WorldWideScience

Sample records for gen-iii passive npps

  1. Applied reliability assessment for the passive safety systems of nuclear power plants (NPPs) using system dynamics (SD)

    Kim, Yun Il; Woo, Tae Ho

    2018-01-01

    The passive system by the free-fall is investigated in the accident of nuclear power plants (NPPs). The complex algorithm of the system dynamics (SD) modeling is done in the passive cooling system. The nuclear passive system by free-fall is successfully modeled for the loss of coolant accident (LOCA). Conventional passive system of gravity or natural circulation is working only when the piping systems is in the good condition. The external coolant supply system is introduced in the case of the piping system failure. The water is poured into the reactor through the guiding piping or tube. If the explosion happens, the coolants could be showering into the reactor core and its building. New kind of passive system is expected successfully in the on-site black out where the drone could be operated by battery or engine.

  2. Gen-III/III+ reactors. Solving the future energy supply shortfall. The SWR-1000 option

    Stosic, Z.V.

    2006-01-01

    Deficiency of non-renewable energy sources, growing demand for electricity and primary energy, increase in population, raised concentration of greenhouse gases in the atmosphere and global warming are the facts which make nuclear energy currently the most realistic option to replace fossil fuels and satisfy global demand. The nuclear power industry has been developing and improving reactor technology for almost five decades and is now ready for the next generation of reactors which should solve the future energy supply shortfall. The advanced Gen-III/III+ (Generation III and/or III+) reactor designs incorporate passive or inherent safety features which require no active controls or operational intervention to manage accidents in the event of system malfunction. The passive safety equipment functions according to basic laws of physics such as gravity and natural convection and is automatically initiated. By combining these passive systems with proven active safety systems, the advanced reactors can be considered to be amongst the safest equipment ever made. Since the beginning of the 90's AREVA NP has been intensively engaged in the design of two advanced Gen-III+ reactors: (i) PWR (Pressurized Water Reactor) EPR (Evolutionary Power Reactor) and (ii) BWR (Boiling Water Reactor) SWR-1000. The SWR-1000 reactor design marks a new era in the successful tradition of BWR technology. It meets the highest safety standards, including control of a core melt accident. This is achieved by supplementing active safety systems with passive safety equipment of diverse design for accident detection and control and by simplifying systems needed for normal plant operation. A short construction period, flexible fuel cycle lengths and a high fuel discharge burn-up contribute towards meeting economic goals. The SWR-1000 completely fulfils international nuclear regulatory requirements. (author)

  3. 'Passive fire protection in nuclear power plants' - German technologies of the company svt Brandschutz in future as well in Korean NPPs? -

    Bremer, Joerg; Kim, Duill; Wendt, Ruediger

    2002-01-01

    Fires in NPPs are unfortunately not avoidable and to consider during the planning and operation period of the plants. The multitude of combustible materials which are used especially cables, oils and other building materials describe a potential source of danger. In Germany recently a new planning guideline for the fire protection field in NPPs has been adopted: the nuclear guideline KTA 1401. This document certainly is one of the most progressive guidelines for the fire protection field and has united · structural engineering elements of fire protection · electrotechnical and machine components · as well as questions of fire alarm and organisation measures. Passive and active fire protection measures are explained and layed down in their complexity within this document. Our group of companies has realised quit a lot of fire protection projects in Europe during the last years, especially within retrofitting measures for NPPs in Germany, Switzerland, Russia, the Ukraine and Lithuania, the Czech and Slovak Republic as well as within decommissioning projects of NPPs. We have carried out international fire protection projects of the EBRD, London, and within the framework of TACIS projects of the European Commission, i. a. linked with the working out of fire protection analyses for NPPs realised in close co-operation with the Germanischer Lloyd, Hamburg. We especially have wide experiences in improving the fire protection of cable installations where a 100% separation of the different safety systems is not any longer possible

  4. Regulatory framework and safety requirements for new (gen III) reactors

    Mourlon, Sophie

    2014-01-01

    Sophie Mourlon, ASN Deputy General Director, described the international process to enhance safety between local safety authorities through organizations such as WENRA. Then she explained to the participants the regulatory issues for the next generation of NPPs

  5. Decommissioning of Ukrainian NPPs

    Skripov, A.E.

    2002-01-01

    The decision about the development of 'Decommissioning Concept of Ukrainian NPPs' being on commercial operational stage was approved by NAEK 'Energoatom' Board of Administration by way of the decommissioning activity effective planning. The Concept will be the branch document, containing common approaches formulations on problem decisions according to the units decommissioning with generated resources, and RAW and SNF management strategy during decommissioning

  6. Output signal analysis for a variation of the R-C passive elements in a 4-2 mA R-L-C equivalent circuit modeling under a high temperature accident condition in NPPs

    Kil-Mo, Koo; Sang-Baik, Kim; Hee-Dong, Kim; Gyu-Tae, Kim

    2007-01-01

    An electrical signal should be checked to see whether it lies within its expected electrical range when there is a doubtful condition. The normal signal level for pressure, flow, level and resistance temperature detector sensors is 4-20 mA in most industrial process controls. In the case of an abnormal signal level from an instrument under a severe accident condition, it is necessary to obtain a more accurate signal validation to operate a system in a control room in NPPs. Diagnostics and analysis for some abnormal signals have been performed through an important equivalent circuits modeling for passive elements under severe accident conditions. Unlike the design basis accidents, there are some inherent uncertainties for the instrumentation capabilities under severe accident conditions. In this paper, to implement a diagnostic analysis for an equivalent circuits modeling, a kind of linked LabVIEW program for each PSpice and MULTI-SIM code is introduced as a one body order system, which can obtain some abnormal signal patterns by a special function such as an advanced simulation tool for each PSpice and Multi-SIM code as a means of a function for a PC based ASSA (Abnormal Signal Simulation Analyzer) module. The output signal can be analyzed by a comparative analysis of each PSpice and Multi-SIM code for a 4-20 mA circuit modeling which is by a composition of an R-L-C passive circuit as an alternating range of the elements for the temperature accident condition. In this simulation, a new simulator through an analysis of the important equivalent circuits modeling has been designed, the designed simulator is composed of the LabVIEW code as a main tool and the out-put file of each PSpice code and a Multi-SIM engine code as an engine tool is exported to the in-put file of the LabVIEW code. There are 3 main function units of the ASSA module, the first one is individual PSpice and Multi-SIM engine code units to comprise an equivalent circuit element, the second one is the

  7. Civil works for NPPs construction

    Portenseigne, Christophe

    2014-01-01

    Christophe Portenseigne, Technical Director of Bouygues Travaux Publics, provided explanations on the main challenges of Civil work for the construction of the 3. generation of NPPs. He then provided an overview of the new Civil Work concepts for the 4. generation of NPPs

  8. Internal communication at Bohunice NPPs

    Dobdk, Dobroslav

    1999-01-01

    Communication is the base of everyday existence of a modern person and every company. It is not easy to work in this area in a changing 'eastern' country. Many tools, which are used are in the mind of people connected with 'propaganda'. I would like to share our experience with you. The goal of an internal communication is to spread and provide continuous current of objective information between the management of Bohunice NPPs and its personnel and between the personnel itself. Communication with the Bohunice NPPs employees helps to get acquainted with their opinions and ideas concerning the subsidiary and nuclear power industry

  9. Organizational factors in Korean NPPs

    Jang, D. J.; Kim, Y. I.; Jeong, C. H.; Kim, J. W.

    2003-01-01

    Organizational factors are referred to as the factors that influence the achievement of a goal of an organization. Latent problems of an organization could contribute to causing human errors in such stages as design, operation and maintenance, and furthermore, leading to an severe accident. In order to evaluate an organization from the safety viewpoint, it is necessary to identify the organizational factors in a systematic fashion. In this paper, some efforts to identify the organizational factors in Korean NPPs are presented. The study was performed in the following steps: 1) Reviewing the definitions and range of the organizational factors used by the previous 13 researches, 2) Structuring the organizational factors by screening and collating factors, 3) Analysing the organizational factors that is considered to have contributed to the trip events based on the trip report of Korean NPPs, 4) Suggesting a more reliable taxonomy of organizational factors for event analysis by applying the Onion Structure Model to the selected factors

  10. A fuzzy controller for NPPs

    Schildt, G.H.

    1997-01-01

    A fuzzy controller for safety related process control is presented for applications in the field of NPPs. The size of necessary rules is relatively small. Thus, there exists a real chance for verification and validation of software due to the fact that the whole software can be structured into standard fuzzy software (like fuzzyfication, inference algorithms, and defuzzyfication), real-time operating system software, and the contents of the rule base. Furthermore, there is an excellent advantage fuel to real-time behaviour, because program execution time is much more predictable than for conventional PID-controller software. Additionally, up to now special know-how does exist to prove stability of fuzzy controller. Hardware design has been done due to fundamental principles of safety technique like watch dog function, dynamization principles, and quiescent current principle. (author). 3 refs, 5 figs

  11. A fuzzy controller for NPPs

    Schildt, G.H.

    1996-01-01

    After an introduction into safety terms a fuzzy controller for safety related process control will be presented, especially for applications in the field of NPPs. One can show that the size of necessary rules is relatively small. Thus, there exists a real chance for verification and validation of software due to the fact that the whole software can be structured into standard fuzzy software (like fuzzyfication, inference algorithms, and defuzzyfication), real-time operating system software, and the contents of the rule base. Furthermore, there is an excellent advantage due to real-time behaviour, because program execution time can be much more planned than for conventional PID-controller software. Additionally, up to now special know-how does exist to prove stability of fuzzy controller. Hardware design has been done due to fundamental principles of safety technique like watch dog function, dynamization principle, and quiescent current principle

  12. A fuzzy controller for NPPs

    Schildt, G H [Technische Univ., Vienna (Austria)

    1997-07-01

    A fuzzy controller for safety related process control is presented for applications in the field of NPPs. The size of necessary rules is relatively small. Thus, there exists a real chance for verification and validation of software due to the fact that the whole software can be structured into standard fuzzy software (like fuzzyfication, inference algorithms, and defuzzyfication), real-time operating system software, and the contents of the rule base. Furthermore, there is an excellent advantage fuel to real-time behaviour, because program execution time is much more predictable than for conventional PID-controller software. Additionally, up to now special know-how does exist to prove stability of fuzzy controller. Hardware design has been done due to fundamental principles of safety technique like watch dog function, dynamization principles, and quiescent current principle. (author). 3 refs, 5 figs.

  13. The actual technological progress of NPPs

    Florescu, Gheorghe; Popa, Adrian; Panaitescu, Valeriu

    2010-01-01

    The actual nuclear R and D issues require new technologies and continuous progress in order to find adequate and effective solutions in sustained and increasing energy demand. The current tendency in energy consumption and occurring of large consumers, especially from Asian countries, imposes finding new means for energy clean, large scale and sustained production. NPPs reliability and availability were permanently monitored and improved; in the mean time the safety of the nuclear energy production was under surveillance. Corresponding development of the new technologies and discovery of improved materials and adequate technological processes offers the possibilities for appropriate implementation and use of them in the NPPs systems configuration and functioning/operation. The modern technologies and scientific discoveries, also the international cooperation, offer the opportunities to brake the actual barriers in order to cumulate and use advanced energy production processes in finding new energy sources and to build improved, reliable and safety power plants. The monitoring systems, intelligent sensors and intelligent SSCs, nanotechnologies and and modern and intelligent materials constitute the main reasons in improvement of the NPPs systems configuration and processes. The paper presents: - The state of the art in the level of actual and useful technologies for nuclear power systems development; - The actual technological limits that need to be over passed for NPPs systems improvements; - The main systems that need improvement and reconfiguration for actual NPPs development and increase in efficient operation, appropriate availability and total safety; - The actual energy production issues; - The key arguments in sustaining the R and D new NPPs systems development; - Future trends in NPPs development; - The limitations in industrial processes knowledge and use. Appropriate R and D in the field of NPPs systems has a specific characteristic that is highlighted in

  14. Causes of fires at NPPs and ways for their prevention

    Denisov, V.A.

    1992-01-01

    Causes of fires at different NPPs are analyzed. The schemes for classification of causes and after-effects of fires at NPPs are suggested. The structure of database on fires at NPPs suggested by IAEA is considered. The conclusion on applicability of the suggested general approaches to fire causes analysis at NPPs for preventive methods development is made

  15. Some aspects of public relation activities at Russian NPPs

    Ermakov, Sergei

    1995-01-01

    Full text: Since 1992 Rosenergoatom has managed most of the Russian NPPs. Here in this report we present its main public relations activities. 1. The leading role of the management of Rosenergoatom (Direction of Public Relations) is in relations with the public. 2. The main public relations activities are: - contact with the selected and administrative authorities of different levels, - interaction with mass media, - information of employees, - information of, and interaction with, the people of the areas close to the NPPs and especially of the nearby towns, - organising and carrying out opinion polls, - celebration campaigns at NPPs. 3. The use of NPPs' information centers and groups for PR activities: - construction and equipping of NPPs' public information centers; organising excursions, lectures, debates at NPPs; - publishing of news papers at NPPs and at NPPs' towns. 4. Public information in the regions close to the NPPs construction sites (Far East, Kostroma, Rostov, Veronezh regions). 5. Conclusions on the activities and plans for the future. (author)

  16. Internal flooding analyses results of Slovak NPPs

    Sopira, Vladimir

    2000-01-01

    The assessment of the flood risk was the objective of the internal flooding analysis for NPPs Bohunice V1, V2 and Mochovce. All important flooding sources were identified. The rooms containing safety important components were analyzed from the point of view of: Integrity of flood boundaries; Capability for drainage; Flood signalisation; Flood localization and liquidation; Vulnerability of safety system component. The redundancies of safety systems are located mostly separately and no flood can endanger more than single train. It can be concluded that NPPs with WWER-440 are very safe against the flooding initiating event

  17. Servicing NPPs in Japan, Korea and Taiwan

    Bohmann, W.; Poetz, F.

    1991-01-01

    More than 45 comparable orders (for equipment or services ) have been carried out in Japan, Korea and Taiwan by ABB Reaktor since 1982. Recently contracts to deliver inspection and repair equipment for the core baffle former bolts of Japanese NPPs, and in 1990, a contract to clean two steam generators in Korea, together with Pacific Nuclear Services, USA, were won. 2 figs

  18. Advantages of viscodampers for NPPs upgrading

    Reinsch, K.H.; Schwahn, K.J.; Podrouzek, J.

    1993-01-01

    Viscodampers GERB are the ideal components for seismic upgrading of flexible pipework systems of the existing operating NPPs, of WWER-440 type, namely in primary reactor part. There are cheap, maintenance-free, simple and their installation minimizes the support forces to the structures. The quoted attests are enclosed in this paper. The references for application on Bohunice NPP upgrading are positive, and they are used in Mochovce and Temelin NPP as well

  19. Application of PSA in Designing New Third-Generation NPPs Equipped with VVE Reactors

    Kuchumov, A. Yu.; Morozov, V.B., E-mail: morozov-sloboda@mail.ru [JSC Atomenergoproekt, Moscow (Russian Federation)

    2014-10-15

    The projects of new third-generation NPPs shall meet more stringent safety requirements. A proper balance between a high level of safety and modern requirements for power unit availability indicators cannot be achieved without applying a probabilistic approach in the course of designing, central to which is probabilistic safety assessment (PSA). The report presents the main results from application of PSA in working out new projects of NPPs equipped with VVER reactors, as well as the obtained quantitative results reflecting the entire spectrum of operational states and initiating events. It is shown that by using an efficient combination of active and passive safety systems it is possible to achieve a safety level in the projects complying with the latest requirements, including those following from the lessons learnt from the Fukushima accident. (author)

  20. Containment leak-tightness enhancement at VVER 440 NPPs

    Prandorfy, M.

    2001-01-01

    The hermetic compartments of VVER 440 NPPs fulfil the function of the containment used at NPPs all over the word. The purpose of the containment is to protect the NPP personal against radioactive impact as well as to prevent radioactive leakage to the environment during a lost of coolant accident. Leak-tightness enhancement in NPPs with VVER 440/213 and VVER 440/230 reactors is an important safety issue. New procedures, measures and methods were adopted at NPPs in Mochovce, J. Bohunice, Dukovany and Paks for leak identification and sealing works performed by VUEZ Levice. (authors)

  1. Containment leak-tightness enhancement at VVER 440 NPPs

    Prandorfy, M.

    2000-01-01

    The hermetic compartments of WWER 440 NPPs fulfil the function of the containment used at NPPs all over the world. The purpose of the containment is to protect the NPP personnel against radioactive impact as well as to prevent radioactive leakage to the. environ ent during a lost of coolant accident. Leak-tightness enhancement in NPPs with WWER 440/213 and WWER 440/230 reactors is an important safety issue. New procedures, measures and methods were adopted at NPPs in Mochovce, Jaslovske Bohunice, Dukovany and PAKS for leak identification and sealing works performed by VUEZ Levice. (authors)

  2. Analysis of human performance in KHNP NPPs

    Tae, Sung Eun

    2004-01-01

    The most important thing in the management of nuclear power plant is safety. One of the key factors to enhance the safety is to analyze human performance and to reflect the results on the practical plant operation. KHNP NPPs experienced human errors in the fields of operation and maintenance. The human errors need to be analyzed and, necessary corrective actions according to the causes should be made to prevent the same event or similar events. Therefore we'd like to introduce the procedure of K-HPES(KHNP-Human Performance Enhancement System) and the results of analysis of HPES reports produced in 2002 and 2003

  3. Programming guidelines for computer systems of NPPs

    Suresh babu, R.M.; Mahapatra, U.

    1999-09-01

    Software quality is assured by systematic development and adherence to established standards. All national and international software quality standards have made it mandatory for the software development organisation to produce programming guidelines as part of software documentation. This document contains a set of programming guidelines for detailed design and coding phases of software development cycle. These guidelines help to improve software quality by increasing visibility, verifiability, testability and maintainability. This can be used organisation-wide for various computer systems being developed for our NPPs. This also serves as a guide for reviewers. (author)

  4. Mound technology for isolation of decommissioned NPPs

    Korovkin, S.V.; Tutunina, E.V.

    2012-01-01

    The problem of NPPs' decommissioning calls for immediate attention. Today the most socially acceptable solution is green lawn, but due to the difficulty of this option, alternative solutions are being developed as well. The authors believe that the option is isolation of shut-down NPPs in-situ by covering them with layers of inert materials, resulting in the formation of a mound. In this case the reactor building itself becomes a repository that holds solid radioactive wastes generated over the time of unit operation. Spent fuel is to be shipped out of the site. A layer of inert materials several meters thick guarantees secure protection against ionising radiation and unauthorised access to the structures in isolation. The structures inside the mound are also inaccessible to ground waters. The green mound concept is considered as well as the mound backfilling technology which excludes collapse under the weight of inert materials that form the mound. It is pointed out that never-completed Voronezh nuclear heating plant is the optimal object for field-testing of the suggested technology [ru

  5. Operational safety performance of Slovak NPPs in 2005

    Tomek, J.

    2006-01-01

    In this presentation author presents operational safety performance of Slovak NPPs in 2005. Operation of Slovak NPPs in 2005 was safe and reliable, with: - high level of performance low risk; - minimal impact on the personnel, environment and public; - positive attitude to safety.

  6. Current activities on safety improvement at Ukrainian NPPs

    Stovbun, V.V.

    2000-01-01

    This report describes general development status of the national programs on safety improvement of the Ukrainian NPPs, basic approaches adopted for planning and implementation of safety improvement works, and state of implementation of principal technical activities aimed at safety improvement of Ukrainian NPPs. (author)

  7. The ways to increase the Ukrainian NPPs ecological safety

    Barbashev, S.V.

    2005-01-01

    The analysis of the approaches to achieve the basic goals of radiation and ecological safety at Ukrainian NPPs has been made. The problems, solution of which will allow to speak of a realization at NPPs of a cardinally other than now ecological approach to the estimation of nuclear energy's influence on the environment and ecological safety maintenance, has been numbered

  8. Spent fuel management of NPPs in Argentina

    Alvarez, D.E.; Lee Gonzalez, H.M.

    2010-01-01

    There are two Nuclear Power Plants in operation in Argentina: 'Atucha I' (unique PHWR design) in operation since 1974, and 'Embalse' (typical Candu reactor) which started operation in 1984. Both NPPs are operated by 'Nucleoelectrica Argentina S.A' which is responsible for the management and interim storage of spent fuel till the end of the operative life of the plants. A third NPP, 'Atucha II' is under construction, with a similar design of Atucha I. The legislative framework establishes that after final shutdown of a NPP the spent fuel will be transferred to the 'National Atomic Energy Commission', which is also responsible for the decommissioning of the Plants. In Atucha I, the spent fuel is stored underwater, until another option is implemented meanwhile in Embalse the spent fuel is stored during six years in pools and then it is moved to a dry storage. A decision about the fuel cycle back-end strategy will be taken before year 2030. (authors)

  9. Safety management in NPPs using evolutionary algorithm

    Mishra, A.; Patwardhan, A.; Chauhan, A.; Verma, A.K.

    2005-01-01

    Technical specification and maintenance (TS and M) activities in a plant are associated with controlling risk or with satisfying requirements, and are candidates to be evaluated for their resource effectiveness in risk-informed applications. The general goal of safety management in Nuclear Power Plants (NPPs) is to make requirements and activities more risk effective and less costly. Accordingly, the risk-based analysis of Technical Specification (RBTS) is being considered in evaluating current TS. The multi objective optimization of the TS and M requirements of a NPP based on risk and cost, gives the pareto-optimal solutions, from which the utility can pick its decision variables suiting its interest. In this paper a multi objective Evolutionary Algorithm technique has been used to make a trade-off between risk and cost both at the system level and at the plant level for Loss of coolant Accident (LOCA) and Main Steam Line Break (MSLB) as initiating events. (authors)

  10. VVER NPPs fuel handling machine control system

    Mini, G.; Rossi, G.; Barabino, M.; Casalini, M.

    2002-01-01

    In order to increase the safety level of the fuel handling machine on WWER NPPs, Ansaldo Nucleare was asked to design and supply a new Control System. Two Fuel Handling Machine (FHM) Control System units have been already supplied for Temelin NPP and others supply are in process for the Atommash company, which has in charge the supply of FHMs for NPPs located in Russia, Ukraine and China.The computer-based system takes into account all the operational safety interlocks so that it is able to avoid incorrect and dangerous manoeuvres in the case of operator error. Control system design criteria, hardware and software architecture, and quality assurance control, are in accordance with the most recent international requirements and standards, and in particular for electromagnetic disturbance immunity demands and seismic compatibility. The hardware architecture of the control system is based on ABB INFI 90 system. The microprocessor-based ABB INFI 90 system incorporates and improves upon many of the time proven control capabilities of Bailey Network 90, validated over 14,000 installations world-wide.The control system complies all the former designed sensors and devices of the machine and markedly the angular position measurement sensors named 'selsyn' of Russian design. Nevertheless it is fully compatible with all the most recent sensors and devices currently available on the market (for ex. Multiturn absolute encoders).All control logic were developed using standard INFI 90 Engineering Work Station, interconnecting blocks extracted from an extensive SAMA library by using a graphical approach (CAD) and allowing and easier intelligibility, more flexibility and updated and coherent documentation. The data acquisition system and the Man Machine Interface are implemented by ABB in co-operation with Ansaldo. The flexible and powerful software structure of 1090 Work-stations (APMS - Advanced Plant Monitoring System, or Tenore NT) has been successfully used to interface the

  11. Regulatory challenges faced first Indonesia NPPs by independent TSOs

    Sri Budi Utami

    2010-01-01

    Technical and scientific support organizations (TSOs) dedicated to supporting national regulatory authorities. At present BAPETEN has internal TSOs. Pertaining to the regulatory control of nuclear safety, security, and safeguards for nuclear power plants (NPPs), independent TSOs providing support to the safety regulatory bodies are facing a number of technical challenges to ensuring the safety of NPPs. It is essential that BAPETEN need independent TSOs in order to warrant a sufficient level of safety, security and non proliferation in building and operating of first NPP. It is essential that BAPETEN need independent TSOs in order to warrant a sufficient level of safety, security and non proliferation in building and operating of first NPPs. (author)

  12. WWER NPPs fuel handling machine control system

    Mini, G.; Rossi, G.; Barabino, M.; Casalini, M.

    2001-01-01

    In order to increase the safety level of the fuel handling machine on WWER NPPs, Ansaldo Nucleare was asked to design and supply a new Control System. Two FHM Control System units have been already supplied for Temelin NPP and others supplies are in process for the Atommash company, which has in charge the supply of FHMs for NPPs located in Russia, Ukraine and China. The Fuel Handling Machine (FHM) Control System is an integrated system capable of a complete management of nuclear fuel assemblies. The computer-based system takes into account all the operational safety interlocks so that it is able to avoid incorrect and dangerous manoeuvres in the case of operator error. Control system design criteria, hardware and software architecture, and quality assurance control, are in accordance with the most recent international requirements and standards, and in particular for electromagnetic disturbance immunity demands and seismic compatibility. The hardware architecture of the control system is based on ABB INFI 90 system. The microprocessor-based ABB INFI 90 system incorporates and improves upon many of the time proven control capabilities of Bailey Network 90, validated over 14,000 installations world-wide. The control system complies all the former designed sensors and devices of the machine and markedly the angular position measurement sensors named 'selsyn' of Russian design. Nevertheless it is fully compatible with all the most recent sensors and devices currently available on the market (for ex. Multiturn absolute encoders). All control logic components were developed using standard INFI 90 Engineering Work Station, interconnecting blocks extracted from an extensive SAMA library by using a graphical approach (CAD) and allowing an easier intelligibility, more flexibility and updated and coherent documentation. The data acquisition system and the Man Machine Interface are implemented by ABB in co-operation with Ansaldo. The flexible and powerful software structure

  13. NPPs of CEZ in 2005 year of CEZ group improvement

    Linhart, Z.

    2006-01-01

    In this presentation author deals with NPPs of CEZ, a.s. group in 2005 year. Structure of the CEZ, a.s., electricity production in NPP Temelin and NPP Dukovany and other exploitation data are presented.

  14. Psychological health of operators in NPPs and accident prevention

    Zhou Huayun

    2004-01-01

    Mental and physical health of operators of nuclear power plants (NPPs) is directly related to normal and safe operation of NPPs. The cognitive process, volitional character, attention, emotion, feeling and personality are important factors that affect operators' safe behavior. Alcohol, medical drugs and operators' biological rhythm are can also make great effects on their psychological health. By means of job-fitness psychological test, better candidates for operators could be primarily selected from point of psychological view. Psychological follow-up of post skill training, simulator training and practical work of operators can make NPPs prevent from operational accidents due to human errors to the greatest extent. It is helpful for NPPs to find and solve some psychological problems by means of psychological counseling, regulation or psychotherapy. (author)

  15. Environmental monitoring around the Nuclear Power Plants (NPPs) in India

    Ravi, P.M.

    2014-01-01

    Environmental Survey Laboratories (ESLs) are established at all major nuclear installations before the commissioning of an installation. As per the lndian regulations, the environmental monitoring around NPPs are carried out by an independent body. Accordingly, Environmental Survey Laboratories (ESLs) under Health Physics Division, Bhabha Atomic Research Centre is entrusted with the responsibility. This paper presents the various aspects of environmental monitoring programmes being pursued around Indian NPPs

  16. Thinned pipe management program of Korean NPPs

    Lee, S.H.; Kim, T.R.; Jeon, S.C.; Hwang, K.M.

    2003-01-01

    Wall thinning of carbon steel pipe components due to Flow-Accelerated Corrosion (FAC) is one of the most serious threats to the integrity of steam cycle systems in Nuclear Power Plants (NPP). If the thickness of a pipe component is reduced below the critical level, it cannot sustain stress and consequently results in leakage or rupture. In order to minimize the possibility of excessive wall thinning, Thinned Pipe Management Program (TPMP) has been set up and being implemented to all Korean NPPs. Important elements of the TPMP include the prediction of the FAC rate for each component based on model analysis, prioritization of pipe components for inspection, thickness measurement, calculation of wear and wear rate for each component. Additionally, decision making associated with replacement or continuous service for thinned pipe components and establishment of long-term strategic management plan based on diagnosis of plant condition regarding overall wall thinning also are essential part of the TPMP. From pre-service inspection data, it has been found that initial thickness is varies, which influences wear and wear rate calculations. (author)

  17. External events analysis in PSA studies for Czech NPPs

    Holy, J.; Hustak, S.; Kolar, L.; Jaros, M.; Hladky, M.; Mlady, O.

    2014-01-01

    The purpose of the paper is to summarize current status of natural external hazards analysis in the PSA projects maintained in Czech Republic for both Czech NPPs - Dukovany and Temelin. The focus of the presentation is put upon the basic milestones in external event analysis effort - identification of external hazards important for Czech NPPs sites, screening out of the irrelevant hazards, modeling of plant response to the initiating events, including the basic activities regarding vulnerability and fragility analysis (supported with on-site analysis), quantification of accident sequences, interpretation of results and development of measures decreasing external events risk. The following external hazards are discussed in the paper, which have been addressed during several last years in PSA projects for Czech NPPs: 1)seismicity, 2)extremely low temperature 3)extremely high temperature 4)extreme wind 5)extreme precipitation (water, snow) 6)transport of dangerous substances (as an example of man-made hazard with some differences identified in comparison with natural hazards) 7)other hazards, which are not considered as very important for Czech NPPs, were screened out in the initial phase of the analysis, but are known as potential problem areas abroad. The paper is a result of coordinated effort with participation of experts and staff from engineering support organization UJV Rez, a.s. and NPPs located in Czech Republic - Dukovany and Temelin. (authors)

  18. Session III: International practice for the requalification of existing NPPs

    Haas, E.

    1993-01-01

    Like in other countries, in Germany, too, a periodic safety reevaluation (Periodische Sicherheitsueberpruefung PSUE) has been recommended to become obligatory for all NPPs. This caused an acceleration of the process of seismic risk evaluation and requalification as a partial aspect of PSUE. For some of the older German NPPs, started up about 1970 to 1980, detailed seismic reevaluations followed by backfitting proposals were performed. In general the seismic acceptance criteria are conform with the demands of the actually valid German standards and regulations. For the methods of evaluation and requalification these standards allow to apply sufficiently variable tools; thus the procedures consist of an adequate combination of analysis, walkdown results, test experience as well as analogue and plausibility considerations. Examples are presented for the main categories of mechanical and electrical equipment of German NPPs

  19. EDF analysis of hydrogen problem on present NPPs

    Guieu, S.

    1997-01-01

    By letter dated March 1995, Electricite de France (EDF) has sent to the French Safety Authority (called DSIN, depending jointly from Industry and Environment Ministries) its position, for Present NPPs, regarding three main topics concerning severe accidents pointed by DSIN: hydrogen problem; high pressure core melt risk; and instrumentation. Concerning 'hydrogen problem', EDF answer is not only a state-of-the art analysis but intend to answer the question of the need (or not) for implementation of countermeasures in Present French NPPs. This position is presently under review by DSIN and its Technical Supports. (author)

  20. Radiation supervision - NPPs A-1, V-1, V-2

    2000-01-01

    In this leaflet the radiation supervision of the nuclear power plants A-1, V-1, V-2 is presented. Off-site radiation supervision laboratory is a part of monitoring scheme of the NPPs. More than 1150 samples are taken from the environment annually. The tele-dosimetric system was constructed to improve the quality of the Bohunice NPPs operation impacts supervision. It has been running in a continuous operation from 1992 and providing supervision of the nuclear power plant off-site area within 25 kilometres. The tele-dosimetric system is described

  1. NPPs Secondary Circuit Piping Wall-Thinning Management in China

    Zhong Zhimin; Li Jinsong; Zheng Hui

    2012-01-01

    Since 1980s, secondary circuit piping wall-thinning incidents happened in nuclear power plants (NPPs) worldwide. Particularly Surry 2 and Mihama 3 accidents resulted from flow-accelerated corrosion (FAC), unplanned outage, huge fatalities and economic loss pushed whole industry to pay more attention on the wall-thinning problem.

  2. Specific features of auxiliary water supply at underground NPPs

    Pergamenshchik, B.K.; Pavlov, A.S.

    1991-01-01

    Specific features of auxiliary water supply systems for underground NPPs related to peculiarities of NPP basis equipment arrangement, are considered. Circulation water supply scheme, in which water cooling storage basin (cooling towers) with operational area corresponding to NPP power is on the surface and has traditional design, is proposed. Sufficiently high efficiency of the arrangement proposed is proved

  3. The status of nuclear safety of Ukrainian NPPS and evaluations by ASSET methodology

    Koltakov, V [State Scientific and Technical Center on Nuclear and Radiational Safety, Kiev (Ukraine)

    1997-10-01

    The presentation discusses the following issues: nuclear power plants and research reactors; electricity production and operating personnel; status of nuclear safety at NPPs of Ukraine; operation of Ukrainian NPPs; violations of NPPs operation; short review of ASSET missions; experience of feedback process. Figs, tabs.

  4. The status of nuclear safety of Ukrainian NPPS and evaluations by ASSET methodology

    Koltakov, V.

    1997-01-01

    The presentation discusses the following issues: nuclear power plants and research reactors; electricity production and operating personnel; status of nuclear safety at NPPs of Ukraine; operation of Ukrainian NPPs; violations of NPPs operation; short review of ASSET missions; experience of feedback process. Figs, tabs

  5. Safety design bases collation for Czech VVER NPPs

    Kadecka, P.; Krhounek, V.; Samohyl, P.; Zdarek, J.

    2004-01-01

    Goals of Safety Design Bases (SDB) Collation for Czech VVER NPPs are following: (i) Collation of SDB up to the component level. (ii) Preparation of necessary supporting information. (iii) The use of the effective knowledge management system DART (product WEE) for work organization and data storage. (iv) Use of the computer network between cooperating organizations with access to DART database. (v) Storage of DB information in format convenient for configuration, change and plant life management. It is concluded that SDB Collation for Czech NPPs continue very well. NPPs Management gives projects high priority and necessary amount of founds covering also active participation of NPPs staff. Current results of the projects are following: (i) DART (Knowledge management system) and other tools work on computer network link together all project participants. All information are stored to regularly backuped databases. (ii) Overall processes for SDB collation were designed and tested. Detail methodologies and working procedures for SDB collation of mechanical, civil, electro and I and C SSC were prepared. (iii) Detail workflow for all steps of the process was designed to organize different working groups of authors (write information) and reviewers (can annotate only or annotate and approve information). (iv) Pilot HP ECCS DBDs were prepared for both NPPs, it means whole methodology and procedures were tested. (v) Activity transfer trees, barrier integrity trees and fault trees for mechanical and civil SSC are finished. (vi) Fault trees for Dukovany NPP electro and I and C SSC were finished, for Temelin are under preparation. (vii) Fault gates description and functional requirements for Temelin mechanical and civil SSC are finished, for Dukovany NPP are under preparation. (P.A.)

  6. Passive safety; Passive Sicherheit

    Rueckert, J. [Skoda Auto a.s., Mlada Boleslav (Czech Republic). Interieurentwicklung und Versuche; Hau, M. [Skoda Auto a.s., Mlada Boleslav (Czech Republic). Koordination der Fahrzeugsicherung

    2004-05-01

    The specifications for passive safety are partly based on the legal requirements for all export markets combined with the strict internal standards of Volkswagen Group. The Euro NCAP tests and their precisely defined testing methods using the new point assessment are very important. (orig.)

  7. Accident transient processes at NPPs with the WWER type reactors

    Bukrinskij, A.M.

    1982-01-01

    Thermal-physical and nuclear-physical transient processes at NPPs with the WWER type reactors during accidents with the main technological equipment failures and the accidents with loss of coolant in the primary and secondary coolant circuits are considered. Mathematical methods used for these processes modelling is described. Examples of concrete calculations for accidents with different failures are given. Comparative analysis of the results of dynamic tests at the Novo-Voronezh-3 reactor is presented. It is concluded that the modern NPP design is impossible without application of mathematical modelling methods. The mathematical modelling of transients is also necessary for proper and safe NPP operation. Mathematical modelling of accidents at NPPs is a comparatively new method of investigation. Its success and development are completely based on the progress in modern computer development. With their improvement the mathematical models will become more complicate and adequacy of real physical process representation by their means will increase

  8. Development of source term PIRT of Fukushima Daiichi NPPs accident

    Suehiro, S.; Okamoto, K.

    2017-01-01

    The severe accident evaluation committee of AESJ (Atomic Energy Society of Japan) developed the thermal hydraulic PIRT (Phenomena Identification and Ranking Table) and the source term PIRT based on findings during the Fukushima Daiichi NPPs accident. These PIRTs aimed to explore the debris distribution and the current condition in the NPPs with high accuracy and to extract higher priority from the aspect of the sophistication of the analytical technology to predict the severe accident phenomena by the code. The source term PIRT was divided into 3 phases for the time domain and 9 categories for the spatial domain. The 68 phenomena were extracted and the importance from viewpoint of the source term was ranked through brainstorming and discussion. This paper describes the developed source term PIRT list and summarized the high ranked phenomena in each phase. (author)

  9. Economic evaluation of I and C modernization approach in NPPs

    Kang, Hyeon Tae; Sung, Chan Ho; Lee, Jae Ki

    2009-01-01

    Utilities have recently been debating the respective pros and cons of implementation of a multi-phase modernization during several normal outages versus a single major modernization implementation during a prolonged outage. We have studied these approaches and have been developing the basic design of NPPs I and C modernization since early 2008. As part of this study, analyses of the NPPs I and C systems were conducted and the need for upgrading the systems was raised. One of the primary concerns regarding the system modernization is a cost-benefit implementation, which will influence the modernization approach. From this viewpoint, the I and C modernization must consider economic factors such as I and C vendor cost, architecture engineering cost, installation cost, utility cost, and other transition costs such as training and procedure development. This paper presents a comparison study of economical aspects including cost evaluation between the aforementioned modernization implementations and suggests a solution for the I and C modernization approach. (author)

  10. Analytical and Experimental Feasibility Study of Combined OTEC on NPPs

    Cho, Jeongtae; Oh, Kyemin; Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Jung, Hoon [KEPCO Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    The concept of the Combined Ocean Thermal Energy Conversion (Combined OTEC) needs to study. Combined OTEC uses exhausted steam on Nuclear Power Plants (NPPs) as heat source instead surface water. Exhausted steam extracted from condenser evaporates working fluid of Combined OTEC at heat exchanger (Hx-W). Essential calculation for conceptual design of Combined OTEC was already performed and presented before. However, the technical issue whether sufficient extraction of exhausted steam from high degree of vacuum of condenser to Hx-W can be supplied or not was unclear, which is significant to continue a demonstration program. In this study, so, we calculated the rate of extracted steam to evaluate whether sufficient steam can be extracted using RELAP code. In aspect of implementation of Combined OTEC, confirmation of sufficient flow of exhausted steam into Hx-W is the starting point of research. As the result of RELAP calculation, we confirmed that exhausted steam would flow into Hx-W. Considering the amount of exhausted steam in NPPs which is 1000 MWe and has 36 % of efficiency, 9 % of flow rate to Hx-W is means that 160 MWt of heat can be available as heat source of Combined OTEC. Using this, it can be possible to improve efficiency of aged NPPs and can compensate power loss caused by increase of circulation water temperature particularly in summer season.

  11. Organisational factors important to the safe operation of NPPs

    Frischknecht, Albert; Baumont, Genevieve

    2000-01-01

    The purpose of this paper is to present the achievements of a group of human factor specialists known as Expanded Task Force on Human Factors (ETF). ETF is part of the Principal Working Group No.1 (PWG1) on 'Operating Experience and Human Factors' of the Committee on Nuclear Safety Installations (CSNI) of the OECD Nuclear Energy Agency (NEA). Today, as shown by incident analysis, technology is so far developed that human behaviour and organisational deficiencies can contribute to a major part of the root causes of incidents in nuclear power plants. The influence of the organisation on the safe behaviour and performance of individuals is recognised as a relevant issue for the safety of nuclear power plants (NPPs). The need for an up-to-date basis of knowledge in this area was recognised by CSNI and therefore the ETF organised a workshop, in Switzerland, in 1998, on Organisational Factors. During the workshop, different aspects of organisational influences on the safe operation of NPPs were discussed and twelve important organisational factors concerning safety related activities in a NPP were identified. The result of the workshop is summarised in a state-of-the-art Report (SOAR) 'Identification and Assessment of Organisational Factors Related to the Safety of NPPs' issued by the OECD/NEA. The present paper gives an overview on the main findings of the workshop and conclusions concerning the evaluation of organisational factors. (author)

  12. Safeguard management for operation security in nuclear power plants (NPPs)

    Woo, Tae-Ho; Lee, Un-Chul

    2011-01-01

    Safeguard modeling is conducted for the successful operations in the nuclear power plants (NPPs). The characteristics of the secure operation in NPPs are investigated using the network effect method which is quantified by the Monte-Carlo algorithm. Fundamentally, it is impossible to predict the exact time of a terror incident. So, the random sampling for the event frequency is a reasonable method, including the characteristics of network effect method such as the zero-sum quantification. The performance of operation with safeguard is the major concern of this study. There are three kinds of considerations as the neutronics, thermo-hydraulics, and safeguard properties which are organized as an aspect of safeguard considerations. The result, therefore, can give the stability of the operations when the power is decided. The maximum value of secure operation is 12.0 in the third month and the minimum value is 1.0 in the 18th and 54th months, in a 10 years period. Thus, the stability of the secure power operation increases 12 times higher than the lowest value according to this study. This means that the secure operation is changeable in the designed NPPs and the dynamical situation of the secure operation can be shown to the operator.

  13. Ergonomic (human factors) problems in design of NPPs. A review of TMI and Chernobyl accidents

    Huang Xiangrui; Zheng Fuyu; Gao Jia

    1994-01-01

    The general principle of ergonomic in design of NPPs is given and some causes of TMI and Chernobyl accidents from the view point of human factor engineering are reviewed. The paper also introduces some Ergonomic problems in design, operation and management of earlier NPPs. Some ergonomic principles of man-machine systems design have been described. Some proposals have been suggested for improving human reliability in NPPs

  14. Analysis of 'human element related trip case book in Korean NPPs' using organizational factors

    Kim, S. Y.; Kim, Y. I.; Lee, Y. S.; Kim, C. S.; Jung, C. H.; Jung, W. D.

    2002-01-01

    There have been no studies appling organizational factors to data analysis in Korean NPPs. In this paper, data in 'human element related trip case book in Korean NPPs' are analyzed and categorized by the 20 organizational factors of NRC-BNL according to the cause of reactor trip. These inform us how organizational factors affected on the safety of Korean NPPs. Consequently important organizational factor are identified through which it is known that NPP organization would have a tendency

  15. Structural seismic upgrading of NPPs in Czech and Slovak republics

    David, M [DAVID Consulting, Engineering and Design Office, Prague (Czech Republic)

    1997-03-01

    Several Nuclear Power Plants of the VVER type has been constructed during the past years in former Czechoslovak Republic. Some of them has been already put in operation and some of them are under construction. Nuclear Power Plants V1(2 units of VVER 440/230), V2(2 units of VVER 440/213) in Slovak and NPP Dukovany (4 units of VVER 440/213) in Czech republic are in operation. NPP Mochovce (4 units of VVER 440/213) in Slovak and NPP Temelin (4 units reduced now to 2 units VVER 1000) have been already almost completed, but still under construction. All above cited NPPs have not been either explicitly designed against earthquake or the design against earthquake or its input data must be upgraded to be compatible with present requirements. The upgrading of seismic input as well the seismic upgrading of all structures and technological equipments for so many NPPs has involved a lot of comprehensive work in Czech as well as in Slovak republics. The upgrading cannot be completed in a short time and as a rule the seismic upgrading has been usually performed in several steps, beginning with the most important arrangements against seismic hazard. The basic principles and requirements for seismic upgrading has been defined in accordance with the international and particularly with the IAEA recommendations. About the requirements for seismic upgrading of NPPs in Czech and Slovak republics will be reported in other contribution. This contribution is dealing with the problems of seismic upgrading of NNPs civil engineering structures. The aim of this contribution is to point out some specific problems connected firstly with very complicated concept of Versa structures and secondly with the difficult task to increase the structural capacity to the required seismic level. (J.P.N.)

  16. Structural seismic upgrading of NPPs in Czech and Slovak republics

    David, M.

    1997-01-01

    Several Nuclear Power Plants of the VVER type has been constructed during the past years in former Czechoslovak Republic. Some of them has been already put in operation and some of them are under construction. Nuclear Power Plants V1(2 units of VVER 440/230), V2(2 units of VVER 440/213) in Slovak and NPP Dukovany (4 units of VVER 440/213) in Czech republic are in operation. NPP Mochovce (4 units of VVER 440/213) in Slovak and NPP Temelin (4 units reduced now to 2 units VVER 1000) have been already almost completed, but still under construction. All above cited NPPs have not been either explicitly designed against earthquake or the design against earthquake or its input data must be upgraded to be compatible with present requirements. The upgrading of seismic input as well the seismic upgrading of all structures and technological equipments for so many NPPs has involved a lot of comprehensive work in Czech as well as in Slovak republics. The upgrading cannot be completed in a short time and as a rule the seismic upgrading has been usually performed in several steps, beginning with the most important arrangements against seismic hazard. The basic principles and requirements for seismic upgrading has been defined in accordance with the international and particularly with the IAEA recommendations. About the requirements for seismic upgrading of NPPs in Czech and Slovak republics will be reported in other contribution. This contribution is dealing with the problems of seismic upgrading of NNPs civil engineering structures. The aim of this contribution is to point out some specific problems connected firstly with very complicated concept of Versa structures and secondly with the difficult task to increase the structural capacity to the required seismic level. (J.P.N.)

  17. Ageing of instrumentation and control cables in NPPs

    Santhosh; Ghosh, A.K.; Fernandes, B.G.

    2011-01-01

    Cables are vital components of instrumentation and control (I and C) systems in nuclear power plants (NPPs). The polymer materials used for insulation and jacket materials for electric cables are susceptible to ageing and degradation mechanisms caused by exposure to many of the stressors encountered in NPP service conditions. Ageing of components in NPP is an important concern since the degradation caused by ageing can impact the performance of susceptible equipment. This is of particular concern for safety-related equipment since the failure due to ageing can compromise the continued safe operation of the plant. The state-of-the art for incorporating cable ageing effects into probabilistic safety assessment (PSA) is still evolving and in the reliability assessment of NPP systems, the ageing effect of electrical cable is generally not considered and also, there is no standard method exists for incorporating such ageing effects into the system reliability. Therefore, identification and quantification of ageing of electrical cables is very much essential for an accurate prediction of system reliability for PSA applications. The objective of this study is to develop a methodology to assess the susceptibility of polymeric cable insulation to various ageing mechanisms; and the state of the insulation at any chosen time in order to evaluate the remaining life-time of operating cables in NPPs. This paper presents the state-of-the-art tools and techniques for insulation condition assessment, insulation life prediction methodologies, equipment qualification guidelines, and ageing management programs relating to I and C cables in NPPs. An approach to calculate the insulation resistance subjecting to different stressors has also been presented in this paper. (author)

  18. Equipment and building structures ageing management for WWER type NPPs

    Mayboroda, O.

    2001-01-01

    This report presents the working group 'Equipment and building structures ageing management for WWER type NPPs' activities. The analysis of experience in ageing management, recommendations for regulatory guidelines on ageing management, investigation of case studies, definition suitable communication channels among regulators for ageing related data are given. Analyses of water chemistry, inspection data (safety margins criteria), plugging criteria, volume and time of ECT implementation in all WWER countries are presented. The results of Working group activity show that it is advisable to concentrate efforts on: set up the permanent communication channel among regulators, collection of regulatory criteria for WWER type NPP key components based on understanding of ageing mechanisms and data collection

  19. Progress of steam generator ageing management of Chinese NPPs

    Hongyun, L.; Chun, G.; Jun, T.; Zhigang, W.

    2012-01-01

    In China, the first two NPPs have operated over 15 years (QNPC) and 13 years (Dayabay). Now, most of Chinese NPPs have started their ageing management project. Steam generator (SG) is one of key safety important components for PWR and CANDU, which is selected as the first group of components to develop component ageing management system. QNPC and TQNPC have made some progress in this area. The basic SG ageing management system has been set up, and some application has been under way. To set up SG basic ageing management system, we start with (1) SG ageing mechanism analysis (2) Developing SG ageing management programme (3) Developing SG ageing management information system, SGAMDB (4) Ageing degradation assessment and remained life evaluation SG ageing mechanisms are classified as function degradation and material/structure degradation. The specific tables with unified format are used to analyze the ageing mechanism. The numbering requirements for ageing mechanism are developed to manage them in ageing information system. All ageing mechanisms are graded I and II and III based on its feasibility, impact on safety and operation experience, so that the key mechanisms are managed more strictly. SG ageing management programme (SGAMP), which is fundamental document for ageing management, provides the requirements for working process, what to do and when to do. SGAMP reviewing and improving requirements are as well included. SG ageing management database (SGAMDB) is the first component ageing management database for Chinese NPP, which have been installed and are in operation in QNPC and TQNPC. SG ageing degradation assessment and remained life evaluation are based on ageing mechanism, which includes integrity of tube bundle, integrity and remained fatigue life of key assemblies, and heat transfer capability degradation. Most NPPs at Chinese mainland have started their plant ageing and life management projects. Steam generator (SG), which is one of safety important

  20. Automatic accounting of nuclear materials at WWER type reactor NPPs

    Babaev, N.S.; Poznyakov, N.L.; Strelkov, D.F.

    1978-01-01

    The possibilities of automatic accounting of nuclear materials at NPPs based on WWER reactors are considered. Organizational and technical principles of an automated system of accounting that takes into consideration IAEA requirements in conducting accounting documentation are proposed. A program is described for accounting materials using a BESM-6 computer. Operation of the program requires that all accounting data be recorded on conventional carriers of computer information (magnetic tapes, discs, perforated cards), which constitute the basic NPP accounting documents and may be directly used as initial data for a corresponding information program

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

    Woo, Tae-Ho; Lee, Un-Chul

    2010-01-01

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

  2. Availability and its correlation with the cost situation of NPPs and an advanced reactor as a possible future solution

    Fuchs, M.

    1998-01-01

    The availability depends from a lot of factors, especially from design approaches. The way for the development of design approaches for attaining the safety requirements with more redundancy and without diversity of the systems, especially of safety systems, in NPPs in the past is not acceptable for the future because of cost reasons. It is necessary to find new technical ways to achieve a better availability, reliability and safety by lower costs. The simplification of safety systems by using passive systems may be a solution in the future. The development of a new boiling water reactor BWR 1000 in Germany by Siemens which is sponsored by German utilities and supported by various European partners can be named as such example. (author)

  3. Trends in development of new generation of NPPs with increased safety

    Rumyantsev, V.V.

    1992-01-01

    The main requirements for designing, construction and operation of NPPs with advanced water cooled ALWR and SBWR reactors being under development in the USA are discussed. The trends in modernization of control systems at NPPs of new generation based on wide introduction of digital computers and visualization of technological parameter measurements are considered

  4. Chemical technologies and life management of Ukrainian NPPs

    Arkhipenko, A.V.; Barbashev, S.V.; Litvinskij, L.L.; Masko, A.N.

    2000-01-01

    Now 11 units with WWER-1000 reactors, 2 units with WWER-440 and 1 unit with RBMK-1000 are operated in Ukraine. State of chemical technologies of NPPs essentially influences on unit operating resource by the next ways: decreasing of corrosion intensity of equipment metal; decreasing of contamination on thermal exchanged surfaces of equipment; decreasing of amounts of radioactive waste. Improvement of these parameters can be achieved by the next measures: improvement of purification schemes for feed water of main systems; introduction of more effective water-chemical regimes (WCR); implementation of new methods and instruments of chemical monitoring for WCR; providing of without-scale regime of thermal-exchanged equipment operating by reactor division users through optimisation of the WCR of the NPP spray pool. (author)

  5. Implications of Japan's NPPs overseas expansion policy

    Kim, S. E.; Yun, S. W. [Nuclear Policy Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The accident at the Fukushima Daiichi contributing to nuclear power's loss of acceptability in most developed countries however new nuclear market has been growing especially in developing countries. According to IAEA, it is estimated that the construction of 121 to 743 nuclear power plants (NPPs) by 2050. Japanese government reviewed national nuclear export strategy after Korea KEPCO consortium ordered for construction of the UAE Project in 2009 and Russia won a contract of the Vietnam 1st Nuclear Power Plant Project in 2010. Japan figured out that reasons of failed at UAE project were price competitiveness and lack of top-level's attention. Also Russia offered to Vietnam military cooperation which was diagnosed as a failure to Japan. In these circumstances Fukushima accident influenced attitudes towards and acceptance of nuclear power immediately compared to before the accident. Nevertheless, Japanese government decided to keep focusing on nuclear export.

  6. Safety management in NPPs using an evolutionary algorithm technique

    Mishra, Alok; Patwardhan, Anand; Verma, A.K.

    2007-01-01

    The general goal of safety management in Nuclear Power Plants (NPPs) is to make requirements and activities more risk effective and less costly. The technical specification and maintenance (TS and M) activities in a plant are associated with controlling risk or with satisfying requirements, and are candidates to be evaluated for their resource effectiveness in risk-informed applications. Accordingly, the risk-based analysis of technical specification (RBTS) is being considered in evaluating current TS. The multi-objective optimization of the TS and M requirements of a NPP based on risk and cost, gives the pareto-optimal solutions, from which the utility can pick its decision variables suiting its interest. In this paper, a multi-objective evolutionary algorithm technique has been used to make a trade-off between risk and cost both at the system level and at the plant level for loss of coolant accident (LOCA) and main steam line break (MSLB) as initiating events

  7. Advanced MMIS Toward Substantial Reduction in Human Errors in NPPs

    Seong, Poong Hyun; Kang, Hyun Gook [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Na, Man Gyun [Chosun Univ., Gwangju (Korea, Republic of); Kim, Jong Hyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of); Heo, Gyunyoung [Kyung Hee Univ., Yongin (Korea, Republic of); Jung, Yoensub [Korea Hydro and Nuclear Power Co., Ltd., Daejeon (Korea, Republic of)

    2013-04-15

    This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs.

  8. Advanced MMIS Toward Substantial Reduction in Human Errors in NPPs

    Seong, Poong Hyun; Kang, Hyun Gook; Na, Man Gyun; Kim, Jong Hyun; Heo, Gyunyoung; Jung, Yoensub

    2013-01-01

    This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS). It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs). Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs

  9. ADVANCED MMIS TOWARD SUBSTANTIAL REDUCTION IN HUMAN ERRORS IN NPPS

    POONG HYUN SEONG

    2013-04-01

    Full Text Available This paper aims to give an overview of the methods to inherently prevent human errors and to effectively mitigate the consequences of such errors by securing defense-in-depth during plant management through the advanced man-machine interface system (MMIS. It is needless to stress the significance of human error reduction during an accident in nuclear power plants (NPPs. Unexpected shutdowns caused by human errors not only threaten nuclear safety but also make public acceptance of nuclear power extremely lower. We have to recognize there must be the possibility of human errors occurring since humans are not essentially perfect particularly under stressful conditions. However, we have the opportunity to improve such a situation through advanced information and communication technologies on the basis of lessons learned from our experiences. As important lessons, authors explained key issues associated with automation, man-machine interface, operator support systems, and procedures. Upon this investigation, we outlined the concept and technical factors to develop advanced automation, operation and maintenance support systems, and computer-based procedures using wired/wireless technology. It should be noted that the ultimate responsibility of nuclear safety obviously belongs to humans not to machines. Therefore, safety culture including education and training, which is a kind of organizational factor, should be emphasized as well. In regard to safety culture for human error reduction, several issues that we are facing these days were described. We expect the ideas of the advanced MMIS proposed in this paper to lead in the future direction of related researches and finally supplement the safety of NPPs.

  10. Passive Education

    Bojesen, Emile

    2018-01-01

    This paper does not present an advocacy of a passive education as opposed to an active education nor does it propose that passive education is in any way 'better' or more important than active education. Through readings of Maurice Blanchot, Jacques Derrida and B.S. Johnson, and gentle critiques of Jacques Rancière and John Dewey, passive…

  11. Opportunities and supporting activities to promote preventive maintenance of NPPs in Japan

    Sanada, A.; Shinkawa, T.; Sakurada, M.

    1998-01-01

    With increase of the number of NPPs and operation history, enhancement of the safety regulation is becoming important for such long-operated NPPs. Centering on the comprehensive preventive maintenance, periodic safety reviews by utilities and its review and evaluation by MITI are in progress. The first reviews have not revealed essential and critical indications to be newly implemented. This means that the most of activities to secure reliability and safety have been done steadily. The present paper addresses the mechanism of on-going preventive maintenance and its essential elements: opportunities to identify issues and problems, and supporting activities to promote decision-makings on feedback, upgrading and modernization of NPPs. (author)

  12. Safety upgrading activities against tsunami, earthquake, and severe accident at Hamaoka NPPs

    Watanabe, Tetsuya; Wakunaga, Takao; Ishida, Takahisa

    2013-01-01

    As the lessons learned by the Fukushima Daiichi NPPs accident, Chubu Electric Power carried out the Emergency Safety Measures at Hamaoka NPPs immediately, and announced the plan for tsunami countermeasures including the construction of 18m-height tsunami protection wall in July 2011. Furthermore, the company announced the additional severe accident and tsunami countermeasures, and etc. in December 2012 and in April 2013, such as the installation of Filtered Containment Venting System and increasing the height of the tsunami protection wall from 18m to 22m. In this paper, we present major safety upgrading activities against tsunami, earthquake and severe accident at Hamaoka NPPs. (author)

  13. Safety aspects in life extension of NPPs. Working material

    2002-01-01

    Due to current social and economical framework, in last years many Member States (MS) started a process of Plant Life Extension (PLEX) for their older nuclear facilities. The process followed many different approaches, being intrinsically dependent on the national regulatory framework and technical tradition. This process has many nuclear safety implications, other than strategic and political ones, and therefore a need for tailoring the available safety assessment tools to such applications has become urgent in recent years. Typical safety assessment processes such as the Periodic Safety Review has been used already and can be used in the future as a framework for a PLEX. Also the review of regular maintenance and ageing management programs and the continuous upgrading of the Safety Analysis Report are tools widely used in a life extension context in many MS. However, recently some MS highlighted the need to identify in a clear way the technical aspects more directly affecting the decision for a long-term operation of a nuclear facility. Many Technical Cooperation projects have been requested for the year 2003-2004 on this subject and a generic task in Nuclear Safety proved necessary as a background activity. Therefore, on May 6-10, 2002, a Consultant Meeting dealing with Safety Aspects of life extension for NPPs was convened at the Nuclear Safety Dept. of the IAEA. It was attended by representatives of Regulatory Bodies and Utilities, both from countries with experience of life extension of NPPs and countries where the process is at the beginning. The main application problems were identified and discussed and a first attempt was carried out to define the key elements of the life extension process, isolating peculiar technical items, LTO related, from generic safety related tasks. The result was a preliminary technical document with a collection of basic experience and information for the implementation of a PLEX program. Therefore the draft document was thought

  14. Inclusion of Premeditated Threats in the Safety Methodology for NPPs

    Levanon, I.

    2014-01-01

    During the last decade the global effort to prevent terrorism or to mitigate its harm, if prevention fails, has increased. The nuclear power community was involved in this effort trying to prevent terrorist attacks on NPPs (Nuclear Power Plants). A natural extension of terror restraining is the prevention of any premeditated damage to the plant, including acts of state. The pre-feasibility study of an Israeli NPP, conducted by the Ministry of National Infrastructures, has identified the risk of hostile damage to the NPP as a major obstacle to the establishment of nuclear power in Israel, second only to the refusal of nuclear exporting nations to sell an NPP to Israelv. The General Director of the Ministry and the Head of the IAEC (Israeli Atomic Energy Commission) have approved continuation of the pre-feasibility study. This synopsis presents a study, regarding premeditated threats to NPPs, commissioned by the Ministry of National Infrastructures as part of the continuation. It focuses on the safety aspect of premeditated threats originating outside the plant, although a significant part of the analysis can be extended to other subjects such as theft or diversion of strategic materials. The study deals only with methodology and does not encompass specific threats or protection measures. Conclusions and recommendations and marked by bold italics Arial font. The theory of nuclear safety regarding non-premeditated safety events (equipment failures, human errors, natural events, etc.) is well developed. The study refers to these events and the theory attached to them as c lassical , distinguishing them from premeditated events. The study defines two postulates, related to premeditated threats: Correspondence – We should adopt the classical methodology whenever possible. Regulation – The safety of an NPP from premeditated threats requires examination, approval and inspection by a regulator. Key issues of the methodology with substantial differences from the

  15. Minimum throttling feedwater control in VVER-1000 and PWR NPPs

    Symkin, B.E.; Thaulez, F.

    2004-01-01

    This paper presents an approach for the design and implementation of advanced digital control systems that use a minimum-throttling algorithm for the feedwater control. The minimum-throttling algorithm for the feedwater control, i.e. for the control of steam generators level and of the feedwater pumps speed, is applicable for NPPs with variable speed feedwater pumps. It operates in such a way that the feedwater control valve in the most loaded loop is wide open, steam generator level in this loop being controlled by the feedwater pumps speed, while the feedwater control valves in the other loops are slightly throttling under the action of their control system, to accommodate the slight loop imbalances. This has the advantage of minimizing the valve pressure losses hence minimizing the feedwater pumps power consumption and increasing the net MWe. The benefit has been evaluated for specific plants as being roughly 0.7 and 2.4 MW. The minimum throttling mode has the further advantages of lowering the actuator efforts with potential positive impact in actuator life and of minimizing the feedwater pipelines vibrations. The minimum throttling mode of operation has been developed by the Ukrainian company LvivORGRES. It has been applied with great deal of success on several VVER-1000 NPPs, six units of Zaporizhzha in Ukraine plus, with participation of Westinghouse, Kozloduy 5 and 6 in Bulgaria and South Ukraine 1 to 3 in Ukraine. The concept operates with both ON-OFF valves and true control valves. A study, jointly conducted by Westinghouse and LvivORGRES, is ongoing to demonstrate the applicability of the concept to PWRs having variable speed feedwater pumps and having, or installing, digital feedwater control, standalone or as part of a global digital control system. The implementation of the algorithm at VVER-1000 plants provided both safety improvement and direct commercial benefits. The minimum-throttling algorithm will similarly increase the performance of PWRs. The

  16. Analytic study for physical protection system (PPS) in nuclear power plants (NPPs)

    Woo, Tae Ho, E-mail: thw@snu.ac.kr

    2013-12-15

    Highlights: • The physical protection system (PPS) is investigated. • General NPPs are modeled in the study. • Possible terror cases, likelihood, and consequence are studied. • PPS is constructed by analytical methods. - Abstract: The nuclear safeguard is analyzed in the aspect of the physical protection system (PPS) in nuclear power plants (NPPs). The PPS is reviewed and its related terror scenarios are investigated. The PPS is developed using analytical methods. In the terror scenarios, there are 8 possible cases for the terror attacks to the NPPs. Then, the likelihood of terror is classified by the general terror incidents. The consequence of terror is classified by Design Basis Threat (DBT) of the International Atomic Energy Agency (IAEA) scale. The physical protection method is suggested by defense-in-depth constraints and severe accident countermeasures. Finally, the advanced PPS is constructed, which could be used for the preparation for the possible terror attacks in the NPPs.

  17. Analytic study for physical protection system (PPS) in nuclear power plants (NPPs)

    Woo, Tae Ho

    2013-01-01

    Highlights: • The physical protection system (PPS) is investigated. • General NPPs are modeled in the study. • Possible terror cases, likelihood, and consequence are studied. • PPS is constructed by analytical methods. - Abstract: The nuclear safeguard is analyzed in the aspect of the physical protection system (PPS) in nuclear power plants (NPPs). The PPS is reviewed and its related terror scenarios are investigated. The PPS is developed using analytical methods. In the terror scenarios, there are 8 possible cases for the terror attacks to the NPPs. Then, the likelihood of terror is classified by the general terror incidents. The consequence of terror is classified by Design Basis Threat (DBT) of the International Atomic Energy Agency (IAEA) scale. The physical protection method is suggested by defense-in-depth constraints and severe accident countermeasures. Finally, the advanced PPS is constructed, which could be used for the preparation for the possible terror attacks in the NPPs

  18. A Cyber Security Risk Assessment Procedure for Digital I and C Systems in NPPs

    Song, J. G.; Lee, J. W.; Lee, C. K.; Kwon, K. C.; Lee, D. Y.

    2011-01-01

    Digital Instrumentation and Control (I and C) systems in nuclear power plants (NPPs) use general digital technologies similar to those used in IT systems. However, one of significant differences between the two systems resides in the duration of their service life. The I and C systems in NPPs operate for more than 20 years. IT systems, on the other hand, are in service for about 3 to 5 years. Hence, a one-time risk assessment for IT systems is normally acceptable. In contrast, the risk assessment for the I and C systems in NPPs should be recursively performed during their longer operation life. A recursive procedure for cyber security risk assessment of the I and C systems in NPPs is studied and proposed in this paper

  19. A Cyber Security Risk Assessment Procedure for Digital I and C Systems in NPPs

    Song, J. G.; Lee, J. W.; Lee, C. K.; Kwon, K. C.; Lee, D. Y. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    Digital Instrumentation and Control (I and C) systems in nuclear power plants (NPPs) use general digital technologies similar to those used in IT systems. However, one of significant differences between the two systems resides in the duration of their service life. The I and C systems in NPPs operate for more than 20 years. IT systems, on the other hand, are in service for about 3 to 5 years. Hence, a one-time risk assessment for IT systems is normally acceptable. In contrast, the risk assessment for the I and C systems in NPPs should be recursively performed during their longer operation life. A recursive procedure for cyber security risk assessment of the I and C systems in NPPs is studied and proposed in this paper

  20. Study on the Post-Fire Safe-Shutdown Analysis for CANDU NPPs

    Kim, In Hwan; Kim, Yun Jung; Park, Mun Hee [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The purpose of this paper is to study a method of the Post-Fire Safe-Shutdown Analysis in order to apply to CANDU NPPs when one group of the Safety Structures, Systems and Components(SCCs) is failed by Fire. The purpose of Fire Protection is prevention, suppression of the fire and mitigation of the effect on the Nuclear Safety. When fire takes place at the Nuclear Power Plants(NPPs), the reactor should achieve and maintain safe shut-down condition and minimize radioactive material release to an environment. The purpose of the Post-Fire SSA process is an evaluation process during a fire at NPPs. At this study, the process was conceptually adopted for control room complex of CANDU NPPs. The Core Damage Frequency of the Reactor will be evaluated more accurately if the SSA is adopted adequately at a fire.

  1. Principal regulations of the Decommissioning Conception of the operating NPPs in Ukraine

    Litvins'kij, L.L.; Lobach, Yu.M.; Rusyinko, P.M.

    2004-01-01

    The paper contains the review of principal regulations of the Decommissioning Conception of the operating NPPs in Ukraine. There are presented the results of analysis based on the consideration of three possible scenarios of the nuclear power complex development corresponding to the different terms of the unit's lifetime extension. Concept decommissioning decisions are established; the results of strategic planning and long-term forecast of decommissioning activity on the operating NPPs in Ukraine are presented too

  2. Perspective decisions of WWER nuclear fuel: Implementation at Russian NPPs

    Molchanov, V.

    2003-01-01

    The scientific and technical policy pursued by JSC TVEL has managed to create a new generation of fuel assembly design on the basis of solutions tested at various units of Russian NPPs - Kola NPP, Kalinin NPP, Unit 1, Balakovo NPP Unit 1. The requirements set for the new generation nuclear fuel for WWER are: 1) High fuel burnup - up to 70 MWxdays/kgU; 2) Extended operation cycle - up to 6 years; 3) Increase of uranium charge to the core; 4) Increased lateral stability - bow not more than 7 mm; 5) High level of operating reliability - fuel rod leakage not worse than 10-5 1/year; 6) Demountable fuel assembly design. Post-irradiation examination results of fuel assemblies discharged from WWER-1000 reactors demonstrate that fuel rods have substantial reserve in general characteristics including that of dealing with planned burnup. In order to meet the requirements, trials are started for: implementation of rigid skeleton (WWER-1000); fuel column length extension (WWER-1000 and WWER-440); increase of UO 2 charge (WWER-1000 and WWER-440); enhancing of operational reliability and demountable design. It is concluded that the Russian nuclear fuel for WWER-type reactors is competitive and enables the implementation of state-of-the-art cost effective fuel cycles

  3. Bohunice NPPs - Part of the Slovak's economy (sustainable) development

    Dobak, Dobroslav

    2001-01-01

    Of the total consumption of electricity in Slovakia, 42% was generated in nuclear power plant units in 1999. Slovakia operates 6 units with a WWER 440 nuclear reactors, 4 of them are at Bohunice site and 2 at Mochovce. The Nuclear Regulatory Authority of SR is not the only regulatory body controlling nuclear activity. Both - the system of nuclear activities regulation in Slovakia as well as the approach to Nuclear Safety enhancement of the operator were positively judged by IAEA and WENRA. In 1993 -Slovakia has accepted the commitments of the UN Convention on Climate Changes, including a reduction of greenhouse gases to 1990 levels by the year 2000. Moreover, as an internal target Slovakia has set the reaching of the ,'Toronto Objective', i.e. 20% reduction in CO x emissions through the year 2005 as compared to 1988. Taking into account the actual situation as well as natural conditions for some renewable sources utilisation, the target won't be reached without nuclear energy. The nuclear energy is free of emissions, does not burn oxygen, and with the share of production in Slovakia will remain significant contributor. To the environment protection it contributes also by replacing fossil heat plants with heat delivery for the region. In case of radiological wastes the environment protection is ensured by very strict system of control, evidence, treatment and repository. To conclude, Bohunice NPPs were, are and will remain very important part of the Slovak's economy, creating conditions for its (sustainable) development

  4. Enhanced Understanding of High Energy Arcing Fault Phenomena in NPPs

    Park, Jong Seuk; Kim, Me Kyoung; Lee, Sang Kyu [KINS, Daejeon (Korea, Republic of)

    2016-05-15

    This study reviews the recent HEAF events in nuclear power plants (NPPs) and investigates the HEAF phenomena with the experiment data performed at KEMA supported by OECD/NEA HEAF project. High Energy Arcing Fault (HEAF) can occur in an electrical components or systems through an arc path to ground and has the potential to cause extensive damage to the equipment involved. The intense radiant heat produced by the arc can cause significant damage or even destructions of equipment and can injure people. Affected components include a specific high-energy electrical devices, such as switch gears, load centers, bus bars/ducts, transformers, cables, etc., operating mainly on voltage levels of more than 380V but the voltage levels in NUREG/CR-6580 is more than 440. As stated before, HEAF may cause the significant damage to adjacent facilities as well as the equipment involved. Quantitative estimation of the equipment damage, determining the damage area, and predicting the secondary fire after initiating HEAF event should be further studied in depth. Draft test report produced by KEMA does not give comprehensive understanding of the HEAF phenomena. It is expected that a detail information of slug calorimeter and the test data to show the HEAF characteristics will be given in the final test reports.

  5. Safeguard assessment for life extension in nuclear power plants (NPPs) using a production function

    Woo, Tae-Ho; Lee, Un-Chul

    2011-01-01

    Research highlights: → The numerical value is constructed for the secure operation. → As the power increases, the NSEF increases. → Specific month could be indicated by the relative value of NSEF. → It is suggested for the better power in NPPs. → There is another possibility for the secure operation factors. - Abstract: Life extension is investigated as a safeguard assessment for the stability on the operation of the nuclear power plants (NPPs). The Cobb-Douglas function, one of the production functions, is modified for the nuclear safeguard in NPPs, which was developed for the life quality of the social and natural objects. Nuclear Safeguard Estimator Function (NSEF) is developed for the application in NPPs. The cases of NPPs are compared with each other in the aspect of the secure performance. The results are obtained by the standard productivity comparisons with the designed power operations. The range of secure life extension is between 1.008 and 5.353 in 2000 MW e and the range is between 0.302 and 0.994 in 600 MW e . So, the successfulness of the power operation increases about 5 times higher than that of the interested power in this study, which means that the safeguard assessment has been performed in the life extension of the NPPs. The technology assessment (TA) is suggested for the safe operation which is an advanced method comparing conventional probabilistic safety assessment (PSA).

  6. Development and application of digital safety system in NPPs

    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

  7. Development and application of digital safety system in NPPs

    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.

  8. Application of the Defense-in-Depth Concept in the Projects of New-Generation NPPs Equipped with VVER Reactors

    Shvyryaev, Yu. V.; Morozov, V. B.; Kuchumov, A.Yu., E-mail: morozov@aep.ru [JSC Atomenergoproekt, Moscow (Russian Federation)

    2014-10-15

    The projects of new-generation NPPs equipped with VVER reactors are developed as projects the safety level of which is superior to that of NPPs that are currently in operation. The main design solutions adopted for implementing the defence-in-depth (DiD) concept in the projects of new-generation NPPs equipped with VVER reactors are briefly characterized in the paper. (author)

  9. Seismic verification methods for structures and equipment of VVER-type and RBMK-type NPPs (summary of experiences)

    Masopust, R.

    2003-01-01

    The main verification methods for structures and equipment of already existing VVER-type and RBMK-type NPPs are briefly described. The following aspects are discussed: fundamental seismic safety assessment principles for VVER/RBMK-type NPPs (seismic safety assessment procedure, typical work plan for seismic safety assessment of existing NPPs, SMA (HCLPF) calculations, modified GIP (GIP-VVER) procedure, similarity of VVER/RBMK equipment to that included in the SQUG databases and seismic interactions

  10. Risk based definition of TS requirements for NPPs with WWER-1000 type reactor

    Morozov, V.; Tokmachev, G.

    2000-01-01

    The main regulations in safety related maintenance for NPPs in Russia are defined as a part of Technical Specifications (TSs). It includes limiting conditions for operation (surveillance requirements, allowed outage time, et.). In Russian practice the two levels of TSs are presented: general TSs that have been established as a master documents for similar designed NPPs and plant specific based on operation practice of each NPP unit. This paper presents a brief review of submissions to TS changes for NPPs with WWER type reactor were issued by AEP PSA team since 1988 year. Besides it provides an approach allows to estimate the complex affect on plant risk for both Limiting Conditions of Operation (LCO) and Surveillance Test Intervals (STI) based on relevant probabilistic tool (Minimal Cut Sets method and Marcov Chains methods). (author)

  11. Overview of human performance improvement initiatives in Nuclear Power Plants (NPPs )

    Sharma, Ashok Kumar

    2006-01-01

    Nuclear Power Plants (NPPs) are very complex systems. Diverse, multiple and redundant technological systems are used for effective control and safety of the NPPs. The increased numbers of such systems require increased operator attention. Additionally, the control stations (man-machine interfaces) are to be kept manageable in size. This sometimes reduces the scope for truly ergonomic design. These limitations, coupled with the shortcomings of human nature, led to unintended human performance problems and errors resulting into poor plant performance worldwide. Some organisational weaknesses, managerial decisions and latent errors also aided and abetted human errors. In view of this, a need was felt for development of performance culture at all levels in NPP organisations. Towards this end, ready-to-use performance improvement tools were developed and used for individual performers, supervisors and managers in the NPPs. This paper describes the experiences of the global nuclear electricity generating industry towards human performance improvement and error reduction. (author)

  12. Radiological Consequences Analysis for Abnormal Condition on NPPs 1000 MWe by Using Radcon Model

    Pande Mande Udiyani; Sri Kuntjoro

    2009-01-01

    The operation of NPPs (Nuclear Power Plants) in Indonesia to anticipates rare of energy will generate various challenges, especially about NPPs safety. So installation organizer of nuclear must provide scientific argument to safety NPPs, one of them is by providing document of safety analysis. Calculation of radiological consequences after abnormal condition applies on generic PWR-1000 power reactor. Calculation is done by using program package RadCon (Radiological Consequences Model), with postulate condition is based on DBA (Design Basis Accident). Calculation of dispersion of radionuclide concentration is using PC-COSYMA as input data for RadCon. Simulation for radiological consequences analysis uses by site data sample. Analysis result shows that maximum receiving of internal - externals radiological consequence for short term and long-term below 1 km radius area is below the limit acceptably effective dose for a member of the public as a result of an accident which should not exceed 5 mSv (ICRP 1990). (author)

  13. Our consistent countermeasure following up with lesson from Fukushima NPPs accident

    Kim, Jae Rok [Korea Academy of Nuclear Safety, Seoul (Korea, Republic of); Ro, Seung Gy [Sung woo E and T, Kyeonggi (Korea, Republic of); Kim, Si Hwan [UNIST, Ulsan (Korea, Republic of); Nam, Jang Soo [Korean Nuclear Society, Daejeon (Korea, Republic of); Yoo, Guk Hee [Nuclear Safety and Security Commission, Seoul (Korea, Republic of); Kim, Soong Pyung [Chosun Univ., Gwangju (Korea, Republic of)

    2012-10-15

    Fukushima NPPs accident has not only resulted in driving out the nuclear Renaissance which is about to revive after several lean years, but also given humankind a very rigorous lessons in nuclear safety. Recently administrative systems were reorganized for stepping up further nuclear safety. Nuclear Safety and Security Commission(NSSC) as a governmental organization, directly under the jurisdiction of the president, which is responsible for a nuclear safety mission separated from Ministry of Education, Science and Technology. A beef up work of 50 safety related items for Korean NPPs identified after Fukushima NPPs accident has been implemented under the supervision of the commission. It has also been emphasized that sincere communications between the nuclear society and the people at large are essential for obtaining public acceptance of nuclear energy by ensuring the credibility of nuclear safety. The main points of lecture materials presented in the nuclear senior members' forum have been reviewed to derive invaluable guidelines.

  14. Containment shells of reactor compartments at foreign NPPs

    Demidov, A.P.; Savchenko, V.A.

    1989-01-01

    The modern designes of containment shells (CS) of NPP reactor compartments is described. Much attention is paid to the PCS-3 project envisaging CS inclusion in the complex of NPP passive safety system. The PCS-3 system is developed in the USA for NPP with the improved PWR type reactor. The above system permits to cool the core quickly, to reduce steam pressure in CS down to a safe level and to prevent the discharge of radioactive products in the atmosphere in the case of accidents, even very serious, caused by loss of coolant and core dryout

  15. Operating experiences with passive systems and components in German nuclear power plants

    Maqua, M.

    1996-01-01

    Operating experience with passive systems and components is limited to the equipment installed in existing NPPs. In German power plants, this experience is available for equipment of the IAEA categories A, C and D. The presentation is focused on typical examples out of these three categories. An overview is given on the number of reported events and typical failure modes. Selected failures are discussed in detail. 1 ref., 6 figs, 7 tabs

  16. Operating experiences with passive systems and components in German nuclear power plants

    Maqua, M [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany)

    1996-12-01

    Operating experience with passive systems and components is limited to the equipment installed in existing NPPs. In German power plants, this experience is available for equipment of the IAEA categories A, C and D. The presentation is focused on typical examples out of these three categories. An overview is given on the number of reported events and typical failure modes. Selected failures are discussed in detail. 1 ref., 6 figs, 7 tabs.

  17. Some remarks on the specification of seismic conditions for NPPs, based on the Romanian experience

    Sandi, H [INCERC Building Research Inst., Bucharest (Romania)

    1993-07-01

    Some introductory remarks are devoted to the importance of revising the level of earthquake protection of NPPs, given the new knowledge at hand. Some summary data on the seismicity of Romania are given, with emphasis on the implications of instrumental data obtained during the recent strong intermediate depth earthquake of 1986 and 1990. Some problems raised by the new data in connection with the Cernavoda NPP (currently under construction), from the viewpoint of ground and floor design conditions, are discussed. Some proposals are then presented in connection with the future activities related to the verification of NPPs of the region. (author)

  18. Some remarks on the specification of seismic conditions for NPPs, based on the Romanian experience

    Sandi, H.

    1993-01-01

    Some introductory remarks are devoted to the importance of revising the level of earthquake protection of NPPs, given the new knowledge at hand. Some summary data on the seismicity of Romania are given, with emphasis on the implications of instrumental data obtained during the recent strong intermediate depth earthquake of 1986 and 1990. Some problems raised by the new data in connection with the Cernavoda NPP (currently under construction), from the viewpoint of ground and floor design conditions, are discussed. Some proposals are then presented in connection with the future activities related to the verification of NPPs of the region. (author)

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

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

    2002-01-01

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

  20. Passive safety systems for integral reactors

    Kuul, V.S.; Samoilov, O.B.

    1996-01-01

    In this paper, a wide range of passive safety systems intended for use on integral reactors is considered. The operation of these systems relies on natural processes and does not require external power supplies. Using these systems, there is the possibility of preventing serious consequences for all classes of accidents including reactivity, loss-of-coolant and loss of heat sink as well as severe accidents. Enhancement of safety system reliability has been achieved through the use of self-actuating devices, capable of providing passive initiation of protective and isolation systems, which respond immediately to variations in the physical parameters of the fluid in the reactor or in a guard vessel. For beyond design base accidents accompanied by complete loss of heat removal capability, autonomous self-actuated ERHR trains have been proposed. These trains are completely independent of the secondary loops and need no action to isolate them from the steam turbine plant. Passive safety principles have been consistently implemented in AST-500, ATETS-200 and VPBER 600 which are new generation NPPs developed by OKBM. Their main characteristic is enhanced stability over a wide range of internal and external emergency initiators. (author). 10 figs

  1. Passive safety systems for integral reactors

    Kuul, V S; Samoilov, O B [OKB Mechanical Engineering (Russian Federation)

    1996-12-01

    In this paper, a wide range of passive safety systems intended for use on integral reactors is considered. The operation of these systems relies on natural processes and does not require external power supplies. Using these systems, there is the possibility of preventing serious consequences for all classes of accidents including reactivity, loss-of-coolant and loss of heat sink as well as severe accidents. Enhancement of safety system reliability has been achieved through the use of self-actuating devices, capable of providing passive initiation of protective and isolation systems, which respond immediately to variations in the physical parameters of the fluid in the reactor or in a guard vessel. For beyond design base accidents accompanied by complete loss of heat removal capability, autonomous self-actuated ERHR trains have been proposed. These trains are completely independent of the secondary loops and need no action to isolate them from the steam turbine plant. Passive safety principles have been consistently implemented in AST-500, ATETS-200 and VPBER 600 which are new generation NPPs developed by OKBM. Their main characteristic is enhanced stability over a wide range of internal and external emergency initiators. (author). 10 figs.

  2. To selecting the characteristics of saturated steam direct cycle NPPs for operation under variable loads

    Khrustalev, V.A.; Demidov, O.I.

    1986-01-01

    Problems for operating process optimization of NPPs with RBMK type reactors under load swings in the power system is considered. Determination technique for optimal values of such parameters as initial steam pressure and fuel enrichment for NPP different load factors is developed. Optimization of these parameters gives a 150000 rouble saving of annual expenditures per each 3200 MW of reactor heat output

  3. An Approach for Effect Analysis of Electromagnetic Pulse in Operating NPPs

    Ryu, Ho Sun; Ye, Song Hae; Kim, Minyi; Lee, Euijong [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    Recently, there is a growing Electromagnetic Pulse (EMP) threat caused by North Korea’s nuclear weapons and unmanned aerial vehicles (UAVs). KHNP CRI is currently conducting a research project that will evaluate the safety of domestic nuclear power plants (NPPs) against EMP effects and prepare safety measures to counter vulnerable points. We will instead use simulation tools to evaluate the electromagnetic shielding ability and the conductivity of cables through vulnerable points in NPPs. Through a study of electromagnetic simulation techniques and tools, this paper suggests a simulation method for analysis of EMP effects in operating NPPs. Although 3D tools are relatively accurate, is difficult to use only 3D tools to simulate EMP effects for huge and complex structures such as NPPs. It is more efficient in terms of cost and time to use a 3D tool and an EMT tool for the simulation of such structures. We have compared the advantages and disadvantages of various methods and have selected the most appropriate tools; we will proceed in our next paper with the simulation of EMP effects.

  4. An Approach for Effect Analysis of Electromagnetic Pulse in Operating NPPs

    Ryu, Ho Sun; Ye, Song Hae; Kim, Minyi; Lee, Euijong

    2016-01-01

    Recently, there is a growing Electromagnetic Pulse (EMP) threat caused by North Korea’s nuclear weapons and unmanned aerial vehicles (UAVs). KHNP CRI is currently conducting a research project that will evaluate the safety of domestic nuclear power plants (NPPs) against EMP effects and prepare safety measures to counter vulnerable points. We will instead use simulation tools to evaluate the electromagnetic shielding ability and the conductivity of cables through vulnerable points in NPPs. Through a study of electromagnetic simulation techniques and tools, this paper suggests a simulation method for analysis of EMP effects in operating NPPs. Although 3D tools are relatively accurate, is difficult to use only 3D tools to simulate EMP effects for huge and complex structures such as NPPs. It is more efficient in terms of cost and time to use a 3D tool and an EMT tool for the simulation of such structures. We have compared the advantages and disadvantages of various methods and have selected the most appropriate tools; we will proceed in our next paper with the simulation of EMP effects

  5. Analysis of the events on the operating of the wrong compartment of NPPs

    Zheng Lixin; Zhou Hong; Zhang Hao; Che Shuwei; Zhang Jiajun

    2013-01-01

    In this paper, an operational event that unit trip caused by the operating of the wrong compartment, due to the personnel error is introduced. Through in-depth research on this kind of events the causes of the events are found, some suggestions are put forward. It can provide a reference for preventing the similar events from recurring to other NPPs. (authors)

  6. Technique for calculating the requirements for housing when designing workers' towns for NPPs

    Vorob'ev, I.E.; Gavrilko, A.P.

    1989-01-01

    Problem of determining housing requirements when constructing and operating NPPs is considered. Concrete variants of ratio of apartments of different types (hotel-type, one-,two, three-and four-room ones) for operating and auxiliary personnel as well as for construction and mounting staff and auxiliary services related to NPP construction, are proposed

  7. Monitoring of coolant temperature stratification on piping components in WWER-440 NPPs

    Hudcovsky, S.; Slanina, M.; Badiar, S.

    2001-01-01

    The presentation deals with the aims of non-standard temperature measurements installed on primary and secondary circuit in WWER-440 NPPs, explains reasons of coolant temperature stratification on the piping components. It describes methods of the measurements on pipings, range of installation of the temperature measurements in EBO and EMO units and illustrates results of measurements of coolant temperature stratification. (Authors)

  8. Compositional properties of passivity

    Kerber, Florian; van der Schaft, Arjan

    2011-01-01

    The classical passivity theorem states that the negative feedback interconnection of passive systems is again passive. The converse statement, - passivity of the interconnected system implies passivity of the subsystems -, turns out to be equally valid. This result implies that among all feasible

  9. Seismic stability of NPPs in Eastern Europe. Final report from June 1993 - June 1994

    Ambriashvili, Y.K.

    1995-01-01

    The present work was fulfilled within the contract between IAEA and 'Atomenegroproject' Institute of the Russian Federation. The program of the work fulfilled within the period from June 1993 till June 1994 was as follows: review and comments of the standards related to aseismic design of the structure and components; aseismic classification of main safety systems and components by function of WWER NPPs; response spectrum which was developed for design of WWER NPPs; comparison of Western and the Russian standards and codes related to aseismic design of NPPs. The general requirements for aseismic designed constructions, comments on the main important points of seismic loads, calculation of the seismic loads, methodology of design and test of the equipment and electrical systems are presented in the work. The main constructions and equipment for NPP WWER-440 provided the functions of plant during and after the earthquakes are also listed. Methodology of calculation and selection of response spectrum for design of WWER NPPs. The comparative analysis of the Western and the Russian Norms are reviewed. The main conclusions of the present work are as follows: General principal stages of the methods and approaches of the design, investigations and testing are almost identified with IAEA and Western approaches. Recommendations corresponding with the IAEA and Western standards should be consumed in a new version of codes of aseismic design of NPPs that are working out now in the Russian Federation. It is connected with maximum acceleration, response spectra, time histories, damping factor and etc. Meanwhile 'Atomenergoproject' now has possibility to fulfil calculations of soil- structure-equipment systems and carry out full scale tests of the equipment on the components seismic platform in accordance with the high level of the technical requirements

  10. Seismic stability of NPPs in Eastern Europe. Final report from June 1993 - June 1994

    Ambriashvili, Y K [Atomenergoproject, Moscow (Russian Federation)

    1995-07-01

    The present work was fulfilled within the contract between IAEA and 'Atomenegroproject' Institute of the Russian Federation. The program of the work fulfilled within the period from June 1993 till June 1994 was as follows: review and comments of the standards related to aseismic design of the structure and components; aseismic classification of main safety systems and components by function of WWER NPPs; response spectrum which was developed for design of WWER NPPs; comparison of Western and the Russian standards and codes related to aseismic design of NPPs. The general requirements for aseismic designed constructions, comments on the main important points of seismic loads, calculation of the seismic loads, methodology of design and test of the equipment and electrical systems are presented in the work. The main constructions and equipment for NPP WWER-440 provided the functions of plant during and after the earthquakes are also listed. Methodology of calculation and selection of response spectrum for design of WWER NPPs. The comparative analysis of the Western and the Russian Norms are reviewed. The main conclusions of the present work are as follows: General principal stages of the methods and approaches of the design, investigations and testing are almost identified with IAEA and Western approaches. Recommendations corresponding with the IAEA and Western standards should be consumed in a new version of codes of aseismic design of NPPs that are working out now in the Russian Federation. It is connected with maximum acceleration, response spectra, time histories, damping factor and etc. Meanwhile 'Atomenergoproject' now has possibility to fulfil calculations of soil- structure-equipment systems and carry out full scale tests of the equipment on the components seismic platform in accordance with the high level of the technical requirements.

  11. Implementation of the RCM approach at EDF NPPs: Current status

    Dubreuil-Chambardel, A.; Martin-Onraet, M.; Degrave, C.

    2001-01-01

    To ensure safest possible operation and to get best overall economic performance of its Nuclear Power Plants, 10 years ago Electricite de France launched a Reliability Centered Maintenance (RCM) project to optimize the preventive maintenance programs. The principles underlying the RCM approach are based on common sense: failures must be prevented by preventive maintenance operations in all cases when the repercussions for the installation could be serious or critical in term of safety, availability or maintenance costs. The approach is a 3-phases process: 1. Evaluation of the functional consequences of failures 2. Evaluation of performances based on the analysis of experience feedback 3. Optimization of the preventive maintenance tasks The new preventive maintenance programs are presently almost completed and progressively implemented. Here and now, the implementation of the RCM approach allows to emphasize some benefits: 1. Same or increased level of safety 2. Same or increased level of plant availability 3. ALARA principles better taken into account 4. Cost control 5. Positive change in maintenance culture. Some new studies are in progress, such as the development of a 'Risk Based In Service Inspection' for passive components. (author)

  12. Cyber security in nuclear industry – Analytic study from the terror incident in nuclear power plants (NPPs)

    Cho, Hyo Sung; Woo, Tae Ho

    2017-01-01

    Highlights: • The cyber terrorism in NPPs of South Korea shows the study motivations. • Analyses of the cyber terrorism in NPPs are investigated. • Designed solutions for the cyber terrorism in NPPs are discussed. • South Korean case is considered as the cyber terrorism in NPPs. - Abstract: The cyber terrorism for nuclear power plants (NPPs) is investigated for the analytic study following the South Korean case on December 2014. There are several possible cyber terror attacks in which the twelve cases are studied for the nuclear terror cases including the computer hacking and data stealing. The defense-in-depth concept is compared for cyber terrorism, which was imported from the physical terror analysis. The conventional three conditions of the physical protection system (PPS) are modified as prevention, detection, and response. The six cases are introduced for the solutions of the facility against the possible cyber terrorism in NPPs. The computer hacking methods and related solutions are analyzed for the applications in the nuclear industry. The nuclear security in the NPPs could be an extremely serious condition and the remedies are very important in the safe plant operations. In addition, the quantitative modeling study is performed.

  13. Coordinated research programme on safety of RBMK type NPPs in relation to external events. V. 1. Working material

    1999-01-01

    The present volume is a collection of progress reports which have been submitted within the scope of the CRP on safety of RBMK type NPPs in relation to external events including seismic related papers and man-induced events (explosions and airplane crash). It includes papers concerned with experience related to RBMK equipment testing and calculations of seismic resistance, soil-structure interactions analysis, safety assurance, aircraft impact qualification and other external events for RBMK type NPP, seismic stability of NPPs in Eastern Europe, probabilistic assessment of NPP safety under aircraft impact, dynamic analysis of NPPs, screening of external hazards for NPP

  14. Highly Reliable Power and Communication System for Essential Instruments under a Severe Accident of NPPs

    Yoo, S. J.; Choi, B. H.; Jung, S. Y.; Rim, Chun T.

    2013-01-01

    In this paper, three survivable strategies to overcome the problems listed above are proposed for the essential instruments under the severe accident of NPPs. First, wire/wireless multi power systems are adopted to the essential instruments for continuous power supply. Second, wire/wireless communication systems are proposed for reliable transmission of measuring information among instruments and operators. Third, a physical protection system such as a harness and a heat isolation box is introduced to ensure operable conditions for the proposed systems. In this paper, a highly reliable strategy, which consists of wire/wireless multi power and communication systems and physical protection system is proposed to ensure the survival of the essential instruments under harsh external conditions. The wire/wireless multi power and communication systems are designed to transfer power and data in spite of the failure of conventional wired systems. The physical protection system provides operable environments to the instruments. Therefore, the proposed system can be considered as a candidate of practical and urgent remedy for NPPs under the severe accident. After the Fukushima nuclear accident, survivability of essential instruments has been emphasized for immediate and accurate response. The essential instruments can measure environment conditions such as temperature, pressure, radioactivity and corium behavior inside nuclear power plants (NPPs) under a severe accident. Access to the inside of NPPs is restricted to human beings because of hazardous environment such as high radioactivity, high temperature and high pressure. Thus, monitoring the inside of NPPs is necessary for avoiding damage from the severe accident. Even though there were a number of instruments in Fukushima Daiichi NPP, they failed to obtain exact monitoring information. According to the details of the Fukushima nuclear accident, following problems can be counted as strong candidates of this instruments

  15. Highly Reliable Power and Communication System for Essential Instruments under a Severe Accident of NPPs

    Yoo, S. J.; Choi, B. H.; Jung, S. Y.; Rim, Chun T. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, three survivable strategies to overcome the problems listed above are proposed for the essential instruments under the severe accident of NPPs. First, wire/wireless multi power systems are adopted to the essential instruments for continuous power supply. Second, wire/wireless communication systems are proposed for reliable transmission of measuring information among instruments and operators. Third, a physical protection system such as a harness and a heat isolation box is introduced to ensure operable conditions for the proposed systems. In this paper, a highly reliable strategy, which consists of wire/wireless multi power and communication systems and physical protection system is proposed to ensure the survival of the essential instruments under harsh external conditions. The wire/wireless multi power and communication systems are designed to transfer power and data in spite of the failure of conventional wired systems. The physical protection system provides operable environments to the instruments. Therefore, the proposed system can be considered as a candidate of practical and urgent remedy for NPPs under the severe accident. After the Fukushima nuclear accident, survivability of essential instruments has been emphasized for immediate and accurate response. The essential instruments can measure environment conditions such as temperature, pressure, radioactivity and corium behavior inside nuclear power plants (NPPs) under a severe accident. Access to the inside of NPPs is restricted to human beings because of hazardous environment such as high radioactivity, high temperature and high pressure. Thus, monitoring the inside of NPPs is necessary for avoiding damage from the severe accident. Even though there were a number of instruments in Fukushima Daiichi NPP, they failed to obtain exact monitoring information. According to the details of the Fukushima nuclear accident, following problems can be counted as strong candidates of this instruments

  16. Quantitative evaluation of fault coverage for digitalized systems in NPPs using simulated fault injection method

    Kim, Suk Joon

    2004-02-01

    Even though digital systems have numerous advantages such as precise processing of data, enhanced calculation capability over the conventional analog systems, there is a strong restriction on the application of digital systems to the safety systems in nuclear power plants (NPPs). This is because we do not fully understand the reliability of digital systems, and therefore we cannot guarantee the safety of digital systems. But, as the need for introduction of digital systems to safety systems in NPPs increasing, the need for the quantitative analysis on the safety of digital systems is also increasing. NPPs, which are quite conservative in terms of safety, require proving the reliability of digital systems when applied them to the NPPs. Moreover, digital systems which are applied to the NPPs are required to increase the overall safety of NPPs. however, it is very difficult to evaluate the reliability of digital systems because they include the complex fault processing mechanisms at various levels of the systems. Software is another obstacle in reliability assessment of the systems that requires ultra-high reliability. In this work, the fault detection coverage for the digital system is evaluated using simulated fault injection method. The target system is the Local Coincidence Logic (LCL) processor in Digital Plant Protection System (DPPS). However, as the LCL processor is difficult to design equally for evaluating the fault detection coverage, the LCL system has to be simplified. The simulations for evaluating the fault detection coverage of components are performed by dividing into two cases and the failure rates of components are evaluated using MIL-HDBK-217F. Using these results, the fault detection coverage of simplified LCL system is evaluated. In the experiments, heartbeat signals were just emitted at regular interval after executing logic without self-checking algorithm. When faults are injected into the simplified system, fault occurrence can be detected by

  17. Core Management of NPPs in China and Experience of Tianwan NPP

    Guohan, G.

    2006-01-01

    The Current Status of the NPPs in China; the Nuclear Power Development Plan till 2020; the Fuel Management and the Core Management Strategy of NPPs are briefly presented in this paper. The gained experience during construction of Taiwan NPP, new design features and major construction milestones of Taiwan NPP are also discussed. The full list of 21 non-conformance reports (NCR) submitted by Jiangsu Nuclear Power Company to NNSA during construction of Taiwan NPP is given. The main issues raised during FSAR review like: RP operation with incomplete number of primary loops; Sedimentation in the construction and piping of service water system; Location of postulated pipe break; Stratification analysis for surge line of pressurizer; Safety classification of equipment in primary circuit; Fire resistant capability of cable insulation; Fire Hazard Analysis; Optimization of protection against ionizing radiation ect. are also listed

  18. Characterization of Radiation Fields for Assessing Concrete Degradation in Biological Shields of NPPs

    Remec, Igor; Rosseel, Thomas M.; Field, Kevin G.; Pape, Yann Le

    2017-09-01

    Life extensions of nuclear power plants (NPPs) to 60 years of operation and the possibility of subsequent license renewal to 80 years have renewed interest in long-term material degradation in NPPs. Large irreplaceable sections of most nuclear generating stations are constructed from concrete, including safety-related structures such as biological shields and containment buildings; therefore, concrete degradation is being considered with particular focus on radiation-induced effects. Based on the projected neutron fluence values (E > 0.1 MeV) in the concrete biological shields of the US pressurized water reactor fleet and the currently available data on radiation effects on concrete, some decrease in mechanical properties of concrete cannot be ruled out during extended operation beyond 60 years. An expansion of the irradiated concrete database is desirable to ensure reliable risk assessment for extended operation of nuclear power plants.

  19. Review of the generic aging lessons learned (GALL) report for U.S. NPPs

    Gong Yi; Dou Yikang

    2014-01-01

    Generic aging lessons learned (GALL) report is a technical basis document issued by U.S. nuclear regulatory commission (NRC) for guiding the review of license renewal application (LRA) of its domestic nuclear power plants (NPPs). By form of tabulations, GALL report addresses the correlation among materials, environments, aging effects/mechanisms, and aging management programs (AMPs) from the level of specific structures and/or components. Based on literature investigation and analysis, the essential information of GALL report in the aspects of background, development history, content framework, and application was reviewed in this paper, which should be the first time in China and would have reference value for establishment of both the AMPs and the nuclear safety regulations of extending the lifetime of its NPPs. (authors)

  20. Development of Human-level Decision Making Algorithm for NPPs through Deep Neural Networks : Conceptual Approach

    Kim, Seung Geun; Seong, Poong Hyun

    2017-01-01

    Development of operation support systems and automation systems are closely related to machine learning field. However, since it is hard to achieve human-level delicacy and flexibility for complex tasks with conventional machine learning technologies, only operation support systems with simple purposes were developed and high-level automation related studies were not actively conducted. As one of the efforts for reducing human error in NPPs and technical advance toward automation, the ultimate goal of this research is to develop human-level decision making algorithm for NPPs during emergency situations. The concepts of SL, RL, policy network, value network, and MCTS, which were applied to decision making algorithm for other fields are introduced and combined with nuclear field specifications. Since the research is currently at the conceptual stage, more research is warranted.

  1. The application of workflow technology in the development of management procedures in NPPs

    Fang Zhaoxia; Huang Fang

    2012-01-01

    According to the national nuclear safety standards and guides, operating organizations of NPPs should document management programs against all safety related activities. One of the preconditions for the implementation of these programs is to setup a comprehensive instructions and procedures. The workflow technology which is a concept originally from computer technology can help in analysing work processes of different working areas in NPP, designing and developing management procedures hierarchy and requirements. The application of the workflow can not only comprehensively analyse the work process but also analyse the requirements for personnel which are related to the work process, therefore the procedures and programs developed could meet the requirements of national nuclear safety standards and guides. This paper also covers the application of workflow in other areas in NPPs. (authors)

  2. Safety Aspects of Ageing Management throughout the Full Life Cycle of NPPs

    Dou, Yikang

    2012-01-01

    Most component failures stem from effects of one or multiple ageing mechanism(s). Ageing management is one of the most robust measures to prevent failure and to maintain and increase safety of nuclear power plants. Based on Nuclear Safety Guideline on Ageing Management (NS-G-2.12) published by IAEA in 2009, the paper summarizes main ageing management activities required for all stages of life cycle of NPPs, including design, construction/manufacture, commissioning, operation, life extension for long-term operation and decommissioning. Interactive relations of ageing management in successive stages are analyzed. Implementation of the IAEA Guideline in comprehensive way will bring new challenges to design conception, modes of construction, manufacture, commissioning, equipment qualification, O and M, licensing, life extension and decommissioning for NPPs, however, it will be beneficial to enhance nuclear safety level, especially to promote development of nuclear power in China in a safe, reliable, profitable and sustainable way. (author)

  3. Regulatory Analysis on the Safety Assessment of NPPs against Aircraft Crash

    Kim, Sang Yun; Park, Jong Seuk; Chung, Yun Suk; Jung, Rae Young

    2011-01-01

    Following the 9/11 terror, a new regulation (10CFR 50.150) was enacted in June 2009 in the United States mandating the assessment of new nuclear power plants (NPPs) against intentional aircraft crashes, along with a regulation (10CFR 50.54 (h)(h)) in March 2009 that requires the establishment of accident mitigation measures for NPPs in operation. The UAE requested that the Korean NPP (APR 1400) design meet the U.S.'s new requirements related to the intentional aircraft crash. During the UAE NPP contract bidding process, France claimed that the Korean NPP is vulnerable to aircraft crashes comparing with the French NPP (EPR). Under these international and domestic environments, the necessity to establish a domestic regulation concerning the intentional aircraft crash was raised. This paper proposes a draft regulatory position on this issue through a comprehensive analysis of various influencing factors

  4. Indicative value of non-pollen palynomorphs (NPPs) and palynofacies for palaeoreconstructions: Holocene Peat, Brazil

    Medeanic, Svetlana; Silva, Maristela Bagatin

    2010-01-01

    The results of the palynological study of the samples from the core, performed in the Aguas Claras peatland, RS, Brazil (50 45'00''W, 30 00'15''S), focus on detailed taxonomic analysis of non-pollen palynomorphs (NPPs) and palynofacies from the Holocene peat and underline the Late Pleistocene mud and sandy mud that were represented. NPPs from the samples revealed taxonomic variety of fungal palynomorphs, presented by Brachysporium, Clastesporium, Dicellaesporites, Dicellaeporisporites, Gelasinospora, Glomus, Sordaria, Helicoon, and others. The habitats of above mentioned taxa are varied: aquatic, mycorrhizal, parasitic, organic matter decaying, and dung-coprophilous. Freshwater algal palynomorphs were composed of Botryococcus, Closterium, Debarya, Mougeotia, Pseudoschizaea, Spirogyra, and Zygnema. The percentage ratio between algal and fungal palynomorphs was changed from the different samples of the core, reflecting climatic oscillations (more humid-dryer). Prevalence of fungal palynomorphs was connected with dryer climate, and on the contrary, freshwater algal palynomorph predominance was related with increasing humidity. The six palynomorph zones that corresponded to the six principal phases of environmental and climatic changes were determined. The zone from the uppermost part of peat was characterized by relatively frequent dung-coprophilous and parasitic fungi, as a result of agricultural and domestic activities. Palynofacies analysis combined to NPPs was used for palaeoenvironmental and paleoclimatic reconstructions. Palynofacies from the samples were characterized by evident changes in relationship (%) between the different types of organic matter, their quality, and quantity and fluorescence index. The obtained data contribute to the understanding of the peat deposition. The combined use of NPPs and palynofacies analyses provided a valuable approach for the paleoenvironmental and paleoclimatic reconstructions. (author)

  5. Indicative value of non-pollen palynomorphs (NPPs) and palynofacies for palaeoreconstructions: Holocene Peat, Brazil

    Medeanic, Svetlana; Silva, Maristela Bagatin [LOG, IO, FURG, Rio Grande (Brazil)

    2010-12-01

    The results of the palynological study of the samples from the core, performed in the Aguas Claras peatland, RS, Brazil (50 45'00''W, 30 00'15''S), focus on detailed taxonomic analysis of non-pollen palynomorphs (NPPs) and palynofacies from the Holocene peat and underline the Late Pleistocene mud and sandy mud that were represented. NPPs from the samples revealed taxonomic variety of fungal palynomorphs, presented by Brachysporium, Clastesporium, Dicellaesporites, Dicellaeporisporites, Gelasinospora, Glomus, Sordaria, Helicoon, and others. The habitats of above mentioned taxa are varied: aquatic, mycorrhizal, parasitic, organic matter decaying, and dung-coprophilous. Freshwater algal palynomorphs were composed of Botryococcus, Closterium, Debarya, Mougeotia, Pseudoschizaea, Spirogyra, and Zygnema. The percentage ratio between algal and fungal palynomorphs was changed from the different samples of the core, reflecting climatic oscillations (more humid-dryer). Prevalence of fungal palynomorphs was connected with dryer climate, and on the contrary, freshwater algal palynomorph predominance was related with increasing humidity. The six palynomorph zones that corresponded to the six principal phases of environmental and climatic changes were determined. The zone from the uppermost part of peat was characterized by relatively frequent dung-coprophilous and parasitic fungi, as a result of agricultural and domestic activities. Palynofacies analysis combined to NPPs was used for palaeoenvironmental and paleoclimatic reconstructions. Palynofacies from the samples were characterized by evident changes in relationship (%) between the different types of organic matter, their quality, and quantity and fluorescence index. The obtained data contribute to the understanding of the peat deposition. The combined use of NPPs and palynofacies analyses provided a valuable approach for the paleoenvironmental and paleoclimatic reconstructions. (author)

  6. Some aspects of nuclear fuel utilisation at Ukrainian's NPPs during last two years

    Ieremenko, M.; Bilodid, Y.; Ovdiienko, Y.

    2011-01-01

    In the first part of the report the brief characteristic of the realized fuel cycles on Ukraine's NPPs, types of loaded fuel is described. Experience of new fuel type implementation are present (FA Second Generation for WWER-440. Westinghouse FA for WWER-1000). Next issue of report is the some of problem with fuel utilisation (leakage FA, problem with C b calculation and other). And the last issue of report is presentation of future new fuel implementation (WWER-440/1000). (authors)

  7. Preliminary Assessment for the Effects of the External Hazard Factors on the Safety of NPPs

    Jin, So Beom; Hyun, Seung Gyu; Kim, Sang Yun; Lee, Sung Kyu; Hur, Youl

    2010-01-01

    The Ch.etsu Offshore Earthquake(2007.7.16) in Japan caused damage to the Kashiwazaki-Kariwa(K-K) Nuclear Power Plants (NPPs) with seismic ground motion that exceeded the design level. This incident drew the interest of the safety evaluation studies for NPPs subjected to earthquakes exceeding the design basis around the world. Also, the Indian Ocean Tsunami(2004.12.26) tripped the Madras NPP by reason of flooding of the intake pump house and inundated the construction site of a fast breeder reactor site in India. In addition, from the various man-made and natural hazards such as the oil spill accident near Mallipo, Taean, Chungnam (2007.12), the forest fire near the Ulchin NPP site, the several inflows of marine organism into the intake of the Ulchin NPP, it was confirmed that the safety of NPPs may be affected by natural and human induced disasters. Intergovernmental Panel on Climate Change (IPCC) has been warned about global warming; the average temperature rose about 1.5 .deg. C during the 20th century and the damages caused by typhoons and heavy rains have also increased in Korea. Accordingly, a natural disaster prevention research team(hereafter team) ,which have been organized and operated since 2009, has assessed the impact of various hazards such as earthquakes and environmental changes due to global warming on the safety of NPP and has discussed to establish countermeasures. This paper introduces that the preliminary assessment for the effects of the external hazard factors on the safety of NPPs was conducted by the team

  8. On the heat exchange tube failures in steam generators at NPPs with WWER reactors

    Titov, V.F.; Banyuk, G.F.; Brykov, S.I.

    1992-01-01

    Data on dynamics of failed heat exchanging tube closing in steam generators of NPPs with WWER type reactors for the whole period of their operation are presented. It is shown that the main cause of the tube failures consists in their corrosion cracking under stresses. The effect of chlorine ions on tubes is intensified by the presence of porous sediments on heat exchaning surfaces in quantities exceeding 150 g/m 2

  9. Passive solar technology

    Watson, D

    1981-04-01

    The present status of passive solar technology is summarized, including passive solar heating, cooling and daylighting. The key roles of the passive solar system designer and of innovation in the building industry are described. After definitions of passive design and a summary of passive design principles are given, performance and costs of passive solar technology are discussed. Passive energy design concepts or methods are then considered in the context of the overall process by which building decisions are made to achieve the integration of new techniques into conventional design. (LEW).

  10. Development of requirements for seismic upgrading of equipment of existing WWER-440 and WWER-1000 type NPPs

    Kaznovsky, S.; Ostretsov, I.

    1993-01-01

    The change in seismology data and safety demands a necessity arose for seismic upgrading of the existing operating NPPs of WWER type which have been originally designed and built without or with simplifies calculations of seismic influences. The paper describes the traditional methods and approaches and calculation-experimental method for examining and ensuring of equipment seismic resistance at the NPPs directly. Method of ground explosions is included as well

  11. Typical design/qualification acceptance criteria for newly installed pipelines and equipment components of VVER-type NPPs

    Masopust, R.

    2003-01-01

    This paper describes in general the typical design/qualification acceptance criteria and seismic acceptance criteria in particular that are applicable for important to safety newly installed pipelines and equipment components of VVER-type already existing NPPs, specifically during the design verification phase of this newly installed equipment. These criteria are currently used for VVER 440-213 and VVER 1000 NPPs in Czech Republic and in Slovakia. The similar criteria are also used in Hungary. (author)

  12. Economic Evaluation of Long-term Operation of NPPs in Korea

    Lee, Kihyun; Kim, Taeryong; Jeong, Cheolwook

    2015-01-01

    It is inevitable for Korean government to establish the energy policy which can support the energy security and independence since Korea depends on approximately 97% of energy resources from abroad. We selected nuclear power plant to overcome the problem. Since Kori unit 1 began operating as a first nuclear power plant, nuclear power generation has been played a big role in providing about 30% of total electricity supply in Korea. Many researchers and economists have already assessed about safety and economic aspects of the nuclear power generation. This paper will deal with the economic benefits for the contribution of nuclear power generation especially long-term operation of NPPs to the Korean society. In this paper, the economic analysis of the LTO for the existing power plant less than and equal to 1,000MW compared to no extension was investigated. The selected durations of LTO are 10 years, 20 years, and 30 years beyond design life. The result from the analysis is that LTO of NPPs is more beneficial than observance of its design life. In the aspects of utility's electricity sales increase and reducing the new construction of APR1400 NPPs with cost savings, LTO is one of the best option in order to provide electric energy with Korean society

  13. An Approach to Human Error Hazard Detection of Unexpected Situations in NPPs

    Park, Sangjun; Oh, Yeonju; Shin, Youmin; Lee, Yong-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Fukushima accident is a typical complex event including the extreme situations induced by the succeeding earthquake, tsunami, explosion, and human errors. And it is judged with incomplete cause of system build-up same manner, procedure as a deficiency of response manual, education and training, team capability and the discharge of operator from human engineering point of view. Especially, the guidelines of current operating NPPs are not enough including countermeasures to the human errors at the extreme situations. Therefore, this paper describes a trial to detect the hazards of human errors at extreme situation, and to define the countermeasures that can properly response to the human error hazards when an individual, team, organization, and working entities that encounter the extreme situation in NPPs. In this paper we try to propose an approach to analyzing and extracting human error hazards for suggesting additional countermeasures to the human errors in unexpected situations. They might be utilized to develop contingency guidelines, especially for reducing the human error accident in NPPs. But the trial application in this study is currently limited since it is not easy to find accidents cases in detail enough to enumerate the proposed steps. Therefore, we will try to analyze as more cases as possible, and consider other environmental factors and human error conditions.

  14. Functional verification of a safety class controller for NPPs using a UVM register Model

    Kim, Kyu Chull [Dept. of Applied Computer Engineering, Dankook University, Cheonan (Korea, Republic of)

    2014-06-15

    A highly reliable safety class controller for NPPs (Nuclear Power Plants) is mandatory as even a minor malfunction can lead to disastrous consequences for people, the environment or the facility. In order to enhance the reliability of a safety class digital controller for NPPs, we employed a diversity approach, in which a PLC-type controller and a PLD-type controller are to be operated in parallel. We built and used structured testbenches based on the classes supported by UVM for functional verification of the PLD-type controller designed for NPPs. We incorporated a UVM register model into the testbenches in order to increase the controllability and the observability of the DUT(Device Under Test). With the increased testability, we could easily verify the datapaths between I/O ports and the register sets of the DUT, otherwise we had to perform black box tests for the datapaths, which is very cumbersome and time consuming. We were also able to perform constrained random verification very easily and systematically. From the study, we confirmed the various advantages of using the UVM register model in verification such as scalability, reusability and interoperability, and set some design guidelines for verification of the NPP controllers.

  15. Dynamic assessment for life extension of nuclear power plants (NPPs) using system dynamics (SD) method

    Woo, Tae Ho

    2012-01-01

    It has been proposed to extend the life of nuclear power plants (NPPs) for the economic purpose. Especially, the primary systems in reactor are considered in the thermohydraulic and neutronic aspect, which is related to the safety system. The electric power and the lifespan of components are expressed as economic situation. In addition, political considerations are given by the presidential change and the nuclear non-proliferation characteristics. The dynamical investigation using system dynamics (SD) shows the effective time for the life extension of the NPPs by Monte-Carlo simulations. This non-linear algorithm is incorporated with the feedback loop of the event sequences. The expected event is related to the past event, which affects to the dynamical simulations of lifetime in the NPPs. In the conclusions, the safety guarantee as well as the economic profit in the re-use of long term operated power plants is presented, which is mentioned as the transient time between 2019 and 2021 in this paper. (orig.)

  16. An Attentional Resources-effectiveness Measure in Complex Diagnostic Tasks in NPPs

    Ha, Jun Su; Seong, Poong Hyun

    2007-01-01

    The main role of the human operators in main control rooms (MCRs) of nuclear power plants (NPPs) is generally to supervise and operate the system. The operator's tasks in NPPs are performed through a series of cognitive activities: monitoring the environment, detecting data or information, understanding and assessing the situation, diagnosing the symptoms, decision-making, planning responses, and implementing the responses. In NPPs, there are a lot of information sources that should be monitored but the operators have only limited capacity of attention and memory. Because it is impossible to monitor all information sources, the operators continuously decide where to allocate their attentional resources. This kind of cognitive skill is called selective attention. In order for operators to effectively monitor, detect, and thus understand the state of a system, the operator should allocate their attentional resources to valuable information sources. Hence, the effectiveness of selective attention is expected to be able to reflect the effectiveness of monitoring, detection, and eventually understanding. In this study, an attentional resources effectiveness measure is proposed which based on cost benefit (or resource-effectiveness) principle

  17. Development project for a residual life evaluation system in LWR NPPs

    Hervia, F.; Francia, L.

    1995-01-01

    Economic and safety factors have stimulated the interest of Spanish NPPs towards the optimisation of NPP Residual Life Management, and consequently the need to have access to tools to support such management. This requirement has been the subject of a project, the main objectives of which are the identification of the most significant ageing factors in NPPs and their corresponding parameters, and the development of an associated integrated monitoring system. Work on the project was started by UNESA in September 1992 and is partly financed from PIE funds. This paper gives a general description of the objectives and activities of Phase 1, the Definition of the Core Project, which is nearing completion, and Phase 2, the Application of the Integrated System in a Pilot Plant. Phase 1 has confirmed the technical feasibility of the system and its suitability as a tool for the continuous evaluation of the plant condition. Furthermore, it has raised issues of great interest to NPPs. The results and conclusions of Phase 1 are currently being used to define the most suitable scope for the development and implementation of the system in the pilot plant (Phase 2), so that all the main functions of the system are tested without incurring unnecessary costs

  18. An Attentional Resources-effectiveness Measure in Complex Diagnostic Tasks in NPPs

    Ha, Jun Su; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of)

    2007-07-01

    The main role of the human operators in main control rooms (MCRs) of nuclear power plants (NPPs) is generally to supervise and operate the system. The operator's tasks in NPPs are performed through a series of cognitive activities: monitoring the environment, detecting data or information, understanding and assessing the situation, diagnosing the symptoms, decision-making, planning responses, and implementing the responses. In NPPs, there are a lot of information sources that should be monitored but the operators have only limited capacity of attention and memory. Because it is impossible to monitor all information sources, the operators continuously decide where to allocate their attentional resources. This kind of cognitive skill is called selective attention. In order for operators to effectively monitor, detect, and thus understand the state of a system, the operator should allocate their attentional resources to valuable information sources. Hence, the effectiveness of selective attention is expected to be able to reflect the effectiveness of monitoring, detection, and eventually understanding. In this study, an attentional resources effectiveness measure is proposed which based on cost benefit (or resource-effectiveness) principle.

  19. Considerations in the evaluation of concrete structures for continued service in aged Nuclear Power Plants (NPPs)

    Naus, D.; Marchbanks, M.; Oland, B.; Arndt, G.; Brown, T.

    1989-01-01

    Currently, there are /approximately/119 commercial nuclear power plants (NPPs) in the US either under construction, operating at low-to-full power, or awaiting an operating license. Together, these units have a net generating capacity of /approximately/110 GW(e). Assuming no life extension of present facilities, the operating licenses for these plants will start to expire in the middle of the next decade with Yankee Rowe being the first plant to attain this status. Where it is noted that with no life extension of facilities, a potential loss of electrical generating capacity in excess of 75 GW(e) could occur during the time period 2006 to 2020 when the operating licenses of 80 to 90 NPPs are scheduled to expire. A potential timely and cost-effective solution to meeting future electricity demand, which has worked well for non-nuclear generating plants, is to extend the service life (operating licenses) of existing NPPs. Since the concrete components in these plants provide a vital safety function, any continued service considerations must include an in-depth assessment of the safety-related concrete structures. 7 refs

  20. Collections and Analyses of Common Cause Failure Data for the Korea Standard and Westinghouse Type NPPs

    Kang, Dae Il; Han, S. H.

    2007-04-01

    The analyses of the CCF events for domestic NPPs were performed to establish the domestic database for the CCF events and to deliver supply them to the operation office of the international common cause failure data exchange (ICDE) project. We collected and analyzed the CCF events of emergency diesel generators, centrifugal pumps, motor-operated valves, check valves, circuit breakers for the Korean Standard Type nuclear power plants (NPPs), Yonggwang Units 3 and 4 and Ulchin Units 3 and 4, and the Westinghouse type NPPs, Kori Unit 3 and 4 and Yonggwang Units 1 and 2. First, the components to be collected and analyzed were classified into the common cause component groups (CCCGs) according to the ICDE coding guidelines. Next, the CCF events were identified based on reviews of the component database for the PSA and its related documents, and consultations with NPP staff. Fourteen CCF events were identified. The ratio of the number of CCF events to that of individual failure events was identified as approximately 10 percentages. However, an in depth review of the CCF events showed that most failure severities of them were identified as partial CCF events, which can be interpreted as some component failures within the CCCGs. Root causes of the CCF events were identified as 9 internal part failures, 2 human errors, 2 design deficiencies, 1 procedure inadequacy. It could be concluded that the major root causes of the CCF events were internal piece part failures

  1. Dynamic assessment for life extension of nuclear power plants (NPPs) using system dynamics (SD) method

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2012-12-15

    It has been proposed to extend the life of nuclear power plants (NPPs) for the economic purpose. Especially, the primary systems in reactor are considered in the thermohydraulic and neutronic aspect, which is related to the safety system. The electric power and the lifespan of components are expressed as economic situation. In addition, political considerations are given by the presidential change and the nuclear non-proliferation characteristics. The dynamical investigation using system dynamics (SD) shows the effective time for the life extension of the NPPs by Monte-Carlo simulations. This non-linear algorithm is incorporated with the feedback loop of the event sequences. The expected event is related to the past event, which affects to the dynamical simulations of lifetime in the NPPs. In the conclusions, the safety guarantee as well as the economic profit in the re-use of long term operated power plants is presented, which is mentioned as the transient time between 2019 and 2021 in this paper. (orig.)

  2. Activation scheme to use performance indicators for the graded regulation on Korean NPPs

    Hwang, M. J.; Kang, D. I.; Kim, G. R.; Sung, G. Y.

    2003-01-01

    In this paper, we will provide an activation scheme of using performance indicators for graded regulation on Korean Nuclear Power Plants (NPPs). The safe operation of NPPs is the basic objective of nuclear society. To achieve the object, the direction of the regulation is established to regulate the risk of public health and safety. Therefore, it's essential to keep the safety of plants. However, it's not easy to define the appropriate safety level. So, the requirement of performance indicator establishment and framework establishment for safety management has been increased. Performance indicators can provide quantified safety value numerically. Therefore, we can increase the acceptance and trust of the public for safety of NPPs. Also, it helps pridictive regulation through the objective comparison of safety. Moreover, according to the importance of safety, we can allocate the resources effectively and lead an effort for the improvement of safety by comparison among nations and plants. The safety of a plant is affected by not only design but also the quality of operators, appropriate operation, maintenance and test. So, in this paper, we reviewed the application of performance indicators in domestic and foreign countries, and groped for a method to activate the use of performance indicators

  3. An Approach to Human Error Hazard Detection of Unexpected Situations in NPPs

    Park, Sangjun; Oh, Yeonju; Shin, Youmin; Lee, Yong-Hee

    2015-01-01

    Fukushima accident is a typical complex event including the extreme situations induced by the succeeding earthquake, tsunami, explosion, and human errors. And it is judged with incomplete cause of system build-up same manner, procedure as a deficiency of response manual, education and training, team capability and the discharge of operator from human engineering point of view. Especially, the guidelines of current operating NPPs are not enough including countermeasures to the human errors at the extreme situations. Therefore, this paper describes a trial to detect the hazards of human errors at extreme situation, and to define the countermeasures that can properly response to the human error hazards when an individual, team, organization, and working entities that encounter the extreme situation in NPPs. In this paper we try to propose an approach to analyzing and extracting human error hazards for suggesting additional countermeasures to the human errors in unexpected situations. They might be utilized to develop contingency guidelines, especially for reducing the human error accident in NPPs. But the trial application in this study is currently limited since it is not easy to find accidents cases in detail enough to enumerate the proposed steps. Therefore, we will try to analyze as more cases as possible, and consider other environmental factors and human error conditions

  4. A Classification Method of Technical Security Controls for Digital I and C Systems in NPPs

    Song, J. G.; Lee, J. W.; Park, G. Y.; Kwon, K. C.; Lee, D. Y.; Lee, C. K.

    2012-01-01

    The instrumentation and control (I and C) systems in nuclear power plants (NPPs) are a key facility to monitor plant state, control plant devices, and prevent accidents. Recent I and C systems have been composed of digital systems in order to enhance the effectiveness of operation and maintenance of NPPs. An assessment method for the analysis of security controls is needed to respond to potential cyber attacks against digital I and C systems. RG 5.71 'Cyber Security Programs for Nuclear Facilities' published by U.S.NRC in 2010 presents a comprehensive set of security controls for NPPs. Although this document provides the requirements of security controls, a guidance describing which security controls should be applied to specific digital assets and how to implement them is still needed for the I and C system design and development. In this paper, a classification method of the technical security controls listed in RG 5.71 is proposed to provide a guide useful for the application of the controls during the design and implementation phases of I and C systems

  5. A Classification Method of Technical Security Controls for Digital I and C Systems in NPPs

    Song, J. G.; Lee, J. W.; Park, G. Y.; Kwon, K. C.; Lee, D. Y.; Lee, C. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    The instrumentation and control (I and C) systems in nuclear power plants (NPPs) are a key facility to monitor plant state, control plant devices, and prevent accidents. Recent I and C systems have been composed of digital systems in order to enhance the effectiveness of operation and maintenance of NPPs. An assessment method for the analysis of security controls is needed to respond to potential cyber attacks against digital I and C systems. RG 5.71 'Cyber Security Programs for Nuclear Facilities' published by U.S.NRC in 2010 presents a comprehensive set of security controls for NPPs. Although this document provides the requirements of security controls, a guidance describing which security controls should be applied to specific digital assets and how to implement them is still needed for the I and C system design and development. In this paper, a classification method of the technical security controls listed in RG 5.71 is proposed to provide a guide useful for the application of the controls during the design and implementation phases of I and C systems

  6. Finite mixture models for sensitivity analysis of thermal hydraulic codes for passive safety systems analysis

    Di Maio, Francesco, E-mail: francesco.dimaio@polimi.it [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Nicola, Giancarlo [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Zio, Enrico [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Chair on System Science and Energetic Challenge Fondation EDF, Ecole Centrale Paris and Supelec, Paris (France); Yu, Yu [School of Nuclear Science and Engineering, North China Electric Power University, 102206 Beijing (China)

    2015-08-15

    Highlights: • Uncertainties of TH codes affect the system failure probability quantification. • We present Finite Mixture Models (FMMs) for sensitivity analysis of TH codes. • FMMs approximate the pdf of the output of a TH code with a limited number of simulations. • The approach is tested on a Passive Containment Cooling System of an AP1000 reactor. • The novel approach overcomes the results of a standard variance decomposition method. - Abstract: For safety analysis of Nuclear Power Plants (NPPs), Best Estimate (BE) Thermal Hydraulic (TH) codes are used to predict system response in normal and accidental conditions. The assessment of the uncertainties of TH codes is a critical issue for system failure probability quantification. In this paper, we consider passive safety systems of advanced NPPs and present a novel approach of Sensitivity Analysis (SA). The approach is based on Finite Mixture Models (FMMs) to approximate the probability density function (i.e., the uncertainty) of the output of the passive safety system TH code with a limited number of simulations. We propose a novel Sensitivity Analysis (SA) method for keeping the computational cost low: an Expectation Maximization (EM) algorithm is used to calculate the saliency of the TH code input variables for identifying those that most affect the system functional failure. The novel approach is compared with a standard variance decomposition method on a case study considering a Passive Containment Cooling System (PCCS) of an Advanced Pressurized reactor AP1000.

  7. A methodology for a quantitative assessment of safety culture in NPPs based on Bayesian networks

    Kim, Young Gab; Lee, Seung Min; Seong, Poong Hyun

    2017-01-01

    Highlights: • A safety culture framework and a quantitative methodology to assess safety culture were proposed. • The relation among Norm system, Safety Management System and worker's awareness was established. • Safety culture probability at NPPs was updated by collecting actual organizational data. • Vulnerable areas and the relationship between safety culture and human error were confirmed. - Abstract: For a long time, safety has been recognized as a top priority in high-reliability industries such as aviation and nuclear power plants (NPPs). Establishing a safety culture requires a number of actions to enhance safety, one of which is changing the safety culture awareness of workers. The concept of safety culture in the nuclear power domain was established in the International Atomic Energy Agency (IAEA) safety series, wherein the importance of employee attitudes for maintaining organizational safety was emphasized. Safety culture assessment is a critical step in the process of enhancing safety culture. In this respect, assessment is focused on measuring the level of safety culture in an organization, and improving any weakness in the organization. However, many continue to think that the concept of safety culture is abstract and unclear. In addition, the results of safety culture assessments are mostly subjective and qualitative. Given the current situation, this paper suggests a quantitative methodology for safety culture assessments based on a Bayesian network. A proposed safety culture framework for NPPs would include the following: (1) a norm system, (2) a safety management system, (3) safety culture awareness of worker, and (4) Worker behavior. The level of safety culture awareness of workers at NPPs was reasoned through the proposed methodology. Then, areas of the organization that were vulnerable in terms of safety culture were derived by analyzing observational evidence. We also confirmed that the frequency of events involving human error

  8. Fundamental studies of passivity and passivity breakdown

    Macdonald, D.D.; Urquidi-Macdonald, M.; Song, H.; Biaggio-Rocha, S.; Searson, P.

    1991-11-01

    This report summarizes the findings of our fundamental research program on passivity and passivity breakdown. During the past three and one half years in this program (including the three year incrementally-funded grant prior to the present grant), we developed and experimentally tested various physical models for the growth and breakdown of passive films on metal surfaces. These models belong to a general class termed ''point defects models'' (PDMs), in which the growth and breakdown of passive films are described in terms of the movement of anion and cation vacancies

  9. Report of a consultants meeting on backfittings and safety enhancement measures in NPPs with WWER 440/213 reactors. Extrabudgetary programme on the safety of WWER NPPS

    1994-01-01

    The purpose of this Consultants' Meeting held by the IAEA in Vienna from 11-15 April 1994 within the framework of the Extrabudgetary Programme on WWER Safety was to review and analyze safety issues revealed during operation and through analyses of NPPs with WWER 440/213 reactors. The initial list of safety issues based on the available reports from various studies had been prepared by the IAEA secretariat before the meeting, together with indications of safety enhancement measures proposed in various NPP units. During the meeting, the underlying safety concerns and actual technical status of the plants were discussed and the ranking of the safety issues was considered. 58 refs, 1 tab

  10. Immunizations: Active vs. Passive

    ... Issues Health Issues Health Issues Conditions Injuries & Emergencies Vaccine Preventable Diseases ... Children > Safety & Prevention > Immunizations > Immunizations: Active vs. Passive Safety & ...

  11. Hydrogenation of passivated contacts

    Nemeth, William; Yuan, Hao-Chih; LaSalvia, Vincenzo; Stradins, Pauls; Page, Matthew R.

    2018-03-06

    Methods of hydrogenation of passivated contacts using materials having hydrogen impurities are provided. An example method includes applying, to a passivated contact, a layer of a material, the material containing hydrogen impurities. The method further includes subsequently annealing the material and subsequently removing the material from the passivated contact.

  12. Design and development of innovative passive valves for Nuclear Power Plant applications

    Sapra, M.K., E-mail: sapramk@barc.gov.in; Kundu, S.; Pal, A.K.; Vijayan, P.K.; Vaze, K.K.; Sinha, R.K.

    2015-05-15

    Highlights: • Passive valves are self-acting valves requiring no external energy to function. • These valves have been developed for Advanced Heavy Water Reactor (AHWR) of India. • Passive valves are core components of passive safety systems of the reactor. • Accumulator Isolation Passive Valve (AIPV) has been developed and tested for ECSS. • AIPV provided passive isolation and flow regulation in ECCS of Integral Test Loop. - Abstract: The recent Fukushima accident has resulted in an increased need for passive safety systems in upcoming advanced reactors. In order to enhance the global contribution and acceptability of nuclear energy, proven evidence is required to show that it is not only green but also safe, in case of extreme natural events. To achieve and establish this fact, we need to design, demonstrate and incorporate reliable ‘passive safety systems’ in our advanced reactor designs. In Nuclear Power Plants (NPPs), the use of passive safety systems such as accumulators, condensing and evaporative heat exchangers and gravity driven cooling systems provide enhanced safety and reliability. In addition, they eliminate the huge costs associated with the installation, maintenance and operation of active safety systems that require multiple pumps with independent and redundant electric power supplies. As a result, passive safety systems are preferred for numerous advanced reactor concepts. In current NPPs, passive safety systems which are not participating in day to day operation, are kept isolated, and require a signal and external energy source to open the valve. It is proposed to replace these valves by passive components and devices such as self-acting valves, rupture disks, etc. Some of these innovative passive valves, which do not require external power, have been recently designed, developed and tested at rated conditions. These valves are proposed to be used for various passive safety systems of an upcoming Nuclear Power Plant being designed

  13. A Study on OBE Exceedance Criteria Using the CAV Concept for NPPs in Korea

    Park, Se Moon; Cho, Sung Il; Yun, Kwan Hee

    2009-01-01

    NPPs in Korea have so far complied with the US Regulatory Guide 1.12 Rev.1 (1974) for the seismic monitoring systems. However, researchers in Korea have been considering attempting to comply with Regulatory Guide 1.12 rev.2 (1997) when implementing all future seismic monitoring systems. To comply with the new regulations, Operating Basis Earthquake (OBE) Exceedance Criteria applied with the Cumulative Absolute Velocity (CAV) has to be developed for local use. The CAV was developed in the USA as one reasonable OBE exceedance criterion for NPPs; however, it has not been widely used outside the USA, not-withstanding its solid technical basis. It is, however, expected that the worldwide NPP construction boom will necessitate development and more frequent use of reasonable OBE exceedance criteria. As multi-units (four or more) are situated in one site in Korea, prevention of simultaneous shutdown of multi-unit caused by non damaging earthquakes is very important; otherwise, a serious economic loss could occur, and there could also be a great impact on the stability of the power grid that would arise due to the unnecessary shutdown. Actually, we have had the experience of observing a Peak Ground Acceleration (PGA)-value greater than 0.1g (the current OBE level for Korean NPPs) due to an M=4.8 earthquake (20 th Jan. '07) that did not even cause any damage to the poorly-designed structures nearby. This experience gave a motivation to the KHNP should concern the needs of study on OBE exceedance criteria in view of application of the CAV to Korean seismic situation, which will be more practical. The present paper is intended to show the intermediate result of the research on Operating Basis Earthquake (OBE) exceedance criteria in Korea

  14. Development of Probabilistic Performance Evaluation Procedure for Umbilical Lines of Seismically Isolated NPPs

    Hahm, Daegi; Park, Junhee; Choi, Inkil

    2013-01-01

    In this study, we proposed a procedure to perform the probabilistic performance evaluation of interface piping system for seismically isolated NPPs, and carried out the preliminary performance evaluation of the target example umbilical line. For EDB level earthquakes, the target performance goal cannot be fulfilled, but we also find out that the result can be changed with respect to the variation of the assumed values, i. e., the distribution of response, and the limit state of piping system. Recently, to design the nuclear power plants (NPPs) more efficiently and safely against the strong seismic load, many researchers focus on the seismic isolation system. For the adoption of seismic isolation system to the NPPs, the seismic performance of isolation devices, structures, and components should be guaranteed firstly. Hence, some researches were performed to determine the seismic performance of such items. For the interface piping system between isolated structure and non-isolated structure, the seismic capacity should be carefully estimated since that the required displacement absorption capacity will be increased significantly by the adoption of the seismic isolation system. Nowadays, in NUREG report, the probabilistic performance criteria for isolated NPP structures and components are proposed. Hence, in this study, we developed the probabilistic performance evaluation method and procedure for interface piping system, and applied the method to an example pipe. The detailed procedure and main results are summarized in next section. For the interface piping system, the seismic capacity should be carefully estimated since that the required displacement absorption capacity will be increased significantly by the adoption of the seismic isolation system

  15. Portable Filtered Air Suction System for Released Radioactive Gases Prevention under a Severe Accident of NPPs

    Gu, Beom W.; Choi, Su Y.; Rim, Chun T.

    2013-01-01

    In this paper, the portable filtered air suction system (PoFASS) for released radioactive gases prevention under a severe accident of NPP is proposed. This technology can prevent the release of the radioactive gases to the atmosphere and it can be more economical than FVCS because PoFASS can cover many NPPs with its high mobility. The conceptual design of PoFASS, which has the highest cost effectiveness and robustness to the environment condition such as wind velocity and precipitation, is suggested and the related previous research is introduced in this paper. The portable filtered air suction system (PoFASS) for released radioactive gases prevention can play a key role to mitigate the severe accident of NPP with its high cost effectiveness and robustness to the environment conditions. As further works, the detail design of PoFASS to fabricate a prototype for a demonstration will be proceeded. When released radioactive gases from the broken containment building in the severe accident of nuclear power plants (NPPs) such as the Chernobyl and Fukushima accidents occur, there are no ways to prevent the released radioactive gases spreading in the air. In order to solve this problem, several European NPPs have adopted the filtered vented containment system (FVCS), which can avoid the containment failure through a pressure relief capability to protect the containment building against overpressure. However, the installation cost of FVCS for a NPP is more than $10 million and this system has not been widely welcomed by NPP operating companies due to its high cost

  16. A Proposal for a Methodology to Develop a Cyber-Attack Penetration Test Scenario Including NPPs Safety

    Lee, In Hyo [KAIST, Daejeon (Korea, Republic of); Son, Han Seong [Joongbu Univ., Geumsan (Korea, Republic of); Kim, Si Won [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of); Kang, Hyun Gook [Rensselaer Polytechnic Institute, Troy (United States)

    2016-10-15

    Penetration test is a method to evaluate the cyber security of NPPs; so, this approach was performed in some studies. Because they focused on vulnerability finding or test bed construction, scenario based approach was not performed. However, to test the cyber security of NPPs, a proper test scenario should be needed. Ahn et al. developed cyber-attack scenarios but those scenarios couldn't be applied in penetration test because they developed the scenarios based on past incidents of NPPs induced by cyber-attack. That is, those scenarios only covered scenarios which were happened before; so, they couldn't cover other various scenarios and couldn't reflect them into a penetration test. In this study, a method to develop a cyber-attack penetration test scenario of NPPs especially focused on safety point of view is suggested. To evaluate the cyber security of NPPs, penetration test can be a possible way. In this study, a method to develop a penetration test scenario was explained. Especially, the goal of hacker was focused on nuclear fuel integrity deterioration. So, in the methodology, Level 1 PSA results were utilized to reflect plant safety into the security. From the PSA results, basic event was post processed and possible cyber-attacks were reviewed with vulnerabilities of digital control system.

  17. A Proposal for a Methodology to Develop a Cyber-Attack Penetration Test Scenario Including NPPs Safety

    Lee, In Hyo; Son, Han Seong; Kim, Si Won; Kang, Hyun Gook

    2016-01-01

    Penetration test is a method to evaluate the cyber security of NPPs; so, this approach was performed in some studies. Because they focused on vulnerability finding or test bed construction, scenario based approach was not performed. However, to test the cyber security of NPPs, a proper test scenario should be needed. Ahn et al. developed cyber-attack scenarios but those scenarios couldn't be applied in penetration test because they developed the scenarios based on past incidents of NPPs induced by cyber-attack. That is, those scenarios only covered scenarios which were happened before; so, they couldn't cover other various scenarios and couldn't reflect them into a penetration test. In this study, a method to develop a cyber-attack penetration test scenario of NPPs especially focused on safety point of view is suggested. To evaluate the cyber security of NPPs, penetration test can be a possible way. In this study, a method to develop a penetration test scenario was explained. Especially, the goal of hacker was focused on nuclear fuel integrity deterioration. So, in the methodology, Level 1 PSA results were utilized to reflect plant safety into the security. From the PSA results, basic event was post processed and possible cyber-attacks were reviewed with vulnerabilities of digital control system

  18. Reduction of waste arising as an option for improvement of waste management systems at NPPs with WWER type reactors

    Dultchenko, A.; Mikolaitchouk, H.

    1995-01-01

    After the USSR breakdown Ukraine inherited five NPPs with 12 WWER type reactor units and 4 RBMK type reactor units and no selected disposal site for NPP operational waste and just a few waste treatment facilities which had not been licensed or certified and could not be considered as complying safety requirements and NPP needs. At the same time the lack of competent designer organizations in Ukraine and the overall economical situation including the payment crisis resulted in significant delays in the development of radioactive waste management infrastructure and brought to the foreground a reduction of waste arisings and implementation of waste recycling technologies. In order to evaluate efficiency of waste management systems at Ukrainian NPPs in comparison with current practices at western NPPs and fix main deficiencies and optimum upgrading measures the comparative analyses of waste management systems at Ukrainian NPPs was initiated within the R and D program supported by the Ukrainian State Committee for Nuclear and Radiation Safety (UkrSCNRS). In carrying out the analyses the results of IAEA Technical Assistance Regional project on Advice on Waste Management at WWER type Reactors were used. Taking into account an influence of the Chernobyl accident consequences on the waste management system of Chernobyl NPP the case of Chernobyl NPP was set apart and cannot be considered typical so the authors confine their analysis to the WWER type reactors. For the purposes of comparison the related information about Kozlodui, Paks, Loviisa and Russian NPPs provided under the above-mentioned IAEA Regional Project was used

  19. Main trends in modernization of I and C systems at NPPs in the Russian Federation

    Pobedonostsev, A.B.; Chudin, A.G.

    1998-01-01

    There are more than 20 nuclear power reactors in operation in Russia, which have been operated over 10 years. Operational time of I and C systems of those NPPs is about 30 years, though the lifetime of individual parts of I and C systems is limited by 10-15 years. I and C systems were designed in 60-70-th in accordance with the existing regulations and available technical solutions. Obsolescence of those I and C systems require the reconstruction of existing systems. There are considerations that don't allow to perform equipment replacement one-to-one but require to modernize I and C systems at NPP. (author)

  20. Application of ASSET methodology and operational experience feedback of NPPs in China

    Lan, Ziyong [The National Nuclear Safety Administration, Beijing (China)

    1997-10-01

    The introductive presentation of ASSET methodology to China started in March 1992, 3 experts from the IAEA held the ASSET Seminar in Wuhan, China. Three years later, an IAEA seminar on ASSET Method and Operational Experience Feedback proceeded in Beijing on 20-24 March 1995. Another ASSET seminar on Self-Assessment and Operational Experience Feedback was held at Guangdong NPP site on 2-6 December 1996, The NNSA and the GNPP hosted the seminar, 2 IAEA experts, 55 participants from the NPPs, research institutes, the regulatory body (NNSA) and its regional offices attended the seminar. 3 figs, 5 tabs.

  1. Realization of sanitary requirements concerning standardization of rare radioactive gas effluents at NPPs

    Doroshenko, G.G.; Panchenko, S.V.; Chudajkin, O.G.

    1987-01-01

    The paper is aimed at determination of ways for practical realization of main sanitary requirements concerning environment and population protection under NPP operation. The idea of the requirements is reduced to not increasing permissible limits for radiation doses, minimum irradiation of population and decrease of unjustified irradiation of personnel. The given problem may be fully solved only in case of studying real chacteristics of operating reactors, taking into account statistic nature of effluents of inert radioactive gases (IRG). Methods of developing a system of working and reference standards of IRG effluents at NPPs are suggested. The considered approach may be realized in practice as the All-Union state on branch standards

  2. Nuclear fuel for NPPs: current status and main trends of development

    Molchanov, V.

    2013-01-01

    The customer’s main requirements to nuclear fuel at the present day are: to provide high performance of operational reliability of fuel; to uprate NPP’s capacity to the level of more than 100% from the designed one; to increase fuel cycle length; to increase the burnup of the fuel; to introduce load-follow mode at NPPs. To achieve this requirements the following TVEL activities are presented: New FA designs; Modern designing methods; New automated technologies of nuclear fuel fabrication; Driving to Zero Failure; Increase in safety and reliability of operation; Increase in economical efficiency of fuel utilization; Decrease in amount of spent fuel

  3. Positive experience in introduction of functional group control at NPPs. What are the future prospects

    Fedorov, O.M.; Antonyuk, A.S.

    1989-01-01

    Experience in introduction of functional group control (FGC) on the basis of the ULU2-computer at the Rovno-3 NPP unit is generalized. A list of additional improvements realized during subsystems RY (steam generator blowing through) and TZ (special waste water system) introduction in the NPP reactor compartment is given. Reguirements to equipment, FGC actuating mechanisms, technological part of the design, necessary for FGC realization, are formulated. FGC relieves NPP operator of routine operations, reduces his fatigue and increases sharply the technological discipline. Rigorous standardization of designs and equipment and centralized management are reguired for FGC introduction at the operating NPPs

  4. Application of ASSET methodology and operational experience feedback of NPPs in China

    Ziyong Lan

    1997-01-01

    The introductive presentation of ASSET methodology to China started in March 1992, 3 experts from the IAEA held the ASSET Seminar in Wuhan, China. Three years later, an IAEA seminar on ASSET Method and Operational Experience Feedback proceeded in Beijing on 20-24 March 1995. Another ASSET seminar on Self-Assessment and Operational Experience Feedback was held at Guangdong NPP site on 2-6 December 1996, The NNSA and the GNPP hosted the seminar, 2 IAEA experts, 55 participants from the NPPs, research institutes, the regulatory body (NNSA) and its regional offices attended the seminar. 3 figs, 5 tabs

  5. An expert system-based aid for analysis of Emergency Operating Procedures in NPPs

    Jakubowski, Z.; Beraha, D.

    1996-01-01

    Emergency Operating Procedures (EOPs) generally and an accident management (AM) particularly play a significant part in the safety philosophy on NPPs since many years. A better methodology for development and validation of EOPs is desired. A prototype of an Emergency Operating Procedures Analysis System (EOPAS), which has been developed at GRS, is presented in the paper. The hardware configuration and software organisation of the system is briefly reviewed. The main components of the system such as the knowledge base of an expert system and the engineering simulator are described. (author)

  6. A study on maintenance rule program and its application at Korean NPPs

    Hwang, Mee Jeong; Kim, Kil Yoo; Kang, Dae Il; Yang, Joon Eon; Ha, Jae Joo

    2000-11-01

    The objective of the Maintenance Rule is to require monitoring of the overall continuing effectiveness of licensee maintenance programs to ensure that safety related and certain nonsafety-related SSCs are capable of performing their intended functions and, for nonsafety-related equipment failures will not occur that prevent the fulfillment of safety-related functions, and failures resulting in scrams and unnecessary actuations of safety-related systems are minimized. That is, proper maintenance is essential to plant safety. U.S. Maintenance Rule, which was effective July 1996 in USA., was not officially adopted in Korea by Korean regulatory body. However, since many PSA and IPE have been performed for NPPs, the philosophy and usefulness of the Maintenance Rule as well as performance-based regulation are being acceptable. We survey the Maintenance Rule program and applications in the USA, and also developed the Maintenance Rule program to apply to Korean NPPs. In addition, we applied the Maintenance Rule Program apply to Ulchin 3,4 Units roughly with the Maintenance Rule Program developed in this project

  7. Organization and mechanization of maintenance operations at NPPs with the WWER type reactors

    Titov, A.A.

    1983-01-01

    The structure of capital investments defining organization and mechanization of maintepance operations at NPPs with the WWER type reactors is analyzed. The trends in development of optimum decisions for organization and mechanization of repair obs at NPPs being designed taking into account the prospects of nuclear powep enginerning development, the system of NPP maintenance servicing, as well as the structure of repair-productive capacities are discussed. On the basis of the analysis of the data obtained in designing the Zaporozhskaya NPP it is shown that the capital investments for organizing and mechanization of maintenance operations at the unified NPP site with four WWER-1000 reactors reach nearly 18 roubles/kW. A conclusion is drawn that at present the design of an NPP with the WWER-1000 reactor totally meets the requirements of realization of periodic maintenance operations. It is advisable to cooperate the NPP management with that of a thermal power station from the viewpoint of using manpower, which would improve the operating conditions and labour productivity of workers engaged in repair and, consequently, reduce the capital investments and repair expenditures

  8. Nuclear safeguard assessment in nuclear power plants (NPPs) using loss function with modified random numbers

    Woo, Tae Ho

    2012-01-01

    Highlights: ► The safeguard is analyzed by quantification. ► Newly introduced SF is analyzed by the electrical power output. ► The relative value of SF is shown in the month level. ► The better operation could be indicated numerical values. ► There are several secure operation factors to be suggested. - Abstract: The energy production in nuclear power plants (NPPs) is investigated for the safeguard risk management using economic factors. The economic loss function is used for the life quality in the social and natural objects. For the basic event elements, the game theory is applied for the basic elements of the incidents in non-secure situations. The Safeguard Factor (SF) is introduced for the quantifications of simulation. The results are shown by the standard productivity comparisons with the designed power operations, which is obtained as the range of secure life extension in 2000 MW e is between 0.0000 and 9.1985 and the range in 600 MW e is between 0.0000 and 2.7600. So, the highest value in the range of secure power operation increases about 3.33 times higher than that of the interested power operation in this study, which means the safeguard assessment is quantified by the power rate in the life extension of the NPPs. The Nuclear Safeguard Protocol (NSP) is constructed for the safe operation successfully.

  9. Evaluation of communication characteristics of operating teams in NPPs using SNA technique

    Kim, H. J.; Lee, S. W.; Kang, H. G.; Seong, P. H. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kang, H. G. [Khalifa Univ. of Science, Abu Dhabi (United Arab Emirates)

    2012-03-15

    Inappropriate communications within operational teams can lead to serious consequences of a system since it can cause lack of exchange of important information to perform the task to secure the safety of the system in nuclear power plants (NPPs). For that reason, we studied the communication characteristics However, existing studies on the communication characteristics seem to have problem since they have characterized team communications from a single perspective. According that, we have developed an evaluation method to characterize team communications using social network techniques which can evaluate them from various perspectives which are group cohesiveness, frequency of communications, degree of hierarchy, and communication contents. In addition, we suggested some kids of specific communication characteristics of operating teams that can reduce the occurrence of inappropriate communications. Eight verbal protocol data which are audio-visual recorded under emergency training sessions by main control room (MCR) operating teams are used. As a result of the study, there was negative relationship between group cohesiveness and the ratio of inappropriate communications. Moreover, some kinds of specific communication contents are related to the ratio of inappropriate communications. Consequently, we can evaluate communications characteristics of operating teams in NPPs and suggest specific characteristics to provide useful insights to prevent inappropriate communications.

  10. Evaluation of communication characteristics of operating teams in NPPs using SNA technique

    Kim, H. J.; Lee, S. W.; Kang, H. G.; Seong, P. H.; Park, J. K.; Kang, H. G.

    2012-01-01

    Inappropriate communications within operational teams can lead to serious consequences of a system since it can cause lack of exchange of important information to perform the task to secure the safety of the system in nuclear power plants (NPPs). For that reason, we studied the communication characteristics However, existing studies on the communication characteristics seem to have problem since they have characterized team communications from a single perspective. According that, we have developed an evaluation method to characterize team communications using social network techniques which can evaluate them from various perspectives which are group cohesiveness, frequency of communications, degree of hierarchy, and communication contents. In addition, we suggested some kids of specific communication characteristics of operating teams that can reduce the occurrence of inappropriate communications. Eight verbal protocol data which are audio-visual recorded under emergency training sessions by main control room (MCR) operating teams are used. As a result of the study, there was negative relationship between group cohesiveness and the ratio of inappropriate communications. Moreover, some kinds of specific communication contents are related to the ratio of inappropriate communications. Consequently, we can evaluate communications characteristics of operating teams in NPPs and suggest specific characteristics to provide useful insights to prevent inappropriate communications

  11. Development status of component reliability database for Korean NPPs and a case study

    Choi, S. Y.; Yang, S. H.; Lee, S. C.; Kim, S. H.; Han, S. H.

    1999-01-01

    We have applied a generic database to the PSA (Probabilistic Safety Assessment) for the Korean Standard NPPs (Nuclear Power Plant) since there is no specific component reliability database. However generic data is not enough to reflect the specific characteristics of domestic plants since it is collected by foreign plants. Therefore we are developing the plant-specific component reliability database for domestic NPPs. In this paper, we describe the development status of the component reliability database and the approach method of data collection and component failure analysis. We also summarize a case study of component failure analysis. We first collect the failure and repair data from the TR (Trouble Report) electronic database and the daily operation report sheet. Now we add a data collection method that checks the original TR sheet to improve the data quality. We input the component failure and repair data of principal components of about 30 systems into the component reliability database. Now, we are analyzing the component failure data of 11 safety systems among the systems to calculate component failure rate and unavailability etc

  12. Setting Component Priorities in Protecting NPPs against Cyber-Attacks Using Reliability Analysis Techniques

    Choi, Moon Kyoung; Seong, Poong Hyun; Son, Han Seong

    2017-01-01

    The digitalization of infrastructure makes systems vulnerable to cyber threats and hybrid attacks. According to ICS-CERT report, as time goes by, the number of vulnerabilities in ICS industries increases rapidly. Digital I and C systems have been developed and installed in nuclear power plants, and due to installation of the digital I and C systems, cyber security concerns are increasing in nuclear industry. However, there are too many critical digital assets to be inspected in digitalized NPPs. In order to reduce the inefficiency of regulation in nuclear facilities, the critical components that are directly related to an accident are elicited by using the reliability analysis techniques. Target initial events are selected, and their headings are analyzed through event tree analysis about whether the headings can be affected by cyber-attacks or not. Among the headings, the headings that can be proceeded directly to the core damage by the cyber-attack when they are fail are finally selected as the target of deriving the minimum cut-sets. We analyze the fault trees and derive the minimum set-cuts. In terms of original PSA, the value of probability for the cut-sets is important but the probability is not important in terms of cyber security of NPPs. The important factors is the number of basic events consisting of the minimal cut-sets that is proportional to vulnerability.

  13. A analysis of cementation technology for liquid radioactive-waste in PWR NPPs

    Chen Liang; Chen Li; Li Junhua

    2009-01-01

    Cementation is one of the most popular solidification technology for the low-and-intermediate level liquid radioactive waste. It has been applied in all of domestic PWR NPPs. The process characteristics and operation of the cementations in the different NPPs are introduced,and the advantage and disadvantage of the cementation are analyzed in this paper. A drum and a cask are compared as a package of the solidified waste, the drum can decrease over 50% final volume of the waste, furthermore the cost for manufacture and transportation for this drum is more cheaper than the cask, but an additional shielding may be necessary for the waste with higher level radioactivity that is packed in drum. More waste can be contained if an appropriate in-drum mixer is used while secondary waste will be unavoidable if the out-drum mixing is adopted. A carriage can make it easier to decontaminate on the surface of equipment and on the floor, furthermore the carriage is more economical than a roller conveyor in manufacture and maintenance. The cementation recipe for the waste should be optimized and additive material should be as less as possible to increase the containing rate of the waste. (authors)

  14. A Case Study on Cyber-security Program for the Programmable Logic Controller of Modern NPPs

    Song, S. H.; Lee, M. S.; Kim, T. H.; Park, C. H.; Park, S. P.; Kim, H. S.

    2014-01-01

    As instrumentation and control (I and C) systems for modern Nuclear Power Plants (NPPs) have been digitalized to cope with their growing complexity, the cyber-security has become an important issue. To protect the I and C systems adequately from cyber threats, such as Stuxnet that attacked Iran's nuclear facilities, regulations of many countries require a cyber-security program covering all the life cycle phases of the system development, from the concept to the retirement. This paper presents a case study of cyber-security program that has been performed during the development of the programmable logic controller (PLC) for modern NPPs of Korea. In the case study, a cyber-security plan, including technical, management, and operational controls, was established through a security risk assessment. Cyber-security activities, such as development of security functions and periodic inspections, were conducted according to the plan: the security functions were applied to the PLC as the technical controls, and periodic inspections and audits were held to check the security of the development environment, as the management and operational controls. A final penetration test was conducted to inspect all the security problems that had been issued during the development. The case study has shown that the systematic cyber-security program detected and removed the vulnerabilities of the target system, which could not be found otherwise, enhancing the cyber-security of the system

  15. A study on maintenance rule program and its application at Korean NPPs

    Hwang, Mee Jeong; Kim, Kil Yoo; Kang, Dae Il; Yang, Joon Eon; Ha, Jae Joo

    2000-11-01

    The objective of the Maintenance Rule is to require monitoring of the overall continuing effectiveness of licensee maintenance programs to ensure that safety related and certain nonsafety-related SSCs are capable of performing their intended functions and, for nonsafety-related equipment failures will not occur that prevent the fulfillment of safety-related functions, and failures resulting in scrams and unnecessary actuations of safety-related systems are minimized. That is, proper maintenance is essential to plant safety. U.S. Maintenance Rule, which was effective July 1996 in USA., was not officially adopted in Korea by Korean regulatory body. However, since many PSA and IPE have been performed for NPPs, the philosophy and usefulness of the Maintenance Rule as well as performance-based regulation are being acceptable. We survey the Maintenance Rule program and applications in the USA, and also developed the Maintenance Rule program to apply to Korean NPPs. In addition, we applied the Maintenance Rule Program apply to Ulchin 3,4 Units roughly with the Maintenance Rule Program developed in this project.

  16. A Case Study on Cyber-security Program for the Programmable Logic Controller of Modern NPPs

    Song, S. H. [Korea University, Seoul (Korea, Republic of); Lee, M. S.; Kim, T. H. [Formal Work Inc., Seoul (Korea, Republic of); Park, C. H. [LINE Corp., Tokyo (Japan); Park, S. P. [Ahnlab Inc., Seoul (Korea, Republic of); Kim, H. S. [Sejong University, Seoul (Korea, Republic of)

    2014-08-15

    As instrumentation and control (I and C) systems for modern Nuclear Power Plants (NPPs) have been digitalized to cope with their growing complexity, the cyber-security has become an important issue. To protect the I and C systems adequately from cyber threats, such as Stuxnet that attacked Iran's nuclear facilities, regulations of many countries require a cyber-security program covering all the life cycle phases of the system development, from the concept to the retirement. This paper presents a case study of cyber-security program that has been performed during the development of the programmable logic controller (PLC) for modern NPPs of Korea. In the case study, a cyber-security plan, including technical, management, and operational controls, was established through a security risk assessment. Cyber-security activities, such as development of security functions and periodic inspections, were conducted according to the plan: the security functions were applied to the PLC as the technical controls, and periodic inspections and audits were held to check the security of the development environment, as the management and operational controls. A final penetration test was conducted to inspect all the security problems that had been issued during the development. The case study has shown that the systematic cyber-security program detected and removed the vulnerabilities of the target system, which could not be found otherwise, enhancing the cyber-security of the system.

  17. Activities in Argentina related to the use of slightly enriched uranium in heavy water reactor NPPs

    Corcuera, R.

    1999-01-01

    An overview of activities related to the use of Slightly Enriched Uranium (SEU) fuel in HWR type NPPs, currently under execution in Argentina, is presented. The activities here described cover certain R and D lines as well as the main aspects of the Project 'Transition from full Natural-U to full SEU core in Atucha-I NPP'. Concerning the R and D lines, a summary is given on investigations related to reduction of void-coefficient using SEU fuel assemblies, annular pellet SEU fuel for bundle power flattening, etc. The main aspects of the above mentioned Project are outlined. At present, Atucha-I core is approaching a 40% of core load with SEU fuel, while the target of full SEU fuel core should be reached in 2-3 years. The expected exit burnup for such a core, namely 11000 MWD/tnU, is already currently obtained for SEU fuel in the present mixed core, while an increase in exit burnup of Natural-U fuel has also been obtained in very good agreement with reactor physics calculations. The comprehensive safety analysis carried out for each phase of the Project showed very moderated changes in plant behaviour under the set of postulated accidents and abnormal transients. A recent development, namely the CARA Project, aimed at unifying manufacturing of fuel assemblies for both operating NPPs in Argentina is presented in an accompanying paper. (author)

  18. ON-POWER DETECTION OF PIPE WALL-THINNED DEFECTS USING IR THERMOGRAPHY IN NPPS

    JU HYUN KIM

    2014-04-01

    Full Text Available Wall-thinned defects caused by accelerated corrosion due to fluid flow in the inner pipe appear in many structures of the secondary systems in nuclear power plants (NPPs and are a major factor in degrading the integrity of pipes. Wall-thinned defects need to be managed not only when the NPP is under maintenance but also when the NPP is in normal operation. To this end, a test technique was developed in this study to detect such wall-thinned defects based on the temperature difference on the surface of a hot pipe using infrared (IR thermography and a cooling device. Finite element analysis (FEA was conducted to examine the tendency and experimental conditions for the cooling experiment. Based on the FEA results, the equipment was configured before the cooling experiment was conducted. The IR camera was then used to detect defects in the inner pipe of the pipe specimen that had artificially induced defects. The IR thermography developed in this study is expected to help resolve the issues related to the limitations of non-destructive inspection techniques that are currently conducted for NPP secondary systems and is expected to be very useful on the NPPs site.

  19. Guidelines for evaluation of anchorage adequacy for safety-related equipment typically used on WWER-type NPPs

    Masopust, R.

    1999-01-01

    This report describes the criteria which should be met when the capacity evaluation of anchorage of safety related equipment is performed for the WWER type NPPs. It should be noted that these criteria were developed specifically for anchorage of WWER type equipment and components to the concrete or steel building structures and they cover different types of anchor bolts and other anchorage details which are typical just for the existing, constructed or reconstructed WWER type NPPs. The screening approach for verifying of equipment anchorage presented in this report is based on a combination of inspections, calculations, and engineering judgement

  20. An Enhancement of Campaign Posters for Human Error Prevention in NPPs

    Lee, Yong Hee; Lee, Yong Hee; Kwon, Soon Il

    2010-01-01

    Accidents in high reliability systems such as nuclear power plants (NPPs) give rise to not only a loss of property and life, but also social problems. One of the most frequently used techniques to grasp the current situation for hazard factors in the NPPs is an event investigation analysis based on the INPO's Human Performance Enhancement System (HPES), and the Korean Human Performance Enhancement System (K-HPES) in Korea, respectively. There are many methods and approaches for an HE assessment that is valuable for investigating the causes of undesirable events and counter-plans to prevent their recurrence in the NPPs. They differ from each other according to the objectives of the analysis; the explanation of the event, the investigation of the causes, the allocation of the responsibility, and the establishment of the counter-plan. Event databases include their own events and information from various sources such as the IAEA, regulatory bodies, and also from the INPO and WANO. As many as 111 reactor trips have occurred in the past 5 years ('01∼'05), and 26 cases of them have occurred due to HE. The trend of human error rate didn't decrease in 2004, so the KHNP started to make efforts to decrease HEs. The KHNP created as many as 40 posters for human performance improvement in 2006. The INPO has been using a traditional form of poster; additionally, the Central Research Institute of Electric Power Industry (CRIEPI) developed a type of caution report. The caution report is comprised of a poster name, a serial number, a figure, work situations, the point at issue, and a countermeasure. The preceding posters which KHNP developed in 2006 give a message about specific information related to HE events. However, it is not enough to arouse interest in the effectiveness of the posters because most people are favorably disposed toward a simple poster with many illustrations. Therefore, we stressed the need for worker's receptiveness rather than notification of information

  1. Of creation of up-to-date system for liquid radwaste management at Ukraine's NPPs. Problem statement

    Andronov, O.B.

    2015-01-01

    The main aspects are addressed of problems in the field of liquid radwaste (LRW) management for Ukrainian NPPs; approaches for its decision, and offers of NNEGC Energoatom SE STC specialists concerning the above issue. Conceptual principle of creation of up-to-date hi-tech complex for LRW management is considered

  2. Comparison of Domestic Safety Review and European Union(EU) Stress Test After Nuclear Accident in Fukushima Daiichi NPPs

    Kang, Hwa Sung; Kim, Jin Weon [Chosun University, Gwangju (Korea, Republic of)

    2016-05-15

    The European Union(EU) nuclear regulators group established stress test criteria and procedures, and utilities performed a self-review in accordance with those criteria and procedures. For Wolsung nuclear unit-1,the stress test was additionally conducted for deciding the continued operation of NPP, even though the safety review had been conducted after Fukushima NPP accident. Thus, this study is to compares the process, criteria, and results of the safety review performed in domestic NPPs and EU stress test performed in Cernavoda NPP. From the comparisons, the effectiveness and necessity of the stress test to decide the continued operation of NPPs is discussed. and the improvement items for safety enhancement are derived. The comparison showed that the process and review criteria of EU stress test was more systematic and specific than those used in domestic NPPs. But it was indicated that the improvement items resulted from the safety review performed in domestic NPPs are more comprehensive and powerful than EU stress tests (Cernavoda NPP) results. EU stress test for Cernavoda NPP evaluated in 3 fieldsand derived 13 design change items. The 50 improvement items derived from domestic safety review were including the contents of these 13 items.

  3. Comparative evaluation of three cognitive error analysis methods through an application to accident management tasks in NPPs

    Jung, Won Dea; Kim, Jae Whan; Ha, Jae Joo; Yoon, Wan C.

    1999-01-01

    This study was performed to comparatively evaluate selected Human Reliability Analysis (HRA) methods which mainly focus on cognitive error analysis, and to derive the requirement of a new human error analysis (HEA) framework for Accident Management (AM) in nuclear power plants(NPPs). In order to achieve this goal, we carried out a case study of human error analysis on an AM task in NPPs. In the study we evaluated three cognitive HEA methods, HRMS, CREAM and PHECA, which were selected through the review of the currently available seven cognitive HEA methods. The task of reactor cavity flooding was chosen for the application study as one of typical tasks of AM in NPPs. From the study, we derived seven requirement items for a new HEA method of AM in NPPs. We could also evaluate the applicability of three cognitive HEA methods to AM tasks. CREAM is considered to be more appropriate than others for the analysis of AM tasks. But, PHECA is regarded less appropriate for the predictive HEA technique as well as for the analysis of AM tasks. In addition to these, the advantages and disadvantages of each method are described. (author)

  4. Development of the relations between the Dukovany NPPs and the local community at present time

    Mozor, B.

    2000-01-01

    Dukovany NPP is the only one operating in Czech Republic, with 4 PWR units, producing about a quarter of the total electricity supplied by the biggest electric power company in the country. On the same site there is a spent fuel storage with a capacity of 600 tones, and a new spent fuel storage planned. This will have sufficient capacity for storing spent fuel for 40 years of Dukovany NPP operation. The communication of the NPP with the public is based on the following rules: open information, open dialog with target groups, mutual exchange of impartial information on operation, serious and tolerant attitude of the Dukovany NPP bilateral dialog with the surroundings. This resulted in the fact that in Czech republic 50% of of the population is in favour of NPPs, and this percent is even higher in the Dukovany region (80%)

  5. Former Soviet Regulations for seismic design of NPPs and comparison with current international practice

    Kostarev, V.; Schukin, A.; Berkovski, A.

    1997-01-01

    This paper presents a summary of current earthquake design criteria used in former Soviet Regulations for equipment and piping systems of nuclear power plants in light of those used in United States and Japan. The detailed comparative seismic analysis of PWR (WWER) Primary Coolant Loop System (PCLS) according to Former Soviet (Russian) PNAE Code and ASME BPV Code with some comments regarding to Japan Code JEAG - 4601 was undertaken for better understanding of the differences and coincidences of seismic design criteria and requirements. The selection of these three guides for the study has very simple explanation: according to ASME BVPC, JEAG and PNAE the huge majority of existing NPPs has been designed. (J.P.N.)

  6. Development of a site specific environmental radiation assessment model for Youngkwang NPPs

    Chung, Yang Geun; Song, Myung Jae; Shon, Soon Hwan; Shin, Sang Woon; Lee, Gap Bock; Yang, Kyung Hwa [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Kim, Seong Pyung; Kim, Jeong Kyu; Shin, Dae Yoon; Kim, Hyun Ku; Lee, Kyung Jin [Chosun University, Kwangju (Korea, Republic of)

    1996-12-31

    During the normal operation of nuclear power plants, a very small amount of radionuclide materials is released to the environment. The radionuclide releases to the environment may give rise to some additional radiation dose through a number of pathways. With a few exception, radionuclide transports are highly dependent on the environmental conditions such as topological features, atmospheric and oceanic conditions and socio-environmental characteristics, etc. The dose calculation in Korea are presently being performed using the models in US NRC Reg. Guide. However, these models which were originally released by the US NRC in 1977 are inadequate to deal with environmental movement of radionuclides in consideration of complex terrain, tidal condition of the Yellow Sea, and Youngkwang site specific conditions. KEPRI has developed the models to consider the site specific characteristics around Youngkwang NPPs, to give the realistic dose assessment, and to improve assurance and reliability in public dose calculation. (author). 41 figs., 70 refs.

  7. Pre-Operational Seismic Walk-Through of NPPs in India

    Soni, R.S.; Mishra, R.K.; Agrawal, M.K.; Reddy, G.R.; Kushwaha, H.S.; Venkat Raj, V.; Badrinarayan, G.; Hawaldar, R.V.; Ingole, S.M.

    2002-01-01

    In nuclear power plants, it is essential to design the various safety and safety related systems and components of the plant in such a manner that they maintain their structural integrity as well as serve their functional performance during a seismic event. The pre-operational seismic walk-through helps in ensuring the installation of various seismic supports as per design intent, identifying the areas where supports are inadequate, identifying the interaction concerns between the systems of various safety classes and locating the various undesired loose, untied / unanchored components, tools, etc. used during the construction activity. A detailed procedure for the pre-operational seismic walk-through of the NPPs was therefore, prepared. Since the types and locations of seismic supports for the various systems and components of the plant had been already reviewed, the major emphasis during the walk-through was laid on their proper installation. (authors)

  8. Probabilistic approach to requalification of existing NPPs under aircraft crash loading

    Birbraer, A.N.; Roleder, A.J.; Shulman, G.S.

    1993-01-01

    A probabilistic approach to the analysis of NPP safety under aircraft impact is discussed. It may be used both for requalification of existing NPPs and in the process of NPP design. NPP is considered as a system of components: structures, pipes, different kinds of equipment, soil, foundation. The exceeding of the limit probability of the radioactive products release out of containment (i.e. of the NPP safety requirements non-fulfilment) is taken as a system failure criterion. An example of an event tree representing the consequence of events causing the failure is given. Described are the methods of estimate of elementary events probabilities through which a composite probability of the failure is evaluated. (author)

  9. Knowledge management in Nordic NPPs. Summary report of the findings from the workshop

    Nilsen, S.

    2005-04-01

    The title of the reported project is 'Nordic Nuclear Safety Research (NKS) Workshop on Knowledge Management in Nordic NPPs'. One important objective of this workshop was to explore if and how knowledge retention activities could be coordinated between the various Nordic utilities. The main conclusions of the workshop can be summed up as follows: Establishing good knowledge management routines is recognized by many utilities today. However, there seem to be no real consensus on what should be focused on in the present situation. Maybe the most pressing problem is to avoid undesirable consequences of the massive retirement soon to follow. Still, there is no consensus on what those consequences might be, and what should be done to avoid them. (au)

  10. Study on Instrument Fault Detection using OLM Techniques for PHM Application in NPPs

    Kim, Jae Hwan; Park, Gee Yong; Kim, Jung Taek; Hur, Seop [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    The diagnosis system is relatively being mature owing to many research. Among the various models, this paper introduces some On-Line Monitoring (OLM) models for instrument health monitoring and review applicability on NPPs. In recent years, many researchers are being focused on the prognostics which is predicting the future failure of instruments or equipment by using the status monitoring data. By using the prognostic techniques, we can expect a lot of advantages such as ease of control, power optimization, or optimal use of maintenance resources. And we have performed the test for detecting fault of safety-critical instruments and analyzed the fault detection sensitivity for various instrument failure modes using OLM techniques. OLM techniques using data-driven based model such AAKR or AANN can be useful tools for securing integrity of safety-critical instrument that should always keep healthy conditions for the plant safety.

  11. Knowledge management in Nordic NPPs. Summary report of the findings from the workshop

    Nilsen, S. [Inst. for Energy Technology, Halden (Norway)

    2005-04-01

    The title of the reported project is 'Nordic Nuclear Safety Research (NKS) Workshop on Knowledge Management in Nordic NPPs'. One important objective of this workshop was to explore if and how knowledge retention activities could be coordinated between the various Nordic utilities. The main conclusions of the workshop can be summed up as follows: Establishing good knowledge management routines is recognized by many utilities today. However, there seem to be no real consensus on what should be focused on in the present situation. Maybe the most pressing problem is to avoid undesirable consequences of the massive retirement soon to follow. Still, there is no consensus on what those consequences might be, and what should be done to avoid them. (au)

  12. A survey on the VXIbus and validity analyses for instrumentation and control in NPPs

    Kwon, Kee Choon; Park, Won Man

    1997-06-01

    This document presents the technical status of the VXIbus system and its interface. VMEbus, while developed as a backplane for Motorola processors, can be used for data acquisition, control and other instrumentation applications. The VXIbus and its associated standard for form, fit, and electrical interface have simplified the process of putting together automated instrumentation systems. The VXIplug and play system alliance was founded in 1993, the alliance's charter to improve the effectiveness of VXI-based solutions by increasing ease-of-use and improving the interoperability of mainframes, computers, instrumentations, and software through open, multivendor standards and practices. This technical report surveys surveys the instrumentation and control in NPPs apply to the VXI-based instruments which are studied expendability, interoperability, maintainability and other features. (author). 10 refs., 4 tabs., 25 figs

  13. Some aspects of nuclear fuel use at Ukrainian NPPs during last two years

    Bilodid, Y.; Shevchenko, I.; Ieremenko, M.; Ovdiienko, I.

    2015-01-01

    For many years SSTC NRS actively participates in licensing of fuel reloading and in the implementation of new nuclear fuel types at the nuclear power plants in Ukraine. Results of the nuclear fuel use for last years are presented in the paper. The results are based on NPP documentation submitted for licensing to the regulating body of Ukraine and based on our estimations and independent calculations. The first part of the paper contains a brief characteristic of the fuel cycles at Ukrainian NPPs. Types of loaded fuel are described also. Experience of new fuel type implementation is presented (Westinghouse FA and TVSA-12 for WWER-1000 reactors). The next part of the paper presents a new regulatory document under development and further new fuel implementation (WWER-1000 reactors). The last part of the paper describes some issues with fuel use. (authors) Keywords: WWER, TVSA, TVSA-12, TVS-W, TVS-WR, Westinghouse, NPP

  14. The installation and operation of the seismic instrumentation in Korean NPPs

    Lee, Kye Hyun; Baek, Yong Lak; Chung, Yun Suk

    1994-01-01

    Including the 7 October, 1978, Hongsung earthquake, many earthquakes have occurred in our country. The Korean peninsular is no longer a safety zone against earthquakes, and there are possibilities of the damage they cause. So therefore, it is essential to verify the safety of the safety-related facilities in the event of an earthquake. If an earthquake occurs, seismic instrumentation provides information on the vibratory ground motion and resultant vibratory responses of representative safety-related structures and equipment so that an evaluation can be made immediately as to whether or not the design response spectra have been exceeded. In this paper, general descriptions of the seismic instrumentation installed in domestic NPPs will be discussed; this includes instrument type and location, the Operating Basis Earthquake (OBE) exceedance criteria, and processing and evaluation of earthquake response data, and items to be studied for further enhancement of post-earthquake evaluation techniques are presented

  15. Impact of Fukushima NPPs Accident on Young Generation's Understanding of Radiation

    Choi, Yoonseok; Kim, Wook; Joo, Yeonjung; Choi, Nowoon [Korea Academy of Nuclear Safety, Seoul (Korea, Republic of)

    2013-05-15

    As this study project has been conducted continuously before and after the breaking-out of the Fukushima NPPs accident (FNPPA), accumulated data were analyzed to seek impact of the accident. Results indicated that the first-hand measurement of radiation carried out so far was turned out to be an effective means for mitigation of students' over-sensitive radiation fear even though some influence of the FNPPA was identified in analysis of questionnaire data. The FNPPA brought about radiation fear to the people all over the country. However, it is believed that radiation together with nuclear energy will favorably be understandable by the public through implementation of this first-hand experience program.

  16. Impact of Fukushima NPPs Accident on Young Generation's Understanding of Radiation

    Choi, Yoonseok; Kim, Wook; Joo, Yeonjung; Choi, Nowoon

    2013-01-01

    As this study project has been conducted continuously before and after the breaking-out of the Fukushima NPPs accident (FNPPA), accumulated data were analyzed to seek impact of the accident. Results indicated that the first-hand measurement of radiation carried out so far was turned out to be an effective means for mitigation of students' over-sensitive radiation fear even though some influence of the FNPPA was identified in analysis of questionnaire data. The FNPPA brought about radiation fear to the people all over the country. However, it is believed that radiation together with nuclear energy will favorably be understandable by the public through implementation of this first-hand experience program

  17. Former Soviet Regulations for seismic design of NPPs and comparison with current international practice

    Kostarev, V; Schukin, A; Berkovski, A [CKTI-Vibroseism Co. Ltd. (Cape Verde)

    1997-03-01

    This paper presents a summary of current earthquake design criteria used in former Soviet Regulations for equipment and piping systems of nuclear power plants in light of those used in United States and Japan. The detailed comparative seismic analysis of PWR (WWER) Primary Coolant Loop System (PCLS) according to Former Soviet (Russian) PNAE Code and ASME BPV Code with some comments regarding to Japan Code JEAG - 4601 was undertaken for better understanding of the differences and coincidences of seismic design criteria and requirements. The selection of these three guides for the study has very simple explanation: according to ASME BVPC, JEAG and PNAE the huge majority of existing NPPs has been designed. (J.P.N.)

  18. Increasing of leak-tightness of hermetic zone and other important components in NPPs

    Murani, J.

    2001-01-01

    The performed by VUEZ resealing works in the hermetic compartments/containment of WWER 440 and WWER 1000 NPPs in Slovakia (Jaslovske Bohunice V-1 NPP, Jaslovske Bohunice V-2 NPP, Mochovce NPP), the Czech Republic (Dukovany NPP, Temelin NPP) and Hungary (Pask NPP) are presented. The leakage rate from hermetic compartments at individual NPP reactor units are shown.The VUEZ activities in field of resealing of weld joints in pools and tanks in the Jaslovske Bohunice V-1 NPP and innovation of the seal of reactor pit protective hood (kolpak) are described. The principle of operation and practical experience of the SMU-V system implemented in the Jaslovske Bohunice V-1 NPP (WWER 440 - V 230) for NPP primary circuit leakage monitoring are also given

  19. Development of technology on natural flaw fabrication and precise diagnosis for the major components in NPPs

    Han, Jung Ho; Choi, Myung Sik; Lee, Doek Hyun; Hur, Do Haeng

    2002-01-01

    The objective of this research is to develop a fabrication technology of natural flaw specimen of major components in NPPs and a technology of precise diagnosis for failure and degradation of components using natural flaw specimen. 1) Successful development of the natural flaw fabrication technology of SG tube 2) Evaluation of ECT signal and development of precise diagnosis using natural flaws. - Determination of length, depth, width, and multiplicity of fabricated natural flaws. - Informations about detectability and accuracy of ECT evaluation on various kinds of defects are collected when the combination of probe and frequency is changed. - An advanced technology for precise ECT evaluation is established. 3) Application of precise ECT diagnosis to failure analysis of SG tube in operation. - Fretting wear of KSNP SG. - ODSCC at tube expanded region of KSNP SG. - Determination of through/non-through wall of axial crack

  20. The concept of information support system for operational personnel of operating NPPs

    Dunaev, V.G.; Golovanov, V.V.

    1993-01-01

    The paper has been prepared on the materials of the concept developed by the order of ''Rosenergoatom'' concern. In the present paper the main definitions, the principal objectives and functions of the operator support system (OSS) are stated, a brief analysis of operation features of some existing operator information systems is presented, the main trends of development of operator information support system are given, the way and the sequence for implementation of the systems for operating NPPs are reviewed. In this proposed concept in the first place are considered the information support systems for the operators of the power unit main control rooms, however, the presented principles may be applied while designing information support systems for operators of other control rooms of NPP. 4 refs

  1. Importance of the Design Basis Knowledge Management for New Builds and Existing NPPs

    Bychkov, Alexander

    2013-01-01

    The Fukushima Daiichi NPP accident in Japan reminds us that sustaining a high level of nuclear safety over the life of a plant is of paramount importance to us all. This and previous major accidents have shaken the confidence of the public and even some governments in the safety of nuclear energy. However, a key message from the St. Petersburg Ministerial Conference this past June was that nuclear power will continue to play an important role in energy security and sustainable development. The IAEA will obviously need to continue to assist Member States in strengthening the safety of NPPs. We will also continue to give technical support to both newcomer countries and to countries with established nuclear energy programmes

  2. Human and Organisational Factors in the Licensing Process for New NPPs: The Swiss Approach

    Ryser, Cornelia

    2011-01-01

    Past and recent construction as well as operating experience has shown the importance of giving due attention to human and organisational factors (HOF) in the design and construction of new NPPs. The present paper primarily deals with the development of regulatory requirements by the Swiss Federal Nuclear Safety Inspectorate (ENSI) concerning HOF engineering aspects, i.e. the design of the work systems of the new NPP (technical systems, work tasks, operating organisation). The requirements concerning quality and project management or the management system in general are not in the main focus of this paper. The approach and requirements presented are not yet fully implemented in the Swiss regulatory framework and are still being worked on. Therefore the issues described in the paper have to be considered as provisional and might still be subject to some change in the next months as the approach and requirements are being further developed and finalised. (author)

  3. Seismic margin assessment and earthquake experience based methods for WWER-440/213 type NPPs

    Masopust, R.

    1996-01-01

    This report covers the review of the already completed studies, namely, safe shutdown system identification and classification for Bohunice NPP and the comparative study of standards and criteria. It contains a report on currently ongoing studies concerning seismic margin assessment and earthquake experience based methods in application for seismic evaluation and verification of structures and equipment components of the operating WWER-440/213 type NPPs. This is based on experiences obtained from Paks NPP. The work plan for the remaining period of Benchmark CRP and the new proposals are included. These are concerned with seismic evaluation of selected safety related mechanical equipment and pipes of Paks NPP, and the actual seismic issues of the Temelin WWER-1000 type NPP

  4. Safety regulations regarding to accident monitoring and accident sampling at Russian NPPs with VVER type reactors

    Sharafutdinov, Rachet; Lankin, Michail; Kharitonova, Nataliya

    2014-01-01

    The paper describes a tendency by development of regulatory document requirements related to accident monitoring and accident sampling at Russia's NPPs. Lessons learned from the Fukushima Daiichi accident pointed at the importance and necessary to carry out an additional safety check at Russia's nuclear power plants in the preparedness for management of severe accidents at NPPs. Planned measures for improvement of severe accidents management include development and implementation of the accident instrumentation systems, providing, monitoring, management and storage of information in a severe accident conditions. The draft of Safety Guidelines <

  5. A study on fatigue measurement of operators for human error prevention in NPPs

    Ju, Oh Yeon; Il, Jang Tong; Meiling, Luo; Hee, Lee Young [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    The identification and the analysis of individual factor of operators, which is one of the various causes of adverse effects in human performance, is not easy in NPPs. There are work types (including shift), environment, personality, qualification, training, education, cognition, fatigue, job stress, workload, etc in individual factors for the operators. Research at the Finnish Institute of Occupational Health (FIOH) reported that a 'burn out (extreme fatigue)' is related to alcohol dependent habits and must be dealt with using a stress management program. USNRC (U.S. Nuclear Regulatory Commission) developed FFD (Fitness for Duty) for improving the task efficiency and preventing human errors. 'Managing Fatigue' of 10CFR26 presented as requirements to control operator fatigue in NPPs. The committee explained that excessive fatigue is due to stressful work environments, working hours, shifts, sleep disorders, and unstable circadian rhythms. In addition, an International Labor Organization (ILO) developed and suggested a checklist to manage fatigue and job stress. In domestic, a systematic evaluation way is presented by the Final Safety Analysis Report (FSAR) chapter 18, Human Factors, in the licensing process. However, it almost focused on the interface design such as HMI (Human Machine Interface), not individual factors. In particular, because our country is in a process of the exporting the NPP to UAE, the development and setting of fatigue management technique is important and urgent to present the technical standard and FFD criteria to UAE. And also, it is anticipated that the domestic regulatory body applies the FFD program as the regulation requirement so that a preparation for that situation is required. In this paper, advanced researches are investigated to find the fatigue measurement and evaluation methods of operators in a high reliability industry. Also, this study tries to review the NRC report and discuss the causal factors and

  6. Principal components based support vector regression model for on-line instrument calibration monitoring in NPPs

    Seo, In Yong; Ha, Bok Nam; Lee, Sung Woo; Shin, Chang Hoon; Kim, Seong Jun

    2010-01-01

    In nuclear power plants (NPPs), periodic sensor calibrations are required to assure that sensors are operating correctly. By checking the sensor's operating status at every fuel outage, faulty sensors may remain undetected for periods of up to 24 months. Moreover, typically, only a few faulty sensors are found to be calibrated. For the safe operation of NPP and the reduction of unnecessary calibration, on-line instrument calibration monitoring is needed. In this study, principal component based auto-associative support vector regression (PCSVR) using response surface methodology (RSM) is proposed for the sensor signal validation of NPPs. This paper describes the design of a PCSVR-based sensor validation system for a power generation system. RSM is employed to determine the optimal values of SVR hyperparameters and is compared to the genetic algorithm (GA). The proposed PCSVR model is confirmed with the actual plant data of Kori Nuclear Power Plant Unit 3 and is compared with the Auto-Associative support vector regression (AASVR) and the auto-associative neural network (AANN) model. The auto-sensitivity of AASVR is improved by around six times by using a PCA, resulting in good detection of sensor drift. Compared to AANN, accuracy and cross-sensitivity are better while the auto-sensitivity is almost the same. Meanwhile, the proposed RSM for the optimization of the PCSVR algorithm performs even better in terms of accuracy, auto-sensitivity, and averaged maximum error, except in averaged RMS error, and this method is much more time efficient compared to the conventional GA method

  7. Implementation of safeguards in Spanish NPPs: advantages of cooperation and coordination

    Estrampes Blanch, J.; Recio Santamaria, M.

    2007-01-01

    In 2002 the Spanish Ministry of Industry, Tourism and Commerce (MITYC) informed the operators of the soon entry into force of the Additional Protocol (AP) to the Safeguards Agreement, once its ratification by the Member States of the EU were completed and the Community and national legislations were adapted to the new requirements. The Spanish association for the electrical industry (UNESA) responded to that announcement setting up the UNESA's Safeguards Working Group (USWG), made up of staff of the NPPs in charge of nuclear material accountancy. The USWG was mandated to ensure coordinated implementation of the new safeguards obligation of the Additional Protocol in close cooperation with the Ministry of Industry, Tourism and Commerce (MITYC), Spanish authority for safeguards implementation follow up. Although the group was initially meant only for NPPs, later on representatives of other main nuclear facilities (i.e. ENUSA's fuel fabrication facility, the national rad waste company ENRESA, and CIEMAT national research centre) have been also participating in the group's meeting and activities when general discussion points on the entry into force of the AP were dealt with. From 2003 on, the USWG has met periodically with the aim of exchanging experiences in the field of safeguards implementation and jointly dealing with changes to EURATOM and IAEA safeguards systems lately introduced to reinforce their effectiveness and efficiency in response to the challenges posed to the international community by the recent discovery of undeclared nuclear programmes. Along the operation of the USWG, presence of Spanish nuclear industry representatives in international for a dealing with safeguards has remarkably grown up. Moreover, representatives of the USWG have also maintained an active participation in the ESARDA working groups on integrated safeguards (ISWG) and nuclear material accountancy and audit focus group (NMAC-AF)

  8. Aspects of a Co-free hardfacing Materials Development to Reduce the Radioactivity in NPPs

    Kim, Joung Soo; Kim, Hong Pyo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Suh, Jeong Hun [Inss Tek Co., Daejeon (Korea, Republic of)

    2007-07-01

    For the last one or two decades, active researches to develop Co-free hardfacing materials in order to replace Co-base stellite alloys have been done to reduce the radioactivity in the primary systems in nuclear power plants(NPPs). However, Co-free materials having superior mechanical properties to stellite alloys have not been developed up to now. There are two ways to increase the performance characteristics of the key parts needed to be coated with hardfacing materials, thus resulting in replacing the Co-base stellite alloys with superior mechanical properties; one of them is to develop new Co-free materials with a better quality in performance than that of satellite alloys. The other is to use new coating techniques developed to increase the coated surface properties of already developed Co-free materials. In this study, the aspect of newly developed Co-free materials is reviewed and the necessity of the development of new Co-free materials is emphasized for the replacement of Co-base satellite alloys. In addition, a new coating technique, which is called a laser hardfacing(cladding) technique(LHT), is introduced and its advantage and applicability to the key parts in NPPs are discussed using our experimental results to improve the properties of a surface coated with existing Co-free hardfacing materials. The coating technique using a laser beam having a high energy density has unique advantages to obtain various microstructures such as crystalline, amorphous, porous, and nano structures and also to get coating layers having high a hardness to result in an excellent resistance to erosion corrosion and wear.

  9. A study on fatigue measurement of operators for human error prevention in NPPs

    Ju, Oh Yeon; Il, Jang Tong; Meiling, Luo; Hee, Lee Young

    2012-01-01

    The identification and the analysis of individual factor of operators, which is one of the various causes of adverse effects in human performance, is not easy in NPPs. There are work types (including shift), environment, personality, qualification, training, education, cognition, fatigue, job stress, workload, etc in individual factors for the operators. Research at the Finnish Institute of Occupational Health (FIOH) reported that a 'burn out (extreme fatigue)' is related to alcohol dependent habits and must be dealt with using a stress management program. USNRC (U.S. Nuclear Regulatory Commission) developed FFD (Fitness for Duty) for improving the task efficiency and preventing human errors. 'Managing Fatigue' of 10CFR26 presented as requirements to control operator fatigue in NPPs. The committee explained that excessive fatigue is due to stressful work environments, working hours, shifts, sleep disorders, and unstable circadian rhythms. In addition, an International Labor Organization (ILO) developed and suggested a checklist to manage fatigue and job stress. In domestic, a systematic evaluation way is presented by the Final Safety Analysis Report (FSAR) chapter 18, Human Factors, in the licensing process. However, it almost focused on the interface design such as HMI (Human Machine Interface), not individual factors. In particular, because our country is in a process of the exporting the NPP to UAE, the development and setting of fatigue management technique is important and urgent to present the technical standard and FFD criteria to UAE. And also, it is anticipated that the domestic regulatory body applies the FFD program as the regulation requirement so that a preparation for that situation is required. In this paper, advanced researches are investigated to find the fatigue measurement and evaluation methods of operators in a high reliability industry. Also, this study tries to review the NRC report and discuss the causal factors and management

  10. Passive magnetic bearing configurations

    Post, Richard F [Walnut Creek, CA

    2011-01-25

    A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

  11. The Initial Test Programme Features for the Advanced Korean NPPs (Shin–Kori NPP Units 3&4)

    Sul, Y.S.

    2015-01-01

    Korea has developed the Advanced Power Reactor 1400 (APR1400), an evolutionary pressurised water reactor and has obtained the standard design approval in 2002. As of 2014, eight nuclear power plants (NPPs) are in preparation for operation or under construction, four in Korea (SKN 3&4, SUN 1&2) and four in UAE (BNPP 1, 2, 3&4), and four NPPs are in planning in Korea (SKN 5&6, SUN 3&4). Especially, SKN Units 3&4 are the first construction NPPs for the APR1400 and are currently in the final stage to get Operating Licence (OL). The initial test programme for NPPs begins as systems and components are turned over to the startup organization and ends with completion of the Power Ascension Tests (PATs). For SKN Unit 3, the Pre-core Hot Functional Testing has been successfully completed and the initial fuel loading would proceed after getting OL. The SKN Unit 4 is preparing for the CHT (Cold Hydrostatic Test). The SKN 3&4 has many new and advanced design features and so has developed the test programmes to demonstrate that those advanced design features can be safely operated and the performance levels can be maintained in accordance with approved safety requirements. Among those test programs, the examples of test programs, newly introduced ones compared to the previous NPPs are as follows; – SIT (Safety Injection Tank) Blowdown Test with FD (Fluidic Device) – IRWST (In-Containment Refueling Water Storage Tank) In-Plant Test – POSRV (Pilot Operated Safety Relief Valve) Test – Low Power Physics Testing and PAT considering FOAK (First Of A Kind) unit – Safe Shutdown Test with DCS (Distrubuted Control System) Fail and CMF (Common Mode Failure) for Safety Instrumentation and Control System. (author)

  12. Passive solar construction handbook

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  13. Passivity and Evolutionary Game Dynamics

    Park, Shinkyu; Shamma, Jeff S.; Martins, Nuno C.

    2018-01-01

    This paper investigates an energy conservation and dissipation -- passivity -- aspect of dynamic models in evolutionary game theory. We define a notion of passivity using the state-space representation of the models, and we devise systematic methods to examine passivity and to identify properties of passive dynamic models. Based on the methods, we describe how passivity is connected to stability in population games and illustrate stability of passive dynamic models using numerical simulations.

  14. Passivity and Evolutionary Game Dynamics

    Park, Shinkyu

    2018-03-21

    This paper investigates an energy conservation and dissipation -- passivity -- aspect of dynamic models in evolutionary game theory. We define a notion of passivity using the state-space representation of the models, and we devise systematic methods to examine passivity and to identify properties of passive dynamic models. Based on the methods, we describe how passivity is connected to stability in population games and illustrate stability of passive dynamic models using numerical simulations.

  15. Aktiv kontra passiv forvaltning

    Bechmann, Ken L.; Pedersen, Lasse Heje

    2017-01-01

    Fordele og ulemper ved aktiv og passiv forvaltning har fået fornyet opmærksomhed blandt andet i forbindelse med den forestående implementering af MiFID II. Som bidrag til denne diskussion indeholder dette nummer af Finans/Invest tre artikler, der behandler aktiv og passiv forvaltning fra...... forskellige vinkler. Denne leder forklarer, hvorfor valget mellem aktiv og passiv forvaltning er mere kompliceret, end hvad man kunne tro ved første øjekast, og konkluderer, at der vil være plads til - og behov for - begge typer forvaltning....

  16. Most energetic passive states.

    Perarnau-Llobet, Martí; Hovhannisyan, Karen V; Huber, Marcus; Skrzypczyk, Paul; Tura, Jordi; Acín, Antonio

    2015-10-01

    Passive states are defined as those states that do not allow for work extraction in a cyclic (unitary) process. Within the set of passive states, thermal states are the most stable ones: they maximize the entropy for a given energy, and similarly they minimize the energy for a given entropy. Here we find the passive states lying in the other extreme, i.e., those that maximize the energy for a given entropy, which we show also minimize the entropy when the energy is fixed. These extremal properties make these states useful to obtain fundamental bounds for the thermodynamics of finite-dimensional quantum systems, which we show in several scenarios.

  17. Techniques for active passivation

    Roscioli, Joseph R.; Herndon, Scott C.; Nelson, Jr., David D.

    2016-12-20

    In one embodiment, active (continuous or intermittent) passivation may be employed to prevent interaction of sticky molecules with interfaces inside of an instrument (e.g., an infrared absorption spectrometer) and thereby improve response time. A passivation species may be continuously or intermittently applied to an inlet of the instrument while a sample gas stream is being applied. The passivation species may have a highly polar functional group that strongly binds to either water or polar groups of the interfaces, and once bound presents a non-polar group to the gas phase in order to prevent further binding of polar molecules. The instrument may be actively used to detect the sticky molecules while the passivation species is being applied.

  18. Passive radon daughter dosimeters

    McElroy, R.G.C.; Johnson, J.R.

    1986-03-01

    On the basis of an extensive review of the recent literature concerning passive radon daughter dosimeters, we have reached the following conclusions: 1) Passive dosimeters for measuring radon are available and reliable. 2) There does not presently exist an acceptable passive dosimeter for radon daughters. There is little if any hope for the development of such a device in the foreseeable future. 3) We are pessimistic about the potential of 'semi-passive dosimeters' but are less firm about stating categorically that these devices cannot be developed into a useful radon daughter dosimeter. This report documents and justifies these conclusions. It does not address the question of the worker's acceptance of these devices because at the present time, no device is sufficiently advanced for this question to be meaningful. 118 refs

  19. Passive Mixing inside Microdroplets

    Chengmin Chen

    2018-04-01

    Full Text Available Droplet-based micromixers are essential units in many microfluidic devices for widespread applications, such as diagnostics and synthesis. The mixers can be either passive or active. When compared to active methods, the passive mixer is widely used because it does not require extra energy input apart from the pump drive. In recent years, several passive droplet-based mixers were developed, where mixing was characterized by both experiments and simulation. A unified physical understanding of both experimental processes and simulation models is beneficial for effectively developing new and efficient mixing techniques. This review covers the state-of-the-art passive droplet-based micromixers in microfluidics, which mainly focuses on three aspects: (1 Mixing parameters and analysis method; (2 Typical mixing element designs and the mixing characters in experiments; and, (3 Comprehensive introduction of numerical models used in microfluidic flow and diffusion.

  20. An experimental approach to estimation of human information processing capacity for diagnosis tasks in NPPs

    Kim, Ji Tae

    2006-02-15

    The objectives of this research are 1) to determine the human's information processing capacity and 2) to describe the relationship between the information processing capacity and human factors. This research centers on the relationship, as experimentally determined, between an operator's mental workload and information flow during accident diagnosis tasks at nuclear power plants (NPPs). The relationship between the information flow rate and operator's mental workload is investigated experimentally. According to this relationship, the operator's information processing capacity can be established. Once the information processing capacity of a main control room (MCR) operator in a NPP is known, it is possible to apply it 1) to predict the operator's performance, 2) to design diagnosis tasks, and 3) to design human-machine interface. In advanced MCR, an operator's mental activity is more important than his or her physical activity. The mental workload is the portion of the operator's limited capacity that is actually required to perform a particular task. A high mental workload may cause an operator to make a mistake and consequently affect that the safe operation of NPPs. Thus, to predict an operator's performance is very important for the nuclear safety. The information processing capacity is the operator's ability to manage the amount of bits per second when an operator is diagnosing tasks or accidents. We can estimate the information processing capacity using the relationship between the information flow rate and human performance. That is, if the operator's performance decreases rapidly as the information flow rate (bit/sec) is increased, it is possible to determine the operator's information processing capacity. A diagnosis task is one of the most complex and mentally demanding tasks as well as a crucial part in maintaining the safe operation of NPPs. Diagnosis tasks refer to the overall tasks of finding the

  1. An experimental approach to estimation of human information processing capacity for diagnosis tasks in NPPs

    Kim, Ji Tae

    2006-02-01

    The objectives of this research are 1) to determine the human's information processing capacity and 2) to describe the relationship between the information processing capacity and human factors. This research centers on the relationship, as experimentally determined, between an operator's mental workload and information flow during accident diagnosis tasks at nuclear power plants (NPPs). The relationship between the information flow rate and operator's mental workload is investigated experimentally. According to this relationship, the operator's information processing capacity can be established. Once the information processing capacity of a main control room (MCR) operator in a NPP is known, it is possible to apply it 1) to predict the operator's performance, 2) to design diagnosis tasks, and 3) to design human-machine interface. In advanced MCR, an operator's mental activity is more important than his or her physical activity. The mental workload is the portion of the operator's limited capacity that is actually required to perform a particular task. A high mental workload may cause an operator to make a mistake and consequently affect that the safe operation of NPPs. Thus, to predict an operator's performance is very important for the nuclear safety. The information processing capacity is the operator's ability to manage the amount of bits per second when an operator is diagnosing tasks or accidents. We can estimate the information processing capacity using the relationship between the information flow rate and human performance. That is, if the operator's performance decreases rapidly as the information flow rate (bit/sec) is increased, it is possible to determine the operator's information processing capacity. A diagnosis task is one of the most complex and mentally demanding tasks as well as a crucial part in maintaining the safe operation of NPPs. Diagnosis tasks refer to the overall tasks of finding the root of cause of the faults or accidents. In this

  2. CANDU passive shutdown systems

    Hart, R S; Olmstead, R A [AECL CANDU, Sheridan Park Research Community, Mississauga, ON (Canada)

    1996-12-01

    CANDU incorporates two diverse, passive shutdown systems, independent of each other and from the reactor regulating system. Both shutdown systems function in the low pressure, low temperature, moderator which surrounds the fuel channels. The shutdown systems are functionally different, physically separate, and passive since the driving force for SDS1 is gravity and the driving force for SDS2 is stored energy. The physics of the reactor core itself ensures a degree of passive safety in that the relatively long prompt neutron generation time inherent in the design of CANDU reactors tend to retard power excursions and reduces the speed required for shutdown action, even for large postulated reactivity increases. All passive systems include a number of active components or initiators. Hence, an important aspect of passive systems is the inclusion of fail safe (activated by active component failure) operation. The mechanisms that achieve the fail safe action should be passive. Consequently the passive performance of the CANDU shutdown systems extends beyond their basic modes of operation to include fail safe operation based on natural phenomenon or stored energy. For example, loss of power to the SDS1 clutches results in the drop of the shutdown rods by gravity, loss of power or instrument air to the injection valves of SDS2 results in valve opening via spring action, and rigorous self checking of logic, data and timing by the shutdown systems computers assures a fail safe reactor trip through the collapse of a fluctuating magnetic field or the discharge of a capacitor. Event statistics from operating CANDU stations indicate a significant decrease in protection system faults that could lead to loss of production and elimination of protection system faults that could lead to loss of protection. This paper provides a comprehensive description of the passive shutdown systems employed by CANDU. (author). 4 figs, 3 tabs.

  3. Pattern Matching Framework to Estimate the Urgency of Off-Normal Situations in NPPs

    Shin, Jin Soo; Park, Sang Jun; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Hyo Jin; Park, Soon Yeol [Korea Hydro and Nuclear Power, Yeonggwang (Korea, Republic of)

    2010-10-15

    According to power plant operators, it was said that they could quite well recognize off-normal situations from an incipient stage and also anticipate the possibility of upcoming trips in case of skilled operators, even though it is difficult to clarify the cause of the off-normal situation. From the interview, we could assure the feasibility of two assumptions for the diagnosis of off-normal conditions: One is that we can predict whether an accidental shutdown happens or not if we observe the early stage when an off-normal starts to grow. The other is the observation at the early stage can provide the remaining time to a trip as well as the cause of such an off-normal situation. For this purpose, the development of on-line monitoring systems using various data processing techniques in nuclear power plants (NPPs) has been the subject of increasing attention and becomes important contributor to improve performance and economics. Many of studies have suggested the diagnostic methodologies. One of representative methods was to use the distance discrimination as a similarity measure, for example, such as the Euclidean distance. A variety of artificial intelligence techniques such as a neural network have been developed as well. In addition, some of these methodologies were to reduce the data dimensions for more effectively work. While sharing the same motivation with the previous achievements, this study proposed non-parametric pattern matching techniques to reduce the uncertainty in pursuance of selection of models and modeling processes. This could be characterized by the following two aspects: First, for overcoming considering only a few typical scenarios in the most of the studies, this study is getting the entire sets of off-normal situations which are anticipated in NPPs, which are created by a full-scope simulator. Second, many of the existing researches adopted the process of forming a diagnosis model which is so-called a training technique or a parametric

  4. Pattern Matching Framework to Estimate the Urgency of Off-Normal Situations in NPPs

    Shin, Jin Soo; Park, Sang Jun; Heo, Gyun Young; Park, Jin Kyun; Kim, Hyo Jin; Park, Soon Yeol

    2010-01-01

    According to power plant operators, it was said that they could quite well recognize off-normal situations from an incipient stage and also anticipate the possibility of upcoming trips in case of skilled operators, even though it is difficult to clarify the cause of the off-normal situation. From the interview, we could assure the feasibility of two assumptions for the diagnosis of off-normal conditions: One is that we can predict whether an accidental shutdown happens or not if we observe the early stage when an off-normal starts to grow. The other is the observation at the early stage can provide the remaining time to a trip as well as the cause of such an off-normal situation. For this purpose, the development of on-line monitoring systems using various data processing techniques in nuclear power plants (NPPs) has been the subject of increasing attention and becomes important contributor to improve performance and economics. Many of studies have suggested the diagnostic methodologies. One of representative methods was to use the distance discrimination as a similarity measure, for example, such as the Euclidean distance. A variety of artificial intelligence techniques such as a neural network have been developed as well. In addition, some of these methodologies were to reduce the data dimensions for more effectively work. While sharing the same motivation with the previous achievements, this study proposed non-parametric pattern matching techniques to reduce the uncertainty in pursuance of selection of models and modeling processes. This could be characterized by the following two aspects: First, for overcoming considering only a few typical scenarios in the most of the studies, this study is getting the entire sets of off-normal situations which are anticipated in NPPs, which are created by a full-scope simulator. Second, many of the existing researches adopted the process of forming a diagnosis model which is so-called a training technique or a parametric

  5. Integral effect test and code analysis on the cooling performance of the PAFS (passive auxiliary feedwater system) during an FLB (feedwater line break) accident

    Bae, Byoung-Uhn; Kim, Seok; Park, Yu-Sun; Kang, Kyoung-Ho

    2014-01-01

    Highlights: • This study focuses on the experimental validation of the operational performance of the PAFS (passive auxiliary feedwater system). • A transient simulation of the FLB (feedwater line break) in the integral effect test facility, ATLAS-PAFS, was performed to investigate thermal hydraulic behavior during the PAFS actuation. • The test result confirmed that the APR+ has the capability of coping with the FLB scenario by adopting the PAFS and proper set-points for its operation. • The experimental result was utilized to evaluate the prediction capability of a thermal hydraulic system analysis code, MARS-KS. - Abstract: APR+ (Advanced Power Reactor Plus), which is a GEN-III+ nuclear power plant developed in Korea, adopts PAFS (passive auxiliary feedwater system) as an advanced safety feature. The PAFS can completely replace an active auxiliary feedwater system by cooling down the secondary side of steam generators with a natural convection mechanism. This study focuses on experimental and analytical investigation for cooling and operational performance of the PAFS during an FLB (feedwater line break) transient with an integral effect test facility, ATLAS-PAFS. To realistically simulate the FLB accident of the APR+, the three-level scaling methodology was taken into account to design the test facility and determine the test condition. From the test result, the PAFS was actuated to successfully cool down the decay heat of the reactor core by the condensation heat transfer at the PCHX (passive condensation heat exchanger), and thus it could be confirmed that the APR+ has the capability of coping with a FLB scenario by adopting the PAFS and proper set-points for its operation. This integral effect test data were used to evaluate the prediction capability of a thermal hydraulic system analysis code, MARS-KS. The code analysis result proved that it could reasonably predict the FLB transient including the actuation of the PAFS and the natural convection

  6. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    Choi, In Kil; Kim, Min Kyu; Hofmayer, Charles; Braverman, Joseph; Nie, Jinsuo

    2009-03-01

    This report describes the research effort performed by BNL for the Year 2 scope of work. This research focused on methods that could be used to represent the long-term behavior of materials used at NPPs. To achieve this BNL reviewed time-dependent models which can approximate the degradation effects of the key materials used in the construction of structures and passive components determined to be of interest in the Year 1 effort. The intent was to review the degradation models that would cover the most common time-dependent changes in material properties for concrete and steel components

  7. Evaluation of Passive Containment Cooling System design of SMART built in GBS for ocean environment under the Fukushima Accident Condition

    Kim, Min Gil; Kim, Seong Gu; Lee, Jeong Ik; Lee, Kang Heon; Lee, Phil Seung [Korea Advanced Institue of Science and Technology, Daejeon (Korea, Republic of)

    2013-10-15

    The ONPP can be towed to the installation site after the SMART is constructed within the GBS in a dry dock. And, by incorporating IPSS (Integrated Passive Safety System), proposed by KAIST, in the ocean SMART the safety of the whole system will be significantly increased which can potentially eliminate any possibility of repeating Fukushima accident again. In recent years, KAIST research team is developing a very advanced concept of ocean NPPs which can avoid natural disasters while potentially increasing economy and enhancing public acceptance. Authors chose Korean small reactor, SMART as a reference system to demonstrate the feasibility of the proposed ocean NPP. Ocean SMART is mounted on GBS (Gravity Based Structure)

  8. Project investigation and analysis of soil-structure interaction effects in seismic response of NPPs EBO, EMO, Slovakia. Final report

    Juhasova, E.

    1999-01-01

    The work described in this report was devoted to investigation of expected seismic response of the structures of WWER-440/213 type NPPs, namely Mochovce and Bohunice. Special attention was devoted to the properties of subsoil materials and the transfer of seismic waves from the bedrock to the foundation structures. Theoretical background was elaborated and discussed for wave propagation of surface waves. Alternative procedure was derived for non-linear media accounting for complex modulus theory. Material characteristics of subsoils were investigated for both NPPs. The obtained results were used as a basis for forecasting and calculation of expected seismic response when the time history records from Paks explosion were used an input. It was pointed out that the used procedure, together with previous calculation of subsoil transfer characteristics completed well the comparison with experimental results

  9. Significant events during the year 2000 for French NPPs. Emphasis on reinforced regulatory supervision of Dampierre NPP

    Amri, A.

    2001-01-01

    Under DSIN request, since 1999 the French utility EDF started a programme to check the compliance of the current safety provisions with those expected at the design stage. 469 significant incidents for the French NPPs are declared. Two incidents, classified at INES 2 have occurred in 2000: errors in the operating procedures in Dampierre, Bugey and Tricastin NPPs which led to an anticipated unavailability of the safety injection system, while its availability is still required, and accumulation at the site of Tricastin of organizational and human malfunctions during a short time, revealing a lack of rigour. Results of the reinforced DSIN supervision like: effective management implication on the site, building of better human and social relationships, operating rigour still insufficient are presented

  10. Operating Experience of Digital, Software-based Components Used in I and C and Electrical Systems in German NPPs

    Blum, Stefanie; Lochthofen, Andre; Quester, Claudia; Arians, Robert

    2015-01-01

    In recent years, many components in instrumentation and control (I and C) and electrical systems of nuclear power plants (NPPs) were replaced by digital, software-based components. Due to the more complex structure, software-based I and C and electrical components show the potential for new failure mechanisms and an increasing number of failure possibilities, including the potential for common cause failures. An evaluation of the operating experience of digital, software-based components may help to determine new failure modes of these components. In this paper, we give an overview over the results of the evaluation of the operating experience of digital, software-based components used in I and C and electrical systems in NPPs in Germany. (authors)

  11. Passive House Solutions

    Strom, I.; Joosten, L.; Boonstra, C. [DHV Sustainability Consultants, Eindhoiven (Netherlands)

    2006-05-15

    PEP stands for 'Promotion of European Passive Houses' and is a consortium of European partners, supported by the European Commission, Directorate General for Energy and Transport. In this working paper an overview is given of Passive House solutions. An inventory has been made of Passive House solutions for new build residences applied in each country. Based on this, the most common basic solutions have been identified and described in further detail, including the extent to which solutions are applied in common and best practice and expected barriers for the implementation in each country. An inventory per country is included in the appendix. The analysis of Passive House solutions in partner countries shows high priority with regard to the performance of the thermal envelope, such as high insulation of walls, roofs, floors and windows/ doors, thermal bridge-free construction and air tightness. Due to the required air tightness, special attention must be paid to indoor air quality through proper ventilation. Finally, efficient ((semi-)solar) heating systems for combined space and DHW heating still require a significant amount of attention in most partner countries. Other basic Passive House solutions show a smaller discrepancy with common practice and fewer barriers have been encountered in partner countries. In the next section, the general barriers in partner countries have been inventoried. For each type of barrier a suggested approach has been given. Most frequently encountered barriers in partner countries are: limited know-how; limited contractor skills; and acceptation of Passive Houses in the market. Based on the suggested approaches to overcoming barriers, this means that a great deal of attention must be paid to providing practical information and solutions to building professionals, providing practical training to installers and contractors and communication about the Passive House concept to the market.

  12. Implementation of safety parameter display system on Russian NPPs with WWER reactors

    Dounaev, V.G.; Neboyan, V.T.

    1996-01-01

    This report gives a short overview of the status of safety parameter display systems (SPDS) implementation on Russian NPPs with WWER reactors and also discusses the SPDS, which is being developed for Kalinin NPP. The assessment of the safety status of the plant is done by the continuous monitoring of six critical safety functions and the corresponding status trees. Besides, a number of additional functions are realized within the scope of KlnNPP, aimed at providing the operator and the safety engineer in the main control room with more detailed information in accidental situation as well as during the normal operation. In particular, these functions are: archiving, data logs and alarm handling, safety actions monitoring, mnemonic diagrams indicating the state of main technological equipment and basic plant parameters, reference data, etc. Also, the operator support function ''computerized procedures'' is included in the scope of SPDS. The basic SPDS implementation platform is ADACS of SEMA GROUP design. The system architecture includes two workstations in the main control room: one is for reactor operator and the other one for safety engineer. Every station has two CRT screens which ensures computerized procedures implementation and provides for extra services for the operator. Also, the information from the SPDS is transmitted to the local crisis centre and to the crisis centre of the State utility organization concern ''Rosenergoatom''. (author). 3 refs

  13. Recent events in NPPs and incident reporting system (IRS) activity. Working material

    1996-01-01

    The IAEA convened the 1996 Joint Meeting to Exchange Information on Recent Events in Nuclear Power Plants and the Technical Committee-Annual Meeting of the Incident Reporting System (IRS) national co-ordinators, organized jointly with the Nuclear Energy Agency (NEA) of the OECD in Paris, France from 22-26 April 1996. These consecutive meetings took place at the OECD Headquarters, 2 rue Andre Pascal. The main objective of the first meeting (22-24 April 1996) was to exchange and discuss information on recent events which occurred in NPPs. The second meeting (25-26 April 1996) was devoted to the IAEA and NEA activity in the framework of the IRS. The main issues of the programme at the meetings were as follows: in-depth discussion on NPP recent events, presented by the participants; panel discussion on operational safety experience issues identified by the participants; IAEA and NEA activities on IRS subjects in 1995-1996 and plans for the future; issues from the inter-agency's IRS Advisory Committee. Annexes I and II provide more information on the programme at the meetings. A list of participants is given in Annex III (50 participants from 22 countries and 3 international organization). Annexes IV and V provide information on national presentations on recent events. Figs, tabs

  14. Online application of a risk management system for risk assessment and monitoring at NPPs

    Yang, Jun, E-mail: youngjun51@hotmail.com [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Yang, Ming, E-mail: yangming@hrbeu.edu.cn [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Wang, Wenlin, E-mail: wlwang0618@126.com [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Li, Fengjun, E-mail: leefengjun@163.com [China Nuclear Power Engineering Co. Ltd (China)

    2016-08-15

    Highlights: • A generic GO-FLOW modeling structure is proposed for easily Living PSA development and analysis. • Hierarchical and modularized scheme is applied in the development of Living PSA models and database. • A risk management system is developed by GO-FLOW method. • Functional testing is conducted on the risk management system for performance evaluation. • The fast solution time derived from Living PSA application is supportive in plant safety management. - Abstract: The paper presents a risk management system on the basis of Living PSA models which are developed under a proposed generic GO-FLOW modeling method with a hierarchical and modular structure. The design of the risk management system is aiming at assisting plant personnel to manage maintenance plan and system configuration, and conduct system reliability monitoring, risk monitoring and risk management quickly and conveniently through graphical user interfaces without going deep into the details of building, updating and analyzing reliability and risk models. The performance of the proposed risk management system was tested on a full-scale simulator of PWR nuclear power plant and demonstrated that the fast solution time derived from utilization of hierarchical and modularized Living PSA models is strongly supportive for instantaneous risk assessment as well as for daily risk management at NPPs.

  15. Design of the AM600 Turbine-Generator for NPPs in Emerging Markets

    Alexandru, Bogdan; Abdoelatef, M. Gomaa; Field, Robert

    2015-01-01

    In this paper, preliminary analysis related to: (i) the T/G steam flow path, and (ii) the turbine cycle heat balance is examined. Analysis of global electric markets indicates that the current and near term capacity of electrical grids for many developing countries (e.g., Bangladesh, Kenya, Vietnam, Malaysia) is insufficient to reliably incorporate Nuclear Power Plants (NPPs) with large unit sizes (e.g., >1000 MWe). Thus a modern NPP design with a smaller output (-600 MWe) is of interest. To address conditions for such markets, the 'AM600' Turbine-Generator (T/G) design proposed here represents a 600 MWe design which is robust and supports a simplified steam cycle. The proposed shaftline starts with a determination of the number of flows, followed by a determination of the number of high and low pressure stages, followed by heat balance analysis. The conceptual design for the AM600 T/G offers the following: • a stiff shaftline which can offer robust performance in smaller grids lacking optimal stability relative to grid disturbances and frequency variation, • a simplified approach to T/G fabrication, installation, operation, testing, inspections, and maintenance due to design with a single LPT cylinder while maintaining high thermal efficiency, and • a reduced component count for MSRs, FWHs, and power train pumps and drivers (and associated support system components) resulting in lower capital outlays, simplified operations, and further reducing the maintenance, testing, and inspection burden

  16. The development of basic technology for instrumentation and control in NPPs

    Ham, Chang Shik; Park, Jae Chang; Kim, Jung Taek; Lee, Dong Young; Jung, Chul Hwan; Hwang, In Koo; Kim, Jung Soo; Kim, Chang Hwoi; Na, Nan Ju; Kim, Inn S.; Park, Kee Yong

    1997-07-01

    The PWR plant operation is normally categorized into plant startup, low power operation, normal operation, cooldown operation. In these operation, however, startup and cooldown operation is performed manually according to the operation procedure. These manual operation is required to operator`s technical skills. And the manual operation can be occurred to operational errors because of operator`s workload during long duration. Automatic startup system, named by Automatic Startup Intelligent Control System (ASICS) is developed for reducing operator tasks, optimizing heatup operation, and enhancement of operation reliability and availability from cold shutdown to reactor power 5%. ADIOS has applied several alarm processing technologies, such as plant mode dependency, state dependence, direct precursor, and level precursor, etc. ADIOS has also applied a model-base diagnostic functions for operator to cope with major transients. To confirm a correctness of alarm processing techniques, prototype have been developed based on KORI 3 and YGN 3 PWR NPPs. The about 3000 alarm objects have been represented as knowledge base in the prototypes. The alarm window like tile for the safety-related alarms, primary and secondary schematic display, and detailed system-level schematic display have been designed. Also ADIOS prototype based on YGN 3 PWR has evaluated a performance of human factor engineering using KAERI-ITF (KAERI-Integrated Test Facility). (author). 72 refs., 32 tabs., 85 figs.

  17. Management of safety and safety culture at the NPPs of Ukraine

    Koltakov, Vladimir

    2002-01-01

    The report contains general aspects of safety and safety culture. The brief description of operational characteristics and basic indexes of atomic power plants at the Ukraine are represented. The information referring to structure of NPPs of Operation organization license-holder, safety responsibility of both Regulatory and Utility Bodies also is given. The main part of the report include seven sections: 1. Practical application of safety management models; 2. erspective on the relationship between safety management and safety culture; 3. The role of leadership in achieving high standards of safety; 4. Current and future challengers that impact on safety culture and safety management (e.g. the impact of competition, changing, economic and political circumstances, workforce demographics, etc.); 5. Key lessons learned from major events; 6. Practical applications of safety culture concepts (e.g. learning organizations, training staff communications, etc.); 7. dvance in human performance. Some of the main pending safety and safety culture problems that are necessary to achieve in the near future are mentioned

  18. Design of the AM600 Turbine-Generator for NPPs in Emerging Markets

    Alexandru, Bogdan; Abdoelatef, M. Gomaa; Field, Robert [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2015-10-15

    In this paper, preliminary analysis related to: (i) the T/G steam flow path, and (ii) the turbine cycle heat balance is examined. Analysis of global electric markets indicates that the current and near term capacity of electrical grids for many developing countries (e.g., Bangladesh, Kenya, Vietnam, Malaysia) is insufficient to reliably incorporate Nuclear Power Plants (NPPs) with large unit sizes (e.g., >1000 MWe). Thus a modern NPP design with a smaller output (-600 MWe) is of interest. To address conditions for such markets, the 'AM600' Turbine-Generator (T/G) design proposed here represents a 600 MWe design which is robust and supports a simplified steam cycle. The proposed shaftline starts with a determination of the number of flows, followed by a determination of the number of high and low pressure stages, followed by heat balance analysis. The conceptual design for the AM600 T/G offers the following: • a stiff shaftline which can offer robust performance in smaller grids lacking optimal stability relative to grid disturbances and frequency variation, • a simplified approach to T/G fabrication, installation, operation, testing, inspections, and maintenance due to design with a single LPT cylinder while maintaining high thermal efficiency, and • a reduced component count for MSRs, FWHs, and power train pumps and drivers (and associated support system components) resulting in lower capital outlays, simplified operations, and further reducing the maintenance, testing, and inspection burden.

  19. Development of an Objective Measurement Method for Situation Awareness of Operation Teams in NPPs

    Lee, Seung Woo; Kim, Ar Ryum; Kim, Hyoung Ju; Seong, Poong Hyun; Park, Jin Kyun

    2011-01-01

    Situation awareness (SA) continues to receive a considerable amount of attention from the ergonomics community since the need for operators to maintain SA is frequently cited as a key to effective and efficient performance. Even though complex and dynamic environments such as main control room (MCR) in the nuclear power plants (NPPs) is operated in teams and still SA which teams posses is important, research is currently focused on individual SA not for team situation awareness (TSA). Since there are not many measurement methods developed for TSA, individual SA measurement methods are at first reviewed and the critical requirements which new TSA measurements should consider are derived. With an assumption that TSA is an integration of individual SA, a new and objective TSA measurement method is developed. This method is developed mainly based on logical connections between TSA and team communication and implements verbal protocol analysis. This method provides measure for each level of TSA. By performing preliminary analysis with this method, it was shown that this method is feasible to some extent

  20. Development of an Objective Measurement Method for Situation Awareness of Operation Teams in NPPs

    Lee, Seung Woo; Kim, Ar Ryum; Kim, Hyoung Ju; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Park, Jin Kyun [KAERI, Daejeon (Korea, Republic of)

    2011-08-15

    Situation awareness (SA) continues to receive a considerable amount of attention from the ergonomics community since the need for operators to maintain SA is frequently cited as a key to effective and efficient performance. Even though complex and dynamic environments such as main control room (MCR) in the nuclear power plants (NPPs) is operated in teams and still SA which teams posses is important, research is currently focused on individual SA not for team situation awareness (TSA). Since there are not many measurement methods developed for TSA, individual SA measurement methods are at first reviewed and the critical requirements which new TSA measurements should consider are derived. With an assumption that TSA is an integration of individual SA, a new and objective TSA measurement method is developed. This method is developed mainly based on logical connections between TSA and team communication and implements verbal protocol analysis. This method provides measure for each level of TSA. By performing preliminary analysis with this method, it was shown that this method is feasible to some extent.

  1. A Strategy for Accomplishing Human-Performance Monitoring of Constructing NPPs

    Sung, Chanho; Jung, Yeonsub [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The main purpose of HPM(Human performance monitoring) is that no significant safety degradation occurs due to changes in design, procedures, training, or staffing during the plant operation. Accordingly, the strategy for accomplishing HPM should be to maintain the acceptable level of human performance for safety operation. This paper presents a strategy to fulfill HPM effectively for constructing NPPs in Korea. Activities for HPM in constructing plants need to be divided into two large parts on the basis of the fuel loading, which could be a good strategy to accomplish HPM effectively. That is, the activities such as making HPM plan and developing its indexes are performed before the fuel loading, while the activities of maintaining acceptable HP levels are conducted after the fuel loading. This HPM strategy includes not only maintaining the criteria of human performance established during ISV, but also improving human performance through existing activities during the plant operation. Constructing plants will also make actively use of the existing programs for enhancing human performance.

  2. The development of basic technology for instrumentation and control in NPPs

    Ham, Chang Shik; Park, Jae Chang; Kim, Jung Taek; Lee, Dong Young; Jung, Chul Hwan; Hwang, In Koo; Kim, Jung Soo; Kim, Chang Hwoi; Na, Nan Ju; Kim, Inn S.; Park, Kee Yong.

    1997-07-01

    The PWR plant operation is normally categorized into plant startup, low power operation, normal operation, cooldown operation. In these operation, however, startup and cooldown operation is performed manually according to the operation procedure. These manual operation is required to operator's technical skills. And the manual operation can be occurred to operational errors because of operator's workload during long duration. Automatic startup system, named by Automatic Startup Intelligent Control System (ASICS) is developed for reducing operator tasks, optimizing heatup operation, and enhancement of operation reliability and availability from cold shutdown to reactor power 5%. ADIOS has applied several alarm processing technologies, such as plant mode dependency, state dependence, direct precursor, and level precursor, etc. ADIOS has also applied a model-base diagnostic functions for operator to cope with major transients. To confirm a correctness of alarm processing techniques, prototype have been developed based on KORI 3 and YGN 3 PWR NPPs. The about 3000 alarm objects have been represented as knowledge base in the prototypes. The alarm window like tile for the safety-related alarms, primary and secondary schematic display, and detailed system-level schematic display have been designed. Also ADIOS prototype based on YGN 3 PWR has evaluated a performance of human factor engineering using KAERI-ITF (KAERI-Integrated Test Facility). (author). 72 refs., 32 tabs., 85 figs

  3. Method of V ampersand V for safety-critical software in NPPs

    Kim, Jang-Yeol; Lee, Jang-Soo; Kwon, Kee-Choon

    1997-01-01

    Safety-critical software is software used in systems in which a failure could affect personal or equipment safety or result in large financial or social loss. Examples of systems using safety-critical software are systems such as plant protection systems in nuclear power plants (NPPs), process control systems in chemical plants, and medical instruments such as the Therac-25 medical accelerator. This paper presents verification and validation (V ampersand V) methodology for safety-critical software in NPP safety systems. In addition, it addresses issues related to NPP safety systems, such as independence parameters, software safety analysis (SSA) concepts, commercial off-the-shelf (COTS) software evaluation criteria, and interrelationships among software and system assurance organizations. It includes the concepts of existing industrial standards on software V ampersand V, Institute of Electrical and Electronics Engineers (IEEE) Standards 1012 and 1059. This safety-critical software V ampersand V methodology covers V ampersand V scope, a regulatory framework as part of its acceptance criteria, V ampersand V activities and task entrance and exit criteria, reviews and audits, testing and quality assurance records of V ampersand V material, configuration management activities related to V ampersand V, and software V ampersand V (SVV) plan (SVVP) production

  4. Comparative Study of Communication Error between Conventional and Digital MCR Operators in NPPs

    Kim, Seung Geun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2015-05-15

    In this regard, the appropriate communication is directly related to the efficient and safe system operation, and inappropriate communication is one of the main causes of the accidents in various industries since inappropriate communications can cause a lack of necessary information exchange between operators and lead to serious consequences in large process systems such as nuclear power plants. According to the study conducted by Y. Hirotsu in 2001, about 25 percents of human error caused incidents in NPPs were related to communication issues. Also, other studies were reported that 85 percents of human error caused incidents in aviation industry and 92 percents in railway industry were related to communication problems. Accordingly, the importance of the efforts for reducing inappropriate communications has been emphasized in order to enhance the safety of pre-described systems. As a result, the average ratio of inappropriate communication in digital MCRs was slightly higher than that in conventional MCRs when the average ratio of no communication in digital MCRs was much smaller than that in conventional MCRs. Regarding the average ratio of inappropriate communication, it can be inferred that operators are still more familiar to the conventional MCRs than digital MCRs. More case studies are required for more delicate comparison since there were only three examined cases for digital MCRs. However, similar result is expected because there are no differences in communication method, although there are many differences in the way of procedure proceeding.

  5. Reliability analysis of road network for estimation of public evacuation time around NPPs

    Bang, Sun-Young; Lee, Gab-Bock; Chung, Yang-Geun [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2007-07-01

    The most strong protection method of radiation emergency preparedness is the evacuation of the public members when a great deal of radioactivity is released to environment. After the Three Mile Island (TMI) nuclear power plant meltdown in the United States and Chernobyl nuclear power plant disaster in the U.S.S.R, many advanced countries including the United States and Japan have continued research on estimation of public evacuation time as one of emergency countermeasure technologies. Also in South Korea, 'Framework Act on Civil Defense: Radioactive Disaster Preparedness Plan' was established in 1983 and nuclear power plants set up a radiation emergency plan and have regularly carried out radiation emergency preparedness trainings. Nonetheless, there is still a need to improve technology to estimate public evacuation time by executing precise analysis of traffic flow to prepare practical and efficient ways to protect the public. In this research, road network for Wolsong and Kori NPPs was constructed by CORSIM code and Reliability analysis of this road network was performed.

  6. Current status and future expectation concerning probabilistic risk assessment of NPPs. 1. Features and issues of probabilistic risk assessment methodology

    Yamashita, Masahiro

    2012-01-01

    Probabilistic risk assessment (PRA) of Nuclear Power Plants (NPPs) could play an important role in assuring safety of NPPs. However PRA had not always effectively used, which was indicated in Japanese government's report on Fukushima Daiichi NPP accident. At the Risk Technical Committee (RTC) of Standards Committee of Atomic Energy Society of Japan, preparation of standards (implementing criteria) focusing on PRA methodology and investigation on basic philosophy for use of PRA had been in progress. Based on activities of RTC, a serial in three articles including this described current status and future expectation concerning probabilistic risk assessment of NPPs. This article introduced features and issues of PRA methodology related to the use of PRA. Features of PRA methodology could be shown as (1) systematic and comprehensive understanding of risk, (2) support of grading approach, (3) identification of effective safety upgrade measures and (4) quantitative understanding of effects of uncertainty. Issues of PRA methodology were (1) extension of PRA application area, (2) upgrade of PRA methodology, (3) quality assurance of PRA, (4) treatment of uncertainty and (5) quantitative evaluation criteria. (T. Tanaka)

  7. Measure Guideline: Passive Vents

    Berger, David [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Neri, Robin [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-05

    This document addresses the use of passive vents as a source of outdoor air in multifamily buildings. The challenges associated with implementing passive vents and the factors affecting performance are outlined. A comprehensive design methodology and quantified performance metrics are provided. Two hypothetical design examples are provided to illustrate the process. This document is intended to be useful to designers, decision-makers, and contractors implementing passive ventilation strategies. It is also intended to be a resource for those responsible for setting high-performance building program requirements, especially pertaining to ventilation and outdoor air. To ensure good indoor air quality, a dedicated source of outdoor air is an integral part of high-performance buildings. Presently, there is a lack of guidance pertaining to the design and installation of passive vents, resulting in poor system performance. This report details the criteria necessary for designing, constructing, and testing passive vent systems to enable them to provide consistent and reliable levels of ventilation air from outdoors.

  8. Application of the integral code MELCOR for German NPPs and use within accident management and PSA projects

    Sonnenkalb, Martin

    2006-01-01

    The paper summarizes the application of MELCOR to German NPPS with PWR and BWR. A development of different code systems like ATHLET/ATHLET-CD, COCOSYS and ASTEC is done as well at GRS but it is not discussed in this paper. GRS has been using MELCOR since 1990 for real plant calculations. The results of MELCOR analyses are used mainly in PSA level 2 studies and in Accident Management projects for both types of NPPs. MELCOR has been a very useful and robust tool for these analyses. The calculations performed within the PSA level 2 studies for both types of German NPPs have shown that typical severe accident scenarios are characterized by several phases and that the consideration of plant specifics are important not only for realistic source term calculations. An overview of typically severe accident phases together with main accident management measures installed in German NPPs is presented in the paper. Several severe accident sequences have been calculated for both reactor types and some detailed nodalisation studies and code to code comparisons have been prepared in the past, to prove the developed core, reactor circuit and containment/building nodalisation schemes. Together with the compilation of the MELCOR data set, the qualification of the nodalisation schemes has been pursued with comparative calculations with detailed GRS codes for selected phases of severe accidents. The results of these comparative analyses showed in most of the areas a good agreement of essential parameters and of the general description of the plant behaviour during the accident progression. The in general detail of the German plant nodalisation schemes developed for MELCOR contributes significantly to this good agreement between integral and detailed code results. The implementation of MELCOR into the GRS simulator ATLAS was very important for the assessment of the results, not only due to the great detail of the nodalisation schemes used. It is used for training of severe accident

  9. Constructing passive houses

    Oehler, S. [Oehler Faigle Archkom Solar Architektur, Bretten (Germany)

    2005-07-01

    Everybody can learn to build energy-efficient. It needs theoretical and practical experience. 1997 we built the first freestanding Passive House in Europe, the Passive House Oehler. There had been a lot of questions, starting with the insecurity, whether the calculation program of the Passive House Institute, the PHPP, is working properly in our case. Nobody knew at that time because nobody tried it out before. It took us a lot of time to find out and every detail of the construction hat to be invented to meet the very high demand of thermal quality. All the following houses needed less time and had fewer open questions, adding one piece of experience with every building. 2002 we realised the biggest Passive House, the office building Energon Ulm with 420 working spaces. In the meantime we have learned a lot like how to produce prefabricated timber elements for the facades, providing good insulation, air tightness and avoiding serious thermal bridges. We have proofed, that any kind of building type can be a Passive House. And with increasing experience the freedom of design and construction is growing. Even the economical efficiency increased. The Energon Ulm is providing a much better indoor climate than any other office building and was build 10 % cheaper than an average German office building. At present the Passive House Standard is the most efficient solution for the user to live in the desired comfort zone between 20 C and 25 C. This zone of individual feeling-well can be described with the term ''operative temperature''. This term is defined by factors like air temperature, radiation temperature of warm and cold surfaces, air speed and humidity. The result of all these factors has to be within 18 C to 25 C without accepting one of the factors getting extreme.

  10. Passive containment system

    Kleimola, F.W.

    1977-01-01

    Disclosed is a containment system that provides complete protection entirely by passive means for the loss of coolant accident in a nuclear power plant and wherein all stored energy released in the coolant blowdown is contained and absorbed while the nuclear fuel is prevented from over-heating by a high containment back-pressure and a reactor vessel refill system. The primary containment vessel is restored to a high sub-atmospheric pressure within a few minutes after accident initiation and the decay heat is safely transferred to the environment while radiolytic hydrogen is contained by passive means. 20 claims, 14 figures

  11. Wireless passive radiation sensor

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  12. Performance Analysis of AP1000 Passive Systems during Direct Vessel Injection (DVI Line Break

    A.S. Ekariansyah

    2016-08-01

    Full Text Available Generation II Nuclear Power Plants (NPPs have a design weakness as shown by the Fukushima accident. Therefore, Generation III+ NPPs are developed with focus on improvements of fuel technology and thermal efficiency, standardized design, and the use of passive safety system. One type of Generation III+ NPP is the AP1000 that is a pressurized water reactor (PWR type that has received the final design acceptance from US-NRC and is already under construction at several sites in China as of 2015. The aim of this study is to investigate the behavior and performance of the passive safety system in the AP1000 and to verify the safety margin during the direct vessel injection (DVI line break as selected event. This event was simulated using RELAP5/SCDAP/Mod3.4 as a best-estimate code developed for transient simulation of light water reactors during postulated accidents. This event is also described in the AP1000 design control document as one of several postulated accidents simulated using the NOTRUMP code. The results obtained from RELAP5 calculation was then compared with the results of simulations using the NOTRUMP code. The results show relatively good agreements in terms of time sequences and characteristics of some injected flow from the passive safety system. The simulation results show that the break of one of the two available DVI lines can be mitigated by the injected coolant flowing, which is operated effectively by gravity and density difference in the cooling system and does not lead to core uncovery. Despite the substantial effort to obtain an apropriate AP1000 model due to lack of detailed geometrical data, the present model can be used as a platform model for other initiating event considered in the AP1000 accident analysis.

  13. Simultaneous and multi-criteria optimization of TS requirements and maintenance at NPPs

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

    2002-01-01

    One of the main concerns of the nuclear industry is to improve the availability of safety-related systems at nuclear power plants (NPPs) to achieve high safety levels. The development of efficient testing and maintenance has been traditionally one of the different ways to guarantee high levels of systems availability, which are implemented at NPP through technical specification and maintenance requirements (TS and M). On the other hand, there is a widely recognized interest in using the probabilistic risk analysis (PRA) for risk-informed applications aimed to emphasize both effective risk control and effective resource expenditures at NPPs. TS and M-related parameters in a plant are associated with controlling risk or with satisfying requirements, and are candidate to be evaluated for their resource effectiveness in risk-informed applications. The resource versus risk-control effectiveness principles formally enter in optimization problems where the cost or the burden for the plant staff is to be minimized while the risk or the availability of the safety equipment is constrained to be at a given level, and vice versa. Optimization of TS and M has been found interesting from the very beginning. However, the resolution of such a kind of optimization problem has been limited to focus on only individual TS and M-related parameters (STI, AOT, PM frequency, etc.) and/or adopting an individual optimization criterion (availability, costs, plant risks, etc.). Nevertheless, a number of reasons exist (e.g. interaction, similar scope, etc.) that justify the growing interest in the last years to focus on the simultaneous and multi-criteria optimization of TS and M. In the simultaneous optimization of TS and M-related parameters based on risk (or unavailability) and cost, like in many other engineering optimization problems, one normally faces multi-modal and non-linear objective functions and a variety of both linear and non-linear constraints. Genetic algorithms (GAs) have

  14. Proceedings of the 4. European Workshop on Occupational Exposure Management at NPPs (ISOE '04)

    D' Ascenzo, Lucie [ISOE ETC - CEPN, BP 48, 92263 Fontenay-aux-Roses Cedex (France)

    2004-07-01

    of radiological protection departments, provide means for benchmarking, create consistency between sites; 5. The radiological protection teams should increase their assistance 'patrols' at workplaces. For the first time, two specific meetings have preceded the workshop: - one for the radiological protection managers from the NPPs; 30 participants attended that meeting; - one for the senior representatives of the authorities; two topics were discussed there, the management of outside workers and the use of ISOE by the regulatory bodies. In conclusion, the success of this Workshop was largely due to the important organisational support from EDF in particular in providing the translation from English to French and French to English, while Framatome and COGEMA Logistics provided the other translations from German and Spanish to English. Many other papers proposed important and interesting conclusions and feedback experience analysis. The workshop had the following structure: Introductory Session; Session 1 - Radiation Protection in the design and modification of installations; Session 2 - Dose trends and dispersion analysis; Session 3 - Evolution of dosimetry at NPPs; Session 4 - ALARA implementation in nuclear installations; Session 5 - Optimisation tools and techniques; 19 Posters.

  15. Proceedings of the 4. European Workshop on Occupational Exposure Management at NPPs (ISOE '04)

    D' Ascenzo, Lucie [ISOE ETC - CEPN, BP 48, 92263 Fontenay-aux-Roses Cedex (France)

    2004-07-01

    protection departments, provide means for benchmarking, create consistency between sites; 5. The radiological protection teams should increase their assistance 'patrols' at workplaces. For the first time, two specific meetings have preceded the workshop: - one for the radiological protection managers from the NPPs; 30 participants attended that meeting; - one for the senior representatives of the authorities; two topics were discussed there, the management of outside workers and the use of ISOE by the regulatory bodies. In conclusion, the success of this Workshop was largely due to the important organisational support from EDF in particular in providing the translation from English to French and French to English, while Framatome and COGEMA Logistics provided the other translations from German and Spanish to English. Many other papers proposed important and interesting conclusions and feedback experience analysis. The workshop had the following structure: Introductory Session; Session 1 - Radiation Protection in the design and modification of installations; Session 2 - Dose trends and dispersion analysis; Session 3 - Evolution of dosimetry at NPPs; Session 4 - ALARA implementation in nuclear installations; Session 5 - Optimisation tools and techniques; 19 Posters.

  16. Proceedings of the 4. European Workshop on Occupational Exposure Management at NPPs (ISOE '04)

    D'Ascenzo, Lucie

    2004-01-01

    protection departments, provide means for benchmarking, create consistency between sites; 5. The radiological protection teams should increase their assistance 'patrols' at workplaces. For the first time, two specific meetings have preceded the workshop: - one for the radiological protection managers from the NPPs; 30 participants attended that meeting; - one for the senior representatives of the authorities; two topics were discussed there, the management of outside workers and the use of ISOE by the regulatory bodies. In conclusion, the success of this Workshop was largely due to the important organisational support from EDF in particular in providing the translation from English to French and French to English, while Framatome and COGEMA Logistics provided the other translations from German and Spanish to English. Many other papers proposed important and interesting conclusions and feedback experience analysis. The workshop had the following structure: Introductory Session; Session 1 - Radiation Protection in the design and modification of installations; Session 2 - Dose trends and dispersion analysis; Session 3 - Evolution of dosimetry at NPPs; Session 4 - ALARA implementation in nuclear installations; Session 5 - Optimisation tools and techniques; 19 Posters

  17. Periodic Verification of the Scaling Factor for Radwastes in Korean NPPs - 13294

    Park, Yong Joon; Ahn, Hong Joo; Song, Byoung Chul; Song, Kyuseok [Korea Atomic Energy Research Institute, P.O. Box 105, Yuseong, Daejeon, 305-330 (Korea, Republic of)

    2013-07-01

    According to the acceptance criteria for a low and intermediate level radioactive waste (LILW) listed in Notice No. 2012-53 of the Nuclear Safety and Security Commission (NSSC), specific concentrations of radionuclides inside a drum has to be identified and quantified. In 5 years of effort, scaling factors were derived through destructive radiochemical analysis, and the dry active waste, spent resin, concentration bottom, spent filter, and sludge drums generated during 2004 ∼ 2008 were evaluated to identify radionuclide inventories. Eventually, only dry active waste among LILWs generated from Korean NPPs were first shipped to a permanent disposal facility on December 2010. For the LILWs generated after 2009, the radionuclides are being radiochemically quantified because the Notice clarifies that the certifications of the scaling factors should be verified biennially. During the operation of NPP, the radionuclides designated in the Notice are formed by neutron activation of primary coolant, reactor structural materials, corrosion products, and fission products released into primary coolant through defects or failures in fuel cladding. Eventually, since the radionuclides released into primary coolant are transported into the numerous auxiliary and support systems connected to primary system, the LILWs can be contaminated, and the radionuclides can have various concentration distributions. Thus, radioactive wastes, such as spent resin and dry active waste generated at various Korean NPP sites, were sampled at each site, and the activities of the regulated radionuclides present in the sample were determined using radiochemical methods. The scaling factors were driven on the basis of the activity ratios between a or β-emitting nuclides and γ-emitting nuclides. The resulting concentrations were directly compared with the established scaling factors' data using statistical methods. In conclusions, the established scaling factors were verified with a reliability

  18. Development of radionuclide inventory estimation method using scaling factor for the Korean NPPs: scope and status

    Hwang, Ki Ha; Lee, Sang Chul; Kang, Sang Hee; Lee, Kun Jai; Jeong, Chan Woo; Ahn, Sang Myeon; Kim, Tae Wook; Kim, Kyoung Doek; Herr, Y. H.

    2003-01-01

    Regulations and guidelines for radionuclide waste disposal require detailed information about the characteristics of radioactive waste drums prior to the transport to the disposal sites. Therefore, it is important to know the accurate radionuclide inventory of radioactive waste. However, estimation of radionuclide concentrations on drummed radioactive waste is difficult and unreliable. In order to overcome these difficulties, scaling factors have been used to assess the activities of radionuclides which could not be directly analyzed. A radionuclides assay system has been operated at Korean nuclear power plant (KORI site) since 1996 and consolidated scaling factor concept has played a dominant role in determination of radionuclides concentrations. For corrosion product radionuclides, generic scaling factors were used due to the similar trend and better-characterized properties of Korean analyzed data compared to the worldwide database. It is not easy to use the generic scaling factors for fission product and TRU radionuclides. Thus simple model reflecting the history of the operation of power plant and nuclear fuel condition is applied. However, some problems are still remained. For examples, disparity between the actual and ideal correlation pairs, inaccuracy of analyzed sample values, uncertainty in representative of derived scaling factor values and so on. As a result, the correlation ratios are somewhat dispersive. So it is planned to establish an assay system using more improved scaling factors. In this study, the scope of research is expanded and planned such as following. 1) Considering more assay target nuclides, 2) Considering more target NPPs, 3) More reliable sampling and measurement techniques, 4) Improvement of accuracy and representativeness of derived scaling factor values and 5) Conformation of correlation pairs based on Korean analyzed data. As this study progresses, it is possible to get more accurate and reliable prediction for the information of

  19. Fault Detection Coverage Quantification of Automatic Test Functions of Digital I and C System in NPPs

    Choi, Jong Gyun; Lee, Seung Jun; Hur, Seop; Lee, Young Jun; Jang, Seung Cheol

    2011-01-01

    Recently, analog instrument and control (I and C) systems in nuclear power plants (NPPs) have been replaced with digital systems for safer and more efficient operations. Digital I and C systems have adopted various fault-tolerant techniques that help the system correctly and safely perform the specific required functions in spite of the presence of faults. Each fault-tolerant technique has a different inspection period from real-time monitoring to monthly testing. The range covered by each fault-tolerant technique is also different. The digital I and C system, therefore, adopts multiple barriers consisting of various fault-tolerant techniques to increase total fault detection coverage. Even though these fault-tolerant techniques are adopted to ensure and improve the safety of a system, their effects have not been properly considered yet in most PSA models. Therefore, it is necessary to develop an evaluation method that can describe these features of a digital I and C system. Several issues must be considered in the fault coverage estimation of a digital I and C system, and two of them were handled in this work. The first is to quantify the fault coverage of each fault-tolerant technique implemented in the system, and the second is to exclude the duplicated effect of fault-tolerant techniques implemented simultaneously at each level of the system's hierarchy, as a fault occurring in a system might be detected by one or more fault-tolerant techniques. For this work, fault injection experiment was used to obtain the exact relations between faults and multiple barriers of fault-tolerant techniques. This experiment was applied to a bistable processor (BP) of a reactor protection system

  20. Application of synthetic fire-resistant oils in oil systems of turbine equipment for NPPs

    Galimova, L. A.

    2017-10-01

    Results of the investigation of the synthetic fire-resistant turbine oil Fyrquel-L state in oil systems of turbosets under their operation in the equipment and oil supply facilities of nuclear power plants (NPPs) are presented. On the basis of the analysis of the operating experience, it is established that, for reliable and safe operation of the turbine equipment, at which oil systems synthetic fire-resistant oils on the phosphoric acid esters basis are used, special attention should be paid to two main factors, namely, both the guarantee of the normalized oil water content under the operation and storage and temperature regime of the operation. Methods of the acid number maintenance and reduction are shown. Results of the analysis and investigation of influence of temperature and of the variation of the qualitative state of the synthetic fair-resistant oil on its water content are reported. It is shown that the fire-resistant turbine oils are characterized by high hydrophilicity, and, in distinction to the mineral turbine oils, are capable to contain a significant amount of dissolved water, which is not extracted under the use of separation technologies. It is shown that the more degradation products are contained in oil and higher acid number, the more amount of dissolved water it is capable to retain. It is demonstrated that the organization of chemical control of the total water content of fireresistant oils with the use of the coulometric method is an important element to support the reliable operation of oil systems. It is recommended to use automatic controls of water content for organization of daily monitoring of oil state in the oil system. Recommendations and measures for improvement of oil operation on the NPP, the water content control, the use of oil cleaning plants, and the oil transfer for storage during repair works are developed.

  1. The Role of Occupational Health and Safety in Complex Outage Services to NPPs

    Rozman, A.; Androjna, A.

    2010-01-01

    Meeting outage schedules in NPPs which are increasingly demanding, apart from all other aspects, introduces a new perspective on occupational health and safety (OHS). Not only is the OHS a constituent part of a plant's overall outage management, it above all dictates paramount objectives to outage service providers. The paper reviews the impacts of reductions of outage durations on OHS and presents related experience of the leading Slovenian outage services provider, NUMIP d.o.o. over the last ten years. The company is now getting prepared for its 12th outage at Krsko NPP in 2010, and has not have recorded a major injury so far, even though these projects engaged over 450 people at a time on-site. To achieve such results, a lot of emphasis is being put onto OHS management prior to and during outages. A certified OHSAS 18001 system has been established and implemented to further support preparation and execution of NUMIP's outage activities at Krsko NPP, and also for other projects. An effective continuous improvement system is built into the project, providing for implementation of lessons learned from domestic and foreign plants. To illustrate the topic in more detail, a case on a Seismic protection of polar crane project is presented. It took place in the 2009 Outage and has certainly been one of the most demanding projects from the OHS point of view for NUMIP so far. The paper aims at contributing to a better understanding of the role of effective management of OHS on the side of a service provider, and, consequently, in the overall outage success of a plant.(author).

  2. Development of accident sequence precursors methodologies for core damage Probabilities in NPPs

    Munoz, R.; Minguez, E.; Melendez, E.; Sanchez-Perea, M.; Izquierdo, J.M.

    1998-01-01

    Several licensing programs have focused on the evaluation of the importance of operating events occurred in NPPs. Some have worked the dynamic aspects of the sequence of events involved, reproducing the incidents, while others are based on PSA applications to incident analysis. A method that controls the two above approaches to determine risk analysis derives from the Integrated Safety Assessment methodology (ISA). The dynamics of the event is followed by transient simulation in tree form, building a Setpoint or Deterministic Dynamic Event Tree (DDET). When a setpoint is reached, the actuation of a protection is triggered, then the tree is opened in branches corresponding to different functioning states. The engineering simulator with the new states followers each branch. One of these states is the nominal one, which is the PSA is associated to the success criterion of the system. The probability of the sequence is calculated in parallel to the dynamics. The following tools should perform the couple simulation: 1. A Scheduler that drives the simulation of the different sequences, and open branches upon demand. It will be the unique generator of processes while constructing the tree calculation, and will develop the computation in a distributed computational environment. 2. The Plant Simulator, which models the plant systems and the operator actions throughout a sequence. It receives the state of the equipment in each sequence and must provide information about setpoint crossing to the Scheduler. It will receive decision flags to continue or to stop each sequence, and to send new conditions to other plant simulators. 3. The Probability Calculator, linked only to the Scheduler, is the fault trees associated with each event tree header and performing their Boolean product. (Author)

  3. Strategy of Risk-Informed Inspection for Secondary Systems in NPPs

    Kim, So Young; Heo, Gyun Young

    2012-01-01

    Recently, unexpected accidents such as large-scale blackout have been occurred due to increasing demand of electricity. The unplanned trips have great influence over the economics although they rarely affect the safety of system. Because the cost for inspection and maintenance is limited, it is beneficial not only economically to take follow-up action in a timely manner to prevent plant trip but also in safety by protecting against the risk which is occurred from trip. In nuclear power plants (NPPs), the importance about risk-informed service such as inspection, maintenance and replacement is becoming on the rise. Risk-informed techniques such as in-service test, in-service inspection, design guide change and etc. are already used in nuclear field but these techniques are applied focusing on primary system for safety-related regulatory issues. It is needed to consider the optimization of inspection informed risk for entire plant including secondary system which is not applied enough. The study about risk-based inspection for boilers in thermal power field is in progress actively, but not for turbine cycle, which is similar with nuclear industry. Today, the most of inspections or tests for turbine cycle are time-based maintenance, being performed on time. It is required to perform condition-based maintenance by evaluating risk analyzing both of probability and consequence simultaneously about damage mechanisms that can be predicted by equipment or devices configuring the secondary system. Probability of failure (POF) is analyzed in terms of materials' ageing mechanisms, but consequence of failure (COF) should be evaluated in terms of thermohydraulic condition then it is needed to check power loss and period of maintenance. This paper is going to propose the idea to quantify the consequence of failure using the fault tree and simulation for secondary system, and propose quantitative risk-informed inspection by these approaches

  4. State-of-the-Art: Evolution of Software Life Cycle Process for NPPs

    Suh, Yong Suk; Park, Heui Youn; Son, Ki Sung; Lee, Ki Hyun; Kim, Hyeon Soo

    2007-01-01

    This paper is to investigate the evolution of software life cycle process (SLCP) for nuclear power plants (NPPs) based on IEEE Std 7-4.3.2 which has been updated twice (namely 1993 and 2003 ) since it was published in 1982 and relevant software certifications. IEEE Std 7-4.3.2 specifies additional computer specific requirements to supplement the criteria and requirements of IEEE Std 603. It also specifies the software quality requirements as follows: computer software shall be developed, modified, or accepted in accordance with an approved software quality assurance (QA) plan. IEEE Std 7-4.3.2-1982 specifies a minimum software development process as follows: plan, design and implementation. ANSI/ASME NQA-1-1979 is not directly related to software development process but to overall quality assurance criteria. IEEE Std 7-4.3.2-1993 addresses ASME NQA-2a-1990 Part 2.7 for software development requirements. ASME NQA-2a-1990 Part 2.7 which was interpreted into KEPIC QAP-2 II.7, specifies software development process in more detail as follows: requirements, design, implementation, test, installation and checkout, operation and maintenance, and retirement. Along with this, software QA plan is emphasized in IEEE Std 730-1989. In IEEE Std 7-4.3.2-2003, IEEE/EIA Std 12207.0-1996 replaces the ASME NQA as a requirement for software development. The evolution of SLCP from ASME NQA to IEEE/EIA Std 12207.0 is discussed in Section 2 of this paper. The publication of IEEE/EIA Std 12207.0 is motivated from industrial experiences and practices to promote the quality of software. In Section 3, three international software certifications relating to the IEEE/EIA Std 12207.0 are introduced

  5. Information about environmental effects of Bohunice NPPs V-1 and V-2 within February 2002

    2002-01-01

    In this leaflet the results of monitoring of chemical gaseous and liquid effluents into the rivers Vah and Dudvah as well as of radiation monitoring of Bohunice V-1 and V-2 NPPs are presented. The radioactive effluents within a February 2002 (for NPP V-1 and NPP V-2, respectively) were: 0.571 TBq and 0.664 TBq of rare gases, 0.711 MBq and 0.244 MBq of aero-soles, 2.121 MBq and 0.138 MBq of iodine, 2.022 MBq and 0.564 MBq of corrosive and fission products, and 1.420 TBq and 1.643 TBq of tritium. For the period January - February 2002 these radioactive effluents represent for rare gases 1.286 TBq for NPP V-1 and 1.475 TBq for NPP V-2 (2.761 TBq (0.069% of annually limit (AL) for the locality Bohunice), for aerosols 2.645 MBq for NPP V-1 and 0.542 MBq for NPP V-2 (3.187 MBq (0.002% of AL for the locality Bohunice), for corrosive and fission products 3.848 MBq for NPP V-1 and 1.510 MBq for NPP V-2 (5.358 MBq (0.01% of AL) for the locality Bohunice), and for iodine 2.616 MBq for NPP V-1 and 0.279 MBq (2.894 MBq (0.002% of AL) for the locality Bohunice), and for tritium it is 2.395 TBq for NPP V-1 and 3.532 TBq for NPP V-2 (5.358 TBq (13.56% of AL) for the locality Bohunice

  6. Passiv-Sammler

    Fritsche, U.

    1991-01-01

    The invention relates to a passive collector for air pollution for the determination of emission rates for dry and wet deposits on construction materials such as natural stone, whereby the collector has a surrogate surface of the stone under investigation, the surrogate surface being linked to a collecting vessel such that any dry or wet contamination occurring can be collected.

  7. Passive houses in Norway

    Halse, Andreas

    2008-12-15

    The paper analyzes the introduction of passive houses in the Norwegian house market. Passive houses are houses with extremely low levels of energy consumption for heating, and have not yet been built in Norway, but have started to enter the market in Germany and some other countries. The construction sector is analyzed as a sectoral innovation system. The different elements of the innovation system are studied. This includes government agencies, producers, consumers, finance and education. The analysis shows that passive and low-energy houses are on the verge of market breakthrough. This can partly be explained by economic calculations, and partly by processes of learning and change in the institutional set-up of the sector. The construction sector is a sector characterized by low innovative intensity and little interaction between different agents. Those working to promote passive houses have to some extent managed to cope with these challenges. This has happened by breaking away from the traditional focus of Norwegian energy efficiency policies on technology and the economically rational agents, by instead focusing on knowledge and institutional change at the level of the producers. (Author)

  8. Hood River Passive House

    Hales, David [BA-PIRC, Spokane, WA (United States)

    2014-01-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to "reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project. The design includes high R-Value assemblies, extremely tight construction, high performance doors and windows, solar thermal DHW, heat recovery ventilation, moveable external shutters and a high performance ductless mini-split heat pump. Cost analysis indicates that many of the measures implemented in this project did not meet the BA standard for cost neutrality. The ductless mini-split heat pump, lighting and advanced air leakage control were the most cost effective measures. The future challenge will be to value engineer the performance levels indicated here in modeling using production based practices at a significantly lower cost.

  9. Passive THz metamaterials

    Lavrinenko, Andrei; Malureanu, Radu; Zalkovskij, Maksim

    2012-01-01

    In this work we present our activities in the fabrication and characterization of passive THz metamaterials. We use two fabrication processes to develop metamaterials either as free-standing metallic membranes or patterned metallic multi-layers on the substrates to achieve different functionalities...

  10. Intrinsically Passive Handling and Grasping

    Stramigioli, Stefano; Scherpen, Jacquelien M.A.; Khodabandehloo, Koorosh

    2000-01-01

    The paper presents a control philosophy called Intrinsically Passive Control, which has the feature to properly behave during interaction with any passive objects. The controlled robot will never become unstable due to the physical structure of the controller.

  11. Decommissioning of NPPs with spent nuclear fuel present - efforts to amend the German regulatory framework to cope with this situation

    Brendebach, Boris; Rehs, Bernd

    2016-01-01

    The authorization to operate an installation for the fission of nuclear fuel for the commercial production of electricity was withdrawn for the seven oldest NPPs and NPP Kruemmel in Germany on August 6, 2011 after the events at Japanese Nuclear Power Plant (NPP) Fukushima Daiichi in March 2011. In the meantime, all these NPPs applied for decommissioning. One aspect reflected in the applications for these NPPs is the possibility that spent nuclear fuel elements or fuel rods will still be present in the cooling ponds at least during the first stage of decommissioning, i.a. due to limited availability of spent fuel casks. Although considerable decommissioning experiences are available in Germany, the approach 'decommissioning with fuel elements present' has been the exceptional case so far. The paper highlights the efforts undertaken to strengthen the regulatory framework with respect to decommissioning in Germany taking into account this changed approach. The paper presents a short introduction to the legal and regulatory requirements for decommissioning in Germany. Afterwards, the updates to the Decommissioning Guide, which includes proposals for an appropriate procedure for the decommissioning, safe enclosure and dismantling of facilities or parts thereof as defined in item 7 of the German Atomic Energy Act in respect of the application of the technical rules for planning and preparation of decommissioning measures as well as for licensing and supervision, are highlighted. In addition, the amendments to the Guidelines for the Decommissioning of Nuclear Facilities of the Nuclear Waste Management Commission (ESK), which is complementary to the Decommissioning Guide in a technical sense, are reported as well. (authors)

  12. Analysis on the Current Status of Chemical Decontamination Technology of Steam Generators in the Oversea Nuclear Power Plants (NPPs)

    Yoon, Taebin; Kim, Sukhoon; Kim, Juyoul; Kim, Juyub; Lee, Seunghee [FNC Technology Co. Ltd., Yongin (Korea, Republic of)

    2015-10-15

    The steam generators in Hanbit Unit 3 and 4 are scheduled to be replaced in 2018 and 2019, respectively. Nevertheless, the wastes from the dismantled steam generators are currently just on-site stored in the NPP because there are no disposal measures for the waste and lack of the decontamination techniques for large-sized metallic equipment. In contrast, in the oversea NPPs, there are many practical cases of chemical decontamination not only for oversized components in the NPPs such as reactor pressure vessel and steam generator, but also for major pipes. Chemical decontamination technique is more effective in decontaminating the components with complicated shape compared with mechanical one. Moreover, a high decontamination factor can be obtained by using strong solvent, and thereby most of radionuclides can be removed. Due to these advantages, the chemical decontamination has been used most frequently for operation of decontaminating the large-sized equipment. In this study, an analysis on the current status of chemical decontamination technique used for the steam generators of the foreign commercial NPPs was performed. In this study, the three major chemical decontamination processes were reviewed, which are applied to the decommissioning process of the steam generators in the commercial NPPs of the United States, Germany, and Belgium. The three processes have the different features in aspect of solvent, while those are based in common on the oxidation and reduction between the target metal surface and solvents. In addition, they have the same goals for improving the decontamination efficiency and decreasing the amount of the secondary waste generation. Based on the analysis results on component sub-processes and major advantages and disadvantages of each process, Table 2 shows the key fundamental technologies for decontamination of the steam generator in Korea and the major considerations in the development process of each technology. It is necessary to prepare

  13. Experience in integration of on-line control systems for turbine plants at the Ignalina and Zaporozhe NPPs

    Gapunin, A.Ya.; Guchshin, V.I.; Kozlov, N.Yu.; Kravtsov, V.F.; Rasskazov, I.Eh.; Fridman, P.Yu.

    1989-01-01

    The main stages of designing and improvement of turbine on-line control systems (TOCS) are considered. TOCS is mainly designed for the optimization of NPP equipment operation modes taking into account power system requirements, as well as reactor and steam generator capabilities. TOCS of the Ignalina (K750-65/1300 turbine) and Zaporozhe (K1000-60/1500-2) NPPs are the systems of the third generation and are produced in the form of decentralized complex of software and hardware on the basis of the Ehlektronika S5-2200 computer. 3 refs.; 2 figs

  14. Doosan Experience on I and C Upgrade for Operating NPPs: Control Rod Control System and Automatic Seismic Trip System

    Nam, C.H.; Kim, K.H.; Lee, D.H.

    2012-01-01

    This paper describes DHIC's experience on upgrading 3 coil type control rod control system(CRCS), 4 coil type control element drive mechanism control system(CEDMCS) and automatic seismic trip system(ASTS). Common main feature of the above systems are full duplex system to prevent unwanted trip and mis-operation. 5 CRCS and CEDMCS have been supplied to Kori 1,2, Ulchin 1,2 and Younggwang 3 since 2010 and 7 CEDMCS are contracted to supply Korea Hydro and Nuclear Power Co.(KHNP) site. Also 16 ASTS are supplied and 12 ASTS will be supplied to operating and new NPPs within 3 years. (author)

  15. Standardization of domestic human reliability analysis and experience of human reliability analysis in probabilistic safety assessment for NPPs under design

    Kang, D. I.; Jung, W. D.

    2002-01-01

    This paper introduces the background and development activities of domestic standardization of procedure and method for Human Reliability Analysis (HRA) to avoid the intervention of subjectivity by HRA analyst in Probabilistic Safety Assessment (PSA) as possible, and the review of the HRA results for domestic nuclear power plants under design studied by Korea Atomic Energy Research Institute. We identify the HRA methods used for PSA for domestic NPPs and discuss the subjectivity of HRA analyst shown in performing a HRA. Also, we introduce the PSA guidelines published in USA and review the HRA results based on them. We propose the system of a standard procedure and method for HRA to be developed

  16. Upgrading safety of NPPs with RBMK-1000 reactors by implementation of the first priority measures and activities

    1996-01-01

    After the accident at the Chernobyl Unit 4 reactor, extensive debates were in place about the future of nuclear power industry, its safety and the role of nuclear power in human life. The major conclusion drawn from those discussions is that the energy demands and ecological problems could not be resolved without further development of nuclear industry. However, the continued development of nuclear power industry, first and foremost, should rest on a wide range of actions aimed at assuring the quality of design and construction of new NPPs, the quality of operation of the existing plants and by means of their backfitting. 1 ref., 3 figs, 1 tab

  17. Passive solar heating

    Wiberg, K

    1981-11-10

    The present work treats the possibilities for heating according to the passive solar heating method. Problems of 'spatial organization in an energy-saving society' are distinguished from among other social problems. The final delimination of the actual problems under investigation consists of the use of passive solar heating and especially the 'consequences of such solar heating exploitation upon the form and structures' of planning and construction. In the concluding chapter an applied example shows how this method can be used in designing an urban area and what are its limitations. The results indicate the possibilities and difficulties in attempting to transfer this ideal and general method into models and directives for form and structure from which examples of the actual possibilities in practical planning can be given.

  18. European Utility Requirements: leveling the European electricity producers' playing ground for new NPPs

    Bernard Roche

    2006-01-01

    Full text of publication follows: Since 1992, the European Utility Requirement (EUR) document has been developed by the major European electricity producers. The main driver to this work has been the construction of a unified European market. The electricity producers have set out design requirements adapted to this new European environment, while keeping in mind experience feedback from operating NPPs worldwide. The EUR document is now fully operational and its set of generic requirements have been recently used as bid specification in Finland and in China. The EUR document keeps developing in two directions: 1- completing the assessment of the projects that could be proposed by the vendors for the European market. Five projects have been assessed between 1999 and 2002: BWR90, EPR, EP1000, ABWR and SWR1000. Two new projects are being assessed, the Westinghouse AP1000 and the Russian VVER AES92. It is currently planned to publish these two new assessments in the first half of 2006. Others may be undertaken meanwhile. 2- revision of the generic requirements. A revision C of the volume 4 dedicated to power generation plant is being completed. It includes responses to vendors comments and feedback from the TVO call for bid for Finland 5. A revision D of the volumes 1 and 2 dedicated to nuclear islands is foreseen. The main contributions to this revision are the harmonization actions going on in Europe about nuclear safety (WENRA study on reactor safety harmonization, EC works, evolution of the IAEA guides and requirements), the harmonization works on the conditions of connection to the European HV grid as well as harmonization works on other matters, like codes and standards. This has given a unified frame in which the future nuclear plants can be designed and built. In this frame development of standards designs usable throughout Europe without major design change is possible, thus helping to increase competition, and ultimately to save investment and operating costs

  19. Safety culture in nuclear installations. Management of safety and safety culture in Indian NPPs

    Rawal, S.C.

    2002-01-01

    Nuclear Power Corporation Of India Ltd. (NPCIL) is a company owned by Government of India and is responsible for Design, Construction, Commissioning, Operation and Decommissioning of Nuclear Power plants in India. Presently, a total of 13 Nuclear power Stations are in operation with an installed capacity of 2620 MWe and 2 VVR type PWR Units of 1000 MWe capacity each, 2 PHWR type units of 500 MWe capacity each and 4 PHWR type 220 MWe capacity each are under construction. NPPs generation capacity has been increased from 70% to 85% in the span Of last 7 years with high level of safety standards. This could be achieved through Management commitment towards building a strong Safety Culture. Safety culture is that assembly of characteristics and attitudes in organisation and individuals which establishes that as an overriding priority nuclear plant safety issues receives the attention warranted by their significance. This definition of safety culture brings out two major components in its manifestation. The framework within which individuals within the organisation works.The attitude and response of individual towards the safety issues over productivity and economics in the organisational work practices. The two attributes of safety culture are built in and upgraded in each individuals through special training at the time of entry in the organisation and later through in built procedures in the work practices, motivation and encouragement for free participation of each individuals. Individuals are encouraged to participate in Quality circle teams at the sectional level and review of safety proposal originated by individuals in Station operation Review Committee at Station level, in addition to this to continuously enhance the safety culture, refresher training courses are being organised at regular intervals. The safety related proposals are categorised in to two namely: Proposals from Operating Plants, and Proposals from projects and Design. The concept of safety

  20. Development and using computer codes for improvement of defect assembly detection on Russian WWER NPPs

    Likhanskii, V.; Evdokimov, I.; Zborovskii, V.; Kanukova, V.; Sorokin, A.; Taran, M.; Ugrumov, A.; Riabinin, Y.

    2009-01-01

    Diagnostic methods of fuel failure detection for improving the radiation safety and shortening of fuel reload time at Russian WWERs are currently in development . The works include creation new computer means for increase of effectiveness of fuel monitoring and reliability of leakage tests. Reliability of failure detection can be noticeably improved when we apply an integrated approach including the following methods. The first is fuel failure analysis under operating conditions. Analysis is performed with the pilot version of the expert system, which has been developed on the basis of the mechanistic code RTOP-CA. The second stage of failure monitoring is 'sipping' tests in the mast of the refueling machine. The leakage tests are the final stage of failure monitoring. A new technique with pressure cycling in the specialized casks was introduced to meet the requirements of higher reliability in detection/confirmation of the leakages. Measurements of the activity release kinetics during the pressure cycling and handling of the acquired data with the RTOP-LT code enable to evaluate a defect size in leaking fuel assembly. The mechanistic codes RTOP-CA and RTOP-LT were verified on a base of specialized experimental data and currently the code were certified by Russian authorities Rostechnadzor. Now the pressure cycling method in the specialized casks has official status and is utilized at the all Russian WWER units. Some results of application of the integrated approach to fuel failure monitoring at several Russian NPPs with WWER units are reported in the present paper. Predictions of the current version of the expert system are compared with the results of the leakage tests and with the estimations of the defect size by the pressure cycling technique. Using the RTOP-CA code the level of activity is assessed for the following fuel campaign if the leaking fuel assembly was decided to be reloaded into the core. A project of the automated computer system on the basis of

  1. Freshwater sediments and sludges: two important terrestrial sinks for emissions from damaged NPPs

    Fischer, Helmut W.; Evangelia Souti, Maria; Ulbrich, Susanne; Hormann, Volker

    2013-04-01

    Surface deposition of radionuclides released from the damaged Fukushima NPPs is well documented and emissions to the Pacific Ocean and their distribution with time and space are also subject to monitoring and research. In both cases, solid matter (soil and sea sediment, respectively) acts as a sink for radioisotopes after their transport through air and water. The possible hazards from direct irradiation of workers and public and from entry of radionuclides into food chains are well recognized. Apart from direct deposition onto soil, plants, building roofs etc., aerosols and contaminated rainwater will reach surface waters, leading to long-term deposition in freshwater sediments (and possibly to interim contamination of drinking water). In populated and industrial areas, drained rainwater will enter the wastewater collection and treatment chain if a combined rain and wastewater sewer is used. Depending on the processes in the wastewater treatment plant and chemical element and speciation, the isotopes will either concentrate in treatment sludge or be released with the effluent to rivers and lakes and their sediments. The mentioned media may act as long-term storage for radioisotopes when disposed of properly, but can also contribute to direct irradiation of workers or public, lead to continuous releases to the environment and possibly enter the food chain in the same way as soil and sea sediments. It appears therefore essential to monitor these environmental compartments as well. However, very few data on Fukushima-related radioisotope concentration in sludges and freshwater sediments have been published to date. We will therefore compare data for regional surface deposition and related concentrations in surface water, river sediments and sewage sludge obtained in Europe during 1986 to published data from Japan in 2011 for the most important common short-lived (I-131, half-life = 8.02 d) and long-lived (Cs-137, half-life = 30.17 yr) isotopes. As in central Europe

  2. Qademah Fault Passive Data

    Hanafy, Sherif M.

    2014-01-01

    OBJECTIVE: In this field trip we collect passive data to 1. Convert passive to surface waves 2. Locate Qademah fault using surface wave migration INTRODUCTION: In this field trip we collected passive data for several days. This data will be used to find the surface waves using interferometry and then compared to active-source seismic data collected at the same location. A total of 288 receivers are used. A 3D layout with 5 m inline intervals and 10 m cross line intervals is used, where we used 12 lines with 24 receivers at each line. You will need to download the file (rec_times.mat), it contains important information about 1. Field record no 2. Record day 3. Record month 4. Record hour 5. Record minute 6. Record second 7. Record length P.S. 1. All files are converted from original format (SEG-2) to matlab format P.S. 2. Overlaps between records (10 to 1.5 sec.) are already removed from these files

  3. Concept research on general passive system

    Han Xu; Yang Yanhua; Zheng Mingguang

    2009-01-01

    This paper summarized the current passive techniques used in nuclear power plants. Through classification and analysis, the functional characteristics and inherent identification of passive systems were elucidated. By improving and extending the concept of passive system, the general passive concept was proposed, and space and time relativity was discussed and assumption of general passive system were illustrated. The function of idealized general passive system is equivalent with the current passive system, but the design of idealized general passive system is more flexible. (authors)

  4. IAEA/USDOE senior management workshop on promotion of safety culture for the NPPS with RBMK reactors. Working material

    NONE

    1997-09-01

    The current workshop, co-sponsored by the IAEA and USDOE, was a continuation of the previous effort for further promotion of safety culture at RBMK NPPs. The objective of the workshop was to provide a forum for senior managers from governmental organizations and operating organizations to further exchange experience in understanding the factors influencing safety culture, in assessing safety culture at their own organizations and developing safety culture at RBMK NPPs. The workshop consisted of a broad scope of presentations to review the basic concepts and major elements of safety culture (ownership, accountability, pride, job satisfaction, trust, openness, etc.), to identify and discuss the various approaches used in different countries in attaining a strong safety culture, and to explain, through the use of practical examples, what the benefits of a strong safety culture are; how to improve the behavior of people, how to gain trust and openness, how to overcome difficulties in changing staff`s attitudes, and how to manage safety culture. 2 figs.

  5. IAEA/USDOE senior management workshop on promotion of safety culture for the NPPS with RBMK reactors. Working material

    1997-01-01

    The current workshop, co-sponsored by the IAEA and USDOE, was a continuation of the previous effort for further promotion of safety culture at RBMK NPPs. The objective of the workshop was to provide a forum for senior managers from governmental organizations and operating organizations to further exchange experience in understanding the factors influencing safety culture, in assessing safety culture at their own organizations and developing safety culture at RBMK NPPs. The workshop consisted of a broad scope of presentations to review the basic concepts and major elements of safety culture (ownership, accountability, pride, job satisfaction, trust, openness, etc.), to identify and discuss the various approaches used in different countries in attaining a strong safety culture, and to explain, through the use of practical examples, what the benefits of a strong safety culture are; how to improve the behavior of people, how to gain trust and openness, how to overcome difficulties in changing staff's attitudes, and how to manage safety culture. 2 figs

  6. Structural mechanics research and development for main components of chinese 300 MWe PWR NPPs: from design to life management

    Yao Weida; Dou Yikang; Xie Yongcheng; He Yinbiao; Zhang Ming; Liang Xingyun

    2005-01-01

    Qinshan Nuclear Power Plant (Unit I), is a 300 MWe prototype PWR independently developed by Chinese own efforts, from design, manufacture, construction, installation, commissioning, to operation, inspection, maintenance, ageing management and lifetime assessment. Shanghai Nuclear Engineering Research and Design Institute (SNERDI) has taken up with and involved in deeply the R and D to tackle problems of this type of reactor since very beginning in early 1970s. Structural mechanics is one of the important aspects to ensure the safety and reliability for NPP components. This paper makes a summary on role of structural mechanics for component safety and reliability assessment in different stages of design, commissioning, operation, as well as lifetime assessment on this type PWR NPPs, including Qinshan-I and Chashma-I, a sister plant in Pakistan designed by SNERDI. The main contents of the paper cover design by analysis for key components of NSSS; mechanical problems relating to safety analysis; special problems relating to pressure retaining components, such as fracture mechanics, sealing analysis and its test verifications, etc.; experimental research on flow-induced vibration; seismic qualification for components; component failure diagnosis and root cause analysis; vibration qualification and diagnosis technique; component online monitoring technique; development of defect assessment; methodology of aging management and lifetime assessment for key components of NPPs, etc. (authors)

  7. Development of a Quantitative Method for Evaluating the Efficacy of Cyber Security Controls in NPPs based on Intrusion Tolerant Concept

    Lee, Chanyoung; Seong, Poong Hyun

    2017-01-01

    Digital I and C systems have been developed and installed in nuclear power plants (NPPs). However, due to installation of digital I and C systems, cyber security concerns are increasing in the nuclear industry. In order to provide useful information about cyber security issues, many regulatory documents, guides and standards were already published in the nuclear industry. The documents include cyber security plans, methods for cyber security assessments and comprehensive set of security controls. In order for useful information about cyber security issues, many regulatory documents, guides and standards have been already published in the nuclear industry. However, there are still difficulties when it comes to deciding which security controls are needed and to defining appropriate security control requirements. It is because practical examples for the application of security controls have not been available to system designers and there is a lack of means for estimating the effectiveness of security controls. In this regard, this paper suggested a framework to quantitatively evaluate how much cyber security is improved when specific cyber security controls are applied in NPPs.

  8. First experience with the installation of passive autocatalytic recombiners

    Snoeck, J.; Solaro, C.; Moeyaert, P.

    1997-01-01

    From the principle decision of installing Passive Autocatalytic Recombiners (PARs) in all Belgian NPPs to the installation on site, several problems needed to be identified and solved; it is the goal of this paper to address these issues and to present the solutions which were adopted. The first section deals with the sizing and the distribution of the catalytic surface inside the containment to be equipped. Rather than to rely on numerous multicompartment calculations, the procedure is based on a single volume approach combined with engineering judgement. The criteria applied in the successive design steps are explained and illustrated for the Doel1 unit. The second section is devoted to additional requirements concerning the resistance to poisoning agents and the maintenance constraints, and to some recommendations for the design of the supports. Because the effectiveness of the PARs entirely relies on the catalyst material, a periodic control of the active parts is of primary importance. Therefore, the Transportable In-Service Inspection Equipment (TIIE) and the test procedures are presented in the third section. Finally, recommendations are made for further work, derived from this first experience. (author)

  9. Condition Based Prognostics of Passive Components - A New Era for Nuclear Power Plant Life Management

    Bakhtiari, S.; Mohanty, S.; Prokofiev, I.; Tregoning, R.

    2012-01-01

    As part of a research project sponsored by the U.S. NRC, Argonne National Laboratory (ANL) conducted scoping studies to identify viable and promising sensors and techniques for in-situ inspection and real-time monitoring of degradation in nuclear power plant (NPP) systems, structures, and components (SSC). Significant advances have been made over the past two decades toward development of online monitoring (OLM) techniques for detection, diagnostics, and prognostics of degradation in active nuclear power plant (NPP) components (e.g., pumps, valves). However, early detection of damage and degradation in safety-critical passive components, (e.g. piping, tubing pressure vessel), is challenging, and will likely remain so for the foreseeable future. Ensuring the structural integrity of the reactor pressure vessel (RPV) and piping systems in particular is a prerequisite to long term safe operation of NPPs. The current practice is to implement inservice inspection (ISI) and preventive maintenance programs. While these programs have generally been successful, they are limited in that information is only obtained during plant outages. Additionally, these inspections, often the critical path in the outage schedule, are costly, time consuming, and involve potentially high dose to nondestructive examination/evaluation (NDE) personnel. A viable plant-wide on-line structural health monitoring program for continuous and automatic monitoring of critical SSCs could be a more effective approach for guarding against unexpected failures. Specifically, OLM information about the current condition of the SSCs could be input to an online prognostics (OLP) system to forecast their remaining useful life in real time. This paper provides an overview of scoping studies performed at ANL on assessing the viability of OLM and OLP systems for real time and automated monitoring and remaining of condition and the remaining useful life of passive components in NPPs. (author)

  10. Passive Power Filters

    Künzi, R.

    2015-06-15

    Power converters require passive low-pass filters which are capable of reducing voltage ripples effectively. In contrast to signal filters, the components of power filters must carry large currents or withstand large voltages, respectively. In this paper, three different suitable filter struc tures for d.c./d.c. power converters with inductive load are introduced. The formulas needed to calculate the filter components are derived step by step and practical examples are given. The behaviour of the three discussed filters is compared by means of the examples. P ractical aspects for the realization of power filters are also discussed.

  11. Investigation of relationship between mental workload and information flow rate of accident diagnosis tasks in NPPs

    Ha, Chang Hoon

    2005-02-01

    The objective of this study is to investigate experimentally the relationship between an operator's mental workload and the information flow rate of accident diagnosis tasks and further to propose the information flow rate as an analytic method for measuring the mental workload. There are two types of mental workload in the advanced MCR of NPPs: the information processing workload, which is the processing that the human operator must actually perform in order to complete the diagnosis task, and emotional stress workload experienced by the operator. In this study, the focus is on the former. Three kinds of methods are used to measure the operator's workload: information flow rate, subjective methods, and physiological measures. Information flows for eight accident diagnosis tasks are modeled qualitatively using a stage model and are quantified using Conant's model. The eight accident cases are considered here are: Loss Of Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Steam Line Break (SLB), Feedwater Line Break (FLB), Pressurizer (PZR) spray and heater failure, Reactor Coolant Pump (RCP) trip, Main Steam Isolation Valve (MSIV) failure, and PZR spray failure. The information flow rate is obtained for each diagnosis task by imposing time limit restrictions for the tasks. Subjective methods require the operators to respond to questionnaires to rate their level of mental effort. NASA-TLX and MCH scale are selected as subjective methods. NASA-TLX is a subjective method used in the various fields including the aviation, automobile, and nuclear industries. It has a multi-dimensional rating technique and provides an overall workload score based on a weighted average on six subscales using pair-wise comparison tests. MCH, on the other hand, is one-dimensional and uses a 10- point rating technique. As with NASA-TLX, the higher the score is, the higher the subjective workload is. For the physiological measurements, an eye tracking system analyzes eye movements

  12. Investigation of relationship between mental workload and information flow rate of accident diagnosis tasks in NPPs

    Ha, Chang Hoon

    2005-02-15

    The objective of this study is to investigate experimentally the relationship between an operator's mental workload and the information flow rate of accident diagnosis tasks and further to propose the information flow rate as an analytic method for measuring the mental workload. There are two types of mental workload in the advanced MCR of NPPs: the information processing workload, which is the processing that the human operator must actually perform in order to complete the diagnosis task, and emotional stress workload experienced by the operator. In this study, the focus is on the former. Three kinds of methods are used to measure the operator's workload: information flow rate, subjective methods, and physiological measures. Information flows for eight accident diagnosis tasks are modeled qualitatively using a stage model and are quantified using Conant's model. The eight accident cases are considered here are: Loss Of Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Steam Line Break (SLB), Feedwater Line Break (FLB), Pressurizer (PZR) spray and heater failure, Reactor Coolant Pump (RCP) trip, Main Steam Isolation Valve (MSIV) failure, and PZR spray failure. The information flow rate is obtained for each diagnosis task by imposing time limit restrictions for the tasks. Subjective methods require the operators to respond to questionnaires to rate their level of mental effort. NASA-TLX and MCH scale are selected as subjective methods. NASA-TLX is a subjective method used in the various fields including the aviation, automobile, and nuclear industries. It has a multi-dimensional rating technique and provides an overall workload score based on a weighted average on six subscales using pair-wise comparison tests. MCH, on the other hand, is one-dimensional and uses a 10- point rating technique. As with NASA-TLX, the higher the score is, the higher the subjective workload is. For the physiological measurements, an eye tracking system analyzes

  13. Needs of thermal-hydraulic codes for analyzing hydrogen behavior of future chinese NPPs

    Zhiwei Zhou; Jianjun Xiao; Mengjia Yang

    2005-01-01

    severe accident management guidelines are therefore needed for dealing with both the in-vessel and ex-vessel phenomena, including hydrogen generation, diffusion/convection and deflagration/detonation. To develop the sophisticated thermalhydraulic codes for analyzing severe accident related hydrogen behavior of a light water reactor system is quite expensive and rather unrealistic for China along to bear the cost. Therefore, the most effective way for China to establish the design capability of analyzing severe accident for new nuclear power plant projects is to participate the international or multi-national R and D program, such as EUROATOM cost-sharing program and GEN-IV program, etc. By international cooperation, China can not only gain in most extent the successful experience of the countries with advanced technology in developing nuclear power plants, but also contribute itself most effectively in keeping the momentum of enlarging the peaceful utilization of nuclear energy in the world. Certainly, the future Chinese nuclear power market will be a significant industrial driver for developing the-state-of-the-art thermal-hydraulic codes, including hydrogen behavior analysis codes. This paper also reports some computational study on hydrogen diffusion/convection behavior in the containment related to Daya Bay NPP severe accident analysis with CFD code GASFLOW. The code validation were largely carried out in past few years in Germany and had been applied to EPR and other German NPPs. (authors)

  14. Expansion of passive safety function

    Inai, Nobuhiko; Nei, Hiromichi; Kumada, Toshiaki.

    1995-01-01

    Expansion of the use of passive safety functions is proposed. Two notions are presented. One is that, in the design of passive safety nuclear reactors where aversion of active components is stressed, some active components are purposely introduced, by which a system is built in such a way that it behaves in an apparently passive manner. The second notion is that, instead of using a passive safety function alone, a passive safety function is combined with some active components, relating the passivity in the safety function with enhanced controllability in normal operation. The nondormant system which the authors propose is one example of the first notion. This is a system in which a standby safety system is a portion of the normal operation system. An interpretation of the nondormant system via synergetics is made. As an example of the second notion, a PIUS density lock aided with active components is proposed and is discussed

  15. Passive cooling containment study

    Shin, J.J.; Iotti, R.C.; Wright, R.F.

    1993-01-01

    Pressure and temperature transients of nuclear reactor containment following postulated loss of coolant accident with a coincident station blackout due to total loss of all alternating current power are studied analytically and experimentally for the full scale NPR (New Production Reactor). All the reactor and containment cooling under this condition would rely on the passive cooling system which removes reactor decay heat and provides emergency core and containment cooling. Containment passive cooling for this study takes place in the annulus between containment steel shell and concrete shield building by natural convection air flow and thermal radiation. Various heat transfer coefficients inside annular air space were investigated by running the modified CONTEMPT code CONTEMPT-NPR. In order to verify proper heat transfer coefficient, temperature, heat flux, and velocity profiles were measured inside annular air space of the test facility which is a 24 foot (7.3m) high, steam heated inner cylinder of three foot (.91m) diameter and five and half foot (1.7m) diameter outer cylinder. Comparison of CONTEMPT-NPR and WGOTHIC was done for reduced scale NPR

  16. Fly ash carbon passivation

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  17. Surface Passivation in Empirical Tight Binding

    He, Yu; Tan, Yaohua; Jiang, Zhengping; Povolotskyi, Michael; Klimeck, Gerhard; Kubis, Tillmann

    2015-01-01

    Empirical Tight Binding (TB) methods are widely used in atomistic device simulations. Existing TB methods to passivate dangling bonds fall into two categories: 1) Method that explicitly includes passivation atoms is limited to passivation with atoms and small molecules only. 2) Method that implicitly incorporates passivation does not distinguish passivation atom types. This work introduces an implicit passivation method that is applicable to any passivation scenario with appropriate parameter...

  18. Passive-solar construction handbook

    Levy, E.; Evans, D.; Gardstein, C.

    1981-02-01

    Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

  19. Human error and the associated recovery probabilities for soft control being used in the advanced MCRs of NPPs

    Jang, Inseok; Jung, Wondea; Seong, Poong Hyun

    2016-01-01

    Highlights: • The operation environment of MCRs in NPPs has changed by adopting digital HSIs. • Most current HRA databases are not explicitly designed to deal with digital HSI. • Empirical analysis for new HRA DB under an advanced MCR mockup are carried. • It is expected that the results can be used for advanced MCR HRA. - Abstract: Since the Three Mile Island (TMI)-2 accident, human error has been recognized as one of the main causes of Nuclear Power Plant (NPP) accidents, and numerous studies related to Human Reliability Analysis (HRA) have been carried out. Most of these studies were focused on considering the conventional Main Control Room (MCR) environment. However, the operating environment of MCRs in NPPs has changed with the adoption of new human-system interfaces (HSI) largely based on up-to-date digital technologies. The MCRs that include these digital and computer technologies, such as large display panels, computerized procedures, and soft controls, are called advanced MCRs. Among the many features of advanced MCRs, soft controls are a particularly important because operating actions in advanced MCRs are performed by soft control. Due to the difference in interfaces between soft control and hardwired conventional controls, different HEP should be used in the HRA for advanced MCRs. Unfortunately, most current HRA databases deal with operations in conventional MCRs and are not explicitly designed to deal with digital Human System Interface (HSI). For this reason, empirical human error and the associated error recovery probabilities were collected from the mockup of an advanced MCR equipped with soft controls. To this end, small-scaled experiments are conducted with 48 graduated students in the department of nuclear engineering in Korea Advanced Institute of Science and Technology (KAIST) are participated, and accident scenarios are designed with respect to the typical Design Basis Accidents (DBAs) in NPPs, such as Steam Generator Tube Rupture

  20. A Regulatory Perspective on the Performance and Reliability of Nuclear Passive Safety Systems

    Quan, Pham Trung; Lee, Sukho

    2016-01-01

    Passive safety systems have been proven to enhance the safety of NPPs. When an accident such as station blackout occurs, these systems can perform the following functions: the decay heat removal, passive safety injection, containment cooling, and the retention of radioactive materials. Following the IAEA definitions, using passive safety systems reduces reliance on active components to achieve proper actuation and not requiring operator intervention in accident conditions. That leads to the deviations in boundary conditions of the critical process or geometric parameters, which activate and operate the system to perform accident prevention and mitigation functions. The main difficulties in evaluation of functional failure of passive systems arise because of (a) lack of plant operational experience; (b) scarcity of adequate experimental data from integral test facilities or from separate effect tests in order to understand the performance characteristics of these passive systems, not only at normal operation but also during accidents and transients; (c) lack of accepted definitions of failure modes for these systems; and (d) difficulty in modeling certain physical behavior of these systems. Reliability assessment of the PSS is still one of the important issues. Several reliability methodologies such as REPAS, RMPS and ASPRA have been applied to the reliability assessments. However, some issues are remained unresolved due to lack of understanding of the treatment of dynamic failure characteristics of components of the PSS, the treatment of dynamic variation of independence process parameters such as ambient temperature and the functional failure criteria of the PSS. Dynamic reliability methodologies should be integrated in the PSS reliability analysis to have a true estimate of system failure probability. The methodology should estimate the physical variation of the parameters and the frequency of the accident sequences when the dynamic effects are considered

  1. Passive magnetic bearing system

    Post, Richard F.

    2014-09-02

    An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.

  2. Steam generator collector integrity of WWER-1000 reactors. IAEA extrabudgetary programme on the safety of WWER NPPs

    Lin, C.; Strupczewski, A. [International Atomic Energy Agency, Vienna (Austria)

    1995-12-31

    At the Consultants` Meeting on `The Safety of WWER-1000 Model 320 Nuclear Power Plants` organized by the IAEA within the framework of its Extrabudgetary Programme on the Safety of WWER-1000 NPPs, which was held in Vienna, 1-5 June 1992, the problem of WWER-1000 steam generator integrity was identified as an important issue of safety concern. Considering the safety importance of this issue, a Consultants` Meeting on `The Steam Generator Integrity of WWER-1000 Nuclear Power Plants` was convened in Vienna in May 1993, attended by 15 international experts in the area to compile information on the steam generator operating experience, deficiencies and corrective measures implemented and planned. In order to also include information from the main designer OKB Gidropress and to finalize the meeting report the IAEA convened a second meeting on the issue on 23-27 November 1993. The present paper summarizes the information and conclusions from those meetings.

  3. Steam generator collector integrity of WWER-1000 reactors. IAEA extrabudgetary programme on the safety of WWER NPPs

    Lin, C; Strupczewski, A [International Atomic Energy Agency, Vienna (Austria)

    1996-12-31

    At the Consultants` Meeting on `The Safety of WWER-1000 Model 320 Nuclear Power Plants` organized by the IAEA within the framework of its Extrabudgetary Programme on the Safety of WWER-1000 NPPs, which was held in Vienna, 1-5 June 1992, the problem of WWER-1000 steam generator integrity was identified as an important issue of safety concern. Considering the safety importance of this issue, a Consultants` Meeting on `The Steam Generator Integrity of WWER-1000 Nuclear Power Plants` was convened in Vienna in May 1993, attended by 15 international experts in the area to compile information on the steam generator operating experience, deficiencies and corrective measures implemented and planned. In order to also include information from the main designer OKB Gidropress and to finalize the meeting report the IAEA convened a second meeting on the issue on 23-27 November 1993. The present paper summarizes the information and conclusions from those meetings.

  4. Some problems of software development for the plant-level automated control system of NPPs with the RBMK reactors

    Gorbunov, V.P.; Egorov, A.K.; Isaev, N.V.; Saprykin, E.M.

    1987-01-01

    Problems on development and operation of automated control system (ACS) software of NPPs with the RBMK reactors are discussed. The ES computer with large on-line storage (not less than 1 Mbite) and fast response (not less than 300.000 of operations per a second) should enter the ACS composition. Several program complexes are used in the NPP ACS. The programs collected into the EhNERGIYa library are used to provide central control system operation. The information-retrival system called the Fuel file is used to automate NPP fuel motion account, as well as to estimate efficiency of fuel application, to carry out calculations of a fuel component of electric and heat energy production cost. The automated information system for unit operation efficiency analysis, which solves both plant and unit-level problems, including engineering and economical factors and complexing of operation parameter bank, is under trial operation

  5. European vehicle passive safety network

    Wismans, J.S.H.M.; Janssen, E.G.

    1999-01-01

    The general objective of the European Vehicle Passive Safety Network is to contribute to the reduction of the number of road traffic victims in Europe by passive safety measures. The aim of the road safety policy of the European Commission is to reduce the annual total of fatalities to 18000 in

  6. Passive films at the nanoscale

    Maurice, Vincent; Marcus, Philippe

    2012-01-01

    Highlights: ► Nanoscale data on growth, structure and local properties of passive films reviewed. ► Preferential role of defects of passive films on the corrosion resistance emphasized. ► Effect of grain boundaries on local electronic properties shown by new data. ► Use of atomistic modeling to test mechanistic hypotheses illustrated. - Abstract: The nanometer scale chemical and structural aspects of ultrathin oxide passive films providing self-protection against corrosion to metals and alloys in aqueous environments are reviewed. Data on the nucleation and growth of 2D anodic oxide films, details on the atomic structure and nanostructure of 3D passive films, the preferential role of surface step edges in dissolution in the passive state and the preferential role of grain boundaries of the passive films in passivity breakdown are presented. Future perspectives are discussed, and exemplified by new data obtained on the relationship between the nanostructure of oxide passive films and their local electronic properties. Atomistic corrosion modeling by ab initio density functional theory (DFT) is illustrated by the example of interactions of chloride ions with hydroxylated oxide surfaces, including the role of surface step edges. Data obtained on well-defined substrate surfaces with surface analytical techniques are emphasized.

  7. Udviklingen i bilers passive sikkerhed

    Hels, Tove; Lyckegaard, Allan; Prato, Carlo Giacomo

    man mellem aktiv og passiv sikkerhed, det vil sige faktorer, der nedsætter • risikoen for, at der sker et uheld (aktiv sikkerhed), henholdsvis • graden af alvorlighed, givet at uheldet er sket (passiv sikkerhed). Rapporten begrænser sig til at undersøge, om der kan påvises en generel sammenhæng mellem...

  8. The Passive in Singapore English.

    Bao, Zhiming; Wee, Lionel

    1999-01-01

    Presents an analysis of the two passive (or passive-like) constructions in Singapore English which exhibit substrate influence from Malay and Chinese. The paper shows that while substrate languages contribute to the grammar of Singapore English, the continued prestige of standard English exerts normative pressure and mitigates the effect of…

  9. Use of FPGA to face electronic component obsolescence in software based safety I and C in NPPS

    Hadj, Abdellah; Bach, Julien; Esmenjaud, Claude; Daumas, Frederic; Salauen, Patrick

    2010-01-01

    In order to extend the life time of their Nuclear Power Plants (NPPs), most utilities are looking for ways to implement the renovation of their existing Instrumentation and Control (I and C) systems. When the I and C to modernize is software based, three paths can be considered: - to keep the legacy microprocessor and limit refurbishment to the associated hardware (i.e. the I/O boards, memories and the CPU board itself), - to move to another I and C platform based on another microprocessor, - to move to a non microprocessor based I and C platform. Software based I and C provide strong advantages such as flexibility and ability to implement advanced functions, however the complexity and the decreasing life time of nowadays microprocessors, mainly developed for the needs of the personal computer market, makes difficult their use and licensing for safety digital I and C systems. Solutions based on re-engineering of legacy microprocessors, or use of microprocessors dedicated to critical application need to be considered. In order to share a prospective vision of the future of I and C systems in NPPs, Electricite de France (EDF) Research and Development division and Rolls-Royce have launched a three year cooperation program on the use of the ASIC/FPGA technology in safety I and C systems. The first step of this program addresses the ability of the ASIC/FPGA technology to provide replacement solutions for former microprocessors taking as example the replacement of the Motorola MC6800 microprocessor. This paper presents the development of an IP cloning the Motorola MC6800 microprocessor, suitable for use in the refurbishment of safety I and C equipment based on this microprocessor. (authors)

  10. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    Lee, Seungmin; Seong, Poonghyun; Kim, Jonghyun

    2013-01-01

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load

  11. Automation-aided Task Loads Index based on the Automation Rate Reflecting the Effects on Human Operators in NPPs

    Lee, Seungmin; Seong, Poonghyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Jonghyun [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-05-15

    Many researchers have found that a high automation rate does not guarantee high performance. Therefore, to reflect the effects of automation on human performance, a new estimation method of the automation rate that considers the effects of automation on human operators in nuclear power plants (NPPs) was suggested. These suggested measures express how much automation support human operators but it cannot express the change of human operators' workload, whether the human operators' workload is increased or decreased. Before considering automation rates, whether the adopted automation is good or bad might be estimated in advance. In this study, to estimate the appropriateness of automation according to the change of the human operators' task loads, automation-aided task loads index is suggested based on the concept of the suggested automation rate. To insure plant safety and efficiency on behalf of human operators, various automation systems have been installed in NPPs, and many works which were previously conducted by human operators can now be supported by computer-based operator aids. According to the characteristics of the automation types, the estimation method of the system automation and the cognitive automation rate were suggested. The proposed estimation method concentrates on the effects of introducing automation, so it directly express how much the automated system support human operators. Based on the suggested automation rates, the way to estimate how much the automated system can affect the human operators' cognitive task load is suggested in this study. When there is no automation, the calculated index is 1, and it means there is no change of human operators' task load.

  12. IAEA-NULIFE VERLIFE - Procedure for integrity and lifetime assessment of components and piping in WWER NPPs during operation - Tool for LTO

    Brumovsky, M.

    2012-01-01

    VERLIFE - 'Unified Procedure for Lifetime Assessment of Components and Piping in WWER NPPs during Operation' was developed within the 5th Framework Programme of the European Union in 2003 and later upgraded within the 6th Framework Programme 'COVERS - Safety of WWER NPPs' of the European Union in 2008. This Procedure had to fill the gap in original Soviet/Russian Codes and Rules for WWER type NPPs, as these codes were developed only for design and manufacture and were not changed since their second edition in 1989. VERLIFE Procedure is based on these Russian codes but incorporates also new developments in research, mainly in fracture mechanics, and also some principal approaches used in PWR codes. To assure that VERLIFE Procedure will remain a living document, new 3-years IAEA project (in close cooperation with another project of the 6th Framework Programme of the European Union 'NULIFE - Plant Life Management of NPPs') has started in 2009. Final document, was approved by expert groups of the IAEA and NULIFE in June 28-30, 2011, and will be issued as 'IAEA/NULIFE Guidelines for Integrity and Lifetime Assessment of Components and Piping in WWER NPPs during Operation'. This document represents a necessary part for any integrity and lifetime assessment during operation that is a bases for further decision about safe and potential long term operation. To prepare documents like TLAA, it is necessary to have a tool that is able to evaluate lifetime of the main NPP components taking into account existing past operation as well as proposal for the future. (author)

  13. The passive system for reflooding of the VVER reactor core from the second-stage hydro-accumulators: design and basic design solutions

    Alexandr D Efanov; Sergey G Kalyakin; Andrey V Morozov; Oleg V Remizov; Vladimir M Berkovich; Victor N Krushelnitskiy; Vladimir G Peresadko; Yuri G Dragunov; Alexey K Podshibyakin; Sergey I Zaitcev

    2005-01-01

    Full text of publication follows: The fundamental difference in the safety assurance of the operating NPPs and those under design implies that the safety in the existing NPPs is achieved by energy-dependent (active) systems and depends on the proficiency of attending personnel. To provide safety, the new NPP designs use the physical processes proceeding in the facility without power supply; and they are unaffected by human errors. As to the safety level, the design of the new generation nuclear power plant NPP-92 relates to the class of the improved NPPs; and it applies a principle of diversity in the structure of systems responsible for critical safety functions. In accordance with the above-mentioned safety concept, the design development required a complex of experimental investigations and numerical modeling to be conducted. Among the passive safety systems of the NPP with RP-392 is the system of the second stage hydro-accumulators (GE-2). The system of the second-stage hydro-accumulators consists of four groups of hydro-accumulating tanks with a total coolant volume of 960 m 3 . The system is intended for the core flooding with coolant during 24 hours. In each group of the hydro-accumulators, the graded coolant flowrate is provided, which depends on residual heat in the reactor. The special check valves are tuned to open at the pressure drop in the circuit below 1.5 MPa. The paper presents the thermalhydraulic substantiation of the serviceability of the second-stage hydro-accumulators system for passive heat removal from the VVER reactor core and the basic design solutions on the GE-2 system. (authors)

  14. Antireflection/Passivation Step For Silicon Cell

    Crotty, Gerald T.; Kachare, Akaram H.; Daud, Taher

    1988-01-01

    New process excludes usual silicon oxide passivation. Changes in principal electrical parameters during two kinds of processing suggest antireflection treatment almost as effective as oxide treatment in passivating cells. Does so without disadvantages of SiOx passivation.

  15. Development of aging management standard guidelines for HVAC facilities of NPPs in Korea

    Won, Se Youl; Lee, Jae Gon; Oh, Seung Jin

    2014-01-01

    Inspection and maintenance activities for air conditioning facilities within the plant are managed mainly for active facilities, and as the years of operation pass, a method for detecting in advance aging-related integrity problems of passive facilities and taking necessary measures against them is required. Therefore, this paper establishes a standard aging management guideline for air conditioning facilities by selecting systems for which those facilities are to be managed, analyzing degradation mechanisms and reviewing the current status of aging degradation management. According to the review of additional equipment-specific aging degradation mechanisms and the current status of management to apply the aging degradation program to air conditioning facilities, it has been found that internal and external visual inspection procedures for fans, dampers, coils, filters and housings have to be added. It has been confirmed that among additional equipment s, fire dampers, fan bearings and belts and air cleaning/conditioning units with charcoal filters do not require additional inspection as they are periodically inspected. It has been found, however, that air cleaning/conditioning units without charcoal filters are to be inspected along with fans, ducts and coils

  16. Large-scale experimental facility for emergency condition investigation of a new generation NPP WWER-640 reactor with passive safety systems

    Aniskevich, Y.N.; Vasilenko, V.A.; Zasukha, V.K.; Migrov, Y.A.; Khabensky, V.B.

    1997-01-01

    The creation of the large-scale integral experimental facility (KMS) is specified by the programme of the experimental investigations to justify the engineering decisions on the safety of the design of the new generation NPP with the reactor WWER-640. The construction of KMS in a full volume will allow to conduct experimental investigations of all physical phenomena and processes, practically, occurring during the accidents on the NPPs with the reactor of WWER type and including the heat - mass exchange processes with low rates of the coolant, which is typical during the utilization of the passive safety systems, process during the accidents with a large leak, and also the complex intercommunicated processes in the reactor unit, passive safety systems and in the containment with the condition of long-term heat removal to the final absorber. KMS is being constructed at the Research Institute of Technology (NITI), Sosnovy Bor, Leningrad region, Russia. (orig.)

  17. Large-scale experimental facility for emergency condition investigation of a new generation NPP WWER-640 reactor with passive safety systems

    Aniskevich, Y.N.; Vasilenko, V.A.; Zasukha, V.K.; Migrov, Y.A.; Khabensky, V.B. [Research Inst. of Technology NITI (Russian Federation)

    1997-12-31

    The creation of the large-scale integral experimental facility (KMS) is specified by the programme of the experimental investigations to justify the engineering decisions on the safety of the design of the new generation NPP with the reactor WWER-640. The construction of KMS in a full volume will allow to conduct experimental investigations of all physical phenomena and processes, practically, occurring during the accidents on the NPPs with the reactor of WWER type and including the heat - mass exchange processes with low rates of the coolant, which is typical during the utilization of the passive safety systems, process during the accidents with a large leak, and also the complex intercommunicated processes in the reactor unit, passive safety systems and in the containment with the condition of long-term heat removal to the final absorber. KMS is being constructed at the Research Institute of Technology (NITI), Sosnovy Bor, Leningrad region, Russia. (orig.). 5 refs.

  18. Large-scale experimental facility for emergency condition investigation of a new generation NPP WWER-640 reactor with passive safety systems

    Aniskevich, Y N; Vasilenko, V A; Zasukha, V K; Migrov, Y A; Khabensky, V B [Research Inst. of Technology NITI (Russian Federation)

    1998-12-31

    The creation of the large-scale integral experimental facility (KMS) is specified by the programme of the experimental investigations to justify the engineering decisions on the safety of the design of the new generation NPP with the reactor WWER-640. The construction of KMS in a full volume will allow to conduct experimental investigations of all physical phenomena and processes, practically, occurring during the accidents on the NPPs with the reactor of WWER type and including the heat - mass exchange processes with low rates of the coolant, which is typical during the utilization of the passive safety systems, process during the accidents with a large leak, and also the complex intercommunicated processes in the reactor unit, passive safety systems and in the containment with the condition of long-term heat removal to the final absorber. KMS is being constructed at the Research Institute of Technology (NITI), Sosnovy Bor, Leningrad region, Russia. (orig.). 5 refs.

  19. Identification and Assessment of Material Models for Age-Related Degradation of Structures and Passive Components in Nuclear Power Plants

    Nie,J.; Braverman, J.; Hofmayer, C.; Kim, M. K.; Choi, I-K.

    2009-04-27

    describes the research effort performed by BNL for the Year 2 scope of work. This research focused on methods that could be used to represent the long-term behavior of materials used at NPPs. To achieve this BNL reviewed time-dependent models which can approximate the degradation effects of the key materials used in the construction of structures and passive components determined to be of interest in the Year 1 effort. The intent was to review the degradation models that would cover the most common time-dependent changes in material properties for concrete and steel components.

  20. French concepts of ''passive safety''

    Dennielou, Y.; Serret, M.

    1990-01-01

    N 4 model, the French 1400 MW PWR of the 90's, exhibits many advanced features. As far as safety is concerned, the fully computerized control room design takes advantage of the operating experience feedback and largely improves the man machine interface. New post-accident procedures have been developed (the so-called ''physical states oriented procedures''). A complete consistent set of ''Fundamental Safety Rules'' have been issued. This however doesn't imply any significant modification of standard PWR with regard to the passive aspects of safety systems or functions. Nevertheless, traditional PWR safety systems largely use passive aspects: natural circulation, reactivity coefficients, gravity driven control rods, injection accumulators, so on. Moreover, probability calculations allow for comparison between the respective contributions of passive and of active failures. In the near future, eventual options of future French PWRs to be commissioned after 2000 will be evaluated; simplification, passive and forgiving aspects of safety systems will be thoroughly considered. (author)

  1. Effectiveness of passive alcohol sensors

    1996-03-01

    Author's abstract: The purpose of this study was to evaluate the effectiveness of passive alcohol sensors for youth alcohol enforcement conducted as part of normal or typical police operations. Three municipal police departments of 100 or more sworn ...

  2. Passive heat removal in CANDU

    Hart, R.S.

    1997-01-01

    CANDU has a tradition of incorporating passive systems and passive components whenever they are shown to offer performance that is equal to or better than that of active systems, and to be economic. Examples include the two independent shutdown systems that employ gravity and stored energy respectively, the dousing subsystem of the CANDU 6 containment system, and the ability of the moderator to cool the fuel in the event that all coolant is lost from the fuel channels. CANDU 9 continues this tradition, incorporating a reserve water system (RWS) that increases the inventory of water in the reactor building and profiles a passive source of makeup water and/or heat sinks to various key process systems. The key component of the CANDU 9 reserve water system is a large (2500 cubic metres) water tank located at a high elevation in the reactor building. The reserve water system, while incorporating the recovery system functions, and the non-dousing functions of the dousing tank in CANDU 6, embraces other key systems to significantly extend the passive makeup/heat sink capability. The capabilities of the reserve water system include makeup to the steam generators secondary side if all other sources of water are lost; makeup to the heat transport system in the event of a leak in excess of the D 2 O makeup system capability; makeup to the moderator in the event of a moderator leak when the moderator heat sink is required; makeup to the emergency core cooling (ECC) system to assure NPSH to the ECC pumps during a loss of coolant accident (LOCA), and provision of a passive heat sink for the shield cooling system. Other passive designs are now being developed by AECL. These will be incorporated in future CANDU plants when their performance has been fully proven. This paper reviews the passive heat removal systems and features of current CANDU plants and the CANDU 9, and briefly reviews some of the passive heat removal concepts now being developed. (author)

  3. Key issues for passive safety

    Hayns, M.R.

    1996-01-01

    The paper represents a summary of the introductory presentation made at this Advisory Group Meeting on the Technical Feasibility and Reliability of Passive Safety Systems. It was intended as an overview of our views on what are the key issues and what are the technical problems which might dominate any future developments of passive safety systems. It is, therefore, not a ''review paper'' as such and only record the highlights. (author)

  4. Key issues for passive safety

    Hayns, M R [AEA Technology, Harwell, Didcot (United Kingdom). European Institutions; Hicken, E F [Forschungszentrum Juelich GmbH (Germany)

    1996-12-01

    The paper represents a summary of the introductory presentation made at this Advisory Group Meeting on the Technical Feasibility and Reliability of Passive Safety Systems. It was intended as an overview of our views on what are the key issues and what are the technical problems which might dominate any future developments of passive safety systems. It is, therefore, not a ``review paper`` as such and only record the highlights. (author).

  5. Passive vapor extraction feasibility study

    Rohay, V.J.

    1994-01-01

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft 3 /min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft 3 /min air flow rates, passive vapor extraction is more cost effective below 100 ppm

  6. Study on a new framework of Human Reliability Analysis to evaluate soft control execution error in advanced MCRs of NPPs

    Jang, Inseok; Kim, Ar Ryum; Jung, Wondea; Seong, Poong Hyun

    2016-01-01

    Highlights: • The operation environment of MCRs in NPPs has changed by adopting new HSIs. • The operation action in NPP Advanced MCRs is performed by soft control. • New HRA framework should be considered in the HRA for advanced MCRs. • HRA framework for evaluation of soft control execution human error is suggested. • Suggested method will be helpful to analyze human reliability in advance MCRs. - Abstract: Since the Three Mile Island (TMI)-2 accident, human error has been recognized as one of the main causes of Nuclear Power Plant (NPP) accidents, and numerous studies related to Human Reliability Analysis (HRA) have been carried out. Most of these methods were developed considering the conventional type of Main Control Rooms (MCRs). However, the operating environment of MCRs in NPPs has changed with the adoption of new Human-System Interfaces (HSIs) that are based on computer-based technologies. The MCRs that include these digital technologies, such as large display panels, computerized procedures, and soft controls, are called advanced MCRs. Among the many features of advanced MCRs, soft controls are a particularly important feature because operating actions in NPP advanced MCRs are performed by soft control. Due to the differences in interfaces between soft control and hardwired conventional type control, different Human Error Probabilities (HEPs) and a new HRA framework should be considered in the HRA for advanced MCRs. To this end, a new framework of a HRA method for evaluating soft control execution human error is suggested by performing a soft control task analysis and the literature regarding widely accepted human error taxonomies is reviewed. Moreover, since most current HRA databases deal with operation in conventional MCRs and are not explicitly designed to deal with digital HSIs, empirical analysis of human error and error recovery considering soft controls under an advanced MCR mockup are carried out to collect human error data, which is

  7. The experience from operation of electronic personal dosimetry system at Dukovany, Temelin and Mochovce NPPs after repair of Siemens dosemeters eliminating false doses

    Malysak, J.; Kocvara, S.; Jurochova, B.; Zelenka, Z.; Schacherl, M.; Zrubec, M.; Kaiser, H.

    2003-01-01

    This presentation summarizes the operational experience of the Electronic Personal Dosimetry Systems installed at Dukovany, Temelin and Mochovce NPPs. The system consists of three basic parts: Electronic personal dosemeters (EPD); Physical layer (HW); Logical layer (SW). Number of false doses before and after correction is presented. This presentation has demonstrated the possibilities of SEOD system and the possibility of easy dose comparison between the individual NPPs after introducing this electronic dosimetry system. Basically, the results of film and electronic dosimetry systems are according to our findings nearly identical. Electronic dosemeter sensitivity to interfering electromagnetic fields is a problem which is easily re-movable. In addition, if we know this problem, these false doses in the SEOD system can be easily revealed (e.g. by investigation of histograms) and repaired

  8. Technical Insight of the High Level Safety Goal for the NPPs Built in China’S Thirteenth Five-Year Period (2016-2020)

    Shi, G.; Zhan, W.; Mei, Q.; Sun, D., E-mail: shi@snerdi.com.cn [Shanghai Nuclear Engineering Research and Design Institute, SNPTC Shanghai (China)

    2014-10-15

    The “Nuclear Safety Planning” has been published in Oct. 2012 in China, which stipulates the safety goals for the NPPs which will be built in the future. As for the NPPs which will be built in China's Thirteenth Five-Year (2016-2020) and later, the high level safety goal is described as “the possibility of the large radioactive release should be practically eliminated by design”. A thorough investigation has been performed at SNERDI to explore the technical insights of this high level safety goal by using MEDP hierarchical safety goal approach. The definition of large release is proposed accordingly, DID requirements and probabilistic requirements are derived from this high level safety goal. (author)

  9. German - Ukrainian collaboration in the assessment of digital I and C systems for safety applications in NPPs

    Yastrebenetsky, M.; Vinogradskaia, S.; Wach, D.; Mulka, B.

    2001-01-01

    German - Ukrainian collaboration in safety assessment of digital Instrumentation and Control (IC) systems began to be in progress since 1995 as part of the established collaboration in the field of Ukrainian NPP safety declared by the German Ministry BMU and Ukrainian Ministry of Environmental Protection and Nuclear Safety and aimed at the support of the Ukrainian Regulatory Body in supervision and licensing of NPPs. The collaboration in IC was triggered by the contract between Rovno NPP (Ukraine) and Siemens (Germany) on procurement of digital emergency protection system for Unit 4. The collaboration has been realized between regulatory authorities and supporting organizations of both countries: GRS/ISTec - Germany and Nuclear Regulatory Authority and State Scientific Technical Center of Nuclear and Radiation Safety (SSTC NRS) - Ukraine. From the beginning the collaboration was intended to cover not only the single specific system, but also a great number of tasks concerned with safety assessment of digital IC systems. As a result the existing Ukrainian standards on IC assessment have been re-evaluated and supplemented by requirements concerning software-based digital IC safety systems. (authors)

  10. A Test Model in a RF Anechoic Chamber for the Application of Wi-Fi Communication in Korean Operating NPPs

    Kim, Yong Sik; Kim, Min Seok; Ryu, Ho Sun; Ye, Song Hae; Lee, Gwang Dae [KHNP, Daejeon (Korea, Republic of)

    2014-08-15

    The objective of this study is to make a test model and confirm its effectiveness in a radio frequency (RF) anechoic chamber before conducting a field test in Korean operating NPPs for use of Wi-Fi communication technology. This paper is focused on electromagnetic/radio-frequency interference (EMI/RFI) issue and discusses a methodology and its test result for overcoming that issue. Whenever wireless communication is performed between an access point (AP) and a smart phone, EMI/RFI problem always happens around those devices. It is necessary to decide how many wireless devices local workers will use and select what facilities and systems to protect from EMI/RFI, which are so-called EMI/RFI sensitive equipment. The number of wireless devices was decided as many as possible in the area where those devices could be used, and some sensitive equipment that shall not malfunction under electromagnetic environment were chosen. The test bed which considered above mentioned conditions was constructed and an experiment was carried out inside a radio-frequency anechoic chamber. Comparing with the allowable operating envelopes for electromagnetic level from RG-1.180, each maximum level of the test results acquired from a RF anechoic chamber is not over the limit even in case of considering the maximum local workers' usage. This result shows that it is highly likely that Wi-Fi communication can be used without any problem if sensitive equipment has observed the electromagnetic susceptibility limit of RG-1.180.

  11. FPGA-based I and C Systems: A Technological Trick or a way to improve NPPs Safety and Security?

    Sklyar, Vladimir; Andrashov, Anton; Kharchenko, Vyacheslav; Sklyar, Vladimir; Bakhmach, Ievgenii [RPC RADIY, Kirovograd (Ukraine)

    2012-03-15

    The objective of this paper is to discuss advantages and values which Field Programmable Gates Array (FPGA) based solutions can add to Instrumentation and Control (I and C) design of Nuclear Power Plants (NPPs). Application of FPGAs as programmable components instead of Programmable Logic Controllers (PLC) is an advanced solution which provides decreasing of software impact on potential common cause failures (CCF). There are the following such advantages: Implementation of safety functions without the use of any operation software and operating system, Flexibility of the I and C platform which can be configured for any type of functions and reactor designs, Reduction in the time necessary for software verification in the design phase, Easy modification of control logic without any need for hardware modification, Possibility of implementing all safety requirements in safety and safety-related I and C systems, Tolerance to internal failures and external environmental impacts, Resilience to obsolescence due to the portability of the Hardware Description Language (HDL) code between various FPGA-chips produced by different manufacturers, Reduction in Corby vulnerability.

  12. German - Ukrainian collaboration in the assessment of digital I and C systems for safety applications in NPPs

    Yastrebenetsky, M.; Vinogradskaia, S. [State Scientific Technical Center of Nuclear and Radiation Safety, Kharkov (Ukraine); Wach, D.; Mulka, B. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Garching (Germany)

    2001-07-01

    German - Ukrainian collaboration in safety assessment of digital Instrumentation and Control (IC) systems began to be in progress since 1995 as part of the established collaboration in the field of Ukrainian NPP safety declared by the German Ministry BMU and Ukrainian Ministry of Environmental Protection and Nuclear Safety and aimed at the support of the Ukrainian Regulatory Body in supervision and licensing of NPPs. The collaboration in IC was triggered by the contract between Rovno NPP (Ukraine) and Siemens (Germany) on procurement of digital emergency protection system for Unit 4. The collaboration has been realized between regulatory authorities and supporting organizations of both countries: GRS/ISTec - Germany and Nuclear Regulatory Authority and State Scientific Technical Center of Nuclear and Radiation Safety (SSTC NRS) - Ukraine. From the beginning the collaboration was intended to cover not only the single specific system, but also a great number of tasks concerned with safety assessment of digital IC systems. As a result the existing Ukrainian standards on IC assessment have been re-evaluated and supplemented by requirements concerning software-based digital IC safety systems. (authors)

  13. Participation in EU SARNET2 Project for an Enhancement of Severe Accident Evaluation Capability in Domestic NPPs

    Ahn, Kwang Il; Hong, S. W.; Kim, S. B.; Park, J. H.; Song, Y. M.

    2010-07-01

    The following results were obtained from the first year SARNET2 research activities. - WP4-2 session : acquisition of ASTEC 2.0 execution version, user manual and modeling/technical report for main six modules, code familiarization via ASTEC 2.0 code structure analysis and sample calculations. - WP6-4 session : preliminary calculations for APR1400 MCCI using MELCOR code. - WP7-1 session : thermal-hydraulic review of particle solidification model for steam explosion, suggestion of further activities for modeling corium material effect, review of physio-chemical particles and its applicability for modeling corium material effect. - WP7-2 session: review and benchmark analysis of ENACCEF experiments by participating in Task 3 'Combustion benchmark', and submission of analysis results for blind tests and preparation of analysis for open tests. - WP8-3 session: acquisition of ISTP Database and recent reports for two experiments (EPICUR/PARIS), review of technical issues in ST/FP, and selection of its domestic application field. The foregoing research results and experimental database for main SA issues obtained by this research are expected to be used for resolving SA issue remained in domestic NPPs (operating, to be constructed, future) and enhancing the evaluating capability of Level-2 PSA

  14. Materials for passively safe reactors

    Simnad, T.

    1993-01-01

    Future nuclear power capacity will be based on reactor designs that include passive safety features if recent progress in advanced nuclear power developments is realized. There is a high potential for nuclear systems that are smaller and easier to operate than the current generation of reactors, especially when passive or intrinsic characteristics are applied to provide inherent stability of the chain reaction and to minimize the burden on equipment and operating personnel. Taylor, has listed the following common generic technical features as the most important goals for the principal reactor development systems: passive stability, simplification, ruggedness, case of operation, and modularity. Economic competitiveness also depends on standardization and assurance of licensing. The performance of passively safe reactors will be greatly influenced by the successful development of advanced fuels and materials that will provide lower fuel-cycle costs. A dozen new designs of advanced power reactors have been described recently, covering a wide spectrum of reactor types, including pressurized water reactors, boiling water reactors, heavy-water reactors, modular high-temperature gas-cooled reactors (MHTGRs), and fast breeder reactors. These new designs address the need for passive safety features as well as the requirement of economic competitiveness

  15. Passive inhalation of cannabis smoke

    Law, B; Mason, P A; Moffat, A C; King, L J; Marks, V

    1984-09-01

    Six volunteers each smoked simultaneously, in a small unventilated room (volume 27 950 liter), a cannabis cigarette containing 17.1 mg delta 9-tetrahydrocannabinol (THC). A further four subjects - passive inhalers - remained in the room during smoking and afterwards for a total of 3 h. Blood and urine samples were taken from all ten subjects and analyzed by radioimmunoassay for THC metabolites. The blood samples from the passive subjects taken up to 3 h after the start of exposure to cannabis smoke showed a complete absence of cannabinoids. In contrast, their urine samples taken up to 6 h after exposure showed significant concentrations of cannabinoid metabolites (less than or equal to 6.8 ng ml-1). These data, taken with the results of other workers, show passive inhalation of cannabis smoke to be possible. These results have important implications for forensic toxicologists who are frequently called upon to interpret cannabinoid levels in body fluids.

  16. Active Versus Passive Academic Networking

    Goel, Rajeev K.; Grimpe, Christoph

    2013-01-01

    This paper examines determinants of networking by academics. Using information from a unique large survey of German researchers, the key contribution focuses on the active versus passive networking distinction. Is active networking by researchers a substitute or a complement to passive networking......? Other contributions include examining the role of geographic factors in networking and whether research bottlenecks affect a researcher's propensity to network. Are the determinants of European conference participation by German researchers different from conferences in rest of the world? Results show...... that some types of passive academic networking are complementary to active networking, while others are substitute. Further, we find differences in factors promoting participation in European conferences versus conferences in rest of the world. Finally, publishing bottlenecks as a group generally do...

  17. Protocol Monitoring Passive Solar Energy

    Van den Ham, E.R.; Bosselaar, L.

    1998-01-01

    A method has been developed by means of which the contribution of passive solar energy to the Dutch energy balance can be quantified univocally. The contribution was 57 PJ in 1990 and also 57 PJ in 1995. The efficiency of passive solar energy systems increased from -31.5% to -28.1% in the period 1990-1995, mainly as a result of the use of extra insulating glazing. As a result of the reduction of energy consumption for heating in houses it is expected that the extra contribution of 2 PJ will not be realized in the year 2010. It is suggested that the method to determine the absolute contribution of passive solar energy to the energy demand of dwellings is to be included in the protocol monitoring renewable energy. For the method to be included in the energy statistics of Statistics Netherlands (CBS) it can be considered only to take into account the difference compared to 1990. 11 refs

  18. Passivation of high temperature superconductors

    Vasquez, Richard P. (Inventor)

    1991-01-01

    The surface of high temperature superconductors such as YBa2Cu3O(7-x) are passivated by reacting the native Y, Ba and Cu metal ions with an anion such as sulfate or oxalate to form a surface film that is impervious to water and has a solubility in water of no more than 10(exp -3) M. The passivating treatment is preferably conducted by immersing the surface in dilute aqueous acid solution since more soluble species dissolve into the solution. The treatment does not degrade the superconducting properties of the bulk material.

  19. Investigations on passive containment cooling

    Knebel, J.U.; Cheng, X.; Neitzel, H.J.; Erbacher, F.J.; Hofmann, F.

    1997-01-01

    The composite containment design for advanced LWRs that has been examined under the PASCO project is a promising design concept for purely passive decay heat removal after a severe accident. The passive cooling processes applied are natural convection and radiative heat transfer. Heat transfer through the latter process removes at an emission coefficient of 0.9 about 50% of the total heat removed via the steel containment, and thus is an essential factor. The heat transferring surfaces must have a high emission coefficient. The sump cooling concept examined under the SUCO project achieves a steady, natural convection-driven flow from the heat source to the heat sink. (orig./CB) [de

  20. Passive solar offices: integrated design

    Evans, B

    1992-05-06

    Passive solar design in out-of-town offices can remove the need for air-conditioning by making greater use of daylight and natural ventilation. To promote the use of passive solar energy a series of design studies are being run by the Energy Technology Support Unit on behalf of the Department of Energy. The three reported here are designs for out-of-town business buildings. Each is a hypothetical building designed to a realistic brief for an organisation taking the role of real client. (author).

  1. The Danish Reportive Passive as a Non-Canonical Passive

    Ørsnes, Bjarne

    2013-01-01

    Danish passive utterance and cognitive verbs allow a construction where the subject of an infinitival complement is raised: Peter siges at være bortrejst (‘Peter is said to be out of town’). Contrary to English, these verbs are not ECM-verbs or subject-to-object raising verbs in the active...

  2. A ORACLE-based system for data collection, storage and analysis of main equipment load factors in NPPs and TPPs

    Ivanova, L.

    1993-01-01

    This data base is developed by the National Electricity Company, Sofia (BG) as an aid to supervision, analysis and administration decision making in a variety of operational situations in NPPs and TPPs. As major indicators of the equipment condition the following primary data are stored: steam or electricity production per month; operation hours per month; equipment stand-by outages; planned outages; unplanned permitted maintenance outages; unplanned emergency maintenance outages; number of outages of the unit per month. These data cover the period from the putting of the corresponding equipment into operation till the present moment, i.e. or about 32 years. The data up to 1990 are annual and for the last three years - monthly. Based on these primary data, the following quantities are calculated: average capacity; average load factors; operation time factors - total and accounting for the planned and the permitted unplanned outages; unpermitted outages factors - total and accounting for the planned and the permitted outages. All the factors are calculated on user's request for a chosen time period, by summing up correspondingly the major indicators (production, operation hours and various outages) for the given period. The system operates on an IBM 4341 under VM/SP and DB ORACLE V.5. The input is entered directly from the TPP and NPP by telex lines from PCs, operating also as telex machines, into the mainframe of Energokibernetika Ltd. They are available to all authorised users from local terminals or PCs, connected to the computer by synchronous or asynchronous lines. A system for data transmission to remote users along commutated telephone lines is also developed. (R. Ts.)

  3. An Experiment on the Impact of Communication Problems in the Multi-cultural Operation of NPPs' Emergency Operation

    Kang, Seongkeun; Lee, Chanyoung; Seong, Poong Hyun; Ha, Jun Su

    2015-01-01

    Korean government won a contract of nuclear power plants to UAE government in 2010 and nuclear power plants are now under construction in Barakah, UAE. However, with technology transfer and international cooperation, there needs to consider several potential problems due to the differences between two culture of the countries such as language, technical culture and expectation. It is unknown how potential problems can lead to an unsafe plant operation as well. We got to know language problem is the main issue from analyzing the OERs. Korean nuclear power plant operators will work in UAE and they will operate the NPPs with other countries' operators and managers. Therefore they will have to use English when they communicate each other. The purpose of this paper is to confirm how much operators get stress and how much accuracy is declined when operators communicate together in English. Reducing human error is quite important to make nuclear power plants safety. As mental workload of human operator is increased, operators get more stress, then the probability of occurring human error may be increased. It will affect bad influence to nuclear power plants safety. There are many factors to make mental workload increased. We focused on communication problem which is a key factor of the increasing mental workload because many Korean operators will work in UAE nuclear power plants and they may work together with UAE operators. We designed experimental methods to be able to check this problem qualitatively and quantitatively. We analyzed four factors to find the communication problems from the experiments which are accuracy, efficiency, NASA-TLX, and brain wave. Accuracy, efficiency, brain wave are quantitative factors, and NASA-TLX is qualitative factor. To find the impact of how much English affects the operators' workload, we did two cases of experiments; one is experiment for diagnosis and the other is experiment for execution

  4. A study on Prediction of Radioactive Source-term from the Decommissioning of Domestic NPPs by using CRUDTRAN Code

    Song, Jong Soon; Lee, Sang Heon; Cho, Hoon Jo [Department of Nuclear Engineering Chosun University, Gwangju (Korea, Republic of)

    2016-10-15

    For the study, the behavior mechanism of corrosion products in the primary system of the Kori no.1 was analyzed, and the volume of activated corrosion products in the primary system was assessed based on domestic plant data with the CRUDTRAN code used to predict the volume. It is expected that the study would be utilized in predicting radiation exposure of workers performing maintenance and repairs in high radiation areas and in selecting the process of decontaminations and decommissioning in the primary system. It is also expected that in the future it would be used as the baseline data to estimate the volume of radioactive wastes when decommissioning a nuclear plant in the future, which would be an important criterion in setting the level of radioactive wastes used to compute the quantity of radioactive wastes. The results of prediction of the radioactive nuclide inventory in the primary system performed in this study would be used as baseline data for the estimation of the volume of radioactive wastes when decommissioning NPPs in the future. It is also expected that the data would be important criteria used to classify the level of radioactive wastes to calculate the volume. In addition, it is expected that the data would be utilized in reducing radiation exposure of workers in charge of system maintenance and repairing in high radiation zones and also predicting the selection of decontaminations and decommissioning processes in the primary systems. In future researches, it is planned to conduct the source term assessment against other NPP types such as CANDU and OPR-1000, in addition to the Westinghouse type nuclear plants.

  5. An Experiment on the Impact of Communication Problems in the Multi-cultural Operation of NPPs' Emergency Operation

    Kang, Seongkeun; Lee, Chanyoung; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Ha, Jun Su [KUSTAR, Abu Dhabi (United Arab Emirates)

    2015-10-15

    Korean government won a contract of nuclear power plants to UAE government in 2010 and nuclear power plants are now under construction in Barakah, UAE. However, with technology transfer and international cooperation, there needs to consider several potential problems due to the differences between two culture of the countries such as language, technical culture and expectation. It is unknown how potential problems can lead to an unsafe plant operation as well. We got to know language problem is the main issue from analyzing the OERs. Korean nuclear power plant operators will work in UAE and they will operate the NPPs with other countries' operators and managers. Therefore they will have to use English when they communicate each other. The purpose of this paper is to confirm how much operators get stress and how much accuracy is declined when operators communicate together in English. Reducing human error is quite important to make nuclear power plants safety. As mental workload of human operator is increased, operators get more stress, then the probability of occurring human error may be increased. It will affect bad influence to nuclear power plants safety. There are many factors to make mental workload increased. We focused on communication problem which is a key factor of the increasing mental workload because many Korean operators will work in UAE nuclear power plants and they may work together with UAE operators. We designed experimental methods to be able to check this problem qualitatively and quantitatively. We analyzed four factors to find the communication problems from the experiments which are accuracy, efficiency, NASA-TLX, and brain wave. Accuracy, efficiency, brain wave are quantitative factors, and NASA-TLX is qualitative factor. To find the impact of how much English affects the operators' workload, we did two cases of experiments; one is experiment for diagnosis and the other is experiment for execution.

  6. Invariant methods for an ensemble-based sensitivity analysis of a passive containment cooling system of an AP1000 nuclear power plant

    Di Maio, Francesco; Nicola, Giancarlo; Borgonovo, Emanuele; Zio, Enrico

    2016-01-01

    Sensitivity Analysis (SA) is performed to gain fundamental insights on a system behavior that is usually reproduced by a model and to identify the most relevant input variables whose variations affect the system model functional response. For the reliability analysis of passive safety systems of Nuclear Power Plants (NPPs), models are Best Estimate (BE) Thermal Hydraulic (TH) codes, that predict the system functional response in normal and accidental conditions and, in this paper, an ensemble of three alternative invariant SA methods is innovatively set up for a SA on the TH code input variables. The ensemble aggregates the input variables raking orders provided by Pearson correlation ratio, Delta method and Beta method. The capability of the ensemble is shown on a BE–TH code of the Passive Containment Cooling System (PCCS) of an Advanced Pressurized water reactor AP1000, during a Loss Of Coolant Accident (LOCA), whose output probability density function (pdf) is approximated by a Finite Mixture Model (FMM), on the basis of a limited number of simulations. - Highlights: • We perform the reliability analysis of a passive safety system of Nuclear Power Plant (NPP). • We use a Thermal Hydraulic (TH) code for predicting the NPP response to accidents. • We propose an ensemble of Invariant Methods for the sensitivity analysis of the TH code • The ensemble aggregates the rankings of Pearson correlation, Delta and Beta methods. • The approach is tested on a Passive Containment Cooling System of an AP1000 NPP.

  7. Antenna for passive RFID tags

    Schiopu, Paul; Manea, Adrian; Cristea, Ionica; Grosu, Neculai; Vladescu, Marian; Craciun, Anca-Ileana; Craciun, Alexandru

    2015-02-01

    Minuscule devices, called RFID tags are attached to objects and persons and emit information which positioned readers may capture wirelessly. Many methods of identification have been used, but that of most common is to use a unique serial number for identification of person or object. RFID tags can be characterized as either active or passive [1,2]. Traditional passive tags are typically in "sleep" state until awakened by the reader's emitted field. In passive tags, the reader's field acts to charge the capacitor that powers the badge and this can be a combination of antenna and barcodes obtained with SAW( Surface Acoustic Wave) devices [1,2,3] . The antenna in an RFID tag is a conductive element that permits the tag to exchange data with the reader. The paper contribution are targeted to antenna for passive RFID tags. The electromagnetic field generated by the reader is somehow oriented by the reader antenna and power is induced in the tag only if the orientation of the tag antenna is appropriate. A tag placed orthogonal to the reader yield field will not be read. This is the reason that guided manufacturers to build circular polarized antenna capable of propagating a field that is alternatively polarized on all planes passing on the diffusion axis. Passive RFID tags are operated at the UHF frequencies of 868MHz (Europe) and 915MHz (USA) and at the microwave frequencies of 2,45 GHz and 5,8 GHz . Because the tags are small dimensions, in paper, we present the possibility to use circular polarization microstrip antenna with fractal edge [2].

  8. Surface Passivation in Empirical Tight Binding

    He, Yu; Tan, Yaohua; Jiang, Zhengping; Povolotskyi, Michael; Klimeck, Gerhard; Kubis, Tillmann

    2016-03-01

    Empirical Tight Binding (TB) methods are widely used in atomistic device simulations. Existing TB methods to passivate dangling bonds fall into two categories: 1) Method that explicitly includes passivation atoms is limited to passivation with atoms and small molecules only. 2) Method that implicitly incorporates passivation does not distinguish passivation atom types. This work introduces an implicit passivation method that is applicable to any passivation scenario with appropriate parameters. This method is applied to a Si quantum well and a Si ultra-thin body transistor oxidized with SiO2 in several oxidation configurations. Comparison with ab-initio results and experiments verifies the presented method. Oxidation configurations that severely hamper the transistor performance are identified. It is also shown that the commonly used implicit H atom passivation overestimates the transistor performance.

  9. Passivation Of High-Temperature Superconductors

    Vasquez, Richard P.

    1991-01-01

    Surfaces of high-temperature superconductors passivated with native iodides, sulfides, or sulfates formed by chemical treatments after superconductors grown. Passivating compounds nearly insoluble in and unreactive with water and protect underlying superconductors from effects of moisture. Layers of cuprous iodide and of barium sulfate grown. Other candidate passivating surface films: iodides and sulfides of bismuth, strontium, and thallium. Other proposed techniques for formation of passivating layers include deposition and gas-phase reaction.

  10. Passive Scalar Evolution in Peripheral Region

    Lebedev, V. V.; Turitsyn, K. S.

    2003-01-01

    We consider evolution of a passive scalar (concentration of pollutants or temperature) in a chaotic (turbulent) flow. A universal asymptotic behavior of the passive scalar decay (homogenization) related to peripheral regions (near walls) is established. The passive scalar moments and its pair correlation function in the peripheral region are analyzed. A special case investigated in our paper is the passive scalar decay along a pipe.

  11. Two or three decades of passive directions

    Cook, J.

    1995-01-01

    This paper presents an overview of the direction of passive solar architecture. The topics of the paper include design temperatures for buildings, active vs passive, fuel vs philosophy, engineering vs architecture, the thermal scale: heating vs cooling, fuel subsidies, divergent practices, sustainability, lighting, health, the place of passive technology

  12. Active house concept versus passive House

    Zeiler, W.; Boxem, G.; Vehler, R.; Verhoeven, M.; Fremouw, M.

    2009-01-01

    The passive house concept is the present trend in energy efficient sustainable dwellings. Within the passive house concept every effort is made to minimize the energy use. Substantial savings can be achieved by passive energy systems, especially natural ventilation, summer shading and winter solar

  13. Innovative solutions in passive house details

    Mlecnik, E.; Hilderson, W.

    2008-01-01

    For the realization of the first passive house demonstration projects in Belgium, passive houses were requested by convinced clients, designed by architects with experience in low energy building, and built by contractors with a feeling for working in building teams. These first passive house

  14. A Lexical Approach to Passive in ESL.

    Marshall, Fred

    Dissatisfaction with the standard transformational grammar approach to teaching passive voice sentences gave rise to the method developed. It is based on the framework of a lexical-functional grammar, which claims that both active and passive sentences are base-generated, and that both active and passive verb forms occur in the lexicon. It would…

  15. Traffic classification with passive measurement

    Pham, Hoang Phong

    2005-01-01

    Abstract This is a master thesis from a collaboration between Oslo University College and Uninett Research. Uninett have a passive monitoring device on a 2.5 Gbps backbone link between Trondheim and Narvik. They uses measurement with optical splitters and specialized measuring interfaces to trace traffic with Gigabit speed. We would like to investigate the structure and patterns in these data. It is of special interest to classify the traffic belonging to different services and protocols. ...

  16. EP1000 passive plant description

    Saiu, G.

    1999-01-01

    In 1994, a group of European Utilities, together with Westinghouse and its Industrial Partner GENESI (an Italian consortium including ANSALDO and FIAT), initiated a program designated EPP (European Passive Plant) to evaluate Westinghouse Passive Nuclear Plant Technology for application in Europe. In Phase I of the European Passive Plant Program which was completed in 1996, a 1000 MWe passive plant reference design (EP1000) was established which conforms to the European Utility Requirements (EUR) and is expected to meet the European Safety Authorities requirements. Phase 2 of the program was initiated in 1997 with the objective of developing the Nuclear Island design details and performing supporting analyses to start development of Safety Case Report (SCR) for submittal to European Licensing Authorities. The first part of Phase 2, 'Design Definition' phase (Phase 2A) will be completed at the end of 1998, the main efforts being design definition of key systems and structures, development of the Nuclear Island layout, and performing preliminary safety analyses to support design efforts. The second part, 'Phase 2B', includes both the analyses and evaluations required to demonstrate the adequacy of the design, and to support the preparation of Safety Case Report. The second part of Phase 2 of the program will start at the beginning of 1999 and will be completed in the 2001. Incorporation of the EUR has been a key design requirement for the EP1000 from the beginning of the program. Detailed design solutions to meet the EUR have been defined and the safety approach has also been developed based on the EUR guidelines. This paper integrates and updates the plant description reported in the IAEA TECDOC-968. The most significant developments of the EP1000 plant design during Phase 2A of the EPP program are described and reference is made to the key design requirements set by the EUR Rev. B document. (author)

  17. Active and Passive Hybrid Sensor

    Carswell, James R.

    2010-01-01

    A hybrid ocean wind sensor (HOWS) can map ocean vector wind in low to hurricane-level winds, and non-precipitating and precipitating conditions. It can acquire active and passive measurements through a single aperture at two wavelengths, two polarizations, and multiple incidence angles. Its low profile, compact geometry, and low power consumption permits installation on air craft platforms, including high-altitude unmanned aerial vehicles (UAVs).

  18. Alternative to Nitric Acid Passivation

    Kessel, Kurt R.

    2016-01-01

    Corrosion is an extensive problem that affects the National Aeronautics and Space Administration (NASA) and European Space Agency (ESA). The deleterious effects of corrosion result in steep costs, asset downtime affecting mission readiness, and safety risks to personnel. It is vital to reduce corrosion costs and risks in a sustainable manner. The primary objective of this effort is to qualify citric acid as an environmentally-preferable alternative to nitric acid for passivation of stainless steel alloys.

  19. Review of off-site emergency preparedness and response plan of Indian NPPs based on experience of Fukushima nuclear accident

    Singh, Hukum; Dash, M.; Shukla, Vikas; Vijayan, P.; Krishnamurthy, P.R.

    2012-01-01

    Nuclear power plants in India are designed, constructed and operated based on the principle of the highest priority to nuclear safety. To deal with any unlikely situation of radiological emergency, the emergency preparedness and response plans are ensured to be in place at all NPPs prior to their commissioning. These plans are periodically reviewed and tested by conducting emergency exercise with the participation of various agencies such as Nuclear Power Corporation of India Limited, NDMA, district authorities, regulatory body and general public. On March 11, 2011 an earthquake of magnitude 9.0 hit the Fukushima Dai-ichi and Dai-ni followed by tsunami waves of height 15 meters above reference sea level. This resulted in large scale release of radioactive material from Fukushima Dai-ichi NPS. This led to the evacuation of a large number of people from the areas surrounding the affected nuclear power plants. The event was rated as level 7 event in International Nuclear Event Scale (INES). The event also revealed the challenges in handling radiological emergency situation in adverse environmental conditions, The experience of managing radiological emergency situation during Fukushima nuclear accident provides opportunities to review and improve emergency preparedness and response programme. The present paper presents the chronology of the emergency situation, challenges faced and handled in Fukushima. Even though the possibility of a Fukushima type nuclear accident in India is very remote due to the low probability of a high intensity earthquake followed by tsunami at NPP sites, the efforts needs to be initiated from the regulatory point of view for an effective Nuclear and Radiological Emergency Preparedness and Response Plans. The Emergency Preparedness and Response Plans of NPP sites were reviewed in the light of unique challenges of accident at Fukushima. It is realized that multi unit events are the realities that must be addressed as part of Emergency

  20. Review of off-site emergency preparedness and response plan of Indian NPPs based on experience of Fukushima nuclear accident

    Singh, Hukum; Dash, M.; Shukla, Vikas; Vijayan, P.; Krishnamurthy, P.R., E-mail: vshukla@aerb.gov.in [Operating Plants Safety Division, Atomic Energy Regulatory Board, Mumbai (India)

    2012-07-01

    Nuclear power plants in India are designed, constructed and operated based on the principle of the highest priority to nuclear safety. To deal with any unlikely situation of radiological emergency, the emergency preparedness and response plans are ensured to be in place at all NPPs prior to their commissioning. These plans are periodically reviewed and tested by conducting emergency exercise with the participation of various agencies such as Nuclear Power Corporation of India Limited, NDMA, district authorities, regulatory body and general public. On March 11, 2011 an earthquake of magnitude 9.0 hit the Fukushima Dai-ichi and Dai-ni followed by tsunami waves of height 15 meters above reference sea level. This resulted in large scale release of radioactive material from Fukushima Dai-ichi NPS. This led to the evacuation of a large number of people from the areas surrounding the affected nuclear power plants. The event was rated as level 7 event in International Nuclear Event Scale (INES). The event also revealed the challenges in handling radiological emergency situation in adverse environmental conditions, The experience of managing radiological emergency situation during Fukushima nuclear accident provides opportunities to review and improve emergency preparedness and response programme. The present paper presents the chronology of the emergency situation, challenges faced and handled in Fukushima. Even though the possibility of a Fukushima type nuclear accident in India is very remote due to the low probability of a high intensity earthquake followed by tsunami at NPP sites, the efforts needs to be initiated from the regulatory point of view for an effective Nuclear and Radiological Emergency Preparedness and Response Plans. The Emergency Preparedness and Response Plans of NPP sites were reviewed in the light of unique challenges of accident at Fukushima. It is realized that multi unit events are the realities that must be addressed as part of Emergency

  1. Experiments on the Impact of language Problems in the Multi-cultural Operation of NPPs' Emergency Operation

    Kang, Seongkeun; Kim, Taehoon; Seong, Poong Hyun; Ha, Jun Su

    2016-01-01

    In 2010, The Korea Electric Power Corporation (KEPCO) was awarded a multi-billion dollar bid to construct the first nuclear power plant in Barakah, UAE. One must keep in mind however, that with technology transfer and international cooperation comes a host of potential problems arising from cultural differences such as language, everyday habitudes and workplace expectation. As of now, how problematic these potential issues may become is unknown. Of the aforementioned factors, communication is perhaps of foremost importance. We investigated UAE culture-related issues through analysis of operating experience reviews (OERs) and came to the conclusion that the language barrier needed utmost attention. Korean nuclear power plant operators will work in UAE and will operate the NPPs with operators and managers of other nationalities as well. The purpose of this paper is firstly to confirm that operators are put under mental stress, and secondly to demonstrate the decline in accuracy when they must work in English. Reducing human error is quite important to make nuclear power plants safer. As the mental workload of human operator is increased, the probability of a human error occurring also increases. It will have a negative influence on the plant’s safety. There are many factors which can potentially increase mental workload. We focused on communication problem which is a key factor of increasing mental workload because many Korean operators will work in UAE nuclear power plants and may work together with UAE operators. From these experiments we compared how performance of both Korean and UAE subjects were decreased when they use English. We designed experimental methods to be able to check this problem qualitatively and quantitatively. We analyzed four factors to find the communication problems from the experiments which are accuracy, efficiency, NASA-TLX, and brain wave. Accuracy, efficiency, brain wave are quantitative factors, and NASA-TLX is qualitative factor. To

  2. Experiments on the Impact of language Problems in the Multi-cultural Operation of NPPs' Emergency Operation

    Kang, Seongkeun; Kim, Taehoon; Seong, Poong Hyun [KAIST, Daejeon (Korea, Republic of); Ha, Jun Su [KUSTAR, Abu Dhabi (United Arab Emirates)

    2016-10-15

    In 2010, The Korea Electric Power Corporation (KEPCO) was awarded a multi-billion dollar bid to construct the first nuclear power plant in Barakah, UAE. One must keep in mind however, that with technology transfer and international cooperation comes a host of potential problems arising from cultural differences such as language, everyday habitudes and workplace expectation. As of now, how problematic these potential issues may become is unknown. Of the aforementioned factors, communication is perhaps of foremost importance. We investigated UAE culture-related issues through analysis of operating experience reviews (OERs) and came to the conclusion that the language barrier needed utmost attention. Korean nuclear power plant operators will work in UAE and will operate the NPPs with operators and managers of other nationalities as well. The purpose of this paper is firstly to confirm that operators are put under mental stress, and secondly to demonstrate the decline in accuracy when they must work in English. Reducing human error is quite important to make nuclear power plants safer. As the mental workload of human operator is increased, the probability of a human error occurring also increases. It will have a negative influence on the plant’s safety. There are many factors which can potentially increase mental workload. We focused on communication problem which is a key factor of increasing mental workload because many Korean operators will work in UAE nuclear power plants and may work together with UAE operators. From these experiments we compared how performance of both Korean and UAE subjects were decreased when they use English. We designed experimental methods to be able to check this problem qualitatively and quantitatively. We analyzed four factors to find the communication problems from the experiments which are accuracy, efficiency, NASA-TLX, and brain wave. Accuracy, efficiency, brain wave are quantitative factors, and NASA-TLX is qualitative factor. To

  3. Interior design for passive solar homes

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems has brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building form incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitability of various interior elements.

  4. Interior design for passive solar homes

    Breen, J. C.

    1981-07-01

    The increasing emphasis on refinement of passive solar systems brought recognition to interior design as an integral part of passive solar architecture. Interior design can be used as a finetuning tool minimizing many of the problems associated with passive solar energy use in residential buildings. In addition, treatment of interior space in solar model homes may be a prime factor in determining sales success. A new style of interior design is evolving in response to changes in building from incorporating passive solar design features. The psychology behind passive solar architecture is reflected in interiors, and selection of interior components increasingly depends on the functional suitably of various interior elements.

  5. Degradation of materials and passivity

    Meisel, W.

    1997-01-01

    Demanding for a reduction in materials degradation is a serious problem all over the world. Moessbauer spectroscopy (MS) is, among others, a very valuable tool to follow many degradation processes. Evidently, Fe is the most important Moessbauer element considering the overall presence of iron in everyday life. MS may contribute to our knowledge about nearly all fields of materials degradation, chemical, mechanical, thermal, irradiative, etc. Following some general lines, corrosion is considered in particular. MS is applicable to investigate the bulk of materials as well as their surface layers with an information depth of ca. 250 nm. In general, it has to be applied as a surface sensitive method in combination with other relevant methods in order to get a detailed insight into ongoing processes. Some examples have been selected to elucidate the application of MS in this field. Another class of examples concerns attempts to prevent corrosion, i.e., the application of coatings and transforming chemicals. A very effective and most natural way to reduce corrosion is the passivation of materials. The effect of passive layers and their destruction by environmental influences are discussed using results of MS and related methods. It is outlined that passivity is not restricted to chemically treated metals but can be considered as a general concept for preventing different kinds of materials from degradation. (orig.)

  6. Passive infrared motion sensing technology

    Doctor, A.P.

    1994-01-01

    In the last 10 years passive IR based (8--12 microns) motion sensing has matured to become the dominant method of volumetric space protection and surveillance. These systems currently cost less than $25 to produce and yet use traditionally expensive IR optics, filters, sensors and electronic circuitry. This IR application is quite interesting in that the volumes of systems produced and the costs and performance level required prove that there is potential for large scale commercial applications of IR technology. This paper will develop the basis and principles of operation of a staring motion sensor system using a technical approach. A model for the motion of the target is developed and compared to the background. The IR power difference between the target and the background as well as the optical requirements are determined from basic principles and used to determine the performance of the system. Low cost reflective and refractive IR optics and bandpass IR filters are discussed. The pyroelectric IR detector commonly used is fully discussed and characterized. Various schemes for ''false alarms'' have been developed and are also explained. This technology is also used in passive IR based motion sensors for other applications such as lighting control. These applications are also discussed. In addition the paper will discuss new developments in IR surveillance technology such as the use of linear motion sensing arrays. This presentation can be considered a ''primer'' on the art of Passive IR Motion Sensing as applied to Surveillance Technology

  7. The passive of reflexive verbs in Icelandic

    Hlíf Árnadóttir

    2011-10-01

    Full Text Available The Reflexive Passive in Icelandic is reminiscent of the so-called New Passive (or New Impersonal in that the oblique case of a passivized object NP is preserved. As is shown by recent surveys, however, speakers who accept the Reflexive Passive do not necessarily accept the New Passive, whereas conversely, speakers who accept the New Passive do also accept the Reflexive Passive. Based on these results we suggest that there is a hierarchy in the acceptance of passive sentences in Icelandic, termed the Passive Acceptability Hierarchy. The validity of this hierarchy is confirmed by our diachronic corpus study of open access digital library texts from Icelandic journals and newspapers dating from the 19th and 20th centuries (tímarit.is. Finally, we sketch an analysis of the Reflexive Passive, proposing that the different acceptability rates of the Reflexive and New Passives lie in the argument status of the object. Simplex reflexive pronouns are semantically dependent on the verbs which select them, and should therefore be analyzed as syntactic arguments only, and not as semantic arguments of these verbs.

  8. Proceedings (slides) of the OECD/NEA Workshop on Innovations in Water-cooled Reactor Technologies

    Spiler, Joze; Kim, Sang-Baik; ); Feron, Fabien; Jaervinen, Marja-Leena; Husse, Julien; ); Ferraro, Giovanni; Bertels, Frank; Denk, Wolfgang; Tuomisto, Harri; Golay, Michael; Buongiorno, J.; Todreas, N.; Adams, E.; Briccetti, A.; Jurewicz, J.; Kindfuller, V.; Srinivasan, G.; Strother, M.; Minelli, P.; Fasil, E.; Zhang, J.; Genzman, G.; Epinois, Bertrand de l'; Kim, Shin Whan; Laaksonen, Jukka; Maltsev, Mikhail; Yu, CHongxing; Powell, David; Gorgemans, Julie; Hopwood, Jerry; Bylov, Igor; Bakhmetyev, Alexander M.; Lepekhin, Andrey N.; Fadeev, Yuriy P.; Bruna, Giovanni; Gulliford, Jim; ); Ham-Su, Rosaura; Thevenot, Caroline; GAUTIER, Guy-Marie; MARSAULT, Philippe; PIGNATEL, Jean-Francois; White, Andrew; )

    2015-02-01

    New technologies and solutions have been developed over more than thirty years to improve the safety, performance and economics of nuclear power plants. Particular efforts were made in designing systems to prevent or mitigate nuclear accidents and, greatly limit or even avoid any offsite release of radioactivity. Reactor designs developed in the 1980's and later are often referred to as Generation III (Gen III) reactors. They offer enhanced safety compared to earlier Generation II (Gen II) designs, as well as improved performance and economics. Examples of Gen III safety design features include solutions for corium localisation, advanced containment structures, improved emergency core-cooling systems, filtered venting systems, hydrogen risk management solutions, etc. Some of these solutions have also been back-fitted or partially adapted to existing reactors, based on recommendations from regulators or modernisation efforts by the utilities operating these reactors, to bring their level of safety to levels approaching those of the more modern designs. Other innovations found in the latest water-cooled reactor designs include the use of passive safety systems, and often associated with those, a simplification in the design of the reactor. Gen III reactors also feature better economics, for example increased design lifetime up to 60 years, ability to use 100% MOX fuel and operate with higher flexibility, higher thermal efficiencies and reduced staff requirements. Modularity is often quoted as a feature of some Gen III designs as a way of reducing the construction times and simplifying the decommissioning of the plant. The scope of the Workshop includes, inter alia: - Evolution of regulatory and design requirements for commercial water-cooled reactors; - Innovations in water-cooled reactor technologies that allowed significant improvement in the level of safety, with a discussion on advantages and challenges of active vs. passive safety systems; - Innovations under

  9. Evaluating remote control and robotics actions in NPPs in an ALARA perspective: lessons from the evolution of steam generator tube plugging technique in France

    Lefaure, C.; Lochard, J.; Blain, A.

    1989-01-01

    Introducing remote tooling and robotics in NPPs raises many questions. Is it better to develop specific robotic tools for each type of operation, or to conceive more generic multipurpose tool carriers. Does the introduction of remote control and robotics always reduce human involvement and collective doses. What are the impacts on individual doses distribution for the most exposed operators. Under what conditions is robotics justified from an economical point of view. Even if robotics and remote tooling actions can reduce significantly individual and collective exposures, because of their high costs of development, they will be adopted only if simultaneously the potential for operational cost savings is also clearly demonstrated. Integrating operational cost savings in the cost evaluation of the ALARA procedure is important to compare and select among different robotics and remote control actions. This paper presents how to evaluate in a systematic way dose reductions, operational costs savings as well as the conditions under which robotics and remote control actions can effectively improve occupational radiation protection in NPPs. The demonstration is based on an analysis of the evolution of the steam generator tube plugging technique developed in French PWRs

  10. A Security Assessment Approach with Graded Importance Score of Security Controls and Asset Consequence for I and C Systems in Operating NPPs

    Lee, Sooill; Kim, Yong Sik; Moon, Insun; Lee, Euijong [KHNP CRI, Daejeon (Korea, Republic of)

    2016-10-15

    This paper introduces a security assessment approach with graded importance score of security controls and the asset consequence through an asset and risk analysis to manage the security levels in operating NPPs (Nuclear Power Plants). Whereas, those are being exposed to various types of new and existing cyber threats, vulnerabilities and risks which significantly increase the likelihood that those could be compromised. U.S. NRC(United States Nuclear Regulatory Commission) and KINAC(Korea Institute of Nuclear Nonproliferation And Control) request the cyber security plan by establishing the cyber security program through assessing and managing the potential for adverse effect on safety, security and emergency preparedness functions so as to provide high assurance that critical functions are properly protected from the cyber-attack. This paper shows the security assessment approach with graded importance score of security controls and the asset consequence. It could lead to manage the security levels consistent with the purpose of defense in- depth strategy based on regulatory rule as well as internal risk-based self-assessment. Also, this management of the security level may make effect of encouraging the installation of high ranked countermeasures in order to rapidly increase the security level. Proposed approach could be conducted for the pilot test on the model plants with each reactor type of operating NPPs.

  11. A Security Assessment Approach with Graded Importance Score of Security Controls and Asset Consequence for I and C Systems in Operating NPPs

    Lee, Sooill; Kim, Yong Sik; Moon, Insun; Lee, Euijong

    2016-01-01

    This paper introduces a security assessment approach with graded importance score of security controls and the asset consequence through an asset and risk analysis to manage the security levels in operating NPPs (Nuclear Power Plants). Whereas, those are being exposed to various types of new and existing cyber threats, vulnerabilities and risks which significantly increase the likelihood that those could be compromised. U.S. NRC(United States Nuclear Regulatory Commission) and KINAC(Korea Institute of Nuclear Nonproliferation And Control) request the cyber security plan by establishing the cyber security program through assessing and managing the potential for adverse effect on safety, security and emergency preparedness functions so as to provide high assurance that critical functions are properly protected from the cyber-attack. This paper shows the security assessment approach with graded importance score of security controls and the asset consequence. It could lead to manage the security levels consistent with the purpose of defense in- depth strategy based on regulatory rule as well as internal risk-based self-assessment. Also, this management of the security level may make effect of encouraging the installation of high ranked countermeasures in order to rapidly increase the security level. Proposed approach could be conducted for the pilot test on the model plants with each reactor type of operating NPPs

  12. Passive film growth on carbon steel and its nanoscale features at various passivating potentials

    Li, Yuan; Cheng, Y. Frank

    2017-01-01

    Highlights: • Imaged the topography of passivated steel at various film-forming potentials. • Characterized the nanoscale features of passive films. • Determined the composition of passive films formed at various potentials. - Abstract: In this work, the passivation and topographic sub-structure of passive films on a carbon steel in a carbonate/bicarbonate solution was characterized by electrochemical measurements, atomic force microscopy and X-ray photoelectron spectroscopy. When passivating at a potential near the active-passive transition, the film contains the mixture of Fe_3O_4, Fe_2O_3 and FeOOH, with numerous nanoscale features. As the film-forming potential shifts positively, the passive film becomes more compact and the nanoscale features disappear. When the film is formed at a passive potential where the oxygen evolution is enabled, the content of FeOOH in the film increases, resulting in an amorphous topography and reduced corrosion resistance.

  13. The passive-aggressive organization.

    Kaplan, Robert S; Norton, David P

    2005-10-01

    Passive-aggressive organizations are friendly places to work: People are congenial, conflict is rare, and consensus is easy to reach. But, at the end of the day, even the best proposals fail to gain traction, and a company can go nowhere so imperturbably that it's easy to pretend everything is fine. Such companies are not necessarily saddled with mulishly passive-aggressive employees. Rather, they are filled with mostly well-intentioned people who are the victirms of flawed processes and policies. Commonly, a growing company's halfhearted or poorly thought-out attempts to decentralize give rise to multiple layers of managers, whose authority for making decisions becomes increasingly unclear. Some managers, as a result, hang back, while others won't own up to the calls they've made, inviting colleagues to second-guess or overturn the decisions. In such organizations, information does not circulate freely, and that makes it difficult for workers to understand the impact of their actions on company performance and for managers to correctly appraise employees' value to the organization. A failure to accurately match incentives to performance stifles initiative, and people do just enough to get by. Breaking free from this pattern is hard; a long history of seeing corporate initiatives ignored and then fade away tends to make people cynical. Often it's best to bring in an outsider to signal that this time things will be different. He or she will need to address every obstacle all at once: clarify decision rights; see to it that decisions stick; and reward people for sharing information and adding value, not for successfully negotiating corporate politics. If those steps are not taken, it's only a matter of time before the diseased elements of a passive-aggressive organization overwhelm the remaining healthy ones and drive the company into financial distress.

  14. The Heat Exchanger for Passive Part ECCS of WWER-1000 on Base of the Thermo siphons

    Kirov, V.; Chulkin, O.

    2008-01-01

    One of NPP's systems providing safe operation is the system of emergency core cooling system (ECCS), which primary function in accidents is to flood the nuclear reactor core and to assure the sub critical condition and core cooling. At injection of cold water in reactor thermal stresses and thermal fatigue in the vessel cladding and constructional materials are arise. Low temperature of the water injected in reactor is a reason of occurrence of these undesirable consequences. Some variants of the water heating in accumulators of ECCS are considered. Now at Ukrainian NPPs the electrical heating in accumulators is used. Electrical heaters create the essential additional loading to diesel generators at imposing of two accidents - the large break and losses of power supplies on own needs. It is offered to use a heater in accumulators that working by a principle two-phase thermal siphon which advantages is: small dimensions, small delay and design reliability. In such heat exchanger the heating medium is a direct steam and the heated up medium is water with boric acid from accumulators of ECCS. Under requirements of the service regulations of ECCS accumulators it is necessary to guarantee injected water heating up to 90 ?? in case of a small break and to 150 ?? in case of the large break. Results of calculations for different external diameters of a tube of thermal siphon which have allowed to define the constructive sizes of heat exchanger, providing necessary conditions for required functioning of passive part ECCS are submitted The calculation and analysis of operating modes of the changed circuit of passive part ECCS for various accidents is carried out. The calculated pressure drop indicates that changes do not have essential influence on system work as a whole. Thus, the submitted decision provides the increase of reliability of ECCS at small and large breaks accidents, i.e. in all modes stipulated by the project.(author)

  15. Architectural Qualities in Passive Houses

    Brunsgaard, Camilla

    2012-01-01

    that it is possible to build this type of houses, but the knowledge and discussion about the architectural quality in the buildings is hardly present. The question is if the strategies for optimising energy use and indoor environment collide with the architectural qualities of buildings. This paper brings forth...... this discussion based in literature and four case studies. The paper highlights cases on how passive strategies for optimising energy use and indoor environment affect, restrict, inspire or create possibilities for the architectural expression and there through the architectural quality of the building....

  16. Passive Containment DataSet

    This data is for Figures 6 and 7 in the journal article. The data also includes the two EPANET input files used for the analysis described in the paper, one for the looped system and one for the block system.This dataset is associated with the following publication:Grayman, W., R. Murray , and D. Savic. Redesign of Water Distribution Systems for Passive Containment of Contamination. JOURNAL OF THE AMERICAN WATER WORKS ASSOCIATION. American Water Works Association, Denver, CO, USA, 108(7): 381-391, (2016).

  17. Passive longitudinal phase space linearizer

    P. Craievich

    2010-03-01

    Full Text Available We report on the possibility to passively linearize the bunch compression process in electron linacs for the next generation x-ray free electron lasers. This can be done by using the monopole wakefields in a dielectric-lined waveguide. The optimum longitudinal voltage loss over the length of the bunch is calculated in order to compensate both the second-order rf time curvature and the second-order momentum compaction terms. Thus, the longitudinal phase space after the compression process is linearized up to a fourth-order term introduced by the convolution between the bunch and the monopole wake function.

  18. Measurement and Treatment of Passive Muscle Stiffness

    Kirk, Henrik

    , which aimed to investigate: 1) The development of a clinical method to evaluate and distinguish neural (reflex mediated stiffness) and non-neural (passive muscle stiffness) components of muscle stiffness in adults with CP by objective and reliable measurements. 2) The association between increased...... and reliability of the method, and argue for the use of the method in the clinical practice. The device is able to distinguish between passive muscle stiffness and reflex-mediated stiffness in subjects with CP. It shows good high intrarater and interrater reliability in evaluation of passive muscle stiffness...... to measure muscle stiffness, and distinguish between passive muscle stiffness and reflex-mediated stiffness. Furthermore, it is a reliable device to measure changes in passive ROM. Treatment of passive muscle stiffness should be directed towards intense training, comprising many repetitions with a functional...

  19. Forekomsten af passiv rygning i Danmark

    Kristensen, T S; Møller, L; Holstein, B E

    1990-01-01

    The occurrence of passive smoking in the adult population in Denmark has not been described previously. This article publishes data from three investigations all of which were carried out in 1987. One was an interview investigation of a random section of the Danish population carried out by the D...... inconvenienced by passive smoking at work and a corresponding fraction had taken steps to reduce the extent of passive smoking in their daily life. Udgivelsesdato: 1990-Aug-27...... showed consistent results as regards the occurrence of passive smoking among adult Danes. About 12% of non-smokers were exposed to passive smoking for at least eight hours and 40% for at least one hour daily. Altogether 73% were exposed to passive smoking daily. About one third of the non-smokers were...

  20. Columbia County Habitat for Humanity Passive Townhomes

    None, None

    2016-03-01

    Columbia County Habitat for Humanity (CCHH) (New York, Climate Zone 5A) built a pair of townhomes to Passive House Institute U.S. (PHIUS+ 2015) criteria to explore approaches for achieving Passive House performance (specifically with respect to exterior wall, space-conditioning, and ventilation strategies) within the labor and budget context inherent in a Habitat for Humanity project. CCHH’s goal is to eventually develop a cost-justified Passive House prototype design for future projects.

  1. Passive Nuclear Plants Program (UPDATE)

    Chimeno, M. A.

    1998-01-01

    The light water passive plants program (PCNP), today Advanced Nuclear Power Plants Program (PCNA), was constituted in order to reach the goals of the Spanish Electrical Sector in the field of advanced nuclear power plants, optimize the efforts of all Spanish initiatives, and increase joint presence in international projects. The last update of this program, featured in revision 5th of the Program Report, reflects the consolidation of the Spanish sector's presence in International programs of the advanced power plants on the basis of the practically concluded American ALWR program. Since the beginning of the program , the PCNP relies on financing from the Electrical sector, Ocide, SEPI-Endesa, Westinghouse, General Electric, as well as from the industrial cooperators, Initec, UTE (Initec- Empresarios Agrupados), Ciemat, Enusa, Ensa and Tecnatom. The program is made up of the following projects, already concluded: - EPRI's Advanced Light Water Plants Certification Project - Westinghouse's AP600 Project - General Electric's SBWR Project (presently paralyzed) and ABWR project Currently, the following project are under development, at different degrees of advance: - EPP project (European Passive Plant) - EBWR project (European Advanced Boiling Water Reactor)

  2. A Portable Passive Physiotherapeutic Exoskeleton

    Dasheek Naidu

    2012-10-01

    Full Text Available The public healthcare system in South Africa is in need of urgent attention in no small part because there has been an escalation in the number of stroke victims which could be due to the increase in hypertension in this urbanizing society. There is a growing need for physiotherapists and occupational therapists in the country, which is further hindered by the division between urban and rural areas. A possible solution is a portable passive physiotherapeutic exoskeleton device. The exoskeleton device has been formulated to encapsulate methodologies that enable the anthropomorphic integration between a biological and mechatronic limb. A physiotherapeutic mechanism was designed to be portable and adjustable, without limiting the spherical motion and workspace of the human arm. The exoskeleton was designed to be portable in the sense that it could be transported geographically. It is a complete device allowing for motion in the shoulder, elbow, wrist and hand joints. The inverse kinematics was solved iteratively via the Damped Least Squares (DLS method. The electronic and computer system allowed for professional personnel to either change an individual joint or a combination of joints angles via the kinematic models. A ramp PI controller was established to provide a smooth response to simulate the passive therapy motion.

  3. Liberal theory of passive citizenship

    Salatić Stevan

    2013-01-01

    Full Text Available In this seminar paper I will focus on the analysis of liberal theory of citizenship. The focus of the study will be on the liberal-communitarian dispute in the theory of citizenship, with main ideas of the most important representatives of liberal discourse in the field of citizenship also being discussed. I will look more closely at the ideas of T.H. Marshall, as the most significant writer of liberal orthodoxy in the second half of the twentieth century, his contribution to liberal theory of passive citizenship, but I will also deal with the ideas of his biggest critics, both from the aspect of liberalism and from the aspect of communitarianism, including Anthony Giddens, Claus Offe, Michael Mann, Barrington Moore and Brian Turner. The emphasis will be on Marshall's term 'conquest of citizenship', as well as on the derivation of various theories of state from the obtained rights achieved through the expansion of the concept of citizenship. Finally, I will say something about modern obstacles to theories of passive citizenship derived from the communitarian school.

  4. Passive propulsion in vortex wakes

    Beal, D. N.; Hover, F. S.; Triantafyllou, M. S.; Liao, J. C.; Lauder, G. V.

    A dead fish is propelled upstream when its flexible body resonates with oncoming vortices formed in the wake of a bluff cylinder, despite being well outside the suction region of the cylinder. Within this passive propulsion mode, the body of the fish extracts sufficient energy from the oncoming vortices to develop thrust to overcome its own drag. In a similar turbulent wake and at roughly the same distance behind a bluff cylinder, a passively mounted high-aspect-ratio foil is also shown to propel itself upstream employing a similar flow energy extraction mechanism. In this case, mechanical energy is extracted from the flow at the same time that thrust is produced. These results prove experimentally that, under proper conditions, a body can follow at a distance or even catch up to another upstream body without expending any energy of its own. This observation is also significant in the development of low-drag energy harvesting devices, and in the energetics of fish dwelling in flowing water and swimming behind wake-forming obstacles.

  5. Utility requirements for advanced LWR passive plants

    Yedidia, J.M.; Sugnet, W.R.

    1992-01-01

    LWR Passive Plants are becoming an increasingly attractive and prominent option for future electric generating capacity for U.S. utilities. Conceptual designs for ALWR Passive Plants are currently being developed by U.S. suppliers. EPRI-sponsored work beginning in 1985 developed preliminary conceptual designs for a passive BWR and PWR. DOE-sponsored work from 1986 to the present in conjunction with further EPRI-sponsored studies has continued this development to the point of mature conceptual designs. The success to date in developing the ALWR Passive Plant concepts has substantially increased utility interest. The EPRI ALWR Program has responded by augmenting its initial scope to develop a Utility Requirements Document for ALWR Passive Plants. These requirements will be largely based on the ALWR Utility Requirements Document for Evolutionary Plants, but with significant changes in areas related to the passive safety functions and system configurations. This work was begun in late 1988, and the thirteen-chapter Passive Plant Utility Requirements Document will be completed in 1990. This paper discusses the progress to date in developing the Passive Plant requirements, reviews the top-level requirements, and discusses key issues related to adaptation of the utility requirements to passive safety functions and system configurations. (orig.)

  6. Multiple mechanisms quench passive spiral galaxies

    Fraser-McKelvie, Amelia; Brown, Michael J. I.; Pimbblet, Kevin; Dolley, Tim; Bonne, Nicolas J.

    2018-02-01

    We examine the properties of a sample of 35 nearby passive spiral galaxies in order to determine their dominant quenching mechanism(s). All five low-mass (M⋆ environments. We postulate that cluster-scale gas stripping and heating mechanisms operating only in rich clusters are required to quench low-mass passive spirals, and ram-pressure stripping and strangulation are obvious candidates. For higher mass passive spirals, while trends are present, the story is less clear. The passive spiral bar fraction is high: 74 ± 15 per cent, compared with 36 ± 5 per cent for a mass, redshift and T-type matched comparison sample of star-forming spiral galaxies. The high mass passive spirals occur mostly, but not exclusively, in groups, and can be central or satellite galaxies. The passive spiral group fraction of 74 ± 15 per cent is similar to that of the comparison sample of star-forming galaxies at 61 ± 7 per cent. We find evidence for both quenching via internal structure and environment in our passive spiral sample, though some galaxies have evidence of neither. From this, we conclude no one mechanism is responsible for quenching star formation in passive spiral galaxies - rather, a mixture of mechanisms is required to produce the passive spiral distribution we see today.

  7. Inherent/passive safety for fusion

    Piet, S.J.

    1986-06-01

    The concept of inherent or passive passive safety for fusion energy is explored, defined, and partially quantified. Four levels of safety assurance are defined, which range from true inherent safety to passive safety to protection via active engineered safeguard systems. Fusion has the clear potential for achieving inherent or passive safety, which should be an objective of fusion research and design. Proper material choice might lead to both inherent safety and high mass power density, improving both safety and economics. When inherent safety is accomplished, fusion will be well on the way to achieving its ultimate potential and to be truly different and superior

  8. Passive Wireless SAW Humidity Sensors, Phase I

    National Aeronautics and Space Administration — This proposal describes the preliminary development of passive wireless surface acoustic wave (SAW) based humidity sensors for NASA application to distributed...

  9. Passive cavitation imaging with ultrasound arrays.

    Salgaonkar, Vasant A; Datta, Saurabh; Holland, Christy K; Mast, T Douglas

    2009-12-01

    A method is presented for passive imaging of cavitational acoustic emissions using an ultrasound array, with potential application in real-time monitoring of ultrasound ablation. To create such images, microbubble emissions were passively sensed by an imaging array and dynamically focused at multiple depths. In this paper, an analytic expression for a passive image is obtained by solving the Rayleigh-Sommerfield integral, under the Fresnel approximation, and passive images were simulated. A 192-element array was used to create passive images, in real time, from 520-kHz ultrasound scattered by a 1-mm steel wire. Azimuthal positions of this target were accurately estimated from the passive images. Next, stable and inertial cavitation was passively imaged in saline solution sonicated at 520 kHz. Bubble clusters formed in the saline samples were consistently located on both passive images and B-scans. Passive images were also created using broadband emissions from bovine liver sonicated at 2.2 MHz. Agreement was found between the images and source beam shape, indicating an ability to map therapeutic ultrasound beams in situ. The relation between these broadband emissions, sonication amplitude, and exposure conditions are discussed.

  10. Hybrid Active-Passive Radiation Shielding System

    National Aeronautics and Space Administration — A radiation shielding system is proposed that integrates active magnetic fields with passive shielding materials. The objective is to increase the shielding...

  11. Universality in passively advected hydrodynamic fields : the case of a passive vector with pressure

    Benzi, R.; Biferale, L.; Toschi, F.

    2001-01-01

    Universality of statistical properties of passive quantities advected by turbulent velocity fields at changing the passive forcing mechanism is discussed. In particular, we concentrate on the statistical properties of an hydrodynamic system with pressure. We present theoretical arguments and

  12. New electricity generating installations - Czech experience

    Biza, K.; Pazdera, F.; Zdarek, J.

    2004-01-01

    Economically and technically are analysed alternatives for new electricity generation installations (GEN 111+ NPPs, finalization of NPPs under construction, lifetime extension of existing NPPs, coal plants and gas plants). Described are experienced with NPP Temelin (lessons learned from its design, construction, start-up and resent operation and service experience) and new Czech Energy Policy, where the nuclear energy is an important source for electricity generation. Discussed is also impact of potential trading with CO 2 limits and strategy on minimization of dependence on energy from politically unstable regions. Underlined is important role of preparation of young generation for safe and reliable long term operation of NPPs. General recommendation is to orient on finalization of NPPs under construction, lifetime extension of existing NPPs and long term orientation on new generation of NPPs (GEN III+ and GEN IV). (author)

  13. Health risks of passive smoking.

    Papier, C M; Stellman, S D

    1986-01-01

    Passive or involuntary smoking is the inhalation of smoke which escapes directly into the air from the lit end of a burning cigarette. This unfiltered smoke contains the same toxic components of the mainstream smoke inhaled directly by the smoker, including numerous carcinogens, many in greater concentrations. It has long been known that exposure to this type of smoke leads to increased respiratory and other adverse health conditions in non-smokers, especially children. During the past five years, evidence has been accumulating that risk of lung cancer is also higher, particularly in non-smoking women whose husbands smoke. Despite uncertainties and differences in interpretation of various cancer studies, there is ample justification for public health measures now in place or proposed, such as restriction or elimination of smoking in the workplace and in public places.

  14. Integrated Passive And Wireless Sensor

    Li, Bodong

    2015-04-30

    A passive and wireless sensor is provided for sensing at least one of magnetic field, temperature or humidity. The sensor can provide only one of the sensing functions, individually or any combination of them simultaneously. It can be used for various applications where magnetic field changes, temperature and/or humidity need to be measured. In one or more embodiments, a surface acoustic wave (SAW) sensor is provided that can measure one or more of a magnetic field (or current that generates the magnetic field), temperature and humidity. In one or more embodiments, a magnetoimpedence (MI) sensor (for example a thin film giant magnetoimpedance (GMI) sensor), a thermally sensitive (for example a Lithium Niobite (LiNbO.sub.3)) substrate, and a humidity sensitive film (for example a hydrogel film) can be used as sensing elements.

  15. Integrated Passive And Wireless Sensor

    Li, Bodong; Kosel, Jü rgen

    2015-01-01

    A passive and wireless sensor is provided for sensing at least one of magnetic field, temperature or humidity. The sensor can provide only one of the sensing functions, individually or any combination of them simultaneously. It can be used for various applications where magnetic field changes, temperature and/or humidity need to be measured. In one or more embodiments, a surface acoustic wave (SAW) sensor is provided that can measure one or more of a magnetic field (or current that generates the magnetic field), temperature and humidity. In one or more embodiments, a magnetoimpedence (MI) sensor (for example a thin film giant magnetoimpedance (GMI) sensor), a thermally sensitive (for example a Lithium Niobite (LiNbO.sub.3)) substrate, and a humidity sensitive film (for example a hydrogel film) can be used as sensing elements.

  16. Specification of requirements for the implementation of ASICs and FPGA in instrumentation and control systems important to safety in German NPPs

    Schnurer, G.

    2007-01-01

    This paper gives an overview concerning the design as well as the verification and validation of Application Specific Integrated Circuits (ASICs) and Field Programmable Gate Arrays (FPGA) in German NPPs which are applied to carry out I and C functions. The qualification procedures dealt with restricted on ASICs without any microcontroller core. Dependent on the different safety categories, recommendations concerning the qualification level and procedures are elaborated which have to be achieved for ASICs and FPGA. Important aspects within the framework of the expert judgement for upgrading of safety relevant I and C by ASICs and FPGA are dealt with. These aspects are of general character and are mainly focused on suitability test procedures and robustness requirements of ASICs and FPGA

  17. The development of advanced instrumentation and control technology -The development of verification and validation technology for instrumentation and control in NPPs-

    Kwon, Kee Choon; Ham, Chang Sik; Lee, Byung Sun; Kim, Jung Taek; Park, Won Man; Park, Jae Chang; Lee, Jang Soo; Um, Heung Sub; Kim, Jang Yul; Ryoo, Chan Hoh; Joo, Jae Yoon; Song, Soon Ja

    1995-07-01

    We collected and analyzed the domestic/international codes, standards and guidelines to develop high reliable software verification and validation methodology which is satisfied to our real situation. The three major parts of work are performed that is the construction of the frame for high reliable software development environment, establishment of high reliable software development methodology and study for the basic technology related to safety-critical software. These three parts are tightly coupled each other to achieve self-reliable software verification and validation technology for digital I and C in NPPs. The configuration of hardware and software are partly performed using requirements which is developed in first stage for the development of I and C test facility. In hardware part, expanded interface using VXI bus and driving software is completed. The main program for math, modelling and supervisor program for instructions are developed. 27 figs, 22 tabs, 69 refs. (Author)

  18. Development of methodologies for optimization of surveillance testing and maintenance of safety related equipment at NPPs. Report of a research coordination meeting. Working material

    NONE

    1997-09-01

    This report summarizes the results of the first meeting of the Coordinated Research Programme (CRP) on Development of Methodologies for Optimization of Surveillance Testing and Maintenance of Safety Related Equipment at NPPs, held at the Agency Headquarters in Vienna, from 16 to 20 December 1996. The purpose of this Research Coordination Meeting (RCM) was that all Chief Scientific Investigators of the groups participating in the CRP presented an outline of their proposed research projects. Additionally, the participants discussed the objective, scope, work plan and information channels of the CRP in detail. Based on these presentations and discussions, the entire project plan was updated, completed and included in this report. This report represents a common agreed project work plan for the CRP. Refs, figs, tabs.

  19. The development of advanced instrumentation and control technology -The development of verification and validation technology for instrumentation and control in NPPs-

    Kwon, Kee Choon; Ham, Chang Sik; Lee, Byung Sun; Kim, Jung Taek; Park, Won Man; Park, Jae Chang; Lee, Jang Soo; Um, Heung Sub; Kim, Jang Yul; Ryoo, Chan Hoh; Joo, Jae Yoon; Song, Soon Ja [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-07-01

    We collected and analyzed the domestic/international codes, standards and guidelines to develop high reliable software verification and validation methodology which is satisfied to our real situation. The three major parts of work are performed that is the construction of the frame for high reliable software development environment, establishment of high reliable software development methodology and study for the basic technology related to safety-critical software. These three parts are tightly coupled each other to achieve self-reliable software verification and validation technology for digital I and C in NPPs. The configuration of hardware and software are partly performed using requirements which is developed in first stage for the development of I and C test facility. In hardware part, expanded interface using VXI bus and driving software is completed. The main program for math, modelling and supervisor program for instructions are developed. 27 figs, 22 tabs, 69 refs. (Author).

  20. Passive and active protection of cotton textiles

    Bochove, C. van

    1967-01-01

    In rotproofing of cotton a distinction is made between passive and active protection. In passive protection, the structure of the cotton fibre is modified in such a way that the fibre can longer be attacked. This modification of structure can be effected on different levels: microscopical,

  1. Influence of passivation process on chip performance

    Lu, J.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2009-01-01

    In this work, we have studied the performance of CMOS chips before and after a low temperature post-processing step. In order to prevent damage to the IC chips by the post-processing steps, a first passivation layers is needed on top of the IC chips. Two different passivation layer deposition

  2. Passive and Portable Polymer Optical Fiber Cleaver

    Saez-Rodriguez, D.; Min, R.; Ortega, B.

    2016-01-01

    opening up the possibility of an electrically passive cleaver. In this letter, we describe the implementation and testing of a high quality cleaver based on a mechanical system formed by a constant force spring and a damper, which leads to the first reported electrical passive and portable cleaver....

  3. Passive house networks : How can they deliver?

    Mlecnik, E.

    2009-01-01

    This paper examines experiences with the diffusion of the passive house concept, applied to the situation of ‘emerging’ countries like Belgium and the Netherlands. Adopter categories considering the passive house concept are defined. A marketing study based on Rogers’ theory of diffusion of

  4. Passive Solar Construction--Design and Performance.

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    Presented is a list of books and reports intended to serve as technical sources of information for the building professional interested in energy conservation. These publications are grouped under these headings: (1) energy-conserving building design; (2) passive systems/design; (3) passive systems/performance; and (4) proceedings (of the American…

  5. Population Games, Stable Games, and Passivity

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  6. Considerations on nuclear reactor passive safety systems

    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)

  7. Passive systems for light water reactors

    Adinolfi, R.; Noviello, L.

    1990-01-01

    The paper reviews the most original concepts that have been considered in Italy for the back-fitting of the nuclear power plants in order to reduce the probability and the importance of the release to the environment in case of a core melt. With reference either to BWR or PWR, passive concepts have been considered for back-fitting in the following areas: pump seals damage prevention and ECCS passive operation; reactor passive depressurization; molten reactor core passive cooling; metal containment passive water cooling through a water tank located at high level; containment isolation improvement through a sealing system; containment leaks control and limitation of environmental release. In addition some considerations will be made on the protection against external events introduced from the beginning on the PUN design either on building and equipment lay-out either on structure design. (author). 5 figs

  8. FSD for operating NPPs as part of sustainable dose reduction - recontamination evaluation for the German PWR Grafenrheinfeld

    Stellwag, Bernhard; Hoffmann-Wankerl, Stephan; Schuetz, Sigrid; Jacob, Astrid

    2012-09-01

    Full-system decontamination (FSD) or replacement of steam generators (SG) and other large components in mature PWR plants results in large bare metal surfaces in the reactor system. The AREVA chemistry concept for sustainable dose rate reduction at such plants includes a passivation treatment for formation of high-quality oxide films in the reactor system and high pH operation in combination with zinc injection during subsequent power operation. The effectiveness of these measures has been proven by plant operation experience. The systematic evaluation of plant-specific experience is used for further optimization of the concept. These measures were also applied at the 1350 MW-class 4-loop PWR Grafenrheinfeld after an FSD with the AREVA decontamination process HP/CORD R UV in 28 th outage. The passivation treatment consisted of zinc injection during plant heat-up and parallel adjustment of a high pH value. It was carried out in the plant operation condition 'subcritical hot' for 200 hours and a pH (300 deg. C) of 7.1. During the cycle, the pH value was increased to 7.4 and zinc injection was continued. This paper evaluates the recontamination of the plant inclusive the first refueling outage since the FSD. The evaluation is based on routine chemistry and dose rate surveillance data and on the results of special measurement programs conducted at the plant before and after the FSD. Results of surface gamma activity measurements and fuel crud analyses are also described. Data is evaluated with regard to release, transport and deposition of corrosion products and nuclides in the reactor system. The plant-specific contamination sources and their pathways are outlined. Compared to the first refueling outage of the plant in 1983, the dose rate level at the main loops could be more than halved in spite of already activated core internals and crud on fuel assemblies, the in-core instrumentation and the control rods including guide assemblies and drive rods. The FSD

  9. Passivity-based design of robust passive damping for LCL-filtered voltage source converters

    Wang, Xiongfei; Blaabjerg, Frede; Loh, Poh Chiang

    2015-01-01

    Passive damping is proven as a robust stabilizing technique for LCL-filtered voltage source converters. However, conventional design methods of passive dampers are based on the passive components only, while the inherent damping effect of time delay in the digital control system is overlooked....... In this paper, a frequency-domain passivity-based design approach is proposed, where the passive dampers are designed to eliminate the negative real part of the converter output admittance with closed-loop current control, rather than shaping the LCL-filter itself. Thus, the influence of time delay...... in the current control is included, which allows a relaxed design of the passive damper with the reduced power loss and improved stability robustness against grid parameters variations. Design procedures of two commonly used passive dampers with LCL-filtered VSCs are illustrated. Experimental results validate...

  10. Citric Acid Passivation of Stainless Steel

    Yasensky, David; Reali, John; Larson, Chris; Carl, Chad

    2009-01-01

    Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.

  11. Evaluating the Relationship between Equilibrium Passive ...

    Objectives. This review evaluates passive sampler uptake of hydrophobic organic contaminants (HOCs) in water column and interstitial water exposures as a surrogate for organism bioaccumulation. Approach/Activities. Fifty-five studies were found where both passive sampler uptake and organism bioaccumulation were measured and 19 of these investigations provided direct comparisons relating passive sampler uptake and organism bioaccumulation. Polymers compared included low density polyethylene (LDPE), polyoxymethylene (POM), and polydimethylsiloxane (PDMS), and organisms ranged from polychaetes and oligochaetes to bivalves, aquatic insects, and gastropods. Regression equations correlating bioaccumulation (CL) and passive sampler uptake (CPS) were used to assess the strength of observed relationships. Results/Lessons Learned. Passive sampling based concentrations resulted in strong logarithmic regression relationships, most of which were within one to two orders of magnitude of measured bioaccumulation. Mean coefficients of determination (r2) for LDPE, PDMS and POM were 0.68, 0.76 and 0.58, respectively. For the available raw data, the mean ratio of CL and CPS was 10.8 ± 18.4 (n = 609). Passive sampler uptake and bioaccumulation were not found to be identical (i.e., CPS ≠ CL) but the logarithmic-based relationships between these values were consistently linear and predictive. This review concludes that in many applications passive sampling may serve as a

  12. Passive detection of vehicle loading

    McKay, Troy R.; Salvaggio, Carl; Faulring, Jason W.; Salvaggio, Philip S.; McKeown, Donald M.; Garrett, Alfred J.; Coleman, David H.; Koffman, Larry D.

    2012-01-01

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  13. Illegal Passive Smoking at Work

    François-Xavier Lesage

    2011-01-01

    Results. Ninety-five percent of a total group of 172 OP of Champagne county filled the postal questionnaire. More than 80% of OP's replies identified illegal PSW. The average prevalence of PSW exposure was 0.7% of the total working population. Environmental tobacco smoke (ETS levels were considered between low and medium for most passive smokers (71%. Main features exposure to ETS at work for non-smokers was associated with female gender (69.5%, age between 40 and 49 years (41.2% and belonging to tertiary sector (75.6%. Environmental tobacco smoke exposures at work was firstly in the office for 49.7% of the subjects and secondly in the restroom for 18% of them. Main medical symptoms encountered by non-smokers were respiratory tractus irritation (81.7%. Eighty-three percent of OPs indicated solution to eradicate PSW. Illegal PSW is really weaker than fifteen years ago. However, the findings support a real ban on smoking in the workplace in order to protect all workers.

  14. [Passive euthanasia and living will].

    Julesz, Máté

    2014-07-06

    This article deals with the intentional distinction between murder of first degree and passive euthanasia. In Hungary, active euthanasia is considered to be a murder of first degree, whilst the Netherlands, Belgium, Luxemburg and Switzerland have legalized the active form of mercy killing in Europe. The palliative terminal care, when e.g. giving pain-killer morphine to the patient, might result in decreasing the patient's life-span, and thus causing indirect euthanasia. However, the legal institution of living will exists in several counter-euthanasia countries. The living will allows future patients to express their decision in advance to refuse a life-sustaining treatment, e.g. in case of irreversible coma. The institution of living will exists in Germany and in Hungary too. Nevertheless, the formal criteria of living will make it hardly applicable. The patient ought to express his/her will before a notary public in advance, and he/she should hand it over when being hospitalized. If the patient is not able to present his/her living will to his/her doctor in the hospital, then his/her only hope remains that he/she has given a copy of the living will to the family doctor previously, and the family doctor will notify the hospital.

  15. PASSIVE DETECTION OF VEHICLE LOADING

    Garrett, A.

    2012-01-03

    The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

  16. Passive fault current limiting device

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  17. Passive Cooling of Body Armor

    Holtz, Ronald; Matic, Peter; Mott, David

    2013-03-01

    Warfighter performance can be adversely affected by heat load and weight of equipment. Current tactical vest designs are good insulators and lack ventilation, thus do not provide effective management of metabolic heat generated. NRL has undertaken a systematic study of tactical vest thermal management, leading to physics-based strategies that provide improved cooling without undesirable consequences such as added weight, added electrical power requirements, or compromised protection. The approach is based on evaporative cooling of sweat produced by the wearer of the vest, in an air flow provided by ambient wind or ambulatory motion of the wearer. Using an approach including thermodynamic analysis, computational fluid dynamics modeling, air flow measurements of model ventilated vest architectures, and studies of the influence of fabric aerodynamic drag characteristics, materials and geometry were identified that optimize passive cooling of tactical vests. Specific architectural features of the vest design allow for optimal ventilation patterns, and selection of fabrics for vest construction optimize evaporation rates while reducing air flow resistance. Cooling rates consistent with the theoretical and modeling predictions were verified experimentally for 3D mockups.

  18. Passivation Effects in Copper Thin Films

    Wiederhirn, G.; Nucci, J.; Richter, G.; Arzt, E.; Balk, T. J.; Dehm, G.

    2006-01-01

    We studied the influence of a 10 nm AlxOy passivation on the stress-temperature behavior of 100 nm and 1 μm thick Cu films. At low temperatures, the passivation induces a large tensile stress increase in the 100 nm film; however, its effect on the 1 μm film is negligible. At high temperatures, the opposite behavior is observed; while the passivation does not change the 100 nm film behavior, it strengthens the 1 μm film by driving it deeper into compression. These observations are explained in light of a combination of constrained diffusional creep and dislocation dynamics unique to ultra-thin films

  19. Python passive network mapping P2NMAP

    Hosmer, Chet

    2015-01-01

    Python Passive Network Mapping: P2NMAP is the first book to reveal a revolutionary and open source method for exposing nefarious network activity. The ""Heartbleed"" vulnerability has revealed significant weaknesses within enterprise environments related to the lack of a definitive mapping of network assets. In Python Passive Network Mapping, Chet Hosmer shows you how to effectively and definitively passively map networks. Active or probing methods to network mapping have traditionally been used, but they have many drawbacks - they can disrupt operations, crash systems, and - most important

  20. Non-Chromate Passivation of Zinc

    Tang, Peter Torben; Bech-Nielsen, G.

    1993-01-01

    Phos). The treatments are within the same concentration region, and they have a mutual pat-ent pending. Although some tests still need to be conducted, the following aspects are clear at the present time: The general appearance of the passivated zinc surface is very similar to a standard yellow chromate treatment...... successfully. The corrosion resistance against white rust on zinc and zinc alloys is just as good as that of yellow chromate, although the result de-pends on the corrosion test method as well as on the nature of the zinc substrate pas-sivated. The passivation procedure is simply a dip for approxi-mately 2...

  1. Lipid-Based Passivation in Nanofluidics

    2012-01-01

    Stretching DNA in nanochannels is a useful tool for direct, visual studies of genomic DNA at the single molecule level. To facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We demonstrate virtually complete long-term passivation of nanochannel surfaces to a range of relevant reagents, including streptavidin-coated quantum dots, RecA proteins, and RecA–DNA complexes. We show that the performance of the lipid bilayer is significantly better than that of standard bovine serum albumin-based passivation. Finally, we show how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation by DNase I. We expect that our approach will open up for detailed, systematic studies of a wide range of protein–DNA interactions with high spatial and temporal resolution. PMID:22432814

  2. Hydrodynamic interaction between bacteria and passive sphere

    Zhang, Bokai; Ding, Yang; Xu, Xinliang

    2017-11-01

    Understanding hydrodynamic interaction between bacteria and passive sphere is important for identifying rheological properties of bacterial and colloidal suspension. Over the past few years, scientists mainly focused on bacterial influences on tracer particle diffusion or hydrodynamic capture of a bacteria around stationary boundary. Here, we use superposition of singularities and regularized method to study changes in bacterial swimming velocity and passive sphere diffusion, simultaneously. On this basis, we present a simple two-bead model that gives a unified interpretation of passive sphere diffusion and bacterial swimming. The model attributes both variation of passive sphere diffusion and changes of speed of bacteria to an effective mobility. Using the effective mobility of bacterial head and tail as an input function, the calculations are consistent with simulation results at a broad range of tracer diameters, incident angles and bacterial shapes.

  3. Decision Support on Small size Passive Samples

    Vladimir Popukaylo

    2018-05-01

    Full Text Available A construction technique of adequate mathematical models for small size passive samples, in conditions when classical probabilistic-statis\\-tical methods do not allow obtaining valid conclusions was developed.

  4. Experiments, Passive Observation and Scenario Analysis

    Hoover, Kevin D.; Juselius, Katarina

    The paper provides a careful, analytical account of Trygve Haavelmo's unsystematic, but important, use of the analogy between controlled experiments common in the natural sciences and econometric techniques. The experimental analogy forms the linchpin of the methodology for passive observation...

  5. Thermophysiological adaptations to passive mild heat acclimation

    Pallubinsky, H; Schellen, L; Kingma, B R M; Dautzenberg, B; van Baak, M A; van Marken Lichtenbelt, W D

    Passive mild heat acclimation (PMHA) reflects realistic temperature challenges encountered in everyday life. Active heat acclimation, combining heat exposure and exercise, influences several important thermophysiological parameters; for example, it decreases core temperature and enhances heat

  6. Passive water and ion transport by cotransporters

    Loo, D D; Hirayama, B A; Meinild, A K

    1999-01-01

    the Lp of control oocytes. Passive Na+ transport (Na+ leak) was obtained from the blocker-sensitive Na+ currents in the absence of substrates (glucose and GABA). 2. Passive Na+ and water transport through SGLT1 were blocked by phlorizin with the same sensitivity (inhibitory constant (Ki), 3-5 micro......1. The rabbit Na+-glucose (SGLT1) and the human Na+-Cl--GABA (GAT1) cotransporters were expressed in Xenopus laevis oocytes, and passive Na+ and water transport were studied using electrical and optical techniques. Passive water permeabilities (Lp) of the cotransporters were determined from......M). When Na+ was replaced with Li+, phlorizin also inhibited Li+ and water transport, but with a lower affinity (Ki, 100 microM). When Na+ was replaced by choline, which is not transported, the SGLT1 Lp was indistinguishable from that in Na+ or Li+, but in this case water transport was less sensitive...

  7. Climate-Specific Passive Building Standards

    Wright, Graham S. [Building Science Corp., Westford, MA (United States); Klingenberg, Katrin [Building Science Corp., Westford, MA (United States)

    2015-07-29

    In 2012, the U.S. Department of Energy (DOE) recognized the value of performance-based passive building standards when it joined with Passive House Institute US (PHIUS) to promote DOE’s Challenge Home program in tandem with the PHIUS+ Certification program. Since then, the number of passive building projects that have been certified under the partnership has grown exponentially because of some synergy. Passive building represents a well-developed approach to arrive at the envelope basis for zero energy and energy-positive projects by employing performance-based criteria and maximizing cost-effective savings from conservation before implementing renewable energy technologies. The Challenge Home program evolved into the Zero Energy Ready Home (ZERH) program in a move toward 1) attaining zero energy and 2) including active renewable energy generation such as photovoltaics (PV)—toward the zero energy goal.

  8. Symmetry Breaking in a random passive scalar

    Kilic, Zeliha; McLaughlin, Richard; Camassa, Roberto

    2017-11-01

    We consider the evolution of a decaying passive scalar in the presence of a gaussian white noise fluctuating shear flow. We focus on deterministic initial data and establish the short, intermediate, and long time symmetry properties of the evolving point wise probability measure for the random passive scalar. Analytical results are compared directly to Monte Carlo simulations. Time permitting we will compare the predictions to experimental observations.

  9. Comprehensive Planning for Passive Solar Architectural Retrofit

    1980-05-01

    technical information, and the natural environ- ment. Since the Air Force Energy plan stresses Passive Solar (Architecture) before using Active Solar...retrofitted by-1990, and the Air Force Energy Plan stresses Passive Solar Applications. Bdcause of this requirement, you must consider the following retrofit...OF THI SUN AT NOON ON O CUMIN 21 EXAWMKU[ AT 3M. AN I S - W Figure 12-4 12-3 Skylight- use a reflector ,with horizontal skylights to ,iincrease solar

  10. An All-Silicon Passive Optical Diode

    Fan, Li; Wang, Jian; Varghese, Leo T.; Shen, Hao; Niu, Ben; Xuan, Yi; Weiner, Andrew M.; Qi, Minghao

    2011-01-01

    A passive optical diode effect would be useful for on-chip optical information processing but has been difficult to achieve. Using a method based on optical nonlinearity, we demonstrate a forward-backward transmission ratio of up to 28 decibels within telecommunication wavelengths. Our device, which uses two silicon rings 5 micrometers in radius, is passive yet maintains optical nonreciprocity for a broad range of input power levels, and it performs equally well even if the backward input pow...

  11. Technical - Economic Research for Passive Buildings

    Miniotaite, Ruta

    2017-10-01

    A newly constructed passive house must save 80 % of heat resources; otherwise it is not a passive house. The heating energy demand of a passive building is less than 15 kWh/m2 per year. However, a passive house is something more than just an energy-saving house. This concept involves sustainable, high-quality, valuable, healthy and durable construction. Features of a passive house: high insulation of envelope components, high-quality windows, good tightness of the building, regenerative ventilation system and elimination of thermal bridges. The Energy Performance of Buildings Directive (EPBD) 61 requires all new public buildings to become near-zero energy buildings by 2019 and will be extended to all new buildings by 2021. This concept involves sustainable, high-quality, valuable, healthy and durable construction. Foundation, walls and roofs are the most essential elements of a house. The type of foundation for a private house is selected considering many factors. The article examines technological and structural solutions for passive buildings foundation, walls and roofs. The technical-economic comparison of the main structures of a passive house revealed that it is cheaper to install an adequately designed concrete slab foundation than to build strip or pile foundation and the floor separately. Timber stud walls are the cheapest wall option for a passive house and 45-51% cheaper compared to other options. The comparison of roofs and ceilings showed that insulation of the ceiling is 25% more efficient than insulation of the roof. The comparison of the main envelope elements efficiency by multiple-criteria evaluation methods showed that it is economically feasible to install concrete slab on ground foundation, stud walls with sheet cladding and a pitched roof with insulated ceiling.

  12. Active and passive cooling methods for dwellings

    Oropeza-Perez, Ivan; Østergaard, Poul Alberg

    2018-01-01

    In this document a review of three active as well as ten passive cooling methods suitable for residential buildings is carried out. The review firstly addresses how the various technologies cool the space according to the terms of the building heat balance, under what technical conditions...... ventilation, controlled ventilation, roof coating and eco-evaporative cooling are the most suitable passive methods for an extensive use in this country....

  13. New Frontiers in Passive and Active Nanoantennas

    Arslanagic, Samel; Ziolkowski, Richard W.

    2017-01-01

    The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers.......The articles included in this special section focus on several recent advances in the field of passive and active nanoantennas that employ not only traditional based realizations but also their new frontiers....

  14. Uncertainty Prediction in Passive Target Motion Analysis

    2016-05-12

    Number 15/152,696 Filing Date 12 May 2016 Inventor John G. Baylog et al Address any questions concerning this matter to the Office of...300118 1 of 25 UNCERTAINTY PREDICTION IN PASSIVE TARGET MOTION ANALYSIS STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein...at an unknown location and following an unknown course relative to an observer 12. Observer 12 has a sensor array such as a passive sonar or radar

  15. Feasibility of passive heat removal systems

    Ashurko, Yu M [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

    1996-12-01

    This paper presents a review of decay heat removal systems (DHRSs) used in liquid metal-cooled fast reactors (LMFRs). Advantages and the disadvantages of these DHRSs, extent of their passivity and prospects for their use in advanced fast reactor projects are analyzed. Methods of extending the limitations on the employment of individual systems, allowing enhancement in their effectiveness as safety systems and assuring their total passivity are described. (author). 10 refs, 10 figs.

  16. Architectural design of passive solar residential building

    Ma Jing

    2015-01-01

    Full Text Available This paper studies thermal environment of closed balconies that commonly exist in residential buildings, and designs a passive solar residential building. The design optimizes the architectural details of the house and passive utilization of solar energy to provide auxiliary heating for house in winter and cooling in summer. This design might provide a more sufficient and reasonable modification for microclimate in the house.

  17. Brookfield Homes Passive House Performance Evaluation

    Herk, A. [IBACOS, Inc., Pittsburgh, PA (United States); Poerschke, A. [IBACOS, Inc., Pittsburgh, PA (United States); Beach, R. [IBACOS, Inc., Pittsburgh, PA (United States)

    2016-02-01

    In 2012-2013, IBACOS worked with a builder, Brookfield Homes in Denver, Colorado, to design and construct a Passive House certified model home. IBACOS used several modeling programs and calculation methods to complete the final design package along with Brookfield's architect KGA Studio. This design package included upgrades to the thermal enclosure, basement insulation, windows, and heating, ventilation, and air conditioning. Short-term performance testing in the Passive House was done during construction and after construction.

  18. Passive Safety Features for Small Modular Reactors

    Ingersoll, Daniel T.

    2010-01-01

    The rapid growth in the size and complexity of commercial nuclear power plants in the 1970s spawned an interest in smaller, simpler designs that are inherently or intrinsically safe through the use of passive design features. Several designs were developed, but none were ever built, although some of their passive safety features were incorporated into large commercial plant designs that are being planned or built today. In recent years, several reactor vendors are actively redeveloping small modular reactor (SMR) designs with even greater use of passive features. Several designs incorporate the ultimate in passive safety they completely eliminate specific accident initiators from the design. Other design features help to reduce the likelihood of an accident or help to mitigate the accidents consequences, should one occur. While some passive safety features are common to most SMR designs, irrespective of the coolant technology, other features are specific to water, gas, or liquid-metal cooled SMR designs. The extensive use of passive safety features in SMRs promise to make these plants highly robust, protecting both the general public and the owner/investor. Once demonstrated, these plants should allow nuclear power to be used confidently for a broader range of customers and applications than will be possible with large plants alone.

  19. Active versus passive screening for entrance control

    McCormick, N.J.

    1976-01-01

    The benefits of different entrance control actions are quantitatively assessed by defining a relative improvement index for the screening activity. Three classes of entrance control measures are investigated: the use of a purely active screening measure (such as a portal monitor), the use of a purely passive screening measure (such as personality typing), and the combined use of active and passive measures. Active entrance control measures have been studied previously [McCormick and Erdmann, Nucl. Mat. Manag. 4, (1975)] where it was determined that the relative improvement index is approximately related to the nondetection probability factor r for the protective system by (1-r + r ln r). It is shown here that the relative improvement index for a purely passive screening system also can be approximately expressed in a convenient manner. Because the probability is very small that a sabotage or diversion action would be attempted, the result for passive screening, multiplied by r, may be combined with the factor (1-r + r ln r) to give the relative improvement index for a combined, active-and-passive entrance control system. Results from simple example calculations indicate that passive screening of nuclear plant personnel or applicants for such positions is orders-of-magnitude less effective than portal monitors or reasonable improvements in them. 5 tables

  20. Passive film growth on carbon steel and its nanoscale features at various passivating potentials

    Li, Yuan; Cheng, Y. Frank, E-mail: fcheng@ucalgary.ca

    2017-02-28

    Highlights: • Imaged the topography of passivated steel at various film-forming potentials. • Characterized the nanoscale features of passive films. • Determined the composition of passive films formed at various potentials. - Abstract: In this work, the passivation and topographic sub-structure of passive films on a carbon steel in a carbonate/bicarbonate solution was characterized by electrochemical measurements, atomic force microscopy and X-ray photoelectron spectroscopy. When passivating at a potential near the active-passive transition, the film contains the mixture of Fe{sub 3}O{sub 4}, Fe{sub 2}O{sub 3} and FeOOH, with numerous nanoscale features. As the film-forming potential shifts positively, the passive film becomes more compact and the nanoscale features disappear. When the film is formed at a passive potential where the oxygen evolution is enabled, the content of FeOOH in the film increases, resulting in an amorphous topography and reduced corrosion resistance.

  1. Passivity and passivity breakdown of 304L stainless steel in hot and concentrated nitric acid

    Gillard-Tcharkhtchi, Elsa

    2014-01-01

    The objective of this study is to characterize the oxidation behavior of 304L stainless steel (SS) in representative conditions of spent nuclear fuel reprocessing, i.e. in hot and concentrated nitric acid. In these conditions the SS electrochemical potential is in the passive domain and its corrosion rate is low. However when the media becomes more aggressive, the potential may be shifted towards the trans-passive domain characterized with a high corrosion rate. Passivity and passivity breakdown in the trans-passive domain are of a major interest for the industry. So as to characterize these phenomenons, this work was undertaken with the following representative conditions: a 304L SS from an industrial sheet was studied, the media was hot and concentrated HNO 3 , long term tests were performed. First, the surface of an immersed 304L SS was characterized with several complementary techniques from the micro to the nanometer scale. Then oxidation kinetics was studied in the passive and in the trans-passive domain. The oxidation behavior was studied thanks to weight loss determination and surface analysis. Finally, oxidation evolution as a function of the potential was studied from the passive to the trans-passive domain. In particular, this allowed us to obtain the anodic curve of 304L SS in hot and concentrated and to define precisely the 304L SS limits of in such conditions. (author) [fr

  2. Injection of nano-particles in mitigating flow accelerated corrosion (FAC) damage in the secondary system of nuclear power plants (NPPs)

    Lim, Dong Seok; Ku, Hee Kwon; Cho, Jae Seon

    2015-01-01

    NPPs produces electric energy through phase transition of water. According to this, a piping, which is flow path, integrity is essential for safety functions. Erosion, FAC and fittings are corrosion failure mechanism by increasing service life. Especially, there are 10-kilometers of piping in secondary systems. It needs to estimate FAC and apply periodic management. Iron oxides produced by FAC cause power reduction and Loss Of Coolant Accident (LOCA) will be occurred through the continued piping wall thinning. In this study, corrosion rate of pipe materials with carbon steel(SA106.Gr.B) and low-alloy steel (SA335.P22) was evaluated for pipe configuration and dissolved oxygen concentration on 150 °C, pH 9.5∼10.0 and flow velocity of 5m/s. Temperature of 150°C is well known that causes high FAC rate and pH consider a NPPs in-service condition. Further corrosion rate test was performed to develop FAC reduction technology through Pt-nanoparticle injection. In this study, corrosion rate is evaluated by weight depletion method. The results of material impact assessment show that corrosion rate of carbon steel is more higher than that of low-alloy steel because of Cr content. And also, the results of pipe configuration test show that case with 90° elbow had maximum wall thinning than with 180° horizontal pipe. The dissolved oxygen concentration test shows that low oxygen condition, ≤5 ppb, had high corrosion rate compared to normal condition and the corrosion rate decreased 50% at Pt-nanoparticle injection test on maximum corrosion rate condition compared to maximum wall thinning condition without Pt-nanoparticle injection. In this study, samples provided by each test case had analyzed through SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy). Behavior evaluation for oxide film was performed and Electrochemical corrosion potential (ECP) was measured for electrochemistry evaluation. To apply Pt-nanoparticle injection technology on nuclear

  3. Passivation of fluorinated activated charcoal

    Del Cul, G.D.; Trowbridge, L.D.; Simmons, D.W.; Williams, D.F.; Toth, L.M.

    1997-10-01

    The Molten Salt Reactor Experiment (MSRE), at the Oak Ridge National Laboratory has been shut down since 1969 when the fuel salt was drained from the core into two Hastelloy N tanks at the reactor site. In 1995, a multiyear project was launched to remediate the potentially hazardous conditions generated by the movement of fissile material and reactive gases from the storage tanks into the piping system and an auxiliary charcoal bed (ACB). The top 12 in. of the ACB is known by gamma scan and thermal analysis to contain about 2.6 kg U-233. According to the laboratory tests, a few feet of fluorinated charcoal are believed to extend beyond the uranium front. The remainder of the ACB should consist of unreacted charcoal. Fluorinated charcoal, when subjected to rapid heating, can decompose generating gaseous products. Under confined conditions, the sudden exothermic decomposition can produce high temperatures and pressures of near-explosive characteristics. Since it will be necessary to drill and tap the ACB to allow installation of piping and instrumentation for remediation and recovery activities, it is necessary to chemically convert the reactive fluorinated charcoal into a more stable material. Ammonia can be administered to the ACB as a volatile denaturing agent that results in the conversion of the C x F to carbon and ammonium fluoride, NH 4 F. The charcoal laden with NH 4 F can then be heated without risking any sudden decomposition. The only consequence of heating the treated material will be the volatilization of NH 4 F as a mixture of NH 3 and HF, which would primarily recombine as NH 4 F on surfaces below 200 C. The planned scheme for the ACB denaturing is to flow diluted ammonia gas in steps of increasing NH 3 concentration, 2% to 50%, followed by the injection of pure ammonia. This report summarizes the planned passivation treatment scheme to stabilize the ACB and remove the potential hazards. It also includes basic information, results of laboratory tests

  4. Passivation of fluorinated activated charcoal

    Del Cul, G.D.; Trowbridge, L.D.; Simmons, D.W.; Williams, D.F.; Toth, L.M.

    1997-10-01

    The Molten Salt Reactor Experiment (MSRE), at the Oak Ridge National Laboratory has been shut down since 1969 when the fuel salt was drained from the core into two Hastelloy N tanks at the reactor site. In 1995, a multiyear project was launched to remediate the potentially hazardous conditions generated by the movement of fissile material and reactive gases from the storage tanks into the piping system and an auxiliary charcoal bed (ACB). The top 12 in. of the ACB is known by gamma scan and thermal analysis to contain about 2.6 kg U-233. According to the laboratory tests, a few feet of fluorinated charcoal are believed to extend beyond the uranium front. The remainder of the ACB should consist of unreacted charcoal. Fluorinated charcoal, when subjected to rapid heating, can decompose generating gaseous products. Under confined conditions, the sudden exothermic decomposition can produce high temperatures and pressures of near-explosive characteristics. Since it will be necessary to drill and tap the ACB to allow installation of piping and instrumentation for remediation and recovery activities, it is necessary to chemically convert the reactive fluorinated charcoal into a more stable material. Ammonia can be administered to the ACB as a volatile denaturing agent that results in the conversion of the C{sub x}F to carbon and ammonium fluoride, NH{sub 4}F. The charcoal laden with NH{sub 4}F can then be heated without risking any sudden decomposition. The only consequence of heating the treated material will be the volatilization of NH{sub 4}F as a mixture of NH{sub 3} and HF, which would primarily recombine as NH{sub 4}F on surfaces below 200 C. The planned scheme for the ACB denaturing is to flow diluted ammonia gas in steps of increasing NH{sub 3} concentration, 2% to 50%, followed by the injection of pure ammonia. This report summarizes the planned passivation treatment scheme to stabilize the ACB and remove the potential hazards. It also includes basic information

  5. Experience in scientific guidance during start-up and normal operation of NPPs with WWER reactors; Opyt nauchnogo rukovodstva puskom i soprovozhdeniya pri ehkspluatatsii ehnergoblokov AEhS s WWER

    Abagyan, A; Kazakov, V; Kryakvin, L [All-Russian Inst. for NPP Operation, Moscow (Russian Federation)

    1996-12-31

    The experience gained in the All-Russian Research Institute of NPP Operation (RU) in improvement of reactor start-up and normal operation of NPPs has been reported. The work was carried out on NPPs in Russia, Ukraine, Bulgaria, Hungary and Czechoslovakia. All scientific programmes applied use the system approach, modern methods of safety assessment and the principle of loss effect optimization. For the Kozloduy NPP the following projects have been implemented: design of accelerated unloading system for WWER-1000; refinement of water feeding unit for the WWER-1000 steam generator; response analysis of the safety anti-breakdown system of the second loop. The importance of technical substantiation in the process of decision making is stressed. 6 refs.

  6. Damages of electrical insulation of cable products used at NPP`s and technique of their detection and operative control; Povrezhdeniya v ehlektricheskoj izolyatsii kabel`nykh izdulij, ehkspluatirue mykh na atomnykh ehlektrostantsiyakh i metody ikh obnaruzheniya i operativnogo kontro lya

    Valeev, R S; Filatov, N I

    1994-12-31

    Analysis of possible damages in electrical insulation of cable products under their application at NPP`s is conducted. Basic methods for detecting such damages and rapid control of technical condition of cable products during the operation are considered.

  7. Comparative Analysis of Norwegian Passive House Criteria and of Criteria related to the Concept of International Passive House Standard

    Anton, Karin; Vestergaard, Inge

    2013-01-01

    The analysis shows differences in definition of apssive house criterias. It also communicates issues os the passive house concept that are nor completely transferred by the Norwegian passive house standard.......The analysis shows differences in definition of apssive house criterias. It also communicates issues os the passive house concept that are nor completely transferred by the Norwegian passive house standard....

  8. IAEA/SiP senior managers workshop on international promotion of safety culture for the NPPs with RBMK reactors. Working material

    1996-01-01

    The IAEA/SiP Senior Managers Workshop on International Promotion of Safety Culture for the NPPs with RMBK reactors was organized in the frame of the IAEA Technical Cooperation Regional Project RER/9/035 and the IAEA Extrabudgetary Project on WWER and RBMK Safety in co-operation with Swedish International Project Nuclear Safety (SiP). It took place at the Forsmark NPP, Sweden, from 1 to 4 October 1996. The objectives of the workshop were to provide a forum for senior managers to exchange national and international experience on factors influencing safety culture, to better understand these factors and to further enhance promotion of safety culture. Twenty-three specialists participated in the workshop from six countries (Canada, Lithuania, Russian Federation, Sweden, Ukraine and USA) and from two international organizations (WANO, EC-G24 coordination). Participants were from regulatory bodies, ministries and operational organizations of respective countries. The INSAG-4 definition of safety culture was taken as a starting point for the discussions, but at the start of the workshop participants did not seem to have the same understanding of what is contained in the safety culture context. Specifically the difference between measures taken to improve safety and establishing a proper safety culture level was discussed with useful results. Some participants proposed quantitative safety culture indicators, but there was no agreement at this stage about how to define them. Refs

  9. IAEA/SiP senior managers workshop on international promotion of safety culture for the NPPs with RBMK reactors. Working material

    NONE

    1997-12-31

    The IAEA/SiP Senior Managers Workshop on International Promotion of Safety Culture for the NPPs with RMBK reactors was organized in the frame of the IAEA Technical Cooperation Regional Project RER/9/035 and the IAEA Extrabudgetary Project on WWER and RBMK Safety in co-operation with Swedish International Project Nuclear Safety (SiP). It took place at the Forsmark NPP, Sweden, from 1 to 4 October 1996. The objectives of the workshop were to provide a forum for senior managers to exchange national and international experience on factors influencing safety culture, to better understand these factors and to further enhance promotion of safety culture. Twenty-three specialists participated in the workshop from six countries (Canada, Lithuania, Russian Federation, Sweden, Ukraine and USA) and from two international organizations (WANO, EC-G24 coordination). Participants were from regulatory bodies, ministries and operational organizations of respective countries. The INSAG-4 definition of safety culture was taken as a starting point for the discussions, but at the start of the workshop participants did not seem to have the same understanding of what is contained in the safety culture context. Specifically the difference between measures taken to improve safety and establishing a proper safety culture level was discussed with useful results. Some participants proposed quantitative safety culture indicators, but there was no agreement at this stage about how to define them. Refs.

  10. Social networking-based simulations for nuclear security: Strategy assessment following nuclear cyber terror on South Korean nuclear power plants (NPPs)

    Woo, Tae Ho; Kwak, Sang Man

    2015-01-01

    Highlights: • The cyber terror modeling is made by the social networking algorithm. • This is applicable by the social networking service (SNS). • Security of nuclear industry could be controlled by the network theory. • Newly developed complex algorithm can be introduced. • Simplified graphics show the operator easily. - Abstract: Nuclear energy has been studied for the secure power productions, which is based on the simulation study following the incident of nuclear cyber terror attack on South Korean nuclear power plants (NPPs). The social networking is used for the terror incident modeling and its prevention strategies. The nuclear industry could be investigated in the aspect of minimizing the dangerous situations caused by possible terror attacks which are considered by the society oriented connectivity among the related people or groups. The social networking circle by system dynamics diagram (SNCSD) is constructed, where the configuration of a model social networking example by system dynamics (SD) is applied. From A to H regions, the values are obtained by the random numbers incorporated with the designed algorithms. The results show the comparative values of terror possibilities which are based on the proposed social networking algorithm. It is possible to prepare for potential terrorism in the nuclear industry

  11. Study on operator’s SA reliability in digital NPPs. Part 1: The analysis method of operator’s errors of situation awareness

    Li, Peng-cheng; Zhang, Li; Dai, Li-cao; Li, Xiao-Fang

    2017-01-01

    Highlights: • The model of ESA is established from an organization perspective, and it is new perspective. • The detailed classification system of ESA is developed based on the built ESA model. It is useful to identify the cause chain and root causes of organization causing ESA. • The analysis method of ESA is also constructed to guide the investigation of ESA event. A case study is provided to illustrate the concrete application of the method. - Abstract: Situation awareness (SA) is a key element that impacts operator’s decision-making and performance in nuclear power plants (NPPs). The subsequent complex cognitive activities cannot be correctly completed due to errors of situation awareness (ESA), which will lead to disastrous consequences. In order to investigate and analyze operator’s ESA in the digitized main control room (DMCR) of a nuclear power plant, the model of ESA is established, the classification system of ESA is developed based on the built ESA model, and the analysis method of ESA is also constructed on the basis of the observation of simulator and operator surveys. Finally, a case study is provided to illustrate the concrete application of the method. It provides a theoretical and practical support for the operator’s SAE analysis in a digitized main control room of a nuclear power plant.

  12. Use of cut-off values as meaningfulness limits in probabilistic studies and its effect on NPPs risk assessment and safety improvement

    Petrangeli, G.; Valeri, A.; Zaffiro, C.

    1991-01-01

    This paper discusses the use of cut-off values in probabilistic risk assessment/probabilistic safety assessment (PRA/PSA) of nuclear power plants (NPPs), in order to explore under which conditions this practice may help improve the meaningfulness of the results of the analyses and safety of plants, and how it may affect the assessment of risk. Reference is made, in particular, to some past practical applications, also taken from the experience of the authors within the frame of the Italian licensing process. The paper describes the Italian probabilistic criteria which use probabilistic targets and cut-off values to assess safety and identify plant safety improvements. The rationale of the approach is also discussed in the paper and results of sample applications are illustrated. The paper concludes that the use of cut-off values, if properly implemented, could be productive to improve the plant safety as it helps the analyst to focus on a restricted field of analysis, ignoring lower probability and less known events. It also points out that cut-off values should be considered as living numbers to be lowered and even eliminated as soon as significant advancements are made, through research and operational experience, in the knowledge of the pertinent events

  13. Brief review of 1995 events at Ukraine's NPPs. Report on the ChNPP unit 1 of November 27.1995 ''strict regime area premises contamination after reactor refuelling''

    Lomakin, V.

    1996-01-01

    In 1995 number of events at NPP had considerably decreased as compared with that for previous 1992-94, amounted in 87. In particular, as compared with 1994, events number had decreased by 36%. It characterizes a total improvement of current NPPs safety level during 1995. The most events number as recalculated per single unit was at the South Ukraine NPP - 8. The least - at the ChNPP - 4 in total, and 1,3 per unit. Decreasing of a total events number for 1995 did also accordingly reduce other quantitative system indices which reflect state of NPPs safety level. Among event root causes, as it was before, ''administrative management deficiencies'' and ''staff training deficiencies'' are still dominanting. ''Human factor'' issues are still pending for NPPs safety, despite of considerable efforts applied to improved efficiency of correcting measures aimed at their solution. Of sufficient importance for events system development in 1995 was the work implemented at the SSTC NRS/NRA as regards preparation of modern edition of the ''Regulation on order of NPP events investigation and account''. The IAEA/Nuclear Safety Division rendered a sufficient assistance for this work to be done through arrangement of advisory help to Ukrainian specialists from international experts. 2 figs, 8 diagrams

  14. Round table on the Supply Chain for NPPs construction: Localization - Daya Bay Experience; REEL Handling and Lifting Systems, More than 60 years expertise in lifting and handling equipment in production process

    Frantz, Philippe; Lachaise, Marc; Lau, Steven

    2014-01-01

    The second day afternoon began with the round table on the Supply Chain for NPPs construction with Philippe Frantz, President of REEL, Marc Lachaise, Head of procurement of NNB at EDF Energy, and Steven Lau, First Deputy General Manager of DNMC. Philippe Frantz started to present the activities and the contribution of REEL in the construction of NPPs as a main supplier of handling system. Then, Marc Lachaise took the lead to present Hinkley Point C Project, the Values of NNB and the key role of the supply chain in this Project. Steven Lau went on to describe the link of the supply chain with the operating of NPPs and explained the cooperation between EDF and CGNPC in order to secure the supply of equipment. Following their presentation, they started the open discussion with the audience by explaining their strategy to make or to buy and the link of this strategy to their core business. They also highlighted the new relations and the new partnership between supplier and customer. They insisted on the necessity to invest on supply chain and to have a strong Nuclear Safety Culture in the supply chain

  15. Alternative to Nitric Acid Passivation Project Overview

    Lewis, Pattie L.

    2013-01-01

    The standard practice for protection of stainless steel is a process called passivation. This procedure results in the formation of a metal oxide layer to prevent corrosion. Typical passivation procedures call for the use of nitric acid which exhibits excellent corrosion performance; however, there are a number of environmental, worker safety, and operational issues associated with its use. The longtime military specification for the passivation of stainless steel was cancelled in favor of newer specifications which allow for the use of citric acid in place of nitric acid. Citric acid offers a variety of benefits that include increased safety for personnel, reduced environmental impact, and reduced operational costs. There have been few studies, however, to determine whether citric acid is an acceptable alternative for NASA and DoD. This paper details activities to date including development of the joint test plan, on-going and planned testing, and preliminary results.

  16. Passive Corrosion Behavior of Alloy 22

    R.B. Rebak; J.H. Payer

    2006-01-01

    Alloy 22 (NO6022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nano-meters per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids

  17. A Passive Optical Location with Limited Range

    Pavel Fiala

    2008-01-01

    Full Text Available We know active and passive methods of a location. This article deals only with a passive location of dynamic targets. The passive optics location is suitable just for tracking of targets with mean velocity which is limited by the hardware basis. The aim of this work is to recognize plasma, particles etc. It is possible to propose such kind of evaluation methods which improve the capture probability markedly. Suggested method is dealing with the short-distance evaluation of targets. We suppose the application of three independent principles how to recognize an object in a scanned picture. These principles use similar stochastic functions in order to evaluate an object location by means of simple mathematical operations. Methods are based on direct evaluation of picture sequence by the help of the histogram and frequency spectrum. We find out the probability of unidentified moving object in pictures. If the probability reaches a setting value we will get a signal.

  18. Passive heat removal characteristics of SMART

    Seo, Jae Kwang; Kang, Hyung Seok; Yoon, Joo Hyun; Kim, Hwan Yeol; Cho, Bong Hyun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    A new advanced integral reactor of 330 MWt thermal capacity named SMART (System-Integrated Modular Advanced Reactor) is currently under development in Korea Atomic Energy Research Institute (KAERI) for multi-purpose applications. Modular once-through steam generator (SG) and self-pressurizing pressurizer equipped with wet thermal insulator and cooler are essential components of the SMART. The SMART provides safety systems such as Passive Residual Heat Removal System (PRHRS). In this study, a computer code for performance analysis of the PRHRS is developed by modeling relevant components and systems of the SMART. Using this computer code, a performance analysis of the PRHRS is performed in order to check whether the passive cooling concept using the PRHRS is feasible. The results of the analysis show that PRHRS of the SMART has excellent passive heat removal characteristics. 2 refs., 4 figs., 1 tab. (Author)

  19. Protocol Monitoring Passive Solar Energy. Background document

    Van den Ham, E.R.

    1998-01-01

    A method has been developed by means of which the contribution of passive solar energy to the Dutch energy balance can be quantified univocally. The monitoring will be directed at the absolute amount of used solar energy, the relative contribution of passive solar energy to the energy demand in the Netherlands, and the average efficiency of passive solar energy systems. Based on a model of the total building stock the quantities to be monitored can be determined. The most important parameters in the model are: the window surface per orientation, the average U-value (heat transfer coefficient) of windows, the average ZTA-value (incoming solar radiation factor) of windows, and the presence of sun lounges and atriums

  20. Climate-Specific Passive Building Standards

    Wright, Graham S. [Passive House Inst., Westford, MA (United States); Klingenberg, Katrin [Passive House Inst., Westford, MA (United States)

    2015-07-01

    Passive design principles (super insulation, airtight envelopes, elimination of thermal bridges, etc.) - pioneered in North America in the 70s and 80s and refined in Europe in the 90s have proven to be universally effective to significantly reduce heating and cooling loads. However, a single, rigid performance metric developed in Germany has led to limited uptake of passive building principles in many regions of the United States. It has also, in many cases, promoted some design decisions that had negative effects on economic feasibility and thermal comfort. This study's main objective is to validate (in a theoretical sense) verifiable, climate-specific passive standards and space conditioning criteria that retain ambitious, environmentally-necessary energy reduction targets and are economically feasible, such standards provide designers an ambitious but achievable performance target on the path to zero.

  1. A passive sampler for atmospheric ozone

    Grosjean, D.; Hisham, M.W.M.

    1992-01-01

    A simple, cost-effective passive sampler has been developed for the determination of atmospheric ozone. This passive sampler is based on a colorant which fades upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Direct, on-site measurements are possible, and no chemical analyses are needed. Sampler design and validation studies have been carried out and included quantitative determination of color change vs exposure time (1-8 days), color change vs. ozone concentration (30-350 ppb), and response to changes in sampler configuration that modify the passive sampling rate. With indigo carmine as the colorant, the detection limits are 30 ppb. day and 120 ppb. day using a plastic grid and Teflon filter, respectively, as diffusion barriers. Interferences from nitrogen dioxide, formaldehyde and peroxyacetyl nitrate are 15, 4 and 16%, respectively, thus resulting in a negligible bias when measuring ozone in ambient air

  2. High-order passive photonic temporal integrators.

    Asghari, Mohammad H; Wang, Chao; Yao, Jianping; Azaña, José

    2010-04-15

    We experimentally demonstrate, for the first time to our knowledge, an ultrafast photonic high-order (second-order) complex-field temporal integrator. The demonstrated device uses a single apodized uniform-period fiber Bragg grating (FBG), and it is based on a general FBG design approach for implementing optimized arbitrary-order photonic passive temporal integrators. Using this same design approach, we also fabricate and test a first-order passive temporal integrator offering an energetic-efficiency improvement of more than 1 order of magnitude as compared with previously reported passive first-order temporal integrators. Accurate and efficient first- and second-order temporal integrations of ultrafast complex-field optical signals (with temporal features as fast as approximately 2.5ps) are successfully demonstrated using the fabricated FBG devices.

  3. Passivated emitters in silicon solar cells

    King, R.R.; Gruenbaum, P.E.; Sinton, R.A.; Swanson, R.M.

    1990-01-01

    In high-efficiency silicon solar cells with low metal contact coverage fractions and high bulk lifetimes, cell performance is often dominated by recombination in the oxide-passivated diffusions on the cell surface. Measurements of the emitter saturation current density, J o , of oxide-passivated, boron and phosphorus diffusions are presented, and from these measurements, the dependence of surface recombination velocity on dopant concentration was extracted. The lowest observed values of J o which are stable under UV light are given for both boron- and phosphorus-doped, oxide-passivated diffusions, for both textured and untextured surfaces. Contour plots which incorporate the above data have been applied to two types of backside-contact solar cells with large area (37.5 cm 2 ) and one-sun efficiencies up to 22.7%

  4. TEPSS - Technology Enhancement for Passive Safety Systems

    Hart, J.; Slegers, W.J.M.; Boer, S.L. de; Huggenberger, M.; Lopez Jimenez, J.; Munoz-Cabo Gonzalez, J.L.; Reventos Puigjaner, F.

    2000-01-01

    The objective of the TEPSS project was to make significant additions to the technology base of the European Simplified Boiling Water Reactor (ESBWR). The project focused on mixing and stratification phenomena in large water pools, passive decay heat removal from containments, and effects of aerosol deposition inside a passive heat exchanger. The PSI experimental facility LINX (Large-scale Investigation of Natural Circulation and Mixing) has been used to investigate venting of steam and steam-noncondensable gas mixtures into water pools. The test revealed that no significant steam bypass could be detected when injecting a mixture of steam or air and that mixing was very efficient. In addition to the tests, 3-D numerical computations and initial model development have been performed to study the behaviour of bubble plumes in water pools. The major part of the TEPSS project studied selective aspects of the response technology of modem pressure-suppression type containment designs and of passive-type decay heat removal systems. The work included an experimental phase using the large-scale experimental facility PANDA (Passive Nachwaermeabfuhr und Druckabbau), operated by PSI, where eight experiments successfully have been executed to test the performance of the ESBWR containment configuration. The PANDA tests have been analysed successfully using thermalhydraulic system analysis codes and 3-D CFD codes. The AIDA (Aerosol Impaction and Deposition Analysis) experimental facility of PSI has been used to investigate the degradation of passive decay heat removal due to fission product aerosols deposited on the inside surfaces of the PCC (Passive Containment Cooler) heat exchanger tubes. The one test performed revealed that the degradation of the heat transfer in the PCC tubes due to the deposition of aerosols reached about 20%. The test has been analysed using the MELCOR severe accident analysis code. (author)

  5. Fast New Method for Temporary Chemical Passivation

    Marek Solčanský

    2012-12-01

    Full Text Available The main material parameter of silicon, that influences the effectiveness of photovoltaic cells, is the minority carrier bulk lifetime.It may change in the technological process especially during high temperature operations. Monitoring of the carrier bulk-lifetimeis necessary for modifying the whole technological process of production. For the measurement of the minority carrier bulk-lifetimethe characterization method MW PCD (Microwave Photoconductance Decay is used, where the result of measurement is the effectivecarrier lifetime, which is very dependent on the surface recombination velocity and therefore on the quality of a silicon surfacepassivation.This work deals with an examination of a different solution types for the chemical passivation of a silicon surface. Varioussolutions are tested on silicon wafers for their consequent comparison. The main purpose of this work is to find optimal solution, whichsuits the requirements of a time stability and start-up velocity of passivation, reproducibility of the measurements and a possibilityof a perfect cleaning of a passivating solution remains from a silicon surface. Another purpose of this work is to identify the parametersof other quinhydrone solutions with different concentrations as compared with the quinhydrone solution in methanol witha concentration of 0.07 mol/dm³ marked QM007 (referential solution.The method of an effective chemical passivation with a quinhydrone in methanol solution was suggested. The solution witha concentration of 0.07 mol /dm3 fulfills all required criteria. The work also confirms the influence of increased concentrationquinhydrone on the temporal stability of the passivation layer and the effect for textured silicon wafers. In conclusion, the influenceof an illumination and the temperature on the properties of the passivating solution QM007 is discussed.

  6. Passive remediation strategies for petroleum contaminated sites

    Everett, L.G.; Cullen, S.J.; Eccles, L.A.

    1991-01-01

    The US EPA is becoming increasingly aware of costs and the limited success of existing remediation strategies. Research teams within the US EPA believe that if passive remediation can be successfully demonstrated, it is a candidate for best available technology. Passive remediation, however, must be demonstrated through the use of monitoring techniques, which demonstrate: contaminants are not moving in the dissolved, adsorbed or free product phase; and contamination is biodegrading in-place. This paper presents a concise monitoring and analysis strategy for passive remediation. Specifically, the paper presents the accuracy, precision and operating range of neutron moderation techniques as a low cost, real-time screening tool to measure the migration of the dissolved phase in soil moisture, the stabilized adsorbed phase and free product movement. In addition, the paper identifies the capillary pressure range through which the dissolved phase will move and identifies techniques for satisfying the risk analysis that movement is not taking place. The rationale for passive remediation taking place is confirmed through a discussion of gas ratios associated with bacterial assimilation of hydrocarbons. Gas ratios which are relatively constant above ground are highly inverted in the subsurface at contamination sites. The use of frequent screening of a vertical geologic profile using least cost techniques and the infrequent analysis of soil gas ratios provides the required data upon which the public will accept passive remediation as best available technology at a particular site. The paper points out that neutron moderation is a high candidate vadose zone monitoring device and identifies alternative techniques using resistivity and dielectric constants, which are in the developmental stage. The economic implications for passive remediation are enormous relative to the excavation and remediation strategies which are currently in use

  7. Study on diverse passive decay heat removal approach

    Lin Qian; Si Shengyi

    2012-01-01

    One of the most important principles for nuclear safety is the decay heat removal in accidents. Passive decay heat removal systems are extremely helpful to enhance the safety. In currently design of many advanced nuclear reactors, kinds of passive systems are proposed or developed, such as the passive residual heat removal system, passive injection system, passive containment cooling system. These systems provide entire passive heat removal paths from core to ultimate heat sink. Various kinds of passive systems for decay heat removal are summarized; their common features or differences on heat removal paths and design principle are analyzed. It is found that, these passive decay heat removal paths are similarly common on and connected by several basic heat transfer modes and steps. By the combinations or connections of basic modes and steps, new passive decay heat removal approach or diverse system can be proposed. (authors)

  8. Inherently safe passive gas monitoring system

    Cordaro, Joseph V.; Bellamy, John Stephen; Shuler, James M.; Shull, Davis J.; Leduc, Daniel R.

    2016-09-06

    Generally, the present disclosure is directed to gas monitoring systems that use inductive power transfer to safely power an electrically passive device included within a nuclear material storage container. In particular, the electrically passive device can include an inductive power receiver for receiving inductive power transfer through a wall of the nuclear material storage container. The power received by the inductive power receiver can be used to power one or more sensors included in the device. Thus, the device is not required to include active power generation components such as, for example, a battery, that increase the risk of a spark igniting flammable gases within the container.

  9. Passive Polarimetric Information Processing for Target Classification

    Sadjadi, Firooz; Sadjadi, Farzad

    Polarimetric sensing is an area of active research in a variety of applications. In particular, the use of polarization diversity has been shown to improve performance in automatic target detection and recognition. Within the diverse scope of polarimetric sensing, the field of passive polarimetric sensing is of particular interest. This chapter presents several new methods for gathering in formation using such passive techniques. One method extracts three-dimensional (3D) information and surface properties using one or more sensors. Another method extracts scene-specific algebraic expressions that remain unchanged under polariza tion transformations (such as along the transmission path to the sensor).

  10. Piping reliability improvement through passive seismic supports

    Baltus, R.; Rubbers, A.

    1999-01-01

    The nuclear plants designed in the 1970's were equipped with large quantities of snubbers in auxiliary piping systems. The experience revealed a poor performance of snubbers during periodic inspection, while non-nuclear facility piping survived through strong earthquakes. Consequently, seismic design rules evolved towards more realistic criteria and passive dynamic supports were developed to reduce snubber quantities. These solutions improve the pipe reliability during normal operation while reducing the radiation exposure in a sample line is presented with the impact on pipe stresses compared to the results obtained with passive supports named Limit Stops. (author)

  11. Superacid Passivation of Crystalline Silicon Surfaces.

    Bullock, James; Kiriya, Daisuke; Grant, Nicholas; Azcatl, Angelica; Hettick, Mark; Kho, Teng; Phang, Pheng; Sio, Hang C; Yan, Di; Macdonald, Daniel; Quevedo-Lopez, Manuel A; Wallace, Robert M; Cuevas, Andres; Javey, Ali

    2016-09-14

    The reduction of parasitic recombination processes commonly occurring within the silicon crystal and at its surfaces is of primary importance in crystalline silicon devices, particularly in photovoltaics. Here we explore a simple, room temperature treatment, involving a nonaqueous solution of the superacid bis(trifluoromethane)sulfonimide, to temporarily deactivate recombination centers at the surface. We show that this treatment leads to a significant enhancement in optoelectronic properties of the silicon wafer, attaining a level of surface passivation in line with state-of-the-art dielectric passivation films. Finally, we demonstrate its advantage as a bulk lifetime and process cleanliness monitor, establishing its compatibility with large area photoluminescence imaging in the process.

  12. Passive cooling systems in power reactors

    Aharon, J.; Harrari, R.; Weiss, Y.; Barnea, Y.; Katz, M.; Szanto, M.

    1996-01-01

    This paper reviews several R and D activities associated with the subject of passive cooling systems, conducted by the N.R.C.Negev thermohydraulic group. A short introduction considering different types of thermosyphons and their applications is followed by a detailed description of the experimental work, its results and conclusions. An ongoing research project is focused on the evaluation of the external dry air passive containment cooling system (PCCS) in the AP-600 (Westinghouse advanced pressurized water reactor). In this context some preliminary theoretical results and planned experimental research are for the fature described

  13. Passive cooling in modern nuclear reactors

    Rouai, N. M.

    1998-01-01

    This paper presents some recent experimental results performed with the aim of understanding the mechanism of passive cooling. The AP 600 passive containment cooling system is simulated by an electrically heated vertical pipe, which is cooled by a naturally induced air flow and by a water film descending under gravity. The results demonstrate that although the presence of the water film improved the heat transfer significantly, the mode of heat transfer was very dependent on the experimental parameters. Preheating the water improved both film stability and overall cooling performance

  14. An all-silicon passive optical diode.

    Fan, Li; Wang, Jian; Varghese, Leo T; Shen, Hao; Niu, Ben; Xuan, Yi; Weiner, Andrew M; Qi, Minghao

    2012-01-27

    A passive optical diode effect would be useful for on-chip optical information processing but has been difficult to achieve. Using a method based on optical nonlinearity, we demonstrate a forward-backward transmission ratio of up to 28 decibels within telecommunication wavelengths. Our device, which uses two silicon rings 5 micrometers in radius, is passive yet maintains optical nonreciprocity for a broad range of input power levels, and it performs equally well even if the backward input power is higher than the forward input. The silicon optical diode is ultracompact and is compatible with current complementary metal-oxide semiconductor processing.

  15. Passive containment system for a nuclear reactor

    Kleimola, F.W.

    1976-01-01

    A containment system is described that provides complete protection entirely by passive means for the loss of coolant accident in a nuclear power plant and wherein all stored energy released in the coolant blowdown is contained and absorbed while the nuclear fuel is continuously maintained submerged in liquid. The primary containment vessel is restored to a high subatmospheric pressure within a few minutes after accident initiation and the decay heat is safely transferred to the environment while radiolytic hydrogen is contained by passive means

  16. The passive diffusion of Leptospira interrogans

    Koens, Lyndon; Lauga, Eric

    2014-01-01

    Motivated by recent experimental measurements, the passive diffusion of the bacterium Leptospira interrogans is investigated theoretically. By approximating the cell shape as a straight helix and using the slender-body-theory approximation of Stokesian hydrodynamics, the resistance matrix of Leptospira is first determined numerically. The passive diffusion of the helical cell is then obtained computationally using a Langevin formulation which is sampled in time in a manner consistent with the experimental procedure. Our results are in excellent quantitative agreement with the experimental results with no adjustable parameters. (paper)

  17. The passive diffusion of Leptospira interrogans

    Koens, Lyndon; Lauga, Eric

    2014-12-01

    Motivated by recent experimental measurements, the passive diffusion of the bacterium Leptospira interrogans is investigated theoretically. By approximating the cell shape as a straight helix and using the slender-body-theory approximation of Stokesian hydrodynamics, the resistance matrix of Leptospira is first determined numerically. The passive diffusion of the helical cell is then obtained computationally using a Langevin formulation which is sampled in time in a manner consistent with the experimental procedure. Our results are in excellent quantitative agreement with the experimental results with no adjustable parameters.

  18. Passive heat transport in advanced CANDU containment

    Krause, M.; Mathew, P.M.

    1994-01-01

    A passive CANDU containment design has been proposed to provide the necessary heat removal following a postulated accident to maintain containment integrity. To study its feasibility and to optimize the design, multi-dimensional containment modelling may be required. This paper presents a comparison of two CFD codes, GOTHIC and PHOENICS, for multi-dimensional containment analysis and gives pressure transient predictions from a lumped-parameter and a three-dimensional GOTHIC model for a modified CANDU-3 containment. GOTHIC proved suitable for multidimensional post-accident containment analysis, as shown by the good agreement with pressure transient predictions from PHOENICS. GOTHIC is, therefore, recommended for passive CANDU containment modelling. (author)

  19. Technical Assessment: WRAP 1 HVAC Passive Shutdown

    Ball, D.E.; Nash, C.R.; Stroup, J.L.

    1993-01-01

    As the result of careful interpretation of DOE Order 6430.lA and other DOE Orders, the HVAC system for WRAP 1 has been greatly simplified. The HVAC system is now designed to safely shut down to Passive State if power fails for any reason. The fans cease functioning, allowing the Zone 1 and Zone 2 HVAC Confinement Systems to breathe with respect to atmospheric pressure changes. Simplifying the HVAC system avoided overdesign. Construction costs were reduced by eliminating unnecessary equipment. This report summarizes work that was done to define the criteria, physical concepts, and operational experiences that lead to the passive shutdown design for WRAP 1 confinement HVAC systems

  20. Perfect and Periphrastic Passive Constructions in Danish

    Bjerre, Tavs; Bjerre, Anne

    2007-01-01

    This paper gives an account of the event and argument structure of past participles and the linking between argument structure and valence structure. It further accounts for how participles form perfect and passiv constructions with auxiliaries. We assume that the same participle form is used...... in both types of construction. Our claim is that the valence structure of a past participle is predictable from its semantic type, and that the valence structure predicts with which auciliary a past participle combines in perfect constructions and whether the past participle may occur in passiv...

  1. Aktive og passive valg i pensionsopsparingen

    Nielsen, Torben Heien

    2017-01-01

    This paper reviews two papers from my own research. I show that the effect of pension policies are highly dependent on which type of decision maker the policy targets. Specifically, the effectiveness of the policy is stronger if it affects passive choice. Such policies, e.g., employer pensions......, are extremely effective in increasing total individual savings. Tax deductions on the other hand are ineffective. The reason is that an estimated 85 % of the population are passive savers, who do not respond to changes in policies. Consequently, an increased labor market pension rate will also make their total...

  2. Primordial black holes from passive density fluctuations

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this Letter, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses ≲10 15 g depending on the number of e-folds when the scale of our observable universe leaves horizon. These PBHs are likely to have evaporated and cannot be a candidate for dark matter but they may still affect the early universe.

  3. Primordial black holes from passive density fluctuations

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this paper, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses $\\lesssim 10^{15}g$ depending on the number of e-folds when the scale of our observable universe leaves horizon...

  4. Passive Smoking in a Displacement Ventilated Room

    Bjørn, Erik; Nielsen, Peter V.

    The aim of this research is to see if the displacement ventilation principle can protect a person from exposure to passive tobacco smoking. This is done by full-scale experiments with two breathing thermal manikins, smoke visualisations, and tracer gas measurements. In some situations, exhaled...... smoke will stratify in a certain height due to the vertical temperature gradient. This horizontal layer of exhaled tobacco smoke may lead to exposure. In other situations, the smoke is mixed into the upper zone, and the passive smoker is protected to some extent by the displacement principle...

  5. THE USE OF PASSIVE SOLAR HEATING SYSTEMS AS PART OF THE PASSIVE HOUSE

    Bryzgalin Vladislav Viktorovich

    2018-05-01

    Full Text Available Subject: systems of passive solar heating, which can, without the use of engineering equipment, capture and accumulate the solar heat used for heating buildings. Research objectives: study of the possibility to reach the passive house standard (buildings with near zero energy consumption for heating in climatic conditions of Russia using the systems of passive solar heating in combination with other solutions for reduction of energy costs of building developed in the past. Materials and methods: search and analysis of literature, containing descriptions of various passive solar heating systems, examples of their use in different climatic conditions and the resulting effect obtained from their use; analysis of thermophysical processes occurring in these systems. Results: we revealed the potential of using the solar heating systems in the climatic conditions of parts of the territories of the Russian Federation, identified the possibility of cheaper construction by the passive house standard with the use of these systems. Conclusions: more detailed analysis of thermophysical and other processes that take place in passive solar heating systems is required for creation of their computational models, which will allow us to more accurately predict their effectiveness and seek the most cost-effective design solutions, and include them in the list of means for achieving the passive house standard.

  6. Passive cyclotron current drive for fusion plasmas

    Kernbichler, W.

    1995-01-01

    The creation of toroidal current using cyclotron radiation in a passive way is, together with the well known bootstrap current, an interesting method for stationary current drive in high-temperature fusion reactors. Here, instead of externally applied RF-waves, fish-scale like structures at the first wall help to create enough asymmetry in the self generated cyclotron radiation intensity to drive a current within the plasma. The problem of computing passive cyclotron current drive consists of actually two linked problems, which are the computation of the electron equilibrium under the presence of self-generated radiation, and the computation of the photon equilibrium in a bounded system with a distorted electron distribution. This system of integro-differential equations cannot be solved directly in an efficient way. Therefore a linearization procedure was developed to decouple both sets of equations, finally linked through a generalized local current drive efficiency. The problem of the exact accounting for the wall profile effects was reduced to the solution of a Fredholm-type integral equation of the 2 nd -kind. Based on all this an extensive computer code was developed to compute the passively driven current as well as radiation losses, radiation transport and overall efficiencies. The results therefrom give an interesting and very detailed insight into the problems related to passive cyclotron current drive

  7. [The consequences of passive smoking in adults].

    Trédaniel, J; Savinelli, F; Vignot, S; Bousquet, G; Le Maignan, C; Misset, J-L

    2006-04-01

    Passive smoking is the involuntary inhalation by a non-smoker of smoke generated in his neighbourhood by one or more smokers. The effect of this exposure is already generally recognised in children. In adults the induction of chronic obstructive lung disease has not been demonstrated. This is no longer the case for ischaemic heart disease and lung cancer where the effect of passive exposure of non-smokers to cigarette smoke is recognised. The biological plausibility together with the concordance of results obtained over successive years, as well as the large numbers of patients included in the studies, lead to a confident conclusion that the risks in adult non-smokers are increased by the order of 25%. There is no evidence that bias affects the conclusions reached and the World Health Organisation has recently classified passive smoking as being carcinogenic in man. As a result of these data prevention of passive exposure to cigarette smoke should be part of a larger framework of smoking prevention, especially among the young.

  8. Surface Passivation for Silicon Heterojunction Solar Cells

    Deligiannis, D.

    2017-01-01

    Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

  9. Recent Developments in SOBEK Passive Sonar Technology

    Hunter, A.J.; Fillinger, L.; Zampolli, M.; Clarijs, M.C.

    2012-01-01

    Surveillance of waterside locations for protection against threats from small fast surface vessels and underwater intruders is a very relevant but challenging problem. For this reason, the Netherlands Organisation for Applied Scientific Research (TNO) is developing SOBEK – a family of passive sonar

  10. The MEMOLED: Active addressing with passive driving

    Asadi, K.; Blom, P.W.M.; Leeuw, D.M. de

    2011-01-01

    Passive or active matrix driving schemes in large displays are prone to high power consumption and cost, respectively. For signage applications such as large out-door displays with low refresh rates there is as yet no technological solution. Here the MEMOLED solution, an organic light-emitting diode

  11. The MEMOLED : Active Addressing with Passive Driving

    Asadi, Kamal; Blom, Paul W. M.; de Leeuw, Dago M.

    2011-01-01

    Passive or active matrix driving schemes in large displays are prone to high power consumption and cost, respectively. For signage applications such as large outdoor displays with low refresh rates there is as yet no technological solution. Here the MEMOLED solution, an organic light-emitting diode

  12. NucleDyne's passive containment system

    Falls, O.B. Jr.; Kleimola, F.W.

    1987-01-01

    A simple definition of the passive containment system is that it is a total safeguards system for light water reactors designed to prevent and contain any accidental release of radioactivity. Its passive features utilize the natural laws of physics and thermodynamics. The system encompasses three basic containments constructed as one integrated structure on the reactor building foundation. The primary containment encloses the reactor pressure vessel and coolant system and passive engineered safety systems and components. Auxiliary containment enclosures house auxiliary systems and components. Secondary containment (the reactor building), housing the primary and auxiliary containment structures, provides a second containment barrier as added defense-in-depth against leakage of radioactivity for all accidents assumed by the industry. The generic features of the passive containment system are applicable to both the boiling water reactors and the pressurized water reactors as standardized features for all power ranges. These features provide for a zero source term, the industry's ultimate safety goal. This paper relates to a four-loop pressurized water reactor

  13. The passive hamstring stretch test: clinical evaluation.

    Fisk, J W

    1979-03-28

    The passive hamstring stretch test is described. Using a modified goniometer it is shown that independent measurements taken by trained examiners approximate very closely to each other. This establishes the test as a valid objective measurement. The possible value of this test as a research tool in low back pain problems is discussed.

  14. Passive containment system in high earthquake motion

    Kleimola, F.W.; Falls, O.B. Jr.

    1977-01-01

    High earthquake motion necessitates major design modifications in the complex of plant structures, systems and components in a nuclear power plant. Distinctive features imposed by seismic category, safety class and quality classification requirements for the high seismic ground acceleration loadings significantly reflect in plant costs. The design features in the Passive Containment System (PCS) responding to high earthquake ground motion are described

  15. Chances and barriers for passive house renovations

    Mlecnik, E.; Opstelten, I.; Rovers, R.; Verdeyen, N.; Wagenaar, A.

    2016-01-01

    There is significant potential for carbon reduction and energy saving in residential buildings. Various market actors are looking for ways to increase the uptake of passive house renovation and its certification.
    This study aimed specifically to draw lessons from research projects towards the

  16. Passive Polarimetric Microwave Signatures Observed Over Antarctica

    WindSat satellite-based fully polarimetric passive microwave observations, expressed in the form of the Stokes vector, were analyzed over the Antarctic ice sheet. The vertically and horizontally polarized brightness temperatures (first two Stokes components) from WindSat are shown to be consistent w...

  17. Indoor environment in Swedish passive houses

    Bekö, Gabriel; Langer, Sarka; Bloom, Erica Bloom

    2014-01-01

    The purpose of this study was to evaluate the indoor air quality (IAQ) in newly built low energy houses. Measurements were performed in 22 passive houses and 21 conventional buildings during 2012-2013 and 2013-2014 heating seasons. The measured parameters were temperature, relative humidity......, concentration of CO2, NO2, formaldehyde, volatile organic compounds, and live microbiological flora. Air exchange rates (AER) were determined from the concentration-time profiles of CO2. The median AER was slightly higher in the passive houses than in conventional buildings (0.66 h-1 vs. 0.60 h-1). The median...... concentrations in passive houses and conventional buildings were 9.7 and 11 μg/m3, respectively, for NO2, 12 and 16 μg/m3 for formaldehyde, and 230 and 145 μg/m3 for TVOC. The indoor microbiological flora did not differ, with a few exceptions, from outdoors. The IAQ in the passive buildings was judged...

  18. Head Pose Estimation from Passive Stereo Images

    Breitenstein, Michael D.; Jensen, Jeppe; Høilund, Carsten

    2009-01-01

    function. Our algorithm incorporates 2D and 3D cues to make the system robust to low-quality range images acquired by passive stereo systems. It handles large pose variations (of ±90 ° yaw and ±45 ° pitch rotation) and facial variations due to expressions or accessories. For a maximally allowed error of 30...

  19. Radio requestable passive SAW water content sensor

    Reindl, L.; Ruppel, C.C.W.; Kirmayr, A.; Stockhausen, N.; Hilhorst, M.A.; Balendonk, J.

    2001-01-01

    A new passive sensor for remote measurement of water content in sandy soil was designed, using a surface acoustic wave (SAW) reflective delay line. Information from this sensor can be obtained by an interrogation device via a radio link operating in the European 434-MHz industrial-scientific-medical

  20. Active and Passive Microrheology: Theory and Simulation

    Zia, Roseanna N.

    2018-01-01

    Microrheological study of complex fluids traces its roots to the work of the botanist Robert Brown in the early nineteenth century. Indeed, passive microrheology and Brownian motion are one and the same. Once thought to reveal a fundamental life force, the phenomenon was ultimately leveraged by Einstein in proof of the atomic nature of matter ( Haw 2006 ). His work simultaneously paved the way for modern-day passive microrheology by connecting observable particle motion—diffusion—to solvent properties—the viscosity—via the well-known Stokes-Einstein relation. Advances in microscopy techniques in the last two decades have prompted extensions of the original model to generalized forms for passive probing of complex fluids. In the last decade, active microrheology has emerged as a means by which to interrogate the nonequilibrium behavior of complex fluids, in particular, the non-Newtonian rheology of dynamically heterogeneous and microscopically small systems. Here we review theoretical and computational approaches and advances in both passive and active microrheology, with a focus on the extent to which these techniques preserve the connection between single-particle motion and flow properties, as well as the rather surprising recovery of non-Newtonian flow behavior observed in bulk rheology.