Safety analysis fundamentals

International Nuclear Information System (INIS)

Wright, A.C.D.

2002-01-01

This paper discusses the safety analysis fundamentals in reactor design. This study includes safety analysis done to show consequences of postulated accidents are acceptable. Safety analysis is also used to set design of special safety systems and includes design assist analysis to support conceptual design. safety analysis is necessary for licensing a reactor, to maintain an operating license, support changes in plant operations

Organizational analysis and safety for utilities with nuclear power plants: an organizational overview. Volume 1

International Nuclear Information System (INIS)

Osborn, R.N.; Olson, J.; Sommers, P.E.; McLaughlin, S.D.; Jackson, M.S.; Scott, W.G.; Connor, P.E.

1983-08-01

This two-volume report presents the results of initial research on the feasibility of applying organizational factors in nuclear power plant (NPP) safety assessment. A model is introduced for the purposes of organizing the literature review and showing key relationships among identified organizational factors and nuclear power plant safety. Volume I of this report contains an overview of the literature, a discussion of available safety indicators, and a series of recommendations for more systematically incorporating organizational analysis into investigations of nuclear power plant safety

Safety margins in deterministic safety analysis

International Nuclear Information System (INIS)

Viktorov, A.

2011-01-01

The concept of safety margins has acquired certain prominence in the attempts to demonstrate quantitatively the level of the nuclear power plant safety by means of deterministic analysis, especially when considering impacts from plant ageing and discovery issues. A number of international or industry publications exist that discuss various applications and interpretations of safety margins. The objective of this presentation is to bring together and examine in some detail, from the regulatory point of view, the safety margins that relate to deterministic safety analysis. In this paper, definitions of various safety margins are presented and discussed along with the regulatory expectations for them. Interrelationships of analysis input and output parameters with corresponding limits are explored. It is shown that the overall safety margin is composed of several components each having different origins and potential uses; in particular, margins associated with analysis output parameters are contrasted with margins linked to the analysis input. While these are separate, it is possible to influence output margins through the analysis input, and analysis method. Preserving safety margins is tantamount to maintaining safety. At the same time, efficiency of operation requires optimization of safety margins taking into account various technical and regulatory considerations. For this, basic definitions and rules for safety margins must be first established. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-12-01

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

Safety evaluation report of the Waste Isolation Pilot Plant safety analysis report: Contact-handled transuranic waste disposal operations

International Nuclear Information System (INIS)

1997-02-01

DOE 5480.23, Nuclear Safety Analysis Reports, requires that the US Department of Energy conduct an independent, defensible, review in order to approve a Safety Analysis Report (SAR). That review and the SAR approval basis is documented in this formal Safety Evaluation Report (SER). This SER documents the DOE's review of the Waste Isolation Pilot Plant SAR and provides the Carlsbad Area Office Manager, the WIPP SAR approval authority, with the basis for approving the safety document. It concludes that the safety basis documented in the WIPP SAR is comprehensive, correct, and commensurate with hazards associated with planned waste disposal operations

Safety of Nuclear Power Plants: Commissioning and Operation. Specific Safety Requirements

International Nuclear Information System (INIS)

2016-01-01

This publication describes the requirements to be met to ensure the safe operation of nuclear power plants. It takes into account developments in areas such as long term operation of nuclear power plants, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles. A review of Safety Requirements publications was commenced in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan. The review revealed no significant areas of weakness and resulted in just a small set of amendments to strengthen the requirements and facilitate their implementation, which are contained in the present publication

Probabilistic analysis of safety in industrial irradiation plants

International Nuclear Information System (INIS)

Alderete, F.; Elechosa, C.

2006-01-01

The Argentinean Nuclear Regulatory Authority is carrying out the Probabilistic Safety Analysis (PSA) of the two industrial irradiation plants existent in the country. The objective of this presentation is to show from the regulatory point of view, the advantages of applying this tool, as well as the appeared difficulties; for it will be made a brief description of the facilities, of the method and of the normative one. Both plants are multipurpose facilities classified as 'industrial irradiator category IV' (panoramic irradiator with source deposited in pool). Basically, the execution of an APS consists of the following stages: 1. Identification of initiating events. 2. Modeling of Accidental Sequences (Event Trees). 3. Analysis of Systems (Fault trees). 4. Quantification of Accidental Sequences. The argentine normative doesn't demand to these facilities the realization of an APS, however the basic standard of Radiological Safety establishes that in the design of this type of facilities in the cases that is justified, should make sure that the annual probability of occurrence of an accidental sequence and the resulting dose in a person gives as result an radiological risk inferior to the risk limit adopted as acceptance criteria. On the other hand the design standard specifies for these irradiators it demands a maximum fault rate of 10 -2 for the related components with the systems of radiological safety. In our case, the possible initiating events have been identified that carried out to not wanted situations (about people exposure, radioactive contamination). Then, for each one of the significant initiating events, the corresponding accidental sequences were modeled and the safety systems that intervene in this sequences by means of fault trees were analyzed, for then to determine the fault probabilities of the same ones. At the moment they are completing these fault trees, but the difficulty resides in the impossibility of obtaining real data of the reliability

Safety analysis of disposal of decommissioning waste from the Olkiluoto nuclear power plant - PURKU-93

International Nuclear Information System (INIS)

Vieno, T.; Meszaros, F.; Nordman, H.; Taivassalo, V.

1993-12-01

Decommissioning waste from the Olkiluoto nuclear power plant will be disposed of at the depth between 60 and 100 meters in the bedrock at the power plant site. The existing VLJ repository for low and medium level operating waste will be extended with three new silos for the decommissioning waste of the TVO I and II reactors and the spent fuel interim store at the Olkiluoto site. Besides dismantling waste also used fuel boxes, control rods and other activated metal components accumulated during the operation of the reactors will be disposed of in the repository. The safety analysis is based on the detailed decommissioning plan of the Olkiluoto power plants and the comprehensive safety analysis carried out for the Final Safety Analysis Report of the VLJ repository. (58 refs., 31 figs., 38 tabs.)

Mathematical Safety Assessment Approaches for Thermal Power Plants

Directory of Open Access Journals (Sweden)

Zong-Xiao Yang

2014-01-01

Full Text Available How to use system analysis methods to identify the hazards in the industrialized process, working environment, and production management for complex industrial processes, such as thermal power plants, is one of the challenges in the systems engineering. A mathematical system safety assessment model is proposed for thermal power plants in this paper by integrating fuzzy analytical hierarchy process, set pair analysis, and system functionality analysis. In the basis of those, the key factors influencing the thermal power plant safety are analyzed. The influence factors are determined based on fuzzy analytical hierarchy process. The connection degree among the factors is obtained by set pair analysis. The system safety preponderant function is constructed through system functionality analysis for inherence properties and nonlinear influence. The decision analysis system is developed by using active server page technology, web resource integration, and cross-platform capabilities for applications to the industrialized process. The availability of proposed safety assessment approach is verified by using an actual thermal power plant, which has improved the enforceability and predictability in enterprise safety assessment.

Time Based Workload Analysis Method for Safety-Related Operator Actions in Safety Analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Yun Goo; Oh, Eung Se [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

2016-05-15

During the design basis event, the safety system performs safety functions to mitigate the event. The most of safety system is actuated by automatic system however, there are operator manual actions that are needed for the plant safety. These operator actions are classified as important human actions in human factors engineering design. The human factors engineering analysis and evaluation is needed for these important human actions to assure that operator successfully perform their tasks for plant safety and operational goals. The work load analysis is one of the required analysis for the important human actions.

Time Based Workload Analysis Method for Safety-Related Operator Actions in Safety Analysis

International Nuclear Information System (INIS)

Kim, Yun Goo; Oh, Eung Se

2016-01-01

During the design basis event, the safety system performs safety functions to mitigate the event. The most of safety system is actuated by automatic system however, there are operator manual actions that are needed for the plant safety. These operator actions are classified as important human actions in human factors engineering design. The human factors engineering analysis and evaluation is needed for these important human actions to assure that operator successfully perform their tasks for plant safety and operational goals. The work load analysis is one of the required analysis for the important human actions.

Safety assessment, safety performance indicators at the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Baji, C.; Vamos, G.; Toth, J.

2001-01-01

The Paks Nuclear Power Plant has been using different methods of safety assessment (event analysis, self-assessment, probabilistic safety analysis), including performance indicators characterizing both operational and safety performance since the early years of operation of the plant. Regarding the safety performance, the indicators include safety system performance, number of scrams, release of radioactive materials, number of safety significant events, industrial safety indicator, etc. The Paks NPP also reports a set of ten indicators to WANO Performance Indicator Programme which, among others, include safety related indicators as well. However, a more systematic approach to structuring and trending safety indicators is needed so that they can contribute to the enhancement of the operational safety. A more comprehensive set of indicators and a systematic evaluation process was introduced in 1996. The performance indicators framework proposed by the IAEA was adapted to Paks in this year to further improve the process. Safety culture assessment and characterizing safety culture is part of the assessment process. (author)

Waste Isolation Pilot Plant Safety Analysis Report. Volume 5

International Nuclear Information System (INIS)

1986-01-01

This Safety Analysis Report (SAR) has been prepared by the US Department of Energy (DOE) to support the construction and operation of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP facility is designed to receive, inspect, emplace, and store unclassified defense-generated transuranic wastes in a retrievable fashion in an underground salt medium and to conduct studies and perform experiments in salt with high-level wastes. Upon the successful completion of these studies and experiments, WIPP is designed to serve as a permanent facility. The first chapter of this report provides a summary of the location and major design features of WIPP. Chapters 2 through 5 describe the site characteristics, design criteria, and design bases used in the design of the plant and the plant operations. Chapter 6 discusses radiation protection; Chapters 7 and 8 present an accident analysis of the plant and an assessment of the long-term waste isolation at WIPP. The conduct of operations and operating controls and limits are discussed in Chapters 9 and 10. The quality assurance programs are described in Chapter 11

Waste Isolation Pilot Plant Safety Analysis Report. Volume 4

International Nuclear Information System (INIS)

1986-01-01

This Safety Analysis Report (SAR) has been prepared by the US Department of Energy (DOE) to support the construction and operation of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP facility is designed to receive, inspect, emplace, and store unclassified defense-generated transuranic wastes in a retrievable fashion in an underground salt medium and to conduct studies and perform experiments in salt with high-level wastes. Upon the successful completion of these studies and experiments, WIPP is designed to serve as a permanent facility. The first chapter of this report provides a summary of the location and major design features of WIPP. Chapters 2 through 5 describe the site characteristics, design criteria, and design bases used in the design of the plant and the plant operations. Chapter 6 discusses radiation protection; Chapters 7 and 8 present an accident analysis of the plant and an assessment of the long-term waste isolation at WIPP. The conduct of operations and operating controls and limits are discussed in Chapters 9 and 10. The quality assurance programs are described in Chapter 11

Waste Isolation Pilot Plant Safety Analysis Report. Volume 1

International Nuclear Information System (INIS)

1986-01-01

This Safety Analysis Report (SAR) has been prepared by the US Department of Energy (DOE) to support the construction and operation of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP facility is designed to receive, inspect, emplace, and store unclassified defense-generated transuranic wastes in a retrievable fashion in an underground salt medium and to conduct studies and perform experiments in salt with high-level wastes. Upon the successful completion of these studies and experiments, WIPP is designed to serve as a permanent facility. The first chapter of this report provides a summary of the location and major design features of WIPP. Chapters 2 through 5 describe the site characteristics, design criteria, and design bases used in the design of the plant and the plant operations. Chapter 6 discusses radiation protection: Chapters 7 and 8 present an accident analysis of the plant and an assessment of the long-term waste isolation at WIPP. The conduct of operations and operating control and limits are discussed in Chapters 9 and 10. The quality assurance programs are described in Chapter 11

Waste Isolation Pilot Plant Safety Analysis Report. Volume 2

International Nuclear Information System (INIS)

1986-01-01

This Safety Analysis Report (SAR) has been prepared by the US Department of Energy (DOE) to support the construction and operation of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP facility is designed to receive, inspect, emplace, and store unclassified defense-generated transuranic wastes in a retrievable fashion in an underground salt medium and to conduct studies and perform experiments in salt with high-level wastes. Upon the successful completion of these studies and experiments, WIPP is designed to serve as a permanent facility. The first chapter of this report provides a summary of the location and major design features of WIPP. Chapters 2 through 5 describe the site characteristics, design criteria, and design bases used in the design of the plant and the plant operations. Chapter 6 discusses radiation protection; Chapters 7 and 8 present an accident analysis of the plant and an assessment of the long-term waste isolation at WIPP. The conduct of operations and operating controls and limits are discussed in Chapters 9 and 10. The quality assurance programs are described in Chapter 11

The safety analysis report for nuclear power plants in the Federal Republic of Germany

International Nuclear Information System (INIS)

Kohler, H.A.G.

1976-01-01

On the basis of the standard format for drawing up safety analysis reports for stationary fission reactors - this format was published in 1959 by the competent Federal Ministry for Atomic Energy - a report is made on the format and scope of German safety analysis reports. The reasons for drawing up a standard safety analysis report for nuclear power plants with pressurized water reactor or boiling water reactor and a KWU draft are discussed. (orig./RW) [de

Present and future of probabilistic safety analysis of Juragua Nuclear Power Plant

International Nuclear Information System (INIS)

Salomon, J.; Rivero, J.J.

1993-01-01

This work present the main conditions of probabilistic safety analysis of Juragua Nuclear Power Plant, which includes the following aspects: Staff preparedness; Creation of ANCON code; Analysis activity; IAEA technical assistance project. The present situation of PSA National Project and its perspectives development are reported

Safety design of Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Ouyang Yu; Zhang Lian; Du Shenghua; Zhao Jiayu

1984-01-01

Safety issues have been greatly emphasized through the design of the Qinshan Nuclear Power Plant. Reasonable safety margine has been taken into account in the plant design parameters, the design incorporated various safeguard systems, such as engineering safety feature systems, safety protection systems and the features to resist natural catastrophes, e. g. earthquake, hurricanes, tide and so on. Preliminary safety analysis and environmental effect assessment have been done and anti-accident provisions and emergency policy were carefully considered. Qinshan Nuclear Power Plant safety related systems are designed in accordance with the common international standards established in the late 70's, as well as the existing engineering standard of China

Seismic safety of nuclear power plants

International Nuclear Information System (INIS)

Guerpinar, A.; Godoy, A.

2001-01-01

This paper summarizes the work performed by the International Atomic Energy Agency in the areas of safety reviews and applied research in support of programmes for the assessment and enhancement of seismic safety in Eastern Europe and in particular WWER type nuclear power plants during the past seven years. Three major topics are discussed; engineering safety review services in relation to external events, technical guidelines for the assessment and upgrading of WWER type nuclear power plants, and the Coordinated Research Programme on 'Benchmark study for the seismic analysis and testing of WWER type nuclear power plants'. These topics are summarized in a way to provide an overview of the past and present safety situation in selected WWER type plants which are all located in Eastern European countries. Main conclusion of the paper is that although there is now a thorough understanding of the seismic safety issues in these operating nuclear power plants, the implementation of seismic upgrades to structures, systems and components are lagging behind, particularly for those cases in which the re-evaluation indicated the necessity to strengthen the safety related structures or install new safety systems. (author)

Nitrogen-system safety study: Portsmouth Gaseous Diffusion Plant

International Nuclear Information System (INIS)

1982-07-01

The Department of Energy has primary responsibility for the safety of operations at DOE-owned nuclear facilities. The guidelines for the analysis of credible accidents are outlined in DOE Order 5481.1. DOE has requested that existing plant facilities and operations be reviewed for potential safety problems not covered by standard industrial safety procedures. This review is being conducted by investigating individual facilities and documenting the results in Safety Study Reports which will be compiled to form the Existing Plant Final Safety Analysis Report which is scheduled for completion in September, 1984. This Safety Study documents the review of the Plant Nitrogen System facilities and operations and consists of Section 4.0, Facility and Process Description, and Section 5.0, Accident Analysis, of the Final Safety Analysis Report format. The existing nitrogen system consists of a Superior Air Products Company Type D Nitrogen Plant, nitrogen storage facilities, vaporization facilities and a distribution system. The system is designed to generate and distribute nitrogen gas used in the cascade for seal feed, buffer systems, and for servicing equipment when exceptionally low dew points are required. Gaseous nitrogen is also distributed to various process auxiliary buildings. The average usage is approximately 130,000 standard cubic feet per day

Safety of Nuclear Power Plants: Commissioning and Operation. Specific Safety Requirements

International Nuclear Information System (INIS)

2017-01-01

This publication is a revision of IAEA Safety Standards Series No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe commissioning, operation, and transition from operation to decommissioning of nuclear power plants. Over recent years there have been developments in areas such as long term operation of nuclear power plants, plant ageing, periodic safety review, probabilistic safety analysis review and risk informed decision making processes. It became necessary to revise the IAEA’s Safety Requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles. A review of Safety Requirements publications, initiated in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan, revealed no significant areas of weakness but resulted in a small set of amendments to strengthen the requirements and facilitate their implementation. These are contained in the present publication.

Plant Operation Station for HTR-PM Low Power and Shutdown operation Probabilistic safety analysis

International Nuclear Information System (INIS)

Liu Tao; Tong Jiejuan

2014-01-01

Full range Probabilistic safety analysis (PSA) is one of key conditions for nuclear power plant (NPP) licensing according to the requirement of nuclear safety regulatory authority. High Temperature Gas Cooled Reactor Pebble-bed Module (HTR-PM) has developed construction design and prepared for the charging license application. So after the normal power operation PSA submitted for review, the Low power and Shutdown operation Probabilistic safety analysis (LSPSA) also begin. The results of LSPSA will together with prior normal power PSA results to demonstrate the safety level of HTR-PM NPP Plant Operation Station (POS) is one of important terms in LSPSA. The definition of POS lays the foundation for LSPSA modeling. POS provides initial and boundary conditions for the following event tree and fault tree model development. The aim of this paper is to describe the state-of-the-art of POS definition for HTR-PM LSPSA. As for the first attempt to the high temperature gas cooled reactor module plant, the methodology and procedure of POS definition refers to the LWR LSPSA guidance, and adds to plant initial status analysis due to the HTR-PM characteristics. A specific set of POS grouping vectors is investigate and suggested for HTR-PM NPP, which reflects the characteristics of plant modularization and on-line refueling. As a result, seven POSs are given according to the grouping vectors at the end of the paper. They will be used to the LSPSA modelling and adjusted if necessary. The papers ’work may provide reference to the analogous NPP LSPSA. (author)

Latest developments on safety analysis methodologies at the Juzbado plant

International Nuclear Information System (INIS)

Zurron-Cifuentes, Oscar; Ortiz-Trujillo, Diego; Blanco-Fernandez, Luis A.

2010-01-01

Over the last few years the Juzbado Plant has developed and implemented several analysis methodologies to cope with specific issues regarding safety management. This paper describes the three most outstanding of them, so as to say, the Integrated Safety Analysis (ISA) project, the adaptation of the MARSSIM methodology for characterization surveys of radioactive contamination spots, and the programme for the Systematic Review of the Operational Conditions of the Safety Systems (SROCSS). Several reasons motivated the decision to implement such methodologies, such as Regulator requirements, operational experience and of course, the strong commitment of ENUSA to maintain the highest standards of nuclear industry on all the safety relevant activities. In this context, since 2004 ENUSA is undertaking the ISA project, which consists on a systematic examination of plant's processes, equipment, structures and personnel activities to ensure that all relevant hazards that could result in unacceptable consequences have been adequately evaluated and the appropriate protective measures have been identified. On the other hand and within the framework of a current programme to ensure the absence of radioactive contamination spots on unintended areas, the MARSSIM methodology is being applied as a tool to conduct the radiation surveys and investigation of potentially contaminated areas. Finally, the SROCSS programme was initiated earlier this year 2009 to assess the actual operating conditions of all the systems with safety relevance, aiming to identify either potential non-conformities or areas for improvement in order to ensure their high performance after years of operation. The following paragraphs describe the key points related to these three methodologies as well as an outline of the results obtained so far. (authors)

Standard model for safety analysis report of fuel fabrication plants

International Nuclear Information System (INIS)

1980-09-01

A standard model for a safety analysis report of fuel fabrication plants is established. This model shows the presentation format, the origin, and the details of the minimal information required by CNEN (Comissao Nacional de Energia Nuclear) aiming to evaluate the requests of construction permits and operation licenses made according to the legislation in force. (E.G.) [pt

Standard model for safety analysis report of fuel reprocessing plants

International Nuclear Information System (INIS)

1979-12-01

A standard model for a safety analysis report of fuel reprocessing plants is established. This model shows the presentation format, the origin, and the details of the minimal information required by CNEN (Comissao Nacional de Energia Nuclear) aiming to evaluate the requests of construction permits and operation licenses made according to the legislation in force. (E.G.) [pt

Organizational analysis and safety for utilities with nuclear power plants: an organizational overview. Volume 1. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Osborn, R.N.; Olson, J.; Sommers, P.E.; McLaughlin, S.D.; Jackson, M.S.; Scott, W.G.; Connor, P.E.

1983-08-01

This two-volume report presents the results of initial research on the feasibility of applying organizational factors in nuclear power plant (NPP) safety assessment. A model is introduced for the purposes of organizing the literature review and showing key relationships among identified organizational factors and nuclear power plant safety. Volume I of this report contains an overview of the literature, a discussion of available safety indicators, and a series of recommendations for more systematically incorporating organizational analysis into investigations of nuclear power plant safety.

Special safety requirements applied to Brazilian nuclear power plant

International Nuclear Information System (INIS)

Lepecki, W.P.S.; Hamel, H.J.E.; Koenig, N.; Vieira, P.C.R.; Fritzsche, J.C.

1981-01-01

Some safety aspects of the Angra 2 and 3 nuclear power plants are presented. An analysis of the civil and mechanical project of these nuclear power plant having in view a safety analysis is done. (E.G.) [pt

Safety of Nuclear Power Plants: Commissioning and Operation. Specific Safety Requirements (French Edition)

International Nuclear Information System (INIS)

2016-01-01

This publication describes the requirements to be met to ensure the safe operation of nuclear power plants. It takes into account developments in areas such as long term operation of nuclear power plants, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles. A review of Safety Requirements publications was commenced in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan. The review revealed no significant areas of weakness and resulted in just a small set of amendments to strengthen the requirements and facilitate their implementation, which are contained in the present publication.

Nuclear power plant's safety and risk

International Nuclear Information System (INIS)

Franzen, L.F.

1975-01-01

Starting with a comprehensive safety strategy as evolved over the past years and the present legal provisions for the construction and operation of nuclear power plants, the risk of the intended operation, of accidents and unforeseen events is discussed. Owing to the excellent safety record of nuclear power plants, main emphasis in discussing accidents is given to the precautionary analysis within the framework of the licensing procedure. In this context, hypothetical accidents are mentioned only as having been utilized for general risk comparisons. The development of a comprehensive risk concept for a completely objective safety assessment of nuclear power plants remains as a final goal. (orig.) [de

Safety strategy and safety analysis of nuclear power plants

International Nuclear Information System (INIS)

Franzen, L.F.

1976-01-01

The safety strategy for nuclear power plants is characterized by the fact that the high level of safety was attained not as a result of experience, but on the basis of preventive accident analyses and the finding derived from such analyses. Although, in these accident analyses, the deterministic approach is predominant, it is supplemented by reliability analyses. The accidents analyzed in nuclear licensing procedures cover a wide spectrum from minor incidents to the design basis accidents which determine the design of the safety devices. The initial and boundary conditions, which are essentail for accident analyses, and the determination of the loads occurring in various states during regular operation and in accidents flow into the design of the individual systems and components. The inevitable residual risk and its origins are discussed. (orig.) [de

Plutonium finishing plant safety systems and equipment list

International Nuclear Information System (INIS)

Bergquist, G.G.

1995-01-01

The Safety Equipment List (SEL) supports Analysis Report (FSAR), WHC-SD-CP-SAR-021 and the Plutonium Finishing Plant Operational Safety Requirements (OSRs), WHC-SD-CP-OSR-010. The SEL is a breakdown and classification of all Safety Class 1, 2, and 3 equipment, components, or system at the Plutonium Finishing Plant complex

Safety of Nuclear Power Plants: Commissioning and Operation

International Nuclear Information System (INIS)

2011-01-01

This publication is a revision of Safety Requirements No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe operation of nuclear power plants. Over recent years there have been developments in areas such as long term operation, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. It became necessary to revise the IAEA's safety requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the Fundamental Safety Principles. Contents: 1. Introduction; 2. Safety objectives and principles; 3. The management and organizational structure of the operating organization; 4. Management of operational safety; 5. Operational safety programmes; 6. Plant commissioning; 7. Plant operations; 8. Maintenance, testing, surveillance and inspection; 9. Preparation for decommissioning.

Armenian nuclear power plant: US NRC assistance programme for seismic upgrade and safety analysis

International Nuclear Information System (INIS)

Simos, N.; Perkins, K.; Jo, J.; Carew, J.; Ramsey, J.

2003-01-01

This paper summarizes the U.S. Nuclear Regulatory Commission's (US NRC) technical support program activities associated with the Armenian Nuclear Power Plant (ANPP) safety upgrade. The US NRC program, integrated within the overall IAEA-led initiative for safety re-evaluation of the WWER plants, has as its main thrust the technical support to the Armenian Nuclear Regulatory Authority (ANRA) through close collaboration with the scientific staff at Brookhaven National Laboratory (BNL). Several major technical areas of support to ANRA form the basis of the NRC program. These include the seismic re-evaluation and upgrade of the ANPP, safety evaluation of critical systems, and the generation of the Safety Analysis Report (SAR). Specifically, the seismic re-evaluation of the ANPP is part of a broader activity that involves the re-assessment of the seismic hazard at the site, the identification of the Safe Shutdown Equipment at the plant and the evaluation of their seismic capacity, the detailed modeling and analysis of the critical facilities at ANPP, and the generation of the Floor Response Spectra (FRS). Based on the new spectra that incorporate all new findings (hazard, site soil, structure, etc.), the overall capacity of the main structures and the seismic capacity of the critical systems are being re-evaluated. In addition, analyses of critical safe shutdown systems and safe shutdown processes are being performed to ensure both the capabilities of the operating systems and the enhancement of safety due to system upgrades. At present, one of the principal goals of the US NRC's regulatory assistance activities with ANRA is enhancing ANRA's regulatory oversight of high-priority safety issues (both generic and plant-specific) associated with operation of the ANPP. As such, assisting ANRA in understanding and assessing plant-specific seismic and other safety issues associated with the ANPP is a high priority given the ANPP's being located in a seismically active area

Selection and verification of safety parameters in safety parameter display system for nuclear power plants

International Nuclear Information System (INIS)

Zhang Yuangfang

1992-02-01

The method and results for safety parameter selection and its verification in safety parameter display system of nuclear power plants are introduced. According to safety analysis, the overall safety is divided into six critical safety functions, and a certain amount of safety parameters which can represent the integrity degree of each function and the causes of change are strictly selected. The verification of safety parameter selection is carried out from the view of applying the plant emergency procedures and in the accident man oeuvres on a full scale nuclear power plant simulator

Systematic safety evaluation of old nuclear power plants

International Nuclear Information System (INIS)

Dredemis, G.; Fourest, B.

1984-01-01

The French safety authorities have undertaken a systematic evaluation of the safety of old nuclear power plants. Apart from a complete revision of safety documents (safety analysis report, general operating rules, incident and accident procedures, internal emergency plan, quality organisation manual), this examination consisted of analysing the operating experience of systems frequently challenged and a systematic examination of the safety-related systems. This paper is based on an exercise at the Ardennes Nuclear Power Plant which has been in operation for 15 years. This paper also summarizes the main surveys and modifications relating to this power plant. (orig.)

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

Organizational analysis and safety for utilities with nuclear power plants: perspectives for organizational assessment. Volume 2

International Nuclear Information System (INIS)

Osborn, R.N.; Olson, J.; Sommers, P.E.

1983-08-01

This two-volume report presents the results of initial research on the feasibility of applying organizational factors in nuclear power plant (NPP) safety assessment. Volume 1 of this report contains an overview of the literature, a discussion of available safety indicators, and a series of recommendations for more systematically incorporating organizational analysis into investigations of nuclear power plant safety. The six chapters of this volume discuss the major elements in our general approach to safety in the nuclear industry. The chapters include information on organizational design and safety; organizational governance; utility environment and safety related outcomes; assessments by selected federal agencies; review of data sources in the nuclear power industry; and existing safety indicators

Safety of Nuclear Power Plants: Design. Specific Safety Requirements

International Nuclear Information System (INIS)

2012-01-01

On the basis of the principles included in the Fundamental Safety Principles, IAEA Safety Standards Series No. SF-1, this Safety Requirements publication establishes requirements applicable to the design of nuclear power plants. It covers the design phase and provides input for the safe operation of the power plant. It elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Initiating events in the safety probabilistic analysis of nuclear power plants

International Nuclear Information System (INIS)

Stasiulevicius, R.

1989-01-01

The importance of the initiating event in the probabilistic safety analysis of nuclear power plants are discussed and the basic procedures necessary for preparing reports, quantification and grouping of the events are described. The examples of initiating events with its occurence medium frequency, included those calculated for OCONEE reactor and Angra-1 reactor are presented. (E.G.)

An empirical analysis of nuclear power plant organization and its effect on safety performance

International Nuclear Information System (INIS)

Thurber, J.A.

1985-01-01

The paper documents work performed on three tasks. The first task concerned the creation of measures of organizational structure. An earlier review of the literature supported the position that organizational structure (e.g., the way the work of the organization is divided, administered, and coordinated) is a likely determinant of plant safety performance. While data were not available on some salient dimensions of organizational structure, Final Safety Analysis Reports (FSARs), Technical Specifications, and a survey of plant technical resources allowed for measurement on three primary dimensions. These are the vertical structure of the plant (e.g., the number of ranks and the ratio of supervisors to subordinates), the horizontal structure of the plant (e.g., the way the organization is divided into administrative and work units), and the coordinative structure of the plant (e.g., the ways that work units are linked)

Safety analysis of a high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Shimazu, Akira; Morimoto, Toshio

1975-01-01

In recent years, in order to satisfy the social requirements of environment and safety and also to cope with the current energy stringency, the installation of safe nuclear power plants is indispensable. Herein, safety analysis and evaluation to confirm quantitatively the safety design of a nuclear power plant become more and more important. The safety analysis and its methods for a high temperature gas-cooled reactor are described, with emphasis placed on the practices by Fuji Electric Manufacturing Co. Fundamental rule of securing plant safety ; safety analysis in normal operation regarding plant dynamic characteristics and radioactivity evaluation ; and safety analysis at the time of accidents regarding plant response to the accidents and radioactivity evaluation are explained. (Mori, K.)

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

Regulatory analysis for resolution of Unresolved Safety Issue A-46, seismic qualification of equipment in operating plants

International Nuclear Information System (INIS)

Chang, T.Y.; Anderson, N.R.

1987-02-01

The margin of safety provided in existing nuclear power plant equipment to resist seismically induced loads and perform required safety functions may vary considerably, because of significant changes in design criteria and methods for the seismic qualification of equipment over the years. Therefore, the seismic qualification of equipment in operating plants must be reassessed to determine whether requalification is necessary. The objective of technical studies performed under Task Action Plan A-46 was to establish an explicit set of guidelines and acceptance criteria to judge the adequacy of equipment under seismic loading at all operating plants, in lieu of requiring these plants to meet the criteria that are applied to new plants. This report presents the regulatory analysis for Unresolved Safety Issue (USI) A-46. It includes: Statement of the Problem; the Objective of USI A-46; a Summary of A-46 Tasks; a Proposed Implementation Procedure; a Value-Impact Analysis; Application of the Backfit Rule; 10 CFR 50.109; Implementation; and Operating Plants To Be Reviewed to USI A-46 Requirements

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2004-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations. To be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. And to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2003-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations. To be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources. And to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Safety of nuclear power plants: Operation. Safety requirements

International Nuclear Information System (INIS)

2000-01-01

The safety of a nuclear power plant is ensured by means of its proper siting, design, construction and commissioning, followed by the proper management and operation of the plant. In a later phase, proper decommissioning is required. This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Operation, which was issued in 1988 as Safety Series No. 50-C-O (Rev. 1). The purpose of this revision was: to restructure Safety Series No. 50-C-O (Rev. 1) in the light of the basic objectives, concepts and principles in the Safety Fundamentals publication The Safety of Nuclear Installations; to be consistent with the requirements of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources; and to reflect current practice and new concepts and technical developments. Guidance on fulfillment of these Safety Requirements may be found in the appropriate Safety Guides relating to plant operation. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the basic objectives, concepts and principles that are presented in the Safety Fundamentals publication The Safety of Nuclear Installations. This publication deals with matters specific to the safe operation of land based stationary thermal neutron nuclear power plants, and also covers their commissioning and subsequent decommissioning

Safety of Nuclear Power Plants: Commissioning and Operation. Specific Safety Requirements (Arabic Edition)

International Nuclear Information System (INIS)

2017-01-01

This publication is a revision of IAEA Safety Standards Series No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe commissioning, operation, and transition from operation to decommissioning of nuclear power plants. Over recent years there have been developments in areas such as long term operation of nuclear power plants, plant ageing, periodic safety review, probabilistic safety analysis review and risk informed decision making processes. It became necessary to revise the IAEA’s Safety Requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles. A review of Safety Requirements publications, initiated in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan, revealed no significant areas of weakness but resulted in a small set of amendments to strengthen the requirements and facilitate their implementation. These are contained in the present publication.

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Results of safety analysis on PWR type nuclear power plants with two and three loops

International Nuclear Information System (INIS)

1979-01-01

The results of safety analysis on PWR type nuclear power plants with two and three loops are presented, which was conducted by the Resource and Energy Agency, in June, 1979. This analysis was made simulating the phenomenon relating to the pressurizer level gauge at the time of the TMI accident. The model plants were the Ikata nuclear power plant with two loops and the Takahama No. 1 nuclear power plant with three loops. The premise conditions for this safety analysis were as follows: 1) the main feed water flow is totally lost suddenly at the full power operation of the plants, and the feed water pump is started manually 15 minutes after the accident initiation, 2) the relief valve on the pressurizer is kept open even after the pressure drop in the primary cooling system, and the primary cooling water flows out into the containment vessel through the rupture disc of the pressurizer relief tank, and 3) the electric circuit, which sends out the signal of safety injection at the abnormal low pressure in the reactor vessel, is added from the view-point of starting the operation of the emergency core cooling system as early as possible. Relating to the analytical results, the pressure in the reactor vessels changes less, the water level in the pressurizers can be regulated, and the water level in the steam generators is recovered safely in both two and three-loop plants. It is recognized that the plants with both two- and three loops show the safe transient phenomena, and the integrity of the cores is kept under the premise conditions. The evaluation for each analyzed result was conducted in detail. (Nakai, Y.)

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Yoshioka, T.; Toyota, M.; Hinoki, M.

1977-01-01

To develop nuclear power generation for the future, it is necessary to put further emphasis on safety assurance and to endeavour to devise measures to improve plant availability, based on the careful analysis of causes that reduce plant availability. The paper discusses the results of studies on the following items from such viewpoints: (1) Safety and operating experience of LWR nuclear power plants in Japan: operating experience with LWRs; improvements in LWR design during the past ten years; analysis of the factors affecting plant availability; (2) Assurance of safety and measures to increase availability: measures for safety and environmental protection; measures to reduce radiation exposure of employees; appropriateness of maintenance and inspection work; measures to increase plant availability; measures to improve reliability of equipment and components; (3) Future technical problems. (author)

Dependability Assessment by Static Analysis of Software Important to Nuclear Power Plant Safety

Energy Technology Data Exchange (ETDEWEB)

Ourghanlian, Alain [EDF Lab, Chatou (France)

2014-08-15

We describe a practical experimentation of safety assessment of safety-critical software used in Nuclear Power Plants. To enhance the credibility of safety assessments and to optimize safety justification costs, Electricite de France (EDF) investigates the use of methods and tools for source code semantic analysis, to obtain indisputable evidence and help assessors focus on the most critical issues. EDF has been using the PolySpace tool for more than 10 years. Today, new industrial tools, based on the same formal approach, Abstract Interpretation, are available. Practical experimentation with these new tools shows that the precision obtained on one of our shutdown systems software is very significantly improved. In a first part, we present the analysis principles of the tools used in our experimentation. In a second part, we present the main characteristics of protection-system software, and why these characteristics are well adapted for the new analysis tools. In the last part, we present an overview of the results and the limitation of the tools.

Documentation of Hanford Site independent review of the Hanford Waste Vitrification Plant Preliminary Safety Analysis Report

International Nuclear Information System (INIS)

Herborn, D.I.

1993-11-01

Westinghouse Hanford Company (WHC) is the Integrating Contractor for the Hanford Waste Vitrification Plant (HWVP) Project, and as such is responsible for preparation of the HWVP Preliminary Safety Analysis Report (PSAR). The HWVP PSAR was prepared pursuant to the requirements for safety analyses contained in US Department of Energy (DOE) Orders 4700.1, Project Management System (DOE 1987); 5480.5, Safety of Nuclear Facilities (DOE 1986a); 5481.lB, Safety Analysis and Review System (DOE 1986b) which was superseded by DOE order 5480-23, Nuclear Safety Analysis Reports, for nuclear facilities effective April 30, 1992 (DOE 1992); and 6430.lA, General Design Criteria (DOE 1989). The WHC procedures that, in large part, implement these DOE requirements are contained in WHC-CM-4-46, Nonreactor Facility Safety Analysis Manual. This manual describes the overall WHC safety analysis process in terms of requirements for safety analyses, responsibilities of the various contributing organizations, and required reviews and approvals

Design of plant safety model in plant enterprise engineering environment

International Nuclear Information System (INIS)

Gabbar, Hossam A.; Suzuki, Kazuhiko; Shimada, Yukiyasu

2001-01-01

Plant enterprise engineering environment (PEEE) is an approach aiming to manage the plant through its lifecycle. In such environment, safety is considered as the common objective for all activities throughout the plant lifecycle. One approach to achieve plant safety is to embed safety aspects within each function and activity within such environment. One ideal way to enable safety aspects within each automated function is through modeling. This paper proposes a theoretical approach to design plant safety model as integrated with the plant lifecycle model within such environment. Object-oriented modeling approach is used to construct the plant safety model using OO CASE tool on the basis of unified modeling language (UML). Multiple views are defined for plant objects to express static, dynamic, and functional semantics of these objects. Process safety aspects are mapped to each model element and inherited from design to operation stage, as it is naturally embedded within plant's objects. By developing and realizing the plant safety model, safer plant operation can be achieved and plant safety can be assured

Most significant preliminary results of the probabilistic safety analysis on the Juragua nuclear power plant

International Nuclear Information System (INIS)

Perdomo, Manuel

1995-01-01

Since 1990 the Group for PSA Development and Applications (GDA/APS) is working on the Level-1 PSA for the Juragua-1 NPP, as a part of an IAEA Technical Assistance Project. The main objective of this study, which is still under way, is to assess, in a preliminary way, the Reactor design safety to find its potential 'weak points' at the construction stage, using a eneric data base. At the same time, the study allows the PSA team to familiarize with the plant design and analysis techniques for the future operational PSA of the plant. This paper presents the most significant preliminary results of the study, which reveal some advantages of the safety characteristics of the plant design in comparison with the homologous VVER-440 reactors and some areas, where including slight modifications would improve the plant safety, considering the level of detail at which the study is carried out. (author). 13 refs, 1 fig, 2 tabs

Standard model for safety analysis report of hexafluoride power plants from natural uranium

International Nuclear Information System (INIS)

1983-01-01

The standard model for safety analysis report for hexafluoride production power plants from natural uranium is presented, showing the presentation form, the nature and the degree of detail, of the minimal information required by the Brazilian Nuclear Energy Commission - CNEN. (E.G.) [pt

Layout of the safety analysis report for nuclear power plants with pressurized water reactor or boiling water reactor in the Federal Republic of Germany

International Nuclear Information System (INIS)

Albrecht, E.

1980-01-01

For a licence according to paragraph 7 of the Atomic Energy Act to construct and operate a nuclear power plant, the applicant has to submit a safety analysis report, which must describe the site, the plant, all hazards in connection with the plant and the proposed safety precautions. For the structure and the content of a safety analysis report, a first guideline was published in 1959. Only a few safety analysis reports were prepared nearly strictly according to this guideline. In 1976 a second guideline was published for a standard safety analysis report. The lecture deals with the guidelines. A survey over the structure and content of the German safety analysis reports will be given. The experience gained by the new safety analysis reports will be discussed. (orig.)

Safety analysis methodology for Chinshan nuclear power plant spent fuel pool under Fukushima-like accident condition

Energy Technology Data Exchange (ETDEWEB)

Lin, Hao-Tzu [Institute of Nuclear Energy Research, Taoyuan, Taiwan (China). Research Atomic Energy Council; Li, Wan-Yun; Wang, Jong-Rong; Tseng, Yung-Shin; Chen, Hsiung-Chih; Shih, Chunkuan; Chen, Shao-Wen [National Tsing Hua Univ., HsinChu, Taiwan (China). Inst. of Nuclear Engineering and Science

2017-03-15

Chinshan nuclear power plant (NPP), a BWR/4 plant, is the first NPP in Taiwan. After Fukushima NPP disaster occurred, there is more concern for the safety of NPPs in Taiwan. Therefore, in order to estimate the safety of Chinshan NPP spent fuel pool (SFP), by using TRACE, MELCOR, CFD, and FRAPTRAN codes, INER (Institute of Nuclear Energy Research, Atomic Energy Council, R.O.C.) performed the safety analysis of Chinshan NPP SFP. There were two main steps in this research. The first step was the establishment of Chinshan NPP SFP models. And the transient analysis under the SFP cooling system failure condition (Fukushima-like accident) was performed. In addition, the sensitive study of the time point for water spray was also performed. The next step was the fuel rod performance analysis by using FRAPTRAN and TRACE's results. Finally, the animation model of Chinshan NPP SFP was presented by using the animation function of SNAP with MELCOR analysis results.

Dukovany nuclear power plant safety

International Nuclear Information System (INIS)

1999-01-01

Presentation covers recommended safety issues for the Dukovany NPP which have been solved with satisfactory conclusions. Safety issues concerned include: radiation safety; nuclear safety; security; emergency preparedness; health protection at work; fire protection; environmental protection; chemical safety; technical safety. Quality assurance programs at all stages on NPP life time is described. Report includes description of NPP staff training provision, training simulator, emergency operating procedures, emergency preparedness, Year 2000 problem, inspections and life time management. Description of Dukovany Plant Safety Analysis Projects including integrity of the equipment, modernisation, equipment innovation and safety upgrading program show that this approach corresponds to the actual practice applied in EU countries, and fulfilment of current IAEA requirements for safety enhancement of the WWER 440/213 units in the course of MORAWA Equipment Upgrading program

Analysis of effect of safety classification on DCS design in nuclear power plants

International Nuclear Information System (INIS)

Gou Guokai; Li Guomin; Wang Qunfeng

2011-01-01

By analyzing the safety classification for the systems and functions of nuclear power plants based on the general design requirements for nuclear power plants, especially the requirement of availability and reliability of I and C systems, the characteristics of modem DCS technology and I and C products currently applied in nuclear power field are interpreted. According to the requirements on the safety operation of nuclear power plants and the regulations for safety audit, the effect of different safety classifications on DCS design in nuclear power plants is analyzed, by considering the actual design process of different DCS solutions in the nuclear power plants under construction. (authors)

Safety analysis of Oi nuclear power plant

International Nuclear Information System (INIS)

1979-01-01

The transient phenomena in Oi nuclear power plant were analyzed, especially on the water level fluctuation and the capability of natural circulation in the primary loop, under the assumptions that the feed water for steam generators is totally lost, and the relief valve on the pressurizer, which is actuated due to the pressure rise in the primary system, is stuck and kept open. These assumptions are related to the TMI accident. The analysing conditions are 1) the main feed water flow is totally lost suddenly during the rated power operation of the reactor, 2) two motor-driven auxiliary feed water pumps are started manually fifteen minutes after the accident initiation, 3) one relief valve on the pressurizer is opened fifteen seconds after the accident initiation and kept open, 4) the reactor is scrammed thirty three seconds after the accident initiation, 5) the turbine is tripped 33.5 seconds after the accident initiation, etc. Two cases were analysed, namely 3,800 seconds and 1,200 seconds after the accident initiation. The analytical code RELEP4/Mod5/U2/J1 was utilized for this analysis. The level fluctuation in the pressurizer after the accident initiation, the flow rate fluctuation through the pressurizer relief valve, especially that of steam, liquid single phase and two phase flows, the water level in the upper plenum in the pressure vessel, the change of flow rate at core inlet, the average pressure in the core, and the temperature fluctuation of coolant in the core, the variation of void fraction in the core, and the change of surface temperature of fuel rods are presented as the analysis results, and they are evaluated. It is recognized that the plant safety is kept under the assumed accident conditions in the Oi nuclear power plant. (Nakai, Y.)

Methodology and development of instruments for the safety analysis of a nuclear reprocessing plant

International Nuclear Information System (INIS)

Markett, J.

1987-01-01

Characteristics and overlapping aspects in the elaboration of safety analyses for the nuclear and conventional units are presented. The current methods are presented and their limits of applicability characterized. The transferability of individual methods or their elements to the analysis of the reference plant of Wackersdorf is examined and the procedure for the systems analysis is determined. It is of great importance to prove that the essential kinds of incidents and possibilities of release with potential effects in the environment are completely identified. The incidents are divided into basic incidents, which are characterized by superior physical/chemical release mechanisms. An essential objective is to systematize the safety analysis and to summarize the presentation of results. Selection criteria are presented, which allow a limitation of the analysis to essential influencing parameters without removing aspects from the overall safety-relevant statement. Besides the selection criteria, instruments and mathematical models are explained with the help of which the representative and possible incidents covering all potential risks for all areas of the plant, systems and components can be selected. These design-basis accidents (criticality, self-heating, fire, explosion, leakages, earth quakes) are decisive for the determination of potential damaging effects in the environment and thus for the overall statement on the licensability. (orig./HP) [de

A proposed approach for enhancing design safety assurance of future plants

International Nuclear Information System (INIS)

Oh, Kyu Myeng; Ahn, Sang Kyu; Lee, Chang Ju; Kim, Inn Seock

2010-01-01

This paper provides various insights from a detailed review of deterministic approaches typically applied to ensure design safety of nuclear power plants (NPPs) and risk-informed approaches proposed to evaluate safety of advanced reactors such as Generation IV reactors. Also considered herein are the risk-informed safety analysis (RISA) methodology suggested by Westinghouse as a means to improve the conventional accident analysis, together with the Technology Neutral Framework recently suggested by the U.S. NRC for safety evaluation of future plants. These insights from the comparative review of deterministic and risk-informed approaches could be used in further enhancing the methodology for design safety assurance of future plants

Approach to uncertainty evaluation for safety analysis

International Nuclear Information System (INIS)

Ogura, Katsunori

2005-01-01

Nuclear power plant safety used to be verified and confirmed through accident simulations using computer codes generally because it is very difficult to perform integrated experiments or tests for the verification and validation of the plant safety due to radioactive consequence, cost, and scaling to the actual plant. Traditionally the plant safety had been secured owing to the sufficient safety margin through the conservative assumptions and models to be applied to those simulations. Meanwhile the best-estimate analysis based on the realistic assumptions and models in support of the accumulated insights could be performed recently, inducing the reduction of safety margin in the analysis results and the increase of necessity to evaluate the reliability or uncertainty of the analysis results. This paper introduces an approach to evaluate the uncertainty of accident simulation and its results. (Note: This research had been done not in the Japan Nuclear Energy Safety Organization but in the Tokyo Institute of Technology.) (author)

Organizational analysis and safety for utilities with nuclear power plants: perspectives for organizational assessment. Volume 2. [PWR; BWR

Energy Technology Data Exchange (ETDEWEB)

Osborn, R.N.; Olson, J.; Sommers, P.E.; McLaughlin, S.D.; Jackson, M.S.; Nadel, M.V.; Scott, W.G.; Connor, P.E.; Kerwin, N.; Kennedy, J.K. Jr.

1983-08-01

This two-volume report presents the results of initial research on the feasibility of applying organizational factors in nuclear power plant (NPP) safety assessment. Volume 1 of this report contains an overview of the literature, a discussion of available safety indicators, and a series of recommendations for more systematically incorporating organizational analysis into investigations of nuclear power plant safety. The six chapters of this volume discuss the major elements in our general approach to safety in the nuclear industry. The chapters include information on organizational design and safety; organizational governance; utility environment and safety related outcomes; assessments by selected federal agencies; review of data sources in the nuclear power industry; and existing safety indicators.

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

The safety of the new reprocessing plants of La Hague

International Nuclear Information System (INIS)

Devillers, C.; Dubois, G.

1987-09-01

In this document the authors show the main guiding lines on which is based the safety of the new reprocessing plant of La Hague. They are: - the objectives: to limit the impacts on workers and environment - the methods: safety analysis based on the checking and evaluation of significant risks. - the means: to make a safety plant by the use of quality assurance in the conception and in the plant construction [fr

Safety of Nuclear Power Plants: Commissioning and Operation (Spanish Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication is a revision of Safety Requirements No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe operation of nuclear power plants. Over recent years there have been developments in areas such as long term operation, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. It became necessary to revise the IAEA's safety requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the Fundamental Safety Principles. Contents: 1. Introduction; 2. Safety objectives and principles; 3. The management and organizational structure of the operating organization; 4. Management of operational safety; 5. Operational safety programmes; 6. Plant commissioning; 7. Plant operations; 8. Maintenance, testing, surveillance and inspection; 9. Preparation for decommissioning.

Safety of Nuclear Power Plants: Commissioning and Operation (French Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication is a revision of Safety Requirements No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe operation of nuclear power plants. Over recent years there have been developments in areas such as long term operation, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. It became necessary to revise the IAEA's safety requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the Fundamental Safety Principles. Contents: 1. Introduction; 2. Safety objectives and principles; 3. The management and organizational structure of the operating organization; 4. Management of operational safety; 5. Operational safety programmes; 6. Plant commissioning; 7. Plant operations; 8. Maintenance, testing, surveillance and inspection; 9. Preparation for decommissioning.

Safety of Nuclear Power Plants: Commissioning and Operation. Arabic Edition

International Nuclear Information System (INIS)

2011-01-01

This publication is a revision of Safety Requirements No. NS-R-2, Safety of Nuclear Power Plants: Operation, and has been extended to cover the commissioning stage. It describes the requirements to be met to ensure the safe operation of nuclear power plants. Over recent years there have been developments in areas such as long term operation, plant ageing, periodic safety review, probabilistic safety analysis and risk informed decision making processes. It became necessary to revise the IAEA's safety requirements in these areas and to correct and/or improve the publication on the basis of feedback from its application by both the IAEA and its Member States. In addition, the requirements are governed by, and must apply, the safety objective and safety principles that are established in the Fundamental Safety Principles. Contents: 1. Introduction; 2. Safety objectives and principles; 3. The management and organizational structure of the operating organization; 4. Management of operational safety; 5. Operational safety programmes; 6. Plant commissioning; 7. Plant operations; 8. Maintenance, testing, surveillance and inspection; 9. Preparation for decommissioning.

Key asset - inherent safety of LMFBR Pool Plant

International Nuclear Information System (INIS)

Marchaterre, J.F.; Sevy, R.H.; Lancet, R.T.; Mills, J.C.

1984-04-01

The safety approach used in the design of the Large Pool Plant emphasizes use of the intrinsic characteristics of Liquid Metal Fast Breeder Reactors to incorporate a high degree of safety in the design and reduce cost by providing simpler (more reliable) dedicated safety systems. Correspondingly, a goal was not to require the action of active systems to prevent significant core damage and/or provide large grace periods for all anticipated transients. The key safety features of the plant are presented and the analysis of representative flow and power transients are presented to show that the design goal has been satisfied

Key asset--Inherent safety of LFMBR pool plant

International Nuclear Information System (INIS)

Marchaterre, J.F.; Lancet, R.T.; Mills, J.C.; Sevy, R.H.

1984-01-01

The safety approach used in the design of the Large Pool Plant emphasizes use of the intrinsic characteristics of Liquid Metal Fast Breeder Reactors to incorporate a high degree of safety in the design and reduce cost by providing simpler (more reliable) dedicated safety systems. Correspondingly, a goal was not to require the action of active systems to prevent significant core damage and/or provide large grace periods for all anticipated transients. The key safety features of the plant are presented and the analysis of representative flow and power transients are presented to show that the design goal has been satisfied

Safety Effect Analysis of the Large-Scale Design Changes in a Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Lee, Eun-Chan; Lee, Hyun-Gyo [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

2015-05-15

These activities were predominantly focused on replacing obsolete systems with new systems, and these efforts were not only to prolong the plant life, but also to guarantee the safe operation of the units. This review demonstrates the safety effect evaluation using the probabilistic safety assessment (PSA) of the design changes, system improvements, and Fukushima accident action items for Kori unit 1 (K1). For the large scale of system design changes for K1, the safety effects from the PSA perspective were reviewed using the risk quantification results before and after the system improvements. This evaluation considered the seven significant design changes including the replacement of the control building air conditioning system and the performance improvement of the containment sump using a new filtering system as well as above five system design changes. The analysis results demonstrated that the CDF was reduced by 12% overall from 1.62E-5/y to 1.43E-5/y. The CDF reduction was larger in the transient group than in the loss of coolant accident (LOCA) group. In conclusion, the analysis using the K1 PSA model supports that the plant safety has been appropriately maintained after the large-scale design changes in consideration of the changed operation factors and failure modes due to the system improvements.

Qualification of safety-critical software for digital reactor safety system in nuclear power plants

International Nuclear Information System (INIS)

Kwon, Kee-Choon; Park, Gee-Yong; Kim, Jang-Yeol; Lee, Jang-Soo

2013-01-01

This paper describes the software qualification activities for the safety-critical software of the digital reactor safety system in nuclear power plants. The main activities of the software qualification processes are the preparation of software planning documentations, verification and validation (V and V) of the software requirements specifications (SRS), software design specifications (SDS) and codes, and the testing of the integrated software and integrated system. Moreover, the software safety analysis and software configuration management are involved in the software qualification processes. The V and V procedure for SRS and SDS contains a technical evaluation, licensing suitability evaluation, inspection and traceability analysis, formal verification, software safety analysis, and an evaluation of the software configuration management. The V and V processes for the code are a traceability analysis, source code inspection, test case and test procedure generation. Testing is the major V and V activity of the software integration and system integration phases. The software safety analysis employs a hazard operability method and software fault tree analysis. The software configuration management in each software life cycle is performed by the use of a nuclear software configuration management tool. Through these activities, we can achieve the functionality, performance, reliability, and safety that are the major V and V objectives of the safety-critical software in nuclear power plants. (author)

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Chinese Ed.)

International Nuclear Information System (INIS)

2012-01-01

On the basis of the principles included in the Fundamental Safety Principles, IAEA Safety Standards Series No. SF-1, this Safety Requirements publication establishes requirements applicable to the design of nuclear power plants. It covers the design phase and provides input for the safe operation of the power plant. It elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (French Ed.)

International Nuclear Information System (INIS)

2012-01-01

On the basis of the principles included in the Fundamental Safety Principles, IAEA Safety Standards Series No. SF-1, this Safety Requirements publication establishes requirements applicable to the design of nuclear power plants. It covers the design phase and provides input for the safe operation of the power plant. It elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Arabic Ed.)

International Nuclear Information System (INIS)

2012-01-01

On the basis of the principles included in the Fundamental Safety Principles, IAEA Safety Standards Series No. SF-1, this Safety Requirements publication establishes requirements applicable to the design of nuclear power plants. It covers the design phase and provides input for the safe operation of the power plant. It elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Spanish Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication is a revision of Safety Requirements No. NS-R-1, Safety of Nuclear Power Plants: Design. It establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in the design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Russian Edition)

International Nuclear Information System (INIS)

2012-01-01

This publication is a revision of Safety Requirements No. NS-R-1, Safety of Nuclear Power Plants: Design. It establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in the design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Development of Draft Regulatory Guide on Accident Analysis for Nuclear Power Plants with New Safety Design Features

Energy Technology Data Exchange (ETDEWEB)

Bang, Young Seok; Woo, Sweng Woong; Hwang, Tae Suk [KINS, Daejeon (Korea, Republic of); Sim, Suk K; Hwang, Min Jeong [Environment and Energy Technology, Daejeon (Korea, Republic of)

2016-05-15

The present paper discusses the development process of the draft version of regulatory guide (DRG) on accident analysis of the NPP having the NSFD and its result. Based on the consideration on the lesson learned from the previous licensing review, a draft regulatory guide (DRG) on accident analysis for NPP with new safety design features (NSDF) was developed. New safety design features (NSDF) have been introduced to the new constructing nuclear power plants (NPP) since the early 2000 and the issuance of construction permit of SKN Units 3 and 4. Typical examples of the new safety features includes Fluidic Device (FD) within Safety Injection Tanks (SIT), Passive Auxiliary Feedwater System (PAFS), ECCS Core Barrel Duct (ECBD) which were adopted in APR1400 design and/or APR+ design to improve the safety margin of the plants for the postulated accidents of interest. Also several studies of new concept of the safety system such as Hybrid ECCS design have been reported. General and/or specific guideline of accident analysis considering the NSDF has been requested. Realistic evaluation of the impact of NSDF on accident with uncertainty and separated accident analysis accounting the NSDF impact were specified in the DRG. Per the developmental process, identification of key issues, demonstration of the DRG with specific accident with specific NSDF, and improvement of DGR for the key issues and their resolution will be conducted.

An approach to review design bases and safety analysis of earlier generation atomic power plants; a case study of TAPS

International Nuclear Information System (INIS)

Malhotra, P.K.; Bajaj, S.S.

2002-01-01

The twin unit boiling water reactor (BWR) station at TAPS has completed 30 years of power operation and for further extending plant operating life, a fresh extensive exercise involving review of plant operating performance, aging management and review of design bases and safety analysis has been carried out. The review exercise resulted in assessment of acceptability of identified non-conformances and recommendation for compensatory measures in the form of design modification or plant operating procedures. The second part of the exercise is related to safety analysis, which is carried out in view of the plant modifications done and advances taken place in methodologies of analytical techniques. Chiefly, it involves LOCA analysis done for various break sizes at different locations and plant transient studies. It also includes the fatigue analysis of the reactor pressure vessel. The related review approach adopted is presented here

A probabilistic safety analysis of UF{sub 6} handling at the Portsmouth Gaseous Diffusion Plant

Energy Technology Data Exchange (ETDEWEB)

Boyd, G.J.; Lewis, S.R.; Summitt, R.L. [Safety and Reliability Optimization Services (SAROS), Inc., Knoxville, TN (United States)

1991-12-31

A probabilistic safety study of UF{sub 6} handling activities at the Portsmouth Gaseous Diffusion Plant has recently been completed. The analysis provides a unique perspective on the safety of UF{sub 6} handling activities. The estimated release frequencies provide an understanding of current risks, and the examination of individual contributors yields a ranking of important plant features and operations. Aside from the probabilistic results, however, there is an even more important benefit derived from a systematic modeling of all operations. The integrated approach employed in the analysis allows the interrelationships among the equipment and the required operations to be explored in depth. This paper summarizes the methods used in the study and provides an overview of some of the technical insights that were obtained. Specific areas of possible improvement in operations are described.

Probabilistic analysis of safety of a production plant of hydrogen using nuclear energy

International Nuclear Information System (INIS)

Flores F, A.; Nelson E, P.F.; Francois L, J.L.

2005-01-01

The present work makes use of the Probabilistic Safety analysis to evaluate and to quantify the safety in a plant producer of hydrogen coupled to a nuclear reactor of high temperature, the one which is building in Japan. It is had the description of systems and devices of the HTTR, the pipe diagrams and instrumentation of the plant, as well as the rates of generic faults for the components of the plant. The first step was to carry out a HAZOP study (Hazard and Operability Study) with the purpose of obtaining the initiator events; once obtained these, it was developed a tree of events by each initiator event and for each system it was developed a fault tree; the data used for the quantification of the failure probability of the systems were obtained starting from several generic sources of information. In each tree of events different final states were obtained and it stops each one, their occurrence frequency. The construction and evaluation of the tree of events and of failures one carries out with the SAPHIRE program. The results show the safety of the shutdown system of the HTTR and they allow to suggest modifications to the auxiliary system of refrigeration and to the heat exchanger helium/water pressurized. (Author)

Seismic safety of nuclear power plants in Eastern Europe

International Nuclear Information System (INIS)

Gurpinar, A.; Godoy, A.

1995-01-01

This paper summarizes the work performed by the International Atomic Energy Agency in the areas of safety reviews and applied research in support of programmes for the assessment and enhancement of seismic safety in WWER type nuclear power plants during the past five years. Three major topics are discussed; engineering safety review services in relation to external events, technical guidelines for the assessment and upgrading of WWER type nuclear power plants, and the Coordinated Research Programme on B enchmark study for the seismic analysis and testing of WWER type nuclear power plants . These topics are summarized in a way to provide an overview of the past and present safety situation in selected WWER type plants which are all located in Eastern European countries. Main conclusion of the paper is that although there is now a thorough understanding of the seismic safety issues in these operating nuclear power plants, the implementation of seismic upgrades to structures, systems and components are lagging behind, particularly for those cases in which the re-evaluation indicated the necessity to strengthen the safety related structures or install new safety systems. (author)

Industrial safety in power plants

International Nuclear Information System (INIS)

1987-01-01

The proceedings of the VGB conference 'Industrial safety in power plants' held in the Gruga-Halle, Essen on January 21 and 22, 1987, contain the papers reporting on: Management responsibility for and legal consequences of industrial safety; VBG 2.0 Industrial Accident Prevention Regulation and the power plant operator; Operational experience gained with wet-type flue gas desulphurization systems; Flue gas desulphurization systems: Industrial-safety-related requirements to be met in planning and operation; the effects of the Hazardous Substances Ordinance on power plant operation; Occupational health aspects of heat-exposed jobs in power plants; Regulations of the Industrial Accident Insurance Associations concerning heat-exposed jobs and industrial medical practice; The new VBG 30 Accident Prevention Regulation 'Nuclear power plants'; Industrial safety in nuclear power plants; safe working on and within containers and confined spaces; Application of respiratory protection equipment in power plants. (HAG) [de

Safety assessment and verification for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

Safety assessment and verification for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

Impact of the specialization from failures data in probability safety analysis for process plants

International Nuclear Information System (INIS)

Ribeiro, Antonio C.O.; Melo, P.F. Frutuoso e

2005-01-01

Full text: The aim of this paper is to show the Bayesian inference in reliability studies, which are used to failures, rates updating in safety analyses. It is developed the impact of its using in quantitative risk assessments (QRA) for industrial process plants. With this approach we find a structured and auditable way of showing the difference between an industrial installation with a good project and maintenance structure from another one that shows a low level of quality in these areas. In general the evidence from failures rates and as follow the frequency of occurrence from scenarios, which the risks taken in account in ERA, are taken from generics data banks, instead of, the installation in analysis. The use of this methodology in probabilistic safety analysis (PSA) for nuclear plants is commonly used when you need to find the final fault tree event evaluation applied to a scenario, but it is not showed in a PSA level III. (author)

Effect Analysis of Digital I and C Systems on Plant Safety based on Fault-Tree Analysis

International Nuclear Information System (INIS)

Lee, Seung Jun; Jung, Wondea

2014-01-01

Deterioration and an inadequate supply of components of analog I and C systems have led to inefficient and costly maintenance. Moreover, since the fast evolution of digital technology has enabled more reliable functions to be designed for NPP safety, the transition from analog to digital has been accelerated. Owing to the distinguishable characteristics of digital I and C systems, a reliability analysis of digital systems has become an important element of a probabilistic safety assessment (PSA). Digital I and C systems have unique characteristics such as fault-tolerant techniques and software. However, these features have not been properly considered yet in most NPP PSA models. The effect of digital I and C systems should be evaluated by comparing them to that of analog I and C systems. Before installing a digital I and C system, even though it is expected that the plant safety can be improved through the advantageous features of digital I and C systems, it should be validated whether the total NPP safety is better than analog systems or is the same at least. In this work, the fault-tree (FT) technique, which is most widely used in a PSA, was used to compare the effects of analog and digital I and C systems. From a case study, the results of plant safety were compared. In this work, the effect of a digital RPS was evaluated by comparing it to that of an analog RPS based on the FT models. In the evaluation results, it was observed that digital RPS has a positive effect on reducing the system unavailability. The analysis results can be used for the development of a guide for evaluating digital I and C systems and reliability requirements

Ignalina Safety Analysis Group

International Nuclear Information System (INIS)

Ushpuras, E.

1995-01-01

The article describes the fields of activities of Ignalina NPP Safety Analysis Group (ISAG) in the Lithuanian Energy Institute and overview the main achievements gained since the group establishment in 1992. The group is working under the following guidelines: in-depth analysis of the fundamental physical processes of RBMK-1500 reactors; collection, systematization and verification of the design and operational data; simulation and analysis of potential accident consequences; analysis of thermohydraulic and neutronic characteristics of the plant; provision of technical and scientific consultations to VATESI, Governmental authorities, and also international institutions, participating in various projects aiming at Ignalina NPP safety enhancement. The ISAG is performing broad scientific co-operation programs with both Eastern and Western scientific groups, supplying engineering assistance for Ignalina NPP. ISAG is also participating in the joint Lithuanian - Swedish - Russian project - Barselina, the first Probabilistic Safety Assessment (PSA) study of Ignalina NPP. The work is underway together with Maryland University (USA) for assessment of the accident confinement system for a range of breaks in the primary circuit. At present the ISAG personnel is also involved in the project under the grant from the Nuclear Safety Account, administered by the European Bank for reconstruction and development for the preparation and review of an in-depth safety assessment of the Ignalina plant

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Hinoki, M.

1977-01-01

From the outset of nuclear power development in Japan, major emphasis has been placed on the safety of the nuclear power plants. There are now twelve nuclear power plants in operation with a total output of 6600 MWe. Their operating records were generally satisfactory, but in the 1974 to 1975 period, they experienced somewhat declined availability due to the repair work under the specific circumstances. After investigation of causes of troubles and the countermeasures thereof were made to ensure safety, they are now keeping good performance. In Japan, nuclear power plants are strictly subject to sufficient and careful inspection in compliance with the safety regulation, and are placed under stringent radiation control of employees. Under the various circumstances, however, the period of annual inspection tends to be prolonged more than originally planned, and this consequently is considered to be one of the causes of reduced availability. In order to develop nuclear power generation for the future, it is necessary to put further emphasis on the assurance of safety and to endeavor to devise measures to improve availability of the plants, based on the careful analysis of causes which reduce plant availability. This paper discusses the results of studies made for the following items from such viewpoints: (1) Safety and Operating Experience of LWR Nuclear Power Plants in Japan; a) Operating experience with light water reactors b) Improvements in design of light water reactors during the past ten years c) Analysis of the factors which affect plant availability; 2) Assurance of Safety and Measures to Increase Availability a) Measures for safety and environmental protection b) Measures to reduce radiation exposure of employees c) Appropriateness of maintenance and inspection work d) Measures to increase plant availability e) Measures to improve reliability of equipments and components; and 3) Future Technical Problems

Results of research into nuclear power plant safety

International Nuclear Information System (INIS)

Polak, V.; Hladky, E.; Moravek, J.; Suchomel, J.; Stehlik, J.

1976-01-01

A survey is given of computer programmes for the safety analysis of nuclear power plants with WWER type reactors and with fast breeder reactors. The programmes solve accidents in the core, the primary circuit and the containment. A comparison is made of Czechoslovak and foreign computer programmes and their agreement proved. Also studied is the problem of radiation safety of nuclear power plants with regard to the leakage of radioactive isotopes and their detection. (J.B.)

Modern licensing approaches for analysis of important to safety processes in Nuclear Power Plants

International Nuclear Information System (INIS)

Andreeva, M.; Groudev, P.; Pavlova, M.; Stoyanov, S.

2008-01-01

It is presented within the paper the modern approaches for analysis of important to safety assessment processes in Nuclear Power Plants, included Bulgarian Regulatory Agency's requirements for quantity assessment of these processes applying deterministic and probabilistic approaches for establishing and confirming the design basis and defence-in-depth effectiveness. (authors)

Westinghouse Advances in Passive Plant Safety

International Nuclear Information System (INIS)

Bruschi, H. J.; Manager, General; Gerstenhaber, E.

1993-01-01

On June 26, 1992, Westinghouse submitted the Ap600 Standard Safety Analysis Report and comprehensive PIRA results to the U. S. NRC for review as part of the Ap600 design certification program. This major milestone was met on time on a schedule set more than 3 years before submittal and is the result of the cooperative efforts of the U. S. Department of Energy (DOE), the Electric Power Requirements Program, and the Westinghouse Ap600 design team. These efforts were initiated in 1985 to develop a 600 MW advanced light water reactor plant design based on specific technical requirements established to provide the safety, simplicity, reliability, and economics necessary for the next generation of nuclear power plants. The Ap600 design achieves the ALRR safety requirements through ample design margins, simplified safety systems based on natural driving forces, and on a human-engineered man-machine interface system. Extensive Probabilistic Risk evolution, have recently shown that even if none of the active defense-in-depth safety systems are available, the passive systems alone meet safety goals. Furthermore, many tests in an extensive test program have begun or have been completed. Early tests show that passive safety perform well and meet design expectations

A study on safety assessment methodology for a vitrification plant

Energy Technology Data Exchange (ETDEWEB)

Seo, Y. C.; Lee, G. S.; Choi, Y. C.; Kim, G. H. [Yonsei Univ., Seoul (Korea, Republic of)

2002-03-15

In this study, the technical and regulatory status of radioactive waste vitrification technologies in foreign and domestic plants is investigated and analyzed, and then significant factors are suggested which must be contained in the final technical guideline or standard for the safety assessment of vitrification plants. Also, the methods to estimate the stability of vitrified waste forms are suggested with property analysis of them. The contents and scope of the study are summarized as follows : survey of the status on radioactive waste vitrification technologies in foreign and domestic plants, survey of the characterization methodology for radioactive waste form, analysis of stability for vitrified waste forms, survey and analysis of technical standards and regulations concerned with them in foreign and domestic plants, suggestion of significant factors for the safety assessment of vitrification plants, submission of regulated technical standard on radioactive waste vitrification plats.

Safety performance indicators used by the Russian Safety Regulatory Authority in its practical activities on nuclear power plant safety regulation

International Nuclear Information System (INIS)

Khazanov, A.L.

2005-01-01

The Sixth Department of the Nuclear, Industrial and Environmental Regulatory Authority of Russia, Scientific and Engineering Centre for Nuclear and Radiation Safety process, analyse and use the information on nuclear power plants (NPPs) operational experience or NPPs safety improvement. Safety performance indicators (SPIs), derived from processing of information on operational violations and analysis of annual NPP Safety Reports, are used as tools to determination of trends towards changing of characteristics of operational safety, to assess the effectiveness of corrective measures, to monitor and evaluate the current operational safety level of NPPs, to regulate NPP safety. This report includes a list of the basic SPIs, those used by the Russian safety regulatory authority in regulatory activity. Some of them are absent in list of IAEA-TECDOC-1141 ('Operational safety performance indicators for nuclear power plants'). (author)

Analysis of events significant with regard to safety of Bohunice V-1 nuclear power plant

International Nuclear Information System (INIS)

Suchomel, J.; Maron, V.; Kmosena, J.

1986-01-01

An analysis was made of operating safety of the V-1 nuclear power plant in Jaslovske Bohunice for the years 1980 - 1983. Of the total number of 676 reported failures only three were events with special safety significance, namely a complete loss of power supply for own consumption from the power grid, a failure of pins on the collectors of steam generators, and a failure of the heads of heat technology inspection channels. The failures were categorized according to the systems used in the USSR and in the USA and compared with data on failures in nuclear power plants in the two countries. The conclusions show that the operation of the V-1 nuclear power plant achieves results which are fully comparable with those recorded in 9 WWER-440 power plants operating in various countries. The average coefficient of availability is 0.72 and ranks the power plant in the fourth place among the said 9 plants. A comparison of the individual power plant units showed that of the total number of 22, the first unit of the V-1 plant ranks fifth with a coefficient of 0.78 and the second unit with a coefficient of 0.69 ranks 15th. (Z.M.)

Nuclear power plant safety

International Nuclear Information System (INIS)

Otway, H.J.

1974-01-01

Action at the international level will assume greater importance as the number of nuclear power plants increases, especially in the more densely populated parts of the world. Predictions of growth made prior to October 1973 [9] indicated that, by 1980, 14% of the electricity would be supplied by nuclear plants and by the year 2000 this figure would be about 50%. This will make the topic of international co-operation and standards of even greater importance. The IAEA has long been active in providing assistance to Member States in the siting design and operation of nuclear reactors. These activities have been pursued through advisory missions, the publication of codes of practice, guide books, technical reports and in arranging meetings to promote information exchange. During the early development of nuclear power, there was no well-established body of experience which would allow formulation of internationally acceptable safety criteria, except in a few special cases. Hence, nuclear power plant safety and reliability matters often received an ad hoc approach which necessarily entailed a lack of consistency in the criteria used and in the levels of safety required. It is clear that the continuation of an ad hoc approach to safety will prove inadequate in the context of a world-wide nuclear power industry, and the international trade which this implies. As in several other fields, the establishment of internationally acceptable safety standards and appropriate guides for use by regulatory bodies, utilities, designers and constructors, is becoming a necessity. The IAEA is presently planning the development of a comprehensive set of basic requirements for nuclear power plant safety, and the associated reliability requirements, which would be internationally acceptable, and could serve as a standard frame of reference for nuclear plant safety and reliability analyses

A framework for the system-of-systems analysis of the risk for a safety-critical plant exposed to external events

International Nuclear Information System (INIS)

Zio, E.; Ferrario, E.

2013-01-01

We consider a critical plant exposed to risk from external events. We propose an original framework of analysis, which extends the boundaries of the study to the interdependent infrastructures which support the plant. For the purpose of clearly illustrating the conceptual framework of system-of-systems analysis, we work out a case study of seismic risk for a nuclear power plant embedded in the connected power and water distribution, and transportation networks which support its operation. The technical details of the systems considered (including the nuclear power plant) are highly simplified, in order to preserve the purpose of illustrating the conceptual, methodological framework of analysis. Yet, as an example of the approaches that can be used to perform the analysis within the proposed framework, we consider the Muir Web as system analysis tool to build the system-of-systems model and Monte Carlo simulation for the quantitative evaluation of the model. The numerical exercise, albeit performed on a simplified case study, serves the purpose of showing the opportunity of accounting for the contribution of the interdependent infrastructure systems to the safety of a critical plant. This is relevant as it can lead to considerations with respect to the decision making related to safety critical-issues. -- Highlights: ► We consider a critical plant exposed to risk from external events. ► We consider also the interdependent infrastructures that support the plant. ► We use Muir Web as system analysis tool to build the system-of-systems model. ► We use Monte Carlo simulation for the quantitative evaluation of the model. ► We find that the interdependent infrastructures should be considered as they can be a support for the critical plant safety

Safety indicators as a tool for operational safety evaluation of nuclear power plants

International Nuclear Information System (INIS)

Araujo, Jefferson Borges; Melo, Paulo Fernando Ferreira Frutuoso e; Schirru, Roberto

2009-01-01

Performance indicators have found a wide use in the conventional and nuclear industries. For the conventional industry, the goal is to optimize production, reducing loss of time with accidents, human error and equipment downtimes. In the nuclear industry, nuclear safety is an additional goal. This paper presents a general methodology to the establishment, selection and use of safety indicators for a two loop PWR plant, as Angra 1. The use of performance indicators is not new. The NRC has its own methodology and the IAEA presents methodology suggestions, but there is no detailed documentation about indicators selection, criteria and bases used. Additionally, only the NRC methodology performs a limited integrated evaluation. The study performed identifies areas considered critical for the plant operational safety. For each of these areas, strategic sub-areas are defined. For each strategic sub-area, specific safety indicators are defined. These proposed Safety Indicators are based on the contribution to risk considering a quantitative risk analysis. For each safety indicator, a goal, a bounded interval and proper bases are developed, to allow for a clear and comprehensive individual behavior evaluation. On the establishment of the intervals and boundaries, a probabilistic safety study, operational experience, international and national standards and technical specifications were used. Additionally, an integrated evaluation of the indicators, using expert systems, was done to obtain an overview of the plant general safety. This evaluation uses well-defined and clear rules and weights for each indicator to be considered. These rules were implemented by means of a computational language, on a friendly interface, so that it is possible to obtain a quick response about operational safety. This methodology can be used to identify situations where the plant safety is challenged, by giving a general overview of the plant operational condition. Additionally, this study can

Power plants and safety 1982

International Nuclear Information System (INIS)

1982-01-01

The papers of this volume deal with the whole range of safety issues from planning and construction to the operation of power plants, and discuss also issues like availability and safety of power plants, protective clothes and their incommodating effect, alternatives for rendering hot-water generators safe and the safety philosophy in steam turbine engineering. (HAG) [de

Review of the safety analysis of the Ignalina Nuclear Power Plant

International Nuclear Information System (INIS)

Weber, J.P.

1999-01-01

Description of the review of safety analysis report (SAR) of Ignalina NPP is presented. this review, called RSR, was conducted by independent group of international experts. SAR and RSR represented a unique international effort in a very short time. It was first attempt to provide Western-type SAR for any Soviet designed NPP. SAR was completed in December 1996, RSR was completed in March 1997. SAR has produced 85 reports, available on CR-ROM and RSR produced 86 reports also available on CD-ROM. SAR presented a large list of recommendations. RSR agreed with most of SAR recommendations and added further recommendations. SAR and RSR contributed significantly to better understanding of RBMK plant behaviour. Ignalina NPP has responded to the SAR/RSR recommendations by an ambitious Safety Improvement Programme SIP-2 which currently is under implementation

Software analysis by simulation for nuclear plant availability and safety goals

International Nuclear Information System (INIS)

Lapassat, A.M.; Segalard, J.; Salichon, M.; Le Meur, M.; Boulc'h, J.

1988-01-01

The microprocessors utilisation for monitoring protection and safety of nuclear reactor has become reality in the eighties. The authorities responsible for reactor safety systems have considered the necessity of the correct functioning of reactor control systems. The problems take off, when analysis of software, has led us in a first time to develop a completely software tool of verification and validation of programs and specifications. The CEA (French Atomic Energie Commission) responsible of reliable distributed techniques of nuclear plant discusses in this paper the software test and simulation tools used to analyse real-time software. The tool O.S.T. make part of a big program of help for the conception and the evaluation for the systems' fault tolerance which the European ESPRIT SMART no. 1609 (System Measurement and Architecture Technique) will be the kernel [fr

Evaluation of static analysis tools used to assess software important to nuclear power plant safety

Energy Technology Data Exchange (ETDEWEB)

Ourghanlian, Alain [EDF Lab CHATOU, Simulation and Information Technologies for Power Generation Systems Department, EDF R and D, Cedex (France)

2015-03-15

We describe a comparative analysis of different tools used to assess safety-critical software used in nuclear power plants. To enhance the credibility of safety assessments and to optimize safety justification costs, Electricit e de France (EDF) investigates the use of methods and tools for source code semantic analysis, to obtain indisputable evidence and help assessors focus on the most critical issues. EDF has been using the PolySpace tool for more than 10 years. Currently, new industrial tools based on the same formal approach, Abstract Interpretation, are available. Practical experimentation with these new tools shows that the precision obtained on one of our shutdown systems software packages is substantially improved. In the first part of this article, we present the analysis principles of the tools used in our experimentation. In the second part, we present the main characteristics of protection-system software, and why these characteristics are well adapted for the new analysis tools.

Evaluation of seismic hazards for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2002-01-01

The main objective of this Safety Guide is to provide recommendations on how to determine the ground motion hazards for a plant at a particular site and the potential for surface faulting, which could affect the feasibility of construction and safe operation of a plant at that site. The guidelines and procedures presented in this Safety Guide can appropriately be used in evaluations of site suitability and seismic hazards for nuclear power plants in any seismotectonic environment. The probabilistic seismic hazard analysis recommended in this Safety Guide also addresses the needs for seismic hazard analysis of external event PSAs conducted for nuclear power plants. Many of the methods and processes described may also be applicable to nuclear facilities other than power plants. Other phenomena of permanent ground displacement (liquefaction, slope instability, subsidence and collapse) as well as the topic of seismically induced flooding are treated in Safety Guides relating to foundation safety and coastal flooding. Recommendations of a general nature are given in Section 2. Section 3 discusses the acquisition of a database containing the information needed to evaluate and address all hazards associated with earthquakes. Section 4 covers the use of this database for construction of a seismotectonic model. Sections 5 and 6 review ground motion hazards and evaluations of the potential for surface faulting, respectively. Section 7 addresses quality assurance in the evaluation of seismic hazards for nuclear power plants

The software safety analysis based on SFTA for reactor power regulating system in nuclear power plant

International Nuclear Information System (INIS)

Liu Zhaohui; Yang Xiaohua; Liao Longtao; Wu Zhiqiang

2015-01-01

The digitalized Instrumentation and Control (I and C) system of Nuclear power plants can provide many advantages. However, digital control systems induce new failure modes that differ from those of analog control systems. While the cost effectiveness and flexibility of software is widely recognized, it is very difficult to achieve and prove high levels of dependability and safety assurance for the functions performed by process control software, due to the very flexibility and potential complexity of the software itself. Software safety analysis (SSA) was one way to improve the software safety by identify the system hazards caused by software failure. This paper describes the application of a software fault tree analysis (SFTA) at the software design phase. At first, we evaluate all the software modules of the reactor power regulating system in nuclear power plant and identify various hazards. The SFTA was applied to some critical modules selected from the previous step. At last, we get some new hazards that had not been identified in the prior processes of the document evaluation which were helpful for our design. (author)

Plant designer's view of the operator's role in nuclear plant safety

International Nuclear Information System (INIS)

Corcoran, W.R.; Church, J.F.; Cross, M.T.; Porter, N.J.

1981-01-01

The nuclear plant operator's role supports the design assumptions and equipment with four functional tasks. He must set up th plant for predictable response to disturbances, operate the plant so as to minimize the likelihood and severity of event initiators, assist in accomplishing the safety functions, and feed back operating experiences to reinforce or redefine the safety analyses' assumptions. The latter role enhances the operator effectiveness in the former three roles. The Safety Level Concept offers a different perspective that enables the operator to view his roles in nuclear plant safety. This paper outlines the operator's role in nuclear safety and classifies his tasks using the Safety Level Concept

Periodic safety reviews of nuclear power plants

International Nuclear Information System (INIS)

Toth, Csilla

2009-01-01

Operational nuclear power plants (NPPs) are generally subject to routine reviews of plant operation and special safety reviews following operational events. In addition, many Member States of the International Atomic Energy Agency (IAEA) have initiated systematic safety reassessment, termed periodic safety review (PSR), to assess the cumulative effects of plant ageing and plant modifications, operating experience, technical developments, site specific, organizational and human aspects. These reviews include assessments of plant design and operation against current safety standards and practices. PSRs are considered an effective way of obtaining an overall view of actual plant safety, to determine reasonable and practical modifications that should be made in order to maintain a high level of safety throughout the plant's operating lifetime. PSRs can be used as a means to identify time limiting features of the plant. The trend is to use PSR as a condition for deciding whether to continue operation of the plant beyond the originally established design lifetime and for assessing the status of the plant for long term operation. To assist Member States in the implementation of PSR, the IAEA develops safety standards, technical documents and provides different services: training courses, workshops, technical meetings and safety review missions for the independent assessment of the PSR at NPPs, including the requirements for PSR, the review process and the PSR final reports. This paper describes the PSR's objectives, scopes, methods and the relationship of PSR with other plant safety related activities and recent experiences of Member States in implementation of PSRs at NPPs. (author)

Safety philosophy for nuclear power plants in egypt

International Nuclear Information System (INIS)

Mervat, S.A.; Hammad, F.H.

1988-01-01

This work establishes the basic principles of a safety philosophy for nuclear power plants in egypt. A number of deterministic requirements stemming the multiple barriers and the defense-in-depth concept are emphasised. other requirements in the areas of siting, operational safety, safety analysis, special issues, and experience feedback are also identified. The role of international cooperation in nuclear safety technology-transfer and nuclear emergencies is highlighted. In addition probabilistic ally based guidelines are set for acceptable risk and dose limits

Uncertainty propagation in probabilistic safety analysis of nuclear power plants

International Nuclear Information System (INIS)

Fleming, P.V.

1981-09-01

The uncertainty propagation in probabilistic safety analysis of nuclear power plants, is done. The methodology of the minimal cut is implemented in the computer code SVALON and the results for several cases are compared with corresponding results obtained with the SAMPLE code, which employs the Monte Carlo method to propagate the uncertanties. The results have show that, for a relatively small number of dominant minimal cut sets (n approximately 25) and error factors (r approximately 5) the SVALON code yields results which are comparable to those obtained with SAMPLE. An analysis of the unavailability of the low pressure recirculation system of Angra 1 for both the short and long term recirculation phases, are presented. The results for the short term phase are in good agreement with the corresponding one given in WASH-1400. (E.G.) [pt

Incorporation of advanced accident analysis methodology into safety analysis reports

International Nuclear Information System (INIS)

2003-05-01

The IAEA Safety Guide on Safety Assessment and Verification defines that the aim of the safety analysis should be by means of appropriate analytical tools to establish and confirm the design basis for the items important to safety, and to ensure that the overall plant design is capable of meeting the prescribed and acceptable limits for radiation doses and releases for each plant condition category. Practical guidance on how to perform accident analyses of nuclear power plants (NPPs) is provided by the IAEA Safety Report on Accident Analysis for Nuclear Power Plants. The safety analyses are performed both in the form of deterministic and probabilistic analyses for NPPs. It is customary to refer to deterministic safety analyses as accident analyses. This report discusses the aspects of using the advanced accident analysis methods to carry out accident analyses in order to introduce them into the Safety Analysis Reports (SARs). In relation to the SAR, purposes of deterministic safety analysis can be further specified as (1) to demonstrate compliance with specific regulatory acceptance criteria; (2) to complement other analyses and evaluations in defining a complete set of design and operating requirements; (3) to identify and quantify limiting safety system set points and limiting conditions for operation to be used in the NPP limits and conditions; (4) to justify appropriateness of the technical solutions employed in the fulfillment of predetermined safety requirements. The essential parts of accident analyses are performed by applying sophisticated computer code packages, which have been specifically developed for this purpose. These code packages include mainly thermal-hydraulic system codes and reactor dynamics codes meant for the transient and accident analyses. There are also specific codes such as those for the containment thermal-hydraulics, for the radiological consequences and for severe accident analyses. In some cases, codes of a more general nature such

Safety studies on Korean fusion DEMO plant using integrated safety assessment methodology

International Nuclear Information System (INIS)

Oh, Kyemin; Kang, Myoung-suk; Heo, Gyunyoung; Kim, Hyoung-chan

2014-01-01

Highlights: •The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant. •The concepts of integrated safety assessment methodology (ISAM) that can be applied in addressing regulatory requirements and recognizing safety issues for K-DEMO were emphasized. •Phenomena identification and ranking table (PIRT) was proposed. It can recognize vulnerabilities of systems and identify the gaps in technical areas requiring additional researches. •This work is expected to contribute on the conceptual design of safety features for K-DEMO to design engineers and the guidance for regulatory requirements to licensers. -- Abstract: The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant (K-DEMO) as a part of R and D program through the National Fusion Research Institute of Korea. Even though nuclear regulation and licensing framework is well setup due to the operating and design experience of Pressurized Water Reactors (PWRs) since 1970s, the regulatory authority of South Korea has concerns on the challenge of facing new nuclear facilities including K-DEMO due to the differences in systems, materials, and inherent safety feature from conventional PWRs. Even though the follow-up of the ITER license process facilitates to deal with significant safety issues of fusion facilities, a licensee as well as a licenser should identify the gaps between ITER and DEMO in terms of safety issues. First we reviewed the methods of conducting safety analysis for unprecedented nuclear facilities such as Generation IV reactors, particularly very high temperature reactor (VHTR), which is called as integrated safety assessment methodology (ISAM). Second, the analysis for the conceptual design of K-DEMO on the basis of ISAM was conducted. The ISAM consists of five analytical tools to develop the safety requirements from licensee

Safety studies on Korean fusion DEMO plant using integrated safety assessment methodology

Energy Technology Data Exchange (ETDEWEB)

Oh, Kyemin; Kang, Myoung-suk [Kyung Hee University, Youngin-si, Gyeonggi-do 446-701 (Korea, Republic of); Heo, Gyunyoung, E-mail: gheo@khu.ac.kr [Kyung Hee University, Youngin-si, Gyeonggi-do 446-701 (Korea, Republic of); Kim, Hyoung-chan [National Fusion Research Institute, Daejeon-si 305-333 (Korea, Republic of)

2014-10-15

Highlights: •The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant. •The concepts of integrated safety assessment methodology (ISAM) that can be applied in addressing regulatory requirements and recognizing safety issues for K-DEMO were emphasized. •Phenomena identification and ranking table (PIRT) was proposed. It can recognize vulnerabilities of systems and identify the gaps in technical areas requiring additional researches. •This work is expected to contribute on the conceptual design of safety features for K-DEMO to design engineers and the guidance for regulatory requirements to licensers. -- Abstract: The purpose of this paper is to suggest methodology that can investigate safety issues and provides a case study for Korean fusion DEMO plant (K-DEMO) as a part of R and D program through the National Fusion Research Institute of Korea. Even though nuclear regulation and licensing framework is well setup due to the operating and design experience of Pressurized Water Reactors (PWRs) since 1970s, the regulatory authority of South Korea has concerns on the challenge of facing new nuclear facilities including K-DEMO due to the differences in systems, materials, and inherent safety feature from conventional PWRs. Even though the follow-up of the ITER license process facilitates to deal with significant safety issues of fusion facilities, a licensee as well as a licenser should identify the gaps between ITER and DEMO in terms of safety issues. First we reviewed the methods of conducting safety analysis for unprecedented nuclear facilities such as Generation IV reactors, particularly very high temperature reactor (VHTR), which is called as integrated safety assessment methodology (ISAM). Second, the analysis for the conceptual design of K-DEMO on the basis of ISAM was conducted. The ISAM consists of five analytical tools to develop the safety requirements from licensee

The effect of management and organizational structure on nuclear power plant safety

International Nuclear Information System (INIS)

Thurber, J.A.

1986-01-01

Many informed observers have proposed that utility management is a key element underlying the safe operation of nuclear power plants (NPP). One way that management likely influences plant safety performance is through the organizational structures it consciously creates or allows to exist. This paper describes an empirical analysis of the relationships between some important dimensions of plant organizational structure and measures of plant safety performance

Upgrading of fire safety in nuclear power plants. Proceedings of an International Symposium

International Nuclear Information System (INIS)

1998-04-01

The document includes 40 papers presented at the International Symposium on Upgrading of Fire Safety in Nuclear Power Plants held in Vienna between 18-21 November 1997. The symposium presentations were grouped in 6 sessions: Fire safety reviews (5 papers), Fire safety analysis - Methodology (6 papers), Fire safety analysis - Applications (3 papers), Panel 1 - Identification of deficiencies in fire safety in nuclear power plants - Operational experience and data (7 papers), Panel 2 - Experience based data in fire safety assessment - Fire safety regulations and licensing (7 papers), Upgrading programmes (10 papers), and a closing session (2 papers). A separate abstract was prepared for each paper

Upgrading of fire safety in nuclear power plants. Proceedings of an International Symposium

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-04-01

The document includes 40 papers presented at the International Symposium on Upgrading of Fire Safety in Nuclear Power Plants held in Vienna between 18-21 November 1997. The symposium presentations were grouped in 6 sessions: Fire safety reviews (5 papers), Fire safety analysis - Methodology (6 papers), Fire safety analysis - Applications (3 papers), Panel 1 - Identification of deficiencies in fire safety in nuclear power plants - Operational experience and data (7 papers), Panel 2 - Experience based data in fire safety assessment - Fire safety regulations and licensing (7 papers), Upgrading programmes (10 papers), and a closing session (2 papers). A separate abstract was prepared for each paper Refs, figs, tabs

A probabilistic method for optimization of fire safety in nuclear power plants

International Nuclear Information System (INIS)

Hosser, D.; Sprey, W.

1986-01-01

As part of a comprehensive fire safety study for German Nuclear Power Plants a probabilistic method for the analysis and optimization of fire safety has been developed. It follows the general line of the American fire hazard analysis, with more or less important modifications in detail. At first, fire event trees in selected critical plant areas are established taking into account active and passive fire protection measures and safety systems endangered by the fire. Failure models for fire protection measures and safety systems are formulated depending on common parameters like time after ignition and fire effects. These dependences are properly taken into account in the analysis of the fire event trees with the help of first-order system reliability theory. In addition to frequencies of fire-induced safety system failures relative weights of event paths, fire protection measures within these paths and parameters of the failure models are calculated as functions of time. Based on these information optimization of fire safety is achieved by modifying primarily event paths, fire protection measures and parameters with the greatest relative weights. This procedure is illustrated using as an example a German 1300 MW PWR reference plant. It is shown that the recommended modifications also reduce the risk to plant personnel and fire damage

Status of Ignalina's safety analysis reports

International Nuclear Information System (INIS)

Uspuras, E.

1999-01-01

Ignalina NPP is unique among RBMK type reactors in the scope and comprehensiveness of international studies which have been performed to verify its design parameters and analyze risk levels. International assistance took several forms, a very valuable mod of assistance utilized the knowledge of international experts in extensive international studies whose purpose was: collection, systematization and verification of plant design data; analysis of risk levels; recommendations leading to improvements in the safety lave; transfer of state of the art analytical methodology to Lithuanian specialists. The major large scale international studies include: probabilistic risk analysis; extensive international study meant to provide comprehensive overview of plant status with special emphasis on safety aspects; an extensive review of the Safety Analysis Report by an independent group of international experts. In spite of the safety improvements and analyses which have been performed at the Ignalina NPP, much remains to be done in the nearest future

Plutonium Finishing Plant safety evaluation report

International Nuclear Information System (INIS)

1995-01-01

The Plutonium Finishing Plant (PFP) previously known as the Plutonium Process and Storage Facility, or Z-Plant, was built and put into operation in 1949. Since 1949 PFP has been used for various processing missions, including plutonium purification, oxide production, metal production, parts fabrication, plutonium recovery, and the recovery of americium (Am-241). The PFP has also been used for receipt and large scale storage of plutonium scrap and product materials. The PFP Final Safety Analysis Report (FSAR) was prepared by WHC to document the hazards associated with the facility, present safety analyses of potential accident scenarios, and demonstrate the adequacy of safety class structures, systems, and components (SSCs) and operational safety requirements (OSRs) necessary to eliminate, control, or mitigate the identified hazards. Documented in this Safety Evaluation Report (SER) is DOE's independent review and evaluation of the PFP FSAR and the basis for approval of the PFP FSAR. The evaluation is presented in a format that parallels the format of the PFP FSAR. As an aid to the reactor, a list of acronyms has been included at the beginning of this report. The DOE review concluded that the risks associated with conducting plutonium handling, processing, and storage operations within PFP facilities, as described in the PFP FSAR, are acceptable, since the accident safety analyses associated with these activities meet the WHC risk acceptance guidelines and DOE safety goals in SEN-35-91

Development of a New Safety Culture Assessment Method for Nuclear Power Plants (NPPs) (A study to suggest a new safety culture assessment method in nuclear power plants)

International Nuclear Information System (INIS)

Han, Sang Min; Seong, Poong Hyun

2014-01-01

This study is conducted to suggest a new safety culture assessment method in nuclear power plants. Criteria with various existing safety culture analysis methods are united, and reliability analysis methods are applied. The concept of the most representative methods, Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), are adopted to assess safety culture. Through this application, it is expected that the suggested method will bring results with convenience and objectiveness

Development of a New Safety Culture Assessment Method for Nuclear Power Plants (NPPs) (A study to suggest a new safety culture assessment method in nuclear power plants)

Energy Technology Data Exchange (ETDEWEB)

Han, Sang Min; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

2014-08-15

This study is conducted to suggest a new safety culture assessment method in nuclear power plants. Criteria with various existing safety culture analysis methods are united, and reliability analysis methods are applied. The concept of the most representative methods, Fault Tree Analysis (FTA) and Failure Mode and Effect Analysis (FMEA), are adopted to assess safety culture. Through this application, it is expected that the suggested method will bring results with convenience and objectiveness.

Modifications to nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA's programme for safety standards for nuclear power plants. It supplements Section 7 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation, which establishes the safety requirements for the modification of nuclear power plants. Reasons for carrying out modifications to nuclear power plants may include: (1) maintaining or strengthening existing safety provisions and thus maintaining consistency with or improving on the current design. (2) recovering from plant faults. (3) improving the thermal performance or increasing the power rating of the plant. (4) increasing the maintainability of the plant, reducing the radiation exposure of personnel or reducing the costs of plant maintenance. And (5) extending the design life of the plant. Most modifications, made on the basis of operating experience, are intended to improve on the design or to improve operational performance and flexibility. Some are rendered necessary by new regulatory requirements, ageing of the plant or obsolescence of equipment. However, the benefits of regularly updating the plant design can be jeopardized if modifications are not kept under rigorous control throughout the lifetime of the plant. The need to reduce costs and improve efficiency, in combination with changes to the structure of the electricity generation sector of the economy in many countries, has led many companies to make changes in the structure of the operating organization for nuclear power plants. Whatever the reason for such organizational changes, consideration should be given to the effects of those changes with the aim of ensuring that they would have no impacts that would compromise the safety of the plant. The objective of this Safety Guide is to provide guidance and recommendations on controlling activities relating to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under

Modifications to nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2007-01-01

This Safety Guide was prepared under the IAEA's programme for safety standards for nuclear power plants. It supplements Section 7 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation, which establishes the safety requirements for the modification of nuclear power plants. Reasons for carrying out modifications to nuclear power plants may include: (1) maintaining or strengthening existing safety provisions and thus maintaining consistency with or improving on the current design. (2) recovering from plant faults. (3) improving the thermal performance or increasing the power rating of the plant. (4) increasing the maintainability of the plant, reducing the radiation exposure of personnel or reducing the costs of plant maintenance. And (5) extending the design life of the plant. Most modifications, made on the basis of operating experience, are intended to improve on the design or to improve operational performance and flexibility. Some are rendered necessary by new regulatory requirements, ageing of the plant or obsolescence of equipment. However, the benefits of regularly updating the plant design can be jeopardized if modifications are not kept under rigorous control throughout the lifetime of the plant. The need to reduce costs and improve efficiency, in combination with changes to the structure of the electricity generation sector of the economy in many countries, has led many companies to make changes in the structure of the operating organization for nuclear power plants. Whatever the reason for such organizational changes, consideration should be given to the effects of those changes with the aim of ensuring that they would have no impacts that would compromise the safety of the plant. The objective of this Safety Guide is to provide guidance and recommendations on controlling activities relating to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under

Safety and security analysis for distributed control system in nuclear power plants

International Nuclear Information System (INIS)

Lu Zhigang; Liu Baoxu

2011-01-01

The Digital Distributed Control System (DCS) is the core that manages all monitoring and operation tasks in a Nuclear Power Plant (NPP). So, Digital Distributed Control System in Nuclear Power Plant has strict requirements for control and automation device safety and security due to many factors. In this article, factors of safety are analyzed firstly, while placing top priority on reliability, quality of supply and stability have also been carefully considered. In particular, advanced digital and electronic technologies are adopted to maintain sufficient reliability and supervisory capabilities in nuclear power plants. Then, security of networking and information technology have been remarked, several design methodologies considering the security characteristics are suggested. Methods and technologies of this article are being used in testing and evaluation for a real implement of a nuclear power plant in China. (author)

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

Adapting a reactor safety assessment system for specific plants

International Nuclear Information System (INIS)

Ballard, T.L.; Cordes, G.A.

1991-01-01

The Reactor Safety Assessment System (RSAS) is an expert system being developed by the Idaho National Engineering Laboratory, the University of Maryland (UofM) and US Nuclear Regulatory Commission (NRC) for use in the NRC Operations center. RSAS is designed to help the Reactor Safety Team monitor and project core status during an emergency at a licensed nuclear power plant. Analysis uses a hierarchical plant model based on equipment availability and automatically input parametric plant information. There are 3 families of designs of pressurized water reactors and 75 plants using modified versions of the basic design. In order to make an RSAS model for each power plant, a generic model for a given plant type is used with differences being specified by plant specific files. Graphical displays of this knowledge are flexible enough to handle any plant configuration. A variety of tools have been implemented to make it easy to modify a design to fit a given plant while minimizing chance for error. 3 refs., 4 figs

The Use of Coupled Code Technique for Best Estimate Safety Analysis of Nuclear Power Plants

International Nuclear Information System (INIS)

Bousbia Salah, A.; D'Auria, F.

2006-01-01

Issues connected with the thermal-hydraulics and neutronics of nuclear plants still challenge the design, safety and the operation of Light Water nuclear Reactors (LWR). The lack of full understanding of complex mechanisms related to the interaction between these issues imposed the adoption of conservative safety limits. Those safety margins put restrictions on the optimal exploitation of the plants and consequently reduced economic profit of the plant. In the light of the sustained development in computer technology, the possibilities of code capabilities have been enlarged substantially. Consequently, advanced safety evaluations and design optimizations that were not possible few years ago can now be performed. In fact, during the last decades Best Estimate (BE) neutronic and thermal-hydraulic calculations were so far carried out following rather parallel paths with only few interactions between them. Nowadays, it becomes possible to switch to new generation of computational tools, namely, Coupled Code technique. The application of such method is mandatory for the analysis of accident conditions where strong coupling between the core neutronics and the primary circuit thermal-hydraulics, and more especially when asymmetrical processes take place in the core leading to local space-dependent power generation. Through the current study, a demonstration of the maturity level achieved in the calculation of 3-D core performance during complex accident scenarios in NPPs is emphasized. Typical applications are outlined and discussed showing the main features and limitations of this technique. (author)

Safety assessment principles for nuclear plants

International Nuclear Information System (INIS)

1992-01-01

The present Safety Assessment Principles result from the revision of those which were drawn up following a recommendation arising from the Sizewell-B enquiry. The principles presented here relate only to nuclear safety; there is a section on risks from normal operation and accident conditions and the standards against which those risks are assessed. A major part of the document deals with the principles that cover the design of nuclear plants. The revised Safety assessment principles are aimed primarily at the safety assessment of new nuclear plants but they will also be used in assessing existing plants. (UK)

Auditable safety analysis for the surveillance and maintenance of U plant

International Nuclear Information System (INIS)

Cuneo, V.J.

1997-02-01

This document provides the auditable safety analysis for the post-deactivation, long-term surveillance and maintenance (S ampersand amp;M) phase of the U Plant. The U Plant is an inactive, surplus facility constructed in 1944 as one of three original chemical separations plants. However, U-Plant was never used for its original purpose and was eventually transferred to S ampersand amp;M. In 1957 it was converted to the tributyl phosphate process to recover uranium from the bismuth phosphate process waste. In 1958 it was placed on standby and was used to store inoperable and contaminated equipment from other facilities.This document evaluates the ability of the U Plant to withstand the effects of natural phenomena hazard events and describes the active support systems used to maintain ventilation and/or prevent the spread of contamination. This document also evaluates S ampersand amp;M activities that are routinely required (i.e., the S ampersand amp;M of facility barriers, equipment, structures, and postings [including repair and upgrade]; measures to identify, remove, or repair damaged asbestos; measures to identify, remove, or appropriately manage existing containers of hazardous substances; the performance of spill response measures as needed; and perform nondestructive assaying, waste characterization, and sampling). This document identifies the type and nature of the hazards presented by the U Plant and the specific controls that are required to maintain these hazards at acceptable levels

Safety culture in nuclear power plants

International Nuclear Information System (INIS)

Weihe, G. von; Pamme, H.

2003-01-01

Experience shows that German nuclear power plants have always been operated reliably and safely. Over the years, the safety level in these plants has been raised considerably so that they can stand any comparison with other countries. This is confirmed by the two reports published by the Federal Ministry for the Environment on the nuclear safety convention. Behind this, there must obviously stand countless appropriate 'good practices' and a safety management system in nuclear power plants. (orig.) [de

Safety analysis program for steam generators replacement and power uprate at Tihange 2 nuclear power plant

International Nuclear Information System (INIS)

Delhaye, X.; Charlier, A.; Damas, Ph.; Druenne, H.; Mandy, C.; Parmentier, F.; Pirson, J.; Zhang, J.

2002-01-01

The Belgian Tihange 2 nuclear power plant went into commercial operation in 1983 producing a thermal power of 2785 MW. Since the commissioning of the plant the steam generators U-tubes have been affected by primary stress corrosion cracking. In order to avoid further degradation of the performance and an increase in repair costs, Electrabel, the owner of the plant, decided in 1997 to replace the 3 steam generators. This decision was supported by the feasibility study performed by Tractebel Energy Engineering which demonstrated that an increase of 10% of the initial power together with a fuel cycle length of 18 months was achieved. Tractebel Energy Engineering was entrusted by Electrabel as the owner's engineer to manage the project. This paper presents the role of Tractebel Energy Engineering in this project and the safety analysis program necessary to justify the new operation point and the fuel cycle extension to 18 months re-analysis of FSAR chapter 15 accidents and verification of the capacity of the safety and auxiliary systems. The FSAR chapter 15 accidents were reanalyzed jointly by Framatome and Tractebel Energy Engineering while the systems verifications were carried out by Tractebel Energy Engineering. (author)

Accident analysis for nuclear power plants

International Nuclear Information System (INIS)

2002-01-01

Deterministic safety analysis (frequently referred to as accident analysis) is an important tool for confirming the adequacy and efficiency of provisions within the defence in depth concept for the safety of nuclear power plants (NPPs). Owing to the close interrelation between accident analysis and safety, an analysis that lacks consistency, is incomplete or is of poor quality is considered a safety issue for a given NPP. Developing IAEA guidance documents for accident analysis is thus an important step towards resolving this issue. Requirements and guidelines pertaining to the scope and content of accident analysis have, in the past, been partially described in various IAEA documents. Several guidelines relevant to WWER and RBMK type reactors have been developed within the IAEA Extrabudgetary Programme on the Safety of WWER and RBMK NPPs. To a certain extent, accident analysis is also covered in several documents of the revised NUSS series, for example, in the Safety Requirements on Safety of Nuclear Power Plants: Design (NS-R-1) and in the Safety Guide on Safety Assessment and Verification for Nuclear Power Plants (NS-G-1.2). Consistent with these documents, the IAEA has developed the present Safety Report on Accident Analysis for Nuclear Power Plants. Many experts have contributed to the development of this Safety Report. Besides several consultants meetings, comments were collected from more than fifty selected organizations. The report was also reviewed at the IAEA Technical Committee Meeting on Accident Analysis held in Vienna from 30 August to 3 September 1999. The present IAEA Safety Report is aimed at providing practical guidance for performing accident analyses. The guidance is based on present good practice worldwide. The report covers all the steps required to perform accident analyses, i.e. selection of initiating events and acceptance criteria, selection of computer codes and modelling assumptions, preparation of input data and presentation of the

EDITORIAL: Safety aspects of fusion power plants

Science.gov (United States)

Kolbasov, B. N.

2007-07-01

importance for the fusion power plant research programmes. The objective of this Technical Meeting was to examine in an integrated way all the safety aspects anticipated to be relevant to the first fusion power plant prototype expected to become operational by the middle of the century, leading to the first generation of economically viable fusion power plants with attractive S&E features. After screening by guest editors and consideration by referees, 13 (out of 28) papers were accepted for publication. They are devoted to the following safety topics: power plant safety; fusion specific operational safety approaches; test blanket modules; accident analysis; tritium safety and inventories; decommissioning and waste. The paper `Main safety issues at the transition from ITER to fusion power plants' by W. Gulden et al (EU) highlights the differences between ITER and future fusion power plants with magnetic confinement (off-site dose acceptance criteria, consequences of accidents inside and outside the design basis, occupational radiation exposure, and waste management, including recycling and/or final disposal in repositories) on the basis of the most recent European fusion power plant conceptual study. Ongoing S&E studies within the US inertial fusion energy (IFE) community are focusing on two design concepts. These are the high average power laser (HAPL) programme for development of a dry-wall, laser-driven IFE power plant, and the Z-pinch IFE programme for the production of an economically-attractive power plant using high-yield Z-pinch-driven targets. The main safety issues related to these programmes are reviewed in the paper `Status of IFE safety and environmental activities in the US' by S. Reyes et al (USA). The authors propose future directions of research in the IFE S&E area. In the paper `Recent accomplishments and future directions in the US Fusion Safety & Environmental Program' D. Petti et al (USA) state that the US fusion programme has long recognized that the S

Posttest analysis of the FFTF inherent safety tests

International Nuclear Information System (INIS)

Padilla, A. Jr.; Claybrook, S.W.

1987-01-01

Inherent safety tests were performed during 1986 in the 400-MW (thermal) Fast Flux Test Facility (FFTF) reactor to demonstrate the effectiveness of an inherent shutdown device called the gas expansion module (GEM). The GEM device provided a strong negative reactivity feedback during loss-of-flow conditions by increasing the neutron leakage as a result of an expanding gas bubble. The best-estimate pretest calculations for these tests were performed using the IANUS plant analysis code (Westinghouse Electric Corporation proprietary code) and the MELT/SIEX3 core analysis code. These two codes were also used to perform the required operational safety analyses for the FFTF reactor and plant. Although it was intended to also use the SASSYS systems (core and plant) analysis code, the calibration of the SASSYS code for FFTF core and plant analysis was not completed in time to perform pretest analyses. The purpose of this paper is to present the results of the posttest analysis of the 1986 FFTF inherent safety tests using the SASSYS code

Protection against internal fires and explosions in the design of nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

Experience of the past two decades in the operation of nuclear power plants and modern analysis techniques confirm that fire may be a real threat to nuclear safety and should receive adequate attention from the beginning of the design process throughout the life of the plant. Within the framework of the NUSS programme, a Safety Guide on fire protection had therefore been developed to enlarge on the general requirements given in the Code. Since its first publication in 1979, there has been considerable development in protection technology and analysis methods and after the Chernobyl accident it was decided to revise the existing Guide. This Safety Guide supplements the requirements established in Safety of Nuclear Power Plants: Design. It supersedes Safety Series No. 50-SG-D2 (Rev. 1), Fire Protection in Nuclear Power Plants: A Safety Guide, issued in 1992.The present Safety Guide is intended to advise designers, safety assessors and regulators on the concept of fire protection in the design of nuclear power plants and on recommended ways of implementing the concept in some detail in practice

Development of specific data of plant for a safety probabilistic analysis

International Nuclear Information System (INIS)

Gonzalez C, M.; Nelson E, P.

2004-01-01

In this work the development of specific data of plant is described for the Safety Probabilistic Analysis (APS) of the Laguna Verde Central. The description of those used methods concentrate on the obtention of rates of failure of the equipment and frequencies of initiator events modeled in the APS, making mention to other types of data that also appeal to specific sources of the plant. The method to obtain the rates of failure of the equipment takes advantage the information of failures of components and unavailability of systems obtained entreaty in execution with the Maintenance Rule (1OCFR50.65). The method to develop the frequencies of initiators take in account the registered operational experience as reportable events. In both cases the own experience is combined with published generic data using Bayesian realized techniques. Details are provided about the gathering of information, the confirmations of consistency and adjustment necessities, presenting examples of the obtained results. (Author)

IAEA Concludes Safety Review at Chooz Nuclear Power Plant in France

International Nuclear Information System (INIS)

2013-01-01

management of corrective maintenance and leak repair to minimize backlogs and maintain plant safety; The plant should enhance the chemistry control program to cover all chemistry aspects of plant systems; The plant should enhance the process of root cause analysis of safety significant events to improve the depth of analysis of such events; and The plant should consider improving systems to allow clear identification of deficiencies in the field once they have been recognized. Chooz management expressed a determination to address all the areas identified for improvement and requested the IAEA to schedule a follow-up mission in approximately 18 months. The team delivered a draft of its recommendations, suggestions and good practices to the plant management in the form of Technical Notes for factual comments. The technical notes and comments from the plant and the French Safety Authority will be reviewed at IAEA headquarters. The final report will be submitted to the Government of France within three months. This was the 175th mission of the OSART programme, which began in 1982, and the 25th mission in France. The next OSART mission in France is scheduled at Flamanville Units 1 and 2 in 2014. Background: General information about OSART missions can be found on the IAEA Website. An OSART mission is designed as a review of programmes and activities essential to operational safety. It is not a regulatory inspection, nor is it a design review or a substitute for an exhaustive assessment of the plant's overall safety status. Experts participating in the IAEA's June 2010 International Conference on Operational Safety of Nuclear Power Plants (NPP) reviewed the experience of the OSART programme and concluded: In OSART missions NPPs are assessed against IAEA Safety Standards which reflect the current international consensus on what constitutes a high level of safety; and OSART recommendations and suggestions are of utmost importance for operational safety improvement of NPPs. The IAEA

The critical safety functions and plant operation

International Nuclear Information System (INIS)

Corcoran, W.R.; Church, J.F.; Cross, M.T.; Guinn, W.M.; Porter, N.J.

1981-01-01

The operator's role in nuclear safety is outlined and the concept of ''safety functions'' introduced. Safety functions are a group of actions that prevent core melt or minimize radiation releases to the general public. They can be used to provide a hierarchy of practical plant protection that an operator should use. The plant safety evaluation uses four inputs in predicting the results of an event: the event initiator, the plant design, the initial plant conditions and setup, and the operator actions. If any of these inputs are not as assumed in the evaluation, confidence that the consequences will be as predicted is reduced. Based on the safety evaluation, the operator has three roles in assuring that the consequences of an event will be no worse than the predicted acceptable results: Maintain plant setup in readiness to properly respond. Operate the plant in a manner such that fewer, milder events minimize the frequency and the severity of adverse events. Monitor the plant to verify that the safety functions are accomplished. The operator needs a systematic approach to mitigating the consequences of an event. The concept of safety functions introduces this systematic approach and presents a hierarchy of protection. If the operator has difficulty identifying an event for any reason, the systematic safety function approach allows accomplishing the overall path of mitigating consequences. Ten functions designed to protect against core melt, preserve containment integrity, prevent indirect release of radioactivity, and maintain vital auxiliaries needed to support the other safety functions are identified

Safety principles for nuclear power plants

International Nuclear Information System (INIS)

Vuorinen, A.

1993-01-01

The role and purpose of safety principles for nuclear power plants are discussed. A brief information is presented on safety objectives as given in the INSAG documents. The possible linkage is discussed between the two mentioned elements of nuclear safety and safety culture. Safety culture is a rather new concept and there is more than one interpretation of the definition given by INSAG. The defence in depth is defined by INSAG as a fundamental principle of safety technology of nuclear power. Discussed is the overall strategy for safety measures, and features of nuclear power plants provided by the defence-in-depth concept. (Z.S.) 7 refs

Assessment of possibility of primary water stress corrosion cracking occurrence based on residual stress analysis in pressurizer safety nozzle of nuclear power plant

International Nuclear Information System (INIS)

Lee, Kyoung Soo; Kim, W.; Lee, Jeong Geun

2012-01-01

Primary water stress corrosion cracking (PWSCC) is a major safety concern in the nuclear power industry worldwide. PWSCC is known to initiate only in the condition in which sufficiently high tensile stress is applied to alloy 600 tube material or alloy 82/182 weld material in pressurized water reactor operating environments. However, it is still uncertain how much tensile stress is required to generate PWSCC or what causes such high tensile stress. This study was performed to predict the magnitude of weld residual stress and operating stress and compare it with previous experimental results for PWSCC initiation. For the study, a pressurizer safety nozzle was selected because it is reported to be vulnerable to PWSCC in overseas plants. The assessment was conducted by numerical analysis. Before performing stress analysis for plant conditions, a preliminary mock-up analysis was done. The result of the preliminary analysis was validated by residual stress measurement in the mockup. After verification of the analysis methodology, an analysis under plant conditions was conducted. The analysis results show that the stress level is not high enough to initiate PWSCC. If a plant is properly welded and operated, PWSCC is not likely to occur in the pressurizer safety nozzle.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (French Edition)

International Nuclear Information System (INIS)

2017-01-01

This publication establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. A review of Safety Requirements publications was commenced in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan. The review revealed no significant areas of weakness and resulted in just a small set of amendments to strengthen the requirements and facilitate their implementation, which are contained in the present publication.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Russian Edition)

International Nuclear Information System (INIS)

2016-01-01

This publication establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. A review of Safety Requirements publications was commenced in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan. The review revealed no significant areas of weakness and resulted in just a small set of amendments to strengthen the requirements and facilitate their implementation, which are contained in the present publication.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Arabic Edition)

International Nuclear Information System (INIS)

2017-01-01

This publication establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. A review of Safety Requirements publications was commenced in 2011 following the accident in the Fukushima Daiichi nuclear power plant in Japan. The review revealed no significant areas of weakness and resulted in just a small set of amendments to strengthen the requirements and facilitate their implementation, which are contained in the present publication.

Human reliability analysis in probabilistic safety assessment for nuclear power plants. A Safety Practice. A publication within the NUSS programme

International Nuclear Information System (INIS)

1995-01-01

Probabilistic safety assessment (PSA) is playing an increasingly important role in the safe operation of nuclear power plants throughout the world. In order to establish a consistent framework for conducting PSA studies, for promoting technology transfer of the state of the art, and for encouraging uniformity in the way PSA is carried out, the IAEA is preparing a set of publications which gives guidance on various aspects of PSA. This document presents a practical approach for incorporating human reliability analysis (HRA) into PSA. It describes the steps needed and the documentation that should be provided both to support the PSA itself and to ensure effective communication of important information arising from the studies. It also describes a framework for analysing those human actions which could affect safety and for relating such human influences to specific parts of a PSA. This Safety Practice also addresses the limitations of PSA in taking account of human factors in relation to safety and risk. Refs, figs and tabs

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).

Plotting and analysis of fault trees in safety evaluation of nuclear power plants

International Nuclear Information System (INIS)

Wild, A.

1979-12-01

Fault tree analysis is a useful tool in determining the safety and reliability of nuclear power plants. The main strength of the fault tree method, its ability to detect cross-links between systems, can be used only if fault trees are constructed for complete nuclear generating stations. Such trees are large and have to be handled by computers. A system is described for handling fault trees using small computers such as the HP-1000 with disc drive, graphics terminal and x-y plotter

Safety analysis of spent fuel packaging

International Nuclear Information System (INIS)

Akamatsu, Hiroshi; Taniuchi, Hiroaki; Tai, Hideto

1987-01-01

Many types of spent fuel packagings have been manufactured and been used for transport of spent fuels discharged from nuclear power plant. These spent fuel packagings need to be assesed thoroughly about safety transportation because spent fuels loaded into the packaging have high radioactivity and generation of heat. This paper explains the outline of safety analysis of a packaging, Safety analysis is performed for structural, thermal, containment, shielding and criticality factors, and MARC-CDC, TRUMP, ORIGEN, QAD, ANISN, KENO, etc computer codes are used for such analysis. (author)

The role of probabilistic safety assessment and probabilistic safety criteria in nuclear power plant safety

International Nuclear Information System (INIS)

1992-01-01

The purpose of this Safety Report is to provide guidelines on the role of probabilistic safety assessment (PSA) and a range of associated reference points, collectively referred to as probabilistic safety criteria (PSC), in nuclear safety. The application of this Safety Report and the supporting Safety Practice publication should help to ensure that PSA methodology is used appropriately to assess and enhance the safety of nuclear power plants. The guidelines are intended for use by nuclear power plant designers, operators and regulators. While these guidelines have been prepared with nuclear power plants in mind, the principles involved have wide application to other nuclear and non-nuclear facilities. In Section 2 of this Safety Report guidelines are established on the role PSA can play as part of an overall safety assurance programme. Section 3 summarizes guidelines for the conduct of PSAs, and in Section 4 a PSC framework is recommended and guidance is provided for the establishment of PSC values

Topics to be covered in safety analysis reports for nuclear power plants with pressurized water reactors or boiling water reactors in the F.R.G

International Nuclear Information System (INIS)

Kohler, H.A.G.

1977-01-01

This manual aims at defining the standards to be used in Safety Analysis Reports for Nuclear Power Plants with Pressurized Water Reactors or Boiling Water Reactors in the Federal Republic of Germany. The topics to be covered are: Information about the site (geographic situation, settlement, industrial and military facilities, transport and communications, meteorological conditions, geological, hydrological and seismic conditions, radiological background), description of the power plant (building structures, safety vessel, reactor core, cooling system, ventilation systems, steam power plant, electrical facilities, systems for measurement and control), indication of operation (commissioning, operation, safety measures, radiation monitoring, organization), incident analysis (reactivity incidents, loss-of-coolant incidents, external impacts). (HP) [de

Barsebaeck power plant - safety and emergency measures

International Nuclear Information System (INIS)

Anon.

1981-01-01

A Swedish-Danish Committee on safety at the Swedish nuclear power plant Barsebaeck was established in 1979 in order to evaluate the nuclear safety at Barsebaeck with a view to the reactor accident at the Three-Mile-Island nuclear power plant March 28, 1979. According to the committees mandate the investigations of the Kemeny Commission, the Rogouin investigation, investigations of the American Nuclear Regulatory Commission, and the Swedish report ''Safe nuclear power'' have been taken into consideration by the Committee. Furthermore, it has formed the basis for the Committees work that the authority responsibility for the safety at Barsebaeck lies with the Swedish authorities, and that these authorities have evaluated the safety aspects before the permissions for operation of the Barsebaeck power plant were given and hereafter currently in connection with the inspection of the power plant. The report prepared by the Commission treats aspects as: a) Nuclear safety at the Barsebaeck power plant, b) reactor safety and emergency provisions, c) common elements in the emergency provision situation in Sweden and Denmark, d) ongoing investigations on course of events during accidents and release limiting safety systems. (BP)

Human actions in the pre-operational probabilistic safety analysis of Juragua Nuclear Power Plant

International Nuclear Information System (INIS)

Ferro, R.

1995-01-01

Human error is one of the main contributors to the biggest industrial disasters that the world has suffered in the last years. Safety probabilistic analysis techniques allow to consider, in the some study, the contribution of a facility's mechanical and human components safety, this guaranteeing a move integral assessment of these two factors although the PSA study of Juragua Nuclear Power Plant is carried out at a preoperational stage which causes important information limitations fos assessment of human reliability some considerations and suppositions in order to conduct treatment of human actions this stage were adopted. The present work describes the projected targets, approach applied and results obtained from the lakes of human reliability of this study

Organizational learning in commercial nuclear power plant safety: An empirical analysis

International Nuclear Information System (INIS)

Marcus, A.A.; Bromiley, P.; Nichols, M.L.

1989-01-01

The need for knowledge in organizations that manage and run high risk technologies is very high. The acquisition of useful knowledge is referred to as organizational learning. The theoretical roots of this concept are well established in the academic literature and in practice, especially in manufacturing industries. This paper focuses on organizational problem solving and learning as it relates to the safe and efficient management of commercial nuclear power plants. The authors are co-investigators on a larger team working under contract with the Nuclear Regulatory Commission to develop a logical framework that enables systematic examination of potential linkages between management and organizational factors and safety in nuclear power plant performance. Management and organizational factors that facilitate or impede organizational learning are only a part of the larger study, but are the major focus of this paper. In this paper, the theoretical roots of the concept of organizational learning are discussed, relationships to measures of safety and efficiency of commercial nuclear power plants are hypothesized, and empirical findings which provide partial tests of the hypotheses are discussed. This line of research appears promising; implications for further research, regulatory application, and nuclear power plant management are described

Safety in nuclear power plants

International Nuclear Information System (INIS)

Koeberlein, K.

1987-01-01

In nuclear power plants large amounts of radioactive fission products ensue from the fission of uranium. In order to protect the environment, the radioactive material is confined in multiple 'activity barriers' (crystal matrix of the fuel, fuel cladding, coolant boundary, safety containment, reactor building). These barriers are protected by applying a defense-in-depth concept (high quality requirements, protection systems which recognize and terminate operational incidents, safety systems to cope with accidents). In spite of a favorable safety record of German nuclear power plants it is obvious - and became most evident by the Chernobyl accident - that absolute safety is not achievable. At Chernobyl, however, design disadvantages of that reactor type (like positive reactivity feedback of coolant voiding, missing safety containment) played an important role in accident initiation and progression. Such features of the Russian 'graphite-moderated pressure tube boiling water reactor' are different from those of light water reactors operating in western countries. The essential steps of the waste management of the nuclear fuel cycle ('Entsorgung') are the interim storage, the shipment, and the reprocessing of the spent fuel and the final repository of radioactive waste. Reprocessing means the separation of fossil material (uranium, plutonium) from radioactive waste. Legal requirements for radiological protection of the environment, which are identical for nuclear power plants and reprocessing plant, are complied with by means of comprehensive filter systems. Safety problems of a reprocessing plant are eased considerably by the fact that system pressures, process temperatures and energy densities are low. In order to confine the radioactive waste from the biosphere for a very long period of time, it is to be discarded after appropriate treatment into the deep geological underground of salt domes. (orig./HP) [de

Basic safety principles for nuclear power plant

International Nuclear Information System (INIS)

Zhang Shiguan

1989-01-01

To ensure the safety operation of nuclear power plant, one should strictly adhere to the implelmentation of safety codes and the establishment of nuclear safety code system, as well as the applicable basic safety principles of nuclear power plants. This article briefly introduce the importance of nuclear codes and its economic benefits and the implementation of basic safety principles to be accumulated in practice for many years by various countries

Safety of Nuclear Power Plants: Commissioning and Operation

International Nuclear Information System (INIS)

2011-01-01

The safety of a nuclear power plant is ensured by means of proper site selection, design, construction and commissioning, and the evaluation of these, followed by proper management, operation and maintenance of the plant. In a later phase, a proper transition to decommissioning is required. The organization and management of plant operations ensures that a high level of safety is achieved through the effective management and control of operational activities. This publication is a revision of the Safety Requirements publication Safety of Nuclear Power Plants: Operation, which was issued in 2000 as IAEA Safety Standards Series No. NS-R-2. The purpose of this revision was to restructure Safety Standards Series No. NS-R-2 in the light of new operating experience and new trends in the nuclear industry; to introduce new requirements that were not included in Safety Standards Series No. NS-R-2 on the operation of nuclear power plants; and to reflect current practices, new concepts and technical developments. This update also reflects feedback on the use of the standards, both from Member States and from the IAEA's safety related activities. The publication is presented in the new format for Safety Requirements publications. The present publication reflects the safety principles of the Fundamental Safety Principles. It has been harmonized with IAEA Safety Standards Series No. GS-R-3 on The Management System for Facilities and Activities. Guidance on the fulfilment of the safety requirements is provided in supporting Safety Guides. The terminology used in this publication is defined and explained in the IAEA Safety Glossary. The objective of this publication is to establish the requirements which, in the light of experience and the present state of technology, must be satisfied to ensure the safe operation of nuclear power plants. These requirements are governed by the safety objective and safety principles that are established in the Fundamental Safety Principles. This

Psychology in nuclear power plants: an integrative approach to safety - general statement

International Nuclear Information System (INIS)

Shikiar, R.

1983-08-01

Since the accident at the Three Mile Island nuclear power plant on March 28, 1979, the commercial nuclear industry in the United States has paid increasing attention to the role of humans in overall plant safety. As the regulatory body with primary responsibility for ensuring public health and safety involving nuclear operations, the United States Nuclear Regulatory Commission (NRC) has also become increasingly involved with the ''human'' side of nuclear operations. The purpose of this symposium is to describe a major program of research and technical assistance that the Pacific Northwest Laboratory is performing for the NRC that deals with the issues of safety at nuclear power plants (NPPs). This program addresses safety from several different levels of analysis, which are all important within the context of an integrative approach to system safety

Use of operational experience in fire safety assessment of nuclear power plants

International Nuclear Information System (INIS)

2000-01-01

Fire hazard has been identified as a major contributor to a plant's operational risk and the international nuclear power industry has been studying and developing tools for defending against this hazard. Considerable progress in design and regulatory requirements for fire safety, in fire protection technology and in related analytical techniques has been made in the past two decades. Substantial efforts have been undertaken worldwide to implement these advances in the interest of improving fire safety both at new and existing nuclear power plants. To assist in these efforts, the IAEA initiated a programme on fire safety that was intended to provide assistance to Member States in improving fire safety in nuclear power plants. In order to achieve this general objective, the IAEA programme aimed at the development of guidelines and good practices, the promotion of advanced fire safety assessment techniques, the exchange of state of the art information between practitioners and the provision of engineering safety advisory services and training in the implementation of internationally accepted practices. During the period 1993-1994, the IAEA activities related to fire safety concentrated on the development of guidelines and good practice documents related to fire safety and fire protection of operating plants. One of the first tasks was the development of a Safety Guide that formulates specific requirements with regard to the fire safety of operating nuclear power plants. Several documents, which provide advice on fire safety inspection, were developed to assist in its implementation. In the period 1995-1996, the programme focused on the preparation of guidelines for the systematic analysis of fire safety at nuclear power plants (NPPs). The IAEA programme on fire safety for 1997-1998 includes tasks aimed at promoting systematic assessment of fire safety related occurrences and dissemination of essential insights from this assessment. One of the topics addressed is the

Analysis of safety information for nuclear power plants and development of source term estimation program

International Nuclear Information System (INIS)

Kim, Tae Woon; Choi, Seong Soo; Park, Jin Hee

1999-12-01

Current CARE(Computerized Advisory System for Radiological Emergency) in KINS(Korea Institute of Nuclear Safety) has no STES(Source Term Estimation System) which links between SIDS(Safety Information Display System) and FADAS(Following Accident Dose Assessment System). So in this study, STES is under development. STES system is the system that estimates the source term based on the safety information provided by SIDS. Estimated source term is given to FADAS as an input for estimation of environmental effect of radiation. Through this first year project STES for the Kori 3,4 and Younggwang 1,2 has been developed. Since there is no CARE for Wolsong(PHWR) plants yet, CARE for Wolsong is under construction. The safety parameters are selected and the safety information display screens and the alarm logic for plant status change are developed for Wolsong Unit 2 based on the design documents for CANDU plants

Discussion of important safety requirements for new nuclear power plants

International Nuclear Information System (INIS)

Zhang Lin; Jia Xiang; Yan Tianwen; Li Wenhong; Li Chun

2014-01-01

This paper presents the analysis of several important safety requirements and improvement direction. Technical view of security goals on site safety evaluation, internal and external events fortification, serious accident prevention and mitigation, as well as the core, containment system and instrument control system design and engineering optimization, and etc are indicated. It will be useful for new plant design, construction and safety improvement. (authors)

Safety standards and safety record of nuclear power plants

International Nuclear Information System (INIS)

Davis, A.B.

1984-01-01

This paper focuses on the use of standards and the measurement and enforcement of these standards to achieve safe operation of nuclear power plants. Since a discussion of the safety standards that the Nuclear Regulatory Commission (NRC) uses to regulate the nuclear power industry can be a rather tedious subject, this discussion will provide you with not only a description of what safety standards are, but some examples of their application, and various indicators that provide an overall perspective on safety. These remarks are confined to the safety standards adopted by the NRC. There are other agencies such as the Environmental Protection Agency, the Occupational Safety and Health Administration, and the state regulatory agencies which impact on a nuclear power plant. The NRC has regulatory authority for the commercial use of the nuclear materials and facilities which are defined in the Atomic Energy Act of 1954 to assure that the public health and safety and national security are protected

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

International Nuclear Information System (INIS)

Schaefer, H.

1987-01-01

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

Improved Management of Part Safety Classification System for Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Park, Jin Young; Park, Youn Won; Park, Heung Gyu; Park, Hyo Chan [BEES Inc., Daejeon (Korea, Republic of)

2016-10-15

As, in recent years, many quality assurance (QA) related incidents, such as falsely-certified parts and forged documentation, etc., were reported in association with the supply of structures, systems, components and parts to nuclear power plants, a need for a better management of safety classification system was addressed so that it would be based more on the level of parts . Presently, the Korean nuclear power plants do not develop and apply relevant procedures for safety classifications, but rather the safety classes of parts are determined solely based on the experience of equipment designers. So proposed in this paper is a better management plan for safety equipment classification system with an aim to strengthen the quality management for parts. The plan was developed through the analysis of newly introduced technical criteria to be applied to parts of nuclear power plant.

Instrumentation and control systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for establishing safety standards for nuclear power plants. It supplements Safety Standards Series No. NS-R-1: Safety of Nuclear Power Plants: Design (the Requirements for Design), which establishes the design requirements for ensuring the safety of nuclear power plants. This Safety Guide describes how the requirements should be met for instrumentation and control (I and C) systems important to safety. This publication is a revision and combination of two previous Safety Guides: Safety Series Nos 50-SG-D3 and 50-SG-D8, which are superseded by this new Safety Guide. The revision takes account of developments in I and C systems important to safety since the earlier Safety Guides were published in 1980 and 1984, respectively. The objective of this Safety Guide is to provide guidance on the design of I and C systems important to safety in nuclear power plants, including all I and C components, from the sensors allocated to the mechanical systems to the actuated equipment, operator interfaces and auxiliary equipment. This Safety Guide deals mainly with design requirements for those I and C systems that are important to safety. It expands on paragraphs of Ref in the area of I and C systems important to safety. This publication is intended for use primarily by designers of nuclear power plants and also by owners and/or operators and regulators of nuclear power plants. This Safety Guide provides general guidance on I and C systems important to safety which is broadly applicable to many nuclear power plants. More detailed requirements and limitations for safe operation specific to a particular plant type should be established as part of the design process. The present guidance is focused on the design principles for systems important to safety that warrant particular attention, and should be applied to both the design of new I and C systems and the modernization of existing systems. Guidance is provided on how design

The fault tree as a tool in safety analysis in nuclear power plants

International Nuclear Information System (INIS)

Waddington, J.G.; Wild, A.

1981-01-01

Modern safety analysis must be able to identify realistic failure modes based on realistic operation and system malfunction, demonstrate rigorously that adequate independence exists between a malfunctioning system and those other systems required to mitigate the effects of the malfunction, design adequate reliability into systems important to plant safety and to demonstrate rigorously that the design reliability is met in operation, and identify the realistic actions expected of the operator. Fault trees, which have proved to be a powerful tool to achieve these objectives, are inevitably large and must be computerized. However, the computerized system must be simple, must allow merging of branches developed independently, must provide for easy modification and the processing must be economical and easily accessible. A new system for displaying, plotting and analysing fault trees has been developed and implemented on a small computer at AECB to demonstrate the viability of the approach to designers, and to provide a tool to assess licensee's submissions on failure modes of support systems such as electrical, service water and air, and to assess reliability predictions for special safety systems. (author)

Analysis of societal recognition about domestic nuclear power plant safety

International Nuclear Information System (INIS)

Kim, S. H.; Kim, J. W.; Kang, C. S.

2003-01-01

The public acceptance to risk from a new technology depends on not only perceived risk but also many conditional factors. Though nuclear energy has many benefits, it is unreasonably perceived to be more dangerous than real. Hence, it is necessary to estimate the public recognition of safety of nuclear power and to study the social aspects relevant to the subject. To achieve the purpose, poll survey was carried out for the public and expert group. Through the poll survey, it has been found that many crucial differences exist between the quantitative risk and the perceived risk of the public. The results of this study are used as the reference data for establishing the social standards and formulating the safety philosophy for the safety of nuclear power plants hereafter

Defense-in-depth for common cause failure of nuclear power plant safety system software

International Nuclear Information System (INIS)

Tian Lu

2012-01-01

This paper briefly describes the development of digital I and C system in nuclear power plant, and analyses the viewpoints of NRC and other nuclear safety authorities on Software Common Cause Failure (SWCCF). In view of the SWCCF issue introduced by the digitized platform adopted in nuclear power plant safety system, this paper illustrated a diversified defence strategy for computer software and hardware. A diversified defence-in-depth solution is provided for digital safety system of nuclear power plant. Meanwhile, analysis on problems may be faced during application of nuclear safety license are analyzed, and direction of future nuclear safety I and C system development are put forward. (author)

Nuclear plant analyzer development and analysis applications

International Nuclear Information System (INIS)

Laats, E.T.

1984-10-01

The Nuclear Plant Analyzer (NPA) is being developed as the US Nuclear Regulatory Commission's (NRC's) state of the art safety analysis and engineering tool to address key nuclear plant safety issues. This paper describes four applications of the NPA in assisting reactor safety analyses. Two analyses evaluated reactor operating procedures, during off-normal operation, for a pressurized water reactor (PWR) and a boiling water reactor (BWR), respectively. The third analysis was performed in support of a reactor safety experiment conducted in the Semiscale facility. The final application demonstrated the usefulness of atmospheric dispersion computer codes for site emergency planning purposes. An overview of the NPA and how it supported these analyses are the topics of this paper

Preliminary systems-interaction results from the Digraph Matrix Analysis of the Watts Bar Nuclear Power Plant safety-injection systems

International Nuclear Information System (INIS)

Sacks, I.J.; Ashmore, B.C.; Champney, J.M.; Alesso, H.P.

1983-06-01

This report provides preliminary results generated by a Digraph Matrix Analysis (DMA) for a Systems Interaction analysis performed on the Safety Injection System of the Tennessee Valley Authority Watts Bar Nuclear Power Plant. An overview of DMA is provided along with a brief description of the computer codes used in DMA

Safety culture in nuclear power plants. Proceedings

International Nuclear Information System (INIS)

1994-12-01

As a consequence of the INSAG-4 report on 'safety culture', published by the IAEA in 1991, the Federal Commission for the Safety of Nuclear Power Plants (KSA) decided to hold a one-day seminar as a first step in this field. The KSA is an advisory body of the Federal Government and the Federal Department of Transport and Energy (EVED). It comments on applications for licenses, observes the operation of nuclear power plants, assists with the preparation of regulations, monitors the progress of research in the field of nuclear safety, and makes proposals for research tasks. The objective of this seminar was to familiarise the participants with the principles of 'safety culture', with the experiences made in Switzerland and abroad with existing concepts, as well as to eliminate existing prejudices. The main points dealt with at this seminar were: - safety culture from the point of view of operators, - safety culture from the point of view of the authorities, - safety culture: collaboration between power plants, the authorities and research organisations, - trends and developments in the field of safety culture. Invitations to attend this seminar were extended to the management boards of companies operating Swiss nuclear power plants, and to representatives of the Swiss authorities responsible for the safety of nuclear power plants. All these organisations were represented by a large number of executive and specialist staff. We would like to express our sincerest thanks to the Head of the Federal Department of Transport and Energy for his kind patronage of this seminar. (author) figs., tabs., refs

Safety provisions of nuclear power plants

International Nuclear Information System (INIS)

Niehaus, F.

1994-01-01

Safety of nuclear power plants is determined by a deterministic approach complemented by probabilistic considerations. Much use has been made of the wealth of information from more than 6000 years of reactor operation. Design, construction and operation is governed by national and international safety standards and practices. The IAEA has prepared a set of Nuclear Safety Standards as recommendations to its Member States, covering the areas of siting, design, operations, quality assurance, and governmental organisations. In 1988 the IAEA published a report by the International Nuclear Safety Advisory Group on Basic Safety Principles for Nuclear Power Plants, summarizing the underlying objectives and principles of excellence in nuclear safety and the way in which its aspects are interrelated. The paper will summarize some of the key safety principles and provisions, and results and uses of Probabilistic Safety Assessments. Some comments will be made on the safety of WWER 440/230 and WWER-1000 reactors which are operated on Bulgaria. 8 figs

The use of probabilistic safety assessment based maintenance indicators to increase the availability of safety related systems in nuclear power plants

International Nuclear Information System (INIS)

Kirchsteiger, C.

1991-04-01

This work describes the theoretical development of a Probabilistic Safety Assessment (PSA) based Performance Indicator (PI) model for a comprehensive Maintenance Efficiency Analysis (MEA) and its practical application to past operational history data of a certain Nuclear Power Plant. Plant specific equipment history and maintenance work order data have been collected and analysed using various advanced statistical procedures (nonparametric methods, multivariate analysis) in order to be able to estimate safety system related equipment and maintenance process trends. The main results of such a MEA case study are the trends in the (in)effectiveness of the performance of a selected safety system and its dominant maintenance related causes of its bad (good) equipment performance. Finally, the therefrom gained results are used to propose a new set of safety system based and maintenance related Performance Indicators, including suggestions for a corresponding plant specific maintenance data collection system. (author)

Use of F.M.E.A. for reliability analysis of safety systems in nuclear power plants

International Nuclear Information System (INIS)

Barbet, J.F.; Llory, M.; Villemeur, A.

1982-01-01

In the framework of the French nuclear power plant program, reliability studies of safety systems have been carried out at the Electricite de France since 1975. The main results of the studies are examined; about the methodological aspects it appears useful to develop an inductive approach such as the Failure Modes and Effects Analysis (F.M.E.A.). The method is described with its advantages and limitations; the possibilities of use of F.M.E.A. to solve specific safety problems are investigated. To conclude, the future trends of research and development in this field at Electricite de France are pointed out [fr

Assessment of Human Performance and Safety Culture at the Paks Nuclear Power Plant

International Nuclear Information System (INIS)

Toth, Janos; Hadnagy, Lajos

2002-01-01

Evaluation of human performance and safety culture of the personnel at a Nuclear Power Plant is a very important element of the self assessment process. At the Paks NPP a systematic approach to this problem started in the early 90's. The first comprehensive analysis of the human performance of the personnel was performed by the Hungarian Research Institute for Electric Power (VEIKI). The analysis of human failures is also a part of the investigation and analysis of safety related reported events. This human performance analysis of events is carried out by the Laboratory of Psychology of the plant and a supporting organisation namely the Department of Ergonomics and Psychology of the Budapest University of Technical and Economical Sciences. The analysis of safety culture at the Paks NPP has been in the focus of attention since the implementation of the INSAG-4 document started world-wide. In 1993 an IAEA model project namely 'Strengthening Training for Operational Safety' was initiated with a sub-project called 'Enhancement of Safety Culture'. Within this project the first step was the initial assessment of the safety culture level at the Paks NPP. It was followed by some corrective actions and safety culture improvement programme. In 1999 the second assessment was performed in order to evaluate the progress as a result of the improvement programme. A few indicators reflecting the elements of safety culture were defined and compared. The assessment of the safety culture with a survey among the managers was performed in September 2000 and the results are being evaluated at the moment. The intention of the plant management is to repeat the assessment every 2-3 years and evaluate the trend of the indicator. (authors)

Ignalina NPP Safety Analysis: Models and Results

International Nuclear Information System (INIS)

Uspuras, E.

1999-01-01

Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

The role of risk analysis in control of complex plants' safety operation

International Nuclear Information System (INIS)

Dumitrescu, Maria; Preda, Irina Aida; Lazar, Roxana Elena; Carcadea, Elena

1999-01-01

The problem of risk estimation, assessment and control is necessary to be discussed at every decision level of an activity. In this way the performances of a system, action or technology are qualitatively assessed by indicating the possible consequences on environmental, people or property. The paper presents methodologies of risk assessment successfully applied on isotopic separation plants. The quantitative methodologies presented use fault tree and event tree to determine the accident states frequency and physical models to analyse the dispersion in atmosphere of dangerous substances. The qualitative methodologies use fuzzy models for the multi-criteria decision making, models based on risk matrix built on the basis of a combination between severity and probability of maximum admissible consequence. These methodologies present the following steps for applying: familiarising with the activity in study, establishing the adequate method of risk assessment, realising of the model of risk assessment for the activity or objective in study, developing of application of the proposed model. Applying this methodology to isotopic separation plants has led to: analysis of operation events and establishing of principal types of events potentially dangerous, analysis of human error in these plants operation and operating experience assessment, technical specifications optimisation by probabilistic safety assessment, reliability analysis and development of reliability and exploitation events database, post accident events analysis (releases, fires, explosions) and mathematical modelling of dispersion in atmosphere of dangerous substances. The risk concept being complex and with multiple implications, it is not the case of a rigid approaching neither of existence of some methods universally valid. Because of these reasons choosing of the most appropriate method for the risk assessment of an activity, leads to solution in due time, of some problems with economic, social

Safety systems and safety analysis of the Qinshan phase III CANDU nuclear power plant

International Nuclear Information System (INIS)

Cai Jianping; Shen Sen; Barkman, N.

1999-01-01

The author introduces the Canadian nuclear reactor safety philosophy and the Qinshan Phase III CANDU NPP safety systems and safety analysis, which are designed and performed according to this philosophy. The concept of 'defence-in-depth' is a key element of the Canadian nuclear reactor safety philosophy. The design concepts of redundancy, diversity, separation, equipment qualification, quality assurance, and use of appropriate design codes and standards are adopted in the design. Four special safety systems as well as a set of reliable safety support systems are incorporated in the design of Qinshan phase III CANDU for accident mitigation. The assessment results for safety systems performance show that the fundamental safety criteria for public dose, and integrity of fuel, channels and the reactor building, are satisfied

Reprocessing plants safety

International Nuclear Information System (INIS)

Davies, A.G.; Leighton, C.; Millington, D.

1989-01-01

The reprocessing of irradiated nuclear fuel at British Nuclear Fuels (BNFL) Sellafield site consists of a number of relatively self-contained activities carried out in separate plants across the site. The physical conditions and time scales applied in reprocessing and storage make it relatively benign. The potential for minor releases of radioactivity under fault conditioning is minimised by plant design definition of control procedures, training and supervision. The risks to both the general public and workforce are shown to be low with all the safety criteria being met. Normal operating conditions also have the potential for some occupational radiation exposure and the plant and workers are monitored continuously. Exposure levels have been reduced steadily and will continue to fall with plant improvements. (U.K.)

Probabilistic safety assessment of nuclear power plants: a monograph

International Nuclear Information System (INIS)

Solanki, R.B.; Prasad, Mahendra

2007-11-01

This monograph on probabilistic safety assessment (PSA) is addressed to the wide community of professionals engaged in the nuclear industry and concerned with the safety issues of nuclear power plants (NPPs). While the monograph describes PSA of NPPs, the principles described in this monograph can be extended to other facilities like spent fuel storage, fuel reprocessing plants and non-nuclear facilities like chemical plants, refineries etc. as applicable. The methodology for risk assessment in chemical plants or refineries is generally known as quantitative risk analysis (QRA). The fundamental difference between NPP and chemical plant is that in NPPs the hazardous material (fuel and fission products) are contained at a single location (i.e. inside containment), whereas in a chemical plant and reprocessing plants, the hazardous material is present simultaneously at many places, like pipelines, reaction towers, storage tanks, etc. Also unlike PSA, QRA does not deal with levels; it uses an integrated approach combining all the levels. The monograph covers the areas of broad interest in the field of PSA such as historical perspective, fundamentals of PSA, strengths and weaknesses of PSA, applications of PSA, role of PSA in the regulatory decision making and issues for advancement of PSA

Kozloduy nuclear power plant. Units 1-4. Status of safety assessment activities. Rev. 2

International Nuclear Information System (INIS)

1999-01-01

This paper presents the results of the status of safety assessment activities carried out by the Kozloduy Nuclear Power Plant (KNPP) in order to evaluate the current status of the safety of its reactor units 1-4. The steam supply system of this units is based of the reactor WWER-440/ B-230, which is a PWR of Russian design developed according to the safety standards in force in USSR in late 60-s. Now a days 10 reactor units of this type are in operation in four NPPs. Despite of efforts of the different plants to implement safety improvements measures during first 10-15 years of operation of this type of reactor its major safety problems were not eliminated and were a subject of international concern. The systematic evaluation of the deficiencies of the original design of this type of reactors have been initiated by IAEA in the beginning of 1990 and brought to developing a comprehensive list of safety problems which required urgent implementation of safety measures in all plants. To solve this problems in 1991 KNPP initiated implementation of so called 'short term' safety improvement program, developed with the help of WANO under agreement with Bulgarian Nuclear Safety Authority (BNSA) and consortium RISKAUDIT. The program was based on a stage approach and was foreseen to be implemented by tree stages in very tight time schedule in order to achieve significant and rapid improvements of the level of safety in operation of the units. The Short Tenn Program was implemented between the years 1991 and 1997 thanks of the strong safety commitment of NEK and KNPP staff and the broad international cooperation and financial support. Important part of resources were supplied under PHARE program of CEC, EBRD grant agreement and EDF support. The plant current safety level analysis has been performed using IAEA analytical methodology according to 50-SG-O12 standard 'Periodic safety review of operational nuclear power plants'. The approach and criteria for acceptable safety level

Nuclear power plant fire protection: philosophy and analysis

International Nuclear Information System (INIS)

Berry, D.L.

1980-05-01

This report combines a fire severity analysis technique with a fault tree methodology for assessing the importance to nuclear power plant safety of certain combinations of components and systems. Characteristics unique to fire, such as propagation induced by the failure of barriers, have been incorporated into the methodology. By applying the resulting fire analysis technique to actual conditions found in a representative nuclear power plant, it is found that some safety and nonsafety areas are both highly vulnerable to fire spread and impotant to overall safety, while other areas prove to be of marginal importance. Suggestions are made for further experimental and analytical work to supplement the fire analysis method

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2001-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

The operating organization for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. The present publication is a revision of the IAEA Safety Guide on Management of Nuclear Power Plants for Safe Operation issued in 1984. It supplements Section 2 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation. Nuclear power technology is different from the customary technology of power generation from fossil fuel and by hydroelectric means. One major difference between the management of nuclear power plants and that of conventional generating plants is the emphasis that should be placed on nuclear safety, quality assurance, the management of radioactive waste and radiological protection, and the accompanying national regulatory requirements. This Safety Guide highlights the important elements of effective management in relation to these aspects of safety. The attention to be paid to safety requires that the management recognize that personnel involved in the nuclear power programme should understand, respond effectively to, and continuously search for ways to enhance safety in the light of any additional requirements socially and legally demanded of nuclear energy. This will help to ensure that safety policies that result in the safe operation of nuclear power plants are implemented and that margins of safety are always maintained. The structure of the organization, management standards and administrative controls should be such that there is a high degree of assurance that safety policies and decisions are implemented, safety is continuously enhanced and a strong safety culture is promoted and supported. The objective of this publication is to guide Member States in setting up an operating organization which facilitates the safe operation of nuclear power plants to a high level internationally. The second objective is to provide guidance on the most important organizational elements in order to contribute to a strong safety

Nuclear power plants: a unique challenge to fire safety

International Nuclear Information System (INIS)

Nowlen, S.P.

1992-01-01

The evaluation of fire safety in a nuclear power plant must include the consideration of the impact of a fire on the operability of plant safety equipment and systems. This issue is not typical of the life safety and property protection issues which dominate traditional fire safety concerns. This paper provides a general discussion of the issue of nuclear power plant fire safety as it currently exists in the USA. Included is a discussion of the past history of nuclear power plant fire events, the development of nuclear industry specific fire safety guidelines, the adverse experience associated with the inadvertent operation of fire suppression systems, and the anticipated direction of fire safety requirements for future reactor designs in the USA. (Author)

[Plant-specific pressured thermal shock safety analysis report

International Nuclear Information System (INIS)

Selby, D.L.

1985-01-01

Information is presented concerning plant data; determination of detailed PTS sequences for analysis; fracture mechanics analysis; integration of analysis; sensitivity and uncertainty analyses of through-wall crack frequencies; and effect of corrective actions on vessel through-wall crack frequency

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.

Effort on Nuclear Power Plants safety

International Nuclear Information System (INIS)

Prayoto.

1979-01-01

Prospects of nuclear power plant on designing, building and operation covering natural safety, technical safety, and emergency safety are discussed. Several problems and their solutions and nuclear energy operation in developing countries especially control and permission are also discussed. (author tr.)

Assessment of IAEA safety series no. 75-INSAG-3 - ''basic safety principles for nuclear power plants''

International Nuclear Information System (INIS)

1989-01-01

The International Atomic Energy Agency Safety Series No. 75-INSAG--3, 'Basic Safety Principles for Nuclear Power Plants' is reviewed in the light of the Advisory Committee on Nuclear Safety reports ACNS--2, 'Safety Objectives for Nuclear Activities in Canada', and ACNS--4, 'Recommended General Safety Requirements for Nuclear Power Plants'. The INSAG safety objectives are consistent with the safety objectives stated in ACNS--2 but are less general, applying only to nuclear power plants. The INSAG safety principles are, in general, consistent with the requirements stated in ACNS--4 but put more emphasis on 'safety culture'. They give little attention to reactor plant effluents, waste management, or decommissioning. (fig., 5 refs.)

Safety assessment for the passive system of the nuclear power plants (NPPs) using safety margin estimation

International Nuclear Information System (INIS)

Woo, Tae-Ho; Lee, Un-Chul

2010-01-01

The probabilistic safety assessment (PSA) for gas-cooled nuclear power plants has been investigated where the operational data are deficient, because there is not any commercial gas-cooled nuclear power plant. Therefore, it is necessary to use the statistical data for the basic event constructions. Several estimations for the safety margin are introduced for the quantification of the failure frequency in the basic event, which is made by the concept of the impact and affordability. Trend of probability of failure (TPF) and fuzzy converter (FC) are introduced using the safety margin, which shows the simplified and easy configurations for the event characteristics. The mass flow rate in the natural circulation is studied for the modeling. The potential energy in the gravity, the temperature and pressure in the heat conduction, and the heat transfer rate in the internal stored energy are also investigated. The values in the probability set are compared with those of the fuzzy set modeling. Non-linearity of the safety margin is expressed by the fuzziness of the membership function. This artificial intelligence analysis of the fuzzy set could enhance the reliability of the system comparing to the probabilistic analysis.

Rock siting of nuclear power plants from a reactor safety standpoint

International Nuclear Information System (INIS)

1975-11-01

The study has aimed at surveying the advantages and disadvantages of a rock sited nuclear power plant from a reactor safety standpoint. The studies performed are almost entirely concentrated on the BWR alternative. The design of a nuclear power plant in rock judged most appropriate has been studied in greater detail, and a relatively extensive safety analysis has been made. It is found that the presented technical design of the rock sited alternative is sufficiently advanced to form a basis for further projecting treatment. The chosen technical design of the reactor plant demands a cavern with a 45-50 metre span. Caverns without strengthening efforts with such spans are used in mines, but have no previously been used for industrial plants. Studies of the stability of such caverns show that a safety level is attainable corresponding to the safety required for the other parts of the nuclear power plant. The conditions are that the rock is of high quality, that necessary strengthening measures are taken and that careful studies of the rock are made before and during the blasting, and also during operation of the plant. When locating a rock sited nuclear power plant, the same criteria must be considered as for an above ground plant, with additional stronger demands for rock quality. The presented rock sited nuclear power plant has been assessed to cost 20 % more in total construction costs than a corresponding above ground plant. The motivations for rock siting also depend on whether a condensing plant for only electricity production, or a plant for combined power production and district heating, is considered. The latter would under certain circumstances make rock siting look more attractive. (author)

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

International Nuclear Information System (INIS)

Balfanz, H.P.

1989-01-01

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

The role of PRA in the safety assessment of VVER Nuclear Power Plants in Ukraine

International Nuclear Information System (INIS)

Kot, C.

1999-01-01

Ukraine operates thirteen (13) Soviet-designed pressurized water reactors, VVERS. All Ukrainian plants are currently operating with annually renewable permits until they update their safety analysis reports (SARs), in accordance with new SAR content requirements issued in September 1995, by the Nuclear Regulatory Authority and the Government Nuclear Power Coordinating Committee of Ukraine. The requirements are in three major areas: design basis accident (DBA) analysis, probabilistic risk assessment (PRA), and beyond design-basis accident (BDBA) analysis. The last two requirements, on PRA and BDBA, are new, and the DBA requirements are an expanded version of the older SAR requirements. The US Department of Energy (USDOE), as part of its Soviet-Designed Reactor Safety activities, is providing assistance and technology transfer to Ukraine to support their nuclear power plants (NPPs) in developing a Western-type technical basis for the new SARs. USDOE sponsored In-Depth Safety Assessments (ISAs) are in progress at three pilot nuclear reactor units in Ukraine, South Ukraine Unit 1, Zaporizhzhya Unit 5, and Rivne Unit 1, and a follow-on study has been initiated at Khmenytskyy Unit 1. The ISA projects encompass most areas of plant safety evaluation, but the initial emphasis is on performing a detailed, plant-specific Level 1 Internal Events PRA. This allows the early definition of the plant risk profile, the identification of risk significant accident sequences and plant vulnerabilities and provides guidance for the remainder of the safety assessments

Development of the safety analysis system - SAIS - application to the Kola nuclear power plant

International Nuclear Information System (INIS)

Balfanz, H.P.; Fuhrmann, C.; Neumann, L.; Rumpf, J.; Kubintsev, B.; Marakulin, I.; Shevelev, V.; Terekhov, I.

1995-01-01

The project was started in July 1991 and finished by the end of 1993. It was aimed at adapting SAIS to WWER-440/W213 plant design and operational procedures, demonstrating the possibilities of SAIS for safety evaluation and examining the system by plant personnel and a PSA team. The project covered -the use of data form as well as fault and event tree methods of SAIS, - a probabilistic assessment of the high pressure injection system in case of a small break loss-of-coolant accident, - a quantification of human error probabilities for operator actions to cool down the primary circuit in case of a small break loss-of-coolant accident when the high pressure injection system has failed and - a comparison of Russian and German operational procedures and safety documents used in the probabilistic analyses of the SAIS-Kola project. As a main result SAIS was found to be an appropriate tool to give assistance to the plant personnel on safety evaluation of the plant within the frame of reconstruction measures and on the establishment of a qualified reliability data collection system at Kola NPP. (orig./HP) [de

Probabilistic safety analysis for nuclear fuel cycle facilities, an exemplary application for a fuel fabrication plant

International Nuclear Information System (INIS)

Gmal, B.; Gaenssmantel, G.; Mayer, G.; Moser, E.F.

2013-01-01

In order to assess the risk of complex technical systems, the application of the Probabilistic Safety Assessment (PSA) in addition to the Deterministic Safety Analysis becomes of increasing interest. Besides nuclear installations this applies to e. g. chemical plants. A PSA is capable of expanding the basis for the risk assessment and of complementing the conventional deterministic analysis, by which means the existing safety standards of that facility can be improved if necessary. In the available paper, the differences between a PSA for a nuclear power plant and a nuclear fuel cycle facility (NFCF) are discussed in shortness and a basic concept for a PSA for a nuclear fuel cycle facility is described. Furthermore, an exemplary PSA for a partial process in a fuel assembly fabrication facility is described. The underlying data are partially taken from an older German facility, other parts are generic. Moreover, a selected set of reported events corresponding to this partial process is taken as auxiliary data. The investigation of this partial process from the fuel fabrication as an example application shows that PSA methods are in principle applicable to nuclear fuel cycle facilities. Here, the focus is on preventing an initiating event, so that the system analysis is directed to the modeling of fault trees for initiating events. The quantitative results of this exemplary study are given as point values for the average occurrence frequencies. They include large uncertainties because of the limited documentation and data basis available, and thus have only methodological character. While quantitative results are given, further detailed information on process components and process flow is strongly required for robust conclusions with respect to the real process. (authors)

Preliminary safety analysis of a PBMR supplying process heat to a co-located ethylene production plant

International Nuclear Information System (INIS)

Scarlat, Raluca O.; Cisneros, Anselmo T.; Koutchesfahani, Tawni; Hong, Rada; Peterson, Per F.

2012-01-01

This paper considers the safety analysis and licensing approach for co-locating a pebble bed modular reactor (PBMR) to provide process heat to an ethylene production unit. The PBMR is an advanced nuclear reactor design that provides 400 MW of thermal energy. Ethylene production is an energy intensive process that utilizes large gas furnaces to provide the heat for the process. Coupling a PBMR with an ethylene production plant would open a new market for nuclear power, and would provide the chemical industry with a cleaner power source, helping to achieve the Clean Air Act standards, and eliminating the 0.5 ton of CO 2 emissions per ton of produced ethylene. Our analysis uses the Chevron Phillips chemical plant in Sweeney, TX as a prototypical site. The plant has four ethylene production trains, with a total power consumption of 2.4 GW, for an ethylene output of 3.7 million tons per year, 4% of the global ethylene production capacity. This paper proposes replacement of the gas furnaces by low-emission PBMR modules, and presents the safety concerns and risk mitigation and management options for this coupled system. Two coupling design options are proposed, and the necessary changes to the design basis events and severe accidents for the PBMR licensing application are discussed. A joint effort between the chemical and the nuclear entities to optimize the coupling design, establish preventive maintenance procedures, and develop emergency response plans for both of the units is recommended.

Preliminary safety analysis of a PBMR supplying process heat to a co-located ethylene production plant

Energy Technology Data Exchange (ETDEWEB)

Scarlat, Raluca O., E-mail: rscarlat@nuc.berkeley.edu [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Cisneros, Anselmo T. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States); Koutchesfahani, Tawni [University of California, Chemical and Biomolecular Engineering, 201 Gilman Hall, Berkeley, CA 94720 (United States); Hong, Rada; Peterson, Per F. [University of California Berkeley, Nuclear Engineering, 4118 Etcheverry Hall, Berkeley, CA 94720 (United States)

2012-10-15

This paper considers the safety analysis and licensing approach for co-locating a pebble bed modular reactor (PBMR) to provide process heat to an ethylene production unit. The PBMR is an advanced nuclear reactor design that provides 400 MW of thermal energy. Ethylene production is an energy intensive process that utilizes large gas furnaces to provide the heat for the process. Coupling a PBMR with an ethylene production plant would open a new market for nuclear power, and would provide the chemical industry with a cleaner power source, helping to achieve the Clean Air Act standards, and eliminating the 0.5 ton of CO{sub 2} emissions per ton of produced ethylene. Our analysis uses the Chevron Phillips chemical plant in Sweeney, TX as a prototypical site. The plant has four ethylene production trains, with a total power consumption of 2.4 GW, for an ethylene output of 3.7 million tons per year, 4% of the global ethylene production capacity. This paper proposes replacement of the gas furnaces by low-emission PBMR modules, and presents the safety concerns and risk mitigation and management options for this coupled system. Two coupling design options are proposed, and the necessary changes to the design basis events and severe accidents for the PBMR licensing application are discussed. A joint effort between the chemical and the nuclear entities to optimize the coupling design, establish preventive maintenance procedures, and develop emergency response plans for both of the units is recommended.

Safety analysis of disposal of decommissioning wastes from Loviisa nuclear power plant

International Nuclear Information System (INIS)

Vieno, T.; Nordman, H.; Rasilainen, K.; Suolanen, V.

1987-12-01

The repository for decommissioning wastes from the Loviisa nuclear power plant consisting of two 445 MWe PWR units is planned to be excavated at the depth of 90-130 meters in the bedrock of the power plant site. The reactor vessels weighing each about 215 tons will be transferred each in one piece into the repository. They are emplaced in an upright position in big holes excavated in the bottom of repository caverns. The reactor vessel internals are then emplaced inside the vessels. Finally, the vessels will be filled with concrete and the lids will be emplaced and sealed. Steam generators and pressurizers will also be disposed of uncutted. Other decommissioning wastes will be cut into smaller pieces and emplaced in concrete or wooden containers. The repository will be situated on the small island on which the power plant is located. The groundwater on the island contains two zones of different salinity: an upper zone of fresh, flowing groundwater and a lower zone of saline, stagnant groundwater where the repository will be situated. Three groundwater scenarios have been considered in the safety analysis: a scenario based on the present site conditions, an altered scenario where the repository is assumed to be situated in a zone of fresh, flowing groundwater and a distruptive event scenario with an intensive groundwater flow through the repository. The obtained results of the analysis show clear safety margins. In the basic scenario the maximum annul dose rate is 6x10 -14 Sv/a via the local sea pathways, 6x10 -11 Sv/a via the lake pathways and 4x10 -8 Sv/a via a well bored in the vicinity of the repository. In the altered groundwater scenario the maximum annual dose rate is 4x10 -10 Sv/a via the sea pathways, 3x10 -7 Sv/a via the lake pathways and 1x10 -5 Sv/a via the well pathway. In the unlikely disruptive event scenario the corresponding dose rates are 8x10 -10 Sv/a (sea), 7x10 -7 Sv/a (lake) and 2x10 -4 Sv/a (well)

Procedures for analysis of accidents in shutdown modes for WWER nuclear power plants. A publication of the extrabudgetary programme on the safety of WWER and RBMK nuclear power plants

International Nuclear Information System (INIS)

1997-07-01

Operational events occurring during shutdown conditions contribute significantly to the NPP risk due to the fact that both preventive and mitigatory capabilities of the plant are somehow degraded. The need for detailed information in the performance and review of accident analysis for WWER type NPPs was identified as a priority within IAEA Extrabudgetary Program on Safety of WWER and RBMK NPPs. The present guidelines were developed through two consultants meetings in 1995 and 1996. The guidelines establish a set of criteria for performing deterministic analysis of accidents, initiated by events occurring under shutdown conditions. This report is mostly relevant for licensing type calculations, and may to a certain extent, also used for development, improvement or justification of the plant limits and conditions, emergency operating procedures, operator training programs and probabilistic safety studies. The guidelines apply to all WWER plants in operation and/or under construction

Safety culture in the maintenance of nuclear power plants

International Nuclear Information System (INIS)

2005-01-01

Safety culture is the complexity of beliefs, shared values and behaviour reflected in making decisions and performing work in a nuclear power plant or nuclear facility. The definition of safety culture and the related concepts presented in the IAEA literature are widely known to experts. Since the publication of Safety Culture, issued by the IAEA as INSAG-4 in 1991, the IAEA has produced a number of publications on strengthening the safety culture in organizations that operate nuclear power plants and nuclear facilities. However, until now the focus has been primarily on the area of operations. Apart from operations, maintenance in plants and nuclear facilities is an aspect that deserves special attention, as maintenance activities can have both a direct and an indirect effect on equipment reliability. Adverse safety effects can arise, depending upon the level of skill of the personnel involved, safety awareness and the complexity of the work process. Any delayed effects resulting from challenges to maintenance can cause interruptions in operation, and hence affect the safety of a plant or facility. Building upon earlier IAEA publications on this topic, this Safety Report reviews how challenges to the maintenance of nuclear power plants can affect safety culture. It also highlights indications of a weakening safety culture. The challenges described are in areas such as maintenance management; human resources management; plant condition assessment and the business environment. The steps that some Member States have taken to address safety culture aspects are detailed and singled out as good practices, with a view to disseminating and exchanging experiences and lessons learned. Although this report is primarily directed at plant maintenance organizations, the subject matter is applicable to a wider audience, including plant contracting organizations and regulatory authorities

Simplified application of probabilistic safety analysis in nuclear power plants by means of artificial neural networks

International Nuclear Information System (INIS)

Oehmgen, T.; Knorr, J.

2004-01-01

Probabilistic safety analyses (PSA) are conducted to assess the balanced nature of plant design in terms of technical safety and the administrative management of plant operation in nuclear power plants. In the evaluation shown in this article of the operating experience accumulated in two nuclear power plants, all failures are traced back consistently to the plant media and component levels, respectively, for the calculation of reliability coefficients. Moreover, the use of neural networks for probabilistic calculations is examined. The results are verified on the basis of test examples. Calculations with neural networks are very easy to carry out in a kind of 'black box'. There is a possibility, for instance, to use the system in plant maintenance. (orig.) [de

Pantex Plant final safety analysis report, Zone 4 magazines. Staging or interim storage for nuclear weapons and components: Issue D

Energy Technology Data Exchange (ETDEWEB)

1993-04-01

This Safety Analysis Report (SAR) contains a detailed description and evaluation of the significant environmental, safety, and health (ES&H) issues associated with the operations of the Pantex Plant modified-Richmond and steel arch construction (SAC) magazines in Zone 4. It provides (1) an overall description of the magazines, the Pantex Plant, and its surroundings; (2) a systematic evaluations of the hazards that could occur as a result of the operations performed in these magazines; (3) descriptions and analyses of the adequacy of the measures taken to eliminate, control, or mitigate the identified hazards; and (4) analyses of potential accidents and their associated risks.

Safety analysis procedures for PHWR

International Nuclear Information System (INIS)

Min, Byung Joo; Kim, Hyoung Tae; Yoo, Kun Joong

2004-03-01

The methodology of safety analyses for CANDU reactors in Canada, a vendor country, uses a combination of best-estimate physical models and conservative input parameters so as to minimize the uncertainty of the plant behavior predictions. As using the conservative input parameters, the results of the safety analyses are assured the regulatory requirements such as the public dose, the integrity of fuel and fuel channel, the integrity of containment and reactor structures, etc. However, there is not the comprehensive and systematic procedures for safety analyses for CANDU reactors in Korea. In this regard, the development of the safety analyses procedures for CANDU reactors is being conducted not only to establish the safety analyses system, but also to enhance the quality assurance of the safety assessment. In the first phase of this study, the general procedures of the deterministic safety analyses are developed. The general safety procedures are covered the specification of the initial event, selection of the methodology and accident sequences, computer codes, safety analysis procedures, verification of errors and uncertainties, etc. Finally, These general procedures of the safety analyses are applied to the Large Break Loss Of Coolant Accident (LBLOCA) in Final Safety Analysis Report (FSAR) for Wolsong units 2, 3, 4

Safety classification of items in Tianwan Nuclear Power Plant

International Nuclear Information System (INIS)

Sun Yongbin

2005-01-01

The principle of integrality, moderation and equilibrium should be considered in the safety classification of items in nuclear power plant. The basic ways for safety classification of items is to classify the safety function based on the effect of the outside enclosure damage of the items (parts) on the safety. Tianwan Nuclear Power Plant adopts Russian VVER-1000/428 type reactor, it safety classification mainly refers to Russian Guidelines and standards. The safety classification of the electric equipment refers to IEEE-308(80) standard, including 1E and Non 1E classification. The safety classification of the instrumentation and control equipment refers to GB/T 15474-1995 standard, including safety 1E, safety-related SR and NC non-safety classification. The safety classification of Tianwan Nuclear Power Plant has to be approved by NNSA and satisfy Chinese Nuclear Safety Guidelines. (authors)

The use of probabilistic safety assessment (PSA) based maintenance indicators to increase the availability of safety related systems in nuclear power plants

International Nuclear Information System (INIS)

Kirchsteiger, C.

1991-04-01

This work describes the theoretical development of a Probabilistic Safety Assessment (PSA) based Performance Indicator (PI) model for a comprehensive Maintenance Efficiency Analysis (MEA) and its practical application to past operational history data of a certain nuclear power plant. Plant specific equipment history and maintenance work on data have been collected and analysed using various advanced statistical procedures (nonparametric methods, multivariate analysis in order to be able to estimate safety system related equipment and maintenance process trends. The main results of such a MEA case study are the trends in the (in)effectiveness of the performance of a selected safety system and its dominant components as well as the detection of the dominant maintenance related causes of its bad (good) equipment performance. Finally, the therefrom gained results are used to propose a new set of safety system-based and maintenance-related performance indicators, including suggestions for a corresponding plant specific maintenance data collection system. (author)

Study on safety subsidiary objective of nuclear power plant in USA

International Nuclear Information System (INIS)

Chen Yan; Zhang Chunming; Fu Zhiwei; Song Wei; Li Chaojun; Wang Zhe; Zuo Jiaxu

2013-01-01

This paper reviewed the development of the quantitative safety objective and subsidiary objective in USA. The expressions of CDF and LERF were obtained according to NUREG-1150. The relationship between the subsidiary objective and the quantitative safety objective was derived. The method was compared with that used in NUREG-1860. The requirements of safety objective for the future nuclear power plant and the development of probabilistic safety analysis (PSA) technology in USA were studied and can be used as reference in China. (authors)

Criticality safety evaluation in Tokai Reprocessing Plant

International Nuclear Information System (INIS)

Shirai, Nobutoshi; Nakajima, Masayoshi; Takaya, Akikazu; Ohnuma, Hideyuki; Shirouzu, Hidetomo; Hayashi, Shinichiro; Yoshikawa, Koji; Suto, Toshiyuki

2000-04-01

Criticality limits for equipments in Tokai Reprocessing Plant which handle fissile material solution and are under shape and dimension control were reevaluated based on the guideline No.10 'Criticality safety of single unit' in the regulatory guide for reprocessing plant safety. This report presents criticality safety evaluation of each equipment as single unit. Criticality safety of multiple units in a cell or a room was also evaluated. The evaluated equipments were ones in dissolution, separation, purification, denitration, Pu product storage, and Pu conversion processes. As a result, it was reconfirmed that the equipments were safe enough from a view point of criticality safety of single unit and multiple units. (author)

Safety in waste management plants: An Indian perspective

International Nuclear Information System (INIS)

Shekhar, P.; Ozarde, P.D.; Gandhi, P.M.

2000-01-01

Assurance of safety of public and plant workers and protection of the environment are prime objectives in the design and construction of Waste Management Plants. In India, waste management principles and strategies have been evolved in accordance with national and international regulations and standards for radiation protection. The regulations governing radiation protection have a far-reaching impact on the management of the radioactive waste. The wastes arise at each stages of the fuel cycle with varying chemical nature, generation rate and specific activity levels depending upon the type of the facility. Segregation of waste based on its chemical nature and specific activity levels is an essential feature, as its aids in selection of treatment and conditioning process. Selection of the process, equipment and materials in the plant, are governed by safety consideration alongside factors like efficiency and simplicity. The plant design considerations like physical separation, general arrangement, ventilation zoning, access control, remote handling, process piping routing, decontamination etc. have major role in realizing waste safety. Stringent quality control measures during all stages of construction have helped in achieving the design intended safety. These aspects together with operating experience gained form basis for the improved safety features in the design and construction of waste management plants. The comprehensive safety is derived from adoption of waste management strategies and appropriate plant design considerations. The paper briefly brings safety in waste management programme in India, in its current perspective. (author)

Tolerability of risk, safety assessment principles and their implications for probabilistic safety analysis

International Nuclear Information System (INIS)

Ewing, D.J.F.; Campbell, J.F.

1994-01-01

This paper gives a regulatory view of probabilistic safety assessment as seen by the Nuclear Installations Inspectorate (NII) and in the light of the general regulatory risk aims set out in the Health and Safety Executive's (HSE) The tolerability of risk from nuclear power stations (TOR) and in Safety assessment principles for nuclear plants (SAPs), prepared by NII on behalf of the HSE. Both of these publications were revised and republished in 1992. This paper describes the SAPs, together with the historical background, the motivation for review, the effects of the Sizewell and Hinkley Point C public inquiries, changes since the original versions, comparison with international standards and use in assessment. For new plant, probabilistic safety analysis (PSA) is seen as an essential tool in balancing the safety of the design and in demonstrating compliance with TOR and the SAPs. (Author)

French-Finnish colloquium on safety of French and Russian type nuclear power plants

International Nuclear Information System (INIS)

Lukka, M.; Jaervinen, M.; Minkkinen, P.; Ukkola, A.; Levomaeki, L.

1994-01-01

The French-Finnish Colloquium on Safety of French and Russian Type Nuclear Power Plants was held in June, 14th - 16th, 1994, in Lappeenranta, Finland. The main topics of the colloquium were: VVER and RBMK reactors; Industrial safety studies for VVER's in FRAMATOME; Structural safety analysis of Ignalina NPP; Thermalhydraulic system (BETHSY) and analytical experiments for French NPP; Test facilities simulating VVER plants during accidents; PACTEL - facility for VVER thermal hydraulics; High burn-up fuel and reactivity accidents; Overview of severe accident research at Nuclear Protection and Safety Institute of CEA; Research of severe accidents in Finland; Review of main activities concerning computer codes used for VVER thermal-hydraulic safety analysis in OKB Gidropress; CATHARE code; APROS computer code, new developments; TRIO and TOLBIAC computer codes; ESTET and N3S softwares; HEXTRAN - 3D reactor dynamics code for VVER accident analysis; An overview the boron dilution issue in PWRs; Boron mixing transients in a 900 MW PWR vessel for a reactor start-up operation; and Problem of boric acid dilution in IVO

Safety upgrading at PAKS Nuclear Power Plant

International Nuclear Information System (INIS)

Bajsz, J.; Elter, J.

2000-01-01

The operation of Paks NPP has reached its half time. Until this time the plant fulfilled expectations raised before its construction: the four units have produced safely and reliably more than 200 TWh electricity. The production of the plant has been at the stable level since its construction and has provided 43-38 % of electricity consumed in Hungary. The annual production is around 14 TWh, which means a load factor higher than 85 %. Safety upgrading activities [1] at Paks had started in the late eighties, when the commissioning work of units 3 and 4 were carried out. That time the main emphases were put to lessons learned of the TMI and Chernobyl accidents. The international reviews hosted by our plant widened our review's scope. To systematize our approach a complete safety review, the AGNES (Advanced General Safety and New Evaluation of Safety) project was started in 1991. The goal of the project was to evaluate to what extent Paks NPP satisfied the current international safety expectations and to help in determining the priorities for safety enhancement and upgrading measures. The project completed in 1994 ranked our safety upgrading measures by safety significance, which became a basis for technical design work and financial scheduling. The other important outcome of the AGNES project was the introduction the Periodical Safety Review regime by our nuclear authority. These periodical reviews held after 10 years of operation offer the possibility - and obligation for the licensee - to perform a comprehensive assessment of the safety of the plant, to evaluate the integral effects of changes of circumstances happened during the review period. The goal of these reviews is to deal with cumulative effects of NPP ageing, modifications, operating experience and technical developments aimed at ensuring a high level of safety throughout plant service life. The execution of our safety-upgrading program is well advancing. For the whole program from 1996 to 2002 250

Kozloduy nuclear power plant. Units 1-4. Status of safety improvements. Rev. 2

International Nuclear Information System (INIS)

1999-01-01

operation of the units. The plant current safety level analysis has been performed using IAEA analytical methodology according to 50-SG-O12 standard 'Periodic safety review of operational nuclear power plants'. The approach and criteria for acceptable safety level definition, developed by IAEA and presented in INSAG-8 ' was used for analysis performance. Based on this analysis a set of activities was developed, to ensures further plant operation with the necessary safety level. The measures were combined in a program called Complex program for modernization of units 1-4. The implementation of the program is foreseen for a period of four next fuel cycles and started at the beginning of 1998. In respond to the requirements for the content of this paper a detailed description of the current status of resolving of the safety issues, classified by IAEA in TECDOC 640 is presented. The whole process of safety evaluation, short and long term safety improvements presents in a systematical manner the efforts of the Government of Bulgaria, NEK Ltd and KNPP to operate these units with due respect of their nuclear safety responsibility according to Nuclear Safety Convention signed at Vienna in 1994 and ratified by Bulgarian Parliament in 1995

RATU - Nuclear power plant structural safety research programme

International Nuclear Information System (INIS)

Rintamaa, R.

1992-07-01

Studies on the structural materials in nuclear power plants create the experimental data and background information necessary for the structural integrity assessments of mechanical components. The research is carried out by developing experimental fracture mechanics methods including statistical analysis methods of materials property data, and by studying material ageing and, in particular, mechanisms of material deterioration due to neutron irradiation, corrosion and water chemistry. Besides material studies, new testing methods and sensors for measurement of loading and water chemistry parameters have been developed. The monitoring data obtained in real power plants has been used to simulate more precisely the real environment during laboratory tests. The research on structural analysis has focused on extending and verifying the analysis capabilities for structural assessments of nuclear power plants. A widely applicable system including various computational fracture assessment methods has been created with which different structural problems can be solved reliably and effectively. Research on reliability assessment of maintenance in nuclear power plants is directed to practical case studies on components and structures of safety importance, and to the development of models for maintenance related decision support. A systematic analysis of motor-operated valve has been performed

Periodic Safety Review of Nuclear Power Plants: Experience of Member States

International Nuclear Information System (INIS)

2010-04-01

Routine reviews of nuclear power plant operation (including modifications to hardware and procedures, operating experience, plant management and personnel competence) and special reviews following major events of safety significance are the primary means of safety verification. In addition, many Member States of the IAEA have initiated systematic safety reassessments, termed periodic safety reviews, of nuclear power plants, to assess the cumulative effects of plant ageing and plant modifications, operating experience, technical developments and siting aspects. The reviews include an assessment of plant design and operation against current safety standards and practices, and they have the objective of ensuring a high level of safety throughout the plant's operating lifetime. They are complementary to the routine and special safety reviews and do not replace them. Periodic safety reviews of nuclear power plants are considered an effective way to obtain an overall view of actual plant safety, and to determine reasonable and practical modifications that should be made in order to maintain a high level of safety. They can be used as a means of identifying time limiting features of the plant in order to determine nuclear power plant operation beyond the designed lifetime. The periodic safety review process can be used to support the decision making process for long term operation or licence renewal. Since 1994, the use of periodic safety reviews by Member States has substantially broadened and confirmed its benefits. Periodic safety review results have, for example, been used by some Member States to help provide a basis for continued operation beyond the current licence term, to communicate more effectively with stakeholders regarding nuclear power plant safety, and to help identify changes to plant operation that enhance safety. This IAEA-TECDOC is intended to assist Member States in the implementation of a periodic safety review. This publication complements the

Improving plant state information for better operational safety

International Nuclear Information System (INIS)

Girard, C.; Olivier, E.; Grimaldi, X.

1994-01-01

Nuclear Power Plant (NPP) safety is strongly dependent on components' reliability and particularly on plant state information reliability. This information, used by the plant operators in order to produce appropriate actions, have to be of a high degree of confidence, especially in accidental conditions where safety is threatened. In this perspective, FRAMATOME, EDF and CEA have started a joint research program to prospect different solutions aiming at a better reliability for critical information needed to safety operate the plant. This paper gives the main results of this program and describes the developments that have been made in order to assess reliability of different information systems used in a Nuclear Power Plant. (Author)

Complex nuclear safety evaluation of the Bohunice V-1 nuclear power plant

International Nuclear Information System (INIS)

Kriz, Z.

1991-01-01

The safety concept of V-230 type reactor units dates back to the late 1960s. The units fail to be sufficiently dimensioned for emergency cooling of the reactor core and are fitted with no containment. So far, operating experience is good. The availability factor is 71.5% for unit 1 and 77.8% for unit 2. There occur 1 to 3 unscheduled shutdowns annually. The quality of steam generator tubes is very good. A complex safety assessment of the plant was accomplished in 1990. It concerned the concept and criteria of safety assessment, the earthquake situation, the condition of the primary coolant circuit equipment, the control system, the effect of the human factor, and preparedness of emergency plans. OSART and ASSET missions were accomplished at the plant. Based on the results of the missions as well as of inspections by the State Surveillance over Nuclear Safety, the decision has been adopted to operate the plant not longer than till 1995; the further fate of the plant will be decided on according to a future technical and economic analysis. (M.D.)

Safety aspects of nuclear power plant ageing

International Nuclear Information System (INIS)

1990-01-01

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

The critical safety functions and plant operation

International Nuclear Information System (INIS)

Corcoran, W.R.; Church, J.F.; Porter, N.J.; Cross, M.T.; Guinn, W.M.

1981-01-01

The paper outlines the operator's role in nuclear safety and introduces the concept of ''safety functions''. Safety functions are a group of actions that prevent core melt or minimize radiation releases to the general public. They can be used to provide a hierarchy of practical plant protection that an operator should use. ''An accident identical to that at Three Mile Island is not going to happen again'', said the Rogovin investigators. The concepts put forward in this paper are intended to help the operator avoid serious consequence from the next unexpected threat. On the basis of the safety evaluation, the operator has three roles in assuring that the consequences of an event will be no worse than the predicted acceptable results. These three operator roles are: first, maintain plant setup in readiness to properly respond; second, operate the plant in a manner such that fewer, milder events minimize the frequency and the severity of adverse events; third, the operator needs to monitor the plant to verify that the safety functions are accomplished. The operator needs a systematic approach to mitigating the consequences of an event. The concept of ''safety function'' introduces that systematic approach and prevents a hierarchy of protection. If the operator has difficulty in identifying an event for any reason, the systematic safety function approach allows ones to accomplish the overall path of mitigating consequences. There are ten identified functions designed to protect against core melt, preserve containment integrity, prevent indirect release of radioactivity, and maintain vital auxiliaries needed to support the other safety functions. The paper describes in detail the operator's role and the safety functions, and provides many examples of the use of alternative success paths to accomplish the safety function

PGDP [Paducah Gaseous Diffusion Plant]-UF6 handling, sampling, analysis and associated QC/QA and safety related procedures

International Nuclear Information System (INIS)

Harris, R.L.

1987-01-01

This document is a compilation of Paducah Gaseous Diffusion Plant procedures on UF 6 handling, sampling, and analysis, along with associated QC/QA and safety related procedures. It was assembled for transmission by the US Department of Energy to the Korean Advanced Energy Institute as a part of the US-Korea technical exchange program

Assessing nuclear power plant safety and recovery from earthquakes using a system-of-systems approach

International Nuclear Information System (INIS)

Ferrario, E.; Zio, E.

2014-01-01

We adopt a ‘system-of-systems’ framework of analysis, previously presented by the authors, to include the interdependent infrastructures which support a critical plant in the study of its safety with respect to the occurrence of an earthquake. We extend the framework to consider the recovery of the system of systems in which the plant is embedded. As a test system, we consider the impacts produced on a nuclear power plant (the critical plant) embedded in the connected power and water distribution, and transportation networks which support its operation. The Seismic Probabilistic Risk Assessment of such system of systems is carried out by Hierarchical modeling and Monte Carlo simulation. First, we perform a top-down analysis through a hierarchical model to identify the elements that at each level have most influence in restoring safety, adopting the criticality importance measure as a quantitative indicator. Then, we evaluate by Monte Carlo simulation the probability that the nuclear power plant enters in an unsafe state and the time needed to recover its safety. The results obtained allow the identification of those elements most critical for the safety and recovery of the nuclear power plant; this is relevant for determining improvements of their structural/functional responses and supporting the decision-making process on safety critical-issues. On the test system considered, under the given assumptions, the components of the external and internal water systems (i.e., pumps and pool) turn out to be the most critical for the safety and recovery of the plant. - Highlights: • We adopt a system-of-system framework to analyze the safety of a critical plant exposed to risk from external events, considering also the interdependent infrastructures that support the plant. • We develop a hierarchical modeling framework to represent the system of systems, accounting also for its recovery. • Monte Carlo simulation is used for the quantitative evaluation of the

Engineered safeguards and passive safety features (safety analysis detailed report no. 6)

Energy Technology Data Exchange (ETDEWEB)

1988-01-15

The Safety-Analysis Summary lists the reactor's safety aspects for passive and active prevention of severe accidents and mitigation of accident consequences, i.e., intrinsic and passive protections of the plant; intrinsic and passive protections of the core; inherent decay-heat removal systems; rapid-shutdown systems; four physical containment barriers. This report goes into further details regarding some of this aspects.

Safety of Nuclear Power Plants: Design. Specific Safety Requirements (Russian Edition); Bezopasnost' atomnykh ehlektrostantsij: proektirovanie. Konkretnye trebovaniya bezopasnosti

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-04-15

This publication is a revision of Safety Requirements No. NS-R-1, Safety of Nuclear Power Plants: Design. It establishes requirements applicable to the design of nuclear power plants and elaborates on the safety objective, safety principles and concepts that provide the basis for deriving the safety requirements that must be met for the design of a nuclear power plant. It will be useful for organizations involved in the design, manufacture, construction, modification, maintenance, operation and decommissioning of nuclear power plants, as well as for regulatory bodies. Contents: 1. Introduction; 2. Applying the safety principles and concepts; 3. Management of safety in design; 4. Principal technical requirements; 5. General plant design; 6. Design of specific plant systems.

Analysis of reactor trips involving balance-of-plant failures

International Nuclear Information System (INIS)

Seth, S.; Skinner, L.; Ettlinger, L.; Lay, R.

1986-01-01

The relatively high frequency of plant transients leading to reactor trips at nuclear power plants in the US is of economic and safety concern to the industry. A majority of such transients is due to failures in the balance-of-plant (BOP) systems. As a part of a study conducted for the US Nuclear Regulatory Commission, Mitre has carried out a further analysis of the BOP failures associated with reactor trips. The major objectives of the analysis were to examine plant-to-plant variations in BOP-related trips, to understand the causes of failures, and to determine the extent of any associated safety system challenges. The analysis was based on the Licensee Event Reports submitted on all commercial light water reactors during the 2-yr period, 1984-1985

Safety Assessment for Inertial Fusion Energy Power Plants: Methodology and Application to the Analysis of the HYLIFE-II and SOMBRERO Conceptual Designs

Science.gov (United States)

Reyes, S.; Latkowski, J. F.; Sanz, J.; Gomez del Rio, J.

2001-06-01

Although the safety and environmental (S & E) characteristics of fusion energy have long been emphasized, these benefits are not automatically achieved. To maximize the potential S & E attractiveness of the inertial fusion energy (IFE), analyses must be performed early in the designs so that lessons can be learned and intelligent decisions made. In this work we have introduced for the first time heat transfer and thermal-hydraulics calculations as part of a state-of-the-art set of codes and libraries in order to establish an updated methodology for IFE safety analysis. We have focused our efforts primarily on two IFE power plant conceptual designs: HYLIFE-II and SOMBRERO. To some degree, these designs represent the extremes in IFE power plant designs. Also, a preliminary safety assessment has been performed for a generic target fabrication facility producing various types of targets and using various production techniques. Although this study cannot address all issues and hazards posed by an IFE power plant, it advances our understanding of radiological safety of such facilities. This will enable better comparisons between IFE designs and competing technologies from the safety point of view.

Software safety hazard analysis

International Nuclear Information System (INIS)

Lawrence, J.D.

1996-02-01

Techniques for analyzing the safety and reliability of analog-based electronic protection systems that serve to mitigate hazards in process control systems have been developed over many years, and are reasonably well understood. An example is the protection system in a nuclear power plant. The extension of these techniques to systems which include digital computers is not well developed, and there is little consensus among software engineering experts and safety experts on how to analyze such systems. One possible technique is to extend hazard analysis to include digital computer-based systems. Software is frequently overlooked during system hazard analyses, but this is unacceptable when the software is in control of a potentially hazardous operation. In such cases, hazard analysis should be extended to fully cover the software. A method for performing software hazard analysis is proposed in this paper

Problems of nuclear power plant safety evaluation

International Nuclear Information System (INIS)

Suchomel, J.

1977-01-01

Nuclear power plant safety is discussed with regard to external effects on the containment and to the human factor. As for external effects, attention is focused on shock waves which may be due to explosions or accidents in flammable material transport and storage, to missiles, and to earthquake effects. The criteria for evaluating nuclear power plant safety in different countries are shown. Factors are discussed affecting the reliability of man with regard to his behaviour in a loss-of-coolant accident in the power plant. Different types of PWR containments and their functions are analyzed, mainly in case of accident. Views are discussed on the role of destructive accidents in the overall evaluation of fast reactor safety. Experiences are summed up gained with the operation of WWER reactors with respect to the environmental impact of the nuclear power plants. (Z.M.)

IAEA Operational Safety Team Reviews Cattenom Nuclear Power Plant

International Nuclear Information System (INIS)

2011-01-01

, transport and storage of the source; Redundant and diversified telecommunication means are deployed in the various on-site emergency response facilities; and In the event of a severe accident, the support which can be provided to plant staff through a wide range of expertise and analytical tools is commendable. The team has made recommendations and suggestions related to areas where operational safety of Cattenom NPP could be improved. Examples include: Ensuring that all management information, directives and expectations are clearly communicated to all staff and fully implemented; Enhancing the organization of the training programme in the areas of assessment, objectives and competencies; Improving the control of the plant surveillance test programme regarding scheduling and acceptance criteria; and Improving the effectiveness of the plant's Root Cause Analysis process. Cattenom management expressed a determination to address all the areas identified for improvement and requested the IAEA to schedule a follow-up mission in approximately 18 months' time. The team handed over a draft of their recommendations, suggestions and good practices to the plant management in the form of ''Technical Notes'' for factual comments. The technical notes will be reviewed at IAEA headquarters including any comments from Cattenom NPP and the French Safety Authority (ASN). The final report will be submitted to the Government of France within three months. This was the 166th mission of the OSART programme, which began in 1982, and the 23rd such mission in France. General information about OSART missions can be found on the IAEA website OSART Missions. Background An OSART mission is designed as a review of programmes and activities essential to operational safety. It is not a regulatory inspection, nor is it a design review or a substitute for an exhaustive assessment of the plant's overall safety status. Experts participating in the IAEA's June 2010 International Conference on Operational

Probabilistic safety analysis procedures guide

International Nuclear Information System (INIS)

Papazoglou, I.A.; Bari, R.A.; Buslik, A.J.

1984-01-01

A procedures guide for the performance of probabilistic safety assessment has been prepared for interim use in the Nuclear Regulatory Commission programs. The probabilistic safety assessment studies performed are intended to produce probabilistic predictive models that can be used and extended by the utilities and by NRC to sharpen the focus of inquiries into a range of tissues affecting reactor safety. This guide addresses the determination of the probability (per year) of core damage resulting from accident initiators internal to the plant and from loss of offsite electric power. The scope includes analyses of problem-solving (cognitive) human errors, a determination of importance of the various core damage accident sequences, and an explicit treatment and display of uncertainties for the key accident sequences. Ultimately, the guide will be augmented to include the plant-specific analysis of in-plant processes (i.e., containment performance) and the risk associated with external accident initiators, as consensus is developed regarding suitable methodologies in these areas. This guide provides the structure of a probabilistic safety study to be performed, and indicates what products of the study are essential for regulatory decision making. Methodology is treated in the guide only to the extent necessary to indicate the range of methods which is acceptable; ample reference is given to alternative methodologies which may be utilized in the performance of the study

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

Software safety analysis practice in installation phase

Energy Technology Data Exchange (ETDEWEB)

Huang, H. W.; Chen, M. H.; Shyu, S. S., E-mail: hwhwang@iner.gov.t [Institute of Nuclear Energy Research, No. 1000 Wenhua Road, Chiaan Village, Longtan Township, 32546 Taoyuan County, Taiwan (China)

2010-10-15

This work performed a software safety analysis in the installation phase of the Lung men nuclear power plant in Taiwan, under the cooperation of Institute of Nuclear Energy Research and Tpc. The US Nuclear Regulatory Commission requests licensee to perform software safety analysis and software verification and validation in each phase of software development life cycle with Branch Technical Position 7-14. In this work, 37 safety grade digital instrumentation and control systems were analyzed by failure mode and effects analysis, which is suggested by IEEE standard 7-4.3.2-2003. During the installation phase, skew tests for safety grade network and point to point tests were performed. The failure mode and effects analysis showed all the single failure modes can be resolved by the redundant means. Most of the common mode failures can be resolved by operator manual actions. (Author)

Software safety analysis practice in installation phase

International Nuclear Information System (INIS)

Huang, H. W.; Chen, M. H.; Shyu, S. S.

2010-10-01

This work performed a software safety analysis in the installation phase of the Lung men nuclear power plant in Taiwan, under the cooperation of Institute of Nuclear Energy Research and Tpc. The US Nuclear Regulatory Commission requests licensee to perform software safety analysis and software verification and validation in each phase of software development life cycle with Branch Technical Position 7-14. In this work, 37 safety grade digital instrumentation and control systems were analyzed by failure mode and effects analysis, which is suggested by IEEE standard 7-4.3.2-2003. During the installation phase, skew tests for safety grade network and point to point tests were performed. The failure mode and effects analysis showed all the single failure modes can be resolved by the redundant means. Most of the common mode failures can be resolved by operator manual actions. (Author)

Utilization of the MCNP-3A code for criticality safety analysis

International Nuclear Information System (INIS)

Maragni, M.G.; Moreira, J.M.L.

1996-01-01

In the last decade, Brazil started to operate facilities for processing and storing uranium in different forms. The necessity of criticality safety analysis appeared in the design phase of the uranium pilot process plants and also in the licensing of transportation and storage of fissile materials. The 2-MW research reactor and the Angra I power plant also required criticality safety assessments because their spent-fuel storage was approaching full-capacity utilization. The criticality safety analysis in Brazil has been based on KENO IV code calculations, which present some difficulties for correct geometry representation. The MCNP-3A code is not reported to be used frequently for criticality safety analysis in Brazil, but its good geometry representation makes it a possible tool for treating problems of complex geometry. A set of benchmark tests was performed to verify its applicability for criticality safety analysis in Brazil. This paper presents several benchmark tests aimed at selecting a set of options available in the MCNP-3A code that would be adequate for criticality safety analysis. The MCNP-3A code is also compared with the KENO-IV code regarding its performance for criticality safety analysis

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

International Nuclear Information System (INIS)

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

2003-04-01

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

Correct safety requirements during the life cycle of heating plants; Korrekta saekerhetskrav under vaermeanlaeggningars livscykel

Energy Technology Data Exchange (ETDEWEB)

Tegehall, Jan; Hedberg, Johan [Swedish National Testing and Research Inst., Boraas (Sweden)

2006-10-15

The safety of old steam boilers or hot water generators is in principle based on electromechanical components which are generally easy to understand. The use of safety-PLC is a new and flexible way to design a safe system. A programmable system offers more degrees of freedom and consequently new problems may arise. As a result, new standards which use the Safety Integrity Level (SIL) concept for the level of safety have been elaborated. The goal is to define a way of working to handle requirements on safety in control systems of heat and power plants. SIL-requirements are relatively new within the domain and there is a need for guidance to be able to follow the requirements. The target of this report is the people who work with safety questions during new construction, reconstruction, or modification of furnace plants. In the work, the Pressure Equipment Directive, 97/23/EC, as well as standards which use the SIL concept have been studied. Additionally, standards for water-tube boilers have been studied. The focus has been on the safety systems (safety functions) which are used in water-tube boilers for heat and power plants; other systems, which are parts of these boilers, have not been considered. Guidance has been given for the aforementioned standards as well as safety requirements specification and risk analysis. An old hot water generator and a relatively new steam boiler have been used as case studies. The design principles and safety functions of the furnaces have been described. During the risk analysis important hazards were identified. A method for performing a risk analysis has been described and the appropriate content of a safety requirements specification has been defined. If a heat or power plant is constructed, modified, or reconstructed, a safety life cycle shall be followed. The purpose of the safety life cycle is to plan, describe, document, perform, check, test, and validate that everything is correctly done. The components of the safety

Status of safety analysis reports

Energy Technology Data Exchange (ETDEWEB)

Cserhati, A

1999-06-01

The safety regulation connected to both of the Atomic Acts from 1980 and 1996 requires preparation of the Preliminary Safety Analysis Report (PSAR) as well as Final SAR (FSAR). In this respect the licensing procedure for the construction and commissioning of Paks NPP did not formally deviate from the standards applied in developed countries; this is particularly true if comparison is made with the standards applied for commissioning NPPs in the second half of the seventies. By the time the overall development of internationally accepted safety standards and some existing deficiencies of earlier SAR made necessary a general reassessment of the plant safety (AGNES project). The carried out PSR for Paks-1 and 2 also added a valuable contribution to the SAR content, however a formal update of SAR is not made yet. A Hungarian nuclear authority decree from 1997 obligates the licensee to prepare and submit a major upgrade of FSAR until the mid of 2000, after finishing the PSR for Paks-3 and 4. From this date a periodic update of FSAR is required every year. The operational license renewal affects only the PSR but not the FSAR updating. The new Nuclear Safety Code outlines the contents of PSAR and FSAR, based on US NRC Reg. Guide 1. 70. Rev. 3. Hungary by now can fulfill the upgrading of SAR without major external technical or financial help. The AGNES project covered the safety analysis chapters of SAR. It was financed mainly by the country. In the project there have been involved in limited cases as performers the VTT (Finland), Belgatom (Belgium), GRS (Germany), etc., the IVO (Finland) fulfilled tasks of an independent reviewer for safety analysis. The AGNES had certain interconnection with the similar IAEA RER safety reassessment project for WWER-440/213. The PSR for Paks-1 and 2 have been carried out by the Paks staff from the resources of the plant. During the evaluation of several parts of Paks-3 and 4 PSR documentation the authority intends to use certain

Status of safety analysis reports

International Nuclear Information System (INIS)

Cserhati, A.

1999-01-01

The safety regulation connected to both of the Atomic Acts from 1980 and 1996 requires preparation of the Preliminary Safety Analysis Report (PSAR) as well as Final SAR (FSAR). In this respect the licensing procedure for the construction and commissioning of Paks NPP did not formally deviate from the standards applied in developed countries; this is particularly true if comparison is made with the standards applied for commissioning NPPs in the second half of the seventies. By the time the overall development of internationally accepted safety standards and some existing deficiencies of earlier SAR made necessary a general reassessment of the plant safety (AGNES project). The carried out PSR for Paks-1 and 2 also added a valuable contribution to the SAR content, however a formal update of SAR is not made yet. A Hungarian nuclear authority decree from 1997 obligates the licensee to prepare and submit a major upgrade of FSAR until the mid of 2000, after finishing the PSR for Paks-3 and 4. From this date a periodic update of FSAR is required every year. The operational license renewal affects only the PSR but not the FSAR updating. The new Nuclear Safety Code outlines the contents of PSAR and FSAR, based on US NRC Reg. Guide 1. 70. Rev. 3. Hungary by now can fulfill the upgrading of SAR without major external technical or financial help. The AGNES project covered the safety analysis chapters of SAR. It was financed mainly by the country. In the project there have been involved in limited cases as performers the VTT (Finland), Belgatom (Belgium), GRS (Germany), etc., the IVO (Finland) fulfilled tasks of an independent reviewer for safety analysis. The AGNES had certain interconnection with the similar IAEA RER safety reassessment project for WWER-440/213. The PSR for Paks-1 and 2 have been carried out by the Paks staff from the resources of the plant. During the evaluation of several parts of Paks-3 and 4 PSR documentation the authority intends to use certain

Different aspects of safety in Nuclear Fuel Plant at Pitesti, Romania

International Nuclear Information System (INIS)

Ivana, T.; Epure, Gh.

2009-01-01

Nuclear Fuel Plant (FCN) is a facility that produces fuel bundles of CANDU-6 type for the CANDU nuclear power plant. Only natural and depleted uranium in bulk and itemized form are present as nuclear materials in this facility. Uranium and wastes from the plant are handled, processed, treated and stored throughout the entire facility. The nuclear materials with natural and depleted uranium are entirely under nuclear safeguards. The amount of uranium present in the plant in different forms and activities together with zircaloy, beryllium and other hazardous substances, wastes, explosive materials at high temperatures, etc. lead to special measures undertaken by Nuclear Safety Department (DNS) to ensure nuclear safety. Different aspects of safety are continuously monitored in the plant: operational safety, industrial safety, radiological safety, labour safety, informational safety. The emergency preparedness and response, physical protection and the security of the plant and of the transportation of radioactive materials are contributing to cover the multitude of safety aspects. The safety culture of workers built directly on the safety components completes this activity in the plant. In addition the aspects of safety, security and safeguards are in permanent synergy, parts of the three components being included in each other. In the future the policy of FCN will be focused so that any improvement of one of the safety components will be reflected in improving the other safety aspects. (authors)

The German nuclear power plant safety study

International Nuclear Information System (INIS)

1979-01-01

With this study a new approach has been chosen, taking nuclear power plants as an example to assess and to describe the risks arising from the use of modern technology, including those hazards emanating from the rather hypothetical possibility of occurrence of very serious accidents. Following the definition of basic concepts and methods to be applied in risk assessment studied, as well as a brief account of the design and operating mode of nuclear power plants with PWRs', accidents and failures to be considered in a safety study are described. Using the course-of-event and fault tree analysis, the probability of fission product release as a consequence of failures in safety systems or of core meltdown is evaluated. Subsequently, the theoretical model for assessment of reactor accident consequences is presented, discussing such aspects as the dispersion of radioactivity in the atmosphere, the radiation dose model, safety and countermeasures, the model for the evaluation of health hazards as well as methods and calculations for estimating the reliability of risk assessments together with the remaining uncertainties. In an appendix to this study, the analyses presented in the study are discussed in the light of the TMI-2 event. This safety study showing the possibilities of detecting, keeping in check and minimizing harmful effects, can be regarded as a contribution to a better understanding of our modern, highly industrialised society, and eventually to an improvement of the quality of life. (GL) 891 GL/GL 892 MB [de

Safety aspects of a fuel reprocessing plant

International Nuclear Information System (INIS)

Donoghue, J.K.; Charlesworth, F.R.; Fairbairn, A.

1977-01-01

The establishment of the basic process must include the determination of the sensitivity of the process to operational errors or plant failures. The probability, and consequences of escapes of activity must be evaluated and emergency procedures set up to deal with accidents which might lead to such escapes. The administrative arrangements for safety should include a safety evaluation and advisory service independent of line management. A quality assurance strategy for the construction and commissioning stages is important. The design and construction of the plant must include: (i) Attention to plant reliability. Maintenance and inspection procedures to maintain reliability must be adopted and the design should include measures to facilitate in-service inspection of highly-active plant. (ii) Suitable and sufficient means of detection and prevention of malfunction, including criticality, bearing in mind both the timescale of development of the fault and its consequences. (iii) Measures for containment of activity. Penetrations from active into operating areas should be eliminated or minimised and maintenance should be separated from operational areas. Secondary containment beyond that provided for operations of a significant magnitude. A ventilation system with appropriate gas clean-up, monitoring and discharge facilities is required. (iv) Adequate shielding, with particular attention paid to multiple activities in a single operational area which might lead to an operator being exposed to radiation from operations which are beyond his control. (v) Means of accounting for active materials and for their recovery, transfer and disposal in the event of a forced shut down. (vi) Suitable methods for segregation and control of wastes within the plant and for their discharge. Solid or liquid wastes should be subject to delay and monitoring procedures before release. Facilities for storage of waste must be subject to the same safety principles as the plant itself. (vii) Final

NPP Temelin safety analysis reports and PSA status

International Nuclear Information System (INIS)

Mlady, O.

1999-01-01

To enhance the safety level of Temelin NPP, recommendations of the international reviews were implemented into the design as well as into organization of the plant construction and preparation for operation. The safety assessment of these design changes has been integrated and reflected in the Safety Analysis Reports, which follow the internationally accepted guidelines. All safety analyses within Safety Analysis Reports were repeated carefully considering technical improvements and replacements to complement preliminary safety documentation. These analyses were performed by advanced western computer codes to the depth and in the structure required by western standards. The Temelin NPP followed a systematic approach in the functional design of the Reactor Protection System and related safety analyses. Modifications of reactor protection system increase defense in depth and facilitate demonstrating that LOCA and radiological limits are met for non-LOCA events. The rigorous safety analysis methodology provides assurance that LOCA and radiological limits are met. Established and accepted safety analysis methodology and accepted criteria were applied to Temelin NPP meeting US NRC and Czech Republic requirements. IAEA guidelines and recommendations

Status of SPACE Safety Analysis Code Development

International Nuclear Information System (INIS)

Lee, Dong Hyuk; Yang, Chang Keun; Kim, Se Yun; Ha, Sang Jun

2009-01-01

In 2006, the Korean the Korean nuclear industry started developing a thermal-hydraulic analysis code for safety analysis of PWR(Pressurized Water Reactor). The new code is named as SPACE(Safety and Performance Analysis Code for Nuclear Power Plant). The SPACE code can solve two-fluid, three-field governing equations in one dimensional or three dimensional geometry. The SPACE code has many component models required for modeling a PWR, such as reactor coolant pump, safety injection tank, etc. The programming language used in the new code is C++, for new generation of engineers who are more comfortable with C/C++ than old FORTRAN language. This paper describes general characteristics of SPACE code and current status of SPACE code development

Code on the safety of nuclear power plants: Design

International Nuclear Information System (INIS)

1988-01-01

This Code is a compilation of nuclear safety principles aimed at defining the essential requirements necessary to ensure nuclear safety. These requirements are applicable to structures, systems and components, and procedures important to safety in nuclear power plants embodying thermal neutron reactors, with emphasis on what safety requirements shall be met rather than on specifying how these requirements can be met. It forms part of the Agency's programme for establishing Codes and Safety Guides relating to land based stationary thermal neutron power plants. The document should be used by organizations designing, manufacturing, constructing and operating nuclear power plants as well as by regulatory bodies

Reviewing industrial safety in nuclear power plants

International Nuclear Information System (INIS)

1990-02-01

This document contains guidance and reference materials for Operational Safety Review Team (OSART) experts, in addition to the OSART Guidelines (TECDOC-449), for use in the review of industrial safety activities at nuclear power plants. It sets out objectives for an excellent industrial safety programme, and suggests investigations which should be made in evaluating industrial safety programmes. The attributes of an excellent industrial safety programme are listed as examples for comparison. Practical hints for reviewing industrial safety are discussed, so that the necessary information can be obtained effectively through a review of documents and records, discussions with counterparts, and field observations. There are several annexes. These deal with major features of industrial safety programmes such as safety committees, reporting and investigation systems and first aid and medical facilities. They include some examples which are considered commendable. The document should be taken into account not only when reviewing management, organization and administration but also in the review of related areas, such as maintenance and operations, so that all aspects of industrial safety in an operating nuclear power plant are covered

Transient analysis for Laguna Verde nuclear power plant

International Nuclear Information System (INIS)

Ramos Pablos, J.C. et.al.

1991-01-01

Relationship between transients analysis and safety of Laguna Verde nuclear power plant is described a general panorama of safety thermal limits of a nuclear station, as well as transients classification and events simulation codes are exposed. Activities of a group of transients analysis of electrical research institute are also mentioned (Author)

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

International Nuclear Information System (INIS)

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

1989-10-01

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

46. The goals of safety engineering department of the plant

International Nuclear Information System (INIS)

Ivanov, A.V.

1993-01-01

The goals of safety engineering department of the plant, including elaboration of instructions on safety engineering on all specialities, safety engineering training of all labours working on the plant and control for abidance by the instructions on safety engineering were discussed.

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

International Nuclear Information System (INIS)

Volkanovski, Andrija

2015-01-01

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

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Software for computer based systems important to safety in nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2000-01-01

Computer based systems are of increasing importance to safety in nuclear power plants as their use in both new and older plants is rapidly increasing. They are used both in safety related applications, such as some functions of the process control and monitoring systems, as well as in safety critical applications, such as reactor protection or actuation of safety features. The dependability of computer based systems important to safety is therefore of prime interest and should be ensured. With current technology, it is possible in principle to develop computer based instrumentation and control systems for systems important to safety that have the potential for improving the level of safety and reliability with sufficient dependability. However, their dependability can be predicted and demonstrated only if a systematic, fully documented and reviewable engineering process is followed. Although a number of national and international standards dealing with quality assurance for computer based systems important to safety have been or are being prepared, internationally agreed criteria for demonstrating the safety of such systems are not generally available. It is recognized that there may be other ways of providing the necessary safety demonstration than those recommended here. The basic requirements for the design of safety systems for nuclear power plants are provided in the Requirements for Design issued in the IAEA Safety Standards Series.The IAEA has issued a Technical Report to assist Member States in ensuring that computer based systems important to safety in nuclear power plants are safe and properly licensed. The report provides information on current software engineering practices and, together with relevant standards, forms a technical basis for this Safety Guide. The objective of this Safety Guide is to provide guidance on the collection of evidence and preparation of documentation to be used in the safety demonstration for the software for computer based

Planning and evaluation of plant under safety aspects

International Nuclear Information System (INIS)

Strnad, H.

1985-01-01

Plant denotes a technical product characterized as being structured, complex, comprising the use of energy, and that of measuring, automatic control and monitoring systems to keep track of present, control and monitor processes. Particular attention is paid to methods of developing plant concepts, measures to exclude or detect risks, integration of safety engineering into the course of planning, safety concept and ergonomics in plant design. (DG) [de

Plant safety review from mass criticality accident

International Nuclear Information System (INIS)

Susanto, B.G.

2000-01-01

The review has been done to understand the resent status of the plant in facing postulated mass criticality accident. From the design concept of the plant all the components in the system including functional groups have been designed based on favorable mass/geometry safety principle. The criticality safety for each component is guaranteed because all the dimensions relevant to criticality of the components are smaller than dimensions of 'favorable mass/geometry'. The procedures covering all aspects affecting quality including the safety related are developed and adhered to at all times. Staff are indoctrinated periodically in short training session to warn the important of the safety in process of production. The plant is fully equipped with 6 (six) criticality detectors in strategic places to alert employees whenever the postulated mass criticality accident occur. In the event of Nuclear Emergency Preparedness, PT BATAN TEKNOLOGI has also proposed the organization structure how promptly to report the crisis to Nuclear Energy Control Board (BAPETEN) Indonesia. (author)

Safety and security aspects in design of digital safety I and C in nuclear power plants

International Nuclear Information System (INIS)

Ding, Yongjian; Waedt, Karl

2016-01-01

The paper describes a safety objective oriented systematic design approach of digital (computerized) safety I and C in modern nuclear power plants which considers the plant safety requirements as well as cybersecurity needs. The defence in depth philosophy is applied by using different defence lines in the I and C architecture and protection zones in the plant IT environment.

Safety and security aspects in design of digital safety I and C in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Ding, Yongjian [University of Applied Sciences Magdeburg-Stendal, Magdeburg (Germany). Inst. of Electrical Engineering; Waedt, Karl [Areva GmbH, Erlangen (Germany). PEAS-G

2016-05-15

The paper describes a safety objective oriented systematic design approach of digital (computerized) safety I and C in modern nuclear power plants which considers the plant safety requirements as well as cybersecurity needs. The defence in depth philosophy is applied by using different defence lines in the I and C architecture and protection zones in the plant IT environment.

Probabilistic safety analysis : a new nuclear power plants licensing method

International Nuclear Information System (INIS)

Oliveira, L.F.S. de.

1982-04-01

After a brief retrospect of the application of Probabilistic Safety Analysis in the nuclear field, the basic differences between the deterministic licensing method, currently in use, and the probabilistic method are explained. Next, the two main proposals (by the AIF and the ACRS) concerning the establishment of the so-called quantitative safety goals (or simply 'safety goals') are separately presented and afterwards compared in their most fundamental aspects. Finally, some recent applications and future possibilities are discussed. (Author) [pt

Standard Review Plan for the review of safety analysis reports for nuclear power plants, Revision No. 7 to Section 9

International Nuclear Information System (INIS)

1978-03-01

Revision No. 1 to Section 9 of the Standard Review Plan incorporates changes that have been developed since the original issuance in September 1975, many of which are editorial in nature, to reflect current staff practice in the review of safety analysis reports for nuclear power plants

Method of safety evaluation in nuclear power plants

International Nuclear Information System (INIS)

Kuraszkiewicz, P.; Zahn, P.

1988-01-01

A novel quantitative technique for evaluating safety of subsystems of nuclear power plants based on expert estimations is presented. It includes methods of mathematical psychology recognizing the effect of subjective factors in the expert estimates and, consequently, contributes to further objectification of evaluation. It may be applied to complementing probabilistic safety assessment. As a result of such evaluations a characteristic 'safety of nuclear power plants' is obtained. (author)

Evaluation of safety assessment methodologies in Rocky Flats Risk Assessment Guide (1985) and Building 707 Final Safety Analysis Report (1987)

International Nuclear Information System (INIS)

Walsh, B.; Fisher, C.; Zigler, G.; Clark, R.A.

1990-01-01

FSARs. Rockwell International, as operating contractor at the Rocky Flats plant, conducted a safety analysis program during the 1980s. That effort resulted in Final Safety Analysis Reports (FSARs) for several buildings, one of them being the Building 707 Final Safety Analysis Report, June 87 (707FSAR) and a Plant Safety Analysis Report. Rocky Flats Risk Assessment Guide, March 1985 (RFRAG85) documents the methodologies that were used for those FSARs. Resources available for preparation of those Rocky Flats FSARs were very limited. After addressing the more pressing safety issues, some of which are described below, the present contractor (EG ampersand G) intends to conduct a program of upgrading the FSARs. This report presents the results of a review of the methodologies described in RFRAG85 and 707FSAR and contains suggestions that might be incorporated into the methodology for the FSAR upgrade effort

Tools for plant safety engineer

International Nuclear Information System (INIS)

Fabic, S.

1996-01-01

This paper contains: - review of tools for monitoring plant safety equipment reliability and readiness, before and accident (performance indicators for monitoring the risk and reliability performance and for determining when degraded performance alert levels are achieved) - brief reviews of tools for use during an accident: Emergency Operating Procedures (EOPs), Emergency Response Data System (ERDS), Reactor Safety Assessment System (RSAS), Computerized Accident Management Support

Safety prediction technique for nuclear power plants

International Nuclear Information System (INIS)

Henry, C.D. III; Anderson, R.T.

1985-01-01

This paper presents a safety prediction technique (SPT) developed by Reliability Technology Associates (RTA) for nuclear power plants. It is based on a technique applied by RTA to assess the flight safety of US Air Force aircraft. The purpose of SPT is to provide a computerized technique for objective measurement of the effect on nuclear plant safety of component failure or procedural, software, or human error. A quantification is determined, called criticality, which is proportional to the probability that a given component or procedural-human action will cause the plant to operate in a hazardous mode. A hazardous mode is characterized by the fact that there has been a failure/error and the plant, its operating crew, and the public are exposed to danger. Whether the event results in an accident, an incident, or merely the exposure to danger is dependent on the skill and reaction of the operating crew as well as external influences. There are three major uses of SPT: (a) to predict unsafe situations so that corrective action can be taken before accidents occur, (b) to quantify the impact of equipment malfunction or procedural, software, or human error on safety and thereby establish priorities for proposed modifications, and (c) to provide a means of evaluating proposed changes for their impact on safety prior to implementation and to provide a method of tracking implemented changes

Implications of power uprates on safety margins of nuclear power plants. Report of a technical meeting

International Nuclear Information System (INIS)

2004-09-01

The safety of nuclear power plants (NPPs) is based on the defence in depth concept, which relies on successive physical barriers (fuel matrix, cladding, primary system pressure boundary and containment) and other provisions to control radioactive materials and on multiple levels of protection against damage to these barriers. Deterministic safety analysis is an important tool for conforming the adequacy and efficiency of provisions within the defence in depth concept and is used to predict the response of an NPP in predetermined operational states. This type of safety analysis applies a specific set of rules and specific acceptance criteria. Deterministic analysis is typically focused on neutronic, thermohydraulic, radiological and structural aspects, which are often analysed with different computational tools. The advanced computational tools developed for deterministic safety analysis are used for better establishment and utilization of licensing margins or safety margins in consideration of analysis results. At the same time, the existence of such margins ensures that NPPs operate safely in all modes of operation and at all times. To properly assess and address the existing margins and to be able to take advantage of unnecessary conservatisms, state of the art analytical tools intended for safety assessment have been developed. Progress made in the development and application of modern codes for safety analysis and better understanding of phenomena involved in plant design and operation enable the analysts to determine safety margins in consideration of analysis results (licensing margins) with higher precision. There is a general tendency for utilities to take advantage of unnecessarily large conservatisms in safety analyses and to utilize them for reactor power uprates, better utilization of nuclear fuel, higher operational flexibility and for justification of lifetime extension. The present publication sets forth the results of a Technical Meeting on the

Licensee responsibility for nuclear power plant safety

International Nuclear Information System (INIS)

Schneider, Horst

2010-01-01

Simple sentences easy to grasp are desirable in regulations and bans. However, in a legal system, their meaning must be unambiguous. Article 6, Paragraph 1 of the EURATOM Directive on a community framework for the nuclear safety of nuclear facilities of June 2009 states that 'responsibility for the nuclear safety of a nuclear facility is incumbent primarily on the licensee.' The draft 'Safety Criteria for Nuclear Power Plants, Revision D, April 2009' of the German Federal Ministry for the Environment, Nature Conservation, and Nuclear Safety (BMU) (A Module 1, 'Safety Criteria for Nuclear Power Plants: Basic Safety Criteria' / '0 Principles' Paragraph 2) reads: 'Responsibility for ensuring safety rests with the licensee. He shall give priority to compliance with the safety goal over the achievement of other operational objectives.' In addition, the existing rules and regulations, whose rank is equivalent to that of international regulations, assign priority to the safety goal to be pursued by the licensee over all other objectives of the company. The operator's responsibility for nuclear safety can be required and achieved only on the basis of permits granted, which must meet legal requirements. The operator's proximity to plant operation is the reason for his 'primary responsibility.' Consequently, verbatim incorporation of Article 6, Paragraph 1 of the EURATOM Directive would only be a superscript added to existing obligations of the operator - inclusive of a safety culture designed as an incentive to further 'the spirit of safety-related actions' - without any new legal contents and consequences. In the reasons of the regulation, this would have to be clarified in addition to the cryptic wording of 'responsibility.. primarily,' at the same time expressing that operators and authorities work together in a spirit of openness and trust. (orig.)

Safety criteria for design of nuclear power plants

International Nuclear Information System (INIS)

1997-01-01

In Finland the general safety requirements for nuclear power plants are presented in the Council of State Decision (395/91). In this guide, safety principles which supplement the Council of State Decision and which are to be used in the design of nuclear power plants are defined

Plant safety and performance indicators for regulatory use

International Nuclear Information System (INIS)

Ferjancic, M.; Nemec, T.; Cimesa, S.

2004-01-01

Slovenian Nuclear Safety Administration (SNSA) supervises nuclear and radiological safety of Krsko NPP. This SNSA supervision is performed through inspections, safety evaluations of plant modifications and event analyses as well as with the safety and performance indicators (SPI) which are a valuable data source for plant safety monitoring. In the past SNSA relied on the SPI provided by Krsko NPP and did not have a set of SPI which would be more appropriate for regulatory use. In 2003 SNSA started with preparation of a new set of SPI which would be more suitable for performing the regulatory oversight of the plant. New internal SNSA procedure which is under preparation will define use and evaluation of SPI and will include definitions for the proposed set of SPI. According to the evaluation of SPI values in comparison with the limiting values and/or trending, the procedure will define SNSA response and actions. (author)

Nuclear power plant systems, structures and components and their safety classification

International Nuclear Information System (INIS)

2000-01-01

The assurance of a nuclear power plant's safety is based on the reliable functioning of the plant as well as on its appropriate maintenance and operation. To ensure the reliability of operation, special attention shall be paid to the design, manufacturing, commissioning and operation of the plant and its components. To control these functions the nuclear power plant is divided into structural and functional entities, i.e. systems. A systems safety class is determined by its safety significance. Safety class specifies the procedures to be employed in plant design, construction, monitoring and operation. The classification document contains all documentation related to the classification of the nuclear power plant. The principles of safety classification and the procedures pertaining to the classification document are presented in this guide. In the Appendix of the guide, examples of systems most typical of each safety class are given to clarify the safety classification principles

IAEA Completes Safety Review at Czech Nuclear Power Plant

International Nuclear Information System (INIS)

2012-01-01

Full text: An international team of nuclear safety experts, led by the International Atomic Energy Agency (IAEA), today completed a review of safety practices at Temelin Nuclear Power Station in the Czech Republic. The team highlighted the Power Plant's good practices and also recommended improvements to some safety measures. At the request of the Government of the Czech Republic, the IAEA assembled a team of nuclear installation safety experts to send an Operational Safety Review Team (OSART) to the Power Plant, and the mission was conducted from 5 to 22 November 2012. The team was comprised of experts from Brazil, Hungary, Slovakia, South Africa, Sweden, Ukraine and the United Kingdom. An OSART mission is designed as a review of programmes and activities essential to operational safety. It is not a regulatory inspection, nor is it a design review or a substitute for an exhaustive assessment of the Plant's overall safety status. The team at Temelin conducted an in-depth review of the functions essential to the safe operation of the Power Plant, which are under the responsibility of the site's management. The review covered the areas of management, organization and administration; operations; maintenance; technical support; operating experience; radiation protection; chemistry; and severe accident management. The conclusions of the review are based on the IAEA's Safety Standards and proven good international practices. The OSART team has identified good plant practices, which will be shared with the rest of the nuclear industry for consideration of potential application elsewhere. Examples include the following: - The Power Plant has adopted effective computer software to improve the efficiency of the plant to prepare and isolate equipment for maintenance; - The Power Plant undertakes measures to control precisely the chemical parameters that limit corrosion in the reactor's coolant system, which in turn reduce radiation exposure to the workforce; and - The Temelin

Failure analysis and success analysis: roles in plant aging assessments

International Nuclear Information System (INIS)

Johnson, A.B. Jr.

1985-06-01

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

Safety culture of nuclear power plant

International Nuclear Information System (INIS)

Zheng Beixin

2008-01-01

This paper is a summary on the basis of DNMC safety culture training material for managerial personnel. It intends to explain the basic contents of safety, design, management, enterprise culture, safety culture of nuclear power plant and the relationship among them. It explains especially the constituent elements of safety culture system, the basic requirements for the three levels of commitments: policy level, management level and employee level. It also makes some analyses and judgments for some typical safety culture cases, for example, transparent culture and habitual violation of procedure. (authors)

ENSI's technical view on the periodic safety review 2008 of the nuclear power plant Goesgen

International Nuclear Information System (INIS)

2012-08-01

The owner of a license for a nuclear power plant operation in Switzerland has to undergo every 10 years a comprehensive safety check called 'periodic safety review' (PSR). The regulatory authority, the Swiss Federal Nuclear Safety Inspectorate (ENSI), reviews the documents supplied by the licensee. The Goesgen power plant (KKG) obtained its operation license and started operation in 1978. A first PSR was performed in the years 1996 to 1998 (PSR 1998) and reported. KKG delivered an analysis of the safety status, an evaluation of subsystems as well as test reports. The new PSR covers the period 1998 to 2007. The basis of the evaluation by ENSI is the new nuclear energy law in force since 1 February 2005. In comparison to PSR 1998, new aspects have to be considered like the description of the safety concept, including the technical safety classification of buildings, systems and components, or consideration of the protection objective 'limitation of the radiation exposure'. The PSR 2008 is focussed on the estimate of the nuclear safety of KKG. Basically, for the operation of a nuclear power plant, a sufficient protection has to be guaranteed against the release of radioactive materials to the environment as well as the irradiation of persons, during normal operation as well as in the case of accidents. The licensee of a nuclear power plant in operation must retrofit his plant according to the experience already gained and the state-of-the-art. The purpose of the PSR is to check the quality of the plant in the domain of safety. A probabilistic safety assessment (PSA) study must prove that the probability of damages to the reactor core is smaller than 10 -5 /year. In Switzerland the life time of a nuclear power plant is not limited by a fixed maximum time of operation. On the contrary, the limitation proceeds from safety criteria. Insufficiencies in the plant design are often recognized only through the evolution of the technique or some unexpected events. Ageing

Probabilistic analysis of safety in industrial irradiation plants; Analisis probabilistico de seguridad en plantas industriales de irradiacion

Energy Technology Data Exchange (ETDEWEB)

Alderete, F.; Elechosa, C. [Autoridad Regulatoria Nuclear, Av. del Libertador 8250 - Buenos Aires (Argentina)]. e-mail: falderet@sede.arn.gov.ar

2006-07-01

The Argentinean Nuclear Regulatory Authority is carrying out the Probabilistic Safety Analysis (PSA) of the two industrial irradiation plants existent in the country. The objective of this presentation is to show from the regulatory point of view, the advantages of applying this tool, as well as the appeared difficulties; for it will be made a brief description of the facilities, of the method and of the normative one. Both plants are multipurpose facilities classified as 'industrial irradiator category IV' (panoramic irradiator with source deposited in pool). Basically, the execution of an APS consists of the following stages: 1. Identification of initiating events. 2. Modeling of Accidental Sequences (Event Trees). 3. Analysis of Systems (Fault trees). 4. Quantification of Accidental Sequences. The argentine normative doesn't demand to these facilities the realization of an APS, however the basic standard of Radiological Safety establishes that in the design of this type of facilities in the cases that is justified, should make sure that the annual probability of occurrence of an accidental sequence and the resulting dose in a person gives as result an radiological risk inferior to the risk limit adopted as acceptance criteria. On the other hand the design standard specifies for these irradiators it demands a maximum fault rate of 10{sup -2} for the related components with the systems of radiological safety. In our case, the possible initiating events have been identified that carried out to not wanted situations (about people exposure, radioactive contamination). Then, for each one of the significant initiating events, the corresponding accidental sequences were modeled and the safety systems that intervene in this sequences by means of fault trees were analyzed, for then to determine the fault probabilities of the same ones. At the moment they are completing these fault trees, but the difficulty resides in the impossibility of obtaining real data

Plant functional modelling as a basis for assessing the impact of management on plant safety

International Nuclear Information System (INIS)

Rasmussen, Birgitte; Petersen, Kurt E.

1999-01-01

A major objective of the present work is to provide means for representing a chemical process plant as a socio-technical system, so as to allow hazard identification at a high level in order to identify major targets for safety development. The main phases of the methodology are: (1) preparation of a plant functional model where a set of plant functions describes coherently hardware, software, operations, work organization and other safety related aspects. The basic principle is that any aspect of the plant can be represented by an object based upon an Intent and associated with each Intent are Methods, by which the Intent is realized, and Constraints, which limit the Intent. (2) Plant level hazard identification based on keywords/checklists and the functional model. (3) Development of incident scenarios and selection of hazardous situation with different safety characteristics. (4) Evaluation of the impact of management on plant safety through interviews. (5) Identification of safety critical ways of action in the management system, i.e. identification of possible error- and violation-producing conditions

Standard Review Plan for the review of safety analysis reports for nuclear power plants: LWR edition

International Nuclear Information System (INIS)

1987-06-01

The Standard Review Plan (SRP) is prepared for the guidance of staff reviewers in the Office of Nuclear Reactor Regulation in performing safety reviews of applications to construct or operate nuclear power plants. The principal purpose of the SRP is to assure the quality and uniformity of staff reviews and to present a well-defined base from which to evaluate proposed changes in the scope and requirements of reviews. It is also a purpose of the SRP to make information about regulatory matters widely available and to improve communication and understanding of the staff review process by interested members of the public and the nuclear power industry. The safety review is primarily based on the information provided by an applicant in a Safety Analysis Report (SAR). The SAR must be sufficiently detailed to permit the staff to determine whether the plant can be built and operated without undue risk to the health and safety of the public. The SAR is the principal document in which the applicant provides the information needed to understand the basis upon which this conclusion has been reached. The individual SRP sections address, in detail, who performs the review, the matters that are reviewed, the basis for review, how the review is accomplished, and the conclusions that are sought. The safety review is performed by 25 primary branches. One of the objectives of the SRP is to assign the review responsibilities to the various branches and to define the sometimes complex interfaces between them. Each SRP section identifies the branch that has the primary review responsibility for that section. In some review areas the primary branch may require support, and the branches that are assigned these secondary review responsibilities are also identified for each SRP section

RISMC Advanced Safety Analysis Project Plan – FY 2015 - FY 2019

Energy Technology Data Exchange (ETDEWEB)

Szilard, Ronaldo H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Curtis L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Youngblood, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

In this report, a project plan is developed, focused on industry applications, using Risk-Informed Safety Margin Characterization (RISMC) tools and methods applied to realistic, relevant, and current interest issues to the operating nuclear fleet. RISMC focuses on modernization of nuclear power safety analysis (tools, methods and data); implementing state-of-the-art modeling techniques (which include, for example, enabling incorporation of more detailed physics as they become available); taking advantage of modern computing hardware; and combining probabilistic and mechanistic analyses to enable a risk informed safety analysis process. The modernized tools will maintain the current high level of safety in our nuclear power plant fleet, while providing an improved understanding of safety margins and the critical parameters that affect them. Thus, the set of tools will provide information to inform decisions on plant modifications, refurbishments, and surveillance programs, while improving economics. This set of tools will also benefit the design of new reactors, enhancing safety per unit cost of a nuclear plant. The proposed plan will focus on application of the RISMC toolkit, in particular, solving realistic problems of important current issues to the nuclear industry, in collaboration with plant owners and operators to demonstrate the usefulness of these tools in decision making.

Most significant preliminary results of the probabilistic safety analysis on the Juragua nuclear power plant; Resultados preliminares mas significativos del analysis probabilista de seguridad de la Central Nuclear de Juragua

Energy Technology Data Exchange (ETDEWEB)

Perdomo, Manuel [Instituto Superior de Ciencia y Tecnologia Nuclear (ISCTN), La Habana (Cuba)

1995-12-31

Since 1990 the Group for PSA Development and Applications (GDA/APS) is working on the Level-1 PSA for the Juragua-1 NPP, as a part of an IAEA Technical Assistance Project. The main objective of this study, which is still under way, is to assess, in a preliminary way, the Reactor design safety to find its potential `weak points` at the construction stage, using a eneric data base. At the same time, the study allows the PSA team to familiarize with the plant design and analysis techniques for the future operational PSA of the plant. This paper presents the most significant preliminary results of the study, which reveal some advantages of the safety characteristics of the plant design in comparison with the homologous VVER-440 reactors and some areas, where including slight modifications would improve the plant safety, considering the level of detail at which the study is carried out. (author). 13 refs, 1 fig, 2 tabs.

Strengthening of nuclear power plant construction safety management

International Nuclear Information System (INIS)

Yu Jun

2012-01-01

The article describes the warning of the Fukushima nuclear accident, and analyzes the major nuclear safety issues in nuclear power development in China, problems in nuclear power plants under construction, and how to strengthen supervision and management in nuclear power construction. It also points out that the development of nuclear power must attach great importance to the safety, and nuclear power plant construction should strictly implement the principle of 'safety first and quality first'. (author)

Probabilistic safety assessment in nuclear power plant management

International Nuclear Information System (INIS)

Holloway, N.J.

1989-06-01

Probabilistic Safety Assessment (PSA) techniques have been widely used over the past few years to assist in understanding how engineered systems respond to abnormal conditions, particularly during a severe accident. The use of PSAs in the design and operation of such systems thus contributes to the safety of nuclear power plants. Probabilistic safety assessments can be maintained to provide a continuous up-to-date assessment (Living PSA), supporting the management of plant operations and modifications

Safety Analysis Report for Ignalina NPP

International Nuclear Information System (INIS)

Negrivoda, G.

1997-01-01

In December 1994 an agreement was signed between the European Bank for Reconstruction and Development and the Republic of Lithuania for the grant of 32.86 MECU for the safety Improvement at Ignalina NPP. One of the conditions for the provision of the grant, was a requirement for an in-depth analysis of the safety level at Ignalina NPP in the scope and according to the standards acceptable for a western nuclear power plant, and to publish a Safety Analysis Report (SAR). The report should investigate and analyze any factor that could limit a safe operation of the plant, and provide recommendations for actual safety improvements. According to the agreement, Lithuania had to finalize the SAR until 31 December, 1995. The bank has also organized and financed investigation of safety at Ignalina NPP and preparation of the SAR. EBRD made an agreement with Sweden's Vattenfall, which subcontracted well-known companies from Canada, USA, Germany, etc., and also the Russian Research and Development Institute of Power Engineering (NIKIET), reactor designer of Ignalina NPP. The SAR is a very comprehensive document and contains about 8000 pages of text, diagrams and tables. The main findings of the SAR are provided in the article. A large number of discrepancies with modern rules and western practices was detected, but they were not proved to be serious enough to require reactors shutdown. Based on the recommendations of the SAR Ignalina NPP has worked out Safety Improvement Program No. 2 (SIP-2), which is planned for three years and will cost 486 MLT. (author)

Safety of industrial irradiation plants

International Nuclear Information System (INIS)

1992-01-01

Radiation is nowadays used in many applications in industry and medicine; accidental exposure, however, can have grave consequences as large doses of radiation occur in the 600 accelerator or gamma source plants in use around the world. This film explains the operation of irradiation plants and the safety procedures that must be followed to prevent accidents and to ensure safe use

Improving the safety of workers in the vicinity of mobile plant

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report investigates possible approaches and technologies to improve the safety of pedestrians around mobile plant. The study has considered mobile plant in underground mining, surface mineral extraction and warehousing and materials handling. It investigates vehicle ergonomics and visual task analysis, aids to improve reversing and sight lines, direct body detection techniques, conventional transponder (RFID) and VLF magnetic dipole detection technologies. 43 refs., 5 apps.

Views on safety culture at Swedish and Finnish nuclear power plants

International Nuclear Information System (INIS)

Hammar, L.; Wahlstroem, B.; Kettunen, J.

2000-02-01

The report presents the results of interviews about safety culture at Swedish and Finnish nuclear power plants. The aim is to promote the safety work and increase the debate about safety in nuclear power plants, by showing that the safety culture is an important safety factor. The interviews point out different threats, which may become real. It is therefor necessary that the safety aspects get support from of the society and the power plant owners. (EHS)

Study on European Nuclear Safety Practices during Planned Outages at Nuclear Power Plants

International Nuclear Information System (INIS)

2001-12-01

The present project was aimed at providing: a description of the current status of nuclear safety practices during planned outages at nuclear power plants followed in Europe; the criteria for the safety analysis of future reactors at the design stage; proposing a set of recommendations on good practices and criteria leading to the improvement of nuclear safety during those conditions. The work was organised in 3 phases: Collecting data on current practices; Analysis of questionnaire answers and drawing up of safety good practices references and recommendations; Collecting relevant ideas related to the future reactors at design stage (European Pressurised Water Reactor, European Passive Plant project, European Utilities Requirements and Utilities Requirement Document project). The key element of the performed work was the detailed questionnaire, based on bibliographical review, expert experience and outage practices available in the working team. Different safety areas and activities were covered: outage context; nuclear safety; outage strategy, organisation and control; operating feedback; use of Probabilistic Safety Assessment. The questionnaire was answered by 12 European nuclear power plants, representing 9 different European countries and three different types of reactors (Pressurised Water Reactor, Boiling Water Reactor and Water Water Energy Reactor). Conclusions were drawn under the following headers: Organisational survey and generalities Organisational effectiveness Quality of maintenance Quality of operation Engineering support, management of modification Specific aspects Each analysed subject includes the following topics: Questions background with a summary and the aim of the questions. Current status, that describes common practices, as derived from the answers to the questionnaire, and some examples of good specific practices. Identified good practices. (author)

The safety of future nuclear power plants in France

International Nuclear Information System (INIS)

Queniart, D.

1988-10-01

The present paper concerns certain personal thoughts on the safety of future French power plants, which will come into operation at the beginning of the next century. These reflections, which are made on the author's own behalf and, under no circumstances, implicate at this stage the official views of the French safety authorities, are aimed at defining some directions for the improvement of safety in these future plants as compared with that of plants presently in operation or under construction

Role of in-house safety analysis and research activities in regulatory decision making

International Nuclear Information System (INIS)

Pradhan, Santosh K.; Nagrale, Dhanesh B.; Gaikwad, Avinash J.

2015-01-01

Achievement of an acceptable level of nuclear safety is an essential requirement for the peaceful utilization of nuclear energy. The success of Global Nuclear Safety Regime is built upon a foundation of research. Such research has been sponsored by Governments and industry and has led to improved designs, safer and more reliable plant operation, and improvements in operating plant efficiency. A key element of this research has been the nuclear safety research performed or sponsored by regulatory organizations. In part, it has been the safety research performed or sponsored by regulatory organizations that has contributed to improved safety and has laid the foundation for activities such as risk-informed regulation, plant life extension, improved plant performance (e.g. power uprates) and new plant designs. The regulatory research program is meant to improve the regulatory authority’s knowledge where uncertainty exists, where safety margins are not well-characterized, and where regulatory decisions need to be confirmed in existing or new designs and technologies. The regulatory body get research initiated either in-house or by the licensee or through technical support organizations (TSOs). Research and analysis carried out within the regulatory body is of immense value in this context. This could be in the form of analysis of safety significant events, analysis of severe accidents, review of operating experience, independent checks of critical designs and even review of operator responses under different situations towards arriving at modifications to training programmes and licensing procedures for operating personnel. A latent benefit of regulatory research carried out by the regulators themselves is that it improves their technical competence considerably which in turn leads to high quality safety reviews and improved regulation in general. The aim of the present paper is to provide an overview of role of regulatory research and the in-house regulatory safety

Development of probabilistic methods for safety assessment of nuclear power plants

International Nuclear Information System (INIS)

Schott, H.; Berg, H.P.

1998-01-01

Since its introduction by the German Risk Study, Probabilistic Safety Assessment (PSA) has developed in Germany to a valuable tool in regulatory decision-making. Plant specific PSAs of Level 1+ are now conducted for all nuclear power plants in the frame of Periodic Safety Reviews. This paper is devoted to the description or key elements set out in the regulatory guidelines for PSA-Level 1+ and the corresponding technical documents and the further development of PSA methodology in the Federal Republic of Germany. In the course of the next years it is intended to make progress in the modeling of common cause failures, human reliability evaluation, reduction of uncertainties in PSA modeling techniques and data estimation, analysis of low power and shut down states as well as in reaching a mature methodology for inclusion of external events into the analysis. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2000-11-15

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

European passive plant program preliminary safety analyses to support system design

International Nuclear Information System (INIS)

Saiu, Gianfranco; Barucca, Luciana; King, K.J.

1999-01-01

In 1994, a group of European Utilities, together with Westinghouse and its Industrial Partner GENESI (an Italian consortium including ANSALDO and FIAT), initiated a program designated EPP (European Passive Plant) to evaluate Westinghouse Passive Nuclear Plant Technology for application in Europe. In the Phase 1 of the European Passive Plant Program which was completed in 1996, a 1000 MWe passive plant reference design (EP1000) was established which conforms to the European Utility Requirements (EUR) and is expected to meet the European Safety Authorities requirements. Phase 2 of the program was initiated in 1997 with the objective of developing the Nuclear Island design details and performing supporting analyses to start development of Safety Case Report (SCR) for submittal to European Licensing Authorities. The first part of Phase 2, 'Design Definition' phase (Phase 2A) was completed at the end of 1998, the main efforts being design definition of key systems and structures, development of the Nuclear Island layout, and performing preliminary safety analyses to support design efforts. Incorporation of the EUR has been a key design requirement for the EP1000 form the beginning of the program. Detailed design solutions to meet the EUR have been defined and the safety approach has also been developed based on the EUR guidelines. The present paper describes the EP1000 approach to safety analysis and, in particular, to the Design Extension Conditions that, according to the EUR, represent the preferred method for giving consideration to the Complex Sequences and Severe Accidents at the design stage without including them in the design bases conditions. Preliminary results of some DEC analyses and an overview of the probabilistic safety assessment (PSA) are also presented. (author)

Aspects of nuclear safety at power plants and fuel cycle plants in the USSR

International Nuclear Information System (INIS)

Kozlov, N.I.; Efimov, E.; Dubovskij, B.G.; Dikarev, V.; Lyubchenko, V.; Kruglov, A.K.

1977-01-01

The paper discusses the problems of organizing inspection monitoring of power plants including the development of some regulations and norms and the interaction between the USSR State Nuclear Safety Organization, scientific and designing organizations and power plants. The principles of computer use to work out advice for operational staff and warning signals and commands for the reactor control and protection system are discussed. Some attention is turned to the importance of using high-speed computers to calculate prompt reactivity values and to determine impurity concentrations in the coolant and margins to permissible operational limits. In particular, reactimeters are considered as signal generators in monitor and protection systems. Some problems of nuclear safety inspection, the issue and inculcation of some regulations and operational documents on nuclear safety, and instrumentation of plants reprocessing or processing fuel elements are presented. Methods of determining the critical parameters of technological units are described, together with the fundamental principles of fuel cycle plant nuclear safety, providing margin coefficients, accounting for deviations from the normal operational process and other problems, as well as methods of keeping the restrictions on nuclear safety requirements at fuel cycle plants. (author)

Safety Second: the NRC and America's nuclear power plants

International Nuclear Information System (INIS)

Adato, M.; MacKenzie, J.; Pollard, R.; Weiss, E.

1987-01-01

In 1975, Congress created the Nuclear Regulatory Commission (NRC). Its primary responsibility was to be the regulation of the nuclear power industry in order to maintain public health and safety. On March 28, 1979, in the worst commercial nuclear accident in US history, the plant at Three Mile Island began to leak radioactive material. How was Three Mile Island possible? Where was the NRC? This analysis by the Union of Concerned Scientists (UCS) of the NRC's first decade, points specifically to the factors that contributed to the accident at Three Mile Island. The NRC, created as a watchdog of the nuclear power industry, suffers from problems of mindset, says the UCS. The commission's problems are political, not technical; it repeatedly ranks special interests above the interest of public safety. This book critiques the NRC's performance in four specific areas. It charges that the agency has avoided tackling the most pervasive safety issues; has limited public participation in decision making and power plant licensing; has failed to enforce safety standards or conduct adequate regulation investigations; and, finally, has maintained a fraternal relationship with the industry it was created to regulate, serving as its advocate rather than it adversary. The final chapter offers recommendations for agency improvement that must be met if the NRC is to fulfill its responsibility for safety first

Safety guide on fire protection in nuclear power plants

International Nuclear Information System (INIS)

1976-01-01

The purpose of the Safety Guide is to give specific design and operational guidance for protection from fire and explosion in nuclear power plants, based on the general guidance given in the relevant sections of the 'Safety Code of Practice - Design' and the 'Safety Code of Practice - Operation' of the International Atomic Energy Agency. The guide will confine itself to fire protection of safety systems and items important to safety, leaving the non-safety matters of fire protection in nuclear power plants to be decided upon the basis of the various available national and international practices and regulations. (HP) [de

Analysis of differences in fuel safety criteria for WWER and western PWR nuclear power plants

International Nuclear Information System (INIS)

2003-11-01

In 2001 the OECD issued a report of the NEA/CSNI (Committee on the Safety of Nuclear Installations) Task Force on the existing safety criteria for reactor fuel for western LWR nuclear power plants (both for PWRs and BWRs) under new design elements. Likewise in 2001, the IAEA released a report by a Working Group on the existing safety criteria for reactor fuel for WWER nuclear power plants under new design requirements. However, it was found that it was not possible to compare the two sets of criteria on the basis upon which they had been established. Therefore, the IAEA initiated an assessment of the common features and differences in fuel safety criteria between plants of eastern and western design, focusing on western PWRs and eastern WWER reactors. Between October 2000 and November 2001, the IAEA organized several workshops with representatives from eastern and western European countries in which the current fuel safety related criteria for PWR and WWER reactors were reviewed and compared. The workshops brought together expert representatives from the Russian Federation, from the Ukraine and from western countries that operate PWRs. The first workshop focused on a general overview of the fuel safety criteria in order for all representatives to appreciate the various criteria and their respective bases. The second workshop (which involved one western and one eastern expert) concentrated on addressing and explaining the differences observed, and documenting all these results in preparation for a panel discussion. This panel discussion took place during the third workshop, where the previously obtained results were reviewed in detail and final recommendations were made. This report documents the findings of the workshops. It highlights the common features and differences between PWR and WWER fuel, and may serve as a general basis for the safety evaluation of these fuels. Therefore, it will be very beneficial for licensing activities for PWR and WWER plants, as it

Software safety analysis application in installation phase

International Nuclear Information System (INIS)

Huang, H. W.; Yih, S.; Wang, L. H.; Liao, B. C.; Lin, J. M.; Kao, T. M.

2010-01-01

This work performed a software safety analysis (SSA) in the installation phase of the Lungmen nuclear power plant (LMNPP) in Taiwan, under the cooperation of INER and TPC. The US Nuclear Regulatory Commission (USNRC) requests licensee to perform software safety analysis (SSA) and software verification and validation (SV and V) in each phase of software development life cycle with Branch Technical Position (BTP) 7-14. In this work, 37 safety grade digital instrumentation and control (I and C) systems were analyzed by Failure Mode and Effects Analysis (FMEA), which is suggested by IEEE Standard 7-4.3.2-2003. During the installation phase, skew tests for safety grade network and point to point tests were performed. The FMEA showed all the single failure modes can be resolved by the redundant means. Most of the common mode failures can be resolved by operator manual actions. (authors)

Computer aided safety analysis 1989

International Nuclear Information System (INIS)

1990-04-01

The meeting was conducted in a workshop style, to encourage involvement of all participants during the discussions. Forty-five (45) experts from 19 countries, plus 22 experts from the GDR participated in the meeting. A list of participants can be found at the end of this volume. Forty-two (42) papers were presented and discussed during the meeting. Additionally an open discussion was held on the possible directions of the IAEA programme on Computer Aided Safety Analysis. A summary of the conclusions of these discussions is presented in the publication. The remainder of this proceedings volume comprises the transcript of selected technical papers (22) presented in the meeting. It is the intention of the IAEA that the publication of these proceedings will extend the benefits of the discussions held during the meeting to a larger audience throughout the world. The Technical Committee/Workshop on Computer Aided Safety Analysis was organized by the IAEA in cooperation with the National Board for Safety and Radiological Protection (SAAS) of the German Democratic Republic in Berlin. The purpose of the meeting was to provide an opportunity for discussions on experiences in the use of computer codes used for safety analysis of nuclear power plants. In particular it was intended to provide a forum for exchange of information among experts using computer codes for safety analysis under the Technical Cooperation Programme on Safety of WWER Type Reactors (RER/9/004) and other experts throughout the world. A separate abstract was prepared for each of the 22 selected papers. Refs, figs tabs and pictures

Operating procedure automation to enhance safety of nuclear power plants

International Nuclear Information System (INIS)

Husseiny, A.A.; Sabri, Z.A.; Adams, S.K.; Rodriguez, R.J.; Packer, D.; Holmes, J.W.

1989-01-01

Use of logic statements and computer assist are explored as means for automation and improvement on design of operating procedures including those employed in abnormal and emergency situations. Operating procedures for downpower and loss of forced circulation are used for demonstration. Human-factors analysis is performed on generic emergency operating procedures for three strategies of control; manual, semi-automatic and automatic, using standard emergency operating procedures. Such preliminary analysis shows that automation of procedures is feasible provided that fault-tolerant software and hardware become available for design of the controllers. Recommendations are provided for tests to substantiate the promise of enhancement of plant safety. Adequate design of operating procedures through automation may alleviate several major operational problems of nuclear power plants. Also, automation of procedures is necessary for partial or overall automatic control of plants. Fully automatic operations are needed for space applications while supervised automation of land-based and offshore plants may become the thrust of new generation of nulcear power plants. (orig.)

Code on the safety of nuclear power plants: Siting

International Nuclear Information System (INIS)

1988-01-01

This Code provides criteria and procedures that are recommended for safety in nuclear power plant siting. It forms part of the Agency's programme for establishing Codes and Safety Guides relating to land based stationary thermal neutron power plants

Fuel reprocessing: safety analysis of extraction cycles

International Nuclear Information System (INIS)

Dinh, B.; Mauborgne, B.; Baron, P.; Mercier, J.P.

1991-01-01

An essential part of the safety analysis related to the extraction cycles of reprocessing plants, is the analysis of their behaviour during steady-state and transient operations, by means of simulation codes. These codes are based on the chemical properties of the main species involved (distribution coefficient and kinetics) and the hydrodynamics inside the contactors (mixer-settlers and pulsed columns). These codes have been consolidated by comparison of calculations with experimental results. The safety analysis is essentially performed in two steps. The first step is a parametric sensitivity analysis of the chemical flowsheet operated: the effect of a misadjustment (flowrate of feed, solvent, etc) is evaluated by successive steady-state calculations. These calculations help the identification of the sensitive parameters for the risk of plutonium accumulation, while indicating the permissible level of misadjustment. These calculations also serve to identify the parameters which should be measured during plant operation. The second step is the study of transient regimes, for the most sensitive parameters related to plutonium accumulation risk. The aim is to confirm the conclusions of the first step and to check that the characteristic process parameters chosen effectively allow, the early and reliable detection of any drift towards a plutonium accumulating regime. The procedures to drive the process backwards to a specified convenient steady-state regime from a drifting-state are also verified. The identification of the sensitive parameters, the process status parameters and the process transient analysis, allow a good control of process operation. This procedure, applied to the first purification cycle of COGEMA's UP3-A La Hague plant has demonstrated the total safety of facility operations

HRA qualitative analysis in a nuclear power plant

International Nuclear Information System (INIS)

Dai Licao; Zhang Li; Huang Shudong

2004-01-01

Human reliability analysis (HRA) is a very important part of probability safety assessment (PSA) in a nuclear power plant. Qualitative analysis is the basis and starting point of HRA. The purpose, the principle, the method and the procedure of qualitative HRA are introduced. SGTR, a pressurized nuclear power plant as an example, is used to illustrate it. (authors)

Safety/security interface assessments at commercial nuclear power plants

International Nuclear Information System (INIS)

Byers, K.R.; Brown, P.J.; Norderhaug, L.R.

1985-01-01

The findings of the Haynes Task Force Committee (NUREG-0992) are used as the basis for defining safety/security assessment team activities at commercial nuclear power plants in NRC Region V. A safety/security interface assessment outline and the approach used for making the assessments are presented along with the composition of team members. As a result of observing simulated plant emergency conditions during scheduled emergency preparedness exercises, examining security and operational response procedures, and interviewing plant personnel, the team has identified instances where safety/security conflicts can occur

Safety/security interface assessments at commercial nuclear power plants

International Nuclear Information System (INIS)

Byers, K.R.; Brown, P.J.; Norderhaug, L.R.

1985-07-01

The findings of the Haynes Task Force Committee (NUREG-0992) are used as the basis for defining safety/security assessment team activities at commercial nuclear power plants in NRC Region V. A safety/security interface assessment outline and the approach used for making the assessments are presented along with the composition of team members. As a result of observing simulated plant emergency conditions during scheduled emergency preparedness exercises, examining security and operational response procedures, and interviewing plant personnel, the team has identified instances where safety/security conflicts can occur. 2 refs

Safety targets for nuclear power plants

International Nuclear Information System (INIS)

Herttrich, P.M.

1985-01-01

By taking as an example the safety targets of the American nuclear energy authority US-NRC, this paper explains what is meant by global, quantitative safety targets for nuclear power plants and what expectations are associated with the selecton of such safety targets. It is shown how probabilistic methods can be an appropriate completion of proven deterministic methods and what are the sectors where their application may become important in future. (orig./HP) [de

Application of disturbance analysis methodology to safety related transients in the electrical systems of a nuclear power plant. Report UCLA-ENG-8056

International Nuclear Information System (INIS)

Guarro, S.; Okrent, D.

1981-08-01

The present study tries to address the question of whether or not the computerized on-line procedures known under the name of DAS (Disturbance Analysis System) can be usefully and successfully applied to provide timely diagnostics and operational suggestions during the occurrence of a major electrical transient in the auxiliary systems of a nuclear power plant. The perspective of the study is from the plant-safety point of view. A short definition of DAS methodology features and capabilities is presented. A discussion of some of the problems of a general nature that are encountered in DAS safety-oriented applications are also included. The event insufficient power on both emergency buses, with reference to a particular plant dsign (San Onofre 1), is presented. Some transients that have recently occurred in the power supply systems of operating plants are examined. Whether or not a DAS could have successfully dealt with such occurrences is considered

Application of disturbance analysis methodology to safety related transients in the electrical systems of a nuclear power plant. Report UCLA-ENG-8056

Energy Technology Data Exchange (ETDEWEB)

Guarro, S.; Okrent, D.

1981-08-01

The present study tries to address the question of whether or not the computerized on-line procedures known under the name of DAS (Disturbance Analysis System) can be usefully and successfully applied to provide timely diagnostics and operational suggestions during the occurrence of a major electrical transient in the auxiliary systems of a nuclear power plant. The perspective of the study is from the plant-safety point of view. A short definition of DAS methodology features and capabilities is presented. A discussion of some of the problems of a general nature that are encountered in DAS safety-oriented applications are also included. The event insufficient power on both emergency buses, with reference to a particular plant dsign (San Onofre 1), is presented. Some transients that have recently occurred in the power supply systems of operating plants are examined. Whether or not a DAS could have successfully dealt with such occurrences is considered.

Integrated Plant Safety Assessment, Systematic Evaluation Program, Palisades Plant (Docket No. 50-255)

International Nuclear Information System (INIS)

1983-11-01

This report documents the review completed under the SEP for those issues that required refined engineering evaluations or the continuation of ongoing evaluations after the Final IPSAR for the Palisades Plant was issued. The review has provided for (1) an assessment of the significance of differences between current technical positions on selected safety issues and those that existed when the Palisades Plant was licensed, (2) a basis for deciding on how these differences should be resolved in an integrated plant review, and (3) a documented evaluation of plant safety when the supplement to the Final IPSAR and the Safety Evaluation Report for converting the license from a provisional to a full-term license have been issued. The Final IPSAR and its supplement will form part of the bases for considering the conversion of the provisional operating license to a full-term operating license

Safety balance: Analysis of safety systems

International Nuclear Information System (INIS)

Delage, M.; Giroux, C.

1990-12-01

Safety analysis, and particularly analysis of exploitation of NPPs is constantly affected by EDF and by the safety authorities and their methodologies. Periodic safety reports ensure that important issues are not missed on daily basis, that incidents are identified and that relevant actions are undertaken. French safety analysis method consists of three principal steps. First type of safety balance is analyzed at the normal start-up phase for each unit including the final safety report. This enables analysis of behaviour of units ten years after their licensing. Second type is periodic operational safety analysis performed during a few years. Finally, the third step consists of safety analysis of the oldest units with the aim to improve the safety standards. The three steps of safety analysis are described in this presentation in detail with the aim to present the objectives and principles. Examples of most recent exercises are included in order to illustrate the importance of such analyses

One safety critical indicators model for regulatory actions on nuclear power plants based on a level 1 PSA

International Nuclear Information System (INIS)

Araujo, Jefferson Borges

2006-03-01

This study presents a general methodology to the establishment, selection and use of safety indicators for a two loop PWR plant, as Angra 1. The study performed identifies areas considered critical for the plant operational safety. For each of these areas, strategic sub-areas are defined. For each strategic sub-area, specific safety indicators are defined. These proposed Safety Indicators are based on the contribution to risk considering a quantitative risk analysis. For each safety indicator, a goal, a bounded interval and proper bases are developed, to allow for a clear and comprehensive individual behavior evaluation. Additionally, an integrated evaluation of the indicators, using expert systems, was done to obtain an overview of the plant general safety. This methodology can be used for identifying situations where the plant safety is challenged, by giving a general overview of the plant operational condition. Additionally, this study can also identify eventual room for improvements by generating suggestions and recommendations, as a complement for regulatory actions and inspections, focusing resources on eventual existing weaknesses, in order to increase or maintain a high pattern of operational safety. (author)

IAEA Concludes Safety Review at Gravelines Nuclear Power Plant, France

International Nuclear Information System (INIS)

2012-01-01

Full text: An IAEA-led international team of nuclear safety experts noted a series of good practices and made recommendations to reinforce some safety measures during a review of operational safety at France's Gravelines Nuclear Power Plant (NPP) that concluded today. The Operational Safety Review Team (OSART) was assembled at the French Government's request. The in-depth review, which began 12 November 2012, focused on aspects essential to the safe operation of the NPP. The team was composed of experts from Bulgaria, China, Germany, Hungary, Japan, Romania, Slovakia, South Africa, Spain, Ukraine and the IAEA. The review covered the areas of management, organization and administration; training and qualification; operations; maintenance; technical support; operating experience; radiation protection; chemistry; emergency planning and preparedness; and severe accident management. The conclusions of the review are based on the IAEA's Safety Standards. The OSART team has identified good plant practices, which will be shared with the rest of the nuclear industry for consideration of their possible use elsewhere. Examples include the following: - The Power Plant uses a staff-skills mapping process that significantly enhances knowledge of the facility's collective and individual skills and provides proactive management to address the loss of such skills; - As a measure to reduce the risk of workers' radiation exposure, the Power Plant uses a system to ensure that dose rate measurements are carried out at a precise distance from the source of radiation; and - Flood protection of the Power Plant is supported by special technical guidance documents and associated arrangements. The team identified a number of proposals for improvements to operational safety at Gravelines NPP. Examples include the following: - The Power Plant should reinforce its measures to prevent foreign objects from entering plant systems; - The Power Plant should ensure the 24-hour presence of an operator

Standard model for the safety analysis report of nuclear fuel reprocessing plants; Modelo padrao para relatorio de analise de seguranca de usinas de reprocessamento de combustiveis nucleares

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-02-15

This norm establishes the Standard Model for the Safety Analysis Report of Nuclear Fuel Reprocessing Plants, comprehending the presentation format, the detailing level of the minimum information required by the CNEN for evaluation the requests of Construction License or Operation Authorization, in accordance with the legislation in force. This regulation applies to the following basic reports: Preliminary Safety Analysis Report - PSAR, integrating part of the requirement of Construction License; and Final Safety Analysis Report (FSAR) which is the integrating part of the requirement for Operation Authorization.

West Valley Reprocessing Plant. Safety analysis report, supplement 21

International Nuclear Information System (INIS)

1976-01-01

Supplement No. 21 contains responses to USNRC questions on quality assurance contained in USNRC letter to NFS dated January 22, 1976, revised pages for the safety analysis report, and Appendix IX ''Quality Assurance Manual--West Valley Construction Projects.''

Systems analysis of radiation safety during dismantling of power-plant equipment at a nuclear power station

International Nuclear Information System (INIS)

Bylkin, B.K.; Shpitser, V.Ya.

1993-01-01

A systems analysis of the radiation safety makes possible an ad hoc determination of the elements forming the system, as well as the establishment of the characteristics of their interaction with radiation-effect factors. Here the authors will present part of the hierarchical analysis procedure, consisting in general of four separate procedures. The purpose is to investigate and analyze the mean and stable (on the average) indices of radiation safety, within the framework of alternative mathematical models of dismantling the power-plant equipment of a nuclear power station. The following three of the four procedures are discussed: (1) simulated projection, of the processing of radioactive waste; (2) analysis of the redistribution of radionuclides during the industrial cycle of waste treatment; (3) planning the collective dose load during the dismantling operation. Within the framework of the first of these procedures, the solutions to the problem of simulating a waste-treatment operation of maximum efficiency are analyzed. This analysis is based on the use of a data base for the parameters of the installations, assemblies, and equipment, enabling the integration of these in a simulation of a complex automated facility. The results were visualized in an AUTOCAD-10 medium using a graphical data base containing an explanation of the rooms

Meteorological events in site evaluation for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2005-01-01

This Safety Guide provides recommendations and guidance on conducting hazard assessments of extreme and rare meteorological phenomena. It is of interest to safety assessors and regulators involved in the licensing process as well as to designers of nuclear power plants. This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. It supplements the IAEA Safety Requirements publication on Site Evaluation for Nuclear Facilities which is to supersede the Code on the Safety of Nuclear Power Plants: Siting, Safety Series No. 50-C-S (Rev. 1), IAEA, Vienna (1988). The present Safety Guide supersedes two earlier Safety Guides: Safety Series No. 50-SG-S11A (1981) on Extreme Meteorological Events in Nuclear Power Plant Siting, Excluding Tropical Cyclones and Safety Series No. 50-SG-S11B (1984) on Design Basis Tropical Cyclone for Nuclear Power Plants. The purpose of this Safety Guide is to provide recommendations and guidance on conducting hazard assessments of extreme and rare meteorological phenomena. This Safety Guide provides interpretation of the Safety Requirements publication on Site Evaluation for Nuclear Facilities and guidance on how to fulfil these requirements. It is aimed at safety assessors or regulators involved in the licensing process as well as designers of nuclear power plants, and provides them with guidance on the methods and procedures for analyses that support the assessment of the hazards associated with extreme and rare meteorological events. This Safety Guide discusses the extreme values of meteorological variables and rare meteorological phenomena, as well as their rates of occurrence, according to the following definitions: (a) Extreme values of meteorological variables such as air temperature and wind speed characterize the meteorological or climatological environment. And (b) Rare meteorological phenomena

Design of reactor containment systems for nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2008-01-01

This Safety Guide was prepared under the IAEA programme for safety standards for nuclear power plants. It is a revision of the Safety Guide on Design of the Reactor Containment Systems in Nuclear Power Plants (Safety Series No. 50-Sg-D1) issued in 1985 and supplements the Safety Requirements publication on Safety of Nuclear Power Plants: Design. The present Safety Guide was prepared on the basis of a systematic review of the relevant publications, including the Safety of Nuclear Power Plants: Design, the Safety fundamentals publication on The Safety of Nuclear Installations, Safety Guides, INSAG Reports, a Technical Report and other publications covering the safety of nuclear power plants. 1.2. The confinement of radioactive material in a nuclear plant, including the control of discharges and the minimization of releases, is a fundamental safety function to be ensured in normal operational modes, for anticipated operational occurrences, in design basis accidents and, to the extent practicable, in selected beyond design basis accidents. In accordance with the concept of defence in depth, this fundamental safety function is achieved by means of several barriers and levels of defence. In most designs, the third and fourth levels of defence are achieved mainly by means of a strong structure enveloping the nuclear reactor. This structure is called the 'containment structure' or simply the 'containment'. This definition also applies to double wall containments. 1.3. The containment structure also protects the reactor against external events and provides radiation shielding in operational states and accident conditions. The containment structure and its associated systems with the functions of isolation, energy management, and control of radionuclides and combustible gases are referred to as the containment systems

Design of reactor containment systems for nuclear power plants. Safety guide

International Nuclear Information System (INIS)