials: From design to degradation mechanisms; 2.1. Operation and equipment (4 papers); 2. Evolution of materials (4 papers); 2.3. Fatigue degradation mechanisms (3 papers); 2.4. Contribution of research and development (4 papers); 3. In-service inspection: Evolutions, methods and strategies; 3.1. Methods and evolution (1 paper); 3.2. Qualification of methods (2 papers); 3.3. Surveillance strategies (2 papers); 4. Testimonies and points of view of utilities (3 papers); 5. Ageing issues taken into account in non nuclear fields (2 papers). The symposium began with workshops devoted to: Operation and equipment; Behaviour of materials; Fatigue degradations; Contributions of research and development. The symposium continued with plenary session that addressed the following issues: Control and supervision of safety of nuclear pressure equipment; Role of international organisations; In-service inspection: Objectives, methods and strategies; Point of view of utilities; Technical summary and

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

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

International Nuclear Information System (INIS)

2002-01-01

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

Impact of age on the selection of nuclear cardiology stress protocols: The INCAPS (IAEA nuclear cardiology protocols) study.

Science.gov (United States)

Al-Mallah, Mouaz H; Pascual, Thomas N B; Mercuri, Mathew; Vitola, João V; Karthikeyan, Ganesan; Better, Nathan; Dondi, Maurizio; Paez, Diana; Einstein, Andrew J

2018-05-15

There is growing concern about radiation exposure from nuclear myocardial perfusion imaging (MPI), particularly among younger patients who are more prone to develop untoward effects of ionizing radiation, and hence US and European professional society guidelines recommend age as a consideration in weighing radiation risk from MPI. We aimed to determine how patient radiation doses from MPI vary across age groups in a large contemporary international cohort. Data were collected as part of a global cross-sectional study of centers performing MPI coordinated by the International Atomic Energy Agency (IAEA). Sites provided information on each MPI study completed during a single week in March-April 2013. We compared across age groups laboratory adherence to pre-specified radiation-related best practices, radiation effective dose (ED; a whole-body measure reflecting the amount of radiation to each organ and its relative sensitivity to radiation's deleterious effects), and the proportion of patients with ED ≤ 9 mSv, a target level specified in guidelines. Among 7911 patients undergoing MPI in 308 laboratories in 65 countries, mean ED was 10.0 ± 4.5 mSv with slightly higher exposure among younger age groups (trend p value < 0.001). There was no difference in the proportion of patients with ED ≤ 9 mSv across age groups, or in adherence to best practices based on the median age of patients in a laboratory. In contemporary nuclear cardiology practice, the age of the patient appears not to impact protocol selection and radiation dose, contrary to professional society guidelines. Copyright © 2018. Published by Elsevier B.V.

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

Aging research

International Nuclear Information System (INIS)

Ross, D.F. Jr.

1988-01-01

The USNRC Office of Nuclear Regulatory Research has developed a program for nuclear plant aging research (NPAR) to achieve an understanding of nuclear plant aging, its potential effects on safety, and methods for its detection and mitigation, sufficient for addressing safety and regulatory issues and supporting regulatory decisions on issues. Specifically, the NRC has aggressive research and regulatory programs associated with aging effects on piping, steam generators, containments, structures, and electrical and mechanical systems and components. In addition to safety assessment for the original license period for nuclear power plants, this aging information will be extremely useful in providing technical bases for efficient and effective regulation associated with possible license extension. This paper discusses the major activities of USNRC sponsored aging research program and recommends an approach to manage and handle aging at nuclear power plants

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

International Nuclear Information System (INIS)

1987-09-01

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

Probabilistic methods in nuclear power plant component ageing analysis

International Nuclear Information System (INIS)

Simola, K.

1992-03-01

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Report on aging of nuclear power plant reinforced concrete structures

International Nuclear Information System (INIS)

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

1996-03-01

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

Report on aging of nuclear power plant reinforced concrete structures

Energy Technology Data Exchange (ETDEWEB)

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

1996-03-01

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

The effects of aging on BWR core isolation cooling systems

International Nuclear Information System (INIS)

Lee, B.S.

1994-10-01

A study was performed to assess the effects of aging on the Reactor Core Isolation Cooling (RCIC) system in commercial Boiling Water Reactors (BWRs). This study is part of the Nuclear Plant Aging Research (NPAR) program sponsored by the US Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. The failure data from national databases, as well as plant specific data were reviewed and analyzed to understand the effects of aging on the RCIC system. This analysis identified important components that should receive the highest priority in terms of aging management. The aging characterization provided information on the effects of aging on component failure frequency, failure modes, and failures causes. Current inspection, surveillance, and monitoring practices were also reviewed

Nuclear graphite ageing and turnaround

International Nuclear Information System (INIS)

Marsden, B.J.; Hall, G.N.; Smart, J.

2001-01-01

Graphite moderated reactors are being operated in many countries including, the UK, Russia, Lithuania, Ukraine and Japan. Many of these reactors will operate well into the next century. New designs of High Temperature Graphite Moderated Reactors (HTRS) are being built in China and Japan. The design life of these graphite-moderated reactors is governed by the ageing of the graphite core due to fast neutron damage, and also, in the case of carbon dioxide cooled reactors by the rate of oxidation of the graphite. Nuclear graphites are polycrystalline in nature and it is the irradiation-induced damage to the individual graphite crystals that determines the material property changes with age. The life of a graphite component in a nuclear reactor can be related to the graphite irradiation induced dimensional changes. Graphites typically shrink with age, until a point is reached where the shrinkage stops and the graphite starts to swell. This change from shrinkage to swelling is known as ''turnaround''. It is well known that pre-oxidising graphite specimens caused ''turnaround'' to be delayed, thus extending the life of the graphite, and hence the life of the reactor. However, there was no satisfactory explanation of this behaviour. This paper presents a numerical crystal based model of dimensional change in graphite, which explains the delay in ''turnaround'' in the pre-oxidised specimens irradiated in a fast neutron flux, in terms of crystal accommodation and orientation and change in compliance due to radiolytic oxidation. (author)

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

International Nuclear Information System (INIS)

Fresco, A.; Subudhi, M.

1992-01-01

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

Aging management of nuclear power plants in Japan

International Nuclear Information System (INIS)

Maeda, Noriyoshi

2003-01-01

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

Effects of spent nuclear fuel aging on disposal requirements

International Nuclear Information System (INIS)

McKee, R.W.; Johnson, K.I.; Huber, H.D.; Bierschbach, M.C.

1991-10-01

This paper describes results of a study to analyze the waste management systems effects of extended spent fuel aging on spent fuel disposal requirements. The analysis considers additional spent fuel aging up to a maximum of 50 years relative to the currently planned 2010 repository startup in the United States. As part of the analysis, an equal energy disposition (EED) methodology was developed for determining allowable waste emplacement densities and waste container loading in a geologic repository. Results of this analysis indicate that substantial benefits of spent fuel aging will already have been achieved by a repository startup in 2010 (spent fuel average age will be 28 years). Even so, further significant aging benefits, in terms of reduced emplacement areas and mining requirements and reduced number of waste containers, will continue to accrue for at least another 50 years when the average spent fuel age would be 78 years, if the repository startup is further delayed

Ageing management in German nuclear power plants

International Nuclear Information System (INIS)

Becker, D.E.; Reiner, M.

1998-01-01

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

Allowance for aging in Spanish nuclear power plants

International Nuclear Information System (INIS)

Rodriguez, C.

2009-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1996-12-01

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

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

International Nuclear Information System (INIS)

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

1996-12-01

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

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

International Nuclear Information System (INIS)

Pachner, J.; Yaremy, E.M.

1991-01-01

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

Aging mitigation and improved programs for nuclear service diesel generators

International Nuclear Information System (INIS)

Hoopingarner, K.R.; Zaloudek, F.R.

1989-12-01

Recent NRC sponsored aging research work on nuclear service diesel generators has resulted in a recommendation that an improved engine management program should be adopted for aging mitigation and reliability improvement. The center of attention should be to ensure diesel-generator operational readiness. This report emphasizes a ''healthy engine concept'' and recommends parameters to be monitored to determine engine condition. The proposed program and approach recommended in this report represent balanced management where diesel generator testing, inspections, monitoring, trending, training, and maintenance all have appropriate importance. Fast-starting and fast-loading test of nuclear service diesels causes very rapid wear of certain engine components. This report documents this aging and wear mechanism and recommends ways to largely eliminate this unique aging stressor. Current periodic intrusive maintenance and engine overhaul practice have been found to be less favorable for safety assurance than engine overhauls based on monitoring and trending results or on a need to correct specific engine defects. This report recommends that the periodic overhaul requirements be re-evaluated. Diesel generator research on aging and wear is sponsored by the US Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research. The research reported in this report was conducted by Pacific Northwest Laboratory (PNL), which is operated for the Department of Energy by Battelle Memorial Institute. 23 refs., 3 figs., 8 tabs

Understanding and Managing Aging of Spent Nuclear Fuel and Facility Components in Wet Storage

International Nuclear Information System (INIS)

Johnson, A. B.

2007-01-01

Storage of nuclear fuel after it has been discharged from reactors has become the leading spent fuel management option. Many storage facilities are being required to operate longer than originally anticipated. Aging is a term that has emerged to focus attention on the consequences of extended operation on systems, structures, and components that comprise the storage facilities. The key to mitigation of age-related degradation in storage facilities is to implement effective strategies to understand and manage aging of the facility materials. A systematic approach to preclude serious effects of age-related degradation is addressed in this paper, directed principally to smaller facilities (test and research reactors). The first need is to assess the materials that comprise the facility and the environments that they are subject to. Access to historical data on facility design, fabrication, and operation can facilitate assessment of expected materials performance. Methods to assess the current condition of facility materials are summarized in the paper. Each facility needs an aging management plan to define the scope of the management program, involving identification of the materials that need specific actions to manage age-related degradation. For each material identified, one or more aging management programs are developed and become part of the plan Several national and international organizations have invested in development of comprehensive and systematic approaches to aging management. A method developed by the US Nuclear Regulatory Commission is recommended as a concise template to organize measures to effectively manage age-related degradation of storage facility materials, including the scope of inspection, surveillance, and maintenance that is needed to assure successful operation of the facility over its required life. Important to effective aging management is a staff that is alert for evidence of materials degradation and committed to carry out the aging

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

International Nuclear Information System (INIS)

Gunther, W.; Taylor, J.

1989-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-12-01

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

Interactive effects of relay and circuit breaker aging in a safety-related system

International Nuclear Information System (INIS)

Toman, G.J.; Bacanskas, V.P.; Shook, T.A.; Ladlow, C.C.; Gunther, W.

1987-01-01

This paper provides an overview of the results of a program to evaluate the aging of circuit breakers and relays and the effects of that aging on the function of a safety system used in nuclear power plants. The program was performed under the Nuclear Plant Aging Research (NPAR) Program of the US Nuclear Regulatory Commission under subcontract to Brookhaven National Laboratory. There were two primary aspects to the program. In the first, the aging and failure modes of relays and circuit breakers were determined by evaluating the construction, design, and materials and the failure data related to nuclear power plant service. In the second, the interactions between a safety system and its relays and circuit breakers were evaluated to determine the effects of relay and circuit breaker aging on the function of the safety system. The aging of relays and circuit breakers was assessed through evaluation of failure data bases, discussions with utility personnel, and evaluation of equipment operating and maintenance manuals. The interaction study was based on an analysis of the safety injection system of a pressurized water reactor. The effects of stresses from the system were analyzed for the tendency to cause deterioration of the relays and circuit breakers in the system. Then the effect of the deterioration of relays and circuit breakers on the functional capability of the safety system was evaluated

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

International Nuclear Information System (INIS)

Chadha, J.A.; Pachner, J.

1989-06-01

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

Effect of nuclear education on public attitude

International Nuclear Information System (INIS)

Ohnishi, Teruaki

1995-01-01

A method is proposed to assess the effect of nuclear education. In this method, the nuclear education is treated as a part of the activities for public acceptance (PA), and a unit PA activity is assumed to give the same effect on the public, in essence, as a unit of nuclear information given by the newsmedia. Moreover, the change of attitude to nuclear energy is assumed to originate from enhanced understanding which, in turn, is brought by the stimulus given by the nuclear education. With the values of constants determined by using the data in Japan, example calculations were made for the educational time b 0 and the infiltration rate of education into minors B as parameters. It became clear from this calculation that the attitude to nuclear energy formed in the age of school children plays an essential role in shaping future public opinion since it is held in individuals without any notable modification for a long time after its formation, and that the effect of nuclear education to minors emerges depending on the variables b 0 and B in a highly non-linear manner. It was also found that there exists an optimum condition for nuclear education to attain the maximum amelioration of public opinion under a given condition of man-power for educational workers. (author)

Nuclear plant service water system aging degradation assessment: Phase 1

International Nuclear Information System (INIS)

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

1989-06-01

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

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

International Nuclear Information System (INIS)

Naus, J.

2009-01-01

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

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Nuclear energy: salvaging the atomic age

International Nuclear Information System (INIS)

Weinberg, A.M.

1979-01-01

The history of atomic power is reviewed from the first chain reaction in Chicago in 1942 to the worst-to-date accident at the Three Mile Island power plant in March, 1979. While media coverage during the Three Mile Island incident made the public aware of some reactor hardware and radiation hazards, Weinberg suggests that an acceptable nuclear future should have six characteristics: increased physical isolation of reactors, further technical improvements, separation of generation and distribution, professionalization of the nuclear cadre, heightened security, and public education about the hazards of radiation. Weinberg feels the question of low-level radiation effects to be critical to public acceptance of nuclear energy. Since the effects (if any) are so rarely seen because exposures are so small, the issue may be beyond the ability of science to decipher. Weinberg again explains his reference to nuclear energy as a Faustian Bargain: ''...nuclear energy, that miraculous and quite unsuspected source of energy, demands an unprecedented degree of expertise, attention to detail, and social stability. In return, man has, in the breeder reactor, an inexhaustible energy source.''

Management of age-related degradation for nuclear power plants

International Nuclear Information System (INIS)

Gregor, Frank E.

2004-01-01

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

Assessment of electrical equipment aging for nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

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

Assessment of electrical equipment aging for nuclear power plant

International Nuclear Information System (INIS)

2013-01-01

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

Monitoring ageing of components in nuclear plants

International Nuclear Information System (INIS)

Fritz, M.R.

1992-01-01

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

Monitoring ageing of components in nuclear plants

Energy Technology Data Exchange (ETDEWEB)

Fritz, M R [FRAMATOME, Paris (France)

1992-07-01

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

Phase I aging assessment of nuclear air-treatment system high efficiency particulate air and adsorbers

International Nuclear Information System (INIS)

Winegardner, W.K.

1996-01-01

A phase I aging assessment of high efficiency particulate air filters and activated carbon gas adsorption units was performed by the Pacific Northwest Laboratory as part of the US Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. Information was compiled concerning design features, failure experience, aging mechanisms, effects, and stressors, and monitoring methods. Over 1100 failures, or 12% of the filter installations, were reported as part of a US Department of energy survey. Investigators from other laboratories have suggested that aging could have contributed to over 80% of these failures. Several instances of impaired performance as the result of the premature aging of carbon were reported. Filter aging mechanisms range from those associated with particle loading to reactions that alter the properties of gaskets. Mechanisms that can lead to impaired adsorber performance include the loss of potentially available active sites as a result of the adsorption of moisture or pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants. (orig.)

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

International Nuclear Information System (INIS)

Goel, V.S.

1985-01-01

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

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

International Nuclear Information System (INIS)

Gunther, W.E.

1988-09-01

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

Nuclear power plant ageing management programmes in foreign countries

International Nuclear Information System (INIS)

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

1992-09-01

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

International network on incorporation of ageing effects into PSA

International Nuclear Information System (INIS)

Kirchsteiger, C.; Patrik, M.

2006-01-01

This paper describes the background and status of a new International Network on ''Incorporating Ageing Effects into Probabilistic Safety Assessment''. The Joint Research Centre (JRC) of the European Commission organized in September 2004 the kickoff meeting of this Network at JRC's Institute for Energy in Petten, Netherlands, with the aims to open the APSA Network, to start discussion of ageing issues in relation to incorporating ageing effects into PSA tools and to come to consensus on objectives and work packages of the Network, taking into account the specific expectations of potential Network partners. The presentations and discussions at the meeting confirmed the main conclusion from the previously organized PSAM 7 pre-conference workshop on ''Incorporating PSA into Ageing Management'', Budapest, June 2004, namely that incorporating ageing effects into PSA seems to be more and more a hot topic particularly for risk assessment and ageing management of nuclear power plants operating at advanced age (more than 25-30 years) and for the purpose of plant life extension. However, it also appeared that, especially regarding the situation in Europe, at present there are several on-going feasibility or full studies in this area, but not yet a completed Ageing PSA leading to applications. The project's working method is a NETWORK of operators, industry, research, academia and consultants with an active interest in the area (physical networking via a series of workshops and virtual networking via the Internet). The resulting knowledge should help PSA developers and users to incorporate the effects of equipment ageing into current PSA tools and models, to identify and/or develop most effective corresponding methods, to focus on dominant ageing contributors and components and to promote the use of PSA for ageing management of Nuclear Power Plants. (orig.)

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

Maeda, N.; Tajima, K.

2003-01-01

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

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

International Nuclear Information System (INIS)

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

1990-01-01

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

Figures of merit for measuring aging management program effectiveness

International Nuclear Information System (INIS)

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

1991-01-01

One of the requirements for nuclear plant license renewal may be the establishment and demonstration of an effective aging management program. An analysis of both qualitative and quantitative information will be required to define the contents of this aging management program. The authors propose two quantitative figures of merit, Mean Event Detection Frequency and Mean Renewal Rate, that can be used to compare the effectiveness of various inspection, surveillance, test, and monitoring (ISTM) activities for aging mitigation. An example showing the relative effectiveness of an enhanced Loose Parts Monitoring System with current ISTM activities for steam generators and reactor internals is provided. (author)

Curriculum for Security in a Nuclear Age.

Science.gov (United States)

Carlson, Helen L.

1984-01-01

A survey of secondary students after they had completed a course entitled "Security in the Nuclear Age" suggests that instruction can make some impact in the area of security information. However, results also showed that students use media rather than school as information sources. Peace curricula are also discussed. (RM)

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

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.

Nuclear compression effects on pion production in nuclear collisions

International Nuclear Information System (INIS)

Sano, M.; Gyulassy, M.; Wakai, M.; Kitazoe, Y.

1984-11-01

The pion multiplicity produced in nuclear collisions between 0.2 and 2 AGeV is calculated assuming shock formation. We also correct the procedure of extracting the nuclear equation of state as proposed by Stock et al. The nuclear equation of state would have to be extremely stiff for this model to reproduce the observed multiplicities. The assumptions of this model are critically analyzed. (author)

Technical strategy map to employing nuclear power plant aging management

International Nuclear Information System (INIS)

Sekimura, Naoto; Kanno, Masanori

2008-01-01

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

Deregulation and Nuclear Training: Cost Effective Alternatives

International Nuclear Information System (INIS)

Richard P. Coe; Patricia A. Lake

2000-01-01

Training is crucial to the success of any organization. It is also expensive, with some estimates exceeding $50 billion annually spent on training by U.S. corporations. Nuclear training, like that of many other highly technical organizations, is both crucial and costly. It is unlikely that the amount of training can be significantly reduced. If anything, current trends indicate that training needs will probably increase as the industry and workforce ages and changes. With the advent of energy deregulation in the United States, greater pressures will surface to make the costs of energy more cost-competitive. This in turn will drive businesses to more closely examine existing costs and find ways to do things in a more cost-effective way. The commercial nuclear industry will be no exception, and nuclear training will be equally affected. It is time for nuclear training and indeed the entire nuclear industry to begin using more aggressive techniques to reduce costs. This includes the need for nuclear training to find alternatives to traditional methods for the delivery of cost-effective high-quality training that meets regulatory requirements and produces well-qualified personnel capable of working in an efficient and safe manner. Computer-based and/or Web-based training are leading emerging technologies

EDF ageing management program of nuclear components: a safety and economical issue

International Nuclear Information System (INIS)

Faidy, C.

2005-01-01

Ageing management of Nuclear Power Plants is an essential issue for utilities, in term of safety and availability and corresponding economical consequences. Practically all nuclear countries have developed a systematic program to deal with ageing of components on their plants. This paper presents the ageing management program developed by EDF and that are compared with different other approaches in other countries (IAEA guidelines and GALL report). The paper presents a general overview of the programs, the major results, recommendations and conclusions. (author)

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

International Nuclear Information System (INIS)

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

1994-02-01

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

Methodology of aging management in structures, systems and components of a nuclear power plant and its application to a pilot program in Laguna Verde

International Nuclear Information System (INIS)

Jarvio C, G.; Fernandez S, G.

2009-10-01

From its origin the nuclear power plants confront the effects of time and of environment, giving as result the aging of its structures, systems and components. In this document the general process is described for the establishment of Aging Management Program developed by IAEA. Following the program methodology is guaranteed that a nuclear power plant manages the aging effects appropriately and to make decisions for its solution, assuring the characteristic functions of structures, systems and components of same nuclear power plant. On the other hand, the implantation of an aging management program constitutes the base for development of a licence renovation program, like it can be the specific case of the Central Laguna Verde Units 1 and 2. (Author)

Overview of synergistic aging effects

International Nuclear Information System (INIS)

Steigelmann, W.; Farber, M.

1982-01-01

Proper, technically defensible qualification of materials and equipment for nuclear power facilities requires that the effects of combined environment exposures be addressed. The full significance of synergistic effects resulting from combined stresses still remains largely an unknown to be provided for by use of conservatisms, allowing a sizeable margin in test programs and analyses to account for possible combined effects. However, these margins, when applied to sequential aging tests, may under- or over-estimate the qualified life of the material or equipment. Experimentation with radiation dose-rate effects, simultaneous vs. sequential ordered exposures, and other combined environment testing are highlighted in this paper to provide an overview of the current state-of-knowledge concerning synergistic effects and their significance to qualification programs

Thermal Aging Effect Analysis of 17-4PH Martensitic Stainless Steel Valves for Nuclear Power Plant

Institute of Scientific and Technical Information of China (English)

BAI; Bing; ZHANG; Chang-yi; TONG; Zhen-feng; YANG; Wen

2015-01-01

The valve stem used in the main steam system of nuclear power plant is usually martensitic stainless steel(such as 17.4ph16.4Mo etc.).When served in high temperature for a long time,the thermal aging embrittlement of valve stem will be significant,and even lead to the fracture.

Dating the age of a recent nuclear event by gamma-spectrometry

International Nuclear Information System (INIS)

Nir-El, Y.

2006-01-01

The age of a recent, i.e., fresh, nuclear event can be determined by measuring the activity of short-lived parent and daughter fission products. The event studied was a short irradiation, of a small sample of uranium, in a nuclear reactor. Two clocks were investigated, 92 Sr- 92 Y and 135 I- 135 Xe. Measurements of the source by gamma-spectrometry yielded very good agreement between true and measured ages. The upper and lower age limits of applicability for the clocks in question were defined. The half-life of 92 Sr was found 2.635±0.008 hours and of 135 I 6.65±0.04 hours. (author)

The (safety-related) heat exchangers aging management guideline for commercial nuclear power plants, and developments since 1994

International Nuclear Information System (INIS)

Clauss, J.M.

1998-01-01

The US Department of Energy (DOE), in cooperation with the Electric Power Research Institute (EPRI) and US nuclear power plant utilities, is preparing a series of aging management guidelines (AMGs) for commodity types of components (e.g., heat exchangers, electrical cable and terminations, pumps). Commodities are included in this series based on their importance to continued nuclear plant operation and license renewal. The AMGs contain a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance and surveillance practices that can be combined to create an effective aging management program. Each AMG is intended for use by the systems engineers and plant maintenance staff (i.e., an AMG is intended to be a hands-on technical document rather than a licensing document). The heat exchangers AMG, published in June 1994, includes the following information of interest to nondestructive examination (NDE) personnel: aging mechanisms determined to be non-significant for all applications; aging mechanisms determined to be significant for some applications; effective conventional programs for managing aging; and effective unconventional programs for managing aging. Since the AMG on heat exchangers was published four years ago, a brief review has been conducted to identify emerging regulatory issues, if any. The results of this review and lessons learned from the collective set of AMGs are presented

IAEA-IFRAM joint development of nuclear plant aging management handbooks

International Nuclear Information System (INIS)

Yeji Kim, II Soon Hwang

2015-01-01

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

Experience in monitoring ageing phenomena for improving nuclear power plant availability. Proceedings of a specialists' meeting. Working material

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-07-01

For more than thirty years nuclear power plants have been supplying electricity to national grids. Today, the nuclear power community is facing great challenges. The safe, reliable operation of existing nuclear power plants (NPPs) must continue to be ensured. From an economic viewpoint, because of the long lead times associated with bringing new plants into service, securing the continued operation of existing plants for their planned lifetimes and possible life extension will be very important in the near term for meeting electrical power demands. The IAEA programmes in nuclear power plant ageing and life extension and in control and instrumentation promote technical information exchange between Member States with new programmes, offers assistance to Member States with an interest in reliability of NPP components, in-service inspection methods and programmes using on-line techniques, component monitoring and special technological topics of nuclear reactors. Significant experience already exists in the nuclear industry in developing and applying the monitoring techniques for different nuclear power plant applications, especially in monitoring of ageing phenomena for improving NPP availability. The purpose of this Specialists' Meeting was to bring together experts from operations, design, research and development and licensing to share their experience in: ageing mechanics of key structural components, methods of monitoring such ageing, tools for cost-effective implementation of the methods and methodologies, life management approaches and examples from current reactors, future direction for monitoring of key structural components in nuclear power plants. The meeting was organized by the IAEA International Working Groups on Life Management of Nuclear Power Plants (IWG-LMNPP) and Nuclear Power Plant Control and Instrumentation (TWG-NPPCI) in co-operation with the Czechoslovak Atomic Energy Commission and Skoda concern. Around 40 participants from 10 countries.

Experience in monitoring ageing phenomena for improving nuclear power plant availability. Proceedings of a specialists' meeting. Working material

International Nuclear Information System (INIS)

1992-01-01

For more than thirty years nuclear power plants have been supplying electricity to national grids. Today, the nuclear power community is facing great challenges. The safe, reliable operation of existing nuclear power plants (NPPs) must continue to be ensured. From an economic viewpoint, because of the long lead times associated with bringing new plants into service, securing the continued operation of existing plants for their planned lifetimes and possible life extension will be very important in the near term for meeting electrical power demands. The IAEA programmes in nuclear power plant ageing and life extension and in control and instrumentation promote technical information exchange between Member States with new programmes, offers assistance to Member States with an interest in reliability of NPP components, in-service inspection methods and programmes using on-line techniques, component monitoring and special technological topics of nuclear reactors. Significant experience already exists in the nuclear industry in developing and applying the monitoring techniques for different nuclear power plant applications, especially in monitoring of ageing phenomena for improving NPP availability. The purpose of this Specialists' Meeting was to bring together experts from operations, design, research and development and licensing to share their experience in: ageing mechanics of key structural components, methods of monitoring such ageing, tools for cost-effective implementation of the methods and methodologies, life management approaches and examples from current reactors, future direction for monitoring of key structural components in nuclear power plants. The meeting was organized by the IAEA International Working Groups on Life Management of Nuclear Power Plants (IWG-LMNPP) and Nuclear Power Plant Control and Instrumentation (TWG-NPPCI) in co-operation with the Czechoslovak Atomic Energy Commission and Skoda concern. Around 40 participants from 10 countries

Proceedings of the international nuclear power plant aging symposium

International Nuclear Information System (INIS)

Beranek, A.

1989-03-01

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

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

Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Workshop

International Nuclear Information System (INIS)

Hoopingarner, K.R.; Vause, J.W.

1987-08-01

Pacific Northwest Laboratory (PNL) evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume II, reports the results of an industry-wide workshop held on May 28 and 29, 1986, to discuss the technical issues associated with aging of nuclear service emergency diesel generators. The technical issues discussed most extensively were: man/machine interfaces, component interfaces, thermal gradients of startup and cooldown and the need for an accurate industry database for trend analysis of the diesel generator system

Aging of concrete containment structures in nuclear power plants

International Nuclear Information System (INIS)

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

1992-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Ageing of significant to safety structure elements of nuclear power plants

International Nuclear Information System (INIS)

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

1999-01-01

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

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

International Nuclear Information System (INIS)

Greenstreet, W.L.

1989-01-01

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

Trend of use and development of nuclear power in USA. Movement of recovery from 'winter age' of nuclear power

International Nuclear Information System (INIS)

Yamada, Eiji

2005-01-01

The winter age of nuclear power industry in USA has begun since the accident of Three Mile Island Nuclear Power Plant, 1979. However, the rate of operation of nuclear power plants has get better since in the middle of 1990s by these factors such as extension of operation cycle, shortening period of the periodic inspection, increase of rated output, extension of approval operating period and change of nuclear power industries. The Department of Energy (DOE) makes budget about 1.9 hundreds million dollars for 2006. The subjects, cooperation between DOE and industry and movement of private enterprise in USA are stated. 434 reactors are operating in the world in 2004. French and Finland decided to build EPR in 2004. China and Korea in The East Asia become the growth market, but Japan enters the winter age. Reorganization of nuclear power industry in the world is explained. (S.Y.)

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

International Nuclear Information System (INIS)

Maeda, Noriyoshi; Tajima, Kenichi

2004-01-01

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

Managing ageing of Karachi nuclear power plant (KANUPP)

International Nuclear Information System (INIS)

Hoda, M. Qamrul; Jamal-ur-Rahman

2002-01-01

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

Mitochondrial and Nuclear DNA Damage and Repair in Age-Related Macular Degeneration

Directory of Open Access Journals (Sweden)

Janusz Blasiak

2013-01-01

Full Text Available Aging and oxidative stress seem to be the most important factors in the pathogenesis of age-related macular degeneration (AMD, a condition affecting many elderly people in the developed world. However, aging is associated with the accumulation of oxidative damage in many biomolecules, including DNA. Furthermore, mitochondria may be especially important in this process because the reactive oxygen species produced in their electron transport chain can damage cellular components. Therefore, the cellular response to DNA damage, expressed mainly through DNA repair, may play an important role in AMD etiology. In several studies the increase in mitochondrial DNA (mtDNA damage and mutations, and the decrease in the efficacy of DNA repair have been correlated with the occurrence and the stage of AMD. It has also been shown that mitochondrial DNA accumulates more DNA lesions than nuclear DNA in AMD. However, the DNA damage response in mitochondria is executed by nucleus-encoded proteins, and thus mutagenesis in nuclear DNA (nDNA may affect the ability to respond to mutagenesis in its mitochondrial counterpart. We reported that lymphocytes from AMD patients displayed a higher amount of total endogenous basal and oxidative DNA damage, exhibited a higher sensitivity to hydrogen peroxide and UV radiation, and repaired the lesions induced by these factors less effectively than did cells from control individuals. We postulate that poor efficacy of DNA repair (i.e., is impaired above average for a particular age when combined with the enhanced sensitivity of retinal pigment epithelium cells to environmental stress factors, contributes to the pathogenesis of AMD. Collectively, these data suggest that the cellular response to both mitochondrial and nuclear DNA damage may play an important role in AMD pathogenesis.

Effect of two activation treatments and age of blastomere karyoplasts on in vitro development of bovine nuclear transfer embryos

DEFF Research Database (Denmark)

Booth, Paul J; Holm, Peter; Vajta, Gabor

2001-01-01

The yield and quality of (a) parthenogenetic blastocysts produced by two activation treatments (cycloheximide [CHX] or 6-dimethylaminopurine [DMAP]) and (b) nuclear transfer blastocysts generated using these two activation treatments and three different ages of karyoplast derived from day 3, 4......, or 5 in vitro produced donor embryos, were examined in order to define an optimal nuclear transfer protocol. The two activation protocols comprised calcium ionophore followed by either CHX or DMAP. Parthenogenetic blastocyst yields were greater (P ....7 +/- 5.1 vs. 31.4 +/- 4.5 [mean +/- SEM]). In contrast, nuclear transfer blastocyst rates per fused embryo were lower (P

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-07-01

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

Health and safety in the nuclear age

International Nuclear Information System (INIS)

1988-01-01

In their Communication to the Council on the development of Community measures for the application of Chapter III of the Euratom Treaty - Health and safety (COM(86) 434 final) the Commission of the European Communities announced their intention to initiate a 'Standing Conference on Health and Safety in the Nuclear Age' in order to contribute to an increase of information on nuclear activities. Following this proposition, the Commission (Directorate-General for Employment, Social Affairs and Education, Health and Safety Directorate) organized the first meeting of this Standing Conference in Luxembourg on 5, 6 and 7 October 1987 with the theme 'Information for the public and the media on health protection and safety with regard to nuclear activities'. About 120 participants representing scientific experts, the media, the bodies concerned with environmental or consumer protection, the social partners and interested national and international organizations, took part in this conference. It was the first time at European Community level that a meeting allowed an exchange of positions on the health problems related to ionizing radiation by all the parties interested in this subject. The Commission was asked to pursue this dialogue in order to improve the perception of citizens of the Community of the potential risks and the methods of protection brought into force in the nuclear field

Aging management guidelines for commercial nuclear power plant equipment

International Nuclear Information System (INIS)

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

1994-01-01

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

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

International Nuclear Information System (INIS)

Laurier, D; Hemon, D; Clavel, J

2008-01-01

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

Aging Evaluation of Nuclear Power Plant Concrete Structures

International Nuclear Information System (INIS)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

1991-01-01

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

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

International Nuclear Information System (INIS)

Bora, J.S.

1997-04-01

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

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

International Nuclear Information System (INIS)

Zhong Zhimin; Li Jinsong; Zhang Mengyi

2014-01-01

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

Toward a nuclear-age ethos

International Nuclear Information System (INIS)

Lifton, R.J.

1986-01-01

We are in the midst of a significant but tortured shift in consciousness concerning the nuclear threat. At precisely such a time, we would do well to consider what might be an appropriate set of convictions - appropriate psychologically and in terms of life enhancement. The 10 principles the authors wish to elaborate are simple ones, already adopted by a growing number of people. We face a new dimension of destruction - not a matter of disaster or even of a war - but rather of an end; an end to human civilization and perhaps humankind. This concept violates our ignored mental constructs concerning human continuity: though we can imagine particular cultures being impaired or even destroyed, we expect humankind to heal itself sufficiently to survive. But the findings of a possible ''nuclear winter'' effect concretize the idea of a nuclear end, and, however grim, serve the imagination in the difficult task of looking into the abyss in order to see beyond it. The image of the nuclear end includes not only death and suffering on the most massive scale but, beyond that, nothingness. Two relatively recent historical events, the Nazi holocaust and the atomic bombings of Hiroshima and Nagasaki, assist that kind of imaginative act

An international data base of nuclear concrete containment ageing

International Nuclear Information System (INIS)

Seni, C.; Ianko, L.

1994-01-01

The ageing of nuclear structures is of special interest because of the extended service life expected of these structures, and the potential impact of their deterioration on safety and reliability. Although there are databases about concrete, they address properties in general, not performance. In 1992, the IAEA, in collaboration with AECL, set out to create a new database that would fill the gap. Functional ageing, i.e. deterioration of leak-tightness, was to be included, not just structural ageing, i.e. deterioration of load-bearing capacity. This paper outlines the project of creating the database

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

International Nuclear Information System (INIS)

Kalinowski, I.

1996-01-01

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

The nuclear age

International Nuclear Information System (INIS)

Leclercq, J.

1986-01-01

This book is divided into 7 chapters bearing on: (1) Nuclear power: an historical perspective (2) Diversity of reactor designs (3) Safety and the environment (4) Architecture and heavy construction (5) Fabrication and installation (6) Nuclear fuel (7) Working for the electric power industry

Obstacles to the nuclear technology development in Brazil: from the beginning of atomic age to the Brazil-Germany Nuclear Agreement

International Nuclear Information System (INIS)

Medeiros, Tharsila Reis de

2005-01-01

This paper intends to comprehend the Brazilian social actors' efforts applied to the nuclear energy control, from the beginning of Atomic Age to Brazil-Germany Nuclear Agreement. It tries to demonstrate that the limits of The Brazilian nuclear development in this period derive from the capitalist development dynamics in Brazil and from the absence of continuity on the motivations of its nuclear policy. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-01

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

Improving nuclear regulatory effectiveness

International Nuclear Information System (INIS)

2001-01-01

Ensuring that nuclear installations are operated and maintained in such a way that their impact on public health and safety is as low as reasonably practicable has been and will continue to be the cornerstone of nuclear regulation. In the past, nuclear incidents provided the main impetus for regulatory change. Today, economic factors, deregulation, technological advancements, government oversight and the general requirements for openness and accountability are leading regulatory bodies to review their effectiveness. In addition, seeking to enhance the present level of nuclear safety by continuously improving the effectiveness of regulatory bodies is seen as one of the ways to strengthen public confidence in the regulatory systems. This report covers the basic concepts underlying nuclear regulatory effectiveness, advances being made and future requirements. The intended audience is primarily nuclear safety regulators, but government authorities, nuclear power plant operators and the general public may also be interested. (author)

Aging and service wear of diesel engines used for emergency power at nuclear power stations

International Nuclear Information System (INIS)

Dingee, P.A.; Johnson, A.B.

1985-01-01

Aging and wear problems associated with emergency standby diesel generators are under study as part of the US Nuclear Regulatory Commission Nuclear Plant Aging Research program. Aging/wear factors identified in this study to date include chemical, mechanical, electrochemical, and bacterial mechanisms. The study also examines the potential of excessive engine testing as a cause of premature wear. To date, the results of this effort are not conclusive. An assessment of current wear mitigation measures such as engine maintenance and surveillance procedures suggests the need for their further development within the nuclear industry

Effective doses in diagnostic nuclear medicine in Brazil: Possibilities of optimisation

International Nuclear Information System (INIS)

Veslasques de Oliveira, S. M.; Tauhata, L.; Lipsztein, J. L.; Boasquevisque, E. M.

2006-01-01

With the aim of analysing protection of patient in diagnostic nuclear medicine, this study present data collected from sixteen nuclear medicine public and private institutions in three regions of the country, namely Northeast, Southeast and South regions 26,782 patients protocols were analysed, 24,371 adults and 2,411 children and teen-ages. Myocardial perfusion and bone imaging were responsible, respectively, for 53% and 23% of all diagnostic procedures. For 3.010 adults with age and weight registered, 96% had more than 40 years and mean weight was (69.9±14.1) kg for both genders. Due to similarities in physical characteristics between Brazilian adults patients and ICRP Reference Man, effective doses were estimated using ICRP conversion factors. For adults, the ratio mean activities per mean weigh was higher for female than male for the majority of procedures. For children and teen-ages, this ratio was higher for younger ages. Protocols should consider mean corporal weight for female and activities may be reduced accordingly. For children and teen-ages, effective doses may be reduced for younger ages. High absolved doses in bone surfaces of children due to 67Ga citrate imaging and bone scintigraphies should be investigated. (Author)

Atom's eve: ending the nuclear age - an anthology

International Nuclear Information System (INIS)

Reader, M.; Hardert, R.A.; Moulton, G.L.

1980-01-01

In this volume over forty experts and advocates examine the implications of the nuclear fuel cycle and its hazards to critical human issues. They address such matters as the link between cancer and low level radiation, the failure to find reliable ways to dispose of radioactive wastes, known genetic effects of radiation, the political repression necessary to maintain a nuclear society, and all the other politics and controversies in the growing movement against nuclear power. Included are a checklist of energy alternatives and organizations, a calendar of major nuclear events from 1945 to the present, and a nuclear bibliography of books and audiovisual material

Effective recordkeeping technologies to manage aging

International Nuclear Information System (INIS)

Dukelow, J.S.; Johnson, A.B. Jr.; Vora, J.P.

1992-10-01

Pacific Northwest Laboratory has investigated the capability of current recordkeeping technology to support aging management. This paper discusses technical issues associated with potential enhancements of nuclear plant records systems--from the perspective of the lessons learned about equipment aging degradation mechanisms and associated surveillance and monitoring techniques during the U. S. Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The paper considers both the specific types of technical data needed to ensure continued safe operation and the use of new technology to upgrade record systems. Specific topics discussed include: equipment reliability data needed to support the assessment of the impact of aging on the continued operation of the plant; operational history data to support the assessment of residual life of mechanical and structural components and piping; tools for the analysis and trending of equipment reliability data and operational history data; design and implementation of plant record systems that will provide a comprehensive and usable engineering design basis for the plant; proposed improvements in the data input process for the plant records system; computerization of plant records systems, including conversion of existing records into machine-readable forms

Effective recordkeeping technologies to manage aging

Energy Technology Data Exchange (ETDEWEB)

Dukelow, J.S.; Johnson, A.B. Jr. (Pacific Northwest Lab., Richland, WA (United States)); Vora, J.P. (Nuclear Regulatory Commission, Washington, DC (United States))

1992-10-01

Pacific Northwest Laboratory has investigated the capability of current recordkeeping technology to support aging management. This paper discusses technical issues associated with potential enhancements of nuclear plant records systems--from the perspective of the lessons learned about equipment aging degradation mechanisms and associated surveillance and monitoring techniques during the U. S. Nuclear Regulatory Commission's Nuclear Plant Aging Research Program. The paper considers both the specific types of technical data needed to ensure continued safe operation and the use of new technology to upgrade record systems. Specific topics discussed include: equipment reliability data needed to support the assessment of the impact of aging on the continued operation of the plant; operational history data to support the assessment of residual life of mechanical and structural components and piping; tools for the analysis and trending of equipment reliability data and operational history data; design and implementation of plant record systems that will provide a comprehensive and usable engineering design basis for the plant; proposed improvements in the data input process for the plant records system; computerization of plant records systems, including conversion of existing records into machine-readable forms.

Effective recordkeeping technologies to manage aging

Energy Technology Data Exchange (ETDEWEB)

Dukelow, J.S.; Johnson, A.B. Jr. [Pacific Northwest Lab., Richland, WA (United States); Vora, J.P. [Nuclear Regulatory Commission, Washington, DC (United States)

1992-10-01

Pacific Northwest Laboratory has investigated the capability of current recordkeeping technology to support aging management. This paper discusses technical issues associated with potential enhancements of nuclear plant records systems--from the perspective of the lessons learned about equipment aging degradation mechanisms and associated surveillance and monitoring techniques during the U. S. Nuclear Regulatory Commission`s Nuclear Plant Aging Research Program. The paper considers both the specific types of technical data needed to ensure continued safe operation and the use of new technology to upgrade record systems. Specific topics discussed include: equipment reliability data needed to support the assessment of the impact of aging on the continued operation of the plant; operational history data to support the assessment of residual life of mechanical and structural components and piping; tools for the analysis and trending of equipment reliability data and operational history data; design and implementation of plant record systems that will provide a comprehensive and usable engineering design basis for the plant; proposed improvements in the data input process for the plant records system; computerization of plant records systems, including conversion of existing records into machine-readable forms.

SAFETY ANALYSIS METHODOLOGY FOR AGED CANDU® 6 NUCLEAR REACTORS

Directory of Open Access Journals (Sweden)

WOLFGANG HARTMANN

2013-10-01

Full Text Available This paper deals with the Safety Analysis for CANDU® 6 nuclear reactors as affected by main Heat Transport System (HTS aging. Operational and aging related changes of the HTS throughout its lifetime may lead to restrictions in certain safety system settings and hence some restriction in performance under certain conditions. A step in confirming safe reactor operation is the tracking of relevant data and their corresponding interpretation by the use of appropriate thermalhydraulic analytic models. Safety analyses ranging from the assessment of safety limits associated with the prevention of intermittent fuel sheath dryout for a slow Loss of Regulation (LOR analysis and fission gas release after a fuel failure are summarized. Specifically for fission gas release, the thermalhydraulic analysis for a fresh core and an 11 Effective Full Power Years (EFPY aged core was summarized, leading to the most severe stagnation break sizes for the inlet feeder break and the channel failure time. Associated coolant conditions provide the input data for fuel analyses. Based on the thermalhydraulic data, the fission product inventory under normal operating conditions may be calculated for both fresh and aged cores, and the fission gas release may be evaluated during the transient. This analysis plays a major role in determining possible radiation doses to the public after postulated accidents have occurred.

Joint Analysis of Nuclear and Mitochondrial Variants in Age-Related Macular Degeneration Identifies Novel Loci TRPM1 and ABHD2/RLBP1

NARCIS (Netherlands)

Persad, P.J.; Heid, I.M.; Weeks, D.E.; Baird, P.N.; Jong, E.K.; Haines, J.L.; Pericak-Vance, M.A.; Scott, W.K.

2017-01-01

Purpose: Presently, 52 independent nuclear single nucleotide polymorphisms (nSNPs) have been associated with age-related macular degeneration (AMD) but their effects do not explain all its variance. Genetic interactions between the nuclear and mitochondrial (mt) genome may unearth additional genetic

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

International Nuclear Information System (INIS)

Minakawa, T.

2012-11-01

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

Ageing management of nuclear power plant - the Tarapur experience

International Nuclear Information System (INIS)

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

2006-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1991-12-31

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1991-01-01

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

Ageing Management for Electrical and I and C Equipment in the Light of Germany's Nuclear Phaseout

International Nuclear Information System (INIS)

Foellner, Lutz; Hienstorfer, Wolfgang; Weich, Alfred

2012-01-01

The political decision in Germany to shut-down operation of several Nuclear Power Reactors (NPP's) and to completely terminate the use of Nuclear Power in Germany by 2022 has extensive consequences in matters of the Aging Management. Physical conditions and presumed accident conditions are different for NPP's in power operation and for NPP's in shut-down operation and different aging effects have to be considered. Nevertheless aging management is still required considering the expected extensive time for shut-down operation in order to guarantee the safety functions and the use of qualified components with a sufficient and approved state. All current Aging Management requirements have to be fulfilled in the future as well without any restriction to ensure functionality, reliability and availability. However, it is expected that business management reasons will not allow realizing greater modifications or projects, e.g. exchange of analogue I and C technologies such as Limitations or Reactor Protection System with digital equipment. In the area of I and C which is characterized by many similar I and C-modules a change of strategy begins to emerge: the repair of discontinued modules within the plant under the owner's responsibility and the redesign of modules. Previously, we had reported on the establishment of a systematic Aging Management approach in order to identify aging processes and effects. Since two years the Aging management system has been installed in the NPPs and now we contribute our experience related to the practical handling, the performance and the results of these systems in German NPP's. (author)

Aging management of instrumentation and control sensors in nuclear power plants

International Nuclear Information System (INIS)

Hashemian, H.M.

2010-01-01

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

Robust nuclear lamina-based cell classification of aging and senescent cells.

Science.gov (United States)

Righolt, Christiaan H; van 't Hoff, Merel L R; Vermolen, Bart J; Young, Ian T; Raz, Vered

2011-12-01

Changes in the shape of the nuclear lamina are exhibited in senescent cells, as well as in cells expressing mutations in lamina genes. To identify cells with defects in the nuclear lamina we developed an imaging method that quantifies the intensity and curvature of the nuclear lamina. We show that this method accurately describes changes in the nuclear lamina. Spatial changes in nuclear lamina coincide with redistribution of lamin A proteins and local reduction in protein mobility in senescent cell. We suggest that local accumulation of lamin A in the nuclear envelope leads to bending of the structure. A quantitative distinction of the nuclear lamina shape in cell populations was found between fresh and senescent cells, and between primary myoblasts from young and old donors. Moreover, with this method mutations in lamina genes were significantly distinct from cells with wild-type genes. We suggest that this method can be applied to identify abnormal cells during aging, in in vitro propagation, and in lamina disorders.

Effects evaluation of artificial aging by temperature and gamma radiation on cables for Laguna Verde nuclear power plant (LVNPP)

Energy Technology Data Exchange (ETDEWEB)

Vazquez C, R. M.; Bonifacio M, J.; Garcia H, E. E.; Loperena Z, J. A. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia M, C., E-mail: raulmario.vazquez@inin.gob.m [CFE, Central Nuclear Laguna Verde, Km. 42.5 Carretera Cardel-Nautla, Veracruz (Mexico)

2010-10-15

A set of tests has been carried out at the Equipment Qualification Laboratory at National Institute of Nuclear Research to perform accelerated aging up to 60 years under temperature and gamma radiation environment for electrical cables. The results obtained from such tests are the base line data for comparison to with the current cable conditions at the plant. This work is intended for establishing the cable aging management program for the Laguna Verde nuclear power plant (LVNPP). For such purpose, the Institute has prepared methodologies and procedures to apply condition monitoring techniques in accelerated aging tests on samples of new cables drawn from the LVNPP warehouse. The condition indicators of the material selected for condition monitoring and the aging management process of cables were: Elongation at Break (EAB) and Oxidation Induction Time (OIT). A cable aging management program includes activities for cable selection, determination of condition indicators of the cable materials (EAB, OIT, Ind enter), accelerated aging of cable samples at the laboratory, analysis of maintenance history, operational experience of the plant and analysis of the environmental and service conditions (temperature and gamma radiation), as well as the establishment of a condition monitoring plan for cables in the plant. Two cable model samples were thermally aged and gamma irradiated with doses corresponding to differential operational periods. EAB and OIT values of cable insulating material (ethylene propylene and cross linked polyethylene) were obtained. It was found that the EAB and OIT data correlation is very closed, and it could be applied to infer values that are not possible to measure directly at the plant and be used for cable aging evaluation and remaining life time determination. (Author)

Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Phase 1, Study

International Nuclear Information System (INIS)

Hoopingarner, K.R.; Vause, J.W.; Dingee, D.A.; Nesbitt, J.F.

1987-08-01

Pacific Northwest Laboratory evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume I, reviews diesel-generator experience to identify the systems and components most subject to aging degradation and isolates the major causes of failure that may affect future operational readiness. Evaluations show that as plants age, the percent of aging-related failures increases and failure modes change. A compilation is presented of recommended corrective actions for the failures identified. This study also includes a review of current, relevant industry programs, research, and standards. Volume II reports the results of an industry-wide workshop held on May 28 and 29, 1986 to discuss the technical issues associated with aging of nuclear service emergency diesel generators

In mortal hands. A cautionary history of the nuclear age

International Nuclear Information System (INIS)

Cooke, Stephanie

2011-01-01

This provocative history of nuclear power is perfectly timed. Americans are gravely concerned with nuclear terrorism even as a nuclear renaissance is seen as a possible solution to global warming. Few have truly come to terms with the complexities of an issue that may determine the future of the planet. It was once hoped nuclear weapons would bring wars to an end. Instead they spurred a massive arms race that has recently expanded to include North Korea and Iran. Once seen as a source of unlimited electricity, nuclear reactors breed contamination and have been used as covers for secret weapons programs from India and Pakistan to Iraq and Iran. The evolving story of nuclear power, as told by industry insider Stephanie Cooke, reveals the gradual deepening of our understanding of the pros and cons of this controversial energy source. Drawing on her unprecedented access, Cooke shows us how, time and again, the stewards of the nuclear age - the more-is-better military commanders and civilian nuclear boosters - have fallen into the traps of their own hubris and wishful thinking as they tried to manage the unmanageable. Their mistakes are on the verge of being repeated again, which is why this book deserves especially close attention.

Aging effects in PWR power plants components

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

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

Age-dependent risk-based methodology and its application to prioritization of nuclear power plant components and to maintenance for managing aging using PRAs

International Nuclear Information System (INIS)

Levy, I.S.; Vesely, W.E.

1990-01-01

This paper is based on a study to demonstrate several important ways that the age-dependent risk-based methodology developed by the Nuclear Plant Aging Research (NPAR) Program may be applied to resolving important issues related to the aging of nuclear power plant systems, structures, and components (SSCs). The study was sponsored by the NPAR Program of the Division of Engineering, Office of Nuclear Regulatory Research of the U.S. Nuclear Regulatory Commission (NRC). Initiated on the basis of a Users Need Request, the age-dependent risk-based methodology has been under development by the NPAR Program for several years. In this methodology, the time-dependent change in a component's risk contribution is the product of two factors: (1) the risk importance of the component (e.g., the change in its risk contribution when it is assumed to be totally unavailable to perform its intended safety function) and (2) the change in its unavailability with time. This change in the component's unavailability with time is a function of the component's aging rate and plant inspection and maintenance practices. The methodology permits evaluations of the age-dependent risk contributions from both single- and multiple-components. Principal results and conclusions generated by the methodology demonstrations are discussed

Aging assessment of surge protective devices in nuclear power plants

International Nuclear Information System (INIS)

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

1996-01-01

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

Safe ageing management of nuclear power plants: An European synthesis

International Nuclear Information System (INIS)

Grandemange, J.M.

2002-01-01

Ageing of nuclear power plants means evolution of material or equipment properties on one side, and evolution of personnel skill and procedure adequacy on the other side, both of which, after a certain time, may not be compatible with the required safety provisions, or with an economic operation of the plant. Repair or replacement of components, as well as change in service conditions for a better compatibility with component reduced capabilities can be used to mitigate ageing effects. The paper summarises the results of a study conducted in this field with the support of the European Commission. It presents: the synthesis of the work done under international auspices, and in the European context; the comparison of ageing management approaches used in several European countries with international recommendations; the summary of the various potential phenomena and their governing parameters, the methods of in-service ageing identification and possible mitigation methods; illustrative ageing management practices, taking material ageing aspects as examples. Concerning the first topic, the European report identifies 56 OECD and IAEA reports on ageing management issues, 35 being summarised in an appendix to the report. It also identifies numerous European and international studies covering topics of interest to ageing and Plant Life management. ageing management approaches have been considered from the regulatory point of view and from the utilities management point of view. Contributors to the study have identified a general consensus in Europe, with no limited time operating authorisation, the safety being a utility responsibility under continuous surveillance by the regulatory authority. Practical ageing management methods include: periodic safety reviews (PSR), a ten years periodicity being a common practice, completed by continuous ageing management taking into account safety and industrial anticipation needs; the implementation of life-time management programmes

Genotoxic Effects of Tobacco on Buccal Epithelium: Cell Nuclear Anomalies as Biomarker

Directory of Open Access Journals (Sweden)

Sohini Das Biswas

2014-12-01

Full Text Available Background: Tobacco use has toxic effects on different organs. This study was carried out to assess the effect of indigenous tobacco both in smoking (bidi and smokeless (gutkha, zarda and khaini forms on buccal cells at chromosomal level, through assessment of different nuclear anomalies as biomarker. Methods:This study was done on people living in Durgapur and its adjacent areas, West Bengal, India during January to July 2011. The samples were collected from 50 smokers (case group, 50 smokeless tobacco consumers or chewers (case group and 50 non-tobacco consumers (control group. Micronucleus assay was used to assess buccal cell nuclear changes. Buccal smears collected from study subjects were prepared on a grease free slide. Prepared slides were observed under light microscope and 2 to 5 fields were observed randomly for counting the different anomalies. In each field, the frequency of each anomaly was assessed in 100 cells and reported with percentage. Results:Chewers had significantly the highest frequency of all nuclear anomalies compared to smokers and healthy controls (HCs. Smokers also had significantly more anomalies compared to HCs. Condensed chromatin (CC, karyolysis (KL and bi-nucleation (BN in chewers and CC, pyknosis and BN in smokers were the most frequent anomalies. KL was significantly more frequent in chewers compared to smokers (59.8 ± 6.4 vs. 24.2 ± 12.4%, P < 0.001, however, the frequency of other nuclear anomalies were not significantly different in these two study groups. Presence of each nuclear anomaly was significantly greater in older ages in all study groups. Conclusion:Tobacco can cause and increase the rate of nuclear anomalies in both smoking and smokeless forms compared to HCs. The genotoxic effects of tobacco on buccal cells are partly age-related. Cell nuclear anomalies in buccal tissue can be used as biomarker indicating the detrimental effects of tobacco.

Ice ages and nuclear waste disposal

International Nuclear Information System (INIS)

Ahonen, L.; Ruskeeniemi, T.; Luukkonen, A.; Pitkaenen, P.; Rasilainen, K.

2002-01-01

This report is an overview of Quaternary Ice Age and its potential consequences for nuclear waste disposal. Geological information on past climatic changes is shortly reviewed, based on the following records: geomorphological information, loessic deposits, deep-sea carbonate sediments, ice-core records, and continental calcite precipitates. Even though the present 'Great Ice Age' has lasted more that two million years, the present variation in cycles of about 100 000 years seems to have commenced only about 600 - 700 thousands years ago. According to the present understanding, southern Finland was during a major span of Weichsel free of continental ice sheet. However, the conditions may have been very cold, periglacial, when the continental ice sheet covered the Caledonian mountains and large areas of central Fennoscandia. The last glacial maximum of Weichsel glaciation was shorter than estimated earlier. Periglacial conditions are characterized by deep permafrost, reaching even the depth of nuclear waste disposal. Calculations of the advancement of permafrost indicate that the permafrost-front may reach the depth of about 500 meters in less than 10 000 years. The crust beneath the continental ice cover depresses, and rebounds when the ice sheet retreats. During the most intensive vertical movement of the crust, some crush zones may be activated and bedrock movements may take place along them. Due to the growth of ice sheets, ocean water table also depresses during glacial maximum, thus changing hydrogeological conditions in non-glaciated terrains. Increase in global ice volume is manifested in the stable oxygen and hydrogen isotope ratios. Based on isotope signals, as well other hydrogeochemical interpretation methods, indications of the earlier glaciations have been recognized in present groundwaters. (orig.)

Working out the standards for nuclear power aging management implementation (PLM Standards)

International Nuclear Information System (INIS)

Miyano, Hiroshi

2008-01-01

Background of preparation of standards, preparation of standards for development of nuclear power aging management technologies, revision of PLM (Product Lifecycle Management) standards, and problems of PLM standards are stated. The placement of social needs, scheme, the standards system, preparation of rules and standards, and practical use of them by road map are illustrated and explained. Relation between the safety regulations and examination standards, and development and preparation of standards system are outlined. The nuclear power plant aging management and the maintenance control are provided by many rules and standards. PLM standards defines the aging phenomena and extracts the measurements and reflects them on the usual maintenance flow under the long term maintenance program. New examination system constructs the usual maintenance and the maintenance based on the aging management and long term maintenance program. Outline and construction of PLM standards are explained with notes and additional books. (S.Y.)

Watermelons Not War! A Support Book for Parenting in the Nuclear Age.

Science.gov (United States)

Cloud, Kate; And Others

The Nuclear Education Project (NEP), a group of five women concerned about parenting in a nuclear age, developed this guide to help parents and others develop a sense of hope and promote a greater involvement in the democratic political process. Chapter I, "The Heart of the Matter," presents sections on answering possible questions children might…

Age-dependent effective doses for radionuclides uniformly distributed in air

International Nuclear Information System (INIS)

Hung, Tran Van

2014-01-01

Age-dependent effective doses for external exposure to photons emitted by radionuclides uniformly distributed in air are reported. The calculations were performed for 160 radionuclides, which are important for safety assessment of nuclear facilities. The energies and intensities of photons emitted from radionuclides were taken from the decay data DECDC used for dose calculations. The results are tabulated in the form of effective dose per unit concentration and time (Sv per Bq s m -3 ) for 6 age groups: newborn, 1, 5, 10 and 15 years-old and adult. The effective doses for the adult are also compared to values given in the literature.

Technical approach to aging management

International Nuclear Information System (INIS)

Vora, J.P.; Johnson, A.B. Jr.; Allen, R.P.

1992-10-01

Systematic and effective control of age-related degradation of safety-related components, systems, and structures in nuclear power plants (NPPs) is an important challenge to plant operators. Several data bases, available to provide guidance on aging management, are summarized. However, the ultimate consideration is: How effectively is aging management being implemented at individual plants? Illustrated here is a specific strategy that served to develop the technical data base for the Nuclear Plant Aging Research Program. The strategy is comprehensive, systematic, and adaptable. Effective aging management at NPPs could be facilitated by a parallel strategy. The elements of a strategy are suggested

CSNI Technical Opinion Papers No. 15 - Ageing management of nuclear fuel cycle facilities

International Nuclear Information System (INIS)

Nocture, Pierre; Daubard, Jean-Paul; Lhomme, Veronique; Martineau, Dominique; Blundell, Neil; Conte, Dorothee; Dobson, Martin; Gmal, Bernhard; Hiltz, Thomas; Ueda, Yoshinori

2012-01-01

Managing the ageing of fuel cycle facilities (FCFs) means, as for other nuclear installations, ensuring the availability of required safety functions throughout their service life while taking into account the changes that occur with time and use. This technical opinion paper identifies a set of good practices by benchmarking strategies and good practices on coping with physical ageing and obsolescence from the facility design stage until decommissioning. It should be of particular interest to nuclear safety regulators, fuel cycle facilities operators and fuel cycle researchers [fr

The effect of aging upon CE and B ampersand W control rod drives

International Nuclear Information System (INIS)

Grove, E.; Gunther, W.

1991-01-01

The effect of aging upon the Babcock ampersand Wilcox (B ampersand W) and Combustion Engineering (CE) Control Rod Drive (CRD) systems has been evaluated as part of the USNRC Nuclear Plant Aging Research (NPAR) program. Operating experience data for the 1980--1990 time period was reviewed to identify predominant failure modes, causes, and effects. These results, in conjunction with an assessment of component materials and operating environment, conclude that both systems are susceptible to age degradation. System failures have resulted in significant plant effects, including power reductions, plant shutdowns, scrams, and Engineered Safety Feature (ESF) actuation. Current industry inspection and maintenance practices were assessed. Some of these practices effectively address aging, while others do not

Nuclear famine: The indirect effects of nuclear war

International Nuclear Information System (INIS)

Harwell, M.A.; Harwell, C.C.

1986-01-01

The indirect effects of a nuclear war, especially as mediated by disruption in food availability, could be much more extensive than the direct effects. Furthermore, this risk is especially severe for noncombatant countries - for the 4 billion or so humans expected to survive the immediate period after a nuclear war relatively physically unharmed. Thus, a fundamentally different picture of the post-nuclear-war world results, where a large-scale nuclear war between the United States and the Soviet Union would probably result in more eventual fatalities in India than in the United States and the Soviet Union combined, and more people would die on the African continent than in all of Europe. Rather than reflecting images of Hiroshima and Nagasaki, a modern nuclear war would, for most of the people of the world, much more resemble current images of Ethiopia and the Sudan

Nuclear constraints on the age of the universe

International Nuclear Information System (INIS)

Schramm, D.N.

1982-12-01

In this paper a review is made of how one can use nuclear physics to put rather stringent limits on the age of the universe and thus the cosmic distance scale. As the other papers in this session have demonstrated there is some disagreement on the distance scale and thus the limits on the age of the universe (if the cosmological constant ν = 0). However, the disagreement is only over the last factor of 2, the basic timescale seems to really be remarkably well agreed upon. The universe is billions of years old - not thousands, not quintillions but bilions of years. That our universe has a finite age is philosophically intriguing. That we can estimate that age to a fair degree of accuracy is truly impressive. No single measurement of the time since the Big Bang gives a specific, unambiguous age. Fortunately, we have at our disposal several methods that together fix the age with surprising precision. In particular, as the other papers show, there are three totally independent techniques for estimating an age and a fourth technique which involves finding consistency of the other three in the framework of the standard Big Bang cosmological model. The three independent methods are: cosmological dynamics, the age of the oldest stars, and radioactive dating. This paper concentrates on the third of the three methods, as well as go into the consistency technique

Interim report on assessment of cable aging for nuclear power plants

International Nuclear Information System (INIS)

2006-12-01

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

Assessment and management of aging of nuclear power plant safety-related structures

International Nuclear Information System (INIS)

Naus, D.J.; Graves, H.L. III; Ellingwood, B.R.

2003-01-01

Background information and data have been developed for improving existing and developing new methods to assist in quantifying the effects of age-related degradation on the performance of nuclear power plant (NPP) safety-related structures. Factors that can lead to age-related degradation of safety-related structures are identified and their manifestations described. Current regulatory testing and inspection requirements are reviewed and a summary of degradation experience presented. Techniques commonly used to inspect NPP concrete structures to assess and quantify age-related degradation are summarized. An approach for conduct of condition assessments of structures in NPPs is presented. Criteria, based primarily on visual indications, are provided for use in classification and assessment of concrete degradation. Materials and techniques for repair of degraded structures are noted and guidance provided on repair options available for various forms of degradation. A probabilistic methodology for condition assessment and reliability-based life prediction has been developed and applied to structures subject to combinations of structural load processes and to structural systems. The methodology has also been used to investigate optimization of in-service inspection and maintenance strategies to maintain failure probability below a specified target value as well as to minimize costs. Fragility assessments involving analytical solutions and finite-element methods have been utilized to predict the effect of aging degradation on structural component performance. (author)

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

International Nuclear Information System (INIS)

2000-11-01

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

Is Soviet society fit for the nuclear age

International Nuclear Information System (INIS)

Kemeny, L.G.

1986-01-01

The author argues that the Kremlin's handling of the Chernobyl crisis is a far greater indictment of Soviet ethos, society and ideology than their technology. The Soviet nuclear plan is seen to be to press on regardless of safety standards. Australia's government and society, through poor education, foreign disinformation and media orchestration, are unable to participate effectively in the responsibilities of a global nuclear society

Nuclear education and training in the Internet age

International Nuclear Information System (INIS)

Bereznai, G.; Garland, W.

2001-01-01

Student enrolment in nuclear engineering programs offered by Canadian universities has been declining, and at some universities has fallen below the minimum level needed to sustain the program. At the same time, a significant number of engineers working in the nuclear industry have retired and many more will be reaching retirement age in the next few years. The operation and maintenance of the 14 in-service CANDU units, the refurbishment of the four Pickering 'A' units and of the four Bruce 'A' units will require a significant level of new engineers and scientists. Service support for the CANDU units operating overseas, the construction of two units in China, the completion of Cernavoda 2, and the market for several more CANDU units in Asia, will also require significant numbers of new graduates. The vast amount of information that the future practitioners of the nuclear power industry need to be aware of will be increasingly difficult to disseminate with the traditional classroom-based education and training methods. Almost all of the documents required for the design, analysis, procurement and operation of a nuclear unit are now generated by computer, and increasingly such information is accessible where and when needed via the company lntranet. The authors have developed an lnternet/Intranet compatible self-paced interactive multimedia approach to deliver a course on CANDU Systems and Operations. The course has been offered at ten universities in six countries, including Thailand, China, Indonesia, Vietnam, the Philippines, as well as Canada. (author)

Nuclear energy and greenhouse effect

International Nuclear Information System (INIS)

Strub, R.A.

1991-01-01

The contribution of nuclear power plants against the greenhouse effects is evaluated, not only nuclear energy is unable to fight greenhouse effect increase but long life wastes endanger environment. 8 refs

Frequency Domain Reflectometry NDE for Aging Cables in Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Glass, Samuel W.; Jones, Anthony M.; Fifield, Leonard S.; Hartman, Trenton S.

2017-02-16

Cable insulation polymers are among the more susceptible materials to age-related degradation within a nuclear power plant. This is recognized by both regulators and utilities, so all plants have developed cable aging management programs to detect damage before critical component failure in compliance with regulatory guidelines. Although a wide range of tools are available to evaluate cables and cable systems, cable aging management programs vary in how condition monitoring and nondestructive examinations are conducted as utilities search for the most reliable and cost-effective ways to assess cable system condition. Frequency domain reflectometry (FDR) is emerging as one valuable tool to locate and assess damaged portions of a cable system with minimal cost and only requires access in most cases to one of the cable terminal ends. Since laboratory studies to evaluate the use of FDR for inspection of aged cables can be expensive and data interpretation may be confounded by multiple factors which influence results, a model-based approach is desired to parametrically investigate the effect of insulation material damage in a controlled manner. This work describes development of a physics-based FDR model which uses finite element simulations of cable segments in conjunction with cascaded circuit element simulations to efficiently study a cable system. One or more segments of the cable system model have altered physical or electrical properties which represent the degree of damage and the location of the damage in the system. This circuit model is then subjected to a simulated FDR examination. The modeling approach is verified using several experimental cases and by comparing it to a commercial simulator suitable for simulation of some cable configurations. The model is used to examine a broad range of parameters including defect length, defect profile, degree of degradation, number and location of defects, FDR bandwidth, and addition of impedance-matched extensions to

Ageing and life-time management in nuclear power stations - concept and examples

International Nuclear Information System (INIS)

Erve, M.; Tenckhoff, E.

1999-01-01

Knowledge, assessment and understanding of phenomena caused by ageing, together with systematic utilization and extension of the technical life-time of components and systems, are of critical importance to the safety and economy of electricity generation in nuclear power stations. Economic use can be optimized by integrated ageing and life-time management; it can also be used to improve performance characteristics. (orig.) [de

Effect of aging on properties of pressure vessel steels

Energy Technology Data Exchange (ETDEWEB)

Druce, S.G.; Gage, G.; Jordan, G.

1986-04-01

Manganese-molybdenum-nickel steels are used in nuclear pressure vessels operating at temperatures up to 350/sup 0/C. The effects of thermal ageing in the temperature range 300-550/sup 0/C for durations up to 2 x 10/sup 4/ h have been studied in conventionally quenched and tempered and simulated heat-affected-zone (HAZ) microstructural conditions. Quantitative fractography and Auger spectroscopy have been used to relate changes in mechanical properties with changes in fracture mode and grain boundary chemistry. Aging increases the ductile-brittle transition temperature by an amount dependent on material, prior heat treatment, aging temperature and time. Embrittlement is associated with segregation of phosphorus to grain boundaries and is modelled using McLean's approach to equilibrium segregation.

Protective Effects of Hydrogen Sulfide in the Ageing Kidney.

Science.gov (United States)

Hou, Cui-Lan; Wang, Ming-Jie; Sun, Chen; Huang, Yong; Jin, Sheng; Mu, Xue-Pan; Chen, Ying; Zhu, Yi-Chun

2016-01-01

Aims . The study aimed to examine whether hydrogen sulfide (H 2 S) generation changed in the kidney of the ageing mouse and its relationship with impaired kidney function. Results . H 2 S levels in the plasma, urine, and kidney decreased significantly in ageing mice. The expression of two known H 2 S-producing enzymes in kidney, cystathionine γ -lyase (CSE) and cystathionine- β -synthase (CBS), decreased significantly during ageing. Chronic H 2 S donor (NaHS, 50  μ mol/kg/day, 10 weeks) treatment could alleviate oxidative stress levels and renal tubular interstitial collagen deposition. These protective effects may relate to transcription factor Nrf2 activation and antioxidant proteins such as HO-1, SIRT1, SOD1, and SOD2 expression upregulation in the ageing kidney after NaHS treatment. Furthermore, the expression of H 2 S-producing enzymes changed with exogenous H 2 S administration and contributed to elevated H 2 S levels in the ageing kidney. Conclusions . Endogenous hydrogen sulfide production in the ageing kidney is insufficient. Exogenous H 2 S can partially rescue ageing-related kidney dysfunction by reducing oxidative stress, decreasing collagen deposition, and enhancing Nrf2 nuclear translocation. Recovery of endogenous hydrogen sulfide production may also contribute to the beneficial effects of NaHS treatment.

Decision making in the digital age: the nuclear industry response

Energy Technology Data Exchange (ETDEWEB)

Edelman, G. [Energy Group, Kepner-Tregoe, Inc. (Canada)

2002-07-01

Ten years ago, the consequences of a prolonged outage - or of choosing a costly alternative - could usually be recovered from the ratepayers without major difficulty. But today, as in the rest of industrial America, poorly crafted decisions have very real economic consequences. This paper discusses the decision making process within the nuclear industry in the age of industry deregulation.

Decision making in the digital age: the nuclear industry response

International Nuclear Information System (INIS)

Edelman, G.

2002-01-01

Ten years ago, the consequences of a prolonged outage - or of choosing a costly alternative - could usually be recovered from the ratepayers without major difficulty. But today, as in the rest of industrial America, poorly crafted decisions have very real economic consequences. This paper discusses the decision making process within the nuclear industry in the age of industry deregulation

Summary of nuclear plant aging research at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Eissenberg, D.M.

1991-01-01

Oak Ridge National Laboratory (ORNL) has been a major contributor to the Nuclear Regulatory Commission (NRC) Nuclear Plant Aging Research Program since its inception. The research at ORNL has consisted primarily of the preparation of comprehensive aging assessments and other studies of safety related and other components and systems. The components and systems have been identified and prioritized based on risk considerations, as well as by operating experience. In each case, ORNL has been preparing a Phase 1 assessment which summarizes design features, operating conditions, and stressors which lead to degradation and failure; identified parameters which could be used to detect, trend and differentiate the degradations; and proposed potential inspection, surveillance, and monitoring methods which could be applied to the parameters. Where appropriate, Phase 2 assessments have been prepared, which verify and recommend inspection, surveillance and monitoring methods based on vendor information, laboratory and field tests, and in-situ inspections and tests. Finally, Phase 3 assessments are prepared which provide recommendations regarding implementing the inspection, surveillance and monitoring methods, and provide recommendations regarding criteria to be applied. Other activities include providing assistance to NRC/Nuclear Regulatory Research and regional offices as requested, and participation in ASME and IEEE codes and standards

Refurbish research and test reactors corresponding to global age of nuclear energy

International Nuclear Information System (INIS)

Mishima, Kaichiro; Oyama, Yukio; Okamoto, Koji; Yamana, Hajime; Yamaguchi, Akira

2011-01-01

This special article featured arguments for refurbishment of research and test reactors corresponding to global age of nuclear energy, based on the report: 'Investigation of research facilities necessary for future joint usage' issued by the special committee of Atomic Energy Society of Japan (AESJ) in September 2010. It consisted of six papers titled as 'Introduction-establishment of AESJ special committee for investigation', 'State of research and test reactors in Japan', 'State of overseas research and test reactors', 'Needs analysis for research and test reactors', 'Proposal of AESJ special committee' and 'Summary and future issues'. In order to develop human resources and promote research and development needed in global age of nuclear energy, research and test reactors would be refurbished as an Asian regional center of excellence. (T. Tanaka)

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

Nuclear explosions and their effects

Energy Technology Data Exchange (ETDEWEB)

1958-01-01

A brief historical background is given of the development of the atomic bomb. Also included is an account of the Hiroshima-Nagasaki bombing, plus some information on the testing and production of nuclear weapons by the United States, United Kingdom, and Russia. More detailed consideration is given to the following: the scientific principles of fission and fusion explosions; the energy released in fission and the radioactivity of fission products; blast, thermal, and radiologicalal effects of nuclear explosions; long-term radiological hazards from fall-out; and genetic effects of nuclear explosions. A brief account is given of the fission chain process, the concept of critical size, and the principles of implosion as applied to nuclear explosions. Limited information is presented on the controlled release of thermonuclear energy and catalyzed fusion reaction. Discussions are included on dose rates from radiation sources inside and outside the body, the effect of nuclear explosions on the weather, and the contamination of fish and marine organisms.

Direct and indirect genetic effects of sex-specific mitonuclear epistasis on reproductive ageing

DEFF Research Database (Denmark)

Immonen, Elina; Collet, Marie; Goenaga, Julieta

2016-01-01

Mitochondria are involved in ageing and their function requires coordinated action of both mitochondrial and nuclear genes. Epistasis between the two genomes can influence lifespan but whether this also holds for reproductive senescence is unclear. Maternal inheritance of mitochondria predicts sex...... to slower senescence relative to novel mitonuclear combinations. We found no evidence for mitonuclear coadaptation in males. Mitonuclear epistasis not only affected age-specific ejaculate weight, but also influenced male age-dependent indirect effects on traits expressed by their female partners (fecundity...... beetle Callosobruchus maculatus, using introgression lines harbouring distinct mitonuclear genotypes. Our results reveal both direct and indirect sex-specific effects of mitonuclear epistasis on reproductive ageing. Females harbouring coadapted mitonuclear genotypes showed higher lifetime fecundity due...

Age-Related Degradation of Nuclear Power Plant Structures and Components

International Nuclear Information System (INIS)

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

1999-01-01

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

The Effects of Nuclear Weapons. Third edition

Energy Technology Data Exchange (ETDEWEB)

Glasstone, S; Dolan, P J

1977-01-01

Since the last edition of ''The Effects of Nuclear Weapons'' in 1962 much new information has become available concerning nuclear weapon effects. This has come in part from the series of atmospheric tests, including several at very high altitudes, conducted in the Pacific Ocean area in 1962. In addition, laboratory studies, theoretical calculations, and computer simulations have provided a better understanding of the various effects. A new chapter has been added on the electromagnetic pulse. The chapter titles are as follows: general principles of nuclear explosions; descriptions of nuclear explosions; air blast phenomena in air and surface bursts; air blast loading; structural damage from air blast; shock effects of surface and subsurface bursts; thermal radiation and its effects; initial nuclear radiation; residual nuclear radiation and fallout; radio and radar effects; the electromagnetic pulse and its effects; and biological effects. (LTN)

Aging research program at the LaCrosse nuclear power plant

International Nuclear Information System (INIS)

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

1988-01-01

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

Obstacles to the nuclear technology development in Brazil: from the beginning of atomic age to the Brazil-Germany Nuclear Agreement; Entraves ao desenvolvimento da tecnologia nuclear no Brasil: dos primordios da era atomica ao Acordo Nuclear Brasil-Alemanha

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Tharsila Reis de

2005-07-01

This paper intends to comprehend the Brazilian social actors' efforts applied to the nuclear energy control, from the beginning of Atomic Age to Brazil-Germany Nuclear Agreement. It tries to demonstrate that the limits of The Brazilian nuclear development in this period derive from the capitalist development dynamics in Brazil and from the absence of continuity on the motivations of its nuclear policy. (author)

Obstacles to the nuclear technology development in Brazil: from the beginning of atomic age to the Brazil-Germany Nuclear Agreement; Entraves ao desenvolvimento da tecnologia nuclear no Brasil: dos primordios da era atomica ao Acordo Nuclear Brasil-Alemanha

Energy Technology Data Exchange (ETDEWEB)

Medeiros, Tharsila Reis de

2005-07-01

This paper intends to comprehend the Brazilian social actors' efforts applied to the nuclear energy control, from the beginning of Atomic Age to Brazil-Germany Nuclear Agreement. It tries to demonstrate that the limits of The Brazilian nuclear development in this period derive from the capitalist development dynamics in Brazil and from the absence of continuity on the motivations of its nuclear policy. (author)

Psychological effects of nuclear warfare

International Nuclear Information System (INIS)

Mickley, G.A.

1987-01-01

This report is divided into five parts. (1) Discussion of the psychological milieu before a nuclear confrontation. (2) Acute psychological reactions to nuclear warfare (some of which may reflect, in part, direct radiogenic alteration of nervous system functions). (3) Chronic psychological effects of a nuclear confrontation. (4) Issues concerning treatment of these psychological changes. (5) Prevention of adverse psychological reactions to nuclear warfare

Understanding and managing the effects of battery charger and inverter aging

International Nuclear Information System (INIS)

Gunther, W.; Aggarwal, S.

1992-01-01

An aging assessment of battery chargers and inverters was conducted under the auspices of the NRC's Nuclear Plant Aging Research (NPAR) Program. The intentions of this program are to resolve issues related to the aging and service wear of equipment and systems at operating reactor facilities and to assess their impact on safety. Inverters and battery chargers are used in nuclear power plants to perform significant functions related to plant safety and availability. The specific impact of a battery charger or inverter failure varies with plant configuration. Operating experience data have demonstrated that reactor trips, safety injection system actuations, and inoperable emergency core cooling systems have resulted from inverter failures; and dc bus degradation leading to diesel generator inoperability or loss of control room annunication and indication have resulted from battery and battery charger failures. For the battery charger and inverter, the aging and service wear of subcomponents have contributed significantly to equipment failures. This paper summarizes the data and then describes methods that can be used to detect battery charger and inverter degradation prior to failure, as well as methods to minimize the failure effects. In both cases, the managing of battery charger and inverter aging is emphasized. 5 refs

Biological effects of nuclear weapons

International Nuclear Information System (INIS)

Frischauf, H.

1983-01-01

Prompt and delayed biological effects of nuclear weapons are discussed. The response to excess pressure on man is estimated, the acute radiation syndrome caused by different radiation doses and cancerogenous and genetic effects are described. Medical care after a nuclear explosion would be difficult and imperfect. (M.J.)

Effect of the Fukushima nuclear disaster on global public acceptance of nuclear energy

International Nuclear Information System (INIS)

Kim, Younghwan; Kim, Minki; Kim, Wonjoon

2013-01-01

The Fukushima nuclear disaster has significantly changed public attitudes toward nuclear energy. It is important to understand how this change has occurred in different countries before the global community revises existing nuclear policies. This study examines the effect of the Fukushima disaster on public acceptance of nuclear energy in 42 countries. We find that the operational experience of nuclear power generation which has significantly affected positive public opinion about nuclear energy became considerably negative after the disaster, suggesting fundamental changes in public acceptance regardless of the level of acceptance before the disaster. In addition, contrary to our expectation, the proportion of nuclear power generation is positively and significantly related to public acceptance of nuclear energy after the Fukushima accident and government pressure on media content led to a greater decrease in the level of public acceptance after the accident. Nuclear energy policymakers should consider the varied factors affecting public acceptance of nuclear energy in each country depending on its historical, environmental, and geographical circumstances before they revise nuclear policy in response to the Fukushima accident. - Highlights: • Fukushima accident has negatively changed public attitudes toward nuclear energy. • Effect of operational experience became considerably negative after the accident. • Effect of proportion of nuclear power generation is positive after the accident. • Effect of government pressure on media content became negative after the accident. • Country specific policy responses on nuclear public acceptance are required

Quantitative relationships between aging failure data and risk

International Nuclear Information System (INIS)

Vesely, W.E.; Vora, J.P.

1988-01-01

As part of the United States Nuclear Regulatory Commission's Nuclear Plant Aging Research program, a project is being carried out to quantify the risk effects of aging. The project is called the Risk Evaluation of Aging Phenomena (REAP) Project. With the REAP Project, a procedure has been developed to quantify nuclear power plant risks from aging failure data. The procedure utilizes the linear aging model and its extensions in order to relate component aging failure rates to aging mechanism parameters which are estimable from failure and maintenance data. The aging failure rates can then be used to quantify the age dependent plant risks, such as system unavailabilities, core melt frequency and public health risks. The REAP procedure is different from standard time dependent approaches in that the failure rates are phenomenologically based, allowing engineering information to be utilized. Furthermore, gross data and incomplete data can be utilized. A software package has been developed which systematically analyzes data for aging effects and interfaces with a time dependent risk analysis module to determine the risk implications of the aging effects. (author). 10 refs, 10 figs

Managing the effects of aging and reliability improvement

International Nuclear Information System (INIS)

Hall, R.E.; Taylor, J.H.; Boccio, J.L.

1987-01-01

Over recent years the electric power generating community has acknowledged the importance of the aging process on plant safety and availability. To cope with time-dependent degradation phenomenon that can affect active as well as passive components and lead to unacceptable, unanticipated failures requires research into the mechanisms of the aging process, advances in productive methods for assessing the aging impact on risk and availability, and a better understanding of power plant operations so that strategies for defending against this pervasive stress can be developed. This paper discusses current research advances and presents a framework to aid in the systematic integration of these three needs. As such it is anchored to research being conducted at Brookhaven National Laboratory in the areas of plant aging, life extension, reliability, performance indication, and risk assessment. The current question facing the industry can be simply stated. ''How can an acceptable level of safety and availability be maintained throughout the operational life of a nuclear power plant?'' The complexity of this question indicates that managing aging effects must be a continuous, coordinated process integrated with day-to-day tactical plant operation decisions. This implies that aging and reliability programs must be systemic properties of an organization's management, and that research into aging technology must be closely linked

Attachment Stability in Children Aged 6 to 9 Years in Extended and Nuclear Families

Science.gov (United States)

Seven, Serdal; Ogelman, Hulya Gulay

2012-01-01

Research Findings: The main aim of this study was to identify whether the attachment security of children living in nuclear and extended families is stable from ages 6 to 9 years in a sample of Turkish children. In total, 54 children participated in the study, of whom 27 lived in nuclear families and the other 27 lived in extended families in Mus…

Thyroid side effects prophylaxis in front of nuclear power plant accidents.

Science.gov (United States)

Agopiantz, Mikaël; Elhanbali, Ouifak; Demore, Béatrice; Cuny, Thomas; Demarquet, Léa; Ndiaye, Cumba; Barbe, Françoise; Brunaud, Laurent; Weryha, Georges; Klein, Marc

2016-02-01

The better knowledge of the mechanisms of nuclear incidents and lessons learned from accidents in the recent past to improve the effectiveness of measures taken following a nuclear accident exposure to fallout of radioactive iodine isotopes. Thus, immediate, passive measures, such as containment, and stopping consumption of contaminated products are paramount. The earliest possible administration of stable iodine as potassium iodide (KI) reduces significantly (up to 90% if taken at the same time of the accident) thyroid radioactive contamination. These tablets should be given in priority to children and pregnant women. The side effects are minor. KI is not recommended for persons aged over 60 years, or for adults suffering from cardiovascular disorders. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Nuclear threshold effects and neutron strength function

International Nuclear Information System (INIS)

Hategan, Cornel; Comisel, Horia

2003-01-01

One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

The Characteristics of an Effective Nuclear Regulator

International Nuclear Information System (INIS)

Cheok, Michael; Wertelaers, An; Lojk, Robert; Santini, Miguel; Alm-Lytz, Kirsi; Rigail, Anne-Cecile; Weidenbruck, Kai-Jochen; Stoppa, Gisela; Rainieri, Roberto; Aoki, Masahiro; Gonzalez-Mercado; Miroshnichenko, Mikhail; Kuznetsov, Nikolay; Kudryavtsev, Evgeny; Cid, Rafael; Franzen, Anna; Skanberg, Lars; Gibson, Steve; Golshan, Mina; Cheok, Michael; Nicic, Adriana; Salgado, Nancy; Creswell, Len

2014-01-01

Both national and international organisations agree that the fundamental objective of all nuclear safety regulatory bodies - the regulator's prime purpose - is to ensure that nuclear licensees operate their facilities at all times in a safe manner. Much has been written about ways to improve regulatory processes or to improve the effectiveness of a regulatory body, including in previous OECD/NEA regulatory guidance booklets. But until now, none have focused on the characteristics of an effective nuclear safety regulator. Effective organisations are those that have good leadership and are able to transform strategic direction into operational programmes. Effectiveness is about how well the organisation is achieving its fundamental purpose - in the case of a nuclear safety regulator, ensuring that licensees operate their facilities and discharge their obligations in a safe manner. This regulatory guidance booklet describes the characteristics of an effective nuclear safety regulator in terms of roles and responsibilities, principles and attributes. Each of the characteristics discussed in this report is a necessary feature of an effective nuclear safety regulator but no one characteristic is sufficient on its own. It is the combination of these characteristics that leads to the effectiveness of a nuclear regulatory body. The report provides a unique resource to countries with existing, mature regulators and can be used for benchmarking as well as training and developing staff. It will also be useful for new entrant countries in the process of developing and maintaining an effective nuclear safety regulator. (authors)

Aging of snubbers in nuclear service: Phase I study results and Phase II plans

International Nuclear Information System (INIS)

Goodman, R.L.; Bush, S.H.; Page, R.E.

1988-01-01

Two major research areas were investigated in the Phase I snubber aging studies. The first area involved a preliminary evaluation of the effects of various aging mechanisms on snubber operation; failure modes of mechanisms were identified and their contributions to aging degradation were assessed relative to other failure modes. The second area involved estimating the efficacy of existing tests and examinations that are intended to determine the effects of aging and degradation. Available data on snubber behavior and operating experience were reviewed, using licensee event reports and other historical data for the 10-year period from 1973 through 1983. Value-impact was considered in terms of (1) exposure of workers to radioactive environments for examination/testing and (2) the cost for expansion of the snubber testing program due to failed snubbers. Results from the Phase I studies identified the need to modify or improve examination and testing procedures to enhance snubber reliability. Based on the results of the Phase I snubber studies, the seals and fluids were identified as the two principal elements affected by aging degradation in hydraulic snubbers. Phase II work, which was initiated in FY 1987, will develop cooperative activities between PNL and operating utilities through the Snubber Utility Group (SNUG), who will work to establish a strong data and experience base for both hydraulic and mechanical snubbers based on actual operating and maintenance history at nuclear power plants. Application guidelines for snubbers will be recommended based on the study results

Quark effects in nuclear physics

International Nuclear Information System (INIS)

Miller, G.A.

1983-01-01

A phenomenological approach which enables the size of quark effects in various nuclear processes is discussed. The principle of conservation of probability provides significant constraints on six quark wave functions. Using this approach, it is found that the low-energy proton-proton weak interaction can be explained in terms of W and Z boson exchanges between quarks. That the value of the asymptotic ratio of D to S state wave functions is influenced (at the 5% level) by quark effects, is another result of our approach. We have not discovered a nuclear effect that can be uniquely explained by quark-quark interactions. However it does seem that quark physics is very relevant for nuclear physics. 52 references

Strengthened International Nuclear Safeguards; burdens and Effects on Nuclear Technology Development

International Nuclear Information System (INIS)

Badawy, I.

2000-01-01

The present paper deals with the recent direction of strengthening the international nuclear safeguards and the effects on the development of nuclear technology for peaceful applications. The new basic principles for strengthening the international nuclear control in the direction of undeclared nuclear activities are elaborated, and the national obligations are indicated. The burdens on the development of nuclear technology are discussed. Approaches are proposed in this work for coping with the present and future situations

Development of finite element models for the study of ageing effects in CANDU 6 concrete containment buildings

Energy Technology Data Exchange (ETDEWEB)

Ding, Y.; Jaffer, S., E-mail: Yuqing.Ding@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

2016-06-15

In nuclear power plants (NPPs), concrete containment buildings (CCBs) provide the final physical barrier against the release of radioactive materials into the environment and protect the nuclear structures housed within the containment building. CCBs have to be maintained to ensure leak tightness and sound structural integrity for the safe operation throughout the life of NPPs. However, the integrity of CCBs may be affected by the ageing of its concrete, post-tensioning cables and reinforcing bars (rebars). Finite element models (FEMs) of CANDU 6 CCBs have been developed using 2 independent finite element programs for the study of the effect of ageing of CCBs. These FEMs have been validated using multiple-source data and have been used for preliminary analyses of the effect of thermal load and ageing degradation on the concrete structure. The modelling assumptions and simplifications, approach, and validation are discussed in this paper. The preliminary analyses for temperature effects and potential applications to the study of ageing degradation in CCBs using the FEMs are briefly introduced. (author)

Proactive pressure relief system management of life cycle and ageing in nuclear power plants

International Nuclear Information System (INIS)

Kolenc, J.; Ferrar, S.

2011-01-01

The last major power nuclear station built in North America was built when the Altair Company introduced the first microcomputer sparking the PC frenzy. It is safe to assume that there have been a great many changes since 1977 on both accounts. As the world's aging nuclear plants continue to be challenged with maintenance and replacement issues (obsolescence), as well making improvements within their facilities, proper pressure relief system management looms as a growing concern. This problem grows more acute as new engineering best practices are promulgated across industries and regulatory standards become more rigorous with much stricter enforcements. Unlike most pieces of operating equipment in a nuclear facility, pressure relief devices demand an extra level of consideration; as they form the 'last line of defense'. Combine the on-going obsolescence issue, with today's ever increasing demands for overall plant and public safety; pressure relief safety management will require increasing 'proactive' efforts to ensure safe facilities. This paper has been written to address some global pressure relief system management issues with respect the worlds aging nuclear facilities. This paper reflects findings we have discovered while conducting engineering pressure relief system audits on various nuclear power stations. It should be noted that these finding are not atypical of similar findings in pressure relief systems in the hydrocarbon processing world. (author)

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

International Nuclear Information System (INIS)

Gunther, W.; Taylor, J.

1990-09-01

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

Nuclear Energy Futures: the Appropriation of the 'Atomic Age' in post-war Austria

International Nuclear Information System (INIS)

Bayer, F.

2015-01-01

While recent scholarship in Science and Technology Studies and Science and Technology Policy carved out that techno-scientific developments take distinct national styles and shapes, less attention has been payed to such differences in the scholarship on nuclear history in Austria. In the context of the struggles over the non-commissioning of the already completed nuclear power plant at Zwentendorf (1978) and in the aftermath of the reactor explosion in Chernobyl (1986) the formation of a specific technopolitical identity, revolving around the sociotechnical imaginary of keeping nuclear technologies out of Austrian territory, has been observed. At the backdrop of this imaginary the history of nuclear enthusiasm in Austria is only present in narratives about how 'the people' have resisted and rejected the implementation of nuclear technologies in Austria and thus overcome u nreasonable promises of the so called atomic age . On the other hand historical scholarship shows that Austria has a long history of nuclear research and nuclear (power) policy that was hardly questioned until the early 1970s. Departing from this discrepancy this master thesis investigates the appropriation of the 'atomic age' in Austria in the mid 1950s. When US President Dwight D. Eisenhower gave his famous Atoms for Peace address in front of the UN General Assembly in late 1953 global nuclear enthusiasm in the immediate post--war era reached a new highpoint. Analyzing the following developments in Austria until late 1955 - of which the formation of an Austrian Commission on Atomic Energy and the participation in the UN Conference on the Peaceful Uses of Atomic Energy are to be considered milestones - thus enables me to observe how the appropriation of the 'atomic age' was deeply entangled with imaginations of national collectivity and different forms of imagining the future. In reference to the broader frameworks of 'appropriating' science and technology

The Second Nuclear Age. Reducing Risk for the People of South Asia

Energy Technology Data Exchange (ETDEWEB)

Vanaik, A

2004-01-01

In the hopeful period following the end of the Cold War, genuine efforts were made to push back the deployment and use of nuclear arms, and some real progress was made.Yet, in recent years, the world has lapsed into a Second Nuclear Age. Backed by rhetoric from the Bush administration on 'tactical nukes', missile defence and pre-emptive strikes, many regions in the world are today entangled in a new arms race. Prospects are especially grim in the South Asian region, where two nuclear powers - Pakistan and India - are constantly but one step away from a nuclear war. In the context of this conflict, the theory of deterrence is not only insufficient, but faulty or missing security measures could trigger unwarranted or unintentional escalation into a global catastrophe. There is an acute need therefore to put in place nuclear risk reduction measures without losing sight of the ultimate need for nuclear disarmament. This requires practical steps being taken by both sides, which in turn requires a certain level of trust. In light of the renewed talks between India and Pakistan, after a two year stand off, a new opportunity may be opening up where such steps could be discussed. This Briefing paper offers practical proposals as to what these might be.

The Second Nuclear Age. Reducing Risk for the People of South Asia

International Nuclear Information System (INIS)

Vanaik, A.

2004-01-01

In the hopeful period following the end of the Cold War, genuine efforts were made to push back the deployment and use of nuclear arms, and some real progress was made.Yet, in recent years, the world has lapsed into a Second Nuclear Age. Backed by rhetoric from the Bush administration on 'tactical nukes', missile defence and pre-emptive strikes, many regions in the world are today entangled in a new arms race. Prospects are especially grim in the South Asian region, where two nuclear powers - Pakistan and India - are constantly but one step away from a nuclear war. In the context of this conflict, the theory of deterrence is not only insufficient, but faulty or missing security measures could trigger unwarranted or unintentional escalation into a global catastrophe. There is an acute need therefore to put in place nuclear risk reduction measures without losing sight of the ultimate need for nuclear disarmament. This requires practical steps being taken by both sides, which in turn requires a certain level of trust. In light of the renewed talks between India and Pakistan, after a two year stand off, a new opportunity may be opening up where such steps could be discussed. This Briefing paper offers practical proposals as to what these might be

Proceedings of standing conference on health and safety in the nuclear age

International Nuclear Information System (INIS)

1990-01-01

From 5 to 6 December 1989 the second meeting of the Standing Conference on Health and Safety in the Nuclear Age was held in Brussels. The subject of the meeting was informing the public on improvements in emergency preparedness and nuclear accident management. The Standing Conference was created by the Commission of the European Communities in 1986 and its goal is to convey to the European public, via the mass media, factual information on nuclear subjects of current interest. About 100 experts and representatives of the mass media, competent authorities and socio-economic organizations followed the meeting, the specific objective of which was to discuss, from the point of view of radiation protection of the public and the environment, the improvements that nuclear accident management and intervention plans have undergone in recent years. Invited contributions underlined the presently improved levels of international and Community cooperation in radiation and nuclear safety, particularly in the fields of emergency preparedness and planning, where recent years have witnessed significant developments. The conference requested the Commission to pursue its public information efforts aimed at improving the understanding that the citizens of the Community have on the potential risks and the protective measures which were implemented in the nuclear sphere

Nuclear Structure Data for the Present Age

International Nuclear Information System (INIS)

Baglin, Coral M.

2005-01-01

The US Nuclear Data Program maintains and provides easy and free access to several comprehensive databases that assist scientists to sift through and assess the vast quantity of published nuclear structure and decay data. These databases are an invaluable asset for nuclear-science experimentalists and theorists alike, and the recommended values provided for nuclear properties such as decay modes, level energies and lifetimes, and radiation properties can also be of great importance to specialists in other fields such as medicine, geophysics, and reactor design. The Evaluated Nuclear Structure Data File (ENSDF) contains experimental nuclear structure data for all known nuclides, evaluated by the US nuclear data program evaluators in collaboration with a number of international data groups; the Nuclear Science Reference (NSR) database provides complementary bibliographic information; the Experimental Unevaluated Nuclear Data Listing (XUNDL) exists to enable rapid access to experimental nuclear-structure data compiled from the most recent publications (primarily in high-spin physics). This paper presents an overview of the nuclear structure and decay data available through these databases, with emphasis on recent and forthcoming additions to and presentations of the available material

The Nuclear Age: Context for Family Interaction.

Science.gov (United States)

Ptacek, Carmen

1988-01-01

Suggests that concerns regarding the nuclear threat are prevalent among family members; parents and children feel powerless in response to the nuclear threat; response to the nuclear threat is a family issue; responding to the nuclear threat requires empowering families and changing the social context; and nuclear concerns need to be addressed in…

Cooperative project on methods and techniques for assessment of ageing and safety of nuclear objects

International Nuclear Information System (INIS)

Bundara, B.; Udovc, M.; Cvelbar, R.; Vojvodic Tuma, J.; Celin, R.; Cizelj, L.; Simonovski, I.; Pirs, B.; Zabric, I.

2007-01-01

Nuclear Power Plants are so far the most demanding electric power plants concerning the extent and complexity of knowledge that is needed for design, construction, installation, safe operation and proper maintenance. For safe operation of the NPP it is important to have reliable inspection procedures and methods to detect the relevant defects in the components. It is also important to have effective techniques and efficient methodology that enable precise estimation of the material degradation and reliable prediction of the remaining period of the safe service of structures and components. During the operation of NPP its materials, structures and components are exposed to various impacts that have for the result changes in the material. Changes usually manifest as deviation from the origin (generally considered as defects) and can be observed at level of microstructure and/or at structural level. Defects are consequence of ageing and ageing is a consequence of mechanical, thermal, chemical, radiation induced and other processes. Complexity of the NPP and continuous operation at high level of safety demands extensive cooperation of researchers and engineers with different scientific and educational background. In the paper is discussed the importance of sufficient support to the NPP related research projects and the need for cooperation between institutes. As an example is presented the cooperative project that bands the research groups with different scientific background into complementary team working on multidisciplinary project focused on assessment of ageing and safety of nuclear objects. (author)

Nuclear age in the Middle East

Energy Technology Data Exchange (ETDEWEB)

Yiftah, S

1976-01-01

The book analyses, clarifies and summarises, from various aspects, some of the many questions concerning the motivation, the meaning, the economics, the dangers and the risks of introducing nuclear technology into the Middle East area following the recent agreements between some Mid Eastern countries and the United States, France, Germany and the U.S.S.R. about the supply of nuclear power reactors and nuclear fuel to the Middle East. The recent strong nuclear prgrams of countries such as India and Iran, who have wide-ranging ties with the Mid-Eastern countries, coupled with the huge revenues of petrodollars by the Arab countries of the area, together with the dangers of another 1973-type oil embargo are discussed and the triple crises of energy, ecology and nuclear weapons proliferation are considered.

The Effects of Nuclear Weapons

Energy Technology Data Exchange (ETDEWEB)

Glasstone, Samuel

1964-02-01

This book is a revision of "The Effects of Nuclear Weapons" which was issued in 1957. It was prepared by the Defense Atomic Support Agency of the Department of Defense in coordination with other cognizant governmental agencies and was published by the U.S. Atomc Energy Commission. Although the complex nature of nuclear weapons effects does not always allow exact evaluation, the conclusions reached herein represent the combined judgment of a number of the most competent scientists working the problem. There is a need for widespread public understanding of the best information available on the effects of nuclear weapons. The purpose of this book is to present as accurately as possible, within the limits of national security, a comprehensive summary of this information.

Nuclear energy: biological effects and environmental impact

International Nuclear Information System (INIS)

Boonefaes, M.

1987-01-01

This thesis is concerned with the large development of nuclear power plants and the recent nuclear catastrophe which has made clear how the hazards resulting from radioactivity affect public health and the environment. Environmental effects of nuclear power plants operating in normal conditions are small, but to obtain nuclear power plants of reduced radioactivity, optimization of their design, construction, operation and waste processing plays a decisive role. Biological effects of ionizing radiations and environmental impacts of Nuclear Power plants are developed [fr

Management of ageing of I and C equipment in nuclear power plants. Report prepared within the framework of the International Working Group on Nuclear Power Plant Control and Instrumentation

International Nuclear Information System (INIS)

2000-06-01

Experience has shown that ageing and obsolescence have the potential to cause the maintainability and operability of many instrumentation and control (I and C) systems to deteriorate well before the end of plant life. An I and C ageing management strategy is therefore required to control and minimize this threat. This report gives guidance on how to develop such a strategy and provides examples and supporting information on how established and recently developed maintenance, surveillance, and testing techniques may be employed to support the strategy. In some cases, equipment refurbishment may be necessary and guidance on this subject is given in a companion publication (IAEA-TECDOC-1016, Modernization of Instrumentation and Control in Nuclear Power Plants, IAEA, Vienna, 1998). The International Working Group on Nuclear Power Plant Control and Instrumentation (IWG-NPPCI) of the IAEA proposed in 1995 that a technical report be prepared to provide general guidelines on the management of ageing of important I and C equipment in nuclear power plants. The purpose of the report would be to guide the worldwide nuclear industry on potential effects of I and C ageing on plant safety and economy, and the means that are available to help minimize or eliminate any detrimental consequences of ageing. In response, a consultants meeting of five experts from Finland, France, Germany, the United Kingdom and the USA was held by the IAEA in Vienna in September 1997 to exchange national experience on the subject and to discuss the possible content of the report. The group of experts was tasked with bringing together all the information that is available on I and C ageing and ageing management methods. After a thorough discussion and analysis of the available information, an extended outline of the report on the subject was produced. The purpose of the extended outline was to identify a structure of the report, bring together information available at the moment and to provide guidance

Maintenance Management Support Systems for component aging estimation at nuclear power plants

International Nuclear Information System (INIS)

Shimizu, Shunichi; Ando, Yasumasa; Morioka, Toshihiko; Okuzumi, Naoaki

1991-01-01

Maintenance Management Support Systems (MMSSs) for nuclear power plants have been developed using component aging estimation methods and decision tree analysis for maintenance planning. The former evaluates actual component reliability through statistical analysis on field maintenance data. The latter provides preventive maintenance (PM) planning guidance using heuristic expert knowledge and estimated reliability parameters. The following aspects have been investigated: (1) A systematic and effective method of managing components/parts design information and field maintenance data (2) A method for estimating component aging based on a statistical analysis of field maintenance data (3) A method for providing PM planning guidance using estimated component reliability/performance parameters and decision tree analysis. Based on these investigations, two MMSSs were developed. One deals with 'general maintenance data', which are common to all component types and are amenable to common data handling. The other system deals with 'specific maintenance data', which are specific to an individual component type. Both systems provide PM planning guidance for PM cycles propriety and the PM work priority. The function of these systems were verified using simulated maintenance data. (author)

Aging management and preventive maintenance for nuclear power plants

International Nuclear Information System (INIS)

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

1995-01-01

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

The nuclear age in popular media a transnational history, 1945-1965

CERN Document Server

van Lente, Dick

2012-01-01

Among the many technical innovations that were introduced after World War II, none left as strong an impression on the public as the atom bombs that destroyed two Japanese cities in August 1945. People spoke of the ""atomic age"" that had now begun, as if this technological innovation would, all by itself, shape a new world. The atomic age was described as one that might soon end in the destruction of human civilization, but from the beginning, utopian images were attached to it as well. Nuclear technology offered the promise of applications in medicine, agriculture, and engineering, and nucle

Special role of scientists as citizens in a nuclear age

International Nuclear Information System (INIS)

Masperi, L.

1999-01-01

We are living in an age dominated by science and technology. There are probably at present more scientists alive than all those that passed away through the history of humankind. It is certain that science and technology have the possibility of solving the problems of society. However, these problems have not so far been satisfactorily treated and some scientifically ordered society which might be envisaged should hurt the common humanitarian feeling. These are probably the reasons for which a part of the public opinion has lost its trust in science and many people try to find a relief for their anguish in esoteric religions. It seems therefore necessary for a change of attitude on the part of scientists to restore the positive consideration from the society and to be able to contribute to the future evolution of humankind according to a peaceful and harmonious pattern. This short essay will start describing the historical search for solutions through science, will continue by attempting to define the values which should he added to science in the present time, and will end with possible recommendations for scientists in their connection with society, with particular emphasis on the nuclear issue. All that will be considered here refers mainly to natural sciences. Trying to find which are the attitudes of scientists that could contribute to the benefit of society, one may start with the need of feeling love for the scientific achievements they are able to make. Concerning the specific nuclear issue, both civilian and military applications must be considered. The military applications of nuclear energy should be completely prohibited. Scientists may play a relevant role in the elimination of the nuclear weapon possibility in regions of threshold states or with undeclared arsenals. On the way to nuclear-weapon-free world, it will be crucial to convince all or some of the nuclear powers to dismantle their nuclear arsenals. Scientists may make contribution to the

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

International Nuclear Information System (INIS)

Deng, Daniel

2004-01-01

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

Radiation and Thermal Ageing of Nuclear Waste Glass

Energy Technology Data Exchange (ETDEWEB)

Weber, William J [ORNL

2014-01-01

The radioactive decay of fission products and actinides incorporated into nuclear waste glass leads to self-heating and self-radiation effects that may affect the stability, structure and performance of the glass in a closed system. Short-lived fission products cause significant self-heating for the first 600 years. Alpha decay of the actinides leads to self-radiation damage that can be significant after a few hundred years, and over the long time periods of geologic disposal, the accumulation of helium and radiation damage from alpha decay may lead to swelling, microstructural evolution and changes in mechanical properties. Four decades of research on the behavior of nuclear waste glass are reviewed.

Safety aspects of nuclear power plant component aging

International Nuclear Information System (INIS)

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

1988-01-01

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

Aging predictions in nuclear power plants: Crosslinked polyolefin and EPR cable insulation materials

International Nuclear Information System (INIS)

Gillen, K.T.; Clough, R.L.

1991-06-01

In two earlier reports, we derived a time-temperature-dose rate superposition methodology, which, when applicable, can be used to predict cable degradation versus dose rate, temperature and exposure time. This methodology results in long-term predictive capabilities at the low dose rates appropriate to ambient nuclear power plant aging environments. The methodology was successfully applied to numerous important cable materials used in nuclear applications and the extrapolated predictions were verified by comparisons with long-term (7 to 12 year) results for similar or identical materials aged in nuclear environments. In this report, we test the methodology on three crosslinked polyolefin (CLPO) and two ethylene propylene rubber (EPR) cable insulation materials. The methodology applies to one of the CLPO materials and one of the EPR materials, allowing predictions to be made for these materials under low dose-rate, low temperature conditions. For the other materials, it is determined that, at low temperatures, a decrease in temperature at a constant radiation dose rate leads to an increase in the degradation rate for the mechanical properties. Since these results contradict the fundamental assumption underlying time-temperature-dose rate superposition, this methodology cannot be applied to such data. As indicated in the earlier reports, such anomalous results might be expected when attempting to model data taken across the crystalline melting region of semicrystalline materials. Nonetheless, the existing experimental evidence suggests that these CLPO and EPR materials have substantial aging endurance for typical reactor conditions. 28 refs., 26 figs., 3 tabs

Japan's search for identity in the nuclear age

Energy Technology Data Exchange (ETDEWEB)

Kenzaburo, O.

Japan's position has been one of an outsider in the nuclear age at the same time it has been a victim to the first use of atomic weapons. Quoting from Japanese poets and writers, the author constructs a model of the time to create an image of modern Japan's cultural identity as a result of the Meiji Restoration and the close of World War II. The end of the Emperor System and alienation from the rest of Asia are significant consequences of these events. The author feels that current arguments that Japan should arm itself with nuclear weapons ignore the miseries Japan alone has felt and should be restricted. Although a new Japanism which is oriented away from western culture is emerging today, efforts to rediscover the folk culture can also recapture the nonnuclear vision of 1945. (DCK)

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

Energy Technology Data Exchange (ETDEWEB)

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

1990-09-01

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

Nuclear knowledge management

International Nuclear Information System (INIS)

2007-01-01

The management of nuclear knowledge has emerged as a growing challenge in recent years. The need to preserve and transfer nuclear knowledge is compounded by recent trends such as ageing of the nuclear workforce, declining student numbers in nuclear-related fields, and the threat of losing accumulated nuclear knowledge. Addressing these challenges, the IAEA promotes a 'knowledge management culture' through: - Providing guidance for policy formulation and implementation of nuclear knowledge management; - Strengthening the contribution of nuclear knowledge in solving development problems, based on needs and priorities of Member States; - Pooling, analysing and sharing nuclear information to facilitate knowledge creation and its utilization; - Implementing effective knowledge management systems; - Preserving and maintaining nuclear knowledge; - Securing sustainable human resources for the nuclear sector; and - Enhancing nuclear education and training

Structural Aging Program to evaluate continued performance of safety-related concrete structures in nuclear power plants

International Nuclear Information System (INIS)

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

1994-01-01

This report discusses the Structural Aging (SAG) Program which is being conducted at the Oak Ridge National Laboratory (ORNL) for the United States Nuclear Regulatory commission (USNRC). The SAG Program is addressing the aging management of safety-related concrete structures in nuclear power plants for the purpose of providing improved technical bases for their continued service. The program is organized into three technical tasks: Materials Property Data Base, Structural Component Assessment/Repair Technologies, and Quantitative Methodology for continued Service Determinations. Objectives and a summary of recent accomplishments under each of these tasks are presented

Adolescents' knowledge of nuclear issues and the effects of nuclear war

International Nuclear Information System (INIS)

Roscoe, B.; Goodwin, M.P.

1987-01-01

Three hundred fifty-seven college students were surveyed to assess later adolescents' awareness of the status of nuclear arms development and possible effects of a nuclear war on people and the environment. Chi-square analyses were performed to determine whether the frequency of correct responses differed with regard to participants' sex, political orientation, and position toward the United States' possession of nuclear weapons. Results suggest that later adolescents are extremely uninformed regarding the current status of nuclear issues and the consequences of a nuclear war. These data, coupled with findings from previous studies reporting children's and adolescents' concerns and fears about nuclear war, indicate that there is a strong need to educate young people concerning nuclear issues

Radiation Effects in Nuclear Waste Materials

International Nuclear Information System (INIS)

Weber, William J.; Wang, Lumin; Hess, Nancy J.; Icenhower, Jonathan P.; Thevuthasan, Suntharampillai

2003-01-01

The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials

Radiation Effects in Nuclear Waste Materials

International Nuclear Information System (INIS)

Weber, William J.

2005-01-01

The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials

Rapid Nuclear Exclusion of Hcm1 in Aging Saccharomyces cerevisiae Leads to Vacuolar Alkalization and Replicative Senescence

Directory of Open Access Journals (Sweden)

Ata Ghavidel

2018-05-01

Full Text Available The yeast, Saccharomyces cerevisiae, like other higher eukaryotes, undergo a finite number of cell divisions before exiting the cell cycle due to the effects of aging. Here, we show that yeast aging begins with the nuclear exclusion of Hcm1 in young cells, resulting in loss of acidic vacuoles. Autophagy is required for healthy aging in yeast, with proteins targeted for turnover by autophagy directed to the vacuole. Consistent with this, vacuolar acidity is necessary for vacuolar function and yeast longevity. Using yeast genetics and immunofluorescence microscopy, we confirm that vacuolar acidity plays a critical role in cell health and lifespan, and is potentially maintained by a series of Forkhead Box (Fox transcription factors. An interconnected transcriptional network involving the Fox proteins (Fkh1, Fkh2 and Hcm1 are required for transcription of v-ATPase subunits and vacuolar acidity. As cells age, Hcm1 is rapidly excluded from the nucleus in young cells, blocking the expression of Hcm1 targets (Fkh1 and Fkh2, leading to loss of v-ATPase gene expression, reduced vacuolar acidification, increased α-syn-GFP vacuolar accumulation, and finally, diminished replicative lifespan (RLS. Loss of vacuolar acidity occurs about the same time as Hcm1 nuclear exclusion and is conserved; we have recently demonstrated that lysosomal alkalization similarly contributes to aging in C. elegans following a transition from progeny producing to post-reproductive life. Our data points to a molecular mechanism regulating vacuolar acidity that signals the end of RLS when acidification is lost.

Probing beer aging chemistry by nuclear magnetic resonance and multivariate analysis

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, J.A. [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Barros, A.S. [QOPNA-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Carvalho, B.; Brandao, T. [UNICER, Bebidas de Portugal, Leca do Balio, 4466-955, S. Mamede de Infesta (Portugal); Gil, Ana M., E-mail: agil@ua.pt [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

2011-09-30

Graphical abstract: The use of nuclear magnetic resonance (NMR) metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging (at 45 deg. C for up to 18 days) is described. Both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and an aging trend was observed. Inspection of PLS-DA loadings and peak integration revealed the importance of well known markers (e.g. 5-HMF) as well as of other compounds: amino acids, higher alcohols, organic acids, dextrins and some still unassigned spin systems. 2D correlation analysis enabled relevant compound variations to be confirmed and inter-compound correlations to be assessed, thus offering improved insight into the chemical aspects of beer aging. Highlights: {center_dot} Use of NMR metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging. {center_dot} Compositional variations evaluated by principal component analysis and partial least squares-discriminant analysis. {center_dot} Results reveal importance of known markers and other compounds: amino and organic acids, higher alcohols, dextrins. {center_dot} 2D correlation analysis reveals inter-compound relationships, offering insight into beer aging chemistry. - Abstract: This paper describes the use of nuclear magnetic resonance (NMR) spectroscopy, in tandem with multivariate analysis (MVA), for monitoring the chemical changes occurring in a lager beer exposed to forced aging (at 45 deg. C for up to 18 days). To evaluate the resulting compositional variations, both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and a clear aging trend was observed. Inspection of PLS-DA loadings and peak integration enabled the changing compounds to be identified, revealing the importance of well known

Probing beer aging chemistry by nuclear magnetic resonance and multivariate analysis

International Nuclear Information System (INIS)

Rodrigues, J.A.; Barros, A.S.; Carvalho, B.; Brandao, T.; Gil, Ana M.

2011-01-01

Graphical abstract: The use of nuclear magnetic resonance (NMR) metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging (at 45 deg. C for up to 18 days) is described. Both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and an aging trend was observed. Inspection of PLS-DA loadings and peak integration revealed the importance of well known markers (e.g. 5-HMF) as well as of other compounds: amino acids, higher alcohols, organic acids, dextrins and some still unassigned spin systems. 2D correlation analysis enabled relevant compound variations to be confirmed and inter-compound correlations to be assessed, thus offering improved insight into the chemical aspects of beer aging. Highlights: · Use of NMR metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging. · Compositional variations evaluated by principal component analysis and partial least squares-discriminant analysis. · Results reveal importance of known markers and other compounds: amino and organic acids, higher alcohols, dextrins. · 2D correlation analysis reveals inter-compound relationships, offering insight into beer aging chemistry. - Abstract: This paper describes the use of nuclear magnetic resonance (NMR) spectroscopy, in tandem with multivariate analysis (MVA), for monitoring the chemical changes occurring in a lager beer exposed to forced aging (at 45 deg. C for up to 18 days). To evaluate the resulting compositional variations, both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and a clear aging trend was observed. Inspection of PLS-DA loadings and peak integration enabled the changing compounds to be identified, revealing the importance of well known markers such as 5-hydroxymethylfurfural (5

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

International Nuclear Information System (INIS)

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

1999-01-01

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

Nursing education and the nuclear age

International Nuclear Information System (INIS)

McKay, S.

1989-01-01

As reflected in the nursing literature, nurses have only recently begun discussing professional responsibilities for avoidance of nuclear war. The literature of the 1950s and 1960s focused on issues of civil defense. The 1970s were mostly silent, but with the onset of the 1980s a few articles identified the need for the nursing profession to recognize the importance of nuclear war prevention. The responsibility of nursing education for including content about nuclear issues has not been discussed in the professional literature. The author surveyed baccalaureate programs of nursing education to determine whether this lack of discussion was reflected in nursing curricula. Responses indicated that the literature does not adequately reflect the level of activity and interest occurring within nursing education about nuclear issues. Nevertheless, because there is so little discussion in the professional literature, an implicit message is sent that nuclear issues are not of importance and that nurses should not openly address them.24 references

Chemical effects of nuclear transformations

Energy Technology Data Exchange (ETDEWEB)

Bulbulian, S

1982-06-01

A brief survey of the present state of knowledge on the chemical effects of nuclear transformations is presented. The recoil energy produced by these transformations in the nuclide is often sufficiently high to disrupt the chemical ligands between these particular atoms affected by the nuclear transformations, while the rest of their molecules. It also contains a discussion of the different annealing processes that produce the cancellation of the chemical change produced by the nuclear transformation.

Living in the Nuclear Age: Families and the threat of nuclear war

International Nuclear Information System (INIS)

Demorest, D.M.

1991-01-01

The main interest of this research was to add to the body of knowledge about the possible psychological impact of the nuclear threat on the family unit. Data were utilized from the Family Interaction, Stress and Nuclear War study conducted by Jules Riskin, M.D. and Victoria Dickerson, Ph.D. at the Mental Research Institute in Palo Alto, California. The sample consisted of ten families who were recruited for this study. In order to examine family-interaction variables and the impact of the threat of nuclear war, a standardized semi-structured family interview was conducted. Topics ranged from ordinary activities to external, non-nuclear stresses such as landslides or hurricanes, to the topic of nuclear war. A distinction is drawn between a family's level of nuclear concern while they discuss nuclear issues and a family's level of nuclear concern when viewed in the context of their overall pattern of family communication. In terms of family coping, family nuclear concern was found to be significantly related to two family-coping strategies. Families who utilized the coping strategies of seeking spiritual support and mobilizing the family to acquire and accept help were significantly less concerned about the threat of nuclear war

Nuclear Deterrence in the Age of Nonproliferation

Energy Technology Data Exchange (ETDEWEB)

Richardson, J

2009-01-21

The fallacy of zero nuclear weapons, even as a virtual goal, is discussed. Because the complete abolition of nuclear weapons is not verifiable, nuclear weapons will always play a role in the calculus of assure, dissuade, deter and defeat (ADDD). However, the relative contribution of nuclear weapons to international security has diminished. To reconstitute the Cold War nuclear capability, with respect to both the nuclear weapons capability and their associated delivery systems, is fiscally daunting and not warranted due to competing budgetary pressures and their relative contribution to international security and nonproliferation. A proposed pathway to a sustainable nuclear weapons capability end-state is suggested which provides enough ADDD; a Dyad composed of fewer delivery and weapon systems, with trickle production at the National Laboratories and private sector to maintain capability and guard against technological surprise.

Health effects study of the nuclear industry workers in Japan

International Nuclear Information System (INIS)

Tamiko Iwasaki

1997-01-01

To clarify the effects of low-dose and low-dose-rate exposure to the human body, study on the health effects of the nuclear industry workers in Japan was conducted since 1990 by the Institute of Radiation Epidemiology, the Radiation Effects Association, which had been entrusted by the Science and Technology Agency of the Japanese Government. In the first phase analysis between 1986 and 1992, the study population was selected from among persons who were engaged in radiation work at nuclear power plants and associated facilities, and registered in the Radiation Dose Registration Center for Workers. The cohort consisted of 114,900 persons who satisfied the criteria of nationality, age, sex, etc. The average follow-up period was 4.6 years, and the average cumulative dose per person was 13.9 mSv. The total number of deaths among the study population was 1,758, including 661 deaths due to all malignant neoplasms. The Standardized Mortality Ratio of various death causes was compared. Furthermore, the cohort was grouped by five different dose levels, and the O/E was calculated to test whether there is a trend for the death rate to increase with dose. Among nuclear workers no significant increase in deaths nor any relationship with radiation dose was found, except the pancreatic cancer with 10-years lag. Since many previous studies of nuclear industry workers have demonstrated no significant association between exposure dose and pancreatic cancer, we cannot immediately conclude a causal relationship between with radiation. (author)

IEEE Std 1205-1993: IEEE guide for assessing, monitoring, and mitigating aging effects on Class 1E equipment used in nuclear power generating stations

International Nuclear Information System (INIS)

Anon.

1993-01-01

The guidelines are provided for assessing, monitoring, and mitigating degradation of Class 1E equipment used in nuclear power generating stations due to aging. The methods described can be used to identify the performance capability of Class 1E equipment beyond its qualified life. A discussion of stressors and aging mechanisms is included. If aging considerations have been satisfactorily addressed through other means (e.g., equipment qualification), then use of this guide may not be warranted. For some equipment, only partial application of this guide may be warranted

The environmental effects of nuclear war

International Nuclear Information System (INIS)

MacCracken, M.C.

1988-09-01

Substantial environmental disruption will significantly add to the disastrous consequences caused by the direct thermal, blast, and radiological effects brought on by a major nuclear war. Local fallout could cover several percent of the Northern Hemisphere with potentially lethal doses. Smoke from post-nuclear fires could darken the skies and induce temperature decreases of tens of degrees in continental interiors. Stratospheric ozone could be significantly reduced due to nitric oxide injections and smoke-induced circulation changes. The environmental effects spread the consequences of a nuclear war to the world population, adding to the potentially large disruptive effects a further reason to avoid such a catastrophe. 27 refs., 4 figs

Detecting and mitigating battery charger and inverter aging

International Nuclear Information System (INIS)

Gunther, W.E.; Lewis, R.; Subudhi, M.

1988-08-01

This report constitutes the second of the two-phase approach for assessing the safety and operational aspects of battery charger and inverter aging in nuclear power plants. This work, conducted by Brookhaven National Laboratory (BNL) under the auspices of the US NRC Nuclear Plant Aging Research (NPAR) Program, evaluated operating experience data, nuclear power plant maintenance practices, and plant design information to determine the impact of battery charger and inverter aging on safety, and the methods which should be used to detect aging degradation and mitigate its effects. A naturally aged inverter and battery charger were tested at BNL to evaluate the naturally aged condition, the effectiveness of condition monitoring techniques, and the practicality of implementing selected maintenance and monitoring recommendations. Temperature monitoring, component parameter measurements, and the periodic observation of critical circuit waveforms are viable methods for monitoring aging degradation. A maintenance program for battery chargers and inverters is recommended. As described in this report, the maintenance program incorporates inspection, monitoring, testing and repair activities which should be performed to detect and mitigate aging effects, and thereby assure the operational readiness of this important equipment throughout the plant's operating life. 32 refs., 43 figs., 19 tabs

Unfolding of the nuclear age: a psychohistorical investigation into the lives of ten men

International Nuclear Information System (INIS)

Gladstone, K.

1987-01-01

This investigation is based on in-depth interviews that cover the life histories of ten American men who were born between 1921 and 1937 and came of age with the Depression and/or World War II and major historical events in their lives. The major emphasis in this work is on the portrayal of the lives of these men who share an historic era and their relations to nuclear weapons. The issues explored include how the fundamental changes in the world brought about by the adoption of nuclear-weapons technology have evolved, how the weapons have been understood, how they have been incorporated into the lives of these men, and what implications and call for action have come from these changes. The ten men span a wide spectrum of views on nuclear weapons. Five of the men feel relatively secure living in the nuclear armed world; they are referred to as the men with the established mode of the nuclear armed world. The other five are referred to as the men in opposition to the nuclear armed world; they believe that the nuclear armed world poses a fundamental crisis in the well-being of humanity

Assessment and Management of Ageing of Major Nuclear Power Plant Components Important to Safety: Steam Generators. 2011 Update

International Nuclear Information System (INIS)

2011-11-01

At present there are over four hundred forty operational nuclear power plants (NPPs) in IAEA Member States. Ageing degradation of the systems, structures of components during their operational life must be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling, within acceptable limits, the ageing degradation and wear-out of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This IAEA-TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring and mitigation of ageing degradation of selected components of Canada deuteriumuranium (CANDU) reactor, boiling water reactor (BWR), pressurized water reactor (PWR), and water moderated, water cooled energy reactor (WWER) plants are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs, and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age related licensing issues. Since the reports are written from a safety perspective, they do not address life or life cycle management of the plant components, which involves the integration of ageing management and economic planning. The target audience of the reports consists of technical experts from NPPs and from regulatory, plant design, manufacturing and technical support organizations dealing with specific plant components addressed in the reports. The component addressed in the present publication is the steam

Aging and condition monitoring of electric cables in nuclear power plants

International Nuclear Information System (INIS)

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

1998-05-01

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

Results of LWR snubber aging research

International Nuclear Information System (INIS)

Brown, D.P.; Werry, E.V.; Blahnik, D.E.

1992-05-01

This report describes the aging research results and recommendations for snubbers used in commercial nuclear power plants. Snubbers are safety-related devices used to restrain undesirable dynamic loads at various piping and equipment locations in nuclear power plants (NPPs). Each snubber must accommodate a plant's normal thermal movements and must be capable of restraining the maximum off-normal dynamic loads, such as a seismic event or a transient, postulated for its specific location. The effects of snubber aging and the factors that contribute to the degradation of their safety performance need to be better understood. Thus, Phase II of Nuclear Plant Aging Research was conducted to enhance the understanding of snubber aging and its consequences. Pacific Northwest Laboratory staff and their subcontractors, Lake Engineering and Wyle Laboratories, visited eight sites (encompassing thirteen plants) to conduct interviews with NPP staff and to collect data on snubber aging, testing, and maintenance. The Phase II research methodology, evaluation, results, conclusions, and recommendations are described in the report. Effective methods for service-life monitoring of snubbers are included in the recommendations

Political aspects of nuclear test effects at Semipalatinsk nuclear test site

International Nuclear Information System (INIS)

Sydykov, E.B.; Panin, M.S.

2003-01-01

The paper describes tense struggle of Kazakhstan people for closure of the Semipalatinsk Nuclear Test Site. It reveals major foreign policy aspects and nuclear test effects for both Kazakhstan and the world community. (author)

Nuclear energy in the age of biotechnology

International Nuclear Information System (INIS)

Deocaris, C.C.

2002-01-01

The unprecedented rate of discovery in molecular biology and biotechnology, in particular, the human genome sciences, has already far surpassed advancements in aerospace and nuclear science. Its influence will not only permanently mold perspectives in health, medicine and the life sciences, but will also create an impact in the field of nuclear energy development. In the next 50 years, nuclear power run by fission-reactions will be relaunched. It is bound to present more diverse applications, e.g., in propelling ships, in the production of heat for industry and for space heating, and perhaps in the desalination of water. The general public will be more at ease with nuclear power knowing that there is no other form of energy capable of delivering so much power at reasonable cost with negligible impact on climate and environment in what is perceived to be the coming of a nuclear rennaissance (Blix, 2001). This paper surveys opportunities for future nuclear energy applications in biotechnology, including DNA-damage sensors, bioelectronics and computers, genetic testing of nuclear workers and upgrading of biofuels. The relevance of these myriads of biosystems applications may not 'ust complement requirements of a nuclear power program in improving overall efficiency and safety but may also provide more diverse uses of nuclear power that may find use for developing nations. (Author)

Effects of age and sedentary lifestyle on skeletal muscle NF-kappaB signaling in men.

Science.gov (United States)

Buford, Thomas W; Cooke, Matthew B; Manini, Todd M; Leeuwenburgh, Christiaan; Willoughby, Darryn S

2010-05-01

Nuclear factor kappa B (NF-kappaB) is a critical signaling molecule of disuse-induced skeletal muscle atrophy. However, few studies have carefully investigated whether similar pathways are modulated with physical activity and age. The present study examined lean mass, maximal force production, and skeletal muscle NF-kappaB signaling in 41 men categorized as sedentary (OS, N = 13, 63.85 +/- 6.59 year), physically active (OA, N = 14, 60.71 +/- 5.54 year), or young and sedentary (YS, N = 14, 21.35 +/- 3.84 year). Muscle tissue from the vastus lateralis was assayed for messenger RNA (mRNA) expression of the beta subunit of IkB kinase (IKKbeta), cytosolic protein content of phosphorylated inhibitor of kappa B alpha (pIKBalpha), and nuclear content of NF-kappaB subunits p50 and p65. When compared with YS, OS demonstrated age-related muscle atrophy and reduced isokinetic knee extension torque. Physical activity in older individuals preserved maximal isokinetic knee extension torque. OS muscle contained 50% more pIKBalpha than OA and 61% more pIKBalpha than YS. Furthermore, nuclear p65 was significantly elevated in OS compared with YS. OS muscle did not differ from either of the other two groups for nuclear p50 or for mRNA expression of IKKbeta. These results indicate that skeletal muscle content of nuclear-bound p65 is elevated by age in humans. The elevation in nuclear-bound p65 appears to be at least partially due to significant increases in pIKBalpha. A sedentary lifestyle appears to play some role in increased IKBalpha; however, further research is needed to identify downstream effects of this increase.

Survey and evaluation of aging risk assessment methods and applications

International Nuclear Information System (INIS)

Sanzo, D.; Kvam, P.; Apostolakis, G.; Wu, J.; Milici, T.; Ghoniem, N.; Guarro, S.

1994-11-01

The US Nuclear Regulatory Commission initiated the nuclear power plant aging research program about 6 years ago to gather information about nuclear power plant aging. Since then, this program has collected a significant amount of information, largely qualitative, on plant aging and its potential effects on plant safety. However, this body of knowledge has not yet been integrated into formalisms that can be used effectively and systematically to assess plant risk resulting from aging, although models for assessing the effect of increasing failure rates on core damage frequency have been proposed. This report surveys the work on the aging of systems, structures, and components (SSCs) of nuclear power plants, as well as associated data bases. We take a critical look at the need to revise probabilistic risk assessments (PRAs) so that they will include the contribution to risk from plant aging, the adequacy of existing methods for evaluating this contribution, and the adequacy of the data that have been used in these evaluation methods. We identify a preliminary framework for integrating the aging of SSCs into the PRA and include the identification of necessary data for such an integration

Nuclear energy and the greenhouse effect

International Nuclear Information System (INIS)

Weinberg, A.M.

1990-01-01

The extent and nature of the greenhouse effect are examined and placed in an environmental and historical context. The effect of energy policies on the greenhouse effect are discussed and the offending countries are identified. What energy policies would mitigate the greenhouse effect, and yet make good sense whether or not the effect proves to be real? Conservation is a desirable though not completely understood strategy. Conservation may not be a better bet in every instance than is increase in supply. If the greenhouse effect turns out to be real, nuclear energy can be one of the supply options that we turn to. If the greenhouse effect turns out to be false, and acceptable, economic nuclear option is surely better than one that does nothing but create strife and dissension. Let us remember that nuclear energy is the only large-scale non-fossil source other than hydropower that has been demonstrated to be practical. (author)

Role of the nuclear envelope in the pathogenesis of age-related bone loss and osteoporosis

Science.gov (United States)

Vidal, Christopher; Bermeo, Sandra; Fatkin, Diane; Duque, Gustavo

2012-01-01

The nuclear envelope is the most important border in the eukaryotic cell. The role of the nuclear envelope in cell differentiation and function is determined by a constant interaction between the elements of the nuclear envelope and the transcriptional regulators involved in signal transcription pathways. Among those components of the nuclear envelope, there is a growing evidence that changes in the expression of A-type lamins, which are essential components of the nuclear lamina, are associated with age-related changes in bone affecting the capacity of differentiation of mesenchymal stem cells into osteoblasts, favoring adipogenesis and affecting the function and survival of the osteocytes. Overall, as A-type lamins are considered as the 'guardians of the soma', these proteins are also essential for the integrity and quality of the bone and pivotal for the longevity of the musculoskeletal system. PMID:23951459

The competitive economics of a middle aged multi unit nuclear generating station

International Nuclear Information System (INIS)

Talbot, K.H.

1994-01-01

In 1992 Ontario Hydro's 15 year old 4 x 850 MWe Candu, Bruce A Nuclear Generating Station was predicted to need considerable capital investment to replace pressure tubes, steam generators and other prematurely ageing equipment in order to restore the station to high performance. Over the subsequent two years the station has undergone 2 major economic assessment studies which have confirmed the economic viability of continued operation of the plant. Declining demand for electricity in Ontario combined with a excess of generating capacity and a need to stabilise electricity rates have however forced significant operational cost reductions and reduced capital availability for rehabilitation work, it's medium and long term future remains in question. This presentation offers a practical illustration of the need to maintain steady high performance from nuclear generating plant via the appropriate life management techniques. The avoidance of mid life infusion of capital is considered as essential if nuclear generation is to successfully survive major changes in economic conditions. 2 tabs., 7 figs

Reliability of some ageing nuclear power plant system: a simple stochastic model

Energy Technology Data Exchange (ETDEWEB)

Suarez-Antola, Roberto [Catholic University of Uruguay, Montevideo (Uruguay). School of Engineering and Technologies; Ministerio de Industria, Energia y Mineria, Montevideo (Uruguay). Direccion Nacional de Energia y Tecnologia Nuclear; E-mail: rsuarez@ucu.edu.uy

2007-07-01

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

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

International Nuclear Information System (INIS)

Suarez Antola, R.

2007-01-01

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

Stochastic Effects; Application in Nuclear Physics

International Nuclear Information System (INIS)

Mazonka, O.

2000-04-01

Stochastic effects in nuclear physics refer to the study of the dynamics of nuclear systems evolving under stochastic equations of motion. In this dissertation we restrict our attention to classical scattering models. We begin with introduction of the model of nuclear dynamics and deterministic equations of evolution. We apply a Langevin approach - an additional property of the model, which reflect the statistical nature of low energy nuclear behaviour. We than concentrate our attention on the problem of calculating tails of distribution functions, which actually is the problem of calculating probabilities of rare outcomes. Two general strategies are proposed. Result and discussion follow. Finally in the appendix we consider stochastic effects in nonequilibrium systems. A few exactly solvable models are presented. For one model we show explicitly that stochastic behaviour in a microscopic description can lead to ordered collective effects on the macroscopic scale. Two others are solved to confirm the predictions of the fluctuation theorem. (author)

Ductal carcinoma in situ of the breast (DCIS with heterogeneity of nuclear grade: prognostic effects of quantitative nuclear assessment

Directory of Open Access Journals (Sweden)

Fu Yuejiao

2007-09-01

Full Text Available Abstract Background Previously, 50% of patients with breast ductal carcinoma in situ (DCIS had more than one nuclear grade, and neither worst nor predominant nuclear grade was significantly associated with development of invasive carcinoma. Here, we used image analysis in addition to histologic evaluation to determine if quantification of nuclear features could provide additional prognostic information and hence impact prognostic assessments. Methods Nuclear image features were extracted from about 200 nuclei of each of 80 patients with DCIS who underwent lumpectomy alone, and received no adjuvant systemic therapy. Nuclear images were obtained from 20 representative nuclei per duct, from each of a group of 5 ducts, in two separate fields, for 10 ducts. Reproducibility of image analysis features was determined, as was the ability of features to discriminate between nuclear grades. Patient information was available about clinical factors (age and method of DCIS detection, pathologic factors (DCIS size, nuclear grade, margin size, and amount of parenchymal involvement, and 39 image features (morphology, densitometry, and texture. The prognostic effects of these factors and features on the development of invasive breast cancer were examined with Cox step-wise multivariate regression. Results Duplicate measurements were similar for 89.7% to 97.4% of assessed image features. For the pooled assessment with ~200 nuclei per patient, a discriminant function with one densitometric and two texture features was significantly (p Conclusion Image analysis provided reproducible assessments of nuclear features which quantitated differences in nuclear grading for patients. Quantitative nuclear image features indicated prognostically significant differences in DCIS, and may contribute additional information to prognostic assessments of which patients are likely to develop invasive disease.

Advance: research project on aging electrical wiring in nuclear power plants; Advance: proyecto de investigacion de envejecimiento en cableado electrico en centrales nucleares

Energy Technology Data Exchange (ETDEWEB)

Cano, J. C.; Ruiz, S.

2013-07-01

As Nuclear Power Plants get older it is more important to know the real condition of low voltage, instrumentation, power and control cables. Additionally, as new plants are being built, the election of cables and the use of in-situ monitoring techniques to get reliable aging indicators, can be very useful during the plant life. The goal of this Project is to adapt, optimize and asses Condition Monitoring techniques for Nuclear Power Plants cables. These techniques, together with the appropriate acceptance criteria, would allow specialists to know the state of the cable over its entire length and estimate its residual life. In the Project, accelerated ageing is used in cables installed in European NPPs in order to evaluate different techniques to detect local and global ageing. Results are compared with accepted tests to validate its use for the estimation of cables residual life. This paper describes the main stages of the Project and some results. (Author)

Matrix metalloproteinase-9 expression in the nuclear compartment of neurons and glial cells in aging and stroke.

Science.gov (United States)

Pirici, Daniel; Pirici, Ionica; Mogoanta, Laurentiu; Margaritescu, Otilia; Tudorica, Valerica; Margaritescu, Claudiu; Ion, Daniela A; Simionescu, Cristiana; Coconu, Marieta

2012-10-01

Matrix metalloproteinases (MMPs) are well-recognized denominators for extracellular matrix remodeling in the pathology of both ischemic and hemorrhagic strokes. Recent data on non-nervous system tissue showed intracellular and even intranuclear localizations for different MMPs, and together with this, a plethora of new functions have been proposed for these intracellular active enzymes, but are mostly related to apoptosis induction and malign transformation. In neurons and glial cells, on human tissue, animal models and cell cultures, different active MMPs have been also proven to be located in the intra-cytoplasmic or intra-nuclear compartments, with no clear-cut function. In the present study we show for the first time on human tissue the nuclear expression of MMP-9, mainly in neurons and to a lesser extent in astrocytes. We have studied ischemic and hemorrhagic stroke patients, as well as aged control patients. Age and ischemic suffering seemed to be the best predictors for an elevated MMP-9 nuclear expression, and there was no evidence of a clear-cut extracellular proteolytic activity for this compartment, as revealed by intact vascular basement membranes and assessment of vascular densities. More, the majority of the cells expressing MMP-9 in the nuclear compartment also co-expressed activated-caspase 3, indicating a possible link between nuclear MMP-9 localization and apoptosis in neuronal and glial cells following an ischemic or hemorrhagic event. These results, besides showing for the first time the nuclear localization of MMP-9 on a large series of human stroke and aged brain tissues, raise new questions regarding the unknown spectrum of the functions MMPs in human CNS pathology. © 2011 Japanese Society of Neuropathology.

Ageing management of nuclear power plants

International Nuclear Information System (INIS)

Cepcek, Stefan; Uhrik, Peter; Ziakova, Marta

2002-01-01

In 1995 the Nuclear Regulatory Authority of the Slovak Republic (UJD) began to issue its own non-periodic publications, as an edition on Safety of Nuclear Installations with the aim to publish generally binding legal regulations, safety requirements, recommendations and guidelines related to UJD task. In the framework of the edition on Safety of Nuclear Installations the UJD issues three groups of publications: The first group of publications deals with generally binding legal regulations and international treaties or conventions related to peaceful use of nuclear energy. Publications are marked by a red stripe. The second group represents guidelines, which should clarify and supplement the requirements of generally binding legal regulations. Recommendations given by these documents are not generally binding, nevertheless following of these recommendations helps licensees to demonstrate fulfilment of generally binding requirements. The third group of publications represents documents, which have only informative character

Nuclear power in an age of uncertainty

International Nuclear Information System (INIS)

1984-02-01

The present nuclear era is drawing to a close. Unit 1 of the Washington Public Power Supply System was indefinitely, perhaps permanently, deferred even though it was 60% complete and $2.1 billion had been invested. This plant and others such as Zimmer and Marble Hill epitomize the difficulties facing the nuclear industry. It is important to remember, however, that other nuclear plants have been very successful and produce reliable, low cost electricity. The future of nuclear power poses a complex dilemma of policymakers. It has advantages that may prove crucial to this nation's energy system in the coming decades, but at present it is an option that no electric utility would seriously consider. OTA examined questions of demand growth, costs, regulation, and public acceptance to evaluate how these factors affect nuclear power's future. We reviewed research directions which could improve conventional light water reactor technology and opportunities to develop other types of reactor concepts that might enhance safe and reliable operation. In addition, the crucial role of utility management in constructing and operating nuclear powerplants is examined at length. The controversy about nuclear safety regulation is also analyzed, and is presented with a review of current proposals for regulatory reform. Finally, the study discusses policy approaches that could assist a revival of the nuclear option should that be a choice of Congress

Recommendations for the treatment of aging in standard technical specifications

International Nuclear Information System (INIS)

Orton, R.D.; Allen, R.P.

1995-09-01

As part of the US Nuclear Regulatory Commission's Nuclear Plant Aging Research Program, Pacific Northwest Laboratory (PNL) evaluated the standard technical specifications for nuclear power plants to determine whether the current surveillance requirements (SRs) were effective in detecting age-related degradation. Nuclear Plant Aging Research findings for selected systems and components were reviewed to identify the stressors and operative aging mechanisms and to evaluate the methods available to detect, differentiate, and trend the resulting aging degradation. Current surveillance and testing requirements for these systems and components were reviewed for their effectiveness in detecting degraded conditions and for potential contributions to premature degradation. When the current surveillance and testing requirements appeared ineffective in detecting aging degradation or potentially could contribute to premature degradation, a possible deficiency in the SRs was identified that could result in undetected degradation. Based on this evaluation, PNL developed recommendations for inspection, surveillance, trending, and condition monitoring methods to be incorporated in the SRs to better detect age- related degradation of these selected systems and components

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

International Nuclear Information System (INIS)

Lofaro, R.J.

1999-01-01

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

Reflections on realism in the nuclear age

International Nuclear Information System (INIS)

Cohen, A.

1987-01-01

It is against the realism of living with nuclear weapons that the author addresses. Indeed, realism as a theory of international relations has been under attack on normative-philosophical grounds in recent years by a number of political theorists. The reasons for my criticism of nuclear realism, however, are quite different and separate from the general moral case against realism put forward by these theorists. The arguments developed in this paper are derived directly from the emergent features of the nuclear predicament itself, the ways in which the rise of nuclear weapons has turned out to negate the fundamental logic of realism. The nuclear predicament brings realism to a reductio ad absurdum and negates the very political framework that is supposed to justify it

RADIATION EFFECTS IN NUCLEAR WASTE MATERIALS

International Nuclear Information System (INIS)

Weber, William J.

2000-01-01

The objective of this research was to develop fundamental understanding and predictive models of radiation effects in glasses and ceramics at the atomic, microscopic, and macroscopic levels, as well as an understanding of the effects of these radiation-induced solid-state changes on dissolution kinetics (i.e., radionuclide release). The research performed during the duration of this project has addressed many of the scientific issues identified in the reports of two DOE panels [1,2], particularly those related to radiation effects on the structure of glasses and ceramics. The research approach taken by this project integrated experimental studies and computer simulations to develop comprehensive fundamental understanding and capabilities for predictive modeling of radiation effects and dissolution kinetics in both glasses and ceramics designed for the stabilization and immobilization of high-level tank waste (HLW), plutonium residues and scraps, surplus weapons plutonium, other actinides, and other highly radioactive waste streams. Such fundamental understanding is necessary in the development of predictive models because all experimental irradiation studies on nuclear waste materials are ''accelerated tests'' that add a great deal of uncertainty to predicted behavior because the damage rates are orders of magnitude higher than the actual damage rates expected in nuclear waste materials. Degradation and dissolution processes will change with damage rate and temperature. Only a fundamental understanding of the kinetics of all the physical and chemical processes induced or affected by radiation will lead to truly predictive models of long-term behavior and performance for nuclear waste materials. Predictive models of performance of nuclear waste materials must be scientifically based and address both radiation effects on structure (i.e., solid-state effects) and the effects of these solid-state structural changes on dissolution kinetics. The ultimate goal of this

Component aging and reliability trends in Loviisa Nuclear Power Plant

International Nuclear Information System (INIS)

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

1989-01-01

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

Effects of Age and Sedentary Lifestyle on Skeletal Muscle NF-κB Signaling in Men

Science.gov (United States)

Buford, Thomas W.; Cooke, Matthew B.; Manini, Todd M.; Leeuwenburgh, Christiaan

2010-01-01

Background. Nuclear factor kappa B (NF-κB) is a critical signaling molecule of disuse-induced skeletal muscle atrophy. However, few studies have carefully investigated whether similar pathways are modulated with physical activity and age. Methods. The present study examined lean mass, maximal force production, and skeletal muscle NF-κB signaling in 41 men categorized as sedentary (OS, N = 13, 63.85 ± 6.59 year), physically active (OA, N = 14, 60.71 ± 5.54 year), or young and sedentary (YS, N = 14, 21.35 ± 3.84 year). Muscle tissue from the vastus lateralis was assayed for messenger RNA (mRNA) expression of the β subunit of IkB kinase (IKKβ), cytosolic protein content of phosphorylated inhibitor of kappa B alpha (pIKBα), and nuclear content of NF-κB subunits p50 and p65. Results. When compared with YS, OS demonstrated age-related muscle atrophy and reduced isokinetic knee extension torque. Physical activity in older individuals preserved maximal isokinetic knee extension torque. OS muscle contained 50% more pIKBα than OA and 61% more pIKBα than YS. Furthermore, nuclear p65 was significantly elevated in OS compared with YS. OS muscle did not differ from either of the other two groups for nuclear p50 or for mRNA expression of IKKβ. Conclusions. These results indicate that skeletal muscle content of nuclear-bound p65 is elevated by age in humans. The elevation in nuclear-bound p65 appears to be at least partially due to significant increases in pIKBα. A sedentary lifestyle appears to play some role in increased IKBα; however, further research is needed to identify downstream effects of this increase. PMID:20045871

Radiant science, dark politics: a memoir of the nuclear age

International Nuclear Information System (INIS)

Kamen, M.D.

1985-01-01

The reviewer describes Radiant Science, Dark Politics: A Memoir of the Nuclear Age in contrast to a memoir by James R. Killian, Jr., a contemporary of Kamen. Kamen, co-discoverer of carbon-14 and a valued member of the Berkeley Radiation Laboratory, was fired in 1944 and blackballed as a security risk. Rehabilitated by the end of the war, his continued fight against political injustice through the McCarthy era colors the book and, for the reviewer, makes it self-serving. Kamen's later scientific work reflected his desire to work alone rather than in collaboration

Assessment and Management of Aging in Phenix Nuclear Power Plant

International Nuclear Information System (INIS)

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

2006-01-01

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

Potential effects of nuclear war on agricultural productivity

International Nuclear Information System (INIS)

Harwell, M.A.; Cropper, W.P. Jr.

1985-01-01

The authors examine the vulnerabilities of agricultural systems to nuclear war-induced climatic perturbations and to other, indirect effects of nuclear war. Discussion is included of the dependency of agricultural production on technological inputs and the effects of loss or reduction of these inputs in a post-nuclear war world

Approach of British Nuclear Fuels to managing ageing

International Nuclear Information System (INIS)

2006-01-01

The approach taken by BNFL to managing ageing is developed at the design stage and builds upon experience gained through designing, building, operating and decommissioning nuclear facilities since 1947. Much of the current philosophy was developed during the design and construction of the Thermal Oxide Reprocessing Plant (THORP). The process of managing ageing encompasses all the phases of the facility's life; that is, design, operation and decommissioning. Underlying all these phases is the input from the results of research and development and plant inspection activities. Plant ageing is managed by a policy of understanding the degradation mechanisms as far as possible and, from that knowledge, targeting for particular attention plants considered as vulnerable or for which we are uncertain of our understanding of the degradation processes; for example, THORP receipt and storage LWR storage racks have been fabricated from 304L stainless steel. In their storage environment, deionized water, the worst case measured corrosion rate for such steels is 0.03 mm/a. Given that the minimum material thickness used is 20 mm, corrosion over the design life is negligible and therefore there are no prescribed monitoring or maintenance requirements. Plant inspection policy was first developed for THORP, where targeted programmes of inspection are established. Inspection may be limited to visual inspection or may involve quantitative non-destructive testing such as ultrasonics, and in certain areas, such as dissolvers, on-line thickness monitors have been installed to facilitate the process. The programmes are updated as the actual plant operating conditions are better known and understood; therefore, for example, an SSC found to be operating at higher temperatures than originally planned or carrying a higher burden of corrodents may become targeted for inspection, whereas SSCs perceived to be benign may have inspection frequencies reduced. Similar policies are being developed for

The climatic effects of nuclear war

Science.gov (United States)

Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, C.

1984-01-01

The effects of various US-USSR nuclear-exchange scenarios on global climate are investigated by means of computer simulations, summarizing the results of Turco et al. (1983) and follow-up studies using 3D global-circulation models. A nuclear-scenario model is used to determine the amounts of dust, smoke, radioactivity, and pyrotoxins generated by a particular type of nuclear exchange (such as a general 5,000-Mt exchange, a 1,000-Mt limited exchange, a 5,000-Mt hard-target counterforce attack, and a 100-Mt attack on cities only): a particle-microphysics model predicts the evolution of the dust and smoke particles; and a radiative-convective climate model estimates the effects of the dust and smoke clouds on the global radiation budget. The findings are presented in graphs, diagrams, and a table. Thick clouds blocking most sunlight over the Northern Hemisphere midlatitudes for weeks or months and producing ground-temperature reductions of 20-40 C, disruption of global circulation patterns, and rapid spread of clouds to the Southern Hemisphere are among the 'nuclear-winter' effects predicted for the 5,000-Mt baseline case. The catastrophic consequences for plant, animal, and human populations are considered, and the revision of superpower nuclear strategies is urged.

Effective citizen advocacy of beneficial nuclear technologies

International Nuclear Information System (INIS)

McKibben, J. Malvyn; Wood, Susan

2007-01-01

In 1991, a small group of citizens from communities near the Savannah River Site (SRS) formed a pro-nuclear education and advocacy group, Citizens for Nuclear Technology Awareness (CNTA). Their purpose was to: (1) counter nuclear misinformation that dominated the nation's news outlets, (2) provide education on nuclear subjects to area citizens, students, elected officials, and (3) provide informed citizen support for potential new missions for SRS when needed. To effectively accomplish these objectives it is also essential to establish and maintain good relations with community leaders and reporters that cover energy and nuclear subjects. The organization has grown considerably since its inception and has expanded its sphere of influence. We believe that our experiences over these fifteen years are a good model for effectively communicating nuclear subjects with the public. This paper describes the structure, operation and some of the results of CNTA. (authors)

The nuclear age in the Middle East

International Nuclear Information System (INIS)

Yiftah, Shimon.

1976-01-01

The book analyses, clarifies and summarises, from various aspects, some of the many questions concerning the motivation, the meaning, the economics, the dangers and the risks of introducing nuclear technology into the Middle East area following the recent agreements between some Mid Eastern countries and the United States, France, Germany and the U.S.S.R. about the supply of nuclear power reactors and nuclear fuel to the Middle East. The recent strong nuclear prgrams of countries such as India and Iran, who have wide-ranging ties with the Mid-Eastern countries, coupled with the huge revenues of petrodollars by the Arab countries of the area, together with the dangers of another 1973-type oil embargo are discussed and the triple crises of energy, ecology and nuclear weapons proliferation are considered. (B.G.)

The nuclear age. Cleaning up the mess

International Nuclear Information System (INIS)

Menezes, M.; Stunell, A.

2001-01-01

This paper focuses on just one essential component of a 'non nuclear' future - the management of nuclear waste. Waste produced by nuclear power is invariably contaminated by radioactivity. It is therefore a serious health and environmental hazard which requires special consideration. As residual radioactive contamination is generally very long lasting, the treatment and disposal options not only have to be robust in themselves, but also capable of retaining their integrity for hundreds, even thousands of years. Until now the debate over the issue of nuclear waste has been polarised; on the one hand there are those who see blocking a long-term solution to waste management as a powerful lever against further nuclear development. On the other, there are those who are in favour of a nuclear-powered future and who consequently have attempted to minimise the problem of dealing with nuclear waste. However, the time is now right for developing a long-term waste strategy for two reasons. Firstly we are confronted with reality, as nuclear plants coming to the end of their life are decommissioned, and secondly, the privatisation of the electricity generation market- has meant that nuclear cannot longer compete in the market with cheaper forms of energy generation and so new build is unlikely. Two options for storing waste have, in the main, been explored: surface storage and geological disposal with the option of retrieval. We believe that geological disposal is the only real option as it does not rely on future societal or climate stability to remain safe and secure. The most vital requirements for the success of finding a long-term solution are public support and legitimacy. Nirex's attempt to gain planning permission for the Rock Characterisation Facility and experience in other countries of gaining support for geological disposal bear this out

Report of the task group reviewing national and international activities in the area of ageing of nuclear power plant concrete structures

International Nuclear Information System (INIS)

1996-01-01

After a background information on the mandate of the task group and its organisation, the longevity of nuclear power plants is first addressed: the present status of nuclear power plants in the 25 OECD Member Countries is summarised and the importance of ensuring continued safe operation of nuclear power plants described. Safety-related concrete structures (primarily containments) for several reactor concepts are briefly described as well as their materials of construction. Primary mechanisms that can produce adverse ageing of the concrete structures are described (e.g., chemical attack and corrosion of steel reinforcement). The overall performance of nuclear power plant concrete structures is described and age-related degradation incidences that have occurred are noted (e.g., corrosion of steel in water intake structures and corrosion of metal liners). National ageing management programmes of OECD Member Countries are then described with the emphasis placed on nuclear power plant safety-related concrete structures. Although the majority of these programmes are addressing components such as the reactor pressure vessel and steam generator, several national programmes have sophisticated activities that address the concrete structures (e.g., Canada, France, Japan, Switzerland, United Kingdom, and the United States). International ageing management activities are then summarised, primarily addressed under the auspices of the International Atomic Energy Agency (IAEA) (ageing management activities for concrete containment buildings) and the Commission of European Communities (CEC) (assessment of the long-term durability of reinforced and prestressed concrete structures and buildings, and steel containments in nuclear power plants). General conclusions and recommendations are provided at the end of the report

Ageing of coolant channels in nuclear reactors (PHWRs)

International Nuclear Information System (INIS)

Mitra, T.L.; Chowdhury, M.K.; Gupta, R.K.; Pandarinathan, P.R.; Seth, V.K.

1994-01-01

In PHWRs, ageing of various components takes place due to factors like fast neutron flux, temperature, stress, environment etc. In coolant channel, the most severely affected component due to ageing is pressure tube, though other components like end fitting, calandria tube, garter spring spacer also show ageing to a limited extent. Ageing effects in pressure tube are seen in the form of diametral and axial creep, corrosion, delayed hydrogen cracking and irradiation hardening. In calandria tube and garter spring spacer, creep and hardening are seen though these are not of concern in PHWRs. In end fitting, irradiation embrittlement and abrasion of sealing faces are the areas of concern. Ageing process in these components are the areas of concern. Ageing process in these components are effectively retarded by taking measures like selection of proper material, manufacturing process, control of environmental chemistry, and design modifications. Experience and information gained in various Indian and foreign reactors have been used to improve upon the design in 220 MWe reactors and have formed the basis of design for 500 MWe reactors. (author). 3 refs., 5 figs

Using systematic aging assessments to improve effectiveness of plant maintenance programs

International Nuclear Information System (INIS)

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

2003-01-01

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

Thermonuclear Propaganda: Presentations of Nuclear Strategy in the Early Atomic Age

Science.gov (United States)

2014-06-01

United States of the epoch of total war in the 20th century took responsibility for educating its population and ensuring they were behind its... comics .17 One scholar of atomic culture noted the ambiguity of the duality of the atomic age as a central tenant to building the “most powerful of all...2004). 18 Ferenc Morton Szasz, Atomic Comics : Cartoonists Confront the Nuclear World (Reno, NV: University of Nevada Press, 2012), 135. 19 Ibid

Ageing model considering effects of maintenance and working conditions

International Nuclear Information System (INIS)

Martorell, S.; Sanchez, A.; Serradell, V.

1998-01-01

Nowadays, there is some doubt about building new Nuclear Power Plants (NPPs). Instead, there is a growing interest in analyzing the possibility to extend current NPP operation where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reliability of its safety components as a function of their age along the NPP operational life. In this paper, a new age-dependent reliability model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions, both environmental and operational, of the equipment. This model may be used to support NPP life management and life extension programs by improving or optimizing surveillance and maintenance tasks using risk and cost models based on such an age-dependent reliability model. The results of the sensitivity study in the application show that the selection of the most appropriate maintenance strategy would directly depend on the previous parameters and very important differences are expected to appear under certain circumstance. (Author) 7 refs

Effects of aging in containment spray injection system of PWR reactor containment

International Nuclear Information System (INIS)

Borges, Diogo da S.; Lava, Deise D.; Affonso, Renato R.W.; Guimaraes, Antonio C.F.; Moreira, Maria de L.

2014-01-01

This paper presents a contribution to the study of the components aging process in commercial plants of Pressurized Water Reactors (PWR). The analysis is done by applying the method of Fault trees, Monte Carlo Method and Fussell-Vesely Importance Measurement. The study on the aging of nuclear plants, is related to economic factors involved directly with the extent of their operational life, and also provides important data on issues of safety. The most recent case involving the process of extending the life of a PWR plant can be seen in Angra 1 Nuclear Power Plant by investing $ 27 million in the installation of a new reactor cover. The corrective action generated an extension of the useful life of Angra 1 estimated in twenty years, and a great savings compared to the cost of building a new plant and the decommissioning of the first, if it had reached the operation time out 40 years. The extension of the lifetime of a nuclear power plant must be accompanied by special attention from the most sensitive components of the systems to the aging process. After the application of the methodology (aging analysis of Containment Spray Injection System (CSIS)) proposed in this paper, it can be seen that increasing the probability of failure of each component, due to the aging process, generate an increased general unavailability of the system that contains these basic components. The final results obtained were as expected and can contribute to the maintenance policy, preventing premature aging in nuclear power systems

Development of evaluation technique on ageing degradation of organic polymer in nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Ki Yup; Nho, Young Chang; Jung, Sung Hee; Park, Eun Hee

1999-03-01

Radiation degradation of chlorosulfonated polyethylene (CSPE, Hypalon), crosslinked polyethylene (XLPE), poly (tetrafluoroethylene) (PTFE), poly (vinylidene fluoride) (PVDF), and ethylene rubber (EPR) of experimental formulation as cable insulating and sheathing materials were performed by accelerated ageing tests and was investigated by measuring the properties such as tensile strength, elongation, insulation resistance, melting temperature, oxygen index and thermal stimulated current. The status of radiation ageing test was reviewed and the requirement of qualification of nuclear equipment was documented.

Development of evaluation technique on ageing degradation of organic polymer in nuclear power plant

International Nuclear Information System (INIS)

Kim, Ki Yup; Nho, Young Chang; Jung, Sung Hee; Park, Eun Hee

1999-03-01

Radiation degradation of chlorosulfonated polyethylene (CSPE, Hypalon), crosslinked polyethylene (XLPE), poly (tetrafluoroethylene) (PTFE), poly (vinylidene fluoride) (PVDF), and ethylene rubber (EPR) of experimental formulation as cable insulating and sheathing materials were performed by accelerated ageing tests and was investigated by measuring the properties such as tensile strength, elongation, insulation resistance, melting temperature, oxygen index and thermal stimulated current. The status of radiation ageing test was reviewed and the requirement of qualification of nuclear equipment was documented

Cable aging management

International Nuclear Information System (INIS)

Anandkumaran, A.; Sedding, H.

2012-01-01

Worldwide, due to the age of the majority of nuclear generating stations significant attention is being paid to the condition of the major components, e.g., reactor, steam generator, turbine generator, transformer, etc., with respect to relicensing and life extension. However, there is recognition that cable systems are critical to the safe, reliable and economic operation of nuclear power plants. Consequently, there is great interest in ageing management of low and medium voltage cables in the nuclear environment. Successful implementation of such programs requires an understanding of how the materials associated with cables and their accessories behave under normal operating and accident conditions. However, there is also a great need to determine the actual condition of the materials and systems in order to make rational decisions on whether or not to replace cables to ensure long term assurance of reliable operation. This proposed contribution describes an approach to cable ageing management of low and medium voltage cables based on measurements of material and electrical properties obtained in the laboratory and in the field. The effectiveness of various chemical, mechanical and electrical test methods are discussed in the context of, • Cable configuration, i.e., low or medium voltage, shielded or unshielded • Material type, i.e., PVC, XLPE, EPR, etc., • Ageing stress, i.e., electrical, thermal, radiation, thermal plus radiation, etc. These factors are key to identifying the most appropriate test method (or methods) to enable understanding of the current condition of the cable. While electrical test methods, e.g., ac withstand testing, partial discharge and various dielectric loss measurement techniques have been found effective for medium voltage cables, they are of very limited use on low voltage cables that constitute the majority of cables in nuclear power plants. This limited effectiveness is due to the lack of a well defined ground plane that is a

Effects of nuclear electromagnetic pulse (EMP) on nuclear power plants

International Nuclear Information System (INIS)

Barnes, P.R.; Manweiler, R.W.; Davis, R.R.

1977-09-01

The electromagnetic pulse (EMP) from a high-altitude nuclear detonation consists of a transient pulse of high intensity electromagnetic fields. These intense fields induce current and voltage transients in electrical conductors. Although most nuclear power plant cables are not directly exposed to these fields, the attenuated EMP fields that propagate into the plant will couple some EMP energy to these cables. The report predicts the probable effects of the EMP transients that could be induced in critical circuits of safety-related systems. It was found that the most likely consequence of EMP for nuclear plants is an unscheduled shutdown. EMP could prolong the shutdown period by the unnecessary actuation of certain safety systems. In general, EMP could be a nuisance to nuclear power plants, but it is not considered a serious threat to plant safety

Radioactive and Other Effects of Nuclear Explosion

International Nuclear Information System (INIS)

Ilijas, B.; Cizmek, A.; Prah, M.; Medakovic, S.

2008-01-01

As a result of long lasting efforts of international community to definitely ban all test nuclear explosions, the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was opened for signature in New York on 24 September 1996, when it was signed by 71 states, including Croatia. The State Office for Nuclear Safety (SONS) which, as an independent state regulatory authority has a responsibility for activities relating to nuclear safety, including the national authority over this Treaty, is actively engaged in CTBTO activities. The nuclear explosion causes a lot of effects (blast, thermal, radioactive, electromagnetic) which differs a lot in its nature, reach, lasting and other. The longest lasting aftermath is from the radioactive effects that cause a radioactive fallout and a lot of radioactive elements in the environment, created by the influence of a primary beam of radiation. Fission and fusion are the main source of radionuclide created by the nuclear explosion, and the longest lasting aftermaths are by the fission products, namely their offspring in natural disintegration chains. This can make contaminated areas inappropriate for life for very long periods. Even in the case of underground nuclear explosion (when underground cavity is formed with no effects on the surface), a leakage of radioactive gases through cracks is possible. A number of radionuclide is created by the neutron activation of elements naturally present in an environment, because a very strong neutron radiation appears in the moment of nuclear explosion. The abundance of particular radionuclide is a very much dependent of a place of performing nuclear explosion and a composition of soil or water in the vicinity.(author)

The nuclear power generation

International Nuclear Information System (INIS)

Serres, R.

1999-01-01

The French nuclear generating industry is highly competitive. The installations have an average age of fifteen years and are half way through their expected life. Nuclear power accounts for 70% of the profits of the French generating company, EDF. Nuclear generation has a minimal effect on the atmosphere and France has a level of CO 2 emissions, thought to be the main cause of the greenhouse effect, half that of Europe as a whole. The air in France is purer than in neighbouring countries, mainly because 75% of all electrical power is generated in nuclear plants and 15% in hydroelectric stations. The operations and maintenance of French nuclear power plants in the service and distribution companies out of a total of 100 000 employees in all, 90 % of whom are based in mainland France. (authors)

Quark effects in nuclear structure

International Nuclear Information System (INIS)

Watt, A.

1987-01-01

Some experimental data in nuclear structure physics cannot be explained on the assumption that nuclei consist of inert protons and neutrons. The quark model attributes a definite internal structure to nucleons and implies that their properties should change when embedded in a nucleus. This article reviews some of the experimental evidence for these effects and discusses some new aspects of nuclear structure predicted by the quark model

Energy loss effect in high energy nuclear Drell-Yan process

International Nuclear Information System (INIS)

Duan, C.G.; Song, L.H.; Huo, L.J.; Li, G.L.

2003-01-01

The energy loss effect in nuclear matter, which is a nuclear effect apart from the nuclear effect on the parton distribution as in deep-inelastic scattering process, can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of the nuclear parton distribution studied only with lepton deep-inelastic scattering experimental data, the measured Drell-Yan production cross sections for 800 GeV proton incident on a variety of nuclear targets are analyzed within the Glauber framework which takes into account the energy loss of the beam proton. It is shown that the theoretical results with considering the energy loss effect are in good agreement with the FNAL E866 data. (orig.)

Realistic effective interactions for nuclear systems

International Nuclear Information System (INIS)

Hjort-Jensen, M.; Osnes, E.; Kuo, T.T.S.

1994-09-01

A review of perturbative many-body descriptions of several nuclear systems is presented. Symmetric and asymmetric nuclear matter and finite nuclei with few valence particles are examples of systems considered. The many-body description starts with the most recent meson-exchange potential models for the nucleon-nucleon interaction, an interaction which in turn is used in perturbative schemes to evaluate the effective interaction for finite nuclei and infinite nuclear matter. A unified perturbative approach based on time-dependent perturbation theory is elaborated. For finite nuclei new results are presented for the effective interaction and the energy spectra in the mass areas of oxygen, calcium and tin. 166 refs., 83 refs., 21 tabs

Managing aging effects on used fuel dry cask for very long-term storage - 59067

International Nuclear Information System (INIS)

Chopra, Omesh; Diercks, Dwight; Ma, David; Shah, Vikram; Tam, Shiu-Wing; Fabian, Ralph; Liu, Yung; Nutt, Mark

2012-01-01

The cancellation of the Yucca Mountain repository program in the Unites States raises the prospect of very long-term storage (i.e., >120 years) and deferred transportation of used fuel at the nuclear power plant sites. While long-term storage of used nuclear fuel in dry cask storage systems (DCSSs) at Independent Spent Fuel Storage Installations (ISFSIs) is already a standard practice among U.S. utilities, recent rule-making activities of the U.S. Nuclear Regulatory Commission (NRC) indicated additional flexibility for the NRC licensees of ISFSIs and certificate holders of the DCSSs to request initial and renewal terms for up to 40 years. The proposed rule also adds a requirement that renewal applicants must provide descriptions of aging management programs (AMPs) and time-limited aging analyses (TLAAs) to ensure that the structures, systems, and components (SSCs) that are important to safety in the DCSSs will perform as designed under the extended license terms. This paper examines issues related to managing aging effects on DCSSs for very long-term storage (VLTS) of used fuels, capitalizing on the extensive knowledge and experience accumulated from the work on aging research and life cycle management at Argonne National Laboratory (ANL) over the last 30 years. The technical basis for acceptable AMPs and TLAAs is described, as are generic AMPs and TLAAs that are being developed by Argonne under the support of the U.S. Department of Energy (DOE) Used Fuel Disposition Campaign for R and D on extended long-term storage and transportation. (authors)

Surface effects of underground nuclear explosions

Energy Technology Data Exchange (ETDEWEB)

Allen, B.M.; Drellack, S.L. Jr.; Townsend, M.J.

1997-06-01

The effects of nuclear explosions have been observed and studied since the first nuclear test (code named Trinity) on July 16, 1945. Since that first detonation, 1,053 nuclear tests have been conducted by the US, most of which were sited underground at the Nevada Test Site (NTS). The effects of underground nuclear explosions (UNEs) on their surroundings have long been the object of much interest and study, especially for containment, engineering, and treaty verification purposes. One aspect of these explosion-induced phenomena is the disruption or alteration of the near-surface environment, also known as surface effects. This report was prepared at the request of the Los Alamos National Laboratory (LANL), to bring together, correlate, and preserve information and techniques used in the recognition and documentation of surface effects of UNEs. This report has several main sections, including pertinent background information (Section 2.0), descriptions of the different types of surface effects (Section 3.0), discussion of their application and limitations (Section 4.0), an extensive bibliography and glossary (Section 6.0 and Appendix A), and procedures used to document geologic surface effects at the NTS (Appendix C). Because a majority of US surface-effects experience is from the NTS, an overview of pertinent NTS-specific information also is provided in Appendix B. It is not within the scope of this report to explore new relationships among test parameters, physiographic setting, and the types or degree of manifestation of surface effects, but rather to compile, summarize, and capture surface-effects observations and interpretations, as well as documentation procedures and the rationale behind them.

Review of nuclear power plant safety cable aging studies with recommendations for improved approaches and for future work

International Nuclear Information System (INIS)

Gillen, Kenneth Todd; Bernstein, Robert

2010-01-01

Many U. S. nuclear power plants are approaching 40 years of age and there is a desire to extend their life for up to 100 total years. Safety-related cables were originally qualified for nuclear power plant applications based on IEEE Standards that were published in 1974. The qualifications involved procedures to simulate 40 years of life under ambient power plant aging conditions followed by simulated loss of coolant accident (LOCA). Over the past 35 years or so, substantial efforts were devoted to determining whether the aging assumptions allowed by the original IEEE Standards could be improved upon. These studies led to better accelerated aging methods so that more confident 40-year lifetime predictions became available. Since there is now a desire to potentially extend the life of nuclear power plants way beyond the original 40 year life, there is an interest in reviewing and critiquing the current state-of-the-art in simulating cable aging. These are two of the goals of this report where the discussion is concentrated on the progress made over the past 15 years or so and highlights the most thorough and careful published studies. An additional goal of the report is to suggest work that might prove helpful in answering some of the questions and dealing with some of the issues that still remain with respect to simulating the aging and predicting the lifetimes of safety-related cable materials.

Nuclear effects in neutrino oscillation experiments

International Nuclear Information System (INIS)

Chauhan, S.; Athar, M. Sajjad; Singh, S. K.

2011-01-01

We have studied the nuclear medium effects in the neutrino(antineutrino) induced interactions in nuclei which are relevant for present neutrino oscillation experiments in the few GeV energy region. The study is specially focused on calculating the cross sections and the event rates for atmospheric and accelerator neutrino experiments. The nuclear effects are found to be important for the quasielastic lepton production and the charged current incoherent and coherent pion production processes.

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

International Nuclear Information System (INIS)

Ellingwood, Bruce R.

1998-01-01

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

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

International Nuclear Information System (INIS)

Gunther, W.; Taylor, J.

1989-01-01

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

Effect of component aging on PWR control rod drive systems

International Nuclear Information System (INIS)

Grove, E.; Gunther, W.; Sullivan, K.

1992-01-01

An aging assessment of PWR control rod drive (CRD) systems has been completed as part of the US NRC Nuclear Plant Aging Research (NPAR) Program. The design, construction, maintenance, and operation of the Babcock ampersand Wilcox (B ampersand W), Combustion Engineering (CE), and Westinghouse (W) systems were evaluated to determine the potential for degradation as each system ages. Operating experience data were evaluated to identify the predominant failure modes, causes, and effects. This, coupled with an assessment of the materials of construction and operating environment, demonstrate that each design is subject to degradation, which if left unchecked, could affect its safety function as the plant ages. An industry survey, conducted with the assistance of EPRI and NUMARC, identified current CRD system maintenance and inspection practices. The results of this survey indicate that some plants have performed system modifications, replaced components, or augmented existing preventive maintenance practices in response to system aging. The survey results also supported the operating experience data, which concluded that the timely replacement of degraded components, prior to failure, was not always possible using existing condition monitoring techniques. The recommendations presented in this study also include a discussion of more advanced monitoring techniques, which provide trendable results capable of detecting aging

Quantum Nuclear Extension of Electron Nuclear Dynamics on Folded Effective-Potential Surfaces

DEFF Research Database (Denmark)

Hall, B.; Deumens, E.; Ohrn, Y.

2014-01-01

A perennial problem in quantum scattering calculations is accurate theoretical treatment of low energy collisions. We propose a method of extracting a folded, nonadiabatic, effective potential energy surface from electron nuclear dynamics (END) trajectories; we then perform nuclear wave packet...

The effect of aging on mitochondrial proteins in germinating soybean embryonic axes

International Nuclear Information System (INIS)

Furman, K.C.

1988-01-01

Aging-induced deterioration is a major problem associated with seed storage. Impairment of mitochondrial function is one of the first effects of aging. The composition and synthesis of nuclear and mito-coded mitochondrial proteins from soybean (Glycine max. L. Merr.) embryonic axes were studied to elucidate the cause of impaired respiratory development during germination of aged seeds. Axes excised from high vigor (HV) seeds and aged or low vigor (LV) seeds were protected from imbibition injury and germinated for various times, or excised from developing seeds, and then radiolabeled for one hour in [ 35 S]methionine. Mitochondria were then isolated and total mitochondrial protein was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), followed by quantitative staining and fluorography of labeled polypeptides. Alternatively, an original two-dimensional native-to-denaturing gel electrophoretic technique was used to analyze native protein associations and to purify a 23 kD polypeptide

Nuclear reaction inputs based on effective interactions

Energy Technology Data Exchange (ETDEWEB)

Hilaire, S.; Peru, S.; Dubray, N.; Dupuis, M.; Bauge, E. [CEA, DAM, DIF, Arpajon (France); Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

2016-11-15

Extensive nuclear structure studies have been performed for decades using effective interactions as sole input. They have shown a remarkable ability to describe rather accurately many types of nuclear properties. In the early 2000 s, a major effort has been engaged to produce nuclear reaction input data out of the Gogny interaction, in order to challenge its quality also with respect to nuclear reaction observables. The status of this project, well advanced today thanks to the use of modern computers as well as modern nuclear reaction codes, is reviewed and future developments are discussed. (orig.)

The greenhouse effect and nuclear energy

International Nuclear Information System (INIS)

Coulter, J.

1988-01-01

The author argues that nuclear power will do little to mitigate the problem of the greenhouse effect and is likely to exacerbate it. Changes since the mid 1970s illustrate the close linking of nuclear and economic growth with the associated growth of fossil fill consumption, the inability of nuclear power to substitute for fossil either technically or economically, and the greater contribution that can be made to energy availability and to reduction of carbon dioxide release by conservation

Isotope effects on nuclear shielding

International Nuclear Information System (INIS)

Hansen, P.E.

1983-01-01

This review concentrates upon empirical trends and practical uses of mostly secondary isotope effects, both of the intrinsic and equilibrium types. The text and the tables are arranged in the following fashion. The most 'popular' isotope effect is treated first, deuterium isotope effects on 13 C nuclear shielding, followed by deuterium on 1 H nuclear shieldings, etc. Focus is thus on the isotopes producing the effect rather than on the nuclei suffering the effect. After a brief treatment of each type of isotope effect, general trends are dealt with. Basic trends of intrinsic isotope effects such as additivity, solvent effects, temperature effects, steric effects, substituent effects and hyperconjugation are discussed. Uses of isotope effects for assignment purposes, in stereochemical studies, in hydrogen bonding and in isotopic tracer studies are dealt with. Kinetic studies, especially of phosphates, are frequently performed by utilizing isotope effects. In addition, equilibrium isotope effects are treated in great detail as these are felt to be new and very important and may lead to new uses of isotope effects. Techniques used to obtain isotope effects are briefly surveyed at the end of the chapter. (author)

Knowledge Management at AMEC Foster Wheeler: A Case Study on Managing ’Age Gap’ and ’Skills Gap’ in Nuclear Industry

International Nuclear Information System (INIS)

Prinja, N.

2016-01-01

Full text: This document describes the knowledge management (KM) process that has been developed at the Clean Energy business of AMEC Foster Wheeler plc to address the challenges of the “skills gap” and “age gap” that the nuclear industry is facing and to address the challenge of effectively managing the corporate knowledge within the organization and growing this to maintain class leading competencies. (author

Nuclear energy

International Nuclear Information System (INIS)

Seidel, J.

1990-01-01

This set of questions is based on an inquiry from the years 1987 to 1989. About 250 people af all age groups - primarily, however, young people between 16 and 25 years of age - were asked to state the questions they considered particularly important on the subject of nuclear energy. The survey was carried out without handicaps according to the brain-storming principle. Although the results cannot claim to be representative, they certainly reflect the areas of interest of many citizens and also their expectations, hopes and fears in connection with nuclear energy. The greater part of the questions were aimed at three topic areas: The security of nuclear power-stations, the effects of radioactivity on people and the problem of waste disposal. The book centres around these sets of questions. The introduction gives a general survey of the significance of nuclear energy as a whole. After this follow questions to do with the function of nuclear power stations, for the problems of security and waste disposal - which are dealt with in the following chapters - are easier to explain and to understand if a few physical and technical basics are understood. In the final section of the book there are questions on the so-called rejection debate and on the possibility of replacing nuclear energy with other energy forms. (orig./HP) [de

Assessment and management of ageing of major nuclear power plant components important to safety: CANDU reactor assemblies

International Nuclear Information System (INIS)

2001-02-01

At present, there are over four hundred operational nuclear power plants (NPPs) in IAEA Member States. Operating experience has shown that ineffective control of the ageing degradation of the major NPP components (e.g. caused by unanticipated phenomena and by operating, maintenance, design or manufacturing errors) can jeopardize plant safety and also plant life. Ageing in these NPPs must therefore be effectively managed to ensure the availability of design functions throughout the plant service life. From the safety perspective, this means controlling within acceptable limits the ageing degradation and wearout of plant components important to safety so that adequate safety margins remain, i.e. integrity and functional capability in excess of normal operating requirements. This TECDOC is one in a series of reports on the assessment and management of ageing of the major NPP components important to safety. The reports are based on experience and practices of NPP operators, regulators, designers, manufacturers, and technical support organizations and a widely accepted Methodology for the Management of Ageing of NPP Components Important to Safety which was issued by the IAEA in 1992. The current practices for the assessment of safety margins (fitness for service) and the inspection, monitoring, and mitigation of ageing degradation of selected components of Canada deuterium-uranium (CANDU) reactors, boiling water reactors (BWRs), pressurized water reactors (PWRs) including the Soviet designed water moderated and water cooled energy reactors (WWERs), are documented in the reports. These practices are intended to help all involved directly and indirectly in ensuring the safe operation of NPPs and also to provide a common technical basis for dialogue between plant operators and regulators when dealing with age-related licensing issues. Since the reports are written from a safety perspective, they do not address life or life-cycle management of the plant components, which

Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms

Energy Technology Data Exchange (ETDEWEB)

Weber, William J. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Zhang, Yanwen [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering

2016-09-20

This is the final report of the NEUP project “Radiation and Thermal Effects on Used Nuclear Fuel and Nuclear Waste Forms.” This project started on July 1, 2012 and was successfully completed on June 30, 2016. This report provides an overview of the main achievements, results and findings through the duration of the project. Additional details can be found in the main body of this report and in the individual Quarterly Reports and associated Deliverables of this project, which have been uploaded in PICS-NE. The objective of this research was to advance understanding and develop validated models on the effects of self-radiation from beta and alpha decay on the response of used nuclear fuel and nuclear waste forms during high-temperature interim storage and long-term permanent disposition. To achieve this objective, model used-fuel materials and model waste form materials were identified, fabricated, and studied.

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Climatic effects of nuclear war

International Nuclear Information System (INIS)

Covey, C.

1985-01-01

Global climatic consequences of a nuclear war have, until recently, been assumed to be insignificant compared with the obviously devastating direct effects from blast, heat, and short-term fallout. But a number of investigations carried out over the past few years indicate that climatic impact could actually be severe enough to threaten the global ecosystem significantly, including regions that may not have been directly involved in the war. This change in perception comes as researchers realize that the fires ignited by nuclear explosions would generate so much smoke that, even spread over a large portion of Earth's surface, densities could be high enough to block most of the sunlight normally reaching the ground. As a result, temperatures could decrease below freezing in a nuclear winter lasting weeks to months. Smoke from fires is what would make nuclear winter so severe. Of necessity, theoretical models are relied upon to estimate the climatic impact of nuclear war. The models incorporate many uncertain assumptions, particularly regarding the small-scale details of smoke production by fires

Natural versus artificial aging of nuclear power plant components

International Nuclear Information System (INIS)

Shaw, M.T.

1992-01-01

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

Widespread after-effects of nuclear war

International Nuclear Information System (INIS)

Teller, E.

1984-01-01

Radioactive fallout and depletion of the ozone layer, once believed catastrophic consequences of nuclear war, are now proved unimportant in comparison to immediate war damage. Today, ''nuclear winter'' is claimed to have apocalyptic effects. Uncertainties in massive smoke production and in meteorological phenomena give reason to doubt this conclusion. (author)

Nuclear power in an age of uncertainty. Summary

International Nuclear Information System (INIS)

1984-02-01

This report examines the future of nuclear power in the USA and what might be done to restore nuclear power as an acceptable economic energy supply option should the nation choose to do so. It describes the current technological, economic, financial and regulatory problems facing the domestic nuclear industry. It identifies what approaches - both technological and institutional - might alleviate those problems to the extent that utilities would consider new nuclear plants. The report also considers how these approaches would be viewed by all the other groups, such as investors and the general public, that influence the decisions that utilities reach on nuclear power. Finally, the report examines the international nuclear industry and discusses the implications for the US industry if no new orders are placed for 10 or 20 years

Studying radiolytic ageing of nuclear power plant electric cables with FTIR spectroscopy.

Science.gov (United States)

Levet, A; Colombani, J; Duponchel, L

2017-09-01

Due to the willingness to extend the nuclear power plants length of life, it is of prime importance to understand long term ageing effect on all constitutive materials. For this purpose gamma-irradiation effects on insulation of instrumentation and control cables are studied. Mid-infrared spectroscopy and principal components analysis (PCA) were used to highlight molecular modifications induced by gamma-irradiation under oxidizing conditions. In order to be closer to real world conditions, a low dose rate of 11Gyh -1 was used to irradiate insulations in full cable or alone with a dose up to 58 kGy. Spectral differences according to irradiation dose were extracted using PCA. It was then possible to observe different behaviors of the insulation constitutive compounds i.e. ethylene vinyl acetate (EVA), ethylene propylene diene monomer (EPDM) and aluminium trihydrate (ATH). Irradiation of insulations led to the oxidation of their constitutive polymers and a modification of filler-polymer ratio. Moreover all these modifications were observed for insulations alone or in full cable indicating that oxygen easily diffuses into the material. Spectral contributions were discussed considering different degradation mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Ageing Management of the reactor internals in Belgian nuclear units in view of Long Term Operation

International Nuclear Information System (INIS)

Gerard, R.; Bertolis, D.; Vissers, S.

2012-01-01

The reactor internals support the reactor core, distribute the coolant flow through the core, and guide and protect the rod control cluster assemblies and in-core instrumentation. Their integrity must be guaranteed in all operating and accident conditions. They are exposed to specific degradation mechanisms linked to the intense neutron irradiation, like Irradiation Assisted Stress Corrosion Cracking (IASCC) or potentially void swelling, in addition to more classical mechanisms like fatigue, wear and stress corrosion cracking. A rigorous follow-up of in-service degradation and an effective ageing management is therefore of crucial importance and contributes to the safe and economical operation of nuclear PWR units. (author)

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)

Health and environmental effects of nuclear weapons

International Nuclear Information System (INIS)

1993-01-01

This report briefly reviews previous WHO work on the health consequences of nuclear war and concentrates on current information about the effects of nuclear weapons on health, and related environmental problems. 15 refs

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

International Nuclear Information System (INIS)

Bouzaiene-Marle, L.

2005-04-01

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

Aging assessment of Westinghouse PWR and General Electric BWR containment isolation functions

Energy Technology Data Exchange (ETDEWEB)

Lee, B.S.; Travis, R.; Grove, E.; DiBiasio, A.

1996-03-01

A study was performed to assess the effects of aging on the Containment Isolation (CI) functions of Westinghouse Pressurized Water Reactors and General Electric Boiling Water Reactors. This study is part of the Nuclear Plant Aging Research (NPAR) program, sponsored by the U.S. Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. Failure data from two national databases, Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LERs), as well as plant specific data were reviewed and analyzed to understand the effects of aging on the CI functions. This study provided information on the effects of aging on component failure frequency, failure modes, and failure causes. Current inspection, surveillance, and monitoring practices were also reviewed.

Aging assessment of Westinghouse PWR and General Electric BWR containment isolation functions

International Nuclear Information System (INIS)

Lee, B.S.; Travis, R.; Grove, E.; DiBiasio, A.

1996-03-01

A study was performed to assess the effects of aging on the Containment Isolation (CI) functions of Westinghouse Pressurized Water Reactors and General Electric Boiling Water Reactors. This study is part of the Nuclear Plant Aging Research (NPAR) program, sponsored by the U.S. Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. Failure data from two national databases, Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LERs), as well as plant specific data were reviewed and analyzed to understand the effects of aging on the CI functions. This study provided information on the effects of aging on component failure frequency, failure modes, and failure causes. Current inspection, surveillance, and monitoring practices were also reviewed

Understanding aging - A key to ensuring safety

International Nuclear Information System (INIS)

Arlotto, G.A.

1985-01-01

The nuclear community has entered a period during which issues related to the advancing age of nuclear power plants will play an ever-increasing role in the decision making process for the continued safe operation of these plants, including extended safe operation beyond the presently authorized forty years. Although progress has been made toward understanding and managing this aging phenomenon, much remains to be done. This paper describes research needs directed toward: (a) systematically identifying those aging effects which could impair safety; (b) assessment of inspection and monitoring methods for detecting aging prior to loss of safety function; and (c) evaluation of effectiveness of maintenance in mitigation aging. To be successful, this research, and its ultimate application, must involve the entire nuclear community - the regulator and the regulated. It must take the advantage of operating experience, include the assessment and tests of aged equipment, and involve coordination of related activities conducted by individual utilities, reactor manufacturers, architect-engineers, equipment suppliers, utility groups that have been (or might be) established, standards-writing bodies, foreign countries, the NRC, other Government agencies, and other knowledgeable organization and persons. The implementation of this research would best be accomplished by obtaining consensus in an open forum of all interested organizations and persons

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

International Nuclear Information System (INIS)

Ramanauskiene, A.

2000-01-01

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

Ductal carcinoma in situ of the breast (DCIS) with heterogeneity of nuclear grade: prognostic effects of quantitative nuclear assessment

International Nuclear Information System (INIS)

Chapman, Judith-Anne W; Miller, Naomi A; Lickley, H Lavina A; Qian, Jin; Christens-Barry, William A; Fu, Yuejiao; Yuan, Yan; Axelrod, David E

2007-01-01

Previously, 50% of patients with breast ductal carcinoma in situ (DCIS) had more than one nuclear grade, and neither worst nor predominant nuclear grade was significantly associated with development of invasive carcinoma. Here, we used image analysis in addition to histologic evaluation to determine if quantification of nuclear features could provide additional prognostic information and hence impact prognostic assessments. Nuclear image features were extracted from about 200 nuclei of each of 80 patients with DCIS who underwent lumpectomy alone, and received no adjuvant systemic therapy. Nuclear images were obtained from 20 representative nuclei per duct, from each of a group of 5 ducts, in two separate fields, for 10 ducts. Reproducibility of image analysis features was determined, as was the ability of features to discriminate between nuclear grades. Patient information was available about clinical factors (age and method of DCIS detection), pathologic factors (DCIS size, nuclear grade, margin size, and amount of parenchymal involvement), and 39 image features (morphology, densitometry, and texture). The prognostic effects of these factors and features on the development of invasive breast cancer were examined with Cox step-wise multivariate regression. Duplicate measurements were similar for 89.7% to 97.4% of assessed image features. For the pooled assessment with ~200 nuclei per patient, a discriminant function with one densitometric and two texture features was significantly (p < 0.001) associated with nuclear grading, and provided 78.8% correct jackknifed classification of a patient's nuclear grade. In multivariate assessments, image analysis nuclear features had significant prognostic associations (p ≤ 0.05) with the development of invasive breast cancer. Texture (difference entropy, p < 0.001; contrast, p < 0.001; peak transition probability, p = 0.01), densitometry (range density, p = 0.004), and measured margin (p = 0.05) were associated with

Age-dependent reliability model considering effects of maintenance and working conditions

International Nuclear Information System (INIS)

Martorell, Sebastian; Sanchez, Ana; Serradell, Vicente

1999-01-01

Nowadays, there is some doubt about building new nuclear power plants (NPPs). Instead, there is a growing interest in analyzing the possibility to extend current NPP operation, where life management programs play an important role. The evolution of the NPP safety depends on the evolution of the reliability of its safety components, which, in turn, is a function of their age along the NPP operational life. In this paper, a new age-dependent reliability model is presented, which includes parameters related to surveillance and maintenance effectiveness and working conditions of the equipment, both environmental and operational. This model may be used to support NPP life management and life extension programs, by improving or optimizing surveillance and maintenance tasks using risk and cost models based on such an age-dependent reliability model. The results of the sensitivity study in the example application show that the selection of the most appropriate maintenance strategy would directly depend on the previous parameters. Then, very important differences are expected to appear under certain circumstances, particularly, in comparison with other models that do not consider maintenance effectiveness and working conditions simultaneously

An Effective Method For Nuclear Technology Transfer

International Nuclear Information System (INIS)

Jeon, Jan Pung

1987-01-01

Three basic entities involved in the implementation of nuclear projects are the Owner, Regulatory Authority and Nuclear Industry. Their ultimate objective is to secure the safe, reliable and economical nuclear energy. For s successful nuclear power program, the owner should maintain a good relationship with the other entities and pursue an optimization of the objectives. On the other hand, he should manage projects along the well - planned paths in order to effectively learn the nuclear technology. One of the problems in the nuclear projects of developing countries was the absence of long - term technology development program, a limited local participation and the technical incapability. For the effective technology transfer, a motivation of the technology supplier and a readiness of the recipient to accommodate such technologies are required. Advanced technology is usually developed at considerable expense with the expectation that the developer will use it in furthering his own business. Therefore, he tends to be reluctant to transfer it to the others, particularly, to the potential competitors. There is a disinclination against further technology transfer beyond the minimum contractual obligation or the requirements by Government Regulatory. So, an additional commercial incentive must be provided to the developer

Hearts and the nuclear age

International Nuclear Information System (INIS)

Wynchank, S.

1982-01-01

There are two types of nuclear cardiological investigations, one is an evaluation of myocardial perfusion and the properties of myocardial cell membranes. Thallium ion is used. The other approach is to trace a radioactive marker into the bloodstream and to observe its motion through that part of the system usually the cardiac chambers of great vessels. A third method, using labbeled molecules which participate in myocardial metabolism is now in its infancy. Nuclear medicine in cardiological application can be most relevant and there are very few problems associated with such techniques, and the costs compare very favourably with radiotherapy costs. The function and metabolism of the heart studies will enter a new era as new techniques (e.g. tomography) and new radiopharmaceuticals (e.g. marked fatty acids) become more available

Effect of dynamic strain aging on isotropic hardening in low cycle fatigue for carbon manganese steel

International Nuclear Information System (INIS)

Huang, Zhi Yong; Chaboche, Jean-Louis; Wang, Qing Yuan; Wagner, Danièle; Bathias, Claude

2014-01-01

Carbon–manganese steel A48 (French standard) is used in steam generator pipes of nuclear reactor pressure vessels at high temperatures (about 200 °C). The steel is sensitive to dynamic strain aging in monotonic tensile test and low cycle fatigue test at certain temperature range and strain rate. Its isotropic hardening behavior observed from experiments has a hardening, softening and hardening evolution with the effect of dynamic strain aging. The isotropic hardening model is improved by coupling the dislocation and dynamic strain aging theory to describe the behavior of A48 at 200 °C

Effect of dynamic strain aging on isotropic hardening in low cycle fatigue for carbon manganese steel

Energy Technology Data Exchange (ETDEWEB)

Huang, Zhi Yong, E-mail: huangzy@scu.edu.cn [Sichuan University, School of Aeronautics and Astronautics, No. 29 Jiuyanqiao Wangjiang Road, Chengdu 610064 (China); Chaboche, Jean-Louis [ONERA, DMSM, 29 avenue de la Division Lecerc, F-92320 Chatillon (France); Wang, Qing Yuan [Sichuan University, School of Aeronautics and Astronautics, No. 29 Jiuyanqiao Wangjiang Road, Chengdu 610064 (China); Wagner, Danièle; Bathias, Claude [Université ParisOuest Nanterre La Défense (France)

2014-01-01

Carbon–manganese steel A48 (French standard) is used in steam generator pipes of nuclear reactor pressure vessels at high temperatures (about 200 °C). The steel is sensitive to dynamic strain aging in monotonic tensile test and low cycle fatigue test at certain temperature range and strain rate. Its isotropic hardening behavior observed from experiments has a hardening, softening and hardening evolution with the effect of dynamic strain aging. The isotropic hardening model is improved by coupling the dislocation and dynamic strain aging theory to describe the behavior of A48 at 200 °C.

Connecting the dots, or nuclear data in the age of supercomputing

International Nuclear Information System (INIS)

Bauge, E.; Dupuis, M.; Hilaire, S.; Peru, S.; Koning, A.J.; Rochman, D.; Goriely, S.

2014-01-01

Recent increases in computing power have allowed for much progress to be made in the field of nuclear data. The advances listed below are each significant, but together bring the potential to completely change our perspective on the nuclear data evaluation process. The use of modern nuclear modeling codes like TALYS and the Monte Carlo sampling of its model parameter space, together with a code system developed at NRG Petten, which automates the production of ENDF-6 formatted files, their processing, and their use in nuclear reactor calculations, constitutes the Total Monte Carlo approach, which directly links physical model parameters with calculated integral observables like k_e_f_f. Together with the Backward-Forward Monte Carlo method for weighting samples according their statistical likelihood, the Total Monte Carlo can be applied to complete isotopic chains in a consistent way, to simultaneously evaluate nuclear data and the associated uncertainties in the continuum region. Another improvement is found in the uses of microscopic models for nuclear reaction calculations. For example, making use of QRPA excited states calculated with the Gogny interaction to solve the long standing question of the origin of the ad hoc 'pseudo-states' that are introduced in evaluated nuclear data files to account for the Livermore pulsed sphere experiments. A third advance consists of the recent optimization of the Gogny D1M effective nuclear interaction, including constraints from experimental nuclear masses at the 'beyond the mean field' level. All these advances are only made possible by the availability of vast resources of computing power, and even greater resources will allow connecting them, going continuously from the parameters of the nuclear interaction to reactor calculations. However, such scheme will surely only be usable for applications if a few fine-tuning 'knobs' are introduced in it. The values of these adjusted parameters will have to be calibrated versus

Management of life cycle and ageing at nuclear power plants: Improved I and C maintenance. Report prepared within the framework of the Technical Working Group on Nuclear Power Plant Control and Instrumentation

International Nuclear Information System (INIS)

2004-08-01

The topic of this TECDOC was originally suggested in the May 2001 meeting of the IAEA Technical Working Group on Nuclear Power Plant Control and Instrumentation (TWG NPPCI). It was then approved by the IAEA for work to begin in 2002. It originated from the remarks of the TWG members that it is now time to address the instrumentation and control (I and C) ageing issues in terms of plant life management and licence renewal. Furthermore, the nuclear industry is believed to be able to survive only if plant economy is favourable in addition to plant safety. Therefore, in dealing with I and C ageing and obsolescence, one has to consider how to proceed in addressing this question, not only from a plant operational and safety standpoint, but also in the context of plant economy in terms of the cost of electricity production, and including initial and recurring capital costs. For this important reason, consideration of new technologies, such as on-line monitoring and in situ testing methods is recommended. These can be used not only to predict the consequences of ageing, and guard against it, but also to verify equipment performance throughout the lifetime of the plant, and help establish replacement schedules for I and C equipment, and predict residual life. The basic ageing and obsolescence management process involves: Understanding the ageing and obsolescence phenomena and identifying the (potential) effects on I and C; Addressing the specific impact of these effects on the plant taking into account operational profiles and analyzing the risks; Carrying out necessary mitigating actions to counteract the effects of ageing and obsolescence. Based on the above listed activities the ageing and obsolescence management programme needs to be an iterative process. The goal of this TECDOC is to provide the latest information on ageing, obsolescence, and performance monitoring of those I and C equipment that are classified as safety equipment and/or safety-related equipment, are

Measurement of ageing effect on chloride diffusion coefficients in cementitious matrices

International Nuclear Information System (INIS)

Andrade, C.; Castellote, M.; D'Andrea, R.

2011-01-01

Most of the low-level nuclear waste disposal facilities are based in engineered multi barrier systems where reinforced concrete is one of the basic materials. The calculation of the time until steel reinforcement depassivation is a need due to the demand of prediction of the service life of concrete structures in radioactive repositories. In doing that, one of the main steps is the transport of chloride ions towards the reinforcement, as one of the most aggressive agents for the rebars in concrete is chloride ions. Ageing of concrete related to chloride penetration leads to significant decrease of the 'apparent diffusion' coefficient with time. If this effect is not considered, considerable bias can be introduced when predicting service life of reinforced concrete of repositories. Several effects have been addressed on their influence on the ageing of concrete, including the evolution with time of the concrete pore refinement, the binding of chlorides to the cement phases and to the changes of chloride 'surface concentration'. These effects have been studied in specimens made with different mixes trying to represent a wide range of mineral addition proportions. The analysis of their evolution with time has shown that the resistivity alone or the joint consideration of resistivity and binding capacity (C b /C f ), are appropriate parameters to appraise the diffusivity ageing. For practical reasons, an accelerated procedure is proposed in order to calculate ageing for short periods of time.

Effectiveness of storage practices in mitigating aging degradation during reactor layup

International Nuclear Information System (INIS)

Enderlin, W.I.

1995-09-01

One of the issues identified in the US Nuclear Regulatory Commission's Nuclear Plant Aging Research program plan is the need to understand the state of ''mothballed'' or other out-of-service equipment to ensure subsequent safe operation. Programs for proper storage and preservation of materials and components are required by NRC regulations (10 CFR 50, Appendix B). However, materials and components have been seriously degraded due to improper storage, protection, or layup, at facilities under construction as well as those with operating licenses. Pacific Northwest Laboratory has evaluated management of aging for unstarted or mothballed nuclear power plants. The investigations revealed that no uniform guidance in the industry addresses reactor layup. In each case investigated, layup was not initiated in a timely manner, primarily because of schedule uncertainty. Hence, it is reasonable to assume that this delay resulted in accelerated aging of some safety-significant structures, systems, and components (SSCs). The applicable layup process is site-specific. The reactor type, climatic setting, operational status, and materials of construction are factors that strongly dictate the layup method to be used. The adequacy of current layup practices, and hence their impact on safety-significant SSCS, is not fully understood

Aging assessment of essential HVAC chillers used in nuclear power plants

International Nuclear Information System (INIS)

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

1993-09-01

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

Biological effects of nuclear war. I. Impact on humans

International Nuclear Information System (INIS)

Harwell, M.A.; Grover, H.D.

1985-01-01

The studies of the effects of nuclear war over the last four decades have concentrated almost exclusively on immediate consequences like these, primarily because these were by far the dominant effects on humans and the environment in Hiroshima and Nagasaki. Long-term and indirect effects have not been obvious. Detailed studies of the individual detonations over Japan and of nuclear tests since then have characterized well the immediate direct effects of blast, ionizing radiation, and thermal radiation. Such studies form the bases decision makers rely on to develop nuclear policies for the major powers. But the consequences of a large-scale nuclear war cannot be so readily extrapolated from the limited experiences in Japan. In this paper the authors review how the indirect and longer-term consequences for humans and the environment are now becoming better understood. This information fundamentally changes the way a modern nuclear war should be perceived

Regulatory Practices on Ageing Management and Long Term Operation of Nuclear Power Plants in the Ibero-American Region. Results of the FORO/IAEA Programme on Nuclear and Radiation Safety in Ibero-America

International Nuclear Information System (INIS)

2014-09-01

Although the operating lifetime of a nuclear power plant was originally anticipated to be in the range of 30-40 years, 200 of the 434 currently in operation are over 30 years old. In this context, Member States have assigned high priority to continuing the operation of nuclear power plants beyond the lifetime initially planned - while also maintaining the highest safety conditions possible. It is thus essential to encourage international cooperative efforts in the development of safety regulatory practices on ageing management and long term operation. Established in 1997, the Ibero-American Forum of Radiological and Nuclear Regulatory Agencies (FORO) aims to strengthen its members' radiological and nuclear safety regulatory organizations. Through a regional network of radiological and nuclear safety regulators, States in the Ibero-American region have worked together to strengthen radiation protection for patients, to improve safety at radiation installations, to tightten controls on radioactive sources used in medicine, agriculture and industry, and to improve safety and security at nuclear power plants. Since FORO's creation, it has cooperated with the IAEA in areas of mututal interest, and a technical programme administered by the IAEA was established in 2003 and formalized in Practical Arrangements signed in 2010. This publication presents the results of the 2009-2010 FORO/IAEA project on regulatory practices on ageing management and safety considerations for extending the operating lifetime of nuclear power plants. The purpose of the project was to provide nuclear regulators in the region with guidance on regulatory criteria, assessment, regulatory inspection and periodic safety reviews relating to ageing management and long term operation of nuclear power plants. The results are presented in a set of four reports, with guidelines for FORO members and a summary report of the project. These reports contain valuable information for the development of future

Ageing implementation and refurbishment development at the IEA-R1 nuclear research reactor: a 15 years experience