On estimation of reliability of a nuclear power plant with tokamak reactor

International Nuclear Information System (INIS)

Klemin, A.I.; Smetannikov, V.P.; Shiverskij, E.A.

1982-01-01

The results of the analysis of INTOR plant reliability are presented. The first stage of the analysis consists in the calculation of the INTOR plant structural reliability factors (15 ibs main systems have been considered). For each system the failure flow parameter (W(1/h)) and operational readiness Ksub(r) have been determined which for the plant as a whole besides these factors-technological utilization coefficient Ksub(TU) and mean-cycles-between failures Tsub(o). The second stage of the reliability analysis consists in investigating methods of improving its reliability factors reratively to the one calculated at the first level stage. It is shown that the reliability of the whole plant to the most essential extent is determined by the power supply system reliability. The following as to the influence extent on the INTOR plant reliability is the cryogenic system. Calculations of the INTOR plant reliability factors have given the following values: W=4,5x10 -3 1/h. Tsub(o)=152 h, Ksub(r)=0,71, Ksub(TU)=o,4 g

Reliability methods in nuclear power plant ageing management

International Nuclear Information System (INIS)

Simola, K.

1999-01-01

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

Reliability methods in nuclear power plant ageing management

Energy Technology Data Exchange (ETDEWEB)

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

1999-07-01

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

Application of genetic algorithm for reliability allocation in nuclear power plants

International Nuclear Information System (INIS)

Yang, Joon-Eon; Hwang, Mee-Jung; Sung, Tae-Yong; Jin, Youngho

1999-01-01

Reliability allocation is an optimization process of minimizing the total plant costs subject to the overall plant safety goal constraints. Reliability allocation was applied to determine the reliability characteristics of reactor systems, subsystems, major components and plant procedures that are consistent with a set of top-level performance goals; the core melt frequency, acute fatalities and latent fatalities. Reliability allocation can be performed to improve the design, operation and safety of new and/or existing nuclear power plants. Reliability allocation is a kind of a difficult multi-objective optimization problem as well as a global optimization problem. The genetic algorithm, known as one of the most powerful tools for most optimization problems, is applied to the reliability allocation problem of a typical pressurized water reactor in this article. One of the main problems of reliability allocation is defining realistic objective functions. Hence, in order to optimize the reliability of the system, the cost for improving and/or degrading the reliability of the system should be included in the reliability allocation process. We used techniques derived from the value impact analysis to define the realistic objective function in this article

Basic research on human reliability in nuclear power plants

International Nuclear Information System (INIS)

Zhang Li; Deng Zhiliang

1996-10-01

Human reliability in nuclear power plants is one of key factors in nuclear safety and economic operation. According to cognitive science, behaviour theory and ergonomic and on the bases of human cognitive behaviour characteristics, performance shaping factors, human error mechanisms and organization management, the project systematically studied the human reliability in nuclear power plant systems, established the basic theory and methods for analyzing human factor accidents and suggested feasible approaches and countermeasures for precaution against human factor accidents and improving human reliability. The achievement has been applied in operation departments, management departments and scientific research institutions of nuclear power, and has produced guiding significance and practical value to design, operation and management in nuclear power plants. (11 refs.)

Structural reliability of atomic power plant

International Nuclear Information System (INIS)

Klemin, A.I.; Polyakov, E.F.

1980-01-01

In 1978 the first specialized technical manual ''Technique of Calculating the Structural Reliability of an Atomic Power Plant and Its Systems in the Design Stage'' was developed. The present article contains information about the main characteristics and capabilities of the manual. The manual gives recommendations concerning the calculations of the reliability of such specific systems as the reactor control and safety system, the system of instrumentation and automatic control, and safety systems. 2 refs

Cost benefit justification of nuclear plant reliability improvement

International Nuclear Information System (INIS)

El-Sayed, M.A.H.; Abdelmonem, N.M.

1986-01-01

Nuclear power costs are evaluated on the bases of general ground rules (a) vary from time to time (b) vary from country to another (c) even vary from one reactor type to another. The main objective of an electric utility is to provide the electric energy to the different consummers at the lowest possible cost with reasonable reliability level. Rapid increase of the construction costs and fuel prices in recent years have stimulated a great deal of interest in improving the reliability and productivity of new and existing power plants. One of the most important areas is the improvement of the secondary steam loop and the reactor cooling system. The method for evaluating the reliability of steam loop and cooling system utilizes the cut-set technique. The developed method can be easily used to show to what extent the overall reliability of the nuclear plant is affected by the possible failures in the steam and cooling subsystem. The cost reliability trade-off analysis is used to evaluate alternative schemes in the design with a view towards meeting a high reliability goal. Based on historical or estimated failure and repair rate, the reliability of the alternate scheme can be calculated

The importance of the reliability study for the safety operation of chemical plants. Application in heavy water plants

International Nuclear Information System (INIS)

Dumitrescu, Maria; Lazar, Roxana Elena; Preda, Irina Aida; Stefanescu, Ioan

1999-01-01

Heavy water production in Romania is based on H 2 O-H 2 S isotopic exchange process followed by vacuum isotopic distillation. The heavy water plant are complex chemical systems, characterized by an ensemble of static and dynamic equipment, AMC components, enclosures. Such equipment must have a high degree of reliability, a maximum safety in technological operation and a high availability index. Safety, reliable and economical operation heavy water plants need to maintain the systems and the components at adequate levels of reliability. The paper is a synthesis of the qualitative and quantitative assessment reliability studies for heavy water plants. The operation analysis on subsystems, each subsystems being a well-defined unit, is required by the plant complexity. For each component the reliability indicators were estimated by parametric and non-parametric methods based on the plant operation data. Also, the reliability qualitative and quantitative assessment was done using the fault tree technique. For the dual temperature isotopic exchange plants the results indicate an increase of the MTBF after the first years of operation, illustrating both the operation experience increasing and maintenance improvement. Also a high degree of availability was illustrated by the reliability studies of the vacuum distillation plant. The establishment of the reliability characteristics for heavy water plant represents an important step, a guide for highlighting the elements and process liable to failure being at the same time a planning modality to correlate the control times with the maintenance operations. This is the way to minimise maintenance, control and costs. The main purpose of the reliability study was the safety increase of the plant operation and the support for decision making. (authors)

Reliability study: maintenance facilities Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Post, B.E.; Sikorski, P.A.; Fankell, R.; Johnson, O.; Ferryman, D.S.; Miller, R.L.; Gearhart, E.C.; Rafferty, M.J.

1981-08-01

A reliability study of the maintenance facilities at the Portsmouth Gaseous Diffusion Plant has been completed. The reliability study team analyzed test data and made visual inspections of each component contributing to the overall operation of the facilities. The impacts of facilities and equipment failures were given consideration with regard to personnel safety, protection of government property, health physics, and environmental control. This study revealed that the maintenance facilities are generally in good condition. After evaluating the physical condition and technology status of the major components, the study team made several basic recommendations. Implementation of the recommendations proposed in this report will help assure reliable maintenance of the plant through the year 2000

Digital Processor Module Reliability Analysis of Nuclear Power Plant

International Nuclear Information System (INIS)

Lee, Sang Yong; Jung, Jae Hyun; Kim, Jae Ho; Kim, Sung Hun

2005-01-01

The system used in plant, military equipment, satellite, etc. consists of many electronic parts as control module, which requires relatively high reliability than other commercial electronic products. Specially, Nuclear power plant related to the radiation safety requires high safety and reliability, so most parts apply to Military-Standard level. Reliability prediction method provides the rational basis of system designs and also provides the safety significance of system operations. Thus various reliability prediction tools have been developed in recent decades, among of them, the MI-HDBK-217 method has been widely used as a powerful tool for the prediction. In this work, It is explained that reliability analysis work for Digital Processor Module (DPM, control module of SMART) is performed by Parts Stress Method based on MIL-HDBK-217F NOTICE2. We are using the Relex 7.6 of Relex software corporation, because reliability analysis process requires enormous part libraries and data for failure rate calculation

Reliability of the emergency ac-power system at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.; Baranowsky, P.W.

1982-01-01

The reliability of the emergency ac-power systems typical of several nuclear power plants was estimated, the costs of several possible improvements was estimated. Fault trees were constructed based on a detailed design review of the emergency ac-power systems of 18 nuclear plants. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports (LERs) and from operating experience information obtained from nuclear plant licensees. It was found that there are not one or two improvements that can be made at all plants to significantly increase the industry-average emergency ac-power-system reliability, but the improvements are varied and plant-specific. Estimates of the improvements in reliability and the associated cost are estimated using plant-specific designs and failure probabilities

Weibull distribution in reliability data analysis in nuclear power plant

International Nuclear Information System (INIS)

Ma Yingfei; Zhang Zhijian; Zhang Min; Zheng Gangyang

2015-01-01

Reliability is an important issue affecting each stage of the life cycle ranging from birth to death of a product or a system. The reliability engineering includes the equipment failure data processing, quantitative assessment of system reliability and maintenance, etc. Reliability data refers to the variety of data that describe the reliability of system or component during its operation. These data may be in the form of numbers, graphics, symbols, texts and curves. Quantitative reliability assessment is the task of the reliability data analysis. It provides the information related to preventing, detect, and correct the defects of the reliability design. Reliability data analysis under proceed with the various stages of product life cycle and reliability activities. Reliability data of Systems Structures and Components (SSCs) in Nuclear Power Plants is the key factor of probabilistic safety assessment (PSA); reliability centered maintenance and life cycle management. The Weibull distribution is widely used in reliability engineering, failure analysis, industrial engineering to represent manufacturing and delivery times. It is commonly used to model time to fail, time to repair and material strength. In this paper, an improved Weibull distribution is introduced to analyze the reliability data of the SSCs in Nuclear Power Plants. An example is given in the paper to present the result of the new method. The Weibull distribution of mechanical equipment for reliability data fitting ability is very strong in nuclear power plant. It's a widely used mathematical model for reliability analysis. The current commonly used methods are two-parameter and three-parameter Weibull distribution. Through comparison and analysis, the three-parameter Weibull distribution fits the data better. It can reflect the reliability characteristics of the equipment and it is more realistic to the actual situation. (author)

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

Operational experience, availability and reliability of nuclear power plants

International Nuclear Information System (INIS)

Kueffer, K.

1981-01-01

This lecture presents a survey on nuclear power production and plant performance in the Western World covering all reactor types and light-water reactors in particular and discusses key parameters such as load factors and non-availability analysis, outlines the main reasons for the reliable performance of Swiss nuclear power plants and explains the management function as applied at the Beznau Nuclear Power Station to ensure high power productivity and reliability. (orig./RW)

Using wind plant data to increase reliability.

Energy Technology Data Exchange (ETDEWEB)

Peters, Valerie A. (Sandia National Laboratories, Livermore, CA); Ogilvie, Alistair B.; McKenney, Bridget L.

2011-01-01

Operators interested in improving reliability should begin with a focus on the performance of the wind plant as a whole. To then understand the factors which drive individual turbine performance, which together comprise the plant performance, it is necessary to track a number of key indicators. Analysis of these key indicators can reveal the type, frequency, and cause of failures and will also identify their contributions to overall plant performance. The ideal approach to using data to drive good decisions includes first determining which critical decisions can be based on data. When those required decisions are understood, then the analysis required to inform those decisions can be identified, and finally the data to be collected in support of those analyses can be determined. Once equipped with high-quality data and analysis capabilities, the key steps to data-based decision making for reliability improvements are to isolate possible improvements, select the improvements with largest return on investment (ROI), implement the selected improvements, and finally to track their impact.

Improvement on reliability of control system in power plant

International Nuclear Information System (INIS)

Taguchi, S.; Mizumoto, T.; Hirose, Y.; Kashiwai, J.; Takami, I.; Shono, M.; Roji, Y.; Kizaki, S.

1985-01-01

Studies made of Japanese PWR operating experiences have revealed that failures in the control system are the primary causes of unscheduled shutdowns. An attempt has, therefore, been made to improve the reliability of the control system in order to raise the plant reliability. The following are the procedures applied to solve the issue; study of operating experiences, fault tree analysis and failure mode and effects analysis. Improvement measures are developed for the control system whose failure threatens to cause the plant trip during the plant life. These systems are the main feedwater control system, rod control system, pressurizer control system and main steam control system in the primary control system. As a result, the plant unavailability is expected to be reduced significantly by applying the improvements. The improvements are applied to the plants under construction and the operating plants in co-operation with utilities and vendors. (author)

Increasing reliability of nuclear energy equipment and at nuclear power plants

International Nuclear Information System (INIS)

Ochrana, L.

1997-01-01

The Institute of Nuclear Energy at the Technical University in Brno cooperates with nuclear power plants in increasing their reliability. The teaching programme is briefly described. The scientific research programme of the Department of Heat and Nuclear Power Energy Equipment in the field of reliability is based on a complex systematic concept securing a high level of reliability. In 1996 the Department prepared a study dealing with the evaluation of the maintenance system in a nuclear power plant. The proposed techniques make it possible to evaluate the reliability and maintenance characteristics of any individual component in a nuclear power plant, and to monitor, record and evaluate data at any given time intervals. (M.D.)

Power plant reliability calculation with Markov chain models

International Nuclear Information System (INIS)

Senegacnik, A.; Tuma, M.

1998-01-01

In the paper power plant operation is modelled using continuous time Markov chains with discrete state space. The model is used to compute the power plant reliability and the importance and influence of individual states, as well as the transition probabilities between states. For comparison the model is fitted to data for coal and nuclear power plants recorded over several years. (orig.) [de

The establish and application of equipment reliability database in Nuclear Power Plant

International Nuclear Information System (INIS)

Zheng Wei; Li He

2006-03-01

Take the case of Daya Bay Nuclear Power Plant, the collecting and handling of equipment reliability data, the calculation method of reliability parameters and the establish and application of reliability databases, etc. are discussed. The data source involved the design information of the equipment, the operation information, the maintenance information and periodically test record, etc. Equipment reliability database built on a base of the operation experience. It provided the valid tool for thoroughly and objectively recording the operation history and the present condition of various equipment of the plant; supervising the appearance of the equipment, especially the safety-related equipment, provided the very practical worth information for enhancing the safety and availability management of the equipment and insuring the safety and economic operation of the plant; and provided the essential data for the research and applications in safety management, reliability analysis, probabilistic safety assessment, reliability centered maintenance and economic management in nuclear power plant. (authors)

Technology success: Integration of power plant reliability and effective maintenance

International Nuclear Information System (INIS)

Ferguson, K.

2008-01-01

The nuclear power generation sector has a tradition of utilizing technology as a key attribute for advancement. Companies that own, manage, and operate nuclear power plants can be expected to continue to rely on technology as a vital element of success. Inherent with the operations of the nuclear power industry in many parts of the world is the close connection between efficiency of power plant operations and successful business survival. The relationship among power plant availability, reliability of systems and components, and viability of the enterprise is more evident than ever. Technology decisions need to be accomplished that reflect business strategies, work processes, as well as needs of stakeholders and authorities. Such rigor is needed to address overarching concerns such as power plant life extension and license renewal, new plant orders, outage management, plant safety, inventory management etc. Particular to power plant reliability, the prudent leveraging of technology as a key to future success is vital. A dominant concern is effective asset management as physical plant assets age. Many plants are in, or are entering in, a situation in which systems and component design life and margins are converging such that failure threats can come into play with increasing frequency. Wisely selected technologies can be vital to the identification of emerging threats to reliable performance of key plant features and initiating effective maintenance actions and investments that can sustain or enhance current reliability in a cost effective manner. This attention to detail is vital to investment in new plants as well This paper and presentation will address (1) specific technology success in place at power plants, including nuclear, that integrates attention to attaining high plant reliability and effective maintenance actions as well as (2) complimentary actions that maximize technology success. In addition, the range of benefits that accrue as a result of

Reliability of nuclear power plants and equipment

International Nuclear Information System (INIS)

1985-01-01

The standard sets the general principles, a list of reliability indexes and demands on their selection. Reliability indexes of nuclear power plants include the simple indexes of fail-safe operation, life and maintainability, and of storage capability. All terms and notions are explained and methods of evaluating the indexes briefly listed - statistical, and calculation experimental. The dates when the standard comes in force in the individual CMEA countries are given. (M.D.)

Theory model and experiment research about the cognition reliability of nuclear power plant operators

International Nuclear Information System (INIS)

Fang Xiang; Zhao Bingquan

2000-01-01

In order to improve the reliability of NPP operation, the simulation research on the reliability of nuclear power plant operators is needed. Making use of simulator of nuclear power plant as research platform, and taking the present international reliability research model-human cognition reliability for reference, the part of the model is modified according to the actual status of Chinese nuclear power plant operators and the research model of Chinese nuclear power plant operators obtained based on two-parameter Weibull distribution. Experiments about the reliability of nuclear power plant operators are carried out using the two-parameter Weibull distribution research model. Compared with those in the world, the same results are achieved. The research would be beneficial to the operation safety of nuclear power plant

Operational experience, availability and reliability of nuclear power plants

International Nuclear Information System (INIS)

Kueffer, K.

1980-01-01

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

Construction of Industrial Electron Beam Plant for Wastewater Treatment

International Nuclear Information System (INIS)

Han, B.; Kim, J.; Kim, Y.; Kim, S.; Lee, M.; Choi, J.; Ahn, S.; Makarov, I.E.; Ponomarev, A.V.

2004-01-01

A pilot plant for treating 1,000 m3/day of dyeing wastewater with e-beam has been constructed and operated since 1998 in Daegu, Korea together with the biological treatment facility. The wastewater from various stages of the existing purification process has been treated with electron beam in this plant, and it gave rise to elaborate the optimal technology of the electron beam treatment of wastewater with increased reliability at instant changes in the composition of wastewater. Installation of the e-beam pilot plant resulted in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable to reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in flow rate limit of existing facilities by 30-40%. Industrial plant for treating 10,000 m3/day, based upon the pilot experimental result, is under construction and will be finished by 2005. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government

The impact of reliability centered maintenance on plant prospects for license renewal

International Nuclear Information System (INIS)

Elliott, J.O.; Nakahara, Y.

1991-01-01

Much attention has been directed in recent years to means of extending nuclear power plant life. As many plants enter their third decade of service, the questions loom large of how to keep aging plants reliable, as well as how to assure reliability and safety to an extent sufficient to warrant license renewal at the end of the current licensing term. Concurrently the nuclear industry has seen a growing interest in reducing the cost and complexity of maintenance activities while at the same time improving plant reliability and availability. Attainment of these seemingly contradictory aims is being aided by the introduction of a maintenance philosophy developed originally by the airline industry and subsequently applied with great success both in that industry and the U.S. military services. Reliability Centered Maintenance (RCM), in its basic form, may be described as a consideration of reliability and maintenance problems from a systems level approach, allowing a focus on preservation of system functions as the aim of a maintenance program optimized for both safety and economics. It is this systematic view of plant maintenance, with the emphasis on preservation of overall functions rather than individual parts and components which sets RCM apart from past nuclear plant maintenance philosophies. It is also the factor which makes application of RCM an ideal first step in development of strategies for life extension and license renewal, both for aging plants, and for plants just beginning their first license term

Estimation of reliability on digital plant protection system in nuclear power plants using fault simulation with self-checking

International Nuclear Information System (INIS)

Lee, Jun Seok; Kim, Suk Joon; Seong, Poong Hyun

2004-01-01

Safety-critical digital systems in nuclear power plants require high design reliability. Reliable software design and accurate prediction methods for the system reliability are important problems. In the reliability analysis, the error detection coverage of the system is one of the crucial factors, however, it is difficult to evaluate the error detection coverage of digital instrumentation and control system in nuclear power plants due to complexity of the system. To evaluate the error detection coverage for high efficiency and low cost, the simulation based fault injections with self checking are needed for digital instrumentation and control system in nuclear power plants. The target system is local coincidence logic in digital plant protection system and a simplified software modeling for this target system is used in this work. C++ based hardware description of micro computer simulator system is used to evaluate the error detection coverage of the system. From the simulation result, it is possible to estimate the error detection coverage of digital plant protection system in nuclear power plants using simulation based fault injection method with self checking. (author)

In-plant application of industry experience to enhance human reliability

International Nuclear Information System (INIS)

Hannaman, G.W.; Singh, A.

1993-01-01

This paper describes the way that modern data-base computer tools can enhance the ability to collect, organize, evaluate, and use industry experience. By combining the computer tools with knowledge from human reliability assessment tools, data, and frameworks, the data base can become a tool for collecting and assessing the lessons learned from past events. By integrating the data-base system with plant risk models, engineers can focus on those activities that can enhance over-all system reliability. The evaluation helps identify technology and tools to reduce human errors during operations and maintenance. Learning from both in-plant and industry experience can help enhance safety and reduce the cost of plant operations. Utility engineers currently assess events that occur in nuclear plants throughout the world for in-plant applicability. Established computer information networks, documents, bulletins, and other information sources provide a large number of event descriptions to help individual plants benefit from this industry experience. The activities for coordinating reviews of event descriptions from other plants for in-plant applications require substantial engineering time to collect, organize, evaluate, and apply. Data-base tools can help engineers efficiently handle and sort the data so that they can concentrate on understanding the importance of the event, developing cost-effective interventions, and communicating implementation plans for plant improvement. An Electric Power Research Institute human reliability project has developed a classification system with modern data-base software to help engineers efficiently process, assess, and apply information contained in the events to enhance plant operation. Plant-specific classification of industry experience provides a practical method for efficiently taking into account industry when planning maintenance activities and reviewing plant safety

Reliability Centered Maintenance as a tool for plant life extension

International Nuclear Information System (INIS)

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

1991-01-01

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

Plant lifetime reliability and risk: Addressing today's strategies for making tomorrow's decisions

International Nuclear Information System (INIS)

Boccio, J.L.

1986-01-01

This paper presents an overview of some of the research projects, conducted for the US Nuclear Regulatory Commission (NRC) that deal with the question: How can an acceptable level of risk of a nuclear power plant be maintained throughout its design life? With a viewpoint that life extension planning for a plant can be viewed as a long-range, strategic maintenance program, the products of this research are discussed from the perspective of being elements that can tie day-to-day, plant operational tactical decisions on component/system reliability with long-range strategic maintenance goals. A common factor in addressing issues associated with design life and life extension is the issue of component aging and the reliability implications of aging. A time-dependent reliability model is described which contains some of the requisite ingredients and is built on a framework from which the component aging/component reliability issue can be addressed. By way of select examples, the additional work needed to further address plant lifetime reliability and risk is indicated

Development of high-reliability control system for nuclear power plants

International Nuclear Information System (INIS)

Asami, K.; Yanai, K.; Hirose, H.; Ito, T.

1983-01-01

In Japan, many nuclear power generating plants are in operation and under construction. There is a general awareness of the problems in connection with nuclear power generation and strong emphasis is put on achieving highly reliable operation of nuclear power plants. Hitachi has developed a new high-reliability control system. NURECS-3000 (NUclear Power Plant High-REliability Control System), which is applied to the main control systems, such as the reactor feedwater control system, the reactor recirculation control system and the main turbine control system. The NURECS-3000 system was designed taking into account the fact that there will be failures, but the aim is for the system to continue to function correctly; it is therefore a fault-tolerant system. It has redundant components which can be completely isolated from each other in order to prevent fault propagation. The system has a hierarchical configuration, with a main controller, consisting of a triplex microcomputer system, and sub-loop controllers. Special care was taken to ensure the independence of these subsystems. Since most of the redundant system failures are caused by common-mode failures and the reliability of redundant systems depends on the reliability of the common-mode parts, the aim was to minimize these parts. (author)

Reliability Analysis Techniques for Communication Networks in Nuclear Power Plant

International Nuclear Information System (INIS)

Lim, T. J.; Jang, S. C.; Kang, H. G.; Kim, M. C.; Eom, H. S.; Lee, H. J.

2006-09-01

The objectives of this project is to investigate and study existing reliability analysis techniques for communication networks in order to develop reliability analysis models for nuclear power plant's safety-critical networks. It is necessary to make a comprehensive survey of current methodologies for communication network reliability. Major outputs of this study are design characteristics of safety-critical communication networks, efficient algorithms for quantifying reliability of communication networks, and preliminary models for assessing reliability of safety-critical communication networks

Research on reliability management systems for Nuclear Power Plant

International Nuclear Information System (INIS)

Maki, Nobuo

2000-01-01

Investigation on a reliability management system for Nuclear Power Plants (NPPs) has been performed on national and international archived documents as well as on current status of studies at Idaho National Engineering and Environmental Laboratory (INEEL), US NPPs (McGuire, Seabrook), a French NPP (St. Laurent-des-Eaux), Japan Atomic Energy Research Institute (JAERI), Central Research Institute of Electric Power Industries (CRIEPI), and power plant manufacturers in Japan. As a result of the investigation, the following points were identified: (i) A reliability management system is composed of a maintenance management system to inclusively manage maintenance data, and an anomalies information and reliability data management system to extract data from maintenance results stored in the maintenance management system and construct a reliability database. (ii) The maintenance management system, which is widely-used among NPPs in the US and Europe, is an indispensable system for the increase of maintenance reliability. (iii) Maintenance management methods utilizing reliability data like Reliability Centered Maintenance are applied for NPP maintenance in the US and Europe, and contributing to cost saving. Maintenance templates are effective in the application process. In addition, the following points were proposed on the design of the system: (i) A detailed database on specifications of facilities and components is necessary for the effective use of the system. (ii) A demand database is indispensable for the application of the methods. (iii) Full-time database managers are important to maintain the quality of the reliability data. (author)

Reliability data of fire protection equipment and features in German nuclear power plants

International Nuclear Information System (INIS)

Roewekamp, M.; Riekert, T.; Sehrbrock, W.

1997-01-01

In order to perform probabilistic fire safety analyses, a comprehensive data base is needed including physical characteristics of fire compartments and their inventory, fire occurrence frequencies, technical reliability data for all fire-related equipment, human actions and human error probabilities, etc. In order to provide updated and realistic reliability data, the operational behaviour of different fire protection features in two German nuclear power plants was analysed in the framework of the study presented here. The analyses are based on the examination of reported results of the regular inspection and maintenance programs for nuclear power plants. Besides a plant specific assessment of the reliability data a generic assessment for an application as input data for fault tree analyses in the framework of probabilistic risk studies for other German plants was carried out. The analyses of failures and unavailabilities gave the impression that most of them are single failures without relevance for the plant safety. The data gained from NPPs were compared to reliability data of the German insurance companies for the same protection features installed in non-nuclear installations and to older nuclear specific reliability data. This comparison showed up a higher reliability. (orig.) [de

Study on evaluation index system of operational performance of municipal wastewater treatment plants in China

Science.gov (United States)

Xiaoxin, Zhang; Jin, Huang; Ling, Lin; Yan, Li

2018-05-01

According to the undeveloped evaluation method for the operational performance of the municipal wastewater treatment plants, this paper analyzes the policies related to sewage treatment industry based on the investigation of the municipal wastewater treatment plants. The applicable evaluation method for the operational performance was proposed from environmental protection performance, resources and energy consumption, technical and economic performance, production management and main equipment, providing a reliable basis for scientific evaluation of the operation as well as improving the operational performance of municipal wastewater treatment plant.

Summary of component reliability data for probabilistic safety analysis of Korean standard nuclear power plant

International Nuclear Information System (INIS)

Choi, S. Y.; Han, S. H.

2004-01-01

The reliability data of Korean NPP that reflects the plant specific characteristics is necessary for PSA of Korean nuclear power plants. We have performed a study to develop the component reliability DB and S/W for component reliability analysis. Based on the system, we had have collected the component operation data and failure/repair data during plant operation data to 1998/2000 for YGN 3,4/UCN 3,4 respectively. Recently, we have upgraded the database by collecting additional data by 2002 for Korean standard nuclear power plants and performed component reliability analysis and Bayesian analysis again. In this paper, we supply the summary of component reliability data for probabilistic safety analysis of Korean standard nuclear power plant and describe the plant specific characteristics compared to the generic data

Plant and control system reliability and risk model

International Nuclear Information System (INIS)

Niemelae, I.M.

1986-01-01

A new reliability modelling technique for control systems and plants is demonstrated. It is based on modified boolean algebra and it has been automated into an efficient computer code called RELVEC. The code is useful for getting an overall view of the reliability parameters or for an in-depth reliability analysis, which is essential in risk analysis, where the model must be capable of answering to specific questions like: 'What is the probability of this temperature limiter to provide a false alarm', or 'what is the probability of air pressure in this subsystem to drop below lower limit'. (orig./DG)

Reliability allocation in nuclear power plants

International Nuclear Information System (INIS)

Bari, R.A.; Cho, N.Z.; Papazoglou, I.A.

1985-01-01

The technical feasibility of allocating reliability and risk to reactor systems, subsystems, components, operations, and structures is investigated. A methodology is discussed which identifies top level risk indices as objective functions and plant-specific performance variables as decision variables. These are related by a risk model which includes cost as a top level risk index. A multiobjective optimization procedure is used to find non-inferior solutions in terms of the objective functions and the decision variables. The approach is illustrated for a boiling water reactor plant. The use of the methodology for both operating reactors and for advanced designs is briefly discussed. 16 refs., 1 fig

Reliability of emergency ac power systems at nuclear power plants

International Nuclear Information System (INIS)

Battle, R.E.; Campbell, D.J.

1983-07-01

Reliability of emergency onsite ac power systems at nuclear power plants has been questioned within the Nuclear Regulatory Commission (NRC) because of the number of diesel generator failures reported by nuclear plant licensees and the reactor core damage that could result from diesel failure during an emergency. This report contains the results of a reliability analysis of the onsite ac power system, and it uses the results of a separate analysis of offsite power systems to calculate the expected frequency of station blackout. Included is a design and operating experience review. Eighteen plants representative of typical onsite ac power systems and ten generic designs were selected to be modeled by fault trees. Operating experience data were collected from the NRC files and from nuclear plant licensee responses to a questionnaire sent out for this project

Electricity supply. Older plants' impact on reliability and air quality

International Nuclear Information System (INIS)

England-Joseph, Judy A.; Adams, Charles M.; Wood, David G.; Feehan, Daniel J.; Veal, Howard F.; Skeen, John H. III; Koenigs, Melvin J.; Lichtenfeld, David I.; Seretakis, Pauline J.

1990-09-01

Life extension of fossil fuel plants is a relatively recent phenomenon; thus, utilities have little experience to demonstrate the longer-term operating reliability of plants with an extended service life. While utility industry officials and government and industry studies express optimism that these plants will continue to operate reliably, the officials and the studies also caution that it is too soon to determine how pursuing life extension will affect the reliability of the nation's electricity supply. According to DOE, the number of fossil fuel generating units' 30 years old or older is expected to increase from about 2,500 in 1989 to roughly 3,700 in 1998, increasing such plants' share of overall generating capacity from 13 percent in 1989 to 27 percent in 1998. EPA estimates that with existing air quality requirements, fossil fuel plant emissions will increase steadily during the coming decade. Proposed acid rain control legislation, which would affect many plants that may have their service life extended, would require utilities to significantly reduce emissions by the year 2000 but would allow utilities flexibility in deciding how and where to achieve the reductions. If such legislation is enacted, utilities generally are expected to find reducing emissions from existing plants more cost-effective than replacing them and to continue extending plants' service life. Officials of DOE and utility organizations expressed concern, however, that EPA could decide, as it did for one plant in 1988, that alterations made in extending the service life of plants exempted from the Clean Air Act would result in increased emissions and thus cause the altered plants to lose their exemption. According to the officials, the additional costs of achieving the Clean Air Act's standards could discourage some life extension projects. However, such decisions by EPA could also reduce the nation's total power plant emissions by eliminating an existing incentive to retain exempt

Of plants and reliability

International Nuclear Information System (INIS)

Schneider Horst

2009-01-01

Behind the political statements made about the transformer event at the Kruemmel nuclear power station (KKK) in the summer of 2009 there are fundamental issues of atomic law. Pursuant to Articles 20 and 28 of its Basic Law, Germany is a state in which the rule of law applies. Consequently, the aspects of atomic law associated with the incident merit a closer look, all the more so as the items concerned have been known for many years. Important aspects in the debate about the Kruemmel nuclear power plant are the fact that the transformer is considered part of the nuclear power station under atomic law and thus a ''plant'' subject to surveillance by the nuclear regulatory agencies, on the one hand, and the reliability under atomic law of the operator and the executive personnel responsible, on the other hand. Both ''plant'' and ''reliability'' are terms focusing on nuclear safety. Hence the question to what extent safety was affected in the Kruemmel incident. The classification of the event as 0 = no or only a very slight safety impact on the INES scale (INES = International Nuclear Event Scale) should not be used to put aside the safety issue once and for all. Points of fact and their technical significance must be considered prior to any legal assessment. Legal assessments and regulations are associated with facts and circumstances. Any legal examination is based on the facts as determined and elucidated. Any other procedure would be tantamount to an inadmissible legal advance conviction. Now, what is the position of political statements, i.e. political assessments and political responsibility? If everything is done the correct way, they come at the end, after exploration of the facts and evaluation under applicable law. Sometimes things are handled differently, with consequences which are not very helpful. In the light of the provisions about the rule of law as laid down in the Basic Law, the new federal government should be made to observe the proper sequence of

The reliability of nuclear power plant safety systems

International Nuclear Information System (INIS)

Susnik, J.

1978-01-01

A criterion was established concerning the protection that nuclear power plant (NPP) safety systems should afford. An estimate of the necessary or adequate reliability of the total complex of safety systems was derived. The acceptable unreliability of auxiliary safety systems is given, provided the reliability built into the specific NPP safety systems (ECCS, Containment) is to be fully utilized. A criterion for the acceptable unreliability of safety (sub)systems which occur in minimum cut sets having three or more components of the analysed fault tree was proposed. A set of input MTBF or MTTF values which fulfil all the set criteria and attain the appropriate overall reliability was derived. The sensitivity of results to input reliability data values was estimated. Numerical reliability evaluations were evaluated by the programs POTI, KOMBI and particularly URSULA, the last being based on Vesely's kinetic fault tree theory. (author)

Trade-offs in size, quantity and reliability of generalized nuclear power plants

International Nuclear Information System (INIS)

Hill, D.; Mubayi, V.

1987-01-01

In the 1960's and 1970's, there was rapid growth in the size of newly started nuclear power plants because of the anticipated advantages of increasing scale. Any such advantages were overwhelmed by the complications that arose with long construction times, and attention is now being given to a ''second generation'' of smaller plants of new design. Providing the same production capacity will require larger numbers of plants if they are smaller. Although it seems to have received little attention previously, there should be compensating economies due to ''learning curve'' effects in the manufacture of multiple units of standardized designs (Hill 1983). Moreover, the use of a large number of smaller units increases the overall system reliability. On balance, however, it is not clear how scale, quantity, and reliability considerations interact to determine optimal plant size. The purpose of this paper is to begin examining the size-quantity tradeoff taking into account scale effects, the manufacturing learning curve, plant availability, and system reliability

Reliability programs for nuclear power plants. Regulatory standard S-98 revision 1

International Nuclear Information System (INIS)

2005-07-01

The purpose of this regulatory standard is to help assure, in accordance with the purpose of the Nuclear Safety and Control Act (NSCA), that a licensee who constructs or operates a nuclear power plant (NPP) develops and implements a reliability program that assures that the systems important to safety at the plant can and will meet their defined design and performance specifications at acceptable levels of reliability throughout the lifetime of the facility. This regulatory standard describes the requirements of a reliability program for a nuclear power plant. The licensee shall implement the requirements described in this regulatory standard when a condition of a licence or other legally enforceable instrument so requires.(author)

Quality assurance/quality control, reliability and availability of nuclear power plants

International Nuclear Information System (INIS)

Kueffer, K.

1981-01-01

In a first part this lectures will present a survey on nuclear power production and plant performance in the Western World and discuss key parameters such as load factors and non-availability. Some main reasons for reliable performance of nuclear power plants are given. The second part of this lecture deals with the question how quality assurance and quality control measures do directly influence plant reliability, availability and, thus, economy. Derived from worldwide experience gained from operating nuclear power plants, it may be concluded that the implementation of an overall quality assurance programme does not only satisfy safety requirements set forth by the nuclear regulatory bodies, but has also a considerable impact on plant reliability and availability. A positive effect on these figures will be achieved if the established quality assurance programme provides for a coordinated approach to all activities affecting quality. It is discussed how the quality of a product should be controlled and what kind of quality assurance measures by performed examples are given to demonstrate that the expenditure for maintenance work on components will decrease if planned and systematic quality assurance actions have been implemented during all procurement stages. (orig./RW)

Optimization of redundancy by using genetic algorithm for reliability of plant protection system

International Nuclear Information System (INIS)

Yoo, D. W.; Seong, S. H.; Kim, D. H.; Park, H. Y.; Gu, I. S.

2000-01-01

The design and development of a reliable protection system has been becoming a key issue in industry field because the reliability of system is considered as an important factor to perform the system's function successfully. Plant Protection System(PPS) guarantees the safety of plant by accident detection and control action against the transient conditions of plant. This paper presents the analysis of PPS reliability and the formal problem statement about optimal redundancy based on the reliability of PPS. And the optimization problem is solved by genetic algorithm. The genetic algorithm is a useful tool to solve the problems, in the case of large searching, complex gradient, existence local minimum. The effectiveness of the proposed optimization technique is proved by the target reliability of one channel of PPS, using the failure rate based on the MIL-HDBK-217

Collection and treatment of reliability data for nuclear plants

International Nuclear Information System (INIS)

McHugh, B.

1973-09-01

This paper describes some of the results achieved with the Argus data bank at the Institution of Thermal Power Engineering at the Chalmers University of Technology. This data bank, or rather data collection system, has been established to cover nuclear activities the world over. The system comprises in essence a number of data files. The prime files are those containing the basic data on the various plants - plant size and type, country and NSSS supplier and an indication of plantstatus. Further files contain plant design data and parameters and all available information on construction as commissioning timetables. To cover the operation of plant two files have been established. One file, which is updated on a monthly basis, contains power production statistics. The other file contains failure data. In this file are recorded the time and duration of plant shutdown together with the primary reason (s) for this. (M.S.)

Reliability of diesel generators in the Finnish and Swedish nuclear power plants

International Nuclear Information System (INIS)

Pulkkinen, U.; Huovinen, T.; Norros, L.; Vanhala, J.

1989-10-01

Diesel generators are used as emergency AC-power sources in nuclear power plants and they produce electric power for other emergency systems during accidents in which offsite power is lost. The reliability of diesel generators is thus of major concern for overall safety of nuclear power plants. In this study we consider the reliability of diesel generators in the Swedish and Finnish nuclear power plants on the basis of collected operational experience. We classify the occurred failures according to their functional criticality, type and cause. The failures caused by human errors in maintenance and testing are analysed in detail. We analyse also the reliability of the diesel generator subsystems. Further, we study the effect of surveillance test and the type of test on the reliability. Finally we construct an unavailability model for single diesel generator unit and discuss the findings of the study giving some practical recommendations

Reliability centred maintenance of nuclear power plant facilities

International Nuclear Information System (INIS)

Kovacs, Zoltan; Novakova, Helena; Hlavac, Pavol; Janicek, Frantisek

2011-01-01

A method for the optimization of preventive maintenance nuclear power plant equipment, i.e. reliability centred maintenance, is described. The method enables procedures and procedure schedules to be defined such as allow the maintenance cost to be minimized without compromising operational safety or reliability. Also, combinations of facilities which remain available and ensure reliable operation of the reactor unit during the maintenance of other pieces of equipment are identified. The condition-based maintenance concept is used in this process, thereby preventing unnecessary operator interventions into the equipment, which are often associated with human errors. Where probabilistic safety assessment is available, the most important structures, systems and components with the highest maintenance priority can be identified. (orig.)

Reliability Analysis Study of Digital Reactor Protection System in Nuclear Power Plant

International Nuclear Information System (INIS)

Guo, Xiao Ming; Liu, Tao; Tong, Jie Juan; Zhao, Jun

2011-01-01

The Digital I and C systems are believed to improve a plants safety and reliability generally. The reliability analysis of digital I and C system has become one research hotspot. Traditional fault tree method is one of means to quantify the digital I and C system reliability. Review of advanced nuclear power plant AP1000 digital protection system evaluation makes clear both the fault tree application and analysis process to the digital system reliability. One typical digital protection system special for advanced reactor has been developed, which reliability evaluation is necessary for design demonstration. The typical digital protection system construction is introduced in the paper, and the process of FMEA and fault tree application to the digital protection system reliability evaluation are described. Reliability data and bypass logic modeling are two points giving special attention in the paper. Because the factors about time sequence and feedback not exist in reactor protection system obviously, the dynamic feature of digital system is not discussed

ASCERTAINMENT OF ELECTRIC-SUPPLY SCHEMES RELIABILITY FOR THE ATOMIC POWER PLANT AUXILIARIES

Directory of Open Access Journals (Sweden)

A. L. Starzhinskij

2015-01-01

Full Text Available The paper completes ascertainment of electrical-supply scheme reliability for the auxiliaries of a nuclear power plant. Thereat the author considers the system behavior during the block normal operation, carrying out current maintenance, and capital repairs in combination with initiating events. The initiating events for reactors include complete blackout, i.e. the loss of outside power supply (normal and reserve; emergency switching one of the working turbogenerators; momentary dumping the normal rating to the level of auxiliaries with seating the cutout valve of one turbo-generator. The combination of any initiating event with the repairing mode in case of one of the system elements failure should not lead to blackout occurrence of more than one system of the reliable power supply. This requirement rests content with the help of the reliable power supply system self-dependence (electrical and functional and the emergency power-supply operational autonomy (diesel generator and accumulator batteries.The reliability indicators of the power supply system for the nuclear power plant auxiliaries are the conditional probabilities of conjoined blackout of one, two, and three sections of the reliable power supply conditional upon an initiating event emerging and the blackout of one, two, and three reliable power-supply sections under the normal operational mode. Furthermore, they also are the blackout periodicity of one and conjointly two, three, and four sections of normal operation under the block normal operational mode. It is established that the blackout of one bus section of normal operation and one section of reliable power-supply system of the auxiliaries that does not lead to complete blackout of the plant auxiliaries may occur once in three years. The probability of simultaneous power failure of two or three normal-operation sections and of two reliable power-supply sections during the power plant service life is unlikely.

System 80+ Design and Licensing : Improving Plant Reliability

International Nuclear Information System (INIS)

Newman, Robert E.

1989-01-01

The U. S. nuclear industry is striving to improve plant reliability and availability through improved plant design, component designs and plant maintenance. In an effort to improve safety and to demonstrate that commercial nuclear power is economically competitive with other energy sources, the utilities, nuclear vendors, architect engineers and constructors, and component suppliers are all participating in an industry-wide effort to develop improved Light Water Reactor (LWR) designs that are based upon the many years of successful LWR operation. In an age when the world faces the environmental pressures of the greenhouse effect and acid rain, electricity generated from nuclear energy must play an increasing role in the energy picture of Korea, the United States and the rest of the world. This paper discusses the plant availability requirement that has been established by the industry-wide effort mentioned above. After briefly describing Combustion Engineering's program for development of the System 80 Plus standard design and the participation of the Korea Advanced Energy Research Institute (KAERI) in the program, the paper then describes the design features that are being incorporated into System 80+. The industry ALRR Program has established a very ambitious criterion of 87% for the plant availability of future nuclear units. To satisfy such a requirement, the next generation of nuclear plants will include a great many design improvements that reflect the hundreds of years of operating experience that we have accrued. C-ESA's System 80+ will include a number of design changes that improve operating margins and make the plant easier to operate and maintain. Not surprisingly, there is a great deal of overlap between improved safety and improved reliability. In the end, our design will satisfy the future needs of the utilities, the regulators, and the public. C-E is very pleased that KAERI is working with US to achieve these important goals

Reliability database development and plant performance improvement effort at Korea Hydro and Nuclear Power Co

International Nuclear Information System (INIS)

Oh, S. J.; Hwang, S. W.; Na, J. H.; Lim, H. S.

2008-01-01

Nuclear utilities in recent years have focused on improved plant performance and equipment reliability. In U.S., there is a movement toward process integration. Examples are INPO AP-913 equipment reliability program and the standard nuclear performance model developed by NEI. Synergistic effect from an integrated approach can be far greater than as compared to individual effects from each program. In Korea, PSA for all Korean NPPs (Nuclear Power Plants) has been completed. Plant performance monitoring and improvement is an important goal for KHNP (Korea Hydro and Nuclear Power Company) and a risk monitoring system called RIMS has been developed for all nuclear plants. KHNP is in the process of voluntarily implementing maintenance rule program similar to that in U.S. In the future, KHNP would like to expand the effort to equipment reliability program and to achieve highest equipment reliability and improved plant performance. For improving equipment reliability, the current trend is moving toward preventive/predictive maintenance from corrective maintenance. With the emphasis on preventive maintenance, the failure cause and operation history and environment are important. Hence, the development of accurate reliability database is necessary. Furthermore, the database should be updated regularly and maintained as a living program to reflect the current status of equipment reliability. This paper examines the development of reliability database system and its application of maintenance optimization or Risk Informed Application (RIA). (authors)

Insights from a reliability review of digital plant protection system

International Nuclear Information System (INIS)

Kim, I.S.; Hwang, S.W.; Kim, B.S.; Jeong, C.H.; Oh, S.H.

2001-01-01

The full text follows: As part of the design efforts for Ulchin nuclear power plant units 5 and 6 of Korea, a reliability analysis of digital plant protection system (DPPS) was performed by ABB-CE. An independent review of the DPPS reliability analysis was undertaken by Hanyang University to assist Korea Institute of Nuclear Safety (KINS), the nuclear regulatory body of Korea, in evaluating the design acceptability of the digital system. The DPPS is designed to encompass both reactor trip function and ESFAS (engineered safety feature actuation system) initiation function. The major methods used by the ABB-CE to assess the Ulchin 5-6 DPPS reliability are failure mode and effect analysis (FMEA) and fault tree analysis. Hence, our independent review was conducted focusing on: -) the establishment of review criteria based on various sources, such as the standard review plan of KINS, 10CFR50 Appendix A, IEEE standards 279, 577, and 603; -) the suitability of the FMEA and fault tree analysis for the Ulchin 5-6 DPPS, including the specific methods used (e.g., for human reliability analysis and common-cause failure analysis), the assumptions made (e.g., with respect to test frequency and watchdog timer coverage), and the data employed (e.g., CCF parameter, human error probability, and processor failure rate); and -) the design acceptability of the DPPS especially as compared to the analog plant protection system from a reliability and safety perspective. The paper shall also discuss key issues requiring further in-depth investigation, such as reliability of programmable logic controllers (PLCs), coverage factor of watchdog timers, and susceptibility of redundant digital units to common cause failure. Sensitivity analyses were carried out to investigate the impact of several parameters of special interest, like the coverage factor of watchdog timer and human error probability (e.g. an operator error to manually trip the reactor, or to mis-calibrate the trip parameters) on

Reliability analysis of safety systems of nuclear power plant and utility experience with reliability safeguarding of systems during specified normal operation

International Nuclear Information System (INIS)

Balfanz, H.P.

1989-01-01

The paper gives an outline of the methods applied for reliability analysis of safety systems in nuclear power plant. The main tasks are to check the system design for detection of weak points, and to find possibilities of optimizing the strategies for inspection, inspection intervals, maintenance periods. Reliability safeguarding measures include the determination and verification of the broundary conditions of the analysis with regard to the reliability parameters and maintenance parameters used in the analysis, and the analysis of data feedback reflecting the plant response during operation. (orig.) [de

Future of structural reliability methodology in nuclear power plant technology

Energy Technology Data Exchange (ETDEWEB)

Schueeller, G I [Technische Univ. Muenchen (Germany, F.R.); Kafka, P [Gesellschaft fuer Reaktorsicherheit m.b.H. (GRS), Garching (Germany, F.R.)

1978-10-01

This paper presents the authors' personal view as to which areas of structural reliability in nuclear power plant design need most urgently to be advanced. Aspects of simulation modeling, design rules, codification and specification of reliability, system analysis, probabilistic structural dynamics, rare events and particularly the interaction of systems and structural reliability are discussed. As an example, some considerations of the interaction effects between the protective systems and the pressure vessel are stated. The paper concludes with recommendation for further research.

Increasing Water System Efficiency with Ultrafiltration Pre-treatment in Power Plants

International Nuclear Information System (INIS)

Majamaa, Katariina; Suarez, Javier; Gasia Eduard

2012-09-01

Water demineralization with reverse osmosis (RO) membranes has a long and successful history in water treatment for power plants. As the industry strives for more efficient, reliable and compact water systems, pressurized hollow-fiber ultrafiltration (UF) has become an increasingly appealing pre-treatment technology. Compared to conventional, non- membrane based pretreatments, ultrafiltration offers higher efficiency in the removal of suspended solids, microorganisms and colloidal matter, which are all common causes for operational challenges experienced in the RO systems. In addition, UF is more capable of handling varying feed water qualities and removes the risk of particle carry-over often seen with conventional filtration techniques. Ultrafiltration is a suitable treatment technology for various water types from surface waters to wastewater, and the more fluctuating or challenging the feed water source is, the better the benefits of UF are seen compared to conventional pretreatments. Regardless of the feed water type, ultrafiltration sustains a constant supply of high quality feed water to downstream RO, allowing a more compact and cost efficient RO system design with improved operational reliability. A detailed focus on the design and operational aspects and experiences of two plants is provided. These examples demonstrate both economical UF operation and tangible impact of RO process improvement. Experience from these plants can be leveraged to new projects. (authors)

Designing reliable wireless sensor network for nuclear power plant

International Nuclear Information System (INIS)

Fujiwara, Takeshi; Takahashi, Hiroyuki

2007-01-01

This study proposes an innovative method for the monitoring the nuclear power plant. In this field, false detection of the trouble, both 'false negative' and 'false positive' will become a serious problem. In the other hand, since nuclear power plant is such a complicated system, wireless is required for implementing into real field. Considering these backgrounds, we propose a new reliable health monitoring system for nuclear power plant. This is based on an idea, 'a network on a network', such as 'wireless global network' on 'local network with self-maintenance function.' (author)

Verification of practicability of quantitative reliability evaluation method (De-BDA) in nuclear power plants

International Nuclear Information System (INIS)

Takahashi, Kinshiro; Yukimachi, Takeo.

1988-01-01

A variety of methods have been applied to study of reliability analysis in which human factors are included in order to enhance the safety and availability of nuclear power plants. De-BDA (Detailed Block Diagram Analysis) is one of such mehtods developed with the objective of creating a more comprehensive and understandable tool for quantitative analysis of reliability associated with plant operations. The practicability of this method has been verified by applying it to reliability analysis of various phases of plant operation as well as evaluation of enhanced man-machine interface in the central control room. (author)

Quality assurance requirements for the reliability of nuclear power plants in developing countries

International Nuclear Information System (INIS)

Bhutta, S.M.

1978-01-01

Quality Assurance (QA) has not been taken very seriously in developing countries despite their having significant nuclear power programmes. This may affect plant reliability and demands that urgent and serious attention be given to the development and implementation of Quality Assurance programmes according to local conditions. Confusion has been created by the differences in definitions and interpretations of terminologies of Quality Assurance and Control. Problems have been aggravated by the lack of clearly defined responsibilities and accountabilities during the projects execution phases of site selection, data collection, design, equipment fabrication and construction, etc. Therefore, reliability of nuclear power plants in developing countries is relatively low. But whenever some programme of QA has been implemented it has helped to improve the plant performance. This is highlighted in this paper by the practical examples for the experience of Karachi Nuclear Power Plant whose forced outages have been reduced by over a half within a period of 3 years. In view of the benefits, a QA programme for Chashma Nuclear Power Project has also been initiated. In this paper urgency is emphasized for the establishment and implementation of a formal QA programme in the developing countries if the reactor suppliers and purchasers both want to ensure higher reliability of their plants. The best way that management can play its role effectively is by setting up a strong QA organization with local personnel, thus helping to attain self-reliance and higher reliability during plant operation. (author)

The contribution of quality assurance to safety and reliability in nuclear power plants

International Nuclear Information System (INIS)

Raisic, N.

1978-01-01

The potential contribution of quality assurance to nuclear power plant safety and reliability is analysed. An attempt is made to establish a relationship between quality and reliability. The reliability may be expressed in quantitative terms as ''the probability that an item will perform a required function for a stated period of time''. Quality, however, cannot be expressed in simple quantitative terms but only as a set of required properties which an item should have for a specific application. The achievement of quality and additional reliability objectives is a task of project activities such as design, construction, installation, operation, etc. The elements of a quality assurance system and its functions in nuclear power projects are presented in some detail. Confidence in plant quality, which should be a basis for the regulatory body issuing the construction permit or operation licence, should be based on the capability of quality assurance activities to prevent errors and correct deficiencies in nuclear power plants. An analysis is made of those errors in plant design, manufacture, construction and operation which contribute most frequently to plant outages. It is concluded that these errors can be avoided or corrected by strict adherence to quality assurance principles and by the efficient functioning of quality assurance systems. In fact, quality assurance may be considered an effective defence against common cause failures originating in errors in the design, manufacture, installation or operation of a nuclear power plant

Trial application of reliability technology to emergency diesel generators at the Trojan Nuclear Power Plant

International Nuclear Information System (INIS)

Wong, S.M.; Boccio, J.L.; Karimian, S.; Azarm, M.A.; Carbonaro, J.; DeMoss, G.

1986-01-01

In this paper, a trial application of reliability technology to the emergency diesel generator system at the Trojan Nuclear Power Plant is presented. An approach for formulating a reliability program plan for this system is being developed. The trial application has shown that a reliability program process, using risk- and reliability-based techniques, can be interwoven into current plant operational activities to help in controlling, analyzing, and predicting faults that can challenge safety systems. With the cooperation of the utility, Portland General Electric Co., this reliability program can eventually be implemented at Trojan to track its effectiveness

Medicinal Plants for the Treatment of Acne Vulgaris: A Review of Recent Evidences.

Science.gov (United States)

Nasri, Hamid; Bahmani, Mahmoud; Shahinfard, Najmeh; Moradi Nafchi, Atefeh; Saberianpour, Shirin; Rafieian Kopaei, Mahmoud

2015-11-01

Acne vulgaris affects about 85% of teenagers and may continue to adulthood. There are about two million visits to physicians per year for teenagers and the direct cost of acne treatment in the US exceeds $1 billion per year. A wide variety of treatment regimens exist for acne vulgaris including benzoil peroxide, retinoids, isotretinoids, keratolytic soaps, alpha hydroxy acids, azelaic acid, salicilic acid as well as hormonal, anti-androgen or antiseborrheic treatments. However, none of these methods is free of side effects and their exact role in therapy is not clear. In this paper apart from presenting the possible causes of acne vulgaris and its available drugs, recently published papers about medicinal plants used in the treatment of acne vulgaris were reviewed. Consumption of alternative and complementary medicine, including medicinal plants, is increasing and is common amongst patients affected by acne and infectious skin diseases. Medicinal plants have a long history of use and have been shown to possess low side effects. These plants are a reliable source for preparation of new drugs. Many plants seem to have inhibitory effects on the growth of bacteria, fungi and viruses in vitro. However, there are a few clinical evidences about the effectiveness and safety of these plants in the treatment of acne and other skin infections.

Health hazards related to Soba sewage treatment plant, Sudan

Directory of Open Access Journals (Sweden)

Rasha Osman Abdelwahab Abdelmoneim

2017-12-01

Full Text Available The aim of this study was to determine the health hazards acquired by the residents nearby Soba sewage treatment plant. A descriptive cross-sectional study was carried out in Soba locality, Khartoum, Sudan. An interviewer-administrated questionnaire was assigned to 462 residents of the area living in four geographically distributed squares around the sewage plant. The data was analyzed in SPSS; Cronbach’s alpha reliability scale of measurement was used to check the internal validity of six variables related to the quality of life. A logistic regression analysis was used to assess the relationship between the health hazards and the quality of life. Among the 462 residents, difficulty in breathing (37.9% and nausea (37.2 were the principal health hazards. Moreover, the residents had a satisfactory level of awareness (88.7% about the health hazards. The utmost impact on the quality of life was psychological (97.2%. It was statistically correlated with the reported factors, which impacted the quality of life in the district as revealed by the Cronbach’s alpha reliability test with absenteeism (P=0.026, disability (P=0.014, socialization (P=0.032 and death (P=0.016. A logistic regression analysis revealed chemical hazards had a statistically significant association (P<0.05 with quality of life of the residents of Soba district. The study strongly entails the fact that sewage treatment plants crave exceptional consideration from the concerned responsible authorities, together with the fact that the evolved health threats should be confronted with immense responsibility as soon as possible.

The development of specific reliability database for a Korean Nuclear Power Plant

International Nuclear Information System (INIS)

Park, S.K.; Park, B.L.; Kim, M.R.; Jeong, B.H.; Kwon, J.J.

2001-01-01

The object of this study is to develop reliability database for PSA application such as failure rate for safety related components, test and maintenance unavailability and common cause failure factors except for initiating event frequencies during the period of 10 years from 1990 to 1999. In this study we developed plant-specific reliability database for PSA (Probabilistic Safety Assessment) application and compared it with generic reliability database developed in the US such as EPRI-URD, IEEE-500, NUCLARR etc, in the component type basis. We have found that there are some general differences in the component failure rate and test and maintenance unavailability. We described the characteristics of differences for some important component types. We also analyzed the reasons for the differences in the aspect of maintenance terms such as maintenance policy and maintenance practice. We found that maintenance terms are important factors for the numbers of plant-specific reliability database. (author)

Identification and Control of Nutrient Removing Processes in Wastewater Treatment Plants

DEFF Research Database (Denmark)

Nielsen, Marinus K.; Madsen, Henrik; Carstensen, Niels Jacob

1994-01-01

the possibility of using statistical methods for identifying dynamical models for the biological processes. These models can then be used for simulating various control strategies and the parameters of the controllers can be found by off-line optimization. Simulation studies have shown that considerable savings......Today the use of on-line control for wastewater treatment plants is very low. A main reason is the lack of quality of the data, and the fact that more sophisticated control strategies must be based on a model of the dynamics of the biological processes. This paper discusses the historical reasons...... for the limited use of modern control strategies for wastewater treatment plants. Today, however, on-line nutrient sensors are more reliable. In the present context the use of on-line monitored values of ammonia, nitrate and phosphate from a full scale plant are used as the background for discussing...

Development of reliability program for emergency diesel generators in domestic nuclear power plants

International Nuclear Information System (INIS)

Kim, Young Ho; Jung, Hyun Jong; Choi, Kwang Hee; Hong, Seoung Yeul

2001-01-01

Surveillance tests of Emergency Diesel Generators (EDGs) in Nuclear Power Plants (NPPs) have been conducted periodically to verify the reliability and integrity of the EDGs, however, it was found that these surveillance methods were so conservative and severe as to accelerate the degradation of the EDGs. Hence, new regulatory guideline, Reg. Guide 1.9 Rev. 3, was established by the U.S. NRC to resolve these problems. But it requires the additional implementation of reliability program of the EDGs to improve the actual reliability of them. In Korea, the EDGs of Yonggwang nuclear units 3 and 4 were the first plant applying new Reg. guide 1.9 rev.3 and implementing EDG reliability program. Furthermore it is expected that new guideline for the EDGs will be applied to other EDGs of Korean NPPs. In this paper, this reliability program is described, and it can be used as a reference for other EDGs in Korean NPPs

A study in the reliability analysis method for nuclear power plant structures (I)

Energy Technology Data Exchange (ETDEWEB)

Oh, Byung Hwan; Choi, Seong Cheol; Shin, Ho Sang; Yang, In Hwan; Kim, Yi Sung; Yu, Young; Kim, Se Hun [Seoul, Nationl Univ., Seoul (Korea, Republic of)

1999-03-15

Nuclear power plant structures may be exposed to aggressive environmental effects that may cause their strength and stiffness to decrease over their service life. Although the physics of these damage mechanisms are reasonably well understood and quantitative evaluation of their effects on time-dependent structural behavior is possible in some instances, such evaluations are generally very difficult and remain novel. The assessment of existing steel containment in nuclear power plants for continued service must provide quantitative evidence that they are able to withstand future extreme loads during a service period with an acceptable level of reliability. Rational methodologies to perform the reliability assessment can be developed from mechanistic models of structural deterioration, using time-dependent structural reliability analysis to take loading and strength uncertainties into account. The final goal of this study is to develop the analysis method for the reliability of containment structures. The cause and mechanism of corrosion is first clarified and the reliability assessment method has been established. By introducing the equivalent normal distribution, the procedure of reliability analysis which can determine the failure probabilities has been established. The influence of design variables to reliability and the relation between the reliability and service life will be continued second year research.

Reliability of microcircuits in nuclear power plants

International Nuclear Information System (INIS)

Cross, P.M.; Taplin, R.C.

1986-06-01

The reliability problems associated with modernizing control systems in nuclear power plants, particularly by using new technology microcircuits, are discussed and twelve problem areas identified. These are: new technology introduction; variability in manufacture; derating necessities; distributed systems; use of redundancy; electrostatic discharge damage; electromagnetic interference; nuclear radiation; thermal effects; contamination, including humidity; mechanical effects, including vibration; and testing. Recommendations for the AECB are given in each area. Guidelines are given for the design, procurement, installation, operation and maintenance stages of use. Recommendations for further work are given

Reliability analyses of safety systems for WWER-440 nuclear power plants

International Nuclear Information System (INIS)

Dusek, J.; Hojny, V.

1985-01-01

The UJV in Rez near Prague studied the reliability of the system of emergency core cooling and of the system for suppressing pressure in the sealed area of the nuclear power plant in the occurrence of a loss-of-coolant accident. The reliability of the systems was evaluated by failure tree analysis. Simulation and analytical calculation programs were developed and used for the reliability analysis. The results are briefly presented of the reliability analyses of the passive system for the immediate short-term flooding of the reactor core, of the active low-pressure system of emergency core cooling, the spray system, the bubble-vacuum system and the system of emergency supply of the steam generators. (E.S.)

Reliability of diesel generators at the Finnish and Swedish nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Pulkkinen, Urho [Technical Research Centre of Finland, Vuorimiehentie 5, SF-02150, Espoo (Finland)

1986-02-15

The operating experiences of 40 stand-by diesel generators at the Finnish and Swedish nuclear power plants have been analysed with special emphasis on the impact of the frequency of surveillance testing and of the test procedure on diesel generator reliability, the contribution of design, manufacturing, testing and maintenance errors and the potential and actual common cause failures, The results pf the analyses consisted both practical recommendations and mathematical reliability models and useful reliability data. (author)

Information flow a data bank preparation in nuclear power plant reliability information system

International Nuclear Information System (INIS)

Kolesa, K.; Vejvodova, I.

1983-01-01

In the year 1981 the reliability information system for nuclear power plants (ISS-JE) was established. The objective of the system is to make a statistical evaluation of the operation of nuclear power plants and to obtain information on the reliability of the equipment of nuclear power plants and the transmission of this information to manufacturers with the aim of inducing them to take corrective measures. The HP 1000 computer with the data base system IMAGE 100 is used which allows to process single queries and periodical outputs. The content of periodical outputs designed for various groups of subcontractors is briefly described and trends of the further development of the system indicated. (Ha)

Reliability evaluation of emergency AC power systems based on operating experience at U.S. nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Baranowsky, P. W. [U.S. Nuclear Regulatory Commission, Washington, DC (United States)

1986-02-15

The reliability of emergency AC power Systems has been under study at the U.S. Nuclear Regulatory Commission and by its contractors for several years. This paper provides the results of work recently performed to evaluate past U.S. nuclear power plant emergency AC power System reliability performance using system level data. Operating experience involving multiple diesel generator failures, unavailabilities, and simultaneous occurrences of failures and out of service diesel generators were used to evaluate reliability performance at individual nuclear power plants covering a 9 year period from 1976 through 1984. The number and nature of failures and distributions of reliability evaluation results are provided. The results show that plant specific performance varied considerably during the period with a large number achieving high reliability performance and a smaller number accounting for lower levels of reliability performance. (author)

Reliability and safety of a new upper cervical spine injury treatment algorithm

Directory of Open Access Journals (Sweden)

Andrei Fernandes Joaquim

Full Text Available ABSTRACT In the present study, we evaluated the reliability and safety of a new upper cervical spine injury treatment algorithm to help in the selection of the best treatment modality for these injuries. Methods Thirty cases, previously treated according to the new algorithm, were presented to four spine surgeons who were questioned about their personal suggestion for treatment, and the treatment suggested according to the application of the algorithm. After four weeks, the same questions were asked again to evaluate reliability (intra- and inter-observer using the Kappa index. Results The reliability of the treatment suggested by applying the algorithm was superior to the reliability of the surgeons’ personal suggestion for treatment. When applying the upper cervical spine injury treatment algorithm, an agreement with the treatment actually performed was obtained in more than 89% of the cases. Conclusion The system is safe and reliable for treating traumatic upper cervical spine injuries. The algorithm can be used to help surgeons in the decision between conservative versus surgical treatment of these injuries.

Conceptual Software Reliability Prediction Models for Nuclear Power Plant Safety Systems

International Nuclear Information System (INIS)

Johnson, G.; Lawrence, D.; Yu, H.

2000-01-01

The objective of this project is to develop a method to predict the potential reliability of software to be used in a digital system instrumentation and control system. The reliability prediction is to make use of existing measures of software reliability such as those described in IEEE Std 982 and 982.2. This prediction must be of sufficient accuracy to provide a value for uncertainty that could be used in a nuclear power plant probabilistic risk assessment (PRA). For the purposes of the project, reliability was defined to be the probability that the digital system will successfully perform its intended safety function (for the distribution of conditions under which it is expected to respond) upon demand with no unintended functions that might affect system safety. The ultimate objective is to use the identified measures to develop a method for predicting the potential quantitative reliability of a digital system. The reliability prediction models proposed in this report are conceptual in nature. That is, possible prediction techniques are proposed and trial models are built, but in order to become a useful tool for predicting reliability, the models must be tested, modified according to the results, and validated. Using methods outlined by this project, models could be constructed to develop reliability estimates for elements of software systems. This would require careful review and refinement of the models, development of model parameters from actual experience data or expert elicitation, and careful validation. By combining these reliability estimates (generated from the validated models for the constituent parts) in structural software models, the reliability of the software system could then be predicted. Modeling digital system reliability will also require that methods be developed for combining reliability estimates for hardware and software. System structural models must also be developed in order to predict system reliability based upon the reliability

Assessment of the technological reliability of a hybrid constructed wetland for wastewater treatment in a mountain eco-tourist farm in Poland.

Science.gov (United States)

Jucherski, Andrzej; Nastawny, Maria; Walczowski, Andrzej; Jóźwiakowski, Krzysztof; Gajewska, Magdalena

2017-06-01

The aim of the present study was to assess the technological reliability of a domestic hybrid wastewater treatment installation consisting of a classic three-chambered (volume 6 m 3 ) septic tank, a vertical flow trickling bed filled with granules of a calcinated clay material (KERAMZYT), a special wetland bed constructed on a slope, and a permeable pond used as a receiver. The test treatment plant was located at a mountain eco-tourist farm on the periphery of the spa municipality of Krynica-Zdrój, Poland. The plant's operational reliability in reducing the concentration of organic matter, measured as biochemical oxygen demand (BOD 5 ) and chemical oxygen demand (COD), was 100% when modelled by both the Weibull and the lognormal distributions. The respective reliability values for total nitrogen removal were 76.8% and 77.0%, total suspended solids - 99.5% and 92.6%, and PO 4 -P - 98.2% and 95.2%, with the differences being negligible. The installation was characterized by a very high level of technological reliability when compared with other solutions of this type. The Weibull method employed for statistical evaluation of technological reliability can also be used for comparison purposes. From the ecological perspective, the facility presented in the study has proven to be an effective tool for protecting local aquifer areas.

Reliability analysis of meteorological data registered during nuclear power plant normal operation

International Nuclear Information System (INIS)

Amado, V.; Ulke, A.; Marino, B.; Thomas, L.

2011-01-01

The atmosphere is the environment in which gaseous radioactive discharges from nuclear power plants are transported. It is therefore essential to have reliable meteorological information to characterize the dispersion and feed evaluation models and radiological environmental impact during normal operation of the plant as well as accidental releases. In this way it is possible to determine the effects on the environment and in humans. The basic data needed to represent adequately the local weather include air temperature, wind speed and direction, rainfall, humidity and pressure. On the other hand, specific data consistent with the used model is required to determine the turbulence, for instance, radiation, cloud cover and vertical temperature gradient. It is important that the recorded data are representative of the local meteorology. This requires, first, properly placed instruments, that should be kept in operation and undergoing maintenance on a regular basis. Second, but equally substantial, a thorough analysis of its reliability must be performed prior to storage and/or data processing. In this paper we present the main criteria to consider choosing the location of a meteorological tower in the area of a nuclear power plant and propose a methodology for assessing the reliability of recorded data. The methodology was developed from the analysis of meteorological data registered in nuclear power plants in Argentina. (authors) [es

Reliability evaluation of nuclear power plants by fault tree analysis

International Nuclear Information System (INIS)

Iwao, H.; Otsuka, T.; Fujita, I.

1993-01-01

As a work sponsored by the Ministry of International Trade and Industry, the Safety Information Research Center of NUPEC, using reliability data based on the operational experience of the domestic LWR Plants, has implemented FTA for the standard PWRs and BWRs in Japan with reactor scram due to system failures being at the top event. Up to this point, we have obtained the FT chart and minimal cut set for each type of system failure for qualitative evaluation, and we have estimated system unavailability, Fussell-Vesely importance and risk worth for components for quantitative evaluation. As the second stage of a series in our reliability evaluation work, another program was started to establish a support system. The aim of this system is to assist foreign and domestic plants in creating countermeasures when incidents occur, by providing them with the necessary information using the above analytical method and its results. (author)

Reliability study: steam generation and distribution system, Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Baker, F.E.; Davis, E.L.; Dent, J.T.; Walters, D.E.; West, R.M.

1982-10-01

A reliability study for determining the ability of the Steam Generation and Distribution System to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the X-600 Steam Plant and the steam distribution system. The Steam Generation and Distribution System is in good overall condition, but to maintain this condition, the reliability study team made twelve recommendations. Eight of the recommendations are for repair or replacement of existing equipment and have a total estimated cost of $540,000. The other four recommendations are for additional testing, new procedure implementation, or continued investigations

Demonstration of Essential Reliability Services by a 300-MW Solar Photovoltaic Power Plant

Energy Technology Data Exchange (ETDEWEB)

Loutan, Clyde; Klauer, Peter; Chowdhury, Sirajul; Hall, Stephen; Morjaria, Mahesh; Chadliev, Vladimir; Milam, Nick; Milan, Christopher; Gevorgian, Vahan

2017-03-24

The California Independent System Operator (CAISO), First Solar, and the National Renewable Energy Laboratory (NREL) conducted a demonstration project on a large utility-scale photovoltaic (PV) power plant in California to test its ability to provide essential ancillary services to the electric grid. With increasing shares of solar- and wind-generated energy on the electric grid, traditional generation resources equipped with automatic governor control (AGC) and automatic voltage regulation controls -- specifically, fossil thermal -- are being displaced. The deployment of utility-scale, grid-friendly PV power plants that incorporate advanced capabilities to support grid stability and reliability is essential for the large-scale integration of PV generation into the electric power grid, among other technical requirements. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, PV power plants can be used to mitigate the impact of variability on the grid, a role typically reserved for conventional generators. In August 2016, testing was completed on First Solar's 300-MW PV power plant, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to use grid-friendly controls to provide essential reliability services. These data showed how the development of advanced power controls can enable PV to become a provider of a wide range of grid services, including spinning reserves, load following, voltage support, ramping, frequency response, variability smoothing, and frequency regulation to power quality. Specifically, the tests conducted included various forms of active power control such as AGC and frequency regulation; droop response; and reactive power, voltage, and power factor controls. This project demonstrated that advanced power electronics and solar generation can be

Impact of power plant reliability on the choice of operating parameter values

International Nuclear Information System (INIS)

Kramer, R.A.

1985-01-01

In this thesis, the basic structure for the development of a methodology to evaluate the effect of operating parameters on plant availability and generating system economic dispatch optimization is described. Plant availability is determined by a fault free model. In this model historic, time dependent, component induced forced outage data is utilized as the basis for the calculation of projected plant forced outage rates. The influence of a particular fuel-cycle length at a specific generating station on the operational planning of a multi unit generating system is considered. The basis of the dispatch of units in this analysis is optimal economic operation, i.e., the minimization of the cost of reliability supplying electricity to the system's customers. As a result of the utilization of this technique, a simplified example that considers the choice between a 12- and 18-month fuel cycle length is evaluated in terms of its impact on plant availability, fuel cycle economics and overall optimal generating system economic dispatch. The reliability portion of this methodology is applied to a simplified representation of the recirculation system of a pressurized water reactor nuclear power plant to illustrate the analytic techniques

Markov modeling and reliability analysis of urea synthesis system of a fertilizer plant

Science.gov (United States)

Aggarwal, Anil Kr.; Kumar, Sanjeev; Singh, Vikram; Garg, Tarun Kr.

2015-12-01

This paper deals with the Markov modeling and reliability analysis of urea synthesis system of a fertilizer plant. This system was modeled using Markov birth-death process with the assumption that the failure and repair rates of each subsystem follow exponential distribution. The first-order Chapman-Kolmogorov differential equations are developed with the use of mnemonic rule and these equations are solved with Runga-Kutta fourth-order method. The long-run availability, reliability and mean time between failures are computed for various choices of failure and repair rates of subsystems of the system. The findings of the paper are discussed with the plant personnel to adopt and practice suitable maintenance policies/strategies to enhance the performance of the urea synthesis system of the fertilizer plant.

Technology development of maintenance optimization and reliability analysis for safety features in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Woon; Choi, Seong Soo; Lee, Dong Gue; Kim, Young Il

1999-12-01

The reliability data management system (RDMS) for safety systems of PHWR type plants has been developed and utilized in the reliability analysis of the special safety systems of Wolsong Unit 1,2 with plant overhaul period lengthened. The RDMS is developed for the periodic efficient reliability analysis of the safety systems of Wolsong Unit 1,2. In addition, this system provides the function of analyzing the effects on safety system unavailability if the test period of a test procedure changes as well as the function of optimizing the test periods of safety-related test procedures. The RDMS can be utilized in handling the requests of the regulatory institute actively with regard to the reliability validation of safety systems. (author)

Implementation of the project of equipment reliability in the nuclear power plant of Laguna Verde

International Nuclear Information System (INIS)

Rios O, J. E.; Martinez L, A. G.

2008-01-01

A equipment is reliable if it fulfills the function for which was designed and when it is required. To implement a project of reliability in a nuclear power plant this associate to a process of continuous analysis of the operation, of the conditions and faults of the equipment. The analysis of the operation of a system, of the equipment of the same faults and the parts that integrate to equipment take to identify the potential causes of faults. The predictive analysis on components and equipment allow to rectify and to establish guides to optimize the maintenance and to guarantee the reliability and function of the same ones. The reliability in the equipment is without place to doubts a wide project that embraces from the more small component of the equipment going by the proof of the parts of reserve, the operation conditions until the operative techniques of analysis. Without place of doubt for a nuclear power plant the taking of decisions based on the reliability of their systems and equipment will be the appropriate for to assure the operation and reliability of the same one. In this work would appear the project of reliability its processes, criteria, indicators action of improvement and the interaction of the different disciplines from the Nuclear Power Plant of Laguna Verde like a fundamental point for it put in operation. (Author)

Reliability analysis of operator's monitoring behavior in digital main control room of nuclear power plants and its application

International Nuclear Information System (INIS)

Zhang Li; Hu Hong; Li Pengcheng; Jiang Jianjun; Yi Cannan; Chen Qingqing

2015-01-01

In order to build a quantitative model to analyze operators' monitoring behavior reliability of digital main control room of nuclear power plants, based on the analysis of the design characteristics of digital main control room of a nuclear power plant and operator's monitoring behavior, and combining with operators' monitoring behavior process, monitoring behavior reliability was divided into three parts including information transfer reliability among screens, inside-screen information sampling reliability and information detection reliability. Quantitative calculation model of information transfer reliability among screens was established based on Senders's monitoring theory; the inside screen information sampling reliability model was established based on the allocation theory of attention resources; and considering the performance shaping factor causality, a fuzzy Bayesian method was presented to quantify information detection reliability and an example of application was given. The results show that the established model of monitoring behavior reliability gives an objective description for monitoring process, which can quantify the monitoring reliability and overcome the shortcomings of traditional methods. Therefore, it provides theoretical support for operator's monitoring behavior reliability analysis in digital main control room of nuclear power plants and improves the precision of human reliability analysis. (authors)

Reliability analysis of common hazardous waste treatment processes

International Nuclear Information System (INIS)

Waters, R.D.

1993-05-01

Five hazardous waste treatment processes are analyzed probabilistically using Monte Carlo simulation to elucidate the relationships between process safety factors and reliability levels. The treatment processes evaluated are packed tower aeration, reverse osmosis, activated sludge, upflow anaerobic sludge blanket, and activated carbon adsorption

Reliability analysis of common hazardous waste treatment processes

Energy Technology Data Exchange (ETDEWEB)

Waters, Robert D. [Vanderbilt Univ., Nashville, TN (United States)

1993-05-01

Five hazardous waste treatment processes are analyzed probabilistically using Monte Carlo simulation to elucidate the relationships between process safety factors and reliability levels. The treatment processes evaluated are packed tower aeration, reverse osmosis, activated sludge, upflow anaerobic sludge blanket, and activated carbon adsorption.

Procedure for conducting a human-reliability analysis for nuclear power plants. Final report

International Nuclear Information System (INIS)

Bell, B.J.; Swain, A.D.

1983-05-01

This document describes in detail a procedure to be followed in conducting a human reliability analysis as part of a probabilistic risk assessment when such an analysis is performed according to the methods described in NUREG/CR-1278, Handbook for Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications. An overview of the procedure describing the major elements of a human reliability analysis is presented along with a detailed description of each element and an example of an actual analysis. An appendix consists of some sample human reliability analysis problems for further study

Performance of nuclear power plants and analysis of some factors affecting their operational reliability and economy

International Nuclear Information System (INIS)

Kozak, M.; Havel, S.

1989-09-01

In Czechoslovakia, there are eight WWER 440 type reactors in operation at present. Since their introduction into operation, nuclear power plants in Czechoslovakia have exhibited high reliability. In the paper, total parameters of reliability with an analysis of causes affecting negatively their annual utilization are presented. Existence of a computerized information system for acquisition, recording and evaluation of reliability-significant data from operation and its feedback to designers and manufacturers of nuclear power plant equipment and components is a basic requirement of a systematic assurance of the needed level of nuclear power plant reliability. The information system is used simultaneously also for realistic evaluation of aging of equipment and systems. Analysis of the state of equipment is important mainly in the final stage of the NPP during consideration of further extension of its service life. Environmental effects of the Czechoslovak NPPs are very low (favourable). It follows from comparison of annual dose equivalents of the Czechoslovak NPPs operational personnel with the foreign NPPs that the values recorded in Czechoslovakia belong to the lowest ones. In conclusion, some ways of assurance of operational safety and reliability of the Czechoslovak nuclear power plants including the role of the State regulatory body are briefly discussed. (author). 3 tabs

Human reliability analysis of performing tasks in plants based on fuzzy integral

International Nuclear Information System (INIS)

Washio, Takashi; Kitamura, Yutaka; Takahashi, Hideaki

1991-01-01

The effective improvement of the human working conditions in nuclear power plants might be a solution for the enhancement of the operation safety. The human reliability analysis (HRA) gives a methodological basis of the improvement based on the evaluation of human reliability under various working conditions. This study investigates some difficulties of the human reliability analysis using conventional linear models and recent fuzzy integral models, and provides some solutions to the difficulties. The following practical features of the provided methods are confirmed in comparison with the conventional methods: (1) Applicability to various types of tasks (2) Capability of evaluating complicated dependencies among working condition factors (3) A priori human reliability evaluation based on a systematic task analysis of human action processes (4) A conversion scheme to probability from indices representing human reliability. (author)

Utilizing clad piping to improve process plant piping integrity, reliability, and operations

International Nuclear Information System (INIS)

Chakravarti, B.

1996-01-01

During the past four years carbon steel piping clad with type 304L (UNS S30403) stainless steel has been used to solve the flow accelerated corrosion (FAC) problem in nuclear power plants with exceptional success. The product is designed to allow ''like for like'' replacement of damaged carbon steel components where the carbon steel remains the pressure boundary and type 304L (UNS S30403) stainless steel the corrosion allowance. More than 3000 feet of piping and 500 fittings in sizes from 6 to 36-in. NPS have been installed in the extraction steam and other lines of these power plants to improve reliability, eliminate inspection program, reduce O and M costs and provide operational benefits. This concept of utilizing clad piping in solving various corrosion problems in industrial and process plants by conservatively selecting a high alloy material as cladding can provide similar, significant benefits in controlling corrosion problems, minimizing maintenance cost, improving operation and reliability to control performance and risks in a highly cost effective manner. This paper will present various material combinations and applications that appear ideally suited for use of the clad piping components in process plants

Advancements in valve technology and industry lessons lead to improved plant reliability and cost savings

International Nuclear Information System (INIS)

Sharma, V.; Kalsi, M.S.

2005-01-01

Plant reliability and safety hinges on the proper functioning of several valves. Recent advancements in valve technology have resulted in new analytical and test methods for evaluating and improving valve and actuator reliability. This is especially significant in critical service applications in which the economic impact of a valve failure on production, outage schedules and consequential damages far surpasses the initial equipment purchase price. This paper presents an overview of recent advances in valve technology driven by reliability concerns and cost savings objectives without comprising safety in the Nuclear Power Industry. This overview is based on over 27 years of experience in supporting US and International nuclear power utilities, and contributing to EPRI, and NSSS Owners' Groups in developing generic models/methodologies to address industry wide issues; performing design basis reviews; and implementing plant-wide valve reliability improvement programs. Various analytical prediction software and hardware solutions and training seminars are now available to implement valve programs covering power plants' lifecycle from the construction phase through life extension and power up rate. These tools and methodologies can enhance valve-engineering activities including the selection, sizing, proper application, condition monitoring, failure analysis, and condition based maintenance optimization with a focus on potential bad actors. This paper offers two such examples, the Kalsi Valve and Actuator Program (KVAP) and Check Valve Analysis and Prioritization (CVAP) [1-3, 8, 9, 11-13]. The advanced, validated torque prediction models incorporated into KVAP software for AOVs and MOVs have improved reliability of margin predictions and enabled cost savings through elimination of unwarranted equipment modifications. CVAP models provides a basis to prioritize the population of valves recommended for preventive maintenance, inspection and/or modification, allowing

The experiences to improve plant performance and reliability of Ko-Ri nuclear power plants

International Nuclear Information System (INIS)

Kang, Ho Weon

1998-01-01

This paper provides a discussion of the lessons learned from operational experience and the future plans to improve performance of the Ko-Ri plant. To operate nuclear power plants safely with good performance is the only way to mitigate the negative image of nuclear power generation to the public and to enhance the economical benefit compared to other electrical generation method. Therefore, in a continuous effort to overcome a negative challenge from outside, we have driven an aggressive 'OCTF' campaign as part of safety. As a result of our efforts, the following remarkable achievements have been accomplished. (1) 3 times of OCTF during recent three years (2) Selected twice as a top notch power plant on the list of NEI magazine in terms of plant capacity factor (3) No scram recorded in 1997 for all 4 units at Ko-Ri site. Ko-Ri is now undergoing the large scale plant betterment projects for retaking-off our operating performance to the level of new challenge target. Such improvement of critical components in the reactor coolant system and turbine system greatly contribute to increase the safety and reliability of the plant and to shortening of the planned outage period as well as to reduction of radiation exposure and radwaste. (Cho, G. S.). 5 tabs., 10 figs

Reliability Calculations

DEFF Research Database (Denmark)

Petersen, Kurt Erling

1986-01-01

Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

Trade-offs in size, quantity and reliability of generalized nuclear power plants: a preliminary assessment

International Nuclear Information System (INIS)

Hill, D.

1985-04-01

An approximate method is used to estimate the effects of system reliability on optimal nuclear plant size, taking into account also scale factors and manufacturing learning curve slopes. The method is used to estimate the additional effective capability gained by adding units of different sizes to an existing electrical system. The number of additional units proves to be sensitive to forced outrage rate, estimated here from trends in US light-water reactors from 1971 to 1980. The relative cost of added units ranging in size from 200 to 800 MW is determined as a function of the parameters: scale factor and learning curve slope. The results generally corrobate the trends found in an earlier study in which the effect of reliability on required installed capacity was not explicitly considered. Optimal plant size decreases with weaker scale effects and stronger learning curve effects. Reliability considerations further reduce the optimal plant size, but the relative reduction is apparently not as great with steeper learning curves. This is a plausible finding inasmuch as the reduction in numbers of additional units due to reliability considerations will affect cost most where the learning curve is steepest. 9 refs., 4 figs., 3 tabs

The number of measurements needed to obtain high reliability for traits related to enzymatic activities and photosynthetic compounds in soybean plants infected with Phakopsora pachyrhizi

Science.gov (United States)

de Oliveira, Tássia Boeno; Teodoro, Paulo Eduardo; de Alvarenga, Amauri Alves; Bhering, Leonardo Lopes; Campo, Clara Beatriz Hoffmann

2018-01-01

Asian rust affects the physiology of soybean plants and causes losses in yield. Repeatability coefficients may help breeders to know how many measurements are needed to obtain a suitable reliability for a target trait. Therefore, the objectives of this study were to determine the repeatability coefficients of 14 traits in soybean plants inoculated with Phakopsora pachyrhizi and to establish the minimum number of measurements needed to predict the breeding value with high accuracy. Experiments were performed in a 3x2 factorial arrangement with three treatments and two inoculations in a random block design. Repeatability coefficients, coefficients of determination and number of measurements needed to obtain a certain reliability were estimated using ANOVA, principal component analysis based on the covariance matrix and the correlation matrix, structural analysis and mixed model. It was observed that the principal component analysis based on the covariance matrix out-performed other methods for almost all traits. Significant differences were observed for all traits except internal CO2 concentration for the treatment effects. For the measurement effects, all traits were significantly different. In addition, significant differences were found for all Treatment x Measurement interaction traits except coumestrol, chitinase and chlorophyll content. Six measurements were suitable to obtain a coefficient of determination higher than 0.7 for all traits based on principal component analysis. The information obtained from this research will help breeders and physiologists determine exactly how many measurements are needed to evaluate each trait in soybean plants infected by P. pachyrhizi with a desirable reliability. PMID:29438380

A Reliability-Based Determination of Economic Life of Marine power plants

International Nuclear Information System (INIS)

Atua, K.

1999-01-01

The reliability-based life approach is utilized. Selective failure modes of marine power plants are used for illustration. A case study of the Egyptian Commercial Fleet owned by the Public Sector Company was analyzed and used to establish a demonstration of the expected economic life based on local operating and maintenance conditions. The data acquired is analyzed and failure trend is derived for each failure mode. Probabilistic techniques are used to randomly generate numbers and times of occurrence of different failure modes. The reliability analysis is performed on the life span expected by the manufacture to predict the total number of failures, dependent failures, and cost of failures. Total expenditure due to random failure and cost of scheduled maintenance together with the annual income are utilized (using the time value of money) to determine the economic life of the plant. Conclusions are derived and recommendations for the enhancement of this work in the future are made

Operational experience of gaseous effluent treatment at the Eurochemic reprocessing plant

International Nuclear Information System (INIS)

Osipenco, A.; Detilleux, E.

1977-01-01

The EUROCHEMIC fuel reprocessing plant applies the PUREX flow sheet. Two particular features of the plant influence gaseous and liquid effluents: chemical decanning and the ability to process a wide range of fuels, uranium metal or oxide, having an initial enrichment typical of power reactors (up to 5%) or material testing reactors (up to 93%). The ventilation circuits, treatment plant and monitoring equipment for gaseous releases are briefly described. No retention facilities for rare gases, tritium, or carbon-14 are provided. The releases are monitored for krypton-85, iodine-131, alpha and beta-gamma aerosols and tritium. Between 1966 and 1974 the plant processes about 200 tonnes of power reactor fuel, from which about 0.7 tonnes of plutonium and 1.5 tonnes of highly enriched uranium were separated. The most important points in the operation of the gas cleaning equipment are indicated: efficiency, operational reliability, incidents, etc.. Actual discharges as measured are compared with the limits set in the operation licence. Using the atmospheric diffusion coefficients, the dose commitment is estimated. The low level liquid effluents are passed, after neutralization, to the treatment plant of the Belgian nuclear center CEN/SCK. However, if the activity exceeds the limit set by the CEN/SCK, the effluents are concentrated by evaporation and stored on the EUROCHEMIC site. (orig.) [de

Reliability of emergency alternating-current power systems at nuclear power plants: a discussion of NUREG/CR-2989

International Nuclear Information System (INIS)

Battle, R.E.

1985-01-01

The reliability of emergency alternating-current power systems typical of most nuclear power plants was estimated by using fault-tree analysis of selected typical designs. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports and from operating experience information obtained from nuclear plant licensees. Trends of diesel generator independent failure on demand are included. No one or two improvements can be made at all plants to increase significantly the industry-average emergency alternating-current power system reliability; the most beneficial improvements are varied and plant specific

Nuclear power plants. Guidelines to ensure quality of collected data on reliability

International Nuclear Information System (INIS)

1983-01-01

This international standard lays down guidelines to be followed in the collection of data relative to nuclear power plants so as to ensure the reliability and completeness of the data and its insertion in a computerized system

A reliability centered maintenance model applied to the auxiliary feedwater system of a nuclear power plant

International Nuclear Information System (INIS)

Araujo, Jefferson Borges

1998-01-01

The main objective of maintenance in a nuclear power plant is to assure that structures, systems and components will perform their design functions with reliability and availability in order to obtain a safety and economic electric power generation. Reliability Centered Maintenance (RCM) is a method of systematic review to develop or optimize Preventive Maintenance Programs. This study presents the objectives, concepts, organization and methods used in the development of RCM application to nuclear power plants. Some examples of this application are included, considering the Auxiliary Feedwater System of a generic two loops PWR nuclear power plant of Westinghouse design. (author)

Beliefs concerning the reliability of nuclear power plant in-service inspections

International Nuclear Information System (INIS)

Kettunen, J.

1997-01-01

The aim of the study was to investigate belief systems held by the officials responsible for the planning and supervision of NDT operations within the Finnish nuclear industry. They were asked to express their opinions on (1) the reliability of NDT methods in general, (2) the factors influencing the reliability of in-service inspections, and (3) the degree of reliability of the current inspections operations conducted by means of NDT methods in the Finnish nuclear power plants. Another goal of the study was to assess the adequacy of officials' beliefs (or belief systems). The research data was collected by interviewing representatives from Finnish power companies (Imatran Voima Oy and Teollisuuden Voima Oy), independent inspection organisations, and the Finnish Centre for Radiation and Nuclear Safety (STUK). The adequacy of the beliefs expressed was assessed by means of the results obtained from international NDT reliability studies and on the basis of interviewees' own justification. (refs.)

Improving human reliability through better nuclear power plant system design. Progress report

International Nuclear Information System (INIS)

Golay, M.W.

1995-01-01

The project on open-quotes Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performanceclose quotes has been undertaken in order to address the important problem of human error in advanced nuclear power plant designs. Most of the creativity in formulating such concepts has focused upon improving the mechanical reliability of safety related plant systems. However, the lack of a mature theory has retarded similar progress in reducing the likely frequencies of human errors. The main design mechanism used to address this class of concerns has been to reduce or eliminate the human role in plant operations and accident response. The plan of work being pursued in this project is to perform a set of experiments involving human subject who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants. In the tests the systems are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds. Ultimately this computer is also to be used in compiling the results of the project. The work of this project is focused upon nuclear power plant applications. However, the persuasiveness of human errors in using all sorts of electromechanical machines gives it a much greater potential importance. Because of this we are attempting to pursue our work in a fashion permitting broad generalizations

The experiences to improve plant performance and reliability of Ko-Ri nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Kang, Ho Weon [Korea Electric Power Corp. Ko-Ri nuclear power division, Ko-Ri (Korea, Republic of)

1998-07-01

This paper provides a discussion of the lessons learned from operational experience and the future plans to improve performance of the Ko-Ri plant. To operate nuclear power plants safely with good performance is the only way to mitigate the negative image of nuclear power generation to the public and to enhance the economical benefit compared to other electrical generation method. Therefore, in a continuous effort to overcome a negative challenge from outside, we have driven an aggressive 'OCTF' campaign as part of safety. As a result of our efforts, the following remarkable achievements have been accomplished. (1) 3 times of OCTF during recent three years (2) Selected twice as a top notch power plant on the list of NEI magazine in terms of plant capacity factor (3) No scram recorded in 1997 for all 4 units at Ko-Ri site. Ko-Ri is now undergoing the large scale plant betterment projects for retaking-off our operating performance to the level of new challenge target. Such improvement of critical components in the reactor coolant system and turbine system greatly contribute to increase the safety and reliability of the plant and to shortening of the planned outage period as well as to reduction of radiation exposure and radwaste. (Cho, G. S.). 5 tabs., 10 figs.

Water chemistry - one of the key technologies for safe and reliable nuclear power plant operation

International Nuclear Information System (INIS)

Uchida, S.; Otoha, K.; Ishigure, K.

2006-01-01

Full text: Full text: Water chemistry control is one of the key technologies to establish safe and reliable operation of nuclear power plants. Continuous and collaborative efforts of plant manufacturers and plant operator utilities have been focused on optimal water chemistry control, for which, a trio of requirements for water chemistry, a) better reliability of reactor structures and fuels, b) lower occupational exposure, and c) fewer radwaste sources, should be simultaneously satisfied. The research committee related to water chemistry of the Atomic Energy Society of Japan has played important roles to enhance improvement in water chemistry control, to share knowledge and experience with water chemistry among plant operators and manufacturers, to establish common technological bases for plant water chemistry and then to transfer them to the next generation related to water chemistry. Furthermore, the committee has tried to contribute to arranging R and D proposals for further improvement in water chemistry control through road map planning

Diesel-generator reliability at nuclear power plants: data and preliminary analysis. Interim report

International Nuclear Information System (INIS)

McClymont, A.; McLagan, G.

1982-06-01

This report summarizes work performed under RP1233-1 relating to the collection and analysis of data pertaining to diesel generator reliability in nuclear power plants. Drawing from data collected on-site at plants, data supplied by utilites, and data from Licensee Event Reports (LERs), the report describes methods of deriving reliability estimates from data for use in probabilistic risk assessment and presents results when these methods are applied to data collected from 14 plants. Specifically, data are used to estimate diesel failure probabilities for failures to start and failure rates for failures to continue to run. A sampling theory approach and a Bayesian approach to failure probability estimation are compared. The data are used to derive estimates of diesel repair time for some plants, maintenance outages, and multiple diesel failure rates. In addition, a section is included that presents suggestions for failure-rate estimation when an accurate count of diesel start attempts at a plant is not available. The final section presents an analysis of diesel failures based on data from LERs, including a breakdown of failure event by subsystem, failure mode, and failure cause. Appendixes include detailed summaries of the data used in the analysis of previous sections

THE ANALYSIS OF STRUCTURAL RELIABILITY OF THE MAIN ELECTRIC CONNECTION CIRCUITS OF NUCLEAR POWER PLANTS

Directory of Open Access Journals (Sweden)

M. A. Korotkevich

2017-01-01

Full Text Available The reliability of the main circuit of electrical connections at a nuclear electric power plant that has two units with a capacity of 1,200 MW each has been determined. Reliability, economical, maneuverable properties of the atomic power plant under study are largely determined by its main circuit, so the choice of the circuit for the design and its status in the process of operation occur to be critical objectives. Main electrical connection circuits in nuclear electric power plants are selected on the basis of the schematic networks of the energy system and the land attached to the plant. The circuit of the connection of a nuclear power plant to the grid in the original normal operating modes at all stages of the construction of such a plant should provide the outcome of the full added capacity of a nuclear power plant and the preservation of its stability in the power system without the influence of the emergency system automatics when any outgoing transmission line is disabled. When selecting the main circuit the individual capacity of the installed units and their number are taken into account as well as the order of development of the plant and power supply system; the voltage on which the power of a plant is delivered; a shortcircuit current for switchgear high voltage and the need for their limitation by circuit means; the most power that can be lost when damage to any switch. A model of reliability of the main circuit of electrical connections is designed to detect all types of accidents that are possible at the coincidence of failures of elements with the repair and operational modes that differs in composition and damageability of the equipment, as well as under conditions of the development of accidents due to failure of operation of devices of relay protection and automation.

The United States nuclear plant reliability data program: Its description and status

International Nuclear Information System (INIS)

Wise, M.J.

1975-01-01

The American National Standards Institute Subcommittee N18-20 has developed and implemented the United States Nuclear Plant Reliability Data System (NPRDS). The NPRDS is designed to accumulate, store, analyse, and report reliability and failure statistics on systems and components of nuclear power plants related to nuclear safety. Input data to the NPRDS consist of engineering, operating, and failure information submitted on a voluntary basis by participating utilities. Prior to entry into the computerized data base, the data are thoroughly checked for accuracy by both the submitting organizations and the NPRDS operating contractor. The data base is the source of various periodic output reports to the nuclear power industry and is utilized to produce special reports upon request. The present data base represents data accumulated from about thirty nuclear units with additional units expected to begin submitting data immediately. The objective is to have essentially all operating nuclear units in the United States of America participating in the program by the end of 1975. The first NPRDS annual reports containing meaningful reliability and failure statistics are expected to be produced following the end of 1975. (author)

Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

International Nuclear Information System (INIS)

Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O.

2016-01-01

During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

Evaluation of piping reliability and failure data for use in risk-based inspections of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, V. de; Soares, W.A.; Costa, A.C.L. da; Rabello, E.G.; Marques, R.O., E-mail: vasconv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2016-07-01

During operation of industrial facilities, components and systems can deteriorate over time, thus increasing the possibility of accidents. Risk-Based Inspection (RBI) involves inspection planning based on information about risks, through assessing of probability and consequence of failures. In-service inspections are used in nuclear power plants, in order to ensure reliable and safe operation. Traditional deterministic inspection approaches investigate generic degradation mechanisms on all systems. However, operating experience indicates that degradation occurs where there are favorable conditions for developing a specific mechanism. Inspections should be prioritized at these places. Risk-Informed In-service Inspections (RI-ISI) are types of RBI that use Probabilistic Safety Assessment results, increasing reliability and plant safety, and reducing radiation exposure. These assessments use both available generic reliability and failure data, as well as plant specific information. This paper proposes a method for evaluating piping reliability and failure data important for RI-ISI programs, as well as the techniques involved. (author)

Study of evaluation techniques of software safety and reliability in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Youn, Cheong; Baek, Y. W.; Kim, H. C.; Park, N. J.; Shin, C. Y. [Chungnam National Univ., Taejon (Korea, Republic of)

1999-04-15

Software system development process and software quality assurance activities are examined in this study. Especially software safety and reliability requirements in nuclear power plant are investigated. For this purpose methodologies and tools which can be applied to software analysis, design, implementation, testing, maintenance step are evaluated. Necessary tasks for each step are investigated. Duty, input, and detailed activity for each task are defined to establish development process of high quality software system. This means applying basic concepts of software engineering and principles of system development. This study establish a guideline that can assure software safety and reliability requirements in digitalized nuclear plant systems and can be used as a guidebook of software development process to assure software quality many software development organization.

Proceeding of 35th domestic symposium on applications of structural reliability and risk assessment methods to nuclear power plants

International Nuclear Information System (INIS)

2005-06-01

As the 35th domestic symposium of Atomic Energy Research Committee, the Japan Welding Engineering Society, the symposium was held titled as Applications of structural reliability/risk assessment methods to nuclear energy'. Six speakers gave lectures titled as 'Structural reliability and risk assessment methods', 'Risk-informed regulation of US nuclear energy and role of probabilistic risk assessment', 'Reliability and risk assessment methods in chemical plants', 'Practical structural design methods based on reliability in architectural and civil areas', 'Maintenance activities based on reliability in thermal power plants' and 'LWR maintenance strategies based on Probabilistic Fracture Mechanics'. (T. Tanaka)

Role of recent research in improving check valve reliability at nuclear power plants

International Nuclear Information System (INIS)

Kalsi, M.S.; Horst, C.L.; Wang, J.K.; Sharma, V.

1990-01-01

Check valve failures at nuclear power plants in recent years have led to serious safety concerns, and caused extensive damage to other plant components which had a significant impact on plant availability. In order to understand the failure mechanism and improve the reliability of check valves, a systematic research effort was proposed by Kalsi Engineering, Inc. to U.S. Nuclear Regulatory Commission (NRC). The overall goal of the research was to develop models for predicting the performance and degradation of swing check valves in nuclear power plant systems so that appropriate preventive maintenance or design modifications can be performed to improve the reliability of check valves. Under Phase I of this research, a large matrix of tests was run with instrumented swing check valves to determine the stability of the disc under a variety of upstream flow disturbances, covering a wide range of disc stop positions and flow velocities in two different valve sizes. The goals of Phase II research were to develop predictive models which quantify the anticipated degradation of swing check valves that have flow disturbances closely upstream of the valve and are operating under flow velocities that do not result in full disc opening. This research allows the inspection/maintenance activities to be focussed on those check valves that are more likely to suffer premature degradation. The quantitative wear and fatigue prediction methodology can be used to develop a sound preventive maintenance program. The results of the research also show the improvements in check valve performance/reliability that can be achieved by certain modifications in the valve design

Plant Reliability - an Integrated System for Management (PR-ISM)

International Nuclear Information System (INIS)

Aukeman, M.C.; Leininger, E.G.; Carr, P.

1984-01-01

The Toledo Edison Company, located in Toledo, Ohio, United States of America, recently implemented a comprehensive maintenance management information system for the Davis-Besse Nuclear Power Station. The system is called PR-ISM, meaning Plant Reliability - An Integrated System for Management. PR-ISM provides the tools needed by station management to effectively plan and control maintenance and other plant activities. The PR-ISM system as it exists today consists of four integrated computer applications: equipment data base maintenance, maintenance work order control, administrative activity tracking, and technical specification compliance. PR-ISM is designed as an integrated on-line system and incorporates strong human factors features. PR-ISM provides each responsible person information to do his job on a daily basis and to look ahead towards future events. It goes beyond 'after the fact' reporting. In this respect, PR-ISM is an 'interactive' control system which: captures work requirements and commitments as they are identified, provides accurate and up-to-date status immediately to those who need it, simplifies paperwork and reduces the associated time delays, provides the information base for work management and reliability analysis, and improves productivity by replacing clerical tasks and consolidating maintenance activities. The functional and technical features of PR-ISM, the experience of Toledo Edison during the first year of operation, and the factors which led to the success of the development project are highlighted. (author)

On estimation of reliability for pipe lines of heat power plants under cyclic loading

International Nuclear Information System (INIS)

Verezemskij, V.G.

1986-01-01

One of the possible methods to obtain a quantitative estimate of the reliability for pipe lines of the welded heat power plants under cyclic loading due to heating-cooling and due to vibration is considered. Reliability estimate is carried out for a common case of loading by simultaneous cycles with different amplitudes and loading asymmetry. It is shown that scattering of the breaking number of cycles for the metal of welds may perceptibly decrease reliability of the welded pipe line

A task analysis-linked approach for integrating the human factor in reliability assessments of nuclear power plants

International Nuclear Information System (INIS)

Ryan, T.G.

1988-01-01

This paper describes an emerging Task Analysis-Linked Evaluation Technique (TALENT) for assessing the contributions of human error to nuclear power plant systems unreliability and risk. Techniques such as TALENT are emerging as a recognition that human error is a primary contributor to plant safety, however, it has been a peripheral consideration to data in plant reliability evaluations. TALENT also recognizes that involvement of persons with behavioral science expertise is required to support plant reliability and risk analyses. A number of state-of-knowledge human reliability analysis tools are also discussed which support the TALENT process. The core of TALENT is comprised of task, timeline and interface analysis data which provide the technology base for event and fault tree development, serve as criteria for selecting and evaluating performance shaping factors, and which provide a basis for auditing TALENT results. Finally, programs and case studies used to refine the TALENT process are described along with future research needs in the area. (author)

Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, Vanderley de; Soares, Wellington Antonio; Marques, Raíssa Oliveira; Silva Júnior, Silvério Ferreira da; Raso, Amanda Laureano, E-mail: vasconv@cdtn.br, E-mail: soaresw@cdtn.br, E-mail: raissaomarques@gmail.com, E-mail: silvasf@cdtn.br, E-mail: amandaraso@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2017-07-01

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. NDI is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI methods are reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components. Among these can be highlighted Failure Modes and Effects Analysis (FMEA) and THERP (Technique for Human Error Rate Prediction). The application of these techniques is illustrated in an example of qualitative and quantitative studies to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues. (author)

Human reliability in non-destructive inspections of nuclear power plant components: modeling and analysis

International Nuclear Information System (INIS)

Vasconcelos, Vanderley de; Soares, Wellington Antonio; Marques, Raíssa Oliveira; Silva Júnior, Silvério Ferreira da; Raso, Amanda Laureano

2017-01-01

Non-destructive inspection (NDI) is one of the key elements in ensuring quality of engineering systems and their safe use. NDI is a very complex task, during which the inspectors have to rely on their sensory, perceptual, cognitive, and motor skills. It requires high vigilance once it is often carried out on large components, over a long period of time, and in hostile environments and restriction of workplace. A successful NDI requires careful planning, choice of appropriate NDI methods and inspection procedures, as well as qualified and trained inspection personnel. A failure of NDI to detect critical defects in safety-related components of nuclear power plants, for instance, may lead to catastrophic consequences for workers, public and environment. Therefore, ensuring that NDI methods are reliable and capable of detecting all critical defects is of utmost importance. Despite increased use of automation in NDI, human inspectors, and thus human factors, still play an important role in NDI reliability. Human reliability is the probability of humans conducting specific tasks with satisfactory performance. Many techniques are suitable for modeling and analyzing human reliability in NDI of nuclear power plant components. Among these can be highlighted Failure Modes and Effects Analysis (FMEA) and THERP (Technique for Human Error Rate Prediction). The application of these techniques is illustrated in an example of qualitative and quantitative studies to improve typical NDI of pipe segments of a core cooling system of a nuclear power plant, through acting on human factors issues. (author)

Fuel Cell Balance-of-Plant Reliability Testbed Project

Energy Technology Data Exchange (ETDEWEB)

Sproat, Vern [Stark State College of Technology, North Canton, OH (United States); LaHurd, Debbie [Lockheed Martin Corp., Oak Ridge, TN (United States)

2016-10-29

Reliability of the fuel cell system balance-of-plant (BoP) components is a critical factor that needs to be addressed prior to fuel cells becoming fully commercialized. Failure or performance degradation of BoP components has been identified as a life-limiting factor in fuel cell systems.1 The goal of this project is to develop a series of test beds that will test system components such as pumps, valves, sensors, fittings, etc., under operating conditions anticipated in real Polymer Electrolyte Membrane (PEM) fuel cell systems. Results will be made generally available to begin removing reliability as a roadblock to the growth of the PEM fuel cell industry. Stark State College students participating in the project, in conjunction with their coursework, have been exposed to technical knowledge and training in the handling and maintenance of hydrogen, fuel cells and system components as well as component failure modes and mechanisms. Three test beds were constructed. Testing was completed on gas flow pumps, tubing, and pressure and temperature sensors and valves.

Strategy for establishing integrated l and c reliability of operating nuclear power plants in korea

International Nuclear Information System (INIS)

Kang, H. T.; Chung, H. Y.; Lee, Y. H.

2008-01-01

Korea hydro and nuclear power co. (KHNP) are in progress of developing a integrated I and C reliability establishing strategy for managing l and C obsolescence and phasing in new technology that both meets the needs of the fleet and captures the benefits of applying proven solutions to multiple plants, with reduced incremental costs. In view of this, we are developing I and C component management which covers major failure mode, symptom of performance degradation, condition-based or time-based preventive management (PM), monitoring, and failure finding and correction based on equipment reliability (ER). Furthermore, for the l and C system replacement management, we are in progress of 3-year-long I and C systems upgrade fundamental designing in developing the long-term major l and C systems implementation plan to improve plant operations, eliminate operator challenges, reduce maintenance costs, and cope with the challenges of component obsolescence. For accomplishing I and C digital upgrade in near future, we chose demonstration plant, Younggwang (YGN) unit 3 and 4 which are Korean Standard Nuclear Power Plant (KSNP). In this paper, we established the long term reliability strategy of I and C system based on ER in component replacement and furthermore I and C systems digital upgrade in system replacement. (authors)

Research on cognitive reliability model for main control room considering human factors in nuclear power plants

International Nuclear Information System (INIS)

Jiang Jianjun; Zhang Li; Wang Yiqun; Zhang Kun; Peng Yuyuan; Zhou Cheng

2012-01-01

Facing the shortcomings of the traditional cognitive factors and cognitive model, this paper presents a Bayesian networks cognitive reliability model by taking the main control room as a reference background and human factors as the key points. The model mainly analyzes the cognitive reliability affected by the human factors, and for the cognitive node and influence factors corresponding to cognitive node, a series of methods and function formulas to compute the node cognitive reliability is proposed. The model and corresponding methods can be applied to the evaluation of cognitive process for the nuclear power plant operators and have a certain significance for the prevention of safety accidents in nuclear power plants. (authors)

Water chemistry data acquisition, processing, evaluation and diagnostic systems in Light Water Reactors: Future improvement of plant reliability and safety

International Nuclear Information System (INIS)

Uchida, S.; Takiguchi, H.; Ishigure, K.

2006-01-01

Data acquisition, processing and evaluation systems have been applied in major Japanese PWRs and BWRs to provide (1) reliable and quick data acquisition with manpower savings in plant chemical laboratories and (2) smooth and reliable information transfer among chemists, plant operators, and supervisors. Data acquisition systems in plants consist of automatic and semi-automatic instruments for chemical analyses, e. g., X-ray fluorescence analysis and ion chromatography, while data processing systems consist of PC base-sub-systems, e.g., data storage, reliability evaluation, clear display, and document preparation for understanding the plant own water chemistry trends. Precise and reliable evaluations of water chemistry data are required in order to improve plant reliability and safety. For this, quality assurance of the water chemistry data acquisition system is needed. At the same time, theoretical models are being applied to bridge the gaps between measured water chemistry data and the information desired to understand the interaction of materials and cooling water in plants. Major models which have already been applied for plant evaluation are: (1) water radiolysis models for BWRs and PWRs; (2) crevice radiolysis model for SCC in BWRs; and (3) crevice pH model for SG tubing in PWRs. High temperature water chemistry sensors and automatic plant diagnostic systems have been applied in only restricted areas. ECP sensors are gaining popularity as tools to determine the effects of hydrogen injection in BWR systems. Automatic plant diagnostic systems based on artificial intelligence will be more popular after having sufficient experience with off line diagnostic systems. (author)

Verification and validation--The key to operating plant software reliability

International Nuclear Information System (INIS)

Daughtrey, H.T.; Daggett, P.W.; Schamp, C.A.

1983-01-01

This paper discusses the design and implementation of a verification and validation (V and V) plan for reviewing the microcomputer software developed for a Safety Parameter Display System (SPDS). Topics considered include a historical perspective on V and V, the function and significance of SPDS software, and testing. An SPDS provides information to nuclear power plant operators about the status of the plant under all operating conditions. It is determined that by implementing V and V activities throughout the development cycle, problems are less expensive to locate in the early phases of software development, problems are less expensive to fix in the early phases of software development, and a parallel V and V activity is more cost effective than a similar effort performed only at the end of software development. It is concluded that V and V is a proven tool for improving power plant software reliability

Evolving inspection technologies for reliable condition assessment of components and plants

International Nuclear Information System (INIS)

Baldev Raj

1994-01-01

Condition assessment of components and plants are being done regularly in many an industry. The methodologies adopted are being continuously refined. However, each of these methodologies are being applied in isolation, without realizing the synergistic advantage we derive when a global approach is taken for condition assessment. Developments in a variety of fields, that have a definite bearing on the reliability of condition assessment, are not applied (or even thought that they could be applied) together. The possible impact of evolving technologies in enhancing the efficiency of condition assessment of components and plants are discussed. (author). 11 refs

Relativity evaluation of reliability on operation in nuclear power plant

International Nuclear Information System (INIS)

Inata, Takashi

1987-01-01

The report presents a quantitative method for evaluating the reliability of operations conducted in nuclear power plants. The quantitative reliability evaluation method is based on the 'detailed block diagram analysis (De-BDA)'. All units of a series of operations are separately displayed for each block and combined sequentially. Then, calculation is performed to evaluate the reliability. Basically, De-BDA calculation is made for pairs of operation labels, which are connected in parallel or in series at different subordination levels. The applicability of the De-BDA method is demonstrated by carrying out calculation for three model cases: operations in the event of malfunction of the control valve in the main water supply system for PWR, switching from an electrically-operated water supply pump to a turbin-operated water supply pump, and isolation and water removal operation for a low-pressure condensate pump. It is shown that the relative importance of each unit of a series of operations can be evaluated, making it possible to extract those units of greater importance, and that the priority among the factors which affect the reliability of operations can be determined. Results of the De-BDA calculation can serve to find important points to be considered in developing an operation manual, conducting education and training, and improving facilities. (Nogami, K.)

Reliability calculations

International Nuclear Information System (INIS)

Petersen, K.E.

1986-03-01

Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

Reliability centered maintenance as an optimization tool for electrical power plants

International Nuclear Information System (INIS)

Jacquot, J.P.; Bryla, P.; Martin-Mattei, C.; Meuwisse, C.

1997-08-01

Seven years ago, Electricite de France launched a Reliability Centered Maintenance (RCM) pilot project to optimize preventive maintenance for its nuclear power plants. After a feasibility study, a RCM method was standardized. It is now applied on a large scale to the 50 EDF nuclear units. A RCM workstation based on this standardized method has been developed and is now used in each plant. In the next step, it is considered whether a Risk based Approach can be included in this RCM process in order to analyze critical passive components such as pipes and supports. Considering the potential advantages of these optimization techniques, a dedicated process has been also developed for maintenance of future plants, gas turbines, or nuclear units. A survey of these different developments of methods and tools is presented. (author)

On the reliability of steam generator performance at nuclear power plants with WWER type reactors

International Nuclear Information System (INIS)

Styrikovich, M.A.; Margulova, T.Kh.

1974-01-01

The problem of ensuring reliable operation of steam generators in a nuclear power plant with a water-cooled, water-moderated reactor (WWER) was studied. At a nuclear power plant with a vertical steam generator (specifically, a Westinghouse product) the steam generator tubes were found to have been penetrated. Shutdown was due to corrosion disintegration of the austenitic stainless steel, type 18/8, used as pipe material for the heater surface. The corrosion was the result of the action of chlorine ions concentrated in the moisture contained in the iron oxide films deposited in low parts of the tube bundle, directly at the tube plate. Blowing through did not ensure complete removal of the film, and in some cases the construction features of the steam generator made removal of the film practically impossible. Replacement of type 18/8 stainless steel by other construction material, e.g., Inconel, did not give good results. To ensure reliable operation of vertical steam generators in domestic practice, the generators are designed without a low tube plate (a variant diagram of the vertical steam generator of such construction for the water-cooled, water-moderated reactor 1000 is presented). When low tube plates are used the film deposition is intolerable. For organization of a non-film regime a complex treatment of the feed water is used, in which the amount of complexion is calculated from the stoichmetric ratios with the composition of the feed water. It is noted that, if 100% condensate purification is used with complexon processing of the feed water to the generator, we can calculate the surface of the steam-generator heater without considering the outer placement on the tubes. In this the cost of the steam generator and all the nuclear power plants with WWER type reactors is decreased even with installation of a 100% condensate purification. It is concluded that only simultaneous solution of construction and water-regime problems will ensure relaible operation of

INPO's role in the improvement of nuclear plant safety and reliability

International Nuclear Information System (INIS)

Pate, Z.T.

1985-01-01

The Institute of Nuclear Power Operations (INPO) is a nonprofit, nongovernment corporation dedicated to promoting safe and reliable operation and quality construction of nuclear power plants. The institute is supported by the US nuclear utility industry. All US utilities building or operating nuclear power plants are INPO members. INPO's many activities fall within four major program areas: (1) Evaluations: INPO conducts detailed evaluations of all US operating plants, utility corporate support of nuclear programs, and nuclear projects under active construction. Events analysis and information exchange: INPO reviews plant reports of abnormal or unusual events and reports the lessons learned to the industry. INPO also fosters improved industry communications through a worldwide telecommunications network. (3) Training and accreditation: INPO assists utilities, including international participants, in developing quality training programs; and (4) Assistance: the Institute provides various forms of assistance to members and participants. INPO places emphasis on visits to facilities to aid members and participants in various program or operational areas

Overview of plant reliability and aging in Sweden

International Nuclear Information System (INIS)

Eckered, T.

1985-01-01

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

Enrichment planting without soil treatment

Energy Technology Data Exchange (ETDEWEB)

Hagner, Mats

1998-12-31

Where enrichment planting had been carried out with either of the two species Picea abies and Pinus contorta, the survival of the planted seedlings was at least as good as after planting in a normal clear cut area treated with soil scarification. This was in spite of the fact that the seedlings were placed shallow in the humus layer without any soil treatment. However, they were sheltered from insects by treatment before planting. Where enrichment planting was carried out with Pinus sylvestris the survival in dense forest was poor, but in open forest the survival was good. The growth of planted seedlings was enhanced by traditional clearing and soil treatment. However, this was for Pinus sylvestris not enough to compensate for the loss of time, 1-2 years, caused by arrangement of soil scarification. The growth of seedlings planted under crown cover was directly related to basal area of retained trees. However, the variation in height growth among individual seedlings was very big, which meant that some seedlings grow well also under a fairly dense forest cover. The pioneer species Pinus sylvestris reacted more strongly to basal area of retained trees than did the shade tolerant species Picea abies. Enrichment planting seems to be a necessary tool for preserving volume productivity, at places where fairly intensive harvest of mature trees has been carried out in stands of ordinary forest type in central Sweden. If double seedlings, with one Picea abies and one Pinus sylvestris, are used, the probability for long term establishment is enhanced 13 refs, 20 figs, 4 tabs

Reliable control system for nuclear power plant

International Nuclear Information System (INIS)

Okamoto, Tetsuo; Miyazaki, Shiro

1980-01-01

The System 1100 for nuclear power plants is the measuring and control system which utilizes the features of the System 1100 for electric power market in addition to the results of nuclear instrumentation with EBS-ZN series, and it has the following features. The maintenance and inspection in operation are easy. The construction of control loops is made flexibly by the combination of modules. The construction of multi-variable control system using mainly feed forward control is easy. Such functions as the automatic switching of control modes can be included. The switching of manual and automatic operations is easy, and if some trouble occurred in a module, the manual operation can be made. The aseismatic ability is improved by rigid structure cubicles. Nonflammable materials are used for wires, multi-core cables, paints and printed boards. The anti-noise characteristics are improved, and the reliability is high. The policy of developing the System 1100 for nuclear power plants, the type approval tests on modules and units and the type approval test on the system are described. The items of the system type approval test were standard performance test, earthquake test, noise isolation test, temperature and humidity test, and drift test. The aseismatic cubicle showed good endurance in its vibration test. (Kako, I.)

Effluent from Wastewater Treatment Plants

DEFF Research Database (Denmark)

Kristensen, Jannie Munk; Nierychlo, Marta; Albertsen, Mads

Incoming microorganisms to wastewater treatment plants (WWTPs) are usually considered to be removed in the treatment process. Analyses of the effluent generally show a very high degree of reduction of pathogens supporting this assumption. However, standard techniques for detecting bacteria......-independent 16SrRNA gene amplicon sequencing was applied for the identification and quantification of the microorganisms. In total 84 effluent samples from 14 full-scale Danish wastewater treatment plants were investigated over a period of 3 months. The microbial community composition was investigated by 16S r...... contain pathogenic species. One of these was Arcobacter (Campylobacteraceae) which was found in up to 16% relative abundance. This indicates that Arcobacter, and perhaps other pathogenic genera, are not being removed efficiently in full-scale plants and may pose a potential health safety problem. Further...

Operating reliability of valves in French pressurized water nuclear power plants

International Nuclear Information System (INIS)

Conte

1986-10-01

Taking into account the large numbers of valves (about 10000) of a PWR nuclear power plant, the importance of some valves in the safety functions and the cost resulting from their unavailability, the individual operability of these equipments has to be ensured at a high reliability level. This assurance can be obtained by means of an effort at all the stages which contribute to the quality of the product: design, qualification tests, fabrication, tests at the start-up stage, maintenance and tests during the power plant operation, experience feedback. This paper emphasizes more particularly on the tests carried out on loops of qualification [fr

Scientific approach and practical experience for reconstruction of waste water treatment plants in Russia

Directory of Open Access Journals (Sweden)

Makisha Nikolay

2017-01-01

Full Text Available Protection of water bodies has a strict dependence on reliable operation of engineering systems and facilities for water supply and sewage. The majority of these plants and stations has been constructed in 1970-1980's in accordance with rules and regulations of that time. So now most of them require reconstruction due to serious physical or/and technological wear. The current condition of water supply and sewage systems and facilities frequently means a hidden source of serious danger for normal life support and ecological safety of cities and towns. The article reveals an obtained experience and modern approaches for reconstruction of waste water and sludge treatment plants that proved their efficiency even if applied in limited conditions such as area limits, investments limits. The main directions of reconstruction: overhaul repair and partial modernization of existing facilities on the basis of initial project; - restoration and modernization of existing systems on the basis on the current documents and their current condition; upgrade of waste water treatment plants (WWTPs performance on the basis of modern technologies and methods; reconstruction of sewage systems and facilities and treatment quality improvement.

Scientific approach and practical experience for reconstruction of waste water treatment plants in Russia

Science.gov (United States)

Makisha, Nikolay; Gogina, Elena

2017-11-01

Protection of water bodies has a strict dependence on reliable operation of engineering systems and facilities for water supply and sewage. The majority of these plants and stations has been constructed in 1970-1980's in accordance with rules and regulations of that time. So now most of them require reconstruction due to serious physical or/and technological wear. The current condition of water supply and sewage systems and facilities frequently means a hidden source of serious danger for normal life support and ecological safety of cities and towns. The article reveals an obtained experience and modern approaches for reconstruction of waste water and sludge treatment plants that proved their efficiency even if applied in limited conditions such as area limits, investments limits. The main directions of reconstruction: overhaul repair and partial modernization of existing facilities on the basis of initial project; - restoration and modernization of existing systems on the basis on the current documents and their current condition; upgrade of waste water treatment plants (WWTPs) performance on the basis of modern technologies and methods; reconstruction of sewage systems and facilities and treatment quality improvement.

Problem of nuclear power plant reliability

International Nuclear Information System (INIS)

Popyrin, L.S.; Nefedov, Yu.V.

1989-01-01

The problem of substantiation of rational and methods of ensurance of NPP reliability at the stage of its designing has been studied. It is shown that the optimal level of NPP reliability is determined by coordinating solution of the proiblems for optimization of reliability of power industry, heat and power supply and nuclear power generation systems comprising NPP, and problems of reliability optimization of NPP proper, as a complex engineering system. The conclusion is made that the greatest attention should be paid to the development of mathematical models of reliability, taking into account different methods of equipment redundancy, as well as dependence of failures on barious factors, improvement of NPP reliability indices, development of data base, working out of the complec of consistent standards of reliability. 230 refs.; 2 figs.; 1 tab

Reliability analysis of the automatic control of the A-1 power plant coolant temperature

International Nuclear Information System (INIS)

Kuklik, B.; Semerad, V.; Chylek, Z.

Reliability analysis of the automatic control of the A-1 reactor coolant temperature is performed taking into account the effect of both the dependent failures and the routine maintenance of control system components. In a separate supplement, reliability analysis is reported of coincidence systems of the A-1 power plant reactor. Both safe and unsafe failures are taken into consideration as well as the effect of maintenance of the respective branch elements

Reliability and maintainability

International Nuclear Information System (INIS)

1994-01-01

Several communications in this conference are concerned with nuclear plant reliability and maintainability; their titles are: maintenance optimization of stand-by Diesels of 900 MW nuclear power plants; CLAIRE: an event-based simulation tool for software testing; reliability as one important issue within the periodic safety review of nuclear power plants; design of nuclear building ventilation by the means of functional analysis; operation characteristic analysis for a power industry plant park, as a function of influence parameters

Reliability of the Solar One plant during the power production phase: August 1, 1984--July 31, 1987

Energy Technology Data Exchange (ETDEWEB)

Kolb, G.J.; Lopez, C.W.

1988-10-01

The power production phase at Solar One spanned three years from August 1, 1984 through July 31, 1987. In that period the plant achieved an average availability, during hours of sunshine, of 81.7%. This report presents the frequencies and causes of the plant outages that occurred. The eleven most important causes composed 75% of the total outage time. Qualitative insights related to the origin and mitigation of these causes are provided. Also presented are insights and statistics regarding the reliability of the heliostat field. The quantitative and qualitative information presented in this report will be useful to studies aimed at improving the reliability of future solar central receiver power plants. 20 refs., 11 figs., 3 tabs.

Technologies for improving the availability and reliability of current and future water cooled nuclear power plants. Proceedings of a technical committee meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-11-01

One of the activities of the IAEA is to provide all Member States with an international source of balanced, objective information on advanced in technology for water cooled reactors. Since the global nuclear industry has a common interest in improving plant availability and reliability to assure specific individual plant and country perspective as well as to have an image of well managed competitive industry, the IAEA held a Technical Committee Meeting on Technologies for Improving the Availability and Reliability of Current and Future Water Cooled Nuclear Power Plants in September 1997. The basic aim to was to identify, review and exchange information on international developments in technologies for achieving high availability and reliability and to suggest areas where further technical advances could contribute to improvement of performance. Designs for future plants were presented in the context of how they can accommodate both the organizational and technical means for reaching even higher levels of performance. This proceedings contains the contributed papers presented at this Meeting each with a separate abstract. Four sessions were concerned with: policies, practices and procedures for achieving high reliability and availability; improving availability and reliability through better use of today`s technologies; recent advances in technologies for improving availability and reliability; achieving high availability for new plants Refs, figs, tabs

Technologies for improving the availability and reliability of current and future water cooled nuclear power plants. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1998-11-01

One of the activities of the IAEA is to provide all Member States with an international source of balanced, objective information on advanced in technology for water cooled reactors. Since the global nuclear industry has a common interest in improving plant availability and reliability to assure specific individual plant and country perspective as well as to have an image of well managed competitive industry, the IAEA held a Technical Committee Meeting on Technologies for Improving the Availability and Reliability of Current and Future Water Cooled Nuclear Power Plants in September 1997. The basic aim to was to identify, review and exchange information on international developments in technologies for achieving high availability and reliability and to suggest areas where further technical advances could contribute to improvement of performance. Designs for future plants were presented in the context of how they can accommodate both the organizational and technical means for reaching even higher levels of performance. This proceedings contains the contributed papers presented at this Meeting each with a separate abstract. Four sessions were concerned with: policies, practices and procedures for achieving high reliability and availability; improving availability and reliability through better use of today's technologies; recent advances in technologies for improving availability and reliability; achieving high availability for new plants

Medicinal plants in the treatment of cancer

Directory of Open Access Journals (Sweden)

Nenad M. Zlatić

2015-07-01

Full Text Available The purpose of this paper is to present a review of highly developed medicinal usages of plants in the treatment of cancer. In the last decades, the cancer treatment has been included in this range of plant use, due to plant active substances. Active substances or secondary metabolites are generally known for their widespread application. When it comes to the cancer treatment, these substances affect the uncontrolled cell division. Therefore, the plants which are the source of these substances are proved to be irreplaceable in this field of medicine. This paper deals with some of the most significant plants well known for their multiple aspects of beneficial medicinal influence. The group of the plants described is comprised of the following species: Taxus brevifolia (Taxaceae, Catharanthus roseus (Apocynaceae, Podophyllum peltatum (Berberidaceae, Camptotheca accuminata (Cornaceae, and Cephalotaxus harringtonia (Cephalotaxaceae. The comprehensive description of the plants in this paper includes the morphological characteristics, the features and the representation of the molecular structures of active substances, the particular influence that these active substances have and the general importance of the substances as seen from the aspect of cancer treatment mostly with reference to the impacts on cell cycle.

A Chronological Reliability Model to Assess Operating Reserve Allocation to Wind Power Plants: Preprint

International Nuclear Information System (INIS)

Milligan, M. R.

2001-01-01

As the use of wind power plants increases worldwide, it is important to understand the effect these power sources have on the operations of the grid. This paper focuses on the operating reserve impact of wind power plants. Many probabilistic methods have been applied to power system analysis, and some of these are the basis of reliability analysis. This paper builds on a probabilistic technique to allocate the operating reserve burden among power plants in the grid. The method was originally posed by Strbac and Kirschen[1] and uses an allocation that prorates the reserve burden based on expected energy not delivered. Extending this method to include wind power plants allows the reserve burden to be allocated among different plants using the same method, yet incorporates information about the intermittent nature of wind power plants

Collection and classification of human error and human reliability data from Indian nuclear power plants for use in PSA

International Nuclear Information System (INIS)

Subramaniam, K.; Saraf, R.K.; Sanyasi Rao, V.V.S.; Venkat Raj, V.; Venkatraman, R.

2000-01-01

Complex systems such as NPPs involve a large number of Human Interactions (HIs) in every phase of plant operations. Human Reliability Analysis (HRA) in the context of a PSA, attempts to model the HIs and evaluate/predict their impact on safety and reliability using human error/human reliability data. A large number of HRA techniques have been developed for modelling and integrating HIs into PSA but there is a significant lack of HAR data. In the face of insufficient data, human reliability analysts have had to resort to expert judgement methods in order to extend the insufficient data sets. In this situation, the generation of data from plant operating experience assumes importance. The development of a HRA data bank for Indian nuclear power plants was therefore initiated as part of the programme of work on HRA. Later, with the establishment of the coordinated research programme (CRP) on collection of human reliability data and use in PSA by IAEA in 1994-95, the development was carried out under the aegis of the IAEA research contract No. 8239/RB. The work described in this report covers the activities of development of a data taxonomy and a human error reporting form (HERF) based on it, data structuring, review and analysis of plant event reports, collection of data on human errors, analysis of the data and calculation of human error probabilities (HEPs). Analysis of plant operating experience does yield a good amount of qualitative data but obtaining quantitative data on human reliability in the form of HEPs is seen to be more difficult. The difficulties have been highlighted and some ways to bring about improvements in the data situation have been discussed. The implementation of a data system for HRA is described and useful features that can be incorporated in future systems are also discussed. (author)

CONSIDERATIONS FOR THE TREATMENT OF COMPUTERIZED PROCEDURES IN HUMAN RELIABILITY ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Ronald L. Boring; David I. Gertman

2012-07-01

Computerized procedures (CPs) are an emerging technology within nuclear power plant control rooms. While CPs have been implemented internationally in advanced control rooms, to date no US nuclear power plant has implemented CPs in its main control room. Yet, CPs are a reality of new plant builds and are an area of considerable interest to existing plants, which see advantages in terms of easier records management by omitting the need for updating hardcopy procedures. The overall intent of this paper is to provide a characterization of human reliability analysis (HRA) issues for computerized procedures. It is beyond the scope of this document to propose a new HRA approach or to recommend specific methods or refinements to those methods. Rather, this paper serves as a review of current HRA as it may be used for the analysis and review of computerized procedures.

25. MPA-seminar: safety and reliability of plant technology with special emphasis on safety and reliability - integrity proofs, qualification of components, damage prevention. Vol. 1. Papers 1-29

International Nuclear Information System (INIS)

1999-01-01

The proceedings of the 25th MPA Seminar on 'Safety and Reliability of Plant Technology' were issued in two volumes. The main topics of the first volume are: 1. Structural and safety analysis, 2. Reliability analysis, 3. Fracture mechanics, and 4. Nondestructive Testing. s

Investigation of the impact of main control room digitalization on operators cognitive reliability in nuclear power plants.

Science.gov (United States)

Zhou, Yong; Mu, Haiying; Jiang, Jianjun; Zhang, Li

2012-01-01

Currently, there is a trend in nuclear power plants (NPPs) toward introducing digital and computer technologies into main control rooms (MCRs). Safe generation of electric power in NPPs requires reliable performance of cognitive tasks such as fault detection, diagnosis, and response planning. The digitalization of MCRs has dramatically changed the whole operating environment, and the ways operators interact with the plant systems. If the design and implementation of the digital technology is incompatible with operators' cognitive characteristics, it may have negative effects on operators' cognitive reliability. Firstly, on the basis of three essential prerequisites for successful cognitive tasks, a causal model is constructed to reveal the typical human performance issues arising from digitalization. The cognitive mechanisms which they impact cognitive reliability are analyzed in detail. Then, Bayesian inference is used to quantify and prioritize the influences of these factors. It suggests that interface management and unbalanced workload distribution have more significant impacts on operators' cognitive reliability.

The significance of motivation in periodontal treatment: validity and reliability of the motivation assessment scale among patients undergoing periodontal treatment.

Science.gov (United States)

Pac, A; Oruba, Z; Olszewska-Czyż, I; Chomyszyn-Gajewska, M

2014-03-01

The individual evaluation of patients' motivation should be introduced to the protocol of periodontal treatment, as it could impact positively on effective treatment planning and treatment outcomes. However, a standardised tool measuring the extent of periodontal patients' motivation has not yet been proposed in the literature. Thus, the objective of the present study was to determine the validity and reliability of the Zychlińscy motivation scale adjusted to the needs of periodontology. Cross sectional study. Department of Periodontology and Oral Medicine, Dental University Clinic, Jagiellonian University, Krakow, Poland. 199 adult periodontal patients, aged 20-78. 14-item questionnaire. The items were adopted from the original Zychlińscy motivation assessment scale. Validity and reliability of the proposed motivation assessment instrument. The assessed Cronbach's alpha of 0.79 indicates the scale is a reliable tool. Principal component analysis revealed a model with three factors, which explained half of the total variance. Those factors represented: the patient's attitude towards treatment and oral hygiene practice; previous experiences during treatment; and the influence of external conditions on the patient's attitude towards treatment. The proposed scale proved to be a reliable and accurate tool for the evaluation of periodontal patients' motivation.

Handbook of human-reliability analysis with emphasis on nuclear power plant applications. Final report

Energy Technology Data Exchange (ETDEWEB)

Swain, A D; Guttmann, H E

1983-08-01

The primary purpose of the Handbook is to present methods, models, and estimated human error probabilities (HEPs) to enable qualified analysts to make quantitative or qualitative assessments of occurrences of human errors in nuclear power plants (NPPs) that affect the availability or operational reliability of engineered safety features and components. The Handbook is intended to provide much of the modeling and information necessary for the performance of human reliability analysis (HRA) as a part of probabilistic risk assessment (PRA) of NPPs. Although not a design guide, a second purpose of the Handbook is to enable the user to recognize error-likely equipment design, plant policies and practices, written procedures, and other human factors problems so that improvements can be considered. The Handbook provides the methodology to identify and quantify the potential for human error in NPP tasks.

Handbook of human-reliability analysis with emphasis on nuclear power plant applications. Final report

International Nuclear Information System (INIS)

Swain, A.D.; Guttmann, H.E.

1983-08-01

The primary purpose of the Handbook is to present methods, models, and estimated human error probabilities (HEPs) to enable qualified analysts to make quantitative or qualitative assessments of occurrences of human errors in nuclear power plants (NPPs) that affect the availability or operational reliability of engineered safety features and components. The Handbook is intended to provide much of the modeling and information necessary for the performance of human reliability analysis (HRA) as a part of probabilistic risk assessment (PRA) of NPPs. Although not a design guide, a second purpose of the Handbook is to enable the user to recognize error-likely equipment design, plant policies and practices, written procedures, and other human factors problems so that improvements can be considered. The Handbook provides the methodology to identify and quantify the potential for human error in NPP tasks

Water chemistry technology. One of the key technologies for safe and reliable nuclear power plant operation

International Nuclear Information System (INIS)

Uchida, Shunsuke; Katsumura, Yosuke

2013-01-01

Water chemistry control is one of the key technologies to establish safe and reliable operation of nuclear power plants. Continuous and collaborative efforts of plant manufacturers and plant operator utilities have been focused on optimal water chemistry control, for which, a trio of requirements for water chemistry should be simultaneously satisfied: (1) better reliability of reactor structures and fuel rods; (2) lower occupational exposure and (3) fewer radwaste sources. Various groups in academia have carried out basic research to support the technical bases of water chemistry in plants. The Research Committee on Water Chemistry of the Atomic Energy Society of Japan (AESJ), which has now been reorganized as the Division of Water Chemistry (DWC) of AESJ, has played important roles to promote improvements in water chemistry control, to share knowledge about and experiences with water chemistry control among plant operators and manufacturers and to establish common technological bases for plant water chemistry and then to transfer them to the next generation of plant workers engaged in water chemistry. Furthermore, the DWC has tried and succeeded arranging R and D proposals for further improvement in water chemistry control through roadmap planning. In the paper, major achievements in plant technologies and in basic research studies of water chemistry in Japan are reviewed. The contributions of the DWC to the long-term safe management of the damaged reactors at the Fukushima Daiichi Nuclear Power Plant until their decommissioning are introduced. (author)

Systems reliability/structural reliability

International Nuclear Information System (INIS)

Green, A.E.

1980-01-01

The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

Advanced chemistry management system for nuclear power plants

International Nuclear Information System (INIS)

Maeda, Katsuji; Kobayashi, Yasuhiro; Nagasawa, Katsumi

2000-01-01

Chemistry control in a boiling water reactor (BWR) plant has a close relationship with radiation field buildup, fuel reliability, integrity of plant components and materials, performance of the water treatment systems and radioactive waste generation. Chemistry management in BWR plants has become more important in order to maintain and enhance plant reliability. Adequate chemistry control and management are also essential to establish, maintain, and enhance plant availability. For these reasons, we have developed the advanced chemistry management system for nuclear power plants in order to effectively collect and evaluate a large number of plant operating and chemistry data. (author)

The obscure factor analysis on the vibration reliability of the internals of nuclear power plant reactor and anti-vibration measures

International Nuclear Information System (INIS)

Fu Geyan; Zhu Qirong

1998-11-01

It is pointed out that the main reason making nuclear power plants reactors leak is the vibration of internals of reactors. The factors which lead the vibration all have randomness and obscureness. The obscure reliability theory is introduced to the vibration system of internals of nuclear power reactor. Based on a quantity of designing and moving data, the obscure factors effecting the vibration reliability of the internals of nuclear power plant reactor are analyzed and the anti-vibration reliability criteria and the evaluating model are given. And the anti-vibration reliability measures are advanced from different quarters of the machine design and building, the thermohydraulics design, the control of reactivity, etc.. They may benefit the theory and practice for building and perfecting the vibration obscure reliability model of the reactor internals

Effect of communication on the reliability of nuclear power plant control room operations - pre study

International Nuclear Information System (INIS)

Kettunen, Jari; Pyy, Pekka

1999-01-01

The objective of the study presented in this paper is to investigate communication practices and their impact on human reliability and plant safety in a nuclear power plant environment. The study aims at developing a general systems approach towards the issue. The ultimate goal of the study is to contribute to the development of probabilistic safety assessment methodologies in the area of communications and crew co-operation. This paper outlines the results of the pre-study. The study is based on the use and further development of different modelling techniques and the application of generic systems engineering as well as crew resource management (CRM) principles. The results so far include a concise literature review on communication and crew performance, a presentation of some potential theoretical concepts and approaches for studying communication in relation to organisational reliability, causal failure sequences and human failures mechanisms, and an introduction of a General Communications Model (GCM) that is presented as a promising approach for studying the reliability and adequacy of communication transactions. Finally, some observations and recommendation concerning next phases of the study are made (author) (ml)

Reliability analysis of mining equipment: A case study of a crushing plant at Jajarm Bauxite Mine in Iran

International Nuclear Information System (INIS)

Barabady, Javad; Kumar, Uday

2008-01-01

The performance of mining machines depends on the reliability of the equipment used, the operating environment, the maintenance efficiency, the operation process, the technical expertise of the miners, etc. As the size and complexity of mining equipments continue to increase, the implications of equipment failure become ever more critical. Therefore, reliability analysis is required to identify the bottlenecks in the system and to find the components or subsystems with low reliability for a given designed performance. It is important to select a suitable method for data collection as well as for reliability analysis. This paper presents a case study describing reliability and availability analysis of the crushing plant number 3 at Jajarm Bauxite Mine in Iran. In this study, the crushing plant number 3 is divided into six subsystems. The parameters of some probability distributions, such as Weibull, Exponential, and Lognormal distributions have been estimated by using ReliaSoft's Weibull++6 software. The results of the analysis show that the conveyer subsystem and secondary screen subsystem are critical from a reliability point of view, and the secondary crusher subsystem and conveyer subsystem are critical from an availability point of view. The study also shows that the reliability analysis is very useful for deciding maintenance intervals

Waste treatment plant

International Nuclear Information System (INIS)

Adesanmi, C.A

2009-01-01

Waste Treatment Plant (WTP) is designed to provide appropriate systems for processing, immobilization and storage of low and medium radioactive waste arising from the operation of the research facilities of the Nuclear Technology Centre (NTC). It will serve as central collection station processing active waste generated through application of radionuclide in science, medicine and industry in the country. WTP building and structures will house the main waste processing systems and supporting facilities. All facilities will be interconnected. The interim storage building for processed waste drums will be located separately nearby. The separate interim storage building is located near the waste treatment building. Considering the low radiation level of the waste, storage building is large with no solid partitioning walls and with no services or extra facilities other than lighting and smoke alarm sensors. The building will be designed such that drums(200-1)are stacked 3 units high using handling by fork lift truck. To prevent radiation exposure to on-site personnel, the interim storage building will be erected apart from waste treatment plant or other buildings. The interim storage building will also be ready for buffer storage of unconditioned waste waiting for processing or decay and for storage material from the WTP

From reliability to maintenance of emergency generator sets in nuclear plants

International Nuclear Information System (INIS)

Reyraud, Y.

1986-01-01

The particular conditions of operation of emergency generator sets in a nuclear energy plant induce to take up a strategy of supervision and of maintenance very different of the one recommended for production generator sets. Mechanical and thermal pulls are affected by the size of the set and the choice of rotation running in respect of the wanted power and the response time requirements for the security of nuclear reactor. Reliability studies are helpful to define the strategy of supervision tests. The importance of the number of starts with respect to the running time requires the introduction of the idea of equivalent hours for the definition of maintenance periods. The security of the equipment and the upholding of the reliability at a value close to the optimum impose rigorous choices and strict conditions of supervision and maintenance [fr

Reliability of computerized safety systems at nuclear power plants. Report of a technical committee meeting held in Vienna, 21-25 June 1993

International Nuclear Information System (INIS)

1995-03-01

Computer based technology is increasingly used in order to perform safety functions. In some recently designed nuclear power plants the whole safety system is computerized. In older plants replacement of conventional technology based system is seen to be of benefit. If the new technology is to be used, it must meet at least the same level of quality and reliability requirements as specified for conventional technology. However, there is a potential for enhancing the safety of nuclear power plants if the full power of computer technology is applied correctly through well designed, engineered and tested systems which are properly installed and maintained. It is essential that areas where reliability and quality can be improved are identified and that methods for assessing and assuring reliability are developed. The results of the Technical Committee Meeting on Reliability of Computerized Safety Systems at Nuclear Power Plants presented in this report are a step on the road to this goal of improved nuclear safety. Refs, figs and tabs

Reliability engineering: Old problems and new challenges

International Nuclear Information System (INIS)

Zio, E.

2009-01-01

The first recorded usage of the word reliability dates back to the 1800s, albeit referred to a person and not a technical system. Since then, the concept of reliability has become a pervasive attribute worth of both qualitative and quantitative connotations. In particular, the revolutionary social, cultural and technological changes that have occurred from the 1800s to the 2000s have contributed to the need for a rational framework and quantitative treatment of the reliability of engineered systems and plants. This has led to the rise of reliability engineering as a scientific discipline. In this paper, some considerations are shared with respect to a number of problems and challenges which researchers and practitioners in reliability engineering are facing when analyzing today's complex systems. The focus will be on the contribution of reliability to system safety and on its role within system risk analysis

Uprading of existing treatment plants in Poland

OpenAIRE

Stene-Johansen, S.; Paulsrud, B.

1994-01-01

During the first Phase, diagnostic studies have been carried out at selected treatment plants in order to identify problems and how to improve treatment efficiency (Report 1 st. Phase). The report in hand (2nd. Phase) gives recommendations for upgrading/rehabilitation and other improvements based on full scale experiments at selected treatment plants. State Pollution Control Authority (SFT) The Royal Norwegian Ministry of Environment (MD)

Operation reliability analysis of independent power plants of gas-transmission system distant production facilities

Science.gov (United States)

Piskunov, Maksim V.; Voytkov, Ivan S.; Vysokomornaya, Olga V.; Vysokomorny, Vladimir S.

2015-01-01

The new approach was developed to analyze the failure causes in operation of linear facilities independent power supply sources (mini-CHP-plants) of gas-transmission system in Eastern part of Russia. Triggering conditions of ceiling operation substance temperature at condenser output were determined with mathematical simulation use of unsteady heat and mass transfer processes in condenser of mini-CHP-plants. Under these conditions the failure probability in operation of independent power supply sources is increased. Influence of environmental factors (in particular, ambient temperature) as well as output electric capability values of power plant on mini-CHP-plant operation reliability was analyzed. Values of mean time to failure and power plant failure density during operation in different regions of Eastern Siberia and Far East of Russia were received with use of numerical simulation results of heat and mass transfer processes at operation substance condensation.

Reliability analysis of microcomputer boards and computer based systems important to safety of nuclear plants

International Nuclear Information System (INIS)

Shrikhande, S.V.; Patil, V.K.; Ganesh, G.; Biswas, B.; Patil, R.K.

2010-01-01

Computer Based Systems (CBS) are employed in Indian nuclear plants for protection, control and monitoring purpose. For forthcoming CBS, Reactor Control Division has designed and developed a new standardized family of microcomputer boards qualified to stringent requirements of nuclear industry. These boards form the basic building blocks of CBS. Reliability analysis of these boards is being carried out using analysis package based on MIL-STD-217Plus methodology. The estimated failure rate values of these standardized microcomputer boards will be useful for reliability assessment of these systems. The paper presents reliability analysis of microcomputer boards and case study of a CBS system built using these boards. (author)

Application of reliability centred maintenance to optimize operation and maintenance in nuclear power plants

International Nuclear Information System (INIS)

2007-05-01

In order to increase Member States capabilities in utilizing good engineering and management practices the Agency has developed a series of Technical Documents (TECDOCs) to describe best practices and members experience in the application of them. This TECDOC describes the concept of Reliability Centred Maintenance (RCM) which is the term used to describe a systematic approach to the evaluation, design and development of cost effective maintenance programmes for plant and equipment. The concept has been in existence for over 25 years originating in the civil aviation sector. This TECDOC supplements previous IAEA publications on the subject and seeks to reflect members experience in the application of the principles involved. The process focuses on the functionality of the plant and equipment and the critical failure mechanisms that could result in the loss of functionality. When employed effectively the process can result in the elimination of unnecessary maintenance activities and the identification and introduction of measures to address deficiencies in the maintenance programme. Overall the process can result in higher levels of reliability for the plant and equipment at reduced cost and demands on finite maintenance resources. The application of the process requires interaction between the operators and the maintenance practitioners which is often lacking in traditional maintenance programmes. The imposition of this discipline produces the added benefit of improved information flows between the key players in plant and equipment management with the result that maintenance activities and operational practices are better informed. This publication was produced within IAEA programme on nuclear power plants operating performance and life cycle management

Integrated Life Cycle Management: A Strategy for Plants to Extend Operating Lifetimes Safely with High Operational Reliability

International Nuclear Information System (INIS)

Esselman, Thomas; Bruck, Paul; Mengers, Charles

2012-01-01

Nuclear plant operators are studying the possibility of extending their existing generating facilities operating lifetime to 60 years and beyond. Many nuclear plants have been granted licenses to operate their facilities beyond the original 40 year term; however, in order to optimize the long term operating strategies, plant decision-makers need a consistent approach to support their options. This paper proposes a standard methodology to support effective decision-making for the long-term management of selected station assets. Methods detailed are intended to be used by nuclear plant site management, equipment reliability personnel, long term planners, capital asset planners, license renewal staff, and others that intend to look at operation between the current time and the end of operation. This methodology, named Integrated Life Cycle Management (ILCM), will provide a technical basis to assist decision makers regarding the timing of large capital investments required to get to the end of operation safely and with high plant reliability. ILCM seeks to identify end of life cycle failure probabilities for individual plant large capital assets and attendant costs associated with their refurbishment or replacement. It will provide a standard basis for evaluation of replacement and refurbishment options for these components. ILCM will also develop methods to integrate the individual assets over the entire plant thus assisting nuclear plant decision-makers in their facility long term operating strategies. (author)

High reliable and Real-time Data Communication Network Technology for Nuclear Power Plant

International Nuclear Information System (INIS)

Jeong, K. I.; Lee, J. K.; Choi, Y. R.; Lee, J. C.; Choi, Y. S.; Cho, J. W.; Hong, S. B.; Jung, J. E.; Koo, I. S.

2008-03-01

As advanced digital Instrumentation and Control (I and C) system of NPP(Nuclear Power Plant) are being introduced to replace analog systems, a Data Communication Network(DCN) is becoming the important system for transmitting the data generated by I and C systems in NPP. In order to apply the DCNs to NPP I and C design, DCNs should conform to applicable acceptance criteria and meet the reliability and safety goals of the system. As response time is impacted by the selected protocol, network topology, network performance, and the network configuration of I and C system, DCNs should transmit a data within time constraints and response time required by I and C systems to satisfy response time requirements of I and C system. To meet these requirements, the DCNs of NPP I and C should be a high reliable and real-time system. With respect to high reliable and real-time system, several reports and techniques having influences upon the reliability and real-time requirements of DCNs are surveyed and analyzed

Modification of water treatment plant at Heavy Water Plant (Kota)

International Nuclear Information System (INIS)

Gajpati, C.R.; Shrivastava, C.S.; Shrivastava, D.C.; Shrivastava, J.; Vithal, G.K.; Bhowmick, A.

2008-01-01

Heavy Water Production by GS process viz. H 2 S - H 2 O bi-thermal exchange process requires a huge quantity of demineralized (DM) water as a source of deuterium. Since the deuterium recovery of GS process is only 18-19%, the water treatment plant (WTP) was designed and commissioned at Heavy Water Plant (Kota) to produce demineralized water at the rate of 680 m 3 /hr. The WTP was commissioned in 1980 and till 2005; the plant was producing DM water of required quality. It was having three streams of strong cation resin, atmospheric degasser and strong anion exchange resin with co-current regeneration. In 2001 a new concept of layered bed resin was developed and engineered for water treatment plant. The concept was attractive in terms of saving of chemicals and thus preservation of environment. Being an ISO 9000 and ISO 14000 plant, the modification of WTP was executed in 2005 during major turn around. After modification, a substantial amount of acid and alkali is saved

Operational safety reliability research

International Nuclear Information System (INIS)

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

1986-01-01

Operating reactor events such as the TMI accident and the Salem automatic-trip failures raised the concern that during a plant's operating lifetime the reliability of systems could degrade from the design level that was considered in the licensing process. To address this concern, NRC is sponsoring the Operational Safety Reliability Research project. The objectives of this project are to identify the essential tasks of a reliability program and to evaluate the effectiveness and attributes of such a reliability program applicable to maintaining an acceptable level of safety during the operating lifetime at the plant

An Ultrasonic Multi-Beam Concentration Meter with a Neuro-Fuzzy Algorithm for Water Treatment Plants.

Science.gov (United States)

Lee, Ho-Hyun; Jang, Sang-Bok; Shin, Gang-Wook; Hong, Sung-Taek; Lee, Dae-Jong; Chun, Myung Geun

2015-10-23

Ultrasonic concentration meters have widely been used at water purification, sewage treatment and waste water treatment plants to sort and transfer high concentration sludges and to control the amount of chemical dosage. When an unusual substance is contained in the sludge, however, the attenuation of ultrasonic waves could be increased or not be transmitted to the receiver. In this case, the value measured by a concentration meter is higher than the actual density value or vibration. As well, it is difficult to automate the residuals treatment process according to the various problems such as sludge attachment or sensor failure. An ultrasonic multi-beam concentration sensor was considered to solve these problems, but an abnormal concentration value of a specific ultrasonic beam degrades the accuracy of the entire measurement in case of using a conventional arithmetic mean for all measurement values, so this paper proposes a method to improve the accuracy of the sludge concentration determination by choosing reliable sensor values and applying a neuro-fuzzy learning algorithm. The newly developed meter is proven to render useful results from a variety of experiments on a real water treatment plant.

Seismic proving tests on the reliability for large components and equipment of nuclear power plants

International Nuclear Information System (INIS)

Ohno, Tokue; Tanaka, Nagatoshi

1988-01-01

Since Japan has destructive earthquakes frequently, the structural reliability for large components and equipment of nuclear power plants are rigorously required. They are designed using sophisticated seismic analyses and have not yet encountered a destructive earthquake. When nuclear power plants are planned, it is very important that the general public understand the structural reliability during and after an earthquake. Seismic Proving Tests have been planned by Ministry of International Trade and Industry (Miti) to comply with public requirement in Japan. A large-scale high-performance vibration table was constructed at Tasted Engineering Laboratory of Nuclear Power Engineering Test Center (NU PEC), in order to prove the structural reliability by vibrating the test model (of full scale or close to the actual size) in the condition of a destructive earthquake. As for the test models, the following four items were selected out of large components and equipment important to the safety: Reactor Containment Vessel; Primary Coolant Loop or Primary Loop Recirculation System; Reactor Pressure Vessel; and Reactor Core Internals. Here is described a brief of the vibration table, the test method and the results of the tests on PWR Reactor Containment Vessel and BWR Primary Loop Recirculation System (author)

Reliability of dc power supplies in nuclear power plant application

International Nuclear Information System (INIS)

Eisenhut, D.G.

1978-01-01

In June 1977 the reliability of dc power supplies at nuclear power facilities was questioned. It was postulated that a sudden gross failure of the redundant dc power supplies might occur during normal plant operation, and that this could lead to insufficient shutdown cooling of the reactor core. It was further suggested that this potential for insufficient cooling is great enough to warrant consideration of prompt remedies. The work described herein was part of the NRC staff's efforts aimed towards putting the performance of dc power supplies in proper perspective and was mainly directed towards the particular concern raised at that time. While the staff did not attempt to perform a systematic study of overall dc power supply reliability including all possible failure modes for such supplies, the work summarized herein describes how a probabilistic approach was used to supplement our more usual deterministic approach to reactor safety. Our evaluation concluded that the likelihood of dc power supply failures leading to insufficient shutdown cooling of the reactor core is sufficiently small as to not require any immediate action

Utilizing reliability concepts in the development of IEEE recommended good practices for nuclear plant maintenance

International Nuclear Information System (INIS)

Gradin, L.P.

1986-01-01

This paper presents information describing the concern for nuclear power plant electrical equipment maintenance and the IEEE Nuclear Power Engineering Committee's method to address that concern. That method includes the creation of Working Group 3.3, ''Maintenance Good Practices'' which is developing specific maintenance good practice documents, supporting technical information exchange, and providing a vehicle to promote practices which can reduce cost and enhance plant safety. The foundation for that effort is the utilization of Reliability concepts

Electron beam treatment plant for textile dyeing wastewater

International Nuclear Information System (INIS)

Han, B.; Kim, J.; Kim, Y.; Choi, J.; Ahn, S.; Makarov, I.E.; Ponomarev, A.V.

2006-01-01

A pilot plant for treating 1,000 m 3 of textile dyeing wastewater per day with electron beam has constructed and operated continuously in Daegu, Korea since 1998. This plant is combined with biological treatment system and it shows the reduction of chemical reagent consumption, and also the reduction in retention time with the increase in removal efficiencies of COD Cr and BOD 5 up to 30∼40%. Increase in biodegradability after radiation treatment of aqueous-organic systems is due to radiolytical conversions of non-biodegradable compounds. On the basis of data obtained from pilot plant operation, construction of actual industrial scale plant has started in 2003, and will be finished by 2005. This plant is located on the area of existing wastewater treatment facility (Daegu Dyeing Industrial Complex) and to have treatment capacity 10,000 m 3 of wastewater per day using one 1 MeV, 400 kW accelerator, and combined with existing bio- treatment facility. The overall construction cost and the operation cost in the radiation processing, when compared to other conventional and advanced oxidation techniques, are more cost-effective and convenient for wastewater treatment. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government. (author)

Fate of pharmaceuticals and personal care products in wastewater treatment plants - Conception of a database and first results

International Nuclear Information System (INIS)

Miege, C.; Choubert, J.M.; Ribeiro, L.; Eusebe, M.; Coquery, M.

2009-01-01

We created a database in order to quantitatively assess the occurrence and removal efficiency of pharmaceuticals and personal care products (PPCPs) in wastewater treatment plants (WWTPs). From 117 scientific publications, we compiled 6641 data covering 184 PPCPs. Data included the concentrations of PPCPs in WWTP influents and effluents, their removal efficiency and their loads to the aquatic environment. The first outputs of our database allowed to identify the most investigated PPCPs in WWTPs and the most persistent ones, and to obtain reliable and quantitative values on their concentrations, frequency of detection and removal efficiency in WWTPs. We were also able to compare various processes and pointed out activated sludge with nitrogen treatment and membrane bioreactor as the most efficient ones. - By means of a database including information from 117 international scientific papers, we present quantitative conclusions on the concentrations, frequencies of detection and removals of pharmaceutical products in wastewater treatment plants.

A method and application study on holistic decision tree for human reliability analysis in nuclear power plant

International Nuclear Information System (INIS)

Sun Feng; Zhong Shan; Wu Zhiyu

2008-01-01

The paper introduces a human reliability analysis method mainly used in Nuclear Power Plant Safety Assessment and the Holistic Decision Tree (HDT) method and how to apply it. The focus is primarily on providing the basic framework and some background of HDT method and steps to perform it. Influence factors and quality descriptors are formed by the interview with operators in Qinshan Nuclear Power Plant and HDT analysis performed for SGTR and SLOCA based on this information. The HDT model can use a graphic tree structure to indicate that error rate is a function of influence factors. HDT method is capable of dealing with the uncertainty in HRA, and it is reliable and practical. (authors)

ORNL process waste treatment plant modifications

International Nuclear Information System (INIS)

Bell, J.P.

1982-01-01

The ORNL Process Waste Treatment Plant removes low levels of radionuclides (primarily Cs-137 and Sr-90) from process waste water prior to discharge. The previous plant operation used a scavenging precipitaton - ion exchange process which produced a radioactive sludge. In order to eliminate the environmental problems associated with sludge disposal, the plant is being converted to a new ion exchange process without the precipitation process

Waste Treatment & Immobilization Plant Project

Data.gov (United States)

Federal Laboratory Consortium — In southeastern Washington State, Bechtel National, Inc. is designing, constructing and commissioning the world's largest radioactive waste treatment plant for the...

Emergence of native plant seeds in response to seed pelleting, planting depth, scarification, and soil anti-crusting treatment, 2009

Science.gov (United States)

Clint Shock; Erik Feibert; Lamont Saunders; Nancy Shaw

2010-01-01

Seed of native plants is needed to restore rangelands of the Intermountain West. Reliable commercial seed production is desirable to provide the quantity of seed needed for restoration efforts. Establishment of native seed crops has been difficult, because fall-planted seed is susceptible to bird damage, soil crusting, and soil erosion. Fall planting is important for...

Neuropsychological Aspects Observed in a Nuclear Plant Simulator and its Relation with Human Reliability Analysis

International Nuclear Information System (INIS)

Prado, E.A.P. do; Martins, M.; Pinheiro, A.; Silveira, J.

2016-01-01

This paper will discuss preliminary results of an evaluation methodology for the analysis and quantification of errors in manual (human) operation by training cognitive parameters and skill levels in the complex control system operation using Neuropsychophysiology and Neuro feedback equipment. The research was conducted using a game (nuclear power plant simulator) that simulates concepts of operation of a nuclear plant with a split sample evaluating aspects of learning and knowledge in the nuclear area. Operators were monitored using biomarkers (ECG, EEG, GSR, face detection and eye tracking) and the results were analyzed by Statistical multivariate techniques. An important component in the evaluation of complex systems is the human reliability during operation. Human reliability refers to the probability of the human element perform the tasks scheduled during the defined period for system operation when tested under specified environmental conditions, and additionally not to take any action detrimental to system operation.

Reliability data book

International Nuclear Information System (INIS)

Bento, J.P.; Boerje, S.; Ericsson, G.; Hasler, A.; Lyden, C.O.; Wallin, L.; Poern, K.; Aakerlund, O.

1985-01-01

The main objective for the report is to improve failure data for reliability calculations as parts of safety analyses for Swedish nuclear power plants. The work is based primarily on evaluations of failure reports as well as information provided by the operation and maintenance staff of each plant. In the report are presented charts of reliability data for: pumps, valves, control rods/rod drives, electrical components, and instruments. (L.E.)

Wastewater sludge treatment at selected wastewater treatment plants of the region Banska Bystrica

International Nuclear Information System (INIS)

Samesova, D.; Mitterpach, J.; Martinkova, A.

2014-01-01

The management of sewage sludges in water treatment plants of Banska Bystrica region. The paper deals with the problems of sewage sludge in wastewater treatment plants, its origin and possibilities how to use it in accordance with the current legislation of the Slovak Republic. We described radioactive pollution of sewage sludges. The paper consists of review of sludge production and its usage in the Slovak Republic and in selected states of the European Union. The paper deals with the sludge treatment in selected wastewater treatment plants in Banska Bystrica region in the context of biogas production and its usage by the help of the electricity and heat production. (authors)

Software reliability evaluation of digital plant protection system development process using V and V

International Nuclear Information System (INIS)

Lee, Na Young; Hwang, Il Soon; Seong, Seung Hwan; Oh, Seung Rok

2001-01-01

In the nuclear power industry, digital technology has been introduced recently for the Instrumentation and Control (I and C) of reactor systems. For its application to the safety critical system such as Reactor Protection System(RPS), a reliability assessment is indispensable. Unlike traditional reliability models, software reliability is hard to evaluate, and should be evaluated throughout development lifecycle. In the development process of Digital Plant Protection System(DPPS), the concept of verification and validation (V and V) was introduced to assure the quality of the product. Also, test should be performed to assure the reliability. Verification procedure with model checking is relatively well defined, however, test is labor intensive and not well organized. In this paper, we developed the methodological process of combining the verification with validation test case generation. For this, we used PVS for the table specification and for the theorem proving. As a result, we could not only save time to design test case but also get more effective and complete verification related test case set. Add to this, we could extract some meaningful factors useful for the reliability evaluation both from the V and V and verification combined tests

System Statement of Tasks of Calculating and Providing the Reliability of Heating Cogeneration Plants in Power Systems

Science.gov (United States)

Biryuk, V. V.; Tsapkova, A. B.; Larin, E. A.; Livshiz, M. Y.; Sheludko, L. P.

2018-01-01

A set of mathematical models for calculating the reliability indexes of structurally complex multifunctional combined installations in heat and power supply systems was developed. Reliability of energy supply is considered as required condition for the creation and operation of heat and power supply systems. The optimal value of the power supply system coefficient F is based on an economic assessment of the consumers’ loss caused by the under-supply of electric power and additional system expences for the creation and operation of an emergency capacity reserve. Rationing of RI of the industrial heat supply is based on the use of concept of technological margin of safety of technological processes. The definition of rationed RI values of heat supply of communal consumers is based on the air temperature level iside the heated premises. The complex allows solving a number of practical tasks for providing reliability of heat supply for consumers. A probabilistic model is developed for calculating the reliability indexes of combined multipurpose heat and power plants in heat-and-power supply systems. The complex of models and calculation programs can be used to solve a wide range of specific tasks of optimization of schemes and parameters of combined heat and power plants and systems, as well as determining the efficiency of various redundance methods to ensure specified reliability of power supply.

Reliability-based service life assessment of concrete structures in nuclear power plants: optimum inspection and repair

International Nuclear Information System (INIS)

Ellingwood, B.R.; Mori, Y.

1995-01-01

Research is being conducted to address aging management of safety-related reinforced concrete structures in nuclear power plants (NPPs). Documentation is being prepared to identify potential structural safety issues and to recommend criteria for use in evaluating reinforced concrete structures for continued service. Time-dependent reliability analysis provides the framework and quantitative tools for the condition assessment. The role of in-service inspection and repair in ensuring continued reliability in-service is examined. (author). 19 refs., 4 figs

RIO: a program to determine reliability importance and allocate optimal reliability goals

International Nuclear Information System (INIS)

Poloski, J.P.

1978-09-01

The designer of a nuclear plant must know the plant's associated risk limitations so that he can design the plant accordingly. To design a safety system, he must understand its importance and how it relates to the overall plant risk. The computer program RIO can aid the designer to understand a system's contribution to the plant's overall risk. The methodology developed and presented was sponsored by the Nuclear Research Applications Division of the Department of Energy for use in the Gas Cooled Fast Breeder Reactor (GCFR) Program. The principal motivation behind its development was the need to translate nuclear plants safety goals into reliability goals for systems which make up that plant. The method described herein will make use of the GCFR Accident Initiation and Progression Analyses (AIPA) event trees and other models in order to determine these reliability goals

Toxicity measurement in a waste water treatment plants using active sludge aerobic biological treatment. Medida de la toxicidad en una estacion depuradora de aguas residuales con tratamiento biologico aerobio por fangos activos

Energy Technology Data Exchange (ETDEWEB)

Serrano, J.E. (Surcis, Guadalajara (Spain))

1994-01-01

The need for reliability in the operation of waste water treatment plants is discussed. In aerobic biological treatments of whatever kind using active sludge, the bio toxicity can be determined by measuring the oxygen consumed in endogenous breathing. The difficulty lies in carrying out the bio toxicity test without effecting the concentration of the organic substrate of the wastes water. This is overcome by operating at maximum organic material load, thereby inducing maximun breathing. (Author)

An Update on Modifications to Water Treatment Plant Model

Science.gov (United States)

Water treatment plant (WTP) model is an EPA tool for informing regulatory options. WTP has a few versions: 1). WTP2.2 can help in regulatory analysis. An updated version (WTP3.0) will allow plant-specific analysis (WTP-ccam) and thus help meet plant-specific treatment objectives...

Developing Predictive Maintenance Expertise to Improve Plant Equipment Reliability

International Nuclear Information System (INIS)

Wurzbach, Richard N.

2002-01-01

On-line equipment condition monitoring is a critical component of the world-class production and safety histories of many successful nuclear plant operators. From addressing availability and operability concerns of nuclear safety-related equipment to increasing profitability through support system reliability and reduced maintenance costs, Predictive Maintenance programs have increasingly become a vital contribution to the maintenance and operation decisions of nuclear facilities. In recent years, significant advancements have been made in the quality and portability of many of the instruments being used, and software improvements have been made as well. However, the single most influential component of the success of these programs is the impact of a trained and experienced team of personnel putting this technology to work. Changes in the nature of the power generation industry brought on by competition, mergers, and acquisitions, has taken the historically stable personnel environment of power generation and created a very dynamic situation. As a result, many facilities have seen a significant turnover in personnel in key positions, including predictive maintenance personnel. It has become the challenge for many nuclear operators to maintain the consistent contribution of quality data and information from predictive maintenance that has become important in the overall equipment decision process. These challenges can be met through the implementation of quality training to predictive maintenance personnel and regular updating and re-certification of key technology holders. The use of data management tools and services aid in the sharing of information across sites within an operating company, and with experts who can contribute value-added data management and analysis. The overall effectiveness of predictive maintenance programs can be improved through the incorporation of newly developed comprehensive technology training courses. These courses address the use of

Human Reliability analysis for digitized nuclear power plants: Case study on the LingAo II nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Zou, Yan Hua; Zhang, Li [Institute of Human Factors Engineering AND Safety Management, Hunan Institute of Technology, Hengyang (China); Dai, Cao; Li, Peng Cheng; Qing, Tao [Human Factors Institute, University of South China, Hengyang (China)

2017-03-15

The main control room (MCR) in advanced nuclear power plants (NPPs) has changed from analog to digital control system (DCS). Operation and control have become more automated, centralized, and accurate due to the digitalization of NPPs, which has improved the efficiency and security of the system. New issues associated with human reliability inevitably arise due to the adoption of new accident procedures and digitalization of main control rooms in NPPs. The LingAo II NPP is the first digital NPP in China to apply the state-oriented procedure. In order to address issues related to human reliability analysis for DCS and DCS + state-oriented procedure, the Hunan Institute of Technology conducted a research project based on a cooperative agreement with the LingDong Nuclear Power Co. Ltd. This paper is a brief introduction to the project.

Human Reliability Analysis for Digitized Nuclear Power Plants: Case Study on the LingAo II Nuclear Power Plant

Directory of Open Access Journals (Sweden)

Yanhua Zou

2017-03-01

Full Text Available The main control room (MCR in advanced nuclear power plants (NPPs has changed from analog to digital control system (DCS. Operation and control have become more automated, centralized, and accurate due to the digitalization of NPPs, which has improved the efficiency and security of the system. New issues associated with human reliability inevitably arise due to the adoption of new accident procedures and digitalization of main control rooms in NPPs. The LingAo II NPP is the first digital NPP in China to apply the state-oriented procedure. In order to address issues related to human reliability analysis for DCS and DCS + state-oriented procedure, the Hunan Institute of Technology conducted a research project based on a cooperative agreement with the LingDong Nuclear Power Co. Ltd. This paper is a brief introduction to the project.

Plant-integrated measurement of greenhouse gas emissions from a municipal wastewater treatment plant

DEFF Research Database (Denmark)

Yoshida, Hiroko; Mønster, Jacob; Scheutz, Charlotte

2014-01-01

experiencing operational problems, such as during foaming events in anaerobic digesters and during sub-optimal operation of biological nitrogen removal in the secondary treatment of wastewater. Methane emissions detected during measurement campaigns corresponded to 2.07-32.7% of the methane generated......Wastewater treatment plants (WWTPs) contribute to anthropogenic greenhouse gas (GHG) emissions. Due to its spatial and temporal variation in emissions, whole plant characterization of GHG emissions from WWTPs face a number of obstacles. In this study, a tracer dispersion method was applied...... in the plant. As high as 4.27% of nitrogen entering the WWTP was emitted as nitrous oxide under the sub-optimal operation of biological treatment processes. The study shows that the unit process configuration, as well as the operation of the WWTP, determines the rate of GHG emission. The applied plant...

Treatment of wastewaters from manufactured gas plants

Energy Technology Data Exchange (ETDEWEB)

Cocheci, V.; Bogatu, C.; Radovan, C. [Technical University of Timisoara, Timisoara (Romania)

1995-12-31

The treatment of wastewaters with high concentrations of organic compounds often represents a difficult problem. In some cases, for the destruction and removal of toxic compounds using processes like biological and chemical oxidation were proposed. Wastewaters from manufactured gas plants contain high concentrations of organic pollutants and ammonia. In this paper a technology for the treatment of these wastewaters is proposed. The experiments were realized with wastewaters from two Romanian manufactured gas plants. The process consists of the following steps: polycondensation-settling-stripping-biological treatment-electrocoagulation-electrochemical oxidation, or chemical oxidation. 6 refs., 4 tabs.

Reliability analysis of repairable safety systems of a reprocessing plant allowing for tolerable system downtimes

International Nuclear Information System (INIS)

Schaefer, H.

1987-01-01

GRS has been engaged in safety analysises of the German Reprocessing Plant for several years. The development and verification of appropriate reliability analysis methods, the generation of data as well as the search for an adequate structural presentation of the results to form a basis of recommendations for technical or administrative measures or contributions to risk oriented evaluations have been or are in the process of being established. In contrast to NPP-studies, the reliability assessment of safety systems of a reprocessing plant is applied to repairable and often relatively small systems allowing for tolerable system downtimes. A sketch of the diverse cooling systems of a vessel containing a selfheating solution is given. The interruption of the cooling function for about one day might be tolerable before boiling will be reached. This interval is suitable for transfer of the solution to a spare vessel or for repairing the failed components, thus restoring the cooling function

A new modular procedure for industrial plant simulations and its reliable implementation

International Nuclear Information System (INIS)

Carcasci, C.; Marini, L.; Morini, B.; Porcelli, M.

2016-01-01

Modeling of industrial plants, and especially energy systems, has become increasingly important in industrial engineering and the need for accurate information on their behavior has grown along with the complexity of the industrial processes. Consequently, accurate and flexible simulation tools became essential yielding the development of modular codes. The aim of this work is to propose a new modular mathematical modeling for industrial plant simulation and its reliable numerical implementation. Regardless of their layout, a large class of plant's configurations is modeled by a library of elementary parts; then the physical properties, compositions of the working fluid, and plant's performance are estimated. Each plant component is represented by equations modeling fundamental mechanical and thermodynamic laws and giving rise to a system of algebraic nonlinear equations; remarkably, suitable restrictions on the variables of such nonlinear equations are imposed to guarantee solutions of physical meaning. The proposed numerical procedure combines an outer iterative process which refines plants characteristic parameters and an inner one which solves the arising nonlinear systems and consists of a trust-region solver for bound-constrained nonlinear equalities. The new procedure has been validated performing simulations against an existing modular tool on two compression train arrangements with both series and parallel-mounted compressors. - Highlights: • A numerical modular tool for industrial plants simulation is presented. • Mathematical modeling is thoroughly described. • Solution of the nonlinear system is performed by a trust-region Gauss–Newton solver. • A detailed explanation of the optimization solver named TRESNEI is provided. • Code flexibility and robustness are investigated through numerical simulations.

Assessing the adequacy and reliability of fire barriers in nuclear power plants

International Nuclear Information System (INIS)

Beard, A.N.

1991-01-01

Fire barriers on nuclear power plants are essential for proper segregation of redundant trains of safety equipment. The contribution they make to nuclear safety is obviously significant, but difficult to quantify. As a result, the analysis of fire barriers for nuclear safety justification purposes tends to concentrate on demonstrating that they are adequate instead. The paper discusses various methods of analysing fire barriers and introduces work being completed on a method for quantifying the reliability of a fire barrier. (orig.)

Effectiveness of different pre-treatments in recovering pre-burial isotopic ratios of charred plants.

Science.gov (United States)

Brinkkemper, O; Braadbaart, F; van Os, B; van Hoesel, A; van Brussel, A A N; Fernandes, R

2018-02-15

Isotopic analysis of archaeological charred plant remains offers useful archaeological information. However, adequate sample pre-treatment protocols may be necessary to provide a contamination-free isotopic signal while limiting sample loss and achieving a high throughput. Under these constraints, research was undertaken to compare the performance of different pre-treatment protocols. Charred archaeological plant material was selected for isotopic analysis (δ 13 C and δ 15 N values) by isotope ratio mass spectrometry from a variety of plant species, time periods and soil conditions. Preservation conditions and the effectiveness of cleaning protocols were assessed through Fourier transform infrared spectroscopy and X-ray fluorescence (XRF) spectrometry. An acid-base-acid protocol, successfully employed in radiocarbon dating, was used to define a contamination-free isotopic reference. Acid-base-acid isotopic measurements were compared with those obtained from untreated material and an acid-only protocol. The isotopic signals of untreated material and the acid-only protocol typically did not differ more than 1‰ from those of the acid-base-acid reference. There were no significant isotopic offsets between acid-base-acid and acid-only or untreated samples. Sample losses in the acid-base-acid protocol were on average 50 ± 17% (maximum = 98.4%). Elemental XRF measurements showed promising results in the detection of more contaminated samples albeit with a high rate of false positives. For the large range of preservation conditions described in the study, untreated charred plant samples, water cleaned of sediments, provide reliable stable isotope ratios of carbon and nitrogen. The use of pre-treatments may be necessary under different preservation conditions or more conservative measurement uncertainties should be reported. Copyright © 2017 John Wiley & Sons, Ltd.

Advanced control systems to improve nuclear power plant reliability and efficiency

International Nuclear Information System (INIS)

1997-07-01

The TECDOC is the result of a series of an advisory and consultants meetings held by the IAEA in 1995-1996 in Vienna (March 1995), in Erlangen Germany (December 1995), in Garching, Germany (June 1996) and in Vienna (November 1996). It was prepared with the participation and contributions of experts from Austria, Canada, Finland, France, Germany, the Republic of Korea, Norway, the Russian Federation, the United Kingdom and the United States of America. The publication not only describes advanced control systems for the improvement of nuclear power plant reliability and efficiency, but also provides a road map to guide interested readers to plan and execute an advanced instrumentation and control project. The subjects include: identification of needs and requirements, justification for safety and user acceptance, and the development of an engineering process. The report should be of interest to nuclear power plant staff, I and C system designers and integrators as well as regulators and researchers. Refs, figs, tabs

Advanced control systems to improve nuclear power plant reliability and efficiency

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-07-01

The TECDOC is the result of a series of an advisory and consultants meetings held by the IAEA in 1995-1996 in Vienna (March 1995), in Erlangen Germany (December 1995), in Garching, Germany (June 1996) and in Vienna (November 1996). It was prepared with the participation and contributions of experts from Austria, Canada, Finland, France, Germany, the Republic of Korea, Norway, the Russian Federation, the United Kingdom and the United States of America. The publication not only describes advanced control systems for the improvement of nuclear power plant reliability and efficiency, but also provides a road map to guide interested readers to plan and execute an advanced instrumentation and control project. The subjects include: identification of needs and requirements, justification for safety and user acceptance, and the development of an engineering process. The report should be of interest to nuclear power plant staff, I and C system designers and integrators as well as regulators and researchers. Refs, figs, tabs.

Pilot plant for flue gas treatment - continuous operation tests

International Nuclear Information System (INIS)

Chmielewski, A.G.; Tyminski, B.; Iller, E.; Zimek, Z.; Licki, J.; Radzio, B.

1995-01-01

Tests of continuous operation have been performed on pilot plant at EPS Kaweczyn in the wide range of SO 2 concentration (500-3000 ppm). The bag filter has been applied for aerosol separation. The high efficiencies of SO 2 and NO x removal, approximately 90% were obtained and influenced by such process parameters as: dose, gas temperature and ammonia stoichiometry. The main apparatus of the pilot plant (e.g. both accelerators) have proved their reliability in hard industrial conditions. (Author)

Study on the Management for the Nuclear Power Plant Maintenance and Equipment Reliability

International Nuclear Information System (INIS)

Yoon, Kyeongseop; Lee, Sangheon; Kim, Myungjin; Lee, Unjang

2015-01-01

In our country, many studies on the regulatory policy of the plant maintenance have ever been performed since 1998, but the relevant regulatory requirements were not established yet. These background mentioned above request us to study on the regulation policy and maintenance plan to improve the safety, reliability and efficiency of NPP. To solve these problems, in this study, we deduct the management methodology for the improvement of NPP maintenance and equipment reliability that is essential to secure the safety and efficiency of the commercial NPP. For analysis the maintenance and equipment reliability management methodology in overseas NPP. We studied maintenance and equipment reliability of USA, Canada and Europe(France, England, German). We also studied status and application condition of Korean NPP maintenance management technical development. We deducted an effective maintenance methodology that is needed to Korean NPP, as a result of comparison on the technical trend of the maintenance management between overseas and Korean, such like following. - Regulation form ·Specific provision of regulation requirement and application of form that is clarifying application standard - Maintenance management methodology, Maintenance management program. This results of study could be applied for regulation policy, law and guideline establishment of NPP maintenance, operation, supervision and a system establishment for maintenance management, education data about maintenance for NPP employees

The purpose and organisation of reliability and risk assessment studies for power plant in operation

International Nuclear Information System (INIS)

Ohlmeier, H.

1989-01-01

Upon recommendation of the Reaktorsicherheitskommission RSK, specific, probabilistic safety analyses have to be made within the next few years for every nuclear power plant in operation. The paper deals with the activities and tasks and the necessary organisational preparations to be made for carrying out the studies. A systematic determination of reliability parameters and establishment of suitable computer codes are one of the major tasks in the preparatory phase, and information for further quantification of safety reserves and more plant-specific emergency management plans will be major results of the studies. (orig.) [de

Method of reliability allocation based on fault tree analysis and fuzzy math in nuclear power plants

International Nuclear Information System (INIS)

Chen Zhaobing; Deng Jian; Cao Xuewu

2005-01-01

Reliability allocation is a kind of a difficult multi-objective optimization problem. It can not only be applied to determine the reliability characteristic of reactor systems, subsystem and main components but also be performed to improve the design, operation and maintenance of nuclear plants. The fuzzy math known as one of the powerful tools for fuzzy optimization and the fault analysis deemed to be one of the effective methods of reliability analysis can be applied to the reliability allocation model so as to work out the problems of fuzzy characteristic of some factors and subsystem's choice respectively in this paper. Thus we develop a failure rate allocation model on the basis of the fault tree analysis and fuzzy math. For the choice of the reliability constraint factors, we choose the six important ones according to practical need for conducting the reliability allocation. The subsystem selected by the top-level fault tree analysis is to avoid allocating reliability for all the equipment and components including the unnecessary parts. During the reliability process, some factors can be calculated or measured quantitatively while others only can be assessed qualitatively by the expert rating method. So we adopt fuzzy decision and dualistic contrast to realize the reliability allocation with the help of fault tree analysis. Finally the example of the emergency diesel generator's reliability allocation is used to illustrate reliability allocation model and improve this model simple and applicable. (authors)

Reliability and risk treatment centered maintenance

International Nuclear Information System (INIS)

Pexa, Martin; Hladik, Tomas; Ales, Zdenek; Legat, Vaclav; Muller, Miroslav; Valasek, Petr; Havlu, Vit

2014-01-01

We propose a new methodology for application of well-known tools - RCM, RBI and SIF pro - with the aim to treat risks by means of suitable maintenance. The basis of the new methodology is the complex application of all three methods at the same time and not separately as is typical today. The proposed methodology suggests having just one managing team for reliability and risk treatment centred maintenance (RRTCM), employing existing RCM, RBI, and SIFpro tools concurrently. This approach allows for significant reduction of engineering activities' duration. In the proposed methodology these activities are staged into five phases and structured to eliminate all duplication resulting from separate application of the three tools. The newly proposed methodology saves 45% to 50% of the engineering workload and dequate significant financial savings.

Reliability and risk treatment centered maintenance

Energy Technology Data Exchange (ETDEWEB)

Pexa, Martin; Hladik, Tomas; Ales, Zdenek; Legat, Vaclav; Muller, Miroslav; Valasek, Petr [Czech University of Life Sciences Prague, Kamycka (Czech Republic); Havlu, Vit [Unipetrol A. S, Prague (Czech Republic)

2014-10-15

We propose a new methodology for application of well-known tools - RCM, RBI and SIF pro - with the aim to treat risks by means of suitable maintenance. The basis of the new methodology is the complex application of all three methods at the same time and not separately as is typical today. The proposed methodology suggests having just one managing team for reliability and risk treatment centred maintenance (RRTCM), employing existing RCM, RBI, and SIFpro tools concurrently. This approach allows for significant reduction of engineering activities' duration. In the proposed methodology these activities are staged into five phases and structured to eliminate all duplication resulting from separate application of the three tools. The newly proposed methodology saves 45% to 50% of the engineering workload and dequate significant financial savings.

Phase I: the pipeline-gas demonstration plant. Demonstration plant engineering and design. Volume 18. Plant Section 2700 - Waste Water Treatment

Energy Technology Data Exchange (ETDEWEB)

None

1981-05-01

Contract No. EF-77-C-01-2542 between Conoco Inc. and the US Department of Energy provides for the design, construction, and operation of a demonstration plant capable of processing bituminous caking coals into clean pipeline quality gas. The project is currently in the design phase (Phase I). This phase is scheduled to be completed in June 1981. One of the major efforts of Phase I is the process and project engineering design of the Demonstration Plant. The design has been completed and is being reported in 24 volumes. This is Volume 18 which reports the design of Plant Section 2700 - Waste Water Treatment. The objective of the Waste Water Treatment system is to collect and treat all plant liquid effluent streams. The system is designed to permit recycle and reuse of the treated waste water. Plant Section 2700 is composed of primary, secondary, and tertiary waste water treatment methods plus an evaporation system which eliminates liquid discharge from the plant. The Waste Water Treatment Section is designed to produce 130 pounds per hour of sludge that is buried in a landfill on the plant site. The evaporated water is condensed and provides a portion of the make-up water to Plant Section 2400 - Cooling Water.

A reliability program for emergency diesel generators at nuclear power plants: Maintenance, surveillance, and condition monitoring

International Nuclear Information System (INIS)

Lofgren, E.V.; Henderson, W.; Burghardt, D.; Kripps, L.; Rothleder, B.

1988-12-01

This report is a companion report on NUREG/CR-5078, Volume 1, ''A Reliability Program for Emergency Diesel Generators at Nuclear Power Plants: Program Structure.'' The purpose of this report is to provide technical findings and insights related to: failure evaluation, troubleshooting, maintenance, surveillance, and condition monitoring. Examples and recommendations are provided for each of these areas based on actual emergency diesel generator (EDG) operating experience and the opinions of diesel generator experts. This report expands the more general guidance provided in Volume 1. In addition, a discussion of EDG interactions with other plant systems (e.g., instrument, air, service water, dc power) is provided since experience has shown that these support systems and their operation can adversely affect EDG reliability. Portions of this report have been designed for use by onsite personnel for evaluating operational characteristics of EDGs. 5 refs., 8 figs., 7 tabs

Rapid and reliable extraction of genomic DNA from various wild-type and transgenic plants

Directory of Open Access Journals (Sweden)

Yang Moon-Sik

2004-09-01

Full Text Available Abstract Background DNA extraction methods for PCR-quality DNA from calluses and plants are not time efficient, since they require that the tissues be ground in liquid nitrogen, followed by precipitation of the DNA pellet in ethanol, washing and drying the pellet, etc. The need for a rapid and simple procedure is urgent, especially when hundreds of samples need to be analyzed. Here, we describe a simple and efficient method of isolating high-quality genomic DNA for PCR amplification and enzyme digestion from calluses, various wild-type and transgenic plants. Results We developed new rapid and reliable genomic DNA extraction method. With our developed method, plant genomic DNA extraction could be performed within 30 min. The method was as follows. Plant tissue was homogenized with salt DNA extraction buffer using hand-operated homogenizer and extracted by phenol:chloroform:isoamyl alcohol (25:24:1. After centrifugation, the supernatant was directly used for DNA template for PCR, resulting in successful amplification for RAPD from various sources of plants and specific foreign genes from transgenic plants. After precipitating the supernatant, the DNA was completely digested by restriction enzymes. Conclusion This DNA extraction procedure promises simplicity, speed, and efficiency, both in terms of time and the amount of plant sample required. In addition, this method does not require expensive facilities for plant genomic DNA extraction.

Determining the reliability function of the thermal power system in power plant "Nikola Tesla, Block B1"

Directory of Open Access Journals (Sweden)

Kalaba Dragan V.

2015-01-01

Full Text Available Representation of probabilistic technique for evaluation of thermal power system reliability is the main subject of this paper. The system of thermal power plant under study consists of three subsystems and the reliability assessment is based on a sixteen-year failure database. By applying the mathematical theory of reliability to exploitation research data and using complex two-parameter Weibull distribution, the theoretical reliability functions of specified system have been determined. Obtained probabilistic laws of failure occurrence have confirmed a hypothesis that the distribution of the observed random variable fully describes behaviour of such a system in terms of reliability. Shown results make possible to acquire a better knowledge of current state of the system, as well as a more accurate estimation of its behavior during future exploitation. Final benefit is opportunity for potential improvement of complex system maintenance policies aimed at the reduction of unexpected failure occurrences.

Technical analysis of advanced wastewater-treatment systems for coal-gasification plants

Energy Technology Data Exchange (ETDEWEB)

1981-03-31

This analysis of advanced wastewater treatment systems for coal gasification plants highlights the three coal gasification demonstration plants proposed by the US Department of Energy: The Memphis Light, Gas and Water Division Industrial Fuel Gas Demonstration Plant, the Illinois Coal Gasification Group Pipeline Gas Demonstration Plant, and the CONOCO Pipeline Gas Demonstration Plant. Technical risks exist for coal gasification wastewater treatment systems, in general, and for the three DOE demonstration plants (as designed), in particular, because of key data gaps. The quantities and compositions of coal gasification wastewaters are not well known; the treatability of coal gasification wastewaters by various technologies has not been adequately studied; the dynamic interactions of sequential wastewater treatment processes and upstream wastewater sources has not been tested at demonstration scale. This report identifies key data gaps and recommends that demonstration-size and commercial-size plants be used for coal gasification wastewater treatment data base development. While certain advanced treatment technologies can benefit from additional bench-scale studies, bench-scale and pilot plant scale operations are not representative of commercial-size facility operation. It is recommended that coal gasification demonstration plants, and other commercial-size facilities that generate similar wastewaters, be used to test advanced wastewater treatment technologies during operation by using sidestreams or collected wastewater samples in addition to the plant's own primary treatment system. Advanced wastewater treatment processes are needed to degrade refractory organics and to concentrate and remove dissolved solids to allow for wastewater reuse. Further study of reverse osmosis, evaporation, electrodialysis, ozonation, activated carbon, and ultrafiltration should take place at bench-scale.

Survey of bayesian belif nets for quantitative reliability assessment of safety critical software used in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Eom, H.S.; Sung, T.Y.; Jeong, H.S.; Park, J.H.; Kang, H.G.; Lee, K

2001-03-01

As part of the Probabilistic Safety Assessment of safety grade digital systems used in Nuclear Power plants research, measures and methodologies applicable to quantitative reliability assessment of safety critical software were surveyed. Among the techniques proposed in the literature we selected those which are in use widely and investigated their limitations in quantitative software reliability assessment. One promising methodology from the survey is Bayesian Belief Nets (BBN) which has a formalism and can combine various disparate evidences relevant to reliability into final decision under uncertainty. Thus we analyzed BBN and its application cases in digital systems assessment area and finally studied the possibility of its application to the quantitative reliability assessment of safety critical software.

Survey of bayesian belif nets for quantitative reliability assessment of safety critical software used in nuclear power plants

International Nuclear Information System (INIS)

Eom, H. S.; Sung, T. Y.; Jeong, H. S.; Park, J. H.; Kang, H. G.; Lee, K.

2001-03-01

As part of the Probabilistic Safety Assessment of safety grade digital systems used in Nuclear Power plants research, measures and methodologies applicable to quantitative reliability assessment of safety critical software were surveyed. Among the techniques proposed in the literature we selected those which are in use widely and investigated their limitations in quantitative software reliability assessment. One promising methodology from the survey is Bayesian Belief Nets (BBN) which has a formalism and can combine various disparate evidences relevant to reliability into final decision under uncertainty. Thus we analyzed BBN and its application cases in digital systems assessment area and finally studied the possibility of its application to the quantitative reliability assessment of safety critical software

Medicinal plants indications from herbal healers for wound treatment

Directory of Open Access Journals (Sweden)

Maria Willianne Alves do Nascimento

2016-06-01

Full Text Available The objective was to identify medicinal plants indicated by commercial herbal healers for wound treatment, in street markets. A descriptive study conducted in a capital city in the northeast of Brazil, through interviews. The results indicate that plant commerce by healers of both genders, aged between 37 to 52 years, from those 69.3% learned about their function with family members. Forty-eight plant species were cited for wound treatment, between those, all participants cited Barbatimão and Mastic. From the plants Sambacaitá, Open Nettle, Yellow Uchi, Corona, Xiquexique, Senna and Pindaíba no properties to prove their indication was found for wound treatment. The stem bark was the most indicated part (96.15%, 81.03% of participants informed that plants should be kept dry for conservation. Studies to clarify the biological activities and collateral effects of medicinal plants are needed, beyond training for healers about indications, prepare, storage/conservation, and expiration date.

Reliability analysis of self-supply system of V-1 nuclear power plant

International Nuclear Information System (INIS)

Kuklik, B.

The results are summarized of the fault tree analysis of the V-1 power plant self-consumption system. The 6 kV busbars providing power for the main circulating pumps, the steam generator feed pumps and other important components including the 0.4 kV busbars are of the highest importance for nuclear safety. A fault tree analysis was also made of the emergency core cooling system of the reactor. Dangerous faults are defined and fault trees are developed. A brief description is given of the calculation algorithm for a digital computer. Some results are discussed. The calculated reliability of the emergency core cooling system is 10 5 years, of the 6 kV busbars it is 6.6x10 4 years. In case of a permanent or a long-term outage of the 220 kV stand-bye power supply, the system reliability is reduced to 7x10 2 years. (Z.M.)

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

Perfluoroalkyl substances (PFASs) in wastewater treatment plants and drinking water treatment plants: Removal efficiency and exposure risk.

Science.gov (United States)

Pan, Chang-Gui; Liu, You-Sheng; Ying, Guang-Guo

2016-12-01

Perfluoroalkyl substances (PFASs) are a group of chemicals with wide industrial and commercial applications, and have been received great attentions due to their persistence in the environment. The information about their presence in urban water cycle is still limited. This study aimed to investigate the occurrence and removal efficiency of eighteen PFASs in wastewater treatment plants (WWTPs) and drinking water plants (DWTPs) with different treatment processes. The results showed that both perfluorobutane sulfonic acid (PFBS) and perfluorooctane sulfonic acid (PFOS) were the predominant compounds in the water phase of WWTPs and DWTPs, while PFOS was dominant in dewatered sludge of WWTPs. The average total PFASs concentrations in the three selected WWTPs were 19.6-232 ng/L in influents, 15.5-234 ng/L in effluents, and 31.5-49.1 ng/g dry weight in sludge. The distribution pattern of PFASs differed between the wastewater and sludge samples, indicating strong partition of PFASs with long carbon chains to sludge. In the WWTPs, most PFASs were not eliminated efficiently in conventional activated sludge treatment, while the membrane bio-reactor (MBR) and Unitank removed approximately 50% of long chain (C ≥ 8) perfluorocarboxylic acids (PFCAs). The daily mass loads of total PFASs in WWTPs were in the range of 1956-24773 mg in influent and 1548-25085 mg in effluent. PFASs were found at higher concentrations in the wastewater from plant A with some industrial wastewater input than from the other two plants (plant B and plant C) with mainly domestic wastewater sources. Meanwhile, the average total PFASs concentrations in the two selected DWTPs were detected at 4.74-14.3 ng/L in the influent and 3.34-13.9 ng/L in the effluent. In DWTPs, only granular activated carbon (GAC) and powder activated carbon (PAC) showed significant removal of PFASs. The PFASs detected in the tap water would not pose immediate health risks in the short term exposure. The findings from this

Modeling cognition dynamics and its application to human reliability analysis

International Nuclear Information System (INIS)

Mosleh, A.; Smidts, C.; Shen, S.H.

1996-01-01

For the past two decades, a number of approaches have been proposed for the identification and estimation of the likelihood of human errors, particularly for use in the risk and reliability studies of nuclear power plants. Despite the wide-spread use of the most popular among these methods, their fundamental weaknesses are widely recognized, and the treatment of human reliability has been considered as one of the soft spots of risk studies of large technological systems. To alleviate the situation, new efforts have focused on the development of human reliability models based on a more fundamental understanding of operator response and its cognitive aspects

Increasing the reliability of electric energy supply to consumers in ROMAG-PROD Heavy Water Plant

International Nuclear Information System (INIS)

Barta, Ioan; Hanes, Marian . E-mail electrica@romag.ro

2004-01-01

Full text: This work aims at achieving an analysis of time evolution of the status of electrical installations, their performances and reliability, at describing the refurbishment measures adopted, at assessing the efficiency of these measures and also to suggest solutions for improving the reliability in the electric energy supply of ROMAG-PROD Heavy Water Plant. The analysis started from the original design, the manner the electrical installations were mounted, the technological level of this equipment and gives an evaluation of the deficiencies and the evolution of incidents occurred during the operation period. On the basis of the experience gathered one advances new items for equipment renewing and refurbishment of electric installations which together with the existing ones would ensure an electric energy supply more secure and efficient, leading directly to a more safe and efficient operation of the ROMAG-PROD Heavy Water Plant. In this work the incidents of electric energy nature which occurred are analyzed, the equipment which generated events identified and measures to solve these problems proposed

The recommissioning of the treatment plant at Mary Kathleen Uranium Ltd

International Nuclear Information System (INIS)

Thomas, J.

1978-01-01

The recommissioning of the plant at Mary Kathleen involved several distinct phases. The previous plant process was modified significantly, the plant capacity was increased by the addition of new equipment and the existing equipment was in most cases overhauled. This equipment was either reused in its original duty or relocated. Maintenance requirements after the plant was commissioned were high because of the amount of modified equipment and also because some old items of equipment were deliberately not overhauled during recommissioning. The equipment that was overhauled has operated reliably. However some new equipment has not been as satisfactory

STUDY ON WASTE WATER TREATMENT PLANTS

Directory of Open Access Journals (Sweden)

Mariana DUMITRU

2015-04-01

Full Text Available Biogas is more and more used as an alternative source of energy, considering the fact that it is obtained from waste materials and it can be easily used in cities and rural communities for many uses, between which, as a fuel for households. Biogas has many energy utilisations, depending on the nature of the biogas source and the local demand. Generally, biogas can be used for heat production by direct combustion, electricity production by fuel cells or micro-turbines, Combined Hest and Power generation or as vehicle fuel. In this paper we search for another uses of biogas and Anaerobe Digestion substrate, such as: waste water treatment plants and agricultural wastewater treatment, which are very important in urban and rural communities, solid waste treatment plants, industrial biogas plants, landfill gas recovery plants. These uses of biogas are very important, because the gas emissions and leaching to ground water from landfill sites are serious threats for the environment, which increase more and more bigger during the constant growth of some human communities. That is why, in the developed European countries, the sewage sludge is treated by anaerobe digestion, depending on national laws. In Romania, in the last years more efforts were destined to use anaerobe digestion for treating waste waters and management of waste in general. This paper can be placed in this trend of searching new ways of using with maximum efficiency the waste resulted in big communities.

Hybrid biomass-wind power plant for reliable energy generation

International Nuclear Information System (INIS)

Perez-Navarro, A.; Alfonso, D.; Alvarez, C.; Ibanez, F.; Sanchez, C.; Segura, I.

2010-01-01

Massive implementation of renewable energy resources is a key element to reduce CO 2 emissions associated to electricity generation. Wind resources can provide an important alternative to conventional electricity generation mainly based on fossil fuels. However, wind generators are greatly affected by the restrictive operating rules of electricity markets because, as wind is naturally variable, wind generators may have serious difficulties on submitting accurate generation schedules on a day ahead basis, and on complying with scheduled obligations in real-time operation. In this paper, an innovative system combining a biomass gasification power plant, a gas storage system and stand-by generators to stabilize a generic 40 MW wind park is proposed and evaluated with real data. The wind park power production model is based on real data about power production of a Spanish wind park and a probabilistic approach to quantify fluctuations and so, power compensation needs. The hybrid wind-biomass system is analysed to obtain main hybrid system design parameters. This hybrid system can mitigate wind prediction errors and so provide a predictable source of electricity. An entire year cycle of hourly power compensations needs has been simulated deducing storage capacity, extra power needs of the biomass power plant and stand-by generation capacity to assure power compensation during critical peak hours with acceptable reliability. (author)

Proof tests on reliability

International Nuclear Information System (INIS)

Mishima, Yoshitsugu

1983-01-01

In order to obtain public understanding on nuclear power plants, tests should be carried out to prove the reliability and safety of present LWR plants. For example, the aseismicity of nuclear power plants must be verified by using a large scale earthquake simulator. Reliability test began in fiscal 1975, and the proof tests on steam generators and on PWR support and flexure pins against stress corrosion cracking have already been completed, and the results have been internationally highly appreciated. The capacity factor of the nuclear power plant operation in Japan rose to 80% in the summer of 1983, and considering the period of regular inspection, it means the operation of almost full capacity. Japanese LWR technology has now risen to the top place in the world after having overcome the defects. The significance of the reliability test is to secure the functioning till the age limit is reached, to confirm the correct forecast of deteriorating process, to confirm the effectiveness of the remedy to defects and to confirm the accuracy of predicting the behavior of facilities. The reliability of nuclear valves, fuel assemblies, the heat affected zones in welding, reactor cooling pumps and electric instruments has been tested or is being tested. (Kako, I.)

Condensate treatment and oxygen control in power plants

International Nuclear Information System (INIS)

Sakai, Toshiaki; Iida, Kei; Ohashi, Shinichi.

1997-01-01

In thermal and nuclear power stations, the steam that operated turbines is cooled and condensed with condensers. The condensate is heated again with boilers, nuclear reactors or steam generators, but if corrosion products or impurities are contained in the condensate, corrosion and scale formation occur in boilers and others. The filtration facility and the desalting facility for condensate are installed to remove impurities, but water quality control is different in thermal, BWR and PWR plants, therefore, the treatment facilities corresponding to respective condensates have been adopted. In order to reduce the amount of clud generation, the treatment of injecting a small quantity of oxygen into condensate has been adopted. In thermal power plants, all volatile treatment is carried out, in which corrosion is prevented by the addition of ammonia and hydrazine to boiler feedwater. The condensate filters of various types and the NH 4 type condensate desalter for thermal power plants are described. In BWR power plants, steam is generated in nuclear reactors, therefore, the addition of chemicals into water is never carried out, and high purity neutral water is used. In PWR power plants, the addition of chemicals to water is done in the primary system, and AVT is adopted in the secondary system. Also the condensate treatment facilities are different for both reactors. (K.I.)

Radiotracer Applications in Wastewater Treatment Plants

International Nuclear Information System (INIS)

2011-01-01

Wastewater containing pollutants resulting from municipal and industrial activities are normally collected in wastewater treatment plants (WWTPs) for processing before discharge to the environment. The WWTPs are the last barrier against contamination of downstream surface waters such as rivers, lakes and sea. Treated wastewater is reused for irrigation, particularly in arid and semi-arid countries. Therefore, it is very important to maintain optimal operating conditions of WWTPs to eliminate or reduce environmental pollution. Wastewater treatment plants are complicated systems, where the processes of mixing, separation, aeration, biological and chemical reactions occur. A WWTP is basically a multiphase system, and the efficiency of an installation strongly depends on liquid, solid and gas phase flow structures and their residence time distributions (RTDs). However, the fluid dynamic properties of such systems are not yet completely understood, rendering difficult the theoretical prediction of important process parameters such as flow rates, phase distributions, mixing and sediment characteristics. Tracer techniques are very useful tools to investigate the efficiency of purification in WWTPs, aiding both their design and performance optimization. There are many kinds of tracers. Radioactive tracers are the most sensitive and are largely used for on-line diagnosis of various operations in WWTPs. The success of radiotracer applications rests upon their extremely high detection sensitivity, and the strong resistance against severe process conditions. During the last few decades, many radiotracer studies have been conducted worldwide for investigation of various installations for wastewater treatment, such as mixer, aeration tank, clarifiers, digester, filter, wetland and oxidation units. Various radiotracer methods and techniques have been developed by individual tracer groups. However, the information necessary for the preservation of knowledge and transfer of

External hazards in reliability and risk assessment of nuclear power plants

International Nuclear Information System (INIS)

Stevenson, J.D.

1977-01-01

It is current practice in the design of nuclear power generating stations to protect against the effects of significant natural and man-made external hazards which can occur at the plant site in excess of those hazards normally considered for conventional facilities. This paper is meant to identify those postulated external hazards typically considered in nuclear facility design. The paper also attempts to fulfill the following four objectives: (1) Define the current state of the art in applying reliability and risk analysis to determine external hazard design requirements. (2) Provide a ready source of literature references applicable to probabilistic design for extreme loads. (3) Provide some quantitative probability assessment estimates of external hazards. (4) Develop exclusion criteria by which postulated external hazards can be eliminated as a design basis. Rigorous evaluation of the design requirements for nuclear power plant facilities based on principles of probability and risk analysis is just beginning. It is hoped these techniques will be used more extensively in the future to provide a more rational basis for developing design requirements. (orig.) [de

Cycle chemistry monitoring system as means of improving the reliability of the equipment at the power plants

Science.gov (United States)

Yegoshina, O. V.; Voronov, V. N.; Yarovoy, V. O.; Bolshakova, N. A.

2017-11-01

There are many problems in domestic energy at the present that require urgent solutions in the near future. One of these problems - the aging of the main and auxiliary equipment. Wear of equipment is the cause of decrease reliability and efficiency of power plants. Reliability of the equipment are associated with the introduction of cycle chemistry monitoring system. The most damageable equipment’s are boilers (52.2 %), turbines (12.6 %) and heating systems (12.3 %) according to the review of failure rate on the power plants. The most part of the damageability of the boiler is heated surfaces (73.2 %). According to the Russian technical requirements, the monitoring systems are responsible to reduce damageability the boiler heating surfaces and to increase the reliability of the equipment. All power units capacity of over 50 MW are equipped with cycle chemistry monitoring systems in order to maintain water chemistry within operating limits. The main idea of cycle chemistry monitoring systems is to improve water chemistry at power plants. According to the guidelines, cycle chemistry monitoring systems of a single unit depends on its type (drum or once-through boiler) and consists of: 20…50 parameters of on-line chemical analyzers; 20…30 «grab» sample analyses (daily) and about 15…20 on-line monitored operating parameters. The operator of modern power plant uses with many data at different points of steam/water cycle. Operators do not can estimate quality of the cycle chemistry due to the large volume of daily and every shift information and dispersion of data, lack of systematization. In this paper, an algorithm for calculating the quality index developed for improving control the water chemistry of the condensate, feed water and prevent scaling and corrosion in the steam/water cycle.

Beliefs concerning the reliability of nuclear power plant in-service inspections; Uskomuksia ydinvoimalaitoksissa suoritettavien tarkastusten luotettavuudesta

Energy Technology Data Exchange (ETDEWEB)

Kettunen, J. [VTT Automation, Espoo (Finland)

1997-01-01

The aim of the study was to investigate belief systems held by the officials responsible for the planning and supervision of NDT operations within the Finnish nuclear industry. They were asked to express their opinions on (1) the reliability of NDT methods in general, (2) the factors influencing the reliability of in-service inspections, and (3) the degree of reliability of the current inspections operations conducted by means of NDT methods in the Finnish nuclear power plants. Another goal of the study was to assess the adequacy of officials` beliefs (or belief systems). The research data was collected by interviewing representatives from Finnish power companies (Imatran Voima Oy and Teollisuuden Voima Oy), independent inspection organisations, and the Finnish Centre for Radiation and Nuclear Safety (STUK). The adequacy of the beliefs expressed was assessed by means of the results obtained from international NDT reliability studies and on the basis of interviewees` own justification. (refs.).

Medicinal Plants for the Treatment of Hypertrophic Scars

Directory of Open Access Journals (Sweden)

Qi Ye

2015-01-01

Full Text Available Hypertrophic scar is a complication of wound healing and has a high recurrence rate which can lead to significant abnormity in aesthetics and functions. To date, no ideal treatment method has been established. Meanwhile, the underlying mechanism of hypertrophic scarring has not been clearly defined. Although a large amount of scientific research has been reported on the use of medicinal plants as a natural source of treatment for hypertrophic scarring, it is currently scattered across a wide range of publications. Therefore, a systematic summary and knowledge for future prospects are necessary to facilitate further medicinal plant research for their potential use as antihypertrophic scar agents. A bibliographic investigation was accomplished by focusing on medicinal plants which have been scientifically tested in vitro and/or in vivo and proved as potential agents for the treatment of hypertrophic scars. Although the chemical components and mechanisms of action of medicinal plants with antihypertrophic scarring potential have been investigated, many others remain unknown. More investigations and clinical trials are necessary to make use of these medical plants reasonably and phytotherapy is a promising therapeutic approach against hypertrophic scars.

Reliability assurance for regulation of advanced reactors

International Nuclear Information System (INIS)

Fullwood, R.; Lofaro, R.; Samanta, P.

1992-01-01

The advanced nuclear power plants must achieve higher levels of safety than the first generation of plants. Showing that this is indeed true provides new challenges to reliability and risk assessment methods in the analysis of the designs employing passive and semi-passive protection. Reliability assurance of the advanced reactor systems is important for determining the safety of the design and for determining the plant operability. Safety is the primary concern, but operability is considered indicative of good and safe operation. this paper discusses several concerns for reliability assurance of the advanced design encompassing reliability determination, level of detail required in advanced reactor submittals, data for reliability assurance, systems interactions and common cause effects, passive component reliability, PRA-based configuration control system, and inspection, training, maintenance and test requirements. Suggested approaches are provided for addressing each of these topics

Reliability assurance for regulation of advanced reactors

International Nuclear Information System (INIS)

Fullwood, R.; Lofaro, R.; Samanta, P.

1991-01-01

The advanced nuclear power plants must achieve higher levels of safety than the first generation of plants. Showing that this is indeed true provides new challenges to reliability and risk assessment methods in the analysis of the designs employing passive and semi-passive protection. Reliability assurance of the advanced reactor systems is important for determining the safety of the design and for determining the plant operability. Safety is the primary concern, but operability is considered indicative of good and safe operation. This paper discusses several concerns for reliability assurance of the advanced design encompassing reliability determination, level of detail required in advanced reactor submittals, data for reliability assurance, systems interactions and common cause effects, passive component reliability, PRA-based configuration control system, and inspection, training, maintenance and test requirements. Suggested approaches are provided for addressing each of these topics

Reliability, validity and treatment sensitivity of the Schizophrenia Cognition Rating Scale.

Science.gov (United States)

Keefe, Richard S E; Davis, Vicki G; Spagnola, Nathan B; Hilt, Dana; Dgetluck, Nancy; Ruse, Stacy; Patterson, Thomas D; Narasimhan, Meera; Harvey, Philip D

2015-02-01

Cognitive functioning can be assessed with performance-based assessments such as neuropsychological tests and with interview-based assessments. Both assessment methods have the potential to assess whether treatments for schizophrenia improve clinically relevant aspects of cognitive impairment. However, little is known about the reliability, validity and treatment responsiveness of interview-based measures, especially in the context of clinical trials. Data from two studies were utilized to assess these features of the Schizophrenia Cognition Rating Scale (SCoRS). One of the studies was a validation study involving 79 patients with schizophrenia assessed at 3 academic research centers in the US. The other study was a 32-site clinical trial conducted in the US and Europe comparing the effects of encenicline, an alpha-7 nicotine agonist, to placebo in 319 patients with schizophrenia. The SCoRS interviewer ratings demonstrated excellent test-retest reliability in several different circumstances, including those that did not involve treatment (ICC> 0.90), and during treatment (ICC>0.80). SCoRS interviewer ratings were related to cognitive performance as measured by the MCCB (r=-0.35), and demonstrated significant sensitivity to treatment with encenicline compared to placebo (Pcognition in schizophrenia, and may be useful for clinical practice. The weaknesses of the SCoRS include its reliance on informant information, which is not available for some patients, and reduced validity when patient's self-report is the sole information source. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

40 CFR 63.1585 - How does an industrial POTW treatment plant demonstrate compliance?

Science.gov (United States)

2010-07-01

... Works Industrial Potw Treatment Plant Description and Requirements § 63.1585 How does an industrial POTW treatment plant demonstrate compliance? (a) An existing industrial POTW treatment plant demonstrates... §§ 63.1586 through 63.1590. Non-industrial POTW Treatment Plant Requirements ...

State-of-art report on digital I and C system reliability issues for nuclear power plants

International Nuclear Information System (INIS)

Hwang, In Koo; Lee, Dong Gyoung; Cha, Kyung Ho; Kwon, Kee Choon; Wood, Richard T.

2000-01-01

As the instrumentation and control (Iand C) equipment suppliers tend to provide digital components rather than conventional analog type components for instrument and control systems of nuclear power plants(NPPs), it is unavoidable to adopt digital equipment for safety I and C systems as well as non-safety systems. However, the full introduction of digital equipment to I and C systems of nuclear power plants raises several concerns which have not been considered for conventional analog I and C systems. The two major examples of the issues of digital systems are electromagnetic compatibility (EMC) and software reliability. KAERI invited a technical expert, Dr. Richard T. Wood, from Oak Ridge National Laboratory (ORNL) in Unites States and held seminars to recognize the state-of-art of the above issues and to share the information on techniques dealing with the problems. Dr. Wood has been working on the development of EMC guidelines and technical basis in using digital equipment for safety systems in nuclear power plants on the sponsorship of US Nuclear Regulatory Commission (NRC). Being based on his statements and discussions during his visit, this report describes technical considerations and issues on digital safety I and C system application in NPPs, EMC methods, environmental effects vulnerable to digital components, reliability assurance methods, etc. (author)

A reliability program approach to operational safety

International Nuclear Information System (INIS)

Mueller, C.J.; Bezella, W.A.

1985-01-01

A Reliability Program (RP) model based on proven reliability techniques is being formulated for potential application in the nuclear power industry. Methods employed under NASA and military direction, commercial airline and related FAA programs were surveyed and a review of current nuclear risk-dominant issues conducted. The need for a reliability approach to address dependent system failures, operating and emergency procedures and human performance, and develop a plant-specific performance data base for safety decision making is demonstrated. Current research has concentrated on developing a Reliability Program approach for the operating phase of a nuclear plant's lifecycle. The approach incorporates performance monitoring and evaluation activities with dedicated tasks that integrate these activities with operation, surveillance, and maintenance of the plant. The detection, root-cause evaluation and before-the-fact correction of incipient or actual systems failures as a mechanism for maintaining plant safety is a major objective of the Reliability Program. (orig./HP)

Equipment Reliability Program in NPP Krsko

International Nuclear Information System (INIS)

Skaler, F.; Djetelic, N.

2006-01-01

Operation that is safe, reliable, effective and acceptable to public is the common message in a mission statement of commercial nuclear power plants (NPPs). To fulfill these goals, nuclear industry, among other areas, has to focus on: 1 Human Performance (HU) and 2 Equipment Reliability (EQ). The performance objective of HU is as follows: The behaviors of all personnel result in safe and reliable station operation. While unwanted human behaviors in operations mostly result directly in the event, the behavior flaws either in the area of maintenance or engineering usually cause decreased equipment reliability. Unsatisfied Human performance leads even the best designed power plants into significant operating events, which can be found as well-known examples in nuclear industry. Equipment reliability is today recognized as the key to success. While the human performance at most NPPs has been improving since the start of WANO / INPO / IAEA evaluations, the open energy market has forced the nuclear plants to reduce production costs and operate more reliably and effectively. The balance between these two (opposite) goals has made equipment reliability even more important for safe, reliable and efficient production. Insisting on on-line operation by ignoring some principles of safety could nowadays in a well-developed safety culture and human performance environment exceed the cost of electricity losses. In last decade the leading USA nuclear companies put a lot of effort to improve equipment reliability primarily based on INPO Equipment Reliability Program AP-913 at their NPP stations. The Equipment Reliability Program is the key program not only for safe and reliable operation, but also for the Life Cycle Management and Aging Management on the way to the nuclear power plant life extension. The purpose of Equipment Reliability process is to identify, organize, integrate and coordinate equipment reliability activities (preventive and predictive maintenance, maintenance

Improving machinery reliability

CERN Document Server

Bloch, Heinz P

1998-01-01

This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

Natural Circulation in Water Cooled Nuclear Power Plants Phenomena, models, and methodology for system reliability assessments

International Nuclear Information System (INIS)

Jose Reyes

2005-01-01

In recent years it has been recognized that the application of passive safety systems (i.e., those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. In 1991 the IAEA Conference on ''The Safety of Nuclear Power: Strategy for the Future'' noted that for new plants the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate''

Reliability study: raw and make-up water system, Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

Peterman, S.M.; Wiehle, W.E.; Walder, A.; Houk, T.C.; West, R.M.

1981-09-01

A reliability study for determining the ability of the raw and make-up water system to provide reliable and adequate service through the year 2000 has been completed. This study includes an evaluation of the well fields, X-608 Raw Water Pump House, X-605 Booster Station Complex, X-611 Water Treatment Complex, and the associated piping. The raw and make-up water system is in good overall condition, but to maintain this condition, the reliability study team made the following recommendations: (1) increase well field capacity; (2) replace certain speed reducers at X-611; (3) repair deteriorated poles, crossarms, and accessories on F-2 and W-1 feeders; (4) stabilize the landslide in vicinity of the 48 in. raw water main; and (5) initiate further investigation, testing, or engineering studies to correct deficiencies in the supervisory control system between well fields, pump house, and X-611, and determine if the 2400 volt underground cables to X-608A wells should be replaced

Reliability in engineering '87

International Nuclear Information System (INIS)

Tuma, M.

1987-01-01

The participants heard 51 papers dealing with the reliability of engineering products. Two of the papers were incorporated in INIS, namely ''Reliability comparison of two designs of low pressure regeneration of the 1000 MW unit at the Temelin nuclear power plant'' and ''Use of probability analysis of reliability in designing nuclear power facilities.''(J.B.)

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

Configuration of risk monitor system by plant defense-in-depth risk monitor and reliability monitor

International Nuclear Information System (INIS)

Yoshikawa, Hidekazu; Lind Morten; Yang Ming; Hashim Muhammad; Zhang Zhijian

2012-01-01

A new method of risk monitor system of a nuclear power plant has been proposed from the aspect by what degree of safety functions incorporated in the plant system is maintained by multiple barriers of defense-in-depth (DiD). Wherein, the central idea is plant DiD risk monitor and reliability monitor derived from the five aspects of (1) design principle of nuclear safety based on DiD concept, (2) definition of risk and risk to be monitored, (3) severe accident phenomena as major risk, (4) scheme of risk ranking, and (5) dynamic risk display. In this paper, the overall frame of the proposed risk monitor system is summarized and the detailed discussion is made on major items such as definition of risk and risk ranking, anatomy of fault occurrence, two-layer configuration of risk monitor, how to configure individual elements of plant DiD risk monitor, and lastly how to apply for a PWR safety system. (author)

Hydraulic modelling of drinking water treatment plant operations

Directory of Open Access Journals (Sweden)

L. C. Rietveld

2009-06-01

Full Text Available The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand filtration and cascade and tower aeration. Using this treatment step library, a hydraulic model was set up, calibrated and validated for the drinking water treatment plant Harderbroek. With the actual valve position and pump speeds, the flows were calculated through the several treatment steps. A case shows the use of the model to calculate the new setpoints for the current frequency converters of the effluent pumps during a filter backwash.

Medicinal plants indications from herbal healers for wound treatment

OpenAIRE

Maria Willianne Alves do Nascimento; Regina Célia Sales Santos Veríssimo; Maria Lysete de Assis Bastos; Thaís Honório Lins Bernardo

2016-01-01

The objective was to identify medicinal plants indicated by commercial herbal healers for wound treatment, in street markets. A descriptive study conducted in a capital city in the northeast of Brazil, through interviews. The results indicate that plant commerce by healers of both genders, aged between 37 to 52 years, from those 69.3% learned about their function with family members. Forty-eight plant species were cited for wound treatment, between those, all participants cited Barbatimão and...

Ejectors of power plants turbine units efficiency and reliability increasing

Science.gov (United States)

Aronson, K. E.; Ryabchikov, A. Yu.; Kuptsov, V. K.; Murmanskii, I. B.; Brodov, Yu. M.; Zhelonkin, N. V.; Khaet, S. I.

2017-11-01

The functioning of steam turbines condensation systems influence on the efficiency and reliability of a power plant a lot. At the same time, the condensation system operating is provided by basic ejectors, which maintain the vacuum level in the condenser. Development of methods of efficiency and reliability increasing for ejector functioning is an actual problem of up-to-date power engineering. In the paper there is presented statistical analysis of ejector breakdowns, revealed during repairing processes, the influence of such damages on the steam turbine operating reliability. It is determined, that 3% of steam turbine equipment breakdowns are the ejector breakdowns. At the same time, about 7% of turbine breakdowns are caused by different ejector malfunctions. Developed and approved design solutions, which can increase the ejector functioning indexes, are presented. Intercoolers are designed in separated cases, so the air-steam mixture can’t move from the high-pressure zones to the low-pressure zones and the maintainability of the apparatuses is increased. By U-type tubes application, the thermal expansion effect of intercooler tubes is compensated and the heat-transfer area is increased. By the applied nozzle fixing construction, it is possible to change the distance between a nozzle and a mixing chamber (nozzle exit position) for operating performance optimization. In operating conditions there are provided experimental researches of more than 30 serial ejectors and also high-efficient 3-staged ejector EPO-3-80, designed by authors. The measurement scheme of the designed ejector includes 21 indicator. The results of experimental tests with different nozzle exit positions of the ejector EPO-3-80 stream devices are presented. The pressure of primary stream (water steam) is optimized. Experimental data are well-approved by the calculation results.

Focus on 14 sewage treatment plants in the Mpumalanga Province ...

African Journals Online (AJOL)

In order to identify the treatment methods used in different sewage treatment plants (STPs) in the Mpumalanga Province and to determine the efficiency of wastewater treatment by these plants, municipal STPs were surveyed, and raw and treated wastewater samples collected. A total of 14 STPs were visited and the ...

TECHNOLOGICAL PROCESS ASSESSMENT OF THE DRINKING WATER TREATMENT AT TARGU-MURES WATER TREATMENT PLANT

Directory of Open Access Journals (Sweden)

CORNELIA DIANA HERTIA

2011-03-01

Full Text Available This paper intends to assess the technological process of obtaining drinking water at Targu-Mures water treatment plant. The assessment was performed before changing the technological process and four months were chosen to be analized during 2008: January, April, July and October for its efficiency analysis on treatment steps. Mures River is the water source for the water treatment plant, being characterized by unsteady flow and quality parameters with possible important variability in a very short period of time. The treatment technological process is the classic one, represented by coagulation, sedimentation, filtration and disinfection, but also prechlorination was constantly applied as additional treatment during 2008. Results showed that for the measured parameters, raw water at the water treatment plant fits into class A3 for surface waters, framing dictated by the bacterial load. The treatment processes efficiency is based on the performance calculation for sedimentation, filtration, global and for disinfection, a better conformation degree of technological steps standing out in January in comparison to the other three analyzed months. A variable non-compliance of turbidity and residual chlorine levels in the disinfected water was observed constantly. Previous treatment steps managed to maintain a low level of oxidisability, chlorine consumption and residual chlorine levels being also low. 12% samples were found inconsistent with the national legislation in terms of bacteriological quality. Measures for the water treatment plant retechnologization are taken primarily for hyperchlorination elimination, which currently constitutes a discomfort factor (taste, smell, and a generating factor of chlorination by-products.

Reliability assessment of the containment of a PWR

International Nuclear Information System (INIS)

Schueller, G.I.; Wellein, R.; Wittmann, F.H.; Boulahdour, T.; Mihashi, M.; Zorn, N.F.; Bauer, J.

1981-09-01

The aim of this research effort was to contribute to the development of methods to quantify the risk involved with nuclear power plants. Using a large component, i.e. the containment of the reference plant BIBLIS B (PWR) as sample structure a reliability analysis was performed which is based on realistic assumptions of loads and material properties. For this purpose in many fields it was necessary to develop new methods, collect data, and where not available, obtain data in tests. This effort concentrated on partial aspects and on the other hand on the development of a methodology for an overall reliability concept. According to the results of the previous project, the keypoints of this effort are the treatment of loss of coolant accidents (small leak), earthquake loading, the possibly resulting crackpropagation in the steel hull, and the structural mechanics and material strength aspects of the reinforced concrete hull subjected to impact loading (aircraft impact). (orig./HP) [de

Reliability and validity of the Treatment Satisfaction Questionnaire for Medication among Portuguese-speaking Brazilian patients with hypertension.

Science.gov (United States)

Sauer Liberato, Ana Carolina; Cunha Matheus Rodrigues, Roberta; Kim, MyoungJin; Mallory, Caroline

2016-07-01

This study examined the reliability and validity of the Brazilian Portuguese version of the Treatment Satisfaction Questionnaire for Medication (version 1.4) among patients with hypertension. Understanding the patient experience with treatment satisfaction will contribute to improved medication adherence and control of hypertension. Hypertension is a serious problem in Brazil that is associated with chronic illness controlled, in part, by consistent adherence to medications. Patient satisfaction with medication treatment is associated with adherence to medication. The Treatment Satisfaction Questionnaire for Medication (version 1.4) is a promising instrument for measuring medication; however, to date there has been no report of the reliability and validity of the instrument with Portuguese-speaking adults with hypertension in Brazil. Cross-sectional descriptive exploratory study. A convenience sample of 300 patients with hypertension in an outpatient setting in the southeast region of São Paulo state in Brazil completed the Treatment Satisfaction Questionnaire for Medication (version 1.4). The instrument, comprised of four subscales, was evaluated for reliability using correlation analyses and internal consistency. Confirmatory factor analysis was used to determine factorial validity. Correlational analyses, internal consistency (Cronbach's alpha) and hierarchical confirmatory factor analysis demonstrate adequate support for the four-factor dimensionality, reliability and factorial validity of the Treatment Satisfaction Questionnaire for Medication (version 1.4). This study provides modest evidence for internal consistency and factorial validity of the Treatment Satisfaction Questionnaire for Medication (version 1.4) in Portuguese-speaking adult Brazilians with hypertension. Future testing should focus on extending reliability testing, discriminant validity and potential translation and literacy issues in this population. Within known limitations, clinicians will

Reliability assessment and correlation analysis of evaluating orthodontic treatment outcome in Chinese patients

OpenAIRE

Song, Guang-Ying; Zhao, Zhi-He; Ding, Yin; Bai, Yu-Xing; Wang, Lin; He, Hong; Shen, Gang; Li, Wei-Ran; Baumrind, Sheldon; Geng, Zhi; Xu, Tian-Min

2013-01-01

This study aimed to assess the reliability of experienced Chinese orthodontists in evaluating treatment outcome and to determine the correlations between three diagnostic information sources. Sixty-nine experienced Chinese orthodontic specialists each evaluated the outcome of orthodontic treatment of 108 Chinese patients. Three different information sources: study casts (SC), lateral cephalometric X-ray images (LX) and facial photographs (PH) were generated at the end of treatment for 108 pat...

Chemical analysis of sewage sludge of southern sewerage treatment plant (SSTP) Hyderabad for achieving sustainable development in sector of agriculture

International Nuclear Information System (INIS)

Qureshi, K.; Shaikh, N.; Ahmed, R.S.; Nawaz, Z.

2003-01-01

A study on the chemical analysis of sewage sludge of southern sewerage treatment plant (SSPP) Hyderabad was studied. Chemical analysis on sludge samples collected form the waste stabilization for different micro-nutrients (essential manures, nitrogen, phosphorus, potassium, calcium and magnesium) were conducted in year 1999-2000. These nutrients and metal were detected by reliable analytical method i.e. Kjeldahls method and Atomic Absorption Spectrophotometer. The analysis showed that sewage sludge contained sufficient quantity of primary and secondary nutrients, hence sewage sludge could be utilized as a natural fertilizer. This will not only solve the disposal problem but it would also be environmentally safer way of providing regulators to the plants. (author)

A note on the application of probabilistic structural reliability methodology to nuclear power plants

International Nuclear Information System (INIS)

Maurer, H.A.

1978-01-01

The interest shown in the general prospects of primary energy in European countries prompted description of the actual European situation. Explanation of the needs for installation of nuclear power plants in most contries of the European Communities are given. Activities of the Commission of the European Communities to initiate a progressive harmonization of already existing European criteria, codes and complementary requirements in order to improve the structural reliability of components and systems of nuclear power plants are summarized. Finally, the applicability of a probabilistic safety analysis to facilitate decision-making as to safety by defining acceptable target and limit values, coupled with a subjective estimate as it is applied in the safety analyses performed in most European countries, is demonstrated. (Auth.)

Study on the reliability of large coal-fired and nuclear power plants. Factors affecting power plant reliability. Volume I. Final report

International Nuclear Information System (INIS)

1975-01-01

The study consisted of a comparative evaluation of 2 nuclear units (Indian Point 2 - Consolidated Edison of New York, Turkey Point 4 - Florida Power and Light Company) and 2 coal-fired units (Bull Run and Widows Creek Unit 8 - Tennessee Valley Authority). The purpose of the study was to identify and assess the underlying causes of unit reliability and the causes of the observed differences in reliability performance of the units. Recommended actions for improving the reliability of one of the study units was to be presented in a format useful to other utility companies for improving reliability of their generating units. The emphasis of the study was on the aspects of management, manning, operations, and maintenance which had a significant impact on unit reliability. Volume 1 includes a summary, a description of the major findings from the comparative evaluation, conclusions based on these findings, and recommendations for improving the reliability of the below average units

Research on the sewage treatment in high altitude region based on Lhasa Sewage Treatment Plant

Science.gov (United States)

Xu, Jin; Li, Shuwen

2017-12-01

Sewage treatment is of great significance to enhance environmental quality, consolidate pollution prevention and ecological protection, and ensure sustainable economic and social development in high altitude region. However, there are numerous difficulties in sewage treatment due to the alpine climate, the relatively low economic development level, and the backward operation and management styles, etc. In this study, the characteristics of influent quality in the sewage treatment plant in Lhasa are investigated by analysing the influent BOD5/COD and BOD5/TN, comparing key indexes recorded from 2014 to 2016 with the hinterland. Results show that the concentration of influent COD, BOD5, NH3-N and SS in the Lhasa sewage treatment plant, in which the sewage belongs to low-concentration urban sewage, is smaller than that in the domestic sewage treatment plants in the mainland. The concentration ratio of BOD5/COD and BOD5/TN is below 0.4 and 4, which indicates that the biodegradation is poor and the carbon sources are in bad demand. The consequences obtained play a vital role in the design, operation and management of sewage treatment plants in high altitude region.

Specification of a Human Reliability Data Bank for conducting HRA segments of PRAs for nuclear power plants

International Nuclear Information System (INIS)

Comer, M.K.; Donovan, M.D.

1985-02-01

The US Nuclear Regulatory Commission (NRC), Sandia National Laboratories (SNL), and General Physics Corporation have conducted a research program to develop a Human Reliability Data Bank for nuclear power industry probabilistic risk assessment (PRA). As part of this program, a survey of existing human reliability data banks from other industries was conducted and a concept of a Data Bank for the nuclear industry was developed. The results of these efforts were published in the two volumes of NUREG/CR-2744: ''Human Reliability Data Bank for Nuclear Power Plant Operations: Volume 1, A Review of Existing Human Reliability Data Banks, and Volume 2, A Data Bank Concept and System Description.'' This document, NUREG/CR-4010, is the revised technical specification for the Human Reliability Data Bank. The organization of the Data Bank and a description of a data publication, the Human Reliability Data Manual, are provided. Details of the administration and operation of the Data Bank are discussed. Appendices present the detailed procedures for processing data, revising the Data Manual, operating the Data Bank, and reviewing data for the Data Bank. The final appendix is a skeleton version (structure only) of the Data Manual

Treatment of some power plant waters

International Nuclear Information System (INIS)

Konecny, C.; Vanura, P.; Franta, P.; Marhol, M.; Tejnecky, M.; Fidler, J.

1987-01-01

Major results are summed up obtained in 1986 in the development of techniques for the treatment of coolant in the fuel transport and storage tank, of reserve coolant in the primary circuit and of waste water from the special nuclear power plant laundries, containing new washing agent Alfa-DES. A service test of the filter filled with Czechoslovak-made cation exchanger Ostion KSN in the boric acid concentrate filter station showed that the filter can be used in some technological circuits of nuclear power plants. New decontamination agents are also listed introduced in production in Czechoslovakia for meeting the needs of nuclear power plants. (author). 6 refs

The collection, storage and use of equipment performance data for the safety and reliability assessment of nuclear power plants

International Nuclear Information System (INIS)

Fothergill, C.D.H.

1975-01-01

It has been characteristic of the Nuclear Industry that it should grow up in an atmosphere where reliability and operational safety considerations have been of vital importance. Consequently all aspects of Nuclear Power Reactor design, construction and operation (in the U.K.A.E.A.) are subjected to rigorous reliability assessments, beginning with the automatic protective devices and the safety shut-down systems. This has resulted in the setting up of large and small private data stores to support this upsurgence of Safety and Reliability assessment work. Unfortunately, much of the information being stored and published falls short of the minimum requirements of Safety Assessors and Reliability Analysts who need to make use of it. That there is still an urgent need for more work to be done in the Reliability Data field is universally acknowledged. The characteristics which make up good quality reliability data must be defined and achievable minimum standards must be set for its identification, collection, storage and retrieval. To this end the United Kingdom Atomic Energy Authority have set up the Systems Reliability Service Data Bank. This includes a computerized storage facility comprised of two principal data stores: (i) Reliability Data Store, (ii) Event Data Store. The figures available in the Reliability Data Store range from those relating to the lifetimes of minute components to those obtained from the assessment of whole plants and complete assemblies. These data have been accumulated from many reliable sources both inside and outside the Nuclear Industry, including the transfer of 'live' data generated from the results of reliability surveillance exercises associated with Event Data collection. Computer techniques developed specifically for the Reliability Data Store enable further 'processing' of these data to be carried out. The Event Data Store consists of three discrete computerized data stores, each one providing the necessary storage, retrieval and

Peer-review study of the draft handbook for human-reliability analysis with emphasis on nuclear-power-plant applications, NUREG/CR-1278

Energy Technology Data Exchange (ETDEWEB)

Brune, R. L.; Weinstein, M.; Fitzwater, M. E.

1983-01-01

This report describes a peer review of the draft Handbook for Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications, NUREG/CR-1278. The purpose of the study was to determine to what extent peers agree with the human behavior models and estimates of human error probabilities (HEPs) contained in the Handbook. Twenty-nine human factors experts participated in the study. Twenty of the participants were Americans; nine were from other countries. The peers performed human reliability analyses of a variety of human performance scenarios describing operator activities in nuclear power plant settings. They also answered questionnaires pertaining to the contents and application of the Handbook. An analysis of peer solutions to the human reliability analysis problems and peer responses to the questionnaire was performed. Recommendations regarding the format and contents of the Handbook were developed from the study findings.

Microbial Communities in Danish Wastewater Treatment Plants with Nutrient Removal

DEFF Research Database (Denmark)

Mielczarek, Artur Tomasz

Activated sludge treatment plants are the most used wastewater treatment systems worldwide for biological nutrient removal from wastewater. Nevertheless, the treatment systems have been for many years operated as so called “black-box”, where specific process parameters were adjusted without...... that plants with return sludge Side-Stream Hydrolysis (SSH) instead of the normal anaerobic process tank tended to have significantly fewer unwanted GAOs in contrast to many plants with traditional mainstream anaerobic tank and thus it was proposed that this system might be an effective strategy of control...

Natural Circulation in Water Cooled Nuclear Power Plants Phenomena, models, and methodology for system reliability assessments

Energy Technology Data Exchange (ETDEWEB)

Jose Reyes

2005-02-14

In recent years it has been recognized that the application of passive safety systems (i.e., those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. In 1991 the IAEA Conference on ''The Safety of Nuclear Power: Strategy for the Future'' noted that for new plants the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate''.

Sludge quantification at water treatment plant and its management scenario.

Science.gov (United States)

Ahmad, Tarique; Ahmad, Kafeel; Alam, Mehtab

2017-08-15

Large volume of sludge is generated at the water treatment plants during the purification of surface water for potable supplies. Handling and disposal of sludge require careful attention from civic bodies, plant operators, and environmentalists. Quantification of the sludge produced at the treatment plants is important to develop suitable management strategies for its economical and environment friendly disposal. Present study deals with the quantification of sludge using empirical relation between turbidity, suspended solids, and coagulant dosing. Seasonal variation has significant effect on the raw water quality received at the water treatment plants so forth sludge generation also varies. Yearly production of the sludge in a water treatment plant at Ghaziabad, India, is estimated to be 29,700 ton. Sustainable disposal of such a quantity of sludge is a challenging task under stringent environmental legislation. Several beneficial reuses of sludge in civil engineering and constructional work have been identified globally such as raw material in manufacturing cement, bricks, and artificial aggregates, as cementitious material, and sand substitute in preparing concrete and mortar. About 54 to 60% sand, 24 to 28% silt, and 16% clay constitute the sludge generated at the water treatment plant under investigation. Characteristics of the sludge are found suitable for its potential utilization as locally available construction material for safe disposal. An overview of the sustainable management scenario involving beneficial reuses of the sludge has also been presented.

Benchmarking of Control Strategies for Wastewater Treatment Plants

DEFF Research Database (Denmark)

Wastewater treatment plants are large non-linear systems subject to large perturbations in wastewater flow rate, load and composition. Nevertheless these plants have to be operated continuously, meeting stricter and stricter regulations. Many control strategies have been proposed in the literature...

A human reliability analysis of the Three Mile power plant accident considering the THERP and ATHEANA methodologies

International Nuclear Information System (INIS)

Fonseca, Renato Alves da

2004-03-01

The main purpose of this work is the study of human reliability using the THERP (Technique for Human Error Prediction) and ATHEANA methods (A Technique for Human Error Analysis), and some tables and also, from case studies presented on the THERP Handbook to develop a qualitative and quantitative study of nuclear power plant accident. This accident occurred in the TMI (Three Mile Island Unit 2) power plant, PWR type plant, on March 28th, 1979. The accident analysis has revealed a series of incorrect actions, which resulted in the Unit 2 shut down and permanent loss of the reactor. This study also aims at enhancing the understanding of the THERP method and ATHEANA, and of its practical applications. In addition, it is possible to understand the influence of plant operational status on human failures and of these on equipment of a system, in this case, a nuclear power plant. (author)

Sequential decision reliability concept and failure rate assessment

International Nuclear Information System (INIS)

Ciftcioglu, O.

1990-11-01

Conventionally, a reliability concept is considered together with both each basic unit and their integration in a complicated large scale system such as a nuclear power plant (NPP). Basically, as the plant's operational status is determined by the information obtained from various sensors, the plant's reliability and the risk assessment is closely related to the reliability of the sensory information and hence the sensor components. However, considering the relevant information-processing systems, e.g. fault detection processors, there exists a further question about the reliability of such systems, specifically the reliability of the systems' decision-based outcomes by means of which the further actions are performed. To this end, a general sequential decision reliability concept and the failure rate assessment methodology is introduced. The implications of the methodology are investigated and the importance of the decision reliability concept in system operation is demonstrated by means of sensory signals in real-time from the Borssele NPP in the Netherlands. (author). 21 refs.; 8 figs

Improving human reliability through better nuclear power plant system design: Program for advanced nuclear power studies

International Nuclear Information System (INIS)

Golay, M.W.

1993-01-01

The project on ''Development of a Theory of the Dependence of Human Reliability upon System Designs as a Means of Improving Nuclear Power Plant Performance'' was been undertaken in order to address the problem of human error in advanced nuclear power plant designs. Lack of a mature theory has retarded progress in reducing likely frequencies of human errors. Work being pursued in this project is to perform a set of experiments involving human subjects who are required to operate, diagnose and respond to changes in computer-simulated systems, relevant to those encountered in nuclear power plants, which are made to differ in complexity in a systematic manner. The computer program used to present the problems to be solved also records the response of the operator as it unfolds

Reliability data banks

International Nuclear Information System (INIS)

Cannon, A.G.; Bendell, A.

1991-01-01

Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

40 CFR 63.1581 - Does the subpart distinguish between different types of POTW treatment plants?

Science.gov (United States)

2010-07-01

... different types of POTW treatment plants? 63.1581 Section 63.1581 Protection of Environment ENVIRONMENTAL... treatment plants? Yes, POTW treatment plants are divided into two subcategories. A POTW treatment plant which does not meet the characteristics of an industrial POTW treatment plant belongs in the non...

Reliability and maintenance in European nuclear power plants: A structural analysis of a controlled stochastic process

International Nuclear Information System (INIS)

Sturm, R.

1991-01-01

Two aspects of performance are of main concern: plant availability and plant reliability (defined as the conditional probability of an unplanned shutdown). The goal of the research is a unified framework that combines behavioral models of optimizing agents with models of complex technical systems that take into account the dynamic and stochastic features of the system. In order to achieve this synthesis, two liens of work are necessary. One line requires a deeper understanding of complex production systems and the type of data they give rise to; the other line involves the specification and estimation of a rigorously specified behavioral model. Plant operations are modeled as a controlled stochastic process, and the sequence of up and downtime spells is analyzed during failure time and point process models. Similar to work on rational expectations and structural econometric models, the behavior model of how the plant process is controlled is formulated at the level of basic processes, i.e., the objective function of the plant manager, technical constraints, and stochastic disturbances

A fuzzy-based reliability approach to evaluate basic events of fault tree analysis for nuclear power plant probabilistic safety assessment

International Nuclear Information System (INIS)

Purba, Julwan Hendry

2014-01-01

Highlights: • We propose a fuzzy-based reliability approach to evaluate basic event reliabilities. • It implements the concepts of failure possibilities and fuzzy sets. • Experts evaluate basic event failure possibilities using qualitative words. • Triangular fuzzy numbers mathematically represent qualitative failure possibilities. • It is a very good alternative for conventional reliability approach. - Abstract: Fault tree analysis has been widely utilized as a tool for nuclear power plant probabilistic safety assessment. This analysis can be completed only if all basic events of the system fault tree have their quantitative failure rates or failure probabilities. However, it is difficult to obtain those failure data due to insufficient data, environment changing or new components. This study proposes a fuzzy-based reliability approach to evaluate basic events of system fault trees whose failure precise probability distributions of their lifetime to failures are not available. It applies the concept of failure possibilities to qualitatively evaluate basic events and the concept of fuzzy sets to quantitatively represent the corresponding failure possibilities. To demonstrate the feasibility and the effectiveness of the proposed approach, the actual basic event failure probabilities collected from the operational experiences of the David–Besse design of the Babcock and Wilcox reactor protection system fault tree are used to benchmark the failure probabilities generated by the proposed approach. The results confirm that the proposed fuzzy-based reliability approach arises as a suitable alternative for the conventional probabilistic reliability approach when basic events do not have the corresponding quantitative historical failure data for determining their reliability characteristics. Hence, it overcomes the limitation of the conventional fault tree analysis for nuclear power plant probabilistic safety assessment

40 CFR 63.1582 - What are the characteristics of an industrial POTW treatment plant?

Science.gov (United States)

2010-07-01

... industrial POTW treatment plant? 63.1582 Section 63.1582 Protection of Environment ENVIRONMENTAL PROTECTION... Works Industrial Potw Treatment Plant Description and Requirements § 63.1582 What are the characteristics of an industrial POTW treatment plant? (a) Your POTW is an industrial POTW treatment plant if an...

RESPONSE OF TOMATO PLANTS EXPOSED TO TREATMENT WITH NANOPARTICLES

Directory of Open Access Journals (Sweden)

Tommaso Giordani

2012-07-01

Full Text Available In this work the response of Tomato plants cv. Micro-Tom to nanoparticles (NPs treatment was investigated. Tomato seedlings were grown in hydroponic condition and NPs treatments were carried out by adding Fe3O4 or TiO2 NPs to nutrient solution. At the end of treatments, NPs root uptake and tissue deposition were investigated using Environmental Scanning Electron Microscope, equipped with energy dispersive spectroscopy for chemical identification. At morphological level, one week after the beginning of NP treatment, seedlings grown with high concentration of TiO2 NPs showed an abnormal proliferation of root hairs, as compared to the control seedlings and to the seedlings exposed to Fe3O4 NPs, Shoot morphology did not differ in tomato seedlings grown under different conditions and no symptoms of toxicity were observed in NP-treated plants. In order to analyse genetic effects of NPs treatments, RNA transcription was studied in roots of NP-exposed and control plants by Illumina RNA sequencing, evidencing the induction of transposable elements.

Nuclear power plant performance monitoring using Data Validation and Reconciliation (DVR). Application at the Brazilian Angra 2 PWR plant

International Nuclear Information System (INIS)

Tran Quang, Anh Tho; Closon, Hervé; Chares, Robert; Azola, Edson

2011-01-01

Operational decisions related to plant performance monitoring mainly result from raw process measurement analysis. When first signs of sub-optimal behavior occur, traditional methods mainly focus on the observation of selective pieces of information. The main disadvantages of these methods are: Investigation efforts are required to localize the problems, entailing time losses and costs; Validity and reliability of the pieces of information cannot be checked as long as the measurements are observed individually. The problem is not the lack of methods and techniques but rather a lack of reliable and consistent data and information across the entire plant. To overcome drawbacks of traditional methods, measurements are considered as interacting with one another. When related to the other measurements of the plant, the observed information becomes of an interest: its incoherency to the others identifies and localizes a problem. The Data Validation and Reconciliation technology (DVR) is based on an advanced process data coherency treatment. By using all available plant information and by closing the plant heat and mass balances based on rigorous thermodynamics, the method generates: A single set of reliable and most accurate plant process data; Alarms for incoherent measurements, highlighting potential problems; Alarms for equipment and process performance degradation; Alarms for faulty and drifting measurements. The use of the advanced DVR software package VALI offers various benefits as it allows to base operational decisions on reliable and accurate data. (author)

Practical applications of probabilistic structural reliability analyses to primary pressure systems of nuclear power plants

International Nuclear Information System (INIS)

Witt, F.J.

1980-01-01

Primary pressure systems of nuclear power plants are built to exacting codes and standards with provisions for inservice inspection and repair if necessary. Analyses and experiments have demonstrated by deterministic means that very large margins exist on safety impacting failures under normal operating and upset conditions. Probabilistic structural reliability analyses provide additional support that failures of significance are very, very remote. They may range in degree of sophistication from very simple calculations to very complex computer analyses involving highly developed mathematical techniques. The end result however should be consistent with the desired usage. In this paper a probabilistic structural reliability analysis is performed as a supplement to in-depth deterministic evaluations with the primary objective to demonstrate an acceptably low probability of failure for the conditions considered. (author)

Job analysis of the electrician position for the nuclear power plant maintenance personnel reliability model

International Nuclear Information System (INIS)

Federman, P.J.; Bartter, W.D.; Siegel, A.I.

1984-02-01

This report presents the methods, procedures, and results of the fourth and final of a series of job analytic studies which characterize maintenance positions in nuclear power plants. The electrician position is the subject of the present report. The characterization of the electrician position takes the form of detailed information about: (1) the frequency of performing various tasks, (2) the time required for performing each task, (3) the training required for adequate performance of each task, and (4) the perceived consequences resulting from inadequate task performance. Additionally, information is presented about the intellective and the perceptual-motor loading imposed by each task. This information contributes to job design and training requirements derivation as well as to the assessment of human performance reliability in nuclear power plants

Component fragility data base for reliability and probability studies

International Nuclear Information System (INIS)

Bandyopadhyay, K.; Hofmayer, C.; Kassier, M.; Pepper, S.

1989-01-01

Safety-related equipment in a nuclear plant plays a vital role in its proper operation and control, and failure of such equipment due to an earthquake may pose a risk to the safe operation of the plant. Therefore, in order to assess the overall reliability of a plant, the reliability of performance of the equipment should be studied first. The success of a reliability or a probability study depends to a great extent on the data base. To meet this demand, Brookhaven National Laboratory (BNL) has formed a test data base relating the seismic capacity of equipment specimens to the earthquake levels. Subsequently, the test data have been analyzed for use in reliability and probability studies. This paper describes the data base and discusses the analysis methods. The final results that can be directly used in plant reliability and probability studies are also presented in this paper

Suitability review of FMEA and reliability analysis for digital plant protection system and digital engineered safety features actuation system

Energy Technology Data Exchange (ETDEWEB)

Kim, I. S.; Kim, T. K.; Kim, M. C.; Kim, B. S.; Hwang, S. W.; Ryu, K. C. [Hanyang Univ., Seoul (Korea, Republic of)

2000-11-15

Of the many items that should be checked out during a review stage of the licensing application for the I and C system of Ulchin 5 and 6 units, this report relates to a suitability review of the reliability analysis of Digital Plant Protection System (DPPS) and Digital Engineered Safety Features Actuation System (DESFAS). In the reliability analysis performed by the system designer, ABB-CE, fault tree analysis was used as the main methods along with Failure Modes and Effect Analysis (FMEA). However, the present regulatory technique dose not allow the system reliability analysis and its results to be appropriately evaluated. Hence, this study was carried out focusing on the following four items ; development of general review items by which to check the validity of a reliability analysis, and the subsequent review of suitability of the reliability analysis for Ulchin 5 and 6 DPPS and DESFAS L development of detailed review items by which to check the validity of an FMEA, and the subsequent review of suitability of the FMEA for Ulchin 5 and 6 DPPS and DESFAS ; development of detailed review items by which to check the validity of a fault tree analysis, and the subsequent review of suitability of the fault tree for Ulchin 5 and 6 DPPS and DESFAS ; an integrated review of the safety and reliability of the Ulchin 5 and 6 DPPS and DESFAS based on the results of the various reviews above and also of a reliability comparison between the digital systems and the comparable analog systems, i.e., and analog Plant Protection System (PPS) and and analog Engineered Safety Features Actuation System (ESFAS). According to the review mentioned above, the reliability analysis of Ulchin 5 and 6 DPPS and DESFAS generally satisfies the review requirements. However, some shortcomings of the analysis were identified in our review such that the assumed test periods for several equipment were not properly incorporated in the analysis, and failures of some equipment were not included in the

Life Cycle Assessment to Municipal Wastewater Treatment Plant

International Nuclear Information System (INIS)

Garcia, J. s.; Herrera, I.; Rodriguez, A.

2011-01-01

The evaluation was done at a Municipal Wastewater Treatment Plant (MWTP), through the application of the methodology of Life Cycle Assessment (LCA) performed by using a commercial tool called SIMAPRO. The objective of this study was to apply Life Cycle Assessment (LCA) in two systems: municipal wastewater effluent without treatment and Wastewater Treatment Plant (WTP) that is operating in poor condition and has a direct discharge to a natural body, which is a threat to the environment. A LCA was done using SIMAPRO 7, in order to determine the environmental impact in each scenery was assessed, a comparison of the impacts and propose improvements to decrease, following the steps this methodology and according to the respective standardized normative (ISO 14040/ ISO 14044). In this study, most of used data have been reported by the plant from early 2010 and some data from literature. We identified the environmental impacts generated by the treatment, making emphasis on those related to the subsequent use of the water body receiving the discharge, such as eutrophication (near to 15% reduction). Likewise, a comparative analysis between the impacts in the two systems, with and without treatment by analyzing the variation in the impact categories studied. Finally within this work, alternatives of improvements, in order to reduce the identified and quantified impacts are proposed. (Author) 33 refs.

Characterization of livestock wastewater at various stages of wastewater treatment plant

International Nuclear Information System (INIS)

Ting Teo Ming; Kim, Tak Hyun; Lee, Myun Joo

2007-01-01

A characterization study has been conducted at Gongju Livestock Wastewater Treatment Plant, Gongju, South Korea. It is owned and operated by the government with treatment capacity of 250 tons per day. Livestock wastewater was collected from individual farmer and treated at the treatment plant. The centralized livestock wastewater treatment plant has various treatment processes namely pre-treatment, anaerobic digestion, nitrification, de-nitrification , chemical treatment, sand filtration and ozonization. The livestock wastewater was characterized by high COD, SS, T-N and T-P with concentration of 20600 mg/l, 6933 mg/l, 2820 mg/l and 700 mg/ l, respectively. After the wastewater has undergone various treatment processes it was discharged to waterways with concentration of COD, SS, T-N and T-P at 105 mg/l, 73 mg/l, 2.1 mg/l and 9 mg/l, respectively. This is part of the study to investigate the potential of irradiation to be applied at the centralized livestock wastewater treatment plant. Although livestock wastewater can be potentially applied to crop as source of nutrients it also affect the water quality due to runoff and leaching. When the wastewater applied at the rates in excess of crop uptake rates, the excess wastewater could potentially enter surface and groundwater and polluted them. (author)

Conceptual project of waste treatment plant of CDTN

International Nuclear Information System (INIS)

Gabriel, J.L.; Astolfi, D.

1983-01-01

This paper presents the conceptual project of the waste treatment plant of CDTN. Several areas, such as: process area, material entrance and exit area are studied. The treatment processes are: evaporation, filtration, cementation, cutting and processing of solid wastes. (C.M.)

Study of wastewater treatment plants efficiency using radiotracers

International Nuclear Information System (INIS)

Dawi, W. D. A.

2010-11-01

This study was performed to investigate and diagnose hydrodynamic behavior of the Military Hospital wastewater treatment plant. The plant comprises two units of treatment, each of them has a separate system. The investigation was carried out using ''1''3''1I as a radiotracer. The concept of residence time distribution (RTD) was used to investigate the efficiency of the aeration tanks, secondary clarifiers and chlorine tanks. Preliminary treatment and modeling of the trace data was performed using two software package applied by the International Atomic Energy Agency (IAEA) namely 4621 counter version 1.0.0 and RTD software. Plug flow pattern (parallel flow) was detected in the aeration tank and secondary clarifier of system 1 in one unit, while no homogeneous mixing was observed in the chlorine tank. Short - circuiting (by - passing) was evident in the aeration tank of system 2 in the other unit, which significantly reduced the operating efficiency. The percentage of dead volumes clearly suggests that the aeration tank and secondary clarifier were well utilized in the whole plant. (Author)

Component reliability analysis for development of component reliability DB of Korean standard NPPs

International Nuclear Information System (INIS)

Choi, S. Y.; Han, S. H.; Kim, S. H.

2002-01-01

The reliability data of Korean NPP that reflects the plant specific characteristics is necessary for PSA and Risk Informed Application. We have performed a project to develop the component reliability DB and calculate the component reliability such as failure rate and unavailability. We have collected the component operation data and failure/repair data of Korean standard NPPs. We have analyzed failure data by developing a data analysis method which incorporates the domestic data situation. And then we have compared the reliability results with the generic data for the foreign NPPs

Human factor reliability program

International Nuclear Information System (INIS)

Knoblochova, L.

2017-01-01

The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

Adaptive model based control for wastewater treatment plants

NARCIS (Netherlands)

de Niet, Arie; van de Vrugt, Noëlle Maria; Korving, Hans; Boucherie, Richardus J.; Savic, D.A.; Kapelan, Z.; Butler, D.

2011-01-01

In biological wastewater treatment, nitrogen and phosphorous are removed by activated sludge. The process requires oxygen input via aeration of the activated sludge tank. Aeration is responsible for about 60% of the energy consumption of a treatment plant. Hence optimization of aeration can

Economics of wastewater treatment in GTL plant using spray technique

Energy Technology Data Exchange (ETDEWEB)

Enyi, G.C.; Nasr, G.G.; Burby, M. [University of Salford, Manchester, M5 4WT (United Kingdom)

2013-07-01

In a Gas-to-liquid (GTL) plant, significant quantities of CO2 and reaction water are produced and various chemicals are used as intermediate treatment chemicals. The reaction water is contaminated by these chemicals which impair the pH and the related properties of the water. The pH has to be controlled in the effluent treatment unit before the water is re-used or released to the environment. The overall aim of this investigation is to create a novel technique to address the problem of waste water treatment in GTL plants which will assist in the reduction of greenhouse gas (CO2) emissions into the atmosphere. A laboratory-scale effluent neutralisation unit for pH control utilising gas injectors was designed and built. The unit used the CO2 produced as a by-product of GTL process as wastewater treatment chemical instead of the conventional Sulphuric acid. The quality of wastewater after treatment with CO2 met the standards set by the state regulatory agency. The economics of the new process shows a better payout period of 3.6 years for capital investment of $1,645 Million compared to 4.7 years for an existing plant layout with capital investment of $1,900 Million. The effects of increase in plant capacity showed a lower payback back of 2.8 years for plant capacity of 140,000 barrels/day (22258 m3/day), 3.6 years for 34,000 barrels/day and 6.0 years for 12,500 barrels/day (1987 m3/day) plant capacity. The sensitivity analysis using crystal ball simulator with 'Microsoft Excel' shows that the annual revenue has the greatest effects on the NPV of the plant than the CAPEX and inflation rate. Apart from the environmental benefits the process generates by reducing CO2 emissions into the atmosphere, the study also concludes that the replacement of conventional Sulphuric acid (H2SO4) unit with CO2 improves the economics of the plant.

Modernization of Kozloduy nuclear plant unit 5 and 6, implementation of measures to improve the reliability of the main generator system

International Nuclear Information System (INIS)

Stinshoff, H.

2003-01-01

To improve the reliability of Kozloduy Nuclear power plant several modernization measures will be implemented during the outages in the years 2003 to 2005. In the area of the main generator the following measures will be performed in unit 6 during 2003 outage: - Replacement of main generator circuit breaker by new SF6 cooled breaker type - Replacement of main generator excitation system by new two channel digital system - Replacement of main generator protection by new digital multi-purpose protections including digital fault recorders - Installation of radio frequency monitoring system of main generator circuit Starting from the present situation the new concept is explained. The project organization under consideration of large Bulgarian participation as well as the sequence and schedule of the implementation during the short outage time window is shown. These modernization measures lead to an increase of reliability and availability for the operation of the power plant and with this to increase power plant safety

Review of Software Reliability Assessment Methodologies for Digital I and C Software of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Cho, Jae Hyun; Lee, Seung Jun; Jung, Won Dea [KAERI, Daejeon (Korea, Republic of)

2014-08-15

Digital instrumentation and control (I and C) systems are increasingly being applied to current nuclear power plants (NPPs) due to its advantages; zero drift, advanced data calculation capacity, and design flexibility. Accordingly, safety issues of software that is main part of the digital I and C system have been raised. As with hardware components, the software failure in NPPs could lead to a large disaster, therefore failure rate test and reliability assessment of software should be properly performed, and after that adopted in NPPs. However, the reliability assessment of the software is quite different with that of hardware, owing to the nature difference between software and hardware. The one of the most different thing is that the software failures arising from design faults as 'error crystal', whereas the hardware failures are caused by deficiencies in design, production, and maintenance. For this reason, software reliability assessment has been focused on the optimal release time considering the economy. However, the safety goal and public acceptance of the NPPs is so distinctive with other industries that the software in NPPs is dependent on reliability quantitative value rather than economy. The safety goal of NPPs compared to other industries is exceptionally high, so conventional methodologies on software reliability assessment already used in other industries could not adjust to safety goal of NPPs. Thus, the new reliability assessment methodology of the software of digital I and C on NPPs need to be developed. In this paper, existing software reliability assessment methodologies are reviewed to obtain the pros and cons of them, and then to assess the usefulness of each method to software of NPPs.

Review of Software Reliability Assessment Methodologies for Digital I and C Software of Nuclear Power Plants

International Nuclear Information System (INIS)

Cho, Jae Hyun; Lee, Seung Jun; Jung, Won Dea

2014-01-01

Digital instrumentation and control (I and C) systems are increasingly being applied to current nuclear power plants (NPPs) due to its advantages; zero drift, advanced data calculation capacity, and design flexibility. Accordingly, safety issues of software that is main part of the digital I and C system have been raised. As with hardware components, the software failure in NPPs could lead to a large disaster, therefore failure rate test and reliability assessment of software should be properly performed, and after that adopted in NPPs. However, the reliability assessment of the software is quite different with that of hardware, owing to the nature difference between software and hardware. The one of the most different thing is that the software failures arising from design faults as 'error crystal', whereas the hardware failures are caused by deficiencies in design, production, and maintenance. For this reason, software reliability assessment has been focused on the optimal release time considering the economy. However, the safety goal and public acceptance of the NPPs is so distinctive with other industries that the software in NPPs is dependent on reliability quantitative value rather than economy. The safety goal of NPPs compared to other industries is exceptionally high, so conventional methodologies on software reliability assessment already used in other industries could not adjust to safety goal of NPPs. Thus, the new reliability assessment methodology of the software of digital I and C on NPPs need to be developed. In this paper, existing software reliability assessment methodologies are reviewed to obtain the pros and cons of them, and then to assess the usefulness of each method to software of NPPs

Experimental Research of Reliability of Plant Stress State Detection by Laser-Induced Fluorescence Method

Directory of Open Access Journals (Sweden)

Yury Fedotov

2016-01-01

Full Text Available Experimental laboratory investigations of the laser-induced fluorescence spectra of watercress and lawn grass were conducted. The fluorescence spectra were excited by YAG:Nd laser emitting at 532 nm. It was established that the influence of stress caused by mechanical damage, overwatering, and soil pollution is manifested in changes of the spectra shapes. The mean values and confidence intervals for the ratio of two fluorescence maxima near 685 and 740 nm were estimated. It is presented that the fluorescence ratio could be considered a reliable characteristic of plant stress state.

26+ Year Old Photovoltaic Power Plant: Degradation and Reliability Evaluation of Crystalline Silicon Modules -- South Array

Science.gov (United States)

Olakonu, Kolapo

As the use of photovoltaic (PV) modules in large power plants continues to increase globally, more studies on degradation, reliability, failure modes, and mechanisms of field aged modules are needed to predict module life expectancy based on accelerated lifetime testing of PV modules. In this work, a 26+ year old PV power plant in Phoenix, Arizona has been evaluated for performance, reliability, and durability. The PV power plant, called Solar One, is owned and operated by John F. Long's homeowners association. It is a 200 kW dc, standard test conditions (STC) rated power plant comprised of 4000 PV modules or frameless laminates, in 100 panel groups (rated at 175 kW ac). The power plant is made of two center-tapped bipolar arrays, the north array and the south array. Due to a limited time frame to execute this large project, this work was performed by two masters students (Jonathan Belmont and Kolapo Olakonu) and the test results are presented in two masters theses. This thesis presents the results obtained on the south array and the other thesis presents the results obtained on the north array. Each of these two arrays is made of four sub arrays, the east sub arrays (positive and negative polarities) and the west sub arrays (positive and negative polarities), making up eight sub arrays. The evaluation and analyses of the power plant included in this thesis consists of: visual inspection, electrical performance measurements, and infrared thermography. A possible presence of potential induced degradation (PID) due to potential difference between ground and strings was also investigated. Some installation practices were also studied and found to contribute to the power loss observed in this investigation. The power output measured in 2011 for all eight sub arrays at STC is approximately 76 kWdc and represents a power loss of 62% (from 200 kW to 76 kW) over 26+ years. The 2011 measured power output for the four south sub arrays at STC is 39 kWdc and represents a power

Fuel reliability experience in Finland

International Nuclear Information System (INIS)

Kekkonen, L.

2015-01-01

Four nuclear reactors have operated in Finland now for 35-38 years. The two VVER-440 units at Loviisa Nuclear Power Plant are operated by Fortum and two BWR’s in Olkiluoto are operated by Teollisuuden Voima Oyj (TVO). The fuel reliability experience of the four reactors operating currently in Finland has been very good and the fuel failure rates have been very low. Systematic inspection of spent fuel assemblies, and especially all failed assemblies, is a good practice that is employed in Finland in order to improve fuel reliability and operational safety. Investigation of the root cause of fuel failures is important in developing ways to prevent similar failures in the future. The operational and fuel reliability experience at the Loviisa Nuclear Power Plant has been reported also earlier in the international seminars on WWER Fuel Performance, Modelling and Experimental Support. In this paper the information on fuel reliability experience at Loviisa NPP is updated and also a short summary of the fuel reliability experience at Olkiluoto NPP is given. Keywords: VVER-440, fuel reliability, operational experience, poolside inspections, fuel failure identification. (author)

Process waste treatment system upgrades: Clarifier startup at the nonradiological wastewater treatment plant

International Nuclear Information System (INIS)

Lucero, A.J.; McTaggart, D.R.; Van Essen, D.C.; Kent, T.E.; West, G.D.; Taylor, P.A.

1998-07-01

The Waste Management Operations Division at Oak Ridge National Laboratory recently modified the design of a reactor/clarifier at the Nonradiological Wastewater Treatment Plant, which is now referred to as the Process Waste Treatment Complex--Building 3608, to replace the sludge-blanket softener/clarifier at the Process Waste Treatment Plant, now referred to as the Process Waste Treatment Complex-Building 3544 (PWTC-3544). This work was conducted because periodic hydraulic overloads caused poor water-softening performance in the PWTC-3544 softener, which was detrimental to the performance and operating costs of downstream ion-exchange operations. Over a 2-month time frame, the modified reactor/clarifier was tested with nonradiological wastewater and then with radioactive wastewater to optimize softening performance. Based on performance to date, the new system has operated more effectively than the former one, with reduced employee radiological exposure, less downtime, lower costs, and improved effluent quality

EVALUATION OF ENERGY CONSUMPTION IN AGRO-INDUSTRIAL WASTEWATER TREATMENT PLANT

Directory of Open Access Journals (Sweden)

Wojciech Dąbrowski

2016-07-01

Full Text Available Energy consumption during waste water treatment is a very important factor affecting food industry plants. Apart from highly efficient treatment of dairy and meat sewage, a low energy consumption is required in order to lower its costs. During the research period parameters of raw and treated sewage were tested (BOD, COD, N-total, P-total. Also, the energy consumption from selected processes as well as total consumption were measured. Indicators of energy consumption per m3 and removed load were calculated. It was found that biological treatment and aeration played the main role in energy consumption in both objects. It was respectively 40 and 47% for Bielmlek and JBB plants. The second biggest energy consuming stage of treatment in both objects was sludge processing. Energy required to process excessive sludge equaled 30% of the total energy usage in both plants. Energy consumption factors related to hydraulic flow gave results in the range from 2,05 to 3,3 kWhm-3 and from 2,72 to 3,23 kWhm-3 for Bielmlek and JBB plants respectively. The research will be continued in order to optimize energy consumption while retaining high efficiency treatment in food industry WWTPs. Finally a mathematical model will be prepared for optimizing energy consumption in food industry WWTPs.

Program integration of predictive maintenance with reliability centered maintenance

International Nuclear Information System (INIS)

Strong, D.K. Jr; Wray, D.M.

1990-01-01

This paper addresses improving the safety and reliability of power plants in a cost-effective manner by integrating the recently developed reliability centered maintenance techniques with the traditional predictive maintenance techniques of nuclear power plants. The topics of the paper include a description of reliability centered maintenance (RCM), enhancing RCM with predictive maintenance, predictive maintenance programs, condition monitoring techniques, performance test techniques, the mid-Atlantic Reliability Centered Maintenance Users Group, test guides and the benefits of shared guide development

FEASIBILITY STUDY OF GAS TREATMENT PLANT BASED ON AN EJECTOR SCRUBBER

Directory of Open Access Journals (Sweden)

S. Iu. Panov

2014-01-01

Full Text Available Summary. The article executed the feasibility study of various options for gas treatment. Rapid development of industry and transport worldwide in recent times raises the problem in the protection of habitat environment from harmful waste. In solving problems of flue gas treatment great attention is given to the economic characteristics and recycling techniques for capturing emissions and disposal must also meet the sanitary health requirements: flue gas treatment plants should not cause air or water pollution. The set objective is solved by developing a two-stage wet treatment system for pyrolysis gas based on ejector scrubbers. Their advantage - a central nozzle supply that allows the scrubber to operate on the principle of an ejector pump. Projected plant can be used in enterprises for processing of solid domestic and industrial waste, where there are steam and hot water boilers, whose operations result in contaminated gases emissions obtained with high temperatures. In particular, this installation can be applied at a cement plant in which a large amount of waste gases containing sulfur oxides is emitted. Assessment of market potential for the plant designed to treat waste gases in the cement factory is performed through a SWOT analysis. SWOT analysis results indicate the possibility of the treatment of exhaust gases without a high cost and with high gas treatment efficiency. Plant competitive analysis was done using an expert method in comparison with market competitors. Technical and economic indicators of the plant are presented. Return on investments is 46% and payback period of capital investments - 2.7 years.

Reliability study: digital engineered safety feature actuation system of Korean Standard Nuclear Power Plant

International Nuclear Information System (INIS)

Sudarno; Kang, H. G.; Jang, S. C.; Eom, H. S.; Ha, J. J.

2003-04-01

The usage of digital Instrumentation and Control (I and C) in a nuclear power plant becomes more extensive, including safety related systems. The PSA application of these new designs are very important in order to evaluate their reliability. In particular, Korean Standard Nuclear Power Plants (KSNPPs), typically Ulchin 5 and 6 (UCN 5 and 6) reactor units, adopted the digital safety-critical systems such as Digital Plant Protection System (DPPS) and Digital Engineered Safety Feature Actuation System (DESFAS). In this research, we developed fault tree models for assessing the unavailability of the DESFAS functions. We also performed an analysis of the quantification results. The unavailability results of different DESFAS functions showed that their values are comprised from 5.461E-5 to 3.14E-4. The system unavailability of DESFAS AFAS-1 is estimated as 5.461E-5, which is about 27% less than that of analog system if we consider the difference of human failure probability estimation between both analyses. The results of this study could be utilized in risk-effect analysis of KSNPP. We expect that the safety analysis result will contribute to design feedback

Optimal design of regional wastewater pipelines and treatment plant systems.

Science.gov (United States)

Brand, Noam; Ostfeld, Avi

2011-01-01

This manuscript describes the application of a genetic algorithm model for the optimal design of regional wastewater systems comprised of transmission gravitational and pumping sewer pipelines, decentralized treatment plants, and end users of reclaimed wastewater. The algorithm seeks the diameter size of the designed pipelines and their flow distribution simultaneously, the number of treatment plants and their size and location, the pump power, and the required excavation work. The model capabilities are demonstrated through a simplified example application using base runs and sensitivity analyses. Scaling of the proposed methodology to real life wastewater collection and treatment plants design problems needs further testing and developments. The model is coded in MATLAB using the GATOOL toolbox and is available from the authors.

Complete physico-chemical treatment for coke plant effluents.

Science.gov (United States)

Ghose, M K

2002-03-01

Naturally found coal is converted to coke which is suitable for metallurgical industries. Large quantities of liquid effluents produced contain a large amount of suspended solids, high COD, BOD, phenols, ammonia and other toxic substances which are causing serious pollution problem in the receiving water to which they are discharged. There are a large number of coke plants in the vicinity of Jharia Coal Field (JCF). Characteristics of the effluents have been evaluated. The present effluent treatment systems were found to be inadequate. Physico-chemical treatment has been considered as a suitable option for the treatment of coke plant effluents. Ammonia removal by synthetic zeolite, activated carbon for the removal of bacteria, viruses, refractory organics, etc. were utilized and the results are discussed. A scheme has been proposed for the complete physico-chemical treatment, which can be suitably adopted for the recycling, reuse and safe disposal of the treated effluent. Various unit process and unit operations involved in the treatment system have been discussed. The process may be useful on industrial scale at various sites.

The performance of plant species in removing nutrients from ...

African Journals Online (AJOL)

2011-10-26

Oct 26, 2011 ... but offered no explicit guidance about how these water quality targets might be achieved. ... the limited knowledge that exists about the performance of local plant ...... reuse: designing biofiltration systems for reliable treatment.

Human performance and reliability studies on nuclear power plant

International Nuclear Information System (INIS)

Miyaoka, S.

1988-01-01

The TMI accident in USA, the Chernobyl accident in USSR and other major accidents overseas have shown that it is necessary to investigate and research human factor problems related to operation, maintenance and others in order to increase the safety and reliability of nuclear power plants. Although a variety of countermeasures have been devised, the accidents and failures due to human factors still occur. So far, the problems related to human factors have not been fundamantally and systematically investigated. Also the data base related to this problem has not been developed. Therefore, the government and electric utility industry began the research on the prevention of the accidents caused by human errors. The basic research is carried out by the government, and the applied research is done by electric utility industry. The Central Research Institute of Electric Power Industry established the Human Factors Research Center on July 1, 1987. The research program in the Human Factors Research Center is divided into the basic research to clarity fundamental human characteristics, the systematic research to apply this information and the analytical research on human error experience. These research activities are reported. (Kako, I.)

[Reliability of endocervical curettage after conservative treatment of intraepithelial neoplasia of the cervix].

Science.gov (United States)

Lecointre, L; Akladios, C-Y; Averous, G; Lefebvre, F; Baulon, E; Thoma, V; Fender, M; Baldauf, J-J

2015-02-01

To evaluate the reliability of endocervical curettage (ECC) in patients previously treated for CIN. Retrospective analysis of data from 85 patients between January 1985 and December 2011 who received an ECC during monitoring after treatment of CIN. The reliability of the ECC was evaluated by comparison with the final histological analysis of the surgical specimen or the data for subsequent cyto-colpo-histological follow-up. Patients were referred to colposcopy either within the immediate post-treatment monitoring (n=42), meanly 9.7±5.3 months after treatment, or if cytological abnormalities were detected during long-term monitoring, meanly 78.6±52.4 months after treatment. Colposcopy was unsatisfactory in 75.3% of patients and normal colposcopic findings were found in 80% of patients. A perfect agreement between the ECC and the endocervical final diagnosis was noted in 68 patients (80%). For the diagnosis of severe cervical lesions (CIN 2+) ECC had a sensitivity of 86.2% (68.3-96.1), a specificity of 94.6% (85.1-98.9) and positive and negative predictive values of 61.4% (47.6-74.0) and 93% (83.0-98.1), respectively. The high sensitivity and negative predictive value of ECC for the diagnosis of severe post-therapeutic endocervical lesions avoid iterative treatment without increasing the risk of progression of a lesion to cancer. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Hydraulic modelling of drinking water treatment plant operations

NARCIS (Netherlands)

Worm, G.I.M.; Mesman, G.A.M.; Van Schagen, K.M.; Borger, K.J.; Rietveld, L.C.

2009-01-01

The flow through a unit of a drinking water treatment plant is one of the most important parameters in terms of a unit's effectiveness. In the present paper, a new EPAnet library is presented with the typical hydraulic elements for drinking water treatment processes well abstraction, rapid sand

Indigenous plant medicines for health care: treatment of Diabetes mellitus and hyperlipidemia.

Science.gov (United States)

Parikh, Nisha H; Parikh, Palak K; Kothari, Charmy

2014-05-01

Medicinal plants have played an important role in treating and preventing a variety of diseases throughout the world. Metabolic syndrome had become a global epidemic, defined as a cluster of three of five criteria: insulin resistance and glucose intolerance, abdominal obesity, hypertension, low high-density cholesterol, and hypertriglyceridemia. The current review focuses on Indian medicinal plant drugs and plants used in the treatment of diabetes and hyperlipidemia. Though there are various approaches to reduce the ill-effects of diabetes and hyperlipidemia and its secondary complications, plant-based drugs are preferred due to lesser side effects and low cost. The current review focuses on twenty-three medicinal plants used in the treatment of Diabetes mellitus and nine medicinal plants used in the treatment of hyperlipidemia. The wealth of knowledge on medicinal plants points to a great potential for research and the discovery of new drugs to fight diseases, including diabetes and hyperlipidemia. Copyright © 2014 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Reliability issues at the LHC

CERN Multimedia

CERN. Geneva. Audiovisual Unit; Gillies, James D

2002-01-01

The Lectures on reliability issues at the LHC will be focused on five main Modules on five days. Module 1: Basic Elements in Reliability Engineering Some basic terms, definitions and methods, from components up to the system and the plant, common cause failures and human factor issues. Module 2: Interrelations of Reliability & Safety (R&S) Reliability and risk informed approach, living models, risk monitoring. Module 3: The ideal R&S Process for Large Scale Systems From R&S goals via the implementation into the system to the proof of the compliance. Module 4: Some Applications of R&S on LHC Master logic, anatomy of risk, cause - consequence diagram, decomposition and aggregation of the system. Module 5: Lessons learned from R&S Application in various Technologies Success stories, pitfalls, constrains in data and methods, limitations per se, experienced in aviation, space, process, nuclear, offshore and transport systems and plants. The Lectures will reflect in summary the compromise in...

Wastewater management in Khartoum Region Soba wastewater treatment plant (stabilization ponds)

International Nuclear Information System (INIS)

Maki, A. M. E.

2010-03-01

Soba wastewater treatment plant will be replaced shortly by new plant based on activate sludge. This study was carried in order to evaluate: the design, physical, chemical and biological characteristics and the capacity of the plant. Outlet Effluents quality was compared with Sudan wastewater treatment standards. Samples analyses were carried by UNESCO CHAIR 2006 (Khartoum State). It was found that the result is not as: The designed and standard level especially for BOD, COD, TBC and TC. It was also found that BOD and COD of the effluents were not complying with adopted standards for treated wastewater to be discharged to the environment. The study reached the conclusions that plant is overloaded and the characteristics of the wastewater received is not as the design which affects the efficiency of the treatment process. (Author)

Use of robotics in a Radwaste treatment plant

International Nuclear Information System (INIS)

Leeks, C.W.E.

1991-01-01

A 762 Unimate Puma, clean room standard Robot has been installed and commissioned in the Radwaste Treatment Plant at the Winfrith Technology Centre. The robot interacts with a variety of purpose designed tools and proprietary welding equipment. It performs 13 dedicated tasks in the final closure and health physics operations, before the 500 litre waste drum is despatched from the plant. (author)

Wastewater treatment and reuse. Indian power plant turns sewage into process water

Energy Technology Data Exchange (ETDEWEB)

Langer, S.; Schroedter, F.; Demmerle, C. [ERM Lahmeyer International, Neu-Isenburg (Germany)

2000-07-01

Lahmeyer International provided consulting services for a private Indian investor of a 200 MW diesel engine power plant, in reviewing and controlling the EPC Contractor from Korea with regard to the treatment plant for dosmestic wastewater and the reverse osmosis plant for desalination. The wastewater treatment and subsequent water treatment for cooling water production comprised: mechanical treatment, biological treatment of domestic wastewater, lime softening, sand filtration, disinfection, micro-filtration, reverse osmosis. The services as Owner's Engineer included: (1) the review of the EPC Contractor's treatment concept, (2) the selection of internationally renowned manufacturer, (3) the review of the detailed design (including civil, mechanical, electrical and I and C work), and (4) onsite technical assistance to the Client during construction and commissioning phase. (orig.)

Medicinal plants used for the treatment of jaundice and hepatitis ...

African Journals Online (AJOL)

The present study deals with socio-economic documentation of medicinal plant species against jaundice and hepatitis. A total of 30 plant species belonging to 24 families were reported by local practitioners for the treatment of jaundice and hepatitis. The most important plant species are Adiantum capillus, Boerhaavia ...

MHTGR thermal performance envelopes: Reliability by design

International Nuclear Information System (INIS)

Etzel, K.T.; Howard, W.W.; Zgliczynski, J.B.

1992-05-01

This document discusses thermal performance envelopes which are used to specify steady-state design requirements for the systems of the Modular High Temperature Gas-Cooled Reactor to maximize plant performance reliability with optimized design. The thermal performance envelopes are constructed around the expected operating point accounting for uncertainties in actual plant as-built parameters and plant operation. The components are then designed to perform successfully at all points within the envelope. As a result, plant reliability is maximized by accounting for component thermal performance variation in the design. The design is optimized by providing a means to determine required margins in a disciplined and visible fashion

Implementation of the project of equipment reliability in the nuclear power plant of Laguna Verde; Implementacion del proyecto de confiabilidad de equipo en la Central Nucleoelectrica Laguna Verde

Energy Technology Data Exchange (ETDEWEB)

Rios O, J. E.; Martinez L, A. G. [CFE, Central Laguna Verde, Subgerencia General de Operacion, Veracruz (Mexico)]. e-mail: jrios@cfe.gob.mx

2008-07-01

A equipment is reliable if it fulfills the function for which was designed and when it is required. To implement a project of reliability in a nuclear power plant this associate to a process of continuous analysis of the operation, of the conditions and faults of the equipment. The analysis of the operation of a system, of the equipment of the same faults and the parts that integrate to equipment take to identify the potential causes of faults. The predictive analysis on components and equipment allow to rectify and to establish guides to optimize the maintenance and to guarantee the reliability and function of the same ones. The reliability in the equipment is without place to doubts a wide project that embraces from the more small component of the equipment going by the proof of the parts of reserve, the operation conditions until the operative techniques of analysis. Without place of doubt for a nuclear power plant the taking of decisions based on the reliability of their systems and equipment will be the appropriate for to assure the operation and reliability of the same one. In this work would appear the project of reliability its processes, criteria, indicators action of improvement and the interaction of the different disciplines from the Nuclear Power Plant of Laguna Verde like a fundamental point for it put in operation. (Author)

Evaluation of Five Treatment Plants for the Removal of Microcystins in Drinking Water

Directory of Open Access Journals (Sweden)

Manuel Álvarez Cortiñas

2017-06-01

Full Text Available In Galicia there are supplies that collect water from reservoirs showing growth of cyanobacteria that could produce toxins. The drinking water treatment plants (DWTPs of these supplies should provide adequate treatment and be subjected to maintenance. WHO guidelines make recommendations on the most suitable treatments for removing microcystins. The Department of Health developed a protocol of action against these events jointly with water basin authorities. 4 reservoirs and five treatment plants were identified for this study. The treatments of the plants, the maintenance carried out at the DWTPs and the results for sestonic and dissolved toxins analyzed by the Public Health Laboratory of Galicia in the reservoirs near the point of collection, before the treatment plants and after them, during the 2013-2014 biennium were evaluated.

Medicinal plants as alternative treatments for female sexual dysfunction: utopian vision or possible treatment in climacteric women?

Science.gov (United States)

Mazaro-Costa, Renata; Andersen, Monica L; Hachul, Helena; Tufik, Sergio

2010-11-01

Female sexual dysfunction (FSD) is a complex and multifactorial condition. An increased incidence of FSD is especially associated with the decline of estrogen. Thus, menopause is a critical phase for FSD complaints. In this context, medicinal plants may be a therapeutic option. To identify and describe the popular and clinical uses of medicinal plants for FSD treatment in climacteric women. We highlighted the majority of the plants commonly involved with the female reproductive system including: Angelica sinensis, Cimicifuga racemosa, Ferula hermonis, Ginkgo biloba, Humulus lupulus, Lepidium meyenii, Tribulus terrestris, Trifolium pratense, and Vitex agnus-castus. This study is a narrative review of studies of plants that are possible alternative treatments for FSD. The species described have clinical and popular uses in different cultures as well as medical indications for female reproductive disturbances, mainly in climacteric women. We have also analyzed the evidence level of clinical studies. The main outcome assessed is the efficacy of plants in improving the symptoms of FSD. There is little evidence from the literature to recommend the use of medicinal plants when treating FSD. The majority of studies with a strong level of evidence are associated with the treatment of the vasomotor symptoms of menopause. Ferula hermonis, Angelica sinensis, and Gingko biloba may be suggested for arousal disorder studies. Cimicifuga racemosa, Trifolium pratense, and Vitex agnus-castus may be recommended for several FSD. Humulus lupulus and Tribulus terrestris may help with desire disorder studies. Lepidium meyenii should be studied further. Studies of these plants indicate that they may be useful as a possible alternative and/or complementary approach for studies aimed at the treatment of FSD. At this time, however, this review cannot recommend a plant that has a strong enough level of evidence for treatment of FSD. Thus, there is a need for clinical (double-blinded and

Experience and perspectives of nuclear power plant reliability evaluation at Institute J. Stefan; Izkusnje in perspektive vrednotenja zanesljivosti jedrskih elekrarn na Institutu Jozef Stefan

Energy Technology Data Exchange (ETDEWEB)

Susnik, J [Institut Jozef Stefan, Ljubljana (Yugoslavia)

1979-07-01

First a short report on development of computer programs for the reliability evaluation and the findings regarding the adequate reliability of Nuclear Power Plant safety systems are given. Then evaluation of the general NPP availability situation is discussed and suggestions for planning and achieving an adequate high availability are presented. (author)

Researching and improving the reliability of reactor protection system of Qinshan nuclear power plant

International Nuclear Information System (INIS)

Jiang Zuyue; Sheng Jiannan

1997-01-01

Due to the original design defects of the Reactor Protection System (RPS) of Qinshan Nuclear Power Plant, this system has brought about a number of reactor shutdown accidents and Engineered Safety Features (ESF) mis-activation events which have seriously endangered safe and steady operation of the nuclear power plant. So over three years have been spent on research on the reform of the original design on the premise that the general wiring of the system should remain the same and that the system size should also remain small to be contained in the original cabinets. The following improvements were made: (1) Increase the system's anti-disturbance capability. The system's zero volt bus floating designs were modified to surmount the disturbance resulting from the bad isolation performance of impedance-isolated amplifier; Double grounds have been added to logical modules to surmount the disturbance resulting from zero volt floating bus during the replacement of single module with two connectors; The opto-coupling circuit in its oscillation input stage of Engineered Safety Features have been improved to increase its reliability. (2)Modify to output activation part of the system. The new type of output relays were selected and the relay activation circuits were redesigned in which switcher activation mode is used instead of amplifier activation mode so as to increase the reliability of relay operation and reduce the power consumption; CMOS buffer gates in the input and output stage of the circuit were used to match TTL circuits to CMOS circuits of the system

Medicinal Plants Used for Treatment of Diarrhoeal Related Diseases in Ethiopia

Directory of Open Access Journals (Sweden)

Bizuneh Woldeab

2018-01-01

Full Text Available This paper presents a review of relevant antidiarrhoeal medicinal plants based on the fundamental knowledge accumulated by indigenous people of Ethiopia. The review includes an inventory carried out on the phytochemical and pharmacological analysis of plant species used in the treatments of diarrhoeal diseases. This study is based on a review of the literature published in scientific journals, books, theses, proceedings, and reports. A total of 132 medicinal plants used by local people of Ethiopia are reported in the reviewed literature. Herbs (43.6% were the primary source of medicinal plants, followed by trees (27%. Some findings include the predominance of leaf material used (78%, as well as the frequent use of crushing of the plant parts (38% as a mode of preparation. This study demonstrates the importance of traditional medicines in the treatment of basic human ailments such as diarrhoeal diseases in Ethiopia. Baseline information gaps were observed in different regions of Ethiopia. Thus, documentation of the knowledge held by other regions of Ethiopia that have so far received less attention and urban ethnobotany is recommended for future ethnobotanical studies. In addition, phytochemical studies are recommended mainly on frequently utilized medicinal plants for treatment of diarrhoeal diseases which can serve as a basis for future investigation of modern drug development. Although societies in Ethiopia have long used medicinal plants for diarrhoeal diseases treatment, it is also a good practice to perform toxicological tests.

Medicinal Plants Used for Treatment of Diarrhoeal Related Diseases in Ethiopia

Science.gov (United States)

Woldeab, Bizuneh; Regassa, Reta

2018-01-01

This paper presents a review of relevant antidiarrhoeal medicinal plants based on the fundamental knowledge accumulated by indigenous people of Ethiopia. The review includes an inventory carried out on the phytochemical and pharmacological analysis of plant species used in the treatments of diarrhoeal diseases. This study is based on a review of the literature published in scientific journals, books, theses, proceedings, and reports. A total of 132 medicinal plants used by local people of Ethiopia are reported in the reviewed literature. Herbs (43.6%) were the primary source of medicinal plants, followed by trees (27%). Some findings include the predominance of leaf material used (78%), as well as the frequent use of crushing of the plant parts (38%) as a mode of preparation. This study demonstrates the importance of traditional medicines in the treatment of basic human ailments such as diarrhoeal diseases in Ethiopia. Baseline information gaps were observed in different regions of Ethiopia. Thus, documentation of the knowledge held by other regions of Ethiopia that have so far received less attention and urban ethnobotany is recommended for future ethnobotanical studies. In addition, phytochemical studies are recommended mainly on frequently utilized medicinal plants for treatment of diarrhoeal diseases which can serve as a basis for future investigation of modern drug development. Although societies in Ethiopia have long used medicinal plants for diarrhoeal diseases treatment, it is also a good practice to perform toxicological tests. PMID:29743923

Performance of wastewater treatment plants in Jordan and suitability ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-04

Aug 4, 2008 ... and NH4; therefore it is classified as a strong waste. ... Key words: Wastewater, treatment plants, water reuse, wastewater characteristics, wastewater treatment,. Jordan. ..... MSc. thesis, university of Jordan. Bataineh F, Najjar ...

Development of web-based reliability data base platform

International Nuclear Information System (INIS)

Hwang, Seok Won; Lee, Chang Ju; Sung, Key Yong

2004-01-01

Probabilistic safety assessment (PSA) is a systematic technique which estimates the degree of risk impacts to the public due to an accident scenario. Estimating the occurrence frequencies and consequences of potential scenarios requires a thorough analysis of the accident details and all fundamental parameters. The robustness of PSA to check weaknesses in a design and operation will allow a better informed and balanced decision to be reached. The fundamental parameters for PSA, such as the component failure rates, should be estimated under the condition of steady collection of the evidence throughout the operational period. However, since any single plant data does not sufficiently enough to provide an adequate PSA result, in actual, the whole operating data was commonly used to estimate the reliability parameters for the same type of components. The reliability data of any component type consists of two categories; the generic that is based on the operating experiences of whole plants, and the plant-specific that is based on the operation of a specific plant of interest. The generic data is highly essential for new or recently-built nuclear power plants (NPPs). Generally, the reliability data base may be categorized into the component reliability, initiating event frequencies, human performance, and so on. Among these data, the component reliability seems a key element because it has the most abundant population. Therefore, the component reliability data is essential for taking a part in the quantification of accident sequences because it becomes an input of various basic events which consists of the fault tree

The effects of Niger State water treatment plant effluent on its ...

African Journals Online (AJOL)

The effect of water treatment plant effluent on its receiving river (Kaduna) was examined. Samples were collected from the effluents discharge from Chanchaga water treatment plant into upstream and down stream of the receiving river monthly for six month. Samples were analyzed in the laboratory for microbial counts and ...

Nuclear plant reliability data system. 1979 annual reports of cumulative system and component reliability

International Nuclear Information System (INIS)

1979-01-01

The primary purposes of the information in these reports are the following: to provide operating statistics of safety-related systems within a unit which may be used to compare and evaluate reliability performance and to provide failure mode and failure rate statistics on components which may be used in failure mode effects analysis, fault hazard analysis, probabilistic reliability analysis, and so forth

Treatment of anxiety and depression: medicinal plants in retrospect.

Science.gov (United States)

Fajemiroye, James O; da Silva, Dayane M; de Oliveira, Danillo R; Costa, Elson A

2016-06-01

Anxiety and depression are complex heterogeneous psychiatric disorders and leading causes of disability worldwide. This review summarizes reports on the fundamentals, prevalence, diagnosis, neurobiology, advancement in treatment of these diseases and preclinical assessment of botanicals. This review was conducted through bibliographic investigation of scientific journals, books, electronic sources, unpublished theses and electronic medium such as ScienceDirect and PubMed. A number of the first-line drugs (benzodiazepine, azapirone, antidepressant tricyclics, monoamine oxidase inhibitors, serotonin selective reuptake inhibitors, noradrenaline reuptake inhibitors, serotonin and noradrenaline reuptake inhibitors, etc.) for the treatment of these psychiatric disorders are products of serendipitous discoveries. Inspite of the numerous classes of drugs that are available for the treatment of anxiety and depression, full remission has remained elusive. The emerging clinical cases have shown increasing interests among health practitioners and patients in phytomedicine. The development of anxiolytic and antidepressant drugs of plant origin takes advantage of multidisciplinary approach including but not limited to ethnopharmacological survey (careful investigation of folkloric application of medicinal plant), phytochemical and pharmacological studies. The selection of a suitable plant for a pharmacological study is a basic and very important step. Relevant clues to achieving this step include traditional use, chemical composition, toxicity, randomized selection or a combination of several criteria. Medicinal plants have been and continue to be a rich source of biomolecule with therapeutic values for the treatment of anxiety and depression. © 2016 Société Française de Pharmacologie et de Thérapeutique.

Reliability engineering for nuclear and other high technology systems

International Nuclear Information System (INIS)

Lakner, A.A.; Anderson, R.T.

1985-01-01

This book is written for the reliability instructor, program manager, system engineer, design engineer, reliability engineer, nuclear regulator, probability risk assessment (PRA) analyst, general manager and others who are involved in system hardware acquisition, design and operation and are concerned with plant safety and operational cost-effectiveness. It provides criteria, guidelines and comprehensive engineering data affecting reliability; it covers the key aspects of system reliability as it relates to conceptual planning, cost tradeoff decisions, specification, contractor selection, design, test and plant acceptance and operation. It treats reliability as an integrated methodology, explicitly describing life cycle management techniques as well as the basic elements of a total hardware development program, including: reliability parameters and design improvement attributes, reliability testing, reliability engineering and control. It describes how these elements can be defined during procurement, and implemented during design and development to yield reliable equipment. (author)

Interim reliability evaluation program: analysis of the Arkansas Nuclear One. Unit 1 Nuclear Power Plant

International Nuclear Information System (INIS)

Kolb, G.J.; Kunsman, D.M.; Bell, B.J.

1982-06-01

This report represents the results of the analysis of Arkansas Nuclear One (ANO) Unit 1 nuclear power plant which was performed as part of the Interim Reliability Evaluation Program (IREP). The IREP has several objectives, two of which are achieved by the analysis presented in this report. These objectives are: (1) the identification, in a preliminary way, of those accident sequences which are expected to dominate the public health and safety risks; and (2) the development of state-of-the-art plant system models which can be used as a foundation for subsequent, more intensive applications of probabilistic risk assessment. The primary methodological tools used in the analysis were event trees and fault trees. These tools were used to study core melt accidents initiated by loss of coolant accidents (LOCAs) of six different break size ranges and eight different types of transients

Seabrook, N.H. Wastewater Treatment Plant Chief Operator Recognized for Outstanding Service

Science.gov (United States)

Dustin Price, a resident of Berwick Maine and the Chief Operator of the Seabrook, N.H. Wastewater Treatment Plant, was honored by EPA with a 2016 Regional Wastewater Treatment Plant Operator of the Year Excellence Award.

Thermal performance envelopes for MHTGRs - Reliability by design

International Nuclear Information System (INIS)

Etzel, K.T.; Howard, W.W.; Zgliczynski, J.

1992-01-01

Thermal performance envelopes are used to specify steady-state design requirements for the systems of the modular high-temperature gas-cooled reactor (MHTGR) to maximize plant performance reliability with optimized design. The thermal performance envelopes are constructed around the expected operating point to account for uncertainties in actual plant as-built parameters and plant operation. The components are then designed to perform successfully at all points within the envelope. As a result, plant reliability is maximized by accounting for component thermal performance variation in the design. The design is optimized by providing a means to determine required margins in a disciplined and visible fashion. This is accomplished by coordinating these requirements with the various system and component designers in the early stages of the design, applying the principles of total quality management. The design is challenged by the more complex requirements associated with a range of operating conditions, but in return, high probability of delivering reliable performance throughout the plant life is ensured

Equipment Reliability Process in Krsko NPP

International Nuclear Information System (INIS)

Gluhak, M.

2016-01-01

To ensure long-term safe and reliable plant operation, equipment operability and availability must also be ensured by setting a group of processes to be established within the nuclear power plant. Equipment reliability process represents the integration and coordination of important equipment reliability activities into one process, which enables equipment performance and condition monitoring, preventive maintenance activities development, implementation and optimization, continuous improvement of the processes and long term planning. The initiative for introducing systematic approach for equipment reliability assuring came from US nuclear industry guided by INPO (Institute of Nuclear Power Operations) and by participation of several US nuclear utilities. As a result of the initiative, first edition of INPO document AP-913, 'Equipment Reliability Process Description' was issued and it became a basic document for implementation of equipment reliability process for the whole nuclear industry. The scope of equipment reliability process in Krsko NPP consists of following programs: equipment criticality classification, preventive maintenance program, corrective action program, system health reports and long-term investment plan. By implementation, supervision and continuous improvement of those programs, guided by more than thirty years of operating experience, Krsko NPP will continue to be on a track of safe and reliable operation until the end of prolonged life time. (author).

Greenhouse gas emission quantification from wastewater treatment plants, using a tracer gas dispersion method

DEFF Research Database (Denmark)

Delre, Antonio; Mønster, Jacob; Scheutz, Charlotte

2017-01-01

Plant-integrated methane (CH4) and nitrous oxide (N2O) emission quantifications were performed at five Scandinavian wastewater treatment plants, using a ground-based remote sensing approach that combines a controlled release of tracer gas from the plant with downwind concentration measurements. CH4...... emission factors were between 1 and 21% of CH4 production, and between 0.2 and 3.2% of COD influent. The main CH4 emitting sources at the five plants were sludge treatment and energy production units. The lowest CH4 emission factors were obtained at plants with enclosed sludge treatment and storage units...... in international guidelines. This study showed that measured CH4 and N2O emission rates from wastewater treatment plants were plant-specific and that emission rates estimated using models in current guidelines, mainly meant for reporting emissions on the country scale, were unsuitable for Scandinavian plant...

Analysis of energy consumption at the Rzeszów Wastewater Treatment Plant

Directory of Open Access Journals (Sweden)

Masłoń Adam

2017-01-01

Full Text Available Wastewater treatment plants can be classified as energy-intensive facilities, as they account for up to 35 percent of municipal energy consumption. Pumps and aeration systems consume a significant portion of energy within the wastewater plants in particular. The cost of energy consumption for wastewater treatment processes reaches up to 40% of the total operating cost. In case of the WWTPs with the activated sludge systems, about 50% of energy is used for aeration and mixing purposes. At WWTPs, energy consumption is often correlated with the magnitude and type of pollutant load, which can influence the treatment methods and technologies used in the WWTP. In many cases wastewater treatment plants are operated without optimized measures for process optimization. A detailed study of the energy consumption should be executed in order to determine the optimization potential. This paper presents the energy consumption in municipal wastewater treatment plant in Rzeszów (Poland. In the year 2016, parameters of raw and treated wastewater were tested. The data related to energy consumption in plants allowed us to determine the energy intensity coefficients. Total consumption was measured. Indicators of energy consumption per cubic meter and removed load were calculated.

Passive safety systems reliability and integration of these systems in nuclear power plant PSA

International Nuclear Information System (INIS)

La Lumia, V.; Mercier, S.; Marques, M.; Pignatel, J.F.

2004-01-01

Innovative nuclear reactor concepts could lead to use passive safety features in combination with active safety systems. A passive system does not need active component, external energy, signal or human interaction to operate. These are attractive advantages for safety nuclear plant improvements and economic competitiveness. But specific reliability problems, linked to physical phenomena, can conduct to stop the physical process. In this context, the European Commission (EC) starts the RMPS (Reliability Methods for Passive Safety functions) program. In this RMPS program, a quantitative reliability evaluation of the RP2 system (Residual Passive heat Removal system on the Primary circuit) has been realised, and the results introduced in a simplified PSA (Probabilistic Safety Assessment). The scope is to get out experience of definition of characteristic parameters for reliability evaluation and PSA including passive systems. The simplified PSA, using event tree method, is carried out for the total loss of power supplies initiating event leading to a severe core damage. Are taken into account: failures of components but also failures of the physical process involved (e.g. natural convection) by a specific method. The physical process failure probabilities are assessed through uncertainty analyses based on supposed probability density functions for the characteristic parameters of the RP2 system. The probabilities are calculated by MONTE CARLO simulation coupled to the CATHARE thermalhydraulic code. The yearly frequency of the severe core damage is evaluated for each accident sequence. This analysis has identified the influence of the passive system RP2 and propose a re-dimensioning of the RP2 system in order to satisfy the safety probabilistic objectives for reactor core severe damage. (authors)

Conflicts concerning sites for waste treatment and waste disposal plants

International Nuclear Information System (INIS)

Werbeck, N.

1993-01-01

The erection of waste treatment and waste disposal flants increasingly meets with the disapproval of local residents. This is due to three factors: Firstly, the erection and operation of waste treatment plants is assumed to necessarily entail harmful effects and risks, which may be true or may not. Secondly, these disadvantages are in part considered to be non-compensable. Thirdly, waste treatment plants have a large catchment area, which means that more people enjoy their benefits than have to suffer their disadvantages. If residents in the vicinity of such plants are not compensated for damage sustained or harmed in ways that cannot be compensated for it becomes a rational stance for them, while not objecting to waste treatment and waste disposal plants in principle to object to their being in their own neighbourhood. The book comprehensively describes the subject area from an economic angle. The causes are analysed in detail and an action strategy is pointed, out, which can help to reduce acceptance problems. The individual chapters deal with emissions, risk potentials, optimization calculus considering individual firms or persons and groups of two or more firms or persons, private-economy approaches for the solving of site selection conflicts, collective decision-making. (orig./HSCH) [de

Nuclear power plant laundry drain treatment using membrane bio reactor

International Nuclear Information System (INIS)

Tsukamoto, Masaaki; Kohanawa, Osamu; Kinugasa, Atsushi; Ogawa, Naoki; Murogaki, Kenta

2012-01-01

In nuclear power plant, the radioactive effluent generated by washing the clothes worn in controlled area and the hand and shower water used at the controlled area are treated in laundry drain treatment system. Although various systems which treat such liquid waste preexist, the traditional treatment system has disadvantages such as high running cost and a large amount of secondary waste generation. To solve these matters, we have considered application of an activated sludge system, membrane bio reactor, which has been practically used in general industry. For nuclear power plant, the activated sludge system has been developed, tested in its adaptability and the adequacy has been proved. Some preexisting treatment systems have been replaced with this activated sludge system for the first time in a domestic nuclear power plant, and the renewal system is now in operation. The result is reported. (author)

Influence of 12% Cr martensite steel quality on power generation reliability

International Nuclear Information System (INIS)

Smolenska, H.; Labanowski, J.; Cwiek, J.; Glowacka, M.; Serbinski, W.

2001-01-01

Influence of manufacturing process and heat treatment on microstructure and mechanical properties of 12% Cr heat resistance martensitic steels has been discussed. These steels are used for elevated temperatures applications like: heat and power plants, chemical and petrochemical installations. Some cases of manufacturing mistakes of steam pipelines and turbine blades had been presented. These mistakes led to imperfect microstructure resulting in reduced lifetime and insufficient reliability of installations. (author)

An evaluation of the Browns Ferry Nuclear Plant preventive maintenance program based on reliability centered maintenance analysis

International Nuclear Information System (INIS)

McCullough, C.L.; McCullough, C.A.

1989-01-01

Reliability centered maintenance (RCM) techniques were used to support a preventative maintenance (PM) upgrade program (PMUP) performed at TVA Browns Ferry Nuclear Plant (BFNP). The purpose of the RCM analysis was to identify critical equipment based on risk and economic importance and to evaluate the PM activities applicable to that equipment. The analysis may be conveniently divided into three steps, which will be outlined in the Approach section of this paper. The net benefit of the RCM approach was a prioritization of the focus of the PM upgrade program so that plant components receive attention proportional to their importance, and assurance that PM activities properly address the most likely component failure causes

Presence of Methicillin Resistant Staphylococcus aureus (MRSA) in sewage treatment plant.

Science.gov (United States)

Boopathy, Raj

2017-09-01

The presence of antibiotic resistant bacteria and antibiotic resistance genes in rural sewage treatment plants are not well reported in the literature. The aim of the present study was to study the frequency occurrence of Methicillin Resistant Staphylococcus aureus (MRSA) in a rural sewage treatment plant. This study was conducted using raw sewage as well as treated sewage from a small town sewage treatment plant in rural southeast Louisiana of USA. Results showed the presence of MRSA consistently in both raw and treated sewage. The presence of mecA gene responsible for methicillin resistance was confirmed in the raw and treated sewage water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brewer, Maine Wastewater Treatment Plant Recognized for Excellence

Science.gov (United States)

The Brewer Water Pollution Control Facility was recently honored with a 2015 Regional Wastewater Treatment Plant Excellence Award by the US Environmental Protection Agency's New England regional office.

EPA Facility Registry Service (FRS): Wastewater Treatment Plants

Data.gov (United States)

U.S. Environmental Protection Agency — This GIS dataset contains data on wastewater treatment plants, based on EPA's Facility Registry Service (FRS), EPA's Integrated Compliance Information System (ICIS)...

Greenhouse gas emissions from wastewater treatment plants: measurements and carbon footprint assessment

DEFF Research Database (Denmark)

Delre, Antonio

evaluation of WWTPs. Fair agreement of the plant-integrated CH4 emission rates was obtained when three analytical instruments, with different detection frequencies and precisions, were used in a simultaneous MTDM application at a WWTP. Emission rates differed between 1 and 18% from the mean emission rate...... quantified by all instruments. In the same campaign, the importance of a high plume signal within a plume traverse was shown, as this resulted in more reliable plant-integrated emission quantifications. An estimation of the MTDM detection limit was introduced by using inverse Gaussian plume modelling...

Region 9 NPDES Facilities - Waste Water Treatment Plants

Science.gov (United States)

Point geospatial dataset representing locations of NPDES Waste Water Treatment Plant Facilities. NPDES (National Pollution Discharge Elimination System) is an EPA permit program that regulates direct discharges from facilities that discharge treated waste water into waters of the US. Facilities are issued NPDES permits regulating their discharge as required by the Clean Water Act. A facility may have one or more outfalls (dischargers). The location represents the facility or operating plant.

Stimulation treatments of large-seed leguminous plants Pt. 1

International Nuclear Information System (INIS)

Nagy, Istvan; Borbely, Ferenc; Nagy, Janos; Dezsi, Zoltan

1983-01-01

The effect of low dose X-ray irradiation on the sprouting and initial growth of some leguminous plants was studied. After having the seeds of peas, beans, lupines and horse beans irradiated, the sprouting rate, the amount of sprouting plants, the length of the roots, the sprouts and the sprouting plants, the electrolyte conductivity and the water uptake were determined. The height and the amount of the plants were measured after a period of 6 weeks. According to the sprout-length values, an increased variation in the plant features can be observed as a result of irradiation treatment: both stimulation and inhibition of plant growth occured, depending on the variety of the leguminosae. The indices of sprouting and initial growth agree well with each other. (V.N.)

Delisting strategy for the Hanford Site 242-A Evaporator PUREX Plant Condensate Treatment Facility

International Nuclear Information System (INIS)

1992-04-01

This document describes the strategy that the US Department of Energy, Richland Field Office intends to use in preparing the delisting petition for the 242-A Evaporator/PUREX Plant Condensate Treatment Facility. Because the 242-A Evaporator/PUREX Plant Condensate Treatment Facility will not be operational until 1994, the delisting petition will be structured as an up-front petition based on the ''multiple waste treatment facility'' approach outline in the 1985 US Environmental Protection Agency's Petitions to Delist Hazardous Waste. The 242-A evaporator/PUREX Plant Condensate Treatment Facility effluent characterization data will not be available to support the delisting petition, because the delisting petition will be submitted to the US Environmental Protection Agency before start-up of the 242-A Evaporator/PUREX Plant Condensate Treatment Facility. Therefore, the delisting petition will be based on data collected during the pilot plant testing for the 242-A Evaporator/PUREX Plant Condensate Treatment Facility. This pilot plant testing will be conducted on synthetic waste. The composition of the synthetic waste will be based on: (1) constituents of regulatory concern, and (2) on process knowledge. The pilot plant testing will be performed to determine the removal efficiencies of the process equipment at concentrations greater than reasonably could be expected in the actual waste. This strategy document also describes the logic used to develop the synthetic waste, to develop the pilot plant testing program, and to prepare the delisting petition. This strategy document also described how full-scale operating data will be collected during initial operation of the 242-A Evaporator/PUREX Plant Condensate Treatment Facility to verify information presented in the delisting petition

Planning of emergency medical treatment in nuclear power plant

International Nuclear Information System (INIS)

Kusama, Tomoko

1989-01-01

Medical staffs and health physicists have shown deep concerning at the emergency plans of nuclear power plants after the TMI nuclear accident. The most important and basic countermeasure for accidents was preparing appropriate and concrete organization and plans for treatment. We have planed emergency medical treatment for radiation workers in a nuclear power plant institute. The emergency medical treatment at institute consisted of two stages, that is on-site emergency treatment at facility medical service. In first step of planning in each stage, we selected and treatment at facility medical service. In first step of planning in each stage, we selected and analyzed all possible accidents in the institute and discussed on practical treatments for some possible accidents. The manuals of concrete procedure of emergency treatment for some accidents were prepared following discussion and facilities and equipment for medical treatment and decontamination were provided. All workers in the institute had periodical training and drilling of on-site emergency treatment and mastered technique of first aid. Decontamination and operation rooms were provided in the facillity medical service. The main functions at the facility medical service have been carried out by industrial nurses. Industrial nurses have been in close co-operation with radiation safety officers and medical doctors in regional hospital. (author)

Advanced wastewater treatment system (SEADS)

International Nuclear Information System (INIS)

Dunn, J.

2002-01-01

'Full text:' This presentation will describe the nature, scope, and findings of a third-party evaluation of a wastewater treatment technology identified as the Advanced Wastewater Treatment System Inc.'s Superior Extended Aerobic Digester System (SEADS). SEADS is an advanced miniaturized wastewater treatment plant that can meet advanced wastewater treatment standards for effluent public reuse. SEADS goes beyond primary and secondary treatment operations to reduce nutrients such as nitrogen and phosphorus, which are typically found in excessive quantities in traditional wastewater treatment effluent. The objective of this evaluation will be to verify the performance and reliability of the SEADS to treat wastewater from a variety of sources, including domestic wastewater and commercial industrial wastewater. SEADS utilizes remote telemetry equipment to achieve added reliability and reduces monitoring costs as compared to many package wastewater treatment plants. The evaluation process will be overseen and coordinated by the Environmental Technology Evaluation Center (EvTEC), a program of the Civil Engineering Research Foundation (CERF), the research and technology transfer arm of the American Society of Civil Engineers (ASCE). EvTEC is a pilot program evaluating innovative environmental technologies under the US Environmental Protection Agency's (USEPA) Environmental Technology Verification (ETV) Program. Among other performance issues, the SEADS technology evaluation will address its ability to treat low flows-from remote individual and clustered housing applications, and individual commercial applications in lieu of a main station conventional wastewater treatment plant. The unneeded reliance on particular soil types for percolation and the improved effluent water quality over septic systems alone look to make these types of package treatment plants a viable option for rural communities, small farms, and other low-flow remote settings. Added benefits to be examined

Handwriting on the power plant wall: flue gas treatment

Energy Technology Data Exchange (ETDEWEB)

Troupe, J.S.

1979-08-01

This paper reviews the present state of flue gas treatment technology. Describes the operation of four basic types of devices used by electric utilities:- mechanical dust collectors, electrostatic precipitators, wet scrubbers and fabric filters. Considers their reliability and cost, and outlines possible future trends.

Design of Korean nuclear reliability data-base network using a two-stage Bayesian concept

International Nuclear Information System (INIS)

Kim, T.W.; Jeong, K.S.; Chae, S.K.

1987-01-01

In an analysis of probabilistic risk, safety, and reliability of a nuclear power plant, the reliability data base (DB) must be established first. As the importance of the reliability data base increases, event reporting systems such as the US Nuclear Regulatory Commission's Licensee Event Report and the International Atomic Energy Agency's Incident Reporting System have been developed. In Korea, however, the systematic reliability data base is not yet available. Therefore, foreign data bases have been directly quoted in reliability analyses of Korean plants. In order to develop a reliability data base for Korean plants, the problem is which methodology is to be used, and the application limits of the selected method must be solved and clarified. After starting the commercial operation of Korea Nuclear Unit-1 (KNU-1) in 1978, six nuclear power plants have begun operation. Of these, only KNU-3 is a Canada Deuterium Uranium pressurized heavy-water reactor, and the others are all pressurized water reactors. This paper describes the proposed reliability data-base network (KNRDS) for Korean nuclear power plants in the context of two-stage Bayesian (TSB) procedure of Kaplan. It describes the concept of TSB to obtain the Korean-specific plant reliability data base, which is updated with the incorporation of both the reported generic reliability data and the operation experiences of similar plants

Feasibility analysis of a sewage sludge treatment by an irradiation plant in Mexico

CERN Document Server

Moreno, J; Colin, A; Tavera, L

2002-01-01

Technical and economic analyses of an irradiation plant for sewage sludge treatment determined that an appropriate place for the first sludge electron irradiator in Mexico would be the sewage water treatment plant located north of Toluca in the State of Mexico. This treatment plant is mainly used for domestic wastewater and produces an approximate volume of 70 ton d-] liquid sewage sludge. Considering a 50 k W power of a 10 MeV electron linear accelerator, an irradiation dose of S KGy and a treatment capacity of 346 tons per day, it is estimated that the treatment cost would be of $9.00 US dollars per ton. (Author)

Saudi medicinal plants for the treatment of scorpion sting envenomation.

Science.gov (United States)

Al-Asmari, Abdulrahman; Manthiri, Rajamohamed Abbas; Abdo, Nasreddien; Al-Duaiji, Fawzi Abdullah; Khan, Haseeb Ahmad

2017-09-01

Scorpion sting envenoming poses major public health problems. The treatment modalities include antivenoms, chemical antidotes and phytotherapy, with varying degrees of effectiveness and side effects. In this investigation, we reviewed the use of Saudi medicinal plants for the treatment of scorpion sting patients. The relevant literature was collected using the online search engines including Science Direct, Google and PubMed with the help of specific keywords. We also used the printed and online resources at our institutional library to gather the relevant information on the use of medicinal plants for the treatment of scorpion sting patients. A descriptive statistics was used for data compilation and presentation. The results of this survey showed the use of at least 92 medicinal plants with beneficial effects for treating victims of stings of different scorpion species. These commonly used herbs spanned to 37 families whilst different parts of these plants were employed therapeutically for alleviation of envenomation symptoms. The application of leaves (41%) was preferred followed by roots (19%), whole plant (14%) and seeds (9%). The use of latex (4%), stem (3%), flowers (3%) and bark (3%) was also reported. In some cases, tannin (2%), rhizome (1%) and shoot (1%) were also used. In conclusion, herbal medicines are effectively used for the treatment of patients with scorpion envenomation. This type of medication is free from side effects as observed with chemical antidotes or antivenom therapy. It is important to identify the active ingredients of herbal drugs for improving their therapeutic potential in traditional medicine.

40 CFR 63.1592 - Which General Provisions apply to my POTW treatment plant?

Science.gov (United States)

2010-07-01

... POTW treatment plant? 63.1592 Section 63.1592 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emission Standards for Hazardous Air Pollutants: Publicly Owned Treatment Works General Requirements § 63.1592 Which General Provisions apply to my POTW treatment plant? (a) Table 1 to this subpart...

Safety and reliability assessment

International Nuclear Information System (INIS)

1979-01-01

This report contains the papers delivered at the course on safety and reliability assessment held at the CSIR Conference Centre, Scientia, Pretoria. The following topics were discussed: safety standards; licensing; biological effects of radiation; what is a PWR; safety principles in the design of a nuclear reactor; radio-release analysis; quality assurance; the staffing, organisation and training for a nuclear power plant project; event trees, fault trees and probability; Automatic Protective Systems; sources of failure-rate data; interpretation of failure data; synthesis and reliability; quantification of human error in man-machine systems; dispersion of noxious substances through the atmosphere; criticality aspects of enrichment and recovery plants; and risk and hazard analysis. Extensive examples are given as well as case studies

Human performance for the success of equipment reliability programs

International Nuclear Information System (INIS)

Woodcock, J.

2007-01-01

Human performance is a critical element of programs directed at equipment reliability. Reliable equipment performance requires broad support from all levels of plant management and throughout all plant departments. Experience at both nuclear power plants and fuel manufacturing plants shows that human performance must be addressed during all phases of program implementation from the beginning through the establishment of a living, on-going process. At the beginning, certain organizational and management actions during the initiation of the program set the stage for successful adoption by station personnel, leading to more rapid benefits. For the long term, equipment reliability is a living process needed throughout the lifetime of a station, a program which must be motivated and measured. Sustained acceptance and participation by the plant personnel is a requirement, and culture is a key ingredient. This paper will provide an overview of key human performance issues to be considered, using the application of the INPO AP-913 Equipment Reliability Guideline as a basis and gives some best practices for training, communicating and implementing programs. The very last part includes ways to tell if the program is effective

Operator reliability assessment system (OPERAS)

International Nuclear Information System (INIS)

Singh, A.; Spurgin, A.J.; Martin, T.; Welsch, J.; Hallam, J.W.

1991-01-01

OPERAS is a personal-computer (PC) based software to collect and process simulator data on control-room operators responses during requalification training scenarios. The data collection scheme is based upon approach developed earlier during the EPRI Operator Reliability Experiments project. The software allows automated data collection from simulator, thus minimizing simulator staff time and resources to collect, maintain and process data which can be useful in monitoring, assessing and enhancing the progress of crew reliability and effectiveness. The system is designed to provide the data and output information in the form of user-friendly charts, tables and figures for use by plant staff. OPERAS prototype software has been implemented at the Diablo Canyon (PWR) and Millstone (BWR) plants and is currently being used to collect operator response data. Data collected from similator include plant-state variables such as reactor pressure and temperature, malfunction, times at which annunciators are activated, operator actions and observations of crew behavior by training staff. The data and systematic analytical results provided by the OPERAS system can contribute to increase objectivity by the utility probabilistic risk analysis (PRA) and training staff in monitoring and assessing reliability of their crews

Reliability issues : a Canadian perspective

International Nuclear Information System (INIS)

Konow, H.

2004-01-01

A Canadian perspective of power reliability issues was presented. Reliability depends on adequacy of supply and a framework for standards. The challenges facing the electric power industry include new demand, plant replacement and exports. It is expected that demand will by 670 TWh by 2020, with 205 TWh coming from new plants. Canada will require an investment of $150 billion to meet this demand and the need is comparable in the United States. As trade grows, the challenge becomes a continental issue and investment in the bi-national transmission grid will be essential. The 5 point plan of the Canadian Electricity Association is to: (1) establish an investment climate to ensure future electricity supply, (2) move government and industry towards smart and effective regulation, (3) work to ensure a sustainable future for the next generation, (4) foster innovation and accelerate skills development, and (5) build on the strengths of an integrated North American system to maximize opportunity for Canadians. The CEA's 7 measures that enhance North American reliability were listed with emphasis on its support for a self-governing international organization for developing and enforcing mandatory reliability standards. CEA also supports the creation of a binational Electric Reliability Organization (ERO) to identify and solve reliability issues in the context of a bi-national grid. tabs., figs

Process plant equipment operation, control, and reliability

CERN Document Server

Holloway, Michael D; Onyewuenyi, Oliver A

2012-01-01

"Process Plant Equipment Book is another great publication from Wiley as a reference book for final year students as well as those who will work or are working in chemical production plants and refinery…" -Associate Prof. Dr. Ramli Mat, Deputy Dean (Academic), Faculty of Chemical Engineering, Universiti Teknologi Malaysia "…give[s] readers access to both fundamental information on process plant equipment and to practical ideas, best practices and experiences of highly successful engineers from around the world… The book is illustrated throughout with numerous black & white p

The comparison of greenhouse gas emissions in sewage treatment plants with different treatment processes.

Science.gov (United States)

Masuda, Shuhei; Sano, Itsumi; Hojo, Toshimasa; Li, Yu-You; Nishimura, Osamu

2018-02-01

Greenhouse gas emissions from different sewage treatment plants: oxidation ditch process, double-circulated anoxic-oxic process and anoxic-oxic process were evaluated based on the survey. The methane and nitrous oxide characteristics were discussed based on the gaseous and dissolved gas profiles. As a result, it was found that methane was produced in the sewer pipes and the primary sedimentation tank. Additionally, a ventilation system would promote the gasification of dissolved methane in the first treatment units. Nitrous oxide was produced and emitted in oxic tanks with nitrite accumulation inside the sewage treatment plant. A certain amount of nitrous oxide was also discharged as dissolved gas through the effluent water. If the amount of dissolved nitrous oxide discharge is not included, 7-14% of total nitrous oxide emission would be overlooked. Based on the greenhouse gas calculation, electrical consumption and the N 2 O emission from incineration process were major sources in all the plants. For greenhouse gas reduction, oxidation ditch process has an advantage over the other advanced systems due to lower energy consumption, sludge production, and nitrogen removal without gas stripping. Copyright © 2017 Elsevier Ltd. All rights reserved.

Performance evaluation of effluent treatment plant for automobile industry

Energy Technology Data Exchange (ETDEWEB)

Ansari, Farid [Department of Applied Science and Humanities, PDM College of Engineering, Bahadurgarh (Haryana) (India); Pandey, Yashwant K. [School of Energy and Environmental Studies, Devi Ahilya Vishwavidyalaya, Indore (India); Kumar, P.; Pandey, Priyanka [Department of Environmental Science, Post Graduate College Ghazipur (IN

2013-07-01

The automobile industry’s wastewater not only contains high levels of suspended and total solids such as oil, grease, dyestuff, chromium, phosphate in washing products, and coloring, at various stages of manufacturing but also, a significant amount of dissolved organics, resulting in high BOD or COD loads. The study reveals the performance, evaluation and operational aspects of effluent treatment plant and its treatability, rather than the contamination status of the real property. The Results revealed that the treated effluent shows most of the parameters are within permissible limits of Central Pollution Control Board (CPCB), India and based on the site visits, discussion with operation peoples, evaluation of process design, treatment system, existing effluent discharge, results of sample analyzed and found that effluent treatment plant of automobile industry are under performance satisfactory.

Comparison of planted soil infiltration systems for treatment of log yard runoff.

Science.gov (United States)

Hedmark, Asa; Scholz, Miklas; Aronsson, Par; Elowson, Torbjorn

2010-07-01

Treatment of log yard runoff is required to avoid contamination of receiving watercourses. The research aim was to assess if infiltration of log yard runoff through planted soil systems is successful and if different plant species affect the treatment performance at a field-scale experimental site in Sweden (2005 to 2007). Contaminated runoff from the log yard of a sawmill was infiltrated through soil planted with Alnus glutinosa (L.) Gärtner (common alder), Salix schwerinii X viminalis (willow variety "Gudrun"), Lolium perenne (L.) (rye grass), and Phalaris arundinacea (L.) (reed canary grass). The study concluded that there were no treatment differences when comparing the four different plants with each other, and there also were no differences between the tree and the grass species. Furthermore, the infiltration treatment was effective in reducing total organic carbon (55%) and total phosphorus (45%) concentrations in the runoff, even when the loads on the infiltration system increased from year to year.

Evaluation and improvement of wastewater treatment plant performance using BioWin

Science.gov (United States)

Oleyiblo, Oloche James; Cao, Jiashun; Feng, Qian; Wang, Gan; Xue, Zhaoxia; Fang, Fang

2015-03-01

In this study, the activated sludge model implemented in the BioWin® software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters ( Y p/acetic and the heterotrophic yield ( Y H)) required calibration. The value 0.42 was used for Y p/acetic in this study, while the default value of the BioWin® software is 0.49, making it comparable with the default values of the corresponding parameter (yield of phosphorus release to substrate uptake ) used in ASM2, ASM2d, and ASM3P, respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant, the possibility of wasting sludge from either the aeration tank or the secondary clarifier, the construction of a new oxidation ditch, and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However, sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore, it is recommended that the design of wastewater treatment plants (WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary, resulting in substantial reductions in operating costs.

Thermal Power Plant Performance Analysis

CERN Document Server

2012-01-01

The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

Biological analysis of endocrine disrupting compounds in Tunisian sewage treatment plants

International Nuclear Information System (INIS)

Minif, W.; Dagnino, S.; Pillon, A.; Escande, A.; Fenet, E.; Gomez, E.; Casellas, C.; Duchesne, M. J.; Cavailles, V.

2009-01-01

The endocrine disrupting compounds (EDCs) are frequently found in sewage treatment plant (STPs) works. Natural and synthetic hormones have been identified as the major contributors to the estrogenic activity in sewage. Dosing and identification of EDCs are certainly of great interest and can lead to the improvement of chemicals treatments. With reporter cell lines developed in the laboratory and allowing the detection of nuclear receptor activities, we characterized the endocrine disrupting profile of water, particulate matter and sludge from three Tunisian sewage, treatment plants (STPs). (Author)

Biological analysis of endocrine disrupting compounds in Tunisian sewage treatment plants

Energy Technology Data Exchange (ETDEWEB)

Minif, W.; Dagnino, S.; Pillon, A.; Escande, A.; Fenet, E.; Gomez, E.; Casellas, C.; Duchesne, M. J.; Cavailles, V.

2009-07-01

The endocrine disrupting compounds (EDCs) are frequently found in sewage treatment plant (STPs) works. Natural and synthetic hormones have been identified as the major contributors to the estrogenic activity in sewage. Dosing and identification of EDCs are certainly of great interest and can lead to the improvement of chemicals treatments. With reporter cell lines developed in the laboratory and allowing the detection of nuclear receptor activities, we characterized the endocrine disrupting profile of water, particulate matter and sludge from three Tunisian sewage, treatment plants (STPs). (Author)

Biotechnological aspects of plants metabolites in the treatment of ulcer: A new prospective

Directory of Open Access Journals (Sweden)

Amit Kishore Singh

2018-06-01

Full Text Available Ulcer is one of the most common diseases affecting throughout the world population. The allopathic treatment of ulcer adversely affects the health by causing harmful side effects. Currently, many herbal plants and secondary metabolites have been used for the ulcer treatment. In the present review, many herbal plants and their parts (root, rhizome, bark, leaves and fruits have been listed in the table are currently being used for ulcer treatment. These metabolites are responsible for ulcer-neutralization or anti-inflammatory properties. In silico study, plant metabolites showed interaction between protodioscin (secondary metabolites of Asparagus racemosus and interferon-γ (virulent factor of gastric ulcer during molecular docking. All the residues of interferon-γ exhibited hydrophobic interactions with plant metabolites. These interactions helps in understanding the plant secondary metabolites vis a vis will open a new door in the research field of new drug discovery and designing for the ulcer treatment.

Chemistry Optimitation of a PWR nuclear power plant

International Nuclear Information System (INIS)

Frandrich, J.; Ramminger, U.

2015-01-01

One of the main objectives for the plant operator of a Nuclear Power Plant is to protect the Steam Generators (SG) during the lifetime of the plant by ensuring a safe and reliable operation. The SGs serve as an important barrier to prevent the spread of contamination out of the primary circuit. One the other hand impurities are accumulated within the SGs leading to extreme chemical and physical conditions. The application of an optimized water chemistry treatment of the secondary side is essential to ensure a good performance of the steam generators. (Author)

Robust Instrumentation[Water treatment for power plant]; Robust Instrumentering

Energy Technology Data Exchange (ETDEWEB)

Wik, Anders [Vattenfall Utveckling AB, Stockholm (Sweden)

2003-08-01

Cementa Slite Power Station is a heat recovery steam generator (HRSG) with moderate steam data; 3.0 MPa and 420 deg C. The heat is recovered from Cementa, a cement industry, without any usage of auxiliary fuel. The Power station commenced operation in 2001. The layout of the plant is unusual, there are no similar in Sweden and very few world-wide, so the operational experiences are limited. In connection with the commissioning of the power plant a R and D project was identified with the objective to minimise the manpower needed for chemistry management of the plant. The lean chemistry management is based on robust instrumentation and chemical-free water treatment plant. The concept with robust instrumentation consists of the following components; choice of on-line instrumentation with a minimum of O and M and a chemical-free water treatment. The parameters are specific conductivity, cation conductivity, oxygen and pH. In addition to that, two fairly new on-line instruments were included; corrosion monitors and differential pH calculated from specific and cation conductivity. The chemical-free water treatment plant consists of softening, reverse osmosis and electro-deionisation. The operational experience shows that the cycle chemistry is not within the guidelines due to major problems with the operation of the power plant. These problems have made it impossible to reach steady state and thereby not viable to fully verify and validate the concept with robust instrumentation. From readings on the panel of the online analysers some conclusions may be drawn, e.g. the differential pH measurements have fulfilled the expectations. The other on-line analysers have been working satisfactorily apart from contamination with turbine oil, which has been noticed at least twice. The corrosion monitors seem to be working but the lack of trend curves from the mainframe computer system makes it hard to draw any clear conclusions. The chemical-free water treatment has met all

NOM characterization and removal at six Southern African water treatment plants

Directory of Open Access Journals (Sweden)

J. Haarhoff

2010-04-01

Full Text Available Organic pollution is a major concern during drinking water treatment. Major challenges attributed to organic pollution include the proliferation of pathogenic micro-organisms, prevalence of toxic and physiologically disruptive organic micro-pollutants, and quality deterioration in water distribution systems. A major component of organic pollution is natural organic matter (NOM. The operational mechanisms of most unit processes are well understood. However, their interaction with NOM is still the subject of scientific research. This paper takes the form of a meta-study to capture some of the experiences with NOM monitoring and analysis at a number of Southern African Water Treatment Plants. It is written from the perspective of practical process selection, to try and coax some pointers from the available data for the design of more detailed pilot work. NOM was tracked at six water treatment plants using dissolved organic carbon (DOC measurements. Fractionation of the DOC based on biodegradability and molecular weight distribution was done at a water treatment plant in Namibia. A third fractionation technique using ion exchange resins was used to assess the impact of ozonation on DOC. DOC measurements alone did not give much insight into NOM evolution through the treatment train. The more detailed characterization techniques showed that different unit processes preferentially remove different NOM fractions. Therefore these techniques provide better information for process design and optimisation than the DOC measurement which is routinely done during full scale operation at these water treatment plants.

An ethnobotanical study of medicinal plants administered for the treatment of hypertension.

Science.gov (United States)

Baharvand-Ahmadi, Babak; Bahmani, Mahmoud; Tajeddini, Pegah; Rafieian-Kopaei, Mahmoud; Naghdi, Nasrollah

2016-01-01

The incidence of cardiovascular diseases (CVDs) is very high in human societies and their prevention and treatment are the most important priority in many countries. Hypertension makes an important contribution to the development of CVDs. This study aimed to collect the ethno-medicinal knowledge of the traditional healers of Shiraz on medicinal plants used in the treatment of hypertension. Ethno-medicinal data were collected from September 2012 to July 2013 through direct interview. Twenty-five healers were interviewed using semi-structured questionnaires and their traditional ethno-medicinal knowledge was recorded. Questionnaires were included apothecary personal information, plant local name, plant parts used, method of preparation, season of harvest and traditional use. Data collected from surveys and interviews were transferred to Microsoft Excel 2007 and analyzed. Analysis of data showed that, 27 medicinal plants from 22 families are used for the treatment of hypertension. The families with most antihypertensive species were Apiaceae (8%), Rosaceae (8%) and Papaveraceae (8%). The most frequently used plant parts were leaves (36%) followed by fruits (30%), aerial part (17%) and branches (7%). The most frequently used preparation method was decoction (95%). Borago officinalis (51.85%), Berberis vulgaris (51.58%) had the highest frequency of mention. The ethno-medicinal survey of medicinal plants recommended by traditional healers for the treatment of hypertension provides new areas of research on the antihypertensive effect of medicinal plants. In the case of safety and effectiveness, they can be refined and processed to produce natural drugs.

The function of advanced treatment process in a drinking water treatment plant with organic matter-polluted source water.

Science.gov (United States)

Lin, Huirong; Zhang, Shuting; Zhang, Shenghua; Lin, Wenfang; Yu, Xin

2017-04-01

To understand the relationship between chemical and microbial treatment at each treatment step, as well as the relationship between microbial community structure in biofilms in biofilters and their ecological functions, a drinking water plant with severe organic matter-polluted source water was investigated. The bacterial community dynamics of two drinking water supply systems (traditional and advanced treatment processes) in this plant were studied from the source to the product water. Analysis by 454 pyrosequencing was conducted to characterize the bacterial diversity in each step of the treatment processes. The bacterial communities in these two treatment processes were highly diverse. Proteobacteria, which mainly consisted of beta-proteobacteria, was the dominant phylum. The two treatment processes used in the plant could effectively remove organic pollutants and microbial polution, especially the advanced treatment process. Significant differences in the detection of the major groups were observed in the product water samples in the treatment processes. The treatment processes, particularly the biological pretreatment and O 3 -biological activated carbon in the advanced treatment process, highly influenced the microbial community composition and the water quality. Some opportunistic pathogens were found in the water. Nitrogen-relative microorganisms found in the biofilm of filters may perform an important function on the microbial community composition and water quality improvement.

Performance analysis and optimization of an advanced pharmaceutical wastewater treatment plant through a visual basic software tool (PWWT.VB).

Science.gov (United States)

Pal, Parimal; Thakura, Ritwik; Chakrabortty, Sankha

2016-05-01

A user-friendly, menu-driven simulation software tool has been developed for the first time to optimize and analyze the system performance of an advanced continuous membrane-integrated pharmaceutical wastewater treatment plant. The software allows pre-analysis and manipulation of input data which helps in optimization and shows the software performance visually on a graphical platform. Moreover, the software helps the user to "visualize" the effects of the operating parameters through its model-predicted output profiles. The software is based on a dynamic mathematical model, developed for a systematically integrated forward osmosis-nanofiltration process for removal of toxic organic compounds from pharmaceutical wastewater. The model-predicted values have been observed to corroborate well with the extensive experimental investigations which were found to be consistent under varying operating conditions like operating pressure, operating flow rate, and draw solute concentration. Low values of the relative error (RE = 0.09) and high values of Willmott-d-index (d will = 0.981) reflected a high degree of accuracy and reliability of the software. This software is likely to be a very efficient tool for system design or simulation of an advanced membrane-integrated treatment plant for hazardous wastewater.

Productivity of sugarcane plants of ratooning with fertilizing treatment

Directory of Open Access Journals (Sweden)

MUHADIONO

2010-01-01

Full Text Available Latief AS, Syarief R, Pramudya B, Muhadiono. 2010. Productivity of sugarcane plants of ratooning with various fertilizing treatments. Nusantara Bioscience 2: 43-47. This research aims to determine the sugarcane plants of ratooning productivity with low external input of fertilization treatment towards farmers can increase profits. The method used is the Completely Randomized Block Design (CRBD with four treatments and three repetitions (4x3. Sugarcane varieties R 579 planted in each patch experiment 5x5 m2. Dosage of fertilizer: P0 = 3.6 kg/year plot experiment was 100% dosage usage of chemical fertilizers used by farmers. Further dosages were P1 (75% = 2.7 kg/plot, P2 (50% = 1.8 kg/plot and P3 (0.25% = 0.9 kg/plot, each supplemented with fertilizer 5 mL of liquid organic/patch a year. Sugarcane crops with a variety of treatment showed no significant difference. The highest productivity was achieved at dosages of P2 (50% chemical fertilizers plus organic fertilizer is 21.67 kg per square meter. Chemical fertilizers can be saved 7 quintals per hectare a year or Rp 997,500 per year. Additional costs of liquid organic fertilizer Rp. 100,000 per hectare year and labor Rp 100,000 per hectare, so the additional advantage of saving farmers fertilizer Rp. 797,500 per year.

Performance indicators and indices of sludge management in urban wastewater treatment plants.

Science.gov (United States)

Silva, C; Saldanha Matos, J; Rosa, M J

2016-12-15

Sludge (or biosolids) management is highly complex and has a significant cost associated with the biosolids disposal, as well as with the energy and flocculant consumption in the sludge processing units. The sludge management performance indicators (PIs) and indices (PXs) are thus core measures of the performance assessment system developed for urban wastewater treatment plants (WWTPs). The key PIs proposed cover the sludge unit production and dry solids concentration (DS), disposal/beneficial use, quality compliance for agricultural use and costs, whereas the complementary PIs assess the plant reliability and the chemical reagents' use. A key PI was also developed for assessing the phosphorus reclamation, namely through the beneficial use of the biosolids and the reclaimed water in agriculture. The results of a field study with 17 Portuguese urban WWTPs in a 5-year period were used to derive the PI reference values which are neither inherent to the PI formulation nor literature-based. Clusters by sludge type (primary, activated, trickling filter and mixed sludge) and by digestion and dewatering processes were analysed and the reference values for sludge production and dry solids were proposed for two clusters: activated sludge or biofilter WWTPs with primary sedimentation, sludge anaerobic digestion and centrifuge dewatering; activated sludge WWTPs without primary sedimentation and anaerobic digestion and with centrifuge dewatering. The key PXs are computed for the DS after each processing unit and the complementary PXs for the energy consumption and the operating conditions DS-determining. The PX reference values are treatment specific and literature based. The PI and PX system was applied to a WWTP and the results demonstrate that it diagnosis the situation and indicates opportunities and measures for improving the WWTP performance in sludge management. Copyright © 2016 Elsevier Ltd. All rights reserved.

Appendix F: Supplemental Risk Management Program Guidance for Wastewater Treatment Plants

Science.gov (United States)

Detail for wastewater treatment plants (WWTPs), including publicly owned treatment works (POTWs) and other industrial treatment systems, on complying with part 68 with respect to chlorine, ammonia (anhydrous and aqueous), sulfur dioxide, and digester gas.

Operation and Maintenance Manual for the Central Facilities Area Sewage Treatment Plant

Energy Technology Data Exchange (ETDEWEB)

Norm Stanley

2011-02-01

This Operation and Maintenance Manual lists operator and management responsibilities, permit standards, general operating procedures, maintenance requirements and monitoring methods for the Sewage Treatment Plant at the Central Facilities Area at the Idaho National Laboratory. The manual is required by the Municipal Wastewater Reuse Permit (LA-000141-03) the sewage treatment plant.

The latest make-up water treatment plant for power plants

International Nuclear Information System (INIS)

Yokomizo, Yuichi

1997-01-01

As the change of the outside environment surrounding power stations, the strengthening of the environmental standard of water quality and the upgrading of required water quality standard are described. The reduction of colloidal silica in thermal power plant water and the reduction of iron and organic chlorine in PWR water are necessary. Recently it became difficult to secure water for power stations, and in dry season, the water for power stations is sometimes cut for securing livelihood and agricultural water. For the means of securing stable water source, the installation of seawater desalting plants increased. The types, the constitution of the plants and the operation performance are reported. Recently the water treatment technology using MF, UF and RO membranes has become to be adopted. The relation of the substances to be removed to the range of filtration of respective membranes is shown. The conventional method is the combination of coagulative sedimentation, filtration and ion exchange resin, but the membrane technology uses UF and RO membranes. The technical features of UF (ultrafiltration) and RO (reverse osmosis) membrane facilities and deaerating membrane are explained. (K.I.)

A systematic methodology for controller tuning in wastewater treatment plants

DEFF Research Database (Denmark)

Mauricio Iglesias, Miguel; Jørgensen, S.B.; Sin, G.

2012-01-01

Wastewater treatment plants are typically subject to continuous disturbances caused by influent variations which exhibits diurnal patterns as well as stochastic changes due to rain and storm water events. In order to achieve an efficient operation, the control system of the plant should be able t...

75 FR 81250 - Pulse Jet Mixing at the Waste Treatment and Immobilization Plant

Science.gov (United States)

2010-12-27

... Immobilization Plant (WTP) in conjunction with the Hanford tank farm waste feed delivery system will operate... imperative requires that the pulse jet mixing and transfer systems relied upon in the WTP design perform reliably and effectively for decades of WTP operations, and that technical issues with the performance of...

Plant-wide (BSM2) evaluation of reject water treatment with a SHARON-Anammox process

DEFF Research Database (Denmark)

Volcke, Eveline; Gernaey, Krist; Vrecko, Darko

2006-01-01

treatment plant, reject water treatment with a combined SHARON-Anammox process seems a promising option. The simulation results indicate that significant improvements of the effluent quality of the main wastewater treatment plant can be realized. An economic evaluation of the different scenarios......In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water...

Six-year experiences in the operation of a low level liquid waste treatment plant

International Nuclear Information System (INIS)

Wen, S.-J.; Hwang, S.-L.; Tsai, C.-M.

1980-01-01

The operation of a low level liquid waste treatment plant is described. The plant is designed for the disposal of liquid waste produced primarily by a 40 MW Taiwan Research Reactor as well as a fuel fabrication plant for the CANDU type reactor and a radioisotopes production laboratory. The monthly volume treated is about 600-2500 ton of low level liquid waste. The activity levels are in the range of 10 -5 -10 -3 μCi/cm 3 . The continuous treatment system of the low level liquid waste treatment plant and the treatment data collected since 1973 are discussed. The advantages and disadvantages of continuous and batch processes are compared. In the continuous process, the efficiency of sludge treatment, vermiculite ion exchange and the adsorption of peat are investigated for further improvement. (H.K.)

Industrial plant for electron beam flue gas treatment

International Nuclear Information System (INIS)

Chmielewski, A.G.; Iller, E.; Tyminnski, B.; Zimek, Z; Ostapczuk, A.; Licki, J.

2001-01-01

The electron beam flue gas treatment technology was invented many years ago. Research on the process has been carried out in Japan, USA, Germany and Poland. However, the recent fidings, based on the experiments performed at pilot plant at Electric Power Station Kaweczyn, led to developments which made process mature just at the dawn of the XXI century. The process is being implemented in the full industrial scale at Electric Power Station Pomorzany (Dolna Odra EPS Group). Other developments are reported in Japan and after Nagoya's pilot plant experiments, an industrial plant has been built in China and another one is constructed in Japan. There are remarkable differences in technological and design solutions applied in all these installations. Developments achieved at EPS Kaweczyn pilot plant and INCT laboratory unit were the basis for the project realized at EPS Pomorzan

Human reliability analysis

International Nuclear Information System (INIS)

Dougherty, E.M.; Fragola, J.R.

1988-01-01

The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach

Application of plant cell and tissue culture for the production of phytochemicals in medicinal plants.

Science.gov (United States)

Pant, Bijaya

2014-01-01

Approximately 80% of the world inhabitants depend on the medicinal plants in the form of traditional formulations for their primary health care system well as in the treatment of a number of diseases since the ancient time. Many commercially used drugs have come from the information of indigenous knowledge of plants and their folk uses. Linking of the indigenous knowledge of medicinal plants to modern research activities provides a new reliable approach, for the discovery of novel drugs much more effectively than with random collection. Increase in population and increasing demand of plant products along with illegal trade are causing depletion of medicinal plants and many are threatened in natural habitat. Plant tissue culture technique has proved potential alternative for the production of desirable bioactive components from plants, to produce the enough amounts of plant material that is needed and for the conservation of threatened species. Different plant tissue culture systems have been extensively studied to improve and enhance the production of plant chemicals in various medicinal plants.

Data on wastewater treatment plant by using wetland method, Babol, Iran

Directory of Open Access Journals (Sweden)

Yousef Dadban Shahamat

2018-02-01

Full Text Available Date in this paper highlights the applications of constructed horizontal surface flow (HF-CW wetland with two different local plants (Louis latifoila and Phragmites -australis (Cav. Trin at the wastewater treatment plant in Babol city. This system was designed as an advanced treatment unit in field scale after the treatment plant. Parameters such as Total Dissolved Solid (TDS, Total Suspended Solid (TSS, Turbidity, Biological Oxygen Demand (BOD and Chemical Oxygen Demand (COD, were investigated. The result shows that treatment efficiency increases with the passage of time. The efficiency of Phragmites planted setups in open environment was fairly good for all studied parameters (28.6% of TDS, 94.4% for TSS, 79.8% for turbidity, 93.7% for BOD and 82.6% for COD. The efficiency of the latifoila set up was also good, but lower than that of Phragmites (26.5% of TDS, 76.9% for TSS, 71.5% for turbidity, 79.1 for BOD and 68.8% for COD. In brief, the obtained dates show that using local plants in (HF-CW wetland not only effectively reduces various contaminants from the effluent of the wastewater according to Effluent Guideline regulations (WHO & EPA, but it is also a cost- effective and environmentally friendly method. Also, it was calculated that in full scale operation [time (1 day and a depth (0.3 m], 8 ha of wetland was needed. Keywords: BOD, Babol, COD, Horizontal subsurface flow wetland, TSS, TSD

Cost effective water treatment program in Heavy Water Plant (Manuguru)

International Nuclear Information System (INIS)

Mohapatra, C.; Prasada Rao, G.

2002-01-01

Water treatment technology is in a state of continuous evolution. The increasing urgency to conserve water and reduce pollution has in recent years produced an enormous demand for new chemical treatment programs and technologies. Heavy water plant (Manuguru) uses water as raw material (about 3000 m 3 /hr) and its treatment and management has benefited the plant in a significant way. It is a fact that if the water treatment is not proper, it can result in deposit formation and corrosion of metals, which can finally leads to production losses. Therefore, before selecting treatment program, complying w.r.t. quality requirements, safety and pollution aspects cost effectiveness shall be examined. The areas where significant benefits are derived, are raw water treatment using polyelectrolyte instead of inorganic coagulant (alum), change over of regenerant of cation exchangers from hydrochloric acid to sulfuric acid and in-house development of cooling water treatment formulation. The advantages and cost effectiveness of these treatments are discussed in detail. Further these treatments has helped the plant in achieving zero discharge and indirectly increased cost reduction of final product (heavy water); the dosage of 3 ppm of polyelectrolyte can replace 90 ppm alum at turbidity level of 300 NTU of raw water which has resulted in cost saving of Rs. 15-20 lakhs in a year beside other advantages; the change over of regenerant from HCl to H 2 SO 4 will result in cost saving of at least Rs.1.4 crore a year besides other advantages; the change over to proprietary formulation to in-house formulation in cooling water treatment has resulted in a saving about Rs.11 lakhs a year. To achieve the above objectives in a sustainable way the performance results are being monitored. (author)

Human reliability analysis data obtainment through fuzzy logic in nuclear plants

International Nuclear Information System (INIS)

Nascimento, C.S. do; Mesquita, R.N. de

2012-01-01

Highlights: ► Human Error Probability estimates from operator's reactions to emergency situations. ► Human Reliability Analysis input data obtainment through fuzzy logic inference. ► Performance Shaping Factors evaluation influence level onto the operator's actions. - Abstract: Human error has been recognized as an important factor for many industrial and nuclear accidents occurrence. Human error data is scarcely available for different reasons among which, lapses in historical database registry methodology is an important one. Human Reliability Analysis (HRA) is an usual tool employed to estimate the probability that an operator will reasonably perform a system required task in required time without degrading the system. This meta-analysis requires specific Human Error Probability estimates for most of its procedure. This work obtains Human Error Probability (HEP) estimates from operator's actions in response to emergency situations hypothesis on Research Reactor IEA-R1 from IPEN, Brazil. Through this proposed methodology HRA should be able to be performed even with shortage of related human error statistical data. A Performance Shaping Factors (PSF's) evaluation in order to classify and estimate their influence level onto the operator's actions and to determine their actual state over the plant was also done. Both HEP estimation and PSF evaluation were done based on expert judgment using interviews and questionnaires. Expert group was established based on selected IEA-R1 operators, and their evaluation were put into a knowledge representation system which used linguistic variables and group evaluation values that were obtained through Fuzzy Logic and Fuzzy Set theory. HEP obtained values show good agreement with literature published data corroborating the proposed methodology as a good alternative to be used on HRA.

Medicinal Plants for the Treatment of Asthma: A Traditional Persian Medicine Perspective.

Science.gov (United States)

Javadi, Behjat; Sahebkar, Amirhossein; Emami, Seyed Ahmad

2017-01-01

To search major Traditional Persian Medicine (TPM) textbooks for medicinal plants used to treat asthma. The conformity of the TPM findings on the anti-asthmatic efficacy of plants with the findings of pharmacological studies was also explored. Major TPM textbooks were hand searched to find medicinal plants used for the treatment of asthma. Scientific names of TPM-suggested plants were determined using botanical databases and were used for a multidatabase electronic search in PubMed, Scopus, ScienceDirect and Google Scholar databases. Then, the antiasthmatic effectiveness of TPM-recommended plants was verified in view of the findings from modern pharmacological investigations. According to the main TPM texts, Adianthum capillus-veneris, Boswellia oleogumresin, Crocus sativus, Glycyrrhiza glabra, Hyssopus officinalis and Ruta graveolens were the most efficacious medicinal plants for the treatment of asthma. This finding was confirmed by pharmacological studies which showed counterbalancing effects of the above-mentioned plants on inflammation, oxidative stress, allergic response, tracheal smooth muscle cell constriction and airway remodeling. The strong ethnobotanical background of plants used in TPM could be a valuable tool to find new anti-asthmatic medications. In this review, TPM-suggested anti-asthmatic plants were found to possess several mechanisms relevant to the treatment of respiratory diseases according to the information retrieved from modern pharmacological studies. This high degree of conformity suggested further proof-of-concept trials to ascertain the role of these plants in the routine management of asthmatic patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Case study: centralized wastewater treatment plant at Rawang Integrated Industrial Park

International Nuclear Information System (INIS)

Ting Teo Ming; Khomsaton Abu Bakar; Zulkafli Ghazali; Khairul Zaman Mohd Dahlan

2006-01-01

Survey has been conducted at Rawang Integrated Industrial Park (RIIP) to investigate the possibility of setting up centralized industrial wastewater treatment plant. Rawang integrated industrial park is selected based on suggestion from department of environment. RIIP consists of about 150 industries with various type of activities operated in the area. Only 9 out of estimated 150 industries have individual wastewater treatment plant. The business activities of the 9 industries include food processing, textile, welding rods manufacturing, steel galvanizing and battery manufacturing. Wastewater generated by the industries are characterized by high oil and grease, cod, bod, organic matter, metal hydroxide and acidic. Besides that most of industries do the monitoring only once a month. This paper will also discuss the advantages of setting up of centralized industrial wastewater treatment plant to the government authorities, industries, people and environment. (Author)

NPDES Permit for Crow Nation Water Treatment Plants in Montana