The German risk study for nuclear power plants

International Nuclear Information System (INIS)

Birkhofer, A.

1980-01-01

In August 1979 results of the ''German Risk Study for Nuclear Power Plants'' were published. The Main Report, in which approach and results of the study are documented, has been available since the end of 1979. It was the charter of the study - which was performed on behalf of the Minister of Research and Technology of the Federal Republic of Germany - to apply as far as possible the methods of the US Reactor Safety Study (WASH-1400) to German plant and site conditions. A direct transfer of the results was not deemed justified, mainly for the following reasons: There is quite a number of differences between the design of the reference plants of WASH-1400 (Surry-1, Peach Bottom-2) and German nuclear power plants. The mean population density in the Federal Republic of Germany is more than ten times of the United States. In the vicinity of nuclear power plants the ratio is about 3:1. To calculate the collective risk resulting from reactor accidents, a total of 25 plants at 19 different sites in the Federal Republic of Germany were considered. This included all plants with 600 MW or more electrical output, which were in operation, under construction or in licensing process by July 1, 1977. As an approximation to the real situation, it has been assumed that all 25 plants are technically identical to the reference plant

Comparison of inhalation risks : oil- versus gas-fired urban power plants

International Nuclear Information System (INIS)

Levin, L.

2000-01-01

The risks due to inhalation of emitted trace substances from natural gas-fired power plants tend to be significantly lower than those from oil- or coal-fired plants. A 1994 study suggested that the median inhalation life-time cancer risk from gas-fired plants was about 4 in one billion. This is an acceptable risk range according to the United States Environmental Protection Agency (US EPA) classification of risks. In the same study, median oil plant risks were 8 in one billion. coal plant median risks ranged from 2 to 3 in one billion depending on the grade of coal being burned. The US EPA classifies risks from 1 to one million to one to 10,000 as being in an acceptable risk range. In some cases, gas plants were shown to exhibit higher inhalation risks than oil plants due to terrain, air circulation patterns, enhanced stack or building downwash or mechanical turbulence. Higher concentrations of very potent trace substances could also result in high inhalation risks. An examination of several power plants in an urban area showed that initial judgements about risk can often be incorrect

Technical specifications review of nuclear power plants: a risk-informed evaluation

International Nuclear Information System (INIS)

Saldanha, Pedro Luiz da Cruz; Sousa, Anna Leticia; Frutuoso e Melo, Paulo Fernando Ferreira; Duarte, Juliana Pacheco

2012-01-01

The use of risk information by a regulatory body as part of an integrated decision making process addresses the way in which risk information is being used as part of an integrated process in making decisions about safety issues at nuclear plants – commonly referred to as risk-informed decision making. The risk-informed approach aims to integrate in a systematic manner quantitative and qualitative, deterministic and probabilistic safety considerations to obtain a balanced decision. Probabilistic Safety Assessment (PSA) is a methodology that can be applied to provide a structured analysis process to evaluate the frequency and consequences of accidents scenarios in nuclear power plants. Technical Specifications (TS) are specifications regarding the characteristics of nuclear power plants (variables, systems or components) of overriding importance to nuclear safety and radiation protection, which is an integral part of plant operation authorization. Limiting Conditions of Operation (LCO) are the minimum levels of performance or capacity or operating system components required for the safe operation of nuclear plants, as defined in technical specifications. The Maintenance Rule (MR) is a requirement established by the U. S. Nuclear Regulatory Commission (NRC) to check the effectiveness of maintenance carried out in nuclear plants, and plant configuration control. The control of plant configuration is necessary to verify the impact of the maintenance of a safety device out of service on plant safety. The Electric Power Research Institute (EPRI) has assessed the role of probabilistic safety analysis in the regulation of nuclear power plants with the following objectives: a) to provide utilities with an approach for developing and implementing nuclear power station risk-managed technical specification programs; and b) to complement and supplement existing successful configuration risk management applications such as MR. This paper focuses on the evaluation of EPRI

Probability problems in seismic risk analysis and load combinations for nuclear power plants

International Nuclear Information System (INIS)

George, L.L.

1983-01-01

This workshop describes some probability problems in power plant reliability and maintenance analysis. The problems are seismic risk analysis, loss of load probability, load combinations, and load sharing. The seismic risk problem is to compute power plant reliability given an earthquake and the resulting risk. Component survival occurs if its peak random response to the earthquake does not exceed its strength. Power plant survival is a complicated Boolean function of component failures and survivals. The responses and strengths of components are dependent random processes, and the peak responses are maxima of random processes. The resulting risk is the expected cost of power plant failure

Risks of potential accidents of nuclear power plants in Europe

International Nuclear Information System (INIS)

Slaper, H.; Eggink, G.J.; Blaauboer, R.O.

1993-12-01

This report is focussed on an integrated assessment of probabilistic cancer mortality risks due to possible accidental releases from the European nuclear power plants. For each of the European nuclear power plants the probability of accidental releases per year of operation is combined with the consequences in terms of the excess doses received over a lifetime (70 years). Risk estimates are restricted to cancer mortality and do not include immediate or short term deaths in the direct vicinity ( -8 per year in Western Europe. Going East the risks increase gradually to over 1000 x 10 -8 per year in regions of the former Soviet Union, where reactors of the Chernobyl type are located. The nuclear power plants in the East European countries dominate the estimated risk pattern and contribute at least 40-50% to the average risk in the West European countries. Improving the reactor safety in eastern European countries could lead to considerable reductions in estimated excess mortality risks. In western Europe the mortality risk might be reduced by a factor of two, and in eastern Europe by a factor of 100 to 1000. (orig.)

Hierarchical structure for risk criteria applicable to nuclear power plants

International Nuclear Information System (INIS)

Hall, R.E.; Mitra, S.P.

1985-01-01

This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply. 5 refs., 2 figs

Feasibility of risk-informed technology for japanese nuclear power plants

International Nuclear Information System (INIS)

Yoshida, Tomoo; Fujioka, Terutaka; Kirimoto, Yorihiro; Ueda, Nobuyuki; Kinoshita, Izumi; Kashima, Koichi

2000-01-01

Risk-informed technology utilizes Probabilistic Safety Assessment for streamlining the maintenance of nuclear power plants. With this technology, plant components are categorized as either high or low-safety-significant components. The Maintenance requirements focuses on high safety-significant components and are relieved for low safety significant ones. This is expected to reduce plant cost while maintaining safety. We investigated especially risk-informed inservice inspection of piping in U.S. nuclear power plants in the interest of determining its feasibility for Japanese plants. Quantitative and qualitative RI-ISI methods were developed by the ASME/Westinghouse Owners Group and EPRI, respectively. These methods have been incorporated in the ASME Section 11 Code Cases and endorsed by the U.S. Nuclear Regulatory Commission. The quantitative method evaluates component segment risks in terms of pipe failure probability calculated with a probabilistic fracture mechanics(PFM) model and pipe failure impact categorization on core damage frequency(CDF) calculated with PSA. The qualitative method uses pipe failure potential categorization derived from the plant service experiences and pipe failure impact on CDF derived from the PSA insight. The PFM model is applicable only to failures from initial welding defects and stress corrosion cracking, therefore it does not cover such significant failure mechanisms found in nuclear power plants as corrosion or high-cycle fatigue, etc.. Thus, a qualitative failure potential categorization method was developed on the basis of the service experiences of the U.S. nuclear power plants, so that appropriate categorization rules must be developed on the service experiences in Japanese plants. Accordingly, we have devised a software framework with a computer-aided system for the selection of risk significant elements. This system consists of a piping failure database module, a piping failure analysis module, and a piping failure potential

Income risk of EU coal-fired power plants after Kyoto

International Nuclear Information System (INIS)

Abadie, Luis M.; Chamorro, Jose M.

2009-01-01

Coal-fired power plants enjoy a significant advantage relative to gas plants in terms of cheaper fuel cost. This advantage may erode (or turn into disadvantage) depending on CO 2 emission allowance price. Financial risks are further reinforced when the price of electricity is determined by natural gas-fired plants' marginal costs. We aim to empirically assess the risks in EU coal plants' margins up to the year 2020. Parameter values are derived from actual market data. Monte Carlo simulation allows compute the expected value and risk profile of coal plants' earnings. Future allowance prices may spell significant risks on utilities' balance sheets. (author)

Nuclear power plant safety - the risk of accidents

International Nuclear Information System (INIS)

Higson, D.; Crancher, D.W.

1975-08-01

Although it is physically impossible for any nuclear plant to explode like an atom bomb, an accidental release of radioactive material into the environment is conceivable. Three factors reduce the probability of such releases, in dangerous quantities, to an extremely low level. Firstly, there are many safety features built into the plant including a leaktight containment building to prevent the escape of such material. Secondly, the quality of engineering and standards used are far more demanding than in conventional power engineering. Thirdly, strict government licensing and regulatory control is enforced at all phases from design through construction to operation. No member of the general public is known to have been injured or died as a result of any accident to a commercial nuclear power plant. Ten workers have died as a result of over-exposure to radiation from experimental reactors and laboratory work connected with the development of nuclear plant since 1945. Because of this excellent safety record the risk of serious accidents can only be estimated. On the basis of such estimates, the chance of an accident in a nuclear power reactor which could cause a detectable increase in the incidence of radiation-induced illnesses would be less than one chance in a million per year. In a typical highly industrialised society, such as the USA, the estimated risk of an individual being killed by such accidents, from one hundred operating reactors, is no greater than one chance in sixteen million per year. There are undoubtedly risks from reactor accidents but estimates of these risks show that they are considerably less than from other activities which are accepted by society. (author)

How to deal with financial risk under the life circles of nuclear power plant

International Nuclear Information System (INIS)

Chen Shilong

2010-01-01

Nuclear power plants don't necessarily form enterprise boundary, in the background of nuclear power booming, what characteristics of financial risk exist in nuclear power plant, how to deal with such financial risk and how to sustain a stable development of nuclear power ? Based on the enterprise boundary theory of transaction fees, the separate of the nuclear power plant owner, engineering company and operating company comply with the cost-efficient principle. The financial risk of the plant owner come from the cash flow characteristics under different life circles of its nuclear power plants, due to the passivation of the asset structure in the construction and early operation periods, considering the effects of asset structure on financial risk is meaningless. Based on the owners with single reactor or constructing reactors, big-scale investment holding company is needed to conduct professional asset management, and to diversify the financial risk, on the other hand, professional engineering and operation companies can realize the scale and the multi-reactor advantages. (author)

Regulatory Risk Management of Advanced Nuclear Power Plants

International Nuclear Information System (INIS)

George, Glenn R.

2002-01-01

Regulatory risk reflects both the likelihood of adverse outcomes during regulatory interactions and the severity of those outcomes. In the arena of advanced nuclear power plant licensing and construction, such adverse outcomes may include, for example, required design changes and construction delays. These, in turn, could significantly affect the economics of the plant and the generation portfolio in which it will operate. In this paper, the author addresses these issues through the lens of risk management. The paper considers various tools and techniques of regulatory risk management, including design diversity and hedging strategies. The effectiveness of alternate approaches is weighed and recommendations are made in several regulatory contexts. (author)

A hierarchical structure for risk criteria applicable to nuclear power plants

International Nuclear Information System (INIS)

Hall, R.E.; Mitra, S.P.

1982-01-01

This paper discusses the development of a hierarchical structure for risk criteria applicable to nuclear power plants. The structure provides a unified framework to systematically analyze the implications of different types of criteria, each focusing on a particular aspect of nuclear power plant risks. The framework allows investigation of the specific coverage of a particular criterion and comparison of different criteria with regard to areas to which they apply

Seismic fragilities for nuclear power plant risk studies

International Nuclear Information System (INIS)

Kennedy, R.P.; Ravindra, M.K.

1983-01-01

Seismic fragilities of critical structures and equipment are developed as families of conditional failure frequency curves plotted against peak ground acceleration. The procedure is based on available data combined with judicious extrapolation of design information on plant structures and equipment. Representative values of fragility parameters for typical modern nuclear power plants are provided. Based on the fragility evaluation for about a dozen nuclear power plants, it is proposed that unnecessary conservatism existing in current seismic design practice could be removed by properly accounting for inelastic energy absorption capabilities of structures. The paper discusses the key contributors to seismic risk and the significance of possible correlation between component failures and potential design and construction errors

Cable fire risk of a nuclear power plant; Ydinvoimalaitoksen kaapelipaloriski

Energy Technology Data Exchange (ETDEWEB)

Aulamo, H.

1998-02-01

The aim of the study is to carry out a comprehensive review of cable fire risk issues of nuclear power plants (NPP) taking into account latest fire and risk assessment research results. A special emphasis is put on considering the fire risk analysis of cable rooms in the framework of TVO Olkiluoto NPP probabilistic safety assessment. The assumptions made in the analysis are assessed. The literature study section considers significant fire events at nuclear power plants, the most severe of which have nearly led to a reactor core damage (Browns Ferry, Greifswald, Armenia, Belojarsk, Narora). Cable fire research results are also examined. 62 refs.

Risk perception of the public living in vicinity of nuclear power plant

International Nuclear Information System (INIS)

Li Xiaojuan; Hou Changsong; Wang Chunyan; Liu Ying; Sun Quanfu; Yu Ningle; Li Ningning; Zhou Rihui; Zhuang Jiayi

2008-01-01

Objective: To investigate the attitude toward and perception of the risk of nuclear power plant among the public residing in vicinity of nuclear power plant, as well as the related factors. Methods: A face-to-face interview on perceived radiation risks was conducted among 1408 individuals in Liangyungang City, Jiangsu Province, where the Tianwan nuclear power plant was under construction. The four groups was defined according to the distance between the residence of the subjects and the Tianwan nuclear power plant: <4 km, 4- 8 km, 8-30 km and 30-50 km. A was used to collect information on education, working history, religion, perception of major industries hazards especially nuclear power plant, and major factors may influence their perceptions. Ordinal logistic regression model was used to analyze the data. Results: About 91.18% of the interviewee heard about the nuclear power plant, 35.36% of them had knowledge about Chernobyl nuclear power plant accident, 71.05% of them believed that the nuclear power plant had no negative effects on environments, 37.03% of them believed that the nuclear energy was safe, 74.27% of them believed that it was necessary for China to develop nuclear energy, 63.29% of them supported the construction of the nuclear power plant in local area. Ordinal logistic regression analysis revealed that the higher education, higher family annual income, male, economic benefits from the nuclear power plant construction, and trust in local government having competency to handling emergencies were positive factors; otherwise, impression on nuclear power plant of bad influences on environment and health were negative factors. An inverted U-shaped with a right tailing relationship between negative attitudes toward nuclear power plant and distance to the plant was found. Conclusions: Education, gender, family annual income and expectation of economic benefit returns were the major factors influencing the perception of and attitudes toward nuclear power

Health-safety and environmental risk assessment of power plants using multi criteria decision making method

Directory of Open Access Journals (Sweden)

Jozi Ali Seyed

2011-01-01

Full Text Available Growing importance of environmental issues at global and regional levels including pollution of water, air etc. as well as the outcomes such as global warming and climate change has led to being considered environmental aspects as effective factors for power generation. Study ahead, aims at examination of risks resulting from activities of Yazd Combined Cycle Power Plant located in Iran. Method applied in the research is analytical hierarchy process. After identification of factors causing risk, the analytical hierarchy structure of the power plant risks were designed and weight of the criteria and sub-criteria were calculated by intensity probability product using Eigenvector Method and EXPERT CHOICE Software as well. Results indicate that in technological, health-safety, biophysical and socio economic sections of the power plant, factors influenced by the power plant activities like fire and explosion, hearing loss, quantity of groundwater, power generation are among the most important factors causing risk in the power plant. The drop in underground water levels is the most important natural consequence influenced on Yazd Combined Cycle Power Plant.

BARC-risk monitor- a tool for operational safety assessment in nuclear power plants

International Nuclear Information System (INIS)

Vinod, Gopika; Saraf, R.K.; Babar, A.K.; Hadap, Nikhil

2000-12-01

Probabilistic safety assessment has become a key tool as on today to identify and understand nuclear power plant vulnerabilities. As a result of the availability of these PSA studies, there is a desire to use them to enhance plant safety and to operate the nuclear stations in the most efficient manner. Risk monitor is a PC based tool, which computes the real time safety level and assists plant personnel to manage day-to-day activities. Risk monitor is a PC based user friendly software tool used for modification and re-analysis of a nuclear power plant. Operation of risk monitor is based on PSA methods for assisting in day to day applications. Risk monitoring programs can assess the risk profile and are used to optimise the operation of nuclear power plants with respect to a minimum risk level over the operating time. This report presents the background activities of risk monitor, its application areas and also gives the status of such tools in international scenarios. The software is based on the PSA model of Kaiga generating station and would be applicable to similar design configuration. (author)

Risk management on nuclear power plant. Application of probabilistic risk assessment

International Nuclear Information System (INIS)

Kojima, Shigeo

2003-01-01

In U.S.A., nuclear safety regulation is moving to risk-informed regulation (RIR), so necessity of a standard to provide contents of probabilistic risk assessment (PRA) constructing its roots has been discussed for a long time. In 1998, the Committee on Nuclear Risk Management (CNRM) of the American Society of Mechanical Engineers (ASME) began to investigate the standard, of which last edition was published as the Standard for Probabilistic Risk Management for Nuclear Power Plant Applications: RA-S-2002 (PRMA) on April, 2002. As in the Committee, the Nuclear Regulatory Commission (NRC), electric power companies, national institutes, PRA specialists, and so on took parts to carry out many discussions with full energies of participants on risk management in U.S.A., the standard was finished after about four years' efforts. In U.S.A., risk management having already used PRA is successfully practiced, U.S.A. is at a stage with more advancing steps of the risk management than Japan is. Here was described on the standard of PRA and a concrete method of the risk management carried out at nuclear power stations. (G.K.)

Public perception of risks from nuclear power plants in Japan, before the Great East Japan Earthquake

International Nuclear Information System (INIS)

Murayama, Rumiko; Nakaune, Naoko; Kishikawa, Hiroki; Uchiyama, Iwao

2011-01-01

On this research we aim to clarify public perception of risks from nuclear power plants before the Great East Japan Earthquake. The findings of the questionnaire survey conducted in 2010 showed that 1) about 70% of the people felt that they gained benefit from nuclear power plants and these were needed for their daily life. 2) Fifty percent respondents recognized there was danger to themselves and their family members with regards to nuclear power plants. The risks of nuclear power plants to Japanese society ware estimated higher than that risk to individuals of Japanese public. 3) Perception of risks from nuclear power plants to individual Japanese tended to be slightly lower between 1999 and 2010. (author)

Maintenance risk management in Dayabay nuclear power plant

International Nuclear Information System (INIS)

He Xuhong; Tong Jiejuan

2005-01-01

The importance of proper maintenance to safe and reliable nuclear plant operation has long been recognized by the nuclear utility and regulatory body. This paper presents a process of maintenance risk management developed for a Chinese Nuclear Power Plant (NPP). The process includes three phases: (I) long term maintenance plan risk management, (II) monthly maintenance plan risk management, and (III) detailed risk management for high risk configuration. A risk matrix is developed for phase I whose purpose is to provide a rough guide for risk management in the making of the annual maintenance plan. For Phase II and Phase III, a software tool named Maintenance- Risk-Monitor is developed based on the internal initiating event, level 1 PSA model. The results of Phase II are the risk information of the all plant configurations caused by the unavailability of the components included the monthly maintenance plan. When the increase of core damage frequency (CDF) or the incremental core damage probability (ICDP) of a configuration is higher than the corresponding thresholds, Phase III is needed for this high risk configuration to get the useful information such as risk-importance components, human actions and initial events, from which appropriate preventive measurements could be derived. It is hoped that the provided process of maintenance risk management, together with the developed software tool, could facilitate the maintenance activities in the NPPs of China. (authors)

Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis

International Nuclear Information System (INIS)

Kim, Jae Young; Bang, Ye Jin; Ee, Won Jin

2016-01-01

There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well designed future studies given the conflicting results from sensitivity analysis.

Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Young [Dept. of Preventive Medicine, Keimyung University College of Medicine, Daegu (Korea, Republic of); Bang, Ye Jin; Ee, Won Jin [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

2016-04-15

There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well designed future studies given the conflicting results from sensitivity analysis.

Nuclear power plants without the risk of a reactor disaster

International Nuclear Information System (INIS)

Merz, L.

1980-01-01

Nowadays everybody believes that all nuclear power plants are an inevitable risk for the life of the people in its environment; this is a prejudice. This article points out that it is possible to plan nuclear power plants in a way that no deaths in the population have to be feared, even in the heaviest possible disturbances. In order to realise such nuclear power plants, it is necessary either to improve the cooling of the fuel rods by passive additional safety measures of which one unlimitedly efficient thus excluding a nuclear melting accident or to improve the safety containers so that it remains sufficiently tight. (orig./HP) [de

Risk-oriented management of system configurations during power plant operation

International Nuclear Information System (INIS)

Kafka, P.

1991-01-01

The paper explains the purpose, design, and functions of an on-line database called risk monitor, which is developed on the basis of a risk model mapping an entire plant and the functions of the system configurations by a probabilistic and risk-oriented approach in a computerized simulation model. The frequency of occurrence of the various failure modes is computed and specified by fault tree analysis and event tree analysis. The monitoring system is a diagnostic tool for power plant operators. (DG) [de

Risk management methodology applied at thermal power plant

International Nuclear Information System (INIS)

Coppolino, R.

2007-01-01

Nowadays, the responsibility of the environmental risks, connected the productive processes and to the products of an enterprise, represent one of the main aspects which an adequate management approach has to foresee. In this paper it has been evaluated the guidelines followed by Edipower Thermoelectric Power plant of S. Filippo di Mela (ME). These guidelines were given in order to manage the chemical risk connected to the usage of various chemicals with which the workers get in touch when identifying the risks of the methodology introduced by the AZ/NZS 4360:2004 Risk Management Standard

Development of full power risk monitoring system for UCN 3 and 4 nuclear power plants

International Nuclear Information System (INIS)

Kim, Seung Hwan; Jang, Seung Chul; Kim, Kil Yoo; Han, Sang Hoon; Jung, Won Dae

2002-03-01

This report describes full power risk monitoring system (DynaRM) of NPPs which evaluates the current plant risk and monitor the risk change caused by the configuration change due to preventive maintenance or periodic maintenance activities. In order to calculate the core damage frequency, the inoperable equipment's basic event should be submitted to a quantification engine. DynaRM uses a risk monitor model converted from PSA model as the quantification engine, which can respond fast for the various equipment configuration changes. DynaRM is developed to solve these kinds of problems and difficulties. The main two key features of DynaRM are real time risk monitoring and real time maintenance plan decision supporting. With DynaRM, the plant risk can be calculated automatically only with out of service equipment information and equipment maintenance scheduling is easy by modifying the detail schedule plan. We have developed the DynaRM for the Korean standard nuclear power plant and it is currently using at Ulchin 3,4 NPP. The adaptation for the other NPPs is also easy with a little modification since DynaRM was developed by considering it to be used in the other NPPs. Moreover, we also expect DynaRM will be a good advisory tool for the plant risk monitoring and maintenance scheduling

Toward risk-based control of nuclear power plant configurations

International Nuclear Information System (INIS)

Samanta, P.K.; Veseley, W.E.; Kim, I.S.

1992-01-01

This paper presents an evaluation of the configuration risks associated with the operation of a nuclear power plant and the approaches to control these risks using risk-based configuration control considerations. In that context, the actual and maximum potential configuration risks at a plant are analyzed and the alternative types criteria for a risk-based configuration control systems are described. The risk-based configuration calculations which are studied here focus on the core-melt frequency impacts from given plant configurations, the configurations which cause large core-melt frequency increases can be identified and controlled. The duration time in which the configuration can exist can then be limited or the core-melt frequency level associated with the configuration can be reduced by various actions. Futhermore, maintenances and tests can be scheduled to avoid the configurations which cause large core-melt frequency increases. Present technical specifications do not control many of these configurations which can cause large core-melt frequency increases but instead focus on many risk-unimportant allowed outage times. Hence, risk-based configuration management can be effectively used to reduce core-melt frequency associated risks at a plant and at the same time can provide flexibility in plant operation. The alternative strategies for controlling the core-melt frequency and other risk contributions include: (1) controlling the increased risk level which is associated with the configuration; (2) controlling the individual configuration risk which is associated with a given duration of a configuration; (3) controlling the time period configuration risk from configurations which occur in a time period. (orig.)

Efforts to utilize risk assessment at nuclear power plants

International Nuclear Information System (INIS)

Narumiya, Yoshiyuki

2015-01-01

Risk assessment means the use of the outputs that have been obtained through risk identification and risk analysis (risk information), followed by the determination of the response policy by comparing these outputs with the risk of judgement standards. This paper discusses the use of risk information with multifaceted nature and its significance, and the challenges to the further penetration of these items. As the lessons and risk assessment learnt from the past accidents, this paper takes up the cases of the severe accidents of Three Mile Island, Chernobyl, and Fukushima Daiichi power stations, and discusses their causes and expansion factors. In particular, at Fukushima Daiichi Nuclear Power Station, important lessons were shortage in measures against the superimposition of earthquake and tsunami, and the insufficient use of risk assessment. This paper classified risk assessment from the viewpoint of risk information, and showed the contents and index for each item of risk reduction trends, risk increase trends, and measures according to the importance of risk. As the benefits of activities due to risk assessment, this paper referred to the application cases of the probabilistic risk assessment (PRA) of IAEA, and summarized the application activities of 10 items of risk indexes by classifying them to safety benefits and operational benefits. For example, in the item of flexible Allowed Outage Time (AOT), the avoidance of plant shutdown and the flexibility improvement of maintenance scheduling at a plant are corresponding to the above-mentioned benefits, respectively. (A.O.)

Modern Risk Assessment for Nuclear Power Plants High-Voltage Substations

International Nuclear Information System (INIS)

Ioan, S.; Hurdubetiu, S.; Marza, F.; Mocanu, M.; Stefan, M.

2002-01-01

The paper describes a first Romanian attempt to set up the methodology for risk assessment and control within high-voltage substations, developed for the Nuclear power plant in Cernavoda (Romania). Considering the present risk assessment methods the MENER Project will develop a new methodology, in line with the European Community legislation and with the specific regional needs. In order to correctly shape the necessary resources required by a risk analysis a large size enterprise (a nuclear power plant) is selected and the following five indicators will be estimated: the economic profit, environmental risk, indirect (future) risk, technology improvement and physic and psychological risk. The results are expected to considerably facilitate risk assessment, by: evaluating project acceptability; evaluating equipment compliance to regulatory criteria; estimating excluding clearances; easing the design of emergency programmes; identifying the equipment use restrictions; identifying the risk sources; selecting the maintenance and risk reduction methods; testing the procedures leading to future regulatory norms; suitability of the risk management system modification. The immediate result of employing modern risk assessment methods could be the decrease by one third of the expenses required by environment protection, staff health and labor safety and quality management. (author)

Risk management: A tool for improving nuclear power plant performance

International Nuclear Information System (INIS)

2001-04-01

This technical document on risk management as a tool for improving nuclear power plant (NPP) operations is part of an ongoing project on management of NPP operations in a competitive environment. The overall objective of this project is to assist the management of operating organizations and NPPs in identifying and implementing appropriate measures to remain competitive in a rapidly changing business environment. Other reports developed through this project have identified overall strategies and techniques that NPP operating organization managers can use to succeed in more competitive energy markets. For example, in IAEA-TECDOC-1123, Strategies for Competitive Nuclear Power Plants, one of the most important strategies identified was integrated risk management. This publication provides a recommended structure for risk management along with examples of how NPP operating organizations are using this tool to help them integrate safety, operational and economic related risks in a changing business environment

Living near nuclear power plants and thyroid cancer risk: A systematic review and meta-analysis.

Science.gov (United States)

Kim, Jaeyoung; Bang, Yejin; Lee, Won Jin

2016-02-01

There has been public concern regarding the safety of residing near nuclear power plants, and the extent of risk for thyroid cancer among adults living near nuclear power plants has not been fully explored. In the present study, a systematic review and meta-analysis of epidemiologic studies was conducted to investigate the association between living near nuclear power plants and the risk of thyroid cancer. A comprehensive literature search was performed on studies published up to March 2015 on the association between nuclear power plants and thyroid cancer risk. The summary standardized incidence ratio (SIR), standardized mortality ratio (SMR), and 95% confidence intervals (CIs) were calculated using a random-effect model of meta-analysis. Sensitivity analyses were performed by study quality. Thirteen studies were included in the meta-analysis, covering 36 nuclear power stations in 10 countries. Overall, summary estimates showed no significant increased thyroid cancer incidence or mortality among residents living near nuclear power plants (summary SIR=0.98; 95% CI 0.87-1.11, summary SMR=0.80; 95% CI 0.62-1.04). The pooled estimates did not reveal different patterns of risk by gender, exposure definition, or reference population. However, sensitivity analysis by exposure definition showed that living less than 20 km from nuclear power plants was associated with a significant increase in the risk of thyroid cancer in well-designed studies (summary OR=1.75; 95% CI 1.17-2.64). Our study does not support an association between living near nuclear power plants and risk of thyroid cancer but does support a need for well-designed future studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

Construction risks of nuclear power plants for use in cost-effectiveness considerations

International Nuclear Information System (INIS)

Bock-Werthmann, W.

1986-08-01

The construction risk study is concerned with a nuclear power station of 1300 MW(e) design output. The risk figures obtained demonstrate that construction risks of nuclear power plants form a substantial share of the total risk from all steps of the nuclear fuel cycle. When compared with other risk figures it is apparent that only the fatalities caused by the extraction of uranium are of similar magnitude. (55 references). (DG)

Risk management in Taiwan's nuclear power plants by adopting TIRM-2

International Nuclear Information System (INIS)

Chao, Chun-Chang; Kao, Tsu-Mu; Huang, Shian-Hung

2003-01-01

The TIRM-2 is the second generation risk monitor developed by INER and TPC. By providing risk indexes such as CDF, LERF, ΔCDF, ΔLERF, importance measurements and availability of safety systems, the TIRM-2 can precisely capture the plant risks and can serve as a better management resource. Examples about how to use TIRM-2 for the risk management are discussed in this paper. For plant at power operation, the TIRM-2 allows the plant staff to change plant configuration directly from the P and I Diagram. For a new plant configuration, only a few minutes will be spent for TIRM-2 to recalculate all the risk indexes. TIRM-2 can also provide risk profile and the associated risk indexes based on a given online maintenance schedule. The risk profile of CDF and LERF with ΔCDF and ΔLERF will help the plant staff with preparing associated information for the applications of risk-informed, performance-based regulation. With the proposed refueling outage schedule, the TIRM-2 can predict status of safety system and risk profile of CDF hourly. All calculations can be done within 40 minutes for a typical 50-days outage schedule. The plant staff and managers can rearrange the maintenance schedule referring to TIRM-2' predicted results and avoiding the plant entering into a potential high-risk situation. With the capability of performing both CDF and LERF calculations, the TIRM-2's will become a very helpful tool in monitoring the risk of different plant status and will provide further information directly for risk-informed applications. (author)

Probabilistic risk assessment in nuclear power plant regulation

Energy Technology Data Exchange (ETDEWEB)

Wall, J B

1980-09-01

A specific program is recommended to utilize more effectively probabilistic risk assessment in nuclear power plant regulation. It is based upon the engineering insights from the Reactor Safety Study (WASH-1400) and some follow-on risk assessment research by USNRC. The Three Mile Island accident is briefly discussed from a risk viewpoint to illustrate a weakness in current practice. The development of a probabilistic safety goal is recommended with some suggestions on underlying principles. Some ongoing work on risk perception and the draft probabilistic safety goal being reviewed on Canada is described. Some suggestions are offered on further risk assessment research. Finally, some recent U.S. Nuclear Regulatory Commission actions are described.

Methodology for risk-based configuration control of nuclear power plant operation

International Nuclear Information System (INIS)

Valle, Antonio Torres; Oliva, Jose de Jesus Rivero

2012-01-01

The hazardous configurations control in Nuclear Power Plants is an application of a previous Probabilistic Safety Analysis (PSA). A more complete option would be the risk monitoring for the online detection of these configurations but expert personnel would be required to deal with the complexities of PSA and risk monitor. The paper presents a simpler but effective approach: a method of configuration control, based on dependencies matrixes. The algorithm is included in a computer code called SECURE A-Z. The configuration control is carried out in a qualitative way, without previous PSA results and not using a Risk Monitor. The simplicity of the method warrants its application to facilities where these tools have not been developed, allowing the detection of hazardous configurations during operation and increasing plant safety. This configuration control system was implemented in the Embalse Nuclear Power Plant in Argentina. The paper shows the application of the algorithm to the analysis of a simplified safety system. (author)

Cost-effectiveness analysis of risk reduction at nuclear power plants

International Nuclear Information System (INIS)

Lochard, J.; Maccia, C.; Pages, P.

1985-01-01

Cost-effectiveness analysis of risk reduction is now widely accepted as a rational analytical framework to consistently address the resource allocation problem underlying any risk management process. This paper presents how this technique can be usefully applied to complex systems such as the management of radioactive releases from nuclear power plants into the environment. (orig.) [de

Applicability of PRA methods and data to the financial risk assessment of nuclear power plants

International Nuclear Information System (INIS)

El-Sheik, K.A.

1985-01-01

Financial risk assessment, where the probability and severity of financial consequences are estimated, offers a logical framework for organizing and evaluating data pertinent to nuclear power plant accidents. Under the sponsorship of the Electric Power Research Institute, General Electric investigated the feasibility of financial risk assessment of nuclear power plants and of applying PRA methods and data in such an assessment. This paper summarizes the main findings of this investigation. Specifically, the paper discussed the following topics: definition of financial consequences and financial risk; overall approach for financial risk assessment and how it compares with the approach for PRA used in the Reactor Safety Study; and specific financial risk assessment procedures for defining initiating events, plant response sequences, institutional scenarios, and financial consequences and how they compare to analogous procedures for PRA

Development of a dynamical systems model of plant programmatic performance on nuclear power plant safety risk

International Nuclear Information System (INIS)

Hess, Stephen M.; Albano, Alfonso M.; Gaertner, John P.

2005-01-01

Application of probabilistic risk assessment (PRA) techniques to model nuclear power plant accident sequences has provided a significant contribution to understanding the potential initiating events, equipment failures and operator errors that can lead to core damage accidents. Application of the lessons learned from these analyses has resulted in significant improvements in plant operation and safety. However, this approach has not been nearly as successful in addressing the impact of plant processes and management effectiveness on the risks of plant operation. The research described in this paper presents an alternative approach to addressing this issue. In this paper we propose a dynamical systems model that describes the interaction of important plant processes on nuclear safety risk. We discuss development of the mathematical model including the identification and interpretation of significant inter-process interactions. Next, we review the techniques applicable to analysis of nonlinear dynamical systems that are utilized in the characterization of the model. This is followed by a preliminary analysis of the model that demonstrates that its dynamical evolution displays features that have been observed at commercially operating plants. From this analysis, several significant insights are presented with respect to the effective control of nuclear safety risk. As an important example, analysis of the model dynamics indicates that significant benefits in effectively managing risk are obtained by integrating the plant operation and work management processes such that decisions are made utilizing a multidisciplinary and collaborative approach. We note that although the model was developed specifically to be applicable to nuclear power plants, many of the insights and conclusions obtained are likely applicable to other process industries

Research on the Application of Risk-based Inspection for the Boiler System in Power Plant

Science.gov (United States)

Li, Henan

2017-12-01

Power plant boiler is one of the three main equipment of coal-fired power plants, is very tall to the requirement of the safe and stable operation, in a significant role in the whole system of thermal power generation, a risk-based inspection is a kind of pursuit of security and economy of unified system management idea and method, can effectively evaluate equipment risk and reduce the operational cost.

Prediction of Maintenance Period of Equipment Through Risk Assessment of Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Song, Gee Wook; Kim, Bum Shin; Choi, Woo Song; Park, Myung Soo [KEPCO Research Institute, Daejeon (Korea, Republic of)

2013-10-15

Risk-based inspection (RBI) is a well-known method that is used to optimize inspection activities based on risk analysis in order to identify the high-risk components of major facilities such as power plants. RBI, when implemented and maintained properly, improves plant reliability and safety while reducing unplanned outages and repair costs. Risk is given by the product of the probability of failure (Pof) and the consequence of failure (COF). A semi-quantitative method is generally used for risk assessment. Semi-quantitative risk assessment complements the low accuracy of qualitative risk assessment and the high expense and long calculation time of quantitative risk assessment. The first step of RB I is to identify important failure modes and causes in the equipment. Once these are defined, the Pof and COF can be assessed for each failure. During Pof and COF assessment, an effective inspection method and range can be easily found. In this paper, the calculation of the Pof is improved for accurate risk assessment. A modified semi-quantitative risk assessment was carried out for boiler facilities of thermal power plants, and the next maintenance schedules for the equipment were decided.

Prediction of Maintenance Period of Equipment Through Risk Assessment of Thermal Power Plants

International Nuclear Information System (INIS)

Song, Gee Wook; Kim, Bum Shin; Choi, Woo Song; Park, Myung Soo

2013-01-01

Risk-based inspection (RBI) is a well-known method that is used to optimize inspection activities based on risk analysis in order to identify the high-risk components of major facilities such as power plants. RBI, when implemented and maintained properly, improves plant reliability and safety while reducing unplanned outages and repair costs. Risk is given by the product of the probability of failure (Pof) and the consequence of failure (COF). A semi-quantitative method is generally used for risk assessment. Semi-quantitative risk assessment complements the low accuracy of qualitative risk assessment and the high expense and long calculation time of quantitative risk assessment. The first step of RB I is to identify important failure modes and causes in the equipment. Once these are defined, the Pof and COF can be assessed for each failure. During Pof and COF assessment, an effective inspection method and range can be easily found. In this paper, the calculation of the Pof is improved for accurate risk assessment. A modified semi-quantitative risk assessment was carried out for boiler facilities of thermal power plants, and the next maintenance schedules for the equipment were decided

Geothermal Risk Reduction via Geothermal/Solar Hybrid Power Plants. Final Report

Energy Technology Data Exchange (ETDEWEB)

Wendt, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mines, Greg [Idaho National Lab. (INL), Idaho Falls, ID (United States); Turchi, Craig [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhu, Guangdong [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-01

There are numerous technical merits associated with a renewable geothermal-solar hybrid plant concept. The performance of air-cooled binary plants is lowest when ambient temperatures are high due to the decrease in air-cooled binary plant performance that occurs when the working fluid condensing temperature, and consequently the turbine exhaust pressure, increases. Electrical power demand is generally at peak levels during periods of elevated ambient temperature and it is therefore especially important to utilities to be able to provide electrical power during these periods. The time periods in which air-cooled binary geothermal power plant performance is lowest generally correspond to periods of high solar insolation. Use of solar heat to increase air-cooled geothermal power plant performance during these periods can improve the correlation between power plant output and utility load curves. While solar energy is a renewable energy source with long term performance that can be accurately characterized, on shorter time scales of hours or days it can be highly intermittent. Concentrating solar power (CSP), aka solar-thermal, plants often incorporate thermal energy storage to ensure continued operation during cloud events or after sunset. Hybridization with a geothermal power plant can eliminate the need for thermal storage due to the constant availability of geothermal heat. In addition to the elimination of the requirement for solar thermal storage, the ability of a geothermal/solar-thermal hybrid plant to share a common power block can reduce capital costs relative to separate, stand-alone geothermal and solar-thermal power plant installations. The common occurrence of long-term geothermal resource productivity decline provides additional motivation to consider the use of hybrid power plants in geothermal power production. Geothermal resource productivity decline is a source of significant risk in geothermal power generation. Many, if not all, geothermal resources

Assessment of inhalation risk due to radioactivity released from coal-based thermal power plant

International Nuclear Information System (INIS)

Sahu, S.K.; Pandit, G.G.; Shukla, V.K.; Puranik, V.D.; Kushwaha, H.S.

2006-01-01

In India, the coal based thermal power plants have been the major source of power generation in the past and would continue for decades to come. As the coal contains naturally occurring primordial radionuclides the burning of pulverized coal to produce energy for generation of electricity in thermal power plants will result in the emission of a variety of natural radioactive elements into the environment in the vicinity of thermal power plants. In this paper we have used two different methods for characterization of uncertainty in inhalation risk to the general public around 10 Kms radius in the neighborhood of a coal-fired thermal power plant. (author)

Fire risk analysis for nuclear power plants: Methodological developments and applications

International Nuclear Information System (INIS)

Kazarians, M.; Apostolakis, G.; Siv, N.O.

1985-01-01

A methodology to quantify the risk from fires in nuclear power plants is described. This methodology combines engineering judgment, statistical evidence, fire phenomenology, and plant system analysis. It can be divided into two major parts: (1) fire scenario identification and quantification, and (2) analysis of the impact on plant safety. This article primarily concentrates on the first part. Statistical analysis of fire occurrence data is used to establish the likelihood of ignition. The temporal behaviors of the two competing phenomena, fire propagation and fire detection and suppression, are studied and their characteristic times are compared. Severity measures are used to further specialize the frequency of the fire scenario. The methodology is applied to a switchgear room of a nuclear power plant

RIMAP demonstration project. Risk-based life management of piping system in power plant Heilbronn

International Nuclear Information System (INIS)

Bareiss, J.; Buck, P.; Matschecko, B.; Jovanovic, A.; Balos, D.; Perunicic, M.

2004-01-01

In the framework of EU project RIMAP [Risk Based Inspection and Maintenance Procedures for European Industry (2000)] a new European Guideline for optimized risk based maintenance and inspection planning of industrial plants (RBLM, Risk Based Life Management) is being developed. The RIMAP project consists of the three clustered projects: - development (RTD); - demonstration (DEMO): - thematic network (TN). Current work and future, planned work in RIMAP demonstration project on applications of the RIMAP methodology in power plants are presented briefly in the first part of the paper. Also presented in the paper are the results of a preliminary analysis of piping system in power plant Heilbronn using the concept of risk-based monitoring as part of overall concept of risk-based life management. Shortly the following issues are discussed in the paper: - identification of critical components; - application of a multilevel risk analysis (...from 'screening' to 'detailed analysis'); - determination of PoF (Probability of Failure); - determination of CoF (Consequence of Failure); - optimation of inspection and maintenance plan. From our experience with the application of the RIMAP methodology the following conclusions can be drawn: The use of risk-based methods in inspection and maintenance of piping systems in power plants gives transparency to the decision making process and gives an optimized maintenance policy based on current state of the components. The results of the work clearly show the power of the proposed method for concentration on critical items: out of 64 monitored components 5 were selected for intermediate analysis and only 1 for the detailed analysis (probabilistic high temperature fracture mechanics)

Risk perception among nuclear power plant employees

International Nuclear Information System (INIS)

Fields, C.D.

1989-01-01

Radiation protection training and general employee training within the nuclear industry are designed to reduce workers' concerns about radiation and to develop skills that will protect against unwarranted exposures. Inaccurate perceptions about radiation by workers can cause a lack of adequate concern or exaggerated fears, which in turn can result in unnecessary radiation exposure to the worker or co-workers. The purpose of the study is threefold: (a) to identify health and safety concerns among nuclear power plant employees, (b) to discover variables that influence the perception of risk among employees, and (c) to ascertain if attitudes of the family, community, and the media affect workers' perception of risk. Workers identified five areas of concern: shift work, radiation, industrial safety, stress, and sabotage

Use of probabilistic risk assessment in expert system usage for nuclear power plant safety

International Nuclear Information System (INIS)

Uhrig, R.E.

1987-01-01

The introduction of probability risk assessments (PRA's) to nuclear power plants in the Rasmussen Report (WASH-1400) gave us a means of evaluating the risk to the public associated with the operation of nuclear power plants, at least on a relative basis. While the choice of the ''source term'' and methodology in a PRA significantly influence the absolute probability and the consequences of core melt, comparison of two PRA calculations for two configurations of the same plant, carried out on a consistent basis, can be readily identify the increase in risk associated with going from one configuration of a plant to another by removing components or systems from service. This ratio of core melt probabilities (assuming no recovery of failed systems) obtained from two PRA calculations for different configurations was the criterion (called ''risk factor'') chosen as a basis for making a decision in an expert system as to what mitigating action, if any, would be taken to avoid a trip situation from developing. PRISIM was developed by JBF Associates of Knoxville under the sponsorship of the NRC as a system for Resident Inspectors at nuclear power plants to provide them with a relative safety status of the plant under all configurations. PRISIM calculated the risk factor---the ration of core melt probabilities of the plant under the current configuration relative to the normal configuration with all systems functioning---using an algorithm that emulates the results of the original PRA. It also presents time and core melt (assuming no recovery of systems or components)

Pathogenic free-living amoebae in a closed-loop power plant; risk assessment and risk management

International Nuclear Information System (INIS)

Cabanes, P.; Pernin, P.

1998-01-01

Since 1980, the water used for cooling in French power plants has been tested for pathogenic amoebae, especially Naegleria fowleri, the causative agent of Primary Amoebic Meningoencephalitis (PAM), a rapid fatal disease of the central nervous system. The replacement of brass condensers by stainless steel condensers resulted in increased Naegleria fowleri development, to a density of as much as 3000 l -1 in the Dampierre power plant cooling water. Downstream from Dampierre, the maximum detected density of this amoeba during the summer of 1995 was 80 l -1 , at low river flow. The replacement of a second condenser in 1996 at the same power plant was expected to double the amoebae concentration in the river. The hypothetical PAM risk for swimmers was then predicted to be 10 -4 per swim. To reduce the risk continuous chlorination of the closed-loop cooling system was implemented at a free residual chlorine level in the range of 0.3-0.5 mg.l -1 . Naegleria fowleri concentrations decreased immediately and thereafter remained under 4 l -1 . Total residual chlorine and chlorinated organic compounds were also monitored in the evaluation of the environmental impact of this preventive action. (authors)

An assessment of mercury emissions and health risks from a coal-fired power plant

Energy Technology Data Exchange (ETDEWEB)

Fthenakis, V.M.; Lipfert, F.W.; Moskowitz, P.D.; Saroff, L. [Brookhaven National Laboratory, Upton, NY (United States)

1995-12-01

Title III of the 1990 Clean Air Act Amendments (CAAA) directed the US Environmental Protection Agency (EPA) to evaluate the rate and effect of mercury emissions in the atmosphere and technologies to control the emissions. The US DOE sponsored a risk assessment project at Brookhaven (BNL) to evaluate health risks of mercury emissions from coal combustion. Methylmercury (MeHg) is the compound predominantly responsible for human exposure to atmospheric mercury in the United States, through fish ingestion. In the BNL study, health risks to adults resulting from Hg emissions from a hypothetical coal-fired power plant were estimated using probabilistic risk assessment techniques. This study showed that the effects of emissions of a single large power plant may double the background exposures to MeHg resulting from consuming fish obtained from a localized are near the power plant. Even at these more elevated exposure levels, the attributable incidence in mild neurological symptoms (paresthesia) was estimated to be quite small, especially when compared with the estimated background incidence in the population. 29 refs., 5 figs., 2 tabs.

An assessment of mercury emissions and health risks from a coal-fired power plant

International Nuclear Information System (INIS)

Fthenakis, V.M.; Lipfert, F.W.; Moskowitz, P.D.; Saroff, L.

1995-01-01

Title III of the 1990 Clean Air Act Amendments (CAAA) directed the US Environmental Protection Agency (EPA) to evaluate the rate and effect of mercury emissions in the atmosphere and technologies to control the emissions. The US DOE sponsored a risk assessment project at Brookhaven (BNL) to evaluate health risks of mercury emissions from coal combustion. Methylmercury (MeHg) is the compound predominantly responsible for human exposure to atmospheric mercury in the United States, through fish ingestion. In the BNL study, health risks to adults resulting from Hg emissions from a hypothetical coal-fired power plant were estimated using probabilistic risk assessment techniques. This study showed that the effects of emissions of a single large power plant may double the background exposures to MeHg resulting from consuming fish obtained from a localized are near the power plant. Even at these more elevated exposure levels, the attributable incidence in mild neurological symptoms (paresthesia) was estimated to be quite small, especially when compared with the estimated background incidence in the population. 29 refs., 5 figs., 2 tabs

Architecture and design of third Qinshan nuclear power plant risk monitor

Energy Technology Data Exchange (ETDEWEB)

Wang, F.; Li, Y.; Wang, J.; Wang, J.; Hu, L. [Inst. of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui, 230031 (China); School of Nuclear Science and Technology, Univ. of Science and Technology of China, No.350 Shushanhu Road, Shushan District, Hefei, Anhui, 230031 (China)

2012-07-01

Risk monitor is a real-time analysis tool to determine the point-in-time risk based on actual plant configuration, which is an important application of PSA (Probabilistic Safety Assessment). In this study the status and development trend of risk monitor were investigated and a risk monitor named TQRM (Third Qinshan nuclear power plant Risk Monitor) was developed. The B/S architecture and the two key computing methods pre-solved and resolving PSA model method adopted in TQRM were introduced. The functions and technical features were also presented. Now TQRM has been on-line for more than one year and used in the operation and maintenance of TQNPP. The experience demonstrates that TQRM's results are accurate and real-time, the architecture is stable, and it could be extended and maintained conveniently for any other Risk-Informed Application. (authors)

Reactor safety study. An assessment of accident risks in U.S. commercial nuclear power plants. Executive summary

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-10-01

The Reactor Safety Study was sponsored by the U. S. Atomic Energy Commission to estimate the public risks that could be involved in potential accidents in commercial nuclear power plants of the type now in use. It was performed under the independent direction of Professor Norman C. Rasmussen of the Massachusetts Institute of Technology. The risks had to be estimated, rather than measured, because although there are about 50 such plants now operating, there have been no nuclear accidents to date resulting in significant releases of radioactivity in U.S. commercial nuclear power plants. The objective of the study was to make a realistic estimate of these risks and, to provide perspective, to compare them with non-nuclear risks to which our society and its individuals are already exposed. This information may be of help in determining the future reliance by society on nuclear power as a source of electricity. The results from this study suggest that the risks to the public from potential accidents in nuclear power plants are comparatively small.

Reactor safety study. An assessment of accident risks in U.S. commercial nuclear power plants. Executive summary

International Nuclear Information System (INIS)

1975-10-01

The Reactor Safety Study was sponsored by the U. S. Atomic Energy Commission to estimate the public risks that could be involved in potential accidents in commercial nuclear power plants of the type now in use. It was performed under the independent direction of Professor Norman C. Rasmussen of the Massachusetts Institute of Technology. The risks had to be estimated, rather than measured, because although there are about 50 such plants now operating, there have been no nuclear accidents to date resulting in significant releases of radioactivity in U.S. commercial nuclear power plants. The objective of the study was to make a realistic estimate of these risks and, to provide perspective, to compare them with non-nuclear risks to which our society and its individuals are already exposed. This information may be of help in determining the future reliance by society on nuclear power as a source of electricity. The results from this study suggest that the risks to the public from potential accidents in nuclear power plants are comparatively small

Risk-informed technology developments for nuclear power plants within the ASME in 2000-2001

International Nuclear Information System (INIS)

Wesley Rowley, C.; Balkey, K.R.

2001-01-01

The purpose of this paper is to provide information on developments within the ASME to support risk-informing NRC regulations for nuclear power plants. This paper builds on a publication at ICONE-8 that discussed ASME risk-informed nuclear power plant initiatives, both in Research and in Codes and Standards, particularly those related to risk-informing Part 50 of the 10 CFR (Code of federal regulations). During the past year, the ASME BNCS formed a Task Force to focus the Society's efforts to support risk-informing 10 CFR Part 50. Key efforts underway that are guided by the task force include finalizing the ASME PRA (probability risk assessment) Standard, developing a Code Case to risk-inform the repair, replacement, and modification activities for ASME components, and developing a Code Case to risk-inform the safety classification of pressure boundary components. Several other initiatives are also under investigation such as introducing risk insights into other ASME nuclear codes and standards supported by appropriate research and technical basis information. Supplementary information will also be provided to update an initial high level plan of ASME risk-informed initiatives for nuclear power plants that was presented at ICONE-8, including plans to communicate these risk-informed technology developments to the public. The authors included and acknowledged contributions from several other cognizant members of the ASME BNCS (board on nuclear codes standards) Task Group on RIP50 in the paper. (authors)

Risk averse optimal operation of a virtual power plant using two stage stochastic programming

International Nuclear Information System (INIS)

Tajeddini, Mohammad Amin; Rahimi-Kian, Ashkan; Soroudi, Alireza

2014-01-01

VPP (Virtual Power Plant) is defined as a cluster of energy conversion/storage units which are centrally operated in order to improve the technical and economic performance. This paper addresses the optimal operation of a VPP considering the risk factors affecting its daily operation profits. The optimal operation is modelled in both day ahead and balancing markets as a two-stage stochastic mixed integer linear programming in order to maximize a GenCo (generation companies) expected profit. Furthermore, the CVaR (Conditional Value at Risk) is used as a risk measure technique in order to control the risk of low profit scenarios. The uncertain parameters, including the PV power output, wind power output and day-ahead market prices are modelled through scenarios. The proposed model is successfully applied to a real case study to show its applicability and the results are presented and thoroughly discussed. - Highlights: • Virtual power plant modelling considering a set of energy generating and conversion units. • Uncertainty modelling using two stage stochastic programming technique. • Risk modelling using conditional value at risk. • Flexible operation of renewable energy resources. • Electricity price uncertainty in day ahead energy markets

A societal risk analysis model for nuclear power plants

International Nuclear Information System (INIS)

Klopp, George T.

2004-01-01

A review of the last decade and a half reveals that the nuclear power industry, world wide, has devoted increased attention to the concepts of reactor risk, probabilistic risk assessment (PRA), and cost benefit analyses. Millions of dollars have been spent by the industry and by regulatory agencies on studies of specific plants, research into severe accident behavior, and the development of national risk goals. In the United States, there is a major effort underway to evaluate each operating nuclear plant using PRA and the latest information on severe accident behavior. This effort constitutes a search for 'outliers' or vulnerabilities which may be profitably addressed by changes to plant design or operation. The question, then, immediately arises: How much is it reasonable to spend on this particular 'outlier?' The answer to this question, in each case, calls for some systematic vehicle for evaluating the worth of risk reduction. In turn, this calls for some means to look at all aspects of risk using a common yardstick or unit of measure. A review of past practices in such evaluations leads one directly to the classical cost benefit analyses which rarely use any guideline more comprehensive than the old $1000 per person-rem. The real costs of the TMI accident point to a need for a more realistic treatment. The BoPhal accident, the Chernobyl accident, and the Exxon Valdez accident highlight risk aspects previously not explored in detail and further support the postulate that a better method is mandated by history

A risk-informed perspective on deterministic safety analysis of nuclear power plants

International Nuclear Information System (INIS)

Wan, P.T.

2009-01-01

In this work, the deterministic safety analysis (DSA) approach to nuclear safety is examined from a risk-informed perspective. One objective of safety analysis of a nuclear power plant is to demonstrate via analysis that the risks to the public from events or accidents that are within the design basis of the power plant are within acceptable levels with a high degree of assurance. This nuclear safety analysis objective can be translated into two requirements on the risk estimates of design basis events or accidents: the nominal risk estimate to the public must be shown to be within acceptable levels, and the uncertainty in the risk estimates must be shown to be small on an absolute or relative basis. The DSA approach combined with the defense-in-depth (DID) principle is a simplified safety analysis approach that attempts to achieve the above safety analysis objective in the face of potentially large uncertainties in the risk estimates of a nuclear power plant by treating the various uncertainty contributors using a stylized conservative binary (yes-no) approach, and applying multiple overlapping physical barriers and defense levels to protect against the release of radioactivity from the reactor. It is shown that by focusing on the consequence aspect of risk, the previous two nuclear safety analysis requirements on risk can be satisfied with the DSA-DID approach to nuclear safety. It is also shown the use of multiple overlapping physical barriers and defense levels in the traditional DSA-DID approach to nuclear safety is risk-informed in the sense that it provides a consistently high level of confidence in the validity of the safety analysis results for various design basis events or accidents with a wide range of frequency of occurrence. It is hoped that by providing a linkage between the consequence analysis approach in DSA with a risk-informed perspective, greater understanding of the limitation and capability of the DSA approach is obtained. (author)

US power plant sites at risk of future sea-level rise

International Nuclear Information System (INIS)

Bierkandt, R; Levermann, A; Auffhammer, M

2015-01-01

Unmitigated greenhouse gas emissions may increase global mean sea-level by about 1 meter during this century. Such elevation of the mean sea-level enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation measures are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to sea-level rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If sea-level rise is properly accounted for in future planning, an adaptation to sea-level rise may be costly but possible. (letter)

On nuclear power plant uprating

International Nuclear Information System (INIS)

Ho, S. Allen; Bailey, James V.; Maginnis, Stephen T.

2004-01-01

Power uprating for commercial nuclear power plants has become increasingly attractive because of pragmatic reasons. It provides quick return on investment and competitive financial benefits, while involving low risks regarding plant safety and public objection. This paper briefly discussed nuclear plant uprating guidelines, scope for design basis analysis and engineering evaluation, and presented the Salem nuclear power plant uprating study for illustration purposes. A cost and benefit evaluation of the Salem power uprating was also included. (author)

Integrated Level 3 risk assessment for the LaSalle Unit 2 nuclear power plant

International Nuclear Information System (INIS)

Payne, A.C. Jr.; Brown, T.D.; Miller, L.A.

1991-01-01

An integrated Level 3 probabilistic risk assessment (PRA) was performed on the LaSalle County Station nuclear power plant using state-of-the-art PRA analysis techniques. The objective of this study was to provide an estimate of the risk to the offsite population during full power operation of the plant and to include a characterization of the uncertainties in the calculated risk values. Uncertainties were included in the accident frequency analysis, accident progression analysis, and the source term analysis. Only weather uncertainties were included in the consequence analysis. In this paper selected results from the accident frequency, accident progression, source term, consequence, and integrated risk analyses are discussed and the methods used to perform a fully integrated Level 3 PRA are examined. LaSalle County Station is a two-unit nuclear power plant located 55 miles southwest of Chicago, Illinois. Each unit utilizes a Mark 2 containment to house a General Electric 3323 MWt BWR-5 reactor. This PRA, which was performed on Unit 2, included internal as well as external events. External events that were propagated through the risk analysis included earthquakes, fires, and floods. The internal event accident scenarios included transients, transient-induced LOCAs (inadvertently stuck open relief valves), anticipated transients without scram, and loss of coolant accidents

Nuclear power plant of Fessenheim: evaluation of the seismic risk; Centrale Nucleaire de Fessenheim: appreciation du risque sismique

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

The seismic risk taken into account during the sizing of the nuclear power plant of Fessenheim seems to have been under evaluated at this time. The revaluation of the seismic risk, as proposed, until this day by EDF in order to the third ten-year visit of the power plant, planned for 2009, leads to a significant under evaluation of the risk and then is not acceptable. The present expertise details point by point the weaknesses of these revaluation. The power plant has been sized in an elastic manner that is generally strongly for the safety side. It is imperative to proceed the most quickly as possible to a deep control of the seismic resistance of the power plant of Fessenheim and then after having proceeded to a revision of the seismic risk in taking into account the actual knowledge in this field. (N.C.)

Probabilistic inhalation risk assessment due to radioactivity released from coal fired thermal power plants

International Nuclear Information System (INIS)

Tiwari, M.; Ajmal, P.Y.; Bhangare, R.C.; Sahu, S.K.; Pandit, G.G.

2014-01-01

This paper deals with assessment of radiological risk to the general public around in the neighborhood of a 1000 MWe coal-based thermal power plant. We have used Monte Carlo simulation for characterization of uncertainty in inhalation risk due to radionuclide escaping from the stack of thermal power plant. Monte Carlo simulation treats parameters as random variables bound to a given probabilistic distribution to evaluate the distribution of the resulting output. Risk assessment is the process that estimates the likelihood of occurrence of adverse effects to humans and ecological receptors as a result of exposure to hazardous chemical, radiation, and/or biological agents. Quantitative risk characterization involves evaluating exposure estimates against a benchmark of toxicity, such as a cancer slope factor. Risk is calculated by multiplying the carcinogenic slope factor (SF) of the radionuclide by the dose an individual receives. The collective effective doses to the population living in the neighborhood of coal-based thermal power plant were calculated using Gaussian plume dispersion model. Monte Carlo Analysis is the most widely used probabilistic method in risk assessment. The MCA technique treats any uncertain parameter as random variable that obeys a given probabilistic distribution. This technique is widely used for analyzing probabilistic uncertainty. In MCA computer simulation are used to combine multiple probability distributions associated with the dose and SF depicted in risk equation. Thus we get a probabilistic distribution for the risk

Environmental impact due to nuclear power plants

International Nuclear Information System (INIS)

Kellermann, O.; Balfanz, H.P.

1975-01-01

The environmental impact due to nuclear power plants is smaller than that due to fossil-fired power plants. The risks of the nuclear power plant operation are determined by the quantity and the probability of the release of radioactive materials. According to the value, the risks of normal operation can be compared to the accident risks. An attempt should be made to effectively reduce the remaining risk at unfavourable sites with the emphasis on accidents with larger effects than design basis accidents. (orig./LH) [de

Risk analysis of warehouse operation in a power plant through a Modified FMEA

Directory of Open Access Journals (Sweden)

Indrawati Sri

2018-01-01

Full Text Available Currently, electricity becomes basic needs for human’s life sustainability. Most of activities require electricity. Some power plant are demanded to be able to fulfil above necessity by distributing electricity as it required within time. Therefore, to accommodate good performance, it needs assessment on risk analysis, specifically at the warehousing division. A risk analysis is needed for assuring a good performance warehouse. A Modified FMEA method is used to analyse the risk. This method id done by identifying sources and root causes of a problem based on the value of risk priority number (RPN. The research is conducted in an Indonesian power plant, located in West Java. There are 10 types of failure modes. The result shows that the failure mode priority is inventory discrepancies. There are no difference ranking on the most impacted failure to be prioritized using FMEA and modified FMEA method.

Study on communicating risk information obtained from PSA within nuclear power plants

International Nuclear Information System (INIS)

Nunogane, Nobuaki; Onoue, Akira; Kojima, Shigeo

2000-01-01

In this study, the communication of PSA information in nuclear power plants (NPPs), namely, how the risk information obtained from the probabilistic safety assessment (PSA) should be presented and communicated to plant personnel, was examined assuming that the safety management system based on the risk information was introduced to NPPs. This is called PSA communication. First, when risk-informed safety management is to be introduced into NPPs, plant personnel should have sufficient related knowledge. In order to provide such knowledge to the personnel through training, risk information is classified into three types: basic information, detailed information and task information. A hierarchical risk information summary for reporting, coordinating and communicating tasks is proposed. In this summary, the concerns of those who have received the information are placed at the top and the related risk information positioned below. At the same time, and by way of a trial, the risk information relating to on-line maintenance (OLM) is prepared. In order to enhance the safety-consciousness and the safety of the entire plant, specific plans such as 'risk tags' which indicate the safety significance of equipment is proposed. Finally, a guideline providing examination procedures for developing detailed PSA communication plans is introduced. (author)

VGB congress 'power plants 2003'. Generation gap - risk and challenge for the electricity market

International Nuclear Information System (INIS)

Anon.

2003-01-01

The VGB Congress 'Power Plants 2003' took place in Copenhagen from 15th to 17th September 2003. The motto of this year's Congress was 'Generation Gap - Risk and Challenge for the Electricity Market'. More than 800 participants took the opportunity for discussion and information in the plenary and technical lectures 'Market and Competition' and 'Technology, Operation and Environment'. Apart from the special features of the Scandinavian and Baltic electricity market, the main focus was on papers reflecting the situation of nuclear power (Finland), operating experience with new power plants, new materials for power plant construction, application of renewables and issues of climate protection. The Congress was again rounded off by technical visits and a side programme. (orig.) [de

Risk factors during construction of power plants using renewable energy sources

Directory of Open Access Journals (Sweden)

Nefedova Lyudmila Veniaminovna

2016-12-01

Full Text Available The authors consider main characteristics of modern development of renewable energy sources (RES. It is dedicated that there are some technical and economic barriers to the widespread use of renewable energy. For example, RES are inconstancy in time and space and have low density of energy flow. High capital intensity and cost price, long-term construction, a considerable degree of different kinds of risk, lack of competitiveness with hydrocarbon species generation in the existing regulatory environment are also inherent to RES. The role of the regulatory framework is shown according to perspective plans of construction of power plants using renewable energy sources. The main requirements which are applied to measures of state support of construction industry of renewable energy development are formulated. Current condition of construction industry of RES in Russia is assessed. The problems of risks which arise during construction of renewable energy facilities according to results of practical use of RES are discussed. And it is rather important to use stage assessment for the construction phase of the project during risk analysis of construction of alternative energy sources. The main groups of RES risks are described. The importance of regulatory and resource risks for effective development of renewable energy in Russia according to the method of strategic planning with the identification of the adverse effects of gradation factors are determined. The analysis of financial risks types and methods of its management during construction power generation projects based on different types of renewable energy resources are made. In the end of the article the authors make a conclusion, that the development of projects for the construction of power plants with the use of innovative technical solutions to ensure minimal risks to the environment and safe operation in various climatic conditions is a priority.

The safety of nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

1988-01-01

Do nuclear power plants present an unjustifiable risk Can there be confidence in their safety The Uranium Institute invited a group of senior safety experts from eight different Western countries operating different types of reactors to provide an authoritative explanation for non-specialists of the basic principles of reactor safety, their application and their implications. The report presents the group's opinion on the level of safety achieved in the Western nuclear power plants with which the authors are directly familiar. Although many of the points made may well also be true for non-Western reactors, the report does not cover them except where specifically stated. It does describe and discuss the causes of the Chernobyl disaster. It does not compare nuclear power with other fuels, nor does it deal with its benefits, since however great the benefits from the peaceful use of nuclear power, and its own advantages over other fuels, they could not compensate for lack of safety. The conclusion reached is that the risk associated with electricity production at nuclear power plants can be kept very low. Proper use of the extensive knowledge available today can guarantee operation of nuclear power plants at very high safety levels, carrying very low risks, both to health and of contamination of the environment: risks that are continually lowered by upgrading existing plants and their operation, and by the design of future power plants. (author).

Multi-Level Risk Assessment of a Power Plant Gas Turbine Applying ...

African Journals Online (AJOL)

Multi-Level Risk Assessment of a Power Plant Gas Turbine Applying the Criticality Index Model. ... Journal of the Nigerian Association of Mathematical Physics ... This study has carefully shown and expressed a step by step computation of the severity level of the Turbine component parts, using the Criticality Index model.

Methods for estimating risks to nuclear power plants from shipping

International Nuclear Information System (INIS)

Walker, D.H.; Hartman, M.G.; Robbins, T.R.

1975-01-01

Nuclear power plants sited on land near shipping lanes or offshore can be exposed to potential risks if there is nearby ship or barge traffic which involves the transport of hazardous cargo. Methods that have been developed for estimating the degree of risk are summarized. Of concern are any accidents which could lead to a release or spill of the hazardous cargo, or to an explosion. A probability of occurrence of the order of 10 -7 per year is a general guideline which has been used to judge whether or not the risk from hazards created by accidents is acceptable. This guideline has been followed in the risk assessment discussed in this paper. 19 references

ESP and NOAH: computer programs for flood-risk analysis of nuclear power plants

International Nuclear Information System (INIS)

Wagner, D.P.; Montague, D.F.; Rooney, J.J.; Fussell, J.B.; Baker, L.S.

1982-06-01

This report describes a computer program package that aids in assessing the impact of floods on risk from nuclear power plants. The package consists of two distinct computer programs: ESP and NOAH. The ESP program improves the efficiency of a flood analysis by screening accident sequences and identifying accident sequences that are potentially significant contributors to risk in the event of a flood. Input to ESP includes accident sequences from an existing risk assessment and flood screening criteria. The NOAH program provides detailed qualitative analysis of the plant systems identified by ESP. NOAH performs a qualitative flood simulation of the fault tree

The application of CFD to hydrogen risk analysis in nuclear power plants

International Nuclear Information System (INIS)

Wang Hui; Han Xu; Chang Meng; Wang Xiaofeng; Wang Shuguo; Lu Xinhua; Wu Lin

2013-01-01

Status of the hydrogen risk analysis method is systemically summarized in this paper and the advantages and limits of CFD (Computational Fluid Dynamic) in hydrogen risk analysis is discussed. The international experimental programs on the CFD hydrogen risk analysis are introduced in this paper. The application of CFD to nuclear power plant (NPP) hydrogen risk analysis is introduced in detail by taking EPR and Ling'ao NPP for example. In these bases, the CFD development prospect of hydrogen risk analysis is also summarized in this paper. (authors)

The risk of storing radioactive wastes from nuclear power plants

International Nuclear Information System (INIS)

Gruemm, H.

1976-09-01

Serious bottle-necks exist in the nuclear fuel cycle and will continue for the next decade. A total of 800 nuclear reactors are now in operation. 153 nuclear power plants represent an installed capacity of 70 GVe. Until 1985 five hundred nuclear power plants will be in operation from which up to this date 53.000 t uranium will have been discharged. Part of this will have to be reprocessed. Associated with the above mentioned amount are 500 t plutonium and 1.500 t highly radioactive wastes. Two risks for the population have to be considered: firstly, the effect of small amounts of radioactive substances released during normal operation of nuclear power plants (the annual dose is about 1 mrem per person). Secondly, the possibility of the release of great amounts of radioactivity during heavy accidents (the probability for which is extremely small). A series of feasible possibilities for conditioning are shown. Firstly, the wastes are packed in substances which are insoluble in water. Secondly, for low and medium wastes these can be mixed with concrete or bitumen and filled into stable containers. Thirdly, the wastes could also be solidified. Fourthly, the wastes could be enclosed in small glass spheres which are embedded in a metal matrix. (H.G.)

Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report

International Nuclear Information System (INIS)

2000-01-01

OAK B188 Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report. The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-formed approach for the design and regulation of nuclear power plants. This approach will include the development and/or confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRS) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go further by focusing on the design of new plants

Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-08-01

OAK B188 Risk-informed assessment of regulatory and design requirements for future nuclear power plants. Annual report. The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-formed approach for the design and regulation of nuclear power plants. This approach will include the development and/or confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRS) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go further by focusing on the design of new plants.

Thermal power plants and environment

International Nuclear Information System (INIS)

1997-01-01

Recent versions of the air quality models which are reviewed and approved from the Environmental Protection Agency (EPA) are analysed in favour of their application in simple and complex terrain, different meteorological conditions and modifications in the sources of pollutant emissions. Improvement of the standard methods for analysis of the risks affecting the environment from different energy sources has been carried out. The application of the newly introduced model enabled (lead to performing) risk analysis of the coal power plants compared to other types of energy sources. Detailed investigation of the risk assessment and perception from coal power plants, has been performed and applied to the Macedonian coal power plants. Introducing the concept of 'psychological pollution', a modification of the standard models and programs for risk assessment from various energy sources has been suggested (proposed). The model has been applied to REK Bitola, where statistically relevant differences in relation to the control groups have been obtained. (Original)

Severe accident risks: An assessment for five US nuclear power plants

International Nuclear Information System (INIS)

1991-01-01

This report summarizes an assessment of the risks from severe accidents in five commercial nuclear power plants in the United State. These risks are measured in a number of ways, including: the estimated frequencies of core damage accidents from internally initiated accidents and externally initiated accidents for two of the plants; the performance of containment structures under severe accident loadings; the potential magnitude of radionuclide releases and offsite consequences of such accidents; and the overall risk (the product of accident frequencies and consequences). Supporting this summary report are a large number of reports written under contract to NRC that provide the detailed discussion of the methods used and results obtained in these risk studies. This report, Volume 3, contains two appendices. Appendix D summarizes comments received, and staff responses, on the first (February 1987) draft of NUREG-1150. Appendix E provides a similar summary of comments and responses, but for the second (June 1989) version of the report

Wind power plant system services

DEFF Research Database (Denmark)

Basit, Abdul; Altin, Müfit

Traditionally, conventional power plants have the task to support the power system, by supplying power balancing services. These services are required by the power system operators in order to secure a safe and reliable operation of the power system. However, as in the future the wind power...... is going more and more to replace conventional power plants, the sources of conventional reserve available to the system will be reduced and fewer conventional plants will be available on-line to share the regulation burden. The reliable operation of highly wind power integrated power system might...... then beat risk unless the wind power plants (WPPs) are able to support and participate in power balancing services. The objective of this PhD project is to develop and analyse control strategies which can increase the WPPs capability to provide system services, such as active power balancing control...

Methodology for flood risk analysis for nuclear power plants

International Nuclear Information System (INIS)

Wagner, D.P.; Casada, M.L.; Fussell, J.B.

1984-01-01

The methodology for flood risk analysis described here addresses the effects of a flood on nuclear power plant safety systems. Combining the results of this method with the probability of a flood allows the effects of flooding to be included in a probabilistic risk assessment. The five-step methodology includes accident sequence screening to focus the detailed analysis efforts on the accident sequences that are significantly affected by a flood event. The quantitative results include the flood's contribution to system failure probability, accident sequence occurrence frequency and consequence category occurrence frequency. The analysis can be added to existing risk assessments without a significant loss in efficiency. The results of two example applications show the usefulness of the methodology. Both examples rely on the Reactor Safety Study for the required risk assessment inputs and present changes in the Reactor Safety Study results as a function of flood probability

Risk analysis of geothermal power plants using Failure Modes and Effects Analysis (FMEA) technique

International Nuclear Information System (INIS)

Feili, Hamid Reza; Akar, Navid; Lotfizadeh, Hossein; Bairampour, Mohammad; Nasiri, Sina

2013-01-01

Highlights: • Using Failure Modes and Effects Analysis (FMEA) to find potential failures in geothermal power plants. • We considered 5 major parts of geothermal power plants for risk analysis. • Risk Priority Number (RPN) is calculated for all failure modes. • Corrective actions are recommended to eliminate or decrease the risk of failure modes. - Abstract: Renewable energy plays a key role in the transition toward a low carbon economy and the provision of a secure supply of energy. Geothermal energy is a versatile source as a form of renewable energy that meets popular demand. Since some Geothermal Power Plants (GPPs) face various failures, the requirement of a technique for team engineering to eliminate or decrease potential failures is considerable. Because no specific published record of considering an FMEA applied to GPPs with common failure modes have been found already, in this paper, the utilization of Failure Modes and Effects Analysis (FMEA) as a convenient technique for determining, classifying and analyzing common failures in typical GPPs is considered. As a result, an appropriate risk scoring of occurrence, detection and severity of failure modes and computing the Risk Priority Number (RPN) for detecting high potential failures is achieved. In order to expedite accuracy and ability to analyze the process, XFMEA software is utilized. Moreover, 5 major parts of a GPP is studied to propose a suitable approach for developing GPPs and increasing reliability by recommending corrective actions for each failure mode

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

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

International Nuclear Information System (INIS)

2014-03-01

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

Current perspectives on nuclear power plant risks and the use of risk-based information in regulation

Energy Technology Data Exchange (ETDEWEB)

Ross, D F; Ernst, M L; Murphy, J

1987-08-01

For the first five years, the U.S. Nuclear Regulatory Commission has supported extensive studies of severe accidents. One outcome of this work is a set of advanced method for analyzing the probabilities, source terms, consequences, and risks of such accidents. These methods are being applied to a set of six U.S. commercial nuclear power plants, covering a wide spread of nuclear steam supply systems and containment designs. This work is to be documented in the Reactor Risk Reference Document, NUREG-1150, and supporting contractors reports. The methods being used for NUREG-1150, and some initial plant results, are briefly described in this paper.

RIMAP demonstration project. Pat. 1: Risk based life management of piping system in power plant Heilbronn

International Nuclear Information System (INIS)

Bareiss, J.; Puck, P.; Matschecko, B.; Jovanovic, A.; Balos, D.; Perunicic

2003-01-01

In the framework of EU project RIMAP [1] a new European Guideline for optimized risk based maintenance and inspection planning of industrial plants (RBLM - Risk Based Life Management) is being developed. The RIMAP project consists of the three clustered projects: development (RTD), demonstration (DEMO) and thematic network (TN). Current work and future, planned work in RIMAP demonstration project on applications of the RIMAP methodology in power plants are presented briefly in the first part of the paper. Also presented in the paper are the results of a preliminary analysis of piping system in power plant Heilbronn using the concept of risk-based monitoring as part of overall concept of risk-based life management. Shortly the following issues are discussed in the paper: identification of critical components, application of a multilevel risk analysis (..from ''screening'' to ''detailed analysis''), determination of PoF - Probability of Failure, determination of COF - Consequence of Failure and optimation of inspection and maintenance plan. (orig.)

Nuclear power plants in populated areas

International Nuclear Information System (INIS)

Wachsmann, F.

1973-01-01

The article first deals with the permanently increasing demand for electical power. Considering the ever growing energy demand which can no longer be covered by conventional power plants, it has become necessary to set up nuclear power plants of larger range. The author presents in a survey the basic function of nuclear power plants as well as the resulting risks and safety measures. The author concludes that according to present knowledge there is no more need to erect nuclear power plants outside densely populated urban areas but there is now the possibility of erecting nuclear power plants in densely populated areas. (orig./LH) [de

Review of problems and methods for radiation risk assessment in the environment of a nuclear power plant

International Nuclear Information System (INIS)

Grgic, M.

1966-01-01

Radiation impact on the nuclear power plant environment is a very important problem which has to be solved during design and construction. Damage that could be caused by release of radioactive material into the environment should be estimated and the magnitude of nuclear and radiation risk of the power plant should be evaluated. In general the accuracy of estimation is rather poor due to statistical fluctuations of the conditions which influence radioactivity expansion in the environment, especially in the air. Different uncertainties and unresolved problems influence the inaccuracy. Since any real risk should be extremely small compared to potential risk i.e. risk induced by nuclear power plant without any safety measures, even inaccurate estimations are very useful. Method for environmental radiation risk assessment is based on relatively simple models of radiation expansion in the environment and in the air. These models are theoretically solved but they are based on relatively limited number of experimental data. Assessment of the radiation effects on the population health and mortality is an important problem [sl

Risk-averse formulations and methods for a virtual power plant

KAUST Repository

Lima, Ricardo M.; Conejo, Antonio J.; Langodan, Sabique; Hoteit, Ibrahim; Knio, Omar M.

2017-01-01

In this paper we address the optimal operation of a virtual power plant using stochastic programming. We consider one risk-neutral and two risk-averse formulations that rely on the conditional value at risk. To handle large-scale problems, we implement two decomposition methods with variants using single- and multiple-cuts. We propose the utilization of wind ensembles obtained from the European Centre for Medium Range Weather Forecasts (ECMWF) to quantify the uncertainty of the wind forecast. We present detailed results relative to the computational performance of the risk-averse formulations, the decomposition methods, and risk management and sensitivities analysis as a function of the number of scenarios and risk parameters. The implementation of the two decomposition methods relies on the parallel solution of subproblems, which turns out to be paramount for computational efficiency. The results show that one of the two decomposition methods is the most efficient.

Risk-averse formulations and methods for a virtual power plant

KAUST Repository

Lima, Ricardo M.

2017-12-15

In this paper we address the optimal operation of a virtual power plant using stochastic programming. We consider one risk-neutral and two risk-averse formulations that rely on the conditional value at risk. To handle large-scale problems, we implement two decomposition methods with variants using single- and multiple-cuts. We propose the utilization of wind ensembles obtained from the European Centre for Medium Range Weather Forecasts (ECMWF) to quantify the uncertainty of the wind forecast. We present detailed results relative to the computational performance of the risk-averse formulations, the decomposition methods, and risk management and sensitivities analysis as a function of the number of scenarios and risk parameters. The implementation of the two decomposition methods relies on the parallel solution of subproblems, which turns out to be paramount for computational efficiency. The results show that one of the two decomposition methods is the most efficient.

Nuclear power plant insurance - experience and loss statistics

International Nuclear Information System (INIS)

Feldmann, J.; Dangelmaier, P.

1982-01-01

Nuclear power plants are treated separately when concluding insurance contracts. National insurance pools have been established in industrial countries, co-operating on an international basis, for insuring a nuclear power plant. In combined property insurance, the nuclear risk is combined with the fire risk. In addition, there are the engineering insurances. Of these, the one of significance for nuclear power plants is the machinery insurance, which can be covered on the free insurance market. Nuclear power plants have had fewer instances of damage than other, conventional installations. (orig.) [de

The role of insurance and risk management in new power plant projects

International Nuclear Information System (INIS)

Ryan, R.

1988-01-01

Insurance, and other risk management techniques, can be used to facilitate the financing and construction of power plant projects. This paper describes certain techniques, then it concentrates on insurance based solutions. The objective of this paper is to point out how the insurance industry can help small power producers. First, the standard insurance coverages will be reviewed. Then coverages that have been specifically designed for the alternative energy, cogeneration and small power producing industries will be explained. Some real life examples will be discussed to show how the coverages really work

An application of risk-informed evaluation on MOVs and AOVs for Taiwan BWR-type nuclear power plants

International Nuclear Information System (INIS)

Ting, K.; Chen, K.T.; Li, Y.C.; Hwang, S.H.; Chien, F.T.; Kang, J.C.

2008-01-01

Implementing a risk-informed inservice testing (RI-IST) program provides a good aspect to the nuclear power plant licensee as an alternating program in the current ASME Section XI and 10 CFR 50.55a relevant testing programs. RI-IST concentrates testing resources on highly significant components, reduces excess testing burden, increases plant's availability, decreases dose rate on the plant's staff and also reduces cost on plant's operation and maintenance under nuclear safety expectations. Furthermore, RI-IST also gives a feature on prospective licensing change basis to a nuclear power plant's licensee. This study will focus on safety-related and PRA-molded motor-operated valves (MOVs) and air-operated valves (AOVs) under the inservice testing program in boiling water reactor (BWR)-type nuclear power plant. As MOVs and AOVs have crucial safety functions throughout the nuclear power plant's safety systems, the steady operation and performance of MOVs and AOVs will definitely ensure that the nuclear power plant operates under safety expectations; therefore, this is the key reason to implement risk-informed evaluation for MOVs and AOVs in this study and being able to provide the safety significance classification for MOVs and AOVs under the current IST program to the plant's management. As a pilot study of RI-IST, the methodology of qualitative assessment will incorporate with probabilistic risk assessment (PRA) analyzing MOVs' and AOVs' safety significance within the current PRA model. The evaluating result will then classify its safety significance into a high-safety significant component (HSSC) and a low-safety significant component (LSSC) for MOVs and AOVs based on relevant regulatory criteria. With this initiating achievement, it can provide a cornerstone for further studies on the other types of valves and pumps in RI-IST program and also provide a valuable reference as proposing license change to the licensee

Assessing Risk-Based Performance Indicators in Safety-Critical Systems for Nuclear Power Plants

OpenAIRE

TONT Gabriela

2011-01-01

The paper proposes framework for a multidisciplinary nuclear risk and safety assessment by modeling uncertainty and combining diverse evidence provided in such a way that it could be used to represent an entire argument about a system's dependability. The identified safety issues are being treated by means of probabilistic safety assessment (PSA). The behavior simulation of power plant in thepresence of risk factors is analyzed from the vulnerability, risk and functional safety viewpoints, hi...

Health Risk Assessment of Nitrogen Dioxide and Sulfur Dioxide Exposure from a New Developing Coal Power Plant in Thailand

Directory of Open Access Journals (Sweden)

Tin Thongthammachart

2017-07-01

Full Text Available Krabi coal-fired power plant is the new power plant development project of the Electricity Generating Authority of Thailand (EGAT. This 800 megawatts power plant is in developing process. The pollutants from coal-fired burning emissions were estimated and included in an environmental impact assessment report. This study aims to apply air quality modeling to predict nitrogen dioxide (NO2 and sulfur dioxide (SO2 concentration which could have health impact to local people. The health risk assessment was studied following U.S. EPA regulatory method. The hazard maps were created by ArcGIS program. The results indicated the influence of the northeast and southwest monsoons and season variation to the pollutants dispersion. The daily average and annual average concentrations of NO2 and SO2 were lower than the NAAQS standard. The hazard quotient (HQ of SO2 and NO2 both short-term and long-term exposure were less than 1. However, there were some possibly potential risk areas indicating in GIS based map. The distribution of pollutions and high HI values were near this power plant site. Although the power plant does not construct yet but the environment health risk assessment was evaluated to compare with future fully developed coal fire plant.

Benchmarking Nuclear Power Plants

International Nuclear Information System (INIS)

Jakic, I.

2016-01-01

One of the main tasks an owner have is to keep its business competitive on the market while delivering its product. Being owner of nuclear power plant bear the same (or even more complex and stern) responsibility due to safety risks and costs. In the past, nuclear power plant managements could (partly) ignore profit or it was simply expected and to some degree assured through the various regulatory processes governing electricity rate design. It is obvious now that, with the deregulation, utility privatization and competitive electricity market, key measure of success used at nuclear power plants must include traditional metrics of successful business (return on investment, earnings and revenue generation) as well as those of plant performance, safety and reliability. In order to analyze business performance of (specific) nuclear power plant, benchmarking, as one of the well-established concept and usual method was used. Domain was conservatively designed, with well-adjusted framework, but results have still limited application due to many differences, gaps and uncertainties. (author).

Effect of the Fukushima nuclear accident on the risk perception of residents near a nuclear power plant in China.

Science.gov (United States)

Huang, Lei; Zhou, Ying; Han, Yuting; Hammitt, James K; Bi, Jun; Liu, Yang

2013-12-03

We assessed the influence of the Fukushima nuclear accident (FNA) on the Chinese public's attitude and acceptance of nuclear power plants in China. Two surveys (before and after the FNA) were administered to separate subsamples of residents near the Tianwan nuclear power plant in Lianyungang, China. A structural equation model was constructed to describe the public acceptance of nuclear power and four risk perception factors: knowledge, perceived risk, benefit, and trust. Regression analysis was conducted to estimate the relationship between acceptance of nuclear power and the risk perception factors while controlling for demographic variables. Meanwhile, we assessed the median public acceptable frequencies for three levels of nuclear events. The FNA had a significant impact on risk perception of the Chinese public, especially on the factor of perceived risk, which increased from limited risk to great risk. Public acceptance of nuclear power decreased significantly after the FNA. The most sensitive groups include females, those not in public service, those with lower income, and those living close to the Tianwan nuclear power plant. Fifty percent of the survey respondents considered it acceptable to have a nuclear anomaly no more than once in 50 y. For nuclear incidents and serious incidents, the frequencies are once in 100 y and 150 y, respectively. The change in risk perception and acceptance may be attributed to the FNA. Decreased acceptance of nuclear power after the FNA among the Chinese public creates additional obstacles to further development of nuclear power in China and require effective communication strategies.

Cooperation of nuclear, thermal and hydroelectric power plants in the power system

International Nuclear Information System (INIS)

1984-01-01

The conference heard 36 papers of which 23 were incorporated in INIS. The subjects discussed were: the development of power industry in Czechoslovakia, methods of statistical analysis of data regarding nuclear power plant operation, the incorporation of WWER nuclear power plants in the power supply system, the standardization of nuclear power plants, the service life of components, use of nuclear energy sources, performance of the reactor accident protection system, the use of nuclear power and heating plants in Hungary, risk analysis, optimization of nuclear power plants, accidents caused by leakage of the primary and secondary circuit. (J.P.)

Survey on the use of configuration risk and safety management tools at nuclear power plants. Final report

International Nuclear Information System (INIS)

Fleming, K.N.; Read, J.W.; Dagan, W.J.; Bidwell, D.A.

1998-09-01

In order to provide input to Electricite de France's (EDF) evaluation of the use of configuration safety and risk management tools in the French plants and to collect information to guide the EPRI efforts to provide useful tools for the EPRI member utilities and international partners, a joint effort to survey US and selected non-US nuclear power stations was conducted. This survey examined the use of various approaches, techniques, and software tools that are being used to evaluate the safety and risk aspects of plant configuration changes and configuration changes during plant outages as well as during power operation. The use of these tools has increased in recent years as a result of efforts to optimize plant maintenance programs, improve plant safety, and increase plant reliability and availability. This report provides the results of the survey of 37 organizations covering 54 nuclear plant sites and 97 reactor units

Alternative off-site power supply improves nuclear power plant safety

International Nuclear Information System (INIS)

Gjorgiev, Blaže; Volkanovski, Andrija; Kančev, Duško; Čepin, Marko

2014-01-01

Highlights: • Additional power supply for mitigation of the station blackout event in NPP is used. • A hydro power plant is considered as an off-site alternative power supply. • An upgrade of the probabilistic safety assessment from its traditional use is made. • The obtained results show improvement of nuclear power plant safety. - Abstract: A reliable power system is important for safe operation of the nuclear power plants. The station blackout event is of great importance for nuclear power plant safety. This event is caused by the loss of all alternating current power supply to the safety and non-safety buses of the nuclear power plant. In this study an independent electrical connection between a pumped-storage hydro power plant and a nuclear power plant is assumed as a standpoint for safety and reliability analysis. The pumped-storage hydro power plant is considered as an alternative power supply. The connection with conventional accumulation type of hydro power plant is analysed in addition. The objective of this paper is to investigate the improvement of nuclear power plant safety resulting from the consideration of the alternative power supplies. The safety of the nuclear power plant is analysed through the core damage frequency, a risk measure assess by the probabilistic safety assessment. The presented method upgrades the probabilistic safety assessment from its common traditional use in sense that it considers non-plant sited systems. The obtained results show significant decrease of the core damage frequency, indicating improvement of nuclear safety if hydro power plant is introduced as an alternative off-site power source

Identification of seismically risk-sensitive systems and components in nuclear power plants: feasibility study

International Nuclear Information System (INIS)

Azarm, M.; Boccio, J.; Farahzad, P.

1983-06-01

An approach for the identification of risk-sensitive components in a nuclear power plant during and after a seismic event is described. Application of the methodology to two hypothetical power plants - a Boiling Water Reactor and a Pressurized Water Reactor - are presented and the results are given in tabular and graphical form. Conclusions drawn and lessons learned through the course of this study, based on the relative importance of various accident scenarios and sensitivity analyses, are discussed. In addition, the areas that may need further investigation are identified

Risks of potential accidents of nuclear power plants in Europe

NARCIS (Netherlands)

Slaper H; Eggink GJ; Blaauboer RO

1993-01-01

Over 200 nuclear power plants for commercial electricity production are presently operational in Europe. The 1986 accident with the nuclear power plant in Chernobyl has shown that severe accidents with a nuclear power plant can lead to a large scale contamination of Europe. This report is focussed

Possibilities of Utilization the Risk – Based Techniques in the Field of Offshore Wind Power Plants

Directory of Open Access Journals (Sweden)

Przemysław Kacprzak

2014-09-01

Full Text Available In the article the risk-based concept that may be applicable to offshore wind power plants has been presented. The aim of the concept is to aid designers in the early design and retrofit phases of the project in case of lack or insufficient information in relevant international standards. Moreover the initial classification of components within main system parts of offshore wind power plant has been performed. Such classification is essential in order to apply risk-based concept. However further scientific researches need to be performed in that field to develop detailed concept useful for future practical applications.

Perceived nuclear risk, organizational commitment, and appraisals of management: A study of nuclear power plant personnel

International Nuclear Information System (INIS)

Kivimaeki, M.; Kalimo, R.; Salminen, S.

1995-01-01

This study examined to what extent nuclear risk perceptions, organizational commitment (OC), and appraisals of management are associated with each other among nuclear power plant personnel. The sample consisted of 428 nuclear power plant workers who completed a questionnaire at their workplace. Perceived nuclear risk and OC were most closely related to the appraisals of the top management of the organization. As the trust in and satisfaction with the top management increased, perceived nuclear safety and acceptance of the organizational goals and values heightened. This result is discussed in the context of industrial safety management. 29 refs., 2 tabs

Circumstances in a nuclear power plant. Organization of risk and institutionalization of safety

International Nuclear Information System (INIS)

Wessblad, H.

1999-01-01

Risk societies are made of risk organisations. This dissertation is an ethnographic study of a risk organisation, of a nuclear power plant. Risk organizations have larger demands on their organization than traditional companies have. Risk societies, to come or already present, have new political agendas. Within a risk society the major task is to reduce and distribute the negative side effects of industrial production, not to increase and distribute well-fare in society, as it has been in an industrial society. This is a study of a risk organisation claimed to produce these negative side effects. The title of this thesis relates to specific occasions in the organisation. The branch concept, circumstances, defines 'situations beyond normal performance', which are to be reported to the nuclear authorities. These circumstances are rarely endangering man or material, but given the nature of nuclear power production, they have a potential to escalate to something larger. This dissertation focuses on how the organisation deals with these issues and reproduces safety as something taken-for-granted. The material is gathered using participant observation of different functions in the plant. The work is based on narration of situations, meetings, interviews, and small talk etc, in every-day-interaction. The dissertation describes how business-as-usual produce safety. It is a description of how values, norms, attitudes, ideas, knowledge are produced and reproduced. These issues are discussed mainly in an institutional theory perspective. What has become apparent is that functions governed by routines and instructions tend to be more flexible and reflecting than those dealing with new tasks, such as problem solving projects. Thus, these new projects tend to reproduce earlier established procedures. Through the narration of the various functions of the plant joined with theoretical discussions, different themes have been found describing how the organisation deals with

Environmental risk assessment of airborne emission from chinese coal-fired power plants with public health detriment criteria

International Nuclear Information System (INIS)

He Huimin; Pan Ziqiang; Zhang Yongxing; Xia Yihua

1997-01-01

On the basis of investigation of types of dust removers and their efficiency in Chinese coal-fired power plants, human health detriment of airborne non-radioactive and radioactive emissions from the power plants is assessed with public health detriment assessment method. The results show that the risk is primarily from airborne non-radioactive emission

Risk-based analysis methods applied to nuclear power plant technical specifications

International Nuclear Information System (INIS)

Wagner, D.P.; Minton, L.A.; Gaertner, J.P.

1989-01-01

A computer-aided methodology and practical applications of risk-based evaluation of technical specifications are described. The methodology, developed for use by the utility industry, is a part of the overall process of improving nuclear power plant technical specifications. The SOCRATES computer program uses the results of a probabilistic risk assessment or a system-level risk analysis to calculate changes in risk due to changes in the surveillance test interval and/or the allowed outage time stated in the technical specification. The computer program can accommodate various testing strategies (such as staggered or simultaneous testing) to allow modeling of component testing as it is carried out at the plant. The methods and computer program are an integral part of a larger decision process aimed at determining benefits from technical specification changes. These benefits can include cost savings to the utilities by reducing forced shutdowns and decreasing labor requirements for test and maintenance activities, with no adverse impacts on risk. The methodology and the SOCRATES computer program have been used extensively toe valuate several actual technical specifications in case studies demonstrating the methods. Summaries of these applications demonstrate the types of results achieved and the usefulness of the risk-based evaluation in improving the technical specifications

PCB transformer fires: the risk in nuclear power plants

International Nuclear Information System (INIS)

Blackmon, K.

1988-01-01

It is estimated that 1/2 of the present nuclear power plants operate with PCB-filled transformer equipment. In an attempt to obtain better estimates of clean-up costs in a nuclear power plant under reasonable-loss scenarios, a study was commissioned. This study was a joint venture between Blackmon-Mooring Steamatic Technologies, Inc., (BMS-TECH) and M and M Protection Consultants. This joint study was conducted at a typical pressurized-water reactor plant consisting of two 1000-MW units. Three specific scenarios were selected and analyzed for this typical power plant. These scenarios were: (1) an electrical failure of a transformer in an isolated switch gear room; (2) a transformer exposed to a 55-gallon transient combustion oil fire in the auxiliary building; and (3) a PCB transformer involved in a major turbine lube fire in the turbine building. Based on results of this study, the insurance carriers for this industry implemented an adjustment in their rate structures for nuclear power plants that have PCB equipment

The control of operational risk in nuclear power plant operations - Some cross-cultural perspectives

International Nuclear Information System (INIS)

Suchard, A.; Rochlin, G.

1992-01-01

The operation of nuclear power plants requires the management of a complex technology under exacting performance and safety criteria. Organizations operating nuclear power plants are faced with the challenge of simultaneously meeting technical, organizational, and social demands, striving toward perfection in a situation where learning by trial and error can be too costly. In this process, they interact with regulatory bodies who seek to help minimize operational risk by imposing and upholding safety standards. The character of this interaction differs in various countries, as does the larger cultural setting. The study generally pursued the question of how organizations operating complex and demanding technologies adapt to such requirements and circumstances, and how they can succeed in delivering nearly error-free performance. One aspect of this study includes the comparison of organizational and cultural environments for nuclear power plant operations in the US, France, Germany, Sweden, and Switzerland. The research involved in-depth, continuous observations on location and interviews with plant personnel, especially control operators, at one plant in each country

A cyber security risk assessment for the design of I and C system in nuclear power plants

International Nuclear Information System (INIS)

Song, Jae Gu; Lee, Jung Woon; Lee, Cheal Kwon; Kwon, Kee Choon; Lee, Dong Young

2012-01-01

The applications of computers and communication system and network technologies in nuclear power plants have expanded recently. This application of digital technologies to the instrumentation and control systems of nuclear power plants brings with it the cyber security concerns similar to other critical infrastructures. Cyber security risk assessments for digital instrumentation and control systems have become more crucial in the development of new systems and in the operation of existing systems. Although the instrumentation and control systems of nuclear power plants are similar to industrial control systems, the former have specifications that differ from the latter in terms of architecture and function, in order to satisfy nuclear safety requirements, which need different methods for the application of cyber security risk assessment. In this paper, the characteristics of nuclear power plant instrumentation and control systems are described, and the considerations needed when conducting cyber security risk assessments in accordance with the life cycle process of instrumentation and control systems are discussed. For cyber security risk assessments of instrumentation and control systems, the activities and considerations necessary for assessments during the system design phase or component design and equipment supply phase are presented in the following 6 steps: 1) System Identification and Cyber Security Modeling, 2) Asset and Impact Analysis, 3) Threat Analysis, 4) Vulnerability Analysis, 5) Security Control Design, and 6) Penetration test. The results from an application of the method to a digital reactor protection system are described.

A cyber security risk assessment for the design of I and C system in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Song, Jae Gu; Lee, Jung Woon; Lee, Cheal Kwon; Kwon, Kee Choon; Lee, Dong Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-12-15

The applications of computers and communication system and network technologies in nuclear power plants have expanded recently. This application of digital technologies to the instrumentation and control systems of nuclear power plants brings with it the cyber security concerns similar to other critical infrastructures. Cyber security risk assessments for digital instrumentation and control systems have become more crucial in the development of new systems and in the operation of existing systems. Although the instrumentation and control systems of nuclear power plants are similar to industrial control systems, the former have specifications that differ from the latter in terms of architecture and function, in order to satisfy nuclear safety requirements, which need different methods for the application of cyber security risk assessment. In this paper, the characteristics of nuclear power plant instrumentation and control systems are described, and the considerations needed when conducting cyber security risk assessments in accordance with the life cycle process of instrumentation and control systems are discussed. For cyber security risk assessments of instrumentation and control systems, the activities and considerations necessary for assessments during the system design phase or component design and equipment supply phase are presented in the following 6 steps: 1) System Identification and Cyber Security Modeling, 2) Asset and Impact Analysis, 3) Threat Analysis, 4) Vulnerability Analysis, 5) Security Control Design, and 6) Penetration test. The results from an application of the method to a digital reactor protection system are described.

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

International Nuclear Information System (INIS)

Ellingwood, B.; Song, J.

1996-03-01

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

Protection of French nuclear power plants against flooding risks - 15307

International Nuclear Information System (INIS)

Barbaud, J.

2015-01-01

In France, the flooding risk has been taken into account since the beginning of the nuclear program and has been reinforced following operating feedback from French and international power plants. The main events which led to reinforcement were the partial flooding in the Blayais NPP that occurred in 1999 and the Fukushima accident in 2011. The current French fleet is composed of 58 PWR reactors located on 19 sites: 4 sites are sea side, 1 side is located on an estuary and all other are located on river side. The lessons learned from the Blayais event are: -) an update of the hazard evaluation of the risks, -) a new assessment of the sufficiency of the protective measures, and -) the taking into account of aggravating risks associated to support functions such as site inaccessibility, loss of off-site power, etc. The lessons learned from the Fukushima accident have confirmed and enhanced lessons from the Blayais event. In addition the Fukushima accident has underlined the need to have sufficient margins beyond the design to avoid cliff edge effects. The improvements implemented on the Blayais and the Belleville sites are detailed

Affective imagery and acceptance of replacing nuclear power plants.

Science.gov (United States)

Keller, Carmen; Visschers, Vivianne; Siegrist, Michael

2012-03-01

This study examined the relationship between the content of spontaneous associations with nuclear power plants and the acceptance of using new-generation nuclear power plants to replace old ones. The study also considered gender as a variable. A representative sample of the German- and French-speaking population of Switzerland (N= 1,221) was used. Log-linear models revealed significant two-way interactions between the association content and acceptance, association content and gender, and gender and acceptance. Correspondence analysis revealed that participants who were opposed to nuclear power plants mainly associated nuclear power plants with risk, negative feelings, accidents, radioactivity, waste disposal, military use, and negative consequences for health and environment; whereas participants favoring nuclear power plants mainly associated them with energy, appearance descriptions of nuclear power plants, and necessity. Thus, individuals opposing nuclear power plants had both more concrete and more diverse associations with them than people who were in favor of nuclear power plants. In addition, participants who were undecided often mentioned similar associations to those participants who were in favor. Males more often expressed associations with energy, waste disposal, and negative health effects. Females more often made associations with appearance descriptions, negative feelings, and negative environmental effects. The results further suggest that acceptance of replacing nuclear power plants was higher in the German-speaking part of the country, where all of the Swiss nuclear power plants are physically located. Practical implications for risk communication are discussed. © 2011 Society for Risk Analysis.

Computer codes to assess risks from nuclear power plants with LWR's

International Nuclear Information System (INIS)

Alonso, A.; Blanco, J.; Francia, L.; Gallego, E.; Morales, L.; Ortega, P.; Torres, C.

1986-01-01

The codes used to quantify risks from nuclear power plants are described. For QRA level 1 (quantitative risk assessment) qualitative and quantitative codes are described. Codes to estimate uncertainties, importance and dependent failures are also included. For QRA-level 2, the most important codes dealing with thermohydraulics, molten core and aerosols behaviour are described. For QRA-level 3 the list includes integrated as well as separate models. Only light water reactors are considered. The presentation is general but the authors describe with more detail those codes they are more familiar with or the ones they have created through their research effort. (author)

Destructiveness criteria for seismic risk evaluation of nuclear power plant

International Nuclear Information System (INIS)

Saragoni, G.R.

1995-01-01

Two criteria of destructiveness for seismic risk evaluation of nuclear power plant are presented. The first one is a simple linear criterion that allows to compute average response spectra in terms of earthquake accelerogram characteristics. The second defines the destructiveness potential factor P D which measures the capacity of earthquake to produce nonlinear damage. This second criterion that shows large differences of destructiveness capacity for earthquake accelerograms of different seismic environment, specially between subductive and transcursive, is strongly recommended. (author). 8 refs., 1 fig. 1 tab

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...

Risk-based management of remaining life of power plant components

International Nuclear Information System (INIS)

Roos, E.; Jovanovic, A.S.; Maile, K.; Auerkari, P.

1999-01-01

The paper describes application of different modules of the MPA-System ALIAS in risk-based management of remaining life of power plant components. The system allows comprehensive coverage of all aspects of the remaining life management, including also the risk analysis and risk management. In addition, thanks to the modular character of the system it is also possible to implement new methods: In the case described here, a new (probabilistic) method for determination of the next inspection time for the components exposed to creep loading has been developed and implemented in the system. Practical application of the method has shown (a) that the mean values obtained by the method fall into the range of results obtained by other methods (based on expert knowledge), and (b) that it is possible to quantify the probability of aberration from the mean values. This in turn allows quantifying the additional risks linked to e.g. prolonging of inspection intervals. (orig.) [de

Nuclear power plants in post-war thought

International Nuclear Information System (INIS)

Toya, Hiroshi

2015-01-01

This paper overviews how nuclear power plants have been talked about in the post-war thought. Science and technology sometimes significantly change the thinking way of humans, and nuclear power generation is an extreme technology. This paper overviews how nuclear power plants and humans are correlated. The following three points are discussed as the major issues of contemporary thought over nuclear power plants. First, on the danger of nuclear power plants, the risk of destructive power that nuclear energy has, and the danger of unreasoning development in science and technology civilization are discussed. Second, on the ethics issues surrounding nuclear power plants, the ethics that are based on unbalanced power relations, and democratic responsibility ethics based on discussion ethics are discussed. Third, on the issues of nuclear power plants and imagination, the limitations of democratic discussion surrounding nuclear power plants, the formation of imagination commensurate with the destructive power of nuclear power plants, and the formation of imagination that can represent the distant future are discussed. (A.O.)

Cost-benefit and risk-benefit assessment for nuclear power plants

International Nuclear Information System (INIS)

Eichholz, G.G.

1976-01-01

A cost benefit assessment is an essential part of the Environmental Impact Statement submitted as part of the licensing considerations for a nuclear facility. Such an assessment forms part of the initial decision to build a nuclear facility, enters critically into the selection of a suitable site, and ultimately forms part of the design procedures to optimize engineering solutions to deal with waste-heat dissipation, treatment methods for radioactive effluent control, and land and site use. Whereas the initial decision usually can be made in purely economic terms, the latter stages involve environmental and social issues that are not readily quantified and involve a qualitative judgment of what constitutes the least, readily achievable impact. The radiological impact of the plant on the surrounding population from the release of low-level effluents can be quantified and treated as a financial ''cost.'' Alternatively it can be treated as a ''risk'' and related to other risks modern man is subjected to and can be used as a means to establish site boundaries. Both cost-benefit and risk-benefit analyses represent essentially optimization approaches to the problem of making nuclear power plants economically competitive, socially and politically acceptable, and as safe or innocuous as one can reasonably make them

Calculation of risk-based detection limits for radionuclides in the liquid effluents from Korean nuclear power plants

International Nuclear Information System (INIS)

Cheong, Jae Hak

2017-01-01

In order to review if present detection limits of radionuclides in liquid effluent from nuclear power plants are effective enough to warrant compliance with regulatory discharge limits, a risk-based approach is developed to derive a new detection limit for each radionuclide based on radiological criteria. Equations and adjustment factors are also proposed to discriminate the validity of the detection limits for multiple radionuclides in the liquid effluent with or without consideration of the nuclide composition. From case studies to three nuclear power plants in Korea with actual operation data from 2006 to 2015, the present detection limits have turned out to be effective for Hanul Unit 1 but may not be sensitive enough for Kori Unit 1 (8 out of 14 radionuclides) and Wolsong Unit 1 (9 out of 42 radionuclides). However, it is shown that the present detection limits for the latter two nuclear power plants can be justified, if credit is given to the radionuclide composition. Otherwise, consideration should be given to adjustment of the present detection limits. The risk-based approach of this study can be used to determine the validity of established detection limits of a specific nuclear power plant. (author)

Development of safety culture by improving risk communication in a nuclear power plant

International Nuclear Information System (INIS)

Sugiman, Toshio; Yoshikawa, Hidekazu

2004-01-01

Safety culture is conceptually examined from the viewpoint of activity theory proposed by Engestroem. The theory is instrumental in broadening our scope of views to the extent that a particular (group of person(s) and his/her (their) environment are regarded as a part of activity of a larger collectivity consisting of people and their physical and institutional environments. Overwhelming orientation toward an unmanned plant is reflected in object → outcome and mediating artifacts in the structure of activity in a nuclear power plant while it is contradicted with another orientation toward the improvement of employee's ability in community, rules, and division of labor. Three possible ways to transform a currently dominant activity into a new form were suggested depending on a preliminary study of our research project headed by the seconds author. First, community of a nuclear power plant may as well be expanded to the extent that nuclear experts outside the plant, especially those working for a plant/equipment manufacturing company, can share information with workers inside the plant through internet system that has been developed in our project. Second, community of workplace may as well be reexamined concerning division of labor between a supervisor and subordinates. Among all, leader behaviors of a supervisor that were effective to reduce psychological stress of subordinates, which, in turn, make positive contribution to safety culture, were identified by a questionnaire survey. Last, a minority of workers who tend to take risks for radiation exposure more seriously than the majority and share similar risk cognition with ordinary citizens may as well be utilized as linking pin that brings a warning signal from both a minority of nuclear experts outside the plant and ordinary citizens to the majority of workers in the plant who tend to be devoted to implementing everyday job. (author)

Risks and challenges associated with the design and construction of a nuclear power plant

International Nuclear Information System (INIS)

Liebana Martinez, B.; Armas Garcia, A.; Martinez Gozalo, I.

2011-01-01

The construction of a nuclear power plant project, considering the period prior to the operation of the plant, requires a very strict risk control to ensure compliance with a series of challenges. The present paper identifying the most important challenges facing the construct ability and license requirements of the process, identifying the interfaces and proposing a methodology of construction to meet the challenge of a construction process in 5 years.

Fire Risk Scoping Study: Investigation of nuclear power plant fire risk, including previously unaddressed issues

International Nuclear Information System (INIS)

Lambright, J.A.; Nowlen, S.P.; Nicolette, V.F.; Bohn, M.P.

1989-01-01

An investigation of nuclear power plant fire risk issues raised as a result of the USNRC sponsored Fire Protection Research Program at Sandia National Laboratories has been performed. The specific objectives of this study were (1) to review and requantify fire risk scenarios from four fire probabilistic risk assessments (PRAs) in light of updated data bases made available as a result of USNRC sponsored Fire Protection Research Program and updated computer fire modeling capabilities, (2) to identify potentially significant fire risk issues that have not been previously addressed in a fire risk context and to quantify the potential impact of those identified fire risk issues where possible, and (3) to review current fire regulations and plant implementation practices for relevance to the identified unaddressed fire risk issues. In performance of the fire risk scenario requantifications several important insights were gained. It was found that utilization of a more extensive operational experience base resulted in both fire occurrence frequencies and fire duration times (i.e., time required for fire suppression) increasing significantly over those assumed in the original works. Additionally, some thermal damage threshold limits assumed in the original works were identified as being nonconservative based on more recent experimental data. Finally, application of the COMPBRN III fire growth model resulted in calculation of considerably longer fire damage times than those calculated in the original works using COMPBRN I. 14 refs., 2 figs., 16 tabs

The application of availability analysis to nuclear power plants

International Nuclear Information System (INIS)

Brooks, A.C.

1984-01-01

The use of probabilistic risk analysis (PRA) to assess the risks from nuclear power plants is now well established. Considerably less attention has been given so far to the use of availability analysis techniques. The economics of power generation are now such that with nuclear power currently supplying a substantial fraction of power in many countries, increasing attention is being paid to improving plant availability. This paper presents a technique for systematically identifying the areas in which measures to improve plant availability will be most effective. (author)

Safety Assessment - Swedish Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kjellstroem, B. [Luleaa Univ. of Technology (Sweden)

1996-12-31

After the reactor accident at Three Mile Island, the Swedish nuclear power plants were equipped with filtered venting of the containment. Several types of accidents can be identified where the filtered venting has no effect on the radioactive release. The probability for such accidents is hopefully very small. It is not possible however to estimate the probability accurately. Experiences gained in the last years, which have been documented in official reports from the Nuclear Power Inspectorate indicate that the probability for core melt accidents in Swedish reactors can be significantly larger than estimated earlier. A probability up to one in a thousand operating years can not be excluded. There are so far no indications that aging of the plants has contributed to an increased accident risk. Maintaining the safety level with aging nuclear power plants can however be expected to be increasingly difficult. It is concluded that the 12 Swedish plants remain a major threat for severe radioactive pollution of the Swedish environment despite measures taken since 1980 to improve their safety. Closing of the nuclear power plants is the only possibility to eliminate this threat. It is recommended that until this is done, quantitative safety goals, same for all Swedish plants, shall be defined and strictly enforced. It is also recommended that utilities distributing misleading information about nuclear power risks shall have their operating license withdrawn. 37 refs.

Safety Assessment - Swedish Nuclear Power Plants

International Nuclear Information System (INIS)

Kjellstroem, B.

1996-01-01

After the reactor accident at Three Mile Island, the Swedish nuclear power plants were equipped with filtered venting of the containment. Several types of accidents can be identified where the filtered venting has no effect on the radioactive release. The probability for such accidents is hopefully very small. It is not possible however to estimate the probability accurately. Experiences gained in the last years, which have been documented in official reports from the Nuclear Power Inspectorate indicate that the probability for core melt accidents in Swedish reactors can be significantly larger than estimated earlier. A probability up to one in a thousand operating years can not be excluded. There are so far no indications that aging of the plants has contributed to an increased accident risk. Maintaining the safety level with aging nuclear power plants can however be expected to be increasingly difficult. It is concluded that the 12 Swedish plants remain a major threat for severe radioactive pollution of the Swedish environment despite measures taken since 1980 to improve their safety. Closing of the nuclear power plants is the only possibility to eliminate this threat. It is recommended that until this is done, quantitative safety goals, same for all Swedish plants, shall be defined and strictly enforced. It is also recommended that utilities distributing misleading information about nuclear power risks shall have their operating license withdrawn. 37 refs

Probabilistic safety assessment technology for commercial nuclear power plant security evaluation

International Nuclear Information System (INIS)

Liming, J.K.; Johnson, D.H.; Dykes, A.A.

2004-01-01

Commercial nuclear power plant physical security has received much more intensive treatment and regulatory attention since September 11, 2001. In light of advancements made by the nuclear power industry in the field of probabilistic safety assessment (PSA) for its power plants over that last 30 years, and given the many examples of successful applications of risk-informed regulation at U. S. nuclear power plants during recent years, it may well be advisable to apply a 'risk-informed' approach to security management at nuclear power plants from now into the future. In fact, plant PSAs developed in response to NRC Generic Letter 88-20 and related requirements are used to help define target sets of critical plant safety equipment in our current security exercises for the industry. With reasonable refinements, plant PSAs can be used to identify, analyze, and evaluate reasonable and prudent approaches to address security issues and associated defensive strategies at nuclear power plants. PSA is the ultimate scenario-based approach to risk assessment, and thus provides a most powerful tool in identifying and evaluating potential risk management decisions. This paper provides a summary of observations of factors that are influencing or could influence cost-effective or 'cost-reasonable' security management decision-making in the current political environment, and provides recommendations for the application of PSA tools and techniques to the nuclear power plant operational safety response exercise process. The paper presents a proposed framework for nuclear power plant probabilistic terrorist risk assessment that applies these tools and techniques. (authors)

Hydrogen risk reduction in Nuclear power plant

International Nuclear Information System (INIS)

Movahed, M.A.; Travis, J.R.

1999-01-01

In case of a severe accident in a nuclear power plant with core melt and hydrogen production, the hydrogen risk is one of the main concerns. It may jeopardize the containment integrity due to violent deflagration that can lead to DDT (Deflagration Detonation Transient) or even detonation of proper hydrogen mitigation means are not available. The design of the EPR (European Pressurized water Reactor) Hydrogen mitigation and control system is based on the lumped parameter code WAVCO and the 3D code GASFLOW. The concept consists of recombiners and igniters to cope with all scenarios including those without steam. The system has been checked to avoid DDT by the 7λ criteria that's implemented in GASFLOW. Future analysis could deal with determining dynamic pressure loads, if appropriate, and some sensitivity studies to check the hydrogen control measures with respect to different source locations and mass flow rates. Also a conditional criterion for determining the likelihood of fast deflagration should be developed. (author)

Safety goals for commercial nuclear power plants

International Nuclear Information System (INIS)

Roe, J.W.

1988-01-01

In its official policy statement on safety goals for the operation of nuclear power plants, the Nuclear Regulatory Commission (NRC) set two qualitative goals, supported by two quantitative objectives. These goals are that (1) individual members of the public should be provided a level of protection from the consequences of nuclear power plant operation such that individuals bear no significant additional risk to life and health; and (2) societal risks to life and health from nuclear power plant operation should be comparable to or less than the risks of generating electricity by viable competing technologies and should not be a significant addition to other societal risks. As an alternative, this study proposes four quantitative safety goals for nuclear power plants. It begins with an analysis of the NRC's safety-goal development process, a key portion of which was devoted to delineating criteria for evaluating goal-development methods. Based on this analysis, recommendations for revision of the NRC's basic benchmarks for goal development are proposed. Using the revised criteria, NRC safety goals are evaluated, and the alternative safety goals are proposed. To further support these recommendations, both the NRC's goals and the proposed goals are compared with the results of three major probabilistic risk assessment studies. Finally, the potential impact of these recommendations on nuclear safety is described

Evaluation and communication of potential risk of radionuclide contamination of foods after Fukushima nuclear power plant accident

International Nuclear Information System (INIS)

Sekizawa, Jun; Nakamura, Yumiko

2011-01-01

A large scale nuclear power plant accident happened after the great earthquake with a huge tsunami in the Eastern part of Japan in March 2011. Potential risk from radionuclide contamination in foods after the nuclear power plant accident was estimated using data of radiological food contamination from the Ministry of Health, Labour and Welfare. Data analyzed by combining nuclide, food, level of radiation detection, period, age-classified population, were compared to provisional index levels of radionuclides, and existing contamination levels in food by natural radioactive potassium. Health risk was shown to be very low or negligible considering presence of background radiological exposure from foods and the environment. Appropriate explanation of risk to various stakeholders of the society is imperative and results of trials were reported. (author)

An Overview of Risk Quantification Issues for Digitalized Nuclear Power Plants using a Static Fault Tree

Energy Technology Data Exchange (ETDEWEB)

Kang, Hyun Gook; Kim, Man Cheol; Lee, Seung Jun; Lee, Ho Jung; Eom, Heung Seop; Chol, Jong Gyun; Jang, Seung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-08-15

Risk caused by safety-critical instrumentation and control (I and C) systems considerably affects overall plant risk. As digitalization of safety-critical systems in nuclear power plants progresses, a risk model of a digitalized safety system is required and must be included in a plant safety model in order to assess this risk effect on the plant. Unique features of a digital system cause some challenges in risk modeling. This article aims at providing an overview of the issues related to the development of a static fault-tree-based risk model. We categorize the complicated issues of digital system probabilistic risk assessment (PRA) into four groups based on their characteristics: hardware module issues, software issues, system issues, and safety function issues. Quantification of the effect of these issues dominates the quality of a developed risk model. Recent research activities for addressing various issues, such as the modeling framework of a software-based system, the software failure probability and the fault coverage of a self monitoring mechanism, are discussed. Although these issues are interrelated and affect each other, the categorized and systematic approach suggested here will provide a proper insight for analyzing risk from a digital system

Analysis of parameter uncertainties in the assessment of seismic risk for nuclear power plants

International Nuclear Information System (INIS)

Yucemen, S.M.

1981-04-01

Probabilistic and statistical methods are used to develop a procedure by which the seismic risk at a specific site can be systematically analyzed. The proposed probabilistic procedure provides a consisted method for the modelling, analysis and updating of uncertainties that are involved in the seismic risk analysis for nuclear power plants. Methods are proposed for including these uncertainties in the final value of calculated risks. Two specific case studies are presented in detail to illustrate the application of the probabilistic method of seismic risk evaluation and to investigate the sensitivity of results to different assumptions

Probabilistic safety assessments of nuclear power plants for low power and shutdown modes

International Nuclear Information System (INIS)

2000-03-01

Within the past several years the results of nuclear power plant operating experience and performance of probabilistic safety assessments (PSAs) for low power and shutdown operating modes have revealed that the risk from operating modes other than full power may contribute significantly to the overall risk from plant operations. These early results have led to an increased focus on safety during low power and shutdown operating modes and to an increased interest of many plant operators in performing shutdown and low power PSAs. This publication was developed to provide guidance and insights on the performance of PSA for shutdown and low power operating modes. The preparation of this publication was initiated in 1994. Two technical consultants meetings were conducted in 1994 and one in February 1999 in support of the development of this report

Framework for ensuring appropriate maintenance of baseline PSA and risk monitor models in a nuclear power plant

International Nuclear Information System (INIS)

Vrbanic, I.; Sorman, J.

2005-01-01

The necessity of observing both long term and short term risk changes many times imposes the need for a nuclear power plant to have a baseline PSA model to produce an estimate of long term averaged risk and a risk monitor to produce a time-dependent risk curve and/or safety functions status at points in time or over a shorter time period of interest. By nature, a baseline PSA reflects plant systems and operation in terms of average conditions and provides time-invariant quantitative risk metrics. Risk monitor, on the other hand, requires condition-specific modeling to produce a quantitative and/or qualitative estimate of plant's condition-specific risk metrics. While risk monitor is used for computing condition-specific risk metrics over time, a baseline PSA model is needed for variety of other risk oriented applications, such as assessments of proposed design modifications or risk ranking of equipment. Having in mind their importance and roles, it is essential that both models, i.e. baseline PSA model and risk monitor are maintained in the way that they represent, as accurately as practically achievable, the actual plant status (e.g. systems' design and plant's procedures in effect) and its history (e.g. numbers of equipment failures and demands that influence relevant PSA parameters). Paper discusses the requirements for appropriate maintenance of plant's baseline PSA model and risk monitor model and presents the framework for plant's engineering and administrative procedures that would ensure they are met. (author)

Comprehensive Health Risk Management after the Fukushima Nuclear Power Plant Accident.

Science.gov (United States)

Yamashita, S

2016-04-01

Five years have passed since the Great East Japan Earthquake and the subsequent Fukushima Daiichi Nuclear Power Plant accident on 11 March 2011. Countermeasures aimed at human protection during the emergency period, including evacuation, sheltering and control of the food chain were implemented in a timely manner by the Japanese Government. However, there is an apparent need for improvement, especially in the areas of nuclear safety and protection, and also in the management of radiation health risk during and even after the accident. Continuous monitoring and characterisation of the levels of radioactivity in the environment and foods in Fukushima are now essential for obtaining informed consent to the decisions on living in the radio-contaminated areas and also on returning back to the evacuated areas once re-entry is allowed; it is also important to carry out a realistic assessment of the radiation doses on the basis of measurements. Until now, various types of radiation health risk management projects and research have been implemented in Fukushima, among which the Fukushima Health Management Survey is the largest health monitoring project. It includes the Basic Survey for the estimation of external radiation doses received during the first 4 months after the accident and four detailed surveys: thyroid ultrasound examination, comprehensive health check-up, mental health and lifestyle survey, and survey on pregnant women and nursing mothers, with the aim to prospectively take care of the health of all the residents of Fukushima Prefecture for a long time. In particular, among evacuees of the Fukushima Nuclear Power Plant accident, concern about radiation risk is associated with psychological stresses. Here, ongoing health risk management will be reviewed, focusing on the difficult challenge of post-disaster recovery and resilience in Fukushima. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Risk management and nuclear human resources management in construction nuclear power plants in the Gulf Countries

International Nuclear Information System (INIS)

Saeed Hakami; Salim Almarmary

2009-01-01

The countries of the Gulf region have the capacity to rapidly expand their economic growth and gross domestic product (GDP). Also, one may observe that their growth rate is very high. To match this, they need a mix of energy sources for this economic growth. Nuclear power plants can have a significant role as a source of energy in the Gulf countries. Although, some of the Gulf countries signed contracts to construct nuclear power plants, they still require high a level of education as well as sufficient and adequate human resources in order to solve complex issues which may happen at nuclear power plants. The objective of this paper is to identify the complex issues that may arise at a nuclear site. Then the paper goes on to discuss how to evaluate these issues. Finally, the paper studies how to manage and control such complex issues in the work place. The advantage of highly educated people as well as sufficient and adequate human resource can increasingly protect and save human health and the natural environment from issues relating to the use of nuclear energy. There are vast theories, strategies and tools that have discussed in regards to human resources management in the nuclear industries. However, this paper chiefly provides a new risk management methodology. This methodology helps to highlight the risk factors and their consequences at nuclear sites. This paper is intended to decrease risks; to protect human health in the work place at nuclear power plants and save the environment within and beyond national borders and for future generations. It aims to increase safety from the use of nuclear energy, particularly in the Gulf countries.(Author)

Reactor safety study. An assessment of accident risks in U.S. commercial nuclear power plants. Executive summary: main report

International Nuclear Information System (INIS)

1975-10-01

Information is presented concerning the objectives and organization of the reactor safety study; the basic concepts of risk; the nature of nuclear power plant accidents; risk assessment methodology; reactor accident risk; and comparison of nuclear risks to other societal risks

Health risk in nuclear power plants

International Nuclear Information System (INIS)

Bliznakov, V.

1997-01-01

Worked out are the health risk indices for NPP personnel that could be used in normal operation and in case of accident. These indices concern temporary incapacity for work, invalidity, lethality, cancer, etc. Risk estimation is based on produced energy in NPP or on the collective dose of personnel exposure. Assessed are the specific risk values for NPP ''Kozloduy'', which show that the risk in normal operation is significantly low (of the order of 2.3 ./. 7.2 x 10 -4 for invalidity, lethality and cancer). Health risk indices can be used when comparing various alternative energy sources, as well as for determination of the power strategy of a country. (author)

Assessment of ISLOCA risk: Methodology and application to a Babcock and Wilcox nuclear power plant

International Nuclear Information System (INIS)

Galyean, W.J.; Gertman, D.I.

1992-04-01

This report presents information essential to understanding the risk associated with inter-system loss-of-coolant accidents (ISLOCAs). The methodology developed and presented in the report provides a state-of-the-art method for identifying and evaluating plant-specific hardware design, human performance issues, and accident consequence factors to relevant to the prediction of the ISLOCA risk. This ISLOCA methodology was developed and then applied to a Babcock and Wilcox (B ampersand W) nuclear power plants. The results from this application are described in detail. For this particular B ampersand W reference plant, the assessment indicated that the probability of a severe ISLOCA is approximately 2.2E-06/reactor-year. This document Volume 3 provides appendices A--H of the report. Topics are: Historical experience related to ISLOCA events; component failure rates; reference B ampersand W plant system descriptions; reference B ampersand W plant ISLOCA event trees; Human reliability analysis for the B ampersand W ISLOCA probabilistic risk assessment; thermal hydraulic calculations; bounding core uncovery time calculations; and system rupture probability

ASME development of risk-based inspection guidelines for nuclear power plants

International Nuclear Information System (INIS)

Gore, B.F.; Balkey, K.R.

1992-08-01

A methodology has been developed for use in preparing guidelines for the in-service inspection of nuclear power plant pressure boundary and structural components. This methodology is a further development of a general methodology previously published by the task force for application to any industry. It is unique in that it utilizes probabilistic risk assessment (PRA) information to improve the quantification of risks associated with component ruptures. A procedure has also been recommended for using the resulting quantified risk estimates to determine target component rupture probability values to be maintained by inspection activities. Characteristics which an inspection strategy must possess in order to maintain target rupture probabilities are being determined by structural risk and reliability analysis (SRRA) calculations. The major features of this methodology are described in this paper, and example applications are briefly discussed. Plans for additional work in developing and applying the methodology are described

Analytic advanced development in the German Risk Study on Nuclear Power Plants

International Nuclear Information System (INIS)

1984-01-01

The study carried out by the Ecological Institute (Oeko-Institut) deals with the difficulties encountered with the decision-making models and statistical models and methods of the German Risk Study on Nuclear Power Plants for the determination of care meltdown frequency and for the estimation of the behaviour of components in the event of a failure. Related deficiencies of the German Risk Study and the absence of completeness and lading representiveness of the course and causes of incidents considered are pointed out. The accident consequences model and the climatological-meteorological data base are considered non-representative. (RF) [de

Safety goals for nuclear power plant operation

International Nuclear Information System (INIS)

1983-05-01

This report presents and discusses the Nuclear Regulatory Commission's, Policy Statement on Safety Goals for the Operation of Nuclear Power Plants. The safety goals have been formulated in terms of qualitative goals and quantitative design objectives. The qualitative goals state that the risk to any individual member of the public from nuclear power plant operation should not be a significant contributor to that individual's risk of accidental death or injury and that the societal risks should be comparable to or less than those of viable competing technologies. The quantitative design objectives state that the average risks to individual and the societal risks of nuclear power plant operation should not exceed 0.1% of certain other risks to which members of the US population are exposed. A subsidiary quantitative design objective is established for the frequency of large-scale core melt. The significance of the goals and objectives, their bases and rationale, and the plan to evaluate the goals are provided. In addition, public comments on the 1982 proposed policy statement and responses to a series of questions that accompanied the 1982 statement are summarized

Comparative Health Risk Assessment of CdTe Solar PV System and Nuclear Power Plant

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2014-01-01

In terms of national energy policy decision-making process, several key factors, including low production cost, negligible risk or impact to environment and population around the facility, must be considered. The purpose of this paper is to assess the public health risk in case of postulated nuclear power plant and CdTe solar PV system accident and compare the estimated public health risk. Both systems release toxic materials to the environment which adversely affect nearby population by exposure from the inhalation and ingestion of the toxic material transported via air. By simulating the airborne transport of released toxic material using Gaussian plume model and modeling exposure pathways to nearby population, average individual health risk is assessed and public health risk per power capacity of each system is compared. The result shows that the average public health risk per power capacity of NPP is less than the case of solar PV system. This implies that NPP has lower risk in terms of public health risk in case of severe accident while it can be used as more reliable energy source than renewable energy source so that NPP would take priority over other renewable energy sources in terms of national energy policy

Forum for fire protection and safety in power plants[Norway

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The conference contains 16 presentations on topics in the fields of fire protection and safety in plants in Western Norway, reorganization and reconstruction of power systems and plants in Norway, various aspects of risk and vulnerability analysis, technological aspects of plant management and construction and problems and risks with particularly transformers. Some views on challenges of the fire departments and the new Norwegian regulations for electrical power supply systems are included. One presentation deals with challenges for Icelandic power production plants.

Advanced digital I ampersand C systems in nuclear power plants: Risk- sensitivities to environmental stressors

International Nuclear Information System (INIS)

Hassan, M.; Vesely, W.E.

1996-01-01

Microprocessor-based advanced digital systems are being used for upgrading analog instrumentation and control (I ampersand C) systems in nuclear power plants (NPPs) in the United States. A concern with using such advanced systems for safety-related applications in NPPs is the limited experience with this equipment in these environments. In this study, we investigate the risk effects of environmental stressors by quantifying the plant's risk-sensitivities to them. The risk- sensitivities are changes in plant risk caused by the stressors, and are quantified by estimating their effects on I ampersand C failure occurrences and the consequent increase in risk in terms of core damage frequency (CDF). We used available data, including military and NPP operating experience, on the effects of environmental stressors on the reliability of digital I ampersand C equipment. The methods developed are applied to determine and compare risk-sensitivities to temperature, humidity, vibration, EMI (electromagnetic interference) from lightning and smoke as stressors in an example plant using a PRA (Probabilistic Risk Assessment). Uncertainties in the estimates of the stressor effects on the equipment's reliability are expressed in terms of ranges for risk-sensitivities. The results show that environmental stressors potentially can cause a significant increase in I ampersand C contributions to the CDF. Further, considerable variations can be expected in some stressor effects, depending on where the equipment is located

The financing of nuclear power plants

International Nuclear Information System (INIS)

2009-01-01

Many countries have recognised that greater use of nuclear power could play a valuable role in reducing carbon dioxide emissions. However, given the high capital cost and complexity of nuclear power plants, financing their construction often remains a challenge. This is especially true where such financing is left to the private sector in the context of competitive electricity markets. This study examines the financial risks involved in investing in a new nuclear power plant, how these can be mitigated, and how projects can be structured so that residual risks are taken by those best able to manage them. Given that expansion of nuclear power programmes will require strong and sustained government support, the study highlights the role of governments in facilitating and encouraging investment in new nuclear generating capacity

A quantitative and comparative evaluation of the risks from nuclear power plants

International Nuclear Information System (INIS)

Vignes, S.; Bertin, M.; Nenot, J.C.

1980-01-01

All the significant data for the assessment of risks from the operation of nuclear power plants was collected and these risks were compared with all the risks of modern life. The scientific bases for the evaluation of individual risks and detriment were defined by UNSCEAR (1977) and by ICRP 26 (1978). In different industries, the risk of death from long term occupational illness is about 130 to 14,000 per million workers. For accidental deaths, the risk is estimated at about 16 to 1,600. The risk for the nuclear industry is lower than 100 per million workers. Comparisons are made with different causes of lethality: deaths from atmospheric pollution (sulfur compounds and dusts) related to fossile fuel combustion; iatrogenic accidents attributed to some drugs used in medicine or to other kind of treatment; calculated mortality for workers exposed to asestosis. The nuclear industr of the safest. The only risk to be considered is the major accident, the probability of which is very low. (H.K.)

Risk informed life cycle plant design

International Nuclear Information System (INIS)

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

2003-01-01

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

Next Generation Geothermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Brugman, John; Hattar, Mai; Nichols, Kenneth; Esaki, Yuri

1995-09-01

A number of current and prospective power plant concepts were investigated to evaluate their potential to serve as the basis of the next generation geothermal power plant (NGGPP). The NGGPP has been envisaged as a power plant that would be more cost competitive (than current geothermal power plants) with fossil fuel power plants, would efficiently use resources and mitigate the risk of reservoir under-performance, and minimize or eliminate emission of pollutants and consumption of surface and ground water. Power plant concepts were analyzed using resource characteristics at ten different geothermal sites located in the western United States. Concepts were developed into viable power plant processes, capital costs were estimated and levelized busbar costs determined. Thus, the study results should be considered as useful indicators of the commercial viability of the various power plants concepts that were investigated. Broadly, the different power plant concepts that were analyzed in this study fall into the following categories: commercial binary and flash plants, advanced binary plants, advanced flash plants, flash/binary hybrid plants, and fossil/geothed hybrid plants. Commercial binary plants were evaluated using commercial isobutane as a working fluid; both air-cooling and water-cooling were considered. Advanced binary concepts included cycles using synchronous turbine-generators, cycles with metastable expansion, and cycles utilizing mixtures as working fluids. Dual flash steam plants were used as the model for the commercial flash cycle. The following advanced flash concepts were examined: dual flash with rotary separator turbine, dual flash with steam reheater, dual flash with hot water turbine, and subatmospheric flash. Both dual flash and binary cycles were combined with other cycles to develop a number of hybrid cycles: dual flash binary bottoming cycle, dual flash backpressure turbine binary cycle, dual flash gas turbine cycle, and binary gas turbine

Layout of nuclear power plants against external hazards

International Nuclear Information System (INIS)

Suetterlin, L.

1975-03-01

The present paper has the purpose to show the risk of operating a nuclear power plant that is not protected against an airplane crash. At first, considerations of probabilities are made and numerical data for various categories of air traffic are given. A general consideration of the possible extent of damage after an airplane impact upon an unprotected nuclear power plant is followed by a discussion of the risk philosophy which is based upon the Farmer-diagrams. Furthermore the facts are specified which led to the decision that nuclear power plants in the Federal Republic of Germany must be protected against an airplane crash. (orig.) [de

Measuring risk in a Philippine power plant: the Philippine experience in transfer of technology

International Nuclear Information System (INIS)

Savellano, R.A.; Leon, G.C. de; Azanon, E.M.

1989-01-01

The Philippine experience in risk assessment and management is more pronounced in the field of energy systems. This particular study focuses on the evaluation and management of pollutant emission from a geothermal power plant. It embraces two main methodologies 1) the systematic calculation of the risks impacts of the energy systems to human health and to the environment, and 2) the evaluation of cost-effectiveness of risk reduction schemes. Presented in detail is how the researchers resolve the problems and the approach perceived as necessary for an effective risk management. (ELC). 12 refs.; 5 tabs.; 3 figs

POTENTIAL HEALTH RISK REDUCTION ARISING FROM REDUCED MERCURY EMISSIONS FROM COAL FIRED POWER PLANTS.

Energy Technology Data Exchange (ETDEWEB)

Sullivan, T. M.; Lipfert, F. W.; Morris, S. C.; Moskowitz, P. D.

2001-09-01

The U.S. Environmental Protection Agency (EPA) has announced plans to regulate mercury (Hg) emissions from coal-fired power plants. EPA has not prepared a quantitative assessment of the reduction in risk that could be achieved through reduction in coal plant emissions of Hg. To address this issue, Brookhaven National Laboratory (BNL) with support from the U.S. Department of Energy Office of Fossil Energy (DOE FE) prepared a quantitative assessment of the reduction in human health risk that could be achieved through reduction in coal plant emissions of Hg. The primary pathway for Hg exposure is through consumption of fish. The most susceptible population to Hg exposure is the fetus. Therefore the risk assessment focused on consumption of fish by women of child-bearing age. Dose response factors were generated from studies on loss of cognitive abilities (language skills, motor skills, etc.) by young children whose mothers consumed large amounts of fish with high Hg levels. Population risks were estimated for the general population in three regions of the country, (the Midwest, Northeast, and Southeast) that were identified by EPA as being heavily impacted by coal emissions. Three scenarios for reducing Hg emissions from coal plants were considered: (1) A base case using current conditions; (2) A 50% reduction; and, (3) A 90% reduction. These reductions in emissions were assumed to translate linearly into a reduction in fish Hg levels of 8.6% and 15.5%, respectively. Population risk estimates were also calculated for two subsistence fisher populations. These groups of people consume substantially more fish than the general public and, depending on location, the fish may contain higher Hg levels than average. Risk estimates for these groups were calculated for the three Hg levels used for the general population analyses. Analysis shows that the general population risks for exposure of the fetus to Hg are small. Estimated risks under current conditions (i.e., no

Application of fire models for risk analysis in french nuclear power plants

International Nuclear Information System (INIS)

Brauns, P.

1989-04-01

Numerical simulations of compartment fires have been carried out in the French 900 MW and 1 300 MW nuclear power plants, to obtain quantitative data about this particular kind of risk: characteristic spreading times from one redundant electrical train to the other one, behaviour of important electrical components... The main stages of both studies were the following: selection of rooms, the location or function of which are essential for the plant safety in case of fire, on-site inspections to collect information about these rooms (amount of fuel, openings...), definition of fire scenarios, improvement of the fire model VESTA-PLUS, and, finally calculations using this computer code. The simulations have shown two major trends: i) the spreading times, without taking into account any external intervention, are always greater than half an hour, and ii) the specific design of the 1 300 MW power plants generally prevents one of the redundant train from being damaged due to a fire occurring in a room containing the other one. Examples of typical results obtained are given, showing the capability of application of the improved fire model to complex problems

Status of ASME risk-based inspection guidelines development for nuclear power plants

International Nuclear Information System (INIS)

Gore, B.F.; Vo, T.V.; Balkey, K.R.

1991-01-01

The general methodology published by the task force is being applied to develop guidelines for the inspection of nuclear power plant components. The methodology has been expanded to include the use of information from probabilistic risk assessments to improve the quantification of risks associated with component ruptures. In addition, a procedure has been recommended for using these quantified risk estimates to determine target component rupture probability values to be maintained by inspection activities. Finally, the method for determining the characteristics which an inspection strategy must possess in order to maintain these target rupture probabilities has been described. This paper presents the major features of this methodology, along with a discussion of the status of efforts to develop and to apply it further

Seismic reevaluation of existing nuclear power plants

International Nuclear Information System (INIS)

Hennart, J.C.

1978-01-01

The codes and regulations governing Nuclear Power Plant seismic analysis are continuously becoming more stringent. In addition, design ground accelerations of existing plants must sometimes be increased as a result of discovery of faulting zones or recording of recent earthquakes near the plant location after plant design. These new factors can result in augmented seismic design criteria. Seismic reanalysius of the existing Nuclear Power Plant structures and equipments is necessary to prevent the consequences of newly postulated accidents that could cause undue risk to the health or safety of the public. This paper reviews the developments of seismic analysis as applied to Nuclear Power Plants and the methods used by Westinghouse to requalify existing plants to the most recent safety requirements. (author)

Critique of the RASMUSSEN report (WASH-1400) on accident risks in U.S. commercial nuclear power plants

International Nuclear Information System (INIS)

Krueger, F.W.

1976-06-01

The RASMUSSEN study represents an excellent survey of the current possibilities to assess quantitatively the operational risk of nuclear power plants. To close the big gaps which turned out to be still existent in calculating the possible accidents sequences and their consequences but also in the statistical materials, only rough models could be used because of the limited capability of theoretical analyses to replace lacking experience. Contrary to previous studies the risk estimates have not deliberately been maximized, apart from the fact that in many cases no 'safe' side does a priori exist. Rather, the RASMUSSEN study tried to make 'reasonable realistic' assumptions concerning accident sequences and activity release consequences, but it is difficult to refute that the results will tend to underestimate systematically the accident consequences. Besides, in every case the range of uncertainty will very likely be greater than stated in the study, not least also because the results are substantially influenced by technical features of the nuclear power plants under discussion. This should be given attention in discussions using the quantitative results of the study as well as the fact that planning, construction and operation of nuclear power plants must be done with utmost accuracy to achieve the specified low orders of risk. (author)

RIBA Project - Risk-Informed approach for In-Service Inspection of Nuclear Power Plant Components. Project summary

International Nuclear Information System (INIS)

Lidbury, D.; Smith, G.

2001-12-01

The need for a European review of a Risk-Informed Approach for In-Service Inspection of Nuclear Power Plant Components (RIBA) was identified in 1998. This was as a priority item in the programme of activities conducted in the framework of the Council Resolutions of 22 July 1975 and of 18 June 1992 on the Technological Problems of Nuclear Safety. The RIBA Project was established in November 1999 as a 24-month Study Contract funded by the European Commission within the frame of the former DG XI WGCS (Working Group on Codes and Standards). The Study Contract was subsequently managed for the EC by DG TREN. The participants in RIBA were Serco Assurance (project coordinator), Ringhals AB, EDF, Tecnatom SA and Westinghouse Electric Europe. The work is presented in a summary report with the detailed results contained in three companion reports as follows: main conclusions and recommendations, Review of Existing Risk-Informed Methodologies, A Comparative Study of Risk-Informed In-Service Inspection Applications, Conclusions and Recommendations for Risk-Informed in-service inspection methodology applied to Nuclear Power Plants in Europe. (author)

A framework of risk-informed seismic safety evaluation of nuclear power plants in Japan

International Nuclear Information System (INIS)

Kondo, S.; Sakagami, M.; Hirano, M.; Shiba, M.

2001-01-01

A framework of risk-informed seismic design and safety evaluation of nuclear power plants is under consideration in Japan so as to utilize the progress in the seismic probabilistic safety assessment methodology. Issues resolved to introduce this framework are discussed after the concept, evaluation process and characteristics of the framework are described. (author)

A risk-based review of Instrument Air systems at nuclear power plants

International Nuclear Information System (INIS)

DeMoss, G.; Lofgren, E.; Rothleder, B.; Villeran, M.; Ruger, C.

1990-01-01

The broad objective of this analysis was to provide risk-based information to help focus regulatory actions related to Instrument Air (IA) systems at operating nuclear power plants. We first created an extensive data base of summarized and characterized IA-related events that gave a qualitative indication of the nature and severity of these events. Additionally, this data base was used to calculate the frequencies of certain events, which were used in the risk analysis. The risk analysis consisted of reviewing published PRAs and NRC Accident Sequence Precursor reports for IA-initiated accident sequences, IA interactions with frontline systems, and IA-related risk significant events. Sensitivity calculations were performed when possible. Generically, IA was found to contribute less to total risk than many safety systems; however, specific design weaknesses in safety systems, non-safety systems, and the IA system were found to be significant in risk. 22 refs., 13 figs., 24 tabs

Plant risk status information management system

International Nuclear Information System (INIS)

Campbell, D.J.; Ellison, B.C.; Glynn, J.C.; Flanagan, G.F.

1985-01-01

The Plant Risk Status Information Management System (PRISIMS) is a PC program that presents information about a nuclear power plant's design, its operation, its technical specifications, and the results of the plant's probabilistic risk assessment (PRA) in a logically and easily accessible format. PRISIMS provides its user with unique information for integrating safety concerns into day-to-day operational decisions and/or long-range management planning

Nuclear power plants and prevention of sanitary risks

International Nuclear Information System (INIS)

Delpla, M.

1977-01-01

The radioprotection specialists know that people irradiation can cause fearful diseases even to their descendance. So they wanted to predict the upper limit of the damage that could be caused by irradiations at the limits of radioprotection doses of IRCP standards recommended for the whole population. For their previsional calculations, they admitted the proportionality between the most fearful risks and the accumulated individual dose, whatever the time is. According to such an hypothesis, the previsional damage would be proportional to the population dose. Observed damages on accidentally or experimentally irradiated population will be compared to the previsional damage, calculated from the values generally admitted for the risks. The author will consider the risks which are usually taken in account in the protection of people against the hazard of nuclear power plants such as: leukemia, thyroid cancer. Such comparisons will allow to propose, in the field of radioprotection: to abandon the hypothesis of proportionality between the risk and the dose; to admit a practical threshold dose for each of the most fearful effects; to admit the same radiation protection standards for eveyone; to try to interpret facts until then unnoticed, or when they have been seen, called 'paradoxical'; these facts may be due to the stimulating effect of a suitable dose of ionizing radiation. Such a stimulating effect is well known by the radiologists, but some of the latter are afraid of secondary delate effects. This new field of research may be as useful to radiotherapy as to radioprotection [fr

A probabilistic seismic risk assessment procedure for nuclear power plants: (II) Application

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

This paper presents the procedures and results of intensity- and time-based seismic risk assessments of a sample nuclear power plant (NPP) to demonstrate the risk-assessment methodology proposed in its companion paper. The intensity-based assessments include three sets of sensitivity studies to identify the impact of the following factors on the seismic vulnerability of the sample NPP, namely: (1) the description of fragility curves for primary and secondary components of NPPs, (2) the number of simulations of NPP response required for risk assessment, and (3) the correlation in responses between NPP components. The time-based assessment is performed as a series of intensity-based assessments. The studies illustrate the utility of the response-based fragility curves and the inclusion of the correlation in the responses of NPP components directly in the risk computation. ?? 2011 Published by Elsevier B.V.

Assessment of risks of accidents and normal operation at nuclear power plants

International Nuclear Information System (INIS)

Savolainen, Ilkka; Vuori, Seppo.

1977-01-01

A probabilistic assessment model for the analysis of risks involved in the operation of nuclear power plants is described. With the computer code ARANO it is possible to estimate the health and economic consequences of reactor accidents both in probabilistic and deterministic sense. In addition the code is applicable to the calculation of individual and collective doses caused by the releases during normal operation. The estimation of release probabilities and magnitudes is not included in the model. (author)

Update on the EPRI power generation risk-based inservice inspection pilot plant studies

International Nuclear Information System (INIS)

Gosselin, S.R.

1997-01-01

The scope for ASME Section XI ISI programs is largely based on deterministic results contained in design stress reports. These reports are normally very conservative and may not be an accurate representation of failure potential. Service experience has shown that failures are due to either corrosion or fatigue and typically occur in areas not included in the plant's ISI program. Consequently, nuclear plants are devoting significant resources to inspection programs that provide minimum benefit. As an alternative, significant industry attention has been devoted to the application of risked-based selection criteria in order to determine the scope of inservice inspection (ISI) programs at nuclear power plants. Preliminary EPRI studies indicate that the application of these techniques will allow operating nuclear plants to reduce the examination scope of current ISI programs by as much as 60 to 80%, significantly reduce costs, and continue to maintain high nuclear plant safety standards

A completely new design and regulatory process - A risk-based approach for new nuclear power plants. Annex 17

International Nuclear Information System (INIS)

Ritterbusch, S.E.

2002-01-01

In the de-regulated electric power market place that is developing in the USA, competition from alternative electric power sources has provided significant downward pressure on the costs of new construction projects. Studies by the Electric Power Research Institute have shown that, in the USA, the capital cost of new nuclear plants must be decreased by at least 35% to 40% relative to the cost of Advanced Light Water Reactors designed in the early 1990s in order to be competitive with capital costs of gas-fired electric power plants. The underlying reasons for the high capital costs estimated for some nuclear plants are (1) long construction times, (2) the high level of 'defense-in-depth' or safety margin, included throughout the design and licensing process, and (3) the use of out-dated design methods and information. Probabilistic Safety Assessments are being used to develop a more accurate assessment of real plant risk and to provide relief if it can be demonstrated that plant equipment is not providing a significant contribution to plant safety. Westinghouse addressed some of these cost drivers in the development of the AP-600 passive plant design. However, because of relatively inexpensive natural gas plant alternative, we need to reduce the costs even further. Therefore, the AP-600 design is now being up-rated to a 1000 MWe design, AP-1000. The development of AP1000 is described in another paper being presented at this meeting. Westinghouse is also managing a project, sponsored by the US Department of Energy, which is aimed at developing an all-new 'risk-based' approach to design and regulation. Methodologies being developed use risk-based information to the extent practical and 'defense-in-depth' only when necessary to address uncertainties in models and equipment performance. Early results, summarized in this paper, include (1) the initial framework for a new design and regulatory process and (2) a sample design analysis which shows that the Emergency Core

Indoor Soiling Method and Outdoor Statistical Risk Analysis of Photovoltaic Power Plants

Science.gov (United States)

Rajasekar, Vidyashree

This is a two-part thesis. Part 1 presents an approach for working towards the development of a standardized artificial soiling method for laminated photovoltaic (PV) cells or mini-modules. Construction of an artificial chamber to maintain controlled environmental conditions and components/chemicals used in artificial soil formulation is briefly explained. Both poly-Si mini-modules and a single cell mono-Si coupons were soiled and characterization tests such as I-V, reflectance and quantum efficiency (QE) were carried out on both soiled, and cleaned coupons. From the results obtained, poly-Si mini-modules proved to be a good measure of soil uniformity, as any non-uniformity present would not result in a smooth curve during I-V measurements. The challenges faced while executing reflectance and QE characterization tests on poly-Si due to smaller size cells was eliminated on the mono-Si coupons with large cells to obtain highly repeatable measurements. This study indicates that the reflectance measurements between 600-700 nm wavelengths can be used as a direct measure of soil density on the modules. Part 2 determines the most dominant failure modes of field aged PV modules using experimental data obtained in the field and statistical analysis, FMECA (Failure Mode, Effect, and Criticality Analysis). The failure and degradation modes of about 744 poly-Si glass/polymer frameless modules fielded for 18 years under the cold-dry climate of New York was evaluated. Defect chart, degradation rates (both string and module levels) and safety map were generated using the field measured data. A statistical reliability tool, FMECA that uses Risk Priority Number (RPN) is used to determine the dominant failure or degradation modes in the strings and modules by means of ranking and prioritizing the modes. This study on PV power plants considers all the failure and degradation modes from both safety and performance perspectives. The indoor and outdoor soiling studies were jointly

Toxic releases from power plants

International Nuclear Information System (INIS)

Rubin, E.S.

1999-01-01

Beginning in 1998, electric power plants burning coal or oil must estimate and report their annual releases of toxic chemicals listed in the Toxics Release Inventory (TRI) published by the US Environmental Protection Agency (EPA). This paper identifies the toxic chemicals of greatest significance for the electric utility sector and develops quantitative estimates of the toxic releases reportable to the TRI for a representative coal-fired power plant. Key factors affecting the magnitude and types of toxic releases for individual power plants also are discussed. A national projection suggests that the magnitude of electric utility industry releases will surpass those of the manufacturing industries which current report to the TRI. Risk communication activities at the community level will be essential to interpret and provide context for the new TRI results

Risk perception of workers at nuclear power plants from Angra dos Reis, Rio de Janeiro State: preliminary study of a reality on health

International Nuclear Information System (INIS)

Scliar, Claudio; Vasconcelos, Ana S.F.; Rodrigues, Anacely S.; Santos, Gloria R.R.; Albuquerque, Patricia O.; Carvalho, Sirlene L.A.; Oliveira, Simone

1999-01-01

The present paper analyses some social and occupational parameters that may have an influence on the risk perception levels of the workers in Brazilian Nuclear Power pLants, emphasizing possible relationship between the specificity of job tasks/literacy and risk perception. This study was based on two findings from the scientific literature: risk perception increases proportionally with literacy; risk perception decreases proportionally with the specificity of job tasks. The results of this pilot study indicates that risk perception levels of the workers in Brazilian Nuclear Power Plants increases proportionally with the literacy and specificity of their job tasks, contrasting with the american and european profiles. These results appears as a singular reality of those workers and the possibility of a new regard over the management and decision making process in the Brazilian Nuclear Power Plants. (author)

Contribution to evaluating nuclear power plant accidents

International Nuclear Information System (INIS)

Razga, J.; Horacek, P.

1990-01-01

Large-scale accidents pose the highest risk in the use of nuclear power. They are the major factor that has to be taken into account when assessing the effect of nuclear power plants on human health and on the environment. In Czechoslovak conditions, the effectiveness of provisions made to reduce the hazard of large-scale nuclear power plant accidents must be considered from the following aspects: effect on human health, consequences of long-term disabling of the infrastructure, potential of human and material reserves in coping with the accident, consequences of power failure for the electricity system, effect on agricultural production and catering, risk of ground and surface water contamination in the Labe or Danube river basin, and international political aspects. (Z.M.). 3 tabs., 18 refs

Nuclear power plants

International Nuclear Information System (INIS)

1985-01-01

Data concerning the existing nuclear power plants in the world are presented. The data was retrieved from the SIEN (Nuclear and Energetic Information System) data bank. The information are organized in table forms as follows: nuclear plants, its status and type; installed nuclear power plants by country; nuclear power plants under construction by country; planned nuclear power plants by country; cancelled nuclear power plants by country; shut-down nuclear power plants by country. (E.G.) [pt

Safety provision for nuclear power plants during remaining running time

International Nuclear Information System (INIS)

Rossnagel, Alexander; Hentschel, Anja

2012-01-01

With the phasing-out of the industrial use of nuclear energy for the power generation, the risk of the nuclear power plants has not been eliminated in principle, but only for a limited period of time. Therefore, the remaining nine nuclear power plants must also be used for the remaining ten years according to the state of science and technology. Regulatory authorities must substantiate the safety requirements for each nuclear power plant and enforce these requirements by means of various regulatory measures. The consequences of Fukushima must be included in the assessment of the safety level of nuclear power plants in Germany. In this respect, the regulatory authorities have the important tasks to investigate and assess the security risks as well as to develop instructions and orders.

Source modelling in seismic risk analysis for nuclear power plants

International Nuclear Information System (INIS)

Yucemen, M.S.

1978-12-01

The proposed probabilistic procedure provides a consistent method for the modelling, analysis and updating of uncertainties that are involved in the seismic risk analysis for nuclear power plants. The potential earthquake activity zones are idealized as point, line or area sources. For these seismic source types, expressions to evaluate their contribution to seismic risk are derived, considering all the possible site-source configurations. The seismic risk at a site is found to depend not only on the inherent randomness of the earthquake occurrences with respect to magnitude, time and space, but also on the uncertainties associated with the predicted values of the seismic and geometric parameters, as well as the uncertainty in the attenuation model. The uncertainty due to the attenuation equation is incorporated into the analysis through the use of random correction factors. The influence of the uncertainty resulting from the insufficient information on the seismic parameters and source geometry is introduced into the analysis by computing a mean risk curve averaged over the various alternative assumptions on the parameters and source geometry. Seismic risk analysis is carried for the city of Denizli, which is located in the seismically most active zone of Turkey. The second analysis is for Akkuyu

Probability analysis of nuclear power plant hazards

International Nuclear Information System (INIS)

Kovacs, Z.

1985-01-01

The probability analysis of risk is described used for quantifying the risk of complex technological systems, especially of nuclear power plants. Risk is defined as the product of the probability of the occurrence of a dangerous event and the significance of its consequences. The process of the analysis may be divided into the stage of power plant analysis to the point of release of harmful material into the environment (reliability analysis) and the stage of the analysis of the consequences of this release and the assessment of the risk. The sequence of operations is characterized in the individual stages. The tasks are listed which Czechoslovakia faces in the development of the probability analysis of risk, and the composition is recommended of the work team for coping with the task. (J.C.)

Public perception on the benefits and risks of nuclear power plants. A simplified study

International Nuclear Information System (INIS)

Ribeiro Junior, Joaquim Apparecido

2007-01-01

Public acceptance of the nuclear based electricity generation depends on many variables that can be affected by circumstances and interests, which although seemingly not close to the issue, can strongly influence the final outcome. Explicit or consented positions assumed by opinion makers and some segments of society are subject to episodic waves of interaction through the media and they permeate to the public in a process that is very complex to be fully understood. The modeling of such process is a very complicated undertaking, and gives no assurance of practical results concerning to what, how and who, should be given prominence in the interactions with the media and the general public. In this context, the risk communication has assumed a leading role and, as a consequence, most of the interaction with the public has been done with both defensive language and content. This study has tried a simple and practical approach to the problem, in such a way as to gather some interesting subsidies to treat this issue in a different way. The basic assumption is that in a similar way as individuals base their decision to acquire a new good or service on a 'intuitive' cost-benefit judgment, society (as a collection of individuals) also manifest their acceptance (or not) with respect to industrial installations and undertakings by comparing risks and benefits according to their perception. An exploratory survey was carried out in a few high schools, colleges and MBA courses in the state of Sao Paulo, Brazil. A first part was aimed to catch and understand the public perception of: the intrinsic value of the electric energy, the need to universalize the access to electricity, nuclear plants, the acceptance deficit of nuclear power as compared to other sources of energy, the benefits a nuclear plant can bring and who does and who does not deserves credibility to speak about nuclear plants. The second part was addressed to grasp a picture of more relevant distortions concerned

LNG plant combined with power plant

Energy Technology Data Exchange (ETDEWEB)

Aoki, I; Kikkawa, Y [Chiyoda Chemical Engineering and Construction Co. Ltd., Tokyo (Japan)

1997-06-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs.

LNG plant combined with power plant

International Nuclear Information System (INIS)

Aoki, I.; Kikkawa, Y.

1997-01-01

The LNG plant consumers a lot of power of natural gas cooling and liquefaction. In some LNG plant location, a rapid growth of electric power demand is expected due to the modernization of area and/or the country. The electric power demand will have a peak in day time and low consumption in night time, while the power demand of the LNG plant is almost constant due to its nature. Combining the LNG plant with power plant will contribute an improvement the thermal efficiency of the power plant by keeping higher average load of the power plant, which will lead to a reduction of electrical power generation cost. The sweet fuel gas to the power plant can be extracted from the LNG plant, which will be favorable from view point of clean air of the area. (Author). 5 figs

German study on the risks of nuclear power plants

International Nuclear Information System (INIS)

Wollny, V.

1987-01-01

The 'Deutsche Risikostudie Kernkraftwerke', DRS, (German study on the risks of nuclear plants) calculates a frequency of 1/10000 years (i.e. once in 10000 years of reactor operation) for the event of insufficient cooling of the reactor core occurring. The resulting collective risk is put at approximately 10 deaths per year for 25 plants. As the explanations show, the error margin of such a risk statement is enormous. Moreover, much seems to indicate that the risk was underrated. Apart from this, risk analyses are of doubtful value in the decision process for or against the introduction of large-scale technologies. They cannot replace the individual decision of all concerned. (orig./HSCH) [de

Quantitative evaluation of the impact of human reliability in risk assessment for nuclear power plants

International Nuclear Information System (INIS)

Samanta, P.K.

1981-01-01

The role of human beings in the safe operation of a nuclear power plant has been a matter of concern. This study describes methods for the quantitative description of that role and its impact on the risk from nuclear power plants. The impact of human errors was calculated by observing the changes in risk parameters, such as core melt probability, release category probabilities, accident sequence probabilities and system unavailabilities due to changes in the contribution to unavailablity of human errors, within the framework of risk assessment methodology. It was found that for operational pressurized water reactors the opportunity for reduction in core melt probability by reducing the human error rates without simultaneous reduction of hardware failures is limited, but that core melt probability would significantly increase as human error rates increased. More importantly, most of the dominant accident sequences showed a significant increase in their probabilities with an increase in human error rates. Release categories resulting in high consequences showed a much larger sensitivity to human errors than categories resulting in low consequences. A combination of structural importance and reliability importance measure was used to describe the importance of individual errors

Information needs in nuclear power plants during low power operation modes

Energy Technology Data Exchange (ETDEWEB)

Tommila, Teemu; Fantoni, Paolo F.; Zander, Ralf M.

1998-02-01

During the past few years an increasing attention has been paid to the safety of shutdown and refuelling operations. It has turned out that the risks during shutdown may be comparable to the risks of power operation. The goal of this report is to identify information requirements related to low power operating modes of nuclear power plants. These include, for example, warm and cold shutdowns, refuelling and maintenance, as well as related state transitions such as start-up and shut-down. The focus of the report is on planned refuelling outages and the role of the control room in managing the outage activities. As a starting point, the basic terminology and characteristics of low power operation are discussed. The current situation at nuclear power plants and some recent developments in information technology are reviewed. End-users' requirements and enabling technologies are combined in order to identify the opportunities for new information technology tools in low power operation. The required features of process control systems and maintenance information systems are described. Common plant modelling techniques, open software architectures and functional structuring of the process control system are suggested to be the key issues in the long-term development of operator support systems. On a shorter time scale, new tools solving limited practical problems should be developed and evaluated. This would provide a basis for the features needed for low power operation, including for example, outage planning, on-line risk monitoring, management of outage tasks, adaptive alarm handling, computerised procedures and task-oriented human interfaces. (author)

Development of fragility descriptions of equipment for seismic risk assessment of nuclear power plants

International Nuclear Information System (INIS)

Hardy, G.S.; Campbell, R.D.

1983-01-01

Probabilistic risk assessment (PRA) of a nuclear power plant for postulated hazard requires the development of fragility relationships for the plants' safety related equipment. The objective of this paper is to present some general results and conclusions concerning the development of these seismic fragility levels. Participation in fragility-related research and experience gained from the completion of several PRA studies of a variety of nuclear power plants have provided much insight as to the most vulnerable equipment and the most efficient use of resources for development of fragilities. Plants studied had seismic design bases ranging from very simple equivalent static analysis for some of the earlier plants to state-of-the-art complex multimode dyanamic analyses for plants currently under construction. Increased sophistication and rigor in seismic qualification of equipment has resulted for the most part in increased seismic resistance. The majority of equipment has been found, however, to possess more than adequate resistance to seismic loading regardless of the degree of sophistication utilized in design as long as seismic loading was included in the design process. This paper presents conclusions of the authors as to which items of equipment typically require an individual ''plant-specific'' fragility analysis and which can be treated in a generic fashion. In addition, general conclusions on the relative seismic capacity levels and most frequent failure modes are summarized for generic equipment groups

Severe accident risks: An assessment for five US nuclear power plants: Appendices A, B, and C

International Nuclear Information System (INIS)

1990-12-01

This report summarizes an assessment of the risks from severe accidents in five commercial nuclear power plants in the United States. These risks are measured in a number of ways, including: the estimated frequencies of core damage accidents from internally initiated accidents and externally initiated accidents for two or the plants; the performance of containment structures under severe accident loadings; the potential magnitude of radionuclide release and offsite consequences of such accidents; and the overall risk (the product of accident frequencies and consequences). Supporting this summary report are a large number of reports written under contract to NRC that provide the detailed discussion of the methods used and results obtained in these risk studies. Volume 2 of this report contains three appendices, providing greater detail on the methods used, an example risk calculation, and more detailed discussion of particular technical issues found important in the risk studies

The risk of nuclear power plants for man. O risco das usinas nucleares para o homem

Energy Technology Data Exchange (ETDEWEB)

Freire-Maia, A [UNESP, Botucatu, SP (Brazil)

1981-01-01

The author analyzes the risk of nuclear power plants for man with respect to biological radiation effects, sources, level and radiation effects in man. He uses the three Mile Island accident as lesson in order to illustrate a situation potentially dangerous. (C.M.).

Cancer rate in children in the vicinity of nuclear power plants

International Nuclear Information System (INIS)

Grosche, B.; Jung, T.; Weiss, W.

2008-01-01

The recent epidemiological study on childhood cancer in the vicinity of nuclear power plants (KiKK) shows that the cancer risk, especially the leukaemia risk, for children below the age of five in Germany increases with increasing proximity to the site of a nuclear power plant. Earlier ecological studies had found an increased leukaemia risk in children under five within a five-kilometre radius. However, the KiKK study used a case-control design and thus the results are more reliable. A clear trend could be ascertained indicating that the risk increases with increasing proximity of the place of residence to the site of a nuclear power plant. Further, the elevated risk was observed in the entire region under study, i.e. also outside the 5-km radius. As it was not possible to determine individual radiation exposures of the more than 6,000 children included in the study, the distance between the nearest site of a nuclear power plant and the place of residence was used as a substitute both for cases and for controls. The study also took into account other risk factors with known or assumed carcinogenic effect. However, no indication was found that the result could be explained by other risk factors than by vicinity of a nuclear power plant. This clear dependence of risk on the distance from the sites is indicative for a potential causal relationship, but it is no proof. (orig.)

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)

Collision risk in white-tailed eagles. Modelling kernel-based collision risk using satellite telemetry data in Smoela wind-power plant

Energy Technology Data Exchange (ETDEWEB)

May, Roel; Nygaard, Torgeir; Dahl, Espen Lie; Reitan, Ole; Bevanger, Kjetil

2011-05-15

Large soaring birds of prey, such as the white-tailed eagle, are recognized to be perhaps the most vulnerable bird group regarding risk of collisions with turbines in wind-power plants. Their mortalities have called for methods capable of modelling collision risks in connection with the planning of new wind-power developments. The so-called 'Band model' estimates collision risk based on the number of birds flying through the rotor swept zone and the probability of being hit by the passing rotor blades. In the calculations for the expected collision mortality a correction factor for avoidance behaviour is included. The overarching objective of this study was to use satellite telemetry data and recorded mortality to back-calculate the correction factor for white-tailed eagles. The Smoela wind-power plant consists of 68 turbines, over an area of approximately 18 km2. Since autumn 2006 the number of collisions has been recorded on a weekly basis. The analyses were based on satellite telemetry data from 28 white-tailed eagles equipped with backpack transmitters since 2005. The correction factor (i.e. 'avoidance rate') including uncertainty levels used within the Band collision risk model for white-tailed eagles was 99% (94-100%) for spring and 100% for the other seasons. The year-round estimate, irrespective of season, was 98% (95-99%). Although the year-round estimate was similar, the correction factor for spring was higher than the correction factor of 95% derived earlier from vantage point data. The satellite telemetry data may provide an alternative way to provide insight into relative risk among seasons, and help identify periods or areas with increased risk either in a pre- or post construction situation. (Author)

Safety improvements made at the Loviisa nuclear power plant to reduce fire risks originating from the turbine generators

International Nuclear Information System (INIS)

Virolainen, T.; Marttila, J.; Aulamo, H.

1998-01-01

Comprehensive upgrading measures have been completed for the Loviisa Nuclear Power Plant (modified VVER440/V213). These were carried out from the start of the design phase and during operation to ensure safe plant shutdown in the event of a large turbine generator oil fire. These modifications were made mainly on a deterministic basis according to specific risk studies and fire analyses. As part of the probabilistic safety assessment, a fire risk analysis was made that confirmed the importance of these upgrading measures. In fact, they should be considered as design basis modifications for all VVER440 plants. (author)

Sabotage at Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Purvis, James W.

1999-07-21

Recently there has been a noted worldwide increase in violent actions including attempted sabotage at nuclear power plants. Several organizations, such as the International Atomic Energy Agency and the US Nuclear Regulatory Commission, have guidelines, recommendations, and formal threat- and risk-assessment processes for the protection of nuclear assets. Other examples are the former Defense Special Weapons Agency, which used a risk-assessment model to evaluate force-protection security requirements for terrorist incidents at DOD military bases. The US DOE uses a graded approach to protect its assets based on risk and vulnerability assessments. The Federal Aviation Administration and Federal Bureau of Investigation conduct joint threat and vulnerability assessments on high-risk US airports. Several private companies under contract to government agencies use formal risk-assessment models and methods to identify security requirements. The purpose of this paper is to survey these methods and present an overview of all potential types of sabotage at nuclear power plants. The paper discusses emerging threats and current methods of choice for sabotage--especially vehicle bombs and chemical attacks. Potential consequences of sabotage acts, including economic and political; not just those that may result in unacceptable radiological exposure to the public, are also discussed. Applicability of risk-assessment methods and mitigation techniques are also presented.

Sabotage at Nuclear Power Plants

International Nuclear Information System (INIS)

Purvis, James W.

1999-01-01

Recently there has been a noted worldwide increase in violent actions including attempted sabotage at nuclear power plants. Several organizations, such as the International Atomic Energy Agency and the US Nuclear Regulatory Commission, have guidelines, recommendations, and formal threat- and risk-assessment processes for the protection of nuclear assets. Other examples are the former Defense Special Weapons Agency, which used a risk-assessment model to evaluate force-protection security requirements for terrorist incidents at DOD military bases. The US DOE uses a graded approach to protect its assets based on risk and vulnerability assessments. The Federal Aviation Administration and Federal Bureau of Investigation conduct joint threat and vulnerability assessments on high-risk US airports. Several private companies under contract to government agencies use formal risk-assessment models and methods to identify security requirements. The purpose of this paper is to survey these methods and present an overview of all potential types of sabotage at nuclear power plants. The paper discusses emerging threats and current methods of choice for sabotage--especially vehicle bombs and chemical attacks. Potential consequences of sabotage acts, including economic and political; not just those that may result in unacceptable radiological exposure to the public, are also discussed. Applicability of risk-assessment methods and mitigation techniques are also presented

Water regime of steam power plants

International Nuclear Information System (INIS)

Oesz, Janos

2011-01-01

The water regime of water-steam thermal power plants (secondary side of pressurized water reactors (PWR); fossil-fired thermal power plants - referred to as steam power plants) has changed in the past 30 years, due to a shift from water chemistry to water regime approach. The article summarizes measures (that have been realised by chemists of NPP Paks) on which the secondary side of NPP Paks has become a high purity water-steam power plant and by which the water chemistry stress corrosion risk of heat transfer tubes in the VVER-440 steam generators was minimized. The measures can also be applied to the water regime of fossil-fired thermal power plants with super- and subcritical steam pressure. Based on the reliability analogue of PWR steam generators, water regime can be defined as the harmony of construction, material(s) and water chemistry, which needs to be provided in not only the steam generators (boiler) but in each heat exchanger of steam power plant: - Construction determines the processes of flow, heat and mass transfer and their local inequalities; - Material(s) determines the minimal rate of general corrosion and the sensitivity for local corrosion damage; - Water chemistry influences the general corrosion of material(s) and the corrosion products transport, as well as the formation of local corrosion environment. (orig.)

Are atomic power plants saver than nuclear power plants

International Nuclear Information System (INIS)

Roeglin, H.C.

1977-01-01

It is rather impossible to establish nuclear power plants against the resistance of the population. To prevail over this resistance, a clarification of the citizens-initiatives motives which led to it will be necessary. This is to say: It is quite impossible for our population to understand what really heappens in nuclear power plants. They cannot identify themselves with nuclear power plants and thus feel very uncomfortable. As the total population feels the same way it is prepared for solidarity with the citizens-initiatives even if they believe in the necessity of nuclear power plants. Only an information-policy making transparent the social-psychological reasons of the population for being against nuclear power plants could be able to prevail over the resistance. More information about the technical procedures is not sufficient at all. (orig.) [de

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

International Nuclear Information System (INIS)

Ellingwood, Bruce R.

1998-01-01

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

Benefits and risks of nuclear power

International Nuclear Information System (INIS)

Barnert, H.; Borsch, P.; Feldmann, A.; Merz, E.; Muench, E.; Oesterwind, D.; Voss, A.

1977-03-01

Discussion, in a popular form, of issues of interest for an unemotional information of the public on problems of nuclear power: 1) Energy consumption, its assumed growth, and possible ways of supply; 2) the physical fundamental and technical realisation of power generation by nuclear fission; 3) problems of the fuel cycle and possible solutions; 4) the effects of radioactive radiation; 5) the safety of nuclear power plants and the risks of nuclear power as compared to other technical and natural risks. (orig./HP) [de

In-plant reliability data base for nuclear power plant components: data collection and methodology report

International Nuclear Information System (INIS)

Drago, J.P.; Borkowski, R.J.; Pike, D.H.; Goldberg, F.F.

1982-07-01

The development of a component reliability data for use in nuclear power plant probabilistic risk assessments and reliabiilty studies is presented in this report. The sources of the data are the in-plant maintenance work request records from a sample of nuclear power plants. This data base is called the In-Plant Reliability Data (IPRD) system. Features of the IPRD system are compared with other data sources such as the Licensee Event Report system, the Nuclear Plant Reliability Data system, and IEEE Standard 500. Generic descriptions of nuclear power plant systems formulated for IPRD are given

Application of risk-informed methods to in-service piping inspection in Framatome type nuclear power plants

International Nuclear Information System (INIS)

Kim, Jin Hoi; Lee, Jeong Seok; Yun, Eun Sub

2014-01-01

The Pressurized water reactor owners group (PWROG) developed and applied a risk-informed in-service inspection (RI-ISI) program, as an alternative to the existing ASME Section XI sampling inspection method. The RI-ISI programs enhance overall safety by focusing inspections of piping at high safety significance (HSS) locations where failure mechanisms are likely to be present. Additionally, the RI-ISI program can reduce nondestructive evaluation (NDE) exams, man-rem exposure for inspectors, and inspection time, among other benefits. The RI-ISI method of in-service piping inspection was applied to 3 units (KSNPs: Korea standard nuclear power plants) and is being deployed to the other units. In this paper, the results of RI-ISI for a Framatome type (France CPI) nuclear power plant are presented. It was concluded that application of RI-ISI to the plant could enhance and maintain plant safety, as well as provide the benefits of greater reliability.

Employing modern power plant simulators in nuclear power plants

International Nuclear Information System (INIS)

Niedorf, V.; Storm, J.

2005-01-01

At the present state of the art, modern power plant simulators are characterized by new qualitative features, thus enabling operators to use them far beyond the traditional field of training. In its first part, this contribution presents an overview of the requirements to be met by simulators for multivalent uses. In part two, a survey of the uses and perspectives of simulation technology in power plants is presented on the basis of experience accumulated by Rheinmetall Defence Electronics (RDE).Modern simulators are shown to have applications by far exceeding traditional training areas. Modular client - sever systems on standard computers allow inexpensive uses to be designed at several levels, thus minimizing maintenance cost. Complex development and running time environments, like the SEMS developed by RDE, have made power plant simulators the workhorses of power plant engineers in all power plant areas. (orig.)

Deterministic and probabilistic approach to determine seismic risk of nuclear power plants; a practical example

International Nuclear Information System (INIS)

Soriano Pena, A.; Lopez Arroyo, A.; Roesset, J.M.

1976-01-01

The probabilistic and deterministic approaches for calculating the seismic risk of nuclear power plants are both applied to a particular case in Southern Spain. The results obtained by both methods, when varying the input data, are presented and some conclusions drawn in relation to the applicability of the methods, their reliability and their sensitivity to change

Reactor safety study. An assessment of accident risks in U. S. commercial nuclear power plants. Executive summary: main report. [PWR and BWR

Energy Technology Data Exchange (ETDEWEB)

1975-10-01

Information is presented concerning the objectives and organization of the reactor safety study; the basic concepts of risk; the nature of nuclear power plant accidents; risk assessment methodology; reactor accident risk; and comparison of nuclear risks to other societal risks.

Analysis of risk-dominant sequences by MAAP3.0 for Kuosheng Nuclear Power Plant

International Nuclear Information System (INIS)

Lin, J.D.; Chieng, C.C.; Wang, T.K.; Hsiue, R.K.

1987-01-01

Kuosheng Nuclear Power Plant is the first operating model-6/Mark III boiling water reactor (BWR6/Mark III) in the world, and a probabilistic risk assessment (PRA) has been performed to determine the likely frequencies of core melt accidents and the magnitude, composition, and fraction of fission products released in these accidents. The final report of this PRA indicates that categories 8 and 15 are ranked No. 1 by risk index (the product of release frequency and release fraction) and release frequency, respectively. The dominant contributors of these two categories are frequent earthquakes and typhoons

Seismic PSA method for multiple nuclear power plants in a site

Energy Technology Data Exchange (ETDEWEB)

Hakata, Tadakuni [Nuclear Safety Commission, Tokyo (Japan)

2007-07-15

The maximum number of nuclear power plants in a site is eight and about 50% of power plants are built in sites with three or more plants in the world. Such nuclear sites have potential risks of simultaneous multiple plant damages especially at external events. Seismic probabilistic safety assessment method (Level-1 PSA) for multi-unit sites with up to 9 units has been developed. The models include Fault-tree linked Monte Carlo computation, taking into consideration multivariate correlations of components and systems from partial to complete, inside and across units. The models were programmed as a computer program CORAL reef. Sample analysis and sensitivity studies were performed to verify the models and algorithms and to understand some of risk insights and risk metrics, such as site core damage frequency (CDF per site-year) for multiple reactor plants. This study will contribute to realistic state of art seismic PSA, taking consideration of multiple reactor power plants, and to enhancement of seismic safety. (author)

Kansas Power Plants

Data.gov (United States)

Kansas Data Access and Support Center — The Kansas Power Plants database depicts, as point features, the locations of the various types of power plant locations in Kansas. The locations of the power plants...

Global risk from the atmospheric dispersion of radionuclides by nuclear power plant accidents in the coming decades

Energy Technology Data Exchange (ETDEWEB)

Christoudias, T.; Proestos, Y. [The Cyprus Institute, Nicosia (Cyprus); Lelieveld, J. [The Cyprus Institute, Nicosia (Cyprus); Max Planck Institute for Chemistry, Mainz (Germany)

2014-07-01

We estimate the global risk from the release and atmospheric dispersion of radionuclides from nuclear power plant accidents using the EMAC atmospheric chemistry-general circulation model. We included all nuclear reactors that are currently operational, under construction and planned or proposed. We implemented constant continuous emissions from each location in the model and simulated atmospheric transport and removal via dry and wet deposition processes over 20 years (2010-2030), driven by boundary conditions based on the IPCC A2 future emissions scenario. We present global overall and seasonal risk maps for potential surface layer concentrations and ground deposition of radionuclides, and estimate potential doses to humans from inhalation and ground-deposition exposures to radionuclides. We find that the risk of harmful doses due to inhalation is typically highest in the Northern Hemisphere during boreal winter, due to relatively shallow boundary layer development and limited mixing. Based on the continued operation of the current nuclear power plants, we calculate that the risk of radioactive contamination to the citizens of the USA will remain to be highest worldwide, followed by India and France. By including stations under construction and those that are planned and proposed, our results suggest that the risk will become highest in China, followed by India and the USA.

Environmental impact assessment of coal power plants in operation

OpenAIRE

Bartan Ayfer; Kucukali Serhat; Ar Irfan

2017-01-01

Coal power plants constitute an important component of the energy mix in many countries. However, coal power plants can cause several environmental risks such as: climate change and biodiversity loss. In this study, a tool has been proposed to calculate the environmental impact of a coal-fired thermal power plant in operation by using multi-criteria scoring and fuzzy logic method. We take into account the following environmental parameters in our tool: CO, SO2, NOx, particulate matter, fly as...

Assessment of environmental impacts of nuclear power plants

International Nuclear Information System (INIS)

Horacek, P.

1990-01-01

The effects of normal operation and of accidents are analyzed. It is pointed out that the public is insufficiently informed, which bears anxiety and prejudice. The effective dose equivalents for the population and for the individual, measured during operation of the Bohunice nuclear power plants are listed and compared with those from natural background and from medical applications. The possible radioactive contamination of a large area of agricultural soil is the highest specific risk of nuclear power plant operation. Problems are growing related to spent fuel disposal and eventually to the decommissioning of the power plant itself. (M.D.). 1 tab., 8 refs

Risk management for independent power projects

International Nuclear Information System (INIS)

Owen, J.L.

1993-01-01

Independent Power, where electric utilities or other bulk electric power users contract with individual electric power generation facilities to meet their projected long term power needs, has grown dramatically over the past ten years or more. This concept, to contract with Independent Power Producers (IPP), is not a new concept and in fact goes back to the early formation of the electric power industry in this country and worldwide. Successful Risk Management is the foundation for ultimate project completion and operation in fulfilling the expectations of all parties. The primary risks associated with the development of Independent Power projects include: predicting long term fuel availability and cost; predicting long term price for the deliverable of electricity; site selection, site characteristics and permitting; innovative or evolving technology; project execution (design and construction), and; lifetime O ampersand M costs and plant reliability. This paper focuses on the risks inherent in the development of IPPs and addresses the management of these risks

Risk assessment and nuclear power

International Nuclear Information System (INIS)

Bodansky, D.

1982-01-01

The range of risk perceptions involving nuclear power is so great that there is little hope of bridging extreme positions, but a consensus based upon reasoned discussion among uncommitted people could determine a sensible path. Our concerns over the uncertainties of risk assessment have made it increasingly difficult to make responsible decisions fast enough to deal with modern needs. The result is an immobility in energy matters that can point to a 2% reduction in oil use as its only triumph. The risk of nuclear war as a result of military action over energy issues suggests to some that the solution is to abolish nuclear power (however impractical) and to others that a rapid spread of nuclear power will eliminate energy as an incentive for war. If nuclear war is the major risk to consider, risk assessments need to include the risks of war, as well as those of carbon dioxide buildup and socio-economic disruptions, all of which loom larger than the risks of nuclear-plant accidents. Energy choices should be aimed at diminishing these major risks, even if they include the use of nuclear power. 26 references

Predicting the environmental risks of radioactive discharges from Belgian nuclear power plants.

Science.gov (United States)

Vandenhove, H; Sweeck, L; Vives I Batlle, J; Wannijn, J; Van Hees, M; Camps, J; Olyslaegers, G; Miliche, C; Lance, B

2013-12-01

An environmental risk assessment (ERA) was performed to evaluate the impact on non-human biota from liquid and atmospheric radioactive discharges by the Belgian Nuclear Power Plants (NPP) of Doel and Tihange. For both sites, characterisation of the source term and wildlife population around the NPPs was provided, whereupon the selection of reference organisms and the general approach taken for the environmental risk assessment was established. A deterministic risk assessment for aquatic and terrestrial ecosystems was performed using the ERICA assessment tool and applying the ERICA screening value of 10 μGy h(-1). The study was performed for the radioactive discharge limits and for the actual releases (maxima and averages over the period 1999-2008 or 2000-2009). It is concluded that the current discharge limits for the Belgian NPPs considered do not result in significant risks to the aquatic and terrestrial environment and that the actual discharges, which are a fraction of the release limits, are unlikely to harm the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cooling water in the study of nuclear power plants sites

International Nuclear Information System (INIS)

Martinez, J.J.C.

1990-01-01

The location of an electric power plant has its limitations as regards the availability of apt sites. The radiosanitary risk, seismic risk and the overload capacity of the ground can be generically enumerated, being the cooling water availability for an electric power plant a basic requirement. Diverse cooling systems may be employed but the aim must always be that thermal contamination in the immediate environment be the least possible. (Author) [es

Hydroelectric Power Plants Dobsina

International Nuclear Information System (INIS)

Majercak, V.; Srenkelova, Z.; Kristak, J.G.

1997-01-01

In this brochure the Hydroelectric Power Plants Dobsina, (VED), subsidiary of the utility Slovenske Elektrarne, a.s. (Slovak Electric, plc. Bratislava) are presented. VED is mainly aimed at generating peak-load electrical energy and maintenance of operational equipment. Reaching its goals, company is first of all focused on reliability of production, economy and effectiveness, keeping principles of work safety and industry safety standards and also ecology. VED operates eight hydroelectric power plants, from which PVE Ruzin I and PVE Dobsina I are pump storage ones and they are controlled directly by the Slovak Energy Dispatch Centre located in Zilina thought the system LS 3200. Those power plants participate in secondary regulation of electrical network of Slovakia. They are used to compensate balance in reference to foreign electrical networks and they are put into operation independently from VED. Activity of the branch is focused mainly on support of fulfilment of such an important aim as electric network regulation. Beginnings of the subsidiary Hydroelectric Power Plants Dobsina are related to the year of 1948. After commissioning of the pump storage Hydroelectric Power Plants Dobsina in 1953, the plant started to carry out its mission. Since that time the subsidiary has been enlarged by other seven power plants, through which it is fulfilling its missions nowadays. The characteristics of these hydroelectric power plants (The pump-storage power plant Dobsina, Small hydroelectric power plant Dobsina II, Small hydroelectric power plant Rakovec, Small hydroelectric power plant Svedlar, Hydroelectric power plant Domasa, The pump-storage power plant Ruzin, and Small hydroelectric power plant Krompachy) are described in detail. Employees welfare and public relations are presented

Radiological protection and nuclear power plants

International Nuclear Information System (INIS)

Delpla, M.

Dosimetric results obtained inside and outside nuclear power plants are examined with a review to proposing revision of the radiological protection standards. Dose limits are considered with regard to leukemia and genetic effects. Other topics discussed are: observed collective damage and mean risk; lethal exposure; healing and sign change of additional risk; and genetic effects of radiation on mice

Comparative studies between nuclear power plants and hydroelectric power plants

International Nuclear Information System (INIS)

Menegassi, J.

1984-01-01

This paper shows the quantitative evolution of the power plants in the main countries of the world. The Brazilian situation is analysed, with emphasys in the technical and economical aspects related to power production by hidroelectric or nuclear power plants. The conclusion is that the electricity produced by hidro power plants becomes not economics when is intended to be produced at large distances from the demand centers. (Author) [pt

Validation of seismic probabilistic risk assessments of nuclear power plants

International Nuclear Information System (INIS)

Ellingwood, B.

1994-01-01

A seismic probabilistic risk assessment (PRA) of a nuclear plant requires identification and information regarding the seismic hazard at the plant site, dominant accident sequences leading to core damage, and structure and equipment fragilities. Uncertainties are associated with each of these ingredients of a PRA. Sources of uncertainty due to seismic hazard and assumptions underlying the component fragility modeling may be significant contributors to uncertainty in estimates of core damage probability. Design and construction errors also may be important in some instances. When these uncertainties are propagated through the PRA, the frequency distribution of core damage probability may span three orders of magnitude or more. This large variability brings into question the credibility of PRA methods and the usefulness of insights to be gained from a PRA. The sensitivity of accident sequence probabilities and high-confidence, low probability of failure (HCLPF) plant fragilities to seismic hazard and fragility modeling assumptions was examined for three nuclear power plants. Mean accident sequence probabilities were found to be relatively insensitive (by a factor of two or less) to: uncertainty in the coefficient of variation (logarithmic standard deviation) describing inherent randomness in component fragility; truncation of lower tail of fragility; uncertainty in random (non-seismic) equipment failures (e.g., diesel generators); correlation between component capacities; and functional form of fragility family. On the other hand, the accident sequence probabilities, expressed in the form of a frequency distribution, are affected significantly by the seismic hazard modeling, including slopes of seismic hazard curves and likelihoods assigned to those curves

Circumstances in a nuclear power plant. Organization of risk and institutionalization of safety; Omstaendigheter paa ett kaernkraftverk. Organisering av risk och institutionalisering av saekerhet

Energy Technology Data Exchange (ETDEWEB)

Wessblad, H

1999-01-01

Risk societies are made of risk organisations. This dissertation is an ethnographic study of a risk organisation, of a nuclear power plant. Risk organizations have larger demands on their organization than traditional companies have. Risk societies, to come or already present, have new political agendas. Within a risk society the major task is to reduce and distribute the negative side effects of industrial production, not to increase and distribute well-fare in society, as it has been in an industrial society. This is a study of a risk organisation claimed to produce these negative side effects. The title of this thesis relates to specific occasions in the organisation. The branch concept, circumstances, defines `situations beyond normal performance`, which are to be reported to the nuclear authorities. These circumstances are rarely endangering man or material, but given the nature of nuclear power production, they have a potential to escalate to something larger. This dissertation focuses on how the organisation deals with these issues and reproduces safety as something taken-for-granted. The material is gathered using participant observation of different functions in the plant. The work is based on narration of situations, meetings, interviews, and small talk etc, in every-day-interaction. The dissertation describes how business-as-usual produce safety. It is a description of how values, norms, attitudes, ideas, knowledge are produced and reproduced. These issues are discussed mainly in an institutional theory perspective. What has become apparent is that functions governed by routines and instructions tend to be more flexible and reflecting than those dealing with new tasks, such as problem solving projects. Thus, these new projects tend to reproduce earlier established procedures. Through the narration of the various functions of the plant joined with theoretical discussions, different themes have been found describing how the organisation deals with

FIRE SAFETY IN NUCLEAR POWER PLANTS: A RISK-INFORMED AND PERFORMANCE-BASED APPROACH

International Nuclear Information System (INIS)

AZARM, M.A.; TRAVIS, R.J.

1999-01-01

The consideration of risk in regulatory decision-making has long been a part of NRC's policy and practice. Initially, these considerations were qualitative and were based on risk insights. The early regulations relied on good practices, past insights, and accepted standards. As a result, most NRC regulations were prescriptive and were applied uniformly to all areas within the regulatory scope. Risk technology is changing regulations by prioritizing the areas within regulatory scope based on risk, thereby focusing on the risk-important areas. Performance technology, on the other hand, is changing the regulations by allowing requirements to be adjusted based on the specific performance expected and manifested, rather than a prior prescriptive requirement. Consistent with the objectives of risk-informed and performance-based regulatory requirements, BNL evaluated the feasibility of applying risk- and performance-technologies to modifying NRC's current regulations on fire protection for nuclear power plants. This feasibility study entailed several case studies (trial applications). This paper describes the results of two of them. Besides the case studies, the paper discusses an overall evaluation of methodologies for fire-risk analysis to support the risk-informed regulation. It identifies some current shortcomings and proposes some near-term solutions

Reanalysis of Epidemiological Investigation of Cancer Risk among People Residing near Nuclear Power Plants in South Korea.

Science.gov (United States)

Kim, Jeong-Min; Kim, Myoung-Hee; Ju, Young-Su; Hwang, Seung-Sik; Ha, Mina; Kim, Bong-Kyu; Zoh, Kyung Ehi; Paek, Domyung

2018-03-09

Background : A 20-year follow-up study on cancer incidence among people living near nuclear power plants in South Korea ended in 2011 with a finding of significantly, but inconsistently, elevated thyroid cancer risk for females. Reanalysis of the original study was carried out to examine the dose-response relationship further, and to investigate any evidence of detection bias. Methods : In addition to replicating the original Cox proportional hazards models, nested case-control analysis was carried out for all subjects and for four different birth cohorts to examine the effects of excluding participants with pre-existing cancer history at enrollment. The potential for detection bias was investigated using the records of medical utilization and voluntary health checks of comparison groups. Results : The overall risk profile of the total sample was similar to that of the original study. However, in the stratified analysis of four birth cohorts, the cancer risk among people living near nuclear power plants became higher in younger birth cohorts. This was especially true for thyroid cancers of females (hazard ratio (HR) 3.38) and males (HR 1.74), female breast cancers (HR 2.24), and radiation-related cancers (HR 1.59 for males, HR 1.77 for females), but not for radiation-insensitive cancers (HR 0.59 for males, HR 0.98 for females). Based on medical records and health check reports, we found no differences between comparison groups that could have led to detection bias. Conclusions : The overall results suggest elevated risk of radiation-related cancers among residents living near nuclear power plants, controlling for the selective survival effect. This is further supported by the lack of evidence of detection bias and by records of environmental exposure from radiation waste discharge.

Reanalysis of Epidemiological Investigation of Cancer Risk among People Residing near Nuclear Power Plants in South Korea

Directory of Open Access Journals (Sweden)

Jeong-Min Kim

2018-03-01

Full Text Available Background: A 20-year follow-up study on cancer incidence among people living near nuclear power plants in South Korea ended in 2011 with a finding of significantly, but inconsistently, elevated thyroid cancer risk for females. Reanalysis of the original study was carried out to examine the dose–response relationship further, and to investigate any evidence of detection bias. Methods: In addition to replicating the original Cox proportional hazards models, nested case-control analysis was carried out for all subjects and for four different birth cohorts to examine the effects of excluding participants with pre-existing cancer history at enrollment. The potential for detection bias was investigated using the records of medical utilization and voluntary health checks of comparison groups. Results: The overall risk profile of the total sample was similar to that of the original study. However, in the stratified analysis of four birth cohorts, the cancer risk among people living near nuclear power plants became higher in younger birth cohorts. This was especially true for thyroid cancers of females (hazard ratio (HR 3.38 and males (HR 1.74, female breast cancers (HR 2.24, and radiation-related cancers (HR 1.59 for males, HR 1.77 for females, but not for radiation-insensitive cancers (HR 0.59 for males, HR 0.98 for females. Based on medical records and health check reports, we found no differences between comparison groups that could have led to detection bias. Conclusions: The overall results suggest elevated risk of radiation-related cancers among residents living near nuclear power plants, controlling for the selective survival effect. This is further supported by the lack of evidence of detection bias and by records of environmental exposure from radiation waste discharge.

Sea water pumping-up power plant system combined with nuclear power plant

International Nuclear Information System (INIS)

Ichiki, Tadaharu; Tanaka, Masayuki.

1991-01-01

It is difficult to find a site suitable to construction for a sea water pumping-up power plant at a place relatively near the electric power consumption area. Then, a nuclear power plant is set at the sea bottom or the land portion of a sea shore near the power consumption area. A cavity is excavated underground or at the bottom of the sea in the vicinity of the power plant to form a lower pond, and the bottom of the sea, as an upper pond and the lower pond are connected by a water pressure pipe and a water discharge pipe. A pump water turbine is disposed therebetween, to which electric power generator is connected. In addition, an ordinary or emergency cooling facility in the nuclear power plant is constituted such that sea water in the cavity is supplied by a sea water pump. Accordingly, the sea water pumping-up plant system in combination with the nuclear power plant is constituted with no injuring from salts to animals and plants on land in the suburbs of a large city. The cost for facilities for supplying power from a remote power plant to large city areas and power loss are decreased and stable electric power can be supplied. (N.H.)

Risk zoning around nuclear power plants in comparison to other major hazardous industrial installations

International Nuclear Information System (INIS)

Kirchsteiger, Christian

2006-01-01

The background and current status of the information basis leading to the definition of risk and emergency zones around Nuclear Power Plants (NPPs) in different countries in Europe and beyond are analysed. Although dependable plant-specific Probabilistic Safety Assessment (PSA) of Level 2 and/or Level 3 could in principle provide sufficiently detailed input to define the geographical dimension of a NPP's risk and emergency zones, the analysis of the status in some European and other countries shows that other, 'deterministic' approaches using a Reference Accident are actually used in practice. Regarding use of Level 2 PSA for emergency planning, the approach so far has been to use the Level 2 PSA information retrospectively to provide the justification for the choice of Reference Accident(s) used to define the emergency plans and Emergency Planning Zones (EPZs). There are significant differences in the EPZs that are defined in different countries, ranging from about 1 km to 30 km. Further, there is a striking contrast in the extent of using probabilistic information to define emergency zones between the nuclear and other high risk industry sectors, such as the chemical process industry, and the reasons for these differences are not entirely clear, but seem to be more related to risk perception than actual risk potential. Finally, based on consensus discussions at a recent JRC/OECD International Seminar on Risk and Emergency Zoning around NPPs, recommendations are given in the areas of more comprehensive use of available risk information for risk zoning purposes, risk communication and comparative risk assessment. (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)

Guidance for emergency planning in nuclear power plants

International Nuclear Information System (INIS)

Magnusson, Tommy; Ekdahl, Maria

2008-06-01

Ringhals has been a model for this study, but the purpose has been to make the report applicable at all nuclear power plants in Sweden. The work has been done in close co-operation with the Swedish nuclear power plants and Rescue Services in the nuclear power municipalities Oesthammar, Oskarshamn, and Varberg. The internal fire brigade at the nuclear power plants has also been involved. A document will also be published as a further guidance at efforts of the type fires, which are mentioned in the enclosed document. After a fire in a switchgear room in 2005 the need of making the existing effort planning more effective at nuclear power plants was observed. The idea with the planning is to plan the effort in order to give the operational and emergency staff a good and actual support to come to a decision and to start the mission without delay. The risk information is showed by planning layouts, symbols and drawings as basis, give risk information and effort information. The effort information shows outer arrangements, manual action points, fire installations, passive fire safety etc. The risk information is shown by risk symbols. Their purpose is to give a fast overview of the existing risks. Reactor safety effects is the ruling influence if an effort has to be done in order to secure safety for a third person. In order to make an effort in an area personal risks for rescue staff, such as electricity risks, radiological risks, chemicals and gas bottles with compressed gases, has to be eliminated. For complicated missions detailed instructions are needed in order to handle specific risks. In a group discussion different people with pertinent knowledge has to value which problematic efforts need detailed instruction. Missions that have to be analyzed in a work group as above are: fire may affect the reactor safety, fire that may threaten the structural integrity, chemical discharge with big consequence on environment/third person and handling of gas system (compressed

Common Risk Target for severe accidents of nuclear power plants based on IAEA INES scale

International Nuclear Information System (INIS)

Vitázková, Jiřina; Cazzoli, Errico

2013-01-01

The IAEA has repeatedly recommended that the nuclear community should arrive at a common understanding and definition of safety goals for severe accidents in nuclear power plants. The recommendation has only found partial answers, despite the numerous working groups and forums devoted to this effort. The most widely accepted definition of goals is based on the concept of Large (Early) Release Frequencies (L(E)RF) and its derivatives, a surrogate concept derived from results of Probabilistic Safety Assessments (PSAs) which was first introduced in the USA almost twenty years ago and much later accepted by the USNRC for risk informed decision making, but not for safety demonstrations. Other types of Safety Goals have been adopted by some nuclear authorities, but the main drawback of all current definitions is that they may apply only to LWRs. The lack of unifying safety/risk parameter throughout of PSAs worldwide is the basis of the present work, and an attempt is made to arrive at the definition of a Risk Target for severe accidents in NPPs, consistent with the IAEA definitions having a technical basis, which can be adopted without modifications for Generation IV power plants. The proposal of Common Risk Target in this work represents an attempt to define a Common Risk Target based on technical reasoning, reflecting IAEA definitions as well as harmonization requirements raised by the whole European Community in various OECD, ASAMPSA2 and SARNET (Guentay et al., 2006) conclusions and Council Directive of The European Union (Community Framework, 2009) as well as lastly performed stress tests of nuclear power plants throughout the Europe (Peer Review Report, 2012). The basic concept of CRT was first introduced and developed within the European project ASAMPSA2 by the authors of this article and was accepted by majority of world PSA experts participating in final evaluation and survey of the project (Guentay, 2011). In the proposed Risk Target concept an innovative

Common Risk Target for severe accidents of nuclear power plants based on IAEA INES scale

Energy Technology Data Exchange (ETDEWEB)

Vitázková, Jiřina, E-mail: jirina@snus.sk [Vitázková-Vitty, Sládkovičova 24, 900 28 Ivanka pri Dunaji (Slovakia); Cazzoli, Errico, E-mail: erik.cazzoli@gmx.net [Cazzoli Consulting, Wiesenweg 14, CH-5415 Nussbaumen (Switzerland)

2013-09-15

The IAEA has repeatedly recommended that the nuclear community should arrive at a common understanding and definition of safety goals for severe accidents in nuclear power plants. The recommendation has only found partial answers, despite the numerous working groups and forums devoted to this effort. The most widely accepted definition of goals is based on the concept of Large (Early) Release Frequencies (L(E)RF) and its derivatives, a surrogate concept derived from results of Probabilistic Safety Assessments (PSAs) which was first introduced in the USA almost twenty years ago and much later accepted by the USNRC for risk informed decision making, but not for safety demonstrations. Other types of Safety Goals have been adopted by some nuclear authorities, but the main drawback of all current definitions is that they may apply only to LWRs. The lack of unifying safety/risk parameter throughout of PSAs worldwide is the basis of the present work, and an attempt is made to arrive at the definition of a Risk Target for severe accidents in NPPs, consistent with the IAEA definitions having a technical basis, which can be adopted without modifications for Generation IV power plants. The proposal of Common Risk Target in this work represents an attempt to define a Common Risk Target based on technical reasoning, reflecting IAEA definitions as well as harmonization requirements raised by the whole European Community in various OECD, ASAMPSA2 and SARNET (Guentay et al., 2006) conclusions and Council Directive of The European Union (Community Framework, 2009) as well as lastly performed stress tests of nuclear power plants throughout the Europe (Peer Review Report, 2012). The basic concept of CRT was first introduced and developed within the European project ASAMPSA2 by the authors of this article and was accepted by majority of world PSA experts participating in final evaluation and survey of the project (Guentay, 2011). In the proposed Risk Target concept an innovative

Licensing issues in the context of terrorist attacks on nuclear power plants

International Nuclear Information System (INIS)

Danwitz, T. von

2002-01-01

The terrorist attack on the World Trade Center in September 2001 has prompted enhanced nuclear risk awareness among the German population. But in the current public debate about the safety of nuclear power plants in Germany in times of new dimensions of danger, aspects such as the role of the constitutional law, the German Atomic Energy Act, and the regulatory system governing nuclear power plant licensing in the context of protection and safety have not been addressed. The author therefore discusses the German nuclear power plant licensing law and administrative regime, elaborating on the significance attributed in those bodies of law to risks like terrorist attacks on nuclear power plants. (orig./CB) [de

Nuclear power investment risk economic model

International Nuclear Information System (INIS)

Houghton, W.J.; Postula, F.D.

1985-12-01

This paper describes an economic model which was developed to evaluate the net costs incurred by a utility due to an accident induced outage at a nuclear power plant. During such an outage the portion of the plant operating costs associated with power production are saved; however, the owning utility faces a sizable expense as fossil fuels are burned as a substitute for the incapacitated nuclear power. Additional expenses are incurred by the utility for plant repair and if necessary, decontamination costs. The model makes provision for mitigating these costs by sales of power, property damage insurance payments, tax write-offs and increased rates. Over 60 economic variables contribute to the net cost uncertainty. The values of these variables are treated as uncertainty distributions and are used in a Monte carlo computer program to evaluate the cost uncertainty (investment risk) associated with damage which could occur from various categories of initiating accidents. As an example, results of computations for various levels of damage associated with a loss of coolant accident are shown as a range of consequential plant downtime and unrecovered cost. A typical investment risk profile is shown for these types of accidents. Cost/revenue values for each economic factor are presented for a Three Mile Island - II type accident, e.g., uncontrolled core heatup. 4 refs., 6 figs., 3 tabs

Coping with nuclear power risks: the electric utility incentives

International Nuclear Information System (INIS)

Starr, C.; Whipple, C.

1982-01-01

The financial risks associated with nuclear power accidents are estimated by interpolating between frequency-vs.-severity data from routine outages and the frequency-vs.-severity estimates from the Nuclear Regulatory Commission's (NRC's) Reactor Safety Study (WASH-1400). This analysis indicates that the expected costs of plant damage and lost power production are large compared to the public risks estimated in WASH-1400, using values from An Approach to Quantitative Safety Goals for Nuclear Power Plants (NUREG-0739), prepared by the NRC Advisory Committee on Reactor Safeguards. Analyses of the cost-effectiveness of accident-prevention investments that include only anticipated public safety benefits will underestimate the value of such investments if reductions in power plant damage risk are not included. The analysis also suggests that utility self-interest and the public interest in safety are generally coincident. It is argued that greater use could be made of this self-interest in regulation if the relationship between the NRC and the industry were more cooperative, less adversary in nature

Risk monitors - The State of the Art in their Development and Use at Nuclear Power Plants - Produced on behalf of IAEA and OECD/NEA WGRisk

International Nuclear Information System (INIS)

Shepherd, C.H.; Yllera, F.J.; Kaufer, B.; Henneke, D.W.; Gaynor, D.; Sedlak, J.; Evans, M.G.K.; Boneham, P.; Horne, B.; Guymer, P.; Hatfield, M.; Hewitt, J.; Shanley, L.; Sorman, J.; Chao, C.C.; Pullen, R.; Reinhart, F.M.; Lantaron, A.; Huerta, A.; Vojnovic, D.; Hollo, E.; Fukuda, M.; De Gelder, P.; Schulz, R.; Lanore, J.M.

2004-01-01

This report provides a description of the state-of-the-art in the development and use of Risk Monitors at nuclear power plants in the Member States. The work has been carried out jointly by IAEA and OECD WGRisk. The information presented in this report has been obtained from three questionnaires on the development and use of Risk Monitors, software and Regulatory perspectives; from OECD and IAEA Workshops on Risk Monitors; and from IAEA consultants meetings and WGRisk Task Group meetings. Some of the work carried out to produce the report has been funded by the United Kingdom Nuclear Installations Inspectorate. The aim is to produce a report that describes the state of the art in the development of Risk Monitors and their use at nuclear power plants. This will: - define the terminology that relates to Risk Monitors as used in this report, - describe the state of the art in the development and use of Risk Monitors at nuclear power plants, and indicate future developments, - provide information on the software packages available for Risk Monitors, - identify the issues that need to be addressed in the development of a Living PSA for use in a Risk Monitor application and give guidance on how these issues can be resolved, - give information on the issues relating to the design of the Risk Monitor operator interface so that it gives a tool that can be used by all station staff, - discuss the issues that relate to the qualitative and quantitative risk measures addressed by Risk Monitors such as the definition of the Operational Safety Criteria which define the risk levels, the calculation of the Allowed Configuration Time and the definition of the qualitative risk levels that relate to the availability of safety systems, - give insights into the costs involved, the benefits that can be obtained from Risk Monitors and their limitations, and - discuss the regulatory perspective on the use of Risk Monitors to provide risk information that can be used during nuclear power

Thermonuclear power plants and the environment

International Nuclear Information System (INIS)

Becka, J.

1978-01-01

Environmental safety and protection from the effects of the thermonuclear power plants are discussed. Factors are assessed which should be considered in the choice of fuel and breeding material of a thermonuclear reactor, the problems of structural material activation and the overall reactor concepts. Main specifications are given of the US thermonuclear power plant projects with D-T reaction based reactors. The overall amounts of tritium in the reactor cycles are shown. The potential biological risk is evaluated for the different materials considered for the UWMAK-1 project. Discussed are possible pathways of activity release in normal plant operation, non-radioactive aspects, such as waste heat, the magnetic field effect on personnel and population, etc., as well as possible environmental impacts in case of accidents. (B.S.)

Evaluation of Foreign Investment in Power Plants using Real Options

Science.gov (United States)

Kato, Moritoshi; Zhou, Yicheng

This paper proposes new methods for evaluating foreign investment in power plants under market uncertainty using a real options approach. We suppose a thermal power plant project in a deregulated electricity market. One of our proposed methods is that we calculate the cash flow generated by the project in a reference year using actual market data to incorporate periodic characteristics of energy prices into a yearly cash flow model. We make the stochastic yearly cash flow model with the initial value which is the cash flow in the reference year, and certain trend and volatility. Then we calculate the real options value (ROV) of the project which has abandonment options using the yearly cash flow model. Another our proposed method is that we evaluate foreign currency/domestic currency exchange rate risk by representing ROV in foreign currency as yearly pay off and exchanging it to ROV in domestic currency using a stochastic exchange rate model. We analyze the effect of the heat rate and operation and maintenance costs of the power plant on ROV, and evaluate exchange rate risk through numerical examples. Our proposed method will be useful for the risk management of foreign investment in power plants.

Significance of earthquake risk in nuclear power plant probabilistic risk assessments

International Nuclear Information System (INIS)

Sues, R.H.; Amico, P.J.; Campbell, R.D.

1990-01-01

During the last eight years, approximately 25 utility-sponsored probabilistic risk assessments (PRAs) have been conducted for US nuclear reactors. Of these, ten have been published, seven of which have included complete seismic risk assessment. The results of the seven published PRAs are reviewed here in order to ascertain the significance of the risk due to earthquake initiating events. While PRA methodology has been in a state of development over the past seven years, and the results are subject to interpretation (as discussed in the paper), from the review conducted it is clear that earthquake-induced initiating events are important risk contributors. It is concluded that earthquake initiating events should not be dismissed, a priori, in any nuclear plant risk assessment. (orig.)

Low Power Shutdown PSA for CANDU Type Plants

Energy Technology Data Exchange (ETDEWEB)

Bae, Yeon Kyoung; Kim, Myung Su [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

KHNP also have concentrated on full power PSA. Some recently constructed OPR1000 type plants and APR1400 type plants have performed the low power and shutdown (LPSD) PSA. The purpose of LPSD PSA is to identify the main contributors on the accident sequences of core damage and to find the measure of safety improvement. After the Fukushima accident, Korean regulatory agency required the shutdown severe accident management guidelines (SSAMG) development for safety enhancement. For the reliability of SSAMG, KHNP should develop the LPSD PSA. Especially, the LPSD PSA for CANDU type plant had developed for the first time in Korea. This paper illustrates how the LPSD PSA for CANDU type developed and the core damage frequency (CDF) is different with that of full power PSA. KHNP performed LPSD PSA to develop the SSAMG after the Fukushima accidents. The results show that risk at the specific operation mode during outage is higher than that of full power operation. Also, the results indicated that recovery failure of class 4 power at the POS 5A, 5B contribute dominantly to the total CDF from importances analysis. LPSD PSA results such as CDF with initiating events and POSs, risk results with plant damage state, and containment failure probability and frequency with POSs can be used by inputs for developing the SSAMG.

Voltage Feedback based Harmonic Compensation for an Offshore Wind Power Plant

DEFF Research Database (Denmark)

Chaudhary, Sanjay K.; Lascu, Cristian; Teodorescu, Remus

2016-01-01

When an offshore wind power plant is connected to the grid, there is a risk of amplification of certain harmonics and appearance resonances at the point of connection due to the interaction between the grid network and the wind power plant network. Hence, the plant developer is obliged to maintain...

The Risk Management in New Technology Deployment to Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Jung, Kil Young; Roh, Myung Sub [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2013-10-15

This paper figures out that it is required to build the structured and integrated risk management system in enterprise level. By means of it, the accumulated data and experience of work can be shared and transferred effectively among workers, and consequently design mistake or error can be reduced. It has been requested to upgrade and replace equipment in Nuclear Power Plant (NPP) with new technology because of obsolescence and spare parts issues, and demands for higher performance. The processes for the new technology deployment to NPP, however, may have risks causing the unpredictable outcomes leading to the degradation of performance or operation. Therefore, the proper risk management is essential for ensuring safety and performance of NPP since it provides means to identify risks and minimizing their impacts. For these reason, this paper aims at investigating how the risk is managed and presents the proper risk management in project for the deployment of new technology to NPP. This paper investigated how the risk is managed in the NPP industry. Risk is perceived as a negative term that brings negative impact on project objectives. 10 key risks are identified and classified as high risk on cost, time, scope, or quality in compliance with the criteria seeking 'Safety First'. Design mistake or error' can significantly influence three project objectives while the rest risks can significantly influence one or two project objectives. However, it is also found that there are neither structured ways nor a systematical approach to perform the proper risk management. As a result, risk management such as identification, assessment, and response is mostly performed in the individual level laying much weight on experience since the most common methods are past experience and review of similar case.

The Risk Management in New Technology Deployment to Nuclear Power Plant

International Nuclear Information System (INIS)

Jung, Kil Young; Roh, Myung Sub

2013-01-01

This paper figures out that it is required to build the structured and integrated risk management system in enterprise level. By means of it, the accumulated data and experience of work can be shared and transferred effectively among workers, and consequently design mistake or error can be reduced. It has been requested to upgrade and replace equipment in Nuclear Power Plant (NPP) with new technology because of obsolescence and spare parts issues, and demands for higher performance. The processes for the new technology deployment to NPP, however, may have risks causing the unpredictable outcomes leading to the degradation of performance or operation. Therefore, the proper risk management is essential for ensuring safety and performance of NPP since it provides means to identify risks and minimizing their impacts. For these reason, this paper aims at investigating how the risk is managed and presents the proper risk management in project for the deployment of new technology to NPP. This paper investigated how the risk is managed in the NPP industry. Risk is perceived as a negative term that brings negative impact on project objectives. 10 key risks are identified and classified as high risk on cost, time, scope, or quality in compliance with the criteria seeking 'Safety First'. Design mistake or error' can significantly influence three project objectives while the rest risks can significantly influence one or two project objectives. However, it is also found that there are neither structured ways nor a systematical approach to perform the proper risk management. As a result, risk management such as identification, assessment, and response is mostly performed in the individual level laying much weight on experience since the most common methods are past experience and review of similar case

Risk based optimization of technical specifications for operation of nuclear power plants

International Nuclear Information System (INIS)

1993-12-01

The objective of the report is to present an overview of the risk and reliability based approaches (using a probabilistic safety assessment (PSA)) for improving nuclear power plant technical specifications (TS). In that case, it will provide an information base to the Member States in seeking PSA based applications to enhance the effectiveness of their technical specifications. To achieve this objective, the report discusses the basic objectives and reasons for seeking TS changes, the methods, data requirements and uses of different types of applications, and an overview of different applications that have been completed, including detailed descriptions of selected applications. Refs, figs and tabs

I and C upgrading at nuclear power plants

International Nuclear Information System (INIS)

Tamiri, A.

2003-01-01

Continuing the operation of existing nuclear power plants will help reduce the number of new base-load nuclear and fossil power plants that need to be built. Old nuclear power plants in Canada are operating with analog instrumentation and control systems. For a number of reasons, such as changes and improvements in the applicable standards and design, maintenance problems due to the lack of spares, technical obsolescence, the need to increase power production, availability, reliability and safety, and in order to reduce operation and maintenance costs, instrumentation and control upgrading at nuclear power plants in a cost effective manner should be considered the greatest priority. Failures of instrumentation and control (I and C) due to aging and obsolescence issues may have an immediate negative impact on plant reliability and availability and also affect long-term plant performance and safety. In today's competitive marketplace, power plants are under pressure to cut spending on maintenance while reducing the risk of equipment failure that could cause unplanned outage. To improve plant safety and availability, old nuclear power plants will require investment in new technologies that can improve the performance and reduce the costs of generation by addressing the long term reliability of systems by up-grading to modem digital instrumentation and control and optimization opportunities. Boiler drum level control at nuclear power plants is critical for both plant protection and equipment safety and applies equality to high and low levels of water within the boiler drum. Plant outage studies at Pickering Nuclear have identified boiler drum level control and feed water control systems as major contributors to plant unavailability. Ways to improve transient and steady state response, upgrading existing poor analog control systems for boiler level and feed-water control systems at Pickering Nuclear, with enhanced and robust controller will be discussed in this paper

Emergency response and nuclear risk governance. Nuclear safety at nuclear power plant accidents

International Nuclear Information System (INIS)

Kuhlen, Johannes

2014-01-01

The present study entitled ''Emergency Response and Nuclear Risk Governance: nuclear safety at nuclear power plant accidents'' deals with issues of the protection of the population and the environment against hazardous radiation (the hazards of nuclear energy) and the harmful effects of radioactivity during nuclear power plant accidents. The aim of this study is to contribute to both the identification and remediation of shortcomings and deficits in the management of severe nuclear accidents like those that occurred at Chernobyl in 1986 and at Fukushima in 2011 as well as to the improvement and harmonization of plans and measures taken on an international level in nuclear emergency management. This thesis is divided into a theoretical part and an empirical part. The theoretical part focuses on embedding the subject in a specifically global governance concept, which includes, as far as Nuclear Risk Governance is concerned, the global governance of nuclear risks. Due to their characteristic features the following governance concepts can be assigned to these risks: Nuclear Safety Governance is related to safety, Nuclear Security Governance to security and NonProliferation Governance to safeguards. The subject of investigation of the present study is as a special case of the Nuclear Safety Governance, the Nuclear Emergency governance, which refers to off-site emergency response. The global impact of nuclear accidents and the concepts of security, safety culture and residual risk are contemplated in this context. The findings (accident sequences, their consequences and implications) from the analyses of two reactor accidents prior to Fukushima (Three Mile Iceland in 1979, Chernobyl in 1986) are examined from a historical analytical perspective and the state of the Nuclear Emergency governance and international cooperation aimed at improving nuclear safety after Chernobyl is portrayed by discussing, among other topics, examples of &apos

Man as a protective barrier in nuclear power plants

International Nuclear Information System (INIS)

Fechner, J.B.

1980-01-01

Evaluation of nuclear power plant incidents frequently reveals man as a major element of risk. Yet, in a nuclear power plant man has the function of an important protective barrier, either by maintaining the plant, by detecting and limiting faults or incidents, or by taking proper measures in accidents. This is true despite, or perhaps because of, the high degree of plant automation. For this reason, it is indispensable that a high level of engineered plant safeguards be accompanied by a minimum of faults contributed by human action. This implies that the staff and their working conditions must meet the same stringent safety requirements as the nuclear power plant proper. Reactor manufacturers, nuclear power plant operators and the responsible authorities try to optimize this human contribution. The Federal Ministry of the Interior, through its Special Technical Guidelines and its continuation training measures, occupies an important position in this respect. Further measures and ordinances are being prepared by that Ministry. (orig.) [de

Safety goals for nuclear power plants: a discussion paper

International Nuclear Information System (INIS)

1982-02-01

This report includes a proposed policy statement on safety goals for nuclear power plants published by the Commission for public comment and a supporting discussion paper. Proposed qualitative goals and associated numerical guidelines for nuclear power-plant accident risks are presented. The significance of the goals and guidelines, their bases and rationale, and their proposed mode of implementation are discussed

Radiation risk analysis of tritium in PWR plants

International Nuclear Information System (INIS)

Yang Maochun; Wang Shimin

1999-03-01

Tritium is a common radionuclide in PWR nuclear power plant. In the normal operation conditions, its radiation risk to plant workers is the internal radiation exposure when tritium existing in air as HTO (hydrogen tritium oxide) is breathed in. As the HTO has the same physical and chemical characteristics as water, the main way that HTO entering the air is by evaporation. There are few opening systems in Nuclear Power Plant, the radiation risk of tritium mainly exists near the area of spent fuel pit and reactor pit. The highest possible radiation risk it may cause--the maximum concentration in air is the level when equilibrium is established between water and air phases for tritium. The author analyzed the relationship among the concentration of HTO in water, in air and the water temperature when equilibrium is established, the equilibrated HTO concentration in air increases with HTO concentration in water and water temperature. The analysis revealed that at 30 degree C, the equilibrated HTO concentration in air might reach 1 DAC (derived air concentration) when the HTO concentration in water is 28 GBq/m 3 . Owing to the operation of plant ventilation systems and the existence of moisture in the input air of the ventilation, the practical tritium concentration in air is much lower than its equilibrated levels, the radiation risk of tritium in PWR plant is quite limited. In 1997, Daya Bay Nuclear Power Plant's practical monitoring result of the HTO concentration in the air of the nuclear island and the urine of workers supported this conclusion. Based on this analysis, some suggestions to the reduction of tritium radiation risk were made

Probabilistic evaluation of risks associated with aviation, road, railway and river traffic adjacent to nuclear power plants in France

International Nuclear Information System (INIS)

Procaccia, H.; Gobert, T.

1978-01-01

Electricite de France has developed a methodology to calculate the potential impact of risks to a nuclear power plant subsequent to an accident occurring on transportation networks in the vicinity of a nuclear site. Risks entailed in aviation, and in road, rail, and river traffic have been estimated. This methodology has been applied to all sites planned in France

FIRE SAFETY IN NUCLEAR POWER PLANTS: A RISK-INFORMED AND PERFORMANCE-BASED APPROACH

Energy Technology Data Exchange (ETDEWEB)

AZARM,M.A.; TRAVIS,R.J.

1999-11-14

The consideration of risk in regulatory decision-making has long been a part of NRC's policy and practice. Initially, these considerations were qualitative and were based on risk insights. The early regulations relied on good practices, past insights, and accepted standards. As a result, most NRC regulations were prescriptive and were applied uniformly to all areas within the regulatory scope. Risk technology is changing regulations by prioritizing the areas within regulatory scope based on risk, thereby focusing on the risk-important areas. Performance technology, on the other hand, is changing the regulations by allowing requirements to be adjusted based on the specific performance expected and manifested, rather than a prior prescriptive requirement. Consistent with the objectives of risk-informed and performance-based regulatory requirements, BNL evaluated the feasibility of applying risk- and performance-technologies to modifying NRC's current regulations on fire protection for nuclear power plants. This feasibility study entailed several case studies (trial applications). This paper describes the results of two of them. Besides the case studies, the paper discusses an overall evaluation of methodologies for fire-risk analysis to support the risk-informed regulation. It identifies some current shortcomings and proposes some near-term solutions.

Financing Solar Thermal Power Plants

International Nuclear Information System (INIS)

Price, Henry W.; Kistner, Rainer

1999-01-01

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

Financing solar thermal power plants

International Nuclear Information System (INIS)

Kistner, R.; Price, H.

1999-01-01

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been built following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply states, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects form the financier's perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies

Financing Solar Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Kistner, Rainer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Price, Henry W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

1999-04-14

The commercialization of concentrating solar power technology took a major step forward in the mid 1980s and early 1990s with the development of the SEGS plants in California. Over the years they have proven that parabolic trough power technologies are the most cost-effective approach for commercial scale solar power generation in the sunbelt countries of the world. However, the question must be asked why no additional solar power plants have been build following the bankruptcy of the developer of the SEGS projects, LUZ International Limited. Although many believe the SEGS projects were a success as a result of parabolic trough technology they employ, in truth, the SEGS projects were developed simply because they represented an attractive opportunity for investors. Simply stated, no additional projects have been developed because no one has been able to put together a similarly attractive financial package to potential investors. More than $1.2 billion in private capital was raised in debt and equity financing for the nine SEGS plants. Investors and bankers who make these investments are the real clients for solar power technologies. They are not interested in annual solar to electric efficiencies, but in risk, return on investments, and coverage ratios. This paper will take a look at solar power projects from the financier’s perspective. The challenge in moving forward is to attract private investors, commercial lenders, and international development agencies and to find innovative solutions to the difficult issues that investment in the global power market poses for solar power technologies.

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

International Nuclear Information System (INIS)

Laurier, D; Hemon, D; Clavel, J

2008-01-01

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

Analysis of the Relationship between Risk Perception and Willingness to Pay for Nuclear Power Plant Risk Reduction

Directory of Open Access Journals (Sweden)

Mirae Yun

2016-01-01

Full Text Available With the adoption of new technologies, more risk is introduced into modern society. Important decisions about new technologies tend to be made by specialists, which can lead to a mismatch of risk perception between citizens and specialists, resulting in high social cost. Using contingent valuation methods, this paper analyzes the relationship between willingness to pay (WTP and the factors expressed through people’s image of nuclear power plants (NPP, their perception of NPP safety, and how these can be affected by their scientific background level. Results indicate that groups with a high scientific background level tend to have low risk perception level, represented through their image and safety levels. Further, the results show that mean WTP is dependent on scientific background and image levels. It is believed that these results could help decision makers address the mismatch of trust between the public and specialists in terms of new policy.

The challenge of financing nuclear power plants

International Nuclear Information System (INIS)

Csik, B.J.

1999-01-01

To date, more then 500 nuclear power reactors have been successfully financed and built. Experience in recent nuclear projects confirms that nuclear power will not cease to be a viable option due to a worldwide financing constraint. For financing nuclear plants there are special considerations: large investment; long lead and construction times; complex technology; regulatory risk and political risk. The principal preconditions to financing are a national policy supporting nuclear power; creditworthiness; economic competitiveness; project feasibility; assurance of adequate revenues; acceptability of risks; and no open-ended liabilities. Generally, nuclear power plants are financed conventionally through multi-sources, where a package covers the entire cost. The first source, the investor/owner/operator responsible for building and operating the plant, should cover a sizable portion of the overall investment. In addition, bond issues, domestic bank credits etc. and, in case of State-owned or controlled enterprises, donations and credits from public entities or the governmental budget, should complete the financing. A financially sound utility should be able to meet this challenge. For importing technology, bids are invited. Export credits should form the basis of foreign financing, because these have favorable terms and conditions. Suppliers from several countries may join in a consortium subdividing the scope of supply and involve several Export Credit Agencies (ECAs). There are also innovative financing approaches that could be applied to nuclear projects. Evolutionary Reactors with smaller overall investment, shorter construction times, reliance on proven technology, together with predictable regulatory regimes and reliable long-term national policies favorable to nuclear power, should make it easier to meet the future challenges of financing. (author)

A comparative thermodynamic, economic and risk analysis concerning implementation of oxy-combustion power plants integrated with cryogenic and hybrid air separation units

International Nuclear Information System (INIS)

Skorek-Osikowska, Anna; Bartela, Łukasz; Kotowicz, Janusz

2015-01-01

Highlights: • Mathematical model of an integrated oxy-combustion power plant. • Comparison of a hybrid membrane–cryogenic oxygen generation plant with a cryogenic plant. • Thermodynamic analysis of the modeled cases of the plant. • Comparative economic analysis of the power plant with cryogenic and hybrid ASU. • Comparative risk analysis using a Monte Carlo method and sensitivity analysis. - Abstract: This paper presents a comparison of two types of oxy-combustion power plant that differ from each other in terms of the method of oxygen separation. For the purpose of the analysis, detailed thermodynamic models of oxy-fuel power plants with gross power of approximately 460 MW were built. In the first variant (Case 1), the plant is integrated with a cryogenic air separation unit (ASU). In the second variant (Case 2), the plant is integrated with a hybrid membrane–cryogenic installation. The models were built and optimized using the GateCycle, Aspen Plus and Aspen Custom Modeller software packages and with the use of our own computational codes. The results of the thermodynamic evaluation of the systems, which primarily uses indicators such as the auxiliary power and efficiencies of the whole system and of the individual components that constitute the unit, are presented. Better plant performance is observed for Case 2, which has a net efficiency of electricity generation that is 1.1 percentage points greater than that of Case 1. For the selected structure of the system, an economic analysis of the solutions was made. This analysis accounts for different scenarios of the functioning of the Emission Trading Scheme and includes detailed estimates of the investment costs in both cases. As an indicator of profitability, the break-even price of electricity was used primarily. The results of the analysis for the assumptions made are presented in this paper. A system with a hybrid air separation unit has slightly better economic performance. The break-even price

Nuclear power plant's safety and risk (requirements of safety and reliability)

International Nuclear Information System (INIS)

Franzen, L.F.

1977-01-01

Starting out from the given safety objectives as they have evolved during the past few years and from the present legal and regulatory provisions for the construction and operation of nuclear power plants, the hazards involved in regular operation, accidents and emergency situations are discussed. In compliance with the positive safety balance of nuclear power plants in the FRG, special attention is focused on the preventive safety analysis within the frame of the nuclear licensing procedure. Reference is made to the beginnings of a comprehensive hazard concept for an unbiased plant assessment. Emergency situations are discussed from the point of view of general hazard comparisons. (orig.) [de

Losses in German nuclear power plants

International Nuclear Information System (INIS)

Abinger, R.

1982-01-01

The author illustrates the special features of engineering insurance for nuclear power plants. The shares of the Allianz Versicherungs-AG in the insurance of construction and erection work and in machinery insurance are dealt with. Risk estimation is usually based on statistical analysis of losses. Loss analysis in the conventional sector of nuclear power plants shows typical characteristics of traditional erection and machinery losses. In the nuclear field, however, costs are greatly increased by added safety measures. For this reason, additional cover is allocated and incorporated in premium assessment. Examples from erection and machinery reveal the greater costs involved in handling losses. (orig.) [de

Cancer incidence in the environment of nuclear power plants

International Nuclear Information System (INIS)

Heller, W.

2008-01-01

An epidemiological study of cancer in children in the environment of nuclear power plants has been written on behalf of the German Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety (BMU) and the Federal Office for Radiation Protection (BfS). The study is a case controlled study based on the German Register of Cancer in Children. The most important outcome of the study is the finding that a connection can be observed in Germany between the proximity to a nuclear power plant of the place of living and the risk of a child to develop cancer in the 5 th year of life. The magnitude of this risk was calculated to be approximately 0.2%, i.e., out of a total of 13,373 cases of cancer, 29 would be attributable to living within the 5 km zone around a nuclear power plant. This finding demands an explanation. The study proper cannot serve as a material witness because it had not been designed to establish cause and effect relations between the risk and potential origins. The expert consultants frankly state that current knowledge about radiation biology and epidemiology in principle does not allow the ionizing radiation emitted by German nuclear power plants in normal operation to be interpreted as the cause. Whether confounders, selection or chance play a role in the observed and documented finding cannot be explained for good by the study. However, although representing an honorable acquittal, the study produces a different effect in the public mind. What is remembered is the link between nuclear power plants and cancer in children. (orig.)

Nuclear plant construction and investment risk

International Nuclear Information System (INIS)

Studness, C.M.

1984-01-01

Escalated cost estimations, delays and cancellations in nuclear construction have caused a preoccupation with the risks of nuclear power plant construction that dominates utility stock investment, overshadowing increased earnings per share and recent growth in production. The issue will be resolved when increased power demand requires new construction, but the effect has so far been to erode the economic advantage of nuclear power and threaten the ability of utilities to get rate increases high enough to cover their costs. Projected delays and cost escalations and their effects must go into an economic appraisal of the investment risks

Best practices for mitigating soiling risk on PV power plants

KAUST Repository

AlDowsari, A.

2015-09-24

Solar power generates proven, predictable and economical energy and new innovations have made solar PV power plants easy to deploy, integrate and maintain. Areas with large solar energy potential are among the dustiest in the world. At first glance, solar would be a natural fit in many of these environments but humidity, airborne dust, and wind of these regions often bring high soiling rates that can accumulate to reduce performance by up to 10% per month on average, where soiling can be a major loss factor that affects the energy yield for PV plants especially in humid and dusty climates. Therefore, to achieve the desired performance ratio and obtain stable generation, mitigation solutions are proposed to overcome dust issues that affect the performance of PV plants. This makes PV module cleaning a key component for long-term plant performance and sustainable profitability. In this paper, a review of the mechanisms and mitigation solutions to overcome soiling on solar installations using real-world testing and verification is investigated with emphasis on dry type cleaning methods. © 2014 IEEE.

Risk-based safety performance indicators for nuclear power plants

International Nuclear Information System (INIS)

Chakraborty, S.; Prohaska, G.; Flodin, Y.; Grint, G.; Habermacher, H.; Hallman, A.; Isasia, R.; Melendez, E.; Verduras, E.; Karsa, Z.; Khatib-Rahbar, M.; Koeberlein, K.; Schwaeger, C.; Matahri, N.; Moravcik, I.; Tkac, M.; Preston, J.

2003-01-01

In a Concerted Action (CA), sponsored by the European Commission within its 5th Framework Program, a consortium of eleven partners from eight countries has reviewed and evaluated the application of Safety Performance Indicators (SPIs), which - in combination with other tools - can be used to monitor and improve the safety of nuclear power plants. The project was aimed at identification of methods that can be used in a risk-informed regulatory system and environment, and to exploit PSA techniques for the development and use of meaningful additional/alternative SPIs. The CA included the review of existing indicator systems, and the collection of information on the experience from indicator systems by means of a specific questionnaire. One of the most important and challenging issues for nuclear plant owners and/or regulators is to recognize early signs of deterioration in safety performance, caused by influences from management, organization and safety culture (MOSC), before actual events and/or mishaps take place. Most of the existing SPIs as proposed by various organizations are considered as 'lagging' indicators, that is, they are expected to show an impact only when a downward trend has already started. Furthermore, most of the available indicators are at a relatively high level, such that they will not provide useful information on fundamental weaknesses causing the problem in the first place. Regulators' and utilities' views on the use of a Safety Performance Indicator System have also been a part of the development of the CA. (author)

Requirements for the support power systems of CANDU nuclear power plants

International Nuclear Information System (INIS)

1990-08-01

This Standard covers principal criteria and requirements for design, fabrication, installation, qualification, inspection, and documentation for assurance that support power will be available as required. The minimum requirements for support power are determined by the special safety systems and other safety-related systems that must function to ensure that the public health risk is acceptably low. Support power systems of a CANDU nuclear power plant include those parts of the electrical systems and instrument air systems that are necessary for the operation of safety-related systems

TEPCO's costs and risks which invited the nuclear power plant accident

International Nuclear Information System (INIS)

Soeda, Takashi

2017-01-01

The National Diet of Japan Fukushima Nuclear Accident Independent Investigation Commission (Diet Accident Investigation Commission) considered two patterns against the tsunami risk of nuclear plant: (1) Risk management for the purpose of safety (Pattern A), and (2) Risk management for the purpose of utilization rate and cost of nuclear reactor (Pattern B). Pattern B emphasizes avoiding 'countermeasure cost generation' and 'operation shutdown' rather than preparing for a tsunami that we do not know when to come. Diet Accident Investigation Commission analyzed that the behavioral principles concerning the crisis response of Tokyo Electric Power Company (TEPCO) had the stronger tendency of Pattern B. Regarding the accident of TEPCO, there were class actions that asked the responsibility of TEPCO and the government. This paper examined the contents of the opinions of government-side experts submitted for this issue. The government-side experts argued that there was no 'scientific consensus' for tsunami forecast, and that preliminary measures against unexpected tsunami was impossible. However, both of these government's arguments are irrational due to difference from the fact. TEPCO president at the time of accident insisted in the firm that 'cost cut in another dimension' was indispensable and reduced expenses. TEPCO and the government had continued Pattern B, even knowing that tsunami risk measures were insufficient from more than ten years ago. (A.O.)

A method for risk informing procedures at operating nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Nelson, P. F.; Martin del Campo, C., E-mail: pnelson_007@yahoo.com [UNAM, Facultad de Ingenieria, Departamento de Sistemas Energeticos, Paseo Cuauhnahuac No. 8532, Col. Progreso, 62550 Jiutepec, Morelos (Mexico)

2012-10-15

The technical approach presented establishes a framework intended to provide the necessary elements for a deployable human performance monitoring program that incorporates insights from plant specific probabilistic risk assessments, human reliability analysis, as well as the development of plant specific human failure data. A human performance monitoring program of this structure would be used to provide the ability to risk inform procedures (e.g., operations or maintenance) to determine the operational risk significance of procedural performance (i.e., precautions, prerequisites, procedure steps), the likelihood of consequential human error dur the performance of the procedure, and the identification of procedure specific barriers to reduce or eliminate consequential human errors. The program would provide the means to assess procedures prior to execution and the means to record and trend human failure events leading to a plant specific human failure database for human activities characterized as pre-initiator. The technical methods and data processing for each of these areas are developed and presented, as well as an example application of an operational procedure error leading to a plant level event (i.e, plant trip). (Author)

Less power plants

International Nuclear Information System (INIS)

TASR

2003-01-01

In the Slovak Republic the number of company power plants decreased as against 2001 by two sources. In present time only 35 companies have their own power plants. The companies Slovnaft, Kappa Sturovo, Slovensky hodvab Senica, Matador Puchov, Maytex Liptovsky MikuIas, Kovohuty Krompachy, Chemko Strazske and some Slovak sugar factories belong to the largest company power plants in force of distributing companies. Installed output of present 35 company sources is 531 MW. The largest of separate power plants as Paroplynovy cyklus Bratislava (218 MW) and VD Zilina (72 MW) belong to independent sources. Total installed output of Slovak sources was 8306 MW in the end of last year

Protection against fire hazards in French nuclear power plants

International Nuclear Information System (INIS)

Chapus, J.

2000-01-01

The prevention of fire in French nuclear power plants has followed the evolution of safety regulations. Today fire hazards are no longer considered as classical industrial risks but as specific risks that deserve to be studied thoroughly and in a more formalized form. In the beginning of the eighties EDF was committed to the redaction of a technical referential against fire gathering all the directives applicable to the N4-type plant (1450 MW). In 1994 this technical referential was reconsidered and enlarged in order to involve 900 MW and 1300 MW units. In each nuclear power plant a PAI (plan against fire) has been elaborated so that the installation can be progressively upgraded according to the last standard defined by the technical referential. (A.C.)

The problem of nuclear power plants site survey and selection

International Nuclear Information System (INIS)

Anh, T.H.; Hung, H.V.; Bui Quoc Thang

1986-01-01

The article presents the main steps of nuclear power plants siting, including the requirements from a nuclear power station onto the site, and the analysis of potential effects of a nuclear power station to the environment. Attentions are called upon the analysis of important factors such as electric transmission losses, cooling water supply, site accessibility, local infrastructure, risks due to man made and natural sources of aggression to the nuclear power plants, population, distribution, hydrological and atmospheric dispersion conditions

'Living PRA' concept for plant risk: Reliability and availability tracking

International Nuclear Information System (INIS)

Sancaktar, S.; Sharp, D.R.

1985-01-01

The 'Living PRA' (Probabilistic Risk Assessment) is based on placing a PRA plant model on an interactive computer. This model consists of fault tree analyses for plant systems, event tree analyses for abnormal events and site specific consequence analysis for public and/or financial risks, for a nuclear power plant. A living PRA allows updates and sensitivity analyses by the plant owner throughout the lifetime of a plant. Recently, event and fault trees from two major PRAs were placed in a computerized format. The BYRON PRA study and the Living PRA and Economic Risk examples for Indian Point Unit-3 enabled analysts to gain experience and insight into the problems of plant operation. The above concept is well established for the Nuclear Power Plant evaluation. It has been also used for evaluation of processing facilities. In these studies, systems modeling was carried out by using the GRAFTER system for automated fault tree construction. Presently both the tools and the experience exists to set up useful and viable living PRA models for nuclear and chemical processing plants to enhance risk management by the plant owners through in-house use of micro computer based models

Feasibility study of component risk ranking for plant maintenance

International Nuclear Information System (INIS)

Ushijima, Koji; Yonebayashi, Kenji; Narumiya, Yoshiyuki; Sakata, Kaoru; Kumano, Tetsuji

1999-01-01

Nuclear power is the base load electricity source in Japan, and reduction of operation and maintenance cost maintaining or improving plant safety is one of the major issues. Recently, Risk Informed Management (RIM) is focused as a solution. In this paper, the outline regarding feasibility study of component risk ranking for plant maintenance for a typical Japanese PWR plant is described. A feasibility study of component risk raking for plant maintenance optimization is performed on check valves and motor-operated valves. Risk ranking is performed in two steps using probabilistic analysis (quantitative method) for risk ranking of components, and deterministic examination (qualitative method) for component review. In this study, plant components are ranked from the viewpoint of plant safety / reliability, and the applicability for maintenance is assessed. As a result, distribution of maintenance resources using risk ranking is considered effective. (author)

Predicting the environmental risks of radioactive discharges from Belgian nuclear power plants

International Nuclear Information System (INIS)

Vandenhove, H.; Sweeck, L.; Vives i Batlle, J.; Wannijn, J.; Van Hees, M.; Camps, J.; Olyslaegers, G.; Miliche, C.; Lance, B.

2013-01-01

An environmental risk assessment (ERA) was performed to evaluate the impact on non-human biota from liquid and atmospheric radioactive discharges by the Belgian Nuclear Power Plants (NPP) of Doel and Tihange. For both sites, characterisation of the source term and wildlife population around the NPPs was provided, whereupon the selection of reference organisms and the general approach taken for the environmental risk assessment was established. A deterministic risk assessment for aquatic and terrestrial ecosystems was performed using the ERICA assessment tool and applying the ERICA screening value of 10 μGy h −1 . The study was performed for the radioactive discharge limits and for the actual releases (maxima and averages over the period 1999–2008 or 2000–2009). It is concluded that the current discharge limits for the Belgian NPPs considered do not result in significant risks to the aquatic and terrestrial environment and that the actual discharges, which are a fraction of the release limits, are unlikely to harm the environment. -- Highlights: • Impact of radioactive discharges by the Belgian NPPs of Doel and Tihange on wildlife was evaluated. • Deterministic risk assessment for aquatic and terrestrial ecosystems performed with the ERICA tool. • NPP discharge limits do not result in significant risks to the aquatic and terrestrial environment. • Actual discharges, a fraction of the release limits, are unlikely to harm the environment

Six sigma management and its application in nuclear power plant

International Nuclear Information System (INIS)

Liu Weihua; Tong Lili

2007-01-01

Six sigma management mode is presented. The feasibility, necessity and the steps to extend six sigma in nuclear power plant are addressed. Nuclear power plant can eliminate or decrease human errors through importing six management concept, the 'zero disfigurement' quality and operation can achieved, decreasing accident risk and realizing safety operation. (authors)

Research on risk communication after the Fukushima nuclear power plant accident

International Nuclear Information System (INIS)

Horiguchi, Itsuko

2013-01-01

This report is about the risk communication cases that the author participated in after the Fukushima nuclear power plant accident. The research aims to clarify the content of information that should be provided in risk communication and to develop a risk communication tool specifically designed for this purpose. The risk communication cases were explanatory meetings intended for the residents in Fukushima Prefecture and the advisory council on radiation health effects sponsored by Tochigi Prefecture. To clarify the kinds of information necessary to provide at such meetings, we conducted a questionnaire survey of 31 food sanitation inspectors using the Delphi method. A gaming simulation was used for the development of the communication tool. We used public disclosure materials at the meetings and the survey was conducted only among those whom we obtained written informed consent. The content regarding the radioactive substances in food which was found to be the most important for the consumers to learn was ''zero risk is impossible'' (84 points), followed by ''radioactive substances and other risks (e.g. smoking and excessive alcohol intake)'' (70 points). To develop the communication tool, we used ''Quartetto (card game)'' and the contents were such as ''daily life'', ''radioactive substances'', and ''measurement''. Considering the questions raised from the residents at the meetings, an information portal such as homepages did not provide clear information on how to evaluate risks by themselves. The results from the questionnaire survey shows that it is difficult to solve this matter unless the public learns to think about the risks of various matters on their own. The lack of experts will make it necessary for the local government officials to provide more information, and therefore training on risk communication is essential. We need to evaluate the Quartetto game and revise the content considering the audience. (author)

Nuclear Energy Research Initiative. Risk Informed Assessment of Regulatory and Design Requirements for Future Nuclear Power Plants. Annual Report

International Nuclear Information System (INIS)

Ritterbusch, S.E.

2000-01-01

The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-informed approach for the design and regulation of nuclear power plants. This approach will include the development and.lor confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRs) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go farther by focusing on the design of new plants

Nuclear Energy Research Initiative. Risk Informed Assessment of Regulatory and Design Requirements for Future Nuclear Power Plants. Annual Report

Energy Technology Data Exchange (ETDEWEB)

Ritterbusch, S.E.

2000-08-01

The overall goal of this research project is to support innovation in new nuclear power plant designs. This project is examining the implications, for future reactors and future safety regulation, of utilizing a new risk-informed regulatory system as a replacement for the current system. This innovation will be made possible through development of a scientific, highly risk-informed approach for the design and regulation of nuclear power plants. This approach will include the development and.lor confirmation of corresponding regulatory requirements and industry standards. The major impediment to long term competitiveness of new nuclear plants in the U.S. is the capital cost component--which may need to be reduced on the order of 35% to 40% for Advanced Light Water Reactors (ALWRs) such as System 80+ and Advanced Boiling Water Reactor (ABWR). The required cost reduction for an ALWR such as AP600 or AP1000 would be expected to be less. Such reductions in capital cost will require a fundamental reevaluation of the industry standards and regulatory bases under which nuclear plants are designed and licensed. Fortunately, there is now an increasing awareness that many of the existing regulatory requirements and industry standards are not significantly contributing to safety and reliability and, therefore, are unnecessarily adding to nuclear plant costs. Not only does this degrade the economic competitiveness of nuclear energy, it results in unnecessary costs to the American electricity consumer. While addressing these concerns, this research project will be coordinated with current efforts of industry and NRC to develop risk-informed, performance-based regulations that affect the operation of the existing nuclear plants; however, this project will go farther by focusing on the design of new plants.

A probabilistic seismic risk assessment procedure for nuclear power plants: (I) Methodology

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

A new procedure for probabilistic seismic risk assessment of nuclear power plants (NPPs) is proposed. This procedure modifies the current procedures using tools developed recently for performance-based earthquake engineering of buildings. The proposed procedure uses (a) response-based fragility curves to represent the capacity of structural and nonstructural components of NPPs, (b) nonlinear response-history analysis to characterize the demands on those components, and (c) Monte Carlo simulations to determine the damage state of the components. The use of response-rather than ground-motion-based fragility curves enables the curves to be independent of seismic hazard and closely related to component capacity. The use of Monte Carlo procedure enables the correlation in the responses of components to be directly included in the risk assessment. An example of the methodology is presented in a companion paper to demonstrate its use and provide the technical basis for aspects of the methodology. ?? 2011 Published by Elsevier B.V.

Upgrading Atucha 1 nuclear power plant. Regulatory perspective

International Nuclear Information System (INIS)

Caruso, G.

1998-01-01

Atucha 1 nuclear power plant has unique design and its commercial operation started in 1974. The upgrading decisions, the basis for an upgrading program and its status of implementation are presented. Regulatory decisions derived from the performance-based approach have the advantage that they enable balancing of the overall plant risk and identifying at different plant levels the areas where improvements are necessary. (author)

Application of the SSMRP methodology to the seismic risk at the Zion Nuclear Power Plant

International Nuclear Information System (INIS)

Bohn, M.P.; Shieh, L.C.; Wells, J.E.

1983-11-01

The Seismic Safety Margins Research Program (SSMRP) has the goal of developing a fully coupled analysis procedure for estimating the risk of an earthquake-induced radioactive release from a commercial nuclear power plant. The risk analysis included a detailed seismological evaluation of the region around Zion, Illinois, which provided the earthquake-hazard function and a randomized set of 180 time histories (having peak ground acceleration values up to 1.8 g). These time histories were used as input for dynamic structural response calculations for four different Zion buildings. Detailed finite-element models of the buildings were used. Calculated time histories at piping support points were then used to determine moments throughout critical piping systems. Twenty separate piping models were analyzed. Finally, the responses of piping and safety system components within the buildings were combined with probabilistic failure criteria and event-tree/fault-tree models of the plant safety systems to produce an estimate of the frequency of core melt and radioactive release due to earthquakes

Methodology and application of surrogate plant PRA analysis to the Rancho Seco Power Plant: Final report

International Nuclear Information System (INIS)

Gore, B.F.; Huenefeld, J.C.

1987-07-01

This report presents the development and the first application of generic probabilistic risk assessment (PRA) information for identifying systems and components important to public risk at nuclear power plants lacking plant-specific PRAs. A methodology is presented for using the results of PRAs for similar (surrogate) plants, along with plant-specific information about the plant of interest and the surrogate plants, to infer important failure modes for systems of the plant of interest. This methodology, and the rationale on which it is based, is presented in the context of its application to the Rancho Seco plant. The Rancho Seco plant has been analyzed using PRA information from two surrogate plants. This analysis has been used to guide development of considerable plant-specific information about Rancho Seco systems and components important to minimizing public risk, which is also presented herein

Nuclear power plants

International Nuclear Information System (INIS)

Margulova, T.Ch.

1976-01-01

The textbook focuses on the technology and the operating characteristics of nuclear power plants equiped with pressurized water or boiling water reactors, which are in operation all over the world at present. The following topics are dealt with in relation to the complete plant and to economics: distribution and consumption of electric and thermal energy, types and equipment of nuclear power plants, chemical processes and material balance, economical characteristics concerning heat and energy, regenerative preheating of feed water, degassing and condenser systems, water supply, evaporators, district heating systems, steam generating systems and turbines, coolant loops and pipes, plant siting, ventilation and decontamination systems, reactor operation and management, heat transfer including its calculation, design of reactor buildings, and nuclear power plants with gas or sodium cooled reactors. Numerous technical data of modern Soviet nuclear power plants are included. The book is of interest to graduate and post-graduate students in the field of nuclear engineering as well as to nuclear engineers

A Study on Structured Simulation Framework for Design and Evaluation of Human-Machine Interface System -Application for On-line Risk Monitoring for PWR Nuclear Power Plant-

International Nuclear Information System (INIS)

Zhan, J.; Yang, M.; Li, S.C.; Peng, M.J.; Yan, S.Y.; Zhang, Z.J.

2006-01-01

The operators in the main control room of Nuclear Power Plant (NPP) need to monitor plant condition through operation panels and understand the system problems by their experiences and skills. It is a very hard work because even a single fault will cause a large number of plant parameters abnormal and operators are required to perform trouble-shooting actions in a short time interval. It will bring potential risks if operators misunderstand the system problems or make a commission error to manipulate an irrelevant switch with their current operation. This study aims at developing an on-line risk monitoring technique based on Multilevel Flow Models (MFM) for monitoring and predicting potential risks in current plant condition by calculating plant reliability. The proposed technique can be also used for navigating operators by estimating the influence of their operations on plant condition before they take an action that will be necessary in plant operation, and therefore, can reduce human errors. This paper describes the risk monitoring technique and illustrates its application by a Steam Generator Tube Rupture (SGTR) accident in a 2-loop Pressurized Water Reactor (PWR) Marine Nuclear Power Plant (MNPP). (authors)

Risk management in the electric power sector, v. 16(61)

International Nuclear Information System (INIS)

Iliev, Atanas; Minovski, Dragan

2008-01-01

This paper presents the basics of the risk theory and the main methods which could be applied for risk management in electrical power system utilities. Taking into consideration that the risk and uncertainty not be completely eliminated, the engineers have to know to manage the risk and uncertainty. The main goal is to minimized the negative effects from accepted risk in order to increase expected incomes and expected profit. Special attention is dedicated to risk management in complex project in Electric Power Systems in a new deregulated electricity market which has the influence to the market stability, expected incomes and quality of the delivered electricity. Specially, the risk management in the companies - producers of the electricity is analysed, since theirs further investments in a rehabilitation of the current power plants as well in the construction of the new plants will be based on the economical principles of profit. (Author)

Risk management in the electric power sector, v. 16(62)

International Nuclear Information System (INIS)

Iliev, Atanas; Minovski, Dragan

2008-01-01

This paper presents the basics of the risk theory and the main methods which could be applied for risk management in electrical power system utilities. Taking into consideration that the risk and uncertainty not be completely eliminated, the engineers have to know to manage the risk and uncertainty. The main goal is to minimized the negative effects from accepted risk in order to increase expected incomes and expected profit. Special attention is dedicated to risk management in complex project in Electric Power Systems in a new deregulated electricity market which has the influence to the market stability, expected incomes and quality of the delivered electricity. Specially, the risk management in the companies - producers of the electricity is analysed, since theirs further investments in a rehabilitation of the current power plants as well in the construction of the new plants will be based on the economical principles of profit. (Author)

Accident prevention in power plants

International Nuclear Information System (INIS)

Steyrer, H.

Large thermal power plants are insured to a great extent at the Industrial Injuries Insurance Institute of Instrument and Electric Engineering. Approximately 4800 employees are registered. The accident frequency according to an evaluation over 12 months lies around 79.8 per year and 1000 employees in fossil-fired power plants, around 34.1 per year and 1000 employees in nuclear power plants, as in nuclear power plants coal handling and ash removal are excluded. Injuries due to radiation were not registered. The crucial points of accidents are mechanical injuries received on solid, sharp-edged and pointed objects (fossil-fired power plants 28.6%, nuclear power plants 41.5%), stumbling, twisting or slipping (fossil-fired power plants 21.8%, nuclear power plants 19.5%) and injuries due to moving machine parts (only nuclear power plants 12.2%). However, accidents due to burns or scalds obtain with 4.2% and less a lower portion than expected. The accident statistics can explain this fact in a way that the typical power plant accident does not exist. (orig./GL) [de

A genetic algorithm solution for a nuclear power plant risk-cost maintenance model

International Nuclear Information System (INIS)

Tong Jiejuan; Mao Dingyuan; Xue Dazhi

2004-01-01

Reliability Centered Maintenance (RCM) is one of the popular maintenance optimization methods according to certain kinds of priorities. Traditional RCM usually analyzes and optimizes the maintenance strategy from the viewpoint of component instead of the whole maintenance program impact. Research presented in this paper is a pilot study using PSA techniques in RCM. How to reflect the effect on component unavailability by the maintenance activities such as surveillance testing and preventive maintenance in PSA model is discussed firstly. Based on the discussion, a maintenance risk-cost model is established for global maintenance optimization in a nuclear power plant, and a genetic algorithm (GA) is applied to solve such a model to get the global optimized maintenance strategy. Finally, the result got from a simple test case based on a risk-cost model consisting of 10 components is presented

Relationship between images of risk and anxiety toward radiation. Comparison of radiation from chest X-rays and nuclear power plants

International Nuclear Information System (INIS)

Matsui, Yuko

2003-01-01

In order to clarify the components of people's images of radiation risk and the determinants for the degree of anxiety about radiation exposure, an investigation was conducted. Two kinds of radiation, from nuclear power plants and during a chest X-ray, which are relatively familiar to people, were focused on. As a result, only a 'dread' factor was common to both radiation types of. Although the degree of anxiety toward both types of radiation showed a positive correlation with the 'dread' image, the anxiety toward X-ray radiation showed a negative correlation with the 'feeling of conquest'. Anxiety toward radiation from nuclear power plants had a negative correlation with 'control by experts'. These results suggest that the words radiation from nuclear power plants' evoke an image of a situation with high radiation exposure, which is beyond the experts' control abilities. (author)

Risk contribution from low power, shutdown, and other operational modes beyond full power

Energy Technology Data Exchange (ETDEWEB)

Whitehead, D.W.; Brown, T.D. [Sandia National Labs., Albuquerque, NM (United States); Chu, T.L. [Brookhaven National Lab., Upton, NY (United States)] [and others

1995-04-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented.

Risk contribution from low power, shutdown, and other operational modes beyond full power

International Nuclear Information System (INIS)

Whitehead, D.W.; Brown, T.D.; Chu, T.L.; Pratt, W.T.

1995-01-01

During 1989 the Nuclear Regulatory Commission (NRC) initiated an extensive program to carefully examine the potential risks during low power and shutdown operations. Two plants, Surry (a pressurized water reactor) and Grand Gulf (a boiling water reactor), were selected for study by Brookhaven National Laboratory and Sandia National Laboratories, respectively. The program objectives included assessing the risks of severe accidents initiated during plant operational states other than full power and comparing estimated core damage frequencies, important accident sequences, and other qualitative and quantitative results with full power accidents as assessed in NUREG-1150. The scope included a Level 3 probabilistic risk assessment (PRA) for traditional internal events and a Level 1 PRA on fire, flooding, and seismically induced core damage sequences. A phased approach was used in Level 1. In Phase 1 the concept of plant operational states (POSs) was developed to provide a better representation of the plant as it transitions from power to nonpower operation. This included a coarse screening analysis of all POSs to identify vulnerable plant configurations, to characterize (on a high, medium, or low basis) potential frequencies of core damage accidents, and to provide a foundation for a detailed Phase 2 analysis. In Phase 2, selected POSs from both Grand Gulf and Surry were chosen for detailed analysis. For Grand Gulf, POS 5 (approximately cold shutdown as defined by Grand Gulf Technical Specifications) during a refueling outage was selected. For Surry, three POSs representing the time the plant spends in midloop operation were chosen for analysis. These included POS 6 and POS 10 of a refueling outage and POS 6 of a drained maintenance outage. Level 1 and Level 2/3 results from both the Surry and Grand Gulf analyses are presented

Maintenance planning for nuclear power plants

International Nuclear Information System (INIS)

Mattu, R.K.; Cooper, S.E.; Lauderdale, J.R.

2004-01-01

Maintenance planning for nuclear power plants is similar to that in other industrial plants but it is heavily influenced by regulatory rules, with consequent costs of compliance. Steps by the nuclear industry and the Nuclear Regulatory Commission to address that problem include development of guidelines for maintenance of risk-critical equipment, using PRA-based techniques to select a set of equipment that requires maintenance and reliability-centered maintenance (RCM) approaches for determining what maintenance is required. The result of the process is a program designed to ensure effective maintenance of the equipment most critical to plant safety. (author)

A practical approach for implementing risk-based inservice testing of pumps at nuclear power plants

International Nuclear Information System (INIS)

Hartley, R.S.; Maret, D.; Seniuk, P.; Smith, L.

1996-01-01

The American Society of Mechanical Engineers (ASME) Center for Research and Technology Development's (CRTD) Research Task Force on Risk-Based Inservice Testing has developed guidelines for risk-based inservice testing (IST) of pumps and valves. These guidelines are intended to help the ASME Operation and Maintenance (OM) Committee to enhance plant safety while focussing appropriate testing resources on critical components. This paper describes a practical approach for implementing those guidelines for pumps at nuclear power plants. The approach, as described in this paper, relies on input, direction, and assistance from several entities such as the ASME Code Committees, United States Nuclear Regulatory Commission (NRC), and the National Laboratories, as well as industry groups and personnel with applicable expertise. Key parts of the risk-based IST process that are addressed here include: identification of important failure modes, identification of significant failure causes, assessing the effectiveness of testing and maintenance activities, development of alternative testing and maintenance strategies, and assessing the effectiveness of alternative testing strategies with present ASME Code requirements. Finally, the paper suggests a method of implementing this process into the ASME OM Code for pump testing

A practical approach for implementing risk-based inservice testing of pumps at nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Hartley, R.S. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Maret, D.; Seniuk, P.; Smith, L.

1996-12-01

The American Society of Mechanical Engineers (ASME) Center for Research and Technology Development`s (CRTD) Research Task Force on Risk-Based Inservice Testing has developed guidelines for risk-based inservice testing (IST) of pumps and valves. These guidelines are intended to help the ASME Operation and Maintenance (OM) Committee to enhance plant safety while focussing appropriate testing resources on critical components. This paper describes a practical approach for implementing those guidelines for pumps at nuclear power plants. The approach, as described in this paper, relies on input, direction, and assistance from several entities such as the ASME Code Committees, United States Nuclear Regulatory Commission (NRC), and the National Laboratories, as well as industry groups and personnel with applicable expertise. Key parts of the risk-based IST process that are addressed here include: identification of important failure modes, identification of significant failure causes, assessing the effectiveness of testing and maintenance activities, development of alternative testing and maintenance strategies, and assessing the effectiveness of alternative testing strategies with present ASME Code requirements. Finally, the paper suggests a method of implementing this process into the ASME OM Code for pump testing.

Socio-environmental impacts of Angra dos Reis nuclear power plant

International Nuclear Information System (INIS)

Rosa, L.P.; Hesles, J.B.S.

1984-01-01

Technological aspects and the social problematic inherent to implementation of nuclear power plants in Brazil are studied. it is showed the study in two levels: one of them, attacks aspects linked to nuclear energy and their risks in Brazil; the other one, treats of impacts of the Angra dos Reis nuclear power plants on the local comunity. (M.C.K.) [pt

Integrated societal risk assessment framework for nuclear power and renewable energy sources

International Nuclear Information System (INIS)

Lee, Sang Hun; Kang, Hyun Gook

2015-01-01

Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh) of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources

Integrated societal risk assessment framework for nuclear power and renewable energy sources

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Hun; Kang, Hyun Gook [Dept. of Nuclear and Quantum Engineering, KAIST, Daejeon (Korea, Republic of)

2015-06-15

Recently, the estimation of the social cost of energy sources has been emphasized as various novel energy options become feasible in addition to conventional ones. In particular, the social cost of introducing measures to protect power-distribution systems from power-source instability and the cost of accident-risk response for various power sources must be investigated. To account for these risk factors, an integrated societal risk assessment framework, based on power-uncertainty analysis and accident-consequence analysis, is proposed. In this study, we applied the proposed framework to nuclear power plants, solar photovoltaic systems, and wind-turbine generators. The required capacity of gas-turbine power plants to be used as backup power facilities to compensate for fluctuations in the power output from the main power source was estimated based on the performance indicators of each power source. The average individual health risk per terawatt-hours (TWh) of electricity produced by each power source was quantitatively estimated by assessing accident frequency and the consequences of specific accident scenarios based on the probabilistic risk assessment methodology. This study is expected to provide insight into integrated societal risk analysis, and can be used to estimate the social cost of various power sources.

Application of the accident consequences model of the German risk study to assessments of accident risks in different types of nuclear power plants

International Nuclear Information System (INIS)

Ehrhardt, J.; Bayer, A.

1982-01-01

Within the scope of the 'German Risk Study for Nuclear Power Plants' (Phase A) the accident consequence model UFOMOD was developed in the Karlsruhe Nuclear Research Center. This model originally developed for pressurized water reactors has now been extended in order to obtain results about accidental releases of activity from fast breeder and high-temperature reactors, too. (RW) [de

The retirement cliff: Power plant lives and their policy implications

International Nuclear Information System (INIS)

Rode, David C.; Fischbeck, Paul S.; Páez, Antonio R.

2017-01-01

This paper examines more than a century of U.S. power plant additions and retirements in conjunction with several decades of utility capital investment data. While policy analyses often invoke assumptions of power plant book life, relatively little analysis has focused on the physical life of power-generating assets. The average age of the U.S. generator fleet has increased significantly over time despite continued investment, in part because more recent investment has tended to focus on shorter-lived assets. This may be due in part to risk-averse power sector investors and lenders responding rationally to regulatory uncertainty in a deregulated market environment. Power plant retirement trends suggest that the pace of retirements will increase significantly in the decade after 2030 for most reasonable estimates of physical life. These capital investment trends have important consequences for carbon policy and highlight the importance of including consideration of the longer term—particularly when evaluating more significant decarbonization policies. - Highlights: • Many policy analyses neglect the physical lives of power plants. • A large database of U.S. power plant additions and retirements is examined. • The average age of power plants has steadily increased despite growing investment. • Long-term CO 2 reduction strategies are challenged by increases in plant retirements.

Financing Nuclear Power Plant Projects. A New Paradigm?

International Nuclear Information System (INIS)

Pehuet Lucet, Fabienne

2015-05-01

There are currently 435 operable nuclear power reactors around the world, with a further 71 under construction. Two main proven financing models were applied to nuclear plants in the past: the national model, and the corporate model. The historical model of financing is the national model. It allowed for the most efficient risk allocation model in then-regulated national electricity markets: government or state-owned utilities with government guarantee assumed the risks of building nuclear power plants locally. The national model has proven to be efficient in France, Russia and the USA where it was modified to support private business initiatives. It was then replicated in Japan, Korea and China where significant nuclear programs were developed. In the corporate business model, the owner of the plant assumes most of the risk, but various schemes are used to mitigate the owner's risk by transmitting large areas of risks to others: vendors for construction risk as in Finland, government through loans guarantees etc. As projects became international, a set of common principles were approved by OECD countries concerning financing and the role of Export Credit Agencies. The objective was to provide competition rules whereby exporters compete on the basis of the price and quality of their products rather than the financial terms provided. Various combinations of these models were and still are implemented. Pure Project Finance was not implemented for nuclear power plants, but the model nurtures reflections about new financing models. The context in which nuclear power projects are now decided and financed changed drastically: it is a new paradigm. Risk allocation and financial conditions are at the forefront of competition to win new nuclear projects' tenders insofar as reducing uncertainties is a decisive competition edge. In a context of electricity market deregulation and high construction risks, investors and lenders require more and more securities to

Survey of numerical safety targets for nuclear power plants

International Nuclear Information System (INIS)

Kelley, A.P. Jr.; Buttemer, D.R.

1981-04-01

The construction of a nuclear power plant implies, as does the construction of any major public work, the acceptance of a finite degree of risk. This risk can be reduced by an increased investment in engineered safeguards. However, at some level of risk, overinvestment in safety can render the project uneconomical. Because of the desirability of fixing safety standards on an absolute basis, there has long been an interest in establishing numerical risk criteria for the design, construction, and operation of nuclear power plants. Interest in the subject of numerical safety goals has recently been intensified by the Three Mile Island Action Plan. The USNRC has been directed by Congress to develop a national safety goal for reactor regulation. This report summarizes actions which have been historically, and are currently, taking place toward establishing national numerical risk targets for reactor regulation. Emphasis is placed upon actions taken, or currently being taken, by federal regulatory agencies and directly associated advisory bodies

Track 6: safety and risk management. Plant operational risk management. Plant Configuration Risk Assessment Methodology Development for Periodic Maintenance

International Nuclear Information System (INIS)

Yang, Huichang; Chung, Chang Hyun; Sung, Key Yong

2001-01-01

As the operation experiences of nuclear power plants (NPPs) in Korea accumulate and NPP safety functions become enhanced, the role of stable and optimal NPP operation within acceptable safety criteria becomes important at present. To accomplish the goal of safe and optimal operation, maintenance and its related activities should be regarded as the issues of most concern. Studies of methodologies for maintenance improvement and optimization have focused on system performance rather than on the hardware itself. From this point of view, the probabilistic methods are most useful. In terms of risk including core damage frequency and unavailability, the cause that might impact plant safety during normal maintenance activities can be identified and evaluated effectively. The results from these probabilistic analyses can provide insightful information for the reallocation of risk-contributing maintenance activity. This information can be utilized in a way that separates the significant risk-contributing maintenance activities from each other unless they are timely related. In Korea, the risk-monitoring program for operating NPPs is under development and will be implemented in 2003. To accomplish the risk-monitoring program objectives, suitable risk evaluation methods should be developed before the implementation of the risk-monitoring program. The plant configuration assessment methodology was developed for these reasons, and this method is to incorporate the field experiences into the risk calculation exactly within the limit of probabilistic methods. During normal plant operation, the plant operational risk changes frequently depending on the status of the plant system and the arrangement of the components. Specific plant systems or components are typically removed from service because of random equipment failure, planned preventive/predictive maintenance, corrective maintenance, surveillance testing, and operational bypass activities, and such events usually impact the

Multiple external hazards compound level 3 PSA methods research of nuclear power plant

Science.gov (United States)

Wang, Handing; Liang, Xiaoyu; Zhang, Xiaoming; Yang, Jianfeng; Liu, Weidong; Lei, Dina

2017-01-01

2011 Fukushima nuclear power plant severe accident was caused by both earthquake and tsunami, which results in large amount of radioactive nuclides release. That accident has caused the radioactive contamination on the surrounding environment. Although this accident probability is extremely small, once such an accident happens that is likely to release a lot of radioactive materials into the environment, and cause radiation contamination. Therefore, studying accidents consequences is important and essential to improve nuclear power plant design and management. Level 3 PSA methods of nuclear power plant can be used to analyze radiological consequences, and quantify risk to the public health effects around nuclear power plants. Based on multiple external hazards compound level 3 PSA methods studies of nuclear power plant, and the description of the multiple external hazards compound level 3 PSA technology roadmap and important technical elements, as well as taking a coastal nuclear power plant as the reference site, we analyzed the impact of off-site consequences of nuclear power plant severe accidents caused by multiple external hazards. At last we discussed the impact of off-site consequences probabilistic risk studies and its applications under multiple external hazards compound conditions, and explained feasibility and reasonableness of emergency plans implementation.

Risk Importance Measures in the Designand Operation of Nuclear Power Plants

Energy Technology Data Exchange (ETDEWEB)

Vrbanic I.; Samanta P.; Basic, I

2017-10-31

This monograph presents and discusses risk importance measures as quantified by the probabilistic risk assessment (PRA) models of nuclear power plants (NPPs) developed according to the current standards and practices. Usually, PRA tools calculate risk importance measures related to a single ?basic event? representing particular failure mode. This is, then, reflected in many current PRA applications. The monograph focuses on the concept of ?component-level? importance measures that take into account different failure modes of the component including common-cause failures (CCFs). In opening sections the roleof risk assessment in safety analysis of an NPP is introduced and discussion given of ?traditional?, mainly deterministic, design principles which have been established to assign a level of importance to a particular system, structure or component. This is followed by an overview of main risk importance measures for risk increase and risk decrease from current PRAs. Basic relations which exist among the measures are shown. Some of the current practical applications of risk importancemeasures from the field of NPP design, operation and regulation are discussed. The core of the monograph provides a discussion on theoreticalbackground and practical aspects of main risk importance measures at the level of ?component? as modeled in a PRA, starting from the simplest case, single basic event, and going toward more complexcases with multiple basic events and involvements in CCF groups. The intent is to express the component-level importance measures via theimportance measures and probabilities of the underlying single basic events, which are the inputs readily available from a PRA model andits results. Formulas are derived and discussed for some typical cases. The formulas and their results are demonstrated through some practicalexamples, done by means of a simplified PRA model developed in and run by RiskSpectrum? tool, which are presented in the appendices. The

The evaluation of environmental effects of nuclear power plants

International Nuclear Information System (INIS)

Oezyurt, M.; Iyit, L.; Seyitogullari, S.

2006-01-01

Energy is today one of the most significant topics in the world. Humans are investigating alternative energy resources due to the fossil energy sources to be exhausted in future. As known, the life of energy resources such as coal and oil is limited. Natural gas will cover the need just for a limited period. On the other hand, developing population will increase the need of energy for the next generation. Therefore, alternative energy has gained much significance in recent years. Nuclear energy is the most criticized energy in public opinion. About 17 pct. of the electric need in the world is being covered by nuclear power plants . This ratio is over 30 pct. in European Union and over 78.2 pct. in France. The most significant risk as regard with environmental pollution is radioactive wastes for these plants. The opposite sides towards nuclear energy claim about the accidents of nuclear power plants and deaths in short and long terms. As long as the security rules are applied, nuclear power plants affect neither human nor environmental health in a detrimental way. The radiation emission scattered by nuclear power plants is very low. In this work, first of all nuclear energy was evaluated from a standpoint of environmental pollution and both positive and negative effects were investigated. As a result, the humanity will have to benefit from all the alternative energy resources , the nuclear energy as well, in order not to live in a dark world. Every technology has its own risks. It seems that if nuclear energy power plants are operated in high technology conditions it will be un given up for humanity

Preliminary regulatory assessment of nuclear power plants vulnerabilities

International Nuclear Information System (INIS)

Kostadinov, V.; Petelin, S.

2004-01-01

Preliminary attempts to develop models for nuclear regulatory vulnerability assessment of nuclear power plants are presented. Development of the philosophy and computer tools could be new and important insight for management of nuclear operators and nuclear regulatory bodies who face difficult questions about how to assess the vulnerability of nuclear power plants and other nuclear facilities to external and internal threats. In the situation where different and hidden threat sources are dispersed throughout the world, the assessment of security and safe operation of nuclear power plants is very important. Capability to evaluate plant vulnerability to different kinds of threats, like human and natural occurrences and terrorist attacks and preparation of emergency response plans and estimation of costs are of vital importance for assurance of national security. On the basis of such vital insights, nuclear operators and nuclear regulatory bodies could plan and optimise changes in oversight procedures, organisations, equipment, hardware and software to reduce risks taking into account security and safety of nuclear power plants operation, budget, manpower, and other limitations. Initial qualitative estimations of adapted assessments for nuclear applications are shortly presented. (author)

Probabilistic risk assessment in the nuclear power industry

International Nuclear Information System (INIS)

Fullwood, R.R.; Hall, R.E.

1988-01-01

This book describes the more important improvements in risk assessment methodology developed over the last decade. The book covers the following areas - a general view of risk pertaining to nuclear power, mathematics necessary to understand the text, a concise overview of the light water reactors and their features for protecting the public, probabilities and consequences calculated to form risk assessment to the plant, and 34 applications of probabilistic risk assessment (PRA) in the power generation industry. There is a glossary of acronyms and unusual words and a list of references. (author)

Risk evaluation for motor operated valves in an Inservice Testing Program at a PWR nuclear power plant in Taiwan

International Nuclear Information System (INIS)

Li, Y.C.; Chen, K.T.; Su, Y.L.; Ting, K.; Chien, F.T.; Li, G.D.; Huang, S.H.

2012-01-01

Safety related valves such as Motor Operated Valves (MOV), Air Operated Valves (AOV) or Check Valves (CV) play an important role in nuclear power plant. Functioning of these valves mainly aim at emergency reactivity control, post-accident residue heat removal, post-accident radioactivity removal and containment isolation when a design basis accident occurred. In order to maintain these valves under operable conditions, an Inservice Testing Program (IST) is defined for routine testing tasks based on the ASME Boiler and Pressure Vessel Code section XI code requirements. Risk based Inservice Testing Programs have been studied and developed extensively in the nuclear energy industry since the 1990s. Risk Based evaluations of IST can bring positive advantages to the licensee such as identifying the vulnerability of the system, reducing unnecessary testing burden, concentrating testing resources on the critical pass oriented valves and saving plant’s personnel dose exposure. This risk evaluation is incorporated with quantitative and qualitative analyses to the Motor Operated Valves under current Inservice Testing Program for PWR nuclear power plant in Taiwan. With the outcome of the risk classifications for the safety related MOVs through numerical or deterministic analyses, a risk based testing frequency relief is suggested to demonstrate the benefits received from the risk based Inservice Testing Program. The goal made of this study, it could be as a reference and cornerstone for the licensee to perform overall scope Risk-Informed Inservice Testing Program (RI-IST) evaluation by referring relevant methodologies established in this study.

Off-shore nuclear power plant

International Nuclear Information System (INIS)

Nakanishi, T.

1980-01-01

In order to avoid losses of energy and seawater pollution an off-shore nuclear power plant is coupled with a power plant which utilizes the temperature difference between seawater and hot reactor cooling water. According to the invention the power plant has a working media loop which is separated from the nuclear power plant. The apparative equipment and the operational characteristics of the power plant are the subject of the patent. (UWI) [de

Solar thermal power plants

International Nuclear Information System (INIS)

Schnatbaum, L.

2009-01-01

The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

Energy choices and risk beliefs: is it just global warming and fear of a nuclear power plant accident?

Science.gov (United States)

Greenberg, Michael; Truelove, Heather Barnes

2011-05-01

A survey of 3,200 U.S. residents focused on two issues associated with the use of nuclear and coal fuels to produce electrical energy. The first was the association between risk beliefs and preferences for coal and nuclear energy. As expected, concern about nuclear power plant accidents led to decreased support for nuclear power, and those who believed that coal causes global warming preferred less coal use. Yet other risk beliefs about the coal and nuclear energy fuel cycles were stronger or equal correlates of public preferences. The second issue is the existence of what we call acknowledged risk takers, respondents who favored increased reliance on nuclear energy, although also noting that there could be a serious nuclear plant accident, and those who favored greater coal use, despite acknowledging a link to global warming. The pro-nuclear group disproportionately was affluent educated white males, and the pro-coal group was relatively poor less educated African-American and Latino females. Yet both shared four similarities: older age, trust in management, belief that the energy facilities help the local economy, and individualistic personal values. These findings show that there is no single public with regard to energy preferences and risk beliefs. Rather, there are multiple populations with different viewpoints that surely would benefit by hearing a clear and comprehensive national energy life cycle policy from the national government. © 2010 Society for Risk Analysis.

Power plant cycle chemistry - a currently neglected power plant chemistry discipline

International Nuclear Information System (INIS)

Bursik, A.

2005-01-01

Power plant cycle chemistry seems to be a stepchild at both utilities and universities and research organizations. It is felt that other power plant chemistry disciplines are more important. The last International Power Cycle Chemistry Conference in Prague may be cited as an example. A critical review of the papers presented at this conference seems to confirm the above-mentioned statements. This situation is very unsatisfactory and has led to an increasing number of component failures and instances of damage to major cycle components. Optimization of cycle chemistry in fossil power plants undoubtedly results in clear benefits and savings with respect to operating costs. It should be kept in mind that many seemingly important chemistry-related issues lose their importance during forced outages of units practicing faulty plant cycle chemistry. (orig.)

Operation of Finnish nuclear power plants

International Nuclear Information System (INIS)

Tossavainen, K.

1990-08-01

During the first quarter of 1990 the Finnish nuclear power plant units Loviisa 1 and 2 and TVO I and II were in commercial operation for most of the time. Nuclear electricity accounted for 32.5% of the total Finnish electricity production during this quarter. The load factor average of the nuclear power plant units was 99.0%. An international nuclear event scale has been introduced for the classification of nuclear power plant events according to their nuclear and radiation safety significance. The scale first undergoes about a year long trial period in several countries. on the scale, events are divided into levels from 1 to 7 of which events at Level 7 are the most serious. Furthermore, Level 0 (Below Scale) is used for events with no safety significance. All events which occurred at the Finnish nuclear power plants this quarter are classified as Level 0. Occupational radiation doses and external releases of radioactivity were considerably below authorised limits. At the Loviisa plant, a back-up emergency feedwater system independent of the plant's other systems has been introduced which offers a new, alternative means of removing residual heat from the reactor. Owing to this system, the risk of a severe accident has been further reduced. At the TVO plants, systems have been introduced by which accident sequences which lead to containment failure could be eliminated and the consequences of a potential severe accident could be mitigated. In this report, also the release of short-lived radioactive materials along the transfer route of an irradiated sample is described which occured at the FiR 1 research reactor. The amounts of radioactive materials individuals received in their bodies in connection with this event were very low

Control of power plants and power systems. Proceedings

International Nuclear Information System (INIS)

Canales-Ruiz, R.

1996-01-01

The 88 papers in this volume constitute the proceedings of the International Federation of Automatic Control Symposium held in Mexico in 1995. The broad areas which they cover are: self tuning control; power plant operations; dynamic stability; fuzzy logic applications; power plants modelling; artificial intelligence applications; power plants simulation; voltage control; control of hydro electric units; state estimation; fault diagnosis and monitoring systems; system expansion and operation planning; security assessment; economic dispatch and optimal load flow; adaptive control; distribution; transient stability and preventive control; modelling and control of nuclear plant; knowledge data bases for automatic learning methods applied to power system dynamic security assessment; control of combined cycle units; power control centres. Separate abstracts have been prepared for the three papers relating to nuclear power plants. (UK)

How to provide risk information. Based on citizen's evaluation of messages concerning radiation protection and anti-earthquake measures of nuclear power plant

International Nuclear Information System (INIS)

Tsuchiya, Tomoko; Kosugi, Motoko; Nakamura, Yasushi; Takahashi, Shigeaki; Harayama, Satoko

2009-01-01

The Framework for Nuclear Energy Policy in Japan, decided in 2005, requests implementation of risk communication to regain social trust on nuclear industry. Electric power companies, however, have few experiences of providing risk information as the first step of risk communication. This report analyzes which message is understandable, useful and trustworthy, by comparing two sets of different messages concerning radiation protection and anti-earthquake measures of nuclear power plant, respectively, based on interview survey for 30 people live in Tokyo metropolitan area. Participants in our survey evaluate the message about radiation protection including risk information is more reliable than one without risk information, but the former is less understandable and more anxious than the latter. In the case of messages regarding seismic measures of nuclear power plant, people are not satisfied with the argument which anti-earthquake measures are implemented, but want to know adequate grounds on which to admit that those measures are thorough. Another message of seismic measures we drafted contains basic knowledge about scales of earthquake, and shows that nuclear industry will consider bigger earthquake than ones in the past records, learn from past experience and improve their measures. 70% of participants assess this message more understandable, useful and trustworthy than the other to explain only seismic measures implemented. (author)

Nuclear energy research initiative, an overview of the cooperative program for the risk-informed assessment of regulatory and design requirements for future nuclear power plants

International Nuclear Information System (INIS)

Ritterbusch, Stanley E.

2000-01-01

EPRI sstudies have shown that nuclear plant capital costs will have to decrease by about 35% to 40% to be competitive with fossil-generated electricity in the Unite States. Also, the ''first concrete'' to fuel load construction schedule will have to be decreased to less than 40 months. Therefore, the U. S. Department of Energy (DOE) initiate the Nuclear Energy Research Initiative (NERI) and ABB CENP proposed a cooperative program with Sandia National Laboratory (SNL) and Duke Engineering and Services (DE and S) to begin an innovative research effort to drastically cut the cost of new nuclear power plant construction for the U. S. de-regulated market place. This program was approved by the DOE through three separate but coordinated ''cooperative agreements.'' They are the ''Risk-Informed Assessment of Regulatory and Design Requirements for Future Nuclear Power Plants'' (Risk-Informed NPP), the ''Smart Nuclear Power Plant Program'' (Smart-NPP), and ''Design, Procure, Construct, Install and Test'' (DPCIT) Program. DOE funded the three cooperative agreements at a level of $2.6 million for the first year of the program. Funding for the complete program is durrently at a level $6.9 million, however, ABB CENP and all partners anticipate that the scope of the NERI program will be increased as a result of the overall importance of NERI to the U. S. Government. The Risk-Informed NPP program, which is aimed at revising costly regularory and design requirements without reducing overall plant safety, has two basic tasks: ''development of Risk-Informed Methods'' and ''strengthening the Reliability Database.'' The overall objective of the first task is to develop a scientific, risk-informed approach for identifying and simplifying deterministic industry standards, regulatory requirements, and safety systems that do not significantly contribute to nuclear power plant reliability and safety. The second basic task is to develop a means for strengthening the reliability database

Assessment of direct radiological risk and indirect associated toxic risks originated by Coal-Fired Power Plants

OpenAIRE

Dinis, M. L.; Fiúza, António; Góis, Joaquim; Carvalho, José Soeiro de; Meira Castro, A C

2011-01-01

Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40K. Since the measurement of radioactive elements released by the gaseous emissions of coal power plants i...

Safety-related decision making at a nuclear power plant

International Nuclear Information System (INIS)

Vaurio, J.K.

1998-01-01

The decision making environment of an operating nuclear power plant is presented. The organizations involved, their roles and interactions as well as the main influencing factors and decision criteria are described. The focus is on safety-related decisions, and the framework is based on the situation at Loviisa power station. The role of probabilistic safety assessment (PSA) is illustrated with decisions concerning plant modifications, optimization, acceptance of temporary configurations and extended repair times. Suggestions are made for rational and flexible risk-based control of allowed times to operate the plant with some components out of service. (orig.)

Preliminary risk assessment of Power Plant Plomin site contaminated by radioactive slag and ash

International Nuclear Information System (INIS)

Skanata, D.; Sinka, D.; Lokner, V.; Schaller, A.

1996-01-01

There is a certain number of radioactively contaminated sites in the Republic of Croatia, one of them being known as Power Plant Plomin site, which contains radioactive slag and ash. Due to a relatively high quantity of the deposited material, as well as relatively high population density of the neighbouring area, it is very important to assess the impact of the site on human health and environment. Using RESRAD computer code and PATHRAE method a preliminary assessment of doses and radiation risks for the workers who spend most of their working day at the pile has been performed. PATHRAE method has also been used for the assessment of radiation risks for the neighbouring population. The assessment is preliminary in its character due to the lack of input data. On the basis of assessment results, recommendations are being given comprising measurements to be taken with a view to coming up with the final risk assessment, as well as protective measures which should be undertaken in the meantime. (author)

Failures of knowledge production in nuclear power risk management

International Nuclear Information System (INIS)

Sanne, Johan M.

2008-09-01

Risks are ascribed in processes of knowledge production, where risk objects are defined and measures taken. This knowledge is also the basis for regulatory action. Thus, uncertainties in knowledge production, based upon choices of assumptions, methods, calculations and evidence criteria for reliable data create vulnerabilities for risk management and risk regulation. A recent incident in Swedish nuclear power plant provides an opportunity to develop theories of knowledge production in complex organizations. Knowledge modes within nuclear power can be characterized as either calculated logics where evidence claims need numbers, real time logics based upon subtle signals and tacit knowledge or as policy logics, navigating between internal and external demands for safety, trustworthiness and profit. The plant had neither foreseen the triggering event nor designed the plant to withstand it. I analyze how the plant and the regulator have interpreted the event, its significance and the measures taken to prevent similar events. I also discuss alternative interpretations, lack of knowledge and the generic deficiencies in knowledge production that the event indicates. First, the plant was not as robustly designed as expected. Deficiencies in diversification may have been caused by overconfidence in the reliability of its design. Second, inadequate design was ascribed to various deficient knowledge production processes: original design of the plant, reconstruction or caused by inadequate learning from previous events. The failures in knowledge production were probably caused by insufficient integration of different knowledge processes and limitations in engineering analysis. Knowledge about risks from nuclear power operations is mainly based upon calculations and simulations, not upon real events. But knowledge and design could be improved also without accidents. Control room operators and maintenance staff can provide invaluable knowledge and methods; to improve causal

Failures of knowledge production in nuclear power risk management

Energy Technology Data Exchange (ETDEWEB)

Sanne, Johan M.

2008-09-15

Risks are ascribed in processes of knowledge production, where risk objects are defined and measures taken. This knowledge is also the basis for regulatory action. Thus, uncertainties in knowledge production, based upon choices of assumptions, methods, calculations and evidence criteria for reliable data create vulnerabilities for risk management and risk regulation. A recent incident in Swedish nuclear power plant provides an opportunity to develop theories of knowledge production in complex organizations. Knowledge modes within nuclear power can be characterized as either calculated logics where evidence claims need numbers, real time logics based upon subtle signals and tacit knowledge or as policy logics, navigating between internal and external demands for safety, trustworthiness and profit. The plant had neither foreseen the triggering event nor designed the plant to withstand it. I analyze how the plant and the regulator have interpreted the event, its significance and the measures taken to prevent similar events. I also discuss alternative interpretations, lack of knowledge and the generic deficiencies in knowledge production that the event indicates. First, the plant was not as robustly designed as expected. Deficiencies in diversification may have been caused by overconfidence in the reliability of its design. Second, inadequate design was ascribed to various deficient knowledge production processes: original design of the plant, reconstruction or caused by inadequate learning from previous events. The failures in knowledge production were probably caused by insufficient integration of different knowledge processes and limitations in engineering analysis. Knowledge about risks from nuclear power operations is mainly based upon calculations and simulations, not upon real events. But knowledge and design could be improved also without accidents. Control room operators and maintenance staff can provide invaluable knowledge and methods; to improve causal