Sample records for safety evaluation system
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International Nuclear Information System (INIS)
Wetzel, N.; Scharfe, A.
1998-01-01
The present report examines the possibilities and limits of a probabilistic safety analysis to evaluate passive safety systems and inherent safety characteristics. The inherent safety characteristics are based on physical principles, that together with the safety system lead to no damage. A probabilistic evaluation of the inherent safety characteristic is not made. An inventory of passive safety systems of accomplished nuclear power plant types in the Federal Republic of Germany was drawn up. The evaluation of the passive safety system in the analysis of the accomplished nuclear power plant types was examined. The analysis showed that the passive manner of working was always assumed to be successful. A probabilistic evaluation was not performed. The unavailability of the passive safety system was determined by the failure of active components which are necessary in order to activate the passive safety system. To evaluate the passive safety features in new concepts of nuclear power plants the AP600 from Westinghouse, the SBWR from General Electric and the SWR 600 from Siemens, were selected. Under these three reactor concepts, the SWR 600 is specially attractive because the safety features need no energy sources and instrumentation in this concept. First approaches for the assessment of the reliability of passively operating systems are summarized. Generally it can be established that the core melt frequency for the passive concepts AP600 and SBWR is advantageous in comparison to the probabilistic objectives from the European Pressurized Water Reactor (EPR). Under the passive concepts is the SWR 600 particularly interesting. In this concept the passive systems need no energy sources and instrumentation, and has active operational systems and active safety equipment. Siemens argues that with this concept the frequency of a core melt will be two orders of magnitude lower than for the conventional reactors. (orig.) [de
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Safety Evaluation Approach with Security Controls for Safety I and C Systems on Nuclear Power Plants
International Nuclear Information System (INIS)
Kim, D. H.; Jeong, S. Y.; Kim, Y. M.; Park, H. S.; Lee, M. S.; Kim, T. H.
2016-01-01
This paper addresses concepts of safety and security and relations between them for assessing effects of security features in safety systems. Also, evaluation approach for avoiding confliction with safety requirements and cyber security features which may be adopted in safety-related digital I and C system will be described. In this paper, safety-security life cycle model based confliction avoidance method was proposed to evaluate the effects when the cyber security control features are implemented in the safety I and C system. Also, safety effect evaluation results using the proposed evaluation method were described. In case of technical security controls, many of them are expected to conflict with safety requirements, otherwise operational and managerial controls are not relatively. Safety measures and cyber security measures for nuclear power plants should be implemented not to conflict with one another. Where safety function and security features are both required within the systems, and also where security features are implemented within safety systems, they should be justified
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Safety Evaluation Approach with Security Controls for Safety I and C Systems on Nuclear Power Plants
Energy Technology Data Exchange (ETDEWEB)
Kim, D. H.; Jeong, S. Y.; Kim, Y. M.; Park, H. S. [KINS, Daejeon (Korea, Republic of); Lee, M. S.; Kim, T. H. [Formal Works Inc., Seoul (Korea, Republic of)
2016-05-15
This paper addresses concepts of safety and security and relations between them for assessing effects of security features in safety systems. Also, evaluation approach for avoiding confliction with safety requirements and cyber security features which may be adopted in safety-related digital I and C system will be described. In this paper, safety-security life cycle model based confliction avoidance method was proposed to evaluate the effects when the cyber security control features are implemented in the safety I and C system. Also, safety effect evaluation results using the proposed evaluation method were described. In case of technical security controls, many of them are expected to conflict with safety requirements, otherwise operational and managerial controls are not relatively. Safety measures and cyber security measures for nuclear power plants should be implemented not to conflict with one another. Where safety function and security features are both required within the systems, and also where security features are implemented within safety systems, they should be justified.
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Research on the Evaluation System for Rural Public Safety Planning
Institute of Scientific and Technical Information of China (English)
Ming; SUN; Jianxin; YAN
2014-01-01
The indicator evaluation system is introduced to the study of rural public safety planning in this article.By researching the current rural public safety planning and environmental carrying capacity,we select some carrying capacity indicators influencing the rural public safety,such as land,population,ecological environment,water resources,infrastructure,economy and society,to establish the environmental carrying capacity indicator system.We standardize the indicators,use gray correlation analysis method to determine the weight of indicators,and make DEA evaluation of the indicator system,to obtain the evaluation results as the basis for decision making in rural safety planning,and provide scientific and quantified technical support for rural public safety planning.
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Evaluating the effectiveness of active vehicle safety systems.
Jeong, Eunbi; Oh, Cheol
2017-03-01
Advanced vehicle safety systems have been widely introduced in transportation systems and are expected to enhance traffic safety. However, these technologies mainly focus on assisting individual vehicles that are equipped with them, and less effort has been made to identify the effect of vehicular technologies on the traffic stream. This study proposed a methodology to assess the effectiveness of active vehicle safety systems (AVSSs), which represent a promising technology to prevent traffic crashes and mitigate injury severity. The proposed AVSS consists of longitudinal and lateral vehicle control systems, which corresponds to the Level 2 vehicle automation presented by the National Highway Safety Administration (NHTSA). The effectiveness evaluation for the proposed technology was conducted in terms of crash potential reduction and congestion mitigation. A microscopic traffic simulator, VISSIM, was used to simulate freeway traffic stream and collect vehicle-maneuvering data. In addition, an external application program interface, VISSIM's COM-interface, was used to implement the AVSS. A surrogate safety assessment model (SSAM) was used to derive indirect safety measures to evaluate the effectiveness of the AVSS. A 16.7-km freeway stretch between the Nakdong and Seonsan interchanges on Korean freeway 45 was selected for the simulation experiments to evaluate the effectiveness of AVSS. A total of five simulation runs for each evaluation scenario were conducted. For the non-incident conditions, the rear-end and lane-change conflicts were reduced by 78.8% and 17.3%, respectively, under the level of service (LOS) D traffic conditions. In addition, the average delay was reduced by 55.5%. However, the system's effectiveness was weakened in the LOS A-C categories. Under incident traffic conditions, the number of rear-end conflicts was reduced by approximately 9.7%. Vehicle delays were reduced by approximately 43.9% with 100% of market penetration rate (MPR). These results
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Safety evaluation of BWR off-gas treatment systems
International Nuclear Information System (INIS)
Schultz, R.J.; Schmitt, R.C.
1975-01-01
Some of the results of a safety evaluation performed on current generic types of BWR off-gas treatment systems including cooled and ambient temperature adsorber beds and cryogenics are presented. The evaluation covered the four generic types of off-gas systems and the systems of five major vendors. This study was part of original work performed under AEC contract for the Directorate of Regulatory Standards. The analysis techniques employed for the safety evaluation of these systems include: Fault Tree Analysis; FMECA (Failure Mode Effects and Criticality Analysis); general system comparisons, contaminant, system control, and design adequacy evaluations; and resultant Off-Site Dose Calculations. The salient areas presented are some of the potential problem areas, the approach that industry has taken to mitigate or design against potential upset conditions, and areas where possible deficiencies still exist. Potential problem areas discussed include hydrogen detonation, hydrogen release to equipment areas, operator/automatic control interface, and needed engineering evaluation to insure safe system operation. Of the systems reviewed, most were in the category of advanced or improved over that commonly in use today, and a conclusion from the study was that these systems offer excellent potential for noble gas control for BWR power plants where more stringent controls may be specified -- now or in the future. (U.S.)
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Safety significance evaluation system
International Nuclear Information System (INIS)
Lew, B.S.; Yee, D.; Brewer, W.K.; Quattro, P.J.; Kirby, K.D.
1991-01-01
This paper reports that the Pacific Gas and Electric Company (PG and E), in cooperation with ABZ, Incorporated and Science Applications International Corporation (SAIC), investigated the use of artificial intelligence-based programming techniques to assist utility personnel in regulatory compliance problems. The result of this investigation is that artificial intelligence-based programming techniques can successfully be applied to this problem. To demonstrate this, a general methodology was developed and several prototype systems based on this methodology were developed. The prototypes address U.S. Nuclear Regulatory Commission (NRC) event reportability requirements, technical specification compliance based on plant equipment status, and quality assurance assistance. This collection of prototype modules is named the safety significance evaluation system
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Evaluating Safety Culture Under the Socio-Technical Complex Systems Perspective
International Nuclear Information System (INIS)
Lemos, F. L. de
2016-01-01
Since the term “safety culture” was coined, it has gained more and more attention as an effort to achieve higher levels of system safety. A good deal of effort has been done in order to better define, evaluate and implement safety culture programs in organizations throughout all industries, and especially in the Nuclear Industry. Unfortunately, despite all those efforts, we continue to witness accidents that are, in great part, attributed to flaws in the safety culture of the organization. Fukushima nuclear accident is one example of a serious accident in which flaws in the safety culture has been pointed to as one of the main contributors. In general, the definitions of safety culture emphasise the social aspect of the system. While the definitions also include the relations with the technical aspects, it does so in a general sense. For example, the International Nuclear Safety Advisory Group (INSAG) defines safety culture as: “The assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receives the attention warranted by their significance.” By the way safety culture is defined we can infer that it represents a property of a social system, or a property of the social aspect of the system. In this sense, the social system is a component of the whole system. Where, “system” is understood to be comprised of a social (humans) and technical (equipment) aspects, as a Nuclear Power Plant, for example. Therefore, treating safety culture as an identity on its own right, finding and fixing flaws in the safety culture may not be enough to improve safety of the system. We also needed to evaluate all the interactions between the components that comprise all the aspects of the system. In some cases a flaw in the safety culture can easily be detected, such as an employee not wearing appropriate individual protection equipment, e.g., dosimeter, or when basic safety
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Evaluating safety management system implementation
International Nuclear Information System (INIS)
Preuss, M.
2009-01-01
Canada is committed to not only maintaining, but also improving upon our record of having one of the safest aviation systems in the world. The development, implementation and maintenance of safety management systems is a significant step towards improving safety performance. Canada is considered a world leader in this area and we are fully engaged in implementation. By integrating risk management systems and business practices, the aviation industry stands to gain better safety performance with less regulatory intervention. These are important steps towards improving safety and enhancing the public's confidence in the safety of Canada's aviation system. (author)
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Safety analysis and evaluation methodology for fusion systems
International Nuclear Information System (INIS)
Fujii-e, Y.; Kozawa, Y.; Namba, C.
1987-03-01
Fusion systems which are under development as future energy systems have reached a stage that the break even is expected to be realized in the near future. It is desirable to demonstrate that fusion systems are well acceptable to the societal environment. There are three crucial viewpoints to measure the acceptability, that is, technological feasibility, economy and safety. These three points have close interrelation. The safety problem is more important since three large scale tokamaks, JET, TFTR and JT-60, start experiment, and tritium will be introduced into some of them as the fusion fuel. It is desirable to establish a methodology to resolve the safety-related issues in harmony with the technological evolution. The promising fusion system toward reactors is not yet settled. This study has the objective to develop and adequate methodology which promotes the safety design of general fusion systems and to present a basis for proposing the R and D themes and establishing the data base. A framework of the methodology, the understanding and modeling of fusion systems, the principle of ensuring safety, the safety analysis based on the function and the application of the methodology are discussed. As the result of this study, the methodology for the safety analysis and evaluation of fusion systems was developed. New idea and approach were presented in the course of the methodology development. (Kako, I.)
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Optimized Evaluation System to Athletic Food Safety
Shanshan Li
2015-01-01
This study presented a new method of optimizing evaluation function in athletic food safety information programming by particle swarm optimization. The process of food information evaluation function is to automatically adjust these parameters in the evaluation function by self-optimizing method accomplished through competition, which is a food information system plays against itself with different evaluation functions. The results show that the particle swarm optimization is successfully app...
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Expert evaluation in NPP safety important systems licensing process
International Nuclear Information System (INIS)
Mikhail, A Yastrebenetsky; Vasilchenko, V.N.
2001-01-01
Expert evaluation of nuclear power plant safety important systems modernization is an integral part of these systems licensing process. The paper contains some aspects of this evaluation which are based on Ukrainian experience of VVER-1000 and VVER-440 modernization. (authors)
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Expert evaluation in NPP safety important systems licensing process
Energy Technology Data Exchange (ETDEWEB)
Mikhail, A Yastrebenetsky; Vasilchenko, V.N. [Ukrainian State Scientific Technical Center of Nuclear and Radiation Safety (Ukraine)
2001-07-01
Expert evaluation of nuclear power plant safety important systems modernization is an integral part of these systems licensing process. The paper contains some aspects of this evaluation which are based on Ukrainian experience of VVER-1000 and VVER-440 modernization. (authors)
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Electronic clinical safety reporting system: a benefits evaluation.
Elliott, Pamela; Martin, Desmond; Neville, Doreen
2014-06-11
Eastern Health, a large health care organization in Newfoundland and Labrador (NL), started a staged implementation of an electronic occurrence reporting system (used interchangeably with "clinical safety reporting system") in 2008, completing Phase One in 2009. The electronic clinical safety reporting system (CSRS) was designed to replace a paper-based system. The CSRS involves reporting on occurrences such as falls, safety/security issues, medication errors, treatment and procedural mishaps, medical equipment malfunctions, and close calls. The electronic system was purchased from a vendor in the United Kingdom that had implemented the system in the United Kingdom and other places, such as British Columbia. The main objective of the new system was to improve the reporting process with the goal of improving clinical safety. The project was funded jointly by Eastern Health and Canada Health Infoway. The objectives of the evaluation were to: (1) assess the CSRS on achieving its stated objectives (particularly, the benefits realized and lessons learned), and (2) identify contributions, if any, that can be made to the emerging field of electronic clinical safety reporting. The evaluation involved mixed methods, including extensive stakeholder participation, pre/post comparative study design, and triangulation of data where possible. The data were collected from several sources, such as project documentation, occurrence reporting records, stakeholder workshops, surveys, focus groups, and key informant interviews. The findings provided evidence that frontline staff and managers support the CSRS, identifying both benefits and areas for improvement. Many benefits were realized, such as increases in the number of occurrences reported, in occurrences reported within 48 hours, in occurrences reported by staff other than registered nurses, in close calls reported, and improved timelines for notification. There was also user satisfaction with the tool regarding ease of use
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Development of Non-safety System Architecture and Evaluation of Components/Systems
International Nuclear Information System (INIS)
Oh, I. S.; Lee, C. K.; Kim, D. H.; Lee, J. W.; Lee, D. Y.; Park, W. M.; Hwang, I. K.; Hur, S.; Kim, J. T.; Park, J. C.; Lee, J. W.
2007-10-01
We describe in this report the works performed for a technical evaluation of the non-safety digital control system of the KNICS, the non-safety process control system of the KNICS, a communication load analysis for the MMIS (including both the non-safety and the safety systems) of the KNICS, the development of MMI and an implementation of the logic for the CVCS, and the works performed to support writing a proposal needed for bidding an I and C system based on the KNICS. The technical evaluation results were aimed to be used by the designers to detect parts needed to be corrected or to be newly inserted, and also by the developers during the development phase. The requirement specifications and the data requirement characteristics have been identified for each subsystem of the determined KNICS structure. For each communication node, the specifications related to the data transfer including the data capacity for interfaces, delay time for the data transfer, and the marginal availability of its performance capabilities have been analyzed to identify the amount of data transfer and hence to verify that both of the designed structures for the safety related communications network and for the digital communications network are appropriate. The results of the supporting work performed for writing the technical specifications related to each subsystem of the KNICS structure, are expected to be useful in writing a proposal for the expected Uljin new units 1 and 2, and in the I and C upgrade for any of the existing nuclear power plants under operation. Also included in this report are the descriptions on a design of the chemical volume control system (CVCS), on the supporting work performed to draw the logic diagrams for CVCS using the tool ISaGRAF, and on the generation of a set of system displays to be used as references
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Development of Non-safety System Architecture and Evaluation of Components/Systems
Energy Technology Data Exchange (ETDEWEB)
Oh, I. S.; Lee, C. K.; Kim, D. H.; Lee, J. W.; Lee, D. Y.; Park, W. M.; Hwang, I. K.; Hur, S.; Kim, J. T.; Park, J. C.; Lee, J. W
2007-10-15
We describe in this report the works performed for a technical evaluation of the non-safety digital control system of the KNICS, the non-safety process control system of the KNICS, a communication load analysis for the MMIS (including both the non-safety and the safety systems) of the KNICS, the development of MMI and an implementation of the logic for the CVCS, and the works performed to support writing a proposal needed for bidding an I and C system based on the KNICS. The technical evaluation results were aimed to be used by the designers to detect parts needed to be corrected or to be newly inserted, and also by the developers during the development phase. The requirement specifications and the data requirement characteristics have been identified for each subsystem of the determined KNICS structure. For each communication node, the specifications related to the data transfer including the data capacity for interfaces, delay time for the data transfer, and the marginal availability of its performance capabilities have been analyzed to identify the amount of data transfer and hence to verify that both of the designed structures for the safety related communications network and for the digital communications network are appropriate. The results of the supporting work performed for writing the technical specifications related to each subsystem of the KNICS structure, are expected to be useful in writing a proposal for the expected Uljin new units 1 and 2, and in the I and C upgrade for any of the existing nuclear power plants under operation. Also included in this report are the descriptions on a design of the chemical volume control system (CVCS), on the supporting work performed to draw the logic diagrams for CVCS using the tool ISaGRAF, and on the generation of a set of system displays to be used as references.
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Scale development of safety management system evaluation for the airline industry.
Chen, Ching-Fu; Chen, Shu-Chuan
2012-07-01
The airline industry relies on the implementation of Safety Management System (SMS) to integrate safety policies and augment safety performance at both organizational and individual levels. Although there are various degrees of SMS implementation in practice, a comprehensive scale measuring the essential dimensions of SMS is still lacking. This paper thus aims to develop an SMS measurement scale from the perspective of aviation experts and airline managers to evaluate the performance of company's safety management system, by adopting Schwab's (1980) three-stage scale development procedure. The results reveal a five-factor structure consisting of 23 items. The five factors include documentation and commands, safety promotion and training, executive management commitment, emergency preparedness and response plan and safety management policy. The implications of this SMS evaluation scale for practitioners and future research are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.
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10CFR50.59 safety evaluation training and expert system development
International Nuclear Information System (INIS)
Kline, S.W.; Dickinson, D.B.
1988-01-01
10CFR50.59 permits utilities to make changes to and conduct tests or experiments on operating nuclear power plants without prior US Nuclear Regulatory Commission (NCR) approval unless the proposed change, test, or experiment (i.e, the proposed activity) involves a change to the plant technical specifications or an unreviewed safety question (USQ). To provide guidance to their engineers for making the determination of whether a proposed activity involves a USQ. Bechtel has developed a safety evaluation training program. This training program incorporates the guidance in and NRC comments to the November 1987 draft Nuclear Management and Resources Council safety evaluation guidance document, NRC statements contained in inspection reports and other documents, and the experience of senior Bechtel engineers. To further develop the question and concerns that need to be addressed in a safety evaluation in a systematic manner, Bechtel is incorporating the training program guidance and other information into an IBM PC-AT-based working model of an expert system using the NEXPERT expert system development tool. The development and use of this expert system working model are being undertaken to provide consistency and completeness to the thought process used and the output provided by Bechtel engineers when performing a safety evaluation
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Safety Evaluation of Kartini Reactor Based on Instrumentation System Design
International Nuclear Information System (INIS)
Tjipta Suhaemi; Djen Djen Dj; Itjeu K; Johnny S; Setyono
2003-01-01
The safety of Kartini reactor has been evaluated based on instrumentation system aspect. The Kartini reactor is designed by BATAN. Design power of the reactor is 250 kW, but it is currently operated at 100 kW. Instrumentation and control system function is to monitor and control the reactor operation. Instrumentation and control system consists of safety system, start-up and automatic power control, and process information system. The linear power channel and logarithmic power channel are used for measuring power. There are 3 types of control rod for controlling the power, i.e. safety rod, shim rod, and regulating rod. The trip and interlock system are used for safety. There are instrumentation equipment used for measuring radiation exposure, flow rate, temperature and conductivity of fluid The system of Kartini reactor has been developed by introducing a process information system, start-up system, and automatic power control. It is concluded that the instrumentation of Kartini reactor has followed the requirement and standard of IAEA. (author)
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Evaluation of intelligent transport systems impact on school transport safety
Directory of Open Access Journals (Sweden)
Jankowska-Karpa Dagmara
2017-01-01
Full Text Available The integrated system of safe transport of children to school using Intelligent Transport Systems was developed and implemented in four locations across Europe under the Safeway2School (SW2S project, funded by the EU. The SW2S system evaluation included speed measurements and an eye-tracking experiment carried out among drivers who used the school bus route, where selected elements of the system were tested. The subject of the evaluation were the following system elements: pedestrian safety system at the bus stop (Intelligent Bus Stop and tags for children, Driver Support System, applications for parents’ and students’ mobile phones, bus stop inventory tool and data server. A new sign designed for buses and bus stops to inform about child transportation/children waiting at the bus stop was added to the system. Training schemes for system users were also provided. The article presents evaluation results of the impact of selected elements of the SW2S system on school transport safety in Poland.
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From extended integrity monitoring to the safety evaluation of satellite-based localisation system
International Nuclear Information System (INIS)
Legrand, Cyril; Beugin, Julie; Marais, Juliette; Conrard, Blaise; El-Koursi, El-Miloudi; Berbineau, Marion
2016-01-01
Global Navigation Satellite Systems (GNSS) such as GPS, already used in aeronautics for safety-related applications, can play a major role in railway safety by allowing a train to locate itself safely. However, in order to implement this positioning solution in any embedded system, its performances must be evaluated according to railway standards. The evaluation of GNSS performances is not based on the same attributes class than RAMS evaluation. Face to these diffculties, we propose to express the integrity attribute, performance of satellite-based localisation. This attribute comes from aeronautical standards and for a hybridised GNSS with inertial system. To achieve this objective, the integrity attribute must be extended to this kind of system and algorithms initially devoted to GNSS integrity monitoring only must be adapted. Thereafter, the formalisation of this integrity attribute permits us to analyse the safety quantitatively through the probabilities of integrity risk and wrong-side failure. In this paper, after an introductory discussion about the use of localisation systems in railway safety context together with integrity issues, a particular integrity monitoring is proposed and described. The detection events of this algorithm permit us to conclude about safety level of satellite-based localisation system.
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A study on the development of the computerized safety evaluation system of the motor operated valve
International Nuclear Information System (INIS)
Kim, J. C.; Park, S. G.; Lee, D. H.; Ahn, N. S.; Bae, H. J.; Hong, J. S.
2001-01-01
The MOVIDIK (Motor-Operated Valves Integrated Database and Information of KEPCO) system was developed to assist the design basis safety evaluation and to manage the overall data made by evaluation on the safety-related Motor-operated Valves(MOV) in the nuclear power plant. The huge amount of safety evaluation data of the MOV is being piled up as the safety evaluation work goes on. Much time and manpower was needed to do safety evaluation works without computerized system and it was not easy to obtain the statistic information from the evaluation data. The MOVIDIK will improve the efficiency of safety evaluation works and standardize the analysis process. But the some process which needs specific evaluation codes and engineering calculation by the specialists was not computerized. The MOVIDIK was developed by JAVA/JSP language known by the flexibility of language and the easiness of transplantation between operating systems. The Oracle 8i which is the world's most popular database was used for MOVIDIK database
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Preliminary safety evaluation for CSR1000 with passive safety system
International Nuclear Information System (INIS)
Wu, Pan; Gou, Junli; Shan, Jianqiang; Zhang, Bo; Li, Xiang
2014-01-01
Highlights: • The basic information of a Chinese SCWR concept CSR1000 is introduced. • An innovative passive safety system is proposed for CSR1000. • 6 Transients and 3 accidents are analysed with system code SCTRAN. • The passive safety systems greatly mitigate the consequences of these incidents. • The inherent safety of CSR1000 is enhanced. - Abstract: This paper describes the preliminary safety analysis of the Chinese Supercritical water cooled Reactor (CSR1000), which is proposed by Nuclear Power Institute of China (NPIC). The two-pass core design applied to CSR1000 decreases the fuel cladding temperature and flattens the power distribution of the core at normal operation condition. Each fuel assembly is made up of four sub-assemblies with downward-flow water rods, which is favorable to the core cooling during abnormal conditions due to the large water inventory of the water rods. Additionally, a passive safety system is proposed for CSR1000 to increase the safety reliability at abnormal conditions. In this paper, accidents of “pump seizure”, “loss of coolant flow accidents (LOFA)”, “core depressurization”, as well as some typical transients are analysed with code SCTRAN, which is a one-dimensional safety analysis code for SCWRs. The results indicate that the maximum cladding surface temperatures (MCST), which is the most important safety criterion, of the both passes in the mentioned incidents are all below the safety criterion by a large margin. The sensitivity analyses of the delay time of RCPs trip in “loss of offsite power” and the delay time of RMT actuation in “loss of coolant flowrate” were also included in this paper. The analyses have shown that the core design of CSR1000 is feasible and the proposed passive safety system is capable of mitigating the consequences of the selected abnormalities
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A Study on the Safety Evaluation of Real-Time Operating System in Nuclear Power Plants
International Nuclear Information System (INIS)
Kim, Hyung Tae; Jeong, Choong Heui; Kim, Dail Il
2008-01-01
Along with the digitalisation of the nuclear Instrumentation and Control (I and C) system, Real-Time Operating System (RTOS) is being widely used. The RTOS used in nuclear I and C system should satisfy strict performance requirements and resolve various technical issues under complicated conditions. In this regard a careful safety evaluation of RTOS is important for the safety of Nuclear Power Plants. The objective of this study is to provide a guideline for safety evaluation of RTOS appropriate to the nuclear I and C system. In this paper, we suggest evaluation approach for the RTOS
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A Study on the Safety Evaluation of Real-Time Operating System in Nuclear Power Plants
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyung Tae; Jeong, Choong Heui; Kim, Dail Il [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)
2008-10-15
Along with the digitalisation of the nuclear Instrumentation and Control (I and C) system, Real-Time Operating System (RTOS) is being widely used. The RTOS used in nuclear I and C system should satisfy strict performance requirements and resolve various technical issues under complicated conditions. In this regard a careful safety evaluation of RTOS is important for the safety of Nuclear Power Plants. The objective of this study is to provide a guideline for safety evaluation of RTOS appropriate to the nuclear I and C system. In this paper, we suggest evaluation approach for the RTOS.
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International Nuclear Information System (INIS)
Hashim Muhammad; Yoshikawa, Hidekazu; Matsuoka, Takeshi; Yang Ming
2014-01-01
The passive safety systems utilized in advanced pressurized water reactor (PWR) design such as AP1000 should be more reliable than that of active safety systems of conventional PWR by less possible opportunities of hardware failures and human errors (less human intervention). The objectives of present study are to evaluate the dynamic reliability of AP1000 plant in order to check the effectiveness of passive safety systems by comparing the reliability-related issues with that of active safety systems in the event of the big accidents. How should the dynamic reliability of passive safety systems properly evaluated? And then what will be the comparison of reliability results of AP1000 passive safety systems with the active safety systems of conventional PWR. For this purpose, a single loop model of AP1000 passive core cooling system (PXS) and passive containment cooling system (PCCS) are assumed separately for quantitative reliability evaluation. The transient behaviors of these passive safety systems are taken under the large break loss-of-coolant accident in the cold leg. The analysis is made by utilizing the qualitative method failure mode and effect analysis in order to identify the potential failure mode and success-oriented reliability analysis tool called GO-FLOW for quantitative reliability evaluation. The GO-FLOW analysis has been conducted separately for PXS and PCCS systems under the same accident. The analysis results show that reliability of AP1000 passive safety systems (PXS and PCCS) is increased due to redundancies and diversity of passive safety subsystems and components, and four stages automatic depressurization system is the key subsystem for successful actuation of PXS and PCCS system. The reliability results of PCCS system of AP1000 are more reliable than that of the containment spray system of conventional PWR. And also GO-FLOW method can be utilized for reliability evaluation of passive safety systems. (author)
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Study on development of education model and its evaluation system for radiation safety
Seo, K W; Nam, Y M
2002-01-01
As one of the detailed action strategy of multi object preparedness for strengthening of radiation safety management by MOST, this project was performed, in order to promote the safety culture for user and radiation worker through effective education program. For the prevention of radiological accident and effective implementation of radiation safety education and training, this project has been carried out the development of education model and its evaluation system on radiation safety. In the development of new education model, education course was classified; new and old radiation worker, temporary worker, lecturer and manager. The education model includes the contents of expanding the education opportunity and workplace training. In the development of evaluation system, the recognition criteria for commission-education institute and inside-education institute which should establish by law were suggested for evaluation program. The recognition criteria contains classification, student, method, facilities, ...
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Evaluating Models of Human Performance: Safety-Critical Systems Applications
Feary, Michael S.
2012-01-01
This presentation is part of panel discussion on Evaluating Models of Human Performance. The purpose of this panel is to discuss the increasing use of models in the world today and specifically focus on how to describe and evaluate models of human performance. My presentation will focus on discussions of generating distributions of performance, and the evaluation of different strategies for humans performing tasks with mixed initiative (Human-Automation) systems. I will also discuss issues with how to provide Human Performance modeling data to support decisions on acceptability and tradeoffs in the design of safety critical systems. I will conclude with challenges for the future.
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A toolbox for safety instrumented system evaluation based on improved continuous-time Markov chain
Wardana, Awang N. I.; Kurniady, Rahman; Pambudi, Galih; Purnama, Jaka; Suryopratomo, Kutut
2017-08-01
Safety instrumented system (SIS) is designed to restore a plant into a safe condition when pre-hazardous event is occur. It has a vital role especially in process industries. A SIS shall be meet with safety requirement specifications. To confirm it, SIS shall be evaluated. Typically, the evaluation is calculated by hand. This paper presents a toolbox for SIS evaluation. It is developed based on improved continuous-time Markov chain. The toolbox supports to detailed approach of evaluation. This paper also illustrates an industrial application of the toolbox to evaluate arch burner safety system of primary reformer. The results of the case study demonstrates that the toolbox can be used to evaluate industrial SIS in detail and to plan the maintenance strategy.
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Review on the Evaluation System of Public Safety Carrying Capacity about Small Town Community
Institute of Scientific and Technical Information of China (English)
Ming; SUN; Tianyu; ZHU
2014-01-01
Recently,small town community public safety problem has been increasingly highlighted,but its research is short on public safety carrying capacity. Through the investigation and study of community public safety carrying capacity,this paper analyzes the problem of community public safety in our country,to construct index evaluation system of public safety carrying capacity in small town community. DEA method is used to evaluate public safety carrying capacity in small town community,to provide scientific basis for the design of support and standardization theory about small town community in public safety planning.
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Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher; Feather, Martin; Rutledge, Peter; Sen, Dev; Youngblood, Robert
2015-01-01
This is the second of two volumes that collectively comprise the NASA System Safety Handbook. Volume 1 (NASASP-210-580) was prepared for the purpose of presenting the overall framework for System Safety and for providing the general concepts needed to implement the framework. Volume 2 provides guidance for implementing these concepts as an integral part of systems engineering and risk management. This guidance addresses the following functional areas: 1.The development of objectives that collectively define adequate safety for a system, and the safety requirements derived from these objectives that are levied on the system. 2.The conduct of system safety activities, performed to meet the safety requirements, with specific emphasis on the conduct of integrated safety analysis (ISA) as a fundamental means by which systems engineering and risk management decisions are risk-informed. 3.The development of a risk-informed safety case (RISC) at major milestone reviews to argue that the systems safety objectives are satisfied (and therefore that the system is adequately safe). 4.The evaluation of the RISC (including supporting evidence) using a defined set of evaluation criteria, to assess the veracity of the claims made therein in order to support risk acceptance decisions.
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Toward an integrated system concept for monitoring and evaluation of safety culture
International Nuclear Information System (INIS)
Makino, Maomi; Sakaue, Takeharu
2004-01-01
The concept of ''nuclear safety culture'' has been advocated and has been much discussed internationally by INSAG (The International Nuclear Safety Advisory Group) under IAEA (the International Atomic Energy Agency) and other institutions since Chernobyl accident. On the safety front, Japan had maintained an excellent track record in nuclear power operations throughout the 1990s. However, there have been a series of new type of problems strongly implying degradation of safety culture, e.g., Monju accident, fire and explosion accident at an Asphalt Solidification Process Facility at Tokai, falsification of annealing data at nuclear power plants (NPP), another data falsification for transport cask of spent fuel and JCO criticality accident. Then the TEPCO (Tokyo Electric Power Company) issue was revealed in 2002. Triggered by this issue, the Nuclear and Industrial Safety Agency (NISA) has been implementing a variety of improvements, one of which was the establishment of a study group in 2003, which invited experts from other fields as well as from nuclear-related industries, to study on how to implement safety culture sufficiently and possible recommendations. Subjects such as the followings piled in the study report will indicate leading keys in case it is going to realize such efforts: ''Foundation of safety culture is a quality management'' and ''Realistic and scientific technique is necessary for the evaluation of safety culture''. In order to respond to these requests, JNES have been advancing the development toward an Integrated System Concept for Monitoring and Evaluation of Safety Culture. This paper describes the outline of the study results reported by the study group and then introduces one of subsystems, SCEST, structuring the integrated system concept for Monitoring and Evaluation of Safety Culture. (author)
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Development Perspective of Regulatory Audit Code System for SFR Nuclear Safety Evaluation
Energy Technology Data Exchange (ETDEWEB)
Bae, Moo Hoon; Lee, Gil Soo; Shin, An Dong; Suh, Nam Duk [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)
2012-05-15
A sodium-cooled fast reactor (SFR) in Korea is based on the KALIMER-600 concept developed by KAERI. Based on 'Long-term R and D Plan for Future Reactor Systems' which was approved by the Korea Atomic Energy Commission in 2008, the KAERI designer is scheduled to apply the design certification of the prototype SFR in 2017. In order to establish regulatory infrastructure for the licensing of a prototype SFR, KINS has develop the regulatory requirements for the demonstration SFR since 2010, and are scheduled to develop the regulatory audit code systems in regard to core, fuel, and system, etc. since 2012. In this study, the domestic code systems used for core design and safety evaluation of PWRs and the nuclear physics and code system for SFRs were briefly reviewed, and the development perspective of regulatory audit code system for SFR nuclear safety evaluation were derived
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International Nuclear Information System (INIS)
1978-11-01
The safety evaluation for the Westinghouse Standard Reactor includes information on general reactor characteristics; design criteria for systems and components; reactor coolant system; engineered safety systems; instrumentation and controls; electric power systems; auxiliary systems; steam and power conversion system; radioactive waste management; radiation protection; conduct of operations; accident analyses; and quality assurance
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Rolita, Lisa; Surarso, Bayu; Gernowo, Rahmat
2018-02-01
In order to improve airport safety management system (SMS) performance, an evaluation system is required to improve on current shortcomings and maximize safety. This study suggests the integration of the DEMATEL and ANP methods in decision making processes by analyzing causal relations between the relevant criteria and taking effective analysis-based decision. The DEMATEL method builds on the ANP method in identifying the interdependencies between criteria. The input data consists of questionnaire data obtained online and then stored in an online database. Furthermore, the questionnaire data is processed using DEMATEL and ANP methods to obtain the results of determining the relationship between criteria and criteria that need to be evaluated. The study cases on this evaluation system were Adi Sutjipto International Airport, Yogyakarta (JOG); Ahmad Yani International Airport, Semarang (SRG); and Adi Sumarmo International Airport, Surakarta (SOC). The integration grades SMS performance criterion weights in a descending order as follow: safety and destination policy, safety risk management, healthcare, and safety awareness. Sturges' formula classified the results into nine grades. JOG and SMG airports were in grade 8, while SOG airport was in grade 7.
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International Nuclear Information System (INIS)
Naito, Yoshitaka; Koyama, Takashi; Komuro, Yuichi
1986-03-01
Critical enrichment and critical density of homogenous infinite systems, such as U-H 2 O, UO 2 -H 2 O, UO 2 F 2 aqueous solution, UO 2 (NO 3 ) 2 aqueous solution, Pu-H 2 O, PuO 2 -H 2 O, Pu(NO 3 ) 4 aqueous solution and PuO 2 ·UO 2 -H 2 O, were calculated with the criticality safety evaluation computer code system JACS for nuclear criticality safety evaluation on fuel facilities. The computed results were compared with the data described in European and American criticality handbooks and showed good agreement with each other. (author)
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Squale: evaluation criteria of functioning safety
International Nuclear Information System (INIS)
Deswarte, Y.; Kaaniche, M.; Benoit, P.
1998-05-01
The SQUALE (security, safety and quality evaluation for dependable systems) project is part of the ACTS (advanced communications, technologies and services) European program. Its aim is to develop confidence evaluation criteria to test the functioning safety of systems. All industrial sectors that use critical applications (nuclear, railway, aerospace..) are concerned. SQUALE evaluation criteria differ from the classical evaluation methods: they are independent of the application domains and industrial sectors, they take into account the overall functioning safety attributes, and they can progressively change according to the level of severity required. In order to validate the approach and to refine the criteria, a first experiment is in progress with the METEOR automatic underground railway and another will be carried out on a telecommunication system developed by Bouygues company. (J.S.)
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Preliminary safety evaluation for the spent nuclear fuel project`s cold vacuum drying system
Energy Technology Data Exchange (ETDEWEB)
Garvin, L.J., Westinghouse Hanford
1996-07-01
This preliminary safety evaluation (PSE) considers only the Cold Vacuum Drying System (CVDS) facility and its mission as it relates to the integrated process strategy (WHC 1995). The purpose of the PSE is to identify those CBDS design functions that may require safety- class and safety-significant accident prevention and mitigation features.
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Study on criticality safety evaluation of a system where flood will never occur
International Nuclear Information System (INIS)
Naito, Yoshitaka; Yamamoto, Toshihiro; Komuro, Yuichi; Itahara, Kuniyuki.
1995-03-01
Criticality safety evaluation for a single unit containing nuclear fuel has usually been performed on the assumption that there is a fully thick water reflector around the unit. For a system where flood will never occur, however, the thick reflector assumption is usually not applied recently. In such cases, a method is proposed, which models surrounding structural material and branch pipes as 2.5cm thick water reflector. This report shows that reactivity worth of structural material and branch pipes is, in many cases, less than that of 2.5cm thick water reflector. Further, another method is shown to evaluate criticality safety for a multiple unit system, using computed results with surrounding structural material and branch pipes neglected. And it is shown with many sample calculations that the method with 2.5cm thick water reflector in place of structural material and pipes gives safety side results to similar systems to real reprocessing plants. (author)
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Nuclear safety culture evaluation model based on SSE-CMM
International Nuclear Information System (INIS)
Yang Xiaohua; Liu Zhenghai; Liu Zhiming; Wan Yaping; Peng Guojian
2012-01-01
Safety culture, which is of great significance to establish safety objectives, characterizes level of enterprise safety production and development. Traditional safety culture evaluation models emphasis on thinking and behavior of individual and organization, and pay attention to evaluation results while ignore process. Moreover, determining evaluation indicators lacks objective evidence. A novel multidimensional safety culture evaluation model, which has scientific and completeness, is addressed by building an preliminary mapping between safety culture and SSE-CMM's (Systems Security Engineering Capability Maturity Model) process area and generic practice. The model focuses on enterprise system security engineering process evaluation and provides new ideas and scientific evidences for the study of safety culture. (authors)
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Safety Information System Guide
International Nuclear Information System (INIS)
Bullock, M.G.
1977-03-01
This Guide provides guidelines for the design and evaluation of a working safety information system. For the relatively few safety professionals who have already adopted computer-based programs, this Guide may aid them in the evaluation of their present system. To those who intend to develop an information system, it will, hopefully, inspire new thinking and encourage steps towards systems safety management. For the line manager who is working where the action is, this Guide may provide insight on the importance of accident facts as a tool for moving ideas up the communication ladder where they will be heard and acted upon; where what he has to say will influence beneficial changes among those who plan and control his operations. In the design of a safety information system, it is suggested that the safety manager make friends with a computer expert or someone on the management team who has some feeling for, and understanding of, the art of information storage and retrieval as a new and better means for communication
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A safety-critical decision support system evaluation using situation awareness and workload measures
International Nuclear Information System (INIS)
Naderpour, Mohsen; Lu, Jie; Zhang, Guangquan
2016-01-01
To ensure the safety of operations in safety-critical systems, it is necessary to maintain operators' situation awareness (SA) at a high level. A situation awareness support system (SASS) has therefore been developed to handle uncertain situations [1]. This paper aims to systematically evaluate the enhancement of SA in SASS by applying a multi-perspective approach. The approach consists of two SA metrics, SAGAT and SART, and one workload metric, NASA-TLX. The first two metrics are used for the direct objective and subjective measurement of SA, while the third is used to estimate operator workload. The approach is applied in a safety-critical environment called residue treater, located at a chemical plant in which a poor human-system interface reduced the operator's SA and caused one of the worst accidents in US history. A counterbalanced within-subjects experiment is performed using a virtual environment interface with and without the support of SASS. The results indicate that SASS improves operators' SA, and specifically has benefits for SA levels 2 and 3. In addition, it is concluded that SASS reduces operator workload, although further investigations in different environments with a larger number of participants have been suggested. - Highlights: • The suitability of a cognitive decision support system is investigated. • An evaluation approach considering situation awareness and workload measures is proposed. • A computerized system based on the proposed approach is implemented. • The implemented system is used in a safety-critical environment.
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International Nuclear Information System (INIS)
Takizawa, Masayuki; Sekimura, Naoto; Miyano, Hiroshi; Aoyama, Katsunobu
2012-01-01
Japanese safety regulatory body, that is, Nuclear and Industrial Safety Agency (NISA) started a 5-year national safety research project as 'the first stage' from 2006 FY to 2010 FY whose objective is 'Improve the technical information basis in order to utilize knowledge as well as information related to ageing management and maintenance of NPPs. Fukushima disaster happened in March 2011, and the priority of research needs for ageing management dramatically changed in Japan. The second-stage national project started in October 2011 with the concept of 'system safety' of NNPs where not only ageing management on degradation phenomena of important components but also safety management on total plant systems are paid attention to. The second-stage project is so called 'Japanese Ageing Management Program for System Safety (JAMPSS)'. (author)
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International Nuclear Information System (INIS)
Beugin, J.; Renaux, D.; Cauffriez, L.
2007-01-01
Safety analysis in guided transportation systems is essential to avoid rare but potentially catastrophic accidents. This article presents a quantitative probabilistic model that integrates Safety Integrity Levels (SIL) for evaluating the safety of such systems. The standardized SIL indicator allows the safety requirements of each safety subsystem, function and/or piece of equipment to be specified, making SILs pivotal parameters in safety evaluation. However, different interpretations of SIL exist, and faced with the complexity of guided transportation systems, the current SIL allocation methods are inadequate for the task of safety assessment. To remedy these problems, the model developed in this paper seeks to verify, during the design phase of guided transportation system, whether or not the safety specifications established by the transport authorities allow the overall safety target to be attained (i.e., if the SIL allocated to the different safety functions are sufficient to ensure the required level of safety). To meet this objective, the model is based both on the operating situation concept and on Monte Carlo simulation. The former allows safety systems to be formalized and their dynamics to be analyzed in order to show the evolution of the system in time and space, and the latter make it possible to perform probabilistic calculations based on the scenario structure obtained
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Guide for understanding and evaluation of safety culture
International Nuclear Information System (INIS)
2008-01-01
This report was the guide of understanding and evaluation of safety culture. Operator's activities for enhancement of safety culture in nuclear installations became an object of safety regulation in the management system. Evaluation of operator's activities (including top management's involvement) to prevent degradation of safety culture and organization climate in daily works needed understanding of safety culture and diversity of operator's activities. This guide was prepared to check indications of degradation of safety culture and organization climate in operator's activities in daily works and encourage operator's activities to enhance safety culture improvement and good practice. Comprehensive evaluation of operator's activities to prevent degradation of safety culture and organization climate would be performed from the standpoints of 14 safety culture elements such as top management commitment, clear plan and implementation of upper manager, measures to avoid wrong decision making, questioning attitude, reporting culture, good communications, accountability and openness, compliance, learning system, activities to prevent accidents or incidents beforehand, self-assessment or third party evaluation, work management, change management and attitudes/motivation. Element-wise examples and targets for evaluation were attached with evaluation check tables. (T. Tanaka)
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Development of a Test Equipment for Performance Evaluation of Safety Systems
International Nuclear Information System (INIS)
Kim, S. J.; Kwon, S. M.; Lee, J. M.; Kim, C. K.; Cho, C. H.; Chun, J. H.; Park, M. K.
2004-07-01
The purpose of this study is to develop a test equipment for performance evaluation of safety systems in nuclear power plants. First, we develop an input-output simulator for reactor protection systems, ESF component control systems, and a data acquisition system for these I/O simulators as a hardware for this equipment. Then, we develop a software for human-machine interface system, which is easy-to-use and easy-to-modify. In addition, a simulation tool for a reactor trip switch gear is developed
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International Nuclear Information System (INIS)
Yamauchi, Takamichi; Maki, Akira; Nojiri, Ichiro
1999-02-01
The fire and explosion incident of the bituminization facility happened in March 1997 although JNC had taken enough care of the safety of TRP. JNC reflected on it and decided to evaluate the safety of TRP voluntarily. This evaluation has included five activities, that is, (1) confirmation of the structure and organization of TRP, (2) research of the data for operation, radiation and maintenance of TRP, (3) research of reflection of the accidents and troubles which have happened at the past, (4) evaluation on the prevention system, (5) evaluation on the mitigation system. We publish this report to contribute to inheritance of accumulated knowledge and techniques from generation to generation, and remind us of lesson from the fire and explosion incident of the bituminization. (author)
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Experiment to evaluate software safety
International Nuclear Information System (INIS)
Soubies, B.; Henry, J.Y.
1994-01-01
The process of licensing nuclear power plants for operation consists of mandatory steps featuring detailed examination of the instrumentation and control system by the safety authorities, including softwares. The criticality of these softwares obliges the manufacturer to develop in accordance with the IEC 880 standard 'Computer software in nuclear power plant safety systems' issued by the International Electronic Commission. The evaluation approach, a two-stage assessment is described in detail. In this context, the IPSN (Institute of Protection and Nuclear Safety), the technical support body of the safety authority uses the MALPAS tool to analyse the quality of the programs. (R.P.). 4 refs
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International Nuclear Information System (INIS)
Johnson, C.
1989-01-01
This paper describes research to develop risk-based indicators of plant safety performance. One measure of the safety-performance of operating nuclear power plants is the unavailability of important safety systems. Brookhaven National Laboratory and Science Applications International Corporation are evaluating ways to aggregate train-level or component-level data to provide such an indicator. This type of indicator would respond to changes in plant safety margins faster than the currently used indicator of safety system unavailability (i.e., safety system failures reported in licensee event reports). Trends in the proposed indicator would be one indication of trends in plant safety performance and maintenance effectiveness. This paper summarizes the basis for such an indicator, identifies technical issues to be resolved, and illustrates the potential usefullness of such indicators by means of computer simulations and case studies
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International Nuclear Information System (INIS)
Inaba, Yoshitomo
2008-03-01
Aiming at the realization of the nuclear heat application system with a High Temperature Gas-cooled Reactor (HTGR), research and development on the whole evaluation of the system, the connection technology between the HTGR and a chemical plant such as the safety evaluation against the fire and explosion and the control technology, and the vessel cooling system of the HTGR were carried out. In the whole evaluation of the nuclear heat application system, an ammonia production system using nuclear heat was examined, and the technical subjects caused by the connection of the chemical plant to the HTGR were distilled. After distilling the subjects, the safety evaluation method against the fire and explosion to the reactor, the mitigation technology of thermal disturbance to the reactor, and the reactor core cooling by the vessel cooling system were discussed. These subjects are very important in terms of safety. About the fire and explosion, the safety evaluation method was established by developing the process and the numerical analysis code system. About the mitigation technology of the thermal disturbance, it was demonstrated that the steam generator, which was installed at the downstream of the chemical reactor in the chemical plant, could mitigate the thermal disturbance to the reactor. In order to enhance the safety of the reactor in accidents, the heat transfer characteristic of the passive indirect core cooling system was investigated, and the heat transfer equation considering both thermal radiation and natural convection was developed for the system design. As a result, some technical subjects related to safety in the nuclear heat application system were solved. (author)
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Safety culture management and quantitative indicator evaluation
International Nuclear Information System (INIS)
Mandula, J.
2002-01-01
This report discuses a relationship between safety culture and evaluation of quantitative indicators. It shows how a systematic use of generally shared operational safety indicators may contribute to formation and reinforcement of safety culture characteristics in routine plant operation. The report also briefly describes the system of operational safety indicators used at the Dukovany plant. It is a PC database application enabling an effective work with the indicators and providing all users with an efficient tool for making synoptic overviews of indicator values in their links and hierarchical structure. Using color coding, the system allows quick indicator evaluation against predefined limits considering indicator value trends. The system, which has resulted from several-year development, was completely established at the plant during the years 2001 and 2002. (author)
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Safety Evaluation of Full Digital Plant Protection System of Shin-Kori 3 and 4 in Korea
International Nuclear Information System (INIS)
Koh, J. S.; Kim, D. I.; Jeong, C. H.; Park, H. S.; Ji, S. H.; Kang, Y. D.; Park, G. Y.
2009-01-01
Keeping pace with the emerging trend of digital computer technologies, KHNP has utilized full digital plant protection system into the design of I and C systems at SKN 3 and 4. This paper presents safety review activities and results related to digital plant protection systems during the licensing of construction permit for the Shin-Kori 3 and 4(SKN 3 and 4) in Korea. The major licensing issues regarding the digital systems were software quality and cyber security during planning stage, system integrity with fail-safe design, EMI equipment qualification of digital systems, FPGA qualification and communication independence between safety and non-safety System. This paper addresses our approach to evaluate full digital protection systems with revised safety review guidelines and the resulting discussion to resolve the licensing issues
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Contribution at the evaluation of safety softwares in nuclear power plants control systems
International Nuclear Information System (INIS)
Soubies, B.; Le Meur, M.; Henry, J.Y.; Boulc'h, J.
1993-06-01
The introduction of programmable systems such the SPIN (Numerical Integrated Protection System) has conducted at particular dispositions for the conception and the use of such systems. The utilization of such systems until 1983 has conducted at modifications in the maintenance procedures. The new methods used for the N4 project in the evaluation of safety softwares are given in this report
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A Methodological Framework for Software Safety in Safety Critical Computer Systems
P. V. Srinivas Acharyulu; P. Seetharamaiah
2012-01-01
Software safety must deal with the principles of safety management, safety engineering and software engineering for developing safety-critical computer systems, with the target of making the system safe, risk-free and fail-safe in addition to provide a clarified differentaition for assessing and evaluating the risk, with the principles of software risk management. Problem statement: Prevailing software quality models, standards were not subsisting in adequately addressing the software safety ...
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Implementation and evaluation of a prototype consumer reporting system for patient safety events.
Weingart, Saul N; Weissman, Joel S; Zimmer, Karen P; Giannini, Robert C; Quigley, Denise D; Hunter, Lauren E; Ridgely, M Susan; Schneider, Eric C
2017-08-01
No methodologically robust system exists for capturing consumer-generated patient safety reports. To address this challenge, we developed and pilot-tested a prototype consumer reporting system for patient safety, the Health Care Safety Hotline. Mixed methods evaluation. The Hotline was implemented in two US healthcare systems from 1 February 2014 through 30 June 2015. Patients, family members and caregivers associated with two US healthcare systems. A consumer-oriented incident reporting system for telephone or web-based administration was developed to elicit medical mistakes and care-related injuries. Key informant interviews, measurement of website traffic and analysis of completed reports. Key informants indicated that Hotline participation was motivated by senior leaders' support and alignment with existing quality and safety initiatives. During the measurement period from 1 October 2014 through 30 June 2015, the home page had 1530 visitors with a unique IP address. During its 17 months of operation, the Hotline received 37 completed reports including 20 mistakes without harm and 15 mistakes with injury. The largest category of mistake concerned problems with diagnosis or advice from a health practitioner. Hotline reports prompted quality reviews, an education intervention, and patient follow-ups. While generating fewer reports than its capacity to manage, the Health Care Safety Hotline demonstrated the feasibility of consumer-oriented patient safety reporting. Further research is needed to understand how to increase consumers' use of these systems. © The Author 2017. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com
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International Nuclear Information System (INIS)
Takano, Kenichi; Tsuge, Tadafumi; Hasegawa, Naoko; Hirose, Ayako; Sasou, Kunihide
2002-01-01
CRIEPI decided to develop the safety evaluation system to investigate the safety level of the industrial sites due to questionnaires of organizational climate, safety managements, and workers' safety consciousness to workers. This report describes the questionnaire survey to apply to the domestic nuclear power plant for using obtained results as a fundamental data in order to construct the safety evaluation system. This system will be used for promoting safety culture in organizations of nuclear power plants. The questionnaire survey was conducted to 14 nuclear power stations for understanding the present status relating to safety issues. This questionnaire involves 122 items classified into following three categories: (1) safety awareness and behavior of plant personnel; (2) safety management; (3) organizational climate, based on the model considering contributing factor groups to safety culture. Obtained results were analyzed by statistical method to prepare functions of evaluation. Additionally, by applying a multivariate analysis, it was possible to extract several crucial factors influencing safety performance and to find a comprehensive safety indicator representing total organizational safety level. Significant relations were identified between accident rates (both labor accidents and facility failures) and above comprehensive safety indicator. Next, 122 questionnaire items were classified into 20 major safety factors to grasp the safety profiles of each site. This profile is considered as indicating the features of each site and also indicating the direction of progress for improvement of safety situation in the site. These findings can be reflected in developing the safety evaluation system, by confirming the validity of the evaluation method and giving specific functions. (author)
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Basic principles on the safety evaluation of the HTGR hydrogen production system
International Nuclear Information System (INIS)
Ohashi, Kazutaka; Nishihara, Tetsuo; Tazawa, Yujiro; Tachibana, Yukio; Kunitomi, Kazuhiko
2009-03-01
As HTGR hydrogen production systems, such as HTTR-IS system or GTHTR300C currently being developed by Japan Atomic Energy Agency, consists of nuclear reactor and chemical plant, which are without a precedent in the world, safety design philosophy and regulatory framework should be newly developed. In this report, phenomena to be considered and events to be postulated in the safety evaluation of the HTGR hydrogen production systems were investigated and basic principles to establish acceptance criteria for the explosion and toxic gas release accidents were provided. Especially for the explosion accident, quantitative criteria to the reactor building are proposed with relating sample calculation results. It is necessary to treat abnormal events occurred in the hydrogen production system as an 'external events to the nuclear plant' in order to classify the hydrogen production system as no-nuclear facility' and basic policy to meet such requirement was also provided. (author)
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Evaluating software for safety systems in nuclear power plants
International Nuclear Information System (INIS)
Lawrence, J.D.; Persons, W.L.; Preckshot, G.G.; Gallagher, J.
1994-01-01
In 1991, LLNL was asked by the NRC to provide technical assistance in various aspects of computer technology that apply to computer-based reactor protection systems. This has involved the review of safety aspects of new reactor designs and the provision of technical advice on the use of computer technology in systems important to reactor safety. The latter includes determining and documenting state-of-the-art subjects that require regulatory involvement by the NRC because of their importance in the development and implementation of digital computer safety systems. These subjects include data communications, formal methods, testing, software hazards analysis, verification and validation, computer security, performance, software complexity and others. One topic software reliability and safety is the subject of this paper
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Energy Technology Data Exchange (ETDEWEB)
Kim, Myung Hyeon; Shin, Myeong Won; Rhy, Seok Jin; Cho, Dong Keon; Park, Dong Hwan [Kyunghee Univ., Seoul (Korea, Republic of); Cheong, Beom Jin [Minstry of Science and Technology, Gwacheon (Korea, Republic of)
1998-03-15
The main objective os to develop a technical standards for the facility operation of the interm, spent fuel storage facility and to develop a draft for the technical criteria to be legislated. The another objective os to define a uncertainty evaluation system for burn up credit application in criticality analysis and to investigate an applicability of this topic for future regulatory activity. Investigate a status of art for the operational criteria of spent fuel interm wet storage. Collect relevant laws, decree, notices and standards related to the operation of storage facility and study on the legislation system. Develop a draft of technical standards and criteria to be legislated. Define an evaluation system for the uncertainty analysis and study on the status of art in the field of criticality safety analysis. Develop an uncertainty evaluation system in criticality analysis with burnup credit and investigate an applicability as well as its benefits of this policy.
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Evaluation of temporary non-code repairs in safety class 3 piping systems
International Nuclear Information System (INIS)
Godha, P.C.; Kupinski, M.; Azevedo, N.F.
1996-01-01
Temporary non-ASME Code repairs in safety class 3 pipe and piping components are permissible during plant operation in accordance with Nuclear Regulatory Commission Generic Letter 90-05. However, regulatory acceptance of such repairs requires the licensee to undertake several timely actions. Consistent with the requirements of GL 90-05, this paper presents an overview of the detailed evaluation and relief request process. The technical criteria encompasses both ductile and brittle piping materials. It also lists appropriate evaluation methods that a utility engineer can select to perform a structural integrity assessment for design basis loading conditions to support the use of temporary non-Code repair for degraded piping components. Most use of temporary non-code repairs at a nuclear generating station is in the service water system which is an essential safety related system providing the ultimate heat sink for various plant systems. Depending on the plant siting, the service water system may use fresh water or salt water as the cooling medium. Various degradation mechanisms including general corrosion, erosion/corrosion, pitting, microbiological corrosion, galvanic corrosion, under-deposit corrosion or a combination thereof continually challenge the pressure boundary structural integrity. A good source for description of corrosion degradation in cooling water systems is provided in a cited reference
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Study on safety performance evaluation system of nuclear engineering construction units based on AHP
International Nuclear Information System (INIS)
Xu Yulin; Sun Jian; Shi Xiaofan
2012-01-01
As a very effectual management mean, the performance management has extensively used by many companies of China for staff assessment. The author explored the establishment of the 'Safety Performance Evaluation System' by finding out the similarities in operation between a company and a team of nuclear power projects. Then the author analyzed the principles of the performance management and good practices and summarized safety management experiences. The weight of the system index by using AHP method was calculated in this article. (authors)
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LNG Safety Assessment Evaluation Methods
Energy Technology Data Exchange (ETDEWEB)
Muna, Alice Baca [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); LaFleur, Angela Christine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-05-01
Sandia National Laboratories evaluated published safety assessment methods across a variety of industries including Liquefied Natural Gas (LNG), hydrogen, land and marine transportation, as well as the US Department of Defense (DOD). All the methods were evaluated for their potential applicability for use in the LNG railroad application. After reviewing the documents included in this report, as well as others not included because of repetition, the Department of Energy (DOE) Hydrogen Safety Plan Checklist is most suitable to be adapted to the LNG railroad application. This report was developed to survey industries related to rail transportation for methodologies and tools that can be used by the FRA to review and evaluate safety assessments submitted by the railroad industry as a part of their implementation plans for liquefied or compressed natural gas storage ( on-board or tender) and engine fueling delivery systems. The main sections of this report provide an overview of various methods found during this survey. In most cases, the reference document is quoted directly. The final section provides discussion and a recommendation for the most appropriate methodology that will allow efficient and consistent evaluations to be made. The DOE Hydrogen Safety Plan Checklist was then revised to adapt it as a methodology for the Federal Railroad Administration’s use in evaluating safety plans submitted by the railroad industry.
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Construction of Earthquake-Proof Safety Evaluation Methods for Pipes with Wall Thinning
International Nuclear Information System (INIS)
Miyano, Hiroshi; Sekimura, Naoto; Takizawa, Masayuki; Matsumoto, Masaaki
2012-01-01
After the accident at the Fukushima Daiichi Nuclear Power Plant, the extreme importance of 'system safety' evaluation has been recognized. In this study, some fundamental ways of thinking about the concept of 'system safety' for operating plants is shown, and concrete evaluation structures of system safety are proposed. System safety for nuclear power plants and safety assessment for aging plants are constructed. (author)
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Philosophy of safety evaluation on fast breeder reactor
International Nuclear Information System (INIS)
1981-01-01
This is the report submitted from the special subcommittee on reactor safety standard to the Nuclear Safety Commission on October 14, 1980, and it was decided to temporarily apply this concept to the safety examination on fast breeder reactors. The examination and discussion of this report were performed by taking the prototype reactor ''Monju'' into consideration, which is to be the present target, referring to the philosophy of the safety evaluation on fast breeder reactors in foreign countries and based on the experiences in the fast experimental reactor ''Joyo''. The items applicable to the safety evaluation for liquid metal-cooled fast breeder reactors (LMFBR) as they are among the existing safety examination guidelines are applied. In addition to the existing guidelines, the report describes the matters to be considered specifically for core, fuel, sodium, sodium void, reactor shut-down system, reactor coolant boundary, cover gas boundary and others, intermediate cooling system, removal of decay heat, containment vessels, high temperature structures, and aseismatic property in the safety design of LMFBR's. For the safety evaluation for LMFBR's, the abnormal transient changes in operation and the phenomena to be evaluated as accidents are enumerated. In order to judge the propriety of the criteria of locating LMFBR facilities, the serious and hypothetical accidents are decided to be evaluated in accordance with the guideline for reactor location investigation. (Wakatsuki, Y.)
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Generic safety evaluation report regarding integrity of BWR scram system piping
International Nuclear Information System (INIS)
1981-08-01
Safety concerns associated with postulated pipe breaks in the boiling water reactor (BWR) scram system were identified during the staff's continuing investigation of the Browns Ferry Unit 3 control rod partial insertion failure on June 28, 1980. This report includes an evaluation of the licensing basis for the BWR scram discharge volume (SDV) piping and an assessment of the potential for the SDV piping to fail while in service. A discussion of the means available for mitigation an unlikely SDV system failure is provided. Generic recommendations are made to improve mitigation capability and ensure that system integrity is maintained in service
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An efficient method for evaluating the effect of input parameters on the integrity of safety systems
International Nuclear Information System (INIS)
Tang, Zhang-Chun; Zuo, Ming J.; Xiao, Ningcong
2016-01-01
Safety systems are significant to reduce or prevent risk from potentially dangerous activities in industry. Probability of failure to perform its functions on demand (PFD) for safety system usually exhibits variation due to the epistemic uncertainty associated with various input parameters. This paper uses the complementary cumulative distribution function of the PFD to define the exceedance probability (EP) that the PFD of the system is larger than the designed value. Sensitivity analysis of safety system is further investigated, which focuses on the effect of the variance of an individual input parameter on the EP resulting from epistemic uncertainty associated with the input parameters. An available numerical technique called finite difference method is first employed to evaluate the effect, which requires extensive computational cost and needs to select a step size. To address these difficulties, this paper proposes an efficient simulation method to estimate the effect. The proposed method needs only an evaluation to estimate the effects corresponding to all input parameters. Two examples are used to demonstrate that the proposed method can obtain more accurate results with less computation time compared to reported methods. - Highlights: • We define a sensitivity index to measure effect of a parameter for safety system. • We analyze the physical meaning of the sensitivity index. • We propose an efficient simulation method to assess the sensitivity index. • We derive the formulations of this index for lognormal and beta distributions. • Results identify important parameters on exceedance probability of safety system.
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Evaluation of Four Bedside Test Systems for Card Performance, Handling and Safety.
Giebel, Felix; Picker, Susanne M; Gathof, Birgit S
2008-01-01
SUMMARY: OBJECTIVE: Pretransfusion ABO compatibility testing is a simple and required precaution against ABO-incompatible transfusion, which is one of the greatest threats in transfusion medicine. While distinct agglutination is most important for correct test interpretation, protection against infectious diseases and ease of handling are crucial for accurate test performance. Therefore, the aim of this study was to evaluate differences in test card design, handling, and user safety. DESIGN: Four different bedside test cards with pre-applied antibodies were evaluated by 100 medical students using packed red blood cells of different ABO blood groups. Criteria of evaluation were: agglutination, labelling, handling, and safety regarding possible user injuries. Criteria were rated subjectively according to German school notes ranging from 1 = very good to 6 = very bad/insufficient. RESULTS: Overall, all cards received very good/good marks. The ABO blood group was identified correctly in all cases. Three cards (no. 1, no. 3, no. 4) received statistically significant (p labelling (1.5 vs. 2.2-2.4), handling (1.9-2.0 vs. 2.5), and user safety (2.5 vs. 3.4). Analysis of card self-explanation revealed no remarkable differences. CONCLUSION: Despite good performance of all card systems tested, the best results when including all criteria evaluated were obtained with card no. 4 (particularly concerning clear agglutination), followed by cards no. 2, no. 1, and no. 3.
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Energy Technology Data Exchange (ETDEWEB)
NONE
2013-08-15
The purposes of this study are to perform the safety evaluations of the fast breeder reactor 'Monju' and to confirm the validity of the safety evaluation methods. In JFY 2012, the following results were obtained. As for the development of safety evaluation methods needed in the safety examination achieved for the reactor establishment permission, development of the analysis codes, such as a core damage analysis code, were carried out according to the plan. As for the development of the safety evaluation method needed for the risk informed safety regulation, the quantification technique of the event tree using the Continuous Markov chain Monte Carlo method (CMMC method) were studied. (author)
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A study of software safety analysis system for safety-critical software
International Nuclear Information System (INIS)
Chang, H. S.; Shin, H. K.; Chang, Y. W.; Jung, J. C.; Kim, J. H.; Han, H. H.; Son, H. S.
2004-01-01
The core factors and requirements for the safety-critical software traced and the methodology adopted in each stage of software life cycle are presented. In concept phase, Failure Modes and Effects Analysis (FMEA) for the system has been performed. The feasibility evaluation of selected safety parameter was performed and Preliminary Hazards Analysis list was prepared using HAZOP(Hazard and Operability) technique. And the check list for management control has been produced via walk-through technique. Based on the evaluation of the check list, activities to be performed in requirement phase have been determined. In the design phase, hazard analysis has been performed to check the safety capability of the system with regard to safety software algorithm using Fault Tree Analysis (FTA). In the test phase, the test items based on FMEA have been checked for fitness guided by an accident scenario. The pressurizer low pressure trip algorithm has been selected to apply FTA method to software safety analysis as a sample. By applying CASE tool, the requirements traceability of safety critical system has been enhanced during all of software life cycle phases
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Evaluation of Safety Culture Implementation and Socialization Results
International Nuclear Information System (INIS)
Situmorang, Johnny
2003-01-01
Evaluation of safety culture implementation and socialization results has been perform. Evaluation is carried out with specifying safety culture indicators, namely: Meeting between management and employee, system for incidents analysis, training activities related to improving safety, meeting with regulator, contractors, surveys on behavioural attitudes, and resources allocated to promote safety culture. Evaluation is based on observation and visiting the facilities to show the compliance indicator in term of good practices in the frame of safety culture implementation. For three facilities of research reactors, Kartini Yogyakarta, TRIGA Mark II Bandung and MPR-GAS Serpong, implementation of safety culture is considered good enough and progressive. Furthermore some indicator should be considered more intensive, for example the allocated resources, self assesment based on own questionnaire in the frame of improving the safety culture implementation. (author)
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International Nuclear Information System (INIS)
Kwon, Kee-Choon; Lee, Jang-Soo; Jee, Eunkyoung
2016-01-01
Nuclear safety-critical software is under strict regulatory requirements and these regulatory requirements are essential for ensuring the safety of nuclear power plants. The verification & validation (V and V) and hazard analysis of the safety-critical software are required to follow regulatory requirements through the entire software life cycle. In order to obtain a license from the regulatory body through the development and validation of safety-critical software, it is essential to meet the standards which are required by the regulatory body throughout the software development process. Generally, large amounts of documents, which demonstrate safety justification including standard compliance, V and V, hazard analysis, and vulnerability assessment activities, are submitted to the regulatory body during the licensing process. It is not easy to accurately read and evaluate the whole documentation for the development activities, implementation technology, and validation activities. The safety case methodology has been kwon a promising approach to evaluate the level and depth of the development and validation results. A safety case is a structured argument, supported by a body of evidence that provides a compelling, comprehensible, and valid case that a system is safe for a given application in a given operating environment. It is suggested to evaluate the level and depth of the results of development and validation by applying safety case methodology to achieve software safety demonstration. A lot of documents provided as evidence are connected to claim that corresponds to the topic for safety demonstration. We demonstrated a case study in which more systematic safety demonstration for the target system software is performed via safety case construction than simply listing the documents
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Energy Technology Data Exchange (ETDEWEB)
Kwon, Kee-Choon; Lee, Jang-Soo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jee, Eunkyoung [KAIST, Daejeon (Korea, Republic of)
2016-10-15
Nuclear safety-critical software is under strict regulatory requirements and these regulatory requirements are essential for ensuring the safety of nuclear power plants. The verification & validation (V and V) and hazard analysis of the safety-critical software are required to follow regulatory requirements through the entire software life cycle. In order to obtain a license from the regulatory body through the development and validation of safety-critical software, it is essential to meet the standards which are required by the regulatory body throughout the software development process. Generally, large amounts of documents, which demonstrate safety justification including standard compliance, V and V, hazard analysis, and vulnerability assessment activities, are submitted to the regulatory body during the licensing process. It is not easy to accurately read and evaluate the whole documentation for the development activities, implementation technology, and validation activities. The safety case methodology has been kwon a promising approach to evaluate the level and depth of the development and validation results. A safety case is a structured argument, supported by a body of evidence that provides a compelling, comprehensible, and valid case that a system is safe for a given application in a given operating environment. It is suggested to evaluate the level and depth of the results of development and validation by applying safety case methodology to achieve software safety demonstration. A lot of documents provided as evidence are connected to claim that corresponds to the topic for safety demonstration. We demonstrated a case study in which more systematic safety demonstration for the target system software is performed via safety case construction than simply listing the documents.
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Parameters Evaluation of PLC Dependability and Safety
Directory of Open Access Journals (Sweden)
Juraj Zdansky
2006-01-01
Full Text Available This paper is focused on evaluation of dependability and safety parameters of PLC (Programmable Logic Controller. Achievement of requested level of these parameters is an application assumption for using PLC in control of safety critical processes. Evaluation of these parameters can be made on the base of suitable model and it can be influenced by system architecture when necessary.
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International Nuclear Information System (INIS)
Hasegawa, Naoko; Hirose, Ayako; Hayase, Kenichi; Tsuge, Tadafumi; Sasou, Kunihide; Takano, Kenichi
2003-01-01
The purpose of our study is to develop a safety evaluation system which clarifies the safety level of an organization. As a basic method of evaluation using a questionnaire had been established, now that the generalization is needed for the system. Hence, this paper is intended to consider the applicability of the system for contract companies. Subjects were workers who belonged to contract companies engaging in the maintenance of power plants in regular inspections. The following results were obtained: 1) The Comprehensive Safety Index (CSI) taking into account individual and organizational factors was identified using the principal component analysis. 2) The validity of CSI was confirmed with significant correlations between the CSI score and the rate of accidents. 3) Careful consideration should be provided for individual factors especially when evaluating the safety level of subcontract companies. 4) It seemed necessary to take into account the influence of parent companies and occupational hazards level. 5) The comparison among different industries should be avoided because of the difference in organizational structures and subjects of attention for keeping safety. (author)
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Mohammadfam, Iraj; Kamalinia, Mojtaba; Momeni, Mansour; Golmohammadi, Rostam; Hamidi, Yadollah; Soltanian, Alireza
2017-06-01
Occupational Health and Safety Management Systems are becoming more widespread in organizations. Consequently, their effectiveness has become a core topic for researchers. This paper evaluates the performance of the Occupational Health and Safety Assessment Series 18001 specification in certified companies in Iran. The evaluation is based on a comparison of specific criteria and indictors related to occupational health and safety management practices in three certified and three noncertified companies. Findings indicate that the performance of certified companies with respect to occupational health and safety management practices is significantly better than that of noncertified companies. Occupational Health and Safety Assessment Series 18001-certified companies have a better level of occupational health and safety; this supports the argument that Occupational Health and Safety Management Systems play an important strategic role in health and safety in the workplace.
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Jefferson Lab IEC 61508/61511 Safety PLC Based Safety System
International Nuclear Information System (INIS)
Mahoney, Kelly; Robertson, Henry
2009-01-01
This paper describes the design of the new 12 GeV Upgrade Personnel Safety System (PSS) at the Thomas Jefferson National Accelerator Facility (TJNAF). The new PSS design is based on the implementation of systems designed to meet international standards IEC61508 and IEC 61511 for programmable safety systems. In order to meet the IEC standards, TJNAF engineers evaluated several SIL 3 Safety PLCs before deciding on an optimal architecture. In addition to hardware considerations, software quality standards and practices must also be considered. Finally, we will discuss R and D that may lead to both high safety reliability and high machine availability that may be applicable to future accelerators such as the ILC.
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Intermediate probabilistic safety assessment approach for safety critical digital systems
International Nuclear Information System (INIS)
Taeyong, Sung; Hyun Gook, Kang
2001-01-01
Even though the conventional probabilistic safety assessment methods are immature for applying to microprocessor-based digital systems, practical needs force to apply it. In the Korea, UCN 5 and 6 units are being constructed and Korean Next Generation Reactor is being designed using the digital instrumentation and control equipment for the safety related functions. Korean regulatory body requires probabilistic safety assessment. This paper analyzes the difficulties on the assessment of digital systems and suggests an intermediate framework for evaluating their safety using fault tree models. The framework deals with several important characteristics of digital systems including software modules and fault-tolerant features. We expect that the analysis result will provide valuable design feedback. (authors)
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Nuclear Power Safety Reporting System. Final evaluation results
International Nuclear Information System (INIS)
Finlayson, F.C.; Newton, R.D.
1986-02-01
This document presents the results of a study conducted by the US Nuclear Regulatory Commission of an unobtrusive, voluntary, anonymous third-party managed, nonpunitive human factors data gathering system (the Nuclear power Safety Reporting System - NPSRS) for the nuclear electric power production industry. The data to be gathered by the NPSRS are intended for use in identifying and quantifying the factors that contribute to the occurrence of significant safety incidents involving humans in nuclear power plants. The NPSRS has been designed to encourage participation in the System through guarantees of reporter anonymity provided by a third-party organization that would be responsible for NPSRS management. As additional motivation to reporters for contributing data to the NPSRS, conditional waivers of NRC disciplinary action would be provided to individuals. These conditional waivers of immunity would apply to potential violations of NRC regulations that might be disclosed through reports submitted to the System about inadvertent, noncriminal incidents in nuclear plants. This document summarizes the overall results of the study of the NPSRS concept. In it, a functional description of the NPSRS is presented together with a review and assessment of potential problem areas that might be met if the System were implemented. Conclusions and recommendations resulting from the study are also presented. A companion volume (NUREG/CR-4133, Nuclear Power Safety Reporting System: Implementation and Operational Specifications'') presented in detail the elements, requirements, forms, and procedures for implementing and operating the System. 13 refs
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Evaluation of food safety management systems in Serbian dairy industry
Directory of Open Access Journals (Sweden)
Igor Tomašević
2016-01-01
Full Text Available This paper reports incentives, costs, difficulties and benefits of food safety management systems implementation in the Serbian dairy industry. The survey involved 27 food business operators with the national milk and dairy market share of 65 %. Almost two thirds of the assessed dairy producers (70.4 % claimed that they had a fully operational and certified HACCP system in place, while 29.6 % implemented HACCP, but had no third party certification. ISO 22000 was implemented and certified in 29.6 % of the companies, while only 11.1 % had implemented and certified IFS standard. The most important incentive for implementing food safety management systems for Serbian dairy producers was to increase and improve safety and quality of dairy products. The cost of product investigation/analysis and hiring external consultants were related to the initial set-up of food safety management system with the greatest importance. Serbian dairy industry was not greatly concerned by the financial side of implementing food safety management systems due to the fact that majority of prerequisite programmes were in place and regularly used by almost 100 % of the producers surveyed. The presence of competency gap between the generic knowledge for manufacturing food products and the knowledge necessary to develop and implement food safety management systems was confirmed, despite the fact that 58.8 % of Serbian dairy managers had university level of education. Our study brings about the innovation emphasizing the attitudes and the motivation of the food production staff as the most important barrier for the development and implementation of HACCP. The most important identified benefit was increased safety of dairy products with the mean rank scores of 6.85. The increased customer confidence and working discipline of staff employed in food processing were also found as important benefits of implementing/operating HACCP. The study shows that the level of HACCP
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Seismic evaluation of safety systems at the Savannah River reactors
International Nuclear Information System (INIS)
Hardy, G.S.; Johnson, J.J.; Eder, S.J.; Monahon, T.M.; Ketcham, D.R.
1989-01-01
A thorough review of all safety related systems in commercial nuclear power plants was prompted by the accident at the Three Mile Island Nuclear Power Plant. As a consequence of this review, the Nuclear Regulatory Commission (NRC) focused its attention on the environmental and seismic qualification of the industry's electrical and mechanical equipment. In 1980, the NRC issued Unresolved Safety Issue (USI) A-46 to verify the seismic adequacy of the equipment required to safely shut down a plant and maintain a stable condition for 72 hours. After extensive research by the NRC, it became apparent that traditional analysis and testing methods would not be a feasible mechanism to address this USI A-46 issue. The costs associated with utilizing the standard analytical and testing qualification approaches were exorbitant and could not be justified. In addition, the only equipment available to be shake table testing which is similar to the item being qualified is typically the nuclear plant component itself. After 8 years of studies and data collection, the NRC issued its ''Generic Safety Evaluation Report'' approving an alternate seismic qualification approach based on the use of seismic experience data. This experience-based seismic assessment approach will be the basis for evaluating each of the 70 pre-1972 commercial nuclear power units in the United States and for an undetermined number of nuclear plants located in foreign countries. This same cost-effective developed for the commercial nuclear power industry is currently being applied to the Savannah River Production Reactors to address similar seismic adequacy issues. This paper documents the results of the Savannah River Plant seismic evaluating program. This effort marks the first complete (non-trial) application of this state-of-the-art USI A-46 resolution methodology
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Seismic evaluation of safety systems at the Savannah River reactors
International Nuclear Information System (INIS)
Hardy, G.S.; Johnson, J.J.; Eder, S.J.; Monahon, T.; Ketcham, D.
1989-01-01
A thorough review of all safety related systems in commercial nuclear power plants was prompted by the accident at the Three Mile Island Nuclear Power Plant. As a consequence of this review, the Nuclear Regulatory Commission (NRC) focused its attention on the environmental and seismic qualification of the industry's electrical and mechanical equipment. In 1980, the NRC issued Unresolved Safety Issue (USI) A-46 to verify the seismic adequacy of the equipment required to safely shut down a plant and maintain a stable condition for 72 hours. After extensive research by the NRC, it became apparent that traditional analysis and testing methods would not be a feasible mechanism to address this USI A-46 issue. The costs associated with utilizing the standard analytical and testing qualification approaches were exorbitant and could not be justified. In addition, the only equipment available to be shake table tested which is similar to the item being qualified is typically the nuclear plant component itself. After 8 years of studies and data collection, the NRC issued its Generic Safety Evaluation Report approving an alternate seismic qualification approach based on the use of seismic experience data. This experience-based seismic assessment approach will be the basis for evaluating each of the 70 pre-1972 commercial nuclear power units in the US and for an undetermined number of nuclear plants located in foreign countries. This same cost-effective approach developed for the commercial nuclear power industry is currently being applied to the Savannah River Production Reactors to address similar seismic adequacy issues. This paper documents the results of the Savannah River Plant seismic evaluation program. This effort marks the first complete (non-trial) application of this state-of-the-art USI A-46 resolution methodology
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Energy systems evaluation of potential for incidents having health or safety impact
International Nuclear Information System (INIS)
Speas, I.G.
1986-01-01
The paper discusses the results of safety surveys of Martin Marietta Energy Systems - operated nuclear facilities. The purpose was to identify potential incidents that could cause large numbers of casualties, evaluate existing prevention/response actions, and identify possible improvements. The survey findings indicate the potential for an accident with consequences similar to those at Bhopal, India, is essentially non-existent
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International Nuclear Information System (INIS)
Aoki, Takayuki
2010-01-01
In this study, a quantitative method on maintenance level which is determined by the two factors, maintenance plan and field work implementation ability by maintenance crew is discussed. And also a quantitative evaluation method on safety level for giant complex plant system is discussed. As a result of consideration, the following results were obtained. (1) It was considered that equipment condition after maintenance work was determined by the two factors, maintenance plan and field work implementation ability possessed by maintenance crew. The equipment condition determined by the two factors was named as 'equipment maintenance level' and its quantitative evaluation method was clarified. (2) It was considered that CDF in a nuclear power plant, evaluated by using a failure rate counting the above maintenance level was quite different from CDF evaluated by using existing failure rates including a safety margin. Then, the former CDF was named as 'plant safety level' of plant system and its quantitative evaluation method was clarified. (3) Enhancing equipment maintenance level means an improvement of maintenance quality. That results in the enhancement of plant safety level. Therefore, plant safety level should be always watched as a plant performance indicator. (author)
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Safety Review related to Commercial Grade Digital Equipment in Safety System
International Nuclear Information System (INIS)
Yu, Yeongjin; Park, Hyunshin; Yu, Yeongjin; Lee, Jaeheung
2013-01-01
The upgrades or replacement of I and C systems on safety system typically involve digital equipment developed in accordance with non-nuclear standards. However, the use of commercial grade digital equipment could include the vulnerability for software common-mode failure, electromagnetic interference and unanticipated problems. Although guidelines and standards for dedication methods of commercial grade digital equipment are provided, there are some difficulties to apply the methods to commercial grade digital equipment for safety system. This paper focuses on regulatory guidelines and relevant documents for commercial grade digital equipment and presents safety review experiences related to commercial grade digital equipment in safety system. This paper focuses on KINS regulatory guides and relevant documents for dedication of commercial grade digital equipment and presents safety review experiences related to commercial grade digital equipment in safety system. Dedication including critical characteristics is required to use the commercial grade digital equipment on safety system in accordance with KEPIC ENB 6370 and EPRI TR-106439. The dedication process should be controlled in a configuration management process. Appropriate methods, criteria and evaluation result should be provided to verify acceptability of the commercial digital equipment used for safety function
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Modelling safety of multistate systems with ageing components
Energy Technology Data Exchange (ETDEWEB)
Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna [Gdynia Maritime University, Department of Mathematics ul. Morska 81-87, Gdynia 81-225 Poland (Poland)
2016-06-08
An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive “m out of n: F” is presented as well.
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Modelling safety of multistate systems with ageing components
International Nuclear Information System (INIS)
Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna
2016-01-01
An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive “m out of n: F” is presented as well.
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Operational safety evaluation for minor reactor accidents
International Nuclear Information System (INIS)
Wang, O.S.
1981-01-01
The purpose of this paper is to address a concern of applying conservatism in analysing minor reactor incidents. A so-called ''conservative'' safety analysis may exaggerate the system responses and result in a reactor scram tripped by the reactor protective system (RPS). In reality, a minor incident may lead the reactor to a new thermal hydraulic steady-state without scram, and the mitigation or termination of the incident may entirely depend on operator actions. An example on a small steamline break evaluation for a pressurized water reactor recently investigated by the staff at the Washington Public Power Supply System is presented to illustrate this point. A safety evaluation using mainly the safety-related systems to be consistent with the conservative assumptions used in the Safety Analysis Report was conducted. For comparison, a realistic analysis was also performed using both the safety- and control-related systems. The analyses were performed using the RETRAN plant simulation computer code. The ''conservative'' safety analysis predicts that the incident can be turned over by the RPS scram trips without operator intervention. However, the realistic analysis concludes that the reactor will reach a new steady-state at a different plant thermal hydraulic condition. As a result, the termination of the incident at this stage depends entirely on proper operator action. On the basis of this investigation it is concluded that, for minor incidents, ''conservative'' assumptions are not necessary, sometimes not justifiable. A realistic investigation from the operational safety point of view is more appropriate. It is essential to highlight the key transient indications for specific incident recognition in the operator training program
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International Nuclear Information System (INIS)
Hashim Muhammad; Yoshikawa, Hidekazu; Yang Ming
2013-01-01
Passive safety systems adopted in advanced Pressurized Water Reactor (PWR), such as AP1000 and EPR, should attain higher reliability than the existing active safety systems of the conventional PWR. The objective of this study is to discuss the fundamental issues relating to the reliability evaluation of AP1000 passive safety systems for a comparison with the active safety systems of conventional PWR, based on several aspects. First, comparisons between conventional PWR and AP1000 are made from the both aspects of safety design and cost reduction. The main differences between these PWR plants exist in the configurations of safety systems: AP1000 employs the passive safety system while reducing the number of active systems. Second, the safety of AP1000 is discussed from the aspect of severe accident prevention in the event of large break loss of coolant accidents (LOCA). Third, detailed fundamental issues on reliability evaluation of AP1000 passive safety systems are discussed qualitatively by using single loop models of safety systems of both PWRs plants. Lastly, methodology to conduct quantitative estimation of dynamic reliability for AP1000 passive safety systems in LOCA condition is discussed, in order to evaluate the reliability of AP1000 in future by a success-path-based reliability analysis method (i.e., GO-FLOW). (author)
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International Nuclear Information System (INIS)
Garrett, Richard L.; Niemi, Belinda J.; Paik, Ingle K.; Buczek, Jeffrey A.; Lietzow, J.; McCoy, F.; Beranek, F.; Gupta, M.
2013-01-01
A Comparative Evaluation was conducted for One System Integrated Project Team to compare the safety bases for the Hanford Waste Treatment and Immobilization Plant Project (WTP) and Tank Operations Contract (TOC) (i.e., Tank Farms) by an Expert Review Team. The evaluation had an overarching purpose to facilitate effective integration between WTP and TOC safety bases. It was to provide One System management with an objective evaluation of identified differences in safety basis process requirements, guidance, direction, procedures, and products (including safety controls, key safety basis inputs and assumptions, and consequence calculation methodologies) between WTP and TOC. The evaluation identified 25 recommendations (Opportunities for Integration). The resolution of these recommendations resulted in 16 implementation plans. The completion of these implementation plans will help ensure consistent safety bases for WTP and TOC along with consistent safety basis processes. procedures, and analyses. and should increase the likelihood of a successful startup of the WTP. This early integration will result in long-term cost savings and significant operational improvements. In addition, the implementation plans lead to the development of eight new safety analysis methodologies that can be used at other U.S. Department of Energy (US DOE) complex sites where URS Corporation is involved
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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.)
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International Nuclear Information System (INIS)
Hasegawa, Naoko; Hirose, Ayako; Hayase, Kenichi; Sasou Kunihide; Takano, Kenichi
2004-01-01
The purpose of our study is to develop a safety evaluation system which clarifies the safety level of an organization. As a basic method of evaluation using a questionnaire had been established, now that the generalization is needed for the system. Hence, this paper is intended to verify the applicability of the system for eight manufacture industries. The investigation using a questionnaire was conducted for 125 factories' workers. The following results were obtained: 1) The Comprehensive Safety Index (CSI) taking into account individual and organizational factors was identified using the principal component analysis. 2) Although the criterion-related validity of CSI was confirmed for some industries, ti will be necessary for the advancement of the system's reliability to compile more data into the system. 3) According to the result of investigations on safety management in secure companies and the causes of current industrial accidents, it was clarified that the CSI had the content validity. 4) It seemed possible to evaluate the safety level using two different industries' data if there were similarities between the industries in the score of the CSI and the aspects to which were attached importance for the improvement of the safety. (author)
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Evaluating safety-critical organizations - emphasis on the nuclear industry
Energy Technology Data Exchange (ETDEWEB)
Reiman, Teemu; Oedewald, Pia (VTT, Technical Research Centre of Finland (Finland))
2009-04-15
An organizational evaluation plays a key role in the monitoring, as well as controlling and steering, of the organizational safety culture. If left unattended, organizations have a tendency to gradually drift into a condition where they have trouble identifying their vulnerabilities and mechanisms or practices that create or maintain these vulnerabilities. The aim of an organizational evaluation should be to promote increased understanding of the sociotechnical system and its changing vulnerabilities. Evaluation contributes to organizational development and management. Evaluations are used in various situations, but when the aim is to learn about possible new vulnerabilities, identify organizational reasons for problems, or prepare for future challenges, the organization is most open to genuine surprises and new findings. It is recommended that organizational evaluations should be conducted when - there are changes in the organizational structures - new tools are implemented - when the people report increased workplace stress or a decreased working climate - when incidents and near-misses increase - when work starts to become routine - when weak signals (such as employees voicing safety concerns or other worries, the organization 'feels' different, organizational climate has changed) are perceived. In organizations that already have a high safety level, safety managers work for their successors. This means that they seldom see the results of their successful efforts to improve safety. This is due to the fact that it takes time for the improvement to become noticeable in terms of increased measurable safety levels. The most challenging issue in an organizational evaluation is the definition of criteria for safety. We have adopted a system safety perspective and we state that an organization has a high potential for safety when - safety is genuinely valued and the members of the organization are motivated to put effort on achieving high levels of safety
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Evaluating safety-critical organizations - emphasis on the nuclear industry
International Nuclear Information System (INIS)
Reiman, Teemu; Oedewald, Pia
2009-04-01
An organizational evaluation plays a key role in the monitoring, as well as controlling and steering, of the organizational safety culture. If left unattended, organizations have a tendency to gradually drift into a condition where they have trouble identifying their vulnerabilities and mechanisms or practices that create or maintain these vulnerabilities. The aim of an organizational evaluation should be to promote increased understanding of the sociotechnical system and its changing vulnerabilities. Evaluation contributes to organizational development and management. Evaluations are used in various situations, but when the aim is to learn about possible new vulnerabilities, identify organizational reasons for problems, or prepare for future challenges, the organization is most open to genuine surprises and new findings. It is recommended that organizational evaluations should be conducted when - there are changes in the organizational structures - new tools are implemented - when the people report increased workplace stress or a decreased working climate - when incidents and near-misses increase - when work starts to become routine - when weak signals (such as employees voicing safety concerns or other worries, the organization 'feels' different, organizational climate has changed) are perceived. In organizations that already have a high safety level, safety managers work for their successors. This means that they seldom see the results of their successful efforts to improve safety. This is due to the fact that it takes time for the improvement to become noticeable in terms of increased measurable safety levels. The most challenging issue in an organizational evaluation is the definition of criteria for safety. We have adopted a system safety perspective and we state that an organization has a high potential for safety when - safety is genuinely valued and the members of the organization are motivated to put effort on achieving high levels of safety - it is
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International Nuclear Information System (INIS)
Kasahara, Naoto; Itoh, Takamoto; Okazaki, Masakazu; Okuda, Yukihiko; Kamaya, Masayuki; Nakamura, Akira; Nakamura, Hitoshi; Machida, Hideo
2012-01-01
Nuclear piping has various kinds of thermal fatigue failure modes. Main causes of thermal loads are structural responses to fluid temperature changes during plant operation. These phenomena have complex mechanisms and so many patterns, that their problems still occur even though well-known issues. To prevent thermal fatigue due to above thermal loads, the JSME guideline is adopted. Both thermal load and fatigue failure mechanism have been investigated and summarized into the knowledgebase. Numerical simulation methods for thermal fatigue evaluation were studied to replace structural tests. Theses knowledge was utilized to validate and justify the JSME guideline. Furthermore, new studies have been launched to apply above knowledge to enhance plant system safety. (author)
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Evaluation of repository safety
Energy Technology Data Exchange (ETDEWEB)
Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S. [Center for Nuclear Waste Regulatory Analyses, San Antonio (United States)
2002-07-01
The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes
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Evaluation of repository safety
International Nuclear Information System (INIS)
Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S.
2002-01-01
The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes
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Aging evaluation methodology of periodic safety review in Korea
International Nuclear Information System (INIS)
Park, Heung-Bae; Jung, Sung-Gyu; Jin, Tae-Eun; Jeong, Ill-Seok
2002-01-01
In Korea plant lifetime management (PLIM) study for Kori Unit 1 has been performed since 1993. Meanwhile, periodic safety review (PSR) for all operating nuclear power plants (NPPs) has been started with Kori Unit 1 since 2000 per IAEA recommendation. The evaluation period is 10 years, and safety (evaluation) factors are 11 per IAEA guidelines as represented in table 1. The relationship between PSR factors and PLIM is also represented. Among these factors evaluation of 'management of aging' is one of the most important and difficult factor. This factor is related to 'actual condition of the NPP', 'use of experience from other nuclear NPPs and of research findings', and 'management of aging'. The object of 'management of aging' is to obtain plant safety through identifying actual condition of system, structure and components (SSCs) and evaluating aging phenomena and residual life of SSCs using operating experience and research findings. The paper describes the scope and procedure of valuation of 'management of aging', such as, screening criteria of SSCs, Code and Standards, evaluation of SSCs and safety issues as represented. Evaluating SSCs are determined using final safety analysis report (FSAR) and power unit maintenance system for Nuclear Ver. III (PUMAS/N-III). The screening criteria of SSCs are safety-related items (quality class Q), safety-impact items (quality class T), backfitting rule items (fire protection (10CFR50.48), environmental qualification (10CFR50.49), pressurized thermal shock (10CFR50.61), anticipated transient without scram (10CFR50.62), and station blackout (10CFR50.63)) and regulating authority requiring items[1∼3]. The purpose of review of Code and Standards is identifying actual condition of the NPP and evaluating aging management using effective Code and Standards corresponding to reactor facilities. Code and Standards is composed of regulating laws, FSAR items, administrative actions, regulating actions, agreement items, and other
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The reliability of nuclear power plant safety systems
International Nuclear Information System (INIS)
Susnik, J.
1978-01-01
A criterion was established concerning the protection that nuclear power plant (NPP) safety systems should afford. An estimate of the necessary or adequate reliability of the total complex of safety systems was derived. The acceptable unreliability of auxiliary safety systems is given, provided the reliability built into the specific NPP safety systems (ECCS, Containment) is to be fully utilized. A criterion for the acceptable unreliability of safety (sub)systems which occur in minimum cut sets having three or more components of the analysed fault tree was proposed. A set of input MTBF or MTTF values which fulfil all the set criteria and attain the appropriate overall reliability was derived. The sensitivity of results to input reliability data values was estimated. Numerical reliability evaluations were evaluated by the programs POTI, KOMBI and particularly URSULA, the last being based on Vesely's kinetic fault tree theory. (author)
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NASA Aviation Safety Reporting System (ASRS)
Connell, Linda J.
2017-01-01
The NASA Aviation Safety Reporting System (ASRS) collects, analyzes, and distributes de-identified safety information provided through confidentially submitted reports from frontline aviation personnel. Since its inception in 1976, the ASRS has collected over 1.4 million reports and has never breached the identity of the people sharing their information about events or safety issues. From this volume of data, the ASRS has released over 6,000 aviation safety alerts concerning potential hazards and safety concerns. The ASRS processes these reports, evaluates the information, and provides selected de-identified report information through the online ASRS Database at http:asrs.arc.nasa.gov. The NASA ASRS is also a founding member of the International Confidential Aviation Safety Systems (ICASS) group which is a collection of other national aviation reporting systems throughout the world. The ASRS model has also been replicated for application to improving safety in railroad, medical, fire fighting, and other domains. This presentation will discuss confidential, voluntary, and non-punitive reporting systems and their advantages in providing information for safety improvements.
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International Nuclear Information System (INIS)
Malkin, S.D.; Sivokon, V.P.; Shmatkova, L.V.
1989-01-01
Fault tolerance is the property of a system to preserve its performance upon failures of its components. Thus, in nuclear-reactor technology one has only a qualitative evaluation of fault tolerance - the single-failure criterion, which does not enable one to compare and perform goal-directed design of fault-tolerant systems, and in the field of computer technology there are no generally accepted evaluations of fault tolerance that could be applied effectively to reactor systems. This paper considers alternative evaluations of fault tolerance and a method of comprehensive automated calculation of the reliability and fault tolerance of complex systems. The authors presented quantitative estimates of fault tolerance that develop the single-failure criterion. They have limiting processes that allow simple and graphical standardization. They worked out a method and a program for comprehensive calculation of the reliability and fault tolerance of systems of complex structure that are important to the safety of atomic power plants. The quantitative evaluation of the fault tolerance of these systems exhibits a degree of insensitivity to failures and shows to what extent their reliability is determined by a rigorously defined structure, and to what extent by the probabilistic reliability characteristics of the components. To increase safety, one must increase the fault tolerance of the most important systems of atomic power plants
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Iraj Mohammadfam; Mojtaba Kamalinia; Mansour Momeni; Rostam Golmohammadi; Yadollah Hamidi; Alireza Soltanian
2017-01-01
Background: Occupational Health and Safety Management Systems are becoming more widespread in organizations. Consequently, their effectiveness has become a core topic for researchers. This paper evaluates the performance of the Occupational Health and Safety Assessment Series 18001 specification in certified companies in Iran. Methods: The evaluation is based on a comparison of specific criteria and indictors related to occupational health and safety management practices in three certified...
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Energy Technology Data Exchange (ETDEWEB)
Deswarte, Y; Kaaniche, M [Centre National de la Recherche Scientifique (CNRS), 31 - Toulouse (France). Laboratoire d` Analyse et d` Architecture des Systemes; Corneillie, P [CE2A-DI, 92 - Courbevoie (France); Benoit, P [Matra Transport International, 92 - Montrouge (France)
1998-05-01
The SQUALE (security, safety and quality evaluation for dependable systems) project is part of the ACTS (advanced communications, technologies and services) European program. Its aim is to develop confidence evaluation criteria to test the functioning safety of systems. All industrial sectors that use critical applications (nuclear, railway, aerospace..) are concerned. SQUALE evaluation criteria differ from the classical evaluation methods: they are independent of the application domains and industrial sectors, they take into account the overall functioning safety attributes, and they can progressively change according to the level of severity required. In order to validate the approach and to refine the criteria, a first experiment is in progress with the METEOR automatic underground railway and another will be carried out on a telecommunication system developed by Bouygues company. (J.S.) 15 refs.
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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
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Development of main steam safety valve set pressure evaluating system
International Nuclear Information System (INIS)
Oketani, Koichiro; Manabe, Yoshihisa.
1991-01-01
A main steam safety valve set pressure test is conducted for all valves during every refueling outage in Japan's PWRs. Almost all operations of the test are manually conducted by a skilled worker. In order to obtain further reliability and reduce the test time, an automatic test system using a personnel computer has been developed in accordance with system concept. Quality assurance was investigated to fix system specifications. The prototype of the system was manufactured to confirm the system reliability. The results revealed that this system had high accuracy measurement and no adverse influence on the safety valve. This system was concluded to be applicable for actual use. (author)
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Technical features of ABWR safety systems
International Nuclear Information System (INIS)
Sugisaki, Toshihiko; Tominaga, Kenji; Horiuchi, Tetsuo
1986-01-01
The engineering safety facilities of ABWRs have been disigned so as to have many excellent characteristics such as safety, reliability and economy, reflecting the merit of adopting new technology such as internal pumps and new control rod driving mechanism, and coupled with the safety peculiar to BWRs. In this paper, about ECCS, containment vessels and others which compose the engineering safety facilities of ABWRs, the characteristics related to the safety owing to the adoption of internal pumps and others, and the evaluation of the performance at the time of various accidents are discussed. As the results of safety evaluation, it was clarified that due to the safety peculiar to ABWRs and the characteristics of the safety facilities, the large increases of safety, reliability and economy have been planned in the ABWRs, and for example, core flooding can be maintained even at the time of a hypothetical loss of coolant accident. BWRs have the simple system constitution, good self controllability, large natural circulation ability, simple operation control method and excellent ability of confining heat and radioactivity. BWRs have three safety functions to stop reactors, to remove heat from reactors, and to confine radioactive substances. These functions of ABWRs were evaluated, and very high safety was confirmed. (Kako, I.)
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FLIGHT SAFETY MANAGEMENT PROBLEMS AND EVALUATION OF FLIGHT SAFETY LEVEL OF AN AVIATION ENTERPRISE
Directory of Open Access Journals (Sweden)
B. V. Zubkov
2017-01-01
Full Text Available This article is devoted to studying the problem of safety management system (SMS and evaluating safety level of an aviation enterprise.This article discusses the problems of SMS, presented at the 41st meeting of the Russian Aviation Production Commanders Club in June 2014 in St. Petersburg in connection with the verification of the status of the CA of the Russian Federation by the International Civil Aviation Organization (ICAO in the same year, a set of urgent measures to eliminate the deficiencies identified in the current safety management system by participants of this meeting were proposed.In addition, the problems of evaluating flight safety level based on operation data of an aviation enterprise were analyzed. This analysis made it possible to take into account the problems listed in this article as a tool for a comprehensive study of SMS parameters and allows to analyze the quantitative indicators of the flights safety level.The concepts of Acceptable Safety Level (ASL indicators are interpreted differently depending on the available/applicable methods of their evaluation and how to implement them in SMS. However, the indicators for assessing ASL under operational condition at the aviation enterprise should become universal. Currently, defined safety levels and safety indicators are not yet established functionally and often with distorted underrepresented models describing their contextual contents, as well as ways of integrating them into SMS aviation enterprise.The results obtained can be used for better implementation of SMS and solving problems determining the aviation enterprise technical level of flight safety.
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International Nuclear Information System (INIS)
Hosseini, M.H.; Nematollahi, M.R.; Sepanloo, K.
2004-01-01
Probabilistic safety assessment application is found to be a practical tool for research reactor safety due to intense involvement of human interactions in an experimental facility. In this document the application of the probabilistic safety assessment to the Tehran Research Reactor is presented. The level 1 practicabilities safety assessment application involved: Familiarization with the plant, selection of accident initiators, mitigating functions and system definitions, event tree constructions and quantifications, fault tree constructions and quantification, human reliability, component failure data base development and dependent failure analysis. Each of the steps of the analysis given above is discussed with highlights from the selected results. Quantification of the constructed models is done using systems analysis programs for hands-on integrated reliability evaluations software
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Directory of Open Access Journals (Sweden)
E Mohammadfam
2015-11-01
Full Text Available Introduction: All organizations, whether public or private, necessitate performance evaluation systems in regard with growth, stability, and development in the competitive fields. One of the existing models for performance evaluation of occupational health and safety management is Total Quality Safety Management model (TQSM. Therefore, the present study aimed to evaluate performance of safety management and occupational health utilizing TQSM model. Methods: In this descriptive-analytic study, the population consisted of 16 individuals, including managers, supervisors, and members of technical protection and work health committee. Then the participants were asked to respond to TQSM questionnaire before and after the implementation of Occupational Health & Safety Advisory Services 18001 (OHSAS18001. Ultimately, the level of each program as well as the TQSM status were determined before and after the implementation of OHSAS18001. Results: The study results showed that the scores obtained by the company before OHSAS 18001’s implementation, was 43.7 out of 312. After implementing OHSAS 18001 in the company and receiving the related certificate, the total score of safety program that company could obtain was 127.12 out of 312 demonstrating a rise of 83.42 scores (26.8%. The paired t-test revealed that mean difference of TQSM scores before and after OHSAS 18001 implementation was proved to be significant (p> 0.05. Conclusion: The study findings demonstrated that TQSM can be regarded as an appropriate model in order to monitor the performance of safety management system and occupational health, since it possesses the ability to quantitatively evaluate the system performance.
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Safety assessment for Generation IV nuclear systems
International Nuclear Information System (INIS)
Leahy, T.J.
2012-01-01
The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Recent RSWG work has focused on the definition of an integrated safety assessment methodology (ISAM) for evaluating the safety of Generation IV systems. ISAM is an integrated 'tool-kit' consisting of 5 analytical techniques that are available and matched to appropriate stages of Generation IV system concept development: 1) qualitative safety features review - QSR, 2) phenomena identification and ranking table - PIRT, 3) objective provision tree - OPT, 4) deterministic and phenomenological analyses - DPA, and 5) probabilistic safety analysis - PSA. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time
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International Nuclear Information System (INIS)
Mitake, Susumu
2003-01-01
Validation of the continuous-energy Monte Carlo criticality-safety analysis system, comprising the MVP code and neutron cross sections based on JENDL-3.2, was examined using benchmarks evaluated in the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments'. Eight experiments (116 configurations) for the plutonium solution and plutonium-uranium mixture systems performed at Valduc, Battelle Pacific Northwest Laboratories, and other facilities were selected and used in the studies. The averaged multiplication factors calculated with MVP and MCNP-4B using the same neutron cross-section libraries based on JENDL-3.2 were in good agreement. Based on methods provided in the Japanese nuclear criticality-safety handbook, the estimated criticality lower-limit multiplication factors to be used as a subcriticality criterion for the criticality-safety evaluation of nuclear facilities were obtained. The analysis proved the applicability of the MVP code to the criticality-safety analysis of nuclear fuel facilities, particularly to the analysis of systems fueled with plutonium and in homogeneous and thermal-energy conditions
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Nuclear criticality safety parameter evaluation for uranium metallic alloy
Energy Technology Data Exchange (ETDEWEB)
Sanchez, Andrea; Abe, Alfredo, E-mail: andreasdpz@hotmail.com, E-mail: abye@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Energia Nuclear
2013-07-01
Nuclear criticality safety during fuel fabrication process, transport and storage of fissile and fissionable materials requires criticality safety analysis. Normally the analysis involves computer calculations and safety parameters determination. There are many different Criticality Safety Handbooks where such safety parameters for several different fissile mixtures are presented. The handbooks have been published to provide data and safety principles for the design, safety evaluation and licensing of operations, transport and storage of fissile and fissionable materials. The data often comprise not only critical values, but also subcritical limits and safe parameters obtained for specific conditions using criticality safety calculation codes such as SCALE system. Although many data are available for different fissile and fissionable materials, compounds, mixtures, different enrichment level, there are a lack of information regarding a uranium metal alloy, specifically UMo and UNbZr. Nowadays uranium metal alloy as fuel have been investigated under RERTR program as possible candidate to became a new fuel for research reactor due to high density. This work aim to evaluate a set of criticality safety parameters for uranium metal alloy using SCALE system and MCNP Monte Carlo code. (author)
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Safety evaluation of a hydrogen fueled transit bus
Energy Technology Data Exchange (ETDEWEB)
Coutts, D.A.; Thomas, J.K.; Hovis, G.L.; Wu, T.T. [Westinghouse Savannah River Co., Aiken, SC (United States)
1997-12-31
Hydrogen fueled vehicle demonstration projects must satisfy management and regulator safety expectations. This is often accomplished using hazard and safety analyses. Such an analysis has been completed to evaluate the safety of the H2Fuel bus to be operated in Augusta, Georgia. The evaluation methods and criteria used reflect the Department of Energy`s graded approach for qualifying and documenting nuclear and chemical facility safety. The work focused on the storage and distribution of hydrogen as the bus motor fuel with emphases on the technical and operational aspects of using metal hydride beds to store hydrogen. The safety evaluation demonstrated that the operation of the H2Fuel bus represents a moderate risk. This is the same risk level determined for operation of conventionally powered transit buses in the United States. By the same criteria, private passenger automobile travel in the United States is considered a high risk. The evaluation also identified several design and operational modifications that resulted in improved safety, operability, and reliability. The hazard assessment methodology used in this project has widespread applicability to other innovative operations and systems, and the techniques can serve as a template for other similar projects.
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Preliminary investigation on reliability assessment of passive safety system
International Nuclear Information System (INIS)
Huang Changfan; Kuang Bo
2012-01-01
The reliability evaluation of passive safety system plays an important part in probabilistic safety assessment (PSA) of nuclear power plant applying passive safety design, which depends quantitatively on reliabilities of passive safety system. According to the object of reliability assessment of passive safety system, relevant parameters are identified. Then passive system behavior during accident scenarios are studied. A practical example of this method is given for the case of reliability assessment of AP1000 passive heat removal system in loss of normal feedwater accident. Key and design parameters of PRHRS are identified and functional failure criteria are established. Parameter combinations acquired by Latin hyper~ cube sampling (LHS) in possible parametric ranges are input and calculations of uncertainty propagation through RELAP5/MOD3 code are carried out. Based on the calculations, sensitivity assessment on PRHRS functional criteria and reliability evaluation of the system are presented, which might provide further PSA with PRHR system reliability. (authors)
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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)
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Evaluation of common mode failure of safety functions for limiting fault events
International Nuclear Information System (INIS)
Rezendes, J.P.; Hyde, A.W.
2004-01-01
The draft U.S. Nuclear Regulatory Commission (NRC) policy on digital protection system software requires all Advanced Light Water Reactors (ALWRs) to be evaluated assuming a hypothetical common mode failure (CMF) which incapacitates the normal automatic initiation of safety functions. The System 80 + ALWR has been evaluated for such hypothetical conditions. The results show that the diverse automatic and manual protective systems in System 80 + provide ample safety performance margins relative to core coolability, offsite radiological releases. Reactor Coolant System (RCS) pressurization and containment integrity. This deterministic evaluation served to quantify the significant inherent safety margins in the System 80 + Standard Plant design even in the event of this extremely low probability scenario of a common mode failure. (author)
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International Nuclear Information System (INIS)
Williams, R.A.
1995-01-01
The Columbia Fuel Fabrication Facility of the Westinghouse Commercial Nuclear Fuel Division manufactures low-enriched uranium fuel and associated components for use in commercial pressurized water power reactors. To support development of a comprehensive integrated safety assessment (ISA) for the facility, as well as to address increasing U.S. Nuclear Regulatory Commission (NRC) expectations regarding such a facility's criticality safety assessments, a project is under way to complete criticality safety evaluations (CSEs) of all plant systems used in processing nuclear materials. Each CSE is made up of seven sections, prepared by a multidisciplinary team of process engineers, systems engineers, safety engineers, maintenance representatives, and operators. This paper provides a cursory outline of the type of information presented in a CSE
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International Nuclear Information System (INIS)
Liu Ying; Yang Ming; Li Fengjun; Ma Zhanguo; Zeng Hai
2014-01-01
In order to analyze the software reliability (SR) in nuclear safety class digital instrumentation and control system (D-I and C), firstly, the international software design standards were analyzed, the standards' framework was built, and we found that the D-I and C software standards should follow the NUREG-0800 BTP7-14, according to the NRC NUREG-0800 review of requirements. Secondly, the quantitative evaluation model of SR using Bayesian Belief Network and thirteen sub-model frameworks were established. Thirdly, each sub-models and the weight of corresponding indexes in the evaluation model were analyzed. Finally, the safety case was introduced. The models lay a foundation for review and quantitative evaluation on the SR in nuclear safety class D-I and C. (authors)
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Jacxsens, L; Uyttendaele, M; Devlieghere, F; Rovira, J; Gomez, S Oses; Luning, P A
2010-07-31
There is a need to measure the food safety performance in the agri-food chain without performing actual microbiological analysis. A food safety performance diagnosis, based on seven indicators and corresponding assessment grids have been developed and validated in nine European food businesses. Validation was conducted on the basis of an extensive microbiological assessment scheme (MAS). The assumption behind the food safety performance diagnosis is that food businesses which evaluate the performance of their food safety management system in a more structured way and according to very strict and specific criteria will have a better insight in their actual microbiological food safety performance, because food safety problems will be more systematically detected. The diagnosis can be a useful tool to have a first indication about the microbiological performance of a food safety management system present in a food business. Moreover, the diagnosis can be used in quantitative studies to get insight in the effect of interventions on sector or governmental level. Copyright 2010 Elsevier B.V. All rights reserved.
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Study on 'Safety qualification of process computers used in safety systems of nuclear power plants'
International Nuclear Information System (INIS)
Bertsche, K.; Hoermann, E.
1991-01-01
The study aims at developing safety standards for hardware and software of computer systems which are increasingly used also for important safety systems in nuclear power plants. The survey of the present state-of-the-art of safety requirements and specifications for safety-relevant systems and, additionally, for process computer systems has been compiled from national and foreign rules. In the Federal Republic of Germany the KTA safety guides and the BMI/BMU safety criteria have to be observed. For the design of future computer-aided systems in nuclear power plants it will be necessary to apply the guidelines in [DIN-880] and [DKE-714] together with [DIN-192]. With the aid of a risk graph the various functions of a system, or of a subsystem, can be evaluated with regard to their significance for safety engineering. (orig./HP) [de
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Intelligent monitoring-based safety system of massage robot
Institute of Scientific and Technical Information of China (English)
胡宁; 李长胜; 王利峰; 胡磊; 徐晓军; 邹雲鹏; 胡玥; 沈晨
2016-01-01
As an important attribute of robots, safety is involved in each link of the full life cycle of robots, including the design, manufacturing, operation and maintenance. The present study on robot safety is a systematic project. Traditionally, robot safety is defined as follows: robots should not collide with humans, or robots should not harm humans when they collide. Based on this definition of robot safety, researchers have proposed ex ante and ex post safety standards and safety strategies and used the risk index and risk level as the evaluation indexes for safety methods. A massage robot realizes its massage therapy function through applying a rhythmic force on the massage object. Therefore, the traditional definition of safety, safety strategies, and safety realization methods cannot satisfy the function and safety requirements of massage robots. Based on the descriptions of the environment of massage robots and the tasks of massage robots, the present study analyzes the safety requirements of massage robots; analyzes the potential safety dangers of massage robots using the fault tree tool; proposes an error monitoring-based intelligent safety system for massage robots through monitoring and evaluating potential safety danger states, as well as decision making based on potential safety danger states; and verifies the feasibility of the intelligent safety system through an experiment.
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Directory of Open Access Journals (Sweden)
Hyun-Kook Shin
2006-08-01
Full Text Available A new Digital Reactor Protection System (DRPS based on VME bus Single Board Computer has been developed by KOPEC to prevent software Common Mode Failure(CMF inside digital system. The new DRPS has been proved to be an effective digital safety system to prevent CMF by Defense-in-Depth and Diversity (DID&D analysis. However, for practical use in Nuclear Power Plants, the performance test and the reliability test are essential for the digital system qualification. In this study, a single channel of DRPS prototype has been manufactured for the evaluation of DRPS capabilities. The integrated functional tests are performed and the system reliability is analyzed and tested. The results of reliability test show that the application software of DRPS has a very high reliability compared with the analog reactor protection systems.
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The REPAS approach to the evaluation of passive safety systems reliability
International Nuclear Information System (INIS)
Bianchi, F.; Burgazzi, L.; D'Auria, F.; Ricotti, M.E.
2002-01-01
Scope of this research, carried out by ENEA in collaboration with University of Pisa and Polytechnic of Milano since 1999, is the identification of a methodology allowing the evaluation of the reliability of passive systems as a whole, in a more physical and phenomenal way. The paper describe the study, named REPAS (Reliability Evaluation of Passive Safety systems), carried out by the partners and finalised to the development and validation of such a procedure. The strategy of engagement moves from the consideration that a passive system should be theoretically more reliable than an active one. In fact it does not need any external input or energy to operate and it relies only upon natural physical laws (e.g. gravity, natural circulation, internally stored energy, etc.) and/or 'intelligent' use of the energy inherently available in the system (e.g. chemical reaction, decay heat, etc.). Nevertheless the passive system may fail its mission not only as a consequence of classical mechanical failure of components, but also for deviation from the expected behaviour, due to physical phenomena mainly related to thermal-hydraulics or due to different boundary and initial conditions. The main sources of physical failure are identified and a probability of occurrence is assigned. The reliability analysis is performed on a passive system which operates in two-phase, natural circulation. The selected system is a loop including a heat source and a heat sink where the condensation occurs. The system behaviour under different configurations has been simulated via best-estimate code (Relap5 mod3.2). The results are shown and can be treated in such a way to give qualitative and quantitative information on the system reliability. Main routes of development of the methodology are also depicted. The analysis of the results shows that the procedure is suitable to evaluate the performance of a passive system on a probabilistic / deterministic basis. Important information can also be
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Cameli, Norma; Mariano, Maria; Ardigò, Marco; Corato, Cristina; De Paoli, Gianfranco; Berardesca, Enzo
2017-09-20
To instrumentally evaluate the efficacy and the safety of a new ternary system chemo exfoliating formulation (water-dimethyl isosorbide-acid) vs traditional binary systems (water and acid) where the acid is maintained in both the systems at the same concentration. Different peelings (binary system pyruvic acid and trichloroacetic acid-TCA, and ternary system pyruvic acid and TCA) were tested on the volar forearm of 20 volunteers of both sexes between 28 and 50 years old. The outcomes were evaluated at the baseline, 10 minutes, 24 hours, and 1 week after the peeling by means of noninvasive skin diagnosis techniques. In vivo reflectance confocal microscopy was used for stratum corneum evaluation, transepidermal waterloss, and Corneometry for skin barrier and hydration, Laser Doppler velocimetry in association with colorimetry for irritation and erythema analysis. The instrumental data obtained showed that the efficacy and safety of the new ternary system peel compounds were significantly higher compared with the binary system formulations tested. The new formulation peels improved chemexfoliation and reduced complications such as irritation, redness, and postinflammatory pigmentation compared to the traditional aqueous solutions. The study showed that ternary system chemexfoliation, using a controlled delivery technology, was able to provide the same clinical effects in term of stratum corneum reduction with a significantly reduced barrier alteration, water loss, and irritation/erythema compared to traditional binary system peels. © 2017 Wiley Periodicals, Inc.
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International Nuclear Information System (INIS)
Ewing, P.D.; Korsah, K.
1994-04-01
This report discusses the development of the technical basis for the control of upsets and malfunctions in safety-related instrumentation and control (I ampersand C) systems caused by electromagnetic and radio-frequency interference (EMI/RFI) and power surges. The research was performed at the Oak Ridge National Laboratory (ORNL) and was sponsored by the USNRC Office of Nuclear Regulatory Research (RES). The motivation for research stems from the safety-related issues that need to be addressed with the application of advanced I ampersand C systems to nuclear power plants. Development of the technical basis centered around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems known to be the source(s) of EMI/RFI and power surges. First, good EMC design and installation practices need to be established to control the impact of interference sources on nearby circuits and systems. These EMC good practices include circuit layouts, terminations, filtering, grounding, bonding, shielding, and adequate physical separation. Second, an EMI/RFI test and evaluation program needs to be established to outline the tests to be performed, the associated test methods to be followed, and carefully formulated acceptance criteria based on the intended environment to ensure that the circuit or system under test meets the recommended guidelines. Third, a program needs to be developed to perform confirmatory tests and evaluate the surge withstand capability (SWC) and of I ampersand C equipment connected to or installed in the vicinity of power circuits within the nuclear power plant. By following these three steps, the design and operability of safety-related I ampersand C systems against EMI/RFI and power surges can be evaluated, acceptance criteria can be developed, and appropriate regulatory guidance can be provided
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Evaluation procedure of software safety plan for digital I and C of KNGR
International Nuclear Information System (INIS)
Lee, Jang Soo; Park, Jong Kyun; Lee, Ki Young; Kwon, Ki Choon; Kim, Jang Yeol; Cheon, Se Woo
2000-05-01
The development, use, and regulation of computer systems in nuclear reactor instrumentation and control (I and C) systems to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Korean next generation reactor (KNGR) software safety verification and validation (SSVV) task, Korea Atomic Energy Research Institute, which investigates different aspects of computer software in reactor I and C systems, and describes the engineering procedures for developing such a software. The purpose of this guideline is to give the software safety evaluator the trail map between the code and standards layer and the design methodology and documents layer for the software important to safety in nuclear power plants. Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organizations. The requirements for software important to safety of nuclear reactor are described in such positions and standards, for example, the new standard review plan (SRP), IEC 880 supplements, IEEE standard 1228-1994, IEEE standard 7-4.3.2-1993, and IAEA safety series No. 50-SG-D3 and D8. We presented the guidance for evaluating the safety plan of the software in the KNGR protection systems. The guideline consists of the regulatory requirements for software safety in chapter 2, the evaluation checklist of software safety plan in chapter3, and the evaluation results of KNGR software safety plan in chapter 4
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Evaluation procedure of software safety plan for digital I and C of KNGR
Energy Technology Data Exchange (ETDEWEB)
Lee, Jang Soo; Park, Jong Kyun; Lee, Ki Young; Kwon, Ki Choon; Kim, Jang Yeol; Cheon, Se Woo
2000-05-01
The development, use, and regulation of computer systems in nuclear reactor instrumentation and control (I and C) systems to enhance reliability and safety is a complex issue. This report is one of a series of reports from the Korean next generation reactor (KNGR) software safety verification and validation (SSVV) task, Korea Atomic Energy Research Institute, which investigates different aspects of computer software in reactor I and C systems, and describes the engineering procedures for developing such a software. The purpose of this guideline is to give the software safety evaluator the trail map between the code and standards layer and the design methodology and documents layer for the software important to safety in nuclear power plants. Recently, the safety planning for safety-critical software systems is being recognized as the most important phase in the software life cycle, and being developed new regulatory positions and standards by the regulatory and the standardization organizations. The requirements for software important to safety of nuclear reactor are described in such positions and standards, for example, the new standard review plan (SRP), IEC 880 supplements, IEEE standard 1228-1994, IEEE standard 7-4.3.2-1993, and IAEA safety series No. 50-SG-D3 and D8. We presented the guidance for evaluating the safety plan of the software in the KNGR protection systems. The guideline consists of the regulatory requirements for software safety in chapter 2, the evaluation checklist of software safety plan in chapter3, and the evaluation results of KNGR software safety plan in chapter 4.
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International Nuclear Information System (INIS)
Grime, L.; Page, E.
1987-01-01
As a plant changes from the design phase to the operational phase, new regulations and standards apply. One such regulation is 10CFR50.59 on safety evaluations. Once an operating license is issued, it is mandatory to submit all applicable changes, tests, and experiments to the safety evaluation process. As preparation for this transition, Detroit Edison had procedures in place and conducted personnel training. Reviews of the safety engineering were conducted by the on-site review board. The off-site board delegated detailed reviews of most safety evaluations to the independent safety evaluation group (ISEG). The on-site group review included presentation of complete design packages by engineers. The ISEG and off-site review group's activity focused on safety evaluation. This paper addresses industry trends that were studied, Detroit Edison's recent actions, and industry issues related to 10CFR50.59 safety evaluations
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Operation safety of complex industrial systems. Main concepts
International Nuclear Information System (INIS)
Zwingelstein, G.
2009-01-01
Operation safety consists in knowing, evaluating, foreseeing, measuring and mastering the technological system and human failures in order to avoid their impacts on health and people's safety, on productivity, and on the environment, and to preserve the Earth's resources. This article recalls the main concepts of operation safety: 1 - evolutions in the domain; 2 - failures, missions and functions of a system and of its components: functional failure, missions and functions, industrial processes, notions of probability; 3 - basic concepts and operation safety: reliability, unreliability, failure density, failure rate, relations between them, availability, maintainability, safety. (J.S.)
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Software Dependability and Safety Evaluations ESA's Initiative
Hernek, M.
ESA has allocated funds for an initiative to evaluate Dependability and Safety methods of Software. The objectives of this initiative are; · More extensive validation of Safety and Dependability techniques for Software · Provide valuable results to improve the quality of the Software thus promoting the application of Dependability and Safety methods and techniques. ESA space systems are being developed according to defined PA requirement specifications. These requirements may be implemented through various design concepts, e.g. redundancy, diversity etc. varying from project to project. Analysis methods (FMECA. FTA, HA, etc) are frequently used during requirements analysis and design activities to assure the correct implementation of system PA requirements. The criticality level of failures, functions and systems is determined and by doing that the critical sub-systems are identified, on which dependability and safety techniques are to be applied during development. Proper performance of the software development requires the development of a technical specification for the products at the beginning of the life cycle. Such technical specification comprises both functional and non-functional requirements. These non-functional requirements address characteristics of the product such as quality, dependability, safety and maintainability. Software in space systems is more and more used in critical functions. Also the trend towards more frequent use of COTS and reusable components pose new difficulties in terms of assuring reliable and safe systems. Because of this, its dependability and safety must be carefully analysed. ESA identified and documented techniques, methods and procedures to ensure that software dependability and safety requirements are specified and taken into account during the design and development of a software system and to verify/validate that the implemented software systems comply with these requirements [R1].
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A Reliability Assessment Method for the VHTR Safety Systems
International Nuclear Information System (INIS)
Lee, Hyung Sok; Jae, Moo Sung; Kim, Yong Wan
2011-01-01
The Passive safety system by very high temperature reactor which has attracted worldwide attention in the last century is the reliability safety system introduced for the improvement in the safety of the next generation nuclear power plant design. The Passive system functionality does not rely on an external source of energy, but on an intelligent use of the natural phenomena, such as gravity, conduction and radiation, which are always present. Because of these features, it is difficult to evaluate the passive safety on the risk analysis methodology having considered the existing active system failure. Therefore new reliability methodology has to be considered. In this study, the preliminary evaluation and conceptualization are tried, applying the concept of the load and capacity from the reliability physics model, designing the new passive system analysis methodology, and the trial applying to paper plant.
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A safety evaluation of fire and explosion in nuclear fuel reprocessing plants
International Nuclear Information System (INIS)
Nishio, Gunji; Takada, Junichi; Tukamoto, Michio; Watanabe, Kouji; Miyata, Teijirou
1996-01-01
The demonstration test was performed in JAERI to prove the adequacy of a safety evaluation for an air-ventilation system in the case of solvent fire and red-oil explosion in a nuclear fuel reprocessing plant. The test objectives were to obtain data of the safety evaluation on a thermofluid behavior and a confinement effect of radioactive materials during fire and explosion while the system is operating in a cell. The computer code was developed to evaluate the safety of associated network in the ventilation system and to estimate the confinement of radioactive materials in the system. The code was verified by comparison of code calculations with results of the demonstration test. (author)
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Safety Culture Evaluation at Research Reactors of Pakistan Atomic Energy Commission
International Nuclear Information System (INIS)
Qamar, M.A.; Saeed, A.; Shah, J.H.
2016-01-01
The concept of safety culture was presented by IAEA in document INSAG-4 (1991), delineated as “assembly of characteristics and attitudes in organizations and individuals which establish that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance”. The purpose of this paper is to describe the evaluation of safety culture at research reactors of the Pakistan Atomic Energy Commission (PAEC). Evaluating the safety culture of a particular organization poses some challenges which can be resolved by using safety culture evaluation models like those of Sachein (1992) and Harber-Barrier(1998). In PAEC, safety culture is the integral part of management system which not only promotes safety culture throughout the organization but also enhances its significance. To strengthen the safety culture, PAEC is also participating in a number of international and regional meetings of IAEA regarding safety culture. PAEC and the national regulator Pakistan Nuclear Regulatory Authority (PNRA) are also arranging workshops, peer reviews, sharing operational experiences and interacting with IAEA missions to enhance its capabilities in the field of safety culture. The Directorate General of Safety (DOS) is a corporate office of PAEC for safety and regulatory matters. DOS is in the process of implementing a program to evaluate safety culture at nuclear installations of PAEC to ensure that safety culture is included as a vital segment of the Integral Management System of the establishment. In this regard, training sessions and lectures on safety culture evaluation are normally conducted in PAEC for awareness and enhancement of the safety culture program. Safety culture is also addressed in PNRA Regulations like PAK-909 and PAK-913. In this paper we will focus on the safety culture evaluation in our research reactors, i.e., PARR-1 and PARR-2. The evaluation results will be based on observations, interviews of employees, group discussions
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Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation
International Nuclear Information System (INIS)
Bess, John D.; Briggs, J. Blair; Nigg, David W.
2009-01-01
One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.
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Evaluation and review of the safety management system implementation in the Royal Thai Air Force
Chaiwan, Sakkarin
This study was designed to determine situation and effectiveness of the safety management system currently implemented in the Royal Thai Air Force. Reviewing the ICAO's SMS and the RTAF's SMS was conducted to identify similarities and differences between the two safety management systems. Later, the researcher acquired safety statistics from the RTAF Safety Center to investigate effectiveness of its safety system. The researcher also collected data to identify other factors affecting effectiveness of the safety system during conducting in-depth interviews. Findings and Conclusions: The study shows that the Royal Thai Air Force has never applied the International Civil Aviation Organization's Safety management System to its safety system. However, the RTAF's SMS and the ICAO's SMS have been developed based on the same concepts. These concepts are from Richard H. Woods's book, Aviation safety programs: A management handbook. However, the effectiveness of the Royal Thai Air Force's safety system is in good stance. An accident rate has been decreasing regularly but there are no known factors to describe the increasing rate, according to the participants' opinion. The participants have informed that there are many issues to be resolved to improve the RTAF's safety system. Those issues are cooperation among safety center's staffs, attitude toward safety of the RTAF senior commanders, and safety standards.
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K West integrated water treatment system subproject safety analysis document
International Nuclear Information System (INIS)
SEMMENS, L.S.
1999-01-01
This Accident Analysis evaluates unmitigated accident scenarios, and identifies Safety Significant and Safety Class structures, systems, and components for the K West Integrated Water Treatment System
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K West integrated water treatment system subproject safety analysis document
Energy Technology Data Exchange (ETDEWEB)
SEMMENS, L.S.
1999-02-24
This Accident Analysis evaluates unmitigated accident scenarios, and identifies Safety Significant and Safety Class structures, systems, and components for the K West Integrated Water Treatment System.
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International Nuclear Information System (INIS)
Oedewald, Pia; Pietikaeinen, Elina; Reiman, Teemu
2011-06-01
Organizations in the nuclear industry need to maintain an overview on their vulnerabilities and strengths with respect to safety. Systematic periodical self assessments are necessary to achieve this overview. This guidebook provides suggestions and examples to assist power companies but also external evaluators and regulators in carrying out organizational evaluations. Organizational evaluation process is divided into five main steps. These are: 1) planning the evaluation framework and the practicalities of the evaluation process, 2) selecting data collection methods and conducting the data acquisition, 3) structuring and analysing the data, 4) interpreting the findings and 5) reporting the evaluation results with possible recommendations. The guidebook emphasises the importance of a solid background framework when dealing with multifaceted phenomena like organisational activities and system safety. The validity and credibility of the evaluation stem largely from the evaluation team's ability to crystallize what they mean by organization and safety when they conduct organisational safety evaluations - and thus, what are the criteria for the evaluation. Another important and often under-considered phase in organizational evaluation is interpretation of the findings. In this guidebook a safety culture evaluation in a Nordic nuclear power plant is presented as an example of organizational evaluation. With the help of the example, challenges of each step in the organizational evaluation process are described. Suggestions for dealing with them are presented. In the case example, the DISC (Design for Integrated Safety culture) model is used as the evaluation framework. The DISC model describes the criteria for a good safety culture and the organizational functions necessary to develop a good safety culture in the organization
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Energy Technology Data Exchange (ETDEWEB)
Williams, R.A. [Westinghouse Electric Corp., Columbia, SC (United States)
1995-12-31
The Columbia Fuel Fabrication Facility of the Westinghouse Commercial Nuclear Fuel Division manufactures low-enriched uranium fuel and associated components for use in commercial pressurized water power reactors. To support development of a comprehensive integrated safety assessment (ISA) for the facility, as well as to address increasing U.S. Nuclear Regulatory Commission (NRC) expectations regarding such a facility`s criticality safety assessments, a project is under way to complete criticality safety evaluations (CSEs) of all plant systems used in processing nuclear materials. Each CSE is made up of seven sections, prepared by a multidisciplinary team of process engineers, systems engineers, safety engineers, maintenance representatives, and operators. This paper provides a cursory outline of the type of information presented in a CSE.
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Barrier performance researches for the safety evaluation
International Nuclear Information System (INIS)
Niibori, Yuichi
2004-01-01
So far, many researches were conducted to propose a scientific evidence (a safety case) for the realization of geological disposal in Japan. In order to regulate the geological disposal system of radioactive wastes, on the other hand, we need also a holistic approach to integrate various data related for the performance evaluations of the engineered barrier system and the natural barrier system. However, the scientific bases are not sufficient to establish the safety regulation for such a natural system. For example, we often apply the specific probability density function (PDF) to the uncertainty of barrier system due to the essential heterogeneity. However, the applicability is not clear in the regulation point of view. A viewpoint to understand such an applicability of PDFs has been presented. (author)
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NASA System Safety Handbook. Volume 1; System Safety Framework and Concepts for Implementation
Dezfuli, Homayoon; Benjamin, Allan; Everett, Christopher; Smith, Curtis; Stamatelatos, Michael; Youngblood, Robert
2011-01-01
basis but to consider measures of aggregate safety risk and to ensure wherever possible that there be quantitative measures for evaluating how effective the controls are in reducing these aggregate risks. The term aggregate risk, when used in this handbook, refers to the accumulation of risks from individual scenarios that lead to a shortfall in safety performance at a high level: e.g., an excessively high probability of loss of crew, loss of mission, planetary contamination, etc. Without aggregated quantitative measures such as these, it is not reasonable to expect that safety has been optimized with respect to other technical and programmatic objectives. At the same time, it is fully recognized that not all sources of risk are amenable to precise quantitative analysis and that the use of qualitative approaches and bounding estimates may be appropriate for those risk sources. Second, the handbook stresses the necessity of developing confidence that the controls derived for the purpose of achieving system safety not only handle risks that have been identified and properly characterized but also provide a general, more holistic means for protecting against unidentified or uncharacterized risks. For example, while it is not possible to be assured that all credible causes of risk have been identified, there are defenses that can provide protection against broad categories of risks and thereby increase the chances that individual causes are contained. Third, the handbook strives at all times to treat uncertainties as an integral aspect of risk and as a part of making decisions. The term "uncertainty" here does not refer to an actuarial type of data analysis, but rather to a characterization of our state of knowledge regarding results from logical and physical models that approximate reality. Uncertainty analysis finds how the output parameters of the models are related to plausible variations in the input parameters and in the modeling assumptions. The evaluation of
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Probabilistic safety criteria at the safety function/system level
International Nuclear Information System (INIS)
1989-09-01
A Technical Committee Meeting was held in Vienna, Austria, from 26-30 January 1987. The objectives of the meeting were: to review the national developments of PSC at the level of safety functions/systems including future trends; to analyse basic principles, assumptions, and objectives; to compare numerical values and the rationale for choosing them; to compile the experience with use of such PSC; to analyse the role of uncertainties in particular regarding procedures for showing compliance. The general objective of establishing PSC at the level of safety functions/systems is to provide a pragmatic tool to evaluate plant safety which is placing emphasis on the prevention principle. Such criteria could thus lead to a better understanding of the importance to safety of the various functions which have to be performed to ensure the safety of the plant, and the engineering means of performing these functions. They would reflect the state-of-the-art in modern PSAs and could contribute to a balance in system design. This report, prepared by the participants of the meeting, reviews the current status and future trends in the field and should assist Member States in developing their national approaches. The draft of this document was also submitted to INSAG to be considered in its work to prepare a document on safety principles for nuclear power plants. Five papers presented at the meeting are also included in this publication. A separate abstract was prepared for each of these papers. Refs, figs and tabs
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PWR reload safety evaluation methodology
International Nuclear Information System (INIS)
Doshi, P.K.; Chapin, D.L.; Love, D.S.
1993-01-01
The current practice for WWER safety analysis is to prepare the plant Safety Analysis Report (SAR) for initial plant operation. However, the existing safety analysis is typically not evaluated for reload cycles to confirm that all safety limits are met. In addition, there is no systematic reanalysis or reevaluation of the safety analyses after there have been changes made to the plant. The Westinghouse process is discussed which is in contrast to this and in which the SAR conclusions are re-validated through evaluation and/or analysis of each reload cycle. (Z.S.)
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System safety education focused on flight safety
Holt, E.
1971-01-01
The measures necessary for achieving higher levels of system safety are analyzed with an eye toward maintaining the combat capability of the Air Force. Several education courses were provided for personnel involved in safety management. Data include: (1) Flight Safety Officer Course, (2) Advanced Safety Program Management, (3) Fundamentals of System Safety, and (4) Quantitative Methods of Safety Analysis.
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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
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Safety features of subcritical fluid fueled systems
International Nuclear Information System (INIS)
Bell, C.R.
1995-01-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible
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Safety features of subcritical fluid fueled systems
International Nuclear Information System (INIS)
Bell, C.R.
1994-01-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved in very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible
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Safety features of subcritical fluid fueled systems
Energy Technology Data Exchange (ETDEWEB)
Bell, C.R. [Los Alamos National Laboratory, NM (United States)
1995-10-01
Accelerator-driven transmutation technology has been under study at Los Alamos for several years for application to nuclear waste treatment, tritium production, energy generation, and recently, to the disposition of excess weapons plutonium. Studies and evaluations performed to date at Los Alamos have led to a current focus on a fluid-fuel, fission system operating in a neutron source-supported subcritical mode, using molten salt reactor technology and accelerator-driven proton-neutron spallation. In this paper, the safety features and characteristics of such systems are explored from the perspective of the fundamental nuclear safety objectives that any reactor-type system should address. This exploration is qualitative in nature and uses current vintage solid-fueled reactors as a baseline for comparison. Based on the safety perspectives presented, such systems should be capable of meeting the fundamental nuclear safety objectives. In addition, they should be able to provide the safety robustness desired for advanced reactors. However, the manner in which safety objectives and robustness are achieved is very different from that associated with conventional reactors. Also, there are a number of safety design and operational challenges that will have to be addressed for the safety potential of such systems to be credible.
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Operation safety of complex industrial systems
International Nuclear Information System (INIS)
Zwingelstein, G.
1999-01-01
Zero fault or zero risk is an unreachable goal in industrial activities like nuclear activities. However, methods and techniques exist to reduce the risks to the lowest possible and acceptable level. The operation safety consists in the recognition, evaluation, prediction, measurement and mastery of technological and human faults. This paper analyses each of these points successively: 1 - evolution of operation safety; 2 - definitions and basic concepts: failure, missions and functions of a system and of its components, basic concepts and operation safety; 3 - forecasting analysis of operation safety: reliability data, data-banks, precautions for the use of experience feedback data; realization of an operation safety study: management of operation safety, quality assurance, critical review and audit of operation safety studies; 6 - conclusions. (J.S.)
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Fuel Receiving and Storage Station. Nuclear Regulatory Commission's safety evaluation report
International Nuclear Information System (INIS)
1976-01-01
The safety evaluation report covers design of structures, components, equipment, and systems; nuclear criticality safety; radiological safety; accident analysis; conduct of operations; quality assurance; common defense and security; financial qualifications; financial protection and indemnity requirements; and technical specifications
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Reliability estimation of safety-critical software-based systems using Bayesian networks
International Nuclear Information System (INIS)
Helminen, A.
2001-06-01
Due to the nature of software faults and the way they cause system failures new methods are needed for the safety and reliability evaluation of software-based safety-critical automation systems in nuclear power plants. In the research project 'Programmable automation system safety integrity assessment (PASSI)', belonging to the Finnish Nuclear Safety Research Programme (FINNUS, 1999-2002), various safety assessment methods and tools for software based systems are developed and evaluated. The project is financed together by the Radiation and Nuclear Safety Authority (STUK), the Ministry of Trade and Industry (KTM) and the Technical Research Centre of Finland (VTT). In this report the applicability of Bayesian networks to the reliability estimation of software-based systems is studied. The applicability is evaluated by building Bayesian network models for the systems of interest and performing simulations for these models. In the simulations hypothetical evidence is used for defining the parameter relations and for determining the ability to compensate disparate evidence in the models. Based on the experiences from modelling and simulations we are able to conclude that Bayesian networks provide a good method for the reliability estimation of software-based systems. (orig.)
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Evaluating fuel cycle safety for CITa
International Nuclear Information System (INIS)
Longhurst, G.R.; Reilly, H.J.; Piet, S.J.
1987-01-01
A safety concern in the design of the Compact Ignition Tokamak (CIT) currently being designed in the U. S. is the accidental release of tritium. To evaluate the basis for that concern, an assessment of the risk to the public posed by CIT was conducted that made use of probabilistic risk assessment (PRA) techniques. These include both frequency and consequence elements of risk. This analysis concluded that the tritium systems on the CIT could be designed and operated as planned with negligible safety impact, well within the established guidelines. (author)
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Safety assessment of complex engineered and natural systems: radioactive waste disposal
International Nuclear Information System (INIS)
McNeish, J.A.; Vallikat, V.; Atkins, J.; Balady, M.A.
1997-01-01
Evaluation of deep, geologic disposal of nuclear waste requires the probabilistic safety assessment of a complex system from the coupling of various processes and sub-systems, parameter and model uncertainties, spatial and temporal variabilities, and the multiplicity of designs and scenarios. Both the engineered and natural system are included in the evaluation. Each system has aspects with considerable uncertainty both in important parameters and in overall conceptual models. The study represented herein provides a probabilistic safety assessment of a potential respository system for multiple engineered barrier system (EBS) design and conceptual model configurations (CRWMS M and O, 1996a) and considers the effects of uncertainty on the overall results. The assessment is based on data and process models available at the time of the study and doesnt necessarily represent the current safety evaluation. In fact, the percolation flux through the repository system is now expected to be higher than the estimate used for this study. The potential effects of higher percolation fluxes are currently under study. The safety of the system was assessed for both 10,000 and 1,000,000 years. Use of alternative conceptual models also produced major improvement in safety. For example, use of a more realistic engineered system release model produced improvement of over an order of magnitude in safety. Alternative measurement locations for the safety assessment produced substantial increases in safety, through the results are based on uncertain dilution factors in the transporting groundwater. (Author)
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Development of evaluation method for software safety analysis techniques
International Nuclear Information System (INIS)
Huang, H.; Tu, W.; Shih, C.; Chen, C.; Yang, W.; Yih, S.; Kuo, C.; Chen, M.
2006-01-01
Full text: Full text: Following the massive adoption of digital Instrumentation and Control (I and C) system for nuclear power plant (NPP), various Software Safety Analysis (SSA) techniques are used to evaluate the NPP safety for adopting appropriate digital I and C system, and then to reduce risk to acceptable level. However, each technique has its specific advantage and disadvantage. If the two or more techniques can be complementarily incorporated, the SSA combination would be more acceptable. As a result, if proper evaluation criteria are available, the analyst can then choose appropriate technique combination to perform analysis on the basis of resources. This research evaluated the applicable software safety analysis techniques nowadays, such as, Preliminary Hazard Analysis (PHA), Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA), Markov chain modeling, Dynamic Flowgraph Methodology (DFM), and simulation-based model analysis; and then determined indexes in view of their characteristics, which include dynamic capability, completeness, achievability, detail, signal/ noise ratio, complexity, and implementation cost. These indexes may help the decision makers and the software safety analysts to choose the best SSA combination arrange their own software safety plan. By this proposed method, the analysts can evaluate various SSA combinations for specific purpose. According to the case study results, the traditional PHA + FMEA + FTA (with failure rate) + Markov chain modeling (without transfer rate) combination is not competitive due to the dilemma for obtaining acceptable software failure rates. However, the systematic architecture of FTA and Markov chain modeling is still valuable for realizing the software fault structure. The system centric techniques, such as DFM and Simulation-based model analysis, show the advantage on dynamic capability, achievability, detail, signal/noise ratio. However, their disadvantage are the completeness complexity
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Evaluation Of Fire Safety And Protection At PUSPATI TRIGA Reactor (RTP)
International Nuclear Information System (INIS)
Ahmad Nabil Ab Rahim; Alfred Sanggau Ligam; Nurhayati Ramli; Mohd Fazli Zakaria; Naim Syauqi Hamzah; Phongsakorn Prak; Mohammad Suhaimi Kassim; Zarina Masood
2014-01-01
Fire hazard is one of many risks that can affect the safety operation of PUSPATI TRIGA Reactor. Reactor building in Malaysian Nuclear Agency was built in 1980s and the fire system has been introduced since then. The evaluation of the fire safety system at this time is important to ensure the efficiency of fire prevention, fighting and mitigation task that probably occurs. This evaluation involves with the fire fighting system and equipment, integrity of the system from the perspective of management and equipment, fire fighting procedure and fire fighting response team. (author)
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Evaluation for nuclear safety-critical software reliability of DCS
International Nuclear Information System (INIS)
Liu Ying
2015-01-01
With the development of control and information technology at NPPs, software reliability is important because software failure is usually considered as one form of common cause failures in Digital I and C Systems (DCS). The reliability analysis of DCS, particularly qualitative and quantitative evaluation on the nuclear safety-critical software reliability belongs to a great challenge. To solve this problem, not only comprehensive evaluation model and stage evaluation models are built in this paper, but also prediction and sensibility analysis are given to the models. It can make besement for evaluating the reliability and safety of DCS. (author)
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Evaluation of periodic safety status analyses
International Nuclear Information System (INIS)
Faber, C.; Staub, G.
1997-01-01
In order to carry out the evaluation of safety status analyses by the safety assessor within the periodical safety reviews of nuclear power plants safety goal oriented requirements have been formulated together with complementary evaluation criteria. Their application in an inter-disciplinary coopertion covering the subject areas involved facilitates a complete safety goal oriented assessment of the plant status. The procedure is outlined briefly by an example for the safety goal 'reactivity control' for BWRs. (orig.) [de
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From Safe Systems to Patient Safety
DEFF Research Database (Denmark)
Aarts, J.; Nøhr, C.
2010-01-01
for the third conference with the theme: The ability to design, implement and evaluate safe, useable and effective systems within complex health care organizations. The theme for this conference was "Designing and Implementing Health IT: from safe systems to patient safety". The contributions have reflected...... and implementation of safe systems and thus contribute to the agenda of patient safety? The contributions demonstrate how the health informatics community has contributed to the performance of significant research and to translating research findings to develop health care delivery and improve patient safety......This volume presents the papers from the fourth International Conference on Information Technology in Health Care: Socio-technical Approaches held in Aalborg, Denmark in June 2010. In 2001 the first conference was held in Rotterdam, The Netherlands with the theme: Sociotechnical' approaches...
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The Evaluation of the Safety Benefits of Combined Passive and On-Board Active Safety Applications
Page, Yves; Cuny, Sophie; Zangmeister, Tobias; Kreiss, Jens-Peter; Hermitte, Thierry
2009-01-01
One of the objectives of the European TRACE project (TRaffic Accident Causation in Europe, 2006–2008) was to estimate the proportion of injury accidents that could be avoided and/or the proportion of injury accidents where the severity could be mitigated for on-the-market safety applications, if 100 % of the car fleet would be equipped with them. We have selected for evaluation the Electronic Stability Control (ESC) and the Emergency Brake Assist (EBA) applications. As for passive safety systems, recent cars are designed to offer overall safety protection. Car structure, load limiters, front airbags, side airbags, knee airbags, pretensioners, padding and non aggressive structures in the door panel, the dashboard, the windshield, the seats, and the head rest also contribute to applying more protection. The whole safety package is very difficult to evaluate separately, one element independently segmented from the others. We decided to consider evaluating the effectivenessof the whole passive safety package, This package,, for the sake of simplicity, was the number of stars awarded at the Euro NCAP testing. The challenges were to compare the effectiveness of some safety configuration SC I, with the effectiveness of a different safety configuration SC II. A safety configuration is understood as a package of safety functions. Ten comparisons have been carried out such as the evaluation of the safety benefit of a fifth star given that the car has four stars and an EBA. The main outcome of this analysis is that any addition of a passive or active safety function selected in this analysis is producing increased safety benefits. For example, if all cars were five stars fitted with EBA and ESC, instead of four stars without ESC and EBA, injury accidents would be reduced by 47.2% for severe injuries and 69.5% for fatal injuries. PMID:20184838
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Progress report: 1996 Radiation Safety Systems Division
International Nuclear Information System (INIS)
Bhagwat, A.M.; Sharma, D.N.; Abani, M.C.; Mehta, S.K.
1997-01-01
The activities of Radiation Safety Systems Division include (i) development of specialised monitoring systems and radiation safety information network, (ii) radiation hazards control at the nuclear fuel cycle facilities, the radioisotope programmes at Bhabha Atomic Research Centre (BARC) and for the accelerators programme at BARC and Centre for Advanced Technology (CAT), Indore. The systems on which development and upgradation work was carried out during the year included aerial gamma spectrometer, automated environment monitor using railway network, radioisotope package monitor and air monitors for tritium and alpha active aerosols. Other R and D efforts at the division included assessment of risk for radiation exposures and evaluation of ICRP 60 recommendations in the Indian context, shielding evaluation and dosimetry for the new upcoming accelerator facilities and solid state nuclear track detector techniques for neutron measurements. The expertise of the divisional members was provided for 36 safety committees of BARC and Atomic Energy Regulatory Board (AERB). Twenty three publications were brought out during the year 1996. (author)
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Proposal of Integrated Safety Assessment Methodology for Embedded System
International Nuclear Information System (INIS)
Sun, Wei; Kageyama, Makoto; Kanemoto, Shigeru
2011-01-01
To do risk analysis and risk evaluation for complicated safety critical embedded systems, there are three things should be paid a good attention: 1) an efficient and integrated model expression of embedded systems: 2) systematic risk analysis based on integrated system model: 3) quantitative risk evaluation for software and hardware integrated system. In this paper, taken electric water boiler as a target system, a proposal of risk analysis and risk evaluation for the embedded system is presented to meet these three purposes. In risk analysis, MFM is used and FT is generated automatically from MFM following some rules: And in risk evaluation, GO-FLOW is used to evaluate the reliability of sensors. And furthermore, FIT is applied to evaluate the safety software logic based on the diversity design concept. Although the electric water boiler is a simple example, it includes the key components of the embedded system like sensors, actuators, and software component. So, the process of modeling, analysis, and evaluation could be applied to other kinds of complicated embedded systems
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Contribution of maintainability and maintenance to problems of safety evaluation
International Nuclear Information System (INIS)
Adnot, Serge; Meriaux, Pierre.
1977-10-01
A method has been developed for defining the contribution of Maintainability and the Maintenance Studies to Safety evaluation problems. The efficiency of this method is shown and results obtained are given for two theoretical examples approximating reality. For repairable systems, the risk defined according to such given safety criterion, becomes a characteristic of the systems in operation [fr
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The LHC personnel safety system
International Nuclear Information System (INIS)
Ninin, P.; Valentini, F.; Ladzinski, T.
2011-01-01
Large particle physics installations such as the CERN Large Hadron Collider require specific Personnel Safety Systems (PSS) to protect the personnel against the radiological and industrial hazards. In order to fulfill the French regulation in matter of nuclear installations, the principles of IEC 61508 and IEC 61513 standard are used as a methodology framework to evaluate the criticality of the installation, to design and to implement the PSS.The LHC PSS deals with the implementation of all physical barriers, access controls and interlock devices around the 27 km of underground tunnel, service zones and experimental caverns of the LHC. The system shall guarantee the absence of personnel in the LHC controlled areas during the machine operations and, on the other hand, ensure the automatic accelerator shutdown in case of any safety condition violation, such as an intrusion during beam circulation. The LHC PSS has been conceived as two separate and independent systems: the LHC Access Control System (LACS) and the LHC Access Safety System (LASS). The LACS, using off the shelf technologies, realizes all physical barriers and regulates all accesses to the underground areas by identifying users and checking their authorizations.The LASS has been designed according to the principles of the IEC 61508 and 61513 standards, starting from a risk analysis conducted on the LHC facility equipped with a standard access control system. It consists in a set of safety functions realized by a dedicated fail-safe and redundant hardware guaranteed to be of SIL3 class. The integration of various technologies combining electronics, sensors, video and operational procedures adopted to establish an efficient personnel safety system for the CERN LHC accelerator is presented in this paper. (authors)
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Survey of electronic safety systems in accelerator applications
International Nuclear Information System (INIS)
Mahoney, K.
1997-01-01
This paper presents the preliminary results and analysis of a comprehensive survey of the implementation of accelerator safety interlock systems from over 30 international labs. At the present time there is not a self consistent means to evaluate both the experiences and level of protection provided by electronic safety interlock systems. This research is intended to analyze the strength and weaknesses of several different types of interlock system implementation methodologies. Research, medical, and industrial accelerators are compared. Thomas Jefferson National Accelerator Facility (TJNAF) was one of the first large particle accelerators to implement a safety interlock system using programmable logic controllers. Since that time all of the major new U.S. accelerator construction projects plan to use some form of programmable electronics as part of a safety interlock system in some capacity
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Directory of Open Access Journals (Sweden)
Jiangdong Bao
2017-01-01
Full Text Available In order to comprehensively evaluate the employee satisfaction of mine occupational health and safety management system, an analytic method based on fuzzy analytic hierarchy process and 2-tuple linguistic model was established. Based on the establishment of 5 first-grade indicators and 20 second-grade ones, method of improved AHP and the time-ordered Weighted Averaging Operator (T-OWA model is constructed. The results demonstrate that the employee satisfaction of the mine occupational health and safety management system is of the ‘general’ rank. The method including the evaluation of employee satisfaction and the quantitative analysis of language evaluation information ensures the authenticity of the language evaluation information.
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Safety implications of electronic driving support systems : an orientation.
Gundy, C.M. Steyvers, F.J.J.M. & Kaptein, N.A.
1995-01-01
This report focuses on traffic safety aspects of driving support systems. The report consists of two parts. First of all, the report discusses a number of topics, relevant for the implementation and evaluation of driving support systems. These topics include: (1) safety research into driving support
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Performance Evaluation of SMART Passive Safety System for Small Break LOCA Using MARS Code
International Nuclear Information System (INIS)
Chun, Ji Han; Lee, Guy Hyung; Bae, Kyoo Hwan; Chung, Young Jong; Kim, Keung Koo
2013-01-01
SMART has significantly enhanced safety by reducing its core damage frequency to 1/10 that of a conventional nuclear power plant. KAERI is developing a passive safety injection system to replace the active safety injection pump in SMART. It consists of four trains, each of which includes gravity-driven core makeup tank (CMT) and safety injection tank (SIT). This system is required to meet the passive safety performance requirements, i.e., the capability to maintain a safe shutdown condition for a minimum of 72 hours without an AC power supply or operator action in the case of design basis accidents (DBAs). The CMT isolation valve is opened by the low pressurizer pressure signal, and the SIT isolation valve is opened at 2 MPa. Additionally, two stages of automatic depressurization systems are used for rapid depressurization. Preliminary safety analysis of SMART passive safety system in the event of a small-break loss-of-coolant accident (SBLOCA) was performed using MARS code. In this study, the safety analysis results of a guillotine break of safety injection line which was identified as the limiting SBLOCA in SMART are given. The preliminary safety analysis of a SBLOCA for the SMART passive safety system was performed using the MARS code. The analysis results of the most limiting SI line guillotine break showed that the collapsed liquid level inside the core support barrel was maintained sufficiently high above the top of core throughout the transient. This means that the passive safety injection flow from the CMT and SIT causes no core uncovery during the 72 hours following the break with no AC power supply or operator action, which in turn results in a consistent decrease in the fuel cladding temperature. Therefore, the SMART passive safety system can meet the passive safety performance requirement of maintaining the plant at a safe shutdown condition for a minimum of 72 hours without AC power or operator action for a representing accident of SBLOCA
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Evaluation of reliability assurance approaches to operational nuclear safety
International Nuclear Information System (INIS)
Mueller, C.J.; Bezella, W.A.
1984-01-01
This report discusses the results of research to evaluate existing and/or recommended safety/reliability assurance activities among nuclear and other high technology industries for potential nuclear industry implementation. Since the Three Mile Island (TMI) accident, there has been increased interest in the use of reliability programs (RP) to assure the performance of nuclear safety systems throughout the plant's lifetime. Recently, several Nuclear Regulatory Commission (NRC) task forces or safety issue review groups have recommended RPs for assuring the continuing safety of nuclear reactor plants. 18 references
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Diversity requirements for safety critical software-based automation systems
International Nuclear Information System (INIS)
Korhonen, J.; Pulkkinen, U.; Haapanen, P.
1998-03-01
System vendors nowadays propose software-based systems even for the most critical safety functions in nuclear power plants. Due to the nature and mechanisms of influence of software faults new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)' various safety assessment methods and tools for software based systems are developed and evaluated. This report first discusses the (common cause) failure mechanisms in software-based systems, then defines fault-tolerant system architectures to avoid common cause failures, then studies the various alternatives to apply diversity and their influence on system reliability. Finally, a method for the assessment of diversity is described. Other recently published reports in OHA-report series handles the statistical reliability assessment of software based (STUK-YTO-TR 119), usage models in reliability assessment of software-based systems (STUK-YTO-TR 128) and handling of programmable automation in plant PSA-studies (STUK-YTO-TR 129)
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Software Safety Risk in Legacy Safety-Critical Computer Systems
Hill, Janice L.; Baggs, Rhoda
2007-01-01
Safety Standards contain technical and process-oriented safety requirements. Technical requirements are those such as "must work" and "must not work" functions in the system. Process-Oriented requirements are software engineering and safety management process requirements. Address the system perspective and some cover just software in the system > NASA-STD-8719.13B Software Safety Standard is the current standard of interest. NASA programs/projects will have their own set of safety requirements derived from the standard. Safety Cases: a) Documented demonstration that a system complies with the specified safety requirements. b) Evidence is gathered on the integrity of the system and put forward as an argued case. [Gardener (ed.)] c) Problems occur when trying to meet safety standards, and thus make retrospective safety cases, in legacy safety-critical computer systems.
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Confirmatory simulation of safety and operational transients in LMFBR systems
International Nuclear Information System (INIS)
Guppy, J.G.; Agrawal, A.K.
1978-01-01
Operational and safety transients that may originate anywhere in an LMFBR system must be adequately simulated to assist in safety evaluation and plant design efforts. This paper describes an advanced thermohydraulic transient code, the Super System Code (SSC), that may be used for confirmatory safety evaluations of plant wide events, such as assurance of adequate decay heat removal capability under natural circulation conditions, and presents results obtained with SSC illustrating the degree of modelling detail present in the code as well as the computing efficiency. (author)
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Performance scorecard for occupational safety and health management systems
Directory of Open Access Journals (Sweden)
Hernâni Veloso Neto
2012-06-01
Full Text Available The pro-active and systematic search for best performances should be the two assumptions of any management system, so safety and health management in organizations must also be guided by these same precepts. However, the scientific production evidences that the performance evaluation processes in safety and health continue to be guided, in their essence, by intermittency, reactivity and negativity, which are not consistent with the assumptions referenced above. Therefore, it is essential that health and safety at work management systems (HSW MS are structured from an active and positive viewpoint, focusing on continuous improvement. This implies considering performance evaluation processes that incorporate, on the one hand, monitoring, measuring and verification procedures, and on the other hand, structured matrixes of results that capture the key factors of success, by mobilizing both reactive and proactive indicators. One of the instruments that can fulfill these precepts of health and safety performance evaluation is the SafetyCard, a performance scorecard for HSW MS that we developed and will seek to outline and demonstrate over this paper.
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Safety climate and attitude as evaluation measures of organizational safety.
Isla Díaz, R; Díaz Cabrera, D
1997-09-01
The main aim of this research is to develop a set of evaluation measures for safety attitudes and safety climate. Specifically it is intended: (a) to test the instruments; (b) to identify the essential dimensions of the safety climate in the airport ground handling companies; (c) to assess the quality of the differences in the safety climate for each company and its relation to the accident rate; (d) to analyse the relationship between attitudes and safety climate; and (e) to evaluate the influences of situational and personal factors on both safety climate and attitude. The study sample consisted of 166 subjects from three airport companies. Specifically, this research was centered on ground handling departments. The factor analysis of the safety climate instrument resulted in six factors which explained 69.8% of the total variance. We found significant differences in safety attitudes and climate in relation to type of enterprise.
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Passive safety systems reliability and integration of these systems in nuclear power plant PSA
International Nuclear Information System (INIS)
La Lumia, V.; Mercier, S.; Marques, M.; Pignatel, J.F.
2004-01-01
Innovative nuclear reactor concepts could lead to use passive safety features in combination with active safety systems. A passive system does not need active component, external energy, signal or human interaction to operate. These are attractive advantages for safety nuclear plant improvements and economic competitiveness. But specific reliability problems, linked to physical phenomena, can conduct to stop the physical process. In this context, the European Commission (EC) starts the RMPS (Reliability Methods for Passive Safety functions) program. In this RMPS program, a quantitative reliability evaluation of the RP2 system (Residual Passive heat Removal system on the Primary circuit) has been realised, and the results introduced in a simplified PSA (Probabilistic Safety Assessment). The scope is to get out experience of definition of characteristic parameters for reliability evaluation and PSA including passive systems. The simplified PSA, using event tree method, is carried out for the total loss of power supplies initiating event leading to a severe core damage. Are taken into account: failures of components but also failures of the physical process involved (e.g. natural convection) by a specific method. The physical process failure probabilities are assessed through uncertainty analyses based on supposed probability density functions for the characteristic parameters of the RP2 system. The probabilities are calculated by MONTE CARLO simulation coupled to the CATHARE thermalhydraulic code. The yearly frequency of the severe core damage is evaluated for each accident sequence. This analysis has identified the influence of the passive system RP2 and propose a re-dimensioning of the RP2 system in order to satisfy the safety probabilistic objectives for reactor core severe damage. (authors)
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Software Quality Assurance for Nuclear Safety Systems
International Nuclear Information System (INIS)
Sparkman, D R; Lagdon, R
2004-01-01
The US Department of Energy has undertaken an initiative to improve the quality of software used to design and operate their nuclear facilities across the United States. One aspect of this initiative is to revise or create new directives and guides associated with quality practices for the safety software in its nuclear facilities. Safety software includes the safety structures, systems, and components software and firmware, support software and design and analysis software used to ensure the safety of the facility. DOE nuclear facilities are unique when compared to commercial nuclear or other industrial activities in terms of the types and quantities of hazards that must be controlled to protect workers, public and the environment. Because of these differences, DOE must develop an approach to software quality assurance that ensures appropriate risk mitigation by developing a framework of requirements that accomplishes the following goals: (sm b ullet) Ensures the software processes developed to address nuclear safety in design, operation, construction and maintenance of its facilities are safe (sm b ullet) Considers the larger system that uses the software and its impacts (sm b ullet) Ensures that the software failures do not create unsafe conditions Software designers for nuclear systems and processes must reduce risks in software applications by incorporating processes that recognize, detect, and mitigate software failure in safety related systems. It must also ensure that fail safe modes and component testing are incorporated into software design. For nuclear facilities, the consideration of risk is not necessarily sufficient to ensure safety. Systematic evaluation, independent verification and system safety analysis must be considered for software design, implementation, and operation. The software industry primarily uses risk analysis to determine the appropriate level of rigor applied to software practices. This risk-based approach distinguishes safety
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Development of a safety parameter supervision system for Angra-1
International Nuclear Information System (INIS)
Silva, R.A. da; Thome Filho, Z.D.; Schirru, R.; Martinez, A.S.; Oliveira, L.F.S. de
1986-01-01
The Safety Parameter Supervision System (SSPS) which is a computerized system for monitoring essential parameters in real time, determining the safety status and emergency procedures for returning normal reactor operation, in case of an anomaly occurrence, is presented. The SSPS consists of three sub-systems: Integrated parameter monitoring system which gives to operators an integrated vision of values of a parameter set, able to detect any deviation of normal reactor operation; safety critical function system which evaluates safety status in terms of a safety critical function set appointed in advance, and in case of violation of any critical function, it initiates the adequate emergency procedure to return normal operation; and safety parameter computer system which carries out the arquirement of analogic and digital control signals of nuclear power plant. (M.C.K.) [pt
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The Management System for Nuclear Installations Safety Guide
International Nuclear Information System (INIS)
2009-01-01
This Safety Guide is applicable throughout the lifetime of a nuclear installation, including any subsequent period of institutional control, until there is no significant residual radiation hazard. For a nuclear installation, the lifetime includes site evaluation, design, construction, commissioning, operation and decommissioning. These stages in the lifetime of a nuclear installation may overlap. This Safety Guide may be applied to nuclear installations in the following ways: (a)To support the development, implementation, assessment and improvement of the management system of those organizations responsible for research, site evaluation, design, construction, commissioning, operation and decommissioning of a nuclear installation; (b)As an aid in the assessment by the regulatory body of the adequacy of the management system of a nuclear installation; (c)To assist an organization in specifying to a supplier, via contractual documentation, any specific element that should be included within the supplier's management system for the supply of products. This Safety Guide follows the structure of the Safety Requirements publication on The Management System for Facilities and Activities, whereby: (a)Section 2 provides recommendations on implementing the management system, including recommendations relating to safety culture, grading and documentation. (b)Section 3 provides recommendations on the responsibilities of senior management for the development and implementation of an effective management system. (c)Section 4 provides recommendations on resource management, including guidance on human resources, infrastructure and the working environment. (d)Section 5 provides recommendations on how the processes of the installation can be specified and developed, including recommendations on some generic processes of the management system. (e)Section 6 provides recommendations on the measurement, assessment and improvement of the management system of a nuclear installation. (f
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Progress in the development of methodology for fusion safety systems studies
International Nuclear Information System (INIS)
Ho, S.K.; Cambi, G.; Ciattaglia, S.; Fujii-e, Y.; Seki, Y.
1994-01-01
The development of fusion safety systems-study methodology, including the aspects of schematic classification of overall fusion safety system, qualitative assessment of fusion system for identification of critical accident scenarios, quantitative analysis of accident consequences and risk for safety design evaluation, and system-level analysis of accident consequences and risk for design optimization, by a consortium of international efforts is presented. The potential application of this methodology into reactor design studies will facilitate the systematic assessment of safety performance of reactor designs and enhance the impacts of safety considerations on the selection of design configurations
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International Nuclear Information System (INIS)
Rashad, S.; El-Fawal, M.; Kandil, M.
2013-01-01
The ventilation and air cleaning system in the nuclear or radiological installations is one of the essential nuclear safety concerns. It is responsible for confining the radioactive materials involved behind suitable barriers during normal and abnormal conditions. It must be designed to prevent the release of harmful products (radioactive gases, or airborne radioactive materials) from the system or facility, impacting the public or workers, and doing environmental damage. There are two important safety functions common to all ventilation and air cleaning system in nuclear facilities. They are: a) the requirements to maintain the pressure of the ventilated volume below that of surrounding, relatively non-active areas, in order to inhibit the spread of contamination during normal and abnormal conditions, and b) the need to treat the ventilated gas so as to minimize the release of any radioactive or toxic materials. Keeping the two important safety functions is achieved by applying the fire protection for the ventilation system to achieve safety and adequate protection in nuclear applications facilities during fire and accidental criticality conditions.The main purpose of this research is to assist ventilation engineers and experts in nuclear installations for safe operation and maintaining ventilation and air cleaning system during fire accident in nuclear facilities. The research focuses on fire prevention and protection of the ventilation systems in nuclear facilities. High-Efficiency particulate air (HEPA) filters are extremely susceptible to damage when exposed to the effects of fire, smoke, and water; it is the intent of this research to provide the designer with the experience gained over the years from hard lessons learned in protecting HEPA filters from fire. It describes briefly and evaluates the design safety features, constituents and working conditions of ventilation and air cleaning system in nuclear and radioactive industry.This paper provides and
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Evaluation on safety issues of SMART
International Nuclear Information System (INIS)
Kim, W. S.; Seol, K. W.; Yoon, Y. K.; Lee, J. H.
2001-01-01
Safety issues on the SMART were evaluated in the light of the compliance with the Ministerial Ordinance of Technical Requirements applying to Nuclear Installations, which was recently revised. Evaluation concludes that regulatory requirements associated with following items have to be developed as the licensing criteria for the SMART: (1) proving the safety of design or materials different form existing reactors; (2) coping with beyond design basis accidents; (3) rulemaking on the safety of reactor safeguard vessel ; (4) ensuring integrity of steam generator tubes; and (5) classifying equipment based on their safety significance. Appropriate actions including implementation of new requirements under development should be taken for safety issues such as diversity of reactivity control and in-service inspection of steam generator tubes that are not complied with the current Technical Requirements. Safety level of the SMART design will be evaluated further by the more detailed assessment according to the Technical Requirements, and additional safety issues will be identified and resolved, if it necessary
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The Interagency Nuclear Safety Review Panel's Galileo safety evaluation report
International Nuclear Information System (INIS)
Nelson, R.C.; Gray, L.B.; Huff, D.A.
1989-01-01
The safety evaluation report (SER) for Galileo was prepared by the Interagency Nuclear Safety Review Panel (INSRP) coordinators in accordance with Presidential directive/National Security Council memorandum 25. The INSRP consists of three coordinators appointed by their respective agencies, the Department of Defense, the Department of Energy (DOE), and the National Aeronautics and Space Administration (NASA). These individuals are independent of the program being evaluated and depend on independent experts drawn from the national technical community to serve on the five INSRP subpanels. The Galileo SER is based on input provided by the NASA Galileo Program Office, review and assessment of the final safety analysis report prepared by the Office of Special Applications of the DOE under a memorandum of understanding between NASA and the DOE, as well as other related data and analyses. The SER was prepared for use by the agencies and the Office of Science and Technology Policy, Executive Office of the Present for use in their launch decision-making process. Although more than 20 nuclear-powered space missions have been previously reviewed via the INSRP process, the Galileo review constituted the first review of a nuclear power source associated with launch aboard the Space Transportation System
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Directory of Open Access Journals (Sweden)
I mohammadfam
2014-03-01
Full Text Available Accident analysis shows that one of the main reasons for accidents is non-integration of maintenance units with safety. Merging these two processes through an integrated system can reduce and or eliminate accidents, diseases, and environmental pollution. These issues lead to improvement in organizational performance, as well. The aim of this study is to design and establish an integrated system for obtaining the aforementioned goal. Integration was carried out at Nirou Moharreke Machine Tools Company via Structured System Analysis & Design Method (SSADM. In order to measure the effectiveness of the system, selected indexes were compared using statistical methods prior and after system establishment. Results show that the accident severity index reduced from 135.46 in 2010, to 43.85 in 2012. Moreover, system effectiveness improved equipment reliability and availability (e.g. reliability of the Pfeiffer Milling machine (P (t>50 increased from 0.89 in 2010, to 0.9 in 2012. This system by forecasting various failures, and planning and designing the required operations for preventing occurrence of these failures, plays an important role in improving safety conditions of equipment, and increasing organizational performance, and is capable of presenting an excellent accident prevention program.
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Upgrading safety systems of industrial irradiation facilities
International Nuclear Information System (INIS)
Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C.; Costa, M.L.L.; Thomé, Z.D.
2017-01-01
The first industrial irradiation facility in operation in Brazil was designed in the 70s. Nowadays, twelve commercial and research facilities are in operation and two already decommissioned. Minor modifications and upgrades, as sensors replacement, have been introduced in these facilities, in order to reduce the technological gap in the control and safety systems. The safety systems are designed in agreement with the codes and standards at the time. Since then, new standards, codes and recommendations, as well as lessons learned from accidents, have been issued by various international committees or regulatory bodies. The rapid advance of the industry makes the safety equipment used in the original construction become obsolete. The decreasing demand for these older products means that they are no longer produced, which can make it impossible or costly to obtain spare parts and the expansion of legacy systems to include new features. This work aims to evaluate existing safety systems at Brazilian irradiation facilities, mainly the oldest facilities, taking into account the recommended IAEA's design requirements. Irrespective of the fact that during its operational period no event with victims have been recorded in Brazilian facilities, and that the regulatory inspections do not present any serious deviations regarding the safety procedures, it is necessary an assessment of safety system with the purpose of bringing their systems to 'the state of the art', avoiding their rapid obsolescence. This study has also taken into account the knowledge, concepts and solutions developed to upgrading safety system in irradiation facilities throughout the world. (author)
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Upgrading safety systems of industrial irradiation facilities
Energy Technology Data Exchange (ETDEWEB)
Gomes, R.S.; Gomes, J.D.R.L.; Costa, E.L.C.; Costa, M.L.L., E-mail: rogeriog@cnen.gov.br, E-mail: jlopes@cnen.gov.br, E-mail: evaldo@cnen.gov.br, E-mail: mara@cnen.gov.br [Comissão Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Diretoria de Radioproteção e Segurança Nuclear; Thomé, Z.D., E-mail: zielithome@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Seção de Engenharia Nuclear
2017-07-01
The first industrial irradiation facility in operation in Brazil was designed in the 70s. Nowadays, twelve commercial and research facilities are in operation and two already decommissioned. Minor modifications and upgrades, as sensors replacement, have been introduced in these facilities, in order to reduce the technological gap in the control and safety systems. The safety systems are designed in agreement with the codes and standards at the time. Since then, new standards, codes and recommendations, as well as lessons learned from accidents, have been issued by various international committees or regulatory bodies. The rapid advance of the industry makes the safety equipment used in the original construction become obsolete. The decreasing demand for these older products means that they are no longer produced, which can make it impossible or costly to obtain spare parts and the expansion of legacy systems to include new features. This work aims to evaluate existing safety systems at Brazilian irradiation facilities, mainly the oldest facilities, taking into account the recommended IAEA's design requirements. Irrespective of the fact that during its operational period no event with victims have been recorded in Brazilian facilities, and that the regulatory inspections do not present any serious deviations regarding the safety procedures, it is necessary an assessment of safety system with the purpose of bringing their systems to 'the state of the art', avoiding their rapid obsolescence. This study has also taken into account the knowledge, concepts and solutions developed to upgrading safety system in irradiation facilities throughout the world. (author)
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Safety implications of electronic driving support systems : an orientation.
Gundy, C.M. Steyvers, F.J.J.M. & Kaptein, N.A.
1995-01-01
This report focuses on traffic safety aspects of driving support systems. The report consists of two parts. First of all, the report discusses a number of topics, relevant for the implementation and evaluation of driving support systems. These topics include: (1) safety research into driving support systems: (2) the importance of research into driver models and the driving task; (3) horizontal integration of driving support systems; (4) vertical integration of driving support systems; (5) tas...
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International Nuclear Information System (INIS)
Kafka, P.
1975-01-01
The spectrum of possible accidents may become characterized by the 'maximum credible accident', which will/will not happen. Similary, the performance of safety systems in a multitude of situations is sometimes simplified to 'the emergency system will/will not work' or even 'reactors are/ are not safe'. In assessing safety, one must avoid this fallacy of reducing a complicated situation to the simple black-and-white picture of yes/no. Similarly, there is a natural tendency continually to improve the safety of a system to assure that it is 'safe enough'. Any system can be made safer and there is usually some additional cost. It is important to balance the increased safety against the increased costs. (orig.) [de
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Development and application of an integrated evaluation framework for preventive safety applications
Scholliers, J.; Joshi, S.; Gemou, M.; Hendriks, F.; Ljung Aust, M.; Luoma, J.; Netto, M.; Engstrom, J.; Leanderson Olsson, S.; Kutzner, R.; Tango, F.; Amditis, A.J.; Blosseville, J.M.; Bekiaris, E.
2011-01-01
Preventive safety functions help drivers avoid or mitigate accidents. No quantitative methods have been available to evaluate the safety impact of these systems. This paper describes a framework for the assessment of preventive and active safety functions, which integrates procedures for technical
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Reactor system safety assurance
International Nuclear Information System (INIS)
Mattson, R.J.
1984-01-01
The philosophy of reactor safety is that design should follow established and conservative engineering practices, there should be safety margins in all modes of plant operation, special systems should be provided for accidents, and safety systems should have redundant components. This philosophy provides ''defense in depth.'' Additionally, the safety of nuclear power plants relies on ''safety systems'' to assure acceptable response to design basis events. Operating experience has shown the need to study plant response to more frequent upset conditions and to account for the influence of operators and non-safety systems on overall performance. Defense in depth is being supplemented by risk and reliability assessment
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Simon, Airin C R; Holleman, Frits; Gude, Wouter T; Hoekstra, Joost B L; Peute, Linda W; Jaspers, Monique W M; Peek, Niels
2013-09-01
The rising incidence of type 2 diabetes mellitus (T2DM) induces severe challenges for the health care system. Our research group developed a web-based system named PANDIT that provides T2DM patients with insulin dosing advice using state of the art clinical decision support technology. The PANDIT interface resembles a glucose diary and provides advice through pop-up messages. Diabetes nurses (DNs) also have access to the system, allowing them to intervene when needed. The objective of this study was to establish whether T2DM patients can safely use PANDIT at home. To this end, we assessed whether patients experience usability problems with a high risk of compromising patient safety when interacting with the system, and whether PANDIT's insulin dosing advice are clinically safe. The study population consisted of patients with T2DM (aged 18-80) who used a once daily basal insulin as well as DNs from a university hospital. The usability evaluation consisted of think-aloud sessions with four patients and three DNs. Video data, audio data and verbal utterances were analyzed for usability problems encountered during PANDIT interactions. Usability problems were rated by a physician and a usability expert according to their potential impact on patient safety. The usability evaluation was followed by an implementation with a duration of four weeks. This implementation took place at the patients' homes with ten patients to evaluate clinical safety of PANDIT advice. PANDIT advice were systematically compared with DN advice. Deviating advice were evaluated with respect to patient safety by a panel of experienced physicians, which specialized in diabetes care. We detected seventeen unique usability problems, none of which was judged to have a high risk of compromising patient safety. Most usability problems concerned the lay-out of the diary, which did not clearly indicate which data entry fields had to be entered in order to obtain an advice. 27 out of 74 (36.5%) PANDIT advice
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Fundamental study on applicability of resilience index for system safety assessment
International Nuclear Information System (INIS)
Suzuki, Masaaki; Demachi, Kazuyuki; Murakami, Kenta
2015-01-01
We have developed a new index called Resilience index, which evaluate the reliability of system safety of nuclear power plant under severe accident by considering the capability to recover from the situation the system safety function was lost. In this paper, a detailed evaluation procedure for the Resilience index was described. System safety of a PWR plant under severe accident was then assessed according to the Resilience index concept to discuss applicability of the index. We found that the Resilience index successfully visualize the management capability, and therefore, resilience capability of a nuclear power plant. (author)
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21 CFR 315.6 - Evaluation of safety.
2010-04-01
... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Evaluation of safety. 315.6 Section 315.6 Food and... USE DIAGNOSTIC RADIOPHARMACEUTICALS § 315.6 Evaluation of safety. (a) Factors considered in the safety...)(1) To establish the safety of a diagnostic radiopharmaceutical, FDA may require, among other...
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Using system dynamics simulation for assessment of hydropower system safety
King, L. M.; Simonovic, S. P.; Hartford, D. N. D.
2017-08-01
Hydropower infrastructure systems are complex, high consequence structures which must be operated safely to avoid catastrophic impacts to human life, the environment, and the economy. Dam safety practitioners must have an in-depth understanding of how these systems function under various operating conditions in order to ensure the appropriate measures are taken to reduce system vulnerability. Simulation of system operating conditions allows modelers to investigate system performance from the beginning of an undesirable event to full system recovery. System dynamics simulation facilitates the modeling of dynamic interactions among complex arrangements of system components, providing outputs of system performance that can be used to quantify safety. This paper presents the framework for a modeling approach that can be used to simulate a range of potential operating conditions for a hydropower infrastructure system. Details of the generic hydropower infrastructure system simulation model are provided. A case study is used to evaluate system outcomes in response to a particular earthquake scenario, with two system safety performance measures shown. Results indicate that the simulation model is able to estimate potential measures of system safety which relate to flow conveyance and flow retention. A comparison of operational and upgrade strategies is shown to demonstrate the utility of the model for comparing various operational response strategies, capital upgrade alternatives, and maintenance regimes. Results show that seismic upgrades to the spillway gates provide the largest improvement in system performance for the system and scenario of interest.
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Radiation safety management system in a radioactive facility
International Nuclear Information System (INIS)
Amador, Zayda H.
2008-01-01
Full text: This paper illustrates the Cuban experience in implementing and promoting an effective radiation safety system for the Centre of Isotopes, the biggest radioactive facility of our country. Current management practice demands that an organization inculcate culture of safety in preventing radiation hazard. The aforementioned objectives of radiation protection can only be met when it is implemented and evaluated continuously. Commitment from the workforce to treat safety as a priority and the ability to turn a requirement into a practical language is also important to implement radiation safety policy efficiently. Maintaining and improving safety culture is a continuous process. There is a need to establish a program to measure, review and audit health and safety performance against predetermined standards. All those areas of the radiation protection program are considered (e.g. licensing and training of the staff, occupational exposure, authorization of the practices, control of the radioactive material, radiological occurrences, monitoring equipment, radioactive waste management, public exposure due to airborne effluents, audits and safety costs). A set of indicators designed to monitor key aspects of operational safety performance are used. Their trends over a period of time are analyzed with the modern information technologies, because this can provide an early warning to plant management for searching causes behind the observed changes. In addition to analyze the changes and trends, these indicators are compared against identified targets and goals to evaluate performance strengths and weaknesses. A structured and proper radiation self-auditing system is seen as a basic requirement to meet the current and future needs in sustainability of radiation safety. The integrated safety management system establishment has been identified as a goal and way for the continuous improvement. (author)
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Interactive effects of relay and circuit breaker aging in a safety-related system
International Nuclear Information System (INIS)
Toman, G.J.; Bacanskas, V.P.; Shook, T.A.; Ladlow, C.C.; Gunther, W.
1987-01-01
This paper provides an overview of the results of a program to evaluate the aging of circuit breakers and relays and the effects of that aging on the function of a safety system used in nuclear power plants. The program was performed under the Nuclear Plant Aging Research (NPAR) Program of the US Nuclear Regulatory Commission under subcontract to Brookhaven National Laboratory. There were two primary aspects to the program. In the first, the aging and failure modes of relays and circuit breakers were determined by evaluating the construction, design, and materials and the failure data related to nuclear power plant service. In the second, the interactions between a safety system and its relays and circuit breakers were evaluated to determine the effects of relay and circuit breaker aging on the function of the safety system. The aging of relays and circuit breakers was assessed through evaluation of failure data bases, discussions with utility personnel, and evaluation of equipment operating and maintenance manuals. The interaction study was based on an analysis of the safety injection system of a pressurized water reactor. The effects of stresses from the system were analyzed for the tendency to cause deterioration of the relays and circuit breakers in the system. Then the effect of the deterioration of relays and circuit breakers on the functional capability of the safety system was evaluated
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Research on safety evaluation model for in-vehicle secondary task driving.
Jin, Lisheng; Xian, Huacai; Niu, Qingning; Bie, Jing
2015-08-01
This paper presents a new method for evaluating in-vehicle secondary task driving safety. There are five in-vehicle distracter tasks: tuning the radio to a local station, touching the touch-screen telephone menu to a certain song, talking with laboratory assistant, answering a telephone via Bluetooth headset, and finding the navigation system from Ipad4 computer. Forty young drivers completed the driving experiment on a driving simulator. Measures of fixations, saccades, and blinks are collected and analyzed. Based on the measures of driver eye movements which have significant difference between the baseline and secondary task driving conditions, the evaluation index system is built. The Analytic Network Process (ANP) theory is applied for determining the importance weight of the evaluation index in a fuzzy environment. On the basis of the importance weight of the evaluation index, Fuzzy Comprehensive Evaluation (FCE) method is utilized to evaluate the secondary task driving safety. Results show that driving with secondary tasks greatly distracts the driver's attention from road and the evaluation model built in this study could estimate driving safety effectively under different driving conditions. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.
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Preliminary safety evaluation for the plutonium stabilization and packaging system
International Nuclear Information System (INIS)
Shapley, J.E.
1997-01-01
This Preliminary Safety Evaluation (PSE) describes and analyzes the installation and operation of the Plutonium Stabilization and Packaging System (SPS) at the Plutonium Finishing Plant (PFP). The SPS is a combination of components required to expedite the safe and timely storage of Plutonium (Pu) oxide. The SPS program will receive site Pu packages, process the Pu for storage, package the Pu into metallic containers, and safely store the containers in a specially modified storage vault. The location of the SPS will be in the 2736- ZB building and the storage vaults will be in the 2736-Z building of the PFP, as shown in Figure 1-1. The SPS will produce storage canisters that are larger than those currently used for Pu storage at the PFP. Therefore, the existing storage areas within the PFP secure vaults will require modification. Other modifications will be performed on the 2736-ZB building complex to facilitate the installation and operation of the SPS
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Safety performance evaluation using proactive indicators in a selected industry
Directory of Open Access Journals (Sweden)
Abolfazl Barkhordari
2015-03-01
Full Text Available Background & Objectives: Quality and effectiveness of safety systems are critical factors in achieving their goals. This study was aimed to represent a method for performance evaluation of safety systems by proactive indicators using different updated models in the field of safety which will be tested in a selected industry. Methods: This study is a cross-sectional study. Proactive indicators used in this study were: Unsafe acts rate, Safety Climate, Accident Proneness, and Near-miss incident rate. The number of in 1473 safety climate questionnaires and 543 Accident Proneness questionnaires was completed. Results: The minimum and maximum safety climate score were 56.88 and 58.2, respectively, and the minimum and maximum scores of Accident Proneness were 98.2 and 140.7, respectively. The maximum number of Near-miss incident rate were 408 and the minimum of that was 196. The maximum number of unsafe acts rate was 43.8 percent and the minimum of that was 27.2 percent. In nine dimensions of Safety climate the eighth dimension (personal perception of risk with the score of 4.07 has the lowest score and the fourth (laws and safety regulations dimension with 8.05 has the highest score. According to expert opinions, the most important indicator in the assessment of safety performance was unsafe acts rate, while near-miss incident rate was the least important one. Conclusion: The results of this survey reveal that using proactive (Prospective indicators could be an appropriate method in organizations safety performance evaluation.
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Safety evaluation of cation-exchange resins
International Nuclear Information System (INIS)
Kalkwarf, D.R.
1977-08-01
Results are presented of a study to evaluate whether sufficient information is available to establish conservative limits for the safe use of cation-exchange resins in separating radionuclides and, if not, to recommend what new data should be acquired. The study was also an attempt to identify in-line analytical techniques for the evaluation of resin degradation during radionuclide processing. The report is based upon a review of the published literature and upon discussions with many people engaged in the use of these resins. It was concluded that the chief hazard in the use of cation-exchange resins for separating radionuclides is a thermal explosion if nitric acid or other strong oxidants are present in the process solution. Thermal explosions can be avoided by limiting process parameters so that the rates of heat and gas generation in the system do not exceed the rates for their transfer to the surroundings. Such parameters include temperature, oxidant concentration, the amounts of possible catalysts, the radiation dose absorbed by the resin and the diameter of the resin column. Current information is not sufficient to define safe upper limits for these parameters. They can be evaluated, however, from equations derived from the Frank-Kamenetskii theory of thermal explosions provided the heat capacities, thermal conductivities and rates of heat evolution in the relevant resin-oxidant mixtures are known. It is recommended that such measurements be made and the appropriate limits be evaluated. A list of additional safety precautions are also presented to aid in the application of these limits and to provide additional margins of safety. In-line evaluation of resin degradation to assess its safety hazard is considered impractical. Rather, it is recommended that the resin be removed from use before it has received the limiting radiation dose, evaluated as described above
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A reliability assessment methodology for the VHTR passive safety system
International Nuclear Information System (INIS)
Lee, Hyungsuk; Jae, Moosung
2014-01-01
The passive safety system of a VHTR (Very High Temperature Reactor), which has recently attracted worldwide attention, is currently being considered for the design of safety improvements for the next generation of nuclear power plants in Korea. The functionality of the passive system does not rely on an external source of an electrical support system, but on the intelligent use of natural phenomena. Its function involves an ultimate heat sink for a passive secondary auxiliary cooling system, especially during a station blackout such as the case of the Fukushima Daiichi reactor accidents. However, it is not easy to quantitatively evaluate the reliability of passive safety for the purpose of risk analysis, considering the existing active system failure since the classical reliability assessment method cannot be applied. Therefore, we present a new methodology to quantify the reliability based on reliability physics models. This evaluation framework is then applied to of the conceptually designed VHTR in Korea. The Response Surface Method (RSM) is also utilized for evaluating the uncertainty of the maximum temperature of nuclear fuel. The proposed method could contribute to evaluating accident sequence frequency and designing new innovative nuclear systems, such as the reactor cavity cooling system (RCCS) in VHTR to be designed and constructed in Korea.
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Design requirements of communication architecture of SMART safety system
International Nuclear Information System (INIS)
Park, H. Y.; Kim, D. H.; Sin, Y. C.; Lee, J. Y.
2001-01-01
To develop the communication network architecture of safety system of SMART, the evaluation elements for reliability and performance factors are extracted from commercial networks and classified the required-level by importance. A predictable determinacy, status and fixed based architecture, separation and isolation from other systems, high reliability, verification and validation are introduced as the essential requirements of safety system communication network. Based on the suggested requirements, optical cable, star topology, synchronous transmission, point-to-point physical link, connection-oriented logical link, MAC (medium access control) with fixed allocation are selected as the design elements. The proposed architecture will be applied as basic communication network architecture of SMART safety system
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Directory of Open Access Journals (Sweden)
Abas Nor Haslinda
2016-01-01
Full Text Available Malaysia’s construction industry has been long considered hazardous, owing to its poor health and safety record. It is proposed that one of the ways to improve safety and health in the construction industry is through the implementation of ‘off-site’ systems, commonly termed ‘industrialised building systems (IBS’ in Malaysia. This is deemed safer based on the risk concept of reduced exposure, brought about by the reduction in onsite workers; however, no method yet exists for determining the relative safety of various construction methods, including IBS. This study presents a comparative evaluation of the occupational health and safety (OHS risk presented by different construction approaches, namely IBS and traditional methods. The evaluation involved developing a model based on the concept of ‘argumentation theory’, which helps construction designers integrate the management of OHS risk into the design process. In addition, an ‘energy damage model’ was used as an underpinning framework. Development of the model was achieved through three phases, namely Phase I – knowledge acquisitaion, Phase II – argument trees mapping, and Phase III – validation of the model. The research revealed that different approaches/methods of construction projects carried a different level of energy damage, depending on how the activities were carried out. A study of the way in which the risks change from one construction process to another shows that there is a difference in the profile of OHS risk between IBS construction and traditional methods.Therefore, whether the option is an IBS or traditional approach, the fundamental idea of the model is to motivate construction designers or decision-makers to address safety in the design process and encourage them to examine carefully the probable OHS risk variables surrounding an action, thus preventing accidents in construction.
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DESIGN PACKAGE 1E SYSTEM SAFETY ANALYSIS
Energy Technology Data Exchange (ETDEWEB)
M. Salem
1995-06-23
The purpose of this analysis is to systematically identify and evaluate hazards related to the Yucca Mountain Project Exploratory Studies Facility (ESF) Design Package 1E, Surface Facilities, (for a list of design items included in the package 1E system safety analysis see section 3). This process is an integral part of the systems engineering process; whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach was used since a radiological System Safety Analysis is not required. The risk assessment in this analysis characterizes the accident scenarios associated with the Design Package 1E structures/systems/components(S/S/Cs) in terms of relative risk and includes recommendations for mitigating all identified risks. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into the structure/system/component design, (2) add safety devices and capabilities to the designs that reduce risk, (3) provide devices that detect and warn personnel of hazardous conditions, and (4) develop procedures and conduct training to increase worker awareness of potential hazards, on methods to reduce exposure to hazards, and on the actions required to avoid accidents or correct hazardous conditions.
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FLIGHT SAFETY MANAGEMENT PROBLEMS AND EVALUATION OF FLIGHT SAFETY LEVEL OF AN AVIATION ENTERPRISE
B. V. Zubkov; H. E. Fourar
2017-01-01
This article is devoted to studying the problem of safety management system (SMS) and evaluating safety level of an aviation enterprise.This article discusses the problems of SMS, presented at the 41st meeting of the Russian Aviation Production Commanders Club in June 2014 in St. Petersburg in connection with the verification of the status of the CA of the Russian Federation by the International Civil Aviation Organization (ICAO) in the same year, a set of urgent measures to eliminate the def...
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Safety system status monitoring
International Nuclear Information System (INIS)
Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.
1984-03-01
The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide
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Safety system status monitoring
Energy Technology Data Exchange (ETDEWEB)
Lewis, J.R.; Morgenstern, M.H.; Rideout, T.H.; Cowley, P.J.
1984-03-01
The Pacific Northwest Laboratory has studied the safety aspects of monitoring the preoperational status of safety systems in nuclear power plants. The goals of the study were to assess for the NRC the effectiveness of current monitoring systems and procedures, to develop near-term guidelines for reducing human errors associated with monitoring safety system status, and to recommend a regulatory position on this issue. A review of safety system status monitoring practices indicated that current systems and procedures do not adequately aid control room operators in monitoring safety system status. This is true even of some systems and procedures installed to meet existing regulatory guidelines (Regulatory Guide 1.47). In consequence, this report suggests acceptance criteria for meeting the functional requirements of an adequate system for monitoring safety system status. Also suggested are near-term guidelines that could reduce the likelihood of human errors in specific, high-priority status monitoring tasks. It is recommended that (1) Regulatory Guide 1.47 be revised to address these acceptance criteria, and (2) the revised Regulatory Guide 1.47 be applied to all plants, including those built since the issuance of the original Regulatory Guide.
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Licensing process for safety-critical software-based systems
Energy Technology Data Exchange (ETDEWEB)
Haapanen, P. [VTT Automation, Espoo (Finland); Korhonen, J. [VTT Electronics, Espoo (Finland); Pulkkinen, U. [VTT Automation, Espoo (Finland)
2000-12-01
System vendors nowadays propose software-based technology even for the most critical safety functions in nuclear power plants. Due to the nature of software faults and the way they cause system failures new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)', financed together by the Radiation and Nuclear Safety Authority (STUK), the Ministry of Trade and Industry (KTM) and the Technical Research Centre of Finland (VTT), various safety assessment methods and tools for software based systems are developed and evaluated. As a part of the OHA-work a reference model for the licensing process for software-based safety automation systems is defined. The licensing process is defined as the set of interrelated activities whose purpose is to produce and assess evidence concerning the safety and reliability of the system/application to be licensed and to make the decision about the granting the construction and operation permissions based on this evidence. The parties of the licensing process are the authority, the licensee (the utility company), system vendors and their subcontractors and possible external independent assessors. The responsibility about the production of the evidence in first place lies at the licensee who in most cases rests heavily on the vendor expertise. The evaluation and gauging of the evidence is carried out by the authority (possibly using external experts), who also can acquire additional evidence by using their own (independent) methods and tools. Central issue in the licensing process is to combine the quality evidence about the system development process with the information acquired through tests, analyses and operational experience. The purpose of the licensing process described in this report is to act as a reference model both for the authority and the licensee when planning the licensing of individual applications
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Licensing process for safety-critical software-based systems
International Nuclear Information System (INIS)
Haapanen, P.; Korhonen, J.; Pulkkinen, U.
2000-12-01
System vendors nowadays propose software-based technology even for the most critical safety functions in nuclear power plants. Due to the nature of software faults and the way they cause system failures new methods are needed for the safety and reliability evaluation of these systems. In the research project 'Programmable automation systems in nuclear power plants (OHA)', financed together by the Radiation and Nuclear Safety Authority (STUK), the Ministry of Trade and Industry (KTM) and the Technical Research Centre of Finland (VTT), various safety assessment methods and tools for software based systems are developed and evaluated. As a part of the OHA-work a reference model for the licensing process for software-based safety automation systems is defined. The licensing process is defined as the set of interrelated activities whose purpose is to produce and assess evidence concerning the safety and reliability of the system/application to be licensed and to make the decision about the granting the construction and operation permissions based on this evidence. The parties of the licensing process are the authority, the licensee (the utility company), system vendors and their subcontractors and possible external independent assessors. The responsibility about the production of the evidence in first place lies at the licensee who in most cases rests heavily on the vendor expertise. The evaluation and gauging of the evidence is carried out by the authority (possibly using external experts), who also can acquire additional evidence by using their own (independent) methods and tools. Central issue in the licensing process is to combine the quality evidence about the system development process with the information acquired through tests, analyses and operational experience. The purpose of the licensing process described in this report is to act as a reference model both for the authority and the licensee when planning the licensing of individual applications. Many of the
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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)
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Site evaluation for nuclear installations. Safety requirements
International Nuclear Information System (INIS)
2003-01-01
This Safety Requirements publication supersedes the Code on the Safety of Nuclear Power Plants: Siting, which was issued in 1988 as Safety Series No. 50-C-S (Rev. 1). It takes account of developments relating to site evaluations for nuclear installations since the Code on Siting was last revised. These developments include the issuing of the Safety Fundamentals publication on The Safety of Nuclear Installations, and the revision of various safety standards and other publications relating to safety. Requirements for site evaluation are intended to ensure adequate protection of site personnel, the public and the environment from the effects of ionizing radiation arising from nuclear installations. It is recognized that there are steady advances in technology and scientific knowledge, in nuclear safety and in what is considered adequate protection. Safety requirements change with these advances and this publication reflects the present consensus among States. This Safety Requirements publication was prepared under the IAEA programme on safety standards for nuclear installations. It establishes requirements and provides criteria for ensuring safety in site evaluation for nuclear installations. The Safety Guides on site evaluation listed in the references provide recommendations on how to meet the requirements established in this Safety Requirements publication. The objective of this publication is to establish the requirements for the elements of a site evaluation for a nuclear installation so as to characterize fully the site specific conditions pertinent to the safety of a nuclear installation. The purpose is to establish requirements for criteria, to be applied as appropriate to site and site-installation interaction in operational states and accident conditions, including those that could lead to emergency measures for: (a) Defining the extent of information on a proposed site to be presented by the applicant; (b) Evaluating a proposed site to ensure that the site
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The Intelligent Safety System: could it introduce complex computing into CANDU shutdown systems
International Nuclear Information System (INIS)
Hall, J.A.; Hinds, H.W.; Pensom, C.F.; Barker, C.J.; Jobse, A.H.
1984-07-01
The Intelligent Safety System is a computerized shutdown system being developed at the Chalk River Nuclear Laboratories (CRNL) for future CANDU nuclear reactors. It differs from current CANDU shutdown systems in both the algorithm used and the size and complexity of computers required to implement the concept. This paper provides an overview of the project, with emphasis on the computing aspects. Early in the project several needs leading to an introduction of computing complexity were identified, and a computing system that met these needs was conceived. The current work at CRNL centers on building a laboratory demonstration of the Intelligent Safety System, and evaluating the reliability and testability of the concept. Some fundamental problems must still be addressed for the Intelligent Safety System to be acceptable to a CANDU owner and to the regulatory authorities. These are also discussed along with a description of how the Intelligent Safety System might solve these problems
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Traceability of Software Safety Requirements in Legacy Safety Critical Systems
Hill, Janice L.
2007-01-01
How can traceability of software safety requirements be created for legacy safety critical systems? Requirements in safety standards are imposed most times during contract negotiations. On the other hand, there are instances where safety standards are levied on legacy safety critical systems, some of which may be considered for reuse for new applications. Safety standards often specify that software development documentation include process-oriented and technical safety requirements, and also require that system and software safety analyses are performed supporting technical safety requirements implementation. So what can be done if the requisite documents for establishing and maintaining safety requirements traceability are not available?
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Quantitative safety assessment of air traffic control systems through system control capacity
Guo, Jingjing
Quantitative Safety Assessments (QSA) are essential to safety benefit verification and regulations of developmental changes in safety critical systems like the Air Traffic Control (ATC) systems. Effectiveness of the assessments is particularly desirable today in the safe implementations of revolutionary ATC overhauls like NextGen and SESAR. QSA of ATC systems are however challenged by system complexity and lack of accident data. Extending from the idea "safety is a control problem" in the literature, this research proposes to assess system safety from the control perspective, through quantifying a system's "control capacity". A system's safety performance correlates to this "control capacity" in the control of "safety critical processes". To examine this idea in QSA of the ATC systems, a Control-capacity Based Safety Assessment Framework (CBSAF) is developed which includes two control capacity metrics and a procedural method. The two metrics are Probabilistic System Control-capacity (PSC) and Temporal System Control-capacity (TSC); each addresses an aspect of a system's control capacity. And the procedural method consists three general stages: I) identification of safety critical processes, II) development of system control models and III) evaluation of system control capacity. The CBSAF was tested in two case studies. The first one assesses an en-route collision avoidance scenario and compares three hypothetical configurations. The CBSAF was able to capture the uncoordinated behavior between two means of control, as was observed in a historic midair collision accident. The second case study compares CBSAF with an existing risk based QSA method in assessing the safety benefits of introducing a runway incursion alert system. Similar conclusions are reached between the two methods, while the CBSAF has the advantage of simplicity and provides a new control-based perspective and interpretation to the assessments. The case studies are intended to investigate the
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An Integrated Safety Assessment Methodology for Generation IV Nuclear Systems
International Nuclear Information System (INIS)
Leahy, Timothy J.
2010-01-01
The Generation IV International Forum (GIF) Risk and Safety Working Group (RSWG) was created to develop an effective approach for the safety of Generation IV advanced nuclear energy systems. Early work of the RSWG focused on defining a safety philosophy founded on lessons learned from current and prior generations of nuclear technologies, and on identifying technology characteristics that may help achieve Generation IV safety goals. More recent RSWG work has focused on the definition of an integrated safety assessment methodology for evaluating the safety of Generation IV systems. The methodology, tentatively called ISAM, is an integrated 'toolkit' consisting of analytical techniques that are available and matched to appropriate stages of Generation IV system concept development. The integrated methodology is intended to yield safety-related insights that help actively drive the evolving design throughout the technology development cycle, potentially resulting in enhanced safety, reduced costs, and shortened development time.
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A bicycle safety index for evaluating urban street facilities.
Asadi-Shekari, Zohreh; Moeinaddini, Mehdi; Zaly Shah, Muhammad
2015-01-01
The objectives of this research are to conceptualize the Bicycle Safety Index (BSI) that considers all parts of the street and to propose a universal guideline with microscale details. A point system method comparing existing safety facilities to a defined standard is proposed to estimate the BSI. Two streets in Singapore and Malaysia are chosen to examine this model. The majority of previous measurements to evaluate street conditions for cyclists usually cannot cover all parts of streets, including segments and intersections. Previous models also did not consider all safety indicators and cycling facilities at a microlevel in particular. This study introduces a new concept of a practical BSI to complete previous studies using its practical, easy-to-follow, point system-based outputs. This practical model can be used in different urban settings to estimate the level of safety for cycling and suggest some improvements based on the standards.
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International Nuclear Information System (INIS)
1982-12-01
Supplement 2 to the Safety Evaluation Report for Washington Public Power Supply System's application for a license to operate WNP-2 (Docket No. 50-397), located in Benton County, Washington, approximately 12 miles north of Richland, Washington, has been prepared by the Office of Nuclear Reactor Regulation of the US Nuclear Regulatory Commission. This supplement reports the status of certain items that had not been resolved at the time of publication of the Safety Evaluation Report and Supplement 1
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Criticality Safety Evaluation for the TACS at DAF
Energy Technology Data Exchange (ETDEWEB)
Percher, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heinrichs, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2011-06-10
Hands-on experimental training in the physical behavior of multiplying systems is one of ten key areas of training required for practitioners to become qualified in the discipline of criticality safety as identified in DOE-STD-1135-99, Guidance for Nuclear Criticality Safety Engineer Training and Qualification. This document is a criticality safety evaluation of the training activities and operations associated with HS-3201-P, Nuclear Criticality 4-Day Training Course (Practical). This course was designed to also address the training needs of nuclear criticality safety professionals under the auspices of the NNSA Nuclear Criticality Safety Program1. The hands-on, or laboratory, portion of the course will utilize the Training Assembly for Criticality Safety (TACS) and will be conducted in the Device Assembly Facility (DAF) at the Nevada Nuclear Security Site (NNSS). The training activities will be conducted by Lawrence Livermore National Laboratory following the requirements of an Integrated Work Sheet (IWS) and associated Safety Plan. Students will be allowed to handle the fissile material under the supervision of an LLNL Certified Fissile Material Handler.
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Safety design guide for safety related systems for CANDU 9
International Nuclear Information System (INIS)
Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young; A. C. D. Wright
1996-03-01
In general, two types of safety related systems and structures exist in the nuclear plant; The one is a systems and structures which perform safety functions during the normal operation of the plant, and the other is a systems and structures which perform safety functions to mitigate events caused by failure of the normally operating systems or by naturally occurring phenomena. In this safety design guide, these systems are identified in detail, and the major events for which the safety functions are required and the major safety requirements are identified in the list. As the probabilistic safety assessments are completed during the course of the project, additions or deletions to the list may be justified. 3 tabs. (Author) .new
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Safety design guide for safety related systems for CANDU 9
Energy Technology Data Exchange (ETDEWEB)
Lee, Duk Su; Chang, Woo Hyun; Lee, Nam Young [Korea Atomic Energy Research Institute, Daeduk (Korea, Republic of); Wright, A.C.D. [Atomic Energy of Canada Ltd., Toronto (Canada)
1996-03-01
In general, two types of safety related systems and structures exist in the nuclear plant; The one is a systems and structures which perform safety functions during the normal operation of the plant, and the other is a systems and structures which perform safety functions to mitigate events caused by failure of the normally operating systems or by naturally occurring phenomena. In this safety design guide, these systems are identified in detail, and the major events for which the safety functions are required and the major safety requirements are identified in the list. As the probabilistic safety assessments are completed during the course of the project, additions or deletions to the list may be justified. 3 tabs. (Author) .new.
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International Nuclear Information System (INIS)
1983-03-01
Supplement No. 1 to the Safety Evaluation Report for the application filed by Combustion Engineering, Inc. for a Final Design Approval for the Combustion Engineering Standard Safety Analysis Report (STN 50-470) has been prepared by the Office of Nuclear Reactor Regulation of the Nuclear Regulatory Commission. The purpose of this supplement is to update the Safety Evaluation by providing: (1) the evaluation of additional information submitted by the applicant since the Safety Evaluation Report was issued, (2) the evaluation of the matters the staff had under review when the Safety Evaluation Report was issued, and (3) the response to comments made by the Advisory Committee on Reactor Safeguards
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Safety study of PCC 2140 and ALILOG 21 used as part of safety measurement systems
International Nuclear Information System (INIS)
Meriaux, Pierre; Adnot, Serge; Rayrolles, Catherine.
1978-03-01
The PCC 2140 and ALILOG 21 equipment may be used at C.E.A. or E.D.F., as part of safety measurement systems. In a study of a similar, but earlier equipment, it was noticed that certain types of failures caused the system to switch to the least sensitive measurement range, which was detrimental to safety. This report analyses failure modes leading to unsafe failures and evaluates the risks ran into taking in account tests during use [fr
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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
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Energy Technology Data Exchange (ETDEWEB)
NONE
1999-03-01
Under the hydrogen-utilizing international clean energy system technology project WE-NET (World Energy NET Work) in fiscal 1998, researches and studies were conducted to clearly define safety designs and to improve on accident-and-safety analyses. In relation with system safety design, investigations continued into Japanese and foreign manuals and regulations about the handling of hydrogen and its peripherals, and safe design guidelines (draft) were compiled. Anomalies and accidents supposed to be typical of each of the systems concerned were investigated. As for accident-and-safety analyses, incorporation of a turbulence model was studied in relation to models representing the leak, evaporation, and diffusion of liquid hydrogen, and improvement was achieved when the scope of evaluation was enlarged concerning the hydrogen detonation model. The integration of the two models was discussed for the due evaluation of a series of processes of liquid hydrogen leak, evaporation, diffusion, and detonation. Calculation was performed for two assumed accidents, and the results were found to justify the integration of the two models. (NEDO)
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IAEA Safety Standards on Management Systems and Safety Culture
International Nuclear Information System (INIS)
Persson, Kerstin Dahlgren
2007-01-01
The IAEA has developed a new set of Safety Standard for applying an integrated Management System for facilities and activities. The objective of the new Safety Standards is to define requirements and provide guidance for establishing, implementing, assessing and continually improving a Management System that integrates safety, health, environmental, security, quality and economic related elements to ensure that safety is properly taken into account in all the activities of an organization. With an integrated approach to management system it is also necessary to include the aspect of culture, where the organizational culture and safety culture is seen as crucial elements of the successful implementation of this management system and the attainment of all the goals and particularly the safety goals of the organization. The IAEA has developed a set of service aimed at assisting it's Member States in establishing. Implementing, assessing and continually improving an integrated management system. (author)
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Development and application of digital safety system in NPPs
International Nuclear Information System (INIS)
Kwon, Keechoon; Kim, Changhwoi; Lee, Dongyoung
2012-01-01
This paper describes the development of digital safety system in NPPs based on safety- grade programmable logic controller (PLC) platform and its application to real NPP construction. The digital safety system consists of a reactor protection system and an engineered safety feature-component control system. The safety-grade PLC platform was developed so that it meets the requirements of the regulation. The PLC consists of various modules such as a power module, a processor module, communication modules, digital input/output modules, analog input/output modules, a LOCA bus extension module, and a high-speed pulse counter module. The reactor protection system is designed with a redundant 4-channel architecture, and every channel is implemented with the same architecture. A single channel consists of a redundant bi-stable processor, a redundant coincidence processor, an automatic test and interface processor, and a cabinet operator module. The engineered safety feature-component control system is designed with four redundant divisions, and implemented with the PLC platform. The principal components of an individual division are fault tolerant group controllers, loop controllers, a test and interface processor, a cabinet operator module and a control channel gateway. The topical report is submitted to the regulatory body, and got safety evaluation report from the regulatory body. Also, the developed system is tested in the integrated performance validation facility. It is decided that the digital safety system applied to Shin-Uljin unit 1 and 2 after a topical report approval and validation test. Design changes occur in the digital safety system that is applied to an actual nuclear power plant construction, and the PLC has also been upgraded
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Development and application of digital safety system in NPPs
Energy Technology Data Exchange (ETDEWEB)
Kwon, Keechoon; Kim, Changhwoi; Lee, Dongyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2012-03-15
This paper describes the development of digital safety system in NPPs based on safety- grade programmable logic controller (PLC) platform and its application to real NPP construction. The digital safety system consists of a reactor protection system and an engineered safety feature-component control system. The safety-grade PLC platform was developed so that it meets the requirements of the regulation. The PLC consists of various modules such as a power module, a processor module, communication modules, digital input/output modules, analog input/output modules, a LOCA bus extension module, and a high-speed pulse counter module. The reactor protection system is designed with a redundant 4-channel architecture, and every channel is implemented with the same architecture. A single channel consists of a redundant bi-stable processor, a redundant coincidence processor, an automatic test and interface processor, and a cabinet operator module. The engineered safety feature-component control system is designed with four redundant divisions, and implemented with the PLC platform. The principal components of an individual division are fault tolerant group controllers, loop controllers, a test and interface processor, a cabinet operator module and a control channel gateway. The topical report is submitted to the regulatory body, and got safety evaluation report from the regulatory body. Also, the developed system is tested in the integrated performance validation facility. It is decided that the digital safety system applied to Shin-Uljin unit 1 and 2 after a topical report approval and validation test. Design changes occur in the digital safety system that is applied to an actual nuclear power plant construction, and the PLC has also been upgraded.
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Safety analysis of tritium processing system based on PHA
International Nuclear Information System (INIS)
Fu Wanfa; Luo Deli; Tang Tao
2012-01-01
Safety analysis on primary confinement of tritium processing system for TBM was carried out with Preliminary Hazard Analysis. Firstly, the basic PHA process was given. Then the function and safe measures with multiple confinements about tritium system were described and analyzed briefly, dividing the two kinds of boundaries of tritium transferring through, that are multiple confinement systems division and fluid loops division. Analysis on tritium releasing is the key of PHA. Besides, PHA table about tritium releasing was put forward, the causes and harmful results being analyzed, and the safety measures were put forward also. On the basis of PHA, several kinds of typical accidents were supposed to be further analyzed. And 8 factors influencing the tritium safety were analyzed, laying the foundation of evaluating quantitatively the safety grade of various nuclear facilities. (authors)
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Lopes, D. F.; Oliveira, M. D.; Costa, C. A. Bana e.
2015-05-01
Risk matrices (RMs) are commonly used to evaluate health and safety risks. Nonetheless, they violate some theoretical principles that compromise their feasibility and use. This study describes how multiple criteria decision analysis methods have been used to improve the design and the deployment of RMs to evaluate health and safety risks at the Occupational Health and Safety Unit (OHSU) of the Regional Health Administration of Lisbon and Tagus Valley. ‘Value risk-matrices’ (VRMs) are built with the MACBETH approach in four modelling steps: a) structuring risk impacts, involving the construction of descriptors of impact that link risk events with health impacts and are informed by scientific evidence; b) generating a value measurement scale of risk impacts, by applying the MACBETH-Choquet procedure; c) building a system for eliciting subjective probabilities that makes use of a numerical probability scale that was constructed with MACBETH qualitative judgments on likelihood; d) and defining a classification colouring scheme for the VRM. A VRM built with OHSU members was implemented in a decision support system which will be used by OHSU members to evaluate health and safety risks and to identify risk mitigation actions.
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Review of studies on criticality safety evaluation and criticality experiment methods
International Nuclear Information System (INIS)
Naito, Yoshitaka; Yamamoto, Toshihiro; Misawa, Tsuyoshi; Yamane, Yuichi
2013-01-01
Since the early 1960s, many studies on criticality safety evaluation have been conducted in Japan. Computer code systems were developed initially by employing finite difference methods, and more recently by using Monte Carlo methods. Criticality experiments have also been carried out in many laboratories in Japan as well as overseas. By effectively using these study results, the Japanese Criticality Safety Handbook was published in 1988, almost the intermediate point of the last 50 years. An increased interest has been shown in criticality safety studies, and a Working Party on Nuclear Criticality Safety (WPNCS) was set up by the Nuclear Science Committee of Organisation Economic Co-operation and Development in 1997. WPNCS has several task forces in charge of each of the International Criticality Safety Benchmark Evaluation Program (ICSBEP), Subcritical Measurement, Experimental Needs, Burn-up Credit Studies and Minimum Critical Values. Criticality safety studies in Japan have been carried out in cooperation with WPNCS. This paper describes criticality safety study activities in Japan along with the contents of the Japanese Criticality Safety Handbook and the tasks of WPNCS. (author)
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Novel modular natural circulation BWR design and safety evaluation
International Nuclear Information System (INIS)
Ishii, Mamoru; Shi, Shanbin; Yang, Won Sik; Wu, Zeyun; Rassame, Somboon; Liu, Yang
2015-01-01
Highlights: • Introduction of BWR-type natural circulation small modular reactor preliminary design (NMR-50). • Design of long fuel cycle length for the NMR-50. • Design of double passive safety systems for the NMR-50. • RELAP5 analyses of design basis accidents for the NMR-50. - Abstract: The Purdue NMR (Novel Modular Reactor) represents a BWR-type small modular reactor with a significantly reduced reactor pressure vessel (RPV) height. Specifically, it has one third the height of a conventional BWR RPV with an electrical output of 50 MWe. The preliminary design of the NMR-50 including reactor, fuel cycle, and safety systems is described and discussed. The improved neutronics design of the NMR-50 extends the fuel cycle length up to 10 years. The NMR-50 is designed with double passive engineering safety system, which is intended to withstand a prolonged station black out with loss of ultimate heat sink accident such as experienced at Fukushima. In order to evaluate the safety features of the NMR-50, two representative design basis accidents, i.e. main steam line break (MSLB) and bottom drain line break (BDLB), are simulated by using the best-estimate thermal–hydraulic code RELAP5. The RPV water inventory, containment pressure, and the performance of engineering safety systems are investigated for about 33 h after the initiation of the accidents
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International Nuclear Information System (INIS)
Epps, R.C.
1980-11-01
This report documents the technical evaluation of the Maine Yankee Atomic Power Station. The purpose of this evaluation was to determine whether the failure of any non-Class I (seismic) equipment could result in a condition, such as flooding, that might adversely affect the performance of the safety-related equipment required for the safe shutdown of the facility, or to mitigate the consequences of an accident. Criteria developed by the US Nuclear Regulatory Commission were used to evaluate the acceptability of the existing protection system as well as measures taken by Maine Yankee Atomic Power Company (MYAPC) to minimize the danger of flooding and to protect safety-related equipment
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International Nuclear Information System (INIS)
Sambasivan, S. Ilango
2004-01-01
Full text : PFBR is provided with two independent, fast acting and diverse shutdown systems to detect any abnormalities and to initiate safety action. Each system consists of sensors, signal processing systems, logics, drive mechanisms and absorber rods. The absorber rods of the first system are Control and Safety Rods (CSR) and that of the second are called as Diverse Safety Rods (DSR). There are nine CSR and three DSR. While CSR are used for startup, control of reactor power, controlled shutdown and SCRAM, the DSR are used only for SCRAM. The respective drive mechanisms are called as CSRDM and DSRDM. Each of these two systems is capable of executing the shutdown satisfactorily with single failure criteria. Two independent safety logic systems based on diverse principles have been designed for the two shut down systems. The analog outputs of the sensors of Core Monitoring Systems comprising of reactor flux monitoring, core temperature monitoring, failed fuel detection and core flow monitoring systems are processed and converted into binary signals depending on their instantaneous values. Safety logic systems receive the binary signals from these core-monitoring systems and process them logically to protect the reactor against postulated initiating events. Neutronic and power to flow (P/Q) signals form the inputs to safety logic system-I and temperature signals are inputs to the safety logic system II. Failed fuel detection signals are processed by both the shut down systems. The two logic systems to actuate the safety rods are also based on two diverse designs and implemented with solid-state devices to meet all the requirements of safety systems. Safety logic system I that caters to neutronic and P/Q signals is designed around combinational logic and has an on-line test facility to detect struck at faults. The second logic system is based on dynamic logic and hence is inherently safe. This paper gives an overview of the two logic systems that have been
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International Nuclear Information System (INIS)
Hwang, H. S.; Kim, B. R.; Oh, S. H.
1999-01-01
Because of obsolescing the components used in safety related systems of nuclear power plants, decreasing the number of suppliers qualified for the nuclear QA program and increasing maintenance costs of them, utilities have been considering to use commercial grade digital computers as an alternative for resolving such issues. However, commercial digital computers use the embedded pre-existing software, including operating system software, which are not developed by using nuclear grade QA program. Thus, it is necessary for utilities to establish processes for dedicating digital commercial grade items. A regulatory body also needs guidance to evaluate the digital commercial products properly. This paper surveyed the regulations and their regulatory guides, which establish the requirements for commercial grade items dedication, industry standards and guidances applicable to safety related systems. This paper provides some guidelines to be applied in evaluating the safety of digital upgrades and new digital plant protection systems in Korea
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Verification and validation issues for digitally-based NPP safety systems
International Nuclear Information System (INIS)
Ets, A.R.
1993-01-01
The trend toward standardization, integration and reduced costs has led to increasing use of digital systems in reactor protection systems. While digital systems provide maintenance and performance advantages, their use also introduces new safety issues, in particular with regard to software. Current practice relies on verification and validation (V and V) to ensure the quality of safety software. However, effective V and V must be done in conjunction with a structured software development process and must consider the context of the safety system application. This paper present some of the issues and concerns that impact on the V and V process. These include documentation of systems requirements, common mode failures, hazards analysis and independence. These issues and concerns arose during evaluations of NPP safety systems for advanced reactor designs and digital I and C retrofits for existing nuclear plants in the United States. The pragmatic lessons from actual systems reviews can provide a basis for further refinement and development of guidelines for applying V and V to NPP safety systems. (author). 14 refs
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International Nuclear Information System (INIS)
Selan, J.C.
1981-07-01
This report documents the technical evaluation of the noise and isolation testing of the safety features actuation system at the Davis Besse Nuclear Power Station, Unit 1. The tests were to verify that faults on the non-Class 1E circuits would not propagate to the Class 1E circuits and degrade them below acceptable levels. The tests conducted demonstrated that the safety features actuation system did not degrade below acceptable levels nor was the system's ability to perform its protective functions affected
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Study on Fuzzy Comprehensive Evaluation Model for the Safety of Mine Belt Conveyor
Directory of Open Access Journals (Sweden)
Gong Xiaoyan
2017-01-01
Full Text Available To improve the situation of the frequent failures of mine belt conveyor during operation, a model was used to evaluate the safety of mine belt conveyor. Based on the foundation of collecting and analyzing a large quantity of fault information of belt conveyor in the nationwide coal mine, the fault tree model of belt conveyor has been built, then the safety evaluation index system was established by analyzing and removing some secondary indicators. Furthermore, the weighted value of safety evaluation indexs was determined by analytic hierarchy process(AHP, and the single factor fuzzy evaluation matrix was constructed by experts grading method. Additionally, the model was applied in evaluating the security of belt conveyor in Nanliang coal mine. The results shows the security level is recognized to the “general”, which means that this model can be adopted widely in evaluating the safety of mine belt conveyor.
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General re-evaluation of the safety on the nuclear ship 'Mutsu' and its repair work
International Nuclear Information System (INIS)
1980-01-01
According to the proposition by the Committee for Investigation Radiation Leak on Mutsu, the works of the general re-evaluation of safety were started after the approval by the Committee for Investigating General Re-evaluation and Repair Techniques for Mutsu. The contents of the general re-evaluation of safety are the inspection of the machines and equipments in the nuclear reactor plant, the review of the design of the nuclear reactor plant, the analysis of the nuclear reactor plant behavior in accidents, and the related experimental researches. These works have been carried out for five years, and problem did not arise at all regarding the nuclear reactor so far, but from the viewpoint of improving the safety and reliability further, it was decided to carry out the repair work based on the general re-evaluation of safety. The contents of the repair work are the improvement of the emergency core-cooling system, the improvement of the safety protection system, the improvement of the radiation monitoring equipments, the improvement of the containment vessel boundary, the improvement of the actuators for technological safety facilities, the improvement of the method controlling secondary water quality, and other repair works. The progress of the general re-evaluation of safety is reported. (Kako, I.)
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Safety of mechanical devices. Safety of automation systems
International Nuclear Information System (INIS)
Pahl, G.; Schweizer, G.; Kapp, K.
1985-01-01
The paper deals with the classic procedures of safety engineering in the sectors mechanical engineering, electrical and energy engineering, construction and transport, medicine technology and process technology. Particular stress is laid on the safety of automation systems, control technology, protection of mechanical devices, reactor safety, mechanical constructions, transport systems, railway signalling devices, road traffic and protection at work in chemical plans. (DG) [de
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A regulatory frame for safety digital systems in nuclear power plants
International Nuclear Information System (INIS)
Mozas Garcia, A.
1998-01-01
The paper focuses on Spanish experience regarding software based systems for safety applications from the regulator's point of view. It describes the actual situation in Spain, number and models of reactors, modernization projects, digital systems implemented and licensing documentation and processes already followed by some upgrading projects. The paper wonders what documents should be required for safety and reliability demonstration of a safety system, when they should be reviewed, and what other activities may be necessary to acquire confidence on a particular system. It describes Spanish laws regarding nuclear safety under which, national standards from the NPP design original country apply to nuclear reactors in Spain. It finally suggests that an international standard jointly used by system manufacturers, nuclear licensees and nuclear safety authorities, both from the country where the NPP is installed, and from the original design country, should be developed so that rapid and easy agreement on licensing issues is reached among all parties. The last part of the paper describes the licensing approach proposed by CSN (Spanish Nuclear Safety Authority). It is still under development and it is based on previous experience on digital systems for non-safety applications. It consists of constructing several frames: 1) databases of existing software based systems, 2) guides for inspection and 3) questionnaires for helping in verification and validation activities evaluation. The scope is to establish a well defined procedure that helps in evaluating the particular system. However, in order for such a procedure to be useful, both regulators and utilities and, perhaps also system manufacturers, should agree on it. Joint CSN-utilities working groups may be suitable for such a purpose. (author)
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Software Safety Life cycle and Method of POSAFE-Q System
International Nuclear Information System (INIS)
Lee, Jang-Soo; Kwon, Kee-Choon
2006-01-01
This paper describes the relationship between the overall safety life cycle and the software safety life cycle during the development of the software based safety systems of Nuclear Power Plants. This includes the design and evaluation activities of components as well as the system. The paper also compares the safety life cycle and planning activities defined in IEC 61508 with those in IEC 60880, IEEE 7-4.3.2, and IEEE 1228. Using the KNICS project as an example, software safety life cycle and safety analysis methods applied to the POSAFE-Q are demonstrated. KNICS software safety life cycle is described by comparing to the software development, testing, and safety analysis process with international standards. The safety assessment of the software for POSAFE-Q is a joint Korean German project. The assessment methods applied in the project and the experiences gained from this project are presented
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Research on the measurement technology and evaluation method of photobiological safety
Dai, Cai-hong; Wu, Zhi-feng; Chen, Bin-hua; Wang, Yan-fei; Li, Xiang-zhao; Fu, Lei
2013-12-01
Lamps and lamp system are widely used in large quantities in an era. The evaluation and control of optical radiation hazards of lamps and lamp systems is far more complicated. A special measurement and traceability facility was set up at NIM (National Institute of Metrology, China) to evaluate the optical radiation safety of lamp and lamp system, which includes a double grating spectroradiometer OL750D with two different entrance systems of spectral radiance and spectral irradiance traceable to the national primary standard of spectral irradiance by a 1000W spectral irradiance standard lamp, 40W deuterium lamp and a standard diffuser plate. The technical requirements of the measurement instrumentation used for optical radiation safety evaluation including monochromator type, wavelength accuracy, input optics, spectral scan interval and calibration sources are recommended also in this paper. Spectral radiance of a series of LED electric torches and infrared sources were measured by using the new developed system, and potential radiation hazards of retinal blue light hazard and retinal thermal hazard are calculated and evaluated. The optical radiation hazards of some samples are listed in Risk Group 2 (Moderate-Risk).
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International Nuclear Information System (INIS)
Johanson, Gunnar; Holmberg, J.
1994-01-01
Living Probabilistic Safety Assessment (PSA) is a daily safety management system and it is based on a plant-specific PSA and supporting information systems. In the living use of PSA, plant status knowledge is used to represent actual plant safety status in monitoring or follow-up perspective. The PSA model must be able to express the risk at a given time and plant configuration. The process, to update the PSA model to represent the current or planned configuration and to use the model to evaluate and direct the changes in the configuration, is called living PSA programme. The main purposes to develop and increase the usefulness of living PSA are: Long term safety planning: To continue the risk assessment process started with the basic PSA by extending and improving the basic models and data to provide a general risk evaluation tool for analyzing the safety effects of changes in plant design and procedures. Risk planning of operational activities: To support the operational management by providing means for searching optimal operational maintenance and testing strategies from the safety point of view. The results provide support for risk decision making in the short term or in a planning mode. The operational limits and conditions given by technical specifications can be analyzed by evaluating the risk effects of alternative requirements in order to balance the requirements with respect to operational flexibility and plant economy. Risk analysis of operating experience: To provide a general risk evaluation tool for analyzing the safety effects of incidents and plant status changes. The analyses are used to: identify possible high risk situations, rank the occurred events from safety point of view, and get feedback from operational events for the identification of risk contributors. This report describes the methods, models and applications required to continue the process towards a living use of PSA. 19 tabs, 20 figs
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Nuclear-power-safety reporting system: feasibility analysis
International Nuclear Information System (INIS)
Finlayson, F.C.; Ims, J.
1983-04-01
The US Nuclear Regulatory Commission (NRC) is evaluating the possibility of instituting a data gathering system for identifying and quantifying the factors that contribute to the occurrence of significant safety problems involving humans in nuclear power plants. This report presents the results of a brief (6 months) study of the feasibility of developing a voluntary, nonpunitive Nuclear Power Safety Reporting System (NPSRS). Reports collected by the system would be used to create a data base for documenting, analyzing and assessing the significance of the incidents. Results of The Aerospace Corporation study are presented in two volumes. This document, Volume I, contains a summary of an assessment of the Aviation Safety Reporting System (ASRS). The FAA-sponsored, NASA-managed ASRS was found to be successful, relatively low in cost, generally acceptable to all facets of the aviation community, and the source of much useful data and valuable reports on human factor problems in the nation's airways. Several significant ASRS features were found to be pertinent and applicable for adoption into a NPSRS
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Researches on nuclear criticality safety evaluation
Energy Technology Data Exchange (ETDEWEB)
Okuno, Hiroshi; Suyama, Kenya; Nomura, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2003-10-01
For criticality safety evaluation of burnup fuel, the general-purpose burnup calculation code, SWAT, was revised, and its precision was confirmed through comparison with other results from OECD/NEA's burnup credit benchmarks. Effect by replacing the evaluated nuclear data from JENDL-3.2 to ENDF/B-VI and JEF-2.2 was also studied. Correction factors were derived for conservative evaluation of nuclide concentrations obtained with the simplified burnup code ORIGEN2.1. The critical masses of curium were calculated and evaluated for nuclear criticality safety management of minor actinides. (author)
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Researches on nuclear criticality safety evaluation
International Nuclear Information System (INIS)
Okuno, Hiroshi; Suyama, Kenya; Nomura, Yasushi
2003-01-01
For criticality safety evaluation of burnup fuel, the general-purpose burnup calculation code, SWAT, was revised, and its precision was confirmed through comparison with other results from OECD/NEA's burnup credit benchmarks. Effect by replacing the evaluated nuclear data from JENDL-3.2 to ENDF/B-VI and JEF-2.2 was also studied. Correction factors were derived for conservative evaluation of nuclide concentrations obtained with the simplified burnup code ORIGEN2.1. The critical masses of curium were calculated and evaluated for nuclear criticality safety management of minor actinides. (author)
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Energy Technology Data Exchange (ETDEWEB)
Irie, Takashi; Hanafusa, Hidemitsu; Suyama, Takeshi [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan); Morota, Hidetsugu; Kojima, Sigeo; Mizuno, Yoshinobu [Computer Software Development Co., Ltd., Tokyo (Japan)
2002-09-01
In this work, risk information was used to evaluate the safety importance of piping welded portions which were important for plant operation and maintenance of nuclear power plants. There are two types of risk-informed safety importance evaluation methods, namely the ASME method and the EPRI method. Since both methods have advantages and disadvantages, elements of each method were combined and reorganized. Considerations included whether the degradation mechanisms would be objectively evaluated and whether plant safety would be efficiently improved. The most objective and efficient method was as follows. Piping failure potential is quantitatively and objectively evaluated for failure with probabilistic fracture mechanics (PFM) and for other degradation mechanisms with empirical failure rates, and conditional core damage probability (CCDP) is calculated with PSA. This method reduces the inspected segment numbers to 1/4 of the deterministic method and increases the ratio of risk, which is covered by the inspected segments, to total risk from 80% of the deterministic method to 95%. Piping inspection numbers decreased for safety injection systems that were required the inspections by the deterministic method. Piping inspections were required for part of main feed water and main steam systems that were not required the inspections by the deterministic method. (author)
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The Management System for Nuclear Installations. Safety Guide (Spanish Edition)
International Nuclear Information System (INIS)
2017-01-01
This Safety Guide is applicable throughout the lifetime of a nuclear installation, including any subsequent period of institutional control, until there is no significant residual radiation hazard. For a nuclear installation, the lifetime includes site evaluation, design, construction, commissioning, operation and decommissioning. These stages in the lifetime of a nuclear installation may overlap. This Safety Guide may be applied to nuclear installations in the following ways: (a) To support the development, implementation, assessment and improvement of the management system of those organizations responsible for research, site evaluation, design, construction, commissioning, operation and decommissioning of a nuclear installation; (b) As an aid in the assessment by the regulatory body of the adequacy of the management system of a nuclear installation; (c) To assist an organization in specifying to a supplier, via contractual documentation, any specific element that should be included within the supplier's management system for the supply of products. This Safety Guide follows the structure of the Safety Requirements publication on The Management System for Facilities and Activities, whereby: (a) Section 2 provides recommendations on implementing the management system, including recommendations relating to safety culture, grading and documentation. (b) Section 3 provides recommendations on the responsibilities of senior management for the development and implementation of an effective management system. (c) Section 4 provides recommendations on resource management, including guidance on human resources, infrastructure and the working environment. (d) Section 5 provides recommendations on how the processes of the installation can be specified and developed, including recommendations on some generic processes of the management system. (e) Section 6 provides recommendations on the measurement, assessment and improvement of the management system of a nuclear
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Safety evaluation of large ventilation networks
International Nuclear Information System (INIS)
Barrocas, M.; Pruchon, P.; Robin, J.P.; Rouyer, J.L.; Salmon, P.
1981-01-01
For large ventilation networks, it is necessary to make a safety evaluation of their responses to perturbations such as blower failure, unexpected transfers, local pressurization. This evaluation is not easy to perform because of the many interrelationships between the different parts of the networks, interrelationships coming from the circulations of workers and matetials between cells and rooms and from the usefulness of air transfers through zones of different classifications. This evaluation is all the more necessary since new imperatives in energy savings push for minimizing the air flows, which tends to render the network more sensitive to perturbations. A program to evaluate safety has been developed by the Service de Protection Technique in cooperation with operators and designers of big nuclear facilities and the first applications presented here show the weak points of the installation studied from the safety view point
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System Design and the Safety Basis
International Nuclear Information System (INIS)
Ellingson, Darrel
2008-01-01
The objective of this paper is to present the Bechtel Jacobs Company, LLC (BJC) Lessons Learned for system design as it relates to safety basis documentation. BJC has had to reconcile incomplete or outdated system description information with current facility safety basis for a number of situations in recent months. This paper has relevance in multiple topical areas including documented safety analysis, decontamination and decommissioning (D and D), safety basis (SB) implementation, safety and design integration, potential inadequacy of the safety analysis (PISA), technical safety requirements (TSR), and unreviewed safety questions. BJC learned that nuclear safety compliance relies on adequate and well documented system design information. A number of PIS As and TSR violations occurred due to inadequate or erroneous system design information. As a corrective action, BJC assessed the occurrences caused by systems design-safety basis interface problems. Safety systems reviewed included the Molten Salt Reactor Experiment (MSRE) Fluorination System, K-1065 fire alarm system, and the K-25 Radiation Criticality Accident Alarm System. The conclusion was that an inadequate knowledge of system design could result in continuous non-compliance issues relating to nuclear safety. This was especially true with older facilities that lacked current as-built drawings coupled with the loss of 'historical knowledge' as personnel retired or moved on in their careers. Walkdown of systems and the updating of drawings are imperative for nuclear safety compliance. System design integration with safety basis has relevance in the Department of Energy (DOE) complex. This paper presents the BJC Lessons Learned in this area. It will be of benefit to DOE contractors that manage and operate an aging population of nuclear facilities
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Mark I containment, short term program. Safety evaluation report
International Nuclear Information System (INIS)
1977-12-01
Presented is a Safety Evaluation Report (SER) prepared by the Office of Nuclear Reactor Regulation addressing the Short Term Program (STP) reassessment of the containment systems of operating Boiler Water Reactor (BWR) facilities with the Mark I containment system design. The information presented in this SER establishes the basis for the NRC staff's conclusion that licensed Mark I BWR facilities can continue to operate safely, without undue risk to the health and safety of the public, during an interim period of approximately two years while a methodical, comprehensive Long Term Program (LTP) is conducted. This SER also provides one of the basic foundations for the NRC staff review of the Mark I containment systems for facilities not yet licensed for operation
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Evaluation of safety implications of control systems in LWR nuclear power plants
International Nuclear Information System (INIS)
Szukiewicz, A.J.
1989-06-01
An in-depth evaluation was performed on non-safety-related control systems (see Section 1) that are typically used during normal plant operation on four nuclear steam supply system plants: a General Electric Company boiling-water reactor, a Westinghouse 3-loop pressurized-water reactor (PWR), a Babcock ampersand Wilcox Co. (B ampersand W) once-through steam generator PWR, and a Combustion Engineering PWR design. A study was also conducted to determine the generic applicability of the results to the class of plants represented by the specific plants analyzed. Generic conclusions were then developed. Steam generator and reactor vessel overfill events and reactor vessel overcooling events were identified as major classes of events having the potential to be more severe than previously analyzed. Specific substasks of this issue were to study these events to determine the need for preventive and/or mitigating design measures. This report describes the technical studies performed by the laboratories, the NRC staff assessment of the results, the generic applicability of the evaluations, and the technical findings resulting from these studies. This final report contains the staff's responses to, and resolution of, the public comments that were solicited and received before September 16,1988, in response to the draft reports issued for public comment on May 27, 1988. 39 refs, 1 fig., 7 tabs
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Evaluation of safety-parameter display concepts. Final report
International Nuclear Information System (INIS)
Woods, D.D.; Wise, J.A.; Hanes, L.F.
1982-02-01
New control room equipment designed to improve operator performance must be evaluated before adoption and installation. Two experimental concepts for a Safety Parameters Display System (SPDS) were evaluated to assess benefits and potential problems associated with the SPDS concept and its integration into control room operations. Participants were licensed utility operators undergoing retraining on a nuclear power plant simulator. Both quantitative and qualitative data were collected and analyzed on crew response to seven simulated accident conditions
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Effects of auditing patient safety in hospital care: design of a mixed-method evaluation.
Hanskamp-Sebregts, Mirelle; Zegers, Marieke; Boeijen, Wilma; Westert, Gert P; van Gurp, Petra J; Wollersheim, Hub
2013-06-22
Auditing of patient safety aims at early detection of risks of adverse events and is intended to encourage the continuous improvement of patient safety. The auditing should be an independent, objective assurance and consulting system. Auditing helps an organisation accomplish its objectives by bringing a systematic, disciplined approach to evaluating and improving the effectiveness of risk management, control, and governance. Audits are broadly conducted in hospitals, but little is known about their effects on the behaviour of healthcare professionals and patient safety outcomes. This study was initiated to evaluate the effects of patient safety auditing in hospital care and to explore the processes and mechanisms underlying these effects. Our study aims to evaluate an audit system to monitor and improve patient safety in a hospital setting. We are using a mixed-method evaluation with a before-and-after study design in eight departments of one university hospital in the period October 2011-July 2014. We measure several outcomes 3 months before the audit and 15 months after the audit. The primary outcomes are adverse events and complications. The secondary outcomes are experiences of patients, the standardised mortality ratio, prolonged hospital stay, patient safety culture, and team climate. We use medical record reviews, questionnaires, hospital administrative data, and observations to assess the outcomes. A process evaluation will be used to find out which components of internal auditing determine the effects. We report a study protocol of an effect and process evaluation to determine whether auditing improves patient safety in hospital care. Because auditing is a complex intervention targeted on several levels, we are using a combination of methods to collect qualitative and quantitative data about patient safety at the patient, professional, and department levels. This study is relevant for hospitals that want to early detect unsafe care and improve patient
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Status of Nuclear Safety evaluation in China
International Nuclear Information System (INIS)
Tian Jiashu
1999-01-01
Chinese nuclear safety management and control follows international practice, the regulations are mainly from IAEA with the Chinese condition. The regulatory body is National Nuclear Safety Administration (NNSA). The nuclear safety management, surveillance, safety review and evaluation are guided by NNSA with technical support by several units. Beijing Review Center of Nuclear Safety is one of these units, which was founded in 1987 within Beijing Institute of nuclear Engineering (BINE), co-directed by NNSA and BINE, it is the first technical support team to NNSA. Most of the safety reviews and evaluations of Chinese nuclear installations has been finished by this unit. It is described briefly in this paper that the NNSA's main function and organization, regulations on the nuclear safety, procedure of application and issuing of license, the main activities performed by Beijing Review Center of Nuclear Safety, the situation of severe accident analyses in China, etc. (author)
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R and D perspectives on the advanced nuclear safety regulation system
International Nuclear Information System (INIS)
Lee, Chang Ju; Ahn, Sang Kyu; Park, Jong Seuk; Chung, Dae Wook; Han, Sang Hoon; Lee, Jung Won
2009-01-01
As current licensing process is much desired to be optimized both plant safety and regulatory efficiency, an advanced safety regulation such as risk informed regulation has been come out. Also, there is a need to have a future oriented safety regulation since a lot of new reactors are conceptualized. Keeping pace with these needs, since early 2007, Korean government has launched a new project for preparing an advanced and future oriented nuclear safety regulation system. In order to get practical achievements, the project team sets up such specific research objectives for the development of: implementation program for graded regulation using risk and performance information; multi purpose PSA models for regulatory uses; a technology neutral regulatory framework for future innovative reactors; evaluation procedure of proliferation resistance; and, performance based fire hazard analysis method and evaluation system. This paper introduces major R and D outputs of this project, and provides some perspectives for achieving effectiveness and efficiency of the nuclear regulation system in Korea
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R and D perspectives on the advanced nuclear safety regulation system
Energy Technology Data Exchange (ETDEWEB)
Lee, Chang Ju; Ahn, Sang Kyu; Park, Jong Seuk; Chung, Dae Wook [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Han, Sang Hoon; Lee, Jung Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)
2009-04-15
As current licensing process is much desired to be optimized both plant safety and regulatory efficiency, an advanced safety regulation such as risk informed regulation has been come out. Also, there is a need to have a future oriented safety regulation since a lot of new reactors are conceptualized. Keeping pace with these needs, since early 2007, Korean government has launched a new project for preparing an advanced and future oriented nuclear safety regulation system. In order to get practical achievements, the project team sets up such specific research objectives for the development of: implementation program for graded regulation using risk and performance information; multi purpose PSA models for regulatory uses; a technology neutral regulatory framework for future innovative reactors; evaluation procedure of proliferation resistance; and, performance based fire hazard analysis method and evaluation system. This paper introduces major R and D outputs of this project, and provides some perspectives for achieving effectiveness and efficiency of the nuclear regulation system in Korea.
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An approach for assessing ALWR passive safety system reliability
International Nuclear Information System (INIS)
Hake, T.M.
1991-01-01
Many of the advanced light water reactor (ALWR) concepts proposed for the next generation of nuclear power plants rely on passive rather than active systems to perform safety functions. Despite the reduced redundancy of the passive systems as compared to active systems in current plants, the assertion is that the overall safety of the plant is enhanced due to the much higher expected reliability of the passive systems. In order to investigate this assertion, a study is being conducted at Sandia National Laboratories to evaluate the reliability of ALWR passive safety features in the context of probabilistic risk assessment (PRA). The purpose of this paper is to provide a brief overview of the approach to this study. The quantification of passive system reliability is not as straightforward as for active systems, due to the lack of operating experience, and to the greater uncertainty in the governing physical phenomena. Thus, the adequacy of current methods for evaluating system reliability must be assessed, and alternatives proposed if necessary. For this study, the Westinghouse Advanced Passive 600 MWe reactor (AP600) was chosen as the advanced reactor for analysis, because of the availability of AP600 design information. This study compares the reliability of AP600 emergency cooling system with that of corresponding systems in a current generation reactor
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Architecture Level Safety Analyses for Safety-Critical Systems
Directory of Open Access Journals (Sweden)
K. S. Kushal
2017-01-01
Full Text Available The dependency of complex embedded Safety-Critical Systems across Avionics and Aerospace domains on their underlying software and hardware components has gradually increased with progression in time. Such application domain systems are developed based on a complex integrated architecture, which is modular in nature. Engineering practices assured with system safety standards to manage the failure, faulty, and unsafe operational conditions are very much necessary. System safety analyses involve the analysis of complex software architecture of the system, a major aspect in leading to fatal consequences in the behaviour of Safety-Critical Systems, and provide high reliability and dependability factors during their development. In this paper, we propose an architecture fault modeling and the safety analyses approach that will aid in identifying and eliminating the design flaws. The formal foundations of SAE Architecture Analysis & Design Language (AADL augmented with the Error Model Annex (EMV are discussed. The fault propagation, failure behaviour, and the composite behaviour of the design flaws/failures are considered for architecture safety analysis. The illustration of the proposed approach is validated by implementing the Speed Control Unit of Power-Boat Autopilot (PBA system. The Error Model Annex (EMV is guided with the pattern of consideration and inclusion of probable failure scenarios and propagation of fault conditions in the Speed Control Unit of Power-Boat Autopilot (PBA. This helps in validating the system architecture with the detection of the error event in the model and its impact in the operational environment. This also provides an insight of the certification impact that these exceptional conditions pose at various criticality levels and design assurance levels and its implications in verifying and validating the designs.
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Radioactive waste disposal system for Cuba. Safety assessment for the long term
International Nuclear Information System (INIS)
Peralta Vital, J.L.; Gil Castillo, R.; Mirta Torrez, B.
1998-01-01
The present work is performed within the frame of evaluating the radiological impact of the post-closure stage of the facility for disposal of the radioactive wastes generated in Cuba, including a description of the waste disposal systems defined in the country, and taking account of significant elements of their long term safety. The Methodology for Safety Assessment includes: the definition of possible scenarios for evaluation, the identification of principal present uncertainties, the model simulating the release of the radionuclides of the facility, their transport through the geosphere, and their final access to man, evaluating ultimately the radiological impact of the disposal system considering the dose for a critical group. The results obtained allow to demonstrate the radiological safety of the nominative barrier in the design of the system for the particular conditions of Cuba. (author)
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International Nuclear Information System (INIS)
Bacurik, J.
1997-01-01
The most important regulatory requirements and issues are described related to the review, evaluation and assessment of computer-based safety-related IandC systems, with emphasis on safety instrumentation and control. These aspects include safety classification and categorization of IandC, ranking of applicable codes and standards, design evaluation on the system level, and software assessment. (author)
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International Nuclear Information System (INIS)
Sheaffer, M.K.; Keeton, S.C.
1993-01-01
This report evaluates nuclear criticality safety for Spray Booth Operations in the Decontamination and Recovery Facility, X-705, at the Portsmouth Gaseous Diffusion Plant. A general description of current procedures and related hardware/equipment is presented. Control parameters relevant to nuclear criticality safety are explained, and a consolidated listing of administrative controls and safety systems is developed. Based on compliance with DOE Orders and MMES practices, the overall operation is evaluated, and recommendations for enhanced safety are suggested
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Donovan, Sarah-Louise; Salmon, Paul M; Lenné, Michael G; Horberry, Tim
2017-10-01
Safety leadership is an important factor in supporting safety in high-risk industries. This article contends that applying systems-thinking methods to examine safety leadership can support improved learning from incidents. A case study analysis was undertaken of a large-scale mining landslide incident in which no injuries or fatalities were incurred. A multi-method approach was adopted, in which the Critical Decision Method, Rasmussen's Risk Management Framework and Accimap method were applied to examine the safety leadership decisions and actions which enabled the safe outcome. The approach enabled Rasmussen's predictions regarding safety and performance to be examined in the safety leadership context, with findings demonstrating the distribution of safety leadership across leader and system levels, and the presence of vertical integration as key to supporting the successful safety outcome. In doing so, the findings also demonstrate the usefulness of applying systems-thinking methods to examine and learn from incidents in terms of what 'went right'. The implications, including future research directions, are discussed. Practitioner Summary: This paper presents a case study analysis, in which systems-thinking methods are applied to the examination of safety leadership decisions and actions during a large-scale mining landslide incident. The findings establish safety leadership as a systems phenomenon, and furthermore, demonstrate the usefulness of applying systems-thinking methods to learn from incidents in terms of what 'went right'. Implications, including future research directions, are discussed.
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Development of Basic Key Technologies for Gen IV SFR Safety Evaluation
International Nuclear Information System (INIS)
Jeong, Hae Yong; Kwon, Young Min; Kim, Tae Woon; Park, Soo Yong; Suk, Soo Dong; Lee, Kwi Lim; Lee, Yong Bum; Chang, Won Pyo; Ha, Kwi Seok; Hahn, Sang Hoon
2010-07-01
Safety issues and design requirements on control rod worth were identified through the evaluation of safety design characteristics and the preliminary safety evaluation. This results will be taken into account for the conceptual design studies of the demonstration reactor in the next stage. The Level-1 Pasa has been performed and a quantitative Cdf value was produced for the selected design from the several candidates. The inherent safety characteristics of the selected design were evaluated through the DBE and ATWS analyses. A surrogate material for Tru has been selected which is applicable to the study of liquidus/solidus temperature test for the metallic fuel containing Tru. A methodology for the regression analysis with surrogate material has been developed and valuable data on metal fuel liquidus/solidus temperature have been measured. A simple mechanistic model describing a bending of subassemblies has been formulated based on the foreign test data and existing models. Its applicability has been evaluated for the Phenix design. New criteria of the core damage for the SFR PSA were identified. The list of initiating events, system response event tree, and core response event tree, which constitute a PSA methodology for an SFR, have been introduced. By developing the SFR PIRT, phenomenological model features, which have to be satisfied in a safety code, were defined and the PIRT results were applied to the design of the PDRC test facility. Bases for a safety evaluation methodology for the SFR DBEs have been also prepared. A draft version of the topical report on the code for local fault analysis has been completed. Since 2007, the MARS-LMR code has been developed and assessments for model validation with the test data from EBR-II and Phenix reactor have been continued. The code has been applied to the evaluation of passive safety of a conceptual design of Gen IV SFR
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FOOD SAFETY CONTROL SYSTEM IN CHINA
Institute of Scientific and Technical Information of China (English)
Liu Wei-jun; Wei Yi-min; Han Jun; Luo Dan; Pan Jia-rong
2007-01-01
Most countries have expended much effort to develop food safety control systems to ensure safe food supplies within their borders. China, as one of the world's largest food producers and consumers,pays a lot of attention to food safety issues. In recent years, China has taken actions and implemented a series of plans in respect to food safety. Food safety control systems including regulatory, supervisory,and science and technology systems, have begun to be established in China. Using, as a base, an analysis of the current Chinese food safety control system as measured against international standards, this paper discusses the need for China to standardize its food safety control system. We then suggest some policies and measures to improve the Chinese food safety control system.
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TAPS safety evaluation criteria for reload fueling
International Nuclear Information System (INIS)
Mahendra Nath; Veeraraghavan, N.
1976-01-01
To improve operating performance of Tarapur reactors, several proposals are under consideration such as core expansion, change-over to an improved fuel design with lower heat rating, extension of fuel cycle lengths etc., which have a bearing on overall plant operating characteristics and reactor safety. For evaluating safety implications of the various proposals, it is necessary to formulate safety evaluation criteria for reload fuelling. Salient features of these criteria are discussed. (author)
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Qualitative safety analysis in accelerator based systems
International Nuclear Information System (INIS)
Sarkar, P.K.; Chowdhury, Lekha M.
2006-01-01
In recent developments connected to high energy and high current accelerators, the accelerator driven systems (ADS) and the Radioactive Ion Beam (RIB) facilities come in the forefront of application. For medical and industrial applications high current accelerators often need to be located in populated areas. These facilities pose significant radiological hazard during their operation and accidental situations. We have done a qualitative evaluation of radiological safety analysis using the probabilistic safety analysis (PSA) methods for accelerator-based systems. The major contribution to hazard comes from a target rupture scenario in both ADS and RIB facilities. Other significant contributors to hazard in the facilities are also discussed using fault tree and event tree methodologies. (author)
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Analysis approach for common cause failure on non-safety digital control system
Energy Technology Data Exchange (ETDEWEB)
Kim, Yun Goo; Oh, Eungse [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)
2014-05-15
The effects of common cause failure (CCF) on safety digital instrumentation and control (I and C) system had been considered in defense in depth and diversity coping analysis with safety analysis method. For the non-safety system, single failure had been considered for safety analysis. IEEE Std. 603-1991, Clause 5.6.3.1(2), 'Isolation' states that no credible failure on the non-safety side of an isolation device shall prevent any portion of a safety system from meeting its minimum performance requirements during and following any design basis event requiring that safety function. The software CCF is one of the credible failure on the non-safety side. In advanced digital I and C system, same hardware component is used for different control system and the defect in manufacture or common external event can generate CCF. Moreover, the non-safety I and C system uses complex software for its various function and software quality assurance for the development process is less severe than safety software for the cost effective design. Therefore the potential defects in software cannot be ignored and the effect of software CCF on non-safety I and C system is needed to be evaluated. This paper proposes the general process and considerations for the analysis of CCF on non-safety I and C system.
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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)
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High Speed Railway Environment Safety Evaluation Based on Measurement Attribute Recognition Model
Directory of Open Access Journals (Sweden)
Qizhou Hu
2014-01-01
Full Text Available In order to rationally evaluate the high speed railway operation safety level, the environmental safety evaluation index system of high speed railway should be well established by means of analyzing the impact mechanism of severe weather such as raining, thundering, lightning, earthquake, winding, and snowing. In addition to that, the attribute recognition will be identified to determine the similarity between samples and their corresponding attribute classes on the multidimensional space, which is on the basis of the Mahalanobis distance measurement function in terms of Mahalanobis distance with the characteristics of noncorrelation and nondimensionless influence. On top of the assumption, the high speed railway of China environment safety situation will be well elaborated by the suggested methods. The results from the detailed analysis show that the evaluation is basically matched up with the actual situation and could lay a scientific foundation for the high speed railway operation safety.
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Confirmatory simulation of safety and operational transients in LMFBR systems
International Nuclear Information System (INIS)
Guppy, J.G.; Agrawal, A.K.
1978-01-01
Operational and safety transients (anticipated, unlikely, or extremely unlikely) that may originate anywhere in a liquid-metal fast breeder reactor (LMFBR) system must be adequately simulated to assist in safety evaluation and plant design efforts. An advanced thermohydraulic transient code, the Super System Code (SSC), is described that may be used for confirmatory safety evaluations of plant-wide events, such as assurance of adequate decay heat removal capability under natural circulation conditions. Results obtained with SSC illustrating the degree of modeling detail present in the code as well as the computing efficiency are presented. A version of the SSC code, SSC-L, applicable to any loop-type LMFBR design, has been developed at Brookhaven. The scope of SSC-L is to enable the simulation of all plant-wide transients covered by Plant Protection System (PPS) action, including sodium pipe rupture and coastdown to natural circulation conditions. The computations are stopped when loss of core integrity (i.e., clad melting temperature exceeded) is indicated
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Safety assessment of HLW geological disposal system
International Nuclear Information System (INIS)
Naito, Morimasa
2006-01-01
that Japan is located in a tectonically active zone. Safety assessment for a disposal system differs from that for other engineered systems such as power stations in terms of: Extremely long timescales must be taken into account. Natural environments, which are heterogeneous and cover large spatial areas, must be evaluated. It is thus impossible to apply conventional engineering approaches, where an entire system is constructed and utilized in such a way as to demonstrate system safety. This is a problem specific to the safety assessment of geological disposal. Taking this into account, this paper describes a general methodology of safety assessment for geological system including presentation of a series of steps for the assessment with examples of JNC's H12 safety assessment. (author)
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A study on a reliability assessment methodology for the VHTR safety systems
International Nuclear Information System (INIS)
Lee, Hyung Sok
2012-02-01
The passive safety system of a 300MWt VHTR (Very High Temperature Reactor)which has attracted worldwide attention recently is actively considered for designing the improvement in the safety of the next generation nuclear power plant. The passive system functionality does not rely on an external source of the electrical support system,but on an intelligent use of the natural phenomena, such as convection, conduction, radiation, and gravity. It is not easy to evaluate quantitatively the reliability of the passive safety for the risk analysis considering the existing active system failure since the classical reliability assessment method could not be applicable. Therefore a new reliability methodology needs to be developed and applied for evaluating the reliability of the conceptual designed VHTR in this study. The preliminary evaluation and conceptualization are performed using the concept of the load and capacity theory related to the reliability physics model. The method of response surface method (RSM) is also utilized for evaluating the maximum temperature of nuclear fuel in this study. The significant variables and their correlation are considered for utilizing the GAMMA+ code. The proposed method might contribute to designing the new passive system of the VHTR
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International Nuclear Information System (INIS)
1996-10-01
Nuclear power plants are increasingly upgrading their instrumentation and control (I ampersand C) systems with commercial digital equipment, which allows them to continue meeting safety and reliability requirements while controlling operating costs. However, the use of commercial software-based devices for safety related applications has raised new issues that impact design, procurement, and licensing activities. This guideline describes a consistent, comprehensive approach for the evaluation and acceptance of commercial digital equipment for nuclear safety systems
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International Nuclear Information System (INIS)
TOFFER, H.
2006-01-01
Since the end of the cold war, the need for operating weapons production facilities has faded. Criticality Safety Limits and controls supporting production modes in these facilities became outdated and furthermore lacked the procedure based rigor dictated by present day requirements. In the past, in many instances, the formalism of present day criticality safety evaluations was not applied. Some of the safety evaluations amounted to a paragraph in a notebook with no safety basis and questionable arguments with respect to double contingency criteria. When material stabilization, clean out, and deactivation activities commenced, large numbers of these older criticality safety evaluations were uncovered with limits and controls backed up by tenuous arguments. A dilemma developed: on the one hand, cleanup activities were placed on very aggressive schedules; on the other hand, a highly structured approach to limits development was required and applied to the cleanup operations. Some creative approaches were needed to cope with the limits development process
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Gross-Schulman, Sandra; Sklaroff, Laura Myerchin; Hertz, Crystal Coyazo; Guterman, Jeffrey J
2017-12-01
Heart Failure (HF) is the most expensive preventable condition, regardless of patient ethnicity, race, socioeconomic status, sex, and insurance status. Remote telemonitoring with timely outpatient care can significantly reduce avoidable HF hospitalizations. Human outreach, the traditional method used for remote monitoring, is effective but costly. Automated systems can potentially provide positive clinical, fiscal, and satisfaction outcomes in chronic disease monitoring. The authors implemented a telephonic HF automated remote monitoring system that utilizes deterministic decision tree logic to identify patients who are at risk of clinical decompensation. This safety study evaluated the degree of clinical concordance between the automated system and traditional human monitoring. This study focused on a broad underserved population and demonstrated a safe, reliable, and inexpensive method of monitoring patients with HF.
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Nuclear power safety reporting system feasibility analysis and concept description
International Nuclear Information System (INIS)
Finlayson, F.C.; Ims, J.R.; Hussman, T.A.
1984-01-01
The Aerospace Corporation is assisting the US Nuclear Regulatory Commission (NRC) in the evaluation of the potential attributes of a voluntary, nonpunitive data gathering system for identifying and quantifying the factors that contribute to the occurrence of significant safety problems involving humans in nuclear power plants. The objectives of the Aerospace Administration (FAA)/National Aeronautics and Space Administration (NASA) Aviation Safety Reporting System (ASRS) in order to determine whether it would be feasible to apply part (or all) of the ASRS concepts for collecting data on human factor related incidents to the nuclear industry; and (2) to identify and define the basic elements and requirements of a Nuclear Power Safety Reporting System (NPSRS), assuming the feasibility of implementing such a system was established
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Safety evaluation of food flavorings
International Nuclear Information System (INIS)
Schrankel, Kenneth R.
2004-01-01
Food flavorings are an essential element in foods. Flavorings are a unique class of food ingredients and excluded from the legislative definition of a food additive because they are regulated by flavor legislation and not food additive legislation. Flavoring ingredients naturally present in foods, have simple chemical structures, low toxicity, and are used in very low levels in foods and beverages resulting in very low levels of human exposure or consumption. Today, the overwhelming regulatory trend is a positive list of flavoring substances, e.g. substances not listed are prohibited. Flavoring substances are added to the list following a safety evaluation based on the conditions of intended use by qualified experts. The basic principles for assessing the safety of flavoring ingredients will be discussed with emphasis on the safety evaluation of flavoring ingredients by the Food and Agriculture Organization (FAO) and World Health Organization (WHO) Joint Expert Committee on Food Additives (JECFA) and the US Flavor and Extract Manufacturers Expert Panel (FEXPAN). The main components of the JECFA evaluation process include chemical structure, human intake (exposure), metabolism to innocuous or harmless substances, and toxicity concerns consistent with JECFA principles. The Flavor and Extract Manufacturers Association (FEMA) evaluation is very similar to the JECFA procedure. Both the JECFA and FEMA evaluation procedures are widely recognized and the results are accepted by many countries. This implies that there is no need for developing countries to conduct their own toxicological assessment of flavoring ingredients unless it is an unique ingredient in one country, but it is helpful to survey intake or exposure assessment. The global safety program established by the International Organization of Flavor Industry (IOFI) resulting in one worldwide open positive list of flavoring substances will be reviewed
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Safety evaluation of advance street name signs
2009-06-01
The Federal Highway Administration (FHWA) organized a pooled fund study of 26 States to evaluate low-cost safety strategies as part of its strategic highway safety effort. The objective of the pooled fund study was to estimate the safety effectivenes...
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International Nuclear Information System (INIS)
Yamano, Naoki; Minami, Kazuyoshi; Koyama, Kinji; Naito, Yoshitaka.
1989-03-01
A modular code system RADHEAT-V4 has been developed for performing precisely neutron and photon transport analyses, and shielding safety evaluations. The system consists of the functional modules for producing coupled multi-group neutron and photon cross section sets, for analyzing the neutron and photon transport, and for calculating the atom displacement and the energy deposition due to radiations in nuclear reactor or shielding material. A precise method named Direct Angular Representation (DAR) has been developed for eliminating an error associated with the method of the finite Legendre expansion in evaluating angular distributions of cross sections and radiation fluxes. The DAR method implemented in the code system has been described in detail. To evaluate the accuracy and applicability of the code system, some test calculations on strong anisotropy problems have been performed. From the results, it has been concluded that RADHEAT-V4 is successfully applicable to evaluating shielding problems accurately for fission and fusion reactors and radiation sources. The method employed in the code system is very effective in eliminating negative values and oscillations of angular fluxes in a medium having an anisotropic source or strong streaming. Definitions of the input data required in various options of the code system and the sample problems are also presented. (author)
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Design and hardware alternatives for a Safety-Parameter Display System
International Nuclear Information System (INIS)
Honeycutt, F.; Merten, W.T.; Roy, G.M.; Segraves, E.; Stone, G.P.
1981-05-01
The SPDS is a dedicated control room operator aid and is viewed as an important safety improvement within the context of other post-TMI fixes. Hardware configurations and components to implement the NSAC display format of a Safety Parameter Display System (SPDS) are evaluated. The evaluation was made on the basis of five alternative hardware configurations which use commercially available components. Four of the alternatives use computer/video display architecture. The fifth alternative is a simple hardwired system which uses strip chart recorders. SPDS regulatory requirements are defined by NUREG 0696. Overall feasibility of the NSAC concept was evaluated in terms of performance, reliability, cost, licensability, and flexibility. The flexibility evaluation relates to the ability to handle other display formats, the data acquisition needs of the other emergency facilities and the impact of expected future NRC requirements
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Analysis Method of Common Cause Failure on Non-safety Digital Control System
Energy Technology Data Exchange (ETDEWEB)
Kim, Yun Goo; Oh, Eun Gse [KHNP, Daejeon (Korea, Republic of)
2014-08-15
The effects of common cause failure on safety digital instrumentation and control system had been considered in defense in depth analysis with safety analysis method. However, the effects of common cause failure on non-safety digital instrumentation and control system also should be evaluated. The common cause failure can be included in credible failure on the non-safety system. In the I and C architecture of nuclear power plant, many design feature has been applied for the functional integrity of control system. One of that is segmentation. Segmentation defenses the propagation of faults in the I and C architecture. Some of effects from common cause failure also can be limited by segmentation. Therefore, in this paper there are two type of failure mode, one is failures in one control group which is segmented, and the other is failures in multiple control group because that the segmentation cannot defense all effects from common cause failure. For each type, the worst failure scenario is needed to be determined, so the analysis method has been proposed in this paper. The evaluation can be qualitative when there is sufficient justification that the effects are bounded in previous safety analysis. When it is not bounded in previous safety analysis, additional analysis should be done with conservative assumptions method of previous safety analysis or best estimation method with realistic assumptions.
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Directory of Open Access Journals (Sweden)
Ifeanyichukwu Ebubechukwu Onyegiri
2016-10-01
Full Text Available In recent years, in the aviation industry, the weak engineering controls and lapses associated with safety management systems (SMSs are responsible for the seemingly unprecedented disasters. A previous study has confirmed the difficulties experienced by safety managers with SMSs and the need to direct research to this area of investigation for more insights and progress in the evaluation and maintenance of SMSs in the aviation industry. The purpose of this work is to examine the application of Decision Trial and Evaluation Laboratory (DEMATEL to the aviation industry in developing countries with illustration using the Nigerian aviation survey data for the validation of the method. The advantage of the procedure over other decision making methods is in its ability to apply feedback in its decision making. It also affords us the opportunity of breaking down the complex aviation SMS components and elements which are multi-variate in nature through the analysis of the contributions of the diverse system criteria from the perspective of cause and effects, which in turn yields easier and yet more effective aviation transportation accident pre-corrective actions. In this work, six revised components of an SMS were identified and DEMATEL was applied to obtain their direct and indirect impacts and influences on the overall SMS performance. Data collection was by the survey questionnaire, which served as the initial direct-relation matrix, coded in Matlab software for establishing the impact relation map (IRM. The IRM was then plotted in MS Excel spread-sheet software. From our results, safety structure and regulation has the highest impact level on an SMS with a corresponding positive relation level value. In conclusion, the results agree with those of previous researchers that used grey relational analysis. Thus, DEMATEL serves as a great tool and resource for the safety manager.
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Preliminary safety analysis of the HTTR-IS nuclear hydrogen production system
International Nuclear Information System (INIS)
Sato, Hiroyuki; Ohashi, Hirofumi; Tazawa, Yujiro; Tachibana, Yukio; Sakaba, Nariaki
2010-06-01
Japan Atomic Energy Agency is planning to demonstrate hydrogen production by thermochemical water-splitting IS process utilizing heat from the high-temperature gas-cooled reactor HTTR (HTTR-IS system). The previous study identified that the HTTR modification due to the coupling of hydrogen production plant requires an additional safety review since the scenario and quantitative values of the evaluation items would be altered from the original HTTR safety review. Hence, preliminary safety analyses are conducted by using the system analysis code. Calculation results showed that evaluation items such as a coolant pressure, temperatures of heat transfer tubes at the pressure boundary, etc., did not exceed allowable values. Also, the peak fuel temperature did not exceed allowable value and therefore the reactor core was not damaged and cooled sufficiently. This report compiles calculation conditions, event scenarios and the calculation results of the preliminary safety analysis. (author)
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Benefits of a systematic approach to maintenance for safety and safety related systems
International Nuclear Information System (INIS)
Dam, R.F.; Ayazzudin, S.; Nickerson, J.H.
2003-01-01
For safety and safety-related systems, nuclear plants have to balance the requirements of demonstrating the reliability of each system, while maintaining the system and plant availability. With the goal of demonstrating statistical reliability, these systems have extensive testing programs, which often results in system unavailability and this can impact the plant capacity. The inputs to the process are often safety and regulatory related, resulting in programs that provide a high level of scrutiny. In such cases, the value of the application of a Systematic Assessment of Maintenance (SAM) process, such as Reliability Centered Maintenance (RCM), is questioned. The special case of Standby-Safety systems was discussed in a previous paper, where it was demonstrated how SAM techniques provide useful insight into current system performance, the impact of testing on component and system reliability, and how PSA considerations can be integrated into a comprehensive Maintenance, Surveillance, and Inspection (MSI) strategy. Although the system reliability requirements are an important part of the strategy evaluation, SAM techniques provide a systematic assessment within a broader context. Testing is only one part of an overall strategy focused on ensuring that component function is maintained through a combination of monitoring technologies (including testing), predictive techniques, and intrusive maintenance strategies. Each strategy is targeted to known component degradation mechanisms. This thinking can be extended to safety and safety related systems in general. Over the past 6 years, AECL has been working with CANDU utilities in the development and implementation of a comprehensive and integrated Plant Life Management (PLiM) program. As part of developing a comprehensive plant asset management approach, SAM techniques are used to develop a technical basis that not only works towards ensuring reliable operation of plant systems, but also facilitates the optimization and
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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
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Effects of auditing patient safety in hospital care: design of a mixed-method evaluation
2013-01-01
Background Auditing of patient safety aims at early detection of risks of adverse events and is intended to encourage the continuous improvement of patient safety. The auditing should be an independent, objective assurance and consulting system. Auditing helps an organisation accomplish its objectives by bringing a systematic, disciplined approach to evaluating and improving the effectiveness of risk management, control, and governance. Audits are broadly conducted in hospitals, but little is known about their effects on the behaviour of healthcare professionals and patient safety outcomes. This study was initiated to evaluate the effects of patient safety auditing in hospital care and to explore the processes and mechanisms underlying these effects. Methods and design Our study aims to evaluate an audit system to monitor and improve patient safety in a hospital setting. We are using a mixed-method evaluation with a before-and-after study design in eight departments of one university hospital in the period October 2011–July 2014. We measure several outcomes 3 months before the audit and 15 months after the audit. The primary outcomes are adverse events and complications. The secondary outcomes are experiences of patients, the standardised mortality ratio, prolonged hospital stay, patient safety culture, and team climate. We use medical record reviews, questionnaires, hospital administrative data, and observations to assess the outcomes. A process evaluation will be used to find out which components of internal auditing determine the effects. Discussion We report a study protocol of an effect and process evaluation to determine whether auditing improves patient safety in hospital care. Because auditing is a complex intervention targeted on several levels, we are using a combination of methods to collect qualitative and quantitative data about patient safety at the patient, professional, and department levels. This study is relevant for hospitals that want to
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How could intelligent safety transport systems enhance safety ?
Wiethoff, M. Heijer, T. & Bekiaris, E.
2017-01-01
In Europe, many deaths and injured each years are the cost of today's road traffic. Therefore, it is wise to look for possible solutions for enhancing traffic safety. Some Advanced Driver Assistance Systems (ADAS) are expected to increase safety, but they may also evoke new safety hazards. Only
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Research on Evaluation Model for Secondary Task Driving Safety Based on Driver Eye Movements
Directory of Open Access Journals (Sweden)
Lisheng Jin
2014-01-01
Full Text Available This study was designed to gain insight into the influence of performing different types of secondary task while driving on driver eye movements and to build a safety evaluation model for secondary task driving. Eighteen young drivers were selected and completed the driving experiment on a driving simulator. Measures of fixations, saccades, and blinks were analyzed. Based on measures which had significant difference between the baseline and secondary tasks driving conditions, the evaluation index system was built. Method of principal component analysis (PCA was applied to analyze evaluation indexes data in order to obtain the coefficient weights of indexes and build the safety evaluation model. Based on evaluation scores, the driving safety was grouped into five levels (very high, high, average, low, and very low using K-means clustering algorithm. Results showed that secondary task driving severely distracts the driver and the evaluation model built in this study could estimate driving safety effectively under different driving conditions.
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International Nuclear Information System (INIS)
Iigaki, Kazuhiko; Saikusa, Akio; Sawahata, Hiroaki; Shinozaki, Masayuki; Tochio, Daisuke; Honma, Fumitaka; Tachibana, Yukio; Iyoku, Tatsuo; Kawasaki, Kozo; Baba, Osamu
2006-06-01
Gas Cooled Reactor has long history of nuclear development, and High Temperature Gas Cooled Reactor (HTGR) has been expected that it can be supply high temperature energy to chemical industry and to power generation from the points of view of the safety, the efficiency, the environment and the economy. The HTGR design is tried to installed passive safety equipment. The current licensing review guideline was made for a Low Water Reactor (LWR) on safety evaluation therefore if it would be directly utilized in the HTGR it needs the special consideration for the HTGR. This paper describes that investigation result of the safety design and the safety evaluation traditions for the HTGR, comparison the safety design and safety evaluation feature for the HTGT with it's the LWR, and reflection for next HTGR based on HTTR operational experiment. (author)
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Conceptual design study for the demonstration reactor of JSFR. (3) Safety design and evaluation
International Nuclear Information System (INIS)
Tani, Akihiro; Shimakawa, Yoshio; Kubo, Shigenobu; Fujimura, Ken; Yamano, Hidemasa
2011-01-01
This paper describes the result of conceptual safety design and evaluation for the demonstration plant of Japan sodium-cooled fast reactor (JSFR), which was preliminarily conducted for providing information necessary to decide the plant specification for further design study. The plant major specifications except for output power and safety design concept are almost the same as those of the commercial JSFR. A set of safety evaluation for typical design basis events (DBEs) is mainly focused here, which was conducted for the 750 MWe design. Safety analyses for DBEs evaluation were performed on the basis of conservative assumptions using a one-dimensional flow network code with point kinetics. For representative DBEs, transient over power type events and loss of flow type events were analyzed. The long-term loss-of-offsite power event was also calculated to evaluate the natural circulation decay heat removal system. All analytical results showed to meet tentative safety criteria, thus it was confirmed that the safety design concept of JSFR is feasible against DBEs. (author)
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Taipower's reload safety evaluation methodology for pressurized water reactors
International Nuclear Information System (INIS)
Huang, Ping-Hue; Yang, Y.S.
1996-01-01
For Westinghouse pressurized water reactors (PWRs) such as Taiwan Power Company's (TPC's) Maanshan Units 1 and 2, each of the safety analysis is performed with conservative reload related parameters such that reanalysis is not expected for all subsequent cycles. For each reload cycle design, it is required to perform a reload safety evaluation (RSE) to confirm the validity of the existing safety analysis for fuel cycle changes. The TPC's reload safety evaluation methodology for PWRs is based on 'Core Design and Safety Analysis Package' developed by the TPC and the Institute of Nuclear Energy Research (INER), and is an important portion of the 'Taipower's Reload Design and Transient Analysis Methodologies for Light Water Reactors'. The Core Management System (CMS) developed by Studsvik of America, the one-dimensional code AXINER developed by TPC, National Tsinghua University and INER, and a modified version of the well-known subchannel core thermal-hydraulic code COBRAIIIC are the major computer codes utilized. Each of the computer models is extensively validated by comparing with measured data and/or vendor's calculational results. Moreover, parallel calculations have been performed for two Maanshan reload cycles to validate the RSE methods. The TPC's in-house RSE tools have been applied to resolve many important plant operational issues and plant improvements, as well as to verify the vendor's fuel and core design data. (author)
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International Nuclear Information System (INIS)
Subramaniam, K.; Biswas, T.
1994-01-01
Ensuring operational safety in nuclear power plants is important as operator errors are observed to contribute significantly to the occurrence of accidents. Computerized operator support systems, which process and structure information, can help operators during both normal and transient conditions, and thereby enhance safety and aid effective response to emergency conditions. An important operator aid being developed and described in this paper, is the safety parameter display system (SPDS). The SPDS is an event-independent, symptom-based operator aid for safety monitoring. Knowledge-based systems can provide operators with an improved quality of information. An information processing model of a knowledge based operator support system (KBOSS) developed for emergency conditions using an expert system shell is also presented. The paper concludes with a discussion of the design issues involved in the use of a knowledge based systems for real time safety monitoring and fault diagnosis. (author). 8 refs., 4 figs., 1 tab
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Safety Analysis for Power Reactor Protection System
International Nuclear Information System (INIS)
Eisawy, E.A.; Sallam, H.
2012-01-01
The main function of a Reactor Protection System (RPS) is to safely shutdown the reactor and prevents the release of radioactive materials. The purpose of this paper is to present a technique and its application for used in the analysis of safety system of the Nuclear Power Plant (NPP). A more advanced technique has been presented to accurately study such problems as the plant availability assessments and Technical Specifications evaluations that are becoming increasingly important. The paper provides the Markov model for the Reactor Protection System of the NPP and presents results of model evaluations for two testing policies in technical specifications. The quantification of the Markov model provides the probability values that the system will occupy each of the possible states as a function of time.
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A probabilistic bridge safety evaluation against floods.
Liao, Kuo-Wei; Muto, Yasunori; Chen, Wei-Lun; Wu, Bang-Ho
2016-01-01
To further capture the influences of uncertain factors on river bridge safety evaluation, a probabilistic approach is adopted. Because this is a systematic and nonlinear problem, MPP-based reliability analyses are not suitable. A sampling approach such as a Monte Carlo simulation (MCS) or importance sampling is often adopted. To enhance the efficiency of the sampling approach, this study utilizes Bayesian least squares support vector machines to construct a response surface followed by an MCS, providing a more precise safety index. Although there are several factors impacting the flood-resistant reliability of a bridge, previous experiences and studies show that the reliability of the bridge itself plays a key role. Thus, the goal of this study is to analyze the system reliability of a selected bridge that includes five limit states. The random variables considered here include the water surface elevation, water velocity, local scour depth, soil property and wind load. Because the first three variables are deeply affected by river hydraulics, a probabilistic HEC-RAS-based simulation is performed to capture the uncertainties in those random variables. The accuracy and variation of our solutions are confirmed by a direct MCS to ensure the applicability of the proposed approach. The results of a numerical example indicate that the proposed approach can efficiently provide an accurate bridge safety evaluation and maintain satisfactory variation.
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Monitoring System For Improving Radiation Safety Management
International Nuclear Information System (INIS)
Osovizky, A.; Paran, J.; Tal, N.; Ankry, N.; Ashkenazi, B.; Tirosh, D.; Marziano, R.; Chisin, R.
1999-01-01
Medi SMARTS (Medical Survey Mapping Automatic Radiation Tracing System), a gamma radiation monitoring system, was installed in a nuclear medicine department. In this paper the evaluation of the system's ability to improve radiation safety management is presented. The system is based on a state of the art software that continuously collects on line radiation measurements for display, analysis and logging. Radiation is measured by GM tubes; the signal is transferred to a data processing unit and then via an RS-485 communication line to a computer. The system automatically identifies the detector type and its calibration factor, thus providing compatibility, maintainability and versatility when changing detectors. Radiation levels are displayed on the nuclear medicine department map at six locations. The system has been operating continuously for more than one year, documenting abnormal events caused by routine operation or failure incidents. In cases where abnormal working conditions were encountered, an alarm message was sent automatically to the supervisor via his tele-pager. An interesting issue observed during the system evaluation, was the inability to distinguish between high radiation levels caused by proper routine operation and those caused by safety failure incidents. The solution included examination of two parameters, radiation levels as well as their duration period. A careful analysis of the historical data, applying the appropriated combined parameters determined for each location, verified that such a system can identify abnormal events, provide alarms to warn in case of incidents and improve standard operating procedures
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Comprehensive Lifecycle for Assuring System Safety
Knight, John C.; Rowanhill, Jonathan C.
2017-01-01
CLASS is a novel approach to the enhancement of system safety in which the system safety case becomes the focus of safety engineering throughout the system lifecycle. CLASS also expands the role of the safety case across all phases of the system's lifetime, from concept formation to decommissioning. As CLASS has been developed, the concept has been generalized to a more comprehensive notion of assurance becoming the driving goal, where safety is an important special case. This report summarizes major aspects of CLASS and contains a bibliography of papers that provide additional details.
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Safety evaluation report on Tennessee Valley Authority: Browns Ferry nuclear performance plan
International Nuclear Information System (INIS)
1989-10-01
This safety evaluation report (SER) on the information submitted by the Tennessee Valley Authority (TVA) in its Nuclear Performance Plan, through Revision 2, for the Browns Ferry Nuclear Plant and in supporting documents has been prepared by the US Nuclear Regulatory commission staff. The Browns Ferry Nuclear Plant consists of three boiling-water reactors at a site in Limestone County, Alabama. The plan addresses the plant-specific concerns requiring resolution before the startup of Unit 2. The staff will inspect implementation of those TVA programs that address these concerns. Where systems are common to Units 1 and 2 or to Units 2 and 3, the staff safety evaluations of those systems are included herein. 85 refs
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Safety-related control air systems
International Nuclear Information System (INIS)
Anon.
1977-01-01
This Standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This Standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this Standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements
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Evaluation of Hazardous Material Management Safety in the Chemical Laboratory in BATAN
International Nuclear Information System (INIS)
Nur-Rahmah-Hidayati
2005-01-01
The management safety of the hazardous material (B3) in the chemical laboratory of BATAN was evaluated. The evaluation is necessary to be done because B3 is often used together with radioactive materials in the laboratory, but the attention to the safety aspect of B3 is not paid sufficiently in spite of its big potential hazard. The potential hazard generated from the nature of B3 could be flammable, explosive, oxidative, corrosive and poisonous. The handling of B3 could be conducted by enforcing the labelling and classification in the usage and disposal processes. Some observations of the chemical laboratory of BATAN show that the management safety of hazardous material in compliance with the government regulation no. 74 year 2001 has not been dully conducted. The management safety of B3 could be improved by, designating one who has adequate skill in hazardous material safety specially as the B3 safety officer, providing the Material Safety Data Sheet that is updated periodically to use in the laboratory and storage room, updating periodically the inventory of B3, performing training in work safety periodically, and monitoring the ventilation system intensively in laboratory and storage room. (author)
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Dependability Evaluation of Advanced Diverse Protection System
International Nuclear Information System (INIS)
Oh, Yang Gyun; Lee, Yoon Hee; Sohn, Se Do; Baek, Seung Min; Lee, Sang Jeong
2014-01-01
For the mitigation of anticipated transients without scram (ATWS) as well as common cause failure (CCF) within the plant protection system (PPS) and the emergency safety feature . component control system (ESF-CCS), the diverse protection system (DPS) has been designed by KEPCO Engineering and Construction Company. Recently KEPCO E and C has developed the advanced diverse protection system (ADPS), which has four redundant channels, in an attempt to enhance a fault-tolerant capability of the system. For the evaluation of overall system improvement effects of the ADPS compared with the DPS, the dependability evaluation results are described herein. For all dependability attributes, this paper suggests a practical dependability evaluation method which uses quantitative dependability scores and indices. An overall dependability evaluation index (DEI) for the ADPS is evaluated with the average value of reliability/ security/maintainability/safety indices (i.e., RID, SID, MID, and SID') for dependability. The evaluation results show that the DEI value of ADPS can be improved by approximately 23% compared with that of the DPS, thanks to its fault-tolerant system architecture, software design changes, and external interface design features. Several suggestions have been made, in this paper, of an overall quantitative dependability evaluation method for the nuclear instrumentation and control (I and C) systems including the DPS and ADPS, and the usefulness of dependability evaluation on nuclear I and C systems has been confirmed
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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)
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International Nuclear Information System (INIS)
Sasou, Kunihide; Hasegawa, Naoko; Hirose, Ayako; Tsuge, Tadashi; Hayase, Kenichi; Takano, Kenichi
2003-01-01
'Safety Culture' has been paid attentions since Chernobyl accident in 1986. The criticality accident in 1999 and other kinds of scandals involving big name companies in Japan make them realize the importance of safety culture. CRIEPI is developing a safety evaluation system. The evaluation is based on the answers to the questionnaire and their statistical analysis such as t-test principal component analysis. This report discusses know-how when applying this evaluation technique to an engineering company whose jobs are ranging from production of products to engineering services to customers. About 15% engineers of the company answered the questionnaire and the answers were statistically analyzed. The results show the followings. First, the evaluation technique is not suitable to evaluations between departments with different kinds of jobs in each. That is because risk on the business of each department differs from each other due to the differences in the kinds of jobs. This indicates that the evaluation technique should be applied to groups whose jobs and risks on their business are equal. Second, the technique is applicable to branches with some kinds of jobs. A branch consists of small groups with different jobs but the ratios of the groups in a branch are nearly equal to those in other branches. Therefore, risks in each branch are equal. Finally, the technique should consider the frequency in which risks of a group to be tested realize. The larger the frequency in which workers face them is, the more the workers pay attention to safety issues. These findings indicate that the safety evaluation system needs several kinds of the standards of comparisons to be applied to evaluate safety levels in wide range of industrial companies. (author)
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Criticality Safety Evaluation of Hanford Tank Farms Facility
Energy Technology Data Exchange (ETDEWEB)
WEISS, E.V.
2000-12-15
Data and calculations from previous criticality safety evaluations and analyses were used to evaluate criticality safety for the entire Tank Farms facility to support the continued waste storage mission. This criticality safety evaluation concludes that a criticality accident at the Tank Farms facility is an incredible event due to the existing form (chemistry) and distribution (neutron absorbers) of tank waste. Limits and controls for receipt of waste from other facilities and maintenance of tank waste condition are set forth to maintain the margin subcriticality in tank waste.
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Criticality Safety Evaluation of Hanford Tank Farms Facility
International Nuclear Information System (INIS)
WEISS, E.V.
2000-01-01
Data and calculations from previous criticality safety evaluations and analyses were used to evaluate criticality safety for the entire Tank Farms facility to support the continued waste storage mission. This criticality safety evaluation concludes that a criticality accident at the Tank Farms facility is an incredible event due to the existing form (chemistry) and distribution (neutron absorbers) of tank waste. Limits and controls for receipt of waste from other facilities and maintenance of tank waste condition are set forth to maintain the margin subcriticality in tank waste
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Evaluation of severe accident safety system value based on averting financial risks
International Nuclear Information System (INIS)
Hatch, S.W.; Benjamin, A.S.; Bennett, P.R.
1983-01-01
The Severe Accident Risk Reduction Program is being performed to benchmark the risks from nuclear power plants and to assess the benefits and impacts of a set of severe accident safety features. This paper describes the program in general and presents some preliminary results. These results include estimates of the financial risks associated with the operation of six reference plants and the value of severe accident prevention and mitigation safety systems in averting these risks. The results represent initial calculations and will be iterated before being used to support NRC decisions
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Energy Technology Data Exchange (ETDEWEB)
Kim, Hee Chul; Kim, Woong Sik; Lee, J. H. [Korea Institute of Nuclear Safety, Taejeon (Korea)
2002-03-01
The Nuclear Desalination Plant (NDP) is being developed to produce electricity and fresh water, and is expected to locate near population zone. In the aspect of safety, it is required to protect the public and environment from the possible releases of fission products and to prevent the fresh water from the contamination of radioactivity. Thus, in this study, the safety characteristics of the integral reactor adopting passive and inherent safety features significantly different from existing nuclear power plants were investigated. Also, safety requirements applicable to the NDP were analyzed based on the regulatory requirements for current light water reactor and advanced reactor designs, and user requirements for small-medium size reactors. Based on these analyses, some safety concerns to be considered in the design stage have been identified and discussed. They include the use of proven technology for new safety features, systematic event classification and selection, strengthening containment function, and the safety impacts on desalination-related systems. The study presents the general safety requirements applicable to licensing of an integral reactor and suggests additional regulatory requirements, which need to be developed, based on the direction to resolution of the safety concerns. The efforts to identify and technically resolve the safety concerns in the design stage will provide the early confidence of SMART safety and the technical basis to evaluate the safety to designers and reviewers in the future. Suggestion on the development of additional regulatory requirements will contribute for the regulator to taking actions for licensing of an integral reactor. 66 refs., 5 figs., 24 tabs. (Author)
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Preliminary safety evaluation for 241-C-106 waste retrieval, project W-320
International Nuclear Information System (INIS)
Conner, J.C.
1994-01-01
This document presents the Preliminary Safety Evaluation for Project W-320, Tank 241-C-106 Waste Retrieval Sluicing System (WRSS). The US DOE has been mandated to develop plans for response to safety issues associated with the waste storage tanks at the Hanford Site, and to report the progress of implementing those plans to Congress. The objectives of Project W-230 are to design, fabricate, develop, test, and operate a new retrieval system capable of removing a minimum of about 75% of the high-heat waste contained in C-106. It is anticipated that sluicing operations can remove enough waste to reduce the remaining radiogenic heat load to levels low enough to resolve the high-heat safety issue as well as allow closure of the tank safety issue
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A Methodology for Evaluating Quantitative Nuclear Safety Culture Impact
Energy Technology Data Exchange (ETDEWEB)
Han, Kiyoon; Jae, Moosung [Hanyang University, Seoul (Korea, Republic of)
2015-05-15
Through several accidents of NPPs including the Fukushima Daiichi in 2011 and Chernobyl accidents in 1986, nuclear safety culture has been emphasized in reactor safety world-widely. In Korea, KHNP evaluates the safety culture of NPP itself. KHNP developed the principles of the safety culture in consideration of the international standards. A questionnaire and interview questions are also developed based on these principles and it is used for evaluating the safety culture. However, existing methodology to evaluate the safety culture has some disadvantages. First, it is difficult to maintain the consistency of the assessment. Second, the period of safety culture assessment is too long (every two years) so it has limitations in preventing accidents occurred by a lack of safety culture. Third, it is not possible to measure the change in the risk of NPPs by weak safety culture since it is not clearly explains the effect of safety culture on the safety of NPPs. In this study, Safety Culture Impact Assessment Model (SCIAM) is developed overcoming these disadvantages. In this study, SCIAM which overcoming disadvantages of exiting safety culture assessment method is developed. SCIAM uses SCII to monitor the statues of the safety culture periodically and also uses RCDF to quantify the safety culture impact on NPP's safety. It is significant that SCIAM represents the standard of the healthy nuclear safety culture, while the exiting safety culture assessment presented only vulnerability of the safety culture of organization. SCIAM might contribute to monitoring the level of safety culture periodically and, to improving the safety of NPP.
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A Methodology for Evaluating Quantitative Nuclear Safety Culture Impact
International Nuclear Information System (INIS)
Han, Kiyoon; Jae, Moosung
2015-01-01
Through several accidents of NPPs including the Fukushima Daiichi in 2011 and Chernobyl accidents in 1986, nuclear safety culture has been emphasized in reactor safety world-widely. In Korea, KHNP evaluates the safety culture of NPP itself. KHNP developed the principles of the safety culture in consideration of the international standards. A questionnaire and interview questions are also developed based on these principles and it is used for evaluating the safety culture. However, existing methodology to evaluate the safety culture has some disadvantages. First, it is difficult to maintain the consistency of the assessment. Second, the period of safety culture assessment is too long (every two years) so it has limitations in preventing accidents occurred by a lack of safety culture. Third, it is not possible to measure the change in the risk of NPPs by weak safety culture since it is not clearly explains the effect of safety culture on the safety of NPPs. In this study, Safety Culture Impact Assessment Model (SCIAM) is developed overcoming these disadvantages. In this study, SCIAM which overcoming disadvantages of exiting safety culture assessment method is developed. SCIAM uses SCII to monitor the statues of the safety culture periodically and also uses RCDF to quantify the safety culture impact on NPP's safety. It is significant that SCIAM represents the standard of the healthy nuclear safety culture, while the exiting safety culture assessment presented only vulnerability of the safety culture of organization. SCIAM might contribute to monitoring the level of safety culture periodically and, to improving the safety of NPP
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Safety significance of ATR passive safety response attributes
International Nuclear Information System (INIS)
Atkinson, S.A.
1990-01-01
The Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory was designed with some passive safety response attributes which contribute to the safety of the facility. The three passive safety attributes being evaluated in the paper are: 1) In-core and in-vessel natural convection cooling, 2) a passive heat sink capability of the ATR primary coolant system (PCS) for the transfer of decay power from the uninsulated piping to the confinement, and 3) gravity feed of emergency coolant makeup. The safety significance of the ATR passive safety response attributes is that the reactor can passively respond to most transients, given a reactor scram, to provide adequate decay power removal and a significant time for operator action should the normal active heat removal systems and their backup systems both fail. The ATR Interim Level 1 Probabilistic Risk Assessment (PRA) models and results were used to evaluate the significance to ATR fuel damage frequency (or probability) of the above three passive response attributes. The results of the evaluation indicate that the first attribute is a major safety characteristic of the ATR. The second attribute has a noticeable but only minor safety significance. The third attribute has no significant influence on the ATR firewater injection system (emergency coolant system)
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Safety evaluation status report for the prototype license application safety analysis report
International Nuclear Information System (INIS)
1989-07-01
The US Nuclear Regulatory Commission (NRC) staff and consultants reviewed a Prototype License Application Safety Analysis Report (PLASAR) submitted by the US Department of Energy (DOE) for the earth-mounded concrete bunker (EMCB) alternative method of low-level radioactive waste disposal. The NRC reviewers relied extensively on the Standard Review Plan (SRP), Rev.1 (NUREG-1200), to evaluate the acceptability of the information provided in the EMCB PLASAR. The NRC staff selected certain review areas in the PLASAR for development of safety evaluation report input to provide examples of safety assessments that are necessary as part of a licensing review. Because of the fictitious nature of the assumed disposal site, and the decision to limit the review to essentially first-round review status, the NRC staff report is labeled a ''Safety Evaluation Status Report'' (SESR). Appendix A comprises the NRC review comments and questions on the information that DOE submitted in the PLASAR. The NRC concentrated its review on the design and operations-related portions of the EMCB PLASAR
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A tool for safety evaluations of road improvements.
Peltola, Harri; Rajamäki, Riikka; Luoma, Juha
2013-11-01
Road safety impact assessments are requested in general, and the directive on road infrastructure safety management makes them compulsory for Member States of the European Union. However, there is no widely used, science-based safety evaluation tool available. We demonstrate a safety evaluation tool called TARVA. It uses EB safety predictions as the basis for selecting locations for implementing road-safety improvements and provides estimates of safety benefits of selected improvements. Comparing different road accident prediction methods, we demonstrate that the most accurate estimates are produced by EB models, followed by simple accident prediction models, the same average number of accidents for every entity and accident record only. Consequently, advanced model-based estimates should be used. Furthermore, we demonstrate regional comparisons that benefit substantially from such tools. Comparisons between districts have revealed significant differences. However, comparisons like these produce useful improvement ideas only after taking into account the differences in road characteristics between areas. Estimates on crash modification factors can be transferred from other countries but their benefit is greatly limited if the number of target accidents is not properly predicted. Our experience suggests that making predictions and evaluations using the same principle and tools will remarkably improve the quality and comparability of safety estimations. Copyright © 2013 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Hendrix, B.L.
1991-01-01
A primary goal of the Superconducting Super Collider Laboratory (SSCL) is to establish an exemplary safety program. Achieving this goal requires leadership, planning, coordination, and technical know-how. To ensure that safety is an inherent part of the design, the Environment, Safety and Health Office employs a systems engineering discipline and process known as System Safety. The goal of System Safety - hazard prevention - is accomplished by analyzing systems to identify hazards and to evaluate design and procedural options and countermeasures to prevent, eliminate, mitigate, or control hazards and risks. Establishment of safety and human factors design criteria at the outset of the project prevents unsafe designs and safety violations, reduces risks, and helps in avoiding costly design changes later. This process requires a considerable amount of coordination with a variety of technical disciplines and safety professionals to integrate methods of hazard prevention, mitigation, and risk reduction throughout the system life-cycle
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International Nuclear Information System (INIS)
Collins, E.K.
1979-08-01
Three separate reviews of the Turkey Point Units 3 and 4 were conducted by the FPLCO between 1972 and 1975. Initially, at the request of NBC in 1972, the FPLCO reviewed several water systems as sources of flooding. Subsequently, as a result of an abnormal occurrence, the drainage system was reviewed. Finally, the facilities were again reviewed at NRC's request and both the potential sources of flooding and safety-related equipment which could be damaged by flooding were identified. The sources of flooding and the appropriate safety equipment are discussed. An evaluation is presented of measures that were taken by FPLCO to minimize the danger of flooding and to protect safety-related equipment
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Trial evaluations in comparison with the 1983 safety goals
International Nuclear Information System (INIS)
Riggs, R.; Sege, G.
1985-06-01
This report provides retrospective comparisons of selected generic regulatory actions to the 1983 NRC safety goals, which had been issued for evaluation during a two-year period. The issues covered are those analyzed by the Office of Nuclear Reactor Regulation (NRR) (assisted in some cases by the Battelle Pacific Northwest Laboratory). The issues include auxiliary feedwater reliability, pressurized thermal shock, power-operated relief valve isolation, asymmetric blowdown loads on PWR primary systems, pool dynamic loads for BWR containments, and steam generator tube rupture. Calculated core-melt frequencies, mortality risks, and cost-benefit ratios are compared with the corresponding safety-goal quantitative design objectives. Considerations that should influence interpretation of the comparisons are discussed. Comments are included on whether and how the safety goals may have helped in the regulatory decision process and on problems encountered
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Priority ranking of safety-related systems for structural assessment at Savannah River Site
International Nuclear Information System (INIS)
Kao, G.C.; Daugherty, W.L.; Barnes, D.M.
1993-01-01
In order to extend the service life of safety related structures and systems in a logical manner, a Structural Enhancement Program was initiated to evaluate the structural integrity of eight systems, namely: cooling water system, emergency cooling system, moderator recovery system, supplementary safety system, water removal system, service raw water system, service clarified water system, and river water system. Since the level of importance of each system to reactor operations varies from one system to another, the scope of structural integrity evaluation for each system should be prioritized accordingly. This paper presents the assessment of system priority for structural evaluation based on a ranking methodology and specifies the level of structural evaluation consistent with the established priority. The effort was undertaken by a five-member panel representing four major disciplines, including: structures, reactor engineering/operations, risk management, and materials. The above systems were divided into a total of thirty-five subsystems. These subsystems were then ranked with six attributes, namely: safety classification, degradation mechanisms, difficulty of replacement, failure mode, radiation dose to workers, and consequence of failure. Each attribute was assigned a set of consequences or events with corresponding weighting scores. The results of the ranking process yielded two groups of subsystems, categorized as Priority I and II subsystems. The level of structural assessment was then formulated accordingly. The prioritized approach will allow more efficient allocation of resources, so that the Structural Enhancement Program can be implemented in a cost-effective and efficient manner
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Use of the event tree method for evaluate the safety of radioactive facilities
International Nuclear Information System (INIS)
Hernandez S, A.; Cornejo D, N.; Callis F, E.
2006-01-01
The work shows the validity of the use of Trees of Events like a quantitative method appropriate to carry out evaluations of radiological safety. Its were took like base the evaluations of safety of five Radiotherapy Departments, carried out in the mark of the process of authorization of these facilities. The risk values were obtained by means of the combination of the probabilities of occurrence of the events with its consequences. The use of the method allowed to suggest improvements to the existent safety systems, as well as to confirm that the current regulator requirements for this type of facilities to lead to practices with acceptable risk levels. (Author)
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International Nuclear Information System (INIS)
Jung, Jae Cheon; Chang, Hoon Seon; Chang, Young Woo; Kim, Jae Hack; Sohn, Se Do
2005-01-01
The major issues of the safety critical software are formalism and V and V. Implementing these two characteristics in the safety critical software will greatly enhance the quality of software product. The structure based development requires lots of output documents from the requirements phase to the testing phase. The requirements analysis phase is open omitted. According to the Standish group report in 2001, 49% of software project is cancelled before completion or never implemented. In addition, 23% is completed and become operational, but over-budget, over the time estimation, and with fewer features and functions than initially specified. They identified ten success factors. Among them, firm basic requirements and formal methods are technically achievable factors while the remaining eight are management related. Misunderstanding of requirements due to lack of communication between the design engineer and verification engineer causes unexpected result such as functionality error of system. Safety critical software shall comply with such characteristics as; modularity, simplicity, minimizing the sub-routine, and excluding the interrupt routine. In addition, the crosslink fault and erroneous function shall be eliminated. The easiness of repairing work after the installation shall be achieved as well. In consideration of the above issues, we evaluate the model driven development (MDD) methods for nuclear I and C systems software. For qualitative analysis, the unified modeling language (UML), functional block language (FBL) and the safety critical application environment (SCADE) are tested for the above characteristics
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[Implementation of a safety and health planning system in a teaching hospital].
Mariani, F; Bravi, C; Dolcetti, L; Moretto, A; Palermo, A; Ronchin, M; Tonelli, F; Carrer, P
2007-01-01
University Hospital "L. Sacco" had started in 2006 a two-year project in order to set up a "Health and Safety Management System (HSMS)" referring to the technical guideline OHSAS 18001:1999 and the UNI and INAIL "Guidelines for a health and safety management system at workplace". So far, the following operations had been implemented: Setting up of a specific Commission within the Risk Management Committee; Identification and appointment of Departmental Representatives of HSMS; Carrying out of a training course addressed to Workers Representatives for Safety and Departmental Representatives of HSMS; Development of an Integrated Informative System for Prevention and Safety; Auditors qualification; Inspection of the Occupational Health Unit and the Prevention and Safety Service: reporting of critical situations and monitoring solutions adopted. Short term objectives are: Self-evaluation through check-lists of each department; Sharing of the Improvement Plan among the departments of the hospital; Planning of Health and Safety training activities in the framework of the Hospital Training Plan; Safety audit.
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Establishment of Safety Analysis System and Technology for CANDU Reactors
International Nuclear Information System (INIS)
Min, Byung Joo; Kim, W. Y.; Kim, H. T.; Rhee, B. W.; Yoon, C.; Kang, H. S.; Yoo, K. J.
2005-03-01
To improve the CANDU design/operation safety analysis codes and the CANDU safety analysis methodology, the following works have been done. From the development of the lattice codes (WIMS/CANDU), the lattice model simulates the real core lattice geometry and the effect of the pressure tube creep to the core lattice parameter has been evaluated. From the development of the 3-dimensional thermal-hydraulic analysis model of the moderator behavior (CFX4-CAMO), validation of the model against STERN Lab experiment has been executed. The butterfly-shaped grid structure and the 3-dimensional flow resistance model for porous media were developed and applied to the moderator analysis for Wolsong units 2/3/4. The single fuel channel analysis codes for blowdown and post-blowdown were unified by CATHENA. The 3-dimensional fuel channel analysis model (CFX-CACH) has been developed for validation of CATHENA fuel channel analysis model. The interlinking analysis system (CANVAS) of the thermal-hydraulic safety analysis codes for the primary heat transport system and containment system has been executed. The database system of core physics and thermal-hydraulics experimental data for safety analysis has been established on the URL: http://CANTHIS.kaeri.re.kr. For documentation and Standardization of the general safety analysis procedure, the general safety analysis procedure is developed and applied to a large break LOCA. The present research results can be utilized for establishment of the independent safety analysis technology and acquisition of the optimal safety analysis technology
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International Nuclear Information System (INIS)
Zorrilla R, S.H.
1978-01-01
In this work we made a safety evaluation of the liquid radioactive effluents system in a plant using a BWR similar to that now installed in Laguna Verde. For that purpose, the computation program ORIGENwas modified, in order to keep up to date and adapt it to the PDP 10 computer, which is operating at the Computation Department of the Nuclear Center of Mexico, the code LIQM03 was the result of this modification. As usual in this work we dealt with problems which were solved opportunely, now we have at our disposal the code LIQM03 which will be in the future a very useful tool for this kind of evaluations. (author)
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Firefighter safety for PV systems: Overview of future requirements and protection systems
DEFF Research Database (Denmark)
Spataru, Sergiu; Sera, Dezso; Blaabjerg, Frede
2013-01-01
for operators during maintenance or fire-fighting. One of the solutions is individual module shutdown by short-circuiting or disconnecting each PV module from the PV string. However, currently no standards have been adopted either for implementing or testing these methods, or doing an evaluation of the module...... shutdown procedures. This paper gives an overview on the most recent fire - and firefighter safety requirements for PV systems, with focus on system and module shutdown systems. Several solutions are presented, analyzed and compared by considering a number of essential characteristics, including......An important and highly discussed safety issue for photovoltaic systems is that, as long as they are illuminated, a high voltage is present at the PV string terminals and cables between the string and inverters, independent of the state of the inverter's dc disconnection switch, which poses a risk...
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Safety analysis for the use of new digital safety I and C systems
International Nuclear Information System (INIS)
Buehler, Cornelia
2012-01-01
Age-induced replacement or modernization of safety I and C systems by digital equipment technology has been one of the topical subjects in nuclear technology for more than a decade. Digital equipment technology in this case means microcontroller- or microprocessor-based systems which implement I and C functions in software (SW) and, on the other hand, systems with programmed hardware (HW) components, such as Application-specific Integrated Circuits (ASIC), Field Programmable Gate Arrays (FPGA) or Programmable Logic Devices (PLS), which can be developed only by means of sophisticated SW development environments. The switch to digital equipment technology is more than a mere change in equipment technology even though the I and C functions remain almost identical in most cases. The switch not only leads to a different approach in equipment qualification, but also requires new focal points in plant design when it comes to assessing plant design, and needs new or adapted methods of analysis and evaluation. The main reason lies in the greater possibilities of systematic errors caused mainly by software-based development, manufacture and maintenance. New and adapted methods of analysis and evaluation for I and C systems are presented and explained. It is safe to say that safety I and C technology in the highest category of requirements necessitates a very far reaching realignment in design and evaluation as well as the use of new analytical techniques. This meets the claim of an I and C technology fit for use, reliable and comparable to the technology it replaces. (orig.)
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Exploration of nuclear power enterprise 'STAR' management performance evaluation system
International Nuclear Information System (INIS)
Wang Sen
2005-01-01
From the angle of nuclear power enterprise safety culture, this essay breaks the connotations of the safety culture down to nine aspects (target management, safety management, quality management, housekeeping, cost control, authorization management, teamwork, communication and continued improvement), with each aspect divided into five levels of star class according to its own characteristics. A comparison is made between the actualities of the enterprise and star management performance evaluation system to find out the gap and identify ways of continued improvement to elevate the enterprise management level, thereby developing a standard system of conducting qualitative and quantitative evaluation to the management process. Apart from its evaluation function, this system provides a guideline on the work orientation, method, and steps to elevate work level and capability for the managers performing specific management actions. It is also a system of measuring and evaluating the executive force of the company's management and its employees. (author)
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Cropper, Douglas P; Harb, Nidal H; Said, Patricia A; Lemke, Jon H; Shammas, Nicolas W
2018-04-01
We hypothesize that implementation of a safety program based on high reliability organization principles will reduce serious safety events (SSE). The safety program focused on 7 essential elements: (a) safety rounding, (b) safety oversight teams, (c) safety huddles, (d) safety coaches, (e) good catches/safety heroes, (f) safety education, and (g) red rule. An educational curriculum was implemented focusing on changing high-risk behaviors and implementing critical safety policies. All unusual occurrences were captured in the Midas system and investigated by risk specialists, the safety officer, and the chief medical officer. A multidepartmental committee evaluated these events, and a root cause analysis (RCA) was performed. Events were tabulated and serious safety event (SSE) recorded and plotted over time. Safety success stories (SSSs) were also evaluated over time. A steady drop in SSEs was seen over 9 years. Also a rise in SSSs was evident, reflecting on staff engagement in the program. The parallel change in SSEs, SSSs, and the implementation of various safety interventions highly suggest that the program was successful in achieving its goals. A safety program based on high-reliability organization principles and made a core value of the institution can have a significant positive impact on reducing SSEs. © 2018 American Society for Healthcare Risk Management of the American Hospital Association.
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Does the concept of safety culture help or hinder systems thinking in safety?
Reiman, Teemu; Rollenhagen, Carl
2014-07-01
The concept of safety culture has become established in safety management applications in all major safety-critical domains. The idea that safety culture somehow represents a "systemic view" on safety is seldom explicitly spoken out, but nevertheless seem to linger behind many safety culture discourses. However, in this paper we argue that the "new" contribution to safety management from safety culture never really became integrated with classical engineering principles and concepts. This integration would have been necessary for the development of a more genuine systems-oriented view on safety; e.g. a conception of safety in which human, technological, organisational and cultural factors are understood as mutually interacting elements. Without of this integration, researchers and the users of the various tools and methods associated with safety culture have sometimes fostered a belief that "safety culture" in fact represents such a systemic view about safety. This belief is, however, not backed up by theoretical or empirical evidence. It is true that safety culture, at least in some sense, represents a holistic term-a totality of factors that include human, organisational and technological aspects. However, the departure for such safety culture models is still human and organisational factors rather than technology (or safety) itself. The aim of this paper is to critically review the various uses of the concept of safety culture as representing a systemic view on safety. The article will take a look at the concepts of culture and safety culture based on previous studies, and outlines in more detail the theoretical challenges in safety culture as a systems concept. The paper also presents recommendations on how to make safety culture more systemic. Copyright © 2013 Elsevier Ltd. All rights reserved.
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The aviation safety reporting system
Reynard, W. D.
1984-01-01
The aviation safety reporting system, an accident reporting system, is presented. The system identifies deficiencies and discrepancies and the data it provides are used for long term identification of problems. Data for planning and policy making are provided. The system offers training in safety education to pilots. Data and information are drawn from the available data bases.
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Safety equipment and methods for evaluating its effectiveness
Energy Technology Data Exchange (ETDEWEB)
Evdokimov, F I; Nadtoka, T B [DPI (Ukraine)
1993-05-01
Analyzes relations between technologies (especially for roof support) used in black coal mining and work safety in mines. The share of manual work and accident rate are compared for mining by narrow and wide web shearer loaders and by coal plows with powered and individual support. Protection from occupational injury is discussed at three levels: safety engineering, work organization and the human factor. A method of evaluating the social and economic effectiveness of protection from occupational injury developed at the DPI institute is presented. The method uses the knowledge of probability distribution of failure situations, failures and protective means to determine the probabilistic characteristics of the functioning of protection systems and to calculate, for a given period, the occurrence probability and mean number of accidents. Each state of the system is characterized by determined social and/or economic results. The method was used in designing equipment intended for protective power cut-off in electric mine networks.
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Potential toxicity and safety evaluation of nanomaterials for the respiratory system and lung cancer
Directory of Open Access Journals (Sweden)
Vlachogianni T
2013-11-01
potential to cause acute respiratory diseases and probably lung cancer in humans. The situation regarding chronic exposure at low doses is more complicated. The long-term accumulation of ENPs in the respiratory system cannot be excluded. However, at present, exposure data for the general public regarding ENPs are not available. Keywords: engineered nanomaterials, nanoparticles, oxidative stress, inflammation, safety evaluation, respiratory diseases
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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
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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
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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
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Technical self reliance of digital safety systems
Energy Technology Data Exchange (ETDEWEB)
Kwon, Kee Choon; Lee, Dong Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Kook Hun [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Choi, Seung Gap [POSCON, Pohang (Korea, Republic of)
2009-04-15
This paper summarizes the development results of the Korea Nuclear Instrumentation and Control System (KNICS) project sponsored by the Korean government. In this project, Man Machine Interface System (MMIS) architecture, two digital platforms, and several control systems are developed. One platform is a programmable Logic Controller (PLC) for a safety system and another platform is a Distributed Control System (DCS) for a non safety system. With the POSAFE Q PLC, a Reactor Protection System (RPS) and an Engineered Safety Feature Component Control System (ESF CCS) are developed. A Power Control System (PCS) is developed based on the DCS. The safety grade platform and the digital safety systems obtained approval for the Topical Report from the Korean regulatory body in February of 2009. Also a Korean utility and a vendor company determined KNICS results to apply them to the planned Nuclear Power Plant (NPP) in March 2009. This paper introduces the technical self reliance experiences of the safety grade platform and the digital safety systems developed in the KNICS R and D project.
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International Nuclear Information System (INIS)
Lambright, J.; Bohn, M.; Lynch, J.; Ross, S.; Brosseau, D.
1992-12-01
Nuclear power plants have experienced actuations of fire protection systems (FPSs) under conditions for which these systems were not intended to actuate and also have experienced advertent actuations with the presence of a fire. These actuations have often damaged safety-related equipment. A review of the impact of past occurrences of both types of such events and their impact on plant safety systems, an analysis of the risk impacts of such events on nuclear power plant safety, and a cost-benefit analysis of potential corrective measures have been performed. Thirteen different scenarios leading to actuation of fire protection systems due to a variety of causes were identified. These scenarios ranged from inadvertent actuation caused by human error to hardware failure, and include seismic root causes and seismic/fire interactions. A quantification of these thirteen root causes, where applicable, was performed on generically applicable scenarios. This document, Volume 4, contains appendices E and F of this report
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Integrating system safety into the basic systems engineering process
Griswold, J. W.
1971-01-01
The basic elements of a systems engineering process are given along with a detailed description of what the safety system requires from the systems engineering process. Also discussed is the safety that the system provides to other subfunctions of systems engineering.
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International Nuclear Information System (INIS)
Neall, Fiona; Pastina, Barbara; Snellman, Margit; Smith, Paul; Gribi, P.; Johnson, Lawrence
2008-12-01
The KBS-3H design is a variant of the more general KBS-3 method for the geological disposal of spent nuclear fuel in Finland and Sweden. In the KBS-3H design, multiple assemblies containing spent fuel are emplaced horizontally in parallel, approximately 300 m long, slightly inclined deposition drifts. The copper canisters, each with a surrounding layer of bentonite clay, are placed in perforated steel shells prior to deposition in the drifts; the assembly is called the 'supercontainer'. The other KBS-3 variant is the KBS-3V design, in which the copper canisters are emplaced vertically in individual deposition holes surrounded by bentonite clay but without steel supercontainer shells. SKB and Posiva have conducted a Research, Development and Demonstration programme over the period 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to KBS-3V. As part of this programme, the long-term safety of a KBS-3H repository has been assessed in the KBS-3H safety studies. In order to focus the safety studies, the Olkiluoto site in the municipality of Eurajoki, which is the proposed site for a spent fuel repository in Finland, was used as a hypothetical site for a KBS-3H repository. The present report is part of a portfolio of reports discussing the long-term safety of the KBS-3H repository. The overall outcome of the KBS-3H safety studies is documented in the summary report, 'Safety assessment for a KBS-3H repository for spent nuclear fuel at Olkiluoto'. The purpose and scope of the KBS-3H complementary evaluations of safety report is provided in Posiva's Safety Case Plan, which is based on Regulatory Guide YVL 8.4 and on international guidelines on complementary lines of argument to long-term safety that are considered an important element of a post-closure safety case for geological repositories. Complementary evaluations of safety require the use of evaluations, evidence and qualitative supporting arguments that lie outside the
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Programmable Electronic Safety Systems
International Nuclear Information System (INIS)
Parry, R.
1993-05-01
Traditionally safety systems intended for protecting personnel from electrical and radiation hazards at particle accelerator laboratories have made extensive use of electromechanical relays. These systems have the advantage of high reliability and allow the designer to easily implement failsafe circuits. Relay based systems are also typically simple to design, implement, and test. As systems, such as those presently under development at the Superconducting Super Collider Laboratory (SSCL), increase in size, and the number of monitored points escalates, relay based systems become cumbersome and inadequate. The move toward Programmable Electronic Safety Systems is becoming more widespread and accepted. In developing these systems there are numerous precautions the designer must be concerned with. Designing fail-safe electronic systems with predictable failure states is difficult at best. Redundancy and self-testing are prime examples of features that should be implemented to circumvent and/or detect failures. Programmable systems also require software which is yet another point of failure and a matter of great concern. Therefore the designer must be concerned with both hardware and software failures and build in the means to assure safe operation or shutdown during failures. This paper describes features that should be considered in developing safety systems and describes a system recently installed at the Accelerator Systems String Test (ASST) facility of the SSCL
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An evaluation of safety-critical Java on a Java processor
Rios Rivas, Juan Ricardo; Schoeberl, Martin
2014-01-01
The safety-critical Java (SCJ) specification provides a restricted set of the Java language intended for applications that require certification. In order to test the specification, implementations are emerging and the need to evaluate those implementations in a systematic way is becoming important. In this paper we evaluate our SCJ implementation which is based on the Java Optimized Processor JOP and we measure different performance and timeliness criteria relevant to hard real-time systems....
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Software Safety Analysis of Digital Protection System Requirements Using a Qualitative Formal Method
International Nuclear Information System (INIS)
Lee, Jang-Soo; Kwon, Kee-Choon; Cha, Sung-Deok
2004-01-01
The safety analysis of requirements is a key problem area in the development of software for the digital protection systems of a nuclear power plant. When specifying requirements for software of the digital protection systems and conducting safety analysis, engineers find that requirements are often known only in qualitative terms and that existing fault-tree analysis techniques provide little guidance on formulating and evaluating potential failure modes. A framework for the requirements engineering process is proposed that consists of a qualitative method for requirements specification, called the qualitative formal method (QFM), and a safety analysis method for the requirements based on causality information, called the causal requirements safety analysis (CRSA). CRSA is a technique that qualitatively evaluates causal relationships between software faults and physical hazards. This technique, extending the qualitative formal method process and utilizing information captured in the state trajectory, provides specific guidelines on how to identify failure modes and the relationship among them. The QFM and CRSA processes are described using shutdown system 2 of the Wolsong nuclear power plants as the digital protection system example
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First investigations on the safety evaluation of smart sensors
Energy Technology Data Exchange (ETDEWEB)
Bousquet, S.; Elsensohn, O. [CEA Fontenay aux Roses, 92 (France). Inst. de Protection et de Surete Nucleaire; Benoit, G. [CEA Saclay, Dir. de la Recherche Technologique DRT, 91 - Gif sur Yvette (France)
2001-10-01
IPSN (Institute for Protection and Nuclear Safety) is the technical support for the French nuclear safety authority and thus involved in the safety evaluation of new I and C technologies and particularly of smart sensors. Smart sensors are characterized by the use of a microprocessor that converts the process variable into digital signals and exchanges other information with I and C control systems. There are two types of smart sensors: HART (Highway Addressable Remote Transducer) sensors, which provide both analogue (4 to 20 mA) and digital signals, and network sensors, which provide only digital signals. The expected benefits for operators are improved accuracy and reliability and cost savings in installation, commissioning, testing and maintenance. Safety evaluation of these smart sensors raises new issues: How does the sensor react to unknown commands? How to avoid unexpected changes in configuration? What is its sensitivity to electromagnetic interferences (EMI), to radiations...? In order to evaluate whether these sensors can be qualified for a safety application and to define the qualification tests to be done, IPSN has planned some functional and hardware tests (EMI, radiations) on 'HART' and field bus sensors. During the functional tests, we were not able to disrupt the HART tested sensors by invalid commands. However, these results cannot be extended to other sensors, because of the use of different technology, of different versions of hardware and software and of constructors' specific commands. Furthermore, easy modifications of configuration parameters can cause additional failures. Environmental tests are in progress on HART sensors and will be followed by experiments on field bus sensors. These preliminary investigations and the latest incident initiated by an incorrect computing algorithm of digital switchgear at Ringhals NPP, clearly illustrate that testing and verification programmes for smart equipment must be meticulously designed
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First investigations on the safety evaluation of smart sensors
International Nuclear Information System (INIS)
Bousquet, S.; Elsensohn, O.
2001-10-01
IPSN (Institute for Protection and Nuclear Safety) is the technical support for the French nuclear safety authority and thus involved in the safety evaluation of new I and C technologies and particularly of smart sensors. Smart sensors are characterized by the use of a microprocessor that converts the process variable into digital signals and exchanges other information with I and C control systems. There are two types of smart sensors: HART (Highway Addressable Remote Transducer) sensors, which provide both analogue (4 to 20 mA) and digital signals, and network sensors, which provide only digital signals. The expected benefits for operators are improved accuracy and reliability and cost savings in installation, commissioning, testing and maintenance. Safety evaluation of these smart sensors raises new issues: How does the sensor react to unknown commands? How to avoid unexpected changes in configuration? What is its sensitivity to electromagnetic interferences (EMI), to radiations...? In order to evaluate whether these sensors can be qualified for a safety application and to define the qualification tests to be done, IPSN has planned some functional and hardware tests (EMI, radiations) on 'HART' and field bus sensors. During the functional tests, we were not able to disrupt the HART tested sensors by invalid commands. However, these results cannot be extended to other sensors, because of the use of different technology, of different versions of hardware and software and of constructors' specific commands. Furthermore, easy modifications of configuration parameters can cause additional failures. Environmental tests are in progress on HART sensors and will be followed by experiments on field bus sensors. These preliminary investigations and the latest incident initiated by an incorrect computing algorithm of digital switchgear at Ringhals NPP, clearly illustrate that testing and verification programmes for smart equipment must be meticulously designed and reviewed
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International Nuclear Information System (INIS)
1994-08-01
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the System 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR section 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of Abb-CE's System 80 design from which it evolved. Unique features of the System 80+ design included: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors, and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE's application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 1, contains Chapters 1 through 14 of this report
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Schneider, Eric C; Ridgely, M Susan; Quigley, Denise D; Hunter, Lauren E; Leuschner, Kristin J; Weingart, Saul N; Weissman, Joel S; Zimmer, Karen P; Giannini, Robert C
2017-06-01
This article describes the design, development, and testing of the Health Care Safety Hotline, a prototype consumer reporting system for patient safety events. The prototype was designed and developed with ongoing review by a technical expert panel and feedback obtained during a public comment period. Two health care delivery organizations in one metropolitan area collaborated with the researchers to demonstrate and evaluate the system. The prototype was deployed and elicited information from patients, family members, and caregivers through a website or an 800 phone number. The reports were considered useful and had little overlap with information received by the health care organizations through their usual risk management, customer service, and patient safety monitoring systems. However, the frequency of reporting was lower than anticipated, suggesting that further refinements, including efforts to raise awareness by actively soliciting reports from subjects, might be necessary to substantially increase the volume of useful reports. It is possible that a single technology platform could be built to meet a variety of different patient safety objectives, but it may not be possible to achieve several objectives simultaneously through a single consumer reporting system while also establishing trust with patients, caregivers, and providers.
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International handbook of evaluated criticality safety benchmark experiments
International Nuclear Information System (INIS)
2010-01-01
The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the United States Department of Energy. The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) became an official activity of the Organization for Economic Cooperation and Development - Nuclear Energy Agency (OECD-NEA) in 1995. This handbook contains criticality safety benchmark specifications that have been derived from experiments performed at various nuclear critical facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculational techniques used to establish minimum subcritical margins for operations with fissile material and to determine criticality alarm requirement and placement. Many of the specifications are also useful for nuclear data testing. Example calculations are presented; however, these calculations do not constitute a validation of the codes or cross section data. The evaluated criticality safety benchmark data are given in nine volumes. These volumes span over 55,000 pages and contain 516 evaluations with benchmark specifications for 4,405 critical, near critical, or subcritical configurations, 24 criticality alarm placement / shielding configurations with multiple dose points for each, and 200 configurations that have been categorized as fundamental physics measurements that are relevant to criticality safety applications. Experiments that are found unacceptable for use as criticality safety benchmark experiments are discussed in these evaluations; however, benchmark specifications are not derived for such experiments (in some cases models are provided in an appendix). Approximately 770 experimental configurations are categorized as unacceptable for use as criticality safety benchmark experiments. Additional evaluations are in progress and will be
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Carden, Tony; Goode, Natassia; Read, Gemma J M; Salmon, Paul M
2017-03-15
Like most work systems, the domain of adventure activities has seen a series of serious incidents and subsequent calls to improve regulation. Safety regulation systems aim to promote safety and reduce accidents. However, there is scant evidence they have led to improved safety outcomes. In fact there is some evidence that the poor integration of regulatory system components has led to adverse safety outcomes in some contexts. Despite this, there is an absence of methods for evaluating regulatory and compliance systems. This article argues that sociotechnical systems theory and methods provide a suitable framework for evaluating regulatory systems. This is demonstrated through an analysis of a recently introduced set of adventure activity regulations. Work Domain Analysis (WDA) was used to describe the regulatory system in terms of its functional purposes, values and priority measures, purpose-related functions, object-related processes and cognitive objects. This allowed judgement to be made on the nature of the new regulatory system and on the constraints that may impact its efficacy following implementation. Importantly, the analysis suggests that the new system's functional purpose of ensuring safe activities is not fully supported in terms of the functions and objects available to fulfil them. Potential improvements to the design of the system are discussed along with the implications for regulatory system design and evaluation across the safety critical domains generally. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Validation of risk-based performance indicators: Safety system function trends
International Nuclear Information System (INIS)
Boccio, J.L.; Vesely, W.E.; Azarm, M.A.; Carbonaro, J.F.; Usher, J.L.; Oden, N.
1989-10-01
This report describes and applies a process for validating a model for a risk-based performance indicator. The purpose of the risk-based indicator evaluated, Safety System Function Trend (SSFT), is to monitor the unavailability of selected safety systems. Interim validation of this indicator is based on three aspects: a theoretical basis, an empirical basis relying on statistical correlations, and case studies employing 25 plant years of historical data collected from five plants for a number of safety systems. Results using the SSFT model are encouraging. Application of the model through case studies dealing with the performance of important safety systems shows that statistically significant trends in, and levels of, system performance can be discerned which thereby can provide leading indications of degrading and/or improving performances. Methods for developing system performance tolerance bounds are discussed and applied to aid in the interpretation of the trends in this risk-based indicator. Some additional characteristics of the SSFT indicator, learned through the data-collection efforts and subsequent data analyses performed, are also discussed. The usefulness and practicality of other data sources for validation purposes are explored. Further validation of this indicator is noted. Also, additional research is underway in developing a more detailed estimator of system unavailability. 9 refs., 18 figs., 5 tabs
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Safety evaluation of the Dalat research reactor operation
International Nuclear Information System (INIS)
Long, V.H.; Lam, P.V.; An, T.K.
1989-01-01
After an introduction presenting the essential characteristics of the Dalat Nuclear Research Reactor, the document presents i) The safety assurance condition of the reactor, ii) Its safety behaviour after 5 years of operation, iii) Safety research being realized on the reactor. Following is questionnaire of safety evaluation and a list of attachments, which concern the reactor
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Statistical evaluation of information reported to ISI and ISKO systems from a safety point of view
International Nuclear Information System (INIS)
Alonso Pallares, C.
1993-01-01
This paper describes he event percentages made by the main systems or equipment groups being the cause of incidents or directly linked to the incident. Command and protection systems, first-circuit equipment (BPC, VPC, volume compensator) safety systems, reactor installation and electrical input systems are analyzed. More over the main causes of notifies events are stressed and those where operation experience obtained in WWER-type nuclear power plants shows that and important part of incidents related to safety are due to personnel errors
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On safety classification of instrumentation and control systems and their components
International Nuclear Information System (INIS)
Yastrebenetskij, M.A.; Rozen, Yu.V.
2004-01-01
Safety classification of instrumentation and control systems (I and C) and their components (hardware, software, software-hardware complexes) is described: - evaluation of classification principles and criteria in Ukrainian standards and rules; comparison between Ukrainian and international principles and criteria; possibility and ways of coordination of Ukrainian and international standards related to (I and C) safety classification
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Considerations on nuclear reactor passive safety systems
International Nuclear Information System (INIS)
2016-01-01
After having indicated some passive safety systems present in electronuclear reactors (control bars, safety injection system accumulators, reactor cooling after stoppage, hydrogen recombination systems), this report recalls the main characteristics of passive safety systems, and discusses the main issues associated with the assessment of new passive systems (notably to face a sustained loss of electric supply systems or of cold water source) and research axis to be developed in this respect. More precisely, the report comments the classification of safety passive systems as it is proposed by the IAEA, outlines and comments specific aspects of these systems regarding their operation and performance. The next part discusses the safety approach, the control of performance of safety passive systems, issues related to their reliability, and the expected contribution of R and D (for example: understanding of physical phenomena which have an influence of these systems, capacities of simulation of these phenomena, needs of experimentations to validate simulation codes)
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Evaluating the Long-Term Safety of a Repository at Yucca Mountain
International Nuclear Information System (INIS)
Luik, Abe Van
2002-01-01
Regulations require that the repository be evaluated for its health and safety effects for 10,000 years for the Site Recommendation process. Regulations also require potential impacts to be evaluated for up to a million years in an Environmental Impact Statement. The Yucca Mountain Project is in the midst of the Site Recommendation process. The Total System Performance Assessment (TSPA) that supports the Site Recommendation evaluated safety for these required periods of time. Results showed it likely that a repository at this site could meet the licensing requirements promulgated by the Nuclear Regulatory Commission. The TSPA is the tool that integrates the results of many years of scientific investigations with design information to allow evaluations of potential far-future impacts of building a Yucca Mountain repository. Knowledge created in several branches of physics is part of the scientific basis of the TSPA that supports the Site Recommendation process.
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Methodology for identifying boundaries of systems important to safety in CANDU nuclear power plants
International Nuclear Information System (INIS)
Therrien, S.; Komljenovic, D.; Therrien, P.; Ruest, C.; Prevost, P.; Vaillancourt, R.
2007-01-01
This paper presents a methodology developed to identify the boundaries of the systems important to safety (SIS) at the Gentilly-2 Nuclear Power Plant (NPP), Hydro-Quebec. The SIS boundaries identification considers nuclear safety only. Components that are not identified as important to safety are systematically identified as related to safety. A global assessment process such as WANO/INPO AP-913 'Equipment Reliability Process' will be needed to implement adequate changes in the management rules of those components. The paper depicts results in applying the methodology to the Shutdown Systems 1 and 2 (SDS 1, 2), and to the Emergency Core Cooling System (ECCS). This validation process enabled fine tuning the methodology, performing a better estimate of the effort required to evaluate a system, and identifying components important to safety of these systems. (author)
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Data Analysis of Occupational Health and Safety Management and Total Quality Management Systems
Directory of Open Access Journals (Sweden)
Ahmet Yakut
2013-01-01
Full Text Available In our study, Total Quality Management, Occupational Health and Safety on the effects of the construction industry, building sites of Istanbul evaluated with the results of the survey of 25 firms. For Occupational Health and Safety program, walked healthy, active employees in her role increased and will increase the importance of education. Due to non-implementation of the OHS system in our country enough, work-related accidents and deaths and injuries resulting from these accidents is very high. Firms as a result of the analysis, an effective health and safety management system needs to be able to fulfill their responsibilities. This system is designated as OHSAS 18001 Occupational Health and Safety Management System and the construction industry can be regarded as the imperatives.
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Potential of acoustic monitoring for safety assessment of primary system
International Nuclear Information System (INIS)
Olma, B.J.
1997-01-01
Safety assessment of the primary system and its components with respect to their mechanical integrity is increasingly supported by acoustic signature analysis during power operation of the plants. Acoustic signals of Loose Parts Monitoring System sensors are continuously monitored by dedicated digital systems for signal bursts associated with metallic impacts. Several years of ISTec/GRS experience and the practical use of its digital systems MEDEA and RAMSES have shown that acoustic monitoring is very successful for detecting component failures at an early stage. Advanced powerful tools for classification and acoustic evaluation of burst signals have recently been realized. The paper presents diagnosis experiences of BWR's and PWR's safety assessment. (author). 7 refs, 8 figs
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System safety engineering analysis handbook
Ijams, T. E.
1972-01-01
The basic requirements and guidelines for the preparation of System Safety Engineering Analysis are presented. The philosophy of System Safety and the various analytic methods available to the engineering profession are discussed. A text-book description of each of the methods is included.
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Safety performance monitoring of autonomous marine systems
International Nuclear Information System (INIS)
Thieme, Christoph A.; Utne, Ingrid B.
2017-01-01
The marine environment is vast, harsh, and challenging. Unanticipated faults and events might lead to loss of vessels, transported goods, collected scientific data, and business reputation. Hence, systems have to be in place that monitor the safety performance of operation and indicate if it drifts into an intolerable safety level. This article proposes a process for developing safety indicators for the operation of autonomous marine systems (AMS). The condition of safety barriers and resilience engineering form the basis for the development of safety indicators, synthesizing and further adjusting the dual assurance and the resilience based early warning indicator (REWI) approaches. The article locates the process for developing safety indicators in the system life cycle emphasizing a timely implementation of the safety indicators. The resulting safety indicators reflect safety in AMS operation and can assist in planning of operations, in daily operational decision-making, and identification of improvements. Operation of an autonomous underwater vehicle (AUV) exemplifies the process for developing safety indicators and their implementation. The case study shows that the proposed process leads to a comprehensive set of safety indicators. It is expected that application of the resulting safety indicators consequently will contribute to safer operation of current and future AMS. - Highlights: • Process for developing safety indicators for autonomous marine systems. • Safety indicators based on safety barriers and resilience thinking. • Location of the development process in the system lifecycle. • Case study on AUV demonstrating applicability of the process.
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2013-05-20
... NUCLEAR REGULATORY COMMISSION [NRC-2013-0098] Embedded Digital Devices in Safety-Related Systems, Systems Important to Safety, and Items Relied on for Safety AGENCY: Nuclear Regulatory Commission. ACTION... (NRC) is issuing for public comment Draft Regulatory Issue Summary (RIS) 2013-XX, ``Embedded Digital...
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Disposal systems evaluations and tool development : Engineered Barrier System (EBS) evaluation.
Energy Technology Data Exchange (ETDEWEB)
Rutqvist, Jonny (LBNL); Liu, Hui-Hai (LBNL); Steefel, Carl I. (LBNL); Serrano de Caro, M. A. (LLNL); Caporuscio, Florie Andre (LANL); Birkholzer, Jens T. (LBNL); Blink, James A. (LLNL); Sutton, Mark A. (LLNL); Xu, Hongwu (LANL); Buscheck, Thomas A. (LLNL); Levy, Schon S. (LANL); Tsang, Chin-Fu (LBNL); Sonnenthal, Eric (LBNL); Halsey, William G. (LLNL); Jove-Colon, Carlos F.; Wolery, Thomas J. (LLNL)
2011-01-01
Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems
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Disposal systems evaluations and tool development: Engineered Barrier System (EBS) evaluation
International Nuclear Information System (INIS)
Rutqvist, Jonny; Liu, Hui-Hai; Steefel, Carl I.; Serrano de Caro, M.A.; Caporuscio, Florie Andre; Birkholzer, Jens T.; Blink, James A.; Sutton, Mark A.; Xu, Hongwu; Buscheck, Thomas A.; Levy, Schon S.; Tsang, Chin-Fu; Sonnenthal, Eric; Halsey, William G.; Jove-Colon, Carlos F.; Wolery, Thomas J.
2011-01-01
Key components of the nuclear fuel cycle are short-term storage and long-term disposal of nuclear waste. The latter encompasses the immobilization of used nuclear fuel (UNF) and radioactive waste streams generated by various phases of the nuclear fuel cycle, and the safe and permanent disposition of these waste forms in geological repository environments. The engineered barrier system (EBS) plays a very important role in the long-term isolation of nuclear waste in geological repository environments. EBS concepts and their interactions with the natural barrier are inherently important to the long-term performance assessment of the safety case where nuclear waste disposition needs to be evaluated for time periods of up to one million years. Making the safety case needed in the decision-making process for the recommendation and the eventual embracement of a disposal system concept requires a multi-faceted integration of knowledge and evidence-gathering to demonstrate the required confidence level in a deep geological disposal site and to evaluate long-term repository performance. The focus of this report is the following: (1) Evaluation of EBS in long-term disposal systems in deep geologic environments with emphasis on the multi-barrier concept; (2) Evaluation of key parameters in the characterization of EBS performance; (3) Identification of key knowledge gaps and uncertainties; and (4) Evaluation of tools and modeling approaches for EBS processes and performance. The above topics will be evaluated through the analysis of the following: (1) Overview of EBS concepts for various NW disposal systems; (2) Natural and man-made analogs, room chemistry, hydrochemistry of deep subsurface environments, and EBS material stability in near-field environments; (3) Reactive Transport and Coupled Thermal-Hydrological-Mechanical-Chemical (THMC) processes in EBS; and (4) Thermal analysis toolkit, metallic barrier degradation mode survey, and development of a Disposal Systems
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The Evolution of System Safety at NASA
Dezfuli, Homayoon; Everett, Chris; Groen, Frank
2014-01-01
The NASA system safety framework is in the process of change, motivated by the desire to promote an objectives-driven approach to system safety that explicitly focuses system safety efforts on system-level safety performance, and serves to unify, in a purposeful manner, safety-related activities that otherwise might be done in a way that results in gaps, redundancies, or unnecessary work. An objectives-driven approach to system safety affords more flexibility to determine, on a system-specific basis, the means by which adequate safety is achieved and verified. Such flexibility and efficiency is becoming increasingly important in the face of evolving engineering modalities and acquisition models, where, for example, NASA will increasingly rely on commercial providers for transportation services to low-earth orbit. A key element of this objectives-driven approach is the use of the risk-informed safety case (RISC): a structured argument, supported by a body of evidence, that provides a compelling, comprehensible and valid case that a system is or will be adequately safe for a given application in a given environment. The RISC addresses each of the objectives defined for the system, providing a rational basis for making informed risk acceptance decisions at relevant decision points in the system life cycle.
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Energy Technology Data Exchange (ETDEWEB)
Han, Sangmin; Lee, Seung Min; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)
2015-05-15
IAEA defined safety culture as follows: 'Safety Culture is that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance'. Also, celebrated behavioral scientist, Cooper, defined safety culture as,'safety culture is that observable degree of effort by which all organizational members direct their attention and actions toward improving safety on a daily basis' with his internal psychological, situational, and behavioral context model. With these various definitions and criteria of safety culture, several safety culture assessment methods have been developed to improve and manage safety culture. To develop a new quantitative safety culture evaluation method for an operating team, we unified and redefined safety culture assessment items. Then we modeled a new safety culture evaluation by adopting level 1 PSA concept. Finally, we suggested the criteria to obtain nominal success probabilities of assessment items by using 'operational definition'. To validate the suggested evaluation method, we analyzed the collected audio-visual recording data collected from a full scope main control room simulator of a NPP in Korea.
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International Nuclear Information System (INIS)
Han, Sangmin; Lee, Seung Min; Seong, Poong Hyun
2015-01-01
IAEA defined safety culture as follows: 'Safety Culture is that assembly of characteristics and attitudes in organizations and individuals which establishes that, as an overriding priority, nuclear plant safety issues receive the attention warranted by their significance'. Also, celebrated behavioral scientist, Cooper, defined safety culture as,'safety culture is that observable degree of effort by which all organizational members direct their attention and actions toward improving safety on a daily basis' with his internal psychological, situational, and behavioral context model. With these various definitions and criteria of safety culture, several safety culture assessment methods have been developed to improve and manage safety culture. To develop a new quantitative safety culture evaluation method for an operating team, we unified and redefined safety culture assessment items. Then we modeled a new safety culture evaluation by adopting level 1 PSA concept. Finally, we suggested the criteria to obtain nominal success probabilities of assessment items by using 'operational definition'. To validate the suggested evaluation method, we analyzed the collected audio-visual recording data collected from a full scope main control room simulator of a NPP in Korea
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77 FR 70409 - System Safety Program
2012-11-26
...-0060, Notice No. 2] 2130-AC31 System Safety Program AGENCY: Federal Railroad Administration (FRA... rulemaking (NPRM) published on September 7, 2012, FRA proposed regulations to require commuter and intercity passenger railroads to develop and implement a system safety program (SSP) to improve the safety of their...
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Context-aware system for pre-triggering irreversible vehicle safety actuators.
Böhmländer, Dennis; Dirndorfer, Tobias; Al-Bayatti, Ali H; Brandmeier, Thomas
2017-06-01
New vehicle safety systems have led to a steady improvement of road safety and a reduction in the risk of suffering a major injury in vehicle accidents. A huge leap forward in the development of new vehicle safety systems are actuators that have to be activated irreversibly shortly before a collision in order to mitigate accident consequences. The triggering decision has to be based on measurements of exteroceptive sensors currently used in driver assistance systems. This paper focuses on developing a novel context-aware system designed to detect potential collisions and to trigger safety actuators even before an accident occurs. In this context, the analysis examines the information that can be collected from exteroceptive sensors (pre-crash data) to predict a certain collision and its severity to decide whether a triggering is entitled or not. A five-layer context-aware architecture is presented, that is able to collect contextual information about the vehicle environment and the actual driving state using different sensors, to perform reasoning about potential collisions, and to trigger safety functions upon that information. Accident analysis is used in a data model to represent uncertain knowledge and to perform reasoning. A simulation concept based on real accident data is introduced to evaluate the presented system concept. Copyright © 2017 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Serghiuta, D.; Tholammakkil, J.
2015-01-01
The use of level-3 reliability approach and the concept of functional failure probability could provide the basis for defining a safety margin metric which would include a limit for the probability of functional failure, in line with the definition of a reliability-based design. It can also allow a quantification of level of confidence, by explicit modeling and quantification of uncertainties, and provide a better framework for representation of actual design and optimization of design margins within an integrated probabilistic-deterministic model. This paper reviews the attributes and challenges in application of functional failure concept in evaluation of risk-informed safety margins using as illustrative example the case of CANDU reactors shutdown systems effectiveness. A risk-informed formulation is first introduced for estimation of a reasonable limit for the functional failure probability using a Swiss cheese model. It is concluded that more research is needed in this area and a deterministic - probabilistic approach may be a reasonable intermediate step for evaluation of functional failure probability at the system level. The views expressed in this paper are those of the authors and do not necessarily reflect those of CNSC, or any part thereof. (authors)
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Programmable electronic safety systems
International Nuclear Information System (INIS)
Parry, R.R.
1993-01-01
Traditionally safety systems intended for protecting personnel from electrical and radiation hazards at particle accelerator laboratories have made extensive use of electromechanical relays. These systems have the advantage of high reliability and allow the designer to easily implement fail-safe circuits. Relay based systems are also typically simple to design, implement, and test. As systems, such as those presently under development at the Superconducting Super Collider Laboratory (SSCL), increase in size, and the number of monitored points escalates, relay based systems become cumbersome and inadequate. The move toward Programmable Electronic Safety Systems is becoming more widespread and accepted. In developing these systems there are numerous precautions the designer must be concerned with. Designing fail-safe electronic systems with predictable failure states is difficult at best. Redundancy and self-testing are prime examples of features that should be implemented to circumvent and/or detect failures. Programmable systems also require software which is yet another point of failure and a matter of great concern. Therefore the designer must be concerned with both hardware and software failures and build in the means to assure safe operation or shutdown during failures. This paper describes features that should be considered in developing safety systems and describes a system recently installed at the Accelerator Systems String Test (ASST) facility of the SSCL
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Evaluation of safety parameter display concepts. Final report
International Nuclear Information System (INIS)
Woods, D.D.; Wise, J.A.; Hanes, L.F.
1982-02-01
New control room equipment designed to improve operator performance must be evaluated before adoption and installation. Two experimental concept for a Safety Parameters Display System (SPDS) were evaluated to assess benefits and potential problems associated with the SPDS concept and its integration into control room operations. Participants were licensed utility operators undergoing retraining on a nuclear power plant simulator. Both quantitative and qualitative data were collected and analyzed on crew response to seven simulated accident conditions. Data on operator decisions and actions have been organized into timelines. Analysis of the timelines and observations collected during testing provide important insights about the potential impact of the SPDS concept on control room operations
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Evaluation issues on real-time operating system in nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Kim, Y. M.; Jeong, C. H.; Koh, J. S. [Regulatory Research Div., Korea Inst. of Nuclear Safety (Korea, Republic of)
2006-07-01
In the recent few years, using the hard real-time operating system (RTOS) of safety-critical applications has gained increased acceptance in the nuclear safety system. Failure of this software could cause catastrophic consequences for human life. The digital I and C systems of nuclear power plants also have used hard RTOSs which are executing a required mission completely within its deadline. Because the nuclear power plants have to maintain a very high level of safety, the hard RTOS software should be reliable and safe. The RTOS used in safety-critical I and C systems is the base software used for the purpose of satisfying the real-time constraints, So, careful evaluation of its safety and functionality is very important, So far, the nuclear power plants of Korea have adopted commercial off-the-shelf (COTS) RTOS software. But, these days the RTOS embedded in safety grade PLC has been developed by KNICS project controlled by Ministry of Commerce, Industry and Energy of Korea. Whether COTS RTOS or newly developed RTOS, it must be evaluated its safety and reliability. (authors)
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Evaluation issues on real-time operating system in nuclear power plants
International Nuclear Information System (INIS)
Kim, Y. M.; Jeong, C. H.; Koh, J. S.
2006-01-01
In the recent few years, using the hard real-time operating system (RTOS) of safety-critical applications has gained increased acceptance in the nuclear safety system. Failure of this software could cause catastrophic consequences for human life. The digital I and C systems of nuclear power plants also have used hard RTOSs which are executing a required mission completely within its deadline. Because the nuclear power plants have to maintain a very high level of safety, the hard RTOS software should be reliable and safe. The RTOS used in safety-critical I and C systems is the base software used for the purpose of satisfying the real-time constraints, So, careful evaluation of its safety and functionality is very important, So far, the nuclear power plants of Korea have adopted commercial off-the-shelf (COTS) RTOS software. But, these days the RTOS embedded in safety grade PLC has been developed by KNICS project controlled by Ministry of Commerce, Industry and Energy of Korea. Whether COTS RTOS or newly developed RTOS, it must be evaluated its safety and reliability. (authors)
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System safety education focused on industrial engineering
Johnston, W. L.; Morris, R. S.
1971-01-01
An educational program, designed to train students with the specific skills needed to become safety specialists, is described. The discussion concentrates on application, selection, and utilization of various system safety analytical approaches. Emphasis is also placed on the management of a system safety program, its relationship with other disciplines, and new developments and applications of system safety techniques.
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Prospective safety performance evaluation on construction sites.
Wu, Xianguo; Liu, Qian; Zhang, Limao; Skibniewski, Miroslaw J; Wang, Yanhong
2015-05-01
This paper presents a systematic Structural Equation Modeling (SEM) based approach for Prospective Safety Performance Evaluation (PSPE) on construction sites, with causal relationships and interactions between enablers and the goals of PSPE taken into account. According to a sample of 450 valid questionnaire surveys from 30 Chinese construction enterprises, a SEM model with 26 items included for PSPE in the context of Chinese construction industry is established and then verified through the goodness-of-fit test. Three typical types of construction enterprises, namely the state-owned enterprise, private enterprise and Sino-foreign joint venture, are selected as samples to measure the level of safety performance given the enterprise scale, ownership and business strategy are different. Results provide a full understanding of safety performance practice in the construction industry, and indicate that the level of overall safety performance situation on working sites is rated at least a level of III (Fair) or above. This phenomenon can be explained that the construction industry has gradually matured with the norms, and construction enterprises should improve the level of safety performance as not to be eliminated from the government-led construction industry. The differences existing in the safety performance practice regarding different construction enterprise categories are compared and analyzed according to evaluation results. This research provides insights into cause-effect relationships among safety performance factors and goals, which, in turn, can facilitate the improvement of high safety performance in the construction industry. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Replacement cross-site transfer system project W-058 safety class upgrade summary report
International Nuclear Information System (INIS)
Schlosser, R.L.
1998-01-01
This report evaluates the design of the replacement cross-site transfer system structures, systems, and components for safety related applications as defined in the Tank Waste Remediation Systems Basis for Interim Operations
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Radiation safety systems at the NSLS
International Nuclear Information System (INIS)
Dickinson, T.
1987-04-01
This report describes design principles that were used to establish the radiation safety systems at the National Synchrotron Light Source. The author described existing safety systems and the history of partial system failures. 1 fig
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Safety assurance logic techniques for evaluation of accident prevention and mitigation
International Nuclear Information System (INIS)
McWethy, L.M.; Hagan, J.W.
1976-01-01
Safety assurance methods have been developed and applied in reactor safety assessments of FFTF. These methods promote visibility of the total safety provided by the plant, both in prevention of off-normal or accident conditions as well as provision of various features which terminate conditions within acceptable bounds if such conditions should occur. One of the primary techniques applied in safety assurance is the development of safety assurance diagrams. These diagrams explicitly identify the multiple lines of defense which prevent accident progression. The diagrams graphically demonstrate the defense-in-depth provided by the plant for each postulated occurrence. Lines of defense are shown against ever having an occurrence in the first place; thus giving appropriate emphasis on accident prevention, and visibility to the designer's role in promoting this level of safety. These diagrams, or accident process trees, also show graphically the various paths of postulated accident progression to their logical termination. Evaluation of the importance and strength of each line-of-defense assures fulfillment of the safety objectives of the overall plant system
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SYSTEMS SAFETY ANALYSIS FOR FIRE EVENTS ASSOCIATED WITH THE ECRB CROSS DRIFT
International Nuclear Information System (INIS)
R. J. Garrett
2001-01-01
The purpose of this analysis is to systematically identify and evaluate fire hazards related to the Yucca Mountain Site Characterization Project (YMP) Enhanced Characterization of the Repository Block (ECRB) East-West Cross Drift (commonly referred to as the ECRB Cross-Drift). This analysis builds upon prior Exploratory Studies Facility (ESF) System Safety Analyses and incorporates Topopah Springs (TS) Main Drift fire scenarios and ECRB Cross-Drift fire scenarios. Accident scenarios involving the fires in the Main Drift and the ECRB Cross-Drift were previously evaluated in ''Topopah Springs Main Drift System Safety Analysis'' (CRWMS M and O 1995) and the ''Yucca Mountain Site Characterization Project East-West Drift System Safety Analysis'' (CRWMS M and O 1998). In addition to listing required mitigation/control features, this analysis identifies the potential need for procedures and training as part of defense-in-depth mitigation/control features. The inclusion of this information in the System Safety Analysis (SSA) is intended to assist the organization(s) (e.g., Construction, Environmental Safety and Health, Design) responsible for these aspects of the ECRB Cross-Drift in developing mitigation/control features for fire events, including Emergency Refuge Station(s). This SSA was prepared, in part, in response to Condition/Issue Identification and Reporting/Resolution System (CIRS) item 1966. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with fires in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate
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Embedding technology into inter-professional best practices in home safety evaluation.
Burns, Suzanne Perea; Pickens, Noralyn Davel
2017-08-01
To explore inter-professional home evaluators' perspectives and needs for building useful and acceptable decision-support tools for the field of home modifications. Twenty semi-structured interviews were conducted with a range of home modification professionals from different regions of the United States. The interview transcripts were analyzed with a qualitative, descriptive, perspective approach. Technology supports current best practice and has potential to inform decision making through features that could enhance home evaluation processes, quality, efficiency and inter-professional communication. Technological advances with app design have created numerous opportunities for the field of home modifications. Integrating technology and inter-professional best practices will improve home safety evaluation and intervention development to meet client-centred and societal needs. Implications for rehabilitation Understanding home evaluators technology needs for home safety evaluations contributes to the development of app-based assessments. Integrating inter-professional perspectives of best practice and technological needs in an app for home assessments improves processes. Novice and expert home evaluators would benefit from decision support systems embedded in app-based assessments. Adoption of app-based assessment would improve efficiency while remaining client-centred.
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CESAR cost-efficient methods and processes for safety-relevant embedded systems
Wahl, Thomas
2013-01-01
The book summarizes the findings and contributions of the European ARTEMIS project, CESAR, for improving and enabling interoperability of methods, tools, and processes to meet the demands in embedded systems development across four domains - avionics, automotive, automation, and rail. The contributions give insight to an improved engineering and safety process life-cycle for the development of safety critical systems. They present new concept of engineering tools integration platform to improve the development of safety critical embedded systems and illustrate capacity of this framework for end-user instantiation to specific domain needs and processes. They also advance state-of-the-art in component-based development as well as component and system validation and verification, with tool support. And finally they describe industry relevant evaluated processes and methods especially designed for the embedded systems sector as well as easy adoptable common interoperability principles for software tool integratio...
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Patient Safety Learning Systems: A Systematic Review and Qualitative Synthesis.
2017-01-01
, and multiple mechanisms to provide feedback through routes to reporters and the wider community (local meetings, email alerts, bulletins, paper contributions, etc.). The design of a patient safety learning system can be optimized by an awareness of the barriers to and facilitators of successful adoption and implementation identified by health care professionals. Evaluation of the effectiveness of a patient safety learning system is needed to refine its design.
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International Nuclear Information System (INIS)
LINTHO, J.E.
2003-01-01
The purpose of this document is to record the technical evaluation of the Technical Safety Requirements described in the Plutonium Finishing Plant (PFP) Safety Technical Requirements, HNF-SD-CP-OSR-010/Rev.1, Section 3.1.1, ''Criticality Prevention System.'' This document also defines the Safety Envelope (SE) for the liquid detection interlock system in the Process Vacuum System. The SE is derived FR-om information in the Plutonium Finishing Plant Final Safety Analysis Report (PFP FSAR), HNF-SD-CP-SAR-021, Rev 4, and the Criticality Safety Analysis Report (CSAR) for the 26-inch Hg Vacuum System, WHC-SD-SQA-CSA-20159, Rev 0-A. This document, with its appendices, provides the following: (1) The system functional requirements for determining system operability (Section 3). (2) Evaluations of equipment to determine the safety envelope boundary for the system (Section 4 list of SE boundary drawings). (3) A list of the safety envelope equipment (Appendix B). (4) Functional requirements for the individual safety envelope equipment, including appropriate set points and process parameters (Section 4). (5) A list of the operational and surveillance procedures necessary to operate and maintain the system equipment within the safety envelope (Sections 5 and 6 and Appendix A)
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International Nuclear Information System (INIS)
Kim, Younggab; Hur, Nam Young; Jeong, Hyeon Jong
2015-01-01
In order to eliminate the vague fears of the people about the nuclear power and operate continuously NPPs, a strong safety culture of NPPs should be demonstrated. Strong safety culture awareness of workers can overcome social distrust about NPPs. KHNP has been a variety efforts to improve and establish safety culture of NPPs. Safety culture framework applying global standards was set up and safety culture assessment has been carried out periodically to enhance safety culture of workers. In addition, KHNP developed various safety culture contents and they are being used in NPPs by workers. As a result of these efforts, safety culture awareness of workers is changed positively and the safety environment of NPPs is expected to be improved. KHNP makes an effort to solve areas for improvement derived from safety culture assessment. However, there are some areas to take a long time in completing the work. Therefore, these actions are necessary to be carried out consistently and continuously. KHNP also developed recently safety culture enhancement system based on web. All information related to safety culture in KHNP will be shared through this web system and this system will be used to safety culture assessment. In addition to, KHNP plans to develop safety culture indicators for monitoring the symptoms of safety culture weakening
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Energy Technology Data Exchange (ETDEWEB)
Kim, Younggab; Hur, Nam Young; Jeong, Hyeon Jong [KHNP Central Research Institute, Daejeon (Korea, Republic of)
2015-05-15
In order to eliminate the vague fears of the people about the nuclear power and operate continuously NPPs, a strong safety culture of NPPs should be demonstrated. Strong safety culture awareness of workers can overcome social distrust about NPPs. KHNP has been a variety efforts to improve and establish safety culture of NPPs. Safety culture framework applying global standards was set up and safety culture assessment has been carried out periodically to enhance safety culture of workers. In addition, KHNP developed various safety culture contents and they are being used in NPPs by workers. As a result of these efforts, safety culture awareness of workers is changed positively and the safety environment of NPPs is expected to be improved. KHNP makes an effort to solve areas for improvement derived from safety culture assessment. However, there are some areas to take a long time in completing the work. Therefore, these actions are necessary to be carried out consistently and continuously. KHNP also developed recently safety culture enhancement system based on web. All information related to safety culture in KHNP will be shared through this web system and this system will be used to safety culture assessment. In addition to, KHNP plans to develop safety culture indicators for monitoring the symptoms of safety culture weakening.
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Role of systems safety in maintaining affordable safety in the 1980's
International Nuclear Information System (INIS)
Hollister, H.; Trauth, C.A. Jr.
1979-01-01
Historically, the Department of Energy and its predecessors have used and supported the development of systems safety programs, practices, and principles, finding them by and large adequate, effective, and managerially efficient. Today, attempts are bing made to resolve increasingly complex environmental, safety, and health problems by turning to increasingly complex and detailed regulation as the primary governmental answer. It is increasingly doubtful that such an approach will provide management of these issues and problems that is either effective or efficient. Challenge is issued to those in systems safety to develop and apply systems safety principles and practices more broadly to total operational systems and not just to hardware and to environmental and health protection and not just to safety, so that the total universe of environmental, safety, and health can be managed effectively and efficiently with encouragement of innovation and creativity, using a relatively brief and concise, but adequate, regulatory base
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Energy Technology Data Exchange (ETDEWEB)
Neall, Fiona; Pastina, Barbara; Snellman, Margit; Smith, Paul; Gribi, P.; Johnson, Lawrence
2008-12-15
The KBS-3H design is a variant of the more general KBS-3 method for the geological disposal of spent nuclear fuel in Finland and Sweden. In the KBS-3H design, multiple assemblies containing spent fuel are emplaced horizontally in parallel, approximately 300 m long, slightly inclined deposition drifts. The copper canisters, each with a surrounding layer of bentonite clay, are placed in perforated steel shells prior to deposition in the drifts; the assembly is called the 'supercontainer'. The other KBS-3 variant is the KBS-3V design, in which the copper canisters are emplaced vertically in individual deposition holes surrounded by bentonite clay but without steel supercontainer shells. SKB and Posiva have conducted a Research, Development and Demonstration programme over the period 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to KBS-3V. As part of this programme, the long-term safety of a KBS-3H repository has been assessed in the KBS-3H safety studies. In order to focus the safety studies, the Olkiluoto site in the municipality of Eurajoki, which is the proposed site for a spent fuel repository in Finland, was used as a hypothetical site for a KBS-3H repository. The present report is part of a portfolio of reports discussing the long-term safety of the KBS-3H repository. The overall outcome of the KBS-3H safety studies is documented in the summary report, 'Safety assessment for a KBS-3H repository for spent nuclear fuel at Olkiluoto'. The purpose and scope of the KBS-3H complementary evaluations of safety report is provided in Posiva's Safety Case Plan, which is based on Regulatory Guide YVL 8.4 and on international guidelines on complementary lines of argument to long-term safety that are considered an important element of a post-closure safety case for geological repositories. Complementary evaluations of safety require the use of evaluations, evidence and qualitative supporting arguments
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Criticality safety benchmark evaluation project: Recovering the past
Energy Technology Data Exchange (ETDEWEB)
Trumble, E.F.
1997-06-01
A very brief summary of the Criticality Safety Benchmark Evaluation Project of the Westinghouse Savannah River Company is provided in this paper. The purpose of the project is to provide a source of evaluated criticality safety experiments in an easily usable format. Another project goal is to search for any experiments that may have been lost or contain discrepancies, and to determine if they can be used. Results of evaluated experiments are being published as US DOE handbooks.
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Systems Safety and Engineering Division
Federal Laboratory Consortium — Volpe's Systems Safety and Engineering Division conducts engineering, research, and analysis to improve transportation safety, capacity, and resiliency. We provide...
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Application of Safety Instrumented System (SIS) approach in older nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Nasimi, Elnara; Gabbar, Hossam A., E-mail: hossam.gabbar@uoit.ca
2016-05-15
Highlights: • Study Safety Instrumented System (SIS) design for older nuclear power plant. • Apply SIS on Reheater Drains (RD) system. • Apply IEC 61508/61511 to design safety system. • Evaluate risk reduction based on proposed SIS design. - Abstract: In order to remain economically effective and financially profitable, the modern industries have to take their safety culture to a higher level and consider production losses in addition to simple accident prevention techniques. Ideally, compliance with safety requirements start during early design stages, but in some older facilities provisions for Safety Instrumented Systems (SIS) may not have been originally included. In this paper, a case study of a Reheater Drains (RD) system is used to illustrate such an example. Frequent failures of tank level controller lead to transients where the operation of shutting down RD pumps requires operators to manually isolate the quenching water and to close the main steam admission valves. Water in this system is at saturation temperature for the reheater steam side pressure, and any manual operation of the system is highly undesirable due to hazards of working with wet steam at approximately 758 kPa(g) pressure, preheated to 237 °C. Additionally, losses of inventory are highly undesirable as well and challenge other systems in the plant. In this paper, it is suggested that RD system can benefit from installation of an independent SIS system in order to address current challenges. This idea is being explored using IEC 61508 framework for “Functional safety of electrical/electronic/programmable electronic safety-related systems” to provide assurance that the SIS will offer the necessary risk reduction required to achieve required safety for the equipment.
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Directory of Open Access Journals (Sweden)
Ai Lin Evelyn Teo
2016-12-01
Full Text Available Despite the safety improvement drive that has been implemented in the construction industry in Singapore for many years, the industry continues to report the highest number of workplace fatalities, compared to other industries. The purpose of this paper is to discuss the theoretical framework of the safety aspect of a proposed BIM System to determine a Safety Index. An online questionnaire survey was conducted to ascertain the current workplace safety and health situation in the construction industry and explore how BIM can be used to improve safety performance in the industry. A safety hazard library was developed based on the main contributors to fatal accidents in the construction industry, determined from the formal records and existing literature, and a series of discussions with representatives from the Workplace Safety and Health Institute (WSH Institute in Singapore. The results from the survey suggested that the majority of the firms have implemented the necessary policies, programmes and procedures on Workplace Safety and Health (WSH practices. However, BIM is still not widely applied or explored beyond the mandatory requirement that building plans should be submitted to the authorities for approval in BIM format. This paper presents a discussion of the safety aspect of the Intelligent Productivity and Safety System (IPASS developed in the study. IPASS is an intelligent system incorporating the buildable design concept, theory on the detection, prevention and control of hazards, and the Construction Safety Audit Scoring System (ConSASS. The system is based on the premise that safety should be considered at the design stage, and BIM can be an effective tool to facilitate the efforts to enhance safety performance. IPASS allows users to analyse and monitor key aspects of the safety performance of the project before the project starts and as the project progresses.
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International Nuclear Information System (INIS)
Matzie, Regis A.; Carpentino, Frederick L.; Robertson, James E.
1996-01-01
Safely systems in the System 80+ TM Standard Plant are designed with more redundancy, diversity and simplicity than earlier nuclear power plant designs. These gains were accomplished by an evolutionary process that preserved the desirable and proven features in currently operating nuclear plants, while improving reliability and defense-in-depth. The System 80+ safety systems are the primary contributors to a core damage frequency that is more than 100 times lower than 1980's vintage U. S. designs, including the predecessor System 80 R standard nuclear steam supply system (NSSS) design. The System 80+ design includes significant improvements to the safety injection system, emergency feedwater system, shutdown cooling system, containment spray system, reactor coolant gas vent system, and to their vital support systems. These improvements enhance performance for traditional design basis events and significantly reduce the probability of a severe accident. The System 80+ design also incorporates safety systems to mitigate a severe accident. The added systems include the rapid depressurization system, the in-containment refueling water storage tank, the cavity flooding system. These systems fully address the U. S. Nuclear Regulatory Commission's (US NRC) severe accident policy. The System 80+ safety systems are integrated with the System 80+ Nuclear Island (NI) design. The NI general arrangement provides quadrant separation of the safety systems for protection from fire and flooding, and large equipment pull spaces and lay down areas for maintenance. This paper will describe the System 80+ safety systems advanced design features, the improved accident prevention and mitigation capabilities, and startup, operating and maintenance benefits
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Product Engineering Class in the Software Safety Risk Taxonomy for Building Safety-Critical Systems
Hill, Janice; Victor, Daniel
2008-01-01
When software safety requirements are imposed on legacy safety-critical systems, retrospective safety cases need to be formulated as part of recertifying the systems for further use and risks must be documented and managed to give confidence for reusing the systems. The SEJ Software Development Risk Taxonomy [4] focuses on general software development issues. It does not, however, cover all the safety risks. The Software Safety Risk Taxonomy [8] was developed which provides a construct for eliciting and categorizing software safety risks in a straightforward manner. In this paper, we present extended work on the taxonomy for safety that incorporates the additional issues inherent in the development and maintenance of safety-critical systems with software. An instrument called a Software Safety Risk Taxonomy Based Questionnaire (TBQ) is generated containing questions addressing each safety attribute in the Software Safety Risk Taxonomy. Software safety risks are surfaced using the new TBQ and then analyzed. In this paper we give the definitions for the specialized Product Engineering Class within the Software Safety Risk Taxonomy. At the end of the paper, we present the tool known as the 'Legacy Systems Risk Database Tool' that is used to collect and analyze the data required to show traceability to a particular safety standard
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Safety evaluation for the prototype Fast Breeder Reactor MONJU as a Japanese TSO
International Nuclear Information System (INIS)
Endo, Hiroshi
2010-01-01
In the safety field of fast breeder reactors (FBRs), JNES is conducting an evaluation work of the safety regulation by Nuclear and Industry Safety Agency (NISA) for the re-start of a prototype FBR MONJU. MONJU has been stopped over 14 years since 1995 due to a sodium leakage accident at a secondary heat transport system, and is now reached to the criticality on 8th of May, 2010. JNES is supporting the safety regulation work conducted by NISA based on the following activities: i) Support of the technical evaluation of the application for the establishment license prepared by Japan Atomic Energy Agency (JAEA), ii) Support of the description of the safety review report by NISA based on independent safety analyses for the major accident events such as unprotected loss-of-flow (ULOF) by employing the latest findings on the study of core disruptive accidents (CDAs) independently conducted by JNES, iii) Support of the risk-informed-regulation (RIR) such as an accident management (AM) review, iv), and Consideration on the safety regulation policy from the points of severe accidents and source-term behaviors including the cesium (Cs). The objective of this paper is to introduce the major activities of JNES in the safety domain of MONJU regulations. (author)
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Safety evaluation of synthetic β-carotene
Woutersen, R.A.; Wolterbeek, A.P.M.; Appel, M.J.; Berg, H. van den; Goldbohm, R.A.; Feron, V.J.
1999-01-01
The safety of β-carotene was reassessed by evaluating the relevant literature on the beneficial and adverse effects of β-carotene on cancer and, in particular, by evaluating the results of toxicity studies. β- Carotene appeared neither genotoxic nor reprotoxic or teratogenic, and no signs of organ
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A New Method for the Evaluation of Vaccine Safety Based on Comprehensive Gene Expression Analysis
Directory of Open Access Journals (Sweden)
Haruka Momose
2010-01-01
Full Text Available For the past 50 years, quality control and safety tests have been used to evaluate vaccine safety. However, conventional animal safety tests need to be improved in several aspects. For example, the number of test animals used needs to be reduced and the test period shortened. It is, therefore, necessary to develop a new vaccine evaluation system. In this review, we show that gene expression patterns are well correlated to biological responses in vaccinated rats. Our findings and methods using experimental biology and genome science provide an important means of assessment for vaccine toxicity.
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Institute of Scientific and Technical Information of China (English)
SHI Shi-liang; LIU Hai-bo; LIU Ai-hua
2004-01-01
Based on the integration analysis of goods and shortcomings of various methods used in safety assessment of coal mines, combining nonlinear feature of mine safety sub-system, this paper establishes the neural network assessment model of mine safety, analyzes the ability of artificial neural network to evaluate mine safety state, and lays the theoretical foundation of artificial neural network using in the systematic optimization of mine safety assessment and getting reasonable accurate safety assessment result.
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Uber, James G.
1988-01-01
Software itself is not hazardous, but since software and hardware share common interfaces there is an opportunity for software to create hazards. Further, these software systems are complex, and proven methods for the design, analysis, and measurement of software safety are not yet available. Some past software failures, future NASA software trends, software engineering methods, and tools and techniques for various software safety analyses are reviewed. Recommendations to NASA are made based on this review.
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Reactor Safety Assessment System
International Nuclear Information System (INIS)
Sebo, D.E.; Bray, M.A.; King, M.A.
1987-01-01
The Reactor Safety Assessment System (RSAS) is an expert system under development for the United States Nuclear Regulatory Commission (USNRC). RSAS is designed for use at the USNRC Operations Center in the event of a serious incident at a licensed nuclear power plant. RSAS is a situation assessment expert system which uses plant parametric data to generate conclusions for use by the NRC Reactor Safety Team. RSAS uses multiple rule bases and plant specific setpoint files to be applicable to all licensed nuclear power plants in the United States. RSAS currently covers several generic reactor categories and multiple plants within each category
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Reactor safety assessment system
International Nuclear Information System (INIS)
Sebo, D.E.; Bray, M.A.; King, M.A.
1987-01-01
The Reactor Safety Assessment System (RSAS) is an expert system under development for the United States Nuclear Regulatory Commission (USNRC). RSA is designed for use at the USNRC Operations Center in the event of a serious incident at a licensed nuclear power plant. RSAS is a situation assessment expert system which uses plant parametric data to generate conclusions for use by the NRC Reactor Safety Team. RSAS uses multiple rule bases and plant specific setpoint files to be applicable to all licensed nuclear power plants in the United States. RSAS currently covers several generic reactor categories and multiple plants within each category
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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
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Energy Technology Data Exchange (ETDEWEB)
1994-08-01
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the System 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR {section} 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of Abb-CE`s System 80 design from which it evolved. Unique features of the System 80+ design included: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors, and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE`s application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 1, contains Chapters 1 through 14 of this report.
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[Monitoring evaluation system for high-specialty hospitals].
Fajardo Dolci, Germán; Aguirre Gas, Héctor G; Robledo Galván, Héctor
2011-01-01
Hospital evaluation is a fundamental process to identify medical units' objective compliance, to analyze efficiency of resource use and allocation, institutional values and mission alignment, patient safety and quality standards, contributions to research and medical education, and the degree of coordination among medical units and the health system as a whole. We propose an evaluation system for highly specialized regional hospitals through the monitoring of performance indicators. The following are established as base thematic elements in the construction of indicators: safe facilities and equipment, financial situation, human resources management, policy management, organizational climate, clinical activity, quality and patient safety, continuity of care, patients' and providers' rights and obligations, teaching, research, social responsibility, coordination mechanisms. Monitoring refers to the planned and systematic evaluation of valid and reliable indicators, aimed at identifying problems and opportunity areas. Moreover, evaluation is a powerful tool to strengthen decision-making and accountability in medical units.
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Ecological Safety Evaluation of Land Use in Ji’an City Based on the Principal Component Analysis
Institute of Scientific and Technical Information of China (English)
2010-01-01
According to the ecological safety evaluation index data of land-use change in Ji’an City from 1999 to 2008,positive treatment on selected reverse indices is conducted by Reciprocal Method.Meanwhile,Index Method is used to standardize the selected indices,and Principal Component Analysis is applied by using year as a unit.FB is obtained,which is related with the ecological safety of land-use change from 1999 to 2008.According to the scientific,integrative,hierarchical,practical and dynamic principles,ecological safety evaluation index system of land-use change in Ji’an City is established.Principal Component Analysis and evaluation model are used to calculate four parameters,including the natural resources safety index of land use,the socio-economic safety indicators of land use,the eco-environmental safety index of land use,and the ecological safety degree of land use in Ji’an City.Result indicates that the ecological safety degree of land use in Ji’an City shows a slow upward trend as a whole.At the same time,ecological safety degree of land-use change is relatively low in Ji’an City with the safety value of 0.645,which is at a weak safety zone and needs further monitoring and maintenance.
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Energy Technology Data Exchange (ETDEWEB)
Gupta, Mukesh [URS Professional Solutions LLC, Aiken, SC (United States); Niemi, Belinda [Washington River Protection Solutions, LLC, Richland, WA (United States); Paik, Ingle [Washington River Protection Solutions, LLC, Richland, WA (United States)
2015-09-02
In 2012, One System Nuclear Safety performed a comparison of the safety bases for the Tank Farms Operations Contractor (TOC) and Hanford Tank Waste Treatment and Immobilization Plant (WTP) (RPP-RPT-53222 / 24590-WTP-RPT-MGT-12-018, “One System Report of Comparative Evaluation of Safety Bases for Hanford Waste Treatment and Immobilization Plant Project and Tank Operations Contract”), and identified 25 recommendations that required further evaluation for consensus disposition. This report documents ten NSSC approved consistent methodologies and guides and the results of the additional evaluation process using a new set of evaluation criteria developed for the evaluation of the new methodologies.
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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
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Dyjack, D T; Levine, S P; Holtshouser, J L; Schork, M A
1998-06-01
Numerous manufacturing and service organizations have integrated or are considering integration of their respective occupational health and safety management and audit systems into the International Organization for Standardization-based (ISO) audit-driven Quality Management Systems (ISO 9000) or Environmental Management Systems (ISO 14000) models. Companies considering one of these options will likely need to identify and evaluate several key factors before embarking on such efforts. The purpose of this article is to identify and address the key factors through a case study approach. Qualitative and quantitative comparisons of the key features of the American Industrial Hygiene Association ISO-9001 harmonized Occupational Health and Safety Management System with The Goodyear Tire & Rubber Co. management and audit system were conducted. The comparisons showed that the two management systems and their respective audit protocols, although structured differently, were not substantially statistically dissimilar in content. The authors recommend that future studies continue to evaluate the advantages and disadvantages of various audit protocols. Ideally, these studies would identify those audit outcome measures that can be reliably correlated with health and safety performance.
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International Nuclear Information System (INIS)
Kao, G.C.; Daugherty, W.L.; Barnes, D.M.
1992-09-01
In order to extend the service life of safety related structures and systems in a logical manner, a Structural Enhancement Program was initiated to evaluate the structural integrity of eight (8) systems, namely: Cooling Water System, Emergency Cooling System, Moderator Recovery System supplementary Safety System, Water Removal System, Service Raw Water System, Service Clarified Water System, and River Water System. Since the level of importance of each system to reactor operations varies from one system to another, the scope of structural integrity evaluation for each system should be prioritized accordingly. This paper presents the assessment of system priority for structural evaluation based on a ranking methodology and specifies the level of structural evaluation consistent with the established priority. The effort was undertaken by a five-member panel representing four (4) major disciplines, including. structures, reactor engineering/operations, risk management and materials. The above systems were divided into a total of thirty-five (35) subsystem. These subsystems were then ranked with six (6) attributes, namely: Safety Classification, Degradation Mechanisms, Difficulty of Replacement, Failure Mode, Radiation Dose to Workers and Consequence of Failure. Each attribute was assigned a set of consequences or events with corresponding weighting scores. The results of the ranking process yielded two groups of subsystems, categorized as Priority I and II subsystems. The level of structural assessment was then formulated accordingly. The prioritized approach will allow more efficient allocation of resources, so that the Structural Enhancement Program can be implemented in a cost-effective and efficient manner
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Safety and interlock system for Tristan
International Nuclear Information System (INIS)
Takeda, S.; Kudo, K.; Katoh, T.; Akiyama, A.
1987-01-01
This report describes alarm and interlock system of TRISTAN, concentrating on personnel safety. The basis of TRISTAN machine-control system (TMS) is an N-to-N computer network and KEK NODAL which offers high software productivity. TMC achieves high flexibility of operation both for normal operation and for the fast commissioning. However, to assure the safety of personnel and the TRISTAN machine operation, the safety system has to continue functioning during TMC failure as well. A distributed safety and interlock system (DSIS) is used for diversification of risks in TRISTAN system. DSIS is functionally subdivided along local system lines and has a hierarchical structure of 12 programmable sequence controllers (PSCs). Optical fiber links connect the PSCs at subsystem level and a PSC at the supervisory level of TRISTAN central control room (TCCR). The subsystem PSCs provide the interlock functions between their local devices. The local PSCs interact with the central system through a limited number of summarized signals. The central PSC provides the interlock functions between the subsystems and interacts with an operator's panel. Personnel safety is based on a system of electrical interlock keys, emergency push-buttons around the tunnel, at the entrance gates or in the control room
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2005 dossier: clay. Tome: safety evaluation of the geologic disposal
International Nuclear Information System (INIS)
2005-01-01
This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the safety aspects of an argilite-type geologic disposal facility for high-level and long-lived (HLLL) radioactive wastes. Content: 1 - safety approach: context and general goals, general safety principles, specificity of the argilite repository safety approach, general approach; 2 - general description: HLLL wastes, geologic context of the Meuse/Haute-Marne site, repository architecture; 3 - safety functions and disposal design: time and space scales, safety approach by functions, functional analysis methodology, analysis of safety functions during the construction, exploitation and observation phases, safety functions analysis during post-closure phase; 4 - operational safety: dosimetric evaluation, risk analysis (explosible gases, fire hazards, lift cage drop, container drop); 5 - long-term efficiency of the disposal facility: normal evolution scenario, from conceptual models to the safety calculation model, description of the safety model, quantitative evaluation of the normal evolution scenario, main lessons learnt from the efficiency analysis; 6 - management of uncertainties: identification, building up of altered situations, mastery of uncertainties; 7 - evaluation of altered evolution scenarios: sealing defect scenario, container defect scenario, drilling scenario, strongly degraded operation scenario; 8 - conclusions: lessons learnt, possible improvements. (J.S.)
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Safety-critical Java for embedded systems
DEFF Research Database (Denmark)
Schoeberl, Martin; Dalsgaard, Andreas Engelbredt; Hansen, René Rydhof
2016-01-01
This paper presents the motivation for and outcomes of an engineering research project on certifiable Javafor embedded systems. The project supports the upcoming standard for safety-critical Java, which defines asubset of Java and libraries aiming for development of high criticality systems....... The outcome of this projectinclude prototype safety-critical Java implementations, a time-predictable Java processor, analysis tools formemory safety, and example applications to explore the usability of safety-critical Java for this applicationarea. The text summarizes developments and key contributions...
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Sophisticated Calculation of the 1oo4-architecture for Safety-related Systems Conforming to IEC61508
International Nuclear Information System (INIS)
Hayek, A; Al Bokhaiti, M; Schwarz, M H; Boercsoek, J
2012-01-01
With the publication and enforcement of the standard IEC 61508 of safety related systems, recent system architectures have been presented and evaluated. Among a number of techniques and measures to the evaluation of safety integrity level (SIL) for safety-related systems, several measures such as reliability block diagrams and Markov models are used to analyze the probability of failure on demand (PFD) and mean time to failure (MTTF) which conform to IEC 61508. The current paper deals with the quantitative analysis of the novel 1oo4-architecture (one out of four) presented in recent work. Therefore sophisticated calculations for the required parameters are introduced. The provided 1oo4-architecture represents an advanced safety architecture based on on-chip redundancy, which is 3-failure safe. This means that at least one of the four channels have to work correctly in order to trigger the safety function.
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Energy Technology Data Exchange (ETDEWEB)
NONE
1997-03-01
Safety measures and assessment technology were studied for the WE-NET project. As the study result in fiscal 1996, the information on safety design, anomaly and accident was collected and arranged. The information on safety measures, ideology and criterion was also collected by visiting some domestic and overseas organizations experienced about handling of liquid hydrogen (LH). The initial survey was made for the safety design ideology, analytical technique and disaster preventive measures of LNG systems as the similar cold liquid system. Accidents and explosion accident of a hydrogen production plant (water electrolysis) in Germany were analyzed. Events on storage tanks and leakage around the tanks were studied as typical risk of LH considering temporary and LNG system design information. The model based on the LH spillage test result and 3-D dispersion of vapor cloud were prepared by modifying a simulation code. The model allowed evaluation of the effect of explosion and fire accidents of compressed hydrogen gas and flying fragments on structures and people, and visual display of distances from a tank and damage conditions. 19 refs., 29 figs., 18 tabs.
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System safety analysis of an autonomous mobile robot
International Nuclear Information System (INIS)
Bartos, R.J.
1994-01-01
Analysis of the safety of operating and maintaining the Stored Waste Autonomous Mobile Inspector (SWAMI) II in a hazardous environment at the Fernald Environmental Management Project (FEMP) was completed. The SWAMI II is a version of a commercial robot, the HelpMate trademark robot produced by the Transitions Research Corporation, which is being updated to incorporate the systems required for inspecting mixed toxic chemical and radioactive waste drums at the FEMP. It also has modified obstacle detection and collision avoidance subsystems. The robot will autonomously travel down the aisles in storage warehouses to record images of containers and collect other data which are transmitted to an inspector at a remote computer terminal. A previous study showed the SWAMI II has economic feasibility. The SWAMI II will more accurately locate radioactive contamination than human inspectors. This thesis includes a System Safety Hazard Analysis and a quantitative Fault Tree Analysis (FTA). The objectives of the analyses are to prevent potentially serious events and to derive a comprehensive set of safety requirements from which the safety of the SWAMI II and other autonomous mobile robots can be evaluated. The Computer-Aided Fault Tree Analysis (CAFTA copyright) software is utilized for the FTA. The FTA shows that more than 99% of the safety risk occurs during maintenance, and that when the derived safety requirements are implemented the rate of serious events is reduced to below one event per million operating hours. Training and procedures in SWAMI II operation and maintenance provide an added safety margin. This study will promote the safe use of the SWAMI II and other autonomous mobile robots in the emerging technology of mobile robotic inspection
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The detector safety system for LHC experiments
Schmeling, Sascha; Lüders, S; Morpurgo, Giulio
2004-01-01
The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four Large Hadron Collider (LHC)**1 experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC**2 front-end, to which the safety- critical part of the DSS task is delegated. This is then supervised by a PVSS**3 SCADA**4 system via an OPC**5 server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "configuration database." Thus, the DSS can easily adapt to the different and constantly ev...
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Reliability of thermal-hydraulic passive safety systems
International Nuclear Information System (INIS)
D'Auria, F.; Araneo, D.; Pierro, F.; Galassi, G.
2014-01-01
The scholar will be informed of reliability concepts applied to passive system adopted for nuclear reactors. Namely, for classical components and systems the failure concept is associated with malfunction of breaking of hardware. In the case of passive systems the failure is associated with phenomena. A method for studying the reliability of passive systems is discussed and is applied. The paper deals with the description of the REPAS (Reliability Evaluation of Passive Safety System) methodology developed by University of Pisa (UNIPI) and with results from its application. The general objective of the REPAS methodology is to characterize the performance of a passive system in order to increase the confidence toward its operation and to compare the performances of active and passive systems and the performances of different passive systems
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Research on communication system of underground safety management based on leaky feeder cable
Institute of Scientific and Technical Information of China (English)
CHEN Jian-hong; ZHANG Tao; CHENG Yun-cai; ZHANG Han
2007-01-01
According to the current working status of underground safety management and production scheduling, the importance and existed problem of underground mine radio communication were summarized, and the basic principle and classification of leaky feeder cable were introduced and the characteristics of cable were analyzed specifically in depth, and the application model of radio communication system for underground mine safety management was put forward. Meanwhile, the research explanation of the system component, function and evaluation was provided. The discussion result indicates that communication system of underground mine safety management which is integrated two-way relay amplifier and other equipment has many communication functions, and underground mine mobile communication can be achieved well.
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Richter, Lars; Bruder, Ralf
2013-05-01
Most medical robotic systems require direct interaction or contact with the robot. Force-Torque (FT) sensors can easily be mounted to the robot to control the contact pressure. However, evaluation is often done in software, which leads to latencies. To overcome that, we developed an independent safety system, named FTA sensor, which is based on an FT sensor and an accelerometer. An embedded system (ES) runs a real-time monitoring system for continuously checking of the readings. In case of a collision or error, it instantaneously stops the robot via the robot's external emergency stop. We found that the ES implementing the FTA sensor has a maximum latency of [Formula: see text] ms to trigger the robot's emergency stop. For the standard settings in the application of robotized transcranial magnetic stimulation, the robot will stop after at most 4 mm. Therefore, it works as an independent safety layer preventing patient and/or operator from serious harm.
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Directory of Open Access Journals (Sweden)
Muhammad Arif
2016-03-01
Full Text Available Background :Turnaround is one of the done by contractor in which if it is not managed well, it could cause work accident. The purpose of this study was to evaluate the implementation of contractor safety management system (CSMS program on turnaround project at PT. Pupuk Sriwidjaja Palembang. Method : This study was a qualitative study. The information was obtained from deep interview, observation and the study of document. The data was analyzed by using content analysis. The validity of the instruments was tested through triangulation of sources, method and data Result : The program implementation Contractor Safety Management System (CSMS on a turnaround project is already well underway only on projects in addition to departments turnaround K3 & LH less involved in the risk assessment stage, pre-qualification and selection of contractors. Conclusion : The implementation of the program Contractor Safety Management System (CSMS on a turnaround project at PT. Pupuk Sriwidjaja Palembang are in accordance with the Code of Labor Management Health, Safety and Environmental Protection Contractor BPMIGAS. It is advisable to PT. Pupuk Sriwidjaja Palembang in order to improve communication between departments procure goods and services with K3 and LH-related departments work tendered as the risk assessment stage, pre-qualification and selection on work tendered. Need sanctions against contractors who do not regularly report performance data K3.
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OBTAINING FOOD SAFETY BY APPLYING HACCP SYSTEM
Directory of Open Access Journals (Sweden)
ION CRIVEANU
2012-01-01
Full Text Available In order to increase the confidence of the trading partners and consumers in the products which are sold on the market, enterprises producing food are required to implement the food safety system HACCP,a particularly useful system because the manufacturer is not able to fully control finished products . SR EN ISO 22000:2005 establishes requirements for a food safety management system where an organization in the food chain needs to proove its ability to control food safety hazards in order to ensure that food is safe at the time of human consumption. This paper presents the main steps which ensure food safety using the HACCP system, and SR EN ISO 20000:2005 requirements for food safety.
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Industrial Personal Computer based Display for Nuclear Safety System
International Nuclear Information System (INIS)
Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min
2014-01-01
The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view
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Industrial Personal Computer based Display for Nuclear Safety System
Energy Technology Data Exchange (ETDEWEB)
Kim, Ji Hyeon; Kim, Aram; Jo, Jung Hee; Kim, Ki Beom; Cheon, Sung Hyun; Cho, Joo Hyun; Sohn, Se Do; Baek, Seung Min [KEPCO, Youngin (Korea, Republic of)
2014-08-15
The safety display of nuclear system has been classified as important to safety (SIL:Safety Integrity Level 3). These days the regulatory agencies are imposing more strict safety requirements for digital safety display system. To satisfy these requirements, it is necessary to develop a safety-critical (SIL 4) grade safety display system. This paper proposes industrial personal computer based safety display system with safety grade operating system and safety grade display methods. The description consists of three parts, the background, the safety requirements and the proposed safety display system design. The hardware platform is designed using commercially available off-the-shelf processor board with back plane bus. The operating system is customized for nuclear safety display application. The display unit is designed adopting two improvement features, i.e., one is to provide two separate processors for main computer and display device using serial communication, and the other is to use Digital Visual Interface between main computer and display device. In this case the main computer uses minimized graphic functions for safety display. The display design is at the conceptual phase, and there are several open areas to be concreted for a solid system. The main purpose of this paper is to describe and suggest a methodology to develop a safety-critical display system and the descriptions are focused on the safety requirement point of view.
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Cost benefit analysis of reactor safety systems
International Nuclear Information System (INIS)
Maurer, H.A.
1984-01-01
Cost/benefit analysis of reactor safety systems is a possibility appropriate to deal with reactor safety. The Commission of the European Communities supported a study on the cost-benefit or cost effectiveness of safety systems installed in modern PWR nuclear power plants. The following systems and their cooperation in emergency cases were in particular investigated in this study: the containment system (double containment), the leakage exhaust and control system, the annulus release exhaust system and the containment spray system. The benefit of a safety system is defined according to its contribution to the reduction of the radiological consequences for the environment after a LOCA. The analysis is so far performed in two different steps: the emergency core cooling system is considered to function properly, failure of the emergency core cooling system is assumed (with the possible consequence of core melt-down) and the results may demonstrate the evidence that striving for cost-effectiveness can produce a safer end result than the philosophy of safety at any cost. (orig.)
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Energy Technology Data Exchange (ETDEWEB)
NONE
1960-04-15
Although the operation of nuclear reactors has a remarkably good record of safety, the prevention of possible reactor accidents is one of the major factors that atomic planners have to contend with. At the same time, excessive caution may breed an attitude that hampers progress, either by resisting new development or by demanding unnecessarily elaborate and expensive precautions out of proportion to the actual hazards involved. The best course obviously is to determine the possible dangers and adopt adequate measures for their prevention, providing of course, for a reasonable margin of error in judging the hazards and the effectiveness of the measures. The greater the expert understanding and thoroughness with which this is done, the narrower need the margin be. This is the basic idea behind the evaluation of reactor safety
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Issues regarding Risk Effect Analysis of Digitalized Safety Systems and Main Risk Contributors
International Nuclear Information System (INIS)
Kang, Hyun Gook; Jang, Seung-Cheol
2008-01-01
Risk factors of safety-critical digital systems affect overall plant risk. In order to assess this risk effect, a risk model of a digitalized safety system is required. This article aims to provide an overview of the issues when developing a risk model and demonstrate their effect on plant risk quantitatively. Research activities in Korea for addressing these various issues, such as the software failure probability and the fault coverage of self monitoring mechanism are also described. The main risk contributors related to the digitalized safety system were determined in a quantitative manner. Reactor protection system and engineered safety feature component control system designed as part of the Korean Nuclear I and C System project are used as example systems. Fault-tree models were developed to assess the failure probability of a system function which is designed to generate an automated signal for actuating both of the reactor trip and the complicated accident-mitigation actions. The developed fault trees were combined with a plant risk model to evaluate the effect of a digitalized system's failure on the plant risk. (authors)
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Safer Systems: A NextGen Aviation Safety Strategic Goal
Darr, Stephen T.; Ricks, Wendell R.; Lemos, Katherine A.
2008-01-01
The Joint Planning and Development Office (JPDO), is charged by Congress with developing the concepts and plans for the Next Generation Air Transportation System (NextGen). The National Aviation Safety Strategic Plan (NASSP), developed by the Safety Working Group of the JPDO, focuses on establishing the goals, objectives, and strategies needed to realize the safety objectives of the NextGen Integrated Plan. The three goal areas of the NASSP are Safer Practices, Safer Systems, and Safer Worldwide. Safer Practices emphasizes an integrated, systematic approach to safety risk management through implementation of formalized Safety Management Systems (SMS) that incorporate safety data analysis processes, and the enhancement of methods for ensuring safety is an inherent characteristic of NextGen. Safer Systems emphasizes implementation of safety-enhancing technologies, which will improve safety for human-centered interfaces and enhance the safety of airborne and ground-based systems. Safer Worldwide encourages coordinating the adoption of the safer practices and safer systems technologies, policies and procedures worldwide, such that the maximum level of safety is achieved across air transportation system boundaries. This paper introduces the NASSP and its development, and focuses on the Safer Systems elements of the NASSP, which incorporates three objectives for NextGen systems: 1) provide risk reducing system interfaces, 2) provide safety enhancements for airborne systems, and 3) provide safety enhancements for ground-based systems. The goal of this paper is to expose avionics and air traffic management system developers to NASSP objectives and Safer Systems strategies.
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Optimal replacement policy for safety-related multi-component multi-state systems
International Nuclear Information System (INIS)
Xu Ming; Chen Tao; Yang Xianhui
2012-01-01
This paper investigates replacement scheduling for non-repairable safety-related systems (SRS) with multiple components and states. The aim is to determine the cost-minimizing time for replacing SRS while meeting the required safety. Traditionally, such scheduling decisions are made without considering the interaction between the SRS and the production system under protection, the interaction being essential to formulate the expected cost to be minimized. In this paper, the SRS is represented by a non-homogeneous continuous time Markov model, and its state distribution is evaluated with the aid of the universal generating function. Moreover, a structure function of SRS with recursive property is developed to evaluate the state distribution efficiently. These methods form the basis to derive an explicit expression of the expected system cost per unit time, and to determine the optimal time to replace the SRS. The proposed methodology is demonstrated through an illustrative example.
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The International Criticality Safety Benchmark Evaluation Project
International Nuclear Information System (INIS)
Briggs, B. J.; Dean, V. F.; Pesic, M. P.
2001-01-01
In order to properly manage the risk of a nuclear criticality accident, it is important to establish the conditions for which such an accident becomes possible for any activity involving fissile material. Only when this information is known is it possible to establish the likelihood of actually achieving such conditions. It is therefore important that criticality safety analysts have confidence in the accuracy of their calculations. Confidence in analytical results can only be gained through comparison of those results with experimental data. The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the US Department of Energy. The project was managed through the Idaho National Engineering and Environmental Laboratory (INEEL), but involved nationally known criticality safety experts from Los Alamos National Laboratory, Lawrence Livermore National Laboratory, Savannah River Technology Center, Oak Ridge National Laboratory and the Y-12 Plant, Hanford, Argonne National Laboratory, and the Rocky Flats Plant. An International Criticality Safety Data Exchange component was added to the project during 1994 and the project became what is currently known as the International Criticality Safety Benchmark Evaluation Project (ICSBEP). Representatives from the United Kingdom, France, Japan, the Russian Federation, Hungary, Kazakhstan, Korea, Slovenia, Yugoslavia, Spain, and Israel are now participating on the project In December of 1994, the ICSBEP became an official activity of the Organization for Economic Cooperation and Development - Nuclear Energy Agency's (OECD-NEA) Nuclear Science Committee. The United States currently remains the lead country, providing most of the administrative support. The purpose of the ICSBEP is to: (1) identify and evaluate a comprehensive set of critical benchmark data; (2) verify the data, to the extent possible, by reviewing original and subsequently revised documentation, and by talking with the
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Promoting radiation protection and safety for X-ray inspection systems
International Nuclear Information System (INIS)
Maharaj, Harri P.
2008-01-01
This paper aims to present a regulatory perspective on radiation protection and safety relevant to facilities utilizing baggage X-ray inspection systems. Over the past several years there has been rapid growth in the acquisition and utilization of X-ray tube based inspection systems for security screening purposes worldwide. In addition to ensuring compliance with prescribed standards applicable to such X-ray systems, facilities subject to federal jurisdiction in Canada are required to comply with established codes of practice, which, not only are in accordance with occupational health and safety legislation but also are consistent with international guidance. Overall, these measures are aimed at reducing radiation risks and adverse health effects. Data, acquired in the past several years in a number of facilities through various instruments, namely, monitoring and surveillance, radiation safety audits, onsite evaluations, device registration processes and information developed, were considered in conjunction with detrimental traits. Changes are necessary to reduce radiation and safety risks from both an ALARA point of view and an accountability perspective. Establishing, developing, implementing and following a radiation protection program is warranted and advocated. Minimally, such a program shall be managed by a radiation safety officer. It shall promote and sustain a radiation safety culture in the workplace; shall ensure properly qualified individuals operate and service the X-ray systems in accordance with established and authorized procedures; and shall incorporate data recording and life cycle management principles. Such a program should be the norm for a facility that utilizes baggage X-ray inspection systems for security purposes, and it shall be subject to continuous regulatory oversight. (author)
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International Nuclear Information System (INIS)
Marono, M.; Pena, J.A.; Santamaria, J.
2006-01-01
The acknowledgement of industrial installations as complex systems in the early 1980s outstands as a milestone in the path to operational safety. Process plants are social-technical complex systems of a dynamic nature, whose properties depend not only on their components, but also on the inter-relations among them. A comprehensive assessment of operational safety requires a systemic approach, i.e. an integrated framework that includes all the relevant factors influencing safety. Risk analysis methodologies and safety management systems head the list of methods that point in this direction, but they normally require important plant resources. As a consequence, their use is frequently restricted to especially dangerous processes often driven by compliance with legal requirements. In this work a new safety index for the chemical industry, termed the 'Proceso' Index (standing for the Spanish terms for PROCedure for the Evaluation of Operational Safety), has been developed. PROCESO is based on the principles of systems theory, has a tree-like structure and considers 25 areas to guide the review of plant safety. The method uses indicators whose respective weight values have been obtained via an expert judgement technique. This paper describes the steps followed to develop this new Operational Safety Index, explains its structure and illustrates its application to process plants
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Development of digital safety system logic and control
International Nuclear Information System (INIS)
Nishikawa, H.; Sakamoto, H.
1995-01-01
Advanced-BWR (ABWR) uses total digital control and instrumentation (C and I) system. In particular, ABWR adopts a newly developed safety system using advanced digital technology. In the presentation the digital safety system design, manufacturing and factory validation test method are shortly overviewed. The digital safety system consists of micro-processor based digital controllers, data and information transmission by optical fibers and human-machine interface using color flat displays. This new developed safety system meet the nuclear safety requirements such as high reliability, independence of divisions, operability and maintainability. (2 refs., 4 figs., 1 tab.)
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Use of modern software - based instrumentation in safety critical systems
International Nuclear Information System (INIS)
Emmett, J.; Smith, B.
2005-01-01
Many Nuclear Power Plants are now ageing and in need of various degrees of refurbishment. Installed instrumentation usually uses out of date 'analogue' technology and is often no longer available in the market place. New technology instrumentation is generally un-qualified for nuclear use and specifically the new 'smart' technology contains 'firmware', (effectively 'soup' (Software of Uncertain Pedigree)) which must be assessed in accordance with relevant safety standards before it may be used in a safety application. Particular standards are IEC 61508 [1] and the British Energy (BE) PES (Programmable Electronic Systems) guidelines EPD/GEN/REP/0277/97. [2] This paper outlines a new instrument evaluation system, which has been developed in conjunction with the UK Nuclear Industry. The paper concludes with a discussion about on-line monitoring of Smart instrumentation in safety critical applications. (author)
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Food safety management systems performance in the lamb production chain
Oses, S.M.; Luning, P.A.; Jacxsens, L.; Jaime, I.; Rovira, J.
2012-01-01
This study describes a performance measurement of implemented food safety management system (FSMS) along the lamb chain using an FSMS-diagnostic instrument (FSMS-DI) and a Microbiological Assessment Scheme (MAS). Three slaughterhouses, 1 processing plant and 5 butcher shops were evaluated. All the
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Simons, Pascale A M; Houben, Ruud; Vlayen, Annemie; Hellings, Johan; Pijls-Johannesma, Madelon; Marneffe, Wim; Vandijck, Dominique
2015-02-01
The importance of a safety culture to maximize safety is no longer questioned. However, achieving sustainable culture improvements are less evident. Evidence is growing for a multifaceted approach, where multiple safety interventions are combined. Lean management is such an integral approach to improve safety, quality and efficiency and therefore, could be expected to improve the safety culture. This paper presents the effects of lean management activities on the patient safety culture in a radiotherapy institute. Patient safety culture was evaluated over a three year period using triangulation of methodologies. Two surveys were distributed three times, workshops were performed twice, data from an incident reporting system (IRS) was monitored and results were explored using structured interviews with professionals. Averages, chi-square, logistical and multi-level regression were used for analysis. The workshops showed no changes in safety culture, whereas the surveys showed improvements on six out of twelve dimensions of safety climate. The intention to report incidents not reaching patient-level decreased in accordance with the decreasing number of reports in the IRS. However, the intention to take action in order to prevent future incidents improved (factorial survey presented β: 1.19 with p: 0.01). Due to increased problem solving and improvements in equipment, the number of incidents decreased. Although the intention to report incidents not reaching patient-level decreased, employees experienced sustained safety awareness and an increased intention to structurally improve. The patient safety culture improved due to the lean activities combined with an organizational restructure, and actual patient safety outcomes might have improved as well. Copyright © 2014 Elsevier Ltd. All rights reserved.
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EMS helicopter incidents reported to the NASA Aviation Safety Reporting System
Connell, Linda J.; Reynard, William D.
1993-01-01
The objectives of this evaluation were to: Identify the types of safety-related incidents reported to the Aviation Safety Reporting System (ASRS) in Emergency Medical Service (EMS) helicopter operations; Describe the operational conditions surrounding these incidents, such as weather, airspace, flight phase, time of day; and Assess the contribution to these incidents of selected human factors considerations, such as communication, distraction, time pressure, workload, and flight/duty impact.
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Economic evaluation in patient safety: a literature review of methods.
de Rezende, Bruna Alves; Or, Zeynep; Com-Ruelle, Laure; Michel, Philippe
2012-06-01
Patient safety practices, targeting organisational changes for improving patient safety, are implemented worldwide but their costs are rarely evaluated. This paper provides a review of the methods used in economic evaluation of such practices. International medical and economics databases were searched for peer-reviewed publications on economic evaluations of patient safety between 2000 and 2010 in English and French. This was complemented by a manual search of the reference lists of relevant papers. Grey literature was excluded. Studies were described using a standardised template and assessed independently by two researchers according to six quality criteria. 33 articles were reviewed that were representative of different patient safety domains, data types and evaluation methods. 18 estimated the economic burden of adverse events, 3 measured the costs of patient safety practices and 12 provided complete economic evaluations. Healthcare-associated infections were the most common subject of evaluation, followed by medication-related errors and all types of adverse events. Of these, 10 were selected that had adequately fulfilled one or several key quality criteria for illustration. This review shows that full cost-benefit/utility evaluations are rarely completed as they are resource intensive and often require unavailable data; some overcome these difficulties by performing stochastic modelling and by using secondary sources. Low methodological transparency can be a problem for building evidence from available economic evaluations. Investing in the economic design and reporting of studies with more emphasis on defining study perspectives, data collection and methodological choices could be helpful for strengthening our knowledge base on practices for improving patient safety.
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2012-02-24
... Organizations: Voluntary Relinquishment From UAB Health System Patient Safety Organization AGENCY: Agency for... notification of voluntary relinquishment from the UAB Health System Patient Safety Organization of its status as a Patient Safety Organization (PSO). The Patient Safety and Quality Improvement Act of 2005...
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Zaki, Gehan R; El-Marakby, Fadia A; H Deign El-Nor, Yasser; Nofal, Faten H; Zakaria, Adel M
2012-12-01
Safety performance evaluation enables decision makers improve safety acts. In Sudan, accident records, statistics, and safety performance were not evaluated before maintenance of accident records became mandatory in 2005. This study aimed at evaluating and comparing safety performance by accident records among different cities and industrial sectors in Khartoum state, Sudan, during the period from 2005 to 2007. This was a retrospective study, the sample in which represented all industrial enterprises in Khartoum state employing 50 workers or more. All industrial accident records of the Ministry of Manpower and Health and those of different enterprises during the period from 2005 to 2007 were reviewed. The safety performance indicators used within this study were the frequency-severity index (FSI) and fatal and disabling accident frequency rates (DAFR). In Khartoum city, the FSI [0.10 (0.17)] was lower than that in Bahari [0.11 (0.21)] and Omdurman [0.84 (0.34)]. It was the maximum in the chemical sector [0.33 (0.64)] and minimum in the metallurgic sector [0.09 (0.19)]. The highest DAFR was observed in Omdurman [5.6 (3.5)] and in the chemical sector [2.5 (4.0)]. The fatal accident frequency rate in the mechanical and electrical engineering industry was the highest [0.0 (0.69)]. Male workers who were older, divorced, and had lower levels of education had the lowest safety performance indicators. The safety performance of the industrial enterprises in Khartoum city was the best. The safety performance in the chemical sector was the worst with regard to FSI and DAFR. The age, sex, and educational level of injured workers greatly affect safety performance.
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Directory of Open Access Journals (Sweden)
Kuligowska Ewa
2017-06-01
Full Text Available The material given in this paper delivers the procedure for numerical approach that allows finding the main practically important safety characteristics of the complex technical systems at the variable operation conditions including operating environment threats. The obtained results are applied to the safety evaluation of the maritime ferry technical system. It is assumed that the conditional safety functions are different at various operation states and have the exponential forms. Using the procedure and the program written in Mathematica, the considered maritime ferry technical system main characteristics including: the conditional and the unconditional expected values and standard deviations of the system lifetimes, the unconditional safety function and the risk function are determined.
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International Nuclear Information System (INIS)
Mengolini, A.; Debarberis, L.
2008-01-01
Safety performance indicators are widely collected and used in hazardous installations. The IAEA, OECD and other international organisations have developed approaches that strongly promote deployment of safety performance indicators. These indicators focus mainly on operational performance, but some of them also address organisational and safety culture aspects. However, operators of hazardous installations, in particular those with limited resources and time constraints, often find it difficult to collect the large number of different safety performance indicators. Moreover, they also have difficulties with giving a meaning to the numbers and trends recorded, especially to those that should reflect a positive safety culture. In this light, the aim of this article is to address the need to monitor and assess progress on implementation of a programme to enhance safety and organisational culture. It proposes a specific process-view approach to effectiveness evaluation of organisational and safety culture indicators by means of a multi-level system in which safety processes and staff involvement in defining improvement activities are central. In this way safety becomes fully embedded in staff activities. Key members of personnel become directly involved in identifying and supplying leading indicators relating to their own daily activity and become responsible and accountable for keeping the measurement system alive. Besides use of lagging indicators, particular emphasis is placed on the importance of identifying and selecting leading indicators which can be used to drive safety performance for organisational and safety culture aspects as well
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Mengolini, A; Debarberis, L
2008-06-30
Safety performance indicators are widely collected and used in hazardous installations. The IAEA, OECD and other international organisations have developed approaches that strongly promote deployment of safety performance indicators. These indicators focus mainly on operational performance, but some of them also address organisational and safety culture aspects. However, operators of hazardous installations, in particular those with limited resources and time constraints, often find it difficult to collect the large number of different safety performance indicators. Moreover, they also have difficulties with giving a meaning to the numbers and trends recorded, especially to those that should reflect a positive safety culture. In this light, the aim of this article is to address the need to monitor and assess progress on implementation of a programme to enhance safety and organisational culture. It proposes a specific process-view approach to effectiveness evaluation of organisational and safety culture indicators by means of a multi-level system in which safety processes and staff involvement in defining improvement activities are central. In this way safety becomes fully embedded in staff activities. Key members of personnel become directly involved in identifying and supplying leading indicators relating to their own daily activity and become responsible and accountable for keeping the measurement system alive. Besides use of lagging indicators, particular emphasis is placed on the importance of identifying and selecting leading indicators which can be used to drive safety performance for organisational and safety culture aspects as well.
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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.)
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Evaluation and Customization of WHO Safety Checklist for Patient Safety in Otorhinolaryngology.
Dabholkar, Yogesh; Velankar, Haritosh; Suryanarayan, Sneha; Dabholkar, Twinkle Y; Saberwal, Akanksha A; Verma, Bhavika
2018-03-01
The WHO has designed a safe surgery checklist to enhance communication and awareness of patient safety during surgery and to minimise complications. WHO recommends that the check-list be evaluated and customised by end users as a tool to promote safe surgery. The aim of present study was to evaluate the impact of WHO safety checklist on patient safety awareness in otorhinolaryngology and to customise it for the speciality. A prospective structured questionnaire based study was done in ENT operating room for duration of 1 month each for cases, before and after implementation of safe surgery checklist. The feedback from respondents (surgeons, nurses and anaesthetists) was used to arrive at a customised checklist for otolaryngology as per WHO guidelines. The checklist significantly improved team member's awareness of patient's identity (from 17 to 86%) and each other's identity and roles (from 46 to 94%) and improved team communication (from 73 to 92%) in operation theatre. There was a significant improvement in preoperative check of equipment and critical events were discussed more frequently. The checklist could be effectively customised to suit otolaryngology needs as per WHO guidelines. The modified checklist needs to be validated by otolaryngology associations. We conclude from our study that the WHO Surgical safety check-list has a favourable impact on patient safety awareness, team-work and communication of operating team and can be customised for otolaryngology setting.
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A guideline for comprehensive evaluation of a licensee's effort to cultivate safety culture
International Nuclear Information System (INIS)
Makino, Maomi; Ishii, Yoichi
2009-01-01
The nuclear industry in Japan had held excellent performance in safety in the world during 90's. However recent events stem from organizational factors and defects of safety culture are pointed out in their contexts. In order to reduce accidents caused by organizational factors, the Japanese Regulatory body NISA (Nuclear and Industrial Safety Agency) decided to evaluate a licensee's effort for the cultivation of safety culture, and to order all licensses to add the provision of cultivating safety culture to their safety preservation rules. The inspection for the new safety preservation rules started in December, 2007. For a measure of evaluation by resident inspectors, NISA and the Japan Nuclear Energy Safety Organization (JNES) prepared a guideline for the prevention of degradation of safety culture and organizational climate. In this guideline, 14 items were defined as the components of the safety culture or as the viewpoints to evaluate the effort made to prevent any degradation of safety culture and organizational climate in the daily safety preservation activities. The 14 items are also used to establish the method to comprehensively evaluate the effort to prevent degradation of safety culture and organizational climate. This method consists of 10 steps: two steps to taken prior to start of the evaluation, two steps to be taken during the evaluation period, 5 steps to be taken during a comprehensive evaluation period and a final step to be taken for comprehensive findings for safety culture. This paper mainly describes the viewpoints to evaluate comprehensively a licensee's effort for cultivation of safety culture. (author)
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An evaluation of safety-critical Java on a Java processor
DEFF Research Database (Denmark)
Rios Rivas, Juan Ricardo; Schoeberl, Martin
2014-01-01
The safety-critical Java (SCJ) specification provides a restricted set of the Java language intended for applications that require certification. In order to test the specification, implementations are emerging and the need to evaluate those implementations in a systematic way is becoming important....... In this paper we evaluate our SCJ implementation which is based on the Java Optimized Processor JOP and we measure different performance and timeliness criteria relevant to hard real-time systems. Our implementation targets Level 0 and Level1 of the specification and to test it we use a series of micro...
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Safety assessment of emergency power systems for nuclear power plants
International Nuclear Information System (INIS)
1992-01-01
This publication is intended to assist the safety assessor within a regulatory body, or one working as a consultant, in assessing the safety of a given design of the emergency power systems (EPS) for a nuclear power plant. The present publication refers closely to the NUSS Safety Guide 50-SG-D7 (Rev. 1), Emergency Power Systems at Nuclear Power Plants. It covers therefore exactly the same technical subject as that Safety Guide. In view of its objective, however, it attempts to help in the evaluation of possible technical solutions which are intended to fulfill the safety requirements. Section 2 clarifies the scope further by giving an outline of the assessment steps in the licensing process. After a general outline of the assessment process in relation to the licensing of a nuclear power plant, the publication is divided into two parts. First, all safety issues are presented in the form of questions that have to be answered in order for the assessor to be confident of a safe design. The second part presents the same topics in tabulated form, listing the required documentation which the assessor has to consult and those international and national technical standards pertinent to the topics. An extensive reference list provides information on standards. 1 tab
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INTEGRATED SAFETY MANAGEMENT SYSTEM IN AIR TRAFFIC SERVICES
Directory of Open Access Journals (Sweden)
Volodymyr Kharchenko
2014-06-01
Full Text Available The article deals with the analysis of the researches conducted in the field of safety management systems.Safety management system framework, methods and tools for safety analysis in Air Traffic Control have been reviewed.Principles of development of Integrated safety management system in Air Traffic Services have been proposed.
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Packaging Evaluation Approach to Improve Cosmetic Product Safety
Benedetta Briasco; Priscilla Capra; Arianna Cecilia Cozzi; Barbara Mannucci; Paola Perugini
2016-01-01
In the Regulation 1223/2009, evaluation of packaging has become mandatory to assure cosmetic product safety. In fact, the safety assessment of a cosmetic product can be successfully carried out only if the hazard deriving from the use of the designed packaging for the specific product is correctly evaluated. Despite the law requirement, there is too little information about the chemical-physical characteristics of finished packaging and the possible interactions between formulation and packag...
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Safety analysis report for packaging (onsite) sample pig transport system
International Nuclear Information System (INIS)
MCCOY, J.C.
1999-01-01
This Safety Analysis Report for Packaging (SARP) provides a technical evaluation of the Sample Pig Transport System as compared to the requirements of the U.S. Department of Energy, Richland Operations Office (RL) Order 5480.1, Change 1, Chapter III. The evaluation concludes that the package is acceptable for the onsite transport of Type B, fissile excepted radioactive materials when used in accordance with this document
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Safety analysis report for packaging (onsite) sample pig transport system
Energy Technology Data Exchange (ETDEWEB)
MCCOY, J.C.
1999-03-16
This Safety Analysis Report for Packaging (SARP) provides a technical evaluation of the Sample Pig Transport System as compared to the requirements of the U.S. Department of Energy, Richland Operations Office (RL) Order 5480.1, Change 1, Chapter III. The evaluation concludes that the package is acceptable for the onsite transport of Type B, fissile excepted radioactive materials when used in accordance with this document.
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Analysis and design on airport safety information management system
Directory of Open Access Journals (Sweden)
Yan Lin
2017-01-01
Full Text Available Airport safety information management system is the foundation of implementing safety operation, risk control, safety performance monitor, and safety management decision for the airport. The paper puts forward the architecture of airport safety information management system based on B/S model, focuses on safety information processing flow, designs the functional modules and proposes the supporting conditions for system operation. The system construction is helpful to perfecting the long effect mechanism driven by safety information, continually increasing airport safety management level and control proficiency．
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Study of evaluation techniques of software safety and reliability in nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Youn, Cheong; Baek, Y. W.; Kim, H. C.; Park, N. J.; Shin, C. Y. [Chungnam National Univ., Taejon (Korea, Republic of)
1999-04-15
Software system development process and software quality assurance activities are examined in this study. Especially software safety and reliability requirements in nuclear power plant are investigated. For this purpose methodologies and tools which can be applied to software analysis, design, implementation, testing, maintenance step are evaluated. Necessary tasks for each step are investigated. Duty, input, and detailed activity for each task are defined to establish development process of high quality software system. This means applying basic concepts of software engineering and principles of system development. This study establish a guideline that can assure software safety and reliability requirements in digitalized nuclear plant systems and can be used as a guidebook of software development process to assure software quality many software development organization.
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International Nuclear Information System (INIS)
1994-08-01
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the system 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR section 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of ABB-CE's System 80 design from which it evolved. Unique features of the System 80+ design include: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE's application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 2, contains Chapters 15 through 22 and Appendices A through E
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System theory and safety models in Swedish, UK, Dutch and Australian road safety strategies.
Hughes, B P; Anund, A; Falkmer, T
2015-01-01
Road safety strategies represent interventions on a complex social technical system level. An understanding of a theoretical basis and description is required for strategies to be structured and developed. Road safety strategies are described as systems, but have not been related to the theory, principles and basis by which systems have been developed and analysed. Recently, road safety strategies, which have been employed for many years in different countries, have moved to a 'vision zero', or 'safe system' style. The aim of this study was to analyse the successful Swedish, United Kingdom and Dutch road safety strategies against the older, and newer, Australian road safety strategies, with respect to their foundations in system theory and safety models. Analysis of the strategies against these foundations could indicate potential improvements. The content of four modern cases of road safety strategy was compared against each other, reviewed against scientific systems theory and reviewed against types of safety model. The strategies contained substantial similarities, but were different in terms of fundamental constructs and principles, with limited theoretical basis. The results indicate that the modern strategies do not include essential aspects of systems theory that describe relationships and interdependencies between key components. The description of these strategies as systems is therefore not well founded and deserves further development. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Safety system function trend indicator: Theory and test application
International Nuclear Information System (INIS)
Azarm, M.A.; Carbonaro, J.F.; Boccio, J.L.; Vesely, W.E.
1989-01-01
The purpose of this paper is to summarize research conducted on the development and validation of quantitative indicators of safety performance. This work, performed under the Risk-Based Performance Indicator (RBPI) Project, FIN A-3295, for the Office of Research (RES), is considered part of NRC's Performance Indicator Program which is being coordinated through the Office for the Analysis and Evaluation of Operational Data (AEOD). The program originally focused on risk-based indicators at high levels of safety indices (e.g., core-damage frequency, functional unavailabilities, and sequence monitoring). The program was then redirected towards a more amenable goal, safety system unavailability indicators, mainly due to the lack of PRA models and plant data. In that regard, BNL published a technical report that introduced the concept of cycle-based indicators and also described various alternatives of monitoring safety system unavailabilities. Further simplification of these indicators was requested by NRC to facilitate their applications to all plants in a timely manner. This resulted in the development of Safety System Function Trend (SSFT) indicators which minimize the need for detailed system model as well as component history. The theoretical bases for these indicators were developed through various simulation studies to determine the ease of detecting a trend and/or unacceptable performance. These indicators, along with several other indicators, were then generated and compared using plant data as a part of a test application. The SSFT indicators, specifically, were constructed for a total of eight plants, consisting of two systems per plant. Emphasis was placed on examining relative changes, as well as the indicator's actual level. Both the trend and actual indicator level were found to be important in identifying plants with potential problems
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Design an optimum safety policy for personnel safety management - A system dynamic approach
International Nuclear Information System (INIS)
Balaji, P.
2014-01-01
Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making
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Design an optimum safety policy for personnel safety management - A system dynamic approach
Energy Technology Data Exchange (ETDEWEB)
Balaji, P. [The Glocal University, Mirzapur Pole, Delhi- Yamuntori Highway, Saharanpur 2470001 (India)
2014-10-06
Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making.
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Design an optimum safety policy for personnel safety management - A system dynamic approach
Balaji, P.
2014-10-01
Personnel safety management (PSM) ensures that employee's work conditions are healthy and safe by various proactive and reactive approaches. Nowadays it is a complex phenomenon because of increasing dynamic nature of organisations which results in an increase of accidents. An important part of accident prevention is to understand the existing system properly and make safety strategies for that system. System dynamics modelling appears to be an appropriate methodology to explore and make strategy for PSM. Many system dynamics models of industrial systems have been built entirely for specific host firms. This thesis illustrates an alternative approach. The generic system dynamics model of Personnel safety management was developed and tested in a host firm. The model was undergone various structural, behavioural and policy tests. The utility and effectiveness of model was further explored through modelling a safety scenario. In order to create effective safety policy under resource constraint, DOE (Design of experiment) was used. DOE uses classic designs, namely, fractional factorials and central composite designs. It used to make second order regression equation which serve as an objective function. That function was optimized under budget constraint and optimum value used for safety policy which shown greatest improvement in overall PSM. The outcome of this research indicates that personnel safety management model has the capability for acting as instruction tool to improve understanding of safety management and also as an aid to policy making.
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International Nuclear Information System (INIS)
1989-04-01
This safety evaluation report (SER) on the information submitted by the Tennessee Valley Authority (TVA) in its Nuclear Performance Plan, through Revision 2, for the Browns Ferry Nuclear Power Station and in supporting documents has been prepared by the US Nuclear Regulatory Commission staff. The plan addresses the plant-specific concerns requiring resolution before startup of Unit 2. The staff will inspect implementation of those programs. Where systems are common to Units 1 and 2 or to Units 2 and 3, the staff safety evaluations of those systems are included herein. 3 refs
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Safety significance of ATR [Advanced Test Reactor] passive safety response attributes
International Nuclear Information System (INIS)
Atkinson, S.A.
1989-01-01
The Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory was designed with some passive safety response attributes which contribute to the safety posture of the facility. The three passive safety attributes being evaluated in the paper are: (1) In-core and in-vessel natural convection cooling, (2) a passive heat sink capability of the ATR primary coolant system (PCS) for the transfer of decay power from the uninsulated piping to the confinement, and (3) gravity feed of emergency coolant makeup. The safety significance of the ATR passive safety response attributes is that the reactor can passively respond for most transients, given a reactor scram, to provide adequate decay power removal and a significant time for operator action should the normal active heat removal systems and their backup systems both fail. The ATR Interim Level 1 Probabilistic Risk Assessment (PRA) model ands results were used to evaluate the significance to ATR fuel damage frequency (or probability) of the above three passive response attributes. The results of the evaluation indicate that the first attribute is a major safety characteristic of the ATR. The second attribute has a noticeable but only minor safety significance. The third attribute has no significant influence on the ATR Level 1 PRA because of the diversity and redundancy of the ATR firewater injection system (emergency coolant system). 8 refs., 4 figs., 1 tab
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International Nuclear Information System (INIS)
Kuzmina, I.
2016-01-01
The Probabilistic Safety Assessment (PSA) represents a comprehensive conceptual and analytical tool for quantitative evaluation of risk of undesirable consequences from nuclear facilities and drawing on qualitative insights for nuclear safety. PSA considers various technical, human, and organizational factors in an integral manner thus explicitly pursuing a true ‘systemic approach’ to safety and enabling holistic insights for further safety improvement. Human Reliability Analysis (HRA) is one of the major tasks within PSA. The poster paper provides an overview of the objectives and scope of PSA and HRA and discusses on further needs in the area of HRA. (author)
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Meeting the maglev system's safety requirements
Energy Technology Data Exchange (ETDEWEB)
Pierick, K
1983-12-01
The author shows how the safety requirements of the maglev track system derive from the general legal conditions for the safety of tracked transport. It is described how their compliance beyond the so-called ''development-accompanying'' and ''acceptance-preparatory'' safety work can be assured for the Transrapid test layout (TVE) now building in Emsland and also for later application as public transport system in Germany within the meaning of the General Railway Act.
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29 CFR 1960.80 - Secretary's evaluations of agency occupational safety and health programs.
2010-07-01
... EMPLOYEE OCCUPATIONAL SAFETY AND HEALTH PROGRAMS AND RELATED MATTERS Evaluation of Federal Occupational Safety and Health Programs § 1960.80 Secretary's evaluations of agency occupational safety and health... evaluating an agency's occupational safety and health program. To accomplish this, the Secretary shall...
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Bump, Gregory M; Calabria, Jaclyn; Gosman, Gabriella; Eckart, Catherine; Metro, David G; Jasti, Harish; McCausland, Julie B; Itri, Jason N; Patel, Rita M; Buchert, Andrew
2015-03-01
The Accreditation Council for Graduate Medical Education has begun to evaluate teaching institutions' learning environments with Clinical Learning Environment Review visits, including trainee involvement in institutions' patient safety and quality improvement efforts. We sought to address the dearth of metrics that assess trainee patient safety perceptions of the clinical environment. Using the Hospital Survey on Patient Safety Culture (HSOPSC), we measured resident and fellow perceptions of patient safety culture in 50 graduate medical education programs at 10 hospitals within an integrated health system. As institution-specific physician scores were not available, resident and fellow scores on the HSOPSC were compared with national data from 29 162 practicing providers at 543 hospitals. Of the 1337 residents and fellows surveyed, 955 (71.4%) responded. Compared with national practicing providers, trainees had lower perceptions of patient safety culture in 6 of 12 domains, including teamwork within units, organizational learning, management support for patient safety, overall perceptions of patient safety, feedback and communication about error, and communication openness. Higher perceptions were observed for manager/supervisor actions promoting patient safety and for staffing. Perceptions equaled national norms in 4 domains. Perceptions of patient safety culture did not improve with advancing postgraduate year. Trainees in a large integrated health system have variable perceptions of patient safety culture, as compared with national norms for some practicing providers. Administration of the HSOPSC was feasible and acceptable to trainees, and may be used to track perceptions over time.
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Safety evaluation of ventilation networks in case of fire
International Nuclear Information System (INIS)
Perdriau, P.; Pourprix, M.; Raboin, S.; Rouyer, J.L.; Tarrago, X.
1983-01-01
Several teams from CEA have cooperated to produce a code for modeling ventilation networks under accidental conditions in nuclear facilities. The objective is to study responses to a network to perturbations which are either mechanical or thermal. Such a tool was necessary for safety and protection studies because ventilation network performances are difficult to evaluate when the network gets complex. There was no requirement for a very sophisticated code, considering the margin of error which generally characterizes the ventilation measurements, but this code should be well validated to become a reliable tool for pointing out safety problems at the design stage and during the operating life of the ventilation system. The code has been called PIAF. It solves a set of equations which simulate a ventilation network in a permanent regime
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Song, Hai-bo; Du, Xiao-xi; Ren, Jing-tian; Yang, Le; Guo, Xiao-xin; Pang, Yu
2015-04-01
The adverse reaction monitoring is important in warning the risks of traditional Chinese medicines at an early stage, finding potential quality problems and ensuring the safe clinical medication. In the study, efforts were made to investigate the risk signal mining techniques in line with the characteristics of traditional Chinese medicines, particularly the complexity in component, processing, compatibility, preparation and clinical medication, find early risk signals of traditional Chinese medicines and establish a traditional Chinese medicine safety evaluation system based on adverse reaction risk signals, in order to improve the target studies on traditional Chinese medicine safety, effective and timely control risks and solve the existing frequent safety issue in traditional Chinese medicines.
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29 CFR 1960.11 - Evaluation of occupational safety and health performance.
2010-07-01
... 29 Labor 9 2010-07-01 2010-07-01 false Evaluation of occupational safety and health performance. 1960.11 Section 1960.11 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH... AND HEALTH PROGRAMS AND RELATED MATTERS Administration § 1960.11 Evaluation of occupational safety and...
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A concept of safety indicator system for nuclear power plants
International Nuclear Information System (INIS)
Lehtinen, E.
1995-12-01
The fundamental principle in the safety technology of nuclear power is embodied in the strategy of defence in depth. The defence lines of the strategy, completed with a PSA logic model and structure, are considered to provide an appropriate framework for identification and structuring of the operational safety performance areas for nuclear power plants. Once these areas are identified the safety indicators can be defined. Based on this approach a concept of safety indicator system was outlined. About one hundred indicator specifications have been collected, refined and related to the performance areas. The specifications enable the utilities and authorities to check the coverage of their indicators set from the operational safety point of view and select or refine indicators for testing and routine use. Finally various statistical approaches and methods for using indicators in performance evaluation are presented. (orig.) (16 refs., 2 figs., 2 tabs.)
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A reliability evaluation method for NPP safety DCS application software
International Nuclear Information System (INIS)
Li Yunjian; Zhang Lei; Liu Yuan
2014-01-01
In the field of nuclear power plant (NPP) digital i and c application, reliability evaluation for safety DCS application software is a key obstacle to be removed. In order to quantitatively evaluate reliability of NPP safety DCS application software, this paper propose a reliability evaluating method based on software development life cycle every stage's v and v defects density characteristics, by which the operating reliability level of the software can be predicted before its delivery, and helps to improve the reliability of NPP safety important software. (authors)
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Strategy to safety grade systems replacements
International Nuclear Information System (INIS)
Stimler, M.; Sullivan, K.E.; Trebincevic, I.
1993-01-01
The introduction of digital instrumentation and control systems in nuclear power plants is characterized by the need to satisfy the requirements of safety, reliability and man-machine ergonomics. Today digital instrumentation and control systems meet these requirements and the trend in Europe is towards full digital based nuclear power plant control systems. This paper describes Siemens (KWU) experience in nuclear power plants and development in trends within Europe. Topics which are the subject of major concern to NPP operators addressed in this paper are: human performance factors - man-machine interface; operating philosophy; safety, availability and reliability. Other aspects addressed are: Siemens open-quotes defense in depthclose quotes concept, description of Siemens digital I ampersand C systems, safety requirements and systems, I ampersand C qualification, control room ergonomics, information systems and retrofitting experience
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The International Criticality Safety Benchmark Evaluation Project (ICSBEP)
International Nuclear Information System (INIS)
Briggs, J.B.
2003-01-01
The International Criticality Safety Benchmark Evaluation Project (ICSBEP) was initiated in 1992 by the United States Department of Energy. The ICSBEP became an official activity of the Organisation for Economic Cooperation and Development (OECD) - Nuclear Energy Agency (NEA) in 1995. Representatives from the United States, United Kingdom, France, Japan, the Russian Federation, Hungary, Republic of Korea, Slovenia, Yugoslavia, Kazakhstan, Israel, Spain, and Brazil are now participating. The purpose of the ICSBEP is to identify, evaluate, verify, and formally document a comprehensive and internationally peer-reviewed set of criticality safety benchmark data. The work of the ICSBEP is published as an OECD handbook entitled 'International Handbook of Evaluated Criticality Safety Benchmark Experiments.' The 2003 Edition of the Handbook contains benchmark model specifications for 3070 critical or subcritical configurations that are intended for validating computer codes that calculate effective neutron multiplication and for testing basic nuclear data. (author)
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International Nuclear Information System (INIS)
Chang, Soon Heung; Kim, Sang Ho; Choi, Jae Young
2013-01-01
Highlights: • We newly propose the design concept of integrated passive safety system (IPSS). • It has five safety functions for decay heat removal and severe accident mitigation. • Simulations for IPSS show that core melt does not occur in accidents with SBO. • IPSS can achieve the passive in-vessel retention and ex-vessel cooling strategy. • The applicability of IPSS is high due to the installation outside the containment. -- Abstract: The design concept of integrated passive safety system (IPSS) which can perform various passive safety functions is proposed in this paper. It has the various functions of passive decay heat removal system, passive safety injection system, passive containment cooling system, passive in-vessel retention and cavity flooding system, and filtered venting system with containment pressure control. The objectives of this paper are to propose the conceptual design of an IPSS and to estimate the design characters of the IPSS with accident simulations using MARS code. Some functions of the IPSS are newly proposed and the other functions are reviewed with the integration of the functions. Consequently, all of the functions are modified and integrated for simplicity of the design in preparation for beyond design based accidents (BDBAs) focused on a station black out (SBO). The simulation results with the IPSS show that the decay heat can be sufficiently removed in accidents that occur with a SBO. Also, the molten core can be retained in a vessel via the passive in-vessel retention strategy of the IPSS. The actual application potential of the IPSS is high, as numerous strong design characters are evaluated. The installation of the IPSS into the original design of a nuclear power plant requires minimal design change using the current penetrations of the containment. The functions are integrated in one or two large tanks outside the containment. Furthermore, the operation time of the IPSS can be increased by refilling coolant from the
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International Nuclear Information System (INIS)
Uchida, S.; Takiguchi, H.; Ishigure, K.
2006-01-01
Data acquisition, processing and evaluation systems have been applied in major Japanese PWRs and BWRs to provide (1) reliable and quick data acquisition with manpower savings in plant chemical laboratories and (2) smooth and reliable information transfer among chemists, plant operators, and supervisors. Data acquisition systems in plants consist of automatic and semi-automatic instruments for chemical analyses, e. g., X-ray fluorescence analysis and ion chromatography, while data processing systems consist of PC base-sub-systems, e.g., data storage, reliability evaluation, clear display, and document preparation for understanding the plant own water chemistry trends. Precise and reliable evaluations of water chemistry data are required in order to improve plant reliability and safety. For this, quality assurance of the water chemistry data acquisition system is needed. At the same time, theoretical models are being applied to bridge the gaps between measured water chemistry data and the information desired to understand the interaction of materials and cooling water in plants. Major models which have already been applied for plant evaluation are: (1) water radiolysis models for BWRs and PWRs; (2) crevice radiolysis model for SCC in BWRs; and (3) crevice pH model for SG tubing in PWRs. High temperature water chemistry sensors and automatic plant diagnostic systems have been applied in only restricted areas. ECP sensors are gaining popularity as tools to determine the effects of hydrogen injection in BWR systems. Automatic plant diagnostic systems based on artificial intelligence will be more popular after having sufficient experience with off line diagnostic systems. (author)
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System safety education focused on system management
Grose, V. L.
1971-01-01
System safety is defined and characteristics of the system are outlined. Some of the principle characteristics include role of humans in hazard analysis, clear language for input and output, system interdependence, self containment, and parallel analysis of elements.
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Yiu, Nicole S N; Sze, N N; Chan, Daniel W M
2018-02-01
In the 1980s, the safety management system (SMS) was introduced in the construction industry to mitigate against workplaces hazards, reduce the risk of injuries, and minimize property damage. Also, the Factories and Industrial Undertakings (Safety Management) Regulation was introduced on 24 November 1999 in Hong Kong to empower the mandatory implementation of a SMS in certain industries including building construction. Therefore, it is essential to evaluate the effectiveness of the SMS in improving construction safety and identify the factors that influence its implementation in Hong Kong. A review of the current state-of-the-practice helped to establish the critical success factors (CSFs), benefits, and difficulties of implementing the SMS in the construction industry, while structured interviews were used to establish the key factors of the SMS implementation. Results of the state-of-the-practice review and structured interviews indicated that visible senior commitment, in terms of manpower and cost allocation, and competency of safety manager as key drivers for the SMS implementation. More so, reduced accident rates and accident costs, improved organization framework, and increased safety audit ratings were identified as core benefits of implementing the SMS. Meanwhile, factors such as insufficient resources, tight working schedule, and high labor turnover rate were the key challenges to the effective SMS implementation in Hong Kong. The findings of the study were consistent and indicative of the future development of safety management practice and the sustainable safety improvement of Hong Kong construction industry in the long run. Copyright © 2018 National Safety Council and Elsevier Ltd. All rights reserved.
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Safety Management System in Croatia Control Ltd.
Pavlin, Stanislav; Sorić, Vedran; Bilać, Dragan; Dimnik, Igor; Galić, Daniel
2009-01-01
International Civil Aviation Organization and other international aviation organizations regulate the safety in civil aviation. In the recent years the International Civil Aviation Organization has introduced the concept of the safety management system through several documents among which the most important is the 2006 Safety Management Manual. It treats the safety management system in all the segments of civil aviation, from carriers, aerodromes and air traffic control to design, constructi...
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International Nuclear Information System (INIS)
St Leger-Barter, G.
1980-11-01
This report documents the technical evaluation and review of NRC Safety Topic VI-10.A, associated with the electrical, instrumentation, and control portions of the testing of reactor trip systems and engineered safety features including response time for the Dresden II nuclear power plant, using current licensing criteria
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Institut Laue Langevin. Complementary safety evaluation in the light of the Fukushima accident
International Nuclear Information System (INIS)
2011-01-01
This report proposes a complementary safety evaluation of Laue Langevin Institute (ILL) in Grenoble, one of the French basic nuclear installations (BNI, in French INB) in the light of the Fukushima accident. This evaluation takes the following risks into account: risks of flooding, earthquake, loss of power supply and loss of cooling, in addition to operational management of accident situations. It presents some characteristics of the installation (location, operator, industrial environment, installation characteristics), reports a macroscopic safety study focused of installation structures, systems and components, evaluates the seismic risk (installation sizing, margin evaluation, reinforcement propositions, possible ground acceleration levels, reactivity, cooling and confinement control), evaluates the flooding risk (installation sizing, margin evaluation), briefly examines other extreme natural phenomena (extreme meteorological conditions related to flooding, earthquake with flooding). It analyzes the risk of a loss of power supply and of cooling (loss of external and internal electric sources, loss of the ultimate cooling system). It analyzes the management of severe accidents: core cooling management, confinement management after fuel damage, cooling management of irradiated fuel element in pool, cliff effect for these three types of accident. It discusses the conditions of the use of subcontractors. In conclusion, reinforcement and strengthening measures are proposed and discussed
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Seismic safety margin assessment program (Annual safety research report, JFY 2010)
International Nuclear Information System (INIS)
Suzuki, Kenichi; Iijima, Toru; Inagaki, Masakatsu; Taoka, Hideto; Hidaka, Shinjiro
2011-01-01
Seismic capacity test data, analysis method and evaluation code provided by Seismic Safety Margin Assessment Program have been utilized for the support of seismic back-check evaluation of existing plants. The summary of the program in 2010 is as follows. 1. Component seismic capacity test and quantitative seismic capacity evaluation. Many seismic capacity tests of various snubbers were conducted and quantitative seismic capacities were evaluated. One of the emergency diesel generator partial-model seismic capacity tests was conducted and quantitative seismic capacity was evaluated. Some of the analytical evaluations of piping-system seismic capacities were conducted. 2. Analysis method for minute evaluation of component seismic response. The difference of seismic response of large components such as primary containment vessel and reactor pressure vessel when they were coupled with 3-dimensional FEM building model or 1-dimensional lumped mass building model, was quantitatively evaluated. 3. Evaluation code for quantitative evaluation of seismic safety margin of systems, structures and components. As the example, quantitative evaluation of seismic safety margin of systems, structures and components were conducted for the reference plant. (author)
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Evaluation of the food safety training for food handlers in restaurant operations
Park, Sung-Hee; Kwak, Tong-Kyung; Chang, Hye-Ja
2010-01-01
This study examined the extent of improvement of food safety knowledge and practices of employee through food safety training. Employee knowledge and practice for food safety were evaluated before and after the food safety training program. The training program and questionnaires for evaluating employee knowledge and practices concerning food safety, and a checklist for determining food safety performance of restaurants were developed. Data were analyzed using the SPSS program. Twelve restaur...
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Safety-related control air systems - approved 1977
International Nuclear Information System (INIS)
Anon.
1978-01-01
This standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements
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Test interval optimization of safety systems of nuclear power plant using fuzzy-genetic approach
International Nuclear Information System (INIS)
Durga Rao, K.; Gopika, V.; Kushwaha, H.S.; Verma, A.K.; Srividya, A.
2007-01-01
Probabilistic safety assessment (PSA) is the most effective and efficient tool for safety and risk management in nuclear power plants (NPP). PSA studies not only evaluate risk/safety of systems but also their results are very useful in safe, economical and effective design and operation of NPPs. The latter application is popularly known as 'Risk-Informed Decision Making'. Evaluation of technical specifications is one such important application of Risk-Informed decision making. Deciding test interval (TI), one of the important technical specifications, with the given resources and risk effectiveness is an optimization problem. Uncertainty is inherently present in the availability parameters such as failure rate and repair time due to the limitation in assessing these parameters precisely. This paper presents a solution to test interval optimization problem with uncertain parameters in the model with fuzzy-genetic approach along with a case of application from a safety system of Indian pressurized heavy water reactor (PHWR)
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Qualification of FPGA-Based Safety-Related PRM System
International Nuclear Information System (INIS)
Miyazaki, Tadashi; Oda, Naotaka; Goto, Yasushi; Hayashi, Toshifumi
2011-01-01
Toshiba has developed Non-rewritable (NRW) Field Programmable Gate Array (FPGA)-based safety-related Instrumentation and Control (I and C) system. Considering application to safety-related systems, nonvolatile and non-rewritable FPGA which is impossible to be changed after once manufactured has been adopted in Toshiba FPGA-based system. FPGA is a device which consists only of basic logic circuits, and FPGA performs defined processing which is configured by connecting the basic logic circuit inside the FPGA. FPGA-based system solves issues existing both in the conventional systems operated by analog circuits (analog-based system) and the systems operated by central processing unit (CPU-based system). The advantages of applying FPGA are to keep the long-life supply of products, improving testability (verification), and to reduce the drift which may occur in analog-based system. The system which Toshiba developed this time is Power Range Neutron Monitor (PRM). Toshiba is planning to expand application of FPGA-based technology by adopting this development process to the other safety-related systems such as RPS from now on. Toshiba developed a special design process for NRW-FPGA-based safety-related I and C systems. The design process resolves issues for many years regarding testability of the digital system for nuclear safety application. Thus, Toshiba NRW-FPGA-based safety-related I and C systems has much advantage to be a would standard of the digital systems for nuclear safety application. (author)
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System Study: High-Pressure Safety Injection 1998-2014
Energy Technology Data Exchange (ETDEWEB)
Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States). Risk Assessment and Management Services Dept.
2015-12-01
This report presents an unreliability evaluation of the high-pressure safety injection system (HPSI) at 69 U.S. commercial nuclear power plants. Demand, run hours, and failure data from fiscal year 1998 through 2014 for selected components were obtained from the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The unreliability results are trended for the most recent 10 year period, while yearly estimates for system unreliability are provided for the entire active period. No statistically significant increasing or decreasing trends were identified in the HPSI results.
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Safety climate and culture: Integrating psychological and systems perspectives.
Casey, Tristan; Griffin, Mark A; Flatau Harrison, Huw; Neal, Andrew
2017-07-01
Safety climate research has reached a mature stage of development, with a number of meta-analyses demonstrating the link between safety climate and safety outcomes. More recently, there has been interest from systems theorists in integrating the concept of safety culture and to a lesser extent, safety climate into systems-based models of organizational safety. Such models represent a theoretical and practical development of the safety climate concept by positioning climate as part of a dynamic work system in which perceptions of safety act to constrain and shape employee behavior. We propose safety climate and safety culture constitute part of the enabling capitals through which organizations build safety capability. We discuss how organizations can deploy different configurations of enabling capital to exert control over work systems and maintain safe and productive performance. We outline 4 key strategies through which organizations to reconcile the system control problems of promotion versus prevention, and stability versus flexibility. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
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FFTF railroad tank car Safety Evaluation for Packaging
International Nuclear Information System (INIS)
Carlstrom, R.F.
1995-01-01
This Safety Evaluation for Packaging (SEP) provides evaluations considered necessary to approve transfer of the 8,000 gallon Liquid Waste Tank Car (LWTC) from Fast Flux Test Facility (FFTF) to the 200 Areas. This SEP will demonstrate that the transfer of the LWTC will provide an equivalent degree of safety as would be provided by packages meeting U.S. Department of Transportation (DOT) requirements. This fulfills onsite transportation requirements implemented in the Hazardous Material Packaging and Shipping, WHC-CM-2-14
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Effects of auditing patient safety in hospital care: design of a mixed-method evaluation
Hanskamp-Sebregts, M.E.; Zegers, M.; Boeijen, W.M.J.; Westert, G.P.; Gurp, P.J.M. van; Wollersheim, H.C.
2013-01-01
BACKGROUND: Auditing of patient safety aims at early detection of risks of adverse events and is intended to encourage the continuous improvement of patient safety. The auditing should be an independent, objective assurance and consulting system. Auditing helps an organisation accomplish its objectives by bringing a systematic, disciplined approach to evaluating and improving the effectiveness of risk management, control, and governance. Audits are broadly conducted in hospitals, but little i...
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Safety assessment of high consequence robotics system
International Nuclear Information System (INIS)
Robinson, D.G.; Atcitty, C.B.
1996-01-01
This paper outlines the use of a failure modes and effects analysis for the safety assessment of a robotic system being developed at Sandia National Laboratories. The robotic system, the weigh and leak check system, is to replace a manual process for weight and leakage of nuclear materials at the DOE Pantex facility. Failure modes and effects analyses were completed for the robotics process to ensure that safety goals for the systems have been met. Due to the flexible nature of the robot configuration, traditional failure modes and effects analysis (FMEA) were not applicable. In addition, the primary focus of safety assessments of robotics systems has been the protection of personnel in the immediate area. In this application, the safety analysis must account for the sensitivities of the payload as well as traditional issues. A unique variation on the classical FMEA was developed that permits an organized and quite effective tool to be used to assure that safety was adequately considered during the development of the robotic system. The fundamental aspects of the approach are outlined in the paper
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International Nuclear Information System (INIS)
1997-05-01
This report supplements the final safety evaluation report (FSER) for the System 80+ standard design. The FSER was issued by the US Nuclear Regulatory Commission (NRC) staff as NUREG-1462 in August 1994 to document the NRC staff's review of the System 80+ design. The System 80+ design was submitted by Asea Brown Boveri-Combustion Engineering (ABB-CE), in accordance with the procedures of Subpart B to Part 52 of Title 10 of the Code of Federal Regulations. This supplement documents the NRC staff's review of the changes to the System 80+ design documentation since the issuance of the FSER. ABB-CE made these changes as a result of its review of the System 80+ design details. The NRC staff concludes that the changes to the System 80+ design documentation are acceptable, and that ABB-CE's application for design certification meets the requirements of Subpart B to 10 CFR Part 52 that are applicable and technically relevant to the System 80+ design
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A formal safety analysis for PLC software-based safety critical system using Z
International Nuclear Information System (INIS)
Koh, Jung Soo
1997-02-01
This paper describes a formal safety analysis technique which is demonstrated by performing empirical formal safety analysis with the case study of beamline hutch door Interlock system that is developed by using PLC (Programmable Logic Controller) systems at the Pohang Accelerator Laboratory. In order to perform formal safety analysis, we have built the Z formal specifications representation from user requirement written in ambiguous natural language and target PLC ladder logic, respectively. We have also studied the effective method to express typical PLC timer component by using specific Z formal notation which is supported by temporal history. We present a formal proof technique specifying and verifying that the hazardous states are not introduced into ladder logic in the PLC-based safety critical system. And also, we have found that some errors or mismatches in user requirement and final implemented PLC ladder logic while analyzing the process of the consistency and completeness of Z translated formal specifications. In the case of relatively small systems like Beamline hutch door interlock system, a formal safety analysis including explicit proof is highly recommended so that the safety of PLC-based critical system may be enhanced and guaranteed. It also provides a helpful benefits enough to comprehend user requirement expressed by ambiguous natural language
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YUCCA MOUNTAIN SITE CHARACTERIZATION PROJECT EAST-WEST DRIFT SYSTEM SAFETY ANALYSIS
Energy Technology Data Exchange (ETDEWEB)
NA
1999-06-08
The purpose of this analysis is to systematically identify and evaluate hazards related to the design of the Yucca Mountain Project Exploratory Studies Facility (ESF) East-West Cross Drift. This analysis builds upon prior ESF System Safety Analyses and incorporates TS Main Drift scenarios, where applicable, into the East-West Drift scenarios. This System Safety Analysis (SSA) focuses on the personnel safety and health hazards associated with the engineered design of the East-West Drift. The analysis also evaluates other aspects of the East-West Drift, including purchased equipment (e.g., scientific mapping platform) or Systems/Structures/Components (SSCs) and out-of-tolerance conditions. In addition to recommending design mitigation features, the analysis identifies the potential need for procedures, training, or Job Safety Analyses (JSAs). The inclusion of this information in the SSA is intended to assist the organization(s) (e.g., constructor, Safety and Health, design) responsible for these aspects of the East-West Drift in evaluating personnel hazards and augment the information developed by these organizations. The SSA is an integral part of the systems engineering process, whereby safety is considered during planning, design, testing, and construction. A largely qualitative approach is used which incorporates operating experiences and recommendations from vendors, the constructor and the operating contractor. The risk assessment in this analysis characterizes the scenarios associated with East-West Drift SSCs in terms of relative risk and includes recommendations for mitigating all identified hazards. The priority for recommending and implementing mitigation control features is: (1) Incorporate measures to reduce risks and hazards into SSC designs. (2) Add safety features and capabilities to existing designs. (3) Develop procedures and conduct training to increase worker awareness of potential hazards, reduce exposure to hazards, and inform personnel of the
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Institute of Scientific and Technical Information of China (English)
无
2001-01-01
In this paper, on the principle of the modern control theory, the safety state equation of the safety systems was established and the dynamic model of the safety evaluation was put out. And finally, the example of its application in an iron and steel corporation was given.
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Reactor safety; Description and evaluation of safety activities in Nordic countries
International Nuclear Information System (INIS)
Wahlstroem, B.; Gunsell, L.
1998-03-01
The report gives a description of safety activities in the nuclear power industry. The study has been carried out as a part of the four year programme in Nordic Safety Research (NKS) which was completed in 1997. The objective of the NKS/RAK-1.1 project 'A survey and an evaluation of safety activities in nuclear power' was to make a broad description of various activities important for safety and to make an assessment of their efficiency. A special consideration was placed on a comparison of practices in Finland and Sweden, and between their nuclear utilities. The study has been divided into two parts, one theoretical part in which a model of the relationships between various activities important for safety has been constructed and one practical part where a total of 62 persons have been interviewed at the authorities, the nuclear utilities and one reactor vendor. To restrict the amount of work two activities, safety analysis and experience feedback, were selected. A few cases connected to incidents at nuclear power plants were discussed in more detail. The report has been structured around a simple model of nuclear safety consisting of the concepts of goals, means and outcomes. This model illustrates the importance of goal formulation, systematic planning and feedback of operational experience as major components in nuclear safety. In assessing organisation and management at authorities and the power utilities there is a clear trend of decentralisation and delegation of authority. The general impression from the study is that the safety activities in Finland and Sweden are efficient and well targeted. The experience from the methodology is favourable and the comparison of practices gives a good ground for a discussion of contents and targeting of safety activities. (EG) activities. (EG)
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Analysis of the reliability of the active injection safety systems of Angra I
International Nuclear Information System (INIS)
Frutuoso e Melo, P.F.F.
1981-01-01
The reliability of the active emergency core cooling systems of Angra I nuclear power plant is evaluated. The fault tree analysis is employed. The unavailability of the above cited systems, is calculated. A parametric sensitivity analysis has been performed, due to the existing scattering in the failure and repair rate data of these system's components. The minimal cut sets were determined and, as a final step, a reliability importance analysis has been performed. This final step has required the development of a computer program. The methodology and data from the 'Reactor Safety Study' (Wash-1400) (in which the reliability of safety systems of a tipical PWR plant is calculated), is employed. The unavailability values for the safety systems analysed are too low, thus showing that in most cases the systems analysed are available to mitigate the effects of a loss-of-coolant accident. (Author) [pt
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Application of Mixed Group Decision Making to Safety Evaluation of Agricultural Products
Institute of Scientific and Technical Information of China (English)
2012-01-01
In view of the gravity of issues concerning safety of agricultural products and urgency of resolving these issues,after analyzing the problems existing in safety of agricultural products,this article offers a method for evaluating safety of agricultural products on the basis of mixed group decision making.First of all,it introduces the factors influencing safety evaluation of agricultural products;subsequently,given that the judgment matrices offered by the group of experts contain both reciprocal and complementary judgment matrices in the process of jointly participating in evaluation arising from personal preference,it proposes to assemble expert information in order to obtain indicator weight using the OWA operator;finally,the process of evaluating safety of agricultural products is given.
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Critical evaluation of nuclear safety reports Pt. 1
International Nuclear Information System (INIS)
Egely, Gy.
1987-01-01
Licensing procedures of siting, commissioning and operation of nuclear power plants in the USA, FRG, France and Japan are compared. The standard format and content of nuclear safety analysis reports including the general description of the plant, the presentation of the characteristics of siting, building structures, components, facilities, the reactors, the cooling system, the safety system, the measuring and control system, the power supply system, the auxilliary system, the energy transformation system, etc. are discussed in detail by the example of the US procedure. (V.N.)
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Safety status system for operating room devices.
Guédon, Annetje C P; Wauben, Linda S G L; Overvelde, Marlies; Blok, Joleen H; van der Elst, Maarten; Dankelman, Jenny; van den Dobbelsteen, John J
2014-01-01
Since the increase of the number of technological aids in the operating room (OR), equipment-related incidents have come to be a common kind of adverse events. This underlines the importance of adequate equipment management to improve the safety in the OR. A system was developed to monitor the safety status (periodic maintenance and registered malfunctions) of OR devices and to facilitate the notification of malfunctions. The objective was to assess whether the system is suitable for use in an busy OR setting and to analyse its effect on the notification of malfunctions. The system checks automatically the safety status of OR devices through constant communication with the technical facility management system, informs the OR staff real-time and facilitates notification of malfunctions. The system was tested for a pilot period of six months in four ORs of a Dutch teaching hospital and 17 users were interviewed on the usability of the system. The users provided positive feedback on the usability. For 86.6% of total time, the localisation of OR devices was accurate. 62 malfunctions of OR devices were reported, an increase of 12 notifications compared to the previous year. The safety status system was suitable for an OR complex, both from a usability and technical point of view, and an increase of reported malfunctions was observed. The system eases monitoring the safety status of equipment and is a promising tool to improve the safety related to OR devices.
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Plant air systems safety study: Portsmouth Gaseous Diffusion Plant
International Nuclear Information System (INIS)
1982-05-01
The Portsmouth Gaseous Diffusion Plant Air System facilities and operations are reviewed for potential safety problems not covered by standard industrial safety procedures. Information is presented under the following section headings: facility and process description (general); air plant equipment; air distribution system; safety systems; accident analysis; plant air system safety overview; and conclusion
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Safety and cost evaluation of nuclear waste management
International Nuclear Information System (INIS)
Vieno, T.; Hautojaervi, A.; Korhonen, R.
1989-11-01
The report introduces the results of the nuclear waste management safety and cost evaluation research carried out in the Nuclear Engineering Laboratory of the Technical Research Centre of Finland (VTT) during the years 1984-1988. The emphasis is on the description of the state-of-art of performance and cost evaluation methods. The report describes VTT's most important assessment models. Development, verification and validation of the models has largely taken place within international projects, including the Stripa, HYDROCOIN, INTRACOIN, INTRAVAL, PSACOIN and BIOMOVS projects. Furthermore, VTT's other laboratories are participating in the Natural Analogue Working Group,k the CHEMVAL project and the CoCo group. Resent safety analyses carried out in the Nuclear Engineering Laboratory include a concept feasibility study of spent fuel disposal, safety analyses for the Preliminary Safety Analysis Reports (PSAR's) of the repositories to be constructed for low and medium level operational reactor waste at the Olkiluoto and Loviisa power plants as well as safety analyses of disposal of decommissioning wastes. Appendix 1 contains a comprehensive list of the most important publications and technical reports produced. They present the content and results of the research in detail
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A philosophy for space nuclear systems safety
International Nuclear Information System (INIS)
Marshall, A.C.
1992-01-01
The unique requirements and contraints of space nuclear systems require careful consideration in the development of a safety policy. The Nuclear Safety Policy Working Group (NSPWG) for the Space Exploration Initiative has proposed a hierarchical approach with safety policy at the top of the hierarchy. This policy allows safety requirements to be tailored to specific applications while still providing reassurance to regulators and the general public that the necessary measures have been taken to assure safe application of space nuclear systems. The safety policy used by the NSPWG is recommended for all space nuclear programs and missions
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International Nuclear Information System (INIS)
Eom, H. S.; Jang, S. C.; Ha, J. J.
2003-01-01
Despite the efforts to avoid undesirable risks, or at least to bring them under control in the world, new risks that are highly difficult to manage continue to emerge from the use of new technologies, such as the use of digital instrumentation and control (I and C) components in nuclear power plant. Whenever new risk issues came out by now, we have endeavored to find the most effective ways to reduce risks, or to allocate limited resources to do this. One of the major challenges is the reliability analysis of safety-critical software associated with digital safety systems. Though many activities such as testing, verification and validation (V and V) techniques have been carried out in the design stage of software, however, the process of quantitatively evaluating the reliability of safety-critical software has not yet been developed because of the irrelevance of the conventional software reliability techniques to apply for the digital safety systems. This paper focuses on the applicability of Bayesian Belief Net (BBN) techniques to quantitatively estimate the reliability of safety-critical software adopted in digital safety system. In this paper, a typical BBN model was constructed using the dedication process of the Commercial-Off-The-Shelf (COTS) installed by KAERI. In conclusion, the adoption of BBN technique can facilitate the process of evaluating the safety-critical software reliability in nuclear power plant, as well as provide very useful information (e.g., 'what if' analysis) associated with software reliability in the viewpoint of practicality
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Resolution of thermal-hydraulic safety and licensing issues for the system 80+trademark design
International Nuclear Information System (INIS)
Carpentino, S.E.; Ritterbusch, S.E.; Schneider, R.E.
1995-01-01
The System 80+ trademark Standard Design is an evolutionary Advanced Light Water Reactor (ALWR) with a generating capacity of 3931 MWt (1350 MWe). The Final Design Approval (FDA) for this design was issued by the Nuclear Regulatory Commission (NRC) in July 1994. The design certification by the NRC is anticipated by the end of 1995 or early 1996. NRC review of the System 80+ design has involved several new safety issues never before addressed in a regulatory atmosphere. In addition, conformance with the Electric Power Research Institute (EPRI) ALWR Utility Requirements Document (URD) required that the System 80+ plant address nuclear industry concerns with regard to design, construction, operation and maintenance of nuclear power plants. A large number of these issues/concerns deals with previously unresolved generic thermal-hydraulic safety issues and severe accident prevention and mitigation. This paper discusses the thermal-hydraulic analyses and evaluations performed for the System 80+ design to resolve safety and licensing issues relevant to both the Nuclear Stream Supply System (NSSS) and containment designs. For the NSSS design, the Safety Depressurization System mitigation capability and resolution of the boron dilution concern are described. Examples of containment design issues dealing with containment shell strength, robustness of the reactor cavity walls and hydrogen mixing under severe accident conditions are also provided. Finally, the overall approach used in the application of NRC's new (NUREG-1465) radiological source term for System 80+ evaluation is described. The robustness of the System 80+ containment design to withstand severe accident consequences was demonstrated through detailed thermal-hydraulic analyses and evaluations. This advanced design to shown to meet NRC severe accident policy goals and ALWR URD requirements without any special design features and unnecessary costs
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Energy Technology Data Exchange (ETDEWEB)
1994-08-01
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the system 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR {section} 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of ABB-CE`s System 80 design from which it evolved. Unique features of the System 80+ design include: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE`s application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 2, contains Chapters 15 through 22 and Appendices A through E.
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Safety assessment of VHTR hydrogen production system against fire, explosion and acute toxicity
International Nuclear Information System (INIS)
Murakami, Tomoyuki; Nishihara, Tetsuo; Kunitomi, Kazuhiko
2008-01-01
The Japan Atomic Energy Agency has been developing a nuclear hydrogen production system by using heat from the Very High Temperature Reactor (VHTR). This system will handle a large amount of combustible gas and toxic gas. The risk from fire, explosion and acute toxic exposure caused by an accident involving chemical material release in a hydrogen production system is assessed. It is important to ensure the safety of the nuclear plant, and the risks for public health should be sufficiently small. This report provides the basic policy for the safety evaluation in cases of accident involving fire, explosion and toxic material release in a hydrogen production system. Preliminary safety analysis of a commercial-sized VHTR hydrogen production system, GTHTR300C, is performed. This analysis provides us with useful information on the separation distance between a nuclear plant and a hydrogen production system and a prospect that an accident in a hydrogen production system does not significantly increase the risks of the public. (author)
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The safety interlocking system at the NAC
International Nuclear Information System (INIS)
Visser, K.; Mostert, H.
1984-01-01
The central safety interlocking system (CSIS) controls the higher level of interlocking between the various cyclotron subsystems. It ensures the safe operation of the entire cyclotron facility as regards personnel safety and proper instrument operation. The system consists of a micro-processor with a ROM-based safety interlocking program, relay output modules providing ''safety OK'' instructions to all interlocked apparatus, alarm input modules connected to transducers providing binary alarm status signals and an interface to the central control computer. All solid state electronic components of the system are situated in a low level radiation area and are interfaced to cyclotron equipment by means of 24 V relays
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Safety Verification for Probabilistic Hybrid Systems
DEFF Research Database (Denmark)
Zhang, Lijun; She, Zhikun; Ratschan, Stefan
2010-01-01
The interplay of random phenomena and continuous real-time control deserves increased attention for instance in wireless sensing and control applications. Safety verification for such systems thus needs to consider probabilistic variations of systems with hybrid dynamics. In safety verification o...... on a number of case studies, tackled using a prototypical implementation....